xref: /illumos-gate/usr/src/uts/common/os/streamio.c (revision 5279807d7e1818eac6f90ac640b7a89cdb37522d)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
22 /*	  All Rights Reserved  	*/
23 
24 
25 /*
26  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
27  * Use is subject to license terms.
28  */
29 
30 #include <sys/types.h>
31 #include <sys/sysmacros.h>
32 #include <sys/param.h>
33 #include <sys/errno.h>
34 #include <sys/signal.h>
35 #include <sys/stat.h>
36 #include <sys/proc.h>
37 #include <sys/cred.h>
38 #include <sys/user.h>
39 #include <sys/vnode.h>
40 #include <sys/file.h>
41 #include <sys/stream.h>
42 #include <sys/strsubr.h>
43 #include <sys/stropts.h>
44 #include <sys/tihdr.h>
45 #include <sys/var.h>
46 #include <sys/poll.h>
47 #include <sys/termio.h>
48 #include <sys/ttold.h>
49 #include <sys/systm.h>
50 #include <sys/uio.h>
51 #include <sys/cmn_err.h>
52 #include <sys/sad.h>
53 #include <sys/netstack.h>
54 #include <sys/priocntl.h>
55 #include <sys/jioctl.h>
56 #include <sys/procset.h>
57 #include <sys/session.h>
58 #include <sys/kmem.h>
59 #include <sys/filio.h>
60 #include <sys/vtrace.h>
61 #include <sys/debug.h>
62 #include <sys/strredir.h>
63 #include <sys/fs/fifonode.h>
64 #include <sys/fs/snode.h>
65 #include <sys/strlog.h>
66 #include <sys/strsun.h>
67 #include <sys/project.h>
68 #include <sys/kbio.h>
69 #include <sys/msio.h>
70 #include <sys/tty.h>
71 #include <sys/ptyvar.h>
72 #include <sys/vuid_event.h>
73 #include <sys/modctl.h>
74 #include <sys/sunddi.h>
75 #include <sys/sunldi_impl.h>
76 #include <sys/autoconf.h>
77 #include <sys/policy.h>
78 #include <sys/dld.h>
79 #include <sys/zone.h>
80 
81 /*
82  * This define helps improve the readability of streams code while
83  * still maintaining a very old streams performance enhancement.  The
84  * performance enhancement basically involved having all callers
85  * of straccess() perform the first check that straccess() will do
86  * locally before actually calling straccess().  (There by reducing
87  * the number of unnecessary calls to straccess().)
88  */
89 #define	i_straccess(x, y)	((stp->sd_sidp == NULL) ? 0 : \
90 				    (stp->sd_vnode->v_type == VFIFO) ? 0 : \
91 				    straccess((x), (y)))
92 
93 /*
94  * what is mblk_pull_len?
95  *
96  * If a streams message consists of many short messages,
97  * a performance degradation occurs from copyout overhead.
98  * To decrease the per mblk overhead, messages that are
99  * likely to consist of many small mblks are pulled up into
100  * one continuous chunk of memory.
101  *
102  * To avoid the processing overhead of examining every
103  * mblk, a quick heuristic is used. If the first mblk in
104  * the message is shorter than mblk_pull_len, it is likely
105  * that the rest of the mblk will be short.
106  *
107  * This heuristic was decided upon after performance tests
108  * indicated that anything more complex slowed down the main
109  * code path.
110  */
111 #define	MBLK_PULL_LEN 64
112 uint32_t mblk_pull_len = MBLK_PULL_LEN;
113 
114 /*
115  * The sgttyb_handling flag controls the handling of the old BSD
116  * TIOCGETP, TIOCSETP, and TIOCSETN ioctls as follows:
117  *
118  * 0 - Emit no warnings at all and retain old, broken behavior.
119  * 1 - Emit no warnings and silently handle new semantics.
120  * 2 - Send cmn_err(CE_NOTE) when either TIOCSETP or TIOCSETN is used
121  *     (once per system invocation).  Handle with new semantics.
122  * 3 - Send SIGSYS when any TIOCGETP, TIOCSETP, or TIOCSETN call is
123  *     made (so that offenders drop core and are easy to debug).
124  *
125  * The "new semantics" are that TIOCGETP returns B38400 for
126  * sg_[io]speed if the corresponding value is over B38400, and that
127  * TIOCSET[PN] accept B38400 in these cases to mean "retain current
128  * bit rate."
129  */
130 int sgttyb_handling = 1;
131 static boolean_t sgttyb_complaint;
132 
133 /* don't push drcompat module by default on Style-2 streams */
134 static int push_drcompat = 0;
135 
136 /*
137  * id value used to distinguish between different ioctl messages
138  */
139 static uint32_t ioc_id;
140 
141 static void putback(struct stdata *, queue_t *, mblk_t *, int);
142 static void strcleanall(struct vnode *);
143 static int strwsrv(queue_t *);
144 static int strdocmd(struct stdata *, struct strcmd *, cred_t *);
145 
146 /*
147  * qinit and module_info structures for stream head read and write queues
148  */
149 struct module_info strm_info = { 0, "strrhead", 0, INFPSZ, STRHIGH, STRLOW };
150 struct module_info stwm_info = { 0, "strwhead", 0, 0, 0, 0 };
151 struct qinit strdata = { strrput, NULL, NULL, NULL, NULL, &strm_info };
152 struct qinit stwdata = { NULL, strwsrv, NULL, NULL, NULL, &stwm_info };
153 struct module_info fiform_info = { 0, "fifostrrhead", 0, PIPE_BUF, FIFOHIWAT,
154     FIFOLOWAT };
155 struct module_info fifowm_info = { 0, "fifostrwhead", 0, 0, 0, 0 };
156 struct qinit fifo_strdata = { strrput, NULL, NULL, NULL, NULL, &fiform_info };
157 struct qinit fifo_stwdata = { NULL, strwsrv, NULL, NULL, NULL, &fifowm_info };
158 
159 extern kmutex_t	strresources;	/* protects global resources */
160 extern kmutex_t muxifier;	/* single-threads multiplexor creation */
161 
162 static boolean_t msghasdata(mblk_t *bp);
163 #define	msgnodata(bp) (!msghasdata(bp))
164 
165 /*
166  * Stream head locking notes:
167  *	There are four monitors associated with the stream head:
168  *	1. v_stream monitor: in stropen() and strclose() v_lock
169  *		is held while the association of vnode and stream
170  *		head is established or tested for.
171  *	2. open/close/push/pop monitor: sd_lock is held while each
172  *		thread bids for exclusive access to this monitor
173  *		for opening or closing a stream.  In addition, this
174  *		monitor is entered during pushes and pops.  This
175  *		guarantees that during plumbing operations there
176  *		is only one thread trying to change the plumbing.
177  *		Any other threads present in the stream are only
178  *		using the plumbing.
179  *	3. read/write monitor: in the case of read, a thread holds
180  *		sd_lock while trying to get data from the stream
181  *		head queue.  if there is none to fulfill a read
182  *		request, it sets RSLEEP and calls cv_wait_sig() down
183  *		in strwaitq() to await the arrival of new data.
184  *		when new data arrives in strrput(), sd_lock is acquired
185  *		before testing for RSLEEP and calling cv_broadcast().
186  *		the behavior of strwrite(), strwsrv(), and WSLEEP
187  *		mirror this.
188  *	4. ioctl monitor: sd_lock is gotten to ensure that only one
189  *		thread is doing an ioctl at a time.
190  */
191 
192 static int
193 push_mod(queue_t *qp, dev_t *devp, struct stdata *stp, const char *name,
194     int anchor, cred_t *crp, uint_t anchor_zoneid)
195 {
196 	int error;
197 	fmodsw_impl_t *fp;
198 
199 	if (stp->sd_flag & (STRHUP|STRDERR|STWRERR)) {
200 		error = (stp->sd_flag & STRHUP) ? ENXIO : EIO;
201 		return (error);
202 	}
203 	if (stp->sd_pushcnt >= nstrpush) {
204 		return (EINVAL);
205 	}
206 
207 	if ((fp = fmodsw_find(name, FMODSW_HOLD | FMODSW_LOAD)) == NULL) {
208 		stp->sd_flag |= STREOPENFAIL;
209 		return (EINVAL);
210 	}
211 
212 	/*
213 	 * push new module and call its open routine via qattach
214 	 */
215 	if ((error = qattach(qp, devp, 0, crp, fp, B_FALSE)) != 0)
216 		return (error);
217 
218 	/*
219 	 * Check to see if caller wants a STREAMS anchor
220 	 * put at this place in the stream, and add if so.
221 	 */
222 	mutex_enter(&stp->sd_lock);
223 	if (anchor == stp->sd_pushcnt) {
224 		stp->sd_anchor = stp->sd_pushcnt;
225 		stp->sd_anchorzone = anchor_zoneid;
226 	}
227 	mutex_exit(&stp->sd_lock);
228 
229 	return (0);
230 }
231 
232 /*
233  * Open a stream device.
234  */
235 int
236 stropen(vnode_t *vp, dev_t *devp, int flag, cred_t *crp)
237 {
238 	struct stdata *stp;
239 	queue_t *qp;
240 	int s;
241 	dev_t dummydev, savedev;
242 	struct autopush *ap;
243 	struct dlautopush dlap;
244 	int error = 0;
245 	ssize_t	rmin, rmax;
246 	int cloneopen;
247 	queue_t *brq;
248 	major_t major;
249 	str_stack_t *ss;
250 	zoneid_t zoneid;
251 	uint_t anchor;
252 
253 	if (audit_active)
254 		audit_stropen(vp, devp, flag, crp);
255 
256 	/*
257 	 * If the stream already exists, wait for any open in progress
258 	 * to complete, then call the open function of each module and
259 	 * driver in the stream.  Otherwise create the stream.
260 	 */
261 	TRACE_1(TR_FAC_STREAMS_FR, TR_STROPEN, "stropen:%p", vp);
262 retry:
263 	mutex_enter(&vp->v_lock);
264 	if ((stp = vp->v_stream) != NULL) {
265 
266 		/*
267 		 * Waiting for stream to be created to device
268 		 * due to another open.
269 		 */
270 		mutex_exit(&vp->v_lock);
271 
272 		if (STRMATED(stp)) {
273 			struct stdata *strmatep = stp->sd_mate;
274 
275 			STRLOCKMATES(stp);
276 			if (strmatep->sd_flag & (STWOPEN|STRCLOSE|STRPLUMB)) {
277 				if (flag & (FNDELAY|FNONBLOCK)) {
278 					error = EAGAIN;
279 					mutex_exit(&strmatep->sd_lock);
280 					goto ckreturn;
281 				}
282 				mutex_exit(&stp->sd_lock);
283 				if (!cv_wait_sig(&strmatep->sd_monitor,
284 				    &strmatep->sd_lock)) {
285 					error = EINTR;
286 					mutex_exit(&strmatep->sd_lock);
287 					mutex_enter(&stp->sd_lock);
288 					goto ckreturn;
289 				}
290 				mutex_exit(&strmatep->sd_lock);
291 				goto retry;
292 			}
293 			if (stp->sd_flag & (STWOPEN|STRCLOSE|STRPLUMB)) {
294 				if (flag & (FNDELAY|FNONBLOCK)) {
295 					error = EAGAIN;
296 					mutex_exit(&strmatep->sd_lock);
297 					goto ckreturn;
298 				}
299 				mutex_exit(&strmatep->sd_lock);
300 				if (!cv_wait_sig(&stp->sd_monitor,
301 				    &stp->sd_lock)) {
302 					error = EINTR;
303 					goto ckreturn;
304 				}
305 				mutex_exit(&stp->sd_lock);
306 				goto retry;
307 			}
308 
309 			if (stp->sd_flag & (STRDERR|STWRERR)) {
310 				error = EIO;
311 				mutex_exit(&strmatep->sd_lock);
312 				goto ckreturn;
313 			}
314 
315 			stp->sd_flag |= STWOPEN;
316 			STRUNLOCKMATES(stp);
317 		} else {
318 			mutex_enter(&stp->sd_lock);
319 			if (stp->sd_flag & (STWOPEN|STRCLOSE|STRPLUMB)) {
320 				if (flag & (FNDELAY|FNONBLOCK)) {
321 					error = EAGAIN;
322 					goto ckreturn;
323 				}
324 				if (!cv_wait_sig(&stp->sd_monitor,
325 				    &stp->sd_lock)) {
326 					error = EINTR;
327 					goto ckreturn;
328 				}
329 				mutex_exit(&stp->sd_lock);
330 				goto retry;  /* could be clone! */
331 			}
332 
333 			if (stp->sd_flag & (STRDERR|STWRERR)) {
334 				error = EIO;
335 				goto ckreturn;
336 			}
337 
338 			stp->sd_flag |= STWOPEN;
339 			mutex_exit(&stp->sd_lock);
340 		}
341 
342 		/*
343 		 * Open all modules and devices down stream to notify
344 		 * that another user is streaming.  For modules, set the
345 		 * last argument to MODOPEN and do not pass any open flags.
346 		 * Ignore dummydev since this is not the first open.
347 		 */
348 		claimstr(stp->sd_wrq);
349 		qp = stp->sd_wrq;
350 		while (_SAMESTR(qp)) {
351 			qp = qp->q_next;
352 			if ((error = qreopen(_RD(qp), devp, flag, crp)) != 0)
353 				break;
354 		}
355 		releasestr(stp->sd_wrq);
356 		mutex_enter(&stp->sd_lock);
357 		stp->sd_flag &= ~(STRHUP|STWOPEN|STRDERR|STWRERR);
358 		stp->sd_rerror = 0;
359 		stp->sd_werror = 0;
360 ckreturn:
361 		cv_broadcast(&stp->sd_monitor);
362 		mutex_exit(&stp->sd_lock);
363 		return (error);
364 	}
365 
366 	/*
367 	 * This vnode isn't streaming.  SPECFS already
368 	 * checked for multiple vnodes pointing to the
369 	 * same stream, so create a stream to the driver.
370 	 */
371 	qp = allocq();
372 	stp = shalloc(qp);
373 
374 	/*
375 	 * Initialize stream head.  shalloc() has given us
376 	 * exclusive access, and we have the vnode locked;
377 	 * we can do whatever we want with stp.
378 	 */
379 	stp->sd_flag = STWOPEN;
380 	stp->sd_siglist = NULL;
381 	stp->sd_pollist.ph_list = NULL;
382 	stp->sd_sigflags = 0;
383 	stp->sd_mark = NULL;
384 	stp->sd_closetime = STRTIMOUT;
385 	stp->sd_sidp = NULL;
386 	stp->sd_pgidp = NULL;
387 	stp->sd_vnode = vp;
388 	stp->sd_rerror = 0;
389 	stp->sd_werror = 0;
390 	stp->sd_wroff = 0;
391 	stp->sd_tail = 0;
392 	stp->sd_iocblk = NULL;
393 	stp->sd_cmdblk = NULL;
394 	stp->sd_pushcnt = 0;
395 	stp->sd_qn_minpsz = 0;
396 	stp->sd_qn_maxpsz = INFPSZ - 1;	/* used to check for initialization */
397 	stp->sd_maxblk = INFPSZ;
398 	qp->q_ptr = _WR(qp)->q_ptr = stp;
399 	STREAM(qp) = STREAM(_WR(qp)) = stp;
400 	vp->v_stream = stp;
401 	mutex_exit(&vp->v_lock);
402 	if (vp->v_type == VFIFO) {
403 		stp->sd_flag |= OLDNDELAY;
404 		/*
405 		 * This means, both for pipes and fifos
406 		 * strwrite will send SIGPIPE if the other
407 		 * end is closed. For putmsg it depends
408 		 * on whether it is a XPG4_2 application
409 		 * or not
410 		 */
411 		stp->sd_wput_opt = SW_SIGPIPE;
412 
413 		/* setq might sleep in kmem_alloc - avoid holding locks. */
414 		setq(qp, &fifo_strdata, &fifo_stwdata, NULL, QMTSAFE,
415 		    SQ_CI|SQ_CO, B_FALSE);
416 
417 		set_qend(qp);
418 		stp->sd_strtab = fifo_getinfo();
419 		_WR(qp)->q_nfsrv = _WR(qp);
420 		qp->q_nfsrv = qp;
421 		/*
422 		 * Wake up others that are waiting for stream to be created.
423 		 */
424 		mutex_enter(&stp->sd_lock);
425 		/*
426 		 * nothing is be pushed on stream yet, so
427 		 * optimized stream head packetsizes are just that
428 		 * of the read queue
429 		 */
430 		stp->sd_qn_minpsz = qp->q_minpsz;
431 		stp->sd_qn_maxpsz = qp->q_maxpsz;
432 		stp->sd_flag &= ~STWOPEN;
433 		goto fifo_opendone;
434 	}
435 	/* setq might sleep in kmem_alloc - avoid holding locks. */
436 	setq(qp, &strdata, &stwdata, NULL, QMTSAFE, SQ_CI|SQ_CO, B_FALSE);
437 
438 	set_qend(qp);
439 
440 	/*
441 	 * Open driver and create stream to it (via qattach).
442 	 */
443 	savedev = *devp;
444 	cloneopen = (getmajor(*devp) == clone_major);
445 	if ((error = qattach(qp, devp, flag, crp, NULL, B_FALSE)) != 0) {
446 		mutex_enter(&vp->v_lock);
447 		vp->v_stream = NULL;
448 		mutex_exit(&vp->v_lock);
449 		mutex_enter(&stp->sd_lock);
450 		cv_broadcast(&stp->sd_monitor);
451 		mutex_exit(&stp->sd_lock);
452 		freeq(_RD(qp));
453 		shfree(stp);
454 		return (error);
455 	}
456 	/*
457 	 * Set sd_strtab after open in order to handle clonable drivers
458 	 */
459 	stp->sd_strtab = STREAMSTAB(getmajor(*devp));
460 
461 	/*
462 	 * Historical note: dummydev used to be be prior to the initial
463 	 * open (via qattach above), which made the value seen
464 	 * inconsistent between an I_PUSH and an autopush of a module.
465 	 */
466 	dummydev = *devp;
467 
468 	/*
469 	 * For clone open of old style (Q not associated) network driver,
470 	 * push DRMODNAME module to handle DL_ATTACH/DL_DETACH
471 	 */
472 	brq = _RD(_WR(qp)->q_next);
473 	major = getmajor(*devp);
474 	if (push_drcompat && cloneopen && NETWORK_DRV(major) &&
475 	    ((brq->q_flag & _QASSOCIATED) == 0)) {
476 		if (push_mod(qp, &dummydev, stp, DRMODNAME, 0, crp, 0) != 0)
477 			cmn_err(CE_WARN, "cannot push " DRMODNAME
478 			    " streams module");
479 	}
480 
481 	if (!NETWORK_DRV(major)) {
482 		savedev = *devp;
483 	} else {
484 		/*
485 		 * For network devices, process differently based on the
486 		 * return value from dld_autopush():
487 		 *
488 		 *   0: the passed-in device points to a GLDv3 datalink with
489 		 *   per-link autopush configuration; use that configuration
490 		 *   and ignore any per-driver autopush configuration.
491 		 *
492 		 *   1: the passed-in device points to a physical GLDv3
493 		 *   datalink without per-link autopush configuration.  The
494 		 *   passed in device was changed to refer to the actual
495 		 *   physical device (if it's not already); we use that new
496 		 *   device to look up any per-driver autopush configuration.
497 		 *
498 		 *   -1: neither of the above cases applied; use the initial
499 		 *   device to look up any per-driver autopush configuration.
500 		 */
501 		switch (dld_autopush(&savedev, &dlap)) {
502 		case 0:
503 			zoneid = crgetzoneid(crp);
504 			for (s = 0; s < dlap.dap_npush; s++) {
505 				error = push_mod(qp, &dummydev, stp,
506 				    dlap.dap_aplist[s], dlap.dap_anchor, crp,
507 				    zoneid);
508 				if (error != 0)
509 					break;
510 			}
511 			goto opendone;
512 		case 1:
513 			break;
514 		case -1:
515 			savedev = *devp;
516 			break;
517 		}
518 	}
519 	/*
520 	 * Find the autopush configuration based on "savedev". Start with the
521 	 * global zone. If not found check in the local zone.
522 	 */
523 	zoneid = GLOBAL_ZONEID;
524 retryap:
525 	ss = netstack_find_by_stackid(zoneid_to_netstackid(zoneid))->
526 	    netstack_str;
527 	if ((ap = sad_ap_find_by_dev(savedev, ss)) == NULL) {
528 		netstack_rele(ss->ss_netstack);
529 		if (zoneid == GLOBAL_ZONEID) {
530 			/*
531 			 * None found. Also look in the zone's autopush table.
532 			 */
533 			zoneid = crgetzoneid(crp);
534 			if (zoneid != GLOBAL_ZONEID)
535 				goto retryap;
536 		}
537 		goto opendone;
538 	}
539 	anchor = ap->ap_anchor;
540 	zoneid = crgetzoneid(crp);
541 	for (s = 0; s < ap->ap_npush; s++) {
542 		error = push_mod(qp, &dummydev, stp, ap->ap_list[s],
543 		    anchor, crp, zoneid);
544 		if (error != 0)
545 			break;
546 	}
547 	sad_ap_rele(ap, ss);
548 	netstack_rele(ss->ss_netstack);
549 
550 opendone:
551 
552 	/*
553 	 * let specfs know that open failed part way through
554 	 */
555 	if (error) {
556 		mutex_enter(&stp->sd_lock);
557 		stp->sd_flag |= STREOPENFAIL;
558 		mutex_exit(&stp->sd_lock);
559 	}
560 
561 	/*
562 	 * Wake up others that are waiting for stream to be created.
563 	 */
564 	mutex_enter(&stp->sd_lock);
565 	stp->sd_flag &= ~STWOPEN;
566 
567 	/*
568 	 * As a performance concern we are caching the values of
569 	 * q_minpsz and q_maxpsz of the module below the stream
570 	 * head in the stream head.
571 	 */
572 	mutex_enter(QLOCK(stp->sd_wrq->q_next));
573 	rmin = stp->sd_wrq->q_next->q_minpsz;
574 	rmax = stp->sd_wrq->q_next->q_maxpsz;
575 	mutex_exit(QLOCK(stp->sd_wrq->q_next));
576 
577 	/* do this processing here as a performance concern */
578 	if (strmsgsz != 0) {
579 		if (rmax == INFPSZ)
580 			rmax = strmsgsz;
581 		else
582 			rmax = MIN(strmsgsz, rmax);
583 	}
584 
585 	mutex_enter(QLOCK(stp->sd_wrq));
586 	stp->sd_qn_minpsz = rmin;
587 	stp->sd_qn_maxpsz = rmax;
588 	mutex_exit(QLOCK(stp->sd_wrq));
589 
590 fifo_opendone:
591 	cv_broadcast(&stp->sd_monitor);
592 	mutex_exit(&stp->sd_lock);
593 	return (error);
594 }
595 
596 static int strsink(queue_t *, mblk_t *);
597 static struct qinit deadrend = {
598 	strsink, NULL, NULL, NULL, NULL, &strm_info, NULL
599 };
600 static struct qinit deadwend = {
601 	NULL, NULL, NULL, NULL, NULL, &stwm_info, NULL
602 };
603 
604 /*
605  * Close a stream.
606  * This is called from closef() on the last close of an open stream.
607  * Strclean() will already have removed the siglist and pollist
608  * information, so all that remains is to remove all multiplexor links
609  * for the stream, pop all the modules (and the driver), and free the
610  * stream structure.
611  */
612 
613 int
614 strclose(struct vnode *vp, int flag, cred_t *crp)
615 {
616 	struct stdata *stp;
617 	queue_t *qp;
618 	int rval;
619 	int freestp = 1;
620 	queue_t *rmq;
621 
622 	if (audit_active)
623 		audit_strclose(vp, flag, crp);
624 
625 	TRACE_1(TR_FAC_STREAMS_FR,
626 	    TR_STRCLOSE, "strclose:%p", vp);
627 	ASSERT(vp->v_stream);
628 
629 	stp = vp->v_stream;
630 	ASSERT(!(stp->sd_flag & STPLEX));
631 	qp = stp->sd_wrq;
632 
633 	/*
634 	 * Needed so that strpoll will return non-zero for this fd.
635 	 * Note that with POLLNOERR STRHUP does still cause POLLHUP.
636 	 */
637 	mutex_enter(&stp->sd_lock);
638 	stp->sd_flag |= STRHUP;
639 	mutex_exit(&stp->sd_lock);
640 
641 	/*
642 	 * If the registered process or process group did not have an
643 	 * open instance of this stream then strclean would not be
644 	 * called. Thus at the time of closing all remaining siglist entries
645 	 * are removed.
646 	 */
647 	if (stp->sd_siglist != NULL)
648 		strcleanall(vp);
649 
650 	ASSERT(stp->sd_siglist == NULL);
651 	ASSERT(stp->sd_sigflags == 0);
652 
653 	if (STRMATED(stp)) {
654 		struct stdata *strmatep = stp->sd_mate;
655 		int waited = 1;
656 
657 		STRLOCKMATES(stp);
658 		while (waited) {
659 			waited = 0;
660 			while (stp->sd_flag & (STWOPEN|STRCLOSE|STRPLUMB)) {
661 				mutex_exit(&strmatep->sd_lock);
662 				cv_wait(&stp->sd_monitor, &stp->sd_lock);
663 				mutex_exit(&stp->sd_lock);
664 				STRLOCKMATES(stp);
665 				waited = 1;
666 			}
667 			while (strmatep->sd_flag &
668 			    (STWOPEN|STRCLOSE|STRPLUMB)) {
669 				mutex_exit(&stp->sd_lock);
670 				cv_wait(&strmatep->sd_monitor,
671 				    &strmatep->sd_lock);
672 				mutex_exit(&strmatep->sd_lock);
673 				STRLOCKMATES(stp);
674 				waited = 1;
675 			}
676 		}
677 		stp->sd_flag |= STRCLOSE;
678 		STRUNLOCKMATES(stp);
679 	} else {
680 		mutex_enter(&stp->sd_lock);
681 		stp->sd_flag |= STRCLOSE;
682 		mutex_exit(&stp->sd_lock);
683 	}
684 
685 	ASSERT(qp->q_first == NULL);	/* No more delayed write */
686 
687 	/* Check if an I_LINK was ever done on this stream */
688 	if (stp->sd_flag & STRHASLINKS) {
689 		netstack_t *ns;
690 		str_stack_t *ss;
691 
692 		ns = netstack_find_by_cred(crp);
693 		ASSERT(ns != NULL);
694 		ss = ns->netstack_str;
695 		ASSERT(ss != NULL);
696 
697 		(void) munlinkall(stp, LINKCLOSE|LINKNORMAL, crp, &rval, ss);
698 		netstack_rele(ss->ss_netstack);
699 	}
700 
701 	while (_SAMESTR(qp)) {
702 		/*
703 		 * Holding sd_lock prevents q_next from changing in
704 		 * this stream.
705 		 */
706 		mutex_enter(&stp->sd_lock);
707 		if (!(flag & (FNDELAY|FNONBLOCK)) && (stp->sd_closetime > 0)) {
708 
709 			/*
710 			 * sleep until awakened by strwsrv() or timeout
711 			 */
712 			for (;;) {
713 				mutex_enter(QLOCK(qp->q_next));
714 				if (!(qp->q_next->q_mblkcnt)) {
715 					mutex_exit(QLOCK(qp->q_next));
716 					break;
717 				}
718 				stp->sd_flag |= WSLEEP;
719 
720 				/* ensure strwsrv gets enabled */
721 				qp->q_next->q_flag |= QWANTW;
722 				mutex_exit(QLOCK(qp->q_next));
723 				/* get out if we timed out or recv'd a signal */
724 				if (str_cv_wait(&qp->q_wait, &stp->sd_lock,
725 				    stp->sd_closetime, 0) <= 0) {
726 					break;
727 				}
728 			}
729 			stp->sd_flag &= ~WSLEEP;
730 		}
731 		mutex_exit(&stp->sd_lock);
732 
733 		rmq = qp->q_next;
734 		if (rmq->q_flag & QISDRV) {
735 			ASSERT(!_SAMESTR(rmq));
736 			wait_sq_svc(_RD(qp)->q_syncq);
737 		}
738 
739 		qdetach(_RD(rmq), 1, flag, crp, B_FALSE);
740 	}
741 
742 	/*
743 	 * Since we call pollwakeup in close() now, the poll list should
744 	 * be empty in most cases. The only exception is the layered devices
745 	 * (e.g. the console drivers with redirection modules pushed on top
746 	 * of it).  We have to do this after calling qdetach() because
747 	 * the redirection module won't have torn down the console
748 	 * redirection until after qdetach() has been invoked.
749 	 */
750 	if (stp->sd_pollist.ph_list != NULL) {
751 		pollwakeup(&stp->sd_pollist, POLLERR);
752 		pollhead_clean(&stp->sd_pollist);
753 	}
754 	ASSERT(stp->sd_pollist.ph_list == NULL);
755 	ASSERT(stp->sd_sidp == NULL);
756 	ASSERT(stp->sd_pgidp == NULL);
757 
758 	/* Prevent qenable from re-enabling the stream head queue */
759 	disable_svc(_RD(qp));
760 
761 	/*
762 	 * Wait until service procedure of each queue is
763 	 * run, if QINSERVICE is set.
764 	 */
765 	wait_svc(_RD(qp));
766 
767 	/*
768 	 * Now, flush both queues.
769 	 */
770 	flushq(_RD(qp), FLUSHALL);
771 	flushq(qp, FLUSHALL);
772 
773 	/*
774 	 * If the write queue of the stream head is pointing to a
775 	 * read queue, we have a twisted stream.  If the read queue
776 	 * is alive, convert the stream head queues into a dead end.
777 	 * If the read queue is dead, free the dead pair.
778 	 */
779 	if (qp->q_next && !_SAMESTR(qp)) {
780 		if (qp->q_next->q_qinfo == &deadrend) {	/* half-closed pipe */
781 			flushq(qp->q_next, FLUSHALL); /* ensure no message */
782 			shfree(qp->q_next->q_stream);
783 			freeq(qp->q_next);
784 			freeq(_RD(qp));
785 		} else if (qp->q_next == _RD(qp)) {	/* fifo */
786 			freeq(_RD(qp));
787 		} else {				/* pipe */
788 			freestp = 0;
789 			/*
790 			 * The q_info pointers are never accessed when
791 			 * SQLOCK is held.
792 			 */
793 			ASSERT(qp->q_syncq == _RD(qp)->q_syncq);
794 			mutex_enter(SQLOCK(qp->q_syncq));
795 			qp->q_qinfo = &deadwend;
796 			_RD(qp)->q_qinfo = &deadrend;
797 			mutex_exit(SQLOCK(qp->q_syncq));
798 		}
799 	} else {
800 		freeq(_RD(qp)); /* free stream head queue pair */
801 	}
802 
803 	mutex_enter(&vp->v_lock);
804 	if (stp->sd_iocblk) {
805 		if (stp->sd_iocblk != (mblk_t *)-1) {
806 			freemsg(stp->sd_iocblk);
807 		}
808 		stp->sd_iocblk = NULL;
809 	}
810 	stp->sd_vnode = NULL;
811 	vp->v_stream = NULL;
812 	mutex_exit(&vp->v_lock);
813 	mutex_enter(&stp->sd_lock);
814 	freemsg(stp->sd_cmdblk);
815 	stp->sd_cmdblk = NULL;
816 	stp->sd_flag &= ~STRCLOSE;
817 	cv_broadcast(&stp->sd_monitor);
818 	mutex_exit(&stp->sd_lock);
819 
820 	if (freestp)
821 		shfree(stp);
822 	return (0);
823 }
824 
825 static int
826 strsink(queue_t *q, mblk_t *bp)
827 {
828 	struct copyresp *resp;
829 
830 	switch (bp->b_datap->db_type) {
831 	case M_FLUSH:
832 		if ((*bp->b_rptr & FLUSHW) && !(bp->b_flag & MSGNOLOOP)) {
833 			*bp->b_rptr &= ~FLUSHR;
834 			bp->b_flag |= MSGNOLOOP;
835 			/*
836 			 * Protect against the driver passing up
837 			 * messages after it has done a qprocsoff.
838 			 */
839 			if (_OTHERQ(q)->q_next == NULL)
840 				freemsg(bp);
841 			else
842 				qreply(q, bp);
843 		} else {
844 			freemsg(bp);
845 		}
846 		break;
847 
848 	case M_COPYIN:
849 	case M_COPYOUT:
850 		if (bp->b_cont) {
851 			freemsg(bp->b_cont);
852 			bp->b_cont = NULL;
853 		}
854 		bp->b_datap->db_type = M_IOCDATA;
855 		bp->b_wptr = bp->b_rptr + sizeof (struct copyresp);
856 		resp = (struct copyresp *)bp->b_rptr;
857 		resp->cp_rval = (caddr_t)1;	/* failure */
858 		/*
859 		 * Protect against the driver passing up
860 		 * messages after it has done a qprocsoff.
861 		 */
862 		if (_OTHERQ(q)->q_next == NULL)
863 			freemsg(bp);
864 		else
865 			qreply(q, bp);
866 		break;
867 
868 	case M_IOCTL:
869 		if (bp->b_cont) {
870 			freemsg(bp->b_cont);
871 			bp->b_cont = NULL;
872 		}
873 		bp->b_datap->db_type = M_IOCNAK;
874 		/*
875 		 * Protect against the driver passing up
876 		 * messages after it has done a qprocsoff.
877 		 */
878 		if (_OTHERQ(q)->q_next == NULL)
879 			freemsg(bp);
880 		else
881 			qreply(q, bp);
882 		break;
883 
884 	default:
885 		freemsg(bp);
886 		break;
887 	}
888 
889 	return (0);
890 }
891 
892 /*
893  * Clean up after a process when it closes a stream.  This is called
894  * from closef for all closes, whereas strclose is called only for the
895  * last close on a stream.  The siglist is scanned for entries for the
896  * current process, and these are removed.
897  */
898 void
899 strclean(struct vnode *vp)
900 {
901 	strsig_t *ssp, *pssp, *tssp;
902 	stdata_t *stp;
903 	int update = 0;
904 
905 	TRACE_1(TR_FAC_STREAMS_FR,
906 	    TR_STRCLEAN, "strclean:%p", vp);
907 	stp = vp->v_stream;
908 	pssp = NULL;
909 	mutex_enter(&stp->sd_lock);
910 	ssp = stp->sd_siglist;
911 	while (ssp) {
912 		if (ssp->ss_pidp == curproc->p_pidp) {
913 			tssp = ssp->ss_next;
914 			if (pssp)
915 				pssp->ss_next = tssp;
916 			else
917 				stp->sd_siglist = tssp;
918 			mutex_enter(&pidlock);
919 			PID_RELE(ssp->ss_pidp);
920 			mutex_exit(&pidlock);
921 			kmem_free(ssp, sizeof (strsig_t));
922 			update = 1;
923 			ssp = tssp;
924 		} else {
925 			pssp = ssp;
926 			ssp = ssp->ss_next;
927 		}
928 	}
929 	if (update) {
930 		stp->sd_sigflags = 0;
931 		for (ssp = stp->sd_siglist; ssp; ssp = ssp->ss_next)
932 			stp->sd_sigflags |= ssp->ss_events;
933 	}
934 	mutex_exit(&stp->sd_lock);
935 }
936 
937 /*
938  * Used on the last close to remove any remaining items on the siglist.
939  * These could be present on the siglist due to I_ESETSIG calls that
940  * use process groups or processed that do not have an open file descriptor
941  * for this stream (Such entries would not be removed by strclean).
942  */
943 static void
944 strcleanall(struct vnode *vp)
945 {
946 	strsig_t *ssp, *nssp;
947 	stdata_t *stp;
948 
949 	stp = vp->v_stream;
950 	mutex_enter(&stp->sd_lock);
951 	ssp = stp->sd_siglist;
952 	stp->sd_siglist = NULL;
953 	while (ssp) {
954 		nssp = ssp->ss_next;
955 		mutex_enter(&pidlock);
956 		PID_RELE(ssp->ss_pidp);
957 		mutex_exit(&pidlock);
958 		kmem_free(ssp, sizeof (strsig_t));
959 		ssp = nssp;
960 	}
961 	stp->sd_sigflags = 0;
962 	mutex_exit(&stp->sd_lock);
963 }
964 
965 /*
966  * Retrieve the next message from the logical stream head read queue
967  * using either rwnext (if sync stream) or getq_noenab.
968  * It is the callers responsibility to call qbackenable after
969  * it is finished with the message. The caller should not call
970  * qbackenable until after any putback calls to avoid spurious backenabling.
971  */
972 mblk_t *
973 strget(struct stdata *stp, queue_t *q, struct uio *uiop, int first,
974     int *errorp)
975 {
976 	mblk_t *bp;
977 	int error;
978 	ssize_t rbytes = 0;
979 
980 	/* Holding sd_lock prevents the read queue from changing  */
981 	ASSERT(MUTEX_HELD(&stp->sd_lock));
982 
983 	if (uiop != NULL && stp->sd_struiordq != NULL &&
984 	    q->q_first == NULL &&
985 	    (!first || (stp->sd_wakeq & RSLEEP))) {
986 		/*
987 		 * Stream supports rwnext() for the read side.
988 		 * If this is the first time we're called by e.g. strread
989 		 * only do the downcall if there is a deferred wakeup
990 		 * (registered in sd_wakeq).
991 		 */
992 		struiod_t uiod;
993 
994 		if (first)
995 			stp->sd_wakeq &= ~RSLEEP;
996 
997 		(void) uiodup(uiop, &uiod.d_uio, uiod.d_iov,
998 		    sizeof (uiod.d_iov) / sizeof (*uiod.d_iov));
999 		uiod.d_mp = 0;
1000 		/*
1001 		 * Mark that a thread is in rwnext on the read side
1002 		 * to prevent strrput from nacking ioctls immediately.
1003 		 * When the last concurrent rwnext returns
1004 		 * the ioctls are nack'ed.
1005 		 */
1006 		ASSERT(MUTEX_HELD(&stp->sd_lock));
1007 		stp->sd_struiodnak++;
1008 		/*
1009 		 * Note: rwnext will drop sd_lock.
1010 		 */
1011 		error = rwnext(q, &uiod);
1012 		ASSERT(MUTEX_NOT_HELD(&stp->sd_lock));
1013 		mutex_enter(&stp->sd_lock);
1014 		stp->sd_struiodnak--;
1015 		while (stp->sd_struiodnak == 0 &&
1016 		    ((bp = stp->sd_struionak) != NULL)) {
1017 			stp->sd_struionak = bp->b_next;
1018 			bp->b_next = NULL;
1019 			bp->b_datap->db_type = M_IOCNAK;
1020 			/*
1021 			 * Protect against the driver passing up
1022 			 * messages after it has done a qprocsoff.
1023 			 */
1024 			if (_OTHERQ(q)->q_next == NULL)
1025 				freemsg(bp);
1026 			else {
1027 				mutex_exit(&stp->sd_lock);
1028 				qreply(q, bp);
1029 				mutex_enter(&stp->sd_lock);
1030 			}
1031 		}
1032 		ASSERT(MUTEX_HELD(&stp->sd_lock));
1033 		if (error == 0 || error == EWOULDBLOCK) {
1034 			if ((bp = uiod.d_mp) != NULL) {
1035 				*errorp = 0;
1036 				ASSERT(MUTEX_HELD(&stp->sd_lock));
1037 				return (bp);
1038 			}
1039 			error = 0;
1040 		} else if (error == EINVAL) {
1041 			/*
1042 			 * The stream plumbing must have
1043 			 * changed while we were away, so
1044 			 * just turn off rwnext()s.
1045 			 */
1046 			error = 0;
1047 		} else if (error == EBUSY) {
1048 			/*
1049 			 * The module might have data in transit using putnext
1050 			 * Fall back on waiting + getq.
1051 			 */
1052 			error = 0;
1053 		} else {
1054 			*errorp = error;
1055 			ASSERT(MUTEX_HELD(&stp->sd_lock));
1056 			return (NULL);
1057 		}
1058 		/*
1059 		 * Try a getq in case a rwnext() generated mblk
1060 		 * has bubbled up via strrput().
1061 		 */
1062 	}
1063 	*errorp = 0;
1064 	ASSERT(MUTEX_HELD(&stp->sd_lock));
1065 
1066 	/*
1067 	 * If we have a valid uio, try and use this as a guide for how
1068 	 * many bytes to retrieve from the queue via getq_noenab().
1069 	 * Doing this can avoid unneccesary counting of overlong
1070 	 * messages in putback(). We currently only do this for sockets
1071 	 * and only if there is no sd_rputdatafunc hook.
1072 	 *
1073 	 * The sd_rputdatafunc hook transforms the entire message
1074 	 * before any bytes in it can be given to a client. So, rbytes
1075 	 * must be 0 if there is a hook.
1076 	 */
1077 	if ((uiop != NULL) && (stp->sd_vnode->v_type == VSOCK) &&
1078 	    (stp->sd_rputdatafunc == NULL))
1079 		rbytes = uiop->uio_resid;
1080 
1081 	return (getq_noenab(q, rbytes));
1082 }
1083 
1084 /*
1085  * Copy out the message pointed to by `bp' into the uio pointed to by `uiop'.
1086  * If the message does not fit in the uio the remainder of it is returned;
1087  * otherwise NULL is returned.  Any embedded zero-length mblk_t's are
1088  * consumed, even if uio_resid reaches zero.  On error, `*errorp' is set to
1089  * the error code, the message is consumed, and NULL is returned.
1090  */
1091 static mblk_t *
1092 struiocopyout(mblk_t *bp, struct uio *uiop, int *errorp)
1093 {
1094 	int error;
1095 	ptrdiff_t n;
1096 	mblk_t *nbp;
1097 
1098 	ASSERT(bp->b_wptr >= bp->b_rptr);
1099 
1100 	do {
1101 		if ((n = MIN(uiop->uio_resid, MBLKL(bp))) != 0) {
1102 			ASSERT(n > 0);
1103 
1104 			error = uiomove(bp->b_rptr, n, UIO_READ, uiop);
1105 			if (error != 0) {
1106 				freemsg(bp);
1107 				*errorp = error;
1108 				return (NULL);
1109 			}
1110 		}
1111 
1112 		bp->b_rptr += n;
1113 		while (bp != NULL && (bp->b_rptr >= bp->b_wptr)) {
1114 			nbp = bp;
1115 			bp = bp->b_cont;
1116 			freeb(nbp);
1117 		}
1118 	} while (bp != NULL && uiop->uio_resid > 0);
1119 
1120 	*errorp = 0;
1121 	return (bp);
1122 }
1123 
1124 /*
1125  * Read a stream according to the mode flags in sd_flag:
1126  *
1127  * (default mode)		- Byte stream, msg boundaries are ignored
1128  * RD_MSGDIS (msg discard)	- Read on msg boundaries and throw away
1129  *				any data remaining in msg
1130  * RD_MSGNODIS (msg non-discard) - Read on msg boundaries and put back
1131  *				any remaining data on head of read queue
1132  *
1133  * Consume readable messages on the front of the queue until
1134  * ttolwp(curthread)->lwp_count
1135  * is satisfied, the readable messages are exhausted, or a message
1136  * boundary is reached in a message mode.  If no data was read and
1137  * the stream was not opened with the NDELAY flag, block until data arrives.
1138  * Otherwise return the data read and update the count.
1139  *
1140  * In default mode a 0 length message signifies end-of-file and terminates
1141  * a read in progress.  The 0 length message is removed from the queue
1142  * only if it is the only message read (no data is read).
1143  *
1144  * An attempt to read an M_PROTO or M_PCPROTO message results in an
1145  * EBADMSG error return, unless either RD_PROTDAT or RD_PROTDIS are set.
1146  * If RD_PROTDAT is set, M_PROTO and M_PCPROTO messages are read as data.
1147  * If RD_PROTDIS is set, the M_PROTO and M_PCPROTO parts of the message
1148  * are unlinked from and M_DATA blocks in the message, the protos are
1149  * thrown away, and the data is read.
1150  */
1151 /* ARGSUSED */
1152 int
1153 strread(struct vnode *vp, struct uio *uiop, cred_t *crp)
1154 {
1155 	struct stdata *stp;
1156 	mblk_t *bp, *nbp;
1157 	queue_t *q;
1158 	int error = 0;
1159 	uint_t old_sd_flag;
1160 	int first;
1161 	char rflg;
1162 	uint_t mark;		/* Contains MSG*MARK and _LASTMARK */
1163 #define	_LASTMARK	0x8000	/* Distinct from MSG*MARK */
1164 	short delim;
1165 	unsigned char pri = 0;
1166 	char waitflag;
1167 	unsigned char type;
1168 
1169 	TRACE_1(TR_FAC_STREAMS_FR,
1170 	    TR_STRREAD_ENTER, "strread:%p", vp);
1171 	ASSERT(vp->v_stream);
1172 	stp = vp->v_stream;
1173 
1174 	mutex_enter(&stp->sd_lock);
1175 
1176 	if ((error = i_straccess(stp, JCREAD)) != 0) {
1177 		mutex_exit(&stp->sd_lock);
1178 		return (error);
1179 	}
1180 
1181 	if (stp->sd_flag & (STRDERR|STPLEX)) {
1182 		error = strgeterr(stp, STRDERR|STPLEX, 0);
1183 		if (error != 0) {
1184 			mutex_exit(&stp->sd_lock);
1185 			return (error);
1186 		}
1187 	}
1188 
1189 	/*
1190 	 * Loop terminates when uiop->uio_resid == 0.
1191 	 */
1192 	rflg = 0;
1193 	waitflag = READWAIT;
1194 	q = _RD(stp->sd_wrq);
1195 	for (;;) {
1196 		ASSERT(MUTEX_HELD(&stp->sd_lock));
1197 		old_sd_flag = stp->sd_flag;
1198 		mark = 0;
1199 		delim = 0;
1200 		first = 1;
1201 		while ((bp = strget(stp, q, uiop, first, &error)) == NULL) {
1202 			int done = 0;
1203 
1204 			ASSERT(MUTEX_HELD(&stp->sd_lock));
1205 
1206 			if (error != 0)
1207 				goto oops;
1208 
1209 			if (stp->sd_flag & (STRHUP|STREOF)) {
1210 				goto oops;
1211 			}
1212 			if (rflg && !(stp->sd_flag & STRDELIM)) {
1213 				goto oops;
1214 			}
1215 			/*
1216 			 * If a read(fd,buf,0) has been done, there is no
1217 			 * need to sleep. We always have zero bytes to
1218 			 * return.
1219 			 */
1220 			if (uiop->uio_resid == 0) {
1221 				goto oops;
1222 			}
1223 
1224 			qbackenable(q, 0);
1225 
1226 			TRACE_3(TR_FAC_STREAMS_FR, TR_STRREAD_WAIT,
1227 			    "strread calls strwaitq:%p, %p, %p",
1228 			    vp, uiop, crp);
1229 			if ((error = strwaitq(stp, waitflag, uiop->uio_resid,
1230 			    uiop->uio_fmode, -1, &done)) != 0 || done) {
1231 				TRACE_3(TR_FAC_STREAMS_FR, TR_STRREAD_DONE,
1232 				    "strread error or done:%p, %p, %p",
1233 				    vp, uiop, crp);
1234 				if ((uiop->uio_fmode & FNDELAY) &&
1235 				    (stp->sd_flag & OLDNDELAY) &&
1236 				    (error == EAGAIN))
1237 					error = 0;
1238 				goto oops;
1239 			}
1240 			TRACE_3(TR_FAC_STREAMS_FR, TR_STRREAD_AWAKE,
1241 			    "strread awakes:%p, %p, %p", vp, uiop, crp);
1242 			if ((error = i_straccess(stp, JCREAD)) != 0) {
1243 				goto oops;
1244 			}
1245 			first = 0;
1246 		}
1247 
1248 		ASSERT(MUTEX_HELD(&stp->sd_lock));
1249 		ASSERT(bp);
1250 		pri = bp->b_band;
1251 		/*
1252 		 * Extract any mark information. If the message is not
1253 		 * completely consumed this information will be put in the mblk
1254 		 * that is putback.
1255 		 * If MSGMARKNEXT is set and the message is completely consumed
1256 		 * the STRATMARK flag will be set below. Likewise, if
1257 		 * MSGNOTMARKNEXT is set and the message is
1258 		 * completely consumed STRNOTATMARK will be set.
1259 		 *
1260 		 * For some unknown reason strread only breaks the read at the
1261 		 * last mark.
1262 		 */
1263 		mark = bp->b_flag & (MSGMARK | MSGMARKNEXT | MSGNOTMARKNEXT);
1264 		ASSERT((mark & (MSGMARKNEXT|MSGNOTMARKNEXT)) !=
1265 		    (MSGMARKNEXT|MSGNOTMARKNEXT));
1266 		if (mark != 0 && bp == stp->sd_mark) {
1267 			if (rflg) {
1268 				putback(stp, q, bp, pri);
1269 				goto oops;
1270 			}
1271 			mark |= _LASTMARK;
1272 			stp->sd_mark = NULL;
1273 		}
1274 		if ((stp->sd_flag & STRDELIM) && (bp->b_flag & MSGDELIM))
1275 			delim = 1;
1276 		mutex_exit(&stp->sd_lock);
1277 
1278 		if (STREAM_NEEDSERVICE(stp))
1279 			stream_runservice(stp);
1280 
1281 		type = bp->b_datap->db_type;
1282 
1283 		switch (type) {
1284 
1285 		case M_DATA:
1286 ismdata:
1287 			if (msgnodata(bp)) {
1288 				if (mark || delim) {
1289 					freemsg(bp);
1290 				} else if (rflg) {
1291 
1292 					/*
1293 					 * If already read data put zero
1294 					 * length message back on queue else
1295 					 * free msg and return 0.
1296 					 */
1297 					bp->b_band = pri;
1298 					mutex_enter(&stp->sd_lock);
1299 					putback(stp, q, bp, pri);
1300 					mutex_exit(&stp->sd_lock);
1301 				} else {
1302 					freemsg(bp);
1303 				}
1304 				error =  0;
1305 				goto oops1;
1306 			}
1307 
1308 			rflg = 1;
1309 			waitflag |= NOINTR;
1310 			bp = struiocopyout(bp, uiop, &error);
1311 			if (error != 0)
1312 				goto oops1;
1313 
1314 			mutex_enter(&stp->sd_lock);
1315 			if (bp) {
1316 				/*
1317 				 * Have remaining data in message.
1318 				 * Free msg if in discard mode.
1319 				 */
1320 				if (stp->sd_read_opt & RD_MSGDIS) {
1321 					freemsg(bp);
1322 				} else {
1323 					bp->b_band = pri;
1324 					if ((mark & _LASTMARK) &&
1325 					    (stp->sd_mark == NULL))
1326 						stp->sd_mark = bp;
1327 					bp->b_flag |= mark & ~_LASTMARK;
1328 					if (delim)
1329 						bp->b_flag |= MSGDELIM;
1330 					if (msgnodata(bp))
1331 						freemsg(bp);
1332 					else
1333 						putback(stp, q, bp, pri);
1334 				}
1335 			} else {
1336 				/*
1337 				 * Consumed the complete message.
1338 				 * Move the MSG*MARKNEXT information
1339 				 * to the stream head just in case
1340 				 * the read queue becomes empty.
1341 				 *
1342 				 * If the stream head was at the mark
1343 				 * (STRATMARK) before we dropped sd_lock above
1344 				 * and some data was consumed then we have
1345 				 * moved past the mark thus STRATMARK is
1346 				 * cleared. However, if a message arrived in
1347 				 * strrput during the copyout above causing
1348 				 * STRATMARK to be set we can not clear that
1349 				 * flag.
1350 				 */
1351 				if (mark &
1352 				    (MSGMARKNEXT|MSGNOTMARKNEXT|MSGMARK)) {
1353 					if (mark & MSGMARKNEXT) {
1354 						stp->sd_flag &= ~STRNOTATMARK;
1355 						stp->sd_flag |= STRATMARK;
1356 					} else if (mark & MSGNOTMARKNEXT) {
1357 						stp->sd_flag &= ~STRATMARK;
1358 						stp->sd_flag |= STRNOTATMARK;
1359 					} else {
1360 						stp->sd_flag &=
1361 						    ~(STRATMARK|STRNOTATMARK);
1362 					}
1363 				} else if (rflg && (old_sd_flag & STRATMARK)) {
1364 					stp->sd_flag &= ~STRATMARK;
1365 				}
1366 			}
1367 
1368 			/*
1369 			 * Check for signal messages at the front of the read
1370 			 * queue and generate the signal(s) if appropriate.
1371 			 * The only signal that can be on queue is M_SIG at
1372 			 * this point.
1373 			 */
1374 			while ((((bp = q->q_first)) != NULL) &&
1375 			    (bp->b_datap->db_type == M_SIG)) {
1376 				bp = getq_noenab(q, 0);
1377 				/*
1378 				 * sd_lock is held so the content of the
1379 				 * read queue can not change.
1380 				 */
1381 				ASSERT(bp != NULL && DB_TYPE(bp) == M_SIG);
1382 				strsignal_nolock(stp, *bp->b_rptr, bp->b_band);
1383 				mutex_exit(&stp->sd_lock);
1384 				freemsg(bp);
1385 				if (STREAM_NEEDSERVICE(stp))
1386 					stream_runservice(stp);
1387 				mutex_enter(&stp->sd_lock);
1388 			}
1389 
1390 			if ((uiop->uio_resid == 0) || (mark & _LASTMARK) ||
1391 			    delim ||
1392 			    (stp->sd_read_opt & (RD_MSGDIS|RD_MSGNODIS))) {
1393 				goto oops;
1394 			}
1395 			continue;
1396 
1397 		case M_SIG:
1398 			strsignal(stp, *bp->b_rptr, (int32_t)bp->b_band);
1399 			freemsg(bp);
1400 			mutex_enter(&stp->sd_lock);
1401 			continue;
1402 
1403 		case M_PROTO:
1404 		case M_PCPROTO:
1405 			/*
1406 			 * Only data messages are readable.
1407 			 * Any others generate an error, unless
1408 			 * RD_PROTDIS or RD_PROTDAT is set.
1409 			 */
1410 			if (stp->sd_read_opt & RD_PROTDAT) {
1411 				for (nbp = bp; nbp; nbp = nbp->b_next) {
1412 					if ((nbp->b_datap->db_type ==
1413 					    M_PROTO) ||
1414 					    (nbp->b_datap->db_type ==
1415 					    M_PCPROTO)) {
1416 						nbp->b_datap->db_type = M_DATA;
1417 					} else {
1418 						break;
1419 					}
1420 				}
1421 				/*
1422 				 * clear stream head hi pri flag based on
1423 				 * first message
1424 				 */
1425 				if (type == M_PCPROTO) {
1426 					mutex_enter(&stp->sd_lock);
1427 					stp->sd_flag &= ~STRPRI;
1428 					mutex_exit(&stp->sd_lock);
1429 				}
1430 				goto ismdata;
1431 			} else if (stp->sd_read_opt & RD_PROTDIS) {
1432 				/*
1433 				 * discard non-data messages
1434 				 */
1435 				while (bp &&
1436 				    ((bp->b_datap->db_type == M_PROTO) ||
1437 				    (bp->b_datap->db_type == M_PCPROTO))) {
1438 					nbp = unlinkb(bp);
1439 					freeb(bp);
1440 					bp = nbp;
1441 				}
1442 				/*
1443 				 * clear stream head hi pri flag based on
1444 				 * first message
1445 				 */
1446 				if (type == M_PCPROTO) {
1447 					mutex_enter(&stp->sd_lock);
1448 					stp->sd_flag &= ~STRPRI;
1449 					mutex_exit(&stp->sd_lock);
1450 				}
1451 				if (bp) {
1452 					bp->b_band = pri;
1453 					goto ismdata;
1454 				} else {
1455 					break;
1456 				}
1457 			}
1458 			/* FALLTHRU */
1459 		case M_PASSFP:
1460 			if ((bp->b_datap->db_type == M_PASSFP) &&
1461 			    (stp->sd_read_opt & RD_PROTDIS)) {
1462 				freemsg(bp);
1463 				break;
1464 			}
1465 			mutex_enter(&stp->sd_lock);
1466 			putback(stp, q, bp, pri);
1467 			mutex_exit(&stp->sd_lock);
1468 			if (rflg == 0)
1469 				error = EBADMSG;
1470 			goto oops1;
1471 
1472 		default:
1473 			/*
1474 			 * Garbage on stream head read queue.
1475 			 */
1476 			cmn_err(CE_WARN, "bad %x found at stream head\n",
1477 			    bp->b_datap->db_type);
1478 			freemsg(bp);
1479 			goto oops1;
1480 		}
1481 		mutex_enter(&stp->sd_lock);
1482 	}
1483 oops:
1484 	mutex_exit(&stp->sd_lock);
1485 oops1:
1486 	qbackenable(q, pri);
1487 	return (error);
1488 #undef	_LASTMARK
1489 }
1490 
1491 /*
1492  * Default processing of M_PROTO/M_PCPROTO messages.
1493  * Determine which wakeups and signals are needed.
1494  * This can be replaced by a user-specified procedure for kernel users
1495  * of STREAMS.
1496  */
1497 /* ARGSUSED */
1498 mblk_t *
1499 strrput_proto(vnode_t *vp, mblk_t *mp,
1500     strwakeup_t *wakeups, strsigset_t *firstmsgsigs,
1501     strsigset_t *allmsgsigs, strpollset_t *pollwakeups)
1502 {
1503 	*wakeups = RSLEEP;
1504 	*allmsgsigs = 0;
1505 
1506 	switch (mp->b_datap->db_type) {
1507 	case M_PROTO:
1508 		if (mp->b_band == 0) {
1509 			*firstmsgsigs = S_INPUT | S_RDNORM;
1510 			*pollwakeups = POLLIN | POLLRDNORM;
1511 		} else {
1512 			*firstmsgsigs = S_INPUT | S_RDBAND;
1513 			*pollwakeups = POLLIN | POLLRDBAND;
1514 		}
1515 		break;
1516 	case M_PCPROTO:
1517 		*firstmsgsigs = S_HIPRI;
1518 		*pollwakeups = POLLPRI;
1519 		break;
1520 	}
1521 	return (mp);
1522 }
1523 
1524 /*
1525  * Default processing of everything but M_DATA, M_PROTO, M_PCPROTO and
1526  * M_PASSFP messages.
1527  * Determine which wakeups and signals are needed.
1528  * This can be replaced by a user-specified procedure for kernel users
1529  * of STREAMS.
1530  */
1531 /* ARGSUSED */
1532 mblk_t *
1533 strrput_misc(vnode_t *vp, mblk_t *mp,
1534     strwakeup_t *wakeups, strsigset_t *firstmsgsigs,
1535     strsigset_t *allmsgsigs, strpollset_t *pollwakeups)
1536 {
1537 	*wakeups = 0;
1538 	*firstmsgsigs = 0;
1539 	*allmsgsigs = 0;
1540 	*pollwakeups = 0;
1541 	return (mp);
1542 }
1543 
1544 /*
1545  * Stream read put procedure.  Called from downstream driver/module
1546  * with messages for the stream head.  Data, protocol, and in-stream
1547  * signal messages are placed on the queue, others are handled directly.
1548  */
1549 int
1550 strrput(queue_t *q, mblk_t *bp)
1551 {
1552 	struct stdata	*stp;
1553 	ulong_t		rput_opt;
1554 	strwakeup_t	wakeups;
1555 	strsigset_t	firstmsgsigs;	/* Signals if first message on queue */
1556 	strsigset_t	allmsgsigs;	/* Signals for all messages */
1557 	strsigset_t	signals;	/* Signals events to generate */
1558 	strpollset_t	pollwakeups;
1559 	mblk_t		*nextbp;
1560 	uchar_t		band = 0;
1561 	int		hipri_sig;
1562 
1563 	stp = (struct stdata *)q->q_ptr;
1564 	/*
1565 	 * Use rput_opt for optimized access to the SR_ flags except
1566 	 * SR_POLLIN. That flag has to be checked under sd_lock since it
1567 	 * is modified by strpoll().
1568 	 */
1569 	rput_opt = stp->sd_rput_opt;
1570 
1571 	ASSERT(qclaimed(q));
1572 	TRACE_2(TR_FAC_STREAMS_FR, TR_STRRPUT_ENTER,
1573 	    "strrput called with message type:q %p bp %p", q, bp);
1574 
1575 	/*
1576 	 * Perform initial processing and pass to the parameterized functions.
1577 	 */
1578 	ASSERT(bp->b_next == NULL);
1579 
1580 	switch (bp->b_datap->db_type) {
1581 	case M_DATA:
1582 		/*
1583 		 * sockfs is the only consumer of STREOF and when it is set,
1584 		 * it implies that the receiver is not interested in receiving
1585 		 * any more data, hence the mblk is freed to prevent unnecessary
1586 		 * message queueing at the stream head.
1587 		 */
1588 		if (stp->sd_flag == STREOF) {
1589 			freemsg(bp);
1590 			return (0);
1591 		}
1592 		if ((rput_opt & SR_IGN_ZEROLEN) &&
1593 		    bp->b_rptr == bp->b_wptr && msgnodata(bp)) {
1594 			/*
1595 			 * Ignore zero-length M_DATA messages. These might be
1596 			 * generated by some transports.
1597 			 * The zero-length M_DATA messages, even if they
1598 			 * are ignored, should effect the atmark tracking and
1599 			 * should wake up a thread sleeping in strwaitmark.
1600 			 */
1601 			mutex_enter(&stp->sd_lock);
1602 			if (bp->b_flag & MSGMARKNEXT) {
1603 				/*
1604 				 * Record the position of the mark either
1605 				 * in q_last or in STRATMARK.
1606 				 */
1607 				if (q->q_last != NULL) {
1608 					q->q_last->b_flag &= ~MSGNOTMARKNEXT;
1609 					q->q_last->b_flag |= MSGMARKNEXT;
1610 				} else {
1611 					stp->sd_flag &= ~STRNOTATMARK;
1612 					stp->sd_flag |= STRATMARK;
1613 				}
1614 			} else if (bp->b_flag & MSGNOTMARKNEXT) {
1615 				/*
1616 				 * Record that this is not the position of
1617 				 * the mark either in q_last or in
1618 				 * STRNOTATMARK.
1619 				 */
1620 				if (q->q_last != NULL) {
1621 					q->q_last->b_flag &= ~MSGMARKNEXT;
1622 					q->q_last->b_flag |= MSGNOTMARKNEXT;
1623 				} else {
1624 					stp->sd_flag &= ~STRATMARK;
1625 					stp->sd_flag |= STRNOTATMARK;
1626 				}
1627 			}
1628 			if (stp->sd_flag & RSLEEP) {
1629 				stp->sd_flag &= ~RSLEEP;
1630 				cv_broadcast(&q->q_wait);
1631 			}
1632 			mutex_exit(&stp->sd_lock);
1633 			freemsg(bp);
1634 			return (0);
1635 		}
1636 		wakeups = RSLEEP;
1637 		if (bp->b_band == 0) {
1638 			firstmsgsigs = S_INPUT | S_RDNORM;
1639 			pollwakeups = POLLIN | POLLRDNORM;
1640 		} else {
1641 			firstmsgsigs = S_INPUT | S_RDBAND;
1642 			pollwakeups = POLLIN | POLLRDBAND;
1643 		}
1644 		if (rput_opt & SR_SIGALLDATA)
1645 			allmsgsigs = firstmsgsigs;
1646 		else
1647 			allmsgsigs = 0;
1648 
1649 		mutex_enter(&stp->sd_lock);
1650 		if ((rput_opt & SR_CONSOL_DATA) &&
1651 		    (q->q_last != NULL) &&
1652 		    (bp->b_flag & (MSGMARK|MSGDELIM)) == 0) {
1653 			/*
1654 			 * Consolidate an M_DATA message onto an M_DATA,
1655 			 * M_PROTO, or M_PCPROTO by merging it with q_last.
1656 			 * The consolidation does not take place if
1657 			 * the old message is marked with either of the
1658 			 * marks or the delim flag or if the new
1659 			 * message is marked with MSGMARK. The MSGMARK
1660 			 * check is needed to handle the odd semantics of
1661 			 * MSGMARK where essentially the whole message
1662 			 * is to be treated as marked.
1663 			 * Carry any MSGMARKNEXT  and MSGNOTMARKNEXT from the
1664 			 * new message to the front of the b_cont chain.
1665 			 */
1666 			mblk_t *lbp = q->q_last;
1667 			unsigned char db_type = lbp->b_datap->db_type;
1668 
1669 			if ((db_type == M_DATA || db_type == M_PROTO ||
1670 			    db_type == M_PCPROTO) &&
1671 			    !(lbp->b_flag & (MSGDELIM|MSGMARK|MSGMARKNEXT))) {
1672 				rmvq_noenab(q, lbp);
1673 				/*
1674 				 * The first message in the b_cont list
1675 				 * tracks MSGMARKNEXT and MSGNOTMARKNEXT.
1676 				 * We need to handle the case where we
1677 				 * are appending:
1678 				 *
1679 				 * 1) a MSGMARKNEXT to a MSGNOTMARKNEXT.
1680 				 * 2) a MSGMARKNEXT to a plain message.
1681 				 * 3) a MSGNOTMARKNEXT to a plain message
1682 				 * 4) a MSGNOTMARKNEXT to a MSGNOTMARKNEXT
1683 				 *    message.
1684 				 *
1685 				 * Thus we never append a MSGMARKNEXT or
1686 				 * MSGNOTMARKNEXT to a MSGMARKNEXT message.
1687 				 */
1688 				if (bp->b_flag & MSGMARKNEXT) {
1689 					lbp->b_flag |= MSGMARKNEXT;
1690 					lbp->b_flag &= ~MSGNOTMARKNEXT;
1691 					bp->b_flag &= ~MSGMARKNEXT;
1692 				} else if (bp->b_flag & MSGNOTMARKNEXT) {
1693 					lbp->b_flag |= MSGNOTMARKNEXT;
1694 					bp->b_flag &= ~MSGNOTMARKNEXT;
1695 				}
1696 
1697 				linkb(lbp, bp);
1698 				bp = lbp;
1699 				/*
1700 				 * The new message logically isn't the first
1701 				 * even though the q_first check below thinks
1702 				 * it is. Clear the firstmsgsigs to make it
1703 				 * not appear to be first.
1704 				 */
1705 				firstmsgsigs = 0;
1706 			}
1707 		}
1708 		break;
1709 
1710 	case M_PASSFP:
1711 		wakeups = RSLEEP;
1712 		allmsgsigs = 0;
1713 		if (bp->b_band == 0) {
1714 			firstmsgsigs = S_INPUT | S_RDNORM;
1715 			pollwakeups = POLLIN | POLLRDNORM;
1716 		} else {
1717 			firstmsgsigs = S_INPUT | S_RDBAND;
1718 			pollwakeups = POLLIN | POLLRDBAND;
1719 		}
1720 		mutex_enter(&stp->sd_lock);
1721 		break;
1722 
1723 	case M_PROTO:
1724 	case M_PCPROTO:
1725 		ASSERT(stp->sd_rprotofunc != NULL);
1726 		bp = (stp->sd_rprotofunc)(stp->sd_vnode, bp,
1727 		    &wakeups, &firstmsgsigs, &allmsgsigs, &pollwakeups);
1728 #define	ALLSIG	(S_INPUT|S_HIPRI|S_OUTPUT|S_MSG|S_ERROR|S_HANGUP|S_RDNORM|\
1729 		S_WRNORM|S_RDBAND|S_WRBAND|S_BANDURG)
1730 #define	ALLPOLL	(POLLIN|POLLPRI|POLLOUT|POLLRDNORM|POLLWRNORM|POLLRDBAND|\
1731 		POLLWRBAND)
1732 
1733 		ASSERT((wakeups & ~(RSLEEP|WSLEEP)) == 0);
1734 		ASSERT((firstmsgsigs & ~ALLSIG) == 0);
1735 		ASSERT((allmsgsigs & ~ALLSIG) == 0);
1736 		ASSERT((pollwakeups & ~ALLPOLL) == 0);
1737 
1738 		mutex_enter(&stp->sd_lock);
1739 		break;
1740 
1741 	default:
1742 		ASSERT(stp->sd_rmiscfunc != NULL);
1743 		bp = (stp->sd_rmiscfunc)(stp->sd_vnode, bp,
1744 		    &wakeups, &firstmsgsigs, &allmsgsigs, &pollwakeups);
1745 		ASSERT((wakeups & ~(RSLEEP|WSLEEP)) == 0);
1746 		ASSERT((firstmsgsigs & ~ALLSIG) == 0);
1747 		ASSERT((allmsgsigs & ~ALLSIG) == 0);
1748 		ASSERT((pollwakeups & ~ALLPOLL) == 0);
1749 #undef	ALLSIG
1750 #undef	ALLPOLL
1751 		mutex_enter(&stp->sd_lock);
1752 		break;
1753 	}
1754 	ASSERT(MUTEX_HELD(&stp->sd_lock));
1755 
1756 	/* By default generate superset of signals */
1757 	signals = (firstmsgsigs | allmsgsigs);
1758 
1759 	/*
1760 	 * The  proto and misc functions can return multiple messages
1761 	 * as a b_next chain. Such messages are processed separately.
1762 	 */
1763 one_more:
1764 	hipri_sig = 0;
1765 	if (bp == NULL) {
1766 		nextbp = NULL;
1767 	} else {
1768 		nextbp = bp->b_next;
1769 		bp->b_next = NULL;
1770 
1771 		switch (bp->b_datap->db_type) {
1772 		case M_PCPROTO:
1773 			/*
1774 			 * Only one priority protocol message is allowed at the
1775 			 * stream head at a time.
1776 			 */
1777 			if (stp->sd_flag & STRPRI) {
1778 				TRACE_0(TR_FAC_STREAMS_FR, TR_STRRPUT_PROTERR,
1779 				    "M_PCPROTO already at head");
1780 				freemsg(bp);
1781 				mutex_exit(&stp->sd_lock);
1782 				goto done;
1783 			}
1784 			stp->sd_flag |= STRPRI;
1785 			hipri_sig = 1;
1786 			/* FALLTHRU */
1787 		case M_DATA:
1788 		case M_PROTO:
1789 		case M_PASSFP:
1790 			band = bp->b_band;
1791 			/*
1792 			 * Marking doesn't work well when messages
1793 			 * are marked in more than one band.  We only
1794 			 * remember the last message received, even if
1795 			 * it is placed on the queue ahead of other
1796 			 * marked messages.
1797 			 */
1798 			if (bp->b_flag & MSGMARK)
1799 				stp->sd_mark = bp;
1800 			(void) putq(q, bp);
1801 
1802 			/*
1803 			 * If message is a PCPROTO message, always use
1804 			 * firstmsgsigs to determine if a signal should be
1805 			 * sent as strrput is the only place to send
1806 			 * signals for PCPROTO. Other messages are based on
1807 			 * the STRGETINPROG flag. The flag determines if
1808 			 * strrput or (k)strgetmsg will be responsible for
1809 			 * sending the signals, in the firstmsgsigs case.
1810 			 */
1811 			if ((hipri_sig == 1) ||
1812 			    (((stp->sd_flag & STRGETINPROG) == 0) &&
1813 			    (q->q_first == bp)))
1814 				signals = (firstmsgsigs | allmsgsigs);
1815 			else
1816 				signals = allmsgsigs;
1817 			break;
1818 
1819 		default:
1820 			mutex_exit(&stp->sd_lock);
1821 			(void) strrput_nondata(q, bp);
1822 			mutex_enter(&stp->sd_lock);
1823 			break;
1824 		}
1825 	}
1826 	ASSERT(MUTEX_HELD(&stp->sd_lock));
1827 	/*
1828 	 * Wake sleeping read/getmsg and cancel deferred wakeup
1829 	 */
1830 	if (wakeups & RSLEEP)
1831 		stp->sd_wakeq &= ~RSLEEP;
1832 
1833 	wakeups &= stp->sd_flag;
1834 	if (wakeups & RSLEEP) {
1835 		stp->sd_flag &= ~RSLEEP;
1836 		cv_broadcast(&q->q_wait);
1837 	}
1838 	if (wakeups & WSLEEP) {
1839 		stp->sd_flag &= ~WSLEEP;
1840 		cv_broadcast(&_WR(q)->q_wait);
1841 	}
1842 
1843 	if (pollwakeups != 0) {
1844 		if (pollwakeups == (POLLIN | POLLRDNORM)) {
1845 			/*
1846 			 * Can't use rput_opt since it was not
1847 			 * read when sd_lock was held and SR_POLLIN is changed
1848 			 * by strpoll() under sd_lock.
1849 			 */
1850 			if (!(stp->sd_rput_opt & SR_POLLIN))
1851 				goto no_pollwake;
1852 			stp->sd_rput_opt &= ~SR_POLLIN;
1853 		}
1854 		mutex_exit(&stp->sd_lock);
1855 		pollwakeup(&stp->sd_pollist, pollwakeups);
1856 		mutex_enter(&stp->sd_lock);
1857 	}
1858 no_pollwake:
1859 
1860 	/*
1861 	 * strsendsig can handle multiple signals with a
1862 	 * single call.
1863 	 */
1864 	if (stp->sd_sigflags & signals)
1865 		strsendsig(stp->sd_siglist, signals, band, 0);
1866 	mutex_exit(&stp->sd_lock);
1867 
1868 
1869 done:
1870 	if (nextbp == NULL)
1871 		return (0);
1872 
1873 	/*
1874 	 * Any signals were handled the first time.
1875 	 * Wakeups and pollwakeups are redone to avoid any race
1876 	 * conditions - all the messages are not queued until the
1877 	 * last message has been processed by strrput.
1878 	 */
1879 	bp = nextbp;
1880 	signals = firstmsgsigs = allmsgsigs = 0;
1881 	mutex_enter(&stp->sd_lock);
1882 	goto one_more;
1883 }
1884 
1885 static void
1886 log_dupioc(queue_t *rq, mblk_t *bp)
1887 {
1888 	queue_t *wq, *qp;
1889 	char *modnames, *mnp, *dname;
1890 	size_t maxmodstr;
1891 	boolean_t islast;
1892 
1893 	/*
1894 	 * Allocate a buffer large enough to hold the names of nstrpush modules
1895 	 * and one driver, with spaces between and NUL terminator.  If we can't
1896 	 * get memory, then we'll just log the driver name.
1897 	 */
1898 	maxmodstr = nstrpush * (FMNAMESZ + 1);
1899 	mnp = modnames = kmem_alloc(maxmodstr, KM_NOSLEEP);
1900 
1901 	/* march down write side to print log message down to the driver */
1902 	wq = WR(rq);
1903 
1904 	/* make sure q_next doesn't shift around while we're grabbing data */
1905 	claimstr(wq);
1906 	qp = wq->q_next;
1907 	do {
1908 		dname = Q2NAME(qp);
1909 		islast = !SAMESTR(qp) || qp->q_next == NULL;
1910 		if (modnames == NULL) {
1911 			/*
1912 			 * If we don't have memory, then get the driver name in
1913 			 * the log where we can see it.  Note that memory
1914 			 * pressure is a possible cause of these sorts of bugs.
1915 			 */
1916 			if (islast) {
1917 				modnames = dname;
1918 				maxmodstr = 0;
1919 			}
1920 		} else {
1921 			mnp += snprintf(mnp, FMNAMESZ + 1, "%s", dname);
1922 			if (!islast)
1923 				*mnp++ = ' ';
1924 		}
1925 		qp = qp->q_next;
1926 	} while (!islast);
1927 	releasestr(wq);
1928 	/* Cannot happen unless stream head is corrupt. */
1929 	ASSERT(modnames != NULL);
1930 	(void) strlog(rq->q_qinfo->qi_minfo->mi_idnum, 0, 1,
1931 	    SL_CONSOLE|SL_TRACE|SL_ERROR,
1932 	    "Warning: stream %p received duplicate %X M_IOC%s; module list: %s",
1933 	    rq->q_ptr, ((struct iocblk *)bp->b_rptr)->ioc_cmd,
1934 	    (DB_TYPE(bp) == M_IOCACK ? "ACK" : "NAK"), modnames);
1935 	if (maxmodstr != 0)
1936 		kmem_free(modnames, maxmodstr);
1937 }
1938 
1939 int
1940 strrput_nondata(queue_t *q, mblk_t *bp)
1941 {
1942 	struct stdata *stp;
1943 	struct iocblk *iocbp;
1944 	struct stroptions *sop;
1945 	struct copyreq *reqp;
1946 	struct copyresp *resp;
1947 	unsigned char bpri;
1948 	unsigned char  flushed_already = 0;
1949 
1950 	stp = (struct stdata *)q->q_ptr;
1951 
1952 	ASSERT(!(stp->sd_flag & STPLEX));
1953 	ASSERT(qclaimed(q));
1954 
1955 	switch (bp->b_datap->db_type) {
1956 	case M_ERROR:
1957 		/*
1958 		 * An error has occurred downstream, the errno is in the first
1959 		 * bytes of the message.
1960 		 */
1961 		if ((bp->b_wptr - bp->b_rptr) == 2) {	/* New flavor */
1962 			unsigned char rw = 0;
1963 
1964 			mutex_enter(&stp->sd_lock);
1965 			if (*bp->b_rptr != NOERROR) {	/* read error */
1966 				if (*bp->b_rptr != 0) {
1967 					if (stp->sd_flag & STRDERR)
1968 						flushed_already |= FLUSHR;
1969 					stp->sd_flag |= STRDERR;
1970 					rw |= FLUSHR;
1971 				} else {
1972 					stp->sd_flag &= ~STRDERR;
1973 				}
1974 				stp->sd_rerror = *bp->b_rptr;
1975 			}
1976 			bp->b_rptr++;
1977 			if (*bp->b_rptr != NOERROR) {	/* write error */
1978 				if (*bp->b_rptr != 0) {
1979 					if (stp->sd_flag & STWRERR)
1980 						flushed_already |= FLUSHW;
1981 					stp->sd_flag |= STWRERR;
1982 					rw |= FLUSHW;
1983 				} else {
1984 					stp->sd_flag &= ~STWRERR;
1985 				}
1986 				stp->sd_werror = *bp->b_rptr;
1987 			}
1988 			if (rw) {
1989 				TRACE_2(TR_FAC_STREAMS_FR, TR_STRRPUT_WAKE,
1990 				    "strrput cv_broadcast:q %p, bp %p",
1991 				    q, bp);
1992 				cv_broadcast(&q->q_wait); /* readers */
1993 				cv_broadcast(&_WR(q)->q_wait); /* writers */
1994 				cv_broadcast(&stp->sd_monitor); /* ioctllers */
1995 
1996 				mutex_exit(&stp->sd_lock);
1997 				pollwakeup(&stp->sd_pollist, POLLERR);
1998 				mutex_enter(&stp->sd_lock);
1999 
2000 				if (stp->sd_sigflags & S_ERROR)
2001 					strsendsig(stp->sd_siglist, S_ERROR, 0,
2002 					    ((rw & FLUSHR) ? stp->sd_rerror :
2003 					    stp->sd_werror));
2004 				mutex_exit(&stp->sd_lock);
2005 				/*
2006 				 * Send the M_FLUSH only
2007 				 * for the first M_ERROR
2008 				 * message on the stream
2009 				 */
2010 				if (flushed_already == rw) {
2011 					freemsg(bp);
2012 					return (0);
2013 				}
2014 
2015 				bp->b_datap->db_type = M_FLUSH;
2016 				*bp->b_rptr = rw;
2017 				bp->b_wptr = bp->b_rptr + 1;
2018 				/*
2019 				 * Protect against the driver
2020 				 * passing up messages after
2021 				 * it has done a qprocsoff
2022 				 */
2023 				if (_OTHERQ(q)->q_next == NULL)
2024 					freemsg(bp);
2025 				else
2026 					qreply(q, bp);
2027 				return (0);
2028 			} else
2029 				mutex_exit(&stp->sd_lock);
2030 		} else if (*bp->b_rptr != 0) {		/* Old flavor */
2031 				if (stp->sd_flag & (STRDERR|STWRERR))
2032 					flushed_already = FLUSHRW;
2033 				mutex_enter(&stp->sd_lock);
2034 				stp->sd_flag |= (STRDERR|STWRERR);
2035 				stp->sd_rerror = *bp->b_rptr;
2036 				stp->sd_werror = *bp->b_rptr;
2037 				TRACE_2(TR_FAC_STREAMS_FR,
2038 				    TR_STRRPUT_WAKE2,
2039 				    "strrput wakeup #2:q %p, bp %p", q, bp);
2040 				cv_broadcast(&q->q_wait); /* the readers */
2041 				cv_broadcast(&_WR(q)->q_wait); /* the writers */
2042 				cv_broadcast(&stp->sd_monitor); /* ioctllers */
2043 
2044 				mutex_exit(&stp->sd_lock);
2045 				pollwakeup(&stp->sd_pollist, POLLERR);
2046 				mutex_enter(&stp->sd_lock);
2047 
2048 				if (stp->sd_sigflags & S_ERROR)
2049 					strsendsig(stp->sd_siglist, S_ERROR, 0,
2050 					    (stp->sd_werror ? stp->sd_werror :
2051 					    stp->sd_rerror));
2052 				mutex_exit(&stp->sd_lock);
2053 
2054 				/*
2055 				 * Send the M_FLUSH only
2056 				 * for the first M_ERROR
2057 				 * message on the stream
2058 				 */
2059 				if (flushed_already != FLUSHRW) {
2060 					bp->b_datap->db_type = M_FLUSH;
2061 					*bp->b_rptr = FLUSHRW;
2062 					/*
2063 					 * Protect against the driver passing up
2064 					 * messages after it has done a
2065 					 * qprocsoff.
2066 					 */
2067 				if (_OTHERQ(q)->q_next == NULL)
2068 					freemsg(bp);
2069 				else
2070 					qreply(q, bp);
2071 				return (0);
2072 				}
2073 		}
2074 		freemsg(bp);
2075 		return (0);
2076 
2077 	case M_HANGUP:
2078 
2079 		freemsg(bp);
2080 		mutex_enter(&stp->sd_lock);
2081 		stp->sd_werror = ENXIO;
2082 		stp->sd_flag |= STRHUP;
2083 		stp->sd_flag &= ~(WSLEEP|RSLEEP);
2084 
2085 		/*
2086 		 * send signal if controlling tty
2087 		 */
2088 
2089 		if (stp->sd_sidp) {
2090 			prsignal(stp->sd_sidp, SIGHUP);
2091 			if (stp->sd_sidp != stp->sd_pgidp)
2092 				pgsignal(stp->sd_pgidp, SIGTSTP);
2093 		}
2094 
2095 		/*
2096 		 * wake up read, write, and exception pollers and
2097 		 * reset wakeup mechanism.
2098 		 */
2099 		cv_broadcast(&q->q_wait);	/* the readers */
2100 		cv_broadcast(&_WR(q)->q_wait);	/* the writers */
2101 		cv_broadcast(&stp->sd_monitor);	/* the ioctllers */
2102 		strhup(stp);
2103 		mutex_exit(&stp->sd_lock);
2104 		return (0);
2105 
2106 	case M_UNHANGUP:
2107 		freemsg(bp);
2108 		mutex_enter(&stp->sd_lock);
2109 		stp->sd_werror = 0;
2110 		stp->sd_flag &= ~STRHUP;
2111 		mutex_exit(&stp->sd_lock);
2112 		return (0);
2113 
2114 	case M_SIG:
2115 		/*
2116 		 * Someone downstream wants to post a signal.  The
2117 		 * signal to post is contained in the first byte of the
2118 		 * message.  If the message would go on the front of
2119 		 * the queue, send a signal to the process group
2120 		 * (if not SIGPOLL) or to the siglist processes
2121 		 * (SIGPOLL).  If something is already on the queue,
2122 		 * OR if we are delivering a delayed suspend (*sigh*
2123 		 * another "tty" hack) and there's no one sleeping already,
2124 		 * just enqueue the message.
2125 		 */
2126 		mutex_enter(&stp->sd_lock);
2127 		if (q->q_first || (*bp->b_rptr == SIGTSTP &&
2128 		    !(stp->sd_flag & RSLEEP))) {
2129 			(void) putq(q, bp);
2130 			mutex_exit(&stp->sd_lock);
2131 			return (0);
2132 		}
2133 		mutex_exit(&stp->sd_lock);
2134 		/* FALLTHRU */
2135 
2136 	case M_PCSIG:
2137 		/*
2138 		 * Don't enqueue, just post the signal.
2139 		 */
2140 		strsignal(stp, *bp->b_rptr, 0L);
2141 		freemsg(bp);
2142 		return (0);
2143 
2144 	case M_CMD:
2145 		if (MBLKL(bp) != sizeof (cmdblk_t)) {
2146 			freemsg(bp);
2147 			return (0);
2148 		}
2149 
2150 		mutex_enter(&stp->sd_lock);
2151 		if (stp->sd_flag & STRCMDWAIT) {
2152 			ASSERT(stp->sd_cmdblk == NULL);
2153 			stp->sd_cmdblk = bp;
2154 			cv_broadcast(&stp->sd_monitor);
2155 			mutex_exit(&stp->sd_lock);
2156 		} else {
2157 			mutex_exit(&stp->sd_lock);
2158 			freemsg(bp);
2159 		}
2160 		return (0);
2161 
2162 	case M_FLUSH:
2163 		/*
2164 		 * Flush queues.  The indication of which queues to flush
2165 		 * is in the first byte of the message.  If the read queue
2166 		 * is specified, then flush it.  If FLUSHBAND is set, just
2167 		 * flush the band specified by the second byte of the message.
2168 		 *
2169 		 * If a module has issued a M_SETOPT to not flush hi
2170 		 * priority messages off of the stream head, then pass this
2171 		 * flag into the flushq code to preserve such messages.
2172 		 */
2173 
2174 		if (*bp->b_rptr & FLUSHR) {
2175 			mutex_enter(&stp->sd_lock);
2176 			if (*bp->b_rptr & FLUSHBAND) {
2177 				ASSERT((bp->b_wptr - bp->b_rptr) >= 2);
2178 				flushband(q, *(bp->b_rptr + 1), FLUSHALL);
2179 			} else
2180 				flushq_common(q, FLUSHALL,
2181 				    stp->sd_read_opt & RFLUSHPCPROT);
2182 			if ((q->q_first == NULL) ||
2183 			    (q->q_first->b_datap->db_type < QPCTL))
2184 				stp->sd_flag &= ~STRPRI;
2185 			else {
2186 				ASSERT(stp->sd_flag & STRPRI);
2187 			}
2188 			mutex_exit(&stp->sd_lock);
2189 		}
2190 		if ((*bp->b_rptr & FLUSHW) && !(bp->b_flag & MSGNOLOOP)) {
2191 			*bp->b_rptr &= ~FLUSHR;
2192 			bp->b_flag |= MSGNOLOOP;
2193 			/*
2194 			 * Protect against the driver passing up
2195 			 * messages after it has done a qprocsoff.
2196 			 */
2197 			if (_OTHERQ(q)->q_next == NULL)
2198 				freemsg(bp);
2199 			else
2200 				qreply(q, bp);
2201 			return (0);
2202 		}
2203 		freemsg(bp);
2204 		return (0);
2205 
2206 	case M_IOCACK:
2207 	case M_IOCNAK:
2208 		iocbp = (struct iocblk *)bp->b_rptr;
2209 		/*
2210 		 * If not waiting for ACK or NAK then just free msg.
2211 		 * If incorrect id sequence number then just free msg.
2212 		 * If already have ACK or NAK for user then this is a
2213 		 *    duplicate, display a warning and free the msg.
2214 		 */
2215 		mutex_enter(&stp->sd_lock);
2216 		if ((stp->sd_flag & IOCWAIT) == 0 || stp->sd_iocblk ||
2217 		    (stp->sd_iocid != iocbp->ioc_id)) {
2218 			/*
2219 			 * If the ACK/NAK is a dup, display a message
2220 			 * Dup is when sd_iocid == ioc_id, and
2221 			 * sd_iocblk == <valid ptr> or -1 (the former
2222 			 * is when an ioctl has been put on the stream
2223 			 * head, but has not yet been consumed, the
2224 			 * later is when it has been consumed).
2225 			 */
2226 			if ((stp->sd_iocid == iocbp->ioc_id) &&
2227 			    (stp->sd_iocblk != NULL)) {
2228 				log_dupioc(q, bp);
2229 			}
2230 			freemsg(bp);
2231 			mutex_exit(&stp->sd_lock);
2232 			return (0);
2233 		}
2234 
2235 		/*
2236 		 * Assign ACK or NAK to user and wake up.
2237 		 */
2238 		stp->sd_iocblk = bp;
2239 		cv_broadcast(&stp->sd_monitor);
2240 		mutex_exit(&stp->sd_lock);
2241 		return (0);
2242 
2243 	case M_COPYIN:
2244 	case M_COPYOUT:
2245 		reqp = (struct copyreq *)bp->b_rptr;
2246 
2247 		/*
2248 		 * If not waiting for ACK or NAK then just fail request.
2249 		 * If already have ACK, NAK, or copy request, then just
2250 		 * fail request.
2251 		 * If incorrect id sequence number then just fail request.
2252 		 */
2253 		mutex_enter(&stp->sd_lock);
2254 		if ((stp->sd_flag & IOCWAIT) == 0 || stp->sd_iocblk ||
2255 		    (stp->sd_iocid != reqp->cq_id)) {
2256 			if (bp->b_cont) {
2257 				freemsg(bp->b_cont);
2258 				bp->b_cont = NULL;
2259 			}
2260 			bp->b_datap->db_type = M_IOCDATA;
2261 			bp->b_wptr = bp->b_rptr + sizeof (struct copyresp);
2262 			resp = (struct copyresp *)bp->b_rptr;
2263 			resp->cp_rval = (caddr_t)1;	/* failure */
2264 			mutex_exit(&stp->sd_lock);
2265 			putnext(stp->sd_wrq, bp);
2266 			return (0);
2267 		}
2268 
2269 		/*
2270 		 * Assign copy request to user and wake up.
2271 		 */
2272 		stp->sd_iocblk = bp;
2273 		cv_broadcast(&stp->sd_monitor);
2274 		mutex_exit(&stp->sd_lock);
2275 		return (0);
2276 
2277 	case M_SETOPTS:
2278 		/*
2279 		 * Set stream head options (read option, write offset,
2280 		 * min/max packet size, and/or high/low water marks for
2281 		 * the read side only).
2282 		 */
2283 
2284 		bpri = 0;
2285 		sop = (struct stroptions *)bp->b_rptr;
2286 		mutex_enter(&stp->sd_lock);
2287 		if (sop->so_flags & SO_READOPT) {
2288 			switch (sop->so_readopt & RMODEMASK) {
2289 			case RNORM:
2290 				stp->sd_read_opt &= ~(RD_MSGDIS | RD_MSGNODIS);
2291 				break;
2292 
2293 			case RMSGD:
2294 				stp->sd_read_opt =
2295 				    ((stp->sd_read_opt & ~RD_MSGNODIS) |
2296 				    RD_MSGDIS);
2297 				break;
2298 
2299 			case RMSGN:
2300 				stp->sd_read_opt =
2301 				    ((stp->sd_read_opt & ~RD_MSGDIS) |
2302 				    RD_MSGNODIS);
2303 				break;
2304 			}
2305 			switch (sop->so_readopt & RPROTMASK) {
2306 			case RPROTNORM:
2307 				stp->sd_read_opt &= ~(RD_PROTDAT | RD_PROTDIS);
2308 				break;
2309 
2310 			case RPROTDAT:
2311 				stp->sd_read_opt =
2312 				    ((stp->sd_read_opt & ~RD_PROTDIS) |
2313 				    RD_PROTDAT);
2314 				break;
2315 
2316 			case RPROTDIS:
2317 				stp->sd_read_opt =
2318 				    ((stp->sd_read_opt & ~RD_PROTDAT) |
2319 				    RD_PROTDIS);
2320 				break;
2321 			}
2322 			switch (sop->so_readopt & RFLUSHMASK) {
2323 			case RFLUSHPCPROT:
2324 				/*
2325 				 * This sets the stream head to NOT flush
2326 				 * M_PCPROTO messages.
2327 				 */
2328 				stp->sd_read_opt |= RFLUSHPCPROT;
2329 				break;
2330 			}
2331 		}
2332 		if (sop->so_flags & SO_ERROPT) {
2333 			switch (sop->so_erropt & RERRMASK) {
2334 			case RERRNORM:
2335 				stp->sd_flag &= ~STRDERRNONPERSIST;
2336 				break;
2337 			case RERRNONPERSIST:
2338 				stp->sd_flag |= STRDERRNONPERSIST;
2339 				break;
2340 			}
2341 			switch (sop->so_erropt & WERRMASK) {
2342 			case WERRNORM:
2343 				stp->sd_flag &= ~STWRERRNONPERSIST;
2344 				break;
2345 			case WERRNONPERSIST:
2346 				stp->sd_flag |= STWRERRNONPERSIST;
2347 				break;
2348 			}
2349 		}
2350 		if (sop->so_flags & SO_COPYOPT) {
2351 			if (sop->so_copyopt & ZCVMSAFE) {
2352 				stp->sd_copyflag |= STZCVMSAFE;
2353 				stp->sd_copyflag &= ~STZCVMUNSAFE;
2354 			} else if (sop->so_copyopt & ZCVMUNSAFE) {
2355 				stp->sd_copyflag |= STZCVMUNSAFE;
2356 				stp->sd_copyflag &= ~STZCVMSAFE;
2357 			}
2358 
2359 			if (sop->so_copyopt & COPYCACHED) {
2360 				stp->sd_copyflag |= STRCOPYCACHED;
2361 			}
2362 		}
2363 		if (sop->so_flags & SO_WROFF)
2364 			stp->sd_wroff = sop->so_wroff;
2365 		if (sop->so_flags & SO_TAIL)
2366 			stp->sd_tail = sop->so_tail;
2367 		if (sop->so_flags & SO_MINPSZ)
2368 			q->q_minpsz = sop->so_minpsz;
2369 		if (sop->so_flags & SO_MAXPSZ)
2370 			q->q_maxpsz = sop->so_maxpsz;
2371 		if (sop->so_flags & SO_MAXBLK)
2372 			stp->sd_maxblk = sop->so_maxblk;
2373 		if (sop->so_flags & SO_HIWAT) {
2374 			if (sop->so_flags & SO_BAND) {
2375 				if (strqset(q, QHIWAT,
2376 				    sop->so_band, sop->so_hiwat)) {
2377 					cmn_err(CE_WARN, "strrput: could not "
2378 					    "allocate qband\n");
2379 				} else {
2380 					bpri = sop->so_band;
2381 				}
2382 			} else {
2383 				q->q_hiwat = sop->so_hiwat;
2384 			}
2385 		}
2386 		if (sop->so_flags & SO_LOWAT) {
2387 			if (sop->so_flags & SO_BAND) {
2388 				if (strqset(q, QLOWAT,
2389 				    sop->so_band, sop->so_lowat)) {
2390 					cmn_err(CE_WARN, "strrput: could not "
2391 					    "allocate qband\n");
2392 				} else {
2393 					bpri = sop->so_band;
2394 				}
2395 			} else {
2396 				q->q_lowat = sop->so_lowat;
2397 			}
2398 		}
2399 		if (sop->so_flags & SO_MREADON)
2400 			stp->sd_flag |= SNDMREAD;
2401 		if (sop->so_flags & SO_MREADOFF)
2402 			stp->sd_flag &= ~SNDMREAD;
2403 		if (sop->so_flags & SO_NDELON)
2404 			stp->sd_flag |= OLDNDELAY;
2405 		if (sop->so_flags & SO_NDELOFF)
2406 			stp->sd_flag &= ~OLDNDELAY;
2407 		if (sop->so_flags & SO_ISTTY)
2408 			stp->sd_flag |= STRISTTY;
2409 		if (sop->so_flags & SO_ISNTTY)
2410 			stp->sd_flag &= ~STRISTTY;
2411 		if (sop->so_flags & SO_TOSTOP)
2412 			stp->sd_flag |= STRTOSTOP;
2413 		if (sop->so_flags & SO_TONSTOP)
2414 			stp->sd_flag &= ~STRTOSTOP;
2415 		if (sop->so_flags & SO_DELIM)
2416 			stp->sd_flag |= STRDELIM;
2417 		if (sop->so_flags & SO_NODELIM)
2418 			stp->sd_flag &= ~STRDELIM;
2419 
2420 		mutex_exit(&stp->sd_lock);
2421 		freemsg(bp);
2422 
2423 		/* Check backenable in case the water marks changed */
2424 		qbackenable(q, bpri);
2425 		return (0);
2426 
2427 	/*
2428 	 * The following set of cases deal with situations where two stream
2429 	 * heads are connected to each other (twisted streams).  These messages
2430 	 * have no meaning at the stream head.
2431 	 */
2432 	case M_BREAK:
2433 	case M_CTL:
2434 	case M_DELAY:
2435 	case M_START:
2436 	case M_STOP:
2437 	case M_IOCDATA:
2438 	case M_STARTI:
2439 	case M_STOPI:
2440 		freemsg(bp);
2441 		return (0);
2442 
2443 	case M_IOCTL:
2444 		/*
2445 		 * Always NAK this condition
2446 		 * (makes no sense)
2447 		 * If there is one or more threads in the read side
2448 		 * rwnext we have to defer the nacking until that thread
2449 		 * returns (in strget).
2450 		 */
2451 		mutex_enter(&stp->sd_lock);
2452 		if (stp->sd_struiodnak != 0) {
2453 			/*
2454 			 * Defer NAK to the streamhead. Queue at the end
2455 			 * the list.
2456 			 */
2457 			mblk_t *mp = stp->sd_struionak;
2458 
2459 			while (mp && mp->b_next)
2460 				mp = mp->b_next;
2461 			if (mp)
2462 				mp->b_next = bp;
2463 			else
2464 				stp->sd_struionak = bp;
2465 			bp->b_next = NULL;
2466 			mutex_exit(&stp->sd_lock);
2467 			return (0);
2468 		}
2469 		mutex_exit(&stp->sd_lock);
2470 
2471 		bp->b_datap->db_type = M_IOCNAK;
2472 		/*
2473 		 * Protect against the driver passing up
2474 		 * messages after it has done a qprocsoff.
2475 		 */
2476 		if (_OTHERQ(q)->q_next == NULL)
2477 			freemsg(bp);
2478 		else
2479 			qreply(q, bp);
2480 		return (0);
2481 
2482 	default:
2483 #ifdef DEBUG
2484 		cmn_err(CE_WARN,
2485 		    "bad message type %x received at stream head\n",
2486 		    bp->b_datap->db_type);
2487 #endif
2488 		freemsg(bp);
2489 		return (0);
2490 	}
2491 
2492 	/* NOTREACHED */
2493 }
2494 
2495 /*
2496  * Check if the stream pointed to by `stp' can be written to, and return an
2497  * error code if not.  If `eiohup' is set, then return EIO if STRHUP is set.
2498  * If `sigpipeok' is set and the SW_SIGPIPE option is enabled on the stream,
2499  * then always return EPIPE and send a SIGPIPE to the invoking thread.
2500  */
2501 static int
2502 strwriteable(struct stdata *stp, boolean_t eiohup, boolean_t sigpipeok)
2503 {
2504 	int error;
2505 
2506 	ASSERT(MUTEX_HELD(&stp->sd_lock));
2507 
2508 	/*
2509 	 * For modem support, POSIX states that on writes, EIO should
2510 	 * be returned if the stream has been hung up.
2511 	 */
2512 	if (eiohup && (stp->sd_flag & (STPLEX|STRHUP)) == STRHUP)
2513 		error = EIO;
2514 	else
2515 		error = strgeterr(stp, STRHUP|STPLEX|STWRERR, 0);
2516 
2517 	if (error != 0) {
2518 		if (!(stp->sd_flag & STPLEX) &&
2519 		    (stp->sd_wput_opt & SW_SIGPIPE) && sigpipeok) {
2520 			tsignal(curthread, SIGPIPE);
2521 			error = EPIPE;
2522 		}
2523 	}
2524 
2525 	return (error);
2526 }
2527 
2528 /*
2529  * Copyin and send data down a stream.
2530  * The caller will allocate and copyin any control part that precedes the
2531  * message and pass that in as mctl.
2532  *
2533  * Caller should *not* hold sd_lock.
2534  * When EWOULDBLOCK is returned the caller has to redo the canputnext
2535  * under sd_lock in order to avoid missing a backenabling wakeup.
2536  *
2537  * Use iosize = -1 to not send any M_DATA. iosize = 0 sends zero-length M_DATA.
2538  *
2539  * Set MSG_IGNFLOW in flags to ignore flow control for hipri messages.
2540  * For sync streams we can only ignore flow control by reverting to using
2541  * putnext.
2542  *
2543  * If sd_maxblk is less than *iosize this routine might return without
2544  * transferring all of *iosize. In all cases, on return *iosize will contain
2545  * the amount of data that was transferred.
2546  */
2547 static int
2548 strput(struct stdata *stp, mblk_t *mctl, struct uio *uiop, ssize_t *iosize,
2549     int b_flag, int pri, int flags)
2550 {
2551 	struiod_t uiod;
2552 	mblk_t *mp;
2553 	queue_t *wqp = stp->sd_wrq;
2554 	int error = 0;
2555 	ssize_t count = *iosize;
2556 
2557 	ASSERT(MUTEX_NOT_HELD(&stp->sd_lock));
2558 
2559 	if (uiop != NULL && count >= 0)
2560 		flags |= stp->sd_struiowrq ? STRUIO_POSTPONE : 0;
2561 
2562 	if (!(flags & STRUIO_POSTPONE)) {
2563 		/*
2564 		 * Use regular canputnext, strmakedata, putnext sequence.
2565 		 */
2566 		if (pri == 0) {
2567 			if (!canputnext(wqp) && !(flags & MSG_IGNFLOW)) {
2568 				freemsg(mctl);
2569 				return (EWOULDBLOCK);
2570 			}
2571 		} else {
2572 			if (!(flags & MSG_IGNFLOW) && !bcanputnext(wqp, pri)) {
2573 				freemsg(mctl);
2574 				return (EWOULDBLOCK);
2575 			}
2576 		}
2577 
2578 		if ((error = strmakedata(iosize, uiop, stp, flags,
2579 		    &mp)) != 0) {
2580 			freemsg(mctl);
2581 			/*
2582 			 * need to change return code to ENOMEM
2583 			 * so that this is not confused with
2584 			 * flow control, EAGAIN.
2585 			 */
2586 
2587 			if (error == EAGAIN)
2588 				return (ENOMEM);
2589 			else
2590 				return (error);
2591 		}
2592 		if (mctl != NULL) {
2593 			if (mctl->b_cont == NULL)
2594 				mctl->b_cont = mp;
2595 			else if (mp != NULL)
2596 				linkb(mctl, mp);
2597 			mp = mctl;
2598 		} else if (mp == NULL)
2599 			return (0);
2600 
2601 		mp->b_flag |= b_flag;
2602 		mp->b_band = (uchar_t)pri;
2603 
2604 		if (flags & MSG_IGNFLOW) {
2605 			/*
2606 			 * XXX Hack: Don't get stuck running service
2607 			 * procedures. This is needed for sockfs when
2608 			 * sending the unbind message out of the rput
2609 			 * procedure - we don't want a put procedure
2610 			 * to run service procedures.
2611 			 */
2612 			putnext(wqp, mp);
2613 		} else {
2614 			stream_willservice(stp);
2615 			putnext(wqp, mp);
2616 			stream_runservice(stp);
2617 		}
2618 		return (0);
2619 	}
2620 	/*
2621 	 * Stream supports rwnext() for the write side.
2622 	 */
2623 	if ((error = strmakedata(iosize, uiop, stp, flags, &mp)) != 0) {
2624 		freemsg(mctl);
2625 		/*
2626 		 * map EAGAIN to ENOMEM since EAGAIN means "flow controlled".
2627 		 */
2628 		return (error == EAGAIN ? ENOMEM : error);
2629 	}
2630 	if (mctl != NULL) {
2631 		if (mctl->b_cont == NULL)
2632 			mctl->b_cont = mp;
2633 		else if (mp != NULL)
2634 			linkb(mctl, mp);
2635 		mp = mctl;
2636 	} else if (mp == NULL) {
2637 		return (0);
2638 	}
2639 
2640 	mp->b_flag |= b_flag;
2641 	mp->b_band = (uchar_t)pri;
2642 
2643 	(void) uiodup(uiop, &uiod.d_uio, uiod.d_iov,
2644 	    sizeof (uiod.d_iov) / sizeof (*uiod.d_iov));
2645 	uiod.d_uio.uio_offset = 0;
2646 	uiod.d_mp = mp;
2647 	error = rwnext(wqp, &uiod);
2648 	if (! uiod.d_mp) {
2649 		uioskip(uiop, *iosize);
2650 		return (error);
2651 	}
2652 	ASSERT(mp == uiod.d_mp);
2653 	if (error == EINVAL) {
2654 		/*
2655 		 * The stream plumbing must have changed while
2656 		 * we were away, so just turn off rwnext()s.
2657 		 */
2658 		error = 0;
2659 	} else if (error == EBUSY || error == EWOULDBLOCK) {
2660 		/*
2661 		 * Couldn't enter a perimeter or took a page fault,
2662 		 * so fall-back to putnext().
2663 		 */
2664 		error = 0;
2665 	} else {
2666 		freemsg(mp);
2667 		return (error);
2668 	}
2669 	/* Have to check canput before consuming data from the uio */
2670 	if (pri == 0) {
2671 		if (!canputnext(wqp) && !(flags & MSG_IGNFLOW)) {
2672 			freemsg(mp);
2673 			return (EWOULDBLOCK);
2674 		}
2675 	} else {
2676 		if (!bcanputnext(wqp, pri) && !(flags & MSG_IGNFLOW)) {
2677 			freemsg(mp);
2678 			return (EWOULDBLOCK);
2679 		}
2680 	}
2681 	ASSERT(mp == uiod.d_mp);
2682 	/* Copyin data from the uio */
2683 	if ((error = struioget(wqp, mp, &uiod, 0)) != 0) {
2684 		freemsg(mp);
2685 		return (error);
2686 	}
2687 	uioskip(uiop, *iosize);
2688 	if (flags & MSG_IGNFLOW) {
2689 		/*
2690 		 * XXX Hack: Don't get stuck running service procedures.
2691 		 * This is needed for sockfs when sending the unbind message
2692 		 * out of the rput procedure - we don't want a put procedure
2693 		 * to run service procedures.
2694 		 */
2695 		putnext(wqp, mp);
2696 	} else {
2697 		stream_willservice(stp);
2698 		putnext(wqp, mp);
2699 		stream_runservice(stp);
2700 	}
2701 	return (0);
2702 }
2703 
2704 /*
2705  * Write attempts to break the write request into messages conforming
2706  * with the minimum and maximum packet sizes set downstream.
2707  *
2708  * Write will not block if downstream queue is full and
2709  * O_NDELAY is set, otherwise it will block waiting for the queue to get room.
2710  *
2711  * A write of zero bytes gets packaged into a zero length message and sent
2712  * downstream like any other message.
2713  *
2714  * If buffers of the requested sizes are not available, the write will
2715  * sleep until the buffers become available.
2716  *
2717  * Write (if specified) will supply a write offset in a message if it
2718  * makes sense. This can be specified by downstream modules as part of
2719  * a M_SETOPTS message.  Write will not supply the write offset if it
2720  * cannot supply any data in a buffer.  In other words, write will never
2721  * send down an empty packet due to a write offset.
2722  */
2723 /* ARGSUSED2 */
2724 int
2725 strwrite(struct vnode *vp, struct uio *uiop, cred_t *crp)
2726 {
2727 	return (strwrite_common(vp, uiop, crp, 0));
2728 }
2729 
2730 /* ARGSUSED2 */
2731 int
2732 strwrite_common(struct vnode *vp, struct uio *uiop, cred_t *crp, int wflag)
2733 {
2734 	struct stdata *stp;
2735 	struct queue *wqp;
2736 	ssize_t rmin, rmax;
2737 	ssize_t iosize;
2738 	int waitflag;
2739 	int tempmode;
2740 	int error = 0;
2741 	int b_flag;
2742 
2743 	ASSERT(vp->v_stream);
2744 	stp = vp->v_stream;
2745 
2746 	mutex_enter(&stp->sd_lock);
2747 
2748 	if ((error = i_straccess(stp, JCWRITE)) != 0) {
2749 		mutex_exit(&stp->sd_lock);
2750 		return (error);
2751 	}
2752 
2753 	if (stp->sd_flag & (STWRERR|STRHUP|STPLEX)) {
2754 		error = strwriteable(stp, B_TRUE, B_TRUE);
2755 		if (error != 0) {
2756 			mutex_exit(&stp->sd_lock);
2757 			return (error);
2758 		}
2759 	}
2760 
2761 	mutex_exit(&stp->sd_lock);
2762 
2763 	wqp = stp->sd_wrq;
2764 
2765 	/* get these values from them cached in the stream head */
2766 	rmin = stp->sd_qn_minpsz;
2767 	rmax = stp->sd_qn_maxpsz;
2768 
2769 	/*
2770 	 * Check the min/max packet size constraints.  If min packet size
2771 	 * is non-zero, the write cannot be split into multiple messages
2772 	 * and still guarantee the size constraints.
2773 	 */
2774 	TRACE_1(TR_FAC_STREAMS_FR, TR_STRWRITE_IN, "strwrite in:q %p", wqp);
2775 
2776 	ASSERT((rmax >= 0) || (rmax == INFPSZ));
2777 	if (rmax == 0) {
2778 		return (0);
2779 	}
2780 	if (rmin > 0) {
2781 		if (uiop->uio_resid < rmin) {
2782 			TRACE_3(TR_FAC_STREAMS_FR, TR_STRWRITE_OUT,
2783 			    "strwrite out:q %p out %d error %d",
2784 			    wqp, 0, ERANGE);
2785 			return (ERANGE);
2786 		}
2787 		if ((rmax != INFPSZ) && (uiop->uio_resid > rmax)) {
2788 			TRACE_3(TR_FAC_STREAMS_FR, TR_STRWRITE_OUT,
2789 			    "strwrite out:q %p out %d error %d",
2790 			    wqp, 1, ERANGE);
2791 			return (ERANGE);
2792 		}
2793 	}
2794 
2795 	/*
2796 	 * Do until count satisfied or error.
2797 	 */
2798 	waitflag = WRITEWAIT | wflag;
2799 	if (stp->sd_flag & OLDNDELAY)
2800 		tempmode = uiop->uio_fmode & ~FNDELAY;
2801 	else
2802 		tempmode = uiop->uio_fmode;
2803 
2804 	if (rmax == INFPSZ)
2805 		rmax = uiop->uio_resid;
2806 
2807 	/*
2808 	 * Note that tempmode does not get used in strput/strmakedata
2809 	 * but only in strwaitq. The other routines use uio_fmode
2810 	 * unmodified.
2811 	 */
2812 
2813 	/* LINTED: constant in conditional context */
2814 	while (1) {	/* breaks when uio_resid reaches zero */
2815 		/*
2816 		 * Determine the size of the next message to be
2817 		 * packaged.  May have to break write into several
2818 		 * messages based on max packet size.
2819 		 */
2820 		iosize = MIN(uiop->uio_resid, rmax);
2821 
2822 		/*
2823 		 * Put block downstream when flow control allows it.
2824 		 */
2825 		if ((stp->sd_flag & STRDELIM) && (uiop->uio_resid == iosize))
2826 			b_flag = MSGDELIM;
2827 		else
2828 			b_flag = 0;
2829 
2830 		for (;;) {
2831 			int done = 0;
2832 
2833 			error = strput(stp, NULL, uiop, &iosize, b_flag, 0, 0);
2834 			if (error == 0)
2835 				break;
2836 			if (error != EWOULDBLOCK)
2837 				goto out;
2838 
2839 			mutex_enter(&stp->sd_lock);
2840 			/*
2841 			 * Check for a missed wakeup.
2842 			 * Needed since strput did not hold sd_lock across
2843 			 * the canputnext.
2844 			 */
2845 			if (canputnext(wqp)) {
2846 				/* Try again */
2847 				mutex_exit(&stp->sd_lock);
2848 				continue;
2849 			}
2850 			TRACE_1(TR_FAC_STREAMS_FR, TR_STRWRITE_WAIT,
2851 			    "strwrite wait:q %p wait", wqp);
2852 			if ((error = strwaitq(stp, waitflag, (ssize_t)0,
2853 			    tempmode, -1, &done)) != 0 || done) {
2854 				mutex_exit(&stp->sd_lock);
2855 				if ((vp->v_type == VFIFO) &&
2856 				    (uiop->uio_fmode & FNDELAY) &&
2857 				    (error == EAGAIN))
2858 					error = 0;
2859 				goto out;
2860 			}
2861 			TRACE_1(TR_FAC_STREAMS_FR, TR_STRWRITE_WAKE,
2862 			    "strwrite wake:q %p awakes", wqp);
2863 			if ((error = i_straccess(stp, JCWRITE)) != 0) {
2864 				mutex_exit(&stp->sd_lock);
2865 				goto out;
2866 			}
2867 			mutex_exit(&stp->sd_lock);
2868 		}
2869 		waitflag |= NOINTR;
2870 		TRACE_2(TR_FAC_STREAMS_FR, TR_STRWRITE_RESID,
2871 		    "strwrite resid:q %p uiop %p", wqp, uiop);
2872 		if (uiop->uio_resid) {
2873 			/* Recheck for errors - needed for sockets */
2874 			if ((stp->sd_wput_opt & SW_RECHECK_ERR) &&
2875 			    (stp->sd_flag & (STWRERR|STRHUP|STPLEX))) {
2876 				mutex_enter(&stp->sd_lock);
2877 				error = strwriteable(stp, B_FALSE, B_TRUE);
2878 				mutex_exit(&stp->sd_lock);
2879 				if (error != 0)
2880 					return (error);
2881 			}
2882 			continue;
2883 		}
2884 		break;
2885 	}
2886 out:
2887 	/*
2888 	 * For historical reasons, applications expect EAGAIN when a data
2889 	 * mblk_t cannot be allocated, so change ENOMEM back to EAGAIN.
2890 	 */
2891 	if (error == ENOMEM)
2892 		error = EAGAIN;
2893 	TRACE_3(TR_FAC_STREAMS_FR, TR_STRWRITE_OUT,
2894 	    "strwrite out:q %p out %d error %d", wqp, 2, error);
2895 	return (error);
2896 }
2897 
2898 /*
2899  * Stream head write service routine.
2900  * Its job is to wake up any sleeping writers when a queue
2901  * downstream needs data (part of the flow control in putq and getq).
2902  * It also must wake anyone sleeping on a poll().
2903  * For stream head right below mux module, it must also invoke put procedure
2904  * of next downstream module.
2905  */
2906 int
2907 strwsrv(queue_t *q)
2908 {
2909 	struct stdata *stp;
2910 	queue_t *tq;
2911 	qband_t *qbp;
2912 	int i;
2913 	qband_t *myqbp;
2914 	int isevent;
2915 	unsigned char	qbf[NBAND];	/* band flushing backenable flags */
2916 
2917 	TRACE_1(TR_FAC_STREAMS_FR,
2918 	    TR_STRWSRV, "strwsrv:q %p", q);
2919 	stp = (struct stdata *)q->q_ptr;
2920 	ASSERT(qclaimed(q));
2921 	mutex_enter(&stp->sd_lock);
2922 	ASSERT(!(stp->sd_flag & STPLEX));
2923 
2924 	if (stp->sd_flag & WSLEEP) {
2925 		stp->sd_flag &= ~WSLEEP;
2926 		cv_broadcast(&q->q_wait);
2927 	}
2928 	mutex_exit(&stp->sd_lock);
2929 
2930 	/* The other end of a stream pipe went away. */
2931 	if ((tq = q->q_next) == NULL) {
2932 		return (0);
2933 	}
2934 
2935 	/* Find the next module forward that has a service procedure */
2936 	claimstr(q);
2937 	tq = q->q_nfsrv;
2938 	ASSERT(tq != NULL);
2939 
2940 	if ((q->q_flag & QBACK)) {
2941 		if ((tq->q_flag & QFULL)) {
2942 			mutex_enter(QLOCK(tq));
2943 			if (!(tq->q_flag & QFULL)) {
2944 				mutex_exit(QLOCK(tq));
2945 				goto wakeup;
2946 			}
2947 			/*
2948 			 * The queue must have become full again. Set QWANTW
2949 			 * again so strwsrv will be back enabled when
2950 			 * the queue becomes non-full next time.
2951 			 */
2952 			tq->q_flag |= QWANTW;
2953 			mutex_exit(QLOCK(tq));
2954 		} else {
2955 		wakeup:
2956 			pollwakeup(&stp->sd_pollist, POLLWRNORM);
2957 			mutex_enter(&stp->sd_lock);
2958 			if (stp->sd_sigflags & S_WRNORM)
2959 				strsendsig(stp->sd_siglist, S_WRNORM, 0, 0);
2960 			mutex_exit(&stp->sd_lock);
2961 		}
2962 	}
2963 
2964 	isevent = 0;
2965 	i = 1;
2966 	bzero((caddr_t)qbf, NBAND);
2967 	mutex_enter(QLOCK(tq));
2968 	if ((myqbp = q->q_bandp) != NULL)
2969 		for (qbp = tq->q_bandp; qbp && myqbp; qbp = qbp->qb_next) {
2970 			ASSERT(myqbp);
2971 			if ((myqbp->qb_flag & QB_BACK)) {
2972 				if (qbp->qb_flag & QB_FULL) {
2973 					/*
2974 					 * The band must have become full again.
2975 					 * Set QB_WANTW again so strwsrv will
2976 					 * be back enabled when the band becomes
2977 					 * non-full next time.
2978 					 */
2979 					qbp->qb_flag |= QB_WANTW;
2980 				} else {
2981 					isevent = 1;
2982 					qbf[i] = 1;
2983 				}
2984 			}
2985 			myqbp = myqbp->qb_next;
2986 			i++;
2987 		}
2988 	mutex_exit(QLOCK(tq));
2989 
2990 	if (isevent) {
2991 		for (i = tq->q_nband; i; i--) {
2992 			if (qbf[i]) {
2993 				pollwakeup(&stp->sd_pollist, POLLWRBAND);
2994 				mutex_enter(&stp->sd_lock);
2995 				if (stp->sd_sigflags & S_WRBAND)
2996 					strsendsig(stp->sd_siglist, S_WRBAND,
2997 					    (uchar_t)i, 0);
2998 				mutex_exit(&stp->sd_lock);
2999 			}
3000 		}
3001 	}
3002 
3003 	releasestr(q);
3004 	return (0);
3005 }
3006 
3007 /*
3008  * Special case of strcopyin/strcopyout for copying
3009  * struct strioctl that can deal with both data
3010  * models.
3011  */
3012 
3013 #ifdef	_LP64
3014 
3015 static int
3016 strcopyin_strioctl(void *from, void *to, int flag, int copyflag)
3017 {
3018 	struct	strioctl32 strioc32;
3019 	struct	strioctl *striocp;
3020 
3021 	if (copyflag & U_TO_K) {
3022 		ASSERT((copyflag & K_TO_K) == 0);
3023 
3024 		if ((flag & FMODELS) == DATAMODEL_ILP32) {
3025 			if (copyin(from, &strioc32, sizeof (strioc32)))
3026 				return (EFAULT);
3027 
3028 			striocp = (struct strioctl *)to;
3029 			striocp->ic_cmd	= strioc32.ic_cmd;
3030 			striocp->ic_timout = strioc32.ic_timout;
3031 			striocp->ic_len	= strioc32.ic_len;
3032 			striocp->ic_dp	= (char *)(uintptr_t)strioc32.ic_dp;
3033 
3034 		} else { /* NATIVE data model */
3035 			if (copyin(from, to, sizeof (struct strioctl))) {
3036 				return (EFAULT);
3037 			} else {
3038 				return (0);
3039 			}
3040 		}
3041 	} else {
3042 		ASSERT(copyflag & K_TO_K);
3043 		bcopy(from, to, sizeof (struct strioctl));
3044 	}
3045 	return (0);
3046 }
3047 
3048 static int
3049 strcopyout_strioctl(void *from, void *to, int flag, int copyflag)
3050 {
3051 	struct	strioctl32 strioc32;
3052 	struct	strioctl *striocp;
3053 
3054 	if (copyflag & U_TO_K) {
3055 		ASSERT((copyflag & K_TO_K) == 0);
3056 
3057 		if ((flag & FMODELS) == DATAMODEL_ILP32) {
3058 			striocp = (struct strioctl *)from;
3059 			strioc32.ic_cmd	= striocp->ic_cmd;
3060 			strioc32.ic_timout = striocp->ic_timout;
3061 			strioc32.ic_len	= striocp->ic_len;
3062 			strioc32.ic_dp	= (caddr32_t)(uintptr_t)striocp->ic_dp;
3063 			ASSERT((char *)(uintptr_t)strioc32.ic_dp ==
3064 			    striocp->ic_dp);
3065 
3066 			if (copyout(&strioc32, to, sizeof (strioc32)))
3067 				return (EFAULT);
3068 
3069 		} else { /* NATIVE data model */
3070 			if (copyout(from, to, sizeof (struct strioctl))) {
3071 				return (EFAULT);
3072 			} else {
3073 				return (0);
3074 			}
3075 		}
3076 	} else {
3077 		ASSERT(copyflag & K_TO_K);
3078 		bcopy(from, to, sizeof (struct strioctl));
3079 	}
3080 	return (0);
3081 }
3082 
3083 #else	/* ! _LP64 */
3084 
3085 /* ARGSUSED2 */
3086 static int
3087 strcopyin_strioctl(void *from, void *to, int flag, int copyflag)
3088 {
3089 	return (strcopyin(from, to, sizeof (struct strioctl), copyflag));
3090 }
3091 
3092 /* ARGSUSED2 */
3093 static int
3094 strcopyout_strioctl(void *from, void *to, int flag, int copyflag)
3095 {
3096 	return (strcopyout(from, to, sizeof (struct strioctl), copyflag));
3097 }
3098 
3099 #endif	/* _LP64 */
3100 
3101 /*
3102  * Determine type of job control semantics expected by user.  The
3103  * possibilities are:
3104  *	JCREAD	- Behaves like read() on fd; send SIGTTIN
3105  *	JCWRITE	- Behaves like write() on fd; send SIGTTOU if TOSTOP set
3106  *	JCSETP	- Sets a value in the stream; send SIGTTOU, ignore TOSTOP
3107  *	JCGETP	- Gets a value in the stream; no signals.
3108  * See straccess in strsubr.c for usage of these values.
3109  *
3110  * This routine also returns -1 for I_STR as a special case; the
3111  * caller must call again with the real ioctl number for
3112  * classification.
3113  */
3114 static int
3115 job_control_type(int cmd)
3116 {
3117 	switch (cmd) {
3118 	case I_STR:
3119 		return (-1);
3120 
3121 	case I_RECVFD:
3122 	case I_E_RECVFD:
3123 		return (JCREAD);
3124 
3125 	case I_FDINSERT:
3126 	case I_SENDFD:
3127 		return (JCWRITE);
3128 
3129 	case TCSETA:
3130 	case TCSETAW:
3131 	case TCSETAF:
3132 	case TCSBRK:
3133 	case TCXONC:
3134 	case TCFLSH:
3135 	case TCDSET:	/* Obsolete */
3136 	case TIOCSWINSZ:
3137 	case TCSETS:
3138 	case TCSETSW:
3139 	case TCSETSF:
3140 	case TIOCSETD:
3141 	case TIOCHPCL:
3142 	case TIOCSETP:
3143 	case TIOCSETN:
3144 	case TIOCEXCL:
3145 	case TIOCNXCL:
3146 	case TIOCFLUSH:
3147 	case TIOCSETC:
3148 	case TIOCLBIS:
3149 	case TIOCLBIC:
3150 	case TIOCLSET:
3151 	case TIOCSBRK:
3152 	case TIOCCBRK:
3153 	case TIOCSDTR:
3154 	case TIOCCDTR:
3155 	case TIOCSLTC:
3156 	case TIOCSTOP:
3157 	case TIOCSTART:
3158 	case TIOCSTI:
3159 	case TIOCSPGRP:
3160 	case TIOCMSET:
3161 	case TIOCMBIS:
3162 	case TIOCMBIC:
3163 	case TIOCREMOTE:
3164 	case TIOCSIGNAL:
3165 	case LDSETT:
3166 	case LDSMAP:	/* Obsolete */
3167 	case DIOCSETP:
3168 	case I_FLUSH:
3169 	case I_SRDOPT:
3170 	case I_SETSIG:
3171 	case I_SWROPT:
3172 	case I_FLUSHBAND:
3173 	case I_SETCLTIME:
3174 	case I_SERROPT:
3175 	case I_ESETSIG:
3176 	case FIONBIO:
3177 	case FIOASYNC:
3178 	case FIOSETOWN:
3179 	case JBOOT:	/* Obsolete */
3180 	case JTERM:	/* Obsolete */
3181 	case JTIMOM:	/* Obsolete */
3182 	case JZOMBOOT:	/* Obsolete */
3183 	case JAGENT:	/* Obsolete */
3184 	case JTRUN:	/* Obsolete */
3185 	case JXTPROTO:	/* Obsolete */
3186 	case TIOCSETLD:
3187 		return (JCSETP);
3188 	}
3189 
3190 	return (JCGETP);
3191 }
3192 
3193 /*
3194  * ioctl for streams
3195  */
3196 int
3197 strioctl(struct vnode *vp, int cmd, intptr_t arg, int flag, int copyflag,
3198     cred_t *crp, int *rvalp)
3199 {
3200 	struct stdata *stp;
3201 	struct strcmd *scp;
3202 	struct strioctl strioc;
3203 	struct uio uio;
3204 	struct iovec iov;
3205 	int access;
3206 	mblk_t *mp;
3207 	int error = 0;
3208 	int done = 0;
3209 	ssize_t	rmin, rmax;
3210 	queue_t *wrq;
3211 	queue_t *rdq;
3212 	boolean_t kioctl = B_FALSE;
3213 
3214 	if (flag & FKIOCTL) {
3215 		copyflag = K_TO_K;
3216 		kioctl = B_TRUE;
3217 	}
3218 	ASSERT(vp->v_stream);
3219 	ASSERT(copyflag == U_TO_K || copyflag == K_TO_K);
3220 	stp = vp->v_stream;
3221 
3222 	TRACE_3(TR_FAC_STREAMS_FR, TR_IOCTL_ENTER,
3223 	    "strioctl:stp %p cmd %X arg %lX", stp, cmd, arg);
3224 
3225 	if (audit_active)
3226 		audit_strioctl(vp, cmd, arg, flag, copyflag, crp, rvalp);
3227 
3228 	/*
3229 	 * If the copy is kernel to kernel, make sure that the FNATIVE
3230 	 * flag is set.  After this it would be a serious error to have
3231 	 * no model flag.
3232 	 */
3233 	if (copyflag == K_TO_K)
3234 		flag = (flag & ~FMODELS) | FNATIVE;
3235 
3236 	ASSERT((flag & FMODELS) != 0);
3237 
3238 	wrq = stp->sd_wrq;
3239 	rdq = _RD(wrq);
3240 
3241 	access = job_control_type(cmd);
3242 
3243 	/* We should never see these here, should be handled by iwscn */
3244 	if (cmd == SRIOCSREDIR || cmd == SRIOCISREDIR)
3245 		return (EINVAL);
3246 
3247 	mutex_enter(&stp->sd_lock);
3248 	if ((access != -1) && ((error = i_straccess(stp, access)) != 0)) {
3249 		mutex_exit(&stp->sd_lock);
3250 		return (error);
3251 	}
3252 	mutex_exit(&stp->sd_lock);
3253 
3254 	/*
3255 	 * Check for sgttyb-related ioctls first, and complain as
3256 	 * necessary.
3257 	 */
3258 	switch (cmd) {
3259 	case TIOCGETP:
3260 	case TIOCSETP:
3261 	case TIOCSETN:
3262 		if (sgttyb_handling >= 2 && !sgttyb_complaint) {
3263 			sgttyb_complaint = B_TRUE;
3264 			cmn_err(CE_NOTE,
3265 			    "application used obsolete TIOC[GS]ET");
3266 		}
3267 		if (sgttyb_handling >= 3) {
3268 			tsignal(curthread, SIGSYS);
3269 			return (EIO);
3270 		}
3271 		break;
3272 	}
3273 
3274 	mutex_enter(&stp->sd_lock);
3275 
3276 	switch (cmd) {
3277 	case I_RECVFD:
3278 	case I_E_RECVFD:
3279 	case I_PEEK:
3280 	case I_NREAD:
3281 	case FIONREAD:
3282 	case FIORDCHK:
3283 	case I_ATMARK:
3284 	case FIONBIO:
3285 	case FIOASYNC:
3286 		if (stp->sd_flag & (STRDERR|STPLEX)) {
3287 			error = strgeterr(stp, STRDERR|STPLEX, 0);
3288 			if (error != 0) {
3289 				mutex_exit(&stp->sd_lock);
3290 				return (error);
3291 			}
3292 		}
3293 		break;
3294 
3295 	default:
3296 		if (stp->sd_flag & (STRDERR|STWRERR|STPLEX)) {
3297 			error = strgeterr(stp, STRDERR|STWRERR|STPLEX, 0);
3298 			if (error != 0) {
3299 				mutex_exit(&stp->sd_lock);
3300 				return (error);
3301 			}
3302 		}
3303 	}
3304 
3305 	mutex_exit(&stp->sd_lock);
3306 
3307 	switch (cmd) {
3308 	default:
3309 		/*
3310 		 * The stream head has hardcoded knowledge of a
3311 		 * miscellaneous collection of terminal-, keyboard- and
3312 		 * mouse-related ioctls, enumerated below.  This hardcoded
3313 		 * knowledge allows the stream head to automatically
3314 		 * convert transparent ioctl requests made by userland
3315 		 * programs into I_STR ioctls which many old STREAMS
3316 		 * modules and drivers require.
3317 		 *
3318 		 * No new ioctls should ever be added to this list.
3319 		 * Instead, the STREAMS module or driver should be written
3320 		 * to either handle transparent ioctls or require any
3321 		 * userland programs to use I_STR ioctls (by returning
3322 		 * EINVAL to any transparent ioctl requests).
3323 		 *
3324 		 * More importantly, removing ioctls from this list should
3325 		 * be done with the utmost care, since our STREAMS modules
3326 		 * and drivers *count* on the stream head performing this
3327 		 * conversion, and thus may panic while processing
3328 		 * transparent ioctl request for one of these ioctls (keep
3329 		 * in mind that third party modules and drivers may have
3330 		 * similar problems).
3331 		 */
3332 		if (((cmd & IOCTYPE) == LDIOC) ||
3333 		    ((cmd & IOCTYPE) == tIOC) ||
3334 		    ((cmd & IOCTYPE) == TIOC) ||
3335 		    ((cmd & IOCTYPE) == KIOC) ||
3336 		    ((cmd & IOCTYPE) == MSIOC) ||
3337 		    ((cmd & IOCTYPE) == VUIOC)) {
3338 			/*
3339 			 * The ioctl is a tty ioctl - set up strioc buffer
3340 			 * and call strdoioctl() to do the work.
3341 			 */
3342 			if (stp->sd_flag & STRHUP)
3343 				return (ENXIO);
3344 			strioc.ic_cmd = cmd;
3345 			strioc.ic_timout = INFTIM;
3346 
3347 			switch (cmd) {
3348 
3349 			case TCXONC:
3350 			case TCSBRK:
3351 			case TCFLSH:
3352 			case TCDSET:
3353 				{
3354 				int native_arg = (int)arg;
3355 				strioc.ic_len = sizeof (int);
3356 				strioc.ic_dp = (char *)&native_arg;
3357 				return (strdoioctl(stp, &strioc, flag,
3358 				    K_TO_K, crp, rvalp));
3359 				}
3360 
3361 			case TCSETA:
3362 			case TCSETAW:
3363 			case TCSETAF:
3364 				strioc.ic_len = sizeof (struct termio);
3365 				strioc.ic_dp = (char *)arg;
3366 				return (strdoioctl(stp, &strioc, flag,
3367 				    copyflag, crp, rvalp));
3368 
3369 			case TCSETS:
3370 			case TCSETSW:
3371 			case TCSETSF:
3372 				strioc.ic_len = sizeof (struct termios);
3373 				strioc.ic_dp = (char *)arg;
3374 				return (strdoioctl(stp, &strioc, flag,
3375 				    copyflag, crp, rvalp));
3376 
3377 			case LDSETT:
3378 				strioc.ic_len = sizeof (struct termcb);
3379 				strioc.ic_dp = (char *)arg;
3380 				return (strdoioctl(stp, &strioc, flag,
3381 				    copyflag, crp, rvalp));
3382 
3383 			case TIOCSETP:
3384 				strioc.ic_len = sizeof (struct sgttyb);
3385 				strioc.ic_dp = (char *)arg;
3386 				return (strdoioctl(stp, &strioc, flag,
3387 				    copyflag, crp, rvalp));
3388 
3389 			case TIOCSTI:
3390 				if ((flag & FREAD) == 0 &&
3391 				    secpolicy_sti(crp) != 0) {
3392 					return (EPERM);
3393 				}
3394 				mutex_enter(&stp->sd_lock);
3395 				mutex_enter(&curproc->p_splock);
3396 				if (stp->sd_sidp != curproc->p_sessp->s_sidp &&
3397 				    secpolicy_sti(crp) != 0) {
3398 					mutex_exit(&curproc->p_splock);
3399 					mutex_exit(&stp->sd_lock);
3400 					return (EACCES);
3401 				}
3402 				mutex_exit(&curproc->p_splock);
3403 				mutex_exit(&stp->sd_lock);
3404 
3405 				strioc.ic_len = sizeof (char);
3406 				strioc.ic_dp = (char *)arg;
3407 				return (strdoioctl(stp, &strioc, flag,
3408 				    copyflag, crp, rvalp));
3409 
3410 			case TIOCSWINSZ:
3411 				strioc.ic_len = sizeof (struct winsize);
3412 				strioc.ic_dp = (char *)arg;
3413 				return (strdoioctl(stp, &strioc, flag,
3414 				    copyflag, crp, rvalp));
3415 
3416 			case TIOCSSIZE:
3417 				strioc.ic_len = sizeof (struct ttysize);
3418 				strioc.ic_dp = (char *)arg;
3419 				return (strdoioctl(stp, &strioc, flag,
3420 				    copyflag, crp, rvalp));
3421 
3422 			case TIOCSSOFTCAR:
3423 			case KIOCTRANS:
3424 			case KIOCTRANSABLE:
3425 			case KIOCCMD:
3426 			case KIOCSDIRECT:
3427 			case KIOCSCOMPAT:
3428 			case KIOCSKABORTEN:
3429 			case KIOCSRPTDELAY:
3430 			case KIOCSRPTRATE:
3431 			case VUIDSFORMAT:
3432 			case TIOCSPPS:
3433 				strioc.ic_len = sizeof (int);
3434 				strioc.ic_dp = (char *)arg;
3435 				return (strdoioctl(stp, &strioc, flag,
3436 				    copyflag, crp, rvalp));
3437 
3438 			case KIOCSETKEY:
3439 			case KIOCGETKEY:
3440 				strioc.ic_len = sizeof (struct kiockey);
3441 				strioc.ic_dp = (char *)arg;
3442 				return (strdoioctl(stp, &strioc, flag,
3443 				    copyflag, crp, rvalp));
3444 
3445 			case KIOCSKEY:
3446 			case KIOCGKEY:
3447 				strioc.ic_len = sizeof (struct kiockeymap);
3448 				strioc.ic_dp = (char *)arg;
3449 				return (strdoioctl(stp, &strioc, flag,
3450 				    copyflag, crp, rvalp));
3451 
3452 			case KIOCSLED:
3453 				/* arg is a pointer to char */
3454 				strioc.ic_len = sizeof (char);
3455 				strioc.ic_dp = (char *)arg;
3456 				return (strdoioctl(stp, &strioc, flag,
3457 				    copyflag, crp, rvalp));
3458 
3459 			case MSIOSETPARMS:
3460 				strioc.ic_len = sizeof (Ms_parms);
3461 				strioc.ic_dp = (char *)arg;
3462 				return (strdoioctl(stp, &strioc, flag,
3463 				    copyflag, crp, rvalp));
3464 
3465 			case VUIDSADDR:
3466 			case VUIDGADDR:
3467 				strioc.ic_len = sizeof (struct vuid_addr_probe);
3468 				strioc.ic_dp = (char *)arg;
3469 				return (strdoioctl(stp, &strioc, flag,
3470 				    copyflag, crp, rvalp));
3471 
3472 			/*
3473 			 * These M_IOCTL's don't require any data to be sent
3474 			 * downstream, and the driver will allocate and link
3475 			 * on its own mblk_t upon M_IOCACK -- thus we set
3476 			 * ic_len to zero and set ic_dp to arg so we know
3477 			 * where to copyout to later.
3478 			 */
3479 			case TIOCGSOFTCAR:
3480 			case TIOCGWINSZ:
3481 			case TIOCGSIZE:
3482 			case KIOCGTRANS:
3483 			case KIOCGTRANSABLE:
3484 			case KIOCTYPE:
3485 			case KIOCGDIRECT:
3486 			case KIOCGCOMPAT:
3487 			case KIOCLAYOUT:
3488 			case KIOCGLED:
3489 			case MSIOGETPARMS:
3490 			case MSIOBUTTONS:
3491 			case VUIDGFORMAT:
3492 			case TIOCGPPS:
3493 			case TIOCGPPSEV:
3494 			case TCGETA:
3495 			case TCGETS:
3496 			case LDGETT:
3497 			case TIOCGETP:
3498 			case KIOCGRPTDELAY:
3499 			case KIOCGRPTRATE:
3500 				strioc.ic_len = 0;
3501 				strioc.ic_dp = (char *)arg;
3502 				return (strdoioctl(stp, &strioc, flag,
3503 				    copyflag, crp, rvalp));
3504 			}
3505 		}
3506 
3507 		/*
3508 		 * Unknown cmd - send it down as a transparent ioctl.
3509 		 */
3510 		strioc.ic_cmd = cmd;
3511 		strioc.ic_timout = INFTIM;
3512 		strioc.ic_len = TRANSPARENT;
3513 		strioc.ic_dp = (char *)&arg;
3514 
3515 		return (strdoioctl(stp, &strioc, flag, copyflag, crp, rvalp));
3516 
3517 	case I_STR:
3518 		/*
3519 		 * Stream ioctl.  Read in an strioctl buffer from the user
3520 		 * along with any data specified and send it downstream.
3521 		 * Strdoioctl will wait allow only one ioctl message at
3522 		 * a time, and waits for the acknowledgement.
3523 		 */
3524 
3525 		if (stp->sd_flag & STRHUP)
3526 			return (ENXIO);
3527 
3528 		error = strcopyin_strioctl((void *)arg, &strioc, flag,
3529 		    copyflag);
3530 		if (error != 0)
3531 			return (error);
3532 
3533 		if ((strioc.ic_len < 0) || (strioc.ic_timout < -1))
3534 			return (EINVAL);
3535 
3536 		access = job_control_type(strioc.ic_cmd);
3537 		mutex_enter(&stp->sd_lock);
3538 		if ((access != -1) &&
3539 		    ((error = i_straccess(stp, access)) != 0)) {
3540 			mutex_exit(&stp->sd_lock);
3541 			return (error);
3542 		}
3543 		mutex_exit(&stp->sd_lock);
3544 
3545 		/*
3546 		 * The I_STR facility provides a trap door for malicious
3547 		 * code to send down bogus streamio(7I) ioctl commands to
3548 		 * unsuspecting STREAMS modules and drivers which expect to
3549 		 * only get these messages from the stream head.
3550 		 * Explicitly prohibit any streamio ioctls which can be
3551 		 * passed downstream by the stream head.  Note that we do
3552 		 * not block all streamio ioctls because the ioctl
3553 		 * numberspace is not well managed and thus it's possible
3554 		 * that a module or driver's ioctl numbers may accidentally
3555 		 * collide with them.
3556 		 */
3557 		switch (strioc.ic_cmd) {
3558 		case I_LINK:
3559 		case I_PLINK:
3560 		case I_UNLINK:
3561 		case I_PUNLINK:
3562 		case _I_GETPEERCRED:
3563 		case _I_PLINK_LH:
3564 			return (EINVAL);
3565 		}
3566 
3567 		error = strdoioctl(stp, &strioc, flag, copyflag, crp, rvalp);
3568 		if (error == 0) {
3569 			error = strcopyout_strioctl(&strioc, (void *)arg,
3570 			    flag, copyflag);
3571 		}
3572 		return (error);
3573 
3574 	case _I_CMD:
3575 		/*
3576 		 * Like I_STR, but without using M_IOC* messages and without
3577 		 * copyins/copyouts beyond the passed-in argument.
3578 		 */
3579 		if (stp->sd_flag & STRHUP)
3580 			return (ENXIO);
3581 
3582 		if ((scp = kmem_alloc(sizeof (strcmd_t), KM_NOSLEEP)) == NULL)
3583 			return (ENOMEM);
3584 
3585 		if (copyin((void *)arg, scp, sizeof (strcmd_t))) {
3586 			kmem_free(scp, sizeof (strcmd_t));
3587 			return (EFAULT);
3588 		}
3589 
3590 		access = job_control_type(scp->sc_cmd);
3591 		mutex_enter(&stp->sd_lock);
3592 		if (access != -1 && (error = i_straccess(stp, access)) != 0) {
3593 			mutex_exit(&stp->sd_lock);
3594 			kmem_free(scp, sizeof (strcmd_t));
3595 			return (error);
3596 		}
3597 		mutex_exit(&stp->sd_lock);
3598 
3599 		*rvalp = 0;
3600 		if ((error = strdocmd(stp, scp, crp)) == 0) {
3601 			if (copyout(scp, (void *)arg, sizeof (strcmd_t)))
3602 				error = EFAULT;
3603 		}
3604 		kmem_free(scp, sizeof (strcmd_t));
3605 		return (error);
3606 
3607 	case I_NREAD:
3608 		/*
3609 		 * Return number of bytes of data in first message
3610 		 * in queue in "arg" and return the number of messages
3611 		 * in queue in return value.
3612 		 */
3613 	{
3614 		size_t	size;
3615 		int	retval;
3616 		int	count = 0;
3617 
3618 		mutex_enter(QLOCK(rdq));
3619 
3620 		size = msgdsize(rdq->q_first);
3621 		for (mp = rdq->q_first; mp != NULL; mp = mp->b_next)
3622 			count++;
3623 
3624 		mutex_exit(QLOCK(rdq));
3625 		if (stp->sd_struiordq) {
3626 			infod_t infod;
3627 
3628 			infod.d_cmd = INFOD_COUNT;
3629 			infod.d_count = 0;
3630 			if (count == 0) {
3631 				infod.d_cmd |= INFOD_FIRSTBYTES;
3632 				infod.d_bytes = 0;
3633 			}
3634 			infod.d_res = 0;
3635 			(void) infonext(rdq, &infod);
3636 			count += infod.d_count;
3637 			if (infod.d_res & INFOD_FIRSTBYTES)
3638 				size = infod.d_bytes;
3639 		}
3640 
3641 		/*
3642 		 * Drop down from size_t to the "int" required by the
3643 		 * interface.  Cap at INT_MAX.
3644 		 */
3645 		retval = MIN(size, INT_MAX);
3646 		error = strcopyout(&retval, (void *)arg, sizeof (retval),
3647 		    copyflag);
3648 		if (!error)
3649 			*rvalp = count;
3650 		return (error);
3651 	}
3652 
3653 	case FIONREAD:
3654 		/*
3655 		 * Return number of bytes of data in all data messages
3656 		 * in queue in "arg".
3657 		 */
3658 	{
3659 		size_t	size = 0;
3660 		int	retval;
3661 
3662 		mutex_enter(QLOCK(rdq));
3663 		for (mp = rdq->q_first; mp != NULL; mp = mp->b_next)
3664 			size += msgdsize(mp);
3665 		mutex_exit(QLOCK(rdq));
3666 
3667 		if (stp->sd_struiordq) {
3668 			infod_t infod;
3669 
3670 			infod.d_cmd = INFOD_BYTES;
3671 			infod.d_res = 0;
3672 			infod.d_bytes = 0;
3673 			(void) infonext(rdq, &infod);
3674 			size += infod.d_bytes;
3675 		}
3676 
3677 		/*
3678 		 * Drop down from size_t to the "int" required by the
3679 		 * interface.  Cap at INT_MAX.
3680 		 */
3681 		retval = MIN(size, INT_MAX);
3682 		error = strcopyout(&retval, (void *)arg, sizeof (retval),
3683 		    copyflag);
3684 
3685 		*rvalp = 0;
3686 		return (error);
3687 	}
3688 	case FIORDCHK:
3689 		/*
3690 		 * FIORDCHK does not use arg value (like FIONREAD),
3691 		 * instead a count is returned. I_NREAD value may
3692 		 * not be accurate but safe. The real thing to do is
3693 		 * to add the msgdsizes of all data  messages until
3694 		 * a non-data message.
3695 		 */
3696 	{
3697 		size_t size = 0;
3698 
3699 		mutex_enter(QLOCK(rdq));
3700 		for (mp = rdq->q_first; mp != NULL; mp = mp->b_next)
3701 			size += msgdsize(mp);
3702 		mutex_exit(QLOCK(rdq));
3703 
3704 		if (stp->sd_struiordq) {
3705 			infod_t infod;
3706 
3707 			infod.d_cmd = INFOD_BYTES;
3708 			infod.d_res = 0;
3709 			infod.d_bytes = 0;
3710 			(void) infonext(rdq, &infod);
3711 			size += infod.d_bytes;
3712 		}
3713 
3714 		/*
3715 		 * Since ioctl returns an int, and memory sizes under
3716 		 * LP64 may not fit, we return INT_MAX if the count was
3717 		 * actually greater.
3718 		 */
3719 		*rvalp = MIN(size, INT_MAX);
3720 		return (0);
3721 	}
3722 
3723 	case I_FIND:
3724 		/*
3725 		 * Get module name.
3726 		 */
3727 	{
3728 		char mname[FMNAMESZ + 1];
3729 		queue_t *q;
3730 
3731 		error = (copyflag & U_TO_K ? copyinstr : copystr)((void *)arg,
3732 		    mname, FMNAMESZ + 1, NULL);
3733 		if (error)
3734 			return ((error == ENAMETOOLONG) ? EINVAL : EFAULT);
3735 
3736 		/*
3737 		 * Return EINVAL if we're handed a bogus module name.
3738 		 */
3739 		if (fmodsw_find(mname, FMODSW_LOAD) == NULL) {
3740 			TRACE_0(TR_FAC_STREAMS_FR,
3741 			    TR_I_CANT_FIND, "couldn't I_FIND");
3742 			return (EINVAL);
3743 		}
3744 
3745 		*rvalp = 0;
3746 
3747 		/* Look downstream to see if module is there. */
3748 		claimstr(stp->sd_wrq);
3749 		for (q = stp->sd_wrq->q_next; q; q = q->q_next) {
3750 			if (q->q_flag & QREADR) {
3751 				q = NULL;
3752 				break;
3753 			}
3754 			if (strcmp(mname, Q2NAME(q)) == 0)
3755 				break;
3756 		}
3757 		releasestr(stp->sd_wrq);
3758 
3759 		*rvalp = (q ? 1 : 0);
3760 		return (error);
3761 	}
3762 
3763 	case I_PUSH:
3764 	case __I_PUSH_NOCTTY:
3765 		/*
3766 		 * Push a module.
3767 		 * For the case __I_PUSH_NOCTTY push a module but
3768 		 * do not allocate controlling tty. See bugid 4025044
3769 		 */
3770 
3771 	{
3772 		char mname[FMNAMESZ + 1];
3773 		fmodsw_impl_t *fp;
3774 		dev_t dummydev;
3775 
3776 		if (stp->sd_flag & STRHUP)
3777 			return (ENXIO);
3778 
3779 		/*
3780 		 * Get module name and look up in fmodsw.
3781 		 */
3782 		error = (copyflag & U_TO_K ? copyinstr : copystr)((void *)arg,
3783 		    mname, FMNAMESZ + 1, NULL);
3784 		if (error)
3785 			return ((error == ENAMETOOLONG) ? EINVAL : EFAULT);
3786 
3787 		if ((fp = fmodsw_find(mname, FMODSW_HOLD | FMODSW_LOAD)) ==
3788 		    NULL)
3789 			return (EINVAL);
3790 
3791 		TRACE_2(TR_FAC_STREAMS_FR, TR_I_PUSH,
3792 		    "I_PUSH:fp %p stp %p", fp, stp);
3793 
3794 		if (error = strstartplumb(stp, flag, cmd)) {
3795 			fmodsw_rele(fp);
3796 			return (error);
3797 		}
3798 
3799 		/*
3800 		 * See if any more modules can be pushed on this stream.
3801 		 * Note that this check must be done after strstartplumb()
3802 		 * since otherwise multiple threads issuing I_PUSHes on
3803 		 * the same stream will be able to exceed nstrpush.
3804 		 */
3805 		mutex_enter(&stp->sd_lock);
3806 		if (stp->sd_pushcnt >= nstrpush) {
3807 			fmodsw_rele(fp);
3808 			strendplumb(stp);
3809 			mutex_exit(&stp->sd_lock);
3810 			return (EINVAL);
3811 		}
3812 		mutex_exit(&stp->sd_lock);
3813 
3814 		/*
3815 		 * Push new module and call its open routine
3816 		 * via qattach().  Modules don't change device
3817 		 * numbers, so just ignore dummydev here.
3818 		 */
3819 		dummydev = vp->v_rdev;
3820 		if ((error = qattach(rdq, &dummydev, 0, crp, fp,
3821 		    B_FALSE)) == 0) {
3822 			if (vp->v_type == VCHR && /* sorry, no pipes allowed */
3823 			    (cmd == I_PUSH) && (stp->sd_flag & STRISTTY)) {
3824 				/*
3825 				 * try to allocate it as a controlling terminal
3826 				 */
3827 				(void) strctty(stp);
3828 			}
3829 		}
3830 
3831 		mutex_enter(&stp->sd_lock);
3832 
3833 		/*
3834 		 * As a performance concern we are caching the values of
3835 		 * q_minpsz and q_maxpsz of the module below the stream
3836 		 * head in the stream head.
3837 		 */
3838 		mutex_enter(QLOCK(stp->sd_wrq->q_next));
3839 		rmin = stp->sd_wrq->q_next->q_minpsz;
3840 		rmax = stp->sd_wrq->q_next->q_maxpsz;
3841 		mutex_exit(QLOCK(stp->sd_wrq->q_next));
3842 
3843 		/* Do this processing here as a performance concern */
3844 		if (strmsgsz != 0) {
3845 			if (rmax == INFPSZ)
3846 				rmax = strmsgsz;
3847 			else  {
3848 				if (vp->v_type == VFIFO)
3849 					rmax = MIN(PIPE_BUF, rmax);
3850 				else	rmax = MIN(strmsgsz, rmax);
3851 			}
3852 		}
3853 
3854 		mutex_enter(QLOCK(wrq));
3855 		stp->sd_qn_minpsz = rmin;
3856 		stp->sd_qn_maxpsz = rmax;
3857 		mutex_exit(QLOCK(wrq));
3858 
3859 		strendplumb(stp);
3860 		mutex_exit(&stp->sd_lock);
3861 		return (error);
3862 	}
3863 
3864 	case I_POP:
3865 	{
3866 		queue_t	*q;
3867 
3868 		if (stp->sd_flag & STRHUP)
3869 			return (ENXIO);
3870 		if (!wrq->q_next)	/* for broken pipes */
3871 			return (EINVAL);
3872 
3873 		if (error = strstartplumb(stp, flag, cmd))
3874 			return (error);
3875 
3876 		/*
3877 		 * If there is an anchor on this stream and popping
3878 		 * the current module would attempt to pop through the
3879 		 * anchor, then disallow the pop unless we have sufficient
3880 		 * privileges; take the cheapest (non-locking) check
3881 		 * first.
3882 		 */
3883 		if (secpolicy_ip_config(crp, B_TRUE) != 0 ||
3884 		    (stp->sd_anchorzone != crgetzoneid(crp))) {
3885 			mutex_enter(&stp->sd_lock);
3886 			/*
3887 			 * Anchors only apply if there's at least one
3888 			 * module on the stream (sd_pushcnt > 0).
3889 			 */
3890 			if (stp->sd_pushcnt > 0 &&
3891 			    stp->sd_pushcnt == stp->sd_anchor &&
3892 			    stp->sd_vnode->v_type != VFIFO) {
3893 				strendplumb(stp);
3894 				mutex_exit(&stp->sd_lock);
3895 				if (stp->sd_anchorzone != crgetzoneid(crp))
3896 					return (EINVAL);
3897 				/* Audit and report error */
3898 				return (secpolicy_ip_config(crp, B_FALSE));
3899 			}
3900 			mutex_exit(&stp->sd_lock);
3901 		}
3902 
3903 		q = wrq->q_next;
3904 		TRACE_2(TR_FAC_STREAMS_FR, TR_I_POP,
3905 		    "I_POP:%p from %p", q, stp);
3906 		if (q->q_next == NULL || (q->q_flag & (QREADR|QISDRV))) {
3907 			error = EINVAL;
3908 		} else {
3909 			qdetach(_RD(q), 1, flag, crp, B_FALSE);
3910 			error = 0;
3911 		}
3912 		mutex_enter(&stp->sd_lock);
3913 
3914 		/*
3915 		 * As a performance concern we are caching the values of
3916 		 * q_minpsz and q_maxpsz of the module below the stream
3917 		 * head in the stream head.
3918 		 */
3919 		mutex_enter(QLOCK(wrq->q_next));
3920 		rmin = wrq->q_next->q_minpsz;
3921 		rmax = wrq->q_next->q_maxpsz;
3922 		mutex_exit(QLOCK(wrq->q_next));
3923 
3924 		/* Do this processing here as a performance concern */
3925 		if (strmsgsz != 0) {
3926 			if (rmax == INFPSZ)
3927 				rmax = strmsgsz;
3928 			else  {
3929 				if (vp->v_type == VFIFO)
3930 					rmax = MIN(PIPE_BUF, rmax);
3931 				else	rmax = MIN(strmsgsz, rmax);
3932 			}
3933 		}
3934 
3935 		mutex_enter(QLOCK(wrq));
3936 		stp->sd_qn_minpsz = rmin;
3937 		stp->sd_qn_maxpsz = rmax;
3938 		mutex_exit(QLOCK(wrq));
3939 
3940 		/* If we popped through the anchor, then reset the anchor. */
3941 		if (stp->sd_pushcnt < stp->sd_anchor) {
3942 			stp->sd_anchor = 0;
3943 			stp->sd_anchorzone = 0;
3944 		}
3945 		strendplumb(stp);
3946 		mutex_exit(&stp->sd_lock);
3947 		return (error);
3948 	}
3949 
3950 	case _I_MUXID2FD:
3951 	{
3952 		/*
3953 		 * Create a fd for a I_PLINK'ed lower stream with a given
3954 		 * muxid.  With the fd, application can send down ioctls,
3955 		 * like I_LIST, to the previously I_PLINK'ed stream.  Note
3956 		 * that after getting the fd, the application has to do an
3957 		 * I_PUNLINK on the muxid before it can do any operation
3958 		 * on the lower stream.  This is required by spec1170.
3959 		 *
3960 		 * The fd used to do this ioctl should point to the same
3961 		 * controlling device used to do the I_PLINK.  If it uses
3962 		 * a different stream or an invalid muxid, I_MUXID2FD will
3963 		 * fail.  The error code is set to EINVAL.
3964 		 *
3965 		 * The intended use of this interface is the following.
3966 		 * An application I_PLINK'ed a stream and exits.  The fd
3967 		 * to the lower stream is gone.  Another application
3968 		 * wants to get a fd to the lower stream, it uses I_MUXID2FD.
3969 		 */
3970 		int muxid = (int)arg;
3971 		int fd;
3972 		linkinfo_t *linkp;
3973 		struct file *fp;
3974 		netstack_t *ns;
3975 		str_stack_t *ss;
3976 
3977 		/*
3978 		 * Do not allow the wildcard muxid.  This ioctl is not
3979 		 * intended to find arbitrary link.
3980 		 */
3981 		if (muxid == 0) {
3982 			return (EINVAL);
3983 		}
3984 
3985 		ns = netstack_find_by_cred(crp);
3986 		ASSERT(ns != NULL);
3987 		ss = ns->netstack_str;
3988 		ASSERT(ss != NULL);
3989 
3990 		mutex_enter(&muxifier);
3991 		linkp = findlinks(vp->v_stream, muxid, LINKPERSIST, ss);
3992 		if (linkp == NULL) {
3993 			mutex_exit(&muxifier);
3994 			netstack_rele(ss->ss_netstack);
3995 			return (EINVAL);
3996 		}
3997 
3998 		if ((fd = ufalloc(0)) == -1) {
3999 			mutex_exit(&muxifier);
4000 			netstack_rele(ss->ss_netstack);
4001 			return (EMFILE);
4002 		}
4003 		fp = linkp->li_fpdown;
4004 		mutex_enter(&fp->f_tlock);
4005 		fp->f_count++;
4006 		mutex_exit(&fp->f_tlock);
4007 		mutex_exit(&muxifier);
4008 		setf(fd, fp);
4009 		*rvalp = fd;
4010 		netstack_rele(ss->ss_netstack);
4011 		return (0);
4012 	}
4013 
4014 	case _I_INSERT:
4015 	{
4016 		/*
4017 		 * To insert a module to a given position in a stream.
4018 		 * In the first release, only allow privileged user
4019 		 * to use this ioctl. Furthermore, the insert is only allowed
4020 		 * below an anchor if the zoneid is the same as the zoneid
4021 		 * which created the anchor.
4022 		 *
4023 		 * Note that we do not plan to support this ioctl
4024 		 * on pipes in the first release.  We want to learn more
4025 		 * about the implications of these ioctls before extending
4026 		 * their support.  And we do not think these features are
4027 		 * valuable for pipes.
4028 		 */
4029 		STRUCT_DECL(strmodconf, strmodinsert);
4030 		char mod_name[FMNAMESZ + 1];
4031 		fmodsw_impl_t *fp;
4032 		dev_t dummydev;
4033 		queue_t *tmp_wrq;
4034 		int pos;
4035 		boolean_t is_insert;
4036 
4037 		STRUCT_INIT(strmodinsert, flag);
4038 		if (stp->sd_flag & STRHUP)
4039 			return (ENXIO);
4040 		if (STRMATED(stp))
4041 			return (EINVAL);
4042 		if ((error = secpolicy_net_config(crp, B_FALSE)) != 0)
4043 			return (error);
4044 		if (stp->sd_anchor != 0 &&
4045 		    stp->sd_anchorzone != crgetzoneid(crp))
4046 			return (EINVAL);
4047 
4048 		error = strcopyin((void *)arg, STRUCT_BUF(strmodinsert),
4049 		    STRUCT_SIZE(strmodinsert), copyflag);
4050 		if (error)
4051 			return (error);
4052 
4053 		/*
4054 		 * Get module name and look up in fmodsw.
4055 		 */
4056 		error = (copyflag & U_TO_K ? copyinstr :
4057 		    copystr)(STRUCT_FGETP(strmodinsert, mod_name),
4058 		    mod_name, FMNAMESZ + 1, NULL);
4059 		if (error)
4060 			return ((error == ENAMETOOLONG) ? EINVAL : EFAULT);
4061 
4062 		if ((fp = fmodsw_find(mod_name, FMODSW_HOLD | FMODSW_LOAD)) ==
4063 		    NULL)
4064 			return (EINVAL);
4065 
4066 		if (error = strstartplumb(stp, flag, cmd)) {
4067 			fmodsw_rele(fp);
4068 			return (error);
4069 		}
4070 
4071 		/*
4072 		 * Is this _I_INSERT just like an I_PUSH?  We need to know
4073 		 * this because we do some optimizations if this is a
4074 		 * module being pushed.
4075 		 */
4076 		pos = STRUCT_FGET(strmodinsert, pos);
4077 		is_insert = (pos != 0);
4078 
4079 		/*
4080 		 * Make sure pos is valid.  Even though it is not an I_PUSH,
4081 		 * we impose the same limit on the number of modules in a
4082 		 * stream.
4083 		 */
4084 		mutex_enter(&stp->sd_lock);
4085 		if (stp->sd_pushcnt >= nstrpush || pos < 0 ||
4086 		    pos > stp->sd_pushcnt) {
4087 			fmodsw_rele(fp);
4088 			strendplumb(stp);
4089 			mutex_exit(&stp->sd_lock);
4090 			return (EINVAL);
4091 		}
4092 		if (stp->sd_anchor != 0) {
4093 			/*
4094 			 * Is this insert below the anchor?
4095 			 * Pushcnt hasn't been increased yet hence
4096 			 * we test for greater than here, and greater or
4097 			 * equal after qattach.
4098 			 */
4099 			if (pos > (stp->sd_pushcnt - stp->sd_anchor) &&
4100 			    stp->sd_anchorzone != crgetzoneid(crp)) {
4101 				fmodsw_rele(fp);
4102 				strendplumb(stp);
4103 				mutex_exit(&stp->sd_lock);
4104 				return (EPERM);
4105 			}
4106 		}
4107 
4108 		mutex_exit(&stp->sd_lock);
4109 
4110 		/*
4111 		 * First find the correct position this module to
4112 		 * be inserted.  We don't need to call claimstr()
4113 		 * as the stream should not be changing at this point.
4114 		 *
4115 		 * Insert new module and call its open routine
4116 		 * via qattach().  Modules don't change device
4117 		 * numbers, so just ignore dummydev here.
4118 		 */
4119 		for (tmp_wrq = stp->sd_wrq; pos > 0;
4120 		    tmp_wrq = tmp_wrq->q_next, pos--) {
4121 			ASSERT(SAMESTR(tmp_wrq));
4122 		}
4123 		dummydev = vp->v_rdev;
4124 		if ((error = qattach(_RD(tmp_wrq), &dummydev, 0, crp,
4125 		    fp, is_insert)) != 0) {
4126 			mutex_enter(&stp->sd_lock);
4127 			strendplumb(stp);
4128 			mutex_exit(&stp->sd_lock);
4129 			return (error);
4130 		}
4131 
4132 		mutex_enter(&stp->sd_lock);
4133 
4134 		/*
4135 		 * As a performance concern we are caching the values of
4136 		 * q_minpsz and q_maxpsz of the module below the stream
4137 		 * head in the stream head.
4138 		 */
4139 		if (!is_insert) {
4140 			mutex_enter(QLOCK(stp->sd_wrq->q_next));
4141 			rmin = stp->sd_wrq->q_next->q_minpsz;
4142 			rmax = stp->sd_wrq->q_next->q_maxpsz;
4143 			mutex_exit(QLOCK(stp->sd_wrq->q_next));
4144 
4145 			/* Do this processing here as a performance concern */
4146 			if (strmsgsz != 0) {
4147 				if (rmax == INFPSZ) {
4148 					rmax = strmsgsz;
4149 				} else  {
4150 					rmax = MIN(strmsgsz, rmax);
4151 				}
4152 			}
4153 
4154 			mutex_enter(QLOCK(wrq));
4155 			stp->sd_qn_minpsz = rmin;
4156 			stp->sd_qn_maxpsz = rmax;
4157 			mutex_exit(QLOCK(wrq));
4158 		}
4159 
4160 		/*
4161 		 * Need to update the anchor value if this module is
4162 		 * inserted below the anchor point.
4163 		 */
4164 		if (stp->sd_anchor != 0) {
4165 			pos = STRUCT_FGET(strmodinsert, pos);
4166 			if (pos >= (stp->sd_pushcnt - stp->sd_anchor))
4167 				stp->sd_anchor++;
4168 		}
4169 
4170 		strendplumb(stp);
4171 		mutex_exit(&stp->sd_lock);
4172 		return (0);
4173 	}
4174 
4175 	case _I_REMOVE:
4176 	{
4177 		/*
4178 		 * To remove a module with a given name in a stream.  The
4179 		 * caller of this ioctl needs to provide both the name and
4180 		 * the position of the module to be removed.  This eliminates
4181 		 * the ambiguity of removal if a module is inserted/pushed
4182 		 * multiple times in a stream.  In the first release, only
4183 		 * allow privileged user to use this ioctl.
4184 		 * Furthermore, the remove is only allowed
4185 		 * below an anchor if the zoneid is the same as the zoneid
4186 		 * which created the anchor.
4187 		 *
4188 		 * Note that we do not plan to support this ioctl
4189 		 * on pipes in the first release.  We want to learn more
4190 		 * about the implications of these ioctls before extending
4191 		 * their support.  And we do not think these features are
4192 		 * valuable for pipes.
4193 		 *
4194 		 * Also note that _I_REMOVE cannot be used to remove a
4195 		 * driver or the stream head.
4196 		 */
4197 		STRUCT_DECL(strmodconf, strmodremove);
4198 		queue_t	*q;
4199 		int pos;
4200 		char mod_name[FMNAMESZ + 1];
4201 		boolean_t is_remove;
4202 
4203 		STRUCT_INIT(strmodremove, flag);
4204 		if (stp->sd_flag & STRHUP)
4205 			return (ENXIO);
4206 		if (STRMATED(stp))
4207 			return (EINVAL);
4208 		if ((error = secpolicy_net_config(crp, B_FALSE)) != 0)
4209 			return (error);
4210 		if (stp->sd_anchor != 0 &&
4211 		    stp->sd_anchorzone != crgetzoneid(crp))
4212 			return (EINVAL);
4213 
4214 		error = strcopyin((void *)arg, STRUCT_BUF(strmodremove),
4215 		    STRUCT_SIZE(strmodremove), copyflag);
4216 		if (error)
4217 			return (error);
4218 
4219 		error = (copyflag & U_TO_K ? copyinstr :
4220 		    copystr)(STRUCT_FGETP(strmodremove, mod_name),
4221 		    mod_name, FMNAMESZ + 1, NULL);
4222 		if (error)
4223 			return ((error == ENAMETOOLONG) ? EINVAL : EFAULT);
4224 
4225 		if ((error = strstartplumb(stp, flag, cmd)) != 0)
4226 			return (error);
4227 
4228 		/*
4229 		 * Match the name of given module to the name of module at
4230 		 * the given position.
4231 		 */
4232 		pos = STRUCT_FGET(strmodremove, pos);
4233 
4234 		is_remove = (pos != 0);
4235 		for (q = stp->sd_wrq->q_next; SAMESTR(q) && pos > 0;
4236 		    q = q->q_next, pos--)
4237 			;
4238 		if (pos > 0 || !SAMESTR(q) ||
4239 		    strcmp(Q2NAME(q), mod_name) != 0) {
4240 			mutex_enter(&stp->sd_lock);
4241 			strendplumb(stp);
4242 			mutex_exit(&stp->sd_lock);
4243 			return (EINVAL);
4244 		}
4245 
4246 		/*
4247 		 * If the position is at or below an anchor, then the zoneid
4248 		 * must match the zoneid that created the anchor.
4249 		 */
4250 		if (stp->sd_anchor != 0) {
4251 			pos = STRUCT_FGET(strmodremove, pos);
4252 			if (pos >= (stp->sd_pushcnt - stp->sd_anchor) &&
4253 			    stp->sd_anchorzone != crgetzoneid(crp)) {
4254 				mutex_enter(&stp->sd_lock);
4255 				strendplumb(stp);
4256 				mutex_exit(&stp->sd_lock);
4257 				return (EPERM);
4258 			}
4259 		}
4260 
4261 
4262 		ASSERT(!(q->q_flag & QREADR));
4263 		qdetach(_RD(q), 1, flag, crp, is_remove);
4264 
4265 		mutex_enter(&stp->sd_lock);
4266 
4267 		/*
4268 		 * As a performance concern we are caching the values of
4269 		 * q_minpsz and q_maxpsz of the module below the stream
4270 		 * head in the stream head.
4271 		 */
4272 		if (!is_remove) {
4273 			mutex_enter(QLOCK(wrq->q_next));
4274 			rmin = wrq->q_next->q_minpsz;
4275 			rmax = wrq->q_next->q_maxpsz;
4276 			mutex_exit(QLOCK(wrq->q_next));
4277 
4278 			/* Do this processing here as a performance concern */
4279 			if (strmsgsz != 0) {
4280 				if (rmax == INFPSZ)
4281 					rmax = strmsgsz;
4282 				else  {
4283 					if (vp->v_type == VFIFO)
4284 						rmax = MIN(PIPE_BUF, rmax);
4285 					else	rmax = MIN(strmsgsz, rmax);
4286 				}
4287 			}
4288 
4289 			mutex_enter(QLOCK(wrq));
4290 			stp->sd_qn_minpsz = rmin;
4291 			stp->sd_qn_maxpsz = rmax;
4292 			mutex_exit(QLOCK(wrq));
4293 		}
4294 
4295 		/*
4296 		 * Need to update the anchor value if this module is removed
4297 		 * at or below the anchor point.  If the removed module is at
4298 		 * the anchor point, remove the anchor for this stream if
4299 		 * there is no module above the anchor point.  Otherwise, if
4300 		 * the removed module is below the anchor point, decrement the
4301 		 * anchor point by 1.
4302 		 */
4303 		if (stp->sd_anchor != 0) {
4304 			pos = STRUCT_FGET(strmodremove, pos);
4305 			if (pos == stp->sd_pushcnt - stp->sd_anchor + 1)
4306 				stp->sd_anchor = 0;
4307 			else if (pos > (stp->sd_pushcnt - stp->sd_anchor + 1))
4308 				stp->sd_anchor--;
4309 		}
4310 
4311 		strendplumb(stp);
4312 		mutex_exit(&stp->sd_lock);
4313 		return (0);
4314 	}
4315 
4316 	case I_ANCHOR:
4317 		/*
4318 		 * Set the anchor position on the stream to reside at
4319 		 * the top module (in other words, the top module
4320 		 * cannot be popped).  Anchors with a FIFO make no
4321 		 * obvious sense, so they're not allowed.
4322 		 */
4323 		mutex_enter(&stp->sd_lock);
4324 
4325 		if (stp->sd_vnode->v_type == VFIFO) {
4326 			mutex_exit(&stp->sd_lock);
4327 			return (EINVAL);
4328 		}
4329 		/* Only allow the same zoneid to update the anchor */
4330 		if (stp->sd_anchor != 0 &&
4331 		    stp->sd_anchorzone != crgetzoneid(crp)) {
4332 			mutex_exit(&stp->sd_lock);
4333 			return (EINVAL);
4334 		}
4335 		stp->sd_anchor = stp->sd_pushcnt;
4336 		stp->sd_anchorzone = crgetzoneid(crp);
4337 		mutex_exit(&stp->sd_lock);
4338 		return (0);
4339 
4340 	case I_LOOK:
4341 		/*
4342 		 * Get name of first module downstream.
4343 		 * If no module, return an error.
4344 		 */
4345 		claimstr(wrq);
4346 		if (_SAMESTR(wrq) && wrq->q_next->q_next != NULL) {
4347 			char *name = Q2NAME(wrq->q_next);
4348 
4349 			error = strcopyout(name, (void *)arg, strlen(name) + 1,
4350 			    copyflag);
4351 			releasestr(wrq);
4352 			return (error);
4353 		}
4354 		releasestr(wrq);
4355 		return (EINVAL);
4356 
4357 	case I_LINK:
4358 	case I_PLINK:
4359 		/*
4360 		 * Link a multiplexor.
4361 		 */
4362 		return (mlink(vp, cmd, (int)arg, crp, rvalp, 0));
4363 
4364 	case _I_PLINK_LH:
4365 		/*
4366 		 * Link a multiplexor: Call must originate from kernel.
4367 		 */
4368 		if (kioctl)
4369 			return (ldi_mlink_lh(vp, cmd, arg, crp, rvalp));
4370 
4371 		return (EINVAL);
4372 	case I_UNLINK:
4373 	case I_PUNLINK:
4374 		/*
4375 		 * Unlink a multiplexor.
4376 		 * If arg is -1, unlink all links for which this is the
4377 		 * controlling stream.  Otherwise, arg is an index number
4378 		 * for a link to be removed.
4379 		 */
4380 	{
4381 		struct linkinfo *linkp;
4382 		int native_arg = (int)arg;
4383 		int type;
4384 		netstack_t *ns;
4385 		str_stack_t *ss;
4386 
4387 		TRACE_1(TR_FAC_STREAMS_FR,
4388 		    TR_I_UNLINK, "I_UNLINK/I_PUNLINK:%p", stp);
4389 		if (vp->v_type == VFIFO) {
4390 			return (EINVAL);
4391 		}
4392 		if (cmd == I_UNLINK)
4393 			type = LINKNORMAL;
4394 		else	/* I_PUNLINK */
4395 			type = LINKPERSIST;
4396 		if (native_arg == 0) {
4397 			return (EINVAL);
4398 		}
4399 		ns = netstack_find_by_cred(crp);
4400 		ASSERT(ns != NULL);
4401 		ss = ns->netstack_str;
4402 		ASSERT(ss != NULL);
4403 
4404 		if (native_arg == MUXID_ALL)
4405 			error = munlinkall(stp, type, crp, rvalp, ss);
4406 		else {
4407 			mutex_enter(&muxifier);
4408 			if (!(linkp = findlinks(stp, (int)arg, type, ss))) {
4409 				/* invalid user supplied index number */
4410 				mutex_exit(&muxifier);
4411 				netstack_rele(ss->ss_netstack);
4412 				return (EINVAL);
4413 			}
4414 			/* munlink drops the muxifier lock */
4415 			error = munlink(stp, linkp, type, crp, rvalp, ss);
4416 		}
4417 		netstack_rele(ss->ss_netstack);
4418 		return (error);
4419 	}
4420 
4421 	case I_FLUSH:
4422 		/*
4423 		 * send a flush message downstream
4424 		 * flush message can indicate
4425 		 * FLUSHR - flush read queue
4426 		 * FLUSHW - flush write queue
4427 		 * FLUSHRW - flush read/write queue
4428 		 */
4429 		if (stp->sd_flag & STRHUP)
4430 			return (ENXIO);
4431 		if (arg & ~FLUSHRW)
4432 			return (EINVAL);
4433 
4434 		for (;;) {
4435 			if (putnextctl1(stp->sd_wrq, M_FLUSH, (int)arg)) {
4436 				break;
4437 			}
4438 			if (error = strwaitbuf(1, BPRI_HI)) {
4439 				return (error);
4440 			}
4441 		}
4442 
4443 		/*
4444 		 * Send down an unsupported ioctl and wait for the nack
4445 		 * in order to allow the M_FLUSH to propagate back
4446 		 * up to the stream head.
4447 		 * Replaces if (qready()) runqueues();
4448 		 */
4449 		strioc.ic_cmd = -1;	/* The unsupported ioctl */
4450 		strioc.ic_timout = 0;
4451 		strioc.ic_len = 0;
4452 		strioc.ic_dp = NULL;
4453 		(void) strdoioctl(stp, &strioc, flag, K_TO_K, crp, rvalp);
4454 		*rvalp = 0;
4455 		return (0);
4456 
4457 	case I_FLUSHBAND:
4458 	{
4459 		struct bandinfo binfo;
4460 
4461 		error = strcopyin((void *)arg, &binfo, sizeof (binfo),
4462 		    copyflag);
4463 		if (error)
4464 			return (error);
4465 		if (stp->sd_flag & STRHUP)
4466 			return (ENXIO);
4467 		if (binfo.bi_flag & ~FLUSHRW)
4468 			return (EINVAL);
4469 		while (!(mp = allocb(2, BPRI_HI))) {
4470 			if (error = strwaitbuf(2, BPRI_HI))
4471 				return (error);
4472 		}
4473 		mp->b_datap->db_type = M_FLUSH;
4474 		*mp->b_wptr++ = binfo.bi_flag | FLUSHBAND;
4475 		*mp->b_wptr++ = binfo.bi_pri;
4476 		putnext(stp->sd_wrq, mp);
4477 		/*
4478 		 * Send down an unsupported ioctl and wait for the nack
4479 		 * in order to allow the M_FLUSH to propagate back
4480 		 * up to the stream head.
4481 		 * Replaces if (qready()) runqueues();
4482 		 */
4483 		strioc.ic_cmd = -1;	/* The unsupported ioctl */
4484 		strioc.ic_timout = 0;
4485 		strioc.ic_len = 0;
4486 		strioc.ic_dp = NULL;
4487 		(void) strdoioctl(stp, &strioc, flag, K_TO_K, crp, rvalp);
4488 		*rvalp = 0;
4489 		return (0);
4490 	}
4491 
4492 	case I_SRDOPT:
4493 		/*
4494 		 * Set read options
4495 		 *
4496 		 * RNORM - default stream mode
4497 		 * RMSGN - message no discard
4498 		 * RMSGD - message discard
4499 		 * RPROTNORM - fail read with EBADMSG for M_[PC]PROTOs
4500 		 * RPROTDAT - convert M_[PC]PROTOs to M_DATAs
4501 		 * RPROTDIS - discard M_[PC]PROTOs and retain M_DATAs
4502 		 */
4503 		if (arg & ~(RMODEMASK | RPROTMASK))
4504 			return (EINVAL);
4505 
4506 		if ((arg & (RMSGD|RMSGN)) == (RMSGD|RMSGN))
4507 			return (EINVAL);
4508 
4509 		mutex_enter(&stp->sd_lock);
4510 		switch (arg & RMODEMASK) {
4511 		case RNORM:
4512 			stp->sd_read_opt &= ~(RD_MSGDIS | RD_MSGNODIS);
4513 			break;
4514 		case RMSGD:
4515 			stp->sd_read_opt = (stp->sd_read_opt & ~RD_MSGNODIS) |
4516 			    RD_MSGDIS;
4517 			break;
4518 		case RMSGN:
4519 			stp->sd_read_opt = (stp->sd_read_opt & ~RD_MSGDIS) |
4520 			    RD_MSGNODIS;
4521 			break;
4522 		}
4523 
4524 		switch (arg & RPROTMASK) {
4525 		case RPROTNORM:
4526 			stp->sd_read_opt &= ~(RD_PROTDAT | RD_PROTDIS);
4527 			break;
4528 
4529 		case RPROTDAT:
4530 			stp->sd_read_opt = ((stp->sd_read_opt & ~RD_PROTDIS) |
4531 			    RD_PROTDAT);
4532 			break;
4533 
4534 		case RPROTDIS:
4535 			stp->sd_read_opt = ((stp->sd_read_opt & ~RD_PROTDAT) |
4536 			    RD_PROTDIS);
4537 			break;
4538 		}
4539 		mutex_exit(&stp->sd_lock);
4540 		return (0);
4541 
4542 	case I_GRDOPT:
4543 		/*
4544 		 * Get read option and return the value
4545 		 * to spot pointed to by arg
4546 		 */
4547 	{
4548 		int rdopt;
4549 
4550 		rdopt = ((stp->sd_read_opt & RD_MSGDIS) ? RMSGD :
4551 		    ((stp->sd_read_opt & RD_MSGNODIS) ? RMSGN : RNORM));
4552 		rdopt |= ((stp->sd_read_opt & RD_PROTDAT) ? RPROTDAT :
4553 		    ((stp->sd_read_opt & RD_PROTDIS) ? RPROTDIS : RPROTNORM));
4554 
4555 		return (strcopyout(&rdopt, (void *)arg, sizeof (int),
4556 		    copyflag));
4557 	}
4558 
4559 	case I_SERROPT:
4560 		/*
4561 		 * Set error options
4562 		 *
4563 		 * RERRNORM - persistent read errors
4564 		 * RERRNONPERSIST - non-persistent read errors
4565 		 * WERRNORM - persistent write errors
4566 		 * WERRNONPERSIST - non-persistent write errors
4567 		 */
4568 		if (arg & ~(RERRMASK | WERRMASK))
4569 			return (EINVAL);
4570 
4571 		mutex_enter(&stp->sd_lock);
4572 		switch (arg & RERRMASK) {
4573 		case RERRNORM:
4574 			stp->sd_flag &= ~STRDERRNONPERSIST;
4575 			break;
4576 		case RERRNONPERSIST:
4577 			stp->sd_flag |= STRDERRNONPERSIST;
4578 			break;
4579 		}
4580 		switch (arg & WERRMASK) {
4581 		case WERRNORM:
4582 			stp->sd_flag &= ~STWRERRNONPERSIST;
4583 			break;
4584 		case WERRNONPERSIST:
4585 			stp->sd_flag |= STWRERRNONPERSIST;
4586 			break;
4587 		}
4588 		mutex_exit(&stp->sd_lock);
4589 		return (0);
4590 
4591 	case I_GERROPT:
4592 		/*
4593 		 * Get error option and return the value
4594 		 * to spot pointed to by arg
4595 		 */
4596 	{
4597 		int erropt = 0;
4598 
4599 		erropt |= (stp->sd_flag & STRDERRNONPERSIST) ? RERRNONPERSIST :
4600 		    RERRNORM;
4601 		erropt |= (stp->sd_flag & STWRERRNONPERSIST) ? WERRNONPERSIST :
4602 		    WERRNORM;
4603 		return (strcopyout(&erropt, (void *)arg, sizeof (int),
4604 		    copyflag));
4605 	}
4606 
4607 	case I_SETSIG:
4608 		/*
4609 		 * Register the calling proc to receive the SIGPOLL
4610 		 * signal based on the events given in arg.  If
4611 		 * arg is zero, remove the proc from register list.
4612 		 */
4613 	{
4614 		strsig_t *ssp, *pssp;
4615 		struct pid *pidp;
4616 
4617 		pssp = NULL;
4618 		pidp = curproc->p_pidp;
4619 		/*
4620 		 * Hold sd_lock to prevent traversal of sd_siglist while
4621 		 * it is modified.
4622 		 */
4623 		mutex_enter(&stp->sd_lock);
4624 		for (ssp = stp->sd_siglist; ssp && (ssp->ss_pidp != pidp);
4625 		    pssp = ssp, ssp = ssp->ss_next)
4626 			;
4627 
4628 		if (arg) {
4629 			if (arg & ~(S_INPUT|S_HIPRI|S_MSG|S_HANGUP|S_ERROR|
4630 			    S_RDNORM|S_WRNORM|S_RDBAND|S_WRBAND|S_BANDURG)) {
4631 				mutex_exit(&stp->sd_lock);
4632 				return (EINVAL);
4633 			}
4634 			if ((arg & S_BANDURG) && !(arg & S_RDBAND)) {
4635 				mutex_exit(&stp->sd_lock);
4636 				return (EINVAL);
4637 			}
4638 
4639 			/*
4640 			 * If proc not already registered, add it
4641 			 * to list.
4642 			 */
4643 			if (!ssp) {
4644 				ssp = kmem_alloc(sizeof (strsig_t), KM_SLEEP);
4645 				ssp->ss_pidp = pidp;
4646 				ssp->ss_pid = pidp->pid_id;
4647 				ssp->ss_next = NULL;
4648 				if (pssp)
4649 					pssp->ss_next = ssp;
4650 				else
4651 					stp->sd_siglist = ssp;
4652 				mutex_enter(&pidlock);
4653 				PID_HOLD(pidp);
4654 				mutex_exit(&pidlock);
4655 			}
4656 
4657 			/*
4658 			 * Set events.
4659 			 */
4660 			ssp->ss_events = (int)arg;
4661 		} else {
4662 			/*
4663 			 * Remove proc from register list.
4664 			 */
4665 			if (ssp) {
4666 				mutex_enter(&pidlock);
4667 				PID_RELE(pidp);
4668 				mutex_exit(&pidlock);
4669 				if (pssp)
4670 					pssp->ss_next = ssp->ss_next;
4671 				else
4672 					stp->sd_siglist = ssp->ss_next;
4673 				kmem_free(ssp, sizeof (strsig_t));
4674 			} else {
4675 				mutex_exit(&stp->sd_lock);
4676 				return (EINVAL);
4677 			}
4678 		}
4679 
4680 		/*
4681 		 * Recalculate OR of sig events.
4682 		 */
4683 		stp->sd_sigflags = 0;
4684 		for (ssp = stp->sd_siglist; ssp; ssp = ssp->ss_next)
4685 			stp->sd_sigflags |= ssp->ss_events;
4686 		mutex_exit(&stp->sd_lock);
4687 		return (0);
4688 	}
4689 
4690 	case I_GETSIG:
4691 		/*
4692 		 * Return (in arg) the current registration of events
4693 		 * for which the calling proc is to be signaled.
4694 		 */
4695 	{
4696 		struct strsig *ssp;
4697 		struct pid  *pidp;
4698 
4699 		pidp = curproc->p_pidp;
4700 		mutex_enter(&stp->sd_lock);
4701 		for (ssp = stp->sd_siglist; ssp; ssp = ssp->ss_next)
4702 			if (ssp->ss_pidp == pidp) {
4703 				error = strcopyout(&ssp->ss_events, (void *)arg,
4704 				    sizeof (int), copyflag);
4705 				mutex_exit(&stp->sd_lock);
4706 				return (error);
4707 			}
4708 		mutex_exit(&stp->sd_lock);
4709 		return (EINVAL);
4710 	}
4711 
4712 	case I_ESETSIG:
4713 		/*
4714 		 * Register the ss_pid to receive the SIGPOLL
4715 		 * signal based on the events is ss_events arg.  If
4716 		 * ss_events is zero, remove the proc from register list.
4717 		 */
4718 	{
4719 		struct strsig *ssp, *pssp;
4720 		struct proc *proc;
4721 		struct pid  *pidp;
4722 		pid_t pid;
4723 		struct strsigset ss;
4724 
4725 		error = strcopyin((void *)arg, &ss, sizeof (ss), copyflag);
4726 		if (error)
4727 			return (error);
4728 
4729 		pid = ss.ss_pid;
4730 
4731 		if (ss.ss_events != 0) {
4732 			/*
4733 			 * Permissions check by sending signal 0.
4734 			 * Note that when kill fails it does a set_errno
4735 			 * causing the system call to fail.
4736 			 */
4737 			error = kill(pid, 0);
4738 			if (error) {
4739 				return (error);
4740 			}
4741 		}
4742 		mutex_enter(&pidlock);
4743 		if (pid == 0)
4744 			proc = curproc;
4745 		else if (pid < 0)
4746 			proc = pgfind(-pid);
4747 		else
4748 			proc = prfind(pid);
4749 		if (proc == NULL) {
4750 			mutex_exit(&pidlock);
4751 			return (ESRCH);
4752 		}
4753 		if (pid < 0)
4754 			pidp = proc->p_pgidp;
4755 		else
4756 			pidp = proc->p_pidp;
4757 		ASSERT(pidp);
4758 		/*
4759 		 * Get a hold on the pid structure while referencing it.
4760 		 * There is a separate PID_HOLD should it be inserted
4761 		 * in the list below.
4762 		 */
4763 		PID_HOLD(pidp);
4764 		mutex_exit(&pidlock);
4765 
4766 		pssp = NULL;
4767 		/*
4768 		 * Hold sd_lock to prevent traversal of sd_siglist while
4769 		 * it is modified.
4770 		 */
4771 		mutex_enter(&stp->sd_lock);
4772 		for (ssp = stp->sd_siglist; ssp && (ssp->ss_pid != pid);
4773 		    pssp = ssp, ssp = ssp->ss_next)
4774 			;
4775 
4776 		if (ss.ss_events) {
4777 			if (ss.ss_events &
4778 			    ~(S_INPUT|S_HIPRI|S_MSG|S_HANGUP|S_ERROR|
4779 			    S_RDNORM|S_WRNORM|S_RDBAND|S_WRBAND|S_BANDURG)) {
4780 				mutex_exit(&stp->sd_lock);
4781 				mutex_enter(&pidlock);
4782 				PID_RELE(pidp);
4783 				mutex_exit(&pidlock);
4784 				return (EINVAL);
4785 			}
4786 			if ((ss.ss_events & S_BANDURG) &&
4787 			    !(ss.ss_events & S_RDBAND)) {
4788 				mutex_exit(&stp->sd_lock);
4789 				mutex_enter(&pidlock);
4790 				PID_RELE(pidp);
4791 				mutex_exit(&pidlock);
4792 				return (EINVAL);
4793 			}
4794 
4795 			/*
4796 			 * If proc not already registered, add it
4797 			 * to list.
4798 			 */
4799 			if (!ssp) {
4800 				ssp = kmem_alloc(sizeof (strsig_t), KM_SLEEP);
4801 				ssp->ss_pidp = pidp;
4802 				ssp->ss_pid = pid;
4803 				ssp->ss_next = NULL;
4804 				if (pssp)
4805 					pssp->ss_next = ssp;
4806 				else
4807 					stp->sd_siglist = ssp;
4808 				mutex_enter(&pidlock);
4809 				PID_HOLD(pidp);
4810 				mutex_exit(&pidlock);
4811 			}
4812 
4813 			/*
4814 			 * Set events.
4815 			 */
4816 			ssp->ss_events = ss.ss_events;
4817 		} else {
4818 			/*
4819 			 * Remove proc from register list.
4820 			 */
4821 			if (ssp) {
4822 				mutex_enter(&pidlock);
4823 				PID_RELE(pidp);
4824 				mutex_exit(&pidlock);
4825 				if (pssp)
4826 					pssp->ss_next = ssp->ss_next;
4827 				else
4828 					stp->sd_siglist = ssp->ss_next;
4829 				kmem_free(ssp, sizeof (strsig_t));
4830 			} else {
4831 				mutex_exit(&stp->sd_lock);
4832 				mutex_enter(&pidlock);
4833 				PID_RELE(pidp);
4834 				mutex_exit(&pidlock);
4835 				return (EINVAL);
4836 			}
4837 		}
4838 
4839 		/*
4840 		 * Recalculate OR of sig events.
4841 		 */
4842 		stp->sd_sigflags = 0;
4843 		for (ssp = stp->sd_siglist; ssp; ssp = ssp->ss_next)
4844 			stp->sd_sigflags |= ssp->ss_events;
4845 		mutex_exit(&stp->sd_lock);
4846 		mutex_enter(&pidlock);
4847 		PID_RELE(pidp);
4848 		mutex_exit(&pidlock);
4849 		return (0);
4850 	}
4851 
4852 	case I_EGETSIG:
4853 		/*
4854 		 * Return (in arg) the current registration of events
4855 		 * for which the calling proc is to be signaled.
4856 		 */
4857 	{
4858 		struct strsig *ssp;
4859 		struct proc *proc;
4860 		pid_t pid;
4861 		struct pid  *pidp;
4862 		struct strsigset ss;
4863 
4864 		error = strcopyin((void *)arg, &ss, sizeof (ss), copyflag);
4865 		if (error)
4866 			return (error);
4867 
4868 		pid = ss.ss_pid;
4869 		mutex_enter(&pidlock);
4870 		if (pid == 0)
4871 			proc = curproc;
4872 		else if (pid < 0)
4873 			proc = pgfind(-pid);
4874 		else
4875 			proc = prfind(pid);
4876 		if (proc == NULL) {
4877 			mutex_exit(&pidlock);
4878 			return (ESRCH);
4879 		}
4880 		if (pid < 0)
4881 			pidp = proc->p_pgidp;
4882 		else
4883 			pidp = proc->p_pidp;
4884 
4885 		/* Prevent the pidp from being reassigned */
4886 		PID_HOLD(pidp);
4887 		mutex_exit(&pidlock);
4888 
4889 		mutex_enter(&stp->sd_lock);
4890 		for (ssp = stp->sd_siglist; ssp; ssp = ssp->ss_next)
4891 			if (ssp->ss_pid == pid) {
4892 				ss.ss_pid = ssp->ss_pid;
4893 				ss.ss_events = ssp->ss_events;
4894 				error = strcopyout(&ss, (void *)arg,
4895 				    sizeof (struct strsigset), copyflag);
4896 				mutex_exit(&stp->sd_lock);
4897 				mutex_enter(&pidlock);
4898 				PID_RELE(pidp);
4899 				mutex_exit(&pidlock);
4900 				return (error);
4901 			}
4902 		mutex_exit(&stp->sd_lock);
4903 		mutex_enter(&pidlock);
4904 		PID_RELE(pidp);
4905 		mutex_exit(&pidlock);
4906 		return (EINVAL);
4907 	}
4908 
4909 	case I_PEEK:
4910 	{
4911 		STRUCT_DECL(strpeek, strpeek);
4912 		size_t n;
4913 		mblk_t *fmp, *tmp_mp = NULL;
4914 
4915 		STRUCT_INIT(strpeek, flag);
4916 
4917 		error = strcopyin((void *)arg, STRUCT_BUF(strpeek),
4918 		    STRUCT_SIZE(strpeek), copyflag);
4919 		if (error)
4920 			return (error);
4921 
4922 		mutex_enter(QLOCK(rdq));
4923 		/*
4924 		 * Skip the invalid messages
4925 		 */
4926 		for (mp = rdq->q_first; mp != NULL; mp = mp->b_next)
4927 			if (mp->b_datap->db_type != M_SIG)
4928 				break;
4929 
4930 		/*
4931 		 * If user has requested to peek at a high priority message
4932 		 * and first message is not, return 0
4933 		 */
4934 		if (mp != NULL) {
4935 			if ((STRUCT_FGET(strpeek, flags) & RS_HIPRI) &&
4936 			    queclass(mp) == QNORM) {
4937 				*rvalp = 0;
4938 				mutex_exit(QLOCK(rdq));
4939 				return (0);
4940 			}
4941 		} else if (stp->sd_struiordq == NULL ||
4942 		    (STRUCT_FGET(strpeek, flags) & RS_HIPRI)) {
4943 			/*
4944 			 * No mblks to look at at the streamhead and
4945 			 * 1). This isn't a synch stream or
4946 			 * 2). This is a synch stream but caller wants high
4947 			 *	priority messages which is not supported by
4948 			 *	the synch stream. (it only supports QNORM)
4949 			 */
4950 			*rvalp = 0;
4951 			mutex_exit(QLOCK(rdq));
4952 			return (0);
4953 		}
4954 
4955 		fmp = mp;
4956 
4957 		if (mp && mp->b_datap->db_type == M_PASSFP) {
4958 			mutex_exit(QLOCK(rdq));
4959 			return (EBADMSG);
4960 		}
4961 
4962 		ASSERT(mp == NULL || mp->b_datap->db_type == M_PCPROTO ||
4963 		    mp->b_datap->db_type == M_PROTO ||
4964 		    mp->b_datap->db_type == M_DATA);
4965 
4966 		if (mp && mp->b_datap->db_type == M_PCPROTO) {
4967 			STRUCT_FSET(strpeek, flags, RS_HIPRI);
4968 		} else {
4969 			STRUCT_FSET(strpeek, flags, 0);
4970 		}
4971 
4972 
4973 		if (mp && ((tmp_mp = dupmsg(mp)) == NULL)) {
4974 			mutex_exit(QLOCK(rdq));
4975 			return (ENOSR);
4976 		}
4977 		mutex_exit(QLOCK(rdq));
4978 
4979 		/*
4980 		 * set mp = tmp_mp, so that I_PEEK processing can continue.
4981 		 * tmp_mp is used to free the dup'd message.
4982 		 */
4983 		mp = tmp_mp;
4984 
4985 		uio.uio_fmode = 0;
4986 		uio.uio_extflg = UIO_COPY_CACHED;
4987 		uio.uio_segflg = (copyflag == U_TO_K) ? UIO_USERSPACE :
4988 		    UIO_SYSSPACE;
4989 		uio.uio_limit = 0;
4990 		/*
4991 		 * First process PROTO blocks, if any.
4992 		 * If user doesn't want to get ctl info by setting maxlen <= 0,
4993 		 * then set len to -1/0 and skip control blocks part.
4994 		 */
4995 		if (STRUCT_FGET(strpeek, ctlbuf.maxlen) < 0)
4996 			STRUCT_FSET(strpeek, ctlbuf.len, -1);
4997 		else if (STRUCT_FGET(strpeek, ctlbuf.maxlen) == 0)
4998 			STRUCT_FSET(strpeek, ctlbuf.len, 0);
4999 		else {
5000 			int	ctl_part = 0;
5001 
5002 			iov.iov_base = STRUCT_FGETP(strpeek, ctlbuf.buf);
5003 			iov.iov_len = STRUCT_FGET(strpeek, ctlbuf.maxlen);
5004 			uio.uio_iov = &iov;
5005 			uio.uio_resid = iov.iov_len;
5006 			uio.uio_loffset = 0;
5007 			uio.uio_iovcnt = 1;
5008 			while (mp && mp->b_datap->db_type != M_DATA &&
5009 			    uio.uio_resid >= 0) {
5010 				ASSERT(STRUCT_FGET(strpeek, flags) == 0 ?
5011 				    mp->b_datap->db_type == M_PROTO :
5012 				    mp->b_datap->db_type == M_PCPROTO);
5013 
5014 				if ((n = MIN(uio.uio_resid,
5015 				    mp->b_wptr - mp->b_rptr)) != 0 &&
5016 				    (error = uiomove((char *)mp->b_rptr, n,
5017 				    UIO_READ, &uio)) != 0) {
5018 					freemsg(tmp_mp);
5019 					return (error);
5020 				}
5021 				ctl_part = 1;
5022 				mp = mp->b_cont;
5023 			}
5024 			/* No ctl message */
5025 			if (ctl_part == 0)
5026 				STRUCT_FSET(strpeek, ctlbuf.len, -1);
5027 			else
5028 				STRUCT_FSET(strpeek, ctlbuf.len,
5029 				    STRUCT_FGET(strpeek, ctlbuf.maxlen) -
5030 				    uio.uio_resid);
5031 		}
5032 
5033 		/*
5034 		 * Now process DATA blocks, if any.
5035 		 * If user doesn't want to get data info by setting maxlen <= 0,
5036 		 * then set len to -1/0 and skip data blocks part.
5037 		 */
5038 		if (STRUCT_FGET(strpeek, databuf.maxlen) < 0)
5039 			STRUCT_FSET(strpeek, databuf.len, -1);
5040 		else if (STRUCT_FGET(strpeek, databuf.maxlen) == 0)
5041 			STRUCT_FSET(strpeek, databuf.len, 0);
5042 		else {
5043 			int	data_part = 0;
5044 
5045 			iov.iov_base = STRUCT_FGETP(strpeek, databuf.buf);
5046 			iov.iov_len = STRUCT_FGET(strpeek, databuf.maxlen);
5047 			uio.uio_iov = &iov;
5048 			uio.uio_resid = iov.iov_len;
5049 			uio.uio_loffset = 0;
5050 			uio.uio_iovcnt = 1;
5051 			while (mp && uio.uio_resid) {
5052 				if (mp->b_datap->db_type == M_DATA) {
5053 					if ((n = MIN(uio.uio_resid,
5054 					    mp->b_wptr - mp->b_rptr)) != 0 &&
5055 					    (error = uiomove((char *)mp->b_rptr,
5056 					    n, UIO_READ, &uio)) != 0) {
5057 						freemsg(tmp_mp);
5058 						return (error);
5059 					}
5060 					data_part = 1;
5061 				}
5062 				ASSERT(data_part == 0 ||
5063 				    mp->b_datap->db_type == M_DATA);
5064 				mp = mp->b_cont;
5065 			}
5066 			/* No data message */
5067 			if (data_part == 0)
5068 				STRUCT_FSET(strpeek, databuf.len, -1);
5069 			else
5070 				STRUCT_FSET(strpeek, databuf.len,
5071 				    STRUCT_FGET(strpeek, databuf.maxlen) -
5072 				    uio.uio_resid);
5073 		}
5074 		freemsg(tmp_mp);
5075 
5076 		/*
5077 		 * It is a synch stream and user wants to get
5078 		 * data (maxlen > 0).
5079 		 * uio setup is done by the codes that process DATA
5080 		 * blocks above.
5081 		 */
5082 		if ((fmp == NULL) && STRUCT_FGET(strpeek, databuf.maxlen) > 0) {
5083 			infod_t infod;
5084 
5085 			infod.d_cmd = INFOD_COPYOUT;
5086 			infod.d_res = 0;
5087 			infod.d_uiop = &uio;
5088 			error = infonext(rdq, &infod);
5089 			if (error == EINVAL || error == EBUSY)
5090 				error = 0;
5091 			if (error)
5092 				return (error);
5093 			STRUCT_FSET(strpeek, databuf.len, STRUCT_FGET(strpeek,
5094 			    databuf.maxlen) - uio.uio_resid);
5095 			if (STRUCT_FGET(strpeek, databuf.len) == 0) {
5096 				/*
5097 				 * No data found by the infonext().
5098 				 */
5099 				STRUCT_FSET(strpeek, databuf.len, -1);
5100 			}
5101 		}
5102 		error = strcopyout(STRUCT_BUF(strpeek), (void *)arg,
5103 		    STRUCT_SIZE(strpeek), copyflag);
5104 		if (error) {
5105 			return (error);
5106 		}
5107 		/*
5108 		 * If there is no message retrieved, set return code to 0
5109 		 * otherwise, set it to 1.
5110 		 */
5111 		if (STRUCT_FGET(strpeek, ctlbuf.len) == -1 &&
5112 		    STRUCT_FGET(strpeek, databuf.len) == -1)
5113 			*rvalp = 0;
5114 		else
5115 			*rvalp = 1;
5116 		return (0);
5117 	}
5118 
5119 	case I_FDINSERT:
5120 	{
5121 		STRUCT_DECL(strfdinsert, strfdinsert);
5122 		struct file *resftp;
5123 		struct stdata *resstp;
5124 		t_uscalar_t	ival;
5125 		ssize_t msgsize;
5126 		struct strbuf mctl;
5127 
5128 		STRUCT_INIT(strfdinsert, flag);
5129 		if (stp->sd_flag & STRHUP)
5130 			return (ENXIO);
5131 		/*
5132 		 * STRDERR, STWRERR and STPLEX tested above.
5133 		 */
5134 		error = strcopyin((void *)arg, STRUCT_BUF(strfdinsert),
5135 		    STRUCT_SIZE(strfdinsert), copyflag);
5136 		if (error)
5137 			return (error);
5138 
5139 		if (STRUCT_FGET(strfdinsert, offset) < 0 ||
5140 		    (STRUCT_FGET(strfdinsert, offset) %
5141 		    sizeof (t_uscalar_t)) != 0)
5142 			return (EINVAL);
5143 		if ((resftp = getf(STRUCT_FGET(strfdinsert, fildes))) != NULL) {
5144 			if ((resstp = resftp->f_vnode->v_stream) == NULL) {
5145 				releasef(STRUCT_FGET(strfdinsert, fildes));
5146 				return (EINVAL);
5147 			}
5148 		} else
5149 			return (EINVAL);
5150 
5151 		mutex_enter(&resstp->sd_lock);
5152 		if (resstp->sd_flag & (STRDERR|STWRERR|STRHUP|STPLEX)) {
5153 			error = strgeterr(resstp,
5154 			    STRDERR|STWRERR|STRHUP|STPLEX, 0);
5155 			if (error != 0) {
5156 				mutex_exit(&resstp->sd_lock);
5157 				releasef(STRUCT_FGET(strfdinsert, fildes));
5158 				return (error);
5159 			}
5160 		}
5161 		mutex_exit(&resstp->sd_lock);
5162 
5163 #ifdef	_ILP32
5164 		{
5165 			queue_t	*q;
5166 			queue_t	*mate = NULL;
5167 
5168 			/* get read queue of stream terminus */
5169 			claimstr(resstp->sd_wrq);
5170 			for (q = resstp->sd_wrq->q_next; q->q_next != NULL;
5171 			    q = q->q_next)
5172 				if (!STRMATED(resstp) && STREAM(q) != resstp &&
5173 				    mate == NULL) {
5174 					ASSERT(q->q_qinfo->qi_srvp);
5175 					ASSERT(_OTHERQ(q)->q_qinfo->qi_srvp);
5176 					claimstr(q);
5177 					mate = q;
5178 				}
5179 			q = _RD(q);
5180 			if (mate)
5181 				releasestr(mate);
5182 			releasestr(resstp->sd_wrq);
5183 			ival = (t_uscalar_t)q;
5184 		}
5185 #else
5186 		ival = (t_uscalar_t)getminor(resftp->f_vnode->v_rdev);
5187 #endif	/* _ILP32 */
5188 
5189 		if (STRUCT_FGET(strfdinsert, ctlbuf.len) <
5190 		    STRUCT_FGET(strfdinsert, offset) + sizeof (t_uscalar_t)) {
5191 			releasef(STRUCT_FGET(strfdinsert, fildes));
5192 			return (EINVAL);
5193 		}
5194 
5195 		/*
5196 		 * Check for legal flag value.
5197 		 */
5198 		if (STRUCT_FGET(strfdinsert, flags) & ~RS_HIPRI) {
5199 			releasef(STRUCT_FGET(strfdinsert, fildes));
5200 			return (EINVAL);
5201 		}
5202 
5203 		/* get these values from those cached in the stream head */
5204 		mutex_enter(QLOCK(stp->sd_wrq));
5205 		rmin = stp->sd_qn_minpsz;
5206 		rmax = stp->sd_qn_maxpsz;
5207 		mutex_exit(QLOCK(stp->sd_wrq));
5208 
5209 		/*
5210 		 * Make sure ctl and data sizes together fall within
5211 		 * the limits of the max and min receive packet sizes
5212 		 * and do not exceed system limit.  A negative data
5213 		 * length means that no data part is to be sent.
5214 		 */
5215 		ASSERT((rmax >= 0) || (rmax == INFPSZ));
5216 		if (rmax == 0) {
5217 			releasef(STRUCT_FGET(strfdinsert, fildes));
5218 			return (ERANGE);
5219 		}
5220 		if ((msgsize = STRUCT_FGET(strfdinsert, databuf.len)) < 0)
5221 			msgsize = 0;
5222 		if ((msgsize < rmin) ||
5223 		    ((msgsize > rmax) && (rmax != INFPSZ)) ||
5224 		    (STRUCT_FGET(strfdinsert, ctlbuf.len) > strctlsz)) {
5225 			releasef(STRUCT_FGET(strfdinsert, fildes));
5226 			return (ERANGE);
5227 		}
5228 
5229 		mutex_enter(&stp->sd_lock);
5230 		while (!(STRUCT_FGET(strfdinsert, flags) & RS_HIPRI) &&
5231 		    !canputnext(stp->sd_wrq)) {
5232 			if ((error = strwaitq(stp, WRITEWAIT, (ssize_t)0,
5233 			    flag, -1, &done)) != 0 || done) {
5234 				mutex_exit(&stp->sd_lock);
5235 				releasef(STRUCT_FGET(strfdinsert, fildes));
5236 				return (error);
5237 			}
5238 			if ((error = i_straccess(stp, access)) != 0) {
5239 				mutex_exit(&stp->sd_lock);
5240 				releasef(
5241 				    STRUCT_FGET(strfdinsert, fildes));
5242 				return (error);
5243 			}
5244 		}
5245 		mutex_exit(&stp->sd_lock);
5246 
5247 		/*
5248 		 * Copy strfdinsert.ctlbuf into native form of
5249 		 * ctlbuf to pass down into strmakemsg().
5250 		 */
5251 		mctl.maxlen = STRUCT_FGET(strfdinsert, ctlbuf.maxlen);
5252 		mctl.len = STRUCT_FGET(strfdinsert, ctlbuf.len);
5253 		mctl.buf = STRUCT_FGETP(strfdinsert, ctlbuf.buf);
5254 
5255 		iov.iov_base = STRUCT_FGETP(strfdinsert, databuf.buf);
5256 		iov.iov_len = STRUCT_FGET(strfdinsert, databuf.len);
5257 		uio.uio_iov = &iov;
5258 		uio.uio_iovcnt = 1;
5259 		uio.uio_loffset = 0;
5260 		uio.uio_segflg = (copyflag == U_TO_K) ? UIO_USERSPACE :
5261 		    UIO_SYSSPACE;
5262 		uio.uio_fmode = 0;
5263 		uio.uio_extflg = UIO_COPY_CACHED;
5264 		uio.uio_resid = iov.iov_len;
5265 		if ((error = strmakemsg(&mctl,
5266 		    &msgsize, &uio, stp,
5267 		    STRUCT_FGET(strfdinsert, flags), &mp)) != 0 || !mp) {
5268 			STRUCT_FSET(strfdinsert, databuf.len, msgsize);
5269 			releasef(STRUCT_FGET(strfdinsert, fildes));
5270 			return (error);
5271 		}
5272 
5273 		STRUCT_FSET(strfdinsert, databuf.len, msgsize);
5274 
5275 		/*
5276 		 * Place the possibly reencoded queue pointer 'offset' bytes
5277 		 * from the start of the control portion of the message.
5278 		 */
5279 		*((t_uscalar_t *)(mp->b_rptr +
5280 		    STRUCT_FGET(strfdinsert, offset))) = ival;
5281 
5282 		/*
5283 		 * Put message downstream.
5284 		 */
5285 		stream_willservice(stp);
5286 		putnext(stp->sd_wrq, mp);
5287 		stream_runservice(stp);
5288 		releasef(STRUCT_FGET(strfdinsert, fildes));
5289 		return (error);
5290 	}
5291 
5292 	case I_SENDFD:
5293 	{
5294 		struct file *fp;
5295 
5296 		if ((fp = getf((int)arg)) == NULL)
5297 			return (EBADF);
5298 		error = do_sendfp(stp, fp, crp);
5299 		if (audit_active) {
5300 			audit_fdsend((int)arg, fp, error);
5301 		}
5302 		releasef((int)arg);
5303 		return (error);
5304 	}
5305 
5306 	case I_RECVFD:
5307 	case I_E_RECVFD:
5308 	{
5309 		struct k_strrecvfd *srf;
5310 		int i, fd;
5311 
5312 		mutex_enter(&stp->sd_lock);
5313 		while (!(mp = getq(rdq))) {
5314 			if (stp->sd_flag & (STRHUP|STREOF)) {
5315 				mutex_exit(&stp->sd_lock);
5316 				return (ENXIO);
5317 			}
5318 			if ((error = strwaitq(stp, GETWAIT, (ssize_t)0,
5319 			    flag, -1, &done)) != 0 || done) {
5320 				mutex_exit(&stp->sd_lock);
5321 				return (error);
5322 			}
5323 			if ((error = i_straccess(stp, access)) != 0) {
5324 				mutex_exit(&stp->sd_lock);
5325 				return (error);
5326 			}
5327 		}
5328 		if (mp->b_datap->db_type != M_PASSFP) {
5329 			putback(stp, rdq, mp, mp->b_band);
5330 			mutex_exit(&stp->sd_lock);
5331 			return (EBADMSG);
5332 		}
5333 		mutex_exit(&stp->sd_lock);
5334 
5335 		srf = (struct k_strrecvfd *)mp->b_rptr;
5336 		if ((fd = ufalloc(0)) == -1) {
5337 			mutex_enter(&stp->sd_lock);
5338 			putback(stp, rdq, mp, mp->b_band);
5339 			mutex_exit(&stp->sd_lock);
5340 			return (EMFILE);
5341 		}
5342 		if (cmd == I_RECVFD) {
5343 			struct o_strrecvfd	ostrfd;
5344 
5345 			/* check to see if uid/gid values are too large. */
5346 
5347 			if (srf->uid > (o_uid_t)USHRT_MAX ||
5348 			    srf->gid > (o_gid_t)USHRT_MAX) {
5349 				mutex_enter(&stp->sd_lock);
5350 				putback(stp, rdq, mp, mp->b_band);
5351 				mutex_exit(&stp->sd_lock);
5352 				setf(fd, NULL);	/* release fd entry */
5353 				return (EOVERFLOW);
5354 			}
5355 
5356 			ostrfd.fd = fd;
5357 			ostrfd.uid = (o_uid_t)srf->uid;
5358 			ostrfd.gid = (o_gid_t)srf->gid;
5359 
5360 			/* Null the filler bits */
5361 			for (i = 0; i < 8; i++)
5362 				ostrfd.fill[i] = 0;
5363 
5364 			error = strcopyout(&ostrfd, (void *)arg,
5365 			    sizeof (struct o_strrecvfd), copyflag);
5366 		} else {		/* I_E_RECVFD */
5367 			struct strrecvfd	strfd;
5368 
5369 			strfd.fd = fd;
5370 			strfd.uid = srf->uid;
5371 			strfd.gid = srf->gid;
5372 
5373 			/* null the filler bits */
5374 			for (i = 0; i < 8; i++)
5375 				strfd.fill[i] = 0;
5376 
5377 			error = strcopyout(&strfd, (void *)arg,
5378 			    sizeof (struct strrecvfd), copyflag);
5379 		}
5380 
5381 		if (error) {
5382 			setf(fd, NULL);	/* release fd entry */
5383 			mutex_enter(&stp->sd_lock);
5384 			putback(stp, rdq, mp, mp->b_band);
5385 			mutex_exit(&stp->sd_lock);
5386 			return (error);
5387 		}
5388 		if (audit_active) {
5389 			audit_fdrecv(fd, srf->fp);
5390 		}
5391 
5392 		/*
5393 		 * Always increment f_count since the freemsg() below will
5394 		 * always call free_passfp() which performs a closef().
5395 		 */
5396 		mutex_enter(&srf->fp->f_tlock);
5397 		srf->fp->f_count++;
5398 		mutex_exit(&srf->fp->f_tlock);
5399 		setf(fd, srf->fp);
5400 		freemsg(mp);
5401 		return (0);
5402 	}
5403 
5404 	case I_SWROPT:
5405 		/*
5406 		 * Set/clear the write options. arg is a bit
5407 		 * mask with any of the following bits set...
5408 		 * 	SNDZERO - send zero length message
5409 		 *	SNDPIPE - send sigpipe to process if
5410 		 *		sd_werror is set and process is
5411 		 *		doing a write or putmsg.
5412 		 * The new stream head write options should reflect
5413 		 * what is in arg.
5414 		 */
5415 		if (arg & ~(SNDZERO|SNDPIPE))
5416 			return (EINVAL);
5417 
5418 		mutex_enter(&stp->sd_lock);
5419 		stp->sd_wput_opt &= ~(SW_SIGPIPE|SW_SNDZERO);
5420 		if (arg & SNDZERO)
5421 			stp->sd_wput_opt |= SW_SNDZERO;
5422 		if (arg & SNDPIPE)
5423 			stp->sd_wput_opt |= SW_SIGPIPE;
5424 		mutex_exit(&stp->sd_lock);
5425 		return (0);
5426 
5427 	case I_GWROPT:
5428 	{
5429 		int wropt = 0;
5430 
5431 		if (stp->sd_wput_opt & SW_SNDZERO)
5432 			wropt |= SNDZERO;
5433 		if (stp->sd_wput_opt & SW_SIGPIPE)
5434 			wropt |= SNDPIPE;
5435 		return (strcopyout(&wropt, (void *)arg, sizeof (wropt),
5436 		    copyflag));
5437 	}
5438 
5439 	case I_LIST:
5440 		/*
5441 		 * Returns all the modules found on this stream,
5442 		 * upto the driver. If argument is NULL, return the
5443 		 * number of modules (including driver). If argument
5444 		 * is not NULL, copy the names into the structure
5445 		 * provided.
5446 		 */
5447 
5448 	{
5449 		queue_t *q;
5450 		char *qname;
5451 		int i, nmods;
5452 		struct str_mlist *mlist;
5453 		STRUCT_DECL(str_list, strlist);
5454 
5455 		if (arg == NULL) { /* Return number of modules plus driver */
5456 			if (stp->sd_vnode->v_type == VFIFO)
5457 				*rvalp = stp->sd_pushcnt;
5458 			else
5459 				*rvalp = stp->sd_pushcnt + 1;
5460 			return (0);
5461 		}
5462 
5463 		STRUCT_INIT(strlist, flag);
5464 
5465 		error = strcopyin((void *)arg, STRUCT_BUF(strlist),
5466 		    STRUCT_SIZE(strlist), copyflag);
5467 		if (error != 0)
5468 			return (error);
5469 
5470 		mlist = STRUCT_FGETP(strlist, sl_modlist);
5471 		nmods = STRUCT_FGET(strlist, sl_nmods);
5472 		if (nmods <= 0)
5473 			return (EINVAL);
5474 
5475 		claimstr(stp->sd_wrq);
5476 		q = stp->sd_wrq;
5477 		for (i = 0; i < nmods && _SAMESTR(q); i++, q = q->q_next) {
5478 			qname = Q2NAME(q->q_next);
5479 			error = strcopyout(qname, &mlist[i], strlen(qname) + 1,
5480 			    copyflag);
5481 			if (error != 0) {
5482 				releasestr(stp->sd_wrq);
5483 				return (error);
5484 			}
5485 		}
5486 		releasestr(stp->sd_wrq);
5487 		return (strcopyout(&i, (void *)arg, sizeof (int), copyflag));
5488 	}
5489 
5490 	case I_CKBAND:
5491 	{
5492 		queue_t *q;
5493 		qband_t *qbp;
5494 
5495 		if ((arg < 0) || (arg >= NBAND))
5496 			return (EINVAL);
5497 		q = _RD(stp->sd_wrq);
5498 		mutex_enter(QLOCK(q));
5499 		if (arg > (int)q->q_nband) {
5500 			*rvalp = 0;
5501 		} else {
5502 			if (arg == 0) {
5503 				if (q->q_first)
5504 					*rvalp = 1;
5505 				else
5506 					*rvalp = 0;
5507 			} else {
5508 				qbp = q->q_bandp;
5509 				while (--arg > 0)
5510 					qbp = qbp->qb_next;
5511 				if (qbp->qb_first)
5512 					*rvalp = 1;
5513 				else
5514 					*rvalp = 0;
5515 			}
5516 		}
5517 		mutex_exit(QLOCK(q));
5518 		return (0);
5519 	}
5520 
5521 	case I_GETBAND:
5522 	{
5523 		int intpri;
5524 		queue_t *q;
5525 
5526 		q = _RD(stp->sd_wrq);
5527 		mutex_enter(QLOCK(q));
5528 		mp = q->q_first;
5529 		if (!mp) {
5530 			mutex_exit(QLOCK(q));
5531 			return (ENODATA);
5532 		}
5533 		intpri = (int)mp->b_band;
5534 		error = strcopyout(&intpri, (void *)arg, sizeof (int),
5535 		    copyflag);
5536 		mutex_exit(QLOCK(q));
5537 		return (error);
5538 	}
5539 
5540 	case I_ATMARK:
5541 	{
5542 		queue_t *q;
5543 
5544 		if (arg & ~(ANYMARK|LASTMARK))
5545 			return (EINVAL);
5546 		q = _RD(stp->sd_wrq);
5547 		mutex_enter(&stp->sd_lock);
5548 		if ((stp->sd_flag & STRATMARK) && (arg == ANYMARK)) {
5549 			*rvalp = 1;
5550 		} else {
5551 			mutex_enter(QLOCK(q));
5552 			mp = q->q_first;
5553 
5554 			if (mp == NULL)
5555 				*rvalp = 0;
5556 			else if ((arg == ANYMARK) && (mp->b_flag & MSGMARK))
5557 				*rvalp = 1;
5558 			else if ((arg == LASTMARK) && (mp == stp->sd_mark))
5559 				*rvalp = 1;
5560 			else
5561 				*rvalp = 0;
5562 			mutex_exit(QLOCK(q));
5563 		}
5564 		mutex_exit(&stp->sd_lock);
5565 		return (0);
5566 	}
5567 
5568 	case I_CANPUT:
5569 	{
5570 		char band;
5571 
5572 		if ((arg < 0) || (arg >= NBAND))
5573 			return (EINVAL);
5574 		band = (char)arg;
5575 		*rvalp = bcanputnext(stp->sd_wrq, band);
5576 		return (0);
5577 	}
5578 
5579 	case I_SETCLTIME:
5580 	{
5581 		int closetime;
5582 
5583 		error = strcopyin((void *)arg, &closetime, sizeof (int),
5584 		    copyflag);
5585 		if (error)
5586 			return (error);
5587 		if (closetime < 0)
5588 			return (EINVAL);
5589 
5590 		stp->sd_closetime = closetime;
5591 		return (0);
5592 	}
5593 
5594 	case I_GETCLTIME:
5595 	{
5596 		int closetime;
5597 
5598 		closetime = stp->sd_closetime;
5599 		return (strcopyout(&closetime, (void *)arg, sizeof (int),
5600 		    copyflag));
5601 	}
5602 
5603 	case TIOCGSID:
5604 	{
5605 		pid_t sid;
5606 
5607 		mutex_enter(&stp->sd_lock);
5608 		if (stp->sd_sidp == NULL) {
5609 			mutex_exit(&stp->sd_lock);
5610 			return (ENOTTY);
5611 		}
5612 		sid = stp->sd_sidp->pid_id;
5613 		mutex_exit(&stp->sd_lock);
5614 		return (strcopyout(&sid, (void *)arg, sizeof (pid_t),
5615 		    copyflag));
5616 	}
5617 
5618 	case TIOCSPGRP:
5619 	{
5620 		pid_t pgrp;
5621 		proc_t *q;
5622 		pid_t	sid, fg_pgid, bg_pgid;
5623 
5624 		if (error = strcopyin((void *)arg, &pgrp, sizeof (pid_t),
5625 		    copyflag))
5626 			return (error);
5627 		mutex_enter(&stp->sd_lock);
5628 		mutex_enter(&pidlock);
5629 		if (stp->sd_sidp != ttoproc(curthread)->p_sessp->s_sidp) {
5630 			mutex_exit(&pidlock);
5631 			mutex_exit(&stp->sd_lock);
5632 			return (ENOTTY);
5633 		}
5634 		if (pgrp == stp->sd_pgidp->pid_id) {
5635 			mutex_exit(&pidlock);
5636 			mutex_exit(&stp->sd_lock);
5637 			return (0);
5638 		}
5639 		if (pgrp <= 0 || pgrp >= maxpid) {
5640 			mutex_exit(&pidlock);
5641 			mutex_exit(&stp->sd_lock);
5642 			return (EINVAL);
5643 		}
5644 		if ((q = pgfind(pgrp)) == NULL ||
5645 		    q->p_sessp != ttoproc(curthread)->p_sessp) {
5646 			mutex_exit(&pidlock);
5647 			mutex_exit(&stp->sd_lock);
5648 			return (EPERM);
5649 		}
5650 		sid = stp->sd_sidp->pid_id;
5651 		fg_pgid = q->p_pgrp;
5652 		bg_pgid = stp->sd_pgidp->pid_id;
5653 		CL_SET_PROCESS_GROUP(curthread, sid, bg_pgid, fg_pgid);
5654 		PID_RELE(stp->sd_pgidp);
5655 		ctty_clear_sighuped();
5656 		stp->sd_pgidp = q->p_pgidp;
5657 		PID_HOLD(stp->sd_pgidp);
5658 		mutex_exit(&pidlock);
5659 		mutex_exit(&stp->sd_lock);
5660 		return (0);
5661 	}
5662 
5663 	case TIOCGPGRP:
5664 	{
5665 		pid_t pgrp;
5666 
5667 		mutex_enter(&stp->sd_lock);
5668 		if (stp->sd_sidp == NULL) {
5669 			mutex_exit(&stp->sd_lock);
5670 			return (ENOTTY);
5671 		}
5672 		pgrp = stp->sd_pgidp->pid_id;
5673 		mutex_exit(&stp->sd_lock);
5674 		return (strcopyout(&pgrp, (void *)arg, sizeof (pid_t),
5675 		    copyflag));
5676 	}
5677 
5678 	case TIOCSCTTY:
5679 	{
5680 		return (strctty(stp));
5681 	}
5682 
5683 	case TIOCNOTTY:
5684 	{
5685 		/* freectty() always assumes curproc. */
5686 		if (freectty(B_FALSE) != 0)
5687 			return (0);
5688 		return (ENOTTY);
5689 	}
5690 
5691 	case FIONBIO:
5692 	case FIOASYNC:
5693 		return (0);	/* handled by the upper layer */
5694 	}
5695 }
5696 
5697 /*
5698  * Custom free routine used for M_PASSFP messages.
5699  */
5700 static void
5701 free_passfp(struct k_strrecvfd *srf)
5702 {
5703 	(void) closef(srf->fp);
5704 	kmem_free(srf, sizeof (struct k_strrecvfd) + sizeof (frtn_t));
5705 }
5706 
5707 /* ARGSUSED */
5708 int
5709 do_sendfp(struct stdata *stp, struct file *fp, struct cred *cr)
5710 {
5711 	queue_t *qp, *nextqp;
5712 	struct k_strrecvfd *srf;
5713 	mblk_t *mp;
5714 	frtn_t *frtnp;
5715 	size_t bufsize;
5716 	queue_t	*mate = NULL;
5717 	syncq_t	*sq = NULL;
5718 	int retval = 0;
5719 
5720 	if (stp->sd_flag & STRHUP)
5721 		return (ENXIO);
5722 
5723 	claimstr(stp->sd_wrq);
5724 
5725 	/* Fastpath, we have a pipe, and we are already mated, use it. */
5726 	if (STRMATED(stp)) {
5727 		qp = _RD(stp->sd_mate->sd_wrq);
5728 		claimstr(qp);
5729 		mate = qp;
5730 	} else { /* Not already mated. */
5731 
5732 		/*
5733 		 * Walk the stream to the end of this one.
5734 		 * assumes that the claimstr() will prevent
5735 		 * plumbing between the stream head and the
5736 		 * driver from changing
5737 		 */
5738 		qp = stp->sd_wrq;
5739 
5740 		/*
5741 		 * Loop until we reach the end of this stream.
5742 		 * On completion, qp points to the write queue
5743 		 * at the end of the stream, or the read queue
5744 		 * at the stream head if this is a fifo.
5745 		 */
5746 		while (((qp = qp->q_next) != NULL) && _SAMESTR(qp))
5747 			;
5748 
5749 		/*
5750 		 * Just in case we get a q_next which is NULL, but
5751 		 * not at the end of the stream.  This is actually
5752 		 * broken, so we set an assert to catch it in
5753 		 * debug, and set an error and return if not debug.
5754 		 */
5755 		ASSERT(qp);
5756 		if (qp == NULL) {
5757 			releasestr(stp->sd_wrq);
5758 			return (EINVAL);
5759 		}
5760 
5761 		/*
5762 		 * Enter the syncq for the driver, so (hopefully)
5763 		 * the queue values will not change on us.
5764 		 * XXXX - This will only prevent the race IFF only
5765 		 *   the write side modifies the q_next member, and
5766 		 *   the put procedure is protected by at least
5767 		 *   MT_PERQ.
5768 		 */
5769 		if ((sq = qp->q_syncq) != NULL)
5770 			entersq(sq, SQ_PUT);
5771 
5772 		/* Now get the q_next value from this qp. */
5773 		nextqp = qp->q_next;
5774 
5775 		/*
5776 		 * If nextqp exists and the other stream is different
5777 		 * from this one claim the stream, set the mate, and
5778 		 * get the read queue at the stream head of the other
5779 		 * stream.  Assumes that nextqp was at least valid when
5780 		 * we got it.  Hopefully the entersq of the driver
5781 		 * will prevent it from changing on us.
5782 		 */
5783 		if ((nextqp != NULL) && (STREAM(nextqp) != stp)) {
5784 			ASSERT(qp->q_qinfo->qi_srvp);
5785 			ASSERT(_OTHERQ(qp)->q_qinfo->qi_srvp);
5786 			ASSERT(_OTHERQ(qp->q_next)->q_qinfo->qi_srvp);
5787 			claimstr(nextqp);
5788 
5789 			/* Make sure we still have a q_next */
5790 			if (nextqp != qp->q_next) {
5791 				releasestr(stp->sd_wrq);
5792 				releasestr(nextqp);
5793 				return (EINVAL);
5794 			}
5795 
5796 			qp = _RD(STREAM(nextqp)->sd_wrq);
5797 			mate = qp;
5798 		}
5799 		/* If we entered the synq above, leave it. */
5800 		if (sq != NULL)
5801 			leavesq(sq, SQ_PUT);
5802 	} /*  STRMATED(STP)  */
5803 
5804 	/* XXX prevents substitution of the ops vector */
5805 	if (qp->q_qinfo != &strdata && qp->q_qinfo != &fifo_strdata) {
5806 		retval = EINVAL;
5807 		goto out;
5808 	}
5809 
5810 	if (qp->q_flag & QFULL) {
5811 		retval = EAGAIN;
5812 		goto out;
5813 	}
5814 
5815 	/*
5816 	 * Since M_PASSFP messages include a file descriptor, we use
5817 	 * esballoc() and specify a custom free routine (free_passfp()) that
5818 	 * will close the descriptor as part of freeing the message.  For
5819 	 * convenience, we stash the frtn_t right after the data block.
5820 	 */
5821 	bufsize = sizeof (struct k_strrecvfd) + sizeof (frtn_t);
5822 	srf = kmem_alloc(bufsize, KM_NOSLEEP);
5823 	if (srf == NULL) {
5824 		retval = EAGAIN;
5825 		goto out;
5826 	}
5827 
5828 	frtnp = (frtn_t *)(srf + 1);
5829 	frtnp->free_arg = (caddr_t)srf;
5830 	frtnp->free_func = free_passfp;
5831 
5832 	mp = esballoc((uchar_t *)srf, bufsize, BPRI_MED, frtnp);
5833 	if (mp == NULL) {
5834 		kmem_free(srf, bufsize);
5835 		retval = EAGAIN;
5836 		goto out;
5837 	}
5838 	mp->b_wptr += sizeof (struct k_strrecvfd);
5839 	mp->b_datap->db_type = M_PASSFP;
5840 
5841 	srf->fp = fp;
5842 	srf->uid = crgetuid(curthread->t_cred);
5843 	srf->gid = crgetgid(curthread->t_cred);
5844 	mutex_enter(&fp->f_tlock);
5845 	fp->f_count++;
5846 	mutex_exit(&fp->f_tlock);
5847 
5848 	put(qp, mp);
5849 out:
5850 	releasestr(stp->sd_wrq);
5851 	if (mate)
5852 		releasestr(mate);
5853 	return (retval);
5854 }
5855 
5856 /*
5857  * Send an ioctl message downstream and wait for acknowledgement.
5858  * flags may be set to either U_TO_K or K_TO_K and a combination
5859  * of STR_NOERROR or STR_NOSIG
5860  * STR_NOSIG: Signals are essentially ignored or held and have
5861  *	no effect for the duration of the call.
5862  * STR_NOERROR: Ignores stream head read, write and hup errors.
5863  *	Additionally, if an existing ioctl times out, it is assumed
5864  *	lost and and this ioctl will continue as if the previous ioctl had
5865  *	finished.  ETIME may be returned if this ioctl times out (i.e.
5866  *	ic_timout is not INFTIM).  Non-stream head errors may be returned if
5867  *	the ioc_error indicates that the driver/module had problems,
5868  *	an EFAULT was found when accessing user data, a lack of
5869  * 	resources, etc.
5870  */
5871 int
5872 strdoioctl(
5873 	struct stdata *stp,
5874 	struct strioctl *strioc,
5875 	int fflags,		/* file flags with model info */
5876 	int flag,
5877 	cred_t *crp,
5878 	int *rvalp)
5879 {
5880 	mblk_t *bp;
5881 	struct iocblk *iocbp;
5882 	struct copyreq *reqp;
5883 	struct copyresp *resp;
5884 	int id;
5885 	int transparent = 0;
5886 	int error = 0;
5887 	int len = 0;
5888 	caddr_t taddr;
5889 	int copyflag = (flag & (U_TO_K | K_TO_K));
5890 	int sigflag = (flag & STR_NOSIG);
5891 	int errs;
5892 	uint_t waitflags;
5893 
5894 	ASSERT(copyflag == U_TO_K || copyflag == K_TO_K);
5895 	ASSERT((fflags & FMODELS) != 0);
5896 
5897 	TRACE_2(TR_FAC_STREAMS_FR,
5898 	    TR_STRDOIOCTL,
5899 	    "strdoioctl:stp %p strioc %p", stp, strioc);
5900 	if (strioc->ic_len == TRANSPARENT) {	/* send arg in M_DATA block */
5901 		transparent = 1;
5902 		strioc->ic_len = sizeof (intptr_t);
5903 	}
5904 
5905 	if (strioc->ic_len < 0 || (strmsgsz > 0 && strioc->ic_len > strmsgsz))
5906 		return (EINVAL);
5907 
5908 	if ((bp = allocb_cred_wait(sizeof (union ioctypes), sigflag, &error,
5909 	    crp, curproc->p_pid)) == NULL)
5910 			return (error);
5911 
5912 	bzero(bp->b_wptr, sizeof (union ioctypes));
5913 
5914 	iocbp = (struct iocblk *)bp->b_wptr;
5915 	iocbp->ioc_count = strioc->ic_len;
5916 	iocbp->ioc_cmd = strioc->ic_cmd;
5917 	iocbp->ioc_flag = (fflags & FMODELS);
5918 
5919 	crhold(crp);
5920 	iocbp->ioc_cr = crp;
5921 	DB_TYPE(bp) = M_IOCTL;
5922 	bp->b_wptr += sizeof (struct iocblk);
5923 
5924 	if (flag & STR_NOERROR)
5925 		errs = STPLEX;
5926 	else
5927 		errs = STRHUP|STRDERR|STWRERR|STPLEX;
5928 
5929 	/*
5930 	 * If there is data to copy into ioctl block, do so.
5931 	 */
5932 	if (iocbp->ioc_count > 0) {
5933 		if (transparent)
5934 			/*
5935 			 * Note: STR_NOERROR does not have an effect
5936 			 * in putiocd()
5937 			 */
5938 			id = K_TO_K | sigflag;
5939 		else
5940 			id = flag;
5941 		if ((error = putiocd(bp, strioc->ic_dp, id, crp)) != 0) {
5942 			freemsg(bp);
5943 			crfree(crp);
5944 			return (error);
5945 		}
5946 
5947 		/*
5948 		 * We could have slept copying in user pages.
5949 		 * Recheck the stream head state (the other end
5950 		 * of a pipe could have gone away).
5951 		 */
5952 		if (stp->sd_flag & errs) {
5953 			mutex_enter(&stp->sd_lock);
5954 			error = strgeterr(stp, errs, 0);
5955 			mutex_exit(&stp->sd_lock);
5956 			if (error != 0) {
5957 				freemsg(bp);
5958 				crfree(crp);
5959 				return (error);
5960 			}
5961 		}
5962 	}
5963 	if (transparent)
5964 		iocbp->ioc_count = TRANSPARENT;
5965 
5966 	/*
5967 	 * Block for up to STRTIMOUT milliseconds if there is an outstanding
5968 	 * ioctl for this stream already running.  All processes
5969 	 * sleeping here will be awakened as a result of an ACK
5970 	 * or NAK being received for the outstanding ioctl, or
5971 	 * as a result of the timer expiring on the outstanding
5972 	 * ioctl (a failure), or as a result of any waiting
5973 	 * process's timer expiring (also a failure).
5974 	 */
5975 
5976 	error = 0;
5977 	mutex_enter(&stp->sd_lock);
5978 	while (stp->sd_flag & (IOCWAIT | IOCWAITNE)) {
5979 		clock_t cv_rval;
5980 
5981 		TRACE_0(TR_FAC_STREAMS_FR,
5982 		    TR_STRDOIOCTL_WAIT,
5983 		    "strdoioctl sleeps - IOCWAIT");
5984 		cv_rval = str_cv_wait(&stp->sd_iocmonitor, &stp->sd_lock,
5985 		    STRTIMOUT, sigflag);
5986 		if (cv_rval <= 0) {
5987 			if (cv_rval == 0) {
5988 				error = EINTR;
5989 			} else {
5990 				if (flag & STR_NOERROR) {
5991 					/*
5992 					 * Terminating current ioctl in
5993 					 * progress -- assume it got lost and
5994 					 * wake up the other thread so that the
5995 					 * operation completes.
5996 					 */
5997 					if (!(stp->sd_flag & IOCWAITNE)) {
5998 						stp->sd_flag |= IOCWAITNE;
5999 						cv_broadcast(&stp->sd_monitor);
6000 					}
6001 					/*
6002 					 * Otherwise, there's a running
6003 					 * STR_NOERROR -- we have no choice
6004 					 * here but to wait forever (or until
6005 					 * interrupted).
6006 					 */
6007 				} else {
6008 					/*
6009 					 * pending ioctl has caused
6010 					 * us to time out
6011 					 */
6012 					error = ETIME;
6013 				}
6014 			}
6015 		} else if ((stp->sd_flag & errs)) {
6016 			error = strgeterr(stp, errs, 0);
6017 		}
6018 		if (error) {
6019 			mutex_exit(&stp->sd_lock);
6020 			freemsg(bp);
6021 			crfree(crp);
6022 			return (error);
6023 		}
6024 	}
6025 
6026 	/*
6027 	 * Have control of ioctl mechanism.
6028 	 * Send down ioctl packet and wait for response.
6029 	 */
6030 	if (stp->sd_iocblk != (mblk_t *)-1) {
6031 		freemsg(stp->sd_iocblk);
6032 	}
6033 	stp->sd_iocblk = NULL;
6034 
6035 	/*
6036 	 * If this is marked with 'noerror' (internal; mostly
6037 	 * I_{P,}{UN,}LINK), then make sure nobody else is able to get
6038 	 * in here by setting IOCWAITNE.
6039 	 */
6040 	waitflags = IOCWAIT;
6041 	if (flag & STR_NOERROR)
6042 		waitflags |= IOCWAITNE;
6043 
6044 	stp->sd_flag |= waitflags;
6045 
6046 	/*
6047 	 * Assign sequence number.
6048 	 */
6049 	iocbp->ioc_id = stp->sd_iocid = getiocseqno();
6050 
6051 	mutex_exit(&stp->sd_lock);
6052 
6053 	TRACE_1(TR_FAC_STREAMS_FR,
6054 	    TR_STRDOIOCTL_PUT, "strdoioctl put: stp %p", stp);
6055 	stream_willservice(stp);
6056 	putnext(stp->sd_wrq, bp);
6057 	stream_runservice(stp);
6058 
6059 	/*
6060 	 * Timed wait for acknowledgment.  The wait time is limited by the
6061 	 * timeout value, which must be a positive integer (number of
6062 	 * milliseconds) to wait, or 0 (use default value of STRTIMOUT
6063 	 * milliseconds), or -1 (wait forever).  This will be awakened
6064 	 * either by an ACK/NAK message arriving, the timer expiring, or
6065 	 * the timer expiring on another ioctl waiting for control of the
6066 	 * mechanism.
6067 	 */
6068 waitioc:
6069 	mutex_enter(&stp->sd_lock);
6070 
6071 
6072 	/*
6073 	 * If the reply has already arrived, don't sleep.  If awakened from
6074 	 * the sleep, fail only if the reply has not arrived by then.
6075 	 * Otherwise, process the reply.
6076 	 */
6077 	while (!stp->sd_iocblk) {
6078 		clock_t cv_rval;
6079 
6080 		if (stp->sd_flag & errs) {
6081 			error = strgeterr(stp, errs, 0);
6082 			if (error != 0) {
6083 				stp->sd_flag &= ~waitflags;
6084 				cv_broadcast(&stp->sd_iocmonitor);
6085 				mutex_exit(&stp->sd_lock);
6086 				crfree(crp);
6087 				return (error);
6088 			}
6089 		}
6090 
6091 		TRACE_0(TR_FAC_STREAMS_FR,
6092 		    TR_STRDOIOCTL_WAIT2,
6093 		    "strdoioctl sleeps awaiting reply");
6094 		ASSERT(error == 0);
6095 
6096 		cv_rval = str_cv_wait(&stp->sd_monitor, &stp->sd_lock,
6097 		    (strioc->ic_timout ?
6098 		    strioc->ic_timout * 1000 : STRTIMOUT), sigflag);
6099 
6100 		/*
6101 		 * There are four possible cases here: interrupt, timeout,
6102 		 * wakeup by IOCWAITNE (above), or wakeup by strrput_nondata (a
6103 		 * valid M_IOCTL reply).
6104 		 *
6105 		 * If we've been awakened by a STR_NOERROR ioctl on some other
6106 		 * thread, then sd_iocblk will still be NULL, and IOCWAITNE
6107 		 * will be set.  Pretend as if we just timed out.  Note that
6108 		 * this other thread waited at least STRTIMOUT before trying to
6109 		 * awaken our thread, so this is indistinguishable (even for
6110 		 * INFTIM) from the case where we failed with ETIME waiting on
6111 		 * IOCWAIT in the prior loop.
6112 		 */
6113 		if (cv_rval > 0 && !(flag & STR_NOERROR) &&
6114 		    stp->sd_iocblk == NULL && (stp->sd_flag & IOCWAITNE)) {
6115 			cv_rval = -1;
6116 		}
6117 
6118 		/*
6119 		 * note: STR_NOERROR does not protect
6120 		 * us here.. use ic_timout < 0
6121 		 */
6122 		if (cv_rval <= 0) {
6123 			if (cv_rval == 0) {
6124 				error = EINTR;
6125 			} else {
6126 				error =  ETIME;
6127 			}
6128 			/*
6129 			 * A message could have come in after we were scheduled
6130 			 * but before we were actually run.
6131 			 */
6132 			bp = stp->sd_iocblk;
6133 			stp->sd_iocblk = NULL;
6134 			if (bp != NULL) {
6135 				if ((bp->b_datap->db_type == M_COPYIN) ||
6136 				    (bp->b_datap->db_type == M_COPYOUT)) {
6137 					mutex_exit(&stp->sd_lock);
6138 					if (bp->b_cont) {
6139 						freemsg(bp->b_cont);
6140 						bp->b_cont = NULL;
6141 					}
6142 					bp->b_datap->db_type = M_IOCDATA;
6143 					bp->b_wptr = bp->b_rptr +
6144 					    sizeof (struct copyresp);
6145 					resp = (struct copyresp *)bp->b_rptr;
6146 					resp->cp_rval =
6147 					    (caddr_t)1; /* failure */
6148 					stream_willservice(stp);
6149 					putnext(stp->sd_wrq, bp);
6150 					stream_runservice(stp);
6151 					mutex_enter(&stp->sd_lock);
6152 				} else {
6153 					freemsg(bp);
6154 				}
6155 			}
6156 			stp->sd_flag &= ~waitflags;
6157 			cv_broadcast(&stp->sd_iocmonitor);
6158 			mutex_exit(&stp->sd_lock);
6159 			crfree(crp);
6160 			return (error);
6161 		}
6162 	}
6163 	bp = stp->sd_iocblk;
6164 	/*
6165 	 * Note: it is strictly impossible to get here with sd_iocblk set to
6166 	 * -1.  This is because the initial loop above doesn't allow any new
6167 	 * ioctls into the fray until all others have passed this point.
6168 	 */
6169 	ASSERT(bp != NULL && bp != (mblk_t *)-1);
6170 	TRACE_1(TR_FAC_STREAMS_FR,
6171 	    TR_STRDOIOCTL_ACK, "strdoioctl got reply: bp %p", bp);
6172 	if ((bp->b_datap->db_type == M_IOCACK) ||
6173 	    (bp->b_datap->db_type == M_IOCNAK)) {
6174 		/* for detection of duplicate ioctl replies */
6175 		stp->sd_iocblk = (mblk_t *)-1;
6176 		stp->sd_flag &= ~waitflags;
6177 		cv_broadcast(&stp->sd_iocmonitor);
6178 		mutex_exit(&stp->sd_lock);
6179 	} else {
6180 		/*
6181 		 * flags not cleared here because we're still doing
6182 		 * copy in/out for ioctl.
6183 		 */
6184 		stp->sd_iocblk = NULL;
6185 		mutex_exit(&stp->sd_lock);
6186 	}
6187 
6188 
6189 	/*
6190 	 * Have received acknowledgment.
6191 	 */
6192 
6193 	switch (bp->b_datap->db_type) {
6194 	case M_IOCACK:
6195 		/*
6196 		 * Positive ack.
6197 		 */
6198 		iocbp = (struct iocblk *)bp->b_rptr;
6199 
6200 		/*
6201 		 * Set error if indicated.
6202 		 */
6203 		if (iocbp->ioc_error) {
6204 			error = iocbp->ioc_error;
6205 			break;
6206 		}
6207 
6208 		/*
6209 		 * Set return value.
6210 		 */
6211 		*rvalp = iocbp->ioc_rval;
6212 
6213 		/*
6214 		 * Data may have been returned in ACK message (ioc_count > 0).
6215 		 * If so, copy it out to the user's buffer.
6216 		 */
6217 		if (iocbp->ioc_count && !transparent) {
6218 			if (error = getiocd(bp, strioc->ic_dp, copyflag))
6219 				break;
6220 		}
6221 		if (!transparent) {
6222 			if (len)	/* an M_COPYOUT was used with I_STR */
6223 				strioc->ic_len = len;
6224 			else
6225 				strioc->ic_len = (int)iocbp->ioc_count;
6226 		}
6227 		break;
6228 
6229 	case M_IOCNAK:
6230 		/*
6231 		 * Negative ack.
6232 		 *
6233 		 * The only thing to do is set error as specified
6234 		 * in neg ack packet.
6235 		 */
6236 		iocbp = (struct iocblk *)bp->b_rptr;
6237 
6238 		error = (iocbp->ioc_error ? iocbp->ioc_error : EINVAL);
6239 		break;
6240 
6241 	case M_COPYIN:
6242 		/*
6243 		 * Driver or module has requested user ioctl data.
6244 		 */
6245 		reqp = (struct copyreq *)bp->b_rptr;
6246 
6247 		/*
6248 		 * M_COPYIN should *never* have a message attached, though
6249 		 * it's harmless if it does -- thus, panic on a DEBUG
6250 		 * kernel and just free it on a non-DEBUG build.
6251 		 */
6252 		ASSERT(bp->b_cont == NULL);
6253 		if (bp->b_cont != NULL) {
6254 			freemsg(bp->b_cont);
6255 			bp->b_cont = NULL;
6256 		}
6257 
6258 		error = putiocd(bp, reqp->cq_addr, flag, crp);
6259 		if (error && bp->b_cont) {
6260 			freemsg(bp->b_cont);
6261 			bp->b_cont = NULL;
6262 		}
6263 
6264 		bp->b_wptr = bp->b_rptr + sizeof (struct copyresp);
6265 		bp->b_datap->db_type = M_IOCDATA;
6266 
6267 		mblk_setcred(bp, crp, curproc->p_pid);
6268 		resp = (struct copyresp *)bp->b_rptr;
6269 		resp->cp_rval = (caddr_t)(uintptr_t)error;
6270 		resp->cp_flag = (fflags & FMODELS);
6271 
6272 		stream_willservice(stp);
6273 		putnext(stp->sd_wrq, bp);
6274 		stream_runservice(stp);
6275 
6276 		if (error) {
6277 			mutex_enter(&stp->sd_lock);
6278 			stp->sd_flag &= ~waitflags;
6279 			cv_broadcast(&stp->sd_iocmonitor);
6280 			mutex_exit(&stp->sd_lock);
6281 			crfree(crp);
6282 			return (error);
6283 		}
6284 
6285 		goto waitioc;
6286 
6287 	case M_COPYOUT:
6288 		/*
6289 		 * Driver or module has ioctl data for a user.
6290 		 */
6291 		reqp = (struct copyreq *)bp->b_rptr;
6292 		ASSERT(bp->b_cont != NULL);
6293 
6294 		/*
6295 		 * Always (transparent or non-transparent )
6296 		 * use the address specified in the request
6297 		 */
6298 		taddr = reqp->cq_addr;
6299 		if (!transparent)
6300 			len = (int)reqp->cq_size;
6301 
6302 		/* copyout data to the provided address */
6303 		error = getiocd(bp, taddr, copyflag);
6304 
6305 		freemsg(bp->b_cont);
6306 		bp->b_cont = NULL;
6307 
6308 		bp->b_wptr = bp->b_rptr + sizeof (struct copyresp);
6309 		bp->b_datap->db_type = M_IOCDATA;
6310 
6311 		mblk_setcred(bp, crp, curproc->p_pid);
6312 		resp = (struct copyresp *)bp->b_rptr;
6313 		resp->cp_rval = (caddr_t)(uintptr_t)error;
6314 		resp->cp_flag = (fflags & FMODELS);
6315 
6316 		stream_willservice(stp);
6317 		putnext(stp->sd_wrq, bp);
6318 		stream_runservice(stp);
6319 
6320 		if (error) {
6321 			mutex_enter(&stp->sd_lock);
6322 			stp->sd_flag &= ~waitflags;
6323 			cv_broadcast(&stp->sd_iocmonitor);
6324 			mutex_exit(&stp->sd_lock);
6325 			crfree(crp);
6326 			return (error);
6327 		}
6328 		goto waitioc;
6329 
6330 	default:
6331 		ASSERT(0);
6332 		mutex_enter(&stp->sd_lock);
6333 		stp->sd_flag &= ~waitflags;
6334 		cv_broadcast(&stp->sd_iocmonitor);
6335 		mutex_exit(&stp->sd_lock);
6336 		break;
6337 	}
6338 
6339 	freemsg(bp);
6340 	crfree(crp);
6341 	return (error);
6342 }
6343 
6344 /*
6345  * Send an M_CMD message downstream and wait for a reply.  This is a ptools
6346  * special used to retrieve information from modules/drivers a stream without
6347  * being subjected to flow control or interfering with pending messages on the
6348  * stream (e.g. an ioctl in flight).
6349  */
6350 int
6351 strdocmd(struct stdata *stp, struct strcmd *scp, cred_t *crp)
6352 {
6353 	mblk_t *mp;
6354 	struct cmdblk *cmdp;
6355 	int error = 0;
6356 	int errs = STRHUP|STRDERR|STWRERR|STPLEX;
6357 	clock_t rval, timeout = STRTIMOUT;
6358 
6359 	if (scp->sc_len < 0 || scp->sc_len > sizeof (scp->sc_buf) ||
6360 	    scp->sc_timeout < -1)
6361 		return (EINVAL);
6362 
6363 	if (scp->sc_timeout > 0)
6364 		timeout = scp->sc_timeout * MILLISEC;
6365 
6366 	if ((mp = allocb_cred(sizeof (struct cmdblk), crp,
6367 	    curproc->p_pid)) == NULL)
6368 		return (ENOMEM);
6369 
6370 	crhold(crp);
6371 
6372 	cmdp = (struct cmdblk *)mp->b_wptr;
6373 	cmdp->cb_cr = crp;
6374 	cmdp->cb_cmd = scp->sc_cmd;
6375 	cmdp->cb_len = scp->sc_len;
6376 	cmdp->cb_error = 0;
6377 	mp->b_wptr += sizeof (struct cmdblk);
6378 
6379 	DB_TYPE(mp) = M_CMD;
6380 	DB_CPID(mp) = curproc->p_pid;
6381 
6382 	/*
6383 	 * Copy in the payload.
6384 	 */
6385 	if (cmdp->cb_len > 0) {
6386 		mp->b_cont = allocb_cred(sizeof (scp->sc_buf), crp,
6387 		    curproc->p_pid);
6388 		if (mp->b_cont == NULL) {
6389 			error = ENOMEM;
6390 			goto out;
6391 		}
6392 
6393 		/* cb_len comes from sc_len, which has already been checked */
6394 		ASSERT(cmdp->cb_len <= sizeof (scp->sc_buf));
6395 		(void) bcopy(scp->sc_buf, mp->b_cont->b_wptr, cmdp->cb_len);
6396 		mp->b_cont->b_wptr += cmdp->cb_len;
6397 		DB_CPID(mp->b_cont) = curproc->p_pid;
6398 	}
6399 
6400 	/*
6401 	 * Since this mechanism is strictly for ptools, and since only one
6402 	 * process can be grabbed at a time, we simply fail if there's
6403 	 * currently an operation pending.
6404 	 */
6405 	mutex_enter(&stp->sd_lock);
6406 	if (stp->sd_flag & STRCMDWAIT) {
6407 		mutex_exit(&stp->sd_lock);
6408 		error = EBUSY;
6409 		goto out;
6410 	}
6411 	stp->sd_flag |= STRCMDWAIT;
6412 	ASSERT(stp->sd_cmdblk == NULL);
6413 	mutex_exit(&stp->sd_lock);
6414 
6415 	putnext(stp->sd_wrq, mp);
6416 	mp = NULL;
6417 
6418 	/*
6419 	 * Timed wait for acknowledgment.  If the reply has already arrived,
6420 	 * don't sleep.  If awakened from the sleep, fail only if the reply
6421 	 * has not arrived by then.  Otherwise, process the reply.
6422 	 */
6423 	mutex_enter(&stp->sd_lock);
6424 	while (stp->sd_cmdblk == NULL) {
6425 		if (stp->sd_flag & errs) {
6426 			if ((error = strgeterr(stp, errs, 0)) != 0)
6427 				goto waitout;
6428 		}
6429 
6430 		rval = str_cv_wait(&stp->sd_monitor, &stp->sd_lock, timeout, 0);
6431 		if (stp->sd_cmdblk != NULL)
6432 			break;
6433 
6434 		if (rval <= 0) {
6435 			error = (rval == 0) ? EINTR : ETIME;
6436 			goto waitout;
6437 		}
6438 	}
6439 
6440 	/*
6441 	 * We received a reply.
6442 	 */
6443 	mp = stp->sd_cmdblk;
6444 	stp->sd_cmdblk = NULL;
6445 	ASSERT(mp != NULL && DB_TYPE(mp) == M_CMD);
6446 	ASSERT(stp->sd_flag & STRCMDWAIT);
6447 	stp->sd_flag &= ~STRCMDWAIT;
6448 	mutex_exit(&stp->sd_lock);
6449 
6450 	cmdp = (struct cmdblk *)mp->b_rptr;
6451 	if ((error = cmdp->cb_error) != 0)
6452 		goto out;
6453 
6454 	/*
6455 	 * Data may have been returned in the reply (cb_len > 0).
6456 	 * If so, copy it out to the user's buffer.
6457 	 */
6458 	if (cmdp->cb_len > 0) {
6459 		if (mp->b_cont == NULL || MBLKL(mp->b_cont) < cmdp->cb_len) {
6460 			error = EPROTO;
6461 			goto out;
6462 		}
6463 
6464 		cmdp->cb_len = MIN(cmdp->cb_len, sizeof (scp->sc_buf));
6465 		(void) bcopy(mp->b_cont->b_rptr, scp->sc_buf, cmdp->cb_len);
6466 	}
6467 	scp->sc_len = cmdp->cb_len;
6468 out:
6469 	freemsg(mp);
6470 	crfree(crp);
6471 	return (error);
6472 waitout:
6473 	ASSERT(stp->sd_cmdblk == NULL);
6474 	stp->sd_flag &= ~STRCMDWAIT;
6475 	mutex_exit(&stp->sd_lock);
6476 	crfree(crp);
6477 	return (error);
6478 }
6479 
6480 /*
6481  * For the SunOS keyboard driver.
6482  * Return the next available "ioctl" sequence number.
6483  * Exported, so that streams modules can send "ioctl" messages
6484  * downstream from their open routine.
6485  */
6486 int
6487 getiocseqno(void)
6488 {
6489 	int	i;
6490 
6491 	mutex_enter(&strresources);
6492 	i = ++ioc_id;
6493 	mutex_exit(&strresources);
6494 	return (i);
6495 }
6496 
6497 /*
6498  * Get the next message from the read queue.  If the message is
6499  * priority, STRPRI will have been set by strrput().  This flag
6500  * should be reset only when the entire message at the front of the
6501  * queue as been consumed.
6502  *
6503  * NOTE: strgetmsg and kstrgetmsg have much of the logic in common.
6504  */
6505 int
6506 strgetmsg(
6507 	struct vnode *vp,
6508 	struct strbuf *mctl,
6509 	struct strbuf *mdata,
6510 	unsigned char *prip,
6511 	int *flagsp,
6512 	int fmode,
6513 	rval_t *rvp)
6514 {
6515 	struct stdata *stp;
6516 	mblk_t *bp, *nbp;
6517 	mblk_t *savemp = NULL;
6518 	mblk_t *savemptail = NULL;
6519 	uint_t old_sd_flag;
6520 	int flg;
6521 	int more = 0;
6522 	int error = 0;
6523 	char first = 1;
6524 	uint_t mark;		/* Contains MSG*MARK and _LASTMARK */
6525 #define	_LASTMARK	0x8000	/* Distinct from MSG*MARK */
6526 	unsigned char pri = 0;
6527 	queue_t *q;
6528 	int	pr = 0;			/* Partial read successful */
6529 	struct uio uios;
6530 	struct uio *uiop = &uios;
6531 	struct iovec iovs;
6532 	unsigned char type;
6533 
6534 	TRACE_1(TR_FAC_STREAMS_FR, TR_STRGETMSG_ENTER,
6535 	    "strgetmsg:%p", vp);
6536 
6537 	ASSERT(vp->v_stream);
6538 	stp = vp->v_stream;
6539 	rvp->r_val1 = 0;
6540 
6541 	mutex_enter(&stp->sd_lock);
6542 
6543 	if ((error = i_straccess(stp, JCREAD)) != 0) {
6544 		mutex_exit(&stp->sd_lock);
6545 		return (error);
6546 	}
6547 
6548 	if (stp->sd_flag & (STRDERR|STPLEX)) {
6549 		error = strgeterr(stp, STRDERR|STPLEX, 0);
6550 		if (error != 0) {
6551 			mutex_exit(&stp->sd_lock);
6552 			return (error);
6553 		}
6554 	}
6555 	mutex_exit(&stp->sd_lock);
6556 
6557 	switch (*flagsp) {
6558 	case MSG_HIPRI:
6559 		if (*prip != 0)
6560 			return (EINVAL);
6561 		break;
6562 
6563 	case MSG_ANY:
6564 	case MSG_BAND:
6565 		break;
6566 
6567 	default:
6568 		return (EINVAL);
6569 	}
6570 	/*
6571 	 * Setup uio and iov for data part
6572 	 */
6573 	iovs.iov_base = mdata->buf;
6574 	iovs.iov_len = mdata->maxlen;
6575 	uios.uio_iov = &iovs;
6576 	uios.uio_iovcnt = 1;
6577 	uios.uio_loffset = 0;
6578 	uios.uio_segflg = UIO_USERSPACE;
6579 	uios.uio_fmode = 0;
6580 	uios.uio_extflg = UIO_COPY_CACHED;
6581 	uios.uio_resid = mdata->maxlen;
6582 	uios.uio_offset = 0;
6583 
6584 	q = _RD(stp->sd_wrq);
6585 	mutex_enter(&stp->sd_lock);
6586 	old_sd_flag = stp->sd_flag;
6587 	mark = 0;
6588 	for (;;) {
6589 		int done = 0;
6590 		mblk_t *q_first = q->q_first;
6591 
6592 		/*
6593 		 * Get the next message of appropriate priority
6594 		 * from the stream head.  If the caller is interested
6595 		 * in band or hipri messages, then they should already
6596 		 * be enqueued at the stream head.  On the other hand
6597 		 * if the caller wants normal (band 0) messages, they
6598 		 * might be deferred in a synchronous stream and they
6599 		 * will need to be pulled up.
6600 		 *
6601 		 * After we have dequeued a message, we might find that
6602 		 * it was a deferred M_SIG that was enqueued at the
6603 		 * stream head.  It must now be posted as part of the
6604 		 * read by calling strsignal_nolock().
6605 		 *
6606 		 * Also note that strrput does not enqueue an M_PCSIG,
6607 		 * and there cannot be more than one hipri message,
6608 		 * so there was no need to have the M_PCSIG case.
6609 		 *
6610 		 * At some time it might be nice to try and wrap the
6611 		 * functionality of kstrgetmsg() and strgetmsg() into
6612 		 * a common routine so to reduce the amount of replicated
6613 		 * code (since they are extremely similar).
6614 		 */
6615 		if (!(*flagsp & (MSG_HIPRI|MSG_BAND))) {
6616 			/* Asking for normal, band0 data */
6617 			bp = strget(stp, q, uiop, first, &error);
6618 			ASSERT(MUTEX_HELD(&stp->sd_lock));
6619 			if (bp != NULL) {
6620 				if (DB_TYPE(bp) == M_SIG) {
6621 					strsignal_nolock(stp, *bp->b_rptr,
6622 					    bp->b_band);
6623 					freemsg(bp);
6624 					continue;
6625 				} else {
6626 					break;
6627 				}
6628 			}
6629 			if (error != 0)
6630 				goto getmout;
6631 
6632 		/*
6633 		 * We can't depend on the value of STRPRI here because
6634 		 * the stream head may be in transit. Therefore, we
6635 		 * must look at the type of the first message to
6636 		 * determine if a high priority messages is waiting
6637 		 */
6638 		} else if ((*flagsp & MSG_HIPRI) && q_first != NULL &&
6639 		    DB_TYPE(q_first) >= QPCTL &&
6640 		    (bp = getq_noenab(q, 0)) != NULL) {
6641 			/* Asked for HIPRI and got one */
6642 			ASSERT(DB_TYPE(bp) >= QPCTL);
6643 			break;
6644 		} else if ((*flagsp & MSG_BAND) && q_first != NULL &&
6645 		    ((q_first->b_band >= *prip) || DB_TYPE(q_first) >= QPCTL) &&
6646 		    (bp = getq_noenab(q, 0)) != NULL) {
6647 			/*
6648 			 * Asked for at least band "prip" and got either at
6649 			 * least that band or a hipri message.
6650 			 */
6651 			ASSERT(bp->b_band >= *prip || DB_TYPE(bp) >= QPCTL);
6652 			if (DB_TYPE(bp) == M_SIG) {
6653 				strsignal_nolock(stp, *bp->b_rptr, bp->b_band);
6654 				freemsg(bp);
6655 				continue;
6656 			} else {
6657 				break;
6658 			}
6659 		}
6660 
6661 		/* No data. Time to sleep? */
6662 		qbackenable(q, 0);
6663 
6664 		/*
6665 		 * If STRHUP or STREOF, return 0 length control and data.
6666 		 * If resid is 0, then a read(fd,buf,0) was done. Do not
6667 		 * sleep to satisfy this request because by default we have
6668 		 * zero bytes to return.
6669 		 */
6670 		if ((stp->sd_flag & (STRHUP|STREOF)) || (mctl->maxlen == 0 &&
6671 		    mdata->maxlen == 0)) {
6672 			mctl->len = mdata->len = 0;
6673 			*flagsp = 0;
6674 			mutex_exit(&stp->sd_lock);
6675 			return (0);
6676 		}
6677 		TRACE_2(TR_FAC_STREAMS_FR, TR_STRGETMSG_WAIT,
6678 		    "strgetmsg calls strwaitq:%p, %p",
6679 		    vp, uiop);
6680 		if (((error = strwaitq(stp, GETWAIT, (ssize_t)0, fmode, -1,
6681 		    &done)) != 0) || done) {
6682 			TRACE_2(TR_FAC_STREAMS_FR, TR_STRGETMSG_DONE,
6683 			    "strgetmsg error or done:%p, %p",
6684 			    vp, uiop);
6685 			mutex_exit(&stp->sd_lock);
6686 			return (error);
6687 		}
6688 		TRACE_2(TR_FAC_STREAMS_FR, TR_STRGETMSG_AWAKE,
6689 		    "strgetmsg awakes:%p, %p", vp, uiop);
6690 		if ((error = i_straccess(stp, JCREAD)) != 0) {
6691 			mutex_exit(&stp->sd_lock);
6692 			return (error);
6693 		}
6694 		first = 0;
6695 	}
6696 	ASSERT(bp != NULL);
6697 	/*
6698 	 * Extract any mark information. If the message is not completely
6699 	 * consumed this information will be put in the mblk
6700 	 * that is putback.
6701 	 * If MSGMARKNEXT is set and the message is completely consumed
6702 	 * the STRATMARK flag will be set below. Likewise, if
6703 	 * MSGNOTMARKNEXT is set and the message is
6704 	 * completely consumed STRNOTATMARK will be set.
6705 	 */
6706 	mark = bp->b_flag & (MSGMARK | MSGMARKNEXT | MSGNOTMARKNEXT);
6707 	ASSERT((mark & (MSGMARKNEXT|MSGNOTMARKNEXT)) !=
6708 	    (MSGMARKNEXT|MSGNOTMARKNEXT));
6709 	if (mark != 0 && bp == stp->sd_mark) {
6710 		mark |= _LASTMARK;
6711 		stp->sd_mark = NULL;
6712 	}
6713 	/*
6714 	 * keep track of the original message type and priority
6715 	 */
6716 	pri = bp->b_band;
6717 	type = bp->b_datap->db_type;
6718 	if (type == M_PASSFP) {
6719 		if ((mark & _LASTMARK) && (stp->sd_mark == NULL))
6720 			stp->sd_mark = bp;
6721 		bp->b_flag |= mark & ~_LASTMARK;
6722 		putback(stp, q, bp, pri);
6723 		qbackenable(q, pri);
6724 		mutex_exit(&stp->sd_lock);
6725 		return (EBADMSG);
6726 	}
6727 	ASSERT(type != M_SIG);
6728 
6729 	/*
6730 	 * Set this flag so strrput will not generate signals. Need to
6731 	 * make sure this flag is cleared before leaving this routine
6732 	 * else signals will stop being sent.
6733 	 */
6734 	stp->sd_flag |= STRGETINPROG;
6735 	mutex_exit(&stp->sd_lock);
6736 
6737 	if (STREAM_NEEDSERVICE(stp))
6738 		stream_runservice(stp);
6739 
6740 	/*
6741 	 * Set HIPRI flag if message is priority.
6742 	 */
6743 	if (type >= QPCTL)
6744 		flg = MSG_HIPRI;
6745 	else
6746 		flg = MSG_BAND;
6747 
6748 	/*
6749 	 * First process PROTO or PCPROTO blocks, if any.
6750 	 */
6751 	if (mctl->maxlen >= 0 && type != M_DATA) {
6752 		size_t	n, bcnt;
6753 		char	*ubuf;
6754 
6755 		bcnt = mctl->maxlen;
6756 		ubuf = mctl->buf;
6757 		while (bp != NULL && bp->b_datap->db_type != M_DATA) {
6758 			if ((n = MIN(bcnt, bp->b_wptr - bp->b_rptr)) != 0 &&
6759 			    copyout(bp->b_rptr, ubuf, n)) {
6760 				error = EFAULT;
6761 				mutex_enter(&stp->sd_lock);
6762 				/*
6763 				 * clear stream head pri flag based on
6764 				 * first message type
6765 				 */
6766 				if (type >= QPCTL) {
6767 					ASSERT(type == M_PCPROTO);
6768 					stp->sd_flag &= ~STRPRI;
6769 				}
6770 				more = 0;
6771 				freemsg(bp);
6772 				goto getmout;
6773 			}
6774 			ubuf += n;
6775 			bp->b_rptr += n;
6776 			if (bp->b_rptr >= bp->b_wptr) {
6777 				nbp = bp;
6778 				bp = bp->b_cont;
6779 				freeb(nbp);
6780 			}
6781 			ASSERT(n <= bcnt);
6782 			bcnt -= n;
6783 			if (bcnt == 0)
6784 				break;
6785 		}
6786 		mctl->len = mctl->maxlen - bcnt;
6787 	} else
6788 		mctl->len = -1;
6789 
6790 	if (bp && bp->b_datap->db_type != M_DATA) {
6791 		/*
6792 		 * More PROTO blocks in msg.
6793 		 */
6794 		more |= MORECTL;
6795 		savemp = bp;
6796 		while (bp && bp->b_datap->db_type != M_DATA) {
6797 			savemptail = bp;
6798 			bp = bp->b_cont;
6799 		}
6800 		savemptail->b_cont = NULL;
6801 	}
6802 
6803 	/*
6804 	 * Now process DATA blocks, if any.
6805 	 */
6806 	if (mdata->maxlen >= 0 && bp) {
6807 		/*
6808 		 * struiocopyout will consume a potential zero-length
6809 		 * M_DATA even if uio_resid is zero.
6810 		 */
6811 		size_t oldresid = uiop->uio_resid;
6812 
6813 		bp = struiocopyout(bp, uiop, &error);
6814 		if (error != 0) {
6815 			mutex_enter(&stp->sd_lock);
6816 			/*
6817 			 * clear stream head hi pri flag based on
6818 			 * first message
6819 			 */
6820 			if (type >= QPCTL) {
6821 				ASSERT(type == M_PCPROTO);
6822 				stp->sd_flag &= ~STRPRI;
6823 			}
6824 			more = 0;
6825 			freemsg(savemp);
6826 			goto getmout;
6827 		}
6828 		/*
6829 		 * (pr == 1) indicates a partial read.
6830 		 */
6831 		if (oldresid > uiop->uio_resid)
6832 			pr = 1;
6833 		mdata->len = mdata->maxlen - uiop->uio_resid;
6834 	} else
6835 		mdata->len = -1;
6836 
6837 	if (bp) {			/* more data blocks in msg */
6838 		more |= MOREDATA;
6839 		if (savemp)
6840 			savemptail->b_cont = bp;
6841 		else
6842 			savemp = bp;
6843 	}
6844 
6845 	mutex_enter(&stp->sd_lock);
6846 	if (savemp) {
6847 		if (pr && (savemp->b_datap->db_type == M_DATA) &&
6848 		    msgnodata(savemp)) {
6849 			/*
6850 			 * Avoid queuing a zero-length tail part of
6851 			 * a message. pr=1 indicates that we read some of
6852 			 * the message.
6853 			 */
6854 			freemsg(savemp);
6855 			more &= ~MOREDATA;
6856 			/*
6857 			 * clear stream head hi pri flag based on
6858 			 * first message
6859 			 */
6860 			if (type >= QPCTL) {
6861 				ASSERT(type == M_PCPROTO);
6862 				stp->sd_flag &= ~STRPRI;
6863 			}
6864 		} else {
6865 			savemp->b_band = pri;
6866 			/*
6867 			 * If the first message was HIPRI and the one we're
6868 			 * putting back isn't, then clear STRPRI, otherwise
6869 			 * set STRPRI again.  Note that we must set STRPRI
6870 			 * again since the flush logic in strrput_nondata()
6871 			 * may have cleared it while we had sd_lock dropped.
6872 			 */
6873 			if (type >= QPCTL) {
6874 				ASSERT(type == M_PCPROTO);
6875 				if (queclass(savemp) < QPCTL)
6876 					stp->sd_flag &= ~STRPRI;
6877 				else
6878 					stp->sd_flag |= STRPRI;
6879 			} else if (queclass(savemp) >= QPCTL) {
6880 				/*
6881 				 * The first message was not a HIPRI message,
6882 				 * but the one we are about to putback is.
6883 				 * For simplicitly, we do not allow for HIPRI
6884 				 * messages to be embedded in the message
6885 				 * body, so just force it to same type as
6886 				 * first message.
6887 				 */
6888 				ASSERT(type == M_DATA || type == M_PROTO);
6889 				ASSERT(savemp->b_datap->db_type == M_PCPROTO);
6890 				savemp->b_datap->db_type = type;
6891 			}
6892 			if (mark != 0) {
6893 				savemp->b_flag |= mark & ~_LASTMARK;
6894 				if ((mark & _LASTMARK) &&
6895 				    (stp->sd_mark == NULL)) {
6896 					/*
6897 					 * If another marked message arrived
6898 					 * while sd_lock was not held sd_mark
6899 					 * would be non-NULL.
6900 					 */
6901 					stp->sd_mark = savemp;
6902 				}
6903 			}
6904 			putback(stp, q, savemp, pri);
6905 		}
6906 	} else {
6907 		/*
6908 		 * The complete message was consumed.
6909 		 *
6910 		 * If another M_PCPROTO arrived while sd_lock was not held
6911 		 * it would have been discarded since STRPRI was still set.
6912 		 *
6913 		 * Move the MSG*MARKNEXT information
6914 		 * to the stream head just in case
6915 		 * the read queue becomes empty.
6916 		 * clear stream head hi pri flag based on
6917 		 * first message
6918 		 *
6919 		 * If the stream head was at the mark
6920 		 * (STRATMARK) before we dropped sd_lock above
6921 		 * and some data was consumed then we have
6922 		 * moved past the mark thus STRATMARK is
6923 		 * cleared. However, if a message arrived in
6924 		 * strrput during the copyout above causing
6925 		 * STRATMARK to be set we can not clear that
6926 		 * flag.
6927 		 */
6928 		if (type >= QPCTL) {
6929 			ASSERT(type == M_PCPROTO);
6930 			stp->sd_flag &= ~STRPRI;
6931 		}
6932 		if (mark & (MSGMARKNEXT|MSGNOTMARKNEXT|MSGMARK)) {
6933 			if (mark & MSGMARKNEXT) {
6934 				stp->sd_flag &= ~STRNOTATMARK;
6935 				stp->sd_flag |= STRATMARK;
6936 			} else if (mark & MSGNOTMARKNEXT) {
6937 				stp->sd_flag &= ~STRATMARK;
6938 				stp->sd_flag |= STRNOTATMARK;
6939 			} else {
6940 				stp->sd_flag &= ~(STRATMARK|STRNOTATMARK);
6941 			}
6942 		} else if (pr && (old_sd_flag & STRATMARK)) {
6943 			stp->sd_flag &= ~STRATMARK;
6944 		}
6945 	}
6946 
6947 	*flagsp = flg;
6948 	*prip = pri;
6949 
6950 	/*
6951 	 * Getmsg cleanup processing - if the state of the queue has changed
6952 	 * some signals may need to be sent and/or poll awakened.
6953 	 */
6954 getmout:
6955 	qbackenable(q, pri);
6956 
6957 	/*
6958 	 * We dropped the stream head lock above. Send all M_SIG messages
6959 	 * before processing stream head for SIGPOLL messages.
6960 	 */
6961 	ASSERT(MUTEX_HELD(&stp->sd_lock));
6962 	while ((bp = q->q_first) != NULL &&
6963 	    (bp->b_datap->db_type == M_SIG)) {
6964 		/*
6965 		 * sd_lock is held so the content of the read queue can not
6966 		 * change.
6967 		 */
6968 		bp = getq(q);
6969 		ASSERT(bp != NULL && bp->b_datap->db_type == M_SIG);
6970 
6971 		strsignal_nolock(stp, *bp->b_rptr, bp->b_band);
6972 		mutex_exit(&stp->sd_lock);
6973 		freemsg(bp);
6974 		if (STREAM_NEEDSERVICE(stp))
6975 			stream_runservice(stp);
6976 		mutex_enter(&stp->sd_lock);
6977 	}
6978 
6979 	/*
6980 	 * stream head cannot change while we make the determination
6981 	 * whether or not to send a signal. Drop the flag to allow strrput
6982 	 * to send firstmsgsigs again.
6983 	 */
6984 	stp->sd_flag &= ~STRGETINPROG;
6985 
6986 	/*
6987 	 * If the type of message at the front of the queue changed
6988 	 * due to the receive the appropriate signals and pollwakeup events
6989 	 * are generated. The type of changes are:
6990 	 *	Processed a hipri message, q_first is not hipri.
6991 	 *	Processed a band X message, and q_first is band Y.
6992 	 * The generated signals and pollwakeups are identical to what
6993 	 * strrput() generates should the message that is now on q_first
6994 	 * arrive to an empty read queue.
6995 	 *
6996 	 * Note: only strrput will send a signal for a hipri message.
6997 	 */
6998 	if ((bp = q->q_first) != NULL && !(stp->sd_flag & STRPRI)) {
6999 		strsigset_t signals = 0;
7000 		strpollset_t pollwakeups = 0;
7001 
7002 		if (flg & MSG_HIPRI) {
7003 			/*
7004 			 * Removed a hipri message. Regular data at
7005 			 * the front of  the queue.
7006 			 */
7007 			if (bp->b_band == 0) {
7008 				signals = S_INPUT | S_RDNORM;
7009 				pollwakeups = POLLIN | POLLRDNORM;
7010 			} else {
7011 				signals = S_INPUT | S_RDBAND;
7012 				pollwakeups = POLLIN | POLLRDBAND;
7013 			}
7014 		} else if (pri != bp->b_band) {
7015 			/*
7016 			 * The band is different for the new q_first.
7017 			 */
7018 			if (bp->b_band == 0) {
7019 				signals = S_RDNORM;
7020 				pollwakeups = POLLIN | POLLRDNORM;
7021 			} else {
7022 				signals = S_RDBAND;
7023 				pollwakeups = POLLIN | POLLRDBAND;
7024 			}
7025 		}
7026 
7027 		if (pollwakeups != 0) {
7028 			if (pollwakeups == (POLLIN | POLLRDNORM)) {
7029 				if (!(stp->sd_rput_opt & SR_POLLIN))
7030 					goto no_pollwake;
7031 				stp->sd_rput_opt &= ~SR_POLLIN;
7032 			}
7033 			mutex_exit(&stp->sd_lock);
7034 			pollwakeup(&stp->sd_pollist, pollwakeups);
7035 			mutex_enter(&stp->sd_lock);
7036 		}
7037 no_pollwake:
7038 
7039 		if (stp->sd_sigflags & signals)
7040 			strsendsig(stp->sd_siglist, signals, bp->b_band, 0);
7041 	}
7042 	mutex_exit(&stp->sd_lock);
7043 
7044 	rvp->r_val1 = more;
7045 	return (error);
7046 #undef	_LASTMARK
7047 }
7048 
7049 /*
7050  * Get the next message from the read queue.  If the message is
7051  * priority, STRPRI will have been set by strrput().  This flag
7052  * should be reset only when the entire message at the front of the
7053  * queue as been consumed.
7054  *
7055  * If uiop is NULL all data is returned in mctlp.
7056  * Note that a NULL uiop implies that FNDELAY and FNONBLOCK are assumed
7057  * not enabled.
7058  * The timeout parameter is in milliseconds; -1 for infinity.
7059  * This routine handles the consolidation private flags:
7060  *	MSG_IGNERROR	Ignore any stream head error except STPLEX.
7061  *	MSG_DELAYERROR	Defer the error check until the queue is empty.
7062  *	MSG_HOLDSIG	Hold signals while waiting for data.
7063  *	MSG_IPEEK	Only peek at messages.
7064  *	MSG_DISCARDTAIL	Discard the tail M_DATA part of the message
7065  *			that doesn't fit.
7066  *	MSG_NOMARK	If the message is marked leave it on the queue.
7067  *
7068  * NOTE: strgetmsg and kstrgetmsg have much of the logic in common.
7069  */
7070 int
7071 kstrgetmsg(
7072 	struct vnode *vp,
7073 	mblk_t **mctlp,
7074 	struct uio *uiop,
7075 	unsigned char *prip,
7076 	int *flagsp,
7077 	clock_t timout,
7078 	rval_t *rvp)
7079 {
7080 	struct stdata *stp;
7081 	mblk_t *bp, *nbp;
7082 	mblk_t *savemp = NULL;
7083 	mblk_t *savemptail = NULL;
7084 	int flags;
7085 	uint_t old_sd_flag;
7086 	int flg;
7087 	int more = 0;
7088 	int error = 0;
7089 	char first = 1;
7090 	uint_t mark;		/* Contains MSG*MARK and _LASTMARK */
7091 #define	_LASTMARK	0x8000	/* Distinct from MSG*MARK */
7092 	unsigned char pri = 0;
7093 	queue_t *q;
7094 	int	pr = 0;			/* Partial read successful */
7095 	unsigned char type;
7096 
7097 	TRACE_1(TR_FAC_STREAMS_FR, TR_KSTRGETMSG_ENTER,
7098 	    "kstrgetmsg:%p", vp);
7099 
7100 	ASSERT(vp->v_stream);
7101 	stp = vp->v_stream;
7102 	rvp->r_val1 = 0;
7103 
7104 	mutex_enter(&stp->sd_lock);
7105 
7106 	if ((error = i_straccess(stp, JCREAD)) != 0) {
7107 		mutex_exit(&stp->sd_lock);
7108 		return (error);
7109 	}
7110 
7111 	flags = *flagsp;
7112 	if (stp->sd_flag & (STRDERR|STPLEX)) {
7113 		if ((stp->sd_flag & STPLEX) ||
7114 		    (flags & (MSG_IGNERROR|MSG_DELAYERROR)) == 0) {
7115 			error = strgeterr(stp, STRDERR|STPLEX,
7116 			    (flags & MSG_IPEEK));
7117 			if (error != 0) {
7118 				mutex_exit(&stp->sd_lock);
7119 				return (error);
7120 			}
7121 		}
7122 	}
7123 	mutex_exit(&stp->sd_lock);
7124 
7125 	switch (flags & (MSG_HIPRI|MSG_ANY|MSG_BAND)) {
7126 	case MSG_HIPRI:
7127 		if (*prip != 0)
7128 			return (EINVAL);
7129 		break;
7130 
7131 	case MSG_ANY:
7132 	case MSG_BAND:
7133 		break;
7134 
7135 	default:
7136 		return (EINVAL);
7137 	}
7138 
7139 retry:
7140 	q = _RD(stp->sd_wrq);
7141 	mutex_enter(&stp->sd_lock);
7142 	old_sd_flag = stp->sd_flag;
7143 	mark = 0;
7144 	for (;;) {
7145 		int done = 0;
7146 		int waitflag;
7147 		int fmode;
7148 		mblk_t *q_first = q->q_first;
7149 
7150 		/*
7151 		 * This section of the code operates just like the code
7152 		 * in strgetmsg().  There is a comment there about what
7153 		 * is going on here.
7154 		 */
7155 		if (!(flags & (MSG_HIPRI|MSG_BAND))) {
7156 			/* Asking for normal, band0 data */
7157 			bp = strget(stp, q, uiop, first, &error);
7158 			ASSERT(MUTEX_HELD(&stp->sd_lock));
7159 			if (bp != NULL) {
7160 				if (DB_TYPE(bp) == M_SIG) {
7161 					strsignal_nolock(stp, *bp->b_rptr,
7162 					    bp->b_band);
7163 					freemsg(bp);
7164 					continue;
7165 				} else {
7166 					break;
7167 				}
7168 			}
7169 			if (error != 0) {
7170 				goto getmout;
7171 			}
7172 		/*
7173 		 * We can't depend on the value of STRPRI here because
7174 		 * the stream head may be in transit. Therefore, we
7175 		 * must look at the type of the first message to
7176 		 * determine if a high priority messages is waiting
7177 		 */
7178 		} else if ((flags & MSG_HIPRI) && q_first != NULL &&
7179 		    DB_TYPE(q_first) >= QPCTL &&
7180 		    (bp = getq_noenab(q, 0)) != NULL) {
7181 			ASSERT(DB_TYPE(bp) >= QPCTL);
7182 			break;
7183 		} else if ((flags & MSG_BAND) && q_first != NULL &&
7184 		    ((q_first->b_band >= *prip) || DB_TYPE(q_first) >= QPCTL) &&
7185 		    (bp = getq_noenab(q, 0)) != NULL) {
7186 			/*
7187 			 * Asked for at least band "prip" and got either at
7188 			 * least that band or a hipri message.
7189 			 */
7190 			ASSERT(bp->b_band >= *prip || DB_TYPE(bp) >= QPCTL);
7191 			if (DB_TYPE(bp) == M_SIG) {
7192 				strsignal_nolock(stp, *bp->b_rptr, bp->b_band);
7193 				freemsg(bp);
7194 				continue;
7195 			} else {
7196 				break;
7197 			}
7198 		}
7199 
7200 		/* No data. Time to sleep? */
7201 		qbackenable(q, 0);
7202 
7203 		/*
7204 		 * Delayed error notification?
7205 		 */
7206 		if ((stp->sd_flag & (STRDERR|STPLEX)) &&
7207 		    (flags & (MSG_IGNERROR|MSG_DELAYERROR)) == MSG_DELAYERROR) {
7208 			error = strgeterr(stp, STRDERR|STPLEX,
7209 			    (flags & MSG_IPEEK));
7210 			if (error != 0) {
7211 				mutex_exit(&stp->sd_lock);
7212 				return (error);
7213 			}
7214 		}
7215 
7216 		/*
7217 		 * If STRHUP or STREOF, return 0 length control and data.
7218 		 * If a read(fd,buf,0) has been done, do not sleep, just
7219 		 * return.
7220 		 *
7221 		 * If mctlp == NULL and uiop == NULL, then the code will
7222 		 * do the strwaitq. This is an understood way of saying
7223 		 * sleep "polling" until a message is received.
7224 		 */
7225 		if ((stp->sd_flag & (STRHUP|STREOF)) ||
7226 		    (uiop != NULL && uiop->uio_resid == 0)) {
7227 			if (mctlp != NULL)
7228 				*mctlp = NULL;
7229 			*flagsp = 0;
7230 			mutex_exit(&stp->sd_lock);
7231 			return (0);
7232 		}
7233 
7234 		waitflag = GETWAIT;
7235 		if (flags &
7236 		    (MSG_HOLDSIG|MSG_IGNERROR|MSG_IPEEK|MSG_DELAYERROR)) {
7237 			if (flags & MSG_HOLDSIG)
7238 				waitflag |= STR_NOSIG;
7239 			if (flags & MSG_IGNERROR)
7240 				waitflag |= STR_NOERROR;
7241 			if (flags & MSG_IPEEK)
7242 				waitflag |= STR_PEEK;
7243 			if (flags & MSG_DELAYERROR)
7244 				waitflag |= STR_DELAYERR;
7245 		}
7246 		if (uiop != NULL)
7247 			fmode = uiop->uio_fmode;
7248 		else
7249 			fmode = 0;
7250 
7251 		TRACE_2(TR_FAC_STREAMS_FR, TR_KSTRGETMSG_WAIT,
7252 		    "kstrgetmsg calls strwaitq:%p, %p",
7253 		    vp, uiop);
7254 		if (((error = strwaitq(stp, waitflag, (ssize_t)0,
7255 		    fmode, timout, &done))) != 0 || done) {
7256 			TRACE_2(TR_FAC_STREAMS_FR, TR_KSTRGETMSG_DONE,
7257 			    "kstrgetmsg error or done:%p, %p",
7258 			    vp, uiop);
7259 			mutex_exit(&stp->sd_lock);
7260 			return (error);
7261 		}
7262 		TRACE_2(TR_FAC_STREAMS_FR, TR_KSTRGETMSG_AWAKE,
7263 		    "kstrgetmsg awakes:%p, %p", vp, uiop);
7264 		if ((error = i_straccess(stp, JCREAD)) != 0) {
7265 			mutex_exit(&stp->sd_lock);
7266 			return (error);
7267 		}
7268 		first = 0;
7269 	}
7270 	ASSERT(bp != NULL);
7271 	/*
7272 	 * Extract any mark information. If the message is not completely
7273 	 * consumed this information will be put in the mblk
7274 	 * that is putback.
7275 	 * If MSGMARKNEXT is set and the message is completely consumed
7276 	 * the STRATMARK flag will be set below. Likewise, if
7277 	 * MSGNOTMARKNEXT is set and the message is
7278 	 * completely consumed STRNOTATMARK will be set.
7279 	 */
7280 	mark = bp->b_flag & (MSGMARK | MSGMARKNEXT | MSGNOTMARKNEXT);
7281 	ASSERT((mark & (MSGMARKNEXT|MSGNOTMARKNEXT)) !=
7282 	    (MSGMARKNEXT|MSGNOTMARKNEXT));
7283 	pri = bp->b_band;
7284 	if (mark != 0) {
7285 		/*
7286 		 * If the caller doesn't want the mark return.
7287 		 * Used to implement MSG_WAITALL in sockets.
7288 		 */
7289 		if (flags & MSG_NOMARK) {
7290 			putback(stp, q, bp, pri);
7291 			qbackenable(q, pri);
7292 			mutex_exit(&stp->sd_lock);
7293 			return (EWOULDBLOCK);
7294 		}
7295 		if (bp == stp->sd_mark) {
7296 			mark |= _LASTMARK;
7297 			stp->sd_mark = NULL;
7298 		}
7299 	}
7300 
7301 	/*
7302 	 * keep track of the first message type
7303 	 */
7304 	type = bp->b_datap->db_type;
7305 
7306 	if (bp->b_datap->db_type == M_PASSFP) {
7307 		if ((mark & _LASTMARK) && (stp->sd_mark == NULL))
7308 			stp->sd_mark = bp;
7309 		bp->b_flag |= mark & ~_LASTMARK;
7310 		putback(stp, q, bp, pri);
7311 		qbackenable(q, pri);
7312 		mutex_exit(&stp->sd_lock);
7313 		return (EBADMSG);
7314 	}
7315 	ASSERT(type != M_SIG);
7316 
7317 	if (flags & MSG_IPEEK) {
7318 		/*
7319 		 * Clear any struioflag - we do the uiomove over again
7320 		 * when peeking since it simplifies the code.
7321 		 *
7322 		 * Dup the message and put the original back on the queue.
7323 		 * If dupmsg() fails, try again with copymsg() to see if
7324 		 * there is indeed a shortage of memory.  dupmsg() may fail
7325 		 * if db_ref in any of the messages reaches its limit.
7326 		 */
7327 
7328 		if ((nbp = dupmsg(bp)) == NULL && (nbp = copymsg(bp)) == NULL) {
7329 			/*
7330 			 * Restore the state of the stream head since we
7331 			 * need to drop sd_lock (strwaitbuf is sleeping).
7332 			 */
7333 			size_t size = msgdsize(bp);
7334 
7335 			if ((mark & _LASTMARK) && (stp->sd_mark == NULL))
7336 				stp->sd_mark = bp;
7337 			bp->b_flag |= mark & ~_LASTMARK;
7338 			putback(stp, q, bp, pri);
7339 			mutex_exit(&stp->sd_lock);
7340 			error = strwaitbuf(size, BPRI_HI);
7341 			if (error) {
7342 				/*
7343 				 * There is no net change to the queue thus
7344 				 * no need to qbackenable.
7345 				 */
7346 				return (error);
7347 			}
7348 			goto retry;
7349 		}
7350 
7351 		if ((mark & _LASTMARK) && (stp->sd_mark == NULL))
7352 			stp->sd_mark = bp;
7353 		bp->b_flag |= mark & ~_LASTMARK;
7354 		putback(stp, q, bp, pri);
7355 		bp = nbp;
7356 	}
7357 
7358 	/*
7359 	 * Set this flag so strrput will not generate signals. Need to
7360 	 * make sure this flag is cleared before leaving this routine
7361 	 * else signals will stop being sent.
7362 	 */
7363 	stp->sd_flag |= STRGETINPROG;
7364 	mutex_exit(&stp->sd_lock);
7365 
7366 	if ((stp->sd_rputdatafunc != NULL) && (DB_TYPE(bp) == M_DATA)) {
7367 		mblk_t *tmp, *prevmp;
7368 
7369 		/*
7370 		 * Put first non-data mblk back to stream head and
7371 		 * cut the mblk chain so sd_rputdatafunc only sees
7372 		 * M_DATA mblks. We can skip the first mblk since it
7373 		 * is M_DATA according to the condition above.
7374 		 */
7375 		for (prevmp = bp, tmp = bp->b_cont; tmp != NULL;
7376 		    prevmp = tmp, tmp = tmp->b_cont) {
7377 			if (DB_TYPE(tmp) != M_DATA) {
7378 				prevmp->b_cont = NULL;
7379 				mutex_enter(&stp->sd_lock);
7380 				putback(stp, q, tmp, tmp->b_band);
7381 				mutex_exit(&stp->sd_lock);
7382 				break;
7383 			}
7384 		}
7385 
7386 		bp = (stp->sd_rputdatafunc)(stp->sd_vnode, bp,
7387 		    NULL, NULL, NULL, NULL);
7388 
7389 		if (bp == NULL)
7390 			goto retry;
7391 	}
7392 
7393 	if (STREAM_NEEDSERVICE(stp))
7394 		stream_runservice(stp);
7395 
7396 	/*
7397 	 * Set HIPRI flag if message is priority.
7398 	 */
7399 	if (type >= QPCTL)
7400 		flg = MSG_HIPRI;
7401 	else
7402 		flg = MSG_BAND;
7403 
7404 	/*
7405 	 * First process PROTO or PCPROTO blocks, if any.
7406 	 */
7407 	if (mctlp != NULL && type != M_DATA) {
7408 		mblk_t *nbp;
7409 
7410 		*mctlp = bp;
7411 		while (bp->b_cont && bp->b_cont->b_datap->db_type != M_DATA)
7412 			bp = bp->b_cont;
7413 		nbp = bp->b_cont;
7414 		bp->b_cont = NULL;
7415 		bp = nbp;
7416 	}
7417 
7418 	if (bp && bp->b_datap->db_type != M_DATA) {
7419 		/*
7420 		 * More PROTO blocks in msg. Will only happen if mctlp is NULL.
7421 		 */
7422 		more |= MORECTL;
7423 		savemp = bp;
7424 		while (bp && bp->b_datap->db_type != M_DATA) {
7425 			savemptail = bp;
7426 			bp = bp->b_cont;
7427 		}
7428 		savemptail->b_cont = NULL;
7429 	}
7430 
7431 	/*
7432 	 * Now process DATA blocks, if any.
7433 	 */
7434 	if (uiop == NULL) {
7435 		/* Append data to tail of mctlp */
7436 
7437 		if (mctlp != NULL) {
7438 			mblk_t **mpp = mctlp;
7439 
7440 			while (*mpp != NULL)
7441 				mpp = &((*mpp)->b_cont);
7442 			*mpp = bp;
7443 			bp = NULL;
7444 		}
7445 	} else if (uiop->uio_resid >= 0 && bp) {
7446 		size_t oldresid = uiop->uio_resid;
7447 
7448 		/*
7449 		 * If a streams message is likely to consist
7450 		 * of many small mblks, it is pulled up into
7451 		 * one continuous chunk of memory.
7452 		 * The size of the first mblk may be bogus because
7453 		 * successive read() calls on the socket reduce
7454 		 * the size of this mblk until it is exhausted
7455 		 * and then the code walks on to the next. Thus
7456 		 * the size of the mblk may not be the original size
7457 		 * that was passed up, it's simply a remainder
7458 		 * and hence can be very small without any
7459 		 * implication that the packet is badly fragmented.
7460 		 * So the size of the possible second mblk is
7461 		 * used to spot a badly fragmented packet.
7462 		 * see longer comment at top of page
7463 		 * by mblk_pull_len declaration.
7464 		 */
7465 
7466 		if (bp->b_cont != NULL && MBLKL(bp->b_cont) < mblk_pull_len) {
7467 			(void) pullupmsg(bp, -1);
7468 		}
7469 
7470 		bp = struiocopyout(bp, uiop, &error);
7471 		if (error != 0) {
7472 			if (mctlp != NULL) {
7473 				freemsg(*mctlp);
7474 				*mctlp = NULL;
7475 			} else
7476 				freemsg(savemp);
7477 			mutex_enter(&stp->sd_lock);
7478 			/*
7479 			 * clear stream head hi pri flag based on
7480 			 * first message
7481 			 */
7482 			if (!(flags & MSG_IPEEK) && (type >= QPCTL)) {
7483 				ASSERT(type == M_PCPROTO);
7484 				stp->sd_flag &= ~STRPRI;
7485 			}
7486 			more = 0;
7487 			goto getmout;
7488 		}
7489 		/*
7490 		 * (pr == 1) indicates a partial read.
7491 		 */
7492 		if (oldresid > uiop->uio_resid)
7493 			pr = 1;
7494 	}
7495 
7496 	if (bp) {			/* more data blocks in msg */
7497 		more |= MOREDATA;
7498 		if (savemp)
7499 			savemptail->b_cont = bp;
7500 		else
7501 			savemp = bp;
7502 	}
7503 
7504 	mutex_enter(&stp->sd_lock);
7505 	if (savemp) {
7506 		if (flags & (MSG_IPEEK|MSG_DISCARDTAIL)) {
7507 			/*
7508 			 * When MSG_DISCARDTAIL is set or
7509 			 * when peeking discard any tail. When peeking this
7510 			 * is the tail of the dup that was copied out - the
7511 			 * message has already been putback on the queue.
7512 			 * Return MOREDATA to the caller even though the data
7513 			 * is discarded. This is used by sockets (to
7514 			 * set MSG_TRUNC).
7515 			 */
7516 			freemsg(savemp);
7517 			if (!(flags & MSG_IPEEK) && (type >= QPCTL)) {
7518 				ASSERT(type == M_PCPROTO);
7519 				stp->sd_flag &= ~STRPRI;
7520 			}
7521 		} else if (pr && (savemp->b_datap->db_type == M_DATA) &&
7522 		    msgnodata(savemp)) {
7523 			/*
7524 			 * Avoid queuing a zero-length tail part of
7525 			 * a message. pr=1 indicates that we read some of
7526 			 * the message.
7527 			 */
7528 			freemsg(savemp);
7529 			more &= ~MOREDATA;
7530 			if (type >= QPCTL) {
7531 				ASSERT(type == M_PCPROTO);
7532 				stp->sd_flag &= ~STRPRI;
7533 			}
7534 		} else {
7535 			savemp->b_band = pri;
7536 			/*
7537 			 * If the first message was HIPRI and the one we're
7538 			 * putting back isn't, then clear STRPRI, otherwise
7539 			 * set STRPRI again.  Note that we must set STRPRI
7540 			 * again since the flush logic in strrput_nondata()
7541 			 * may have cleared it while we had sd_lock dropped.
7542 			 */
7543 
7544 			if (type >= QPCTL) {
7545 				ASSERT(type == M_PCPROTO);
7546 				if (queclass(savemp) < QPCTL)
7547 					stp->sd_flag &= ~STRPRI;
7548 				else
7549 					stp->sd_flag |= STRPRI;
7550 			} else if (queclass(savemp) >= QPCTL) {
7551 				/*
7552 				 * The first message was not a HIPRI message,
7553 				 * but the one we are about to putback is.
7554 				 * For simplicitly, we do not allow for HIPRI
7555 				 * messages to be embedded in the message
7556 				 * body, so just force it to same type as
7557 				 * first message.
7558 				 */
7559 				ASSERT(type == M_DATA || type == M_PROTO);
7560 				ASSERT(savemp->b_datap->db_type == M_PCPROTO);
7561 				savemp->b_datap->db_type = type;
7562 			}
7563 			if (mark != 0) {
7564 				if ((mark & _LASTMARK) &&
7565 				    (stp->sd_mark == NULL)) {
7566 					/*
7567 					 * If another marked message arrived
7568 					 * while sd_lock was not held sd_mark
7569 					 * would be non-NULL.
7570 					 */
7571 					stp->sd_mark = savemp;
7572 				}
7573 				savemp->b_flag |= mark & ~_LASTMARK;
7574 			}
7575 			putback(stp, q, savemp, pri);
7576 		}
7577 	} else if (!(flags & MSG_IPEEK)) {
7578 		/*
7579 		 * The complete message was consumed.
7580 		 *
7581 		 * If another M_PCPROTO arrived while sd_lock was not held
7582 		 * it would have been discarded since STRPRI was still set.
7583 		 *
7584 		 * Move the MSG*MARKNEXT information
7585 		 * to the stream head just in case
7586 		 * the read queue becomes empty.
7587 		 * clear stream head hi pri flag based on
7588 		 * first message
7589 		 *
7590 		 * If the stream head was at the mark
7591 		 * (STRATMARK) before we dropped sd_lock above
7592 		 * and some data was consumed then we have
7593 		 * moved past the mark thus STRATMARK is
7594 		 * cleared. However, if a message arrived in
7595 		 * strrput during the copyout above causing
7596 		 * STRATMARK to be set we can not clear that
7597 		 * flag.
7598 		 * XXX A "perimeter" would help by single-threading strrput,
7599 		 * strread, strgetmsg and kstrgetmsg.
7600 		 */
7601 		if (type >= QPCTL) {
7602 			ASSERT(type == M_PCPROTO);
7603 			stp->sd_flag &= ~STRPRI;
7604 		}
7605 		if (mark & (MSGMARKNEXT|MSGNOTMARKNEXT|MSGMARK)) {
7606 			if (mark & MSGMARKNEXT) {
7607 				stp->sd_flag &= ~STRNOTATMARK;
7608 				stp->sd_flag |= STRATMARK;
7609 			} else if (mark & MSGNOTMARKNEXT) {
7610 				stp->sd_flag &= ~STRATMARK;
7611 				stp->sd_flag |= STRNOTATMARK;
7612 			} else {
7613 				stp->sd_flag &= ~(STRATMARK|STRNOTATMARK);
7614 			}
7615 		} else if (pr && (old_sd_flag & STRATMARK)) {
7616 			stp->sd_flag &= ~STRATMARK;
7617 		}
7618 	}
7619 
7620 	*flagsp = flg;
7621 	*prip = pri;
7622 
7623 	/*
7624 	 * Getmsg cleanup processing - if the state of the queue has changed
7625 	 * some signals may need to be sent and/or poll awakened.
7626 	 */
7627 getmout:
7628 	qbackenable(q, pri);
7629 
7630 	/*
7631 	 * We dropped the stream head lock above. Send all M_SIG messages
7632 	 * before processing stream head for SIGPOLL messages.
7633 	 */
7634 	ASSERT(MUTEX_HELD(&stp->sd_lock));
7635 	while ((bp = q->q_first) != NULL &&
7636 	    (bp->b_datap->db_type == M_SIG)) {
7637 		/*
7638 		 * sd_lock is held so the content of the read queue can not
7639 		 * change.
7640 		 */
7641 		bp = getq(q);
7642 		ASSERT(bp != NULL && bp->b_datap->db_type == M_SIG);
7643 
7644 		strsignal_nolock(stp, *bp->b_rptr, bp->b_band);
7645 		mutex_exit(&stp->sd_lock);
7646 		freemsg(bp);
7647 		if (STREAM_NEEDSERVICE(stp))
7648 			stream_runservice(stp);
7649 		mutex_enter(&stp->sd_lock);
7650 	}
7651 
7652 	/*
7653 	 * stream head cannot change while we make the determination
7654 	 * whether or not to send a signal. Drop the flag to allow strrput
7655 	 * to send firstmsgsigs again.
7656 	 */
7657 	stp->sd_flag &= ~STRGETINPROG;
7658 
7659 	/*
7660 	 * If the type of message at the front of the queue changed
7661 	 * due to the receive the appropriate signals and pollwakeup events
7662 	 * are generated. The type of changes are:
7663 	 *	Processed a hipri message, q_first is not hipri.
7664 	 *	Processed a band X message, and q_first is band Y.
7665 	 * The generated signals and pollwakeups are identical to what
7666 	 * strrput() generates should the message that is now on q_first
7667 	 * arrive to an empty read queue.
7668 	 *
7669 	 * Note: only strrput will send a signal for a hipri message.
7670 	 */
7671 	if ((bp = q->q_first) != NULL && !(stp->sd_flag & STRPRI)) {
7672 		strsigset_t signals = 0;
7673 		strpollset_t pollwakeups = 0;
7674 
7675 		if (flg & MSG_HIPRI) {
7676 			/*
7677 			 * Removed a hipri message. Regular data at
7678 			 * the front of  the queue.
7679 			 */
7680 			if (bp->b_band == 0) {
7681 				signals = S_INPUT | S_RDNORM;
7682 				pollwakeups = POLLIN | POLLRDNORM;
7683 			} else {
7684 				signals = S_INPUT | S_RDBAND;
7685 				pollwakeups = POLLIN | POLLRDBAND;
7686 			}
7687 		} else if (pri != bp->b_band) {
7688 			/*
7689 			 * The band is different for the new q_first.
7690 			 */
7691 			if (bp->b_band == 0) {
7692 				signals = S_RDNORM;
7693 				pollwakeups = POLLIN | POLLRDNORM;
7694 			} else {
7695 				signals = S_RDBAND;
7696 				pollwakeups = POLLIN | POLLRDBAND;
7697 			}
7698 		}
7699 
7700 		if (pollwakeups != 0) {
7701 			if (pollwakeups == (POLLIN | POLLRDNORM)) {
7702 				if (!(stp->sd_rput_opt & SR_POLLIN))
7703 					goto no_pollwake;
7704 				stp->sd_rput_opt &= ~SR_POLLIN;
7705 			}
7706 			mutex_exit(&stp->sd_lock);
7707 			pollwakeup(&stp->sd_pollist, pollwakeups);
7708 			mutex_enter(&stp->sd_lock);
7709 		}
7710 no_pollwake:
7711 
7712 		if (stp->sd_sigflags & signals)
7713 			strsendsig(stp->sd_siglist, signals, bp->b_band, 0);
7714 	}
7715 	mutex_exit(&stp->sd_lock);
7716 
7717 	rvp->r_val1 = more;
7718 	return (error);
7719 #undef	_LASTMARK
7720 }
7721 
7722 /*
7723  * Put a message downstream.
7724  *
7725  * NOTE: strputmsg and kstrputmsg have much of the logic in common.
7726  */
7727 int
7728 strputmsg(
7729 	struct vnode *vp,
7730 	struct strbuf *mctl,
7731 	struct strbuf *mdata,
7732 	unsigned char pri,
7733 	int flag,
7734 	int fmode)
7735 {
7736 	struct stdata *stp;
7737 	queue_t *wqp;
7738 	mblk_t *mp;
7739 	ssize_t msgsize;
7740 	ssize_t rmin, rmax;
7741 	int error;
7742 	struct uio uios;
7743 	struct uio *uiop = &uios;
7744 	struct iovec iovs;
7745 	int xpg4 = 0;
7746 
7747 	ASSERT(vp->v_stream);
7748 	stp = vp->v_stream;
7749 	wqp = stp->sd_wrq;
7750 
7751 	/*
7752 	 * If it is an XPG4 application, we need to send
7753 	 * SIGPIPE below
7754 	 */
7755 
7756 	xpg4 = (flag & MSG_XPG4) ? 1 : 0;
7757 	flag &= ~MSG_XPG4;
7758 
7759 	if (audit_active)
7760 		audit_strputmsg(vp, mctl, mdata, pri, flag, fmode);
7761 
7762 	mutex_enter(&stp->sd_lock);
7763 
7764 	if ((error = i_straccess(stp, JCWRITE)) != 0) {
7765 		mutex_exit(&stp->sd_lock);
7766 		return (error);
7767 	}
7768 
7769 	if (stp->sd_flag & (STWRERR|STRHUP|STPLEX)) {
7770 		error = strwriteable(stp, B_FALSE, xpg4);
7771 		if (error != 0) {
7772 			mutex_exit(&stp->sd_lock);
7773 			return (error);
7774 		}
7775 	}
7776 
7777 	mutex_exit(&stp->sd_lock);
7778 
7779 	/*
7780 	 * Check for legal flag value.
7781 	 */
7782 	switch (flag) {
7783 	case MSG_HIPRI:
7784 		if ((mctl->len < 0) || (pri != 0))
7785 			return (EINVAL);
7786 		break;
7787 	case MSG_BAND:
7788 		break;
7789 
7790 	default:
7791 		return (EINVAL);
7792 	}
7793 
7794 	TRACE_1(TR_FAC_STREAMS_FR, TR_STRPUTMSG_IN,
7795 	    "strputmsg in:stp %p", stp);
7796 
7797 	/* get these values from those cached in the stream head */
7798 	rmin = stp->sd_qn_minpsz;
7799 	rmax = stp->sd_qn_maxpsz;
7800 
7801 	/*
7802 	 * Make sure ctl and data sizes together fall within the
7803 	 * limits of the max and min receive packet sizes and do
7804 	 * not exceed system limit.
7805 	 */
7806 	ASSERT((rmax >= 0) || (rmax == INFPSZ));
7807 	if (rmax == 0) {
7808 		return (ERANGE);
7809 	}
7810 	/*
7811 	 * Use the MAXIMUM of sd_maxblk and q_maxpsz.
7812 	 * Needed to prevent partial failures in the strmakedata loop.
7813 	 */
7814 	if (stp->sd_maxblk != INFPSZ && rmax != INFPSZ && rmax < stp->sd_maxblk)
7815 		rmax = stp->sd_maxblk;
7816 
7817 	if ((msgsize = mdata->len) < 0) {
7818 		msgsize = 0;
7819 		rmin = 0;	/* no range check for NULL data part */
7820 	}
7821 	if ((msgsize < rmin) ||
7822 	    ((msgsize > rmax) && (rmax != INFPSZ)) ||
7823 	    (mctl->len > strctlsz)) {
7824 		return (ERANGE);
7825 	}
7826 
7827 	/*
7828 	 * Setup uio and iov for data part
7829 	 */
7830 	iovs.iov_base = mdata->buf;
7831 	iovs.iov_len = msgsize;
7832 	uios.uio_iov = &iovs;
7833 	uios.uio_iovcnt = 1;
7834 	uios.uio_loffset = 0;
7835 	uios.uio_segflg = UIO_USERSPACE;
7836 	uios.uio_fmode = fmode;
7837 	uios.uio_extflg = UIO_COPY_DEFAULT;
7838 	uios.uio_resid = msgsize;
7839 	uios.uio_offset = 0;
7840 
7841 	/* Ignore flow control in strput for HIPRI */
7842 	if (flag & MSG_HIPRI)
7843 		flag |= MSG_IGNFLOW;
7844 
7845 	for (;;) {
7846 		int done = 0;
7847 
7848 		/*
7849 		 * strput will always free the ctl mblk - even when strput
7850 		 * fails.
7851 		 */
7852 		if ((error = strmakectl(mctl, flag, fmode, &mp)) != 0) {
7853 			TRACE_3(TR_FAC_STREAMS_FR, TR_STRPUTMSG_OUT,
7854 			    "strputmsg out:stp %p out %d error %d",
7855 			    stp, 1, error);
7856 			return (error);
7857 		}
7858 		/*
7859 		 * Verify that the whole message can be transferred by
7860 		 * strput.
7861 		 */
7862 		ASSERT(stp->sd_maxblk == INFPSZ ||
7863 		    stp->sd_maxblk >= mdata->len);
7864 
7865 		msgsize = mdata->len;
7866 		error = strput(stp, mp, uiop, &msgsize, 0, pri, flag);
7867 		mdata->len = msgsize;
7868 
7869 		if (error == 0)
7870 			break;
7871 
7872 		if (error != EWOULDBLOCK)
7873 			goto out;
7874 
7875 		mutex_enter(&stp->sd_lock);
7876 		/*
7877 		 * Check for a missed wakeup.
7878 		 * Needed since strput did not hold sd_lock across
7879 		 * the canputnext.
7880 		 */
7881 		if (bcanputnext(wqp, pri)) {
7882 			/* Try again */
7883 			mutex_exit(&stp->sd_lock);
7884 			continue;
7885 		}
7886 		TRACE_2(TR_FAC_STREAMS_FR, TR_STRPUTMSG_WAIT,
7887 		    "strputmsg wait:stp %p waits pri %d", stp, pri);
7888 		if (((error = strwaitq(stp, WRITEWAIT, (ssize_t)0, fmode, -1,
7889 		    &done)) != 0) || done) {
7890 			mutex_exit(&stp->sd_lock);
7891 			TRACE_3(TR_FAC_STREAMS_FR, TR_STRPUTMSG_OUT,
7892 			    "strputmsg out:q %p out %d error %d",
7893 			    stp, 0, error);
7894 			return (error);
7895 		}
7896 		TRACE_1(TR_FAC_STREAMS_FR, TR_STRPUTMSG_WAKE,
7897 		    "strputmsg wake:stp %p wakes", stp);
7898 		if ((error = i_straccess(stp, JCWRITE)) != 0) {
7899 			mutex_exit(&stp->sd_lock);
7900 			return (error);
7901 		}
7902 		mutex_exit(&stp->sd_lock);
7903 	}
7904 out:
7905 	/*
7906 	 * For historic reasons, applications expect EAGAIN
7907 	 * when data mblk could not be allocated. so change
7908 	 * ENOMEM back to EAGAIN
7909 	 */
7910 	if (error == ENOMEM)
7911 		error = EAGAIN;
7912 	TRACE_3(TR_FAC_STREAMS_FR, TR_STRPUTMSG_OUT,
7913 	    "strputmsg out:stp %p out %d error %d", stp, 2, error);
7914 	return (error);
7915 }
7916 
7917 /*
7918  * Put a message downstream.
7919  * Can send only an M_PROTO/M_PCPROTO by passing in a NULL uiop.
7920  * The fmode flag (NDELAY, NONBLOCK) is the or of the flags in the uio
7921  * and the fmode parameter.
7922  *
7923  * This routine handles the consolidation private flags:
7924  *	MSG_IGNERROR	Ignore any stream head error except STPLEX.
7925  *	MSG_HOLDSIG	Hold signals while waiting for data.
7926  *	MSG_IGNFLOW	Don't check streams flow control.
7927  *
7928  * NOTE: strputmsg and kstrputmsg have much of the logic in common.
7929  */
7930 int
7931 kstrputmsg(
7932 	struct vnode *vp,
7933 	mblk_t *mctl,
7934 	struct uio *uiop,
7935 	ssize_t msgsize,
7936 	unsigned char pri,
7937 	int flag,
7938 	int fmode)
7939 {
7940 	struct stdata *stp;
7941 	queue_t *wqp;
7942 	ssize_t rmin, rmax;
7943 	int error;
7944 
7945 	ASSERT(vp->v_stream);
7946 	stp = vp->v_stream;
7947 	wqp = stp->sd_wrq;
7948 	if (audit_active)
7949 		audit_strputmsg(vp, NULL, NULL, pri, flag, fmode);
7950 	if (mctl == NULL)
7951 		return (EINVAL);
7952 
7953 	mutex_enter(&stp->sd_lock);
7954 
7955 	if ((error = i_straccess(stp, JCWRITE)) != 0) {
7956 		mutex_exit(&stp->sd_lock);
7957 		freemsg(mctl);
7958 		return (error);
7959 	}
7960 
7961 	if ((stp->sd_flag & STPLEX) || !(flag & MSG_IGNERROR)) {
7962 		if (stp->sd_flag & (STWRERR|STRHUP|STPLEX)) {
7963 			error = strwriteable(stp, B_FALSE, B_TRUE);
7964 			if (error != 0) {
7965 				mutex_exit(&stp->sd_lock);
7966 				freemsg(mctl);
7967 				return (error);
7968 			}
7969 		}
7970 	}
7971 
7972 	mutex_exit(&stp->sd_lock);
7973 
7974 	/*
7975 	 * Check for legal flag value.
7976 	 */
7977 	switch (flag & (MSG_HIPRI|MSG_BAND|MSG_ANY)) {
7978 	case MSG_HIPRI:
7979 		if (pri != 0) {
7980 			freemsg(mctl);
7981 			return (EINVAL);
7982 		}
7983 		break;
7984 	case MSG_BAND:
7985 		break;
7986 	default:
7987 		freemsg(mctl);
7988 		return (EINVAL);
7989 	}
7990 
7991 	TRACE_1(TR_FAC_STREAMS_FR, TR_KSTRPUTMSG_IN,
7992 	    "kstrputmsg in:stp %p", stp);
7993 
7994 	/* get these values from those cached in the stream head */
7995 	rmin = stp->sd_qn_minpsz;
7996 	rmax = stp->sd_qn_maxpsz;
7997 
7998 	/*
7999 	 * Make sure ctl and data sizes together fall within the
8000 	 * limits of the max and min receive packet sizes and do
8001 	 * not exceed system limit.
8002 	 */
8003 	ASSERT((rmax >= 0) || (rmax == INFPSZ));
8004 	if (rmax == 0) {
8005 		freemsg(mctl);
8006 		return (ERANGE);
8007 	}
8008 	/*
8009 	 * Use the MAXIMUM of sd_maxblk and q_maxpsz.
8010 	 * Needed to prevent partial failures in the strmakedata loop.
8011 	 */
8012 	if (stp->sd_maxblk != INFPSZ && rmax != INFPSZ && rmax < stp->sd_maxblk)
8013 		rmax = stp->sd_maxblk;
8014 
8015 	if (uiop == NULL) {
8016 		msgsize = -1;
8017 		rmin = -1;	/* no range check for NULL data part */
8018 	} else {
8019 		/* Use uio flags as well as the fmode parameter flags */
8020 		fmode |= uiop->uio_fmode;
8021 
8022 		if ((msgsize < rmin) ||
8023 		    ((msgsize > rmax) && (rmax != INFPSZ))) {
8024 			freemsg(mctl);
8025 			return (ERANGE);
8026 		}
8027 	}
8028 
8029 	/* Ignore flow control in strput for HIPRI */
8030 	if (flag & MSG_HIPRI)
8031 		flag |= MSG_IGNFLOW;
8032 
8033 	for (;;) {
8034 		int done = 0;
8035 		int waitflag;
8036 		mblk_t *mp;
8037 
8038 		/*
8039 		 * strput will always free the ctl mblk - even when strput
8040 		 * fails. If MSG_IGNFLOW is set then any error returned
8041 		 * will cause us to break the loop, so we don't need a copy
8042 		 * of the message. If MSG_IGNFLOW is not set, then we can
8043 		 * get hit by flow control and be forced to try again. In
8044 		 * this case we need to have a copy of the message. We
8045 		 * do this using copymsg since the message may get modified
8046 		 * by something below us.
8047 		 *
8048 		 * We've observed that many TPI providers do not check db_ref
8049 		 * on the control messages but blindly reuse them for the
8050 		 * T_OK_ACK/T_ERROR_ACK. Thus using copymsg is more
8051 		 * friendly to such providers than using dupmsg. Also, note
8052 		 * that sockfs uses MSG_IGNFLOW for all TPI control messages.
8053 		 * Only data messages are subject to flow control, hence
8054 		 * subject to this copymsg.
8055 		 */
8056 		if (flag & MSG_IGNFLOW) {
8057 			mp = mctl;
8058 			mctl = NULL;
8059 		} else {
8060 			do {
8061 				/*
8062 				 * If a message has a free pointer, the message
8063 				 * must be dupmsg to maintain this pointer.
8064 				 * Code using this facility must be sure
8065 				 * that modules below will not change the
8066 				 * contents of the dblk without checking db_ref
8067 				 * first. If db_ref is > 1, then the module
8068 				 * needs to do a copymsg first. Otherwise,
8069 				 * the contents of the dblk may become
8070 				 * inconsistent because the freesmg/freeb below
8071 				 * may end up calling atomic_add_32_nv.
8072 				 * The atomic_add_32_nv in freeb (accessing
8073 				 * all of db_ref, db_type, db_flags, and
8074 				 * db_struioflag) does not prevent other threads
8075 				 * from concurrently trying to modify e.g.
8076 				 * db_type.
8077 				 */
8078 				if (mctl->b_datap->db_frtnp != NULL)
8079 					mp = dupmsg(mctl);
8080 				else
8081 					mp = copymsg(mctl);
8082 
8083 				if (mp != NULL)
8084 					break;
8085 
8086 				error = strwaitbuf(msgdsize(mctl), BPRI_MED);
8087 				if (error) {
8088 					freemsg(mctl);
8089 					return (error);
8090 				}
8091 			} while (mp == NULL);
8092 		}
8093 		/*
8094 		 * Verify that all of msgsize can be transferred by
8095 		 * strput.
8096 		 */
8097 		ASSERT(stp->sd_maxblk == INFPSZ || stp->sd_maxblk >= msgsize);
8098 		error = strput(stp, mp, uiop, &msgsize, 0, pri, flag);
8099 		if (error == 0)
8100 			break;
8101 
8102 		if (error != EWOULDBLOCK)
8103 			goto out;
8104 
8105 		/*
8106 		 * IF MSG_IGNFLOW is set we should have broken out of loop
8107 		 * above.
8108 		 */
8109 		ASSERT(!(flag & MSG_IGNFLOW));
8110 		mutex_enter(&stp->sd_lock);
8111 		/*
8112 		 * Check for a missed wakeup.
8113 		 * Needed since strput did not hold sd_lock across
8114 		 * the canputnext.
8115 		 */
8116 		if (bcanputnext(wqp, pri)) {
8117 			/* Try again */
8118 			mutex_exit(&stp->sd_lock);
8119 			continue;
8120 		}
8121 		TRACE_2(TR_FAC_STREAMS_FR, TR_KSTRPUTMSG_WAIT,
8122 		    "kstrputmsg wait:stp %p waits pri %d", stp, pri);
8123 
8124 		waitflag = WRITEWAIT;
8125 		if (flag & (MSG_HOLDSIG|MSG_IGNERROR)) {
8126 			if (flag & MSG_HOLDSIG)
8127 				waitflag |= STR_NOSIG;
8128 			if (flag & MSG_IGNERROR)
8129 				waitflag |= STR_NOERROR;
8130 		}
8131 		if (((error = strwaitq(stp, waitflag,
8132 		    (ssize_t)0, fmode, -1, &done)) != 0) || done) {
8133 			mutex_exit(&stp->sd_lock);
8134 			TRACE_3(TR_FAC_STREAMS_FR, TR_KSTRPUTMSG_OUT,
8135 			    "kstrputmsg out:stp %p out %d error %d",
8136 			    stp, 0, error);
8137 			freemsg(mctl);
8138 			return (error);
8139 		}
8140 		TRACE_1(TR_FAC_STREAMS_FR, TR_KSTRPUTMSG_WAKE,
8141 		    "kstrputmsg wake:stp %p wakes", stp);
8142 		if ((error = i_straccess(stp, JCWRITE)) != 0) {
8143 			mutex_exit(&stp->sd_lock);
8144 			freemsg(mctl);
8145 			return (error);
8146 		}
8147 		mutex_exit(&stp->sd_lock);
8148 	}
8149 out:
8150 	freemsg(mctl);
8151 	/*
8152 	 * For historic reasons, applications expect EAGAIN
8153 	 * when data mblk could not be allocated. so change
8154 	 * ENOMEM back to EAGAIN
8155 	 */
8156 	if (error == ENOMEM)
8157 		error = EAGAIN;
8158 	TRACE_3(TR_FAC_STREAMS_FR, TR_KSTRPUTMSG_OUT,
8159 	    "kstrputmsg out:stp %p out %d error %d", stp, 2, error);
8160 	return (error);
8161 }
8162 
8163 /*
8164  * Determines whether the necessary conditions are set on a stream
8165  * for it to be readable, writeable, or have exceptions.
8166  *
8167  * strpoll handles the consolidation private events:
8168  *	POLLNOERR	Do not return POLLERR even if there are stream
8169  *			head errors.
8170  *			Used by sockfs.
8171  *	POLLRDDATA	Do not return POLLIN unless at least one message on
8172  *			the queue contains one or more M_DATA mblks. Thus
8173  *			when this flag is set a queue with only
8174  *			M_PROTO/M_PCPROTO mblks does not return POLLIN.
8175  *			Used by sockfs to ignore T_EXDATA_IND messages.
8176  *
8177  * Note: POLLRDDATA assumes that synch streams only return messages with
8178  * an M_DATA attached (i.e. not messages consisting of only
8179  * an M_PROTO/M_PCPROTO part).
8180  */
8181 int
8182 strpoll(
8183 	struct stdata *stp,
8184 	short events_arg,
8185 	int anyyet,
8186 	short *reventsp,
8187 	struct pollhead **phpp)
8188 {
8189 	int events = (ushort_t)events_arg;
8190 	int retevents = 0;
8191 	mblk_t *mp;
8192 	qband_t *qbp;
8193 	long sd_flags = stp->sd_flag;
8194 	int headlocked = 0;
8195 
8196 	/*
8197 	 * For performance, a single 'if' tests for most possible edge
8198 	 * conditions in one shot
8199 	 */
8200 	if (sd_flags & (STPLEX | STRDERR | STWRERR)) {
8201 		if (sd_flags & STPLEX) {
8202 			*reventsp = POLLNVAL;
8203 			return (EINVAL);
8204 		}
8205 		if (((events & (POLLIN | POLLRDNORM | POLLRDBAND | POLLPRI)) &&
8206 		    (sd_flags & STRDERR)) ||
8207 		    ((events & (POLLOUT | POLLWRNORM | POLLWRBAND)) &&
8208 		    (sd_flags & STWRERR))) {
8209 			if (!(events & POLLNOERR)) {
8210 				*reventsp = POLLERR;
8211 				return (0);
8212 			}
8213 		}
8214 	}
8215 	if (sd_flags & STRHUP) {
8216 		retevents |= POLLHUP;
8217 	} else if (events & (POLLWRNORM | POLLWRBAND)) {
8218 		queue_t *tq;
8219 		queue_t	*qp = stp->sd_wrq;
8220 
8221 		claimstr(qp);
8222 		/* Find next module forward that has a service procedure */
8223 		tq = qp->q_next->q_nfsrv;
8224 		ASSERT(tq != NULL);
8225 
8226 		polllock(&stp->sd_pollist, QLOCK(tq));
8227 		if (events & POLLWRNORM) {
8228 			queue_t *sqp;
8229 
8230 			if (tq->q_flag & QFULL)
8231 				/* ensure backq svc procedure runs */
8232 				tq->q_flag |= QWANTW;
8233 			else if ((sqp = stp->sd_struiowrq) != NULL) {
8234 				/* Check sync stream barrier write q */
8235 				mutex_exit(QLOCK(tq));
8236 				polllock(&stp->sd_pollist, QLOCK(sqp));
8237 				if (sqp->q_flag & QFULL)
8238 					/* ensure pollwakeup() is done */
8239 					sqp->q_flag |= QWANTWSYNC;
8240 				else
8241 					retevents |= POLLOUT;
8242 				/* More write events to process ??? */
8243 				if (! (events & POLLWRBAND)) {
8244 					mutex_exit(QLOCK(sqp));
8245 					releasestr(qp);
8246 					goto chkrd;
8247 				}
8248 				mutex_exit(QLOCK(sqp));
8249 				polllock(&stp->sd_pollist, QLOCK(tq));
8250 			} else
8251 				retevents |= POLLOUT;
8252 		}
8253 		if (events & POLLWRBAND) {
8254 			qbp = tq->q_bandp;
8255 			if (qbp) {
8256 				while (qbp) {
8257 					if (qbp->qb_flag & QB_FULL)
8258 						qbp->qb_flag |= QB_WANTW;
8259 					else
8260 						retevents |= POLLWRBAND;
8261 					qbp = qbp->qb_next;
8262 				}
8263 			} else {
8264 				retevents |= POLLWRBAND;
8265 			}
8266 		}
8267 		mutex_exit(QLOCK(tq));
8268 		releasestr(qp);
8269 	}
8270 chkrd:
8271 	if (sd_flags & STRPRI) {
8272 		retevents |= (events & POLLPRI);
8273 	} else if (events & (POLLRDNORM | POLLRDBAND | POLLIN)) {
8274 		queue_t	*qp = _RD(stp->sd_wrq);
8275 		int normevents = (events & (POLLIN | POLLRDNORM));
8276 
8277 		/*
8278 		 * Note: Need to do polllock() here since ps_lock may be
8279 		 * held. See bug 4191544.
8280 		 */
8281 		polllock(&stp->sd_pollist, &stp->sd_lock);
8282 		headlocked = 1;
8283 		mp = qp->q_first;
8284 		while (mp) {
8285 			/*
8286 			 * For POLLRDDATA we scan b_cont and b_next until we
8287 			 * find an M_DATA.
8288 			 */
8289 			if ((events & POLLRDDATA) &&
8290 			    mp->b_datap->db_type != M_DATA) {
8291 				mblk_t *nmp = mp->b_cont;
8292 
8293 				while (nmp != NULL &&
8294 				    nmp->b_datap->db_type != M_DATA)
8295 					nmp = nmp->b_cont;
8296 				if (nmp == NULL) {
8297 					mp = mp->b_next;
8298 					continue;
8299 				}
8300 			}
8301 			if (mp->b_band == 0)
8302 				retevents |= normevents;
8303 			else
8304 				retevents |= (events & (POLLIN | POLLRDBAND));
8305 			break;
8306 		}
8307 		if (! (retevents & normevents) &&
8308 		    (stp->sd_wakeq & RSLEEP)) {
8309 			/*
8310 			 * Sync stream barrier read queue has data.
8311 			 */
8312 			retevents |= normevents;
8313 		}
8314 		/* Treat eof as normal data */
8315 		if (sd_flags & STREOF)
8316 			retevents |= normevents;
8317 	}
8318 
8319 	*reventsp = (short)retevents;
8320 	if (retevents) {
8321 		if (headlocked)
8322 			mutex_exit(&stp->sd_lock);
8323 		return (0);
8324 	}
8325 
8326 	/*
8327 	 * If poll() has not found any events yet, set up event cell
8328 	 * to wake up the poll if a requested event occurs on this
8329 	 * stream.  Check for collisions with outstanding poll requests.
8330 	 */
8331 	if (!anyyet) {
8332 		*phpp = &stp->sd_pollist;
8333 		if (headlocked == 0) {
8334 			polllock(&stp->sd_pollist, &stp->sd_lock);
8335 			headlocked = 1;
8336 		}
8337 		stp->sd_rput_opt |= SR_POLLIN;
8338 	}
8339 	if (headlocked)
8340 		mutex_exit(&stp->sd_lock);
8341 	return (0);
8342 }
8343 
8344 /*
8345  * The purpose of putback() is to assure sleeping polls/reads
8346  * are awakened when there are no new messages arriving at the,
8347  * stream head, and a message is placed back on the read queue.
8348  *
8349  * sd_lock must be held when messages are placed back on stream
8350  * head.  (getq() holds sd_lock when it removes messages from
8351  * the queue)
8352  */
8353 
8354 static void
8355 putback(struct stdata *stp, queue_t *q, mblk_t *bp, int band)
8356 {
8357 	mblk_t	*qfirst;
8358 	ASSERT(MUTEX_HELD(&stp->sd_lock));
8359 
8360 	/*
8361 	 * As a result of lock-step ordering around q_lock and sd_lock,
8362 	 * it's possible for function calls like putnext() and
8363 	 * canputnext() to get an inaccurate picture of how much
8364 	 * data is really being processed at the stream head.
8365 	 * We only consolidate with existing messages on the queue
8366 	 * if the length of the message we want to put back is smaller
8367 	 * than the queue hiwater mark.
8368 	 */
8369 	if ((stp->sd_rput_opt & SR_CONSOL_DATA) &&
8370 	    (DB_TYPE(bp) == M_DATA) && ((qfirst = q->q_first) != NULL) &&
8371 	    (DB_TYPE(qfirst) == M_DATA) &&
8372 	    ((qfirst->b_flag & (MSGMARK|MSGDELIM)) == 0) &&
8373 	    ((bp->b_flag & (MSGMARK|MSGDELIM|MSGMARKNEXT)) == 0) &&
8374 	    (mp_cont_len(bp, NULL) < q->q_hiwat)) {
8375 		/*
8376 		 * We use the same logic as defined in strrput()
8377 		 * but in reverse as we are putting back onto the
8378 		 * queue and want to retain byte ordering.
8379 		 * Consolidate M_DATA messages with M_DATA ONLY.
8380 		 * strrput() allows the consolidation of M_DATA onto
8381 		 * M_PROTO | M_PCPROTO but not the other way round.
8382 		 *
8383 		 * The consolidation does not take place if the message
8384 		 * we are returning to the queue is marked with either
8385 		 * of the marks or the delim flag or if q_first
8386 		 * is marked with MSGMARK. The MSGMARK check is needed to
8387 		 * handle the odd semantics of MSGMARK where essentially
8388 		 * the whole message is to be treated as marked.
8389 		 * Carry any MSGMARKNEXT and MSGNOTMARKNEXT from q_first
8390 		 * to the front of the b_cont chain.
8391 		 */
8392 		rmvq_noenab(q, qfirst);
8393 
8394 		/*
8395 		 * The first message in the b_cont list
8396 		 * tracks MSGMARKNEXT and MSGNOTMARKNEXT.
8397 		 * We need to handle the case where we
8398 		 * are appending:
8399 		 *
8400 		 * 1) a MSGMARKNEXT to a MSGNOTMARKNEXT.
8401 		 * 2) a MSGMARKNEXT to a plain message.
8402 		 * 3) a MSGNOTMARKNEXT to a plain message
8403 		 * 4) a MSGNOTMARKNEXT to a MSGNOTMARKNEXT
8404 		 *    message.
8405 		 *
8406 		 * Thus we never append a MSGMARKNEXT or
8407 		 * MSGNOTMARKNEXT to a MSGMARKNEXT message.
8408 		 */
8409 		if (qfirst->b_flag & MSGMARKNEXT) {
8410 			bp->b_flag |= MSGMARKNEXT;
8411 			bp->b_flag &= ~MSGNOTMARKNEXT;
8412 			qfirst->b_flag &= ~MSGMARKNEXT;
8413 		} else if (qfirst->b_flag & MSGNOTMARKNEXT) {
8414 			bp->b_flag |= MSGNOTMARKNEXT;
8415 			qfirst->b_flag &= ~MSGNOTMARKNEXT;
8416 		}
8417 
8418 		linkb(bp, qfirst);
8419 	}
8420 	(void) putbq(q, bp);
8421 
8422 	/*
8423 	 * A message may have come in when the sd_lock was dropped in the
8424 	 * calling routine. If this is the case and STR*ATMARK info was
8425 	 * received, need to move that from the stream head to the q_last
8426 	 * so that SIOCATMARK can return the proper value.
8427 	 */
8428 	if (stp->sd_flag & (STRATMARK | STRNOTATMARK)) {
8429 		unsigned short *flagp = &q->q_last->b_flag;
8430 		uint_t b_flag = (uint_t)*flagp;
8431 
8432 		if (stp->sd_flag & STRATMARK) {
8433 			b_flag &= ~MSGNOTMARKNEXT;
8434 			b_flag |= MSGMARKNEXT;
8435 			stp->sd_flag &= ~STRATMARK;
8436 		} else {
8437 			b_flag &= ~MSGMARKNEXT;
8438 			b_flag |= MSGNOTMARKNEXT;
8439 			stp->sd_flag &= ~STRNOTATMARK;
8440 		}
8441 		*flagp = (unsigned short) b_flag;
8442 	}
8443 
8444 #ifdef	DEBUG
8445 	/*
8446 	 * Make sure that the flags are not messed up.
8447 	 */
8448 	{
8449 		mblk_t *mp;
8450 		mp = q->q_last;
8451 		while (mp != NULL) {
8452 			ASSERT((mp->b_flag & (MSGMARKNEXT|MSGNOTMARKNEXT)) !=
8453 			    (MSGMARKNEXT|MSGNOTMARKNEXT));
8454 			mp = mp->b_cont;
8455 		}
8456 	}
8457 #endif
8458 	if (q->q_first == bp) {
8459 		short pollevents;
8460 
8461 		if (stp->sd_flag & RSLEEP) {
8462 			stp->sd_flag &= ~RSLEEP;
8463 			cv_broadcast(&q->q_wait);
8464 		}
8465 		if (stp->sd_flag & STRPRI) {
8466 			pollevents = POLLPRI;
8467 		} else {
8468 			if (band == 0) {
8469 				if (!(stp->sd_rput_opt & SR_POLLIN))
8470 					return;
8471 				stp->sd_rput_opt &= ~SR_POLLIN;
8472 				pollevents = POLLIN | POLLRDNORM;
8473 			} else {
8474 				pollevents = POLLIN | POLLRDBAND;
8475 			}
8476 		}
8477 		mutex_exit(&stp->sd_lock);
8478 		pollwakeup(&stp->sd_pollist, pollevents);
8479 		mutex_enter(&stp->sd_lock);
8480 	}
8481 }
8482 
8483 /*
8484  * Return the held vnode attached to the stream head of a
8485  * given queue
8486  * It is the responsibility of the calling routine to ensure
8487  * that the queue does not go away (e.g. pop).
8488  */
8489 vnode_t *
8490 strq2vp(queue_t *qp)
8491 {
8492 	vnode_t *vp;
8493 	vp = STREAM(qp)->sd_vnode;
8494 	ASSERT(vp != NULL);
8495 	VN_HOLD(vp);
8496 	return (vp);
8497 }
8498 
8499 /*
8500  * return the stream head write queue for the given vp
8501  * It is the responsibility of the calling routine to ensure
8502  * that the stream or vnode do not close.
8503  */
8504 queue_t *
8505 strvp2wq(vnode_t *vp)
8506 {
8507 	ASSERT(vp->v_stream != NULL);
8508 	return (vp->v_stream->sd_wrq);
8509 }
8510 
8511 /*
8512  * pollwakeup stream head
8513  * It is the responsibility of the calling routine to ensure
8514  * that the stream or vnode do not close.
8515  */
8516 void
8517 strpollwakeup(vnode_t *vp, short event)
8518 {
8519 	ASSERT(vp->v_stream);
8520 	pollwakeup(&vp->v_stream->sd_pollist, event);
8521 }
8522 
8523 /*
8524  * Mate the stream heads of two vnodes together. If the two vnodes are the
8525  * same, we just make the write-side point at the read-side -- otherwise,
8526  * we do a full mate.  Only works on vnodes associated with streams that are
8527  * still being built and thus have only a stream head.
8528  */
8529 void
8530 strmate(vnode_t *vp1, vnode_t *vp2)
8531 {
8532 	queue_t *wrq1 = strvp2wq(vp1);
8533 	queue_t *wrq2 = strvp2wq(vp2);
8534 
8535 	/*
8536 	 * Verify that there are no modules on the stream yet.  We also
8537 	 * rely on the stream head always having a service procedure to
8538 	 * avoid tweaking q_nfsrv.
8539 	 */
8540 	ASSERT(wrq1->q_next == NULL && wrq2->q_next == NULL);
8541 	ASSERT(wrq1->q_qinfo->qi_srvp != NULL);
8542 	ASSERT(wrq2->q_qinfo->qi_srvp != NULL);
8543 
8544 	/*
8545 	 * If the queues are the same, just twist; otherwise do a full mate.
8546 	 */
8547 	if (wrq1 == wrq2) {
8548 		wrq1->q_next = _RD(wrq1);
8549 	} else {
8550 		wrq1->q_next = _RD(wrq2);
8551 		wrq2->q_next = _RD(wrq1);
8552 		STREAM(wrq1)->sd_mate = STREAM(wrq2);
8553 		STREAM(wrq1)->sd_flag |= STRMATE;
8554 		STREAM(wrq2)->sd_mate = STREAM(wrq1);
8555 		STREAM(wrq2)->sd_flag |= STRMATE;
8556 	}
8557 }
8558 
8559 /*
8560  * XXX will go away when console is correctly fixed.
8561  * Clean up the console PIDS, from previous I_SETSIG,
8562  * called only for cnopen which never calls strclean().
8563  */
8564 void
8565 str_cn_clean(struct vnode *vp)
8566 {
8567 	strsig_t *ssp, *pssp, *tssp;
8568 	struct stdata *stp;
8569 	struct pid  *pidp;
8570 	int update = 0;
8571 
8572 	ASSERT(vp->v_stream);
8573 	stp = vp->v_stream;
8574 	pssp = NULL;
8575 	mutex_enter(&stp->sd_lock);
8576 	ssp = stp->sd_siglist;
8577 	while (ssp) {
8578 		mutex_enter(&pidlock);
8579 		pidp = ssp->ss_pidp;
8580 		/*
8581 		 * Get rid of PID if the proc is gone.
8582 		 */
8583 		if (pidp->pid_prinactive) {
8584 			tssp = ssp->ss_next;
8585 			if (pssp)
8586 				pssp->ss_next = tssp;
8587 			else
8588 				stp->sd_siglist = tssp;
8589 			ASSERT(pidp->pid_ref <= 1);
8590 			PID_RELE(ssp->ss_pidp);
8591 			mutex_exit(&pidlock);
8592 			kmem_free(ssp, sizeof (strsig_t));
8593 			update = 1;
8594 			ssp = tssp;
8595 			continue;
8596 		} else
8597 			mutex_exit(&pidlock);
8598 		pssp = ssp;
8599 		ssp = ssp->ss_next;
8600 	}
8601 	if (update) {
8602 		stp->sd_sigflags = 0;
8603 		for (ssp = stp->sd_siglist; ssp; ssp = ssp->ss_next)
8604 			stp->sd_sigflags |= ssp->ss_events;
8605 	}
8606 	mutex_exit(&stp->sd_lock);
8607 }
8608 
8609 /*
8610  * Return B_TRUE if there is data in the message, B_FALSE otherwise.
8611  */
8612 static boolean_t
8613 msghasdata(mblk_t *bp)
8614 {
8615 	for (; bp; bp = bp->b_cont)
8616 		if (bp->b_datap->db_type == M_DATA) {
8617 			ASSERT(bp->b_wptr >= bp->b_rptr);
8618 			if (bp->b_wptr > bp->b_rptr)
8619 				return (B_TRUE);
8620 		}
8621 	return (B_FALSE);
8622 }
8623