xref: /illumos-gate/usr/src/uts/common/os/streamio.c (revision 2850d85b7b93f31e578520dc3b3feb24db609c62)
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 2007 Sun Microsystems, Inc.  All rights reserved.
27  * Use is subject to license terms.
28  */
29 
30 #pragma ident	"%Z%%M%	%I%	%E% SMI"
31 
32 #include <sys/types.h>
33 #include <sys/sysmacros.h>
34 #include <sys/param.h>
35 #include <sys/errno.h>
36 #include <sys/signal.h>
37 #include <sys/stat.h>
38 #include <sys/proc.h>
39 #include <sys/cred.h>
40 #include <sys/user.h>
41 #include <sys/vnode.h>
42 #include <sys/file.h>
43 #include <sys/stream.h>
44 #include <sys/strsubr.h>
45 #include <sys/stropts.h>
46 #include <sys/tihdr.h>
47 #include <sys/var.h>
48 #include <sys/poll.h>
49 #include <sys/termio.h>
50 #include <sys/ttold.h>
51 #include <sys/systm.h>
52 #include <sys/uio.h>
53 #include <sys/cmn_err.h>
54 #include <sys/sad.h>
55 #include <sys/netstack.h>
56 #include <sys/priocntl.h>
57 #include <sys/jioctl.h>
58 #include <sys/procset.h>
59 #include <sys/session.h>
60 #include <sys/kmem.h>
61 #include <sys/filio.h>
62 #include <sys/vtrace.h>
63 #include <sys/debug.h>
64 #include <sys/strredir.h>
65 #include <sys/fs/fifonode.h>
66 #include <sys/fs/snode.h>
67 #include <sys/strlog.h>
68 #include <sys/strsun.h>
69 #include <sys/project.h>
70 #include <sys/kbio.h>
71 #include <sys/msio.h>
72 #include <sys/tty.h>
73 #include <sys/ptyvar.h>
74 #include <sys/vuid_event.h>
75 #include <sys/modctl.h>
76 #include <sys/sunddi.h>
77 #include <sys/sunldi_impl.h>
78 #include <sys/autoconf.h>
79 #include <sys/policy.h>
80 #include <sys/zone.h>
81 
82 
83 /*
84  * This define helps improve the readability of streams code while
85  * still maintaining a very old streams performance enhancement.  The
86  * performance enhancement basically involved having all callers
87  * of straccess() perform the first check that straccess() will do
88  * locally before actually calling straccess().  (There by reducing
89  * the number of unnecessary calls to straccess().)
90  */
91 #define	i_straccess(x, y)	((stp->sd_sidp == NULL) ? 0 : \
92 				    (stp->sd_vnode->v_type == VFIFO) ? 0 : \
93 				    straccess((x), (y)))
94 
95 /*
96  * what is mblk_pull_len?
97  *
98  * If a streams message consists of many short messages,
99  * a performance degradation occurs from copyout overhead.
100  * To decrease the per mblk overhead, messages that are
101  * likely to consist of many small mblks are pulled up into
102  * one continuous chunk of memory.
103  *
104  * To avoid the processing overhead of examining every
105  * mblk, a quick heuristic is used. If the first mblk in
106  * the message is shorter than mblk_pull_len, it is likely
107  * that the rest of the mblk will be short.
108  *
109  * This heuristic was decided upon after performance tests
110  * indicated that anything more complex slowed down the main
111  * code path.
112  */
113 #define	MBLK_PULL_LEN 64
114 uint32_t mblk_pull_len = MBLK_PULL_LEN;
115 
116 /*
117  * The sgttyb_handling flag controls the handling of the old BSD
118  * TIOCGETP, TIOCSETP, and TIOCSETN ioctls as follows:
119  *
120  * 0 - Emit no warnings at all and retain old, broken behavior.
121  * 1 - Emit no warnings and silently handle new semantics.
122  * 2 - Send cmn_err(CE_NOTE) when either TIOCSETP or TIOCSETN is used
123  *     (once per system invocation).  Handle with new semantics.
124  * 3 - Send SIGSYS when any TIOCGETP, TIOCSETP, or TIOCSETN call is
125  *     made (so that offenders drop core and are easy to debug).
126  *
127  * The "new semantics" are that TIOCGETP returns B38400 for
128  * sg_[io]speed if the corresponding value is over B38400, and that
129  * TIOCSET[PN] accept B38400 in these cases to mean "retain current
130  * bit rate."
131  */
132 int sgttyb_handling = 1;
133 static boolean_t sgttyb_complaint;
134 
135 /* don't push drcompat module by default on Style-2 streams */
136 static int push_drcompat = 0;
137 
138 /*
139  * id value used to distinguish between different ioctl messages
140  */
141 static uint32_t ioc_id;
142 
143 static void putback(struct stdata *, queue_t *, mblk_t *, int);
144 static void strcleanall(struct vnode *);
145 static int strwsrv(queue_t *);
146 
147 /*
148  * qinit and module_info structures for stream head read and write queues
149  */
150 struct module_info strm_info = { 0, "strrhead", 0, INFPSZ, STRHIGH, STRLOW };
151 struct module_info stwm_info = { 0, "strwhead", 0, 0, 0, 0 };
152 struct qinit strdata = { strrput, NULL, NULL, NULL, NULL, &strm_info };
153 struct qinit stwdata = { NULL, strwsrv, NULL, NULL, NULL, &stwm_info };
154 struct module_info fiform_info = { 0, "fifostrrhead", 0, PIPE_BUF, FIFOHIWAT,
155     FIFOLOWAT };
156 struct module_info fifowm_info = { 0, "fifostrwhead", 0, 0, 0, 0 };
157 struct qinit fifo_strdata = { strrput, NULL, NULL, NULL, NULL, &fiform_info };
158 struct qinit fifo_stwdata = { NULL, strwsrv, NULL, NULL, NULL, &fifowm_info };
159 
160 extern kmutex_t	strresources;	/* protects global resources */
161 extern kmutex_t muxifier;	/* single-threads multiplexor creation */
162 
163 static boolean_t msghasdata(mblk_t *bp);
164 #define	msgnodata(bp) (!msghasdata(bp))
165 
166 /*
167  * Stream head locking notes:
168  *	There are four monitors associated with the stream head:
169  *	1. v_stream monitor: in stropen() and strclose() v_lock
170  *		is held while the association of vnode and stream
171  *		head is established or tested for.
172  *	2. open/close/push/pop monitor: sd_lock is held while each
173  *		thread bids for exclusive access to this monitor
174  *		for opening or closing a stream.  In addition, this
175  *		monitor is entered during pushes and pops.  This
176  *		guarantees that during plumbing operations there
177  *		is only one thread trying to change the plumbing.
178  *		Any other threads present in the stream are only
179  *		using the plumbing.
180  *	3. read/write monitor: in the case of read, a thread holds
181  *		sd_lock while trying to get data from the stream
182  *		head queue.  if there is none to fulfill a read
183  *		request, it sets RSLEEP and calls cv_wait_sig() down
184  *		in strwaitq() to await the arrival of new data.
185  *		when new data arrives in strrput(), sd_lock is acquired
186  *		before testing for RSLEEP and calling cv_broadcast().
187  *		the behavior of strwrite(), strwsrv(), and WSLEEP
188  *		mirror this.
189  *	4. ioctl monitor: sd_lock is gotten to ensure that only one
190  *		thread is doing an ioctl at a time.
191  */
192 
193 static int
194 push_mod(queue_t *qp, dev_t *devp, struct stdata *stp, const char *name,
195     int anchor, cred_t *crp, uint_t anchor_zoneid)
196 {
197 	int error;
198 	fmodsw_impl_t *fp;
199 
200 	if (stp->sd_flag & (STRHUP|STRDERR|STWRERR)) {
201 		error = (stp->sd_flag & STRHUP) ? ENXIO : EIO;
202 		return (error);
203 	}
204 	if (stp->sd_pushcnt >= nstrpush) {
205 		return (EINVAL);
206 	}
207 
208 	if ((fp = fmodsw_find(name, FMODSW_HOLD | FMODSW_LOAD)) == NULL) {
209 		stp->sd_flag |= STREOPENFAIL;
210 		return (EINVAL);
211 	}
212 
213 	/*
214 	 * push new module and call its open routine via qattach
215 	 */
216 	if ((error = qattach(qp, devp, 0, crp, fp, B_FALSE)) != 0)
217 		return (error);
218 
219 	/*
220 	 * Check to see if caller wants a STREAMS anchor
221 	 * put at this place in the stream, and add if so.
222 	 */
223 	mutex_enter(&stp->sd_lock);
224 	if (anchor == stp->sd_pushcnt) {
225 		stp->sd_anchor = stp->sd_pushcnt;
226 		stp->sd_anchorzone = anchor_zoneid;
227 	}
228 	mutex_exit(&stp->sd_lock);
229 
230 	return (0);
231 }
232 
233 /*
234  * Open a stream device.
235  */
236 int
237 stropen(vnode_t *vp, dev_t *devp, int flag, cred_t *crp)
238 {
239 	struct stdata *stp;
240 	queue_t *qp;
241 	int s;
242 	dev_t dummydev;
243 	struct autopush *ap;
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_pushcnt = 0;
394 	stp->sd_qn_minpsz = 0;
395 	stp->sd_qn_maxpsz = INFPSZ - 1;	/* used to check for initialization */
396 	stp->sd_maxblk = INFPSZ;
397 	qp->q_ptr = _WR(qp)->q_ptr = stp;
398 	STREAM(qp) = STREAM(_WR(qp)) = stp;
399 	vp->v_stream = stp;
400 	mutex_exit(&vp->v_lock);
401 	if (vp->v_type == VFIFO) {
402 		stp->sd_flag |= OLDNDELAY;
403 		/*
404 		 * This means, both for pipes and fifos
405 		 * strwrite will send SIGPIPE if the other
406 		 * end is closed. For putmsg it depends
407 		 * on whether it is a XPG4_2 application
408 		 * or not
409 		 */
410 		stp->sd_wput_opt = SW_SIGPIPE;
411 
412 		/* setq might sleep in kmem_alloc - avoid holding locks. */
413 		setq(qp, &fifo_strdata, &fifo_stwdata, NULL, QMTSAFE,
414 		    SQ_CI|SQ_CO, B_FALSE);
415 
416 		set_qend(qp);
417 		stp->sd_strtab = fifo_getinfo();
418 		_WR(qp)->q_nfsrv = _WR(qp);
419 		qp->q_nfsrv = qp;
420 		/*
421 		 * Wake up others that are waiting for stream to be created.
422 		 */
423 		mutex_enter(&stp->sd_lock);
424 		/*
425 		 * nothing is be pushed on stream yet, so
426 		 * optimized stream head packetsizes are just that
427 		 * of the read queue
428 		 */
429 		stp->sd_qn_minpsz = qp->q_minpsz;
430 		stp->sd_qn_maxpsz = qp->q_maxpsz;
431 		stp->sd_flag &= ~STWOPEN;
432 		goto fifo_opendone;
433 	}
434 	/* setq might sleep in kmem_alloc - avoid holding locks. */
435 	setq(qp, &strdata, &stwdata, NULL, QMTSAFE, SQ_CI|SQ_CO, B_FALSE);
436 
437 	set_qend(qp);
438 
439 	/*
440 	 * Open driver and create stream to it (via qattach).
441 	 */
442 	cloneopen = (getmajor(*devp) == clone_major);
443 	if ((error = qattach(qp, devp, flag, crp, NULL, B_FALSE)) != 0) {
444 		mutex_enter(&vp->v_lock);
445 		vp->v_stream = NULL;
446 		mutex_exit(&vp->v_lock);
447 		mutex_enter(&stp->sd_lock);
448 		cv_broadcast(&stp->sd_monitor);
449 		mutex_exit(&stp->sd_lock);
450 		freeq(_RD(qp));
451 		shfree(stp);
452 		return (error);
453 	}
454 	/*
455 	 * Set sd_strtab after open in order to handle clonable drivers
456 	 */
457 	stp->sd_strtab = STREAMSTAB(getmajor(*devp));
458 
459 	/*
460 	 * Historical note: dummydev used to be be prior to the initial
461 	 * open (via qattach above), which made the value seen
462 	 * inconsistent between an I_PUSH and an autopush of a module.
463 	 */
464 	dummydev = *devp;
465 
466 	/*
467 	 * For clone open of old style (Q not associated) network driver,
468 	 * push DRMODNAME module to handle DL_ATTACH/DL_DETACH
469 	 */
470 	brq = _RD(_WR(qp)->q_next);
471 	major = getmajor(*devp);
472 	if (push_drcompat && cloneopen && NETWORK_DRV(major) &&
473 	    ((brq->q_flag & _QASSOCIATED) == 0)) {
474 		if (push_mod(qp, &dummydev, stp, DRMODNAME, 0, crp, 0) != 0)
475 			cmn_err(CE_WARN, "cannot push " DRMODNAME
476 			    " streams module");
477 	}
478 
479 	/*
480 	 * Check for autopush. Start with the global zone. If not found
481 	 * check in the local zone.
482 	 */
483 	zoneid = GLOBAL_ZONEID;
484 retryap:
485 	ss = netstack_find_by_stackid(zoneid_to_netstackid(zoneid))->
486 	    netstack_str;
487 	if ((ap = sad_ap_find_by_dev(*devp, ss)) == NULL) {
488 		netstack_rele(ss->ss_netstack);
489 		if (zoneid == GLOBAL_ZONEID) {
490 			/*
491 			 * None found. Also look in the zone's autopush table.
492 			 */
493 			zoneid = crgetzoneid(crp);
494 			if (zoneid != GLOBAL_ZONEID)
495 				goto retryap;
496 		}
497 		goto opendone;
498 	}
499 	anchor = ap->ap_anchor;
500 	zoneid = crgetzoneid(crp);
501 	for (s = 0; s < ap->ap_npush; s++) {
502 		error = push_mod(qp, &dummydev, stp, ap->ap_list[s],
503 		    anchor, crp, zoneid);
504 		if (error != 0)
505 			break;
506 	}
507 	sad_ap_rele(ap, ss);
508 	netstack_rele(ss->ss_netstack);
509 
510 	/*
511 	 * let specfs know that open failed part way through
512 	 */
513 	if (error) {
514 		mutex_enter(&stp->sd_lock);
515 		stp->sd_flag |= STREOPENFAIL;
516 		mutex_exit(&stp->sd_lock);
517 	}
518 
519 opendone:
520 
521 	/*
522 	 * Wake up others that are waiting for stream to be created.
523 	 */
524 	mutex_enter(&stp->sd_lock);
525 	stp->sd_flag &= ~STWOPEN;
526 
527 	/*
528 	 * As a performance concern we are caching the values of
529 	 * q_minpsz and q_maxpsz of the module below the stream
530 	 * head in the stream head.
531 	 */
532 	mutex_enter(QLOCK(stp->sd_wrq->q_next));
533 	rmin = stp->sd_wrq->q_next->q_minpsz;
534 	rmax = stp->sd_wrq->q_next->q_maxpsz;
535 	mutex_exit(QLOCK(stp->sd_wrq->q_next));
536 
537 	/* do this processing here as a performance concern */
538 	if (strmsgsz != 0) {
539 		if (rmax == INFPSZ)
540 			rmax = strmsgsz;
541 		else
542 			rmax = MIN(strmsgsz, rmax);
543 	}
544 
545 	mutex_enter(QLOCK(stp->sd_wrq));
546 	stp->sd_qn_minpsz = rmin;
547 	stp->sd_qn_maxpsz = rmax;
548 	mutex_exit(QLOCK(stp->sd_wrq));
549 
550 fifo_opendone:
551 	cv_broadcast(&stp->sd_monitor);
552 	mutex_exit(&stp->sd_lock);
553 	return (error);
554 }
555 
556 static int strsink(queue_t *, mblk_t *);
557 static struct qinit deadrend = {
558 	strsink, NULL, NULL, NULL, NULL, &strm_info, NULL
559 };
560 static struct qinit deadwend = {
561 	NULL, NULL, NULL, NULL, NULL, &stwm_info, NULL
562 };
563 
564 /*
565  * Close a stream.
566  * This is called from closef() on the last close of an open stream.
567  * Strclean() will already have removed the siglist and pollist
568  * information, so all that remains is to remove all multiplexor links
569  * for the stream, pop all the modules (and the driver), and free the
570  * stream structure.
571  */
572 
573 int
574 strclose(struct vnode *vp, int flag, cred_t *crp)
575 {
576 	struct stdata *stp;
577 	queue_t *qp;
578 	int rval;
579 	int freestp = 1;
580 	queue_t *rmq;
581 
582 	if (audit_active)
583 		audit_strclose(vp, flag, crp);
584 
585 	TRACE_1(TR_FAC_STREAMS_FR,
586 	    TR_STRCLOSE, "strclose:%p", vp);
587 	ASSERT(vp->v_stream);
588 
589 	stp = vp->v_stream;
590 	ASSERT(!(stp->sd_flag & STPLEX));
591 	qp = stp->sd_wrq;
592 
593 	/*
594 	 * Needed so that strpoll will return non-zero for this fd.
595 	 * Note that with POLLNOERR STRHUP does still cause POLLHUP.
596 	 */
597 	mutex_enter(&stp->sd_lock);
598 	stp->sd_flag |= STRHUP;
599 	mutex_exit(&stp->sd_lock);
600 
601 	/*
602 	 * If the registered process or process group did not have an
603 	 * open instance of this stream then strclean would not be
604 	 * called. Thus at the time of closing all remaining siglist entries
605 	 * are removed.
606 	 */
607 	if (stp->sd_siglist != NULL)
608 		strcleanall(vp);
609 
610 	ASSERT(stp->sd_siglist == NULL);
611 	ASSERT(stp->sd_sigflags == 0);
612 
613 	if (STRMATED(stp)) {
614 		struct stdata *strmatep = stp->sd_mate;
615 		int waited = 1;
616 
617 		STRLOCKMATES(stp);
618 		while (waited) {
619 			waited = 0;
620 			while (stp->sd_flag & (STWOPEN|STRCLOSE|STRPLUMB)) {
621 				mutex_exit(&strmatep->sd_lock);
622 				cv_wait(&stp->sd_monitor, &stp->sd_lock);
623 				mutex_exit(&stp->sd_lock);
624 				STRLOCKMATES(stp);
625 				waited = 1;
626 			}
627 			while (strmatep->sd_flag &
628 			    (STWOPEN|STRCLOSE|STRPLUMB)) {
629 				mutex_exit(&stp->sd_lock);
630 				cv_wait(&strmatep->sd_monitor,
631 				    &strmatep->sd_lock);
632 				mutex_exit(&strmatep->sd_lock);
633 				STRLOCKMATES(stp);
634 				waited = 1;
635 			}
636 		}
637 		stp->sd_flag |= STRCLOSE;
638 		STRUNLOCKMATES(stp);
639 	} else {
640 		mutex_enter(&stp->sd_lock);
641 		stp->sd_flag |= STRCLOSE;
642 		mutex_exit(&stp->sd_lock);
643 	}
644 
645 	ASSERT(qp->q_first == NULL);	/* No more delayed write */
646 
647 	/* Check if an I_LINK was ever done on this stream */
648 	if (stp->sd_flag & STRHASLINKS) {
649 		netstack_t *ns;
650 		str_stack_t *ss;
651 
652 		ns = netstack_find_by_cred(crp);
653 		ASSERT(ns != NULL);
654 		ss = ns->netstack_str;
655 		ASSERT(ss != NULL);
656 
657 		(void) munlinkall(stp, LINKCLOSE|LINKNORMAL, crp, &rval, ss);
658 		netstack_rele(ss->ss_netstack);
659 	}
660 
661 	while (_SAMESTR(qp)) {
662 		/*
663 		 * Holding sd_lock prevents q_next from changing in
664 		 * this stream.
665 		 */
666 		mutex_enter(&stp->sd_lock);
667 		if (!(flag & (FNDELAY|FNONBLOCK)) && (stp->sd_closetime > 0)) {
668 
669 			/*
670 			 * sleep until awakened by strwsrv() or timeout
671 			 */
672 			for (;;) {
673 				mutex_enter(QLOCK(qp->q_next));
674 				if (!(qp->q_next->q_mblkcnt)) {
675 					mutex_exit(QLOCK(qp->q_next));
676 					break;
677 				}
678 				stp->sd_flag |= WSLEEP;
679 
680 				/* ensure strwsrv gets enabled */
681 				qp->q_next->q_flag |= QWANTW;
682 				mutex_exit(QLOCK(qp->q_next));
683 				/* get out if we timed out or recv'd a signal */
684 				if (str_cv_wait(&qp->q_wait, &stp->sd_lock,
685 				    stp->sd_closetime, 0) <= 0) {
686 					break;
687 				}
688 			}
689 			stp->sd_flag &= ~WSLEEP;
690 		}
691 		mutex_exit(&stp->sd_lock);
692 
693 		rmq = qp->q_next;
694 		if (rmq->q_flag & QISDRV) {
695 			ASSERT(!_SAMESTR(rmq));
696 			wait_sq_svc(_RD(qp)->q_syncq);
697 		}
698 
699 		qdetach(_RD(rmq), 1, flag, crp, B_FALSE);
700 	}
701 
702 	/*
703 	 * Since we call pollwakeup in close() now, the poll list should
704 	 * be empty in most cases. The only exception is the layered devices
705 	 * (e.g. the console drivers with redirection modules pushed on top
706 	 * of it).  We have to do this after calling qdetach() because
707 	 * the redirection module won't have torn down the console
708 	 * redirection until after qdetach() has been invoked.
709 	 */
710 	if (stp->sd_pollist.ph_list != NULL) {
711 		pollwakeup(&stp->sd_pollist, POLLERR);
712 		pollhead_clean(&stp->sd_pollist);
713 	}
714 	ASSERT(stp->sd_pollist.ph_list == NULL);
715 	ASSERT(stp->sd_sidp == NULL);
716 	ASSERT(stp->sd_pgidp == NULL);
717 
718 	/* Prevent qenable from re-enabling the stream head queue */
719 	disable_svc(_RD(qp));
720 
721 	/*
722 	 * Wait until service procedure of each queue is
723 	 * run, if QINSERVICE is set.
724 	 */
725 	wait_svc(_RD(qp));
726 
727 	/*
728 	 * Now, flush both queues.
729 	 */
730 	flushq(_RD(qp), FLUSHALL);
731 	flushq(qp, FLUSHALL);
732 
733 	/*
734 	 * If the write queue of the stream head is pointing to a
735 	 * read queue, we have a twisted stream.  If the read queue
736 	 * is alive, convert the stream head queues into a dead end.
737 	 * If the read queue is dead, free the dead pair.
738 	 */
739 	if (qp->q_next && !_SAMESTR(qp)) {
740 		if (qp->q_next->q_qinfo == &deadrend) {	/* half-closed pipe */
741 			flushq(qp->q_next, FLUSHALL); /* ensure no message */
742 			shfree(qp->q_next->q_stream);
743 			freeq(qp->q_next);
744 			freeq(_RD(qp));
745 		} else if (qp->q_next == _RD(qp)) {	/* fifo */
746 			freeq(_RD(qp));
747 		} else {				/* pipe */
748 			freestp = 0;
749 			/*
750 			 * The q_info pointers are never accessed when
751 			 * SQLOCK is held.
752 			 */
753 			ASSERT(qp->q_syncq == _RD(qp)->q_syncq);
754 			mutex_enter(SQLOCK(qp->q_syncq));
755 			qp->q_qinfo = &deadwend;
756 			_RD(qp)->q_qinfo = &deadrend;
757 			mutex_exit(SQLOCK(qp->q_syncq));
758 		}
759 	} else {
760 		freeq(_RD(qp)); /* free stream head queue pair */
761 	}
762 
763 	mutex_enter(&vp->v_lock);
764 	if (stp->sd_iocblk) {
765 		if (stp->sd_iocblk != (mblk_t *)-1) {
766 			freemsg(stp->sd_iocblk);
767 		}
768 		stp->sd_iocblk = NULL;
769 	}
770 	stp->sd_vnode = NULL;
771 	vp->v_stream = NULL;
772 	mutex_exit(&vp->v_lock);
773 	mutex_enter(&stp->sd_lock);
774 	stp->sd_flag &= ~STRCLOSE;
775 	cv_broadcast(&stp->sd_monitor);
776 	mutex_exit(&stp->sd_lock);
777 
778 	if (freestp)
779 		shfree(stp);
780 	return (0);
781 }
782 
783 static int
784 strsink(queue_t *q, mblk_t *bp)
785 {
786 	struct copyresp *resp;
787 
788 	switch (bp->b_datap->db_type) {
789 	case M_FLUSH:
790 		if ((*bp->b_rptr & FLUSHW) && !(bp->b_flag & MSGNOLOOP)) {
791 			*bp->b_rptr &= ~FLUSHR;
792 			bp->b_flag |= MSGNOLOOP;
793 			/*
794 			 * Protect against the driver passing up
795 			 * messages after it has done a qprocsoff.
796 			 */
797 			if (_OTHERQ(q)->q_next == NULL)
798 				freemsg(bp);
799 			else
800 				qreply(q, bp);
801 		} else {
802 			freemsg(bp);
803 		}
804 		break;
805 
806 	case M_COPYIN:
807 	case M_COPYOUT:
808 		if (bp->b_cont) {
809 			freemsg(bp->b_cont);
810 			bp->b_cont = NULL;
811 		}
812 		bp->b_datap->db_type = M_IOCDATA;
813 		bp->b_wptr = bp->b_rptr + sizeof (struct copyresp);
814 		resp = (struct copyresp *)bp->b_rptr;
815 		resp->cp_rval = (caddr_t)1;	/* failure */
816 		/*
817 		 * Protect against the driver passing up
818 		 * messages after it has done a qprocsoff.
819 		 */
820 		if (_OTHERQ(q)->q_next == NULL)
821 			freemsg(bp);
822 		else
823 			qreply(q, bp);
824 		break;
825 
826 	case M_IOCTL:
827 		if (bp->b_cont) {
828 			freemsg(bp->b_cont);
829 			bp->b_cont = NULL;
830 		}
831 		bp->b_datap->db_type = M_IOCNAK;
832 		/*
833 		 * Protect against the driver passing up
834 		 * messages after it has done a qprocsoff.
835 		 */
836 		if (_OTHERQ(q)->q_next == NULL)
837 			freemsg(bp);
838 		else
839 			qreply(q, bp);
840 		break;
841 
842 	default:
843 		freemsg(bp);
844 		break;
845 	}
846 
847 	return (0);
848 }
849 
850 /*
851  * Clean up after a process when it closes a stream.  This is called
852  * from closef for all closes, whereas strclose is called only for the
853  * last close on a stream.  The siglist is scanned for entries for the
854  * current process, and these are removed.
855  */
856 void
857 strclean(struct vnode *vp)
858 {
859 	strsig_t *ssp, *pssp, *tssp;
860 	stdata_t *stp;
861 	int update = 0;
862 
863 	TRACE_1(TR_FAC_STREAMS_FR,
864 	    TR_STRCLEAN, "strclean:%p", vp);
865 	stp = vp->v_stream;
866 	pssp = NULL;
867 	mutex_enter(&stp->sd_lock);
868 	ssp = stp->sd_siglist;
869 	while (ssp) {
870 		if (ssp->ss_pidp == curproc->p_pidp) {
871 			tssp = ssp->ss_next;
872 			if (pssp)
873 				pssp->ss_next = tssp;
874 			else
875 				stp->sd_siglist = tssp;
876 			mutex_enter(&pidlock);
877 			PID_RELE(ssp->ss_pidp);
878 			mutex_exit(&pidlock);
879 			kmem_free(ssp, sizeof (strsig_t));
880 			update = 1;
881 			ssp = tssp;
882 		} else {
883 			pssp = ssp;
884 			ssp = ssp->ss_next;
885 		}
886 	}
887 	if (update) {
888 		stp->sd_sigflags = 0;
889 		for (ssp = stp->sd_siglist; ssp; ssp = ssp->ss_next)
890 			stp->sd_sigflags |= ssp->ss_events;
891 	}
892 	mutex_exit(&stp->sd_lock);
893 }
894 
895 /*
896  * Used on the last close to remove any remaining items on the siglist.
897  * These could be present on the siglist due to I_ESETSIG calls that
898  * use process groups or processed that do not have an open file descriptor
899  * for this stream (Such entries would not be removed by strclean).
900  */
901 static void
902 strcleanall(struct vnode *vp)
903 {
904 	strsig_t *ssp, *nssp;
905 	stdata_t *stp;
906 
907 	stp = vp->v_stream;
908 	mutex_enter(&stp->sd_lock);
909 	ssp = stp->sd_siglist;
910 	stp->sd_siglist = NULL;
911 	while (ssp) {
912 		nssp = ssp->ss_next;
913 		mutex_enter(&pidlock);
914 		PID_RELE(ssp->ss_pidp);
915 		mutex_exit(&pidlock);
916 		kmem_free(ssp, sizeof (strsig_t));
917 		ssp = nssp;
918 	}
919 	stp->sd_sigflags = 0;
920 	mutex_exit(&stp->sd_lock);
921 }
922 
923 /*
924  * Retrieve the next message from the logical stream head read queue
925  * using either rwnext (if sync stream) or getq_noenab.
926  * It is the callers responsibility to call qbackenable after
927  * it is finished with the message. The caller should not call
928  * qbackenable until after any putback calls to avoid spurious backenabling.
929  */
930 mblk_t *
931 strget(struct stdata *stp, queue_t *q, struct uio *uiop, int first,
932     int *errorp)
933 {
934 	mblk_t *bp;
935 	int error;
936 
937 	ASSERT(MUTEX_HELD(&stp->sd_lock));
938 	/* Holding sd_lock prevents the read queue from changing  */
939 
940 	if (uiop != NULL && stp->sd_struiordq != NULL &&
941 	    q->q_first == NULL &&
942 	    (!first || (stp->sd_wakeq & RSLEEP))) {
943 		/*
944 		 * Stream supports rwnext() for the read side.
945 		 * If this is the first time we're called by e.g. strread
946 		 * only do the downcall if there is a deferred wakeup
947 		 * (registered in sd_wakeq).
948 		 */
949 		struiod_t uiod;
950 
951 		if (first)
952 			stp->sd_wakeq &= ~RSLEEP;
953 
954 		(void) uiodup(uiop, &uiod.d_uio, uiod.d_iov,
955 		    sizeof (uiod.d_iov) / sizeof (*uiod.d_iov));
956 		uiod.d_mp = 0;
957 		/*
958 		 * Mark that a thread is in rwnext on the read side
959 		 * to prevent strrput from nacking ioctls immediately.
960 		 * When the last concurrent rwnext returns
961 		 * the ioctls are nack'ed.
962 		 */
963 		ASSERT(MUTEX_HELD(&stp->sd_lock));
964 		stp->sd_struiodnak++;
965 		/*
966 		 * Note: rwnext will drop sd_lock.
967 		 */
968 		error = rwnext(q, &uiod);
969 		ASSERT(MUTEX_NOT_HELD(&stp->sd_lock));
970 		mutex_enter(&stp->sd_lock);
971 		stp->sd_struiodnak--;
972 		while (stp->sd_struiodnak == 0 &&
973 		    ((bp = stp->sd_struionak) != NULL)) {
974 			stp->sd_struionak = bp->b_next;
975 			bp->b_next = NULL;
976 			bp->b_datap->db_type = M_IOCNAK;
977 			/*
978 			 * Protect against the driver passing up
979 			 * messages after it has done a qprocsoff.
980 			 */
981 			if (_OTHERQ(q)->q_next == NULL)
982 				freemsg(bp);
983 			else {
984 				mutex_exit(&stp->sd_lock);
985 				qreply(q, bp);
986 				mutex_enter(&stp->sd_lock);
987 			}
988 		}
989 		ASSERT(MUTEX_HELD(&stp->sd_lock));
990 		if (error == 0 || error == EWOULDBLOCK) {
991 			if ((bp = uiod.d_mp) != NULL) {
992 				*errorp = 0;
993 				ASSERT(MUTEX_HELD(&stp->sd_lock));
994 				return (bp);
995 			}
996 			error = 0;
997 		} else if (error == EINVAL) {
998 			/*
999 			 * The stream plumbing must have
1000 			 * changed while we were away, so
1001 			 * just turn off rwnext()s.
1002 			 */
1003 			error = 0;
1004 		} else if (error == EBUSY) {
1005 			/*
1006 			 * The module might have data in transit using putnext
1007 			 * Fall back on waiting + getq.
1008 			 */
1009 			error = 0;
1010 		} else {
1011 			*errorp = error;
1012 			ASSERT(MUTEX_HELD(&stp->sd_lock));
1013 			return (NULL);
1014 		}
1015 		/*
1016 		 * Try a getq in case a rwnext() generated mblk
1017 		 * has bubbled up via strrput().
1018 		 */
1019 	}
1020 	*errorp = 0;
1021 	ASSERT(MUTEX_HELD(&stp->sd_lock));
1022 	return (getq_noenab(q));
1023 }
1024 
1025 /*
1026  * Copy out the message pointed to by `bp' into the uio pointed to by `uiop'.
1027  * If the message does not fit in the uio the remainder of it is returned;
1028  * otherwise NULL is returned.  Any embedded zero-length mblk_t's are
1029  * consumed, even if uio_resid reaches zero.  On error, `*errorp' is set to
1030  * the error code, the message is consumed, and NULL is returned.
1031  */
1032 static mblk_t *
1033 struiocopyout(mblk_t *bp, struct uio *uiop, int *errorp)
1034 {
1035 	int error;
1036 	ptrdiff_t n;
1037 	mblk_t *nbp;
1038 
1039 	ASSERT(bp->b_wptr >= bp->b_rptr);
1040 
1041 	do {
1042 		if ((n = MIN(uiop->uio_resid, MBLKL(bp))) != 0) {
1043 			ASSERT(n > 0);
1044 
1045 			error = uiomove(bp->b_rptr, n, UIO_READ, uiop);
1046 			if (error != 0) {
1047 				freemsg(bp);
1048 				*errorp = error;
1049 				return (NULL);
1050 			}
1051 		}
1052 
1053 		bp->b_rptr += n;
1054 		while (bp != NULL && (bp->b_rptr >= bp->b_wptr)) {
1055 			nbp = bp;
1056 			bp = bp->b_cont;
1057 			freeb(nbp);
1058 		}
1059 	} while (bp != NULL && uiop->uio_resid > 0);
1060 
1061 	*errorp = 0;
1062 	return (bp);
1063 }
1064 
1065 /*
1066  * Read a stream according to the mode flags in sd_flag:
1067  *
1068  * (default mode)		- Byte stream, msg boundaries are ignored
1069  * RD_MSGDIS (msg discard)	- Read on msg boundaries and throw away
1070  *				any data remaining in msg
1071  * RD_MSGNODIS (msg non-discard) - Read on msg boundaries and put back
1072  *				any remaining data on head of read queue
1073  *
1074  * Consume readable messages on the front of the queue until
1075  * ttolwp(curthread)->lwp_count
1076  * is satisfied, the readable messages are exhausted, or a message
1077  * boundary is reached in a message mode.  If no data was read and
1078  * the stream was not opened with the NDELAY flag, block until data arrives.
1079  * Otherwise return the data read and update the count.
1080  *
1081  * In default mode a 0 length message signifies end-of-file and terminates
1082  * a read in progress.  The 0 length message is removed from the queue
1083  * only if it is the only message read (no data is read).
1084  *
1085  * An attempt to read an M_PROTO or M_PCPROTO message results in an
1086  * EBADMSG error return, unless either RD_PROTDAT or RD_PROTDIS are set.
1087  * If RD_PROTDAT is set, M_PROTO and M_PCPROTO messages are read as data.
1088  * If RD_PROTDIS is set, the M_PROTO and M_PCPROTO parts of the message
1089  * are unlinked from and M_DATA blocks in the message, the protos are
1090  * thrown away, and the data is read.
1091  */
1092 /* ARGSUSED */
1093 int
1094 strread(struct vnode *vp, struct uio *uiop, cred_t *crp)
1095 {
1096 	struct stdata *stp;
1097 	mblk_t *bp, *nbp;
1098 	queue_t *q;
1099 	int error = 0;
1100 	uint_t old_sd_flag;
1101 	int first;
1102 	char rflg;
1103 	uint_t mark;		/* Contains MSG*MARK and _LASTMARK */
1104 #define	_LASTMARK	0x8000	/* Distinct from MSG*MARK */
1105 	short delim;
1106 	unsigned char pri = 0;
1107 	char waitflag;
1108 	unsigned char type;
1109 
1110 	TRACE_1(TR_FAC_STREAMS_FR,
1111 	    TR_STRREAD_ENTER, "strread:%p", vp);
1112 	ASSERT(vp->v_stream);
1113 	stp = vp->v_stream;
1114 
1115 	mutex_enter(&stp->sd_lock);
1116 
1117 	if ((error = i_straccess(stp, JCREAD)) != 0) {
1118 		mutex_exit(&stp->sd_lock);
1119 		return (error);
1120 	}
1121 
1122 	if (stp->sd_flag & (STRDERR|STPLEX)) {
1123 		error = strgeterr(stp, STRDERR|STPLEX, 0);
1124 		if (error != 0) {
1125 			mutex_exit(&stp->sd_lock);
1126 			return (error);
1127 		}
1128 	}
1129 
1130 	/*
1131 	 * Loop terminates when uiop->uio_resid == 0.
1132 	 */
1133 	rflg = 0;
1134 	waitflag = READWAIT;
1135 	q = _RD(stp->sd_wrq);
1136 	for (;;) {
1137 		ASSERT(MUTEX_HELD(&stp->sd_lock));
1138 		old_sd_flag = stp->sd_flag;
1139 		mark = 0;
1140 		delim = 0;
1141 		first = 1;
1142 		while ((bp = strget(stp, q, uiop, first, &error)) == NULL) {
1143 			int done = 0;
1144 
1145 			ASSERT(MUTEX_HELD(&stp->sd_lock));
1146 
1147 			if (error != 0)
1148 				goto oops;
1149 
1150 			if (stp->sd_flag & (STRHUP|STREOF)) {
1151 				goto oops;
1152 			}
1153 			if (rflg && !(stp->sd_flag & STRDELIM)) {
1154 				goto oops;
1155 			}
1156 			/*
1157 			 * If a read(fd,buf,0) has been done, there is no
1158 			 * need to sleep. We always have zero bytes to
1159 			 * return.
1160 			 */
1161 			if (uiop->uio_resid == 0) {
1162 				goto oops;
1163 			}
1164 
1165 			qbackenable(q, 0);
1166 
1167 			TRACE_3(TR_FAC_STREAMS_FR, TR_STRREAD_WAIT,
1168 			    "strread calls strwaitq:%p, %p, %p",
1169 			    vp, uiop, crp);
1170 			if ((error = strwaitq(stp, waitflag, uiop->uio_resid,
1171 			    uiop->uio_fmode, -1, &done)) != 0 || done) {
1172 				TRACE_3(TR_FAC_STREAMS_FR, TR_STRREAD_DONE,
1173 				    "strread error or done:%p, %p, %p",
1174 				    vp, uiop, crp);
1175 				if ((uiop->uio_fmode & FNDELAY) &&
1176 				    (stp->sd_flag & OLDNDELAY) &&
1177 				    (error == EAGAIN))
1178 					error = 0;
1179 				goto oops;
1180 			}
1181 			TRACE_3(TR_FAC_STREAMS_FR, TR_STRREAD_AWAKE,
1182 			    "strread awakes:%p, %p, %p", vp, uiop, crp);
1183 			if ((error = i_straccess(stp, JCREAD)) != 0) {
1184 				goto oops;
1185 			}
1186 			first = 0;
1187 		}
1188 		ASSERT(MUTEX_HELD(&stp->sd_lock));
1189 		ASSERT(bp);
1190 		pri = bp->b_band;
1191 		/*
1192 		 * Extract any mark information. If the message is not
1193 		 * completely consumed this information will be put in the mblk
1194 		 * that is putback.
1195 		 * If MSGMARKNEXT is set and the message is completely consumed
1196 		 * the STRATMARK flag will be set below. Likewise, if
1197 		 * MSGNOTMARKNEXT is set and the message is
1198 		 * completely consumed STRNOTATMARK will be set.
1199 		 *
1200 		 * For some unknown reason strread only breaks the read at the
1201 		 * last mark.
1202 		 */
1203 		mark = bp->b_flag & (MSGMARK | MSGMARKNEXT | MSGNOTMARKNEXT);
1204 		ASSERT((mark & (MSGMARKNEXT|MSGNOTMARKNEXT)) !=
1205 		    (MSGMARKNEXT|MSGNOTMARKNEXT));
1206 		if (mark != 0 && bp == stp->sd_mark) {
1207 			if (rflg) {
1208 				putback(stp, q, bp, pri);
1209 				goto oops;
1210 			}
1211 			mark |= _LASTMARK;
1212 			stp->sd_mark = NULL;
1213 		}
1214 		if ((stp->sd_flag & STRDELIM) && (bp->b_flag & MSGDELIM))
1215 			delim = 1;
1216 		mutex_exit(&stp->sd_lock);
1217 
1218 		if (STREAM_NEEDSERVICE(stp))
1219 			stream_runservice(stp);
1220 
1221 		type = bp->b_datap->db_type;
1222 
1223 		switch (type) {
1224 
1225 		case M_DATA:
1226 ismdata:
1227 			if (msgnodata(bp)) {
1228 				if (mark || delim) {
1229 					freemsg(bp);
1230 				} else if (rflg) {
1231 
1232 					/*
1233 					 * If already read data put zero
1234 					 * length message back on queue else
1235 					 * free msg and return 0.
1236 					 */
1237 					bp->b_band = pri;
1238 					mutex_enter(&stp->sd_lock);
1239 					putback(stp, q, bp, pri);
1240 					mutex_exit(&stp->sd_lock);
1241 				} else {
1242 					freemsg(bp);
1243 				}
1244 				error =  0;
1245 				goto oops1;
1246 			}
1247 
1248 			rflg = 1;
1249 			waitflag |= NOINTR;
1250 			bp = struiocopyout(bp, uiop, &error);
1251 			if (error != 0)
1252 				goto oops1;
1253 
1254 			mutex_enter(&stp->sd_lock);
1255 			if (bp) {
1256 				/*
1257 				 * Have remaining data in message.
1258 				 * Free msg if in discard mode.
1259 				 */
1260 				if (stp->sd_read_opt & RD_MSGDIS) {
1261 					freemsg(bp);
1262 				} else {
1263 					bp->b_band = pri;
1264 					if ((mark & _LASTMARK) &&
1265 					    (stp->sd_mark == NULL))
1266 						stp->sd_mark = bp;
1267 					bp->b_flag |= mark & ~_LASTMARK;
1268 					if (delim)
1269 						bp->b_flag |= MSGDELIM;
1270 					if (msgnodata(bp))
1271 						freemsg(bp);
1272 					else
1273 						putback(stp, q, bp, pri);
1274 				}
1275 			} else {
1276 				/*
1277 				 * Consumed the complete message.
1278 				 * Move the MSG*MARKNEXT information
1279 				 * to the stream head just in case
1280 				 * the read queue becomes empty.
1281 				 *
1282 				 * If the stream head was at the mark
1283 				 * (STRATMARK) before we dropped sd_lock above
1284 				 * and some data was consumed then we have
1285 				 * moved past the mark thus STRATMARK is
1286 				 * cleared. However, if a message arrived in
1287 				 * strrput during the copyout above causing
1288 				 * STRATMARK to be set we can not clear that
1289 				 * flag.
1290 				 */
1291 				if (mark &
1292 				    (MSGMARKNEXT|MSGNOTMARKNEXT|MSGMARK)) {
1293 					if (mark & MSGMARKNEXT) {
1294 						stp->sd_flag &= ~STRNOTATMARK;
1295 						stp->sd_flag |= STRATMARK;
1296 					} else if (mark & MSGNOTMARKNEXT) {
1297 						stp->sd_flag &= ~STRATMARK;
1298 						stp->sd_flag |= STRNOTATMARK;
1299 					} else {
1300 						stp->sd_flag &=
1301 						    ~(STRATMARK|STRNOTATMARK);
1302 					}
1303 				} else if (rflg && (old_sd_flag & STRATMARK)) {
1304 					stp->sd_flag &= ~STRATMARK;
1305 				}
1306 			}
1307 
1308 			/*
1309 			 * Check for signal messages at the front of the read
1310 			 * queue and generate the signal(s) if appropriate.
1311 			 * The only signal that can be on queue is M_SIG at
1312 			 * this point.
1313 			 */
1314 			while ((((bp = q->q_first)) != NULL) &&
1315 			    (bp->b_datap->db_type == M_SIG)) {
1316 				bp = getq_noenab(q);
1317 				/*
1318 				 * sd_lock is held so the content of the
1319 				 * read queue can not change.
1320 				 */
1321 				ASSERT(bp != NULL &&
1322 				    bp->b_datap->db_type == M_SIG);
1323 				strsignal_nolock(stp, *bp->b_rptr,
1324 				    (int32_t)bp->b_band);
1325 				mutex_exit(&stp->sd_lock);
1326 				freemsg(bp);
1327 				if (STREAM_NEEDSERVICE(stp))
1328 					stream_runservice(stp);
1329 				mutex_enter(&stp->sd_lock);
1330 			}
1331 
1332 			if ((uiop->uio_resid == 0) || (mark & _LASTMARK) ||
1333 			    delim ||
1334 			    (stp->sd_read_opt & (RD_MSGDIS|RD_MSGNODIS))) {
1335 				goto oops;
1336 			}
1337 			continue;
1338 
1339 		case M_SIG:
1340 			strsignal(stp, *bp->b_rptr, (int32_t)bp->b_band);
1341 			freemsg(bp);
1342 			mutex_enter(&stp->sd_lock);
1343 			continue;
1344 
1345 		case M_PROTO:
1346 		case M_PCPROTO:
1347 			/*
1348 			 * Only data messages are readable.
1349 			 * Any others generate an error, unless
1350 			 * RD_PROTDIS or RD_PROTDAT is set.
1351 			 */
1352 			if (stp->sd_read_opt & RD_PROTDAT) {
1353 				for (nbp = bp; nbp; nbp = nbp->b_next) {
1354 					if ((nbp->b_datap->db_type ==
1355 					    M_PROTO) ||
1356 					    (nbp->b_datap->db_type ==
1357 					    M_PCPROTO)) {
1358 						nbp->b_datap->db_type = M_DATA;
1359 					} else {
1360 						break;
1361 					}
1362 				}
1363 				/*
1364 				 * clear stream head hi pri flag based on
1365 				 * first message
1366 				 */
1367 				if (type == M_PCPROTO) {
1368 					mutex_enter(&stp->sd_lock);
1369 					stp->sd_flag &= ~STRPRI;
1370 					mutex_exit(&stp->sd_lock);
1371 				}
1372 				goto ismdata;
1373 			} else if (stp->sd_read_opt & RD_PROTDIS) {
1374 				/*
1375 				 * discard non-data messages
1376 				 */
1377 				while (bp &&
1378 				    ((bp->b_datap->db_type == M_PROTO) ||
1379 				    (bp->b_datap->db_type == M_PCPROTO))) {
1380 					nbp = unlinkb(bp);
1381 					freeb(bp);
1382 					bp = nbp;
1383 				}
1384 				/*
1385 				 * clear stream head hi pri flag based on
1386 				 * first message
1387 				 */
1388 				if (type == M_PCPROTO) {
1389 					mutex_enter(&stp->sd_lock);
1390 					stp->sd_flag &= ~STRPRI;
1391 					mutex_exit(&stp->sd_lock);
1392 				}
1393 				if (bp) {
1394 					bp->b_band = pri;
1395 					goto ismdata;
1396 				} else {
1397 					break;
1398 				}
1399 			}
1400 			/* FALLTHRU */
1401 		case M_PASSFP:
1402 			if ((bp->b_datap->db_type == M_PASSFP) &&
1403 			    (stp->sd_read_opt & RD_PROTDIS)) {
1404 				freemsg(bp);
1405 				break;
1406 			}
1407 			mutex_enter(&stp->sd_lock);
1408 			putback(stp, q, bp, pri);
1409 			mutex_exit(&stp->sd_lock);
1410 			if (rflg == 0)
1411 				error = EBADMSG;
1412 			goto oops1;
1413 
1414 		default:
1415 			/*
1416 			 * Garbage on stream head read queue.
1417 			 */
1418 			cmn_err(CE_WARN, "bad %x found at stream head\n",
1419 			    bp->b_datap->db_type);
1420 			freemsg(bp);
1421 			goto oops1;
1422 		}
1423 		mutex_enter(&stp->sd_lock);
1424 	}
1425 oops:
1426 	mutex_exit(&stp->sd_lock);
1427 oops1:
1428 	qbackenable(q, pri);
1429 	return (error);
1430 #undef	_LASTMARK
1431 }
1432 
1433 /*
1434  * Default processing of M_PROTO/M_PCPROTO messages.
1435  * Determine which wakeups and signals are needed.
1436  * This can be replaced by a user-specified procedure for kernel users
1437  * of STREAMS.
1438  */
1439 /* ARGSUSED */
1440 mblk_t *
1441 strrput_proto(vnode_t *vp, mblk_t *mp,
1442     strwakeup_t *wakeups, strsigset_t *firstmsgsigs,
1443     strsigset_t *allmsgsigs, strpollset_t *pollwakeups)
1444 {
1445 	*wakeups = RSLEEP;
1446 	*allmsgsigs = 0;
1447 
1448 	switch (mp->b_datap->db_type) {
1449 	case M_PROTO:
1450 		if (mp->b_band == 0) {
1451 			*firstmsgsigs = S_INPUT | S_RDNORM;
1452 			*pollwakeups = POLLIN | POLLRDNORM;
1453 		} else {
1454 			*firstmsgsigs = S_INPUT | S_RDBAND;
1455 			*pollwakeups = POLLIN | POLLRDBAND;
1456 		}
1457 		break;
1458 	case M_PCPROTO:
1459 		*firstmsgsigs = S_HIPRI;
1460 		*pollwakeups = POLLPRI;
1461 		break;
1462 	}
1463 	return (mp);
1464 }
1465 
1466 /*
1467  * Default processing of everything but M_DATA, M_PROTO, M_PCPROTO and
1468  * M_PASSFP messages.
1469  * Determine which wakeups and signals are needed.
1470  * This can be replaced by a user-specified procedure for kernel users
1471  * of STREAMS.
1472  */
1473 /* ARGSUSED */
1474 mblk_t *
1475 strrput_misc(vnode_t *vp, mblk_t *mp,
1476     strwakeup_t *wakeups, strsigset_t *firstmsgsigs,
1477     strsigset_t *allmsgsigs, strpollset_t *pollwakeups)
1478 {
1479 	*wakeups = 0;
1480 	*firstmsgsigs = 0;
1481 	*allmsgsigs = 0;
1482 	*pollwakeups = 0;
1483 	return (mp);
1484 }
1485 
1486 /*
1487  * Stream read put procedure.  Called from downstream driver/module
1488  * with messages for the stream head.  Data, protocol, and in-stream
1489  * signal messages are placed on the queue, others are handled directly.
1490  */
1491 int
1492 strrput(queue_t *q, mblk_t *bp)
1493 {
1494 	struct stdata	*stp;
1495 	ulong_t		rput_opt;
1496 	strwakeup_t	wakeups;
1497 	strsigset_t	firstmsgsigs;	/* Signals if first message on queue */
1498 	strsigset_t	allmsgsigs;	/* Signals for all messages */
1499 	strsigset_t	signals;	/* Signals events to generate */
1500 	strpollset_t	pollwakeups;
1501 	mblk_t		*nextbp;
1502 	uchar_t		band = 0;
1503 	int		hipri_sig;
1504 
1505 	stp = (struct stdata *)q->q_ptr;
1506 	/*
1507 	 * Use rput_opt for optimized access to the SR_ flags except
1508 	 * SR_POLLIN. That flag has to be checked under sd_lock since it
1509 	 * is modified by strpoll().
1510 	 */
1511 	rput_opt = stp->sd_rput_opt;
1512 
1513 	ASSERT(qclaimed(q));
1514 	TRACE_2(TR_FAC_STREAMS_FR, TR_STRRPUT_ENTER,
1515 	    "strrput called with message type:q %p bp %p", q, bp);
1516 
1517 	/*
1518 	 * Perform initial processing and pass to the parameterized functions.
1519 	 */
1520 	ASSERT(bp->b_next == NULL);
1521 
1522 	switch (bp->b_datap->db_type) {
1523 	case M_DATA:
1524 		/*
1525 		 * sockfs is the only consumer of STREOF and when it is set,
1526 		 * it implies that the receiver is not interested in receiving
1527 		 * any more data, hence the mblk is freed to prevent unnecessary
1528 		 * message queueing at the stream head.
1529 		 */
1530 		if (stp->sd_flag == STREOF) {
1531 			freemsg(bp);
1532 			return (0);
1533 		}
1534 		if ((rput_opt & SR_IGN_ZEROLEN) &&
1535 		    bp->b_rptr == bp->b_wptr && msgnodata(bp)) {
1536 			/*
1537 			 * Ignore zero-length M_DATA messages. These might be
1538 			 * generated by some transports.
1539 			 * The zero-length M_DATA messages, even if they
1540 			 * are ignored, should effect the atmark tracking and
1541 			 * should wake up a thread sleeping in strwaitmark.
1542 			 */
1543 			mutex_enter(&stp->sd_lock);
1544 			if (bp->b_flag & MSGMARKNEXT) {
1545 				/*
1546 				 * Record the position of the mark either
1547 				 * in q_last or in STRATMARK.
1548 				 */
1549 				if (q->q_last != NULL) {
1550 					q->q_last->b_flag &= ~MSGNOTMARKNEXT;
1551 					q->q_last->b_flag |= MSGMARKNEXT;
1552 				} else {
1553 					stp->sd_flag &= ~STRNOTATMARK;
1554 					stp->sd_flag |= STRATMARK;
1555 				}
1556 			} else if (bp->b_flag & MSGNOTMARKNEXT) {
1557 				/*
1558 				 * Record that this is not the position of
1559 				 * the mark either in q_last or in
1560 				 * STRNOTATMARK.
1561 				 */
1562 				if (q->q_last != NULL) {
1563 					q->q_last->b_flag &= ~MSGMARKNEXT;
1564 					q->q_last->b_flag |= MSGNOTMARKNEXT;
1565 				} else {
1566 					stp->sd_flag &= ~STRATMARK;
1567 					stp->sd_flag |= STRNOTATMARK;
1568 				}
1569 			}
1570 			if (stp->sd_flag & RSLEEP) {
1571 				stp->sd_flag &= ~RSLEEP;
1572 				cv_broadcast(&q->q_wait);
1573 			}
1574 			mutex_exit(&stp->sd_lock);
1575 			freemsg(bp);
1576 			return (0);
1577 		}
1578 		wakeups = RSLEEP;
1579 		if (bp->b_band == 0) {
1580 			firstmsgsigs = S_INPUT | S_RDNORM;
1581 			pollwakeups = POLLIN | POLLRDNORM;
1582 		} else {
1583 			firstmsgsigs = S_INPUT | S_RDBAND;
1584 			pollwakeups = POLLIN | POLLRDBAND;
1585 		}
1586 		if (rput_opt & SR_SIGALLDATA)
1587 			allmsgsigs = firstmsgsigs;
1588 		else
1589 			allmsgsigs = 0;
1590 
1591 		mutex_enter(&stp->sd_lock);
1592 		if ((rput_opt & SR_CONSOL_DATA) &&
1593 		    (q->q_last != NULL) &&
1594 		    (bp->b_flag & (MSGMARK|MSGDELIM)) == 0) {
1595 			/*
1596 			 * Consolidate an M_DATA message onto an M_DATA,
1597 			 * M_PROTO, or M_PCPROTO by merging it with q_last.
1598 			 * The consolidation does not take place if
1599 			 * the old message is marked with either of the
1600 			 * marks or the delim flag or if the new
1601 			 * message is marked with MSGMARK. The MSGMARK
1602 			 * check is needed to handle the odd semantics of
1603 			 * MSGMARK where essentially the whole message
1604 			 * is to be treated as marked.
1605 			 * Carry any MSGMARKNEXT  and MSGNOTMARKNEXT from the
1606 			 * new message to the front of the b_cont chain.
1607 			 */
1608 			mblk_t *lbp = q->q_last;
1609 			unsigned char db_type = lbp->b_datap->db_type;
1610 
1611 			if ((db_type == M_DATA || db_type == M_PROTO ||
1612 			    db_type == M_PCPROTO) &&
1613 			    !(lbp->b_flag & (MSGDELIM|MSGMARK|MSGMARKNEXT))) {
1614 				rmvq_noenab(q, lbp);
1615 				/*
1616 				 * The first message in the b_cont list
1617 				 * tracks MSGMARKNEXT and MSGNOTMARKNEXT.
1618 				 * We need to handle the case where we
1619 				 * are appending:
1620 				 *
1621 				 * 1) a MSGMARKNEXT to a MSGNOTMARKNEXT.
1622 				 * 2) a MSGMARKNEXT to a plain message.
1623 				 * 3) a MSGNOTMARKNEXT to a plain message
1624 				 * 4) a MSGNOTMARKNEXT to a MSGNOTMARKNEXT
1625 				 *    message.
1626 				 *
1627 				 * Thus we never append a MSGMARKNEXT or
1628 				 * MSGNOTMARKNEXT to a MSGMARKNEXT message.
1629 				 */
1630 				if (bp->b_flag & MSGMARKNEXT) {
1631 					lbp->b_flag |= MSGMARKNEXT;
1632 					lbp->b_flag &= ~MSGNOTMARKNEXT;
1633 					bp->b_flag &= ~MSGMARKNEXT;
1634 				} else if (bp->b_flag & MSGNOTMARKNEXT) {
1635 					lbp->b_flag |= MSGNOTMARKNEXT;
1636 					bp->b_flag &= ~MSGNOTMARKNEXT;
1637 				}
1638 
1639 				linkb(lbp, bp);
1640 				bp = lbp;
1641 				/*
1642 				 * The new message logically isn't the first
1643 				 * even though the q_first check below thinks
1644 				 * it is. Clear the firstmsgsigs to make it
1645 				 * not appear to be first.
1646 				 */
1647 				firstmsgsigs = 0;
1648 			}
1649 		}
1650 		break;
1651 
1652 	case M_PASSFP:
1653 		wakeups = RSLEEP;
1654 		allmsgsigs = 0;
1655 		if (bp->b_band == 0) {
1656 			firstmsgsigs = S_INPUT | S_RDNORM;
1657 			pollwakeups = POLLIN | POLLRDNORM;
1658 		} else {
1659 			firstmsgsigs = S_INPUT | S_RDBAND;
1660 			pollwakeups = POLLIN | POLLRDBAND;
1661 		}
1662 		mutex_enter(&stp->sd_lock);
1663 		break;
1664 
1665 	case M_PROTO:
1666 	case M_PCPROTO:
1667 		ASSERT(stp->sd_rprotofunc != NULL);
1668 		bp = (stp->sd_rprotofunc)(stp->sd_vnode, bp,
1669 		    &wakeups, &firstmsgsigs, &allmsgsigs, &pollwakeups);
1670 #define	ALLSIG	(S_INPUT|S_HIPRI|S_OUTPUT|S_MSG|S_ERROR|S_HANGUP|S_RDNORM|\
1671 		S_WRNORM|S_RDBAND|S_WRBAND|S_BANDURG)
1672 #define	ALLPOLL	(POLLIN|POLLPRI|POLLOUT|POLLRDNORM|POLLWRNORM|POLLRDBAND|\
1673 		POLLWRBAND)
1674 
1675 		ASSERT((wakeups & ~(RSLEEP|WSLEEP)) == 0);
1676 		ASSERT((firstmsgsigs & ~ALLSIG) == 0);
1677 		ASSERT((allmsgsigs & ~ALLSIG) == 0);
1678 		ASSERT((pollwakeups & ~ALLPOLL) == 0);
1679 
1680 		mutex_enter(&stp->sd_lock);
1681 		break;
1682 
1683 	default:
1684 		ASSERT(stp->sd_rmiscfunc != NULL);
1685 		bp = (stp->sd_rmiscfunc)(stp->sd_vnode, bp,
1686 		    &wakeups, &firstmsgsigs, &allmsgsigs, &pollwakeups);
1687 		ASSERT((wakeups & ~(RSLEEP|WSLEEP)) == 0);
1688 		ASSERT((firstmsgsigs & ~ALLSIG) == 0);
1689 		ASSERT((allmsgsigs & ~ALLSIG) == 0);
1690 		ASSERT((pollwakeups & ~ALLPOLL) == 0);
1691 #undef	ALLSIG
1692 #undef	ALLPOLL
1693 		mutex_enter(&stp->sd_lock);
1694 		break;
1695 	}
1696 	ASSERT(MUTEX_HELD(&stp->sd_lock));
1697 
1698 	/* By default generate superset of signals */
1699 	signals = (firstmsgsigs | allmsgsigs);
1700 
1701 	/*
1702 	 * The  proto and misc functions can return multiple messages
1703 	 * as a b_next chain. Such messages are processed separately.
1704 	 */
1705 one_more:
1706 	hipri_sig = 0;
1707 	if (bp == NULL) {
1708 		nextbp = NULL;
1709 	} else {
1710 		nextbp = bp->b_next;
1711 		bp->b_next = NULL;
1712 
1713 		switch (bp->b_datap->db_type) {
1714 		case M_PCPROTO:
1715 			/*
1716 			 * Only one priority protocol message is allowed at the
1717 			 * stream head at a time.
1718 			 */
1719 			if (stp->sd_flag & STRPRI) {
1720 				TRACE_0(TR_FAC_STREAMS_FR, TR_STRRPUT_PROTERR,
1721 				    "M_PCPROTO already at head");
1722 				freemsg(bp);
1723 				mutex_exit(&stp->sd_lock);
1724 				goto done;
1725 			}
1726 			stp->sd_flag |= STRPRI;
1727 			hipri_sig = 1;
1728 			/* FALLTHRU */
1729 		case M_DATA:
1730 		case M_PROTO:
1731 		case M_PASSFP:
1732 			band = bp->b_band;
1733 			/*
1734 			 * Marking doesn't work well when messages
1735 			 * are marked in more than one band.  We only
1736 			 * remember the last message received, even if
1737 			 * it is placed on the queue ahead of other
1738 			 * marked messages.
1739 			 */
1740 			if (bp->b_flag & MSGMARK)
1741 				stp->sd_mark = bp;
1742 			(void) putq(q, bp);
1743 
1744 			/*
1745 			 * If message is a PCPROTO message, always use
1746 			 * firstmsgsigs to determine if a signal should be
1747 			 * sent as strrput is the only place to send
1748 			 * signals for PCPROTO. Other messages are based on
1749 			 * the STRGETINPROG flag. The flag determines if
1750 			 * strrput or (k)strgetmsg will be responsible for
1751 			 * sending the signals, in the firstmsgsigs case.
1752 			 */
1753 			if ((hipri_sig == 1) ||
1754 			    (((stp->sd_flag & STRGETINPROG) == 0) &&
1755 			    (q->q_first == bp)))
1756 				signals = (firstmsgsigs | allmsgsigs);
1757 			else
1758 				signals = allmsgsigs;
1759 			break;
1760 
1761 		default:
1762 			mutex_exit(&stp->sd_lock);
1763 			(void) strrput_nondata(q, bp);
1764 			mutex_enter(&stp->sd_lock);
1765 			break;
1766 		}
1767 	}
1768 	ASSERT(MUTEX_HELD(&stp->sd_lock));
1769 	/*
1770 	 * Wake sleeping read/getmsg and cancel deferred wakeup
1771 	 */
1772 	if (wakeups & RSLEEP)
1773 		stp->sd_wakeq &= ~RSLEEP;
1774 
1775 	wakeups &= stp->sd_flag;
1776 	if (wakeups & RSLEEP) {
1777 		stp->sd_flag &= ~RSLEEP;
1778 		cv_broadcast(&q->q_wait);
1779 	}
1780 	if (wakeups & WSLEEP) {
1781 		stp->sd_flag &= ~WSLEEP;
1782 		cv_broadcast(&_WR(q)->q_wait);
1783 	}
1784 
1785 	if (pollwakeups != 0) {
1786 		if (pollwakeups == (POLLIN | POLLRDNORM)) {
1787 			/*
1788 			 * Can't use rput_opt since it was not
1789 			 * read when sd_lock was held and SR_POLLIN is changed
1790 			 * by strpoll() under sd_lock.
1791 			 */
1792 			if (!(stp->sd_rput_opt & SR_POLLIN))
1793 				goto no_pollwake;
1794 			stp->sd_rput_opt &= ~SR_POLLIN;
1795 		}
1796 		mutex_exit(&stp->sd_lock);
1797 		pollwakeup(&stp->sd_pollist, pollwakeups);
1798 		mutex_enter(&stp->sd_lock);
1799 	}
1800 no_pollwake:
1801 
1802 	/*
1803 	 * strsendsig can handle multiple signals with a
1804 	 * single call.
1805 	 */
1806 	if (stp->sd_sigflags & signals)
1807 		strsendsig(stp->sd_siglist, signals, band, 0);
1808 	mutex_exit(&stp->sd_lock);
1809 
1810 
1811 done:
1812 	if (nextbp == NULL)
1813 		return (0);
1814 
1815 	/*
1816 	 * Any signals were handled the first time.
1817 	 * Wakeups and pollwakeups are redone to avoid any race
1818 	 * conditions - all the messages are not queued until the
1819 	 * last message has been processed by strrput.
1820 	 */
1821 	bp = nextbp;
1822 	signals = firstmsgsigs = allmsgsigs = 0;
1823 	mutex_enter(&stp->sd_lock);
1824 	goto one_more;
1825 }
1826 
1827 static void
1828 log_dupioc(queue_t *rq, mblk_t *bp)
1829 {
1830 	queue_t *wq, *qp;
1831 	char *modnames, *mnp, *dname;
1832 	size_t maxmodstr;
1833 	boolean_t islast;
1834 
1835 	/*
1836 	 * Allocate a buffer large enough to hold the names of nstrpush modules
1837 	 * and one driver, with spaces between and NUL terminator.  If we can't
1838 	 * get memory, then we'll just log the driver name.
1839 	 */
1840 	maxmodstr = nstrpush * (FMNAMESZ + 1);
1841 	mnp = modnames = kmem_alloc(maxmodstr, KM_NOSLEEP);
1842 
1843 	/* march down write side to print log message down to the driver */
1844 	wq = WR(rq);
1845 
1846 	/* make sure q_next doesn't shift around while we're grabbing data */
1847 	claimstr(wq);
1848 	qp = wq->q_next;
1849 	do {
1850 		if ((dname = qp->q_qinfo->qi_minfo->mi_idname) == NULL)
1851 			dname = "?";
1852 		islast = !SAMESTR(qp) || qp->q_next == NULL;
1853 		if (modnames == NULL) {
1854 			/*
1855 			 * If we don't have memory, then get the driver name in
1856 			 * the log where we can see it.  Note that memory
1857 			 * pressure is a possible cause of these sorts of bugs.
1858 			 */
1859 			if (islast) {
1860 				modnames = dname;
1861 				maxmodstr = 0;
1862 			}
1863 		} else {
1864 			mnp += snprintf(mnp, FMNAMESZ + 1, "%s", dname);
1865 			if (!islast)
1866 				*mnp++ = ' ';
1867 		}
1868 		qp = qp->q_next;
1869 	} while (!islast);
1870 	releasestr(wq);
1871 	/* Cannot happen unless stream head is corrupt. */
1872 	ASSERT(modnames != NULL);
1873 	(void) strlog(rq->q_qinfo->qi_minfo->mi_idnum, 0, 1,
1874 	    SL_CONSOLE|SL_TRACE|SL_ERROR,
1875 	    "Warning: stream %p received duplicate %X M_IOC%s; module list: %s",
1876 	    rq->q_ptr, ((struct iocblk *)bp->b_rptr)->ioc_cmd,
1877 	    (DB_TYPE(bp) == M_IOCACK ? "ACK" : "NAK"), modnames);
1878 	if (maxmodstr != 0)
1879 		kmem_free(modnames, maxmodstr);
1880 }
1881 
1882 int
1883 strrput_nondata(queue_t *q, mblk_t *bp)
1884 {
1885 	struct stdata *stp;
1886 	struct iocblk *iocbp;
1887 	struct stroptions *sop;
1888 	struct copyreq *reqp;
1889 	struct copyresp *resp;
1890 	unsigned char bpri;
1891 	unsigned char  flushed_already = 0;
1892 
1893 	stp = (struct stdata *)q->q_ptr;
1894 
1895 	ASSERT(!(stp->sd_flag & STPLEX));
1896 	ASSERT(qclaimed(q));
1897 
1898 	switch (bp->b_datap->db_type) {
1899 	case M_ERROR:
1900 		/*
1901 		 * An error has occurred downstream, the errno is in the first
1902 		 * bytes of the message.
1903 		 */
1904 		if ((bp->b_wptr - bp->b_rptr) == 2) {	/* New flavor */
1905 			unsigned char rw = 0;
1906 
1907 			mutex_enter(&stp->sd_lock);
1908 			if (*bp->b_rptr != NOERROR) {	/* read error */
1909 				if (*bp->b_rptr != 0) {
1910 					if (stp->sd_flag & STRDERR)
1911 						flushed_already |= FLUSHR;
1912 					stp->sd_flag |= STRDERR;
1913 					rw |= FLUSHR;
1914 				} else {
1915 					stp->sd_flag &= ~STRDERR;
1916 				}
1917 				stp->sd_rerror = *bp->b_rptr;
1918 			}
1919 			bp->b_rptr++;
1920 			if (*bp->b_rptr != NOERROR) {	/* write error */
1921 				if (*bp->b_rptr != 0) {
1922 					if (stp->sd_flag & STWRERR)
1923 						flushed_already |= FLUSHW;
1924 					stp->sd_flag |= STWRERR;
1925 					rw |= FLUSHW;
1926 				} else {
1927 					stp->sd_flag &= ~STWRERR;
1928 				}
1929 				stp->sd_werror = *bp->b_rptr;
1930 			}
1931 			if (rw) {
1932 				TRACE_2(TR_FAC_STREAMS_FR, TR_STRRPUT_WAKE,
1933 				    "strrput cv_broadcast:q %p, bp %p",
1934 				    q, bp);
1935 				cv_broadcast(&q->q_wait); /* readers */
1936 				cv_broadcast(&_WR(q)->q_wait); /* writers */
1937 				cv_broadcast(&stp->sd_monitor); /* ioctllers */
1938 
1939 				mutex_exit(&stp->sd_lock);
1940 				pollwakeup(&stp->sd_pollist, POLLERR);
1941 				mutex_enter(&stp->sd_lock);
1942 
1943 				if (stp->sd_sigflags & S_ERROR)
1944 					strsendsig(stp->sd_siglist, S_ERROR, 0,
1945 					    ((rw & FLUSHR) ? stp->sd_rerror :
1946 					    stp->sd_werror));
1947 				mutex_exit(&stp->sd_lock);
1948 				/*
1949 				 * Send the M_FLUSH only
1950 				 * for the first M_ERROR
1951 				 * message on the stream
1952 				 */
1953 				if (flushed_already == rw) {
1954 					freemsg(bp);
1955 					return (0);
1956 				}
1957 
1958 				bp->b_datap->db_type = M_FLUSH;
1959 				*bp->b_rptr = rw;
1960 				bp->b_wptr = bp->b_rptr + 1;
1961 				/*
1962 				 * Protect against the driver
1963 				 * passing up messages after
1964 				 * it has done a qprocsoff
1965 				 */
1966 				if (_OTHERQ(q)->q_next == NULL)
1967 					freemsg(bp);
1968 				else
1969 					qreply(q, bp);
1970 				return (0);
1971 			} else
1972 				mutex_exit(&stp->sd_lock);
1973 		} else if (*bp->b_rptr != 0) {		/* Old flavor */
1974 				if (stp->sd_flag & (STRDERR|STWRERR))
1975 					flushed_already = FLUSHRW;
1976 				mutex_enter(&stp->sd_lock);
1977 				stp->sd_flag |= (STRDERR|STWRERR);
1978 				stp->sd_rerror = *bp->b_rptr;
1979 				stp->sd_werror = *bp->b_rptr;
1980 				TRACE_2(TR_FAC_STREAMS_FR,
1981 				    TR_STRRPUT_WAKE2,
1982 				    "strrput wakeup #2:q %p, bp %p", q, bp);
1983 				cv_broadcast(&q->q_wait); /* the readers */
1984 				cv_broadcast(&_WR(q)->q_wait); /* the writers */
1985 				cv_broadcast(&stp->sd_monitor); /* ioctllers */
1986 
1987 				mutex_exit(&stp->sd_lock);
1988 				pollwakeup(&stp->sd_pollist, POLLERR);
1989 				mutex_enter(&stp->sd_lock);
1990 
1991 				if (stp->sd_sigflags & S_ERROR)
1992 					strsendsig(stp->sd_siglist, S_ERROR, 0,
1993 					    (stp->sd_werror ? stp->sd_werror :
1994 					    stp->sd_rerror));
1995 				mutex_exit(&stp->sd_lock);
1996 
1997 				/*
1998 				 * Send the M_FLUSH only
1999 				 * for the first M_ERROR
2000 				 * message on the stream
2001 				 */
2002 				if (flushed_already != FLUSHRW) {
2003 					bp->b_datap->db_type = M_FLUSH;
2004 					*bp->b_rptr = FLUSHRW;
2005 					/*
2006 					 * Protect against the driver passing up
2007 					 * messages after it has done a
2008 					 * qprocsoff.
2009 					 */
2010 				if (_OTHERQ(q)->q_next == NULL)
2011 					freemsg(bp);
2012 				else
2013 					qreply(q, bp);
2014 				return (0);
2015 				}
2016 		}
2017 		freemsg(bp);
2018 		return (0);
2019 
2020 	case M_HANGUP:
2021 
2022 		freemsg(bp);
2023 		mutex_enter(&stp->sd_lock);
2024 		stp->sd_werror = ENXIO;
2025 		stp->sd_flag |= STRHUP;
2026 		stp->sd_flag &= ~(WSLEEP|RSLEEP);
2027 
2028 		/*
2029 		 * send signal if controlling tty
2030 		 */
2031 
2032 		if (stp->sd_sidp) {
2033 			prsignal(stp->sd_sidp, SIGHUP);
2034 			if (stp->sd_sidp != stp->sd_pgidp)
2035 				pgsignal(stp->sd_pgidp, SIGTSTP);
2036 		}
2037 
2038 		/*
2039 		 * wake up read, write, and exception pollers and
2040 		 * reset wakeup mechanism.
2041 		 */
2042 		cv_broadcast(&q->q_wait);	/* the readers */
2043 		cv_broadcast(&_WR(q)->q_wait);	/* the writers */
2044 		cv_broadcast(&stp->sd_monitor);	/* the ioctllers */
2045 		strhup(stp);
2046 		mutex_exit(&stp->sd_lock);
2047 		return (0);
2048 
2049 	case M_UNHANGUP:
2050 		freemsg(bp);
2051 		mutex_enter(&stp->sd_lock);
2052 		stp->sd_werror = 0;
2053 		stp->sd_flag &= ~STRHUP;
2054 		mutex_exit(&stp->sd_lock);
2055 		return (0);
2056 
2057 	case M_SIG:
2058 		/*
2059 		 * Someone downstream wants to post a signal.  The
2060 		 * signal to post is contained in the first byte of the
2061 		 * message.  If the message would go on the front of
2062 		 * the queue, send a signal to the process group
2063 		 * (if not SIGPOLL) or to the siglist processes
2064 		 * (SIGPOLL).  If something is already on the queue,
2065 		 * OR if we are delivering a delayed suspend (*sigh*
2066 		 * another "tty" hack) and there's no one sleeping already,
2067 		 * just enqueue the message.
2068 		 */
2069 		mutex_enter(&stp->sd_lock);
2070 		if (q->q_first || (*bp->b_rptr == SIGTSTP &&
2071 		    !(stp->sd_flag & RSLEEP))) {
2072 			(void) putq(q, bp);
2073 			mutex_exit(&stp->sd_lock);
2074 			return (0);
2075 		}
2076 		mutex_exit(&stp->sd_lock);
2077 		/* FALLTHRU */
2078 
2079 	case M_PCSIG:
2080 		/*
2081 		 * Don't enqueue, just post the signal.
2082 		 */
2083 		strsignal(stp, *bp->b_rptr, 0L);
2084 		freemsg(bp);
2085 		return (0);
2086 
2087 	case M_FLUSH:
2088 		/*
2089 		 * Flush queues.  The indication of which queues to flush
2090 		 * is in the first byte of the message.  If the read queue
2091 		 * is specified, then flush it.  If FLUSHBAND is set, just
2092 		 * flush the band specified by the second byte of the message.
2093 		 *
2094 		 * If a module has issued a M_SETOPT to not flush hi
2095 		 * priority messages off of the stream head, then pass this
2096 		 * flag into the flushq code to preserve such messages.
2097 		 */
2098 
2099 		if (*bp->b_rptr & FLUSHR) {
2100 			mutex_enter(&stp->sd_lock);
2101 			if (*bp->b_rptr & FLUSHBAND) {
2102 				ASSERT((bp->b_wptr - bp->b_rptr) >= 2);
2103 				flushband(q, *(bp->b_rptr + 1), FLUSHALL);
2104 			} else
2105 				flushq_common(q, FLUSHALL,
2106 				    stp->sd_read_opt & RFLUSHPCPROT);
2107 			if ((q->q_first == NULL) ||
2108 			    (q->q_first->b_datap->db_type < QPCTL))
2109 				stp->sd_flag &= ~STRPRI;
2110 			else {
2111 				ASSERT(stp->sd_flag & STRPRI);
2112 			}
2113 			mutex_exit(&stp->sd_lock);
2114 		}
2115 		if ((*bp->b_rptr & FLUSHW) && !(bp->b_flag & MSGNOLOOP)) {
2116 			*bp->b_rptr &= ~FLUSHR;
2117 			bp->b_flag |= MSGNOLOOP;
2118 			/*
2119 			 * Protect against the driver passing up
2120 			 * messages after it has done a qprocsoff.
2121 			 */
2122 			if (_OTHERQ(q)->q_next == NULL)
2123 				freemsg(bp);
2124 			else
2125 				qreply(q, bp);
2126 			return (0);
2127 		}
2128 		freemsg(bp);
2129 		return (0);
2130 
2131 	case M_IOCACK:
2132 	case M_IOCNAK:
2133 		iocbp = (struct iocblk *)bp->b_rptr;
2134 		/*
2135 		 * If not waiting for ACK or NAK then just free msg.
2136 		 * If incorrect id sequence number then just free msg.
2137 		 * If already have ACK or NAK for user then this is a
2138 		 *    duplicate, display a warning and free the msg.
2139 		 */
2140 		mutex_enter(&stp->sd_lock);
2141 		if ((stp->sd_flag & IOCWAIT) == 0 || stp->sd_iocblk ||
2142 		    (stp->sd_iocid != iocbp->ioc_id)) {
2143 			/*
2144 			 * If the ACK/NAK is a dup, display a message
2145 			 * Dup is when sd_iocid == ioc_id, and
2146 			 * sd_iocblk == <valid ptr> or -1 (the former
2147 			 * is when an ioctl has been put on the stream
2148 			 * head, but has not yet been consumed, the
2149 			 * later is when it has been consumed).
2150 			 */
2151 			if ((stp->sd_iocid == iocbp->ioc_id) &&
2152 			    (stp->sd_iocblk != NULL)) {
2153 				log_dupioc(q, bp);
2154 			}
2155 			freemsg(bp);
2156 			mutex_exit(&stp->sd_lock);
2157 			return (0);
2158 		}
2159 
2160 		/*
2161 		 * Assign ACK or NAK to user and wake up.
2162 		 */
2163 		stp->sd_iocblk = bp;
2164 		cv_broadcast(&stp->sd_monitor);
2165 		mutex_exit(&stp->sd_lock);
2166 		return (0);
2167 
2168 	case M_COPYIN:
2169 	case M_COPYOUT:
2170 		reqp = (struct copyreq *)bp->b_rptr;
2171 
2172 		/*
2173 		 * If not waiting for ACK or NAK then just fail request.
2174 		 * If already have ACK, NAK, or copy request, then just
2175 		 * fail request.
2176 		 * If incorrect id sequence number then just fail request.
2177 		 */
2178 		mutex_enter(&stp->sd_lock);
2179 		if ((stp->sd_flag & IOCWAIT) == 0 || stp->sd_iocblk ||
2180 		    (stp->sd_iocid != reqp->cq_id)) {
2181 			if (bp->b_cont) {
2182 				freemsg(bp->b_cont);
2183 				bp->b_cont = NULL;
2184 			}
2185 			bp->b_datap->db_type = M_IOCDATA;
2186 			bp->b_wptr = bp->b_rptr + sizeof (struct copyresp);
2187 			resp = (struct copyresp *)bp->b_rptr;
2188 			resp->cp_rval = (caddr_t)1;	/* failure */
2189 			mutex_exit(&stp->sd_lock);
2190 			putnext(stp->sd_wrq, bp);
2191 			return (0);
2192 		}
2193 
2194 		/*
2195 		 * Assign copy request to user and wake up.
2196 		 */
2197 		stp->sd_iocblk = bp;
2198 		cv_broadcast(&stp->sd_monitor);
2199 		mutex_exit(&stp->sd_lock);
2200 		return (0);
2201 
2202 	case M_SETOPTS:
2203 		/*
2204 		 * Set stream head options (read option, write offset,
2205 		 * min/max packet size, and/or high/low water marks for
2206 		 * the read side only).
2207 		 */
2208 
2209 		bpri = 0;
2210 		sop = (struct stroptions *)bp->b_rptr;
2211 		mutex_enter(&stp->sd_lock);
2212 		if (sop->so_flags & SO_READOPT) {
2213 			switch (sop->so_readopt & RMODEMASK) {
2214 			case RNORM:
2215 				stp->sd_read_opt &= ~(RD_MSGDIS | RD_MSGNODIS);
2216 				break;
2217 
2218 			case RMSGD:
2219 				stp->sd_read_opt =
2220 				    ((stp->sd_read_opt & ~RD_MSGNODIS) |
2221 				    RD_MSGDIS);
2222 				break;
2223 
2224 			case RMSGN:
2225 				stp->sd_read_opt =
2226 				    ((stp->sd_read_opt & ~RD_MSGDIS) |
2227 				    RD_MSGNODIS);
2228 				break;
2229 			}
2230 			switch (sop->so_readopt & RPROTMASK) {
2231 			case RPROTNORM:
2232 				stp->sd_read_opt &= ~(RD_PROTDAT | RD_PROTDIS);
2233 				break;
2234 
2235 			case RPROTDAT:
2236 				stp->sd_read_opt =
2237 				    ((stp->sd_read_opt & ~RD_PROTDIS) |
2238 				    RD_PROTDAT);
2239 				break;
2240 
2241 			case RPROTDIS:
2242 				stp->sd_read_opt =
2243 				    ((stp->sd_read_opt & ~RD_PROTDAT) |
2244 				    RD_PROTDIS);
2245 				break;
2246 			}
2247 			switch (sop->so_readopt & RFLUSHMASK) {
2248 			case RFLUSHPCPROT:
2249 				/*
2250 				 * This sets the stream head to NOT flush
2251 				 * M_PCPROTO messages.
2252 				 */
2253 				stp->sd_read_opt |= RFLUSHPCPROT;
2254 				break;
2255 			}
2256 		}
2257 		if (sop->so_flags & SO_ERROPT) {
2258 			switch (sop->so_erropt & RERRMASK) {
2259 			case RERRNORM:
2260 				stp->sd_flag &= ~STRDERRNONPERSIST;
2261 				break;
2262 			case RERRNONPERSIST:
2263 				stp->sd_flag |= STRDERRNONPERSIST;
2264 				break;
2265 			}
2266 			switch (sop->so_erropt & WERRMASK) {
2267 			case WERRNORM:
2268 				stp->sd_flag &= ~STWRERRNONPERSIST;
2269 				break;
2270 			case WERRNONPERSIST:
2271 				stp->sd_flag |= STWRERRNONPERSIST;
2272 				break;
2273 			}
2274 		}
2275 		if (sop->so_flags & SO_COPYOPT) {
2276 			if (sop->so_copyopt & ZCVMSAFE) {
2277 				stp->sd_copyflag |= STZCVMSAFE;
2278 				stp->sd_copyflag &= ~STZCVMUNSAFE;
2279 			} else if (sop->so_copyopt & ZCVMUNSAFE) {
2280 				stp->sd_copyflag |= STZCVMUNSAFE;
2281 				stp->sd_copyflag &= ~STZCVMSAFE;
2282 			}
2283 
2284 			if (sop->so_copyopt & COPYCACHED) {
2285 				stp->sd_copyflag |= STRCOPYCACHED;
2286 			}
2287 		}
2288 		if (sop->so_flags & SO_WROFF)
2289 			stp->sd_wroff = sop->so_wroff;
2290 		if (sop->so_flags & SO_TAIL)
2291 			stp->sd_tail = sop->so_tail;
2292 		if (sop->so_flags & SO_MINPSZ)
2293 			q->q_minpsz = sop->so_minpsz;
2294 		if (sop->so_flags & SO_MAXPSZ)
2295 			q->q_maxpsz = sop->so_maxpsz;
2296 		if (sop->so_flags & SO_MAXBLK)
2297 			stp->sd_maxblk = sop->so_maxblk;
2298 		if (sop->so_flags & SO_HIWAT) {
2299 			if (sop->so_flags & SO_BAND) {
2300 				if (strqset(q, QHIWAT,
2301 				    sop->so_band, sop->so_hiwat)) {
2302 					cmn_err(CE_WARN, "strrput: could not "
2303 					    "allocate qband\n");
2304 				} else {
2305 					bpri = sop->so_band;
2306 				}
2307 			} else {
2308 				q->q_hiwat = sop->so_hiwat;
2309 			}
2310 		}
2311 		if (sop->so_flags & SO_LOWAT) {
2312 			if (sop->so_flags & SO_BAND) {
2313 				if (strqset(q, QLOWAT,
2314 				    sop->so_band, sop->so_lowat)) {
2315 					cmn_err(CE_WARN, "strrput: could not "
2316 					    "allocate qband\n");
2317 				} else {
2318 					bpri = sop->so_band;
2319 				}
2320 			} else {
2321 				q->q_lowat = sop->so_lowat;
2322 			}
2323 		}
2324 		if (sop->so_flags & SO_MREADON)
2325 			stp->sd_flag |= SNDMREAD;
2326 		if (sop->so_flags & SO_MREADOFF)
2327 			stp->sd_flag &= ~SNDMREAD;
2328 		if (sop->so_flags & SO_NDELON)
2329 			stp->sd_flag |= OLDNDELAY;
2330 		if (sop->so_flags & SO_NDELOFF)
2331 			stp->sd_flag &= ~OLDNDELAY;
2332 		if (sop->so_flags & SO_ISTTY)
2333 			stp->sd_flag |= STRISTTY;
2334 		if (sop->so_flags & SO_ISNTTY)
2335 			stp->sd_flag &= ~STRISTTY;
2336 		if (sop->so_flags & SO_TOSTOP)
2337 			stp->sd_flag |= STRTOSTOP;
2338 		if (sop->so_flags & SO_TONSTOP)
2339 			stp->sd_flag &= ~STRTOSTOP;
2340 		if (sop->so_flags & SO_DELIM)
2341 			stp->sd_flag |= STRDELIM;
2342 		if (sop->so_flags & SO_NODELIM)
2343 			stp->sd_flag &= ~STRDELIM;
2344 
2345 		mutex_exit(&stp->sd_lock);
2346 		freemsg(bp);
2347 
2348 		/* Check backenable in case the water marks changed */
2349 		qbackenable(q, bpri);
2350 		return (0);
2351 
2352 	/*
2353 	 * The following set of cases deal with situations where two stream
2354 	 * heads are connected to each other (twisted streams).  These messages
2355 	 * have no meaning at the stream head.
2356 	 */
2357 	case M_BREAK:
2358 	case M_CTL:
2359 	case M_DELAY:
2360 	case M_START:
2361 	case M_STOP:
2362 	case M_IOCDATA:
2363 	case M_STARTI:
2364 	case M_STOPI:
2365 		freemsg(bp);
2366 		return (0);
2367 
2368 	case M_IOCTL:
2369 		/*
2370 		 * Always NAK this condition
2371 		 * (makes no sense)
2372 		 * If there is one or more threads in the read side
2373 		 * rwnext we have to defer the nacking until that thread
2374 		 * returns (in strget).
2375 		 */
2376 		mutex_enter(&stp->sd_lock);
2377 		if (stp->sd_struiodnak != 0) {
2378 			/*
2379 			 * Defer NAK to the streamhead. Queue at the end
2380 			 * the list.
2381 			 */
2382 			mblk_t *mp = stp->sd_struionak;
2383 
2384 			while (mp && mp->b_next)
2385 				mp = mp->b_next;
2386 			if (mp)
2387 				mp->b_next = bp;
2388 			else
2389 				stp->sd_struionak = bp;
2390 			bp->b_next = NULL;
2391 			mutex_exit(&stp->sd_lock);
2392 			return (0);
2393 		}
2394 		mutex_exit(&stp->sd_lock);
2395 
2396 		bp->b_datap->db_type = M_IOCNAK;
2397 		/*
2398 		 * Protect against the driver passing up
2399 		 * messages after it has done a qprocsoff.
2400 		 */
2401 		if (_OTHERQ(q)->q_next == NULL)
2402 			freemsg(bp);
2403 		else
2404 			qreply(q, bp);
2405 		return (0);
2406 
2407 	default:
2408 #ifdef DEBUG
2409 		cmn_err(CE_WARN,
2410 		    "bad message type %x received at stream head\n",
2411 		    bp->b_datap->db_type);
2412 #endif
2413 		freemsg(bp);
2414 		return (0);
2415 	}
2416 
2417 	/* NOTREACHED */
2418 }
2419 
2420 /*
2421  * Check if the stream pointed to by `stp' can be written to, and return an
2422  * error code if not.  If `eiohup' is set, then return EIO if STRHUP is set.
2423  * If `sigpipeok' is set and the SW_SIGPIPE option is enabled on the stream,
2424  * then always return EPIPE and send a SIGPIPE to the invoking thread.
2425  */
2426 static int
2427 strwriteable(struct stdata *stp, boolean_t eiohup, boolean_t sigpipeok)
2428 {
2429 	int error;
2430 
2431 	ASSERT(MUTEX_HELD(&stp->sd_lock));
2432 
2433 	/*
2434 	 * For modem support, POSIX states that on writes, EIO should
2435 	 * be returned if the stream has been hung up.
2436 	 */
2437 	if (eiohup && (stp->sd_flag & (STPLEX|STRHUP)) == STRHUP)
2438 		error = EIO;
2439 	else
2440 		error = strgeterr(stp, STRHUP|STPLEX|STWRERR, 0);
2441 
2442 	if (error != 0) {
2443 		if (!(stp->sd_flag & STPLEX) &&
2444 		    (stp->sd_wput_opt & SW_SIGPIPE) && sigpipeok) {
2445 			tsignal(curthread, SIGPIPE);
2446 			error = EPIPE;
2447 		}
2448 	}
2449 
2450 	return (error);
2451 }
2452 
2453 /*
2454  * Copyin and send data down a stream.
2455  * The caller will allocate and copyin any control part that precedes the
2456  * message and pass than in as mctl.
2457  *
2458  * Caller should *not* hold sd_lock.
2459  * When EWOULDBLOCK is returned the caller has to redo the canputnext
2460  * under sd_lock in order to avoid missing a backenabling wakeup.
2461  *
2462  * Use iosize = -1 to not send any M_DATA. iosize = 0 sends zero-length M_DATA.
2463  *
2464  * Set MSG_IGNFLOW in flags to ignore flow control for hipri messages.
2465  * For sync streams we can only ignore flow control by reverting to using
2466  * putnext.
2467  *
2468  * If sd_maxblk is less than *iosize this routine might return without
2469  * transferring all of *iosize. In all cases, on return *iosize will contain
2470  * the amount of data that was transferred.
2471  */
2472 static int
2473 strput(struct stdata *stp, mblk_t *mctl, struct uio *uiop, ssize_t *iosize,
2474     int b_flag, int pri, int flags)
2475 {
2476 	struiod_t uiod;
2477 	mblk_t *mp;
2478 	queue_t *wqp = stp->sd_wrq;
2479 	int error = 0;
2480 	ssize_t count = *iosize;
2481 	cred_t *cr;
2482 
2483 	ASSERT(MUTEX_NOT_HELD(&stp->sd_lock));
2484 
2485 	if (uiop != NULL && count >= 0)
2486 		flags |= stp->sd_struiowrq ? STRUIO_POSTPONE : 0;
2487 
2488 	if (!(flags & STRUIO_POSTPONE)) {
2489 		/*
2490 		 * Use regular canputnext, strmakedata, putnext sequence.
2491 		 */
2492 		if (pri == 0) {
2493 			if (!canputnext(wqp) && !(flags & MSG_IGNFLOW)) {
2494 				freemsg(mctl);
2495 				return (EWOULDBLOCK);
2496 			}
2497 		} else {
2498 			if (!(flags & MSG_IGNFLOW) && !bcanputnext(wqp, pri)) {
2499 				freemsg(mctl);
2500 				return (EWOULDBLOCK);
2501 			}
2502 		}
2503 
2504 		if ((error = strmakedata(iosize, uiop, stp, flags,
2505 		    &mp)) != 0) {
2506 			freemsg(mctl);
2507 			/*
2508 			 * need to change return code to ENOMEM
2509 			 * so that this is not confused with
2510 			 * flow control, EAGAIN.
2511 			 */
2512 
2513 			if (error == EAGAIN)
2514 				return (ENOMEM);
2515 			else
2516 				return (error);
2517 		}
2518 		if (mctl != NULL) {
2519 			if (mctl->b_cont == NULL)
2520 				mctl->b_cont = mp;
2521 			else if (mp != NULL)
2522 				linkb(mctl, mp);
2523 			mp = mctl;
2524 			/*
2525 			 * Note that for interrupt thread, the CRED() is
2526 			 * NULL. Don't bother with the pid either.
2527 			 */
2528 			if ((cr = CRED()) != NULL) {
2529 				mblk_setcred(mp, cr);
2530 				DB_CPID(mp) = curproc->p_pid;
2531 			}
2532 		} else if (mp == NULL)
2533 			return (0);
2534 
2535 		mp->b_flag |= b_flag;
2536 		mp->b_band = (uchar_t)pri;
2537 
2538 		if (flags & MSG_IGNFLOW) {
2539 			/*
2540 			 * XXX Hack: Don't get stuck running service
2541 			 * procedures. This is needed for sockfs when
2542 			 * sending the unbind message out of the rput
2543 			 * procedure - we don't want a put procedure
2544 			 * to run service procedures.
2545 			 */
2546 			putnext(wqp, mp);
2547 		} else {
2548 			stream_willservice(stp);
2549 			putnext(wqp, mp);
2550 			stream_runservice(stp);
2551 		}
2552 		return (0);
2553 	}
2554 	/*
2555 	 * Stream supports rwnext() for the write side.
2556 	 */
2557 	if ((error = strmakedata(iosize, uiop, stp, flags, &mp)) != 0) {
2558 		freemsg(mctl);
2559 		/*
2560 		 * map EAGAIN to ENOMEM since EAGAIN means "flow controlled".
2561 		 */
2562 		return (error == EAGAIN ? ENOMEM : error);
2563 	}
2564 	if (mctl != NULL) {
2565 		if (mctl->b_cont == NULL)
2566 			mctl->b_cont = mp;
2567 		else if (mp != NULL)
2568 			linkb(mctl, mp);
2569 		mp = mctl;
2570 		/*
2571 		 * Note that for interrupt thread, the CRED() is
2572 		 * NULL.  Don't bother with the pid either.
2573 		 */
2574 		if ((cr = CRED()) != NULL) {
2575 			mblk_setcred(mp, cr);
2576 			DB_CPID(mp) = curproc->p_pid;
2577 		}
2578 	} else if (mp == NULL) {
2579 		return (0);
2580 	}
2581 
2582 	mp->b_flag |= b_flag;
2583 	mp->b_band = (uchar_t)pri;
2584 
2585 	(void) uiodup(uiop, &uiod.d_uio, uiod.d_iov,
2586 	    sizeof (uiod.d_iov) / sizeof (*uiod.d_iov));
2587 	uiod.d_uio.uio_offset = 0;
2588 	uiod.d_mp = mp;
2589 	error = rwnext(wqp, &uiod);
2590 	if (! uiod.d_mp) {
2591 		uioskip(uiop, *iosize);
2592 		return (error);
2593 	}
2594 	ASSERT(mp == uiod.d_mp);
2595 	if (error == EINVAL) {
2596 		/*
2597 		 * The stream plumbing must have changed while
2598 		 * we were away, so just turn off rwnext()s.
2599 		 */
2600 		error = 0;
2601 	} else if (error == EBUSY || error == EWOULDBLOCK) {
2602 		/*
2603 		 * Couldn't enter a perimeter or took a page fault,
2604 		 * so fall-back to putnext().
2605 		 */
2606 		error = 0;
2607 	} else {
2608 		freemsg(mp);
2609 		return (error);
2610 	}
2611 	/* Have to check canput before consuming data from the uio */
2612 	if (pri == 0) {
2613 		if (!canputnext(wqp) && !(flags & MSG_IGNFLOW)) {
2614 			freemsg(mp);
2615 			return (EWOULDBLOCK);
2616 		}
2617 	} else {
2618 		if (!bcanputnext(wqp, pri) && !(flags & MSG_IGNFLOW)) {
2619 			freemsg(mp);
2620 			return (EWOULDBLOCK);
2621 		}
2622 	}
2623 	ASSERT(mp == uiod.d_mp);
2624 	/* Copyin data from the uio */
2625 	if ((error = struioget(wqp, mp, &uiod, 0)) != 0) {
2626 		freemsg(mp);
2627 		return (error);
2628 	}
2629 	uioskip(uiop, *iosize);
2630 	if (flags & MSG_IGNFLOW) {
2631 		/*
2632 		 * XXX Hack: Don't get stuck running service procedures.
2633 		 * This is needed for sockfs when sending the unbind message
2634 		 * out of the rput procedure - we don't want a put procedure
2635 		 * to run service procedures.
2636 		 */
2637 		putnext(wqp, mp);
2638 	} else {
2639 		stream_willservice(stp);
2640 		putnext(wqp, mp);
2641 		stream_runservice(stp);
2642 	}
2643 	return (0);
2644 }
2645 
2646 /*
2647  * Write attempts to break the write request into messages conforming
2648  * with the minimum and maximum packet sizes set downstream.
2649  *
2650  * Write will not block if downstream queue is full and
2651  * O_NDELAY is set, otherwise it will block waiting for the queue to get room.
2652  *
2653  * A write of zero bytes gets packaged into a zero length message and sent
2654  * downstream like any other message.
2655  *
2656  * If buffers of the requested sizes are not available, the write will
2657  * sleep until the buffers become available.
2658  *
2659  * Write (if specified) will supply a write offset in a message if it
2660  * makes sense. This can be specified by downstream modules as part of
2661  * a M_SETOPTS message.  Write will not supply the write offset if it
2662  * cannot supply any data in a buffer.  In other words, write will never
2663  * send down an empty packet due to a write offset.
2664  */
2665 /* ARGSUSED2 */
2666 int
2667 strwrite(struct vnode *vp, struct uio *uiop, cred_t *crp)
2668 {
2669 	return (strwrite_common(vp, uiop, crp, 0));
2670 }
2671 
2672 /* ARGSUSED2 */
2673 int
2674 strwrite_common(struct vnode *vp, struct uio *uiop, cred_t *crp, int wflag)
2675 {
2676 	struct stdata *stp;
2677 	struct queue *wqp;
2678 	ssize_t rmin, rmax;
2679 	ssize_t iosize;
2680 	int waitflag;
2681 	int tempmode;
2682 	int error = 0;
2683 	int b_flag;
2684 
2685 	ASSERT(vp->v_stream);
2686 	stp = vp->v_stream;
2687 
2688 	mutex_enter(&stp->sd_lock);
2689 
2690 	if ((error = i_straccess(stp, JCWRITE)) != 0) {
2691 		mutex_exit(&stp->sd_lock);
2692 		return (error);
2693 	}
2694 
2695 	if (stp->sd_flag & (STWRERR|STRHUP|STPLEX)) {
2696 		error = strwriteable(stp, B_TRUE, B_TRUE);
2697 		if (error != 0) {
2698 			mutex_exit(&stp->sd_lock);
2699 			return (error);
2700 		}
2701 	}
2702 
2703 	mutex_exit(&stp->sd_lock);
2704 
2705 	wqp = stp->sd_wrq;
2706 
2707 	/* get these values from them cached in the stream head */
2708 	rmin = stp->sd_qn_minpsz;
2709 	rmax = stp->sd_qn_maxpsz;
2710 
2711 	/*
2712 	 * Check the min/max packet size constraints.  If min packet size
2713 	 * is non-zero, the write cannot be split into multiple messages
2714 	 * and still guarantee the size constraints.
2715 	 */
2716 	TRACE_1(TR_FAC_STREAMS_FR, TR_STRWRITE_IN, "strwrite in:q %p", wqp);
2717 
2718 	ASSERT((rmax >= 0) || (rmax == INFPSZ));
2719 	if (rmax == 0) {
2720 		return (0);
2721 	}
2722 	if (rmin > 0) {
2723 		if (uiop->uio_resid < rmin) {
2724 			TRACE_3(TR_FAC_STREAMS_FR, TR_STRWRITE_OUT,
2725 			    "strwrite out:q %p out %d error %d",
2726 			    wqp, 0, ERANGE);
2727 			return (ERANGE);
2728 		}
2729 		if ((rmax != INFPSZ) && (uiop->uio_resid > rmax)) {
2730 			TRACE_3(TR_FAC_STREAMS_FR, TR_STRWRITE_OUT,
2731 			    "strwrite out:q %p out %d error %d",
2732 			    wqp, 1, ERANGE);
2733 			return (ERANGE);
2734 		}
2735 	}
2736 
2737 	/*
2738 	 * Do until count satisfied or error.
2739 	 */
2740 	waitflag = WRITEWAIT | wflag;
2741 	if (stp->sd_flag & OLDNDELAY)
2742 		tempmode = uiop->uio_fmode & ~FNDELAY;
2743 	else
2744 		tempmode = uiop->uio_fmode;
2745 
2746 	if (rmax == INFPSZ)
2747 		rmax = uiop->uio_resid;
2748 
2749 	/*
2750 	 * Note that tempmode does not get used in strput/strmakedata
2751 	 * but only in strwaitq. The other routines use uio_fmode
2752 	 * unmodified.
2753 	 */
2754 
2755 	/* LINTED: constant in conditional context */
2756 	while (1) {	/* breaks when uio_resid reaches zero */
2757 		/*
2758 		 * Determine the size of the next message to be
2759 		 * packaged.  May have to break write into several
2760 		 * messages based on max packet size.
2761 		 */
2762 		iosize = MIN(uiop->uio_resid, rmax);
2763 
2764 		/*
2765 		 * Put block downstream when flow control allows it.
2766 		 */
2767 		if ((stp->sd_flag & STRDELIM) && (uiop->uio_resid == iosize))
2768 			b_flag = MSGDELIM;
2769 		else
2770 			b_flag = 0;
2771 
2772 		for (;;) {
2773 			int done = 0;
2774 
2775 			error = strput(stp, NULL, uiop, &iosize, b_flag, 0, 0);
2776 			if (error == 0)
2777 				break;
2778 			if (error != EWOULDBLOCK)
2779 				goto out;
2780 
2781 			mutex_enter(&stp->sd_lock);
2782 			/*
2783 			 * Check for a missed wakeup.
2784 			 * Needed since strput did not hold sd_lock across
2785 			 * the canputnext.
2786 			 */
2787 			if (canputnext(wqp)) {
2788 				/* Try again */
2789 				mutex_exit(&stp->sd_lock);
2790 				continue;
2791 			}
2792 			TRACE_1(TR_FAC_STREAMS_FR, TR_STRWRITE_WAIT,
2793 			    "strwrite wait:q %p wait", wqp);
2794 			if ((error = strwaitq(stp, waitflag, (ssize_t)0,
2795 			    tempmode, -1, &done)) != 0 || done) {
2796 				mutex_exit(&stp->sd_lock);
2797 				if ((vp->v_type == VFIFO) &&
2798 				    (uiop->uio_fmode & FNDELAY) &&
2799 				    (error == EAGAIN))
2800 					error = 0;
2801 				goto out;
2802 			}
2803 			TRACE_1(TR_FAC_STREAMS_FR, TR_STRWRITE_WAKE,
2804 			    "strwrite wake:q %p awakes", wqp);
2805 			if ((error = i_straccess(stp, JCWRITE)) != 0) {
2806 				mutex_exit(&stp->sd_lock);
2807 				goto out;
2808 			}
2809 			mutex_exit(&stp->sd_lock);
2810 		}
2811 		waitflag |= NOINTR;
2812 		TRACE_2(TR_FAC_STREAMS_FR, TR_STRWRITE_RESID,
2813 		    "strwrite resid:q %p uiop %p", wqp, uiop);
2814 		if (uiop->uio_resid) {
2815 			/* Recheck for errors - needed for sockets */
2816 			if ((stp->sd_wput_opt & SW_RECHECK_ERR) &&
2817 			    (stp->sd_flag & (STWRERR|STRHUP|STPLEX))) {
2818 				mutex_enter(&stp->sd_lock);
2819 				error = strwriteable(stp, B_FALSE, B_TRUE);
2820 				mutex_exit(&stp->sd_lock);
2821 				if (error != 0)
2822 					return (error);
2823 			}
2824 			continue;
2825 		}
2826 		break;
2827 	}
2828 out:
2829 	/*
2830 	 * For historical reasons, applications expect EAGAIN when a data
2831 	 * mblk_t cannot be allocated, so change ENOMEM back to EAGAIN.
2832 	 */
2833 	if (error == ENOMEM)
2834 		error = EAGAIN;
2835 	TRACE_3(TR_FAC_STREAMS_FR, TR_STRWRITE_OUT,
2836 	    "strwrite out:q %p out %d error %d", wqp, 2, error);
2837 	return (error);
2838 }
2839 
2840 /*
2841  * Stream head write service routine.
2842  * Its job is to wake up any sleeping writers when a queue
2843  * downstream needs data (part of the flow control in putq and getq).
2844  * It also must wake anyone sleeping on a poll().
2845  * For stream head right below mux module, it must also invoke put procedure
2846  * of next downstream module.
2847  */
2848 int
2849 strwsrv(queue_t *q)
2850 {
2851 	struct stdata *stp;
2852 	queue_t *tq;
2853 	qband_t *qbp;
2854 	int i;
2855 	qband_t *myqbp;
2856 	int isevent;
2857 	unsigned char	qbf[NBAND];	/* band flushing backenable flags */
2858 
2859 	TRACE_1(TR_FAC_STREAMS_FR,
2860 	    TR_STRWSRV, "strwsrv:q %p", q);
2861 	stp = (struct stdata *)q->q_ptr;
2862 	ASSERT(qclaimed(q));
2863 	mutex_enter(&stp->sd_lock);
2864 	ASSERT(!(stp->sd_flag & STPLEX));
2865 
2866 	if (stp->sd_flag & WSLEEP) {
2867 		stp->sd_flag &= ~WSLEEP;
2868 		cv_broadcast(&q->q_wait);
2869 	}
2870 	mutex_exit(&stp->sd_lock);
2871 
2872 	/* The other end of a stream pipe went away. */
2873 	if ((tq = q->q_next) == NULL) {
2874 		return (0);
2875 	}
2876 
2877 	/* Find the next module forward that has a service procedure */
2878 	claimstr(q);
2879 	tq = q->q_nfsrv;
2880 	ASSERT(tq != NULL);
2881 
2882 	if ((q->q_flag & QBACK)) {
2883 		if ((tq->q_flag & QFULL)) {
2884 			mutex_enter(QLOCK(tq));
2885 			if (!(tq->q_flag & QFULL)) {
2886 				mutex_exit(QLOCK(tq));
2887 				goto wakeup;
2888 			}
2889 			/*
2890 			 * The queue must have become full again. Set QWANTW
2891 			 * again so strwsrv will be back enabled when
2892 			 * the queue becomes non-full next time.
2893 			 */
2894 			tq->q_flag |= QWANTW;
2895 			mutex_exit(QLOCK(tq));
2896 		} else {
2897 		wakeup:
2898 			pollwakeup(&stp->sd_pollist, POLLWRNORM);
2899 			mutex_enter(&stp->sd_lock);
2900 			if (stp->sd_sigflags & S_WRNORM)
2901 				strsendsig(stp->sd_siglist, S_WRNORM, 0, 0);
2902 			mutex_exit(&stp->sd_lock);
2903 		}
2904 	}
2905 
2906 	isevent = 0;
2907 	i = 1;
2908 	bzero((caddr_t)qbf, NBAND);
2909 	mutex_enter(QLOCK(tq));
2910 	if ((myqbp = q->q_bandp) != NULL)
2911 		for (qbp = tq->q_bandp; qbp && myqbp; qbp = qbp->qb_next) {
2912 			ASSERT(myqbp);
2913 			if ((myqbp->qb_flag & QB_BACK)) {
2914 				if (qbp->qb_flag & QB_FULL) {
2915 					/*
2916 					 * The band must have become full again.
2917 					 * Set QB_WANTW again so strwsrv will
2918 					 * be back enabled when the band becomes
2919 					 * non-full next time.
2920 					 */
2921 					qbp->qb_flag |= QB_WANTW;
2922 				} else {
2923 					isevent = 1;
2924 					qbf[i] = 1;
2925 				}
2926 			}
2927 			myqbp = myqbp->qb_next;
2928 			i++;
2929 		}
2930 	mutex_exit(QLOCK(tq));
2931 
2932 	if (isevent) {
2933 		for (i = tq->q_nband; i; i--) {
2934 			if (qbf[i]) {
2935 				pollwakeup(&stp->sd_pollist, POLLWRBAND);
2936 				mutex_enter(&stp->sd_lock);
2937 				if (stp->sd_sigflags & S_WRBAND)
2938 					strsendsig(stp->sd_siglist, S_WRBAND,
2939 					    (uchar_t)i, 0);
2940 				mutex_exit(&stp->sd_lock);
2941 			}
2942 		}
2943 	}
2944 
2945 	releasestr(q);
2946 	return (0);
2947 }
2948 
2949 /*
2950  * Special case of strcopyin/strcopyout for copying
2951  * struct strioctl that can deal with both data
2952  * models.
2953  */
2954 
2955 #ifdef	_LP64
2956 
2957 static int
2958 strcopyin_strioctl(void *from, void *to, int flag, int copyflag)
2959 {
2960 	struct	strioctl32 strioc32;
2961 	struct	strioctl *striocp;
2962 
2963 	if (copyflag & U_TO_K) {
2964 		ASSERT((copyflag & K_TO_K) == 0);
2965 
2966 		if ((flag & FMODELS) == DATAMODEL_ILP32) {
2967 			if (copyin(from, &strioc32, sizeof (strioc32)))
2968 				return (EFAULT);
2969 
2970 			striocp = (struct strioctl *)to;
2971 			striocp->ic_cmd	= strioc32.ic_cmd;
2972 			striocp->ic_timout = strioc32.ic_timout;
2973 			striocp->ic_len	= strioc32.ic_len;
2974 			striocp->ic_dp	= (char *)(uintptr_t)strioc32.ic_dp;
2975 
2976 		} else { /* NATIVE data model */
2977 			if (copyin(from, to, sizeof (struct strioctl))) {
2978 				return (EFAULT);
2979 			} else {
2980 				return (0);
2981 			}
2982 		}
2983 	} else {
2984 		ASSERT(copyflag & K_TO_K);
2985 		bcopy(from, to, sizeof (struct strioctl));
2986 	}
2987 	return (0);
2988 }
2989 
2990 static int
2991 strcopyout_strioctl(void *from, void *to, int flag, int copyflag)
2992 {
2993 	struct	strioctl32 strioc32;
2994 	struct	strioctl *striocp;
2995 
2996 	if (copyflag & U_TO_K) {
2997 		ASSERT((copyflag & K_TO_K) == 0);
2998 
2999 		if ((flag & FMODELS) == DATAMODEL_ILP32) {
3000 			striocp = (struct strioctl *)from;
3001 			strioc32.ic_cmd	= striocp->ic_cmd;
3002 			strioc32.ic_timout = striocp->ic_timout;
3003 			strioc32.ic_len	= striocp->ic_len;
3004 			strioc32.ic_dp	= (caddr32_t)(uintptr_t)striocp->ic_dp;
3005 			ASSERT((char *)(uintptr_t)strioc32.ic_dp ==
3006 			    striocp->ic_dp);
3007 
3008 			if (copyout(&strioc32, to, sizeof (strioc32)))
3009 				return (EFAULT);
3010 
3011 		} else { /* NATIVE data model */
3012 			if (copyout(from, to, sizeof (struct strioctl))) {
3013 				return (EFAULT);
3014 			} else {
3015 				return (0);
3016 			}
3017 		}
3018 	} else {
3019 		ASSERT(copyflag & K_TO_K);
3020 		bcopy(from, to, sizeof (struct strioctl));
3021 	}
3022 	return (0);
3023 }
3024 
3025 #else	/* ! _LP64 */
3026 
3027 /* ARGSUSED2 */
3028 static int
3029 strcopyin_strioctl(void *from, void *to, int flag, int copyflag)
3030 {
3031 	return (strcopyin(from, to, sizeof (struct strioctl), copyflag));
3032 }
3033 
3034 /* ARGSUSED2 */
3035 static int
3036 strcopyout_strioctl(void *from, void *to, int flag, int copyflag)
3037 {
3038 	return (strcopyout(from, to, sizeof (struct strioctl), copyflag));
3039 }
3040 
3041 #endif	/* _LP64 */
3042 
3043 /*
3044  * Determine type of job control semantics expected by user.  The
3045  * possibilities are:
3046  *	JCREAD	- Behaves like read() on fd; send SIGTTIN
3047  *	JCWRITE	- Behaves like write() on fd; send SIGTTOU if TOSTOP set
3048  *	JCSETP	- Sets a value in the stream; send SIGTTOU, ignore TOSTOP
3049  *	JCGETP	- Gets a value in the stream; no signals.
3050  * See straccess in strsubr.c for usage of these values.
3051  *
3052  * This routine also returns -1 for I_STR as a special case; the
3053  * caller must call again with the real ioctl number for
3054  * classification.
3055  */
3056 static int
3057 job_control_type(int cmd)
3058 {
3059 	switch (cmd) {
3060 	case I_STR:
3061 		return (-1);
3062 
3063 	case I_RECVFD:
3064 	case I_E_RECVFD:
3065 		return (JCREAD);
3066 
3067 	case I_FDINSERT:
3068 	case I_SENDFD:
3069 		return (JCWRITE);
3070 
3071 	case TCSETA:
3072 	case TCSETAW:
3073 	case TCSETAF:
3074 	case TCSBRK:
3075 	case TCXONC:
3076 	case TCFLSH:
3077 	case TCDSET:	/* Obsolete */
3078 	case TIOCSWINSZ:
3079 	case TCSETS:
3080 	case TCSETSW:
3081 	case TCSETSF:
3082 	case TIOCSETD:
3083 	case TIOCHPCL:
3084 	case TIOCSETP:
3085 	case TIOCSETN:
3086 	case TIOCEXCL:
3087 	case TIOCNXCL:
3088 	case TIOCFLUSH:
3089 	case TIOCSETC:
3090 	case TIOCLBIS:
3091 	case TIOCLBIC:
3092 	case TIOCLSET:
3093 	case TIOCSBRK:
3094 	case TIOCCBRK:
3095 	case TIOCSDTR:
3096 	case TIOCCDTR:
3097 	case TIOCSLTC:
3098 	case TIOCSTOP:
3099 	case TIOCSTART:
3100 	case TIOCSTI:
3101 	case TIOCSPGRP:
3102 	case TIOCMSET:
3103 	case TIOCMBIS:
3104 	case TIOCMBIC:
3105 	case TIOCREMOTE:
3106 	case TIOCSIGNAL:
3107 	case LDSETT:
3108 	case LDSMAP:	/* Obsolete */
3109 	case DIOCSETP:
3110 	case I_FLUSH:
3111 	case I_SRDOPT:
3112 	case I_SETSIG:
3113 	case I_SWROPT:
3114 	case I_FLUSHBAND:
3115 	case I_SETCLTIME:
3116 	case I_SERROPT:
3117 	case I_ESETSIG:
3118 	case FIONBIO:
3119 	case FIOASYNC:
3120 	case FIOSETOWN:
3121 	case JBOOT:	/* Obsolete */
3122 	case JTERM:	/* Obsolete */
3123 	case JTIMOM:	/* Obsolete */
3124 	case JZOMBOOT:	/* Obsolete */
3125 	case JAGENT:	/* Obsolete */
3126 	case JTRUN:	/* Obsolete */
3127 	case JXTPROTO:	/* Obsolete */
3128 	case TIOCSETLD:
3129 		return (JCSETP);
3130 	}
3131 
3132 	return (JCGETP);
3133 }
3134 
3135 /*
3136  * ioctl for streams
3137  */
3138 int
3139 strioctl(struct vnode *vp, int cmd, intptr_t arg, int flag, int copyflag,
3140     cred_t *crp, int *rvalp)
3141 {
3142 	struct stdata *stp;
3143 	struct strioctl strioc;
3144 	struct uio uio;
3145 	struct iovec iov;
3146 	int access;
3147 	mblk_t *mp;
3148 	int error = 0;
3149 	int done = 0;
3150 	ssize_t	rmin, rmax;
3151 	queue_t *wrq;
3152 	queue_t *rdq;
3153 	boolean_t kioctl = B_FALSE;
3154 
3155 	if (flag & FKIOCTL) {
3156 		copyflag = K_TO_K;
3157 		kioctl = B_TRUE;
3158 	}
3159 	ASSERT(vp->v_stream);
3160 	ASSERT(copyflag == U_TO_K || copyflag == K_TO_K);
3161 	stp = vp->v_stream;
3162 
3163 	TRACE_3(TR_FAC_STREAMS_FR, TR_IOCTL_ENTER,
3164 	    "strioctl:stp %p cmd %X arg %lX", stp, cmd, arg);
3165 
3166 	if (audit_active)
3167 		audit_strioctl(vp, cmd, arg, flag, copyflag, crp, rvalp);
3168 
3169 	/*
3170 	 * If the copy is kernel to kernel, make sure that the FNATIVE
3171 	 * flag is set.  After this it would be a serious error to have
3172 	 * no model flag.
3173 	 */
3174 	if (copyflag == K_TO_K)
3175 		flag = (flag & ~FMODELS) | FNATIVE;
3176 
3177 	ASSERT((flag & FMODELS) != 0);
3178 
3179 	wrq = stp->sd_wrq;
3180 	rdq = _RD(wrq);
3181 
3182 	access = job_control_type(cmd);
3183 
3184 	/* We should never see these here, should be handled by iwscn */
3185 	if (cmd == SRIOCSREDIR || cmd == SRIOCISREDIR)
3186 		return (EINVAL);
3187 
3188 	mutex_enter(&stp->sd_lock);
3189 	if ((access != -1) && ((error = i_straccess(stp, access)) != 0)) {
3190 		mutex_exit(&stp->sd_lock);
3191 		return (error);
3192 	}
3193 	mutex_exit(&stp->sd_lock);
3194 
3195 	/*
3196 	 * Check for sgttyb-related ioctls first, and complain as
3197 	 * necessary.
3198 	 */
3199 	switch (cmd) {
3200 	case TIOCGETP:
3201 	case TIOCSETP:
3202 	case TIOCSETN:
3203 		if (sgttyb_handling >= 2 && !sgttyb_complaint) {
3204 			sgttyb_complaint = B_TRUE;
3205 			cmn_err(CE_NOTE,
3206 			    "application used obsolete TIOC[GS]ET");
3207 		}
3208 		if (sgttyb_handling >= 3) {
3209 			tsignal(curthread, SIGSYS);
3210 			return (EIO);
3211 		}
3212 		break;
3213 	}
3214 
3215 	mutex_enter(&stp->sd_lock);
3216 
3217 	switch (cmd) {
3218 	case I_RECVFD:
3219 	case I_E_RECVFD:
3220 	case I_PEEK:
3221 	case I_NREAD:
3222 	case FIONREAD:
3223 	case FIORDCHK:
3224 	case I_ATMARK:
3225 	case FIONBIO:
3226 	case FIOASYNC:
3227 		if (stp->sd_flag & (STRDERR|STPLEX)) {
3228 			error = strgeterr(stp, STRDERR|STPLEX, 0);
3229 			if (error != 0) {
3230 				mutex_exit(&stp->sd_lock);
3231 				return (error);
3232 			}
3233 		}
3234 		break;
3235 
3236 	default:
3237 		if (stp->sd_flag & (STRDERR|STWRERR|STPLEX)) {
3238 			error = strgeterr(stp, STRDERR|STWRERR|STPLEX, 0);
3239 			if (error != 0) {
3240 				mutex_exit(&stp->sd_lock);
3241 				return (error);
3242 			}
3243 		}
3244 	}
3245 
3246 	mutex_exit(&stp->sd_lock);
3247 
3248 	switch (cmd) {
3249 	default:
3250 		/*
3251 		 * The stream head has hardcoded knowledge of a
3252 		 * miscellaneous collection of terminal-, keyboard- and
3253 		 * mouse-related ioctls, enumerated below.  This hardcoded
3254 		 * knowledge allows the stream head to automatically
3255 		 * convert transparent ioctl requests made by userland
3256 		 * programs into I_STR ioctls which many old STREAMS
3257 		 * modules and drivers require.
3258 		 *
3259 		 * No new ioctls should ever be added to this list.
3260 		 * Instead, the STREAMS module or driver should be written
3261 		 * to either handle transparent ioctls or require any
3262 		 * userland programs to use I_STR ioctls (by returning
3263 		 * EINVAL to any transparent ioctl requests).
3264 		 *
3265 		 * More importantly, removing ioctls from this list should
3266 		 * be done with the utmost care, since our STREAMS modules
3267 		 * and drivers *count* on the stream head performing this
3268 		 * conversion, and thus may panic while processing
3269 		 * transparent ioctl request for one of these ioctls (keep
3270 		 * in mind that third party modules and drivers may have
3271 		 * similar problems).
3272 		 */
3273 		if (((cmd & IOCTYPE) == LDIOC) ||
3274 		    ((cmd & IOCTYPE) == tIOC) ||
3275 		    ((cmd & IOCTYPE) == TIOC) ||
3276 		    ((cmd & IOCTYPE) == KIOC) ||
3277 		    ((cmd & IOCTYPE) == MSIOC) ||
3278 		    ((cmd & IOCTYPE) == VUIOC)) {
3279 			/*
3280 			 * The ioctl is a tty ioctl - set up strioc buffer
3281 			 * and call strdoioctl() to do the work.
3282 			 */
3283 			if (stp->sd_flag & STRHUP)
3284 				return (ENXIO);
3285 			strioc.ic_cmd = cmd;
3286 			strioc.ic_timout = INFTIM;
3287 
3288 			switch (cmd) {
3289 
3290 			case TCXONC:
3291 			case TCSBRK:
3292 			case TCFLSH:
3293 			case TCDSET:
3294 				{
3295 				int native_arg = (int)arg;
3296 				strioc.ic_len = sizeof (int);
3297 				strioc.ic_dp = (char *)&native_arg;
3298 				return (strdoioctl(stp, &strioc, flag,
3299 				    K_TO_K, crp, rvalp));
3300 				}
3301 
3302 			case TCSETA:
3303 			case TCSETAW:
3304 			case TCSETAF:
3305 				strioc.ic_len = sizeof (struct termio);
3306 				strioc.ic_dp = (char *)arg;
3307 				return (strdoioctl(stp, &strioc, flag,
3308 				    copyflag, crp, rvalp));
3309 
3310 			case TCSETS:
3311 			case TCSETSW:
3312 			case TCSETSF:
3313 				strioc.ic_len = sizeof (struct termios);
3314 				strioc.ic_dp = (char *)arg;
3315 				return (strdoioctl(stp, &strioc, flag,
3316 				    copyflag, crp, rvalp));
3317 
3318 			case LDSETT:
3319 				strioc.ic_len = sizeof (struct termcb);
3320 				strioc.ic_dp = (char *)arg;
3321 				return (strdoioctl(stp, &strioc, flag,
3322 				    copyflag, crp, rvalp));
3323 
3324 			case TIOCSETP:
3325 				strioc.ic_len = sizeof (struct sgttyb);
3326 				strioc.ic_dp = (char *)arg;
3327 				return (strdoioctl(stp, &strioc, flag,
3328 				    copyflag, crp, rvalp));
3329 
3330 			case TIOCSTI:
3331 				if ((flag & FREAD) == 0 &&
3332 				    secpolicy_sti(crp) != 0) {
3333 					return (EPERM);
3334 				}
3335 				mutex_enter(&stp->sd_lock);
3336 				mutex_enter(&curproc->p_splock);
3337 				if (stp->sd_sidp != curproc->p_sessp->s_sidp &&
3338 				    secpolicy_sti(crp) != 0) {
3339 					mutex_exit(&curproc->p_splock);
3340 					mutex_exit(&stp->sd_lock);
3341 					return (EACCES);
3342 				}
3343 				mutex_exit(&curproc->p_splock);
3344 				mutex_exit(&stp->sd_lock);
3345 
3346 				strioc.ic_len = sizeof (char);
3347 				strioc.ic_dp = (char *)arg;
3348 				return (strdoioctl(stp, &strioc, flag,
3349 				    copyflag, crp, rvalp));
3350 
3351 			case TIOCSWINSZ:
3352 				strioc.ic_len = sizeof (struct winsize);
3353 				strioc.ic_dp = (char *)arg;
3354 				return (strdoioctl(stp, &strioc, flag,
3355 				    copyflag, crp, rvalp));
3356 
3357 			case TIOCSSIZE:
3358 				strioc.ic_len = sizeof (struct ttysize);
3359 				strioc.ic_dp = (char *)arg;
3360 				return (strdoioctl(stp, &strioc, flag,
3361 				    copyflag, crp, rvalp));
3362 
3363 			case TIOCSSOFTCAR:
3364 			case KIOCTRANS:
3365 			case KIOCTRANSABLE:
3366 			case KIOCCMD:
3367 			case KIOCSDIRECT:
3368 			case KIOCSCOMPAT:
3369 			case KIOCSKABORTEN:
3370 			case KIOCSRPTDELAY:
3371 			case KIOCSRPTRATE:
3372 			case VUIDSFORMAT:
3373 			case TIOCSPPS:
3374 				strioc.ic_len = sizeof (int);
3375 				strioc.ic_dp = (char *)arg;
3376 				return (strdoioctl(stp, &strioc, flag,
3377 				    copyflag, crp, rvalp));
3378 
3379 			case KIOCSETKEY:
3380 			case KIOCGETKEY:
3381 				strioc.ic_len = sizeof (struct kiockey);
3382 				strioc.ic_dp = (char *)arg;
3383 				return (strdoioctl(stp, &strioc, flag,
3384 				    copyflag, crp, rvalp));
3385 
3386 			case KIOCSKEY:
3387 			case KIOCGKEY:
3388 				strioc.ic_len = sizeof (struct kiockeymap);
3389 				strioc.ic_dp = (char *)arg;
3390 				return (strdoioctl(stp, &strioc, flag,
3391 				    copyflag, crp, rvalp));
3392 
3393 			case KIOCSLED:
3394 				/* arg is a pointer to char */
3395 				strioc.ic_len = sizeof (char);
3396 				strioc.ic_dp = (char *)arg;
3397 				return (strdoioctl(stp, &strioc, flag,
3398 				    copyflag, crp, rvalp));
3399 
3400 			case MSIOSETPARMS:
3401 				strioc.ic_len = sizeof (Ms_parms);
3402 				strioc.ic_dp = (char *)arg;
3403 				return (strdoioctl(stp, &strioc, flag,
3404 				    copyflag, crp, rvalp));
3405 
3406 			case VUIDSADDR:
3407 			case VUIDGADDR:
3408 				strioc.ic_len = sizeof (struct vuid_addr_probe);
3409 				strioc.ic_dp = (char *)arg;
3410 				return (strdoioctl(stp, &strioc, flag,
3411 				    copyflag, crp, rvalp));
3412 
3413 			/*
3414 			 * These M_IOCTL's don't require any data to be sent
3415 			 * downstream, and the driver will allocate and link
3416 			 * on its own mblk_t upon M_IOCACK -- thus we set
3417 			 * ic_len to zero and set ic_dp to arg so we know
3418 			 * where to copyout to later.
3419 			 */
3420 			case TIOCGSOFTCAR:
3421 			case TIOCGWINSZ:
3422 			case TIOCGSIZE:
3423 			case KIOCGTRANS:
3424 			case KIOCGTRANSABLE:
3425 			case KIOCTYPE:
3426 			case KIOCGDIRECT:
3427 			case KIOCGCOMPAT:
3428 			case KIOCLAYOUT:
3429 			case KIOCGLED:
3430 			case MSIOGETPARMS:
3431 			case MSIOBUTTONS:
3432 			case VUIDGFORMAT:
3433 			case TIOCGPPS:
3434 			case TIOCGPPSEV:
3435 			case TCGETA:
3436 			case TCGETS:
3437 			case LDGETT:
3438 			case TIOCGETP:
3439 			case KIOCGRPTDELAY:
3440 			case KIOCGRPTRATE:
3441 				strioc.ic_len = 0;
3442 				strioc.ic_dp = (char *)arg;
3443 				return (strdoioctl(stp, &strioc, flag,
3444 				    copyflag, crp, rvalp));
3445 			}
3446 		}
3447 
3448 		/*
3449 		 * Unknown cmd - send it down as a transparent ioctl.
3450 		 */
3451 		strioc.ic_cmd = cmd;
3452 		strioc.ic_timout = INFTIM;
3453 		strioc.ic_len = TRANSPARENT;
3454 		strioc.ic_dp = (char *)&arg;
3455 
3456 		return (strdoioctl(stp, &strioc, flag, copyflag, crp, rvalp));
3457 
3458 	case I_STR:
3459 		/*
3460 		 * Stream ioctl.  Read in an strioctl buffer from the user
3461 		 * along with any data specified and send it downstream.
3462 		 * Strdoioctl will wait allow only one ioctl message at
3463 		 * a time, and waits for the acknowledgement.
3464 		 */
3465 
3466 		if (stp->sd_flag & STRHUP)
3467 			return (ENXIO);
3468 
3469 		error = strcopyin_strioctl((void *)arg, &strioc, flag,
3470 		    copyflag);
3471 		if (error != 0)
3472 			return (error);
3473 
3474 		if ((strioc.ic_len < 0) || (strioc.ic_timout < -1))
3475 			return (EINVAL);
3476 
3477 		access = job_control_type(strioc.ic_cmd);
3478 		mutex_enter(&stp->sd_lock);
3479 		if ((access != -1) &&
3480 		    ((error = i_straccess(stp, access)) != 0)) {
3481 			mutex_exit(&stp->sd_lock);
3482 			return (error);
3483 		}
3484 		mutex_exit(&stp->sd_lock);
3485 
3486 		/*
3487 		 * The I_STR facility provides a trap door for malicious
3488 		 * code to send down bogus streamio(7I) ioctl commands to
3489 		 * unsuspecting STREAMS modules and drivers which expect to
3490 		 * only get these messages from the stream head.
3491 		 * Explicitly prohibit any streamio ioctls which can be
3492 		 * passed downstream by the stream head.  Note that we do
3493 		 * not block all streamio ioctls because the ioctl
3494 		 * numberspace is not well managed and thus it's possible
3495 		 * that a module or driver's ioctl numbers may accidentally
3496 		 * collide with them.
3497 		 */
3498 		switch (strioc.ic_cmd) {
3499 		case I_LINK:
3500 		case I_PLINK:
3501 		case I_UNLINK:
3502 		case I_PUNLINK:
3503 		case _I_GETPEERCRED:
3504 		case _I_PLINK_LH:
3505 			return (EINVAL);
3506 		}
3507 
3508 		error = strdoioctl(stp, &strioc, flag, copyflag, crp, rvalp);
3509 		if (error == 0) {
3510 			error = strcopyout_strioctl(&strioc, (void *)arg,
3511 			    flag, copyflag);
3512 		}
3513 		return (error);
3514 
3515 	case I_NREAD:
3516 		/*
3517 		 * Return number of bytes of data in first message
3518 		 * in queue in "arg" and return the number of messages
3519 		 * in queue in return value.
3520 		 */
3521 	{
3522 		size_t	size;
3523 		int	retval;
3524 		int	count = 0;
3525 
3526 		mutex_enter(QLOCK(rdq));
3527 
3528 		size = msgdsize(rdq->q_first);
3529 		for (mp = rdq->q_first; mp != NULL; mp = mp->b_next)
3530 			count++;
3531 
3532 		mutex_exit(QLOCK(rdq));
3533 		if (stp->sd_struiordq) {
3534 			infod_t infod;
3535 
3536 			infod.d_cmd = INFOD_COUNT;
3537 			infod.d_count = 0;
3538 			if (count == 0) {
3539 				infod.d_cmd |= INFOD_FIRSTBYTES;
3540 				infod.d_bytes = 0;
3541 			}
3542 			infod.d_res = 0;
3543 			(void) infonext(rdq, &infod);
3544 			count += infod.d_count;
3545 			if (infod.d_res & INFOD_FIRSTBYTES)
3546 				size = infod.d_bytes;
3547 		}
3548 
3549 		/*
3550 		 * Drop down from size_t to the "int" required by the
3551 		 * interface.  Cap at INT_MAX.
3552 		 */
3553 		retval = MIN(size, INT_MAX);
3554 		error = strcopyout(&retval, (void *)arg, sizeof (retval),
3555 		    copyflag);
3556 		if (!error)
3557 			*rvalp = count;
3558 		return (error);
3559 	}
3560 
3561 	case FIONREAD:
3562 		/*
3563 		 * Return number of bytes of data in all data messages
3564 		 * in queue in "arg".
3565 		 */
3566 	{
3567 		size_t	size = 0;
3568 		int	retval;
3569 
3570 		mutex_enter(QLOCK(rdq));
3571 		for (mp = rdq->q_first; mp != NULL; mp = mp->b_next)
3572 			size += msgdsize(mp);
3573 		mutex_exit(QLOCK(rdq));
3574 
3575 		if (stp->sd_struiordq) {
3576 			infod_t infod;
3577 
3578 			infod.d_cmd = INFOD_BYTES;
3579 			infod.d_res = 0;
3580 			infod.d_bytes = 0;
3581 			(void) infonext(rdq, &infod);
3582 			size += infod.d_bytes;
3583 		}
3584 
3585 		/*
3586 		 * Drop down from size_t to the "int" required by the
3587 		 * interface.  Cap at INT_MAX.
3588 		 */
3589 		retval = MIN(size, INT_MAX);
3590 		error = strcopyout(&retval, (void *)arg, sizeof (retval),
3591 		    copyflag);
3592 
3593 		*rvalp = 0;
3594 		return (error);
3595 	}
3596 	case FIORDCHK:
3597 		/*
3598 		 * FIORDCHK does not use arg value (like FIONREAD),
3599 		 * instead a count is returned. I_NREAD value may
3600 		 * not be accurate but safe. The real thing to do is
3601 		 * to add the msgdsizes of all data  messages until
3602 		 * a non-data message.
3603 		 */
3604 	{
3605 		size_t size = 0;
3606 
3607 		mutex_enter(QLOCK(rdq));
3608 		for (mp = rdq->q_first; mp != NULL; mp = mp->b_next)
3609 			size += msgdsize(mp);
3610 		mutex_exit(QLOCK(rdq));
3611 
3612 		if (stp->sd_struiordq) {
3613 			infod_t infod;
3614 
3615 			infod.d_cmd = INFOD_BYTES;
3616 			infod.d_res = 0;
3617 			infod.d_bytes = 0;
3618 			(void) infonext(rdq, &infod);
3619 			size += infod.d_bytes;
3620 		}
3621 
3622 		/*
3623 		 * Since ioctl returns an int, and memory sizes under
3624 		 * LP64 may not fit, we return INT_MAX if the count was
3625 		 * actually greater.
3626 		 */
3627 		*rvalp = MIN(size, INT_MAX);
3628 		return (0);
3629 	}
3630 
3631 	case I_FIND:
3632 		/*
3633 		 * Get module name.
3634 		 */
3635 	{
3636 		char mname[FMNAMESZ + 1];
3637 		queue_t *q;
3638 
3639 		error = (copyflag & U_TO_K ? copyinstr : copystr)((void *)arg,
3640 		    mname, FMNAMESZ + 1, NULL);
3641 		if (error)
3642 			return ((error == ENAMETOOLONG) ? EINVAL : EFAULT);
3643 
3644 		/*
3645 		 * Return EINVAL if we're handed a bogus module name.
3646 		 */
3647 		if (fmodsw_find(mname, FMODSW_LOAD) == NULL) {
3648 			TRACE_0(TR_FAC_STREAMS_FR,
3649 			    TR_I_CANT_FIND, "couldn't I_FIND");
3650 			return (EINVAL);
3651 		}
3652 
3653 		*rvalp = 0;
3654 
3655 		/* Look downstream to see if module is there. */
3656 		claimstr(stp->sd_wrq);
3657 		for (q = stp->sd_wrq->q_next; q; q = q->q_next) {
3658 			if (q->q_flag&QREADR) {
3659 				q = NULL;
3660 				break;
3661 			}
3662 			if (strcmp(mname, q->q_qinfo->qi_minfo->mi_idname) == 0)
3663 				break;
3664 		}
3665 		releasestr(stp->sd_wrq);
3666 
3667 		*rvalp = (q ? 1 : 0);
3668 		return (error);
3669 	}
3670 
3671 	case I_PUSH:
3672 	case __I_PUSH_NOCTTY:
3673 		/*
3674 		 * Push a module.
3675 		 * For the case __I_PUSH_NOCTTY push a module but
3676 		 * do not allocate controlling tty. See bugid 4025044
3677 		 */
3678 
3679 	{
3680 		char mname[FMNAMESZ + 1];
3681 		fmodsw_impl_t *fp;
3682 		dev_t dummydev;
3683 
3684 		if (stp->sd_flag & STRHUP)
3685 			return (ENXIO);
3686 
3687 		/*
3688 		 * Get module name and look up in fmodsw.
3689 		 */
3690 		error = (copyflag & U_TO_K ? copyinstr : copystr)((void *)arg,
3691 		    mname, FMNAMESZ + 1, NULL);
3692 		if (error)
3693 			return ((error == ENAMETOOLONG) ? EINVAL : EFAULT);
3694 
3695 		if ((fp = fmodsw_find(mname, FMODSW_HOLD | FMODSW_LOAD)) ==
3696 		    NULL)
3697 			return (EINVAL);
3698 
3699 		TRACE_2(TR_FAC_STREAMS_FR, TR_I_PUSH,
3700 		    "I_PUSH:fp %p stp %p", fp, stp);
3701 
3702 		if (error = strstartplumb(stp, flag, cmd)) {
3703 			fmodsw_rele(fp);
3704 			return (error);
3705 		}
3706 
3707 		/*
3708 		 * See if any more modules can be pushed on this stream.
3709 		 * Note that this check must be done after strstartplumb()
3710 		 * since otherwise multiple threads issuing I_PUSHes on
3711 		 * the same stream will be able to exceed nstrpush.
3712 		 */
3713 		mutex_enter(&stp->sd_lock);
3714 		if (stp->sd_pushcnt >= nstrpush) {
3715 			fmodsw_rele(fp);
3716 			strendplumb(stp);
3717 			mutex_exit(&stp->sd_lock);
3718 			return (EINVAL);
3719 		}
3720 		mutex_exit(&stp->sd_lock);
3721 
3722 		/*
3723 		 * Push new module and call its open routine
3724 		 * via qattach().  Modules don't change device
3725 		 * numbers, so just ignore dummydev here.
3726 		 */
3727 		dummydev = vp->v_rdev;
3728 		if ((error = qattach(rdq, &dummydev, 0, crp, fp,
3729 		    B_FALSE)) == 0) {
3730 			if (vp->v_type == VCHR && /* sorry, no pipes allowed */
3731 			    (cmd == I_PUSH) && (stp->sd_flag & STRISTTY)) {
3732 				/*
3733 				 * try to allocate it as a controlling terminal
3734 				 */
3735 				(void) strctty(stp);
3736 			}
3737 		}
3738 
3739 		mutex_enter(&stp->sd_lock);
3740 
3741 		/*
3742 		 * As a performance concern we are caching the values of
3743 		 * q_minpsz and q_maxpsz of the module below the stream
3744 		 * head in the stream head.
3745 		 */
3746 		mutex_enter(QLOCK(stp->sd_wrq->q_next));
3747 		rmin = stp->sd_wrq->q_next->q_minpsz;
3748 		rmax = stp->sd_wrq->q_next->q_maxpsz;
3749 		mutex_exit(QLOCK(stp->sd_wrq->q_next));
3750 
3751 		/* Do this processing here as a performance concern */
3752 		if (strmsgsz != 0) {
3753 			if (rmax == INFPSZ)
3754 				rmax = strmsgsz;
3755 			else  {
3756 				if (vp->v_type == VFIFO)
3757 					rmax = MIN(PIPE_BUF, rmax);
3758 				else	rmax = MIN(strmsgsz, rmax);
3759 			}
3760 		}
3761 
3762 		mutex_enter(QLOCK(wrq));
3763 		stp->sd_qn_minpsz = rmin;
3764 		stp->sd_qn_maxpsz = rmax;
3765 		mutex_exit(QLOCK(wrq));
3766 
3767 		strendplumb(stp);
3768 		mutex_exit(&stp->sd_lock);
3769 		return (error);
3770 	}
3771 
3772 	case I_POP:
3773 	{
3774 		queue_t	*q;
3775 
3776 		if (stp->sd_flag & STRHUP)
3777 			return (ENXIO);
3778 		if (!wrq->q_next)	/* for broken pipes */
3779 			return (EINVAL);
3780 
3781 		if (error = strstartplumb(stp, flag, cmd))
3782 			return (error);
3783 
3784 		/*
3785 		 * If there is an anchor on this stream and popping
3786 		 * the current module would attempt to pop through the
3787 		 * anchor, then disallow the pop unless we have sufficient
3788 		 * privileges; take the cheapest (non-locking) check
3789 		 * first.
3790 		 */
3791 		if (secpolicy_ip_config(crp, B_TRUE) != 0 ||
3792 		    (stp->sd_anchorzone != crgetzoneid(crp))) {
3793 			mutex_enter(&stp->sd_lock);
3794 			/*
3795 			 * Anchors only apply if there's at least one
3796 			 * module on the stream (sd_pushcnt > 0).
3797 			 */
3798 			if (stp->sd_pushcnt > 0 &&
3799 			    stp->sd_pushcnt == stp->sd_anchor &&
3800 			    stp->sd_vnode->v_type != VFIFO) {
3801 				strendplumb(stp);
3802 				mutex_exit(&stp->sd_lock);
3803 				if (stp->sd_anchorzone != crgetzoneid(crp))
3804 					return (EINVAL);
3805 				/* Audit and report error */
3806 				return (secpolicy_ip_config(crp, B_FALSE));
3807 			}
3808 			mutex_exit(&stp->sd_lock);
3809 		}
3810 
3811 		q = wrq->q_next;
3812 		TRACE_2(TR_FAC_STREAMS_FR, TR_I_POP,
3813 		    "I_POP:%p from %p", q, stp);
3814 		if (q->q_next == NULL || (q->q_flag & (QREADR|QISDRV))) {
3815 			error = EINVAL;
3816 		} else {
3817 			qdetach(_RD(q), 1, flag, crp, B_FALSE);
3818 			error = 0;
3819 		}
3820 		mutex_enter(&stp->sd_lock);
3821 
3822 		/*
3823 		 * As a performance concern we are caching the values of
3824 		 * q_minpsz and q_maxpsz of the module below the stream
3825 		 * head in the stream head.
3826 		 */
3827 		mutex_enter(QLOCK(wrq->q_next));
3828 		rmin = wrq->q_next->q_minpsz;
3829 		rmax = wrq->q_next->q_maxpsz;
3830 		mutex_exit(QLOCK(wrq->q_next));
3831 
3832 		/* Do this processing here as a performance concern */
3833 		if (strmsgsz != 0) {
3834 			if (rmax == INFPSZ)
3835 				rmax = strmsgsz;
3836 			else  {
3837 				if (vp->v_type == VFIFO)
3838 					rmax = MIN(PIPE_BUF, rmax);
3839 				else	rmax = MIN(strmsgsz, rmax);
3840 			}
3841 		}
3842 
3843 		mutex_enter(QLOCK(wrq));
3844 		stp->sd_qn_minpsz = rmin;
3845 		stp->sd_qn_maxpsz = rmax;
3846 		mutex_exit(QLOCK(wrq));
3847 
3848 		/* If we popped through the anchor, then reset the anchor. */
3849 		if (stp->sd_pushcnt < stp->sd_anchor) {
3850 			stp->sd_anchor = 0;
3851 			stp->sd_anchorzone = 0;
3852 		}
3853 		strendplumb(stp);
3854 		mutex_exit(&stp->sd_lock);
3855 		return (error);
3856 	}
3857 
3858 	case _I_MUXID2FD:
3859 	{
3860 		/*
3861 		 * Create a fd for a I_PLINK'ed lower stream with a given
3862 		 * muxid.  With the fd, application can send down ioctls,
3863 		 * like I_LIST, to the previously I_PLINK'ed stream.  Note
3864 		 * that after getting the fd, the application has to do an
3865 		 * I_PUNLINK on the muxid before it can do any operation
3866 		 * on the lower stream.  This is required by spec1170.
3867 		 *
3868 		 * The fd used to do this ioctl should point to the same
3869 		 * controlling device used to do the I_PLINK.  If it uses
3870 		 * a different stream or an invalid muxid, I_MUXID2FD will
3871 		 * fail.  The error code is set to EINVAL.
3872 		 *
3873 		 * The intended use of this interface is the following.
3874 		 * An application I_PLINK'ed a stream and exits.  The fd
3875 		 * to the lower stream is gone.  Another application
3876 		 * wants to get a fd to the lower stream, it uses I_MUXID2FD.
3877 		 */
3878 		int muxid = (int)arg;
3879 		int fd;
3880 		linkinfo_t *linkp;
3881 		struct file *fp;
3882 		netstack_t *ns;
3883 		str_stack_t *ss;
3884 
3885 		/*
3886 		 * Do not allow the wildcard muxid.  This ioctl is not
3887 		 * intended to find arbitrary link.
3888 		 */
3889 		if (muxid == 0) {
3890 			return (EINVAL);
3891 		}
3892 
3893 		ns = netstack_find_by_cred(crp);
3894 		ASSERT(ns != NULL);
3895 		ss = ns->netstack_str;
3896 		ASSERT(ss != NULL);
3897 
3898 		mutex_enter(&muxifier);
3899 		linkp = findlinks(vp->v_stream, muxid, LINKPERSIST, ss);
3900 		if (linkp == NULL) {
3901 			mutex_exit(&muxifier);
3902 			netstack_rele(ss->ss_netstack);
3903 			return (EINVAL);
3904 		}
3905 
3906 		if ((fd = ufalloc(0)) == -1) {
3907 			mutex_exit(&muxifier);
3908 			netstack_rele(ss->ss_netstack);
3909 			return (EMFILE);
3910 		}
3911 		fp = linkp->li_fpdown;
3912 		mutex_enter(&fp->f_tlock);
3913 		fp->f_count++;
3914 		mutex_exit(&fp->f_tlock);
3915 		mutex_exit(&muxifier);
3916 		setf(fd, fp);
3917 		*rvalp = fd;
3918 		netstack_rele(ss->ss_netstack);
3919 		return (0);
3920 	}
3921 
3922 	case _I_INSERT:
3923 	{
3924 		/*
3925 		 * To insert a module to a given position in a stream.
3926 		 * In the first release, only allow privileged user
3927 		 * to use this ioctl. Furthermore, the insert is only allowed
3928 		 * below an anchor if the zoneid is the same as the zoneid
3929 		 * which created the anchor.
3930 		 *
3931 		 * Note that we do not plan to support this ioctl
3932 		 * on pipes in the first release.  We want to learn more
3933 		 * about the implications of these ioctls before extending
3934 		 * their support.  And we do not think these features are
3935 		 * valuable for pipes.
3936 		 *
3937 		 * Neither do we support O/C hot stream.  Note that only
3938 		 * the upper streams of TCP/IP stack are O/C hot streams.
3939 		 * The lower IP stream is not.
3940 		 * When there is a O/C cold barrier, we only allow inserts
3941 		 * above the barrier.
3942 		 */
3943 		STRUCT_DECL(strmodconf, strmodinsert);
3944 		char mod_name[FMNAMESZ + 1];
3945 		fmodsw_impl_t *fp;
3946 		dev_t dummydev;
3947 		queue_t *tmp_wrq;
3948 		int pos;
3949 		boolean_t is_insert;
3950 
3951 		STRUCT_INIT(strmodinsert, flag);
3952 		if (stp->sd_flag & STRHUP)
3953 			return (ENXIO);
3954 		if (STRMATED(stp))
3955 			return (EINVAL);
3956 		if ((error = secpolicy_net_config(crp, B_FALSE)) != 0)
3957 			return (error);
3958 		if (stp->sd_anchor != 0 &&
3959 		    stp->sd_anchorzone != crgetzoneid(crp))
3960 			return (EINVAL);
3961 
3962 		error = strcopyin((void *)arg, STRUCT_BUF(strmodinsert),
3963 		    STRUCT_SIZE(strmodinsert), copyflag);
3964 		if (error)
3965 			return (error);
3966 
3967 		/*
3968 		 * Get module name and look up in fmodsw.
3969 		 */
3970 		error = (copyflag & U_TO_K ? copyinstr :
3971 		    copystr)(STRUCT_FGETP(strmodinsert, mod_name),
3972 		    mod_name, FMNAMESZ + 1, NULL);
3973 		if (error)
3974 			return ((error == ENAMETOOLONG) ? EINVAL : EFAULT);
3975 
3976 		if ((fp = fmodsw_find(mod_name, FMODSW_HOLD | FMODSW_LOAD)) ==
3977 		    NULL)
3978 			return (EINVAL);
3979 
3980 		if (error = strstartplumb(stp, flag, cmd)) {
3981 			fmodsw_rele(fp);
3982 			return (error);
3983 		}
3984 
3985 		/*
3986 		 * Is this _I_INSERT just like an I_PUSH?  We need to know
3987 		 * this because we do some optimizations if this is a
3988 		 * module being pushed.
3989 		 */
3990 		pos = STRUCT_FGET(strmodinsert, pos);
3991 		is_insert = (pos != 0);
3992 
3993 		/*
3994 		 * Make sure pos is valid.  Even though it is not an I_PUSH,
3995 		 * we impose the same limit on the number of modules in a
3996 		 * stream.
3997 		 */
3998 		mutex_enter(&stp->sd_lock);
3999 		if (stp->sd_pushcnt >= nstrpush || pos < 0 ||
4000 		    pos > stp->sd_pushcnt) {
4001 			fmodsw_rele(fp);
4002 			strendplumb(stp);
4003 			mutex_exit(&stp->sd_lock);
4004 			return (EINVAL);
4005 		}
4006 		if (stp->sd_anchor != 0) {
4007 			/*
4008 			 * Is this insert below the anchor?
4009 			 * Pushcnt hasn't been increased yet hence
4010 			 * we test for greater than here, and greater or
4011 			 * equal after qattach.
4012 			 */
4013 			if (pos > (stp->sd_pushcnt - stp->sd_anchor) &&
4014 			    stp->sd_anchorzone != crgetzoneid(crp)) {
4015 				fmodsw_rele(fp);
4016 				strendplumb(stp);
4017 				mutex_exit(&stp->sd_lock);
4018 				return (EPERM);
4019 			}
4020 		}
4021 
4022 		mutex_exit(&stp->sd_lock);
4023 
4024 		/*
4025 		 * First find the correct position this module to
4026 		 * be inserted.  We don't need to call claimstr()
4027 		 * as the stream should not be changing at this point.
4028 		 *
4029 		 * Insert new module and call its open routine
4030 		 * via qattach().  Modules don't change device
4031 		 * numbers, so just ignore dummydev here.
4032 		 */
4033 		for (tmp_wrq = stp->sd_wrq; pos > 0;
4034 		    tmp_wrq = tmp_wrq->q_next, pos--) {
4035 			ASSERT(SAMESTR(tmp_wrq));
4036 		}
4037 		dummydev = vp->v_rdev;
4038 		if ((error = qattach(_RD(tmp_wrq), &dummydev, 0, crp,
4039 		    fp, is_insert)) != 0) {
4040 			mutex_enter(&stp->sd_lock);
4041 			strendplumb(stp);
4042 			mutex_exit(&stp->sd_lock);
4043 			return (error);
4044 		}
4045 
4046 		mutex_enter(&stp->sd_lock);
4047 
4048 		/*
4049 		 * As a performance concern we are caching the values of
4050 		 * q_minpsz and q_maxpsz of the module below the stream
4051 		 * head in the stream head.
4052 		 */
4053 		if (!is_insert) {
4054 			mutex_enter(QLOCK(stp->sd_wrq->q_next));
4055 			rmin = stp->sd_wrq->q_next->q_minpsz;
4056 			rmax = stp->sd_wrq->q_next->q_maxpsz;
4057 			mutex_exit(QLOCK(stp->sd_wrq->q_next));
4058 
4059 			/* Do this processing here as a performance concern */
4060 			if (strmsgsz != 0) {
4061 				if (rmax == INFPSZ) {
4062 					rmax = strmsgsz;
4063 				} else  {
4064 					rmax = MIN(strmsgsz, rmax);
4065 				}
4066 			}
4067 
4068 			mutex_enter(QLOCK(wrq));
4069 			stp->sd_qn_minpsz = rmin;
4070 			stp->sd_qn_maxpsz = rmax;
4071 			mutex_exit(QLOCK(wrq));
4072 		}
4073 
4074 		/*
4075 		 * Need to update the anchor value if this module is
4076 		 * inserted below the anchor point.
4077 		 */
4078 		if (stp->sd_anchor != 0) {
4079 			pos = STRUCT_FGET(strmodinsert, pos);
4080 			if (pos >= (stp->sd_pushcnt - stp->sd_anchor))
4081 				stp->sd_anchor++;
4082 		}
4083 
4084 		strendplumb(stp);
4085 		mutex_exit(&stp->sd_lock);
4086 		return (0);
4087 	}
4088 
4089 	case _I_REMOVE:
4090 	{
4091 		/*
4092 		 * To remove a module with a given name in a stream.  The
4093 		 * caller of this ioctl needs to provide both the name and
4094 		 * the position of the module to be removed.  This eliminates
4095 		 * the ambiguity of removal if a module is inserted/pushed
4096 		 * multiple times in a stream.  In the first release, only
4097 		 * allow privileged user to use this ioctl.
4098 		 * Furthermore, the remove is only allowed
4099 		 * below an anchor if the zoneid is the same as the zoneid
4100 		 * which created the anchor.
4101 		 *
4102 		 * Note that we do not plan to support this ioctl
4103 		 * on pipes in the first release.  We want to learn more
4104 		 * about the implications of these ioctls before extending
4105 		 * their support.  And we do not think these features are
4106 		 * valuable for pipes.
4107 		 *
4108 		 * Neither do we support O/C hot stream.  Note that only
4109 		 * the upper streams of TCP/IP stack are O/C hot streams.
4110 		 * The lower IP stream is not.
4111 		 * When there is a O/C cold barrier we do not allow removal
4112 		 * below the barrier.
4113 		 *
4114 		 * Also note that _I_REMOVE cannot be used to remove a
4115 		 * driver or the stream head.
4116 		 */
4117 		STRUCT_DECL(strmodconf, strmodremove);
4118 		queue_t	*q;
4119 		int pos;
4120 		char mod_name[FMNAMESZ + 1];
4121 		boolean_t is_remove;
4122 
4123 		STRUCT_INIT(strmodremove, flag);
4124 		if (stp->sd_flag & STRHUP)
4125 			return (ENXIO);
4126 		if (STRMATED(stp))
4127 			return (EINVAL);
4128 		if ((error = secpolicy_net_config(crp, B_FALSE)) != 0)
4129 			return (error);
4130 		if (stp->sd_anchor != 0 &&
4131 		    stp->sd_anchorzone != crgetzoneid(crp))
4132 			return (EINVAL);
4133 
4134 		error = strcopyin((void *)arg, STRUCT_BUF(strmodremove),
4135 		    STRUCT_SIZE(strmodremove), copyflag);
4136 		if (error)
4137 			return (error);
4138 
4139 		error = (copyflag & U_TO_K ? copyinstr :
4140 		    copystr)(STRUCT_FGETP(strmodremove, mod_name),
4141 		    mod_name, FMNAMESZ + 1, NULL);
4142 		if (error)
4143 			return ((error == ENAMETOOLONG) ? EINVAL : EFAULT);
4144 
4145 		if ((error = strstartplumb(stp, flag, cmd)) != 0)
4146 			return (error);
4147 
4148 		/*
4149 		 * Match the name of given module to the name of module at
4150 		 * the given position.
4151 		 */
4152 		pos = STRUCT_FGET(strmodremove, pos);
4153 
4154 		is_remove = (pos != 0);
4155 		for (q = stp->sd_wrq->q_next; SAMESTR(q) && pos > 0;
4156 		    q = q->q_next, pos--)
4157 			;
4158 		if (pos > 0 || ! SAMESTR(q) ||
4159 		    strncmp(q->q_qinfo->qi_minfo->mi_idname, mod_name,
4160 		    strlen(q->q_qinfo->qi_minfo->mi_idname)) != 0) {
4161 			mutex_enter(&stp->sd_lock);
4162 			strendplumb(stp);
4163 			mutex_exit(&stp->sd_lock);
4164 			return (EINVAL);
4165 		}
4166 
4167 		/*
4168 		 * If the position is at or below an anchor, then the zoneid
4169 		 * must match the zoneid that created the anchor.
4170 		 */
4171 		if (stp->sd_anchor != 0) {
4172 			pos = STRUCT_FGET(strmodremove, pos);
4173 			if (pos >= (stp->sd_pushcnt - stp->sd_anchor) &&
4174 			    stp->sd_anchorzone != crgetzoneid(crp)) {
4175 				mutex_enter(&stp->sd_lock);
4176 				strendplumb(stp);
4177 				mutex_exit(&stp->sd_lock);
4178 				return (EPERM);
4179 			}
4180 		}
4181 
4182 
4183 		ASSERT(!(q->q_flag & QREADR));
4184 		qdetach(_RD(q), 1, flag, crp, is_remove);
4185 
4186 		mutex_enter(&stp->sd_lock);
4187 
4188 		/*
4189 		 * As a performance concern we are caching the values of
4190 		 * q_minpsz and q_maxpsz of the module below the stream
4191 		 * head in the stream head.
4192 		 */
4193 		if (!is_remove) {
4194 			mutex_enter(QLOCK(wrq->q_next));
4195 			rmin = wrq->q_next->q_minpsz;
4196 			rmax = wrq->q_next->q_maxpsz;
4197 			mutex_exit(QLOCK(wrq->q_next));
4198 
4199 			/* Do this processing here as a performance concern */
4200 			if (strmsgsz != 0) {
4201 				if (rmax == INFPSZ)
4202 					rmax = strmsgsz;
4203 				else  {
4204 					if (vp->v_type == VFIFO)
4205 						rmax = MIN(PIPE_BUF, rmax);
4206 					else	rmax = MIN(strmsgsz, rmax);
4207 				}
4208 			}
4209 
4210 			mutex_enter(QLOCK(wrq));
4211 			stp->sd_qn_minpsz = rmin;
4212 			stp->sd_qn_maxpsz = rmax;
4213 			mutex_exit(QLOCK(wrq));
4214 		}
4215 
4216 		/*
4217 		 * Need to update the anchor value if this module is removed
4218 		 * at or below the anchor point.  If the removed module is at
4219 		 * the anchor point, remove the anchor for this stream if
4220 		 * there is no module above the anchor point.  Otherwise, if
4221 		 * the removed module is below the anchor point, decrement the
4222 		 * anchor point by 1.
4223 		 */
4224 		if (stp->sd_anchor != 0) {
4225 			pos = STRUCT_FGET(strmodremove, pos);
4226 			if (pos == stp->sd_pushcnt - stp->sd_anchor + 1)
4227 				stp->sd_anchor = 0;
4228 			else if (pos > (stp->sd_pushcnt - stp->sd_anchor + 1))
4229 				stp->sd_anchor--;
4230 		}
4231 
4232 		strendplumb(stp);
4233 		mutex_exit(&stp->sd_lock);
4234 		return (0);
4235 	}
4236 
4237 	case I_ANCHOR:
4238 		/*
4239 		 * Set the anchor position on the stream to reside at
4240 		 * the top module (in other words, the top module
4241 		 * cannot be popped).  Anchors with a FIFO make no
4242 		 * obvious sense, so they're not allowed.
4243 		 */
4244 		mutex_enter(&stp->sd_lock);
4245 
4246 		if (stp->sd_vnode->v_type == VFIFO) {
4247 			mutex_exit(&stp->sd_lock);
4248 			return (EINVAL);
4249 		}
4250 		/* Only allow the same zoneid to update the anchor */
4251 		if (stp->sd_anchor != 0 &&
4252 		    stp->sd_anchorzone != crgetzoneid(crp)) {
4253 			mutex_exit(&stp->sd_lock);
4254 			return (EINVAL);
4255 		}
4256 		stp->sd_anchor = stp->sd_pushcnt;
4257 		stp->sd_anchorzone = crgetzoneid(crp);
4258 		mutex_exit(&stp->sd_lock);
4259 		return (0);
4260 
4261 	case I_LOOK:
4262 		/*
4263 		 * Get name of first module downstream.
4264 		 * If no module, return an error.
4265 		 */
4266 	{
4267 		claimstr(wrq);
4268 		if (_SAMESTR(wrq) && wrq->q_next->q_next) {
4269 			char *name = wrq->q_next->q_qinfo->qi_minfo->mi_idname;
4270 			error = strcopyout(name, (void *)arg, strlen(name) + 1,
4271 			    copyflag);
4272 			releasestr(wrq);
4273 			return (error);
4274 		}
4275 		releasestr(wrq);
4276 		return (EINVAL);
4277 	}
4278 
4279 	case I_LINK:
4280 	case I_PLINK:
4281 		/*
4282 		 * Link a multiplexor.
4283 		 */
4284 		error = mlink(vp, cmd, (int)arg, crp, rvalp, 0);
4285 		return (error);
4286 
4287 	case _I_PLINK_LH:
4288 		/*
4289 		 * Link a multiplexor: Call must originate from kernel.
4290 		 */
4291 		if (kioctl)
4292 			return (ldi_mlink_lh(vp, cmd, arg, crp, rvalp));
4293 
4294 		return (EINVAL);
4295 	case I_UNLINK:
4296 	case I_PUNLINK:
4297 		/*
4298 		 * Unlink a multiplexor.
4299 		 * If arg is -1, unlink all links for which this is the
4300 		 * controlling stream.  Otherwise, arg is an index number
4301 		 * for a link to be removed.
4302 		 */
4303 	{
4304 		struct linkinfo *linkp;
4305 		int native_arg = (int)arg;
4306 		int type;
4307 		netstack_t *ns;
4308 		str_stack_t *ss;
4309 
4310 		TRACE_1(TR_FAC_STREAMS_FR,
4311 		    TR_I_UNLINK, "I_UNLINK/I_PUNLINK:%p", stp);
4312 		if (vp->v_type == VFIFO) {
4313 			return (EINVAL);
4314 		}
4315 		if (cmd == I_UNLINK)
4316 			type = LINKNORMAL;
4317 		else	/* I_PUNLINK */
4318 			type = LINKPERSIST;
4319 		if (native_arg == 0) {
4320 			return (EINVAL);
4321 		}
4322 		ns = netstack_find_by_cred(crp);
4323 		ASSERT(ns != NULL);
4324 		ss = ns->netstack_str;
4325 		ASSERT(ss != NULL);
4326 
4327 		if (native_arg == MUXID_ALL)
4328 			error = munlinkall(stp, type, crp, rvalp, ss);
4329 		else {
4330 			mutex_enter(&muxifier);
4331 			if (!(linkp = findlinks(stp, (int)arg, type, ss))) {
4332 				/* invalid user supplied index number */
4333 				mutex_exit(&muxifier);
4334 				netstack_rele(ss->ss_netstack);
4335 				return (EINVAL);
4336 			}
4337 			/* munlink drops the muxifier lock */
4338 			error = munlink(stp, linkp, type, crp, rvalp, ss);
4339 		}
4340 		netstack_rele(ss->ss_netstack);
4341 		return (error);
4342 	}
4343 
4344 	case I_FLUSH:
4345 		/*
4346 		 * send a flush message downstream
4347 		 * flush message can indicate
4348 		 * FLUSHR - flush read queue
4349 		 * FLUSHW - flush write queue
4350 		 * FLUSHRW - flush read/write queue
4351 		 */
4352 		if (stp->sd_flag & STRHUP)
4353 			return (ENXIO);
4354 		if (arg & ~FLUSHRW)
4355 			return (EINVAL);
4356 
4357 		for (;;) {
4358 			if (putnextctl1(stp->sd_wrq, M_FLUSH, (int)arg)) {
4359 				break;
4360 			}
4361 			if (error = strwaitbuf(1, BPRI_HI)) {
4362 				return (error);
4363 			}
4364 		}
4365 
4366 		/*
4367 		 * Send down an unsupported ioctl and wait for the nack
4368 		 * in order to allow the M_FLUSH to propagate back
4369 		 * up to the stream head.
4370 		 * Replaces if (qready()) runqueues();
4371 		 */
4372 		strioc.ic_cmd = -1;	/* The unsupported ioctl */
4373 		strioc.ic_timout = 0;
4374 		strioc.ic_len = 0;
4375 		strioc.ic_dp = NULL;
4376 		(void) strdoioctl(stp, &strioc, flag, K_TO_K, crp, rvalp);
4377 		*rvalp = 0;
4378 		return (0);
4379 
4380 	case I_FLUSHBAND:
4381 	{
4382 		struct bandinfo binfo;
4383 
4384 		error = strcopyin((void *)arg, &binfo, sizeof (binfo),
4385 		    copyflag);
4386 		if (error)
4387 			return (error);
4388 		if (stp->sd_flag & STRHUP)
4389 			return (ENXIO);
4390 		if (binfo.bi_flag & ~FLUSHRW)
4391 			return (EINVAL);
4392 		while (!(mp = allocb(2, BPRI_HI))) {
4393 			if (error = strwaitbuf(2, BPRI_HI))
4394 				return (error);
4395 		}
4396 		mp->b_datap->db_type = M_FLUSH;
4397 		*mp->b_wptr++ = binfo.bi_flag | FLUSHBAND;
4398 		*mp->b_wptr++ = binfo.bi_pri;
4399 		putnext(stp->sd_wrq, mp);
4400 		/*
4401 		 * Send down an unsupported ioctl and wait for the nack
4402 		 * in order to allow the M_FLUSH to propagate back
4403 		 * up to the stream head.
4404 		 * Replaces if (qready()) runqueues();
4405 		 */
4406 		strioc.ic_cmd = -1;	/* The unsupported ioctl */
4407 		strioc.ic_timout = 0;
4408 		strioc.ic_len = 0;
4409 		strioc.ic_dp = NULL;
4410 		(void) strdoioctl(stp, &strioc, flag, K_TO_K, crp, rvalp);
4411 		*rvalp = 0;
4412 		return (0);
4413 	}
4414 
4415 	case I_SRDOPT:
4416 		/*
4417 		 * Set read options
4418 		 *
4419 		 * RNORM - default stream mode
4420 		 * RMSGN - message no discard
4421 		 * RMSGD - message discard
4422 		 * RPROTNORM - fail read with EBADMSG for M_[PC]PROTOs
4423 		 * RPROTDAT - convert M_[PC]PROTOs to M_DATAs
4424 		 * RPROTDIS - discard M_[PC]PROTOs and retain M_DATAs
4425 		 */
4426 		if (arg & ~(RMODEMASK | RPROTMASK))
4427 			return (EINVAL);
4428 
4429 		if ((arg & (RMSGD|RMSGN)) == (RMSGD|RMSGN))
4430 			return (EINVAL);
4431 
4432 		mutex_enter(&stp->sd_lock);
4433 		switch (arg & RMODEMASK) {
4434 		case RNORM:
4435 			stp->sd_read_opt &= ~(RD_MSGDIS | RD_MSGNODIS);
4436 			break;
4437 		case RMSGD:
4438 			stp->sd_read_opt = (stp->sd_read_opt & ~RD_MSGNODIS) |
4439 			    RD_MSGDIS;
4440 			break;
4441 		case RMSGN:
4442 			stp->sd_read_opt = (stp->sd_read_opt & ~RD_MSGDIS) |
4443 			    RD_MSGNODIS;
4444 			break;
4445 		}
4446 
4447 		switch (arg & RPROTMASK) {
4448 		case RPROTNORM:
4449 			stp->sd_read_opt &= ~(RD_PROTDAT | RD_PROTDIS);
4450 			break;
4451 
4452 		case RPROTDAT:
4453 			stp->sd_read_opt = ((stp->sd_read_opt & ~RD_PROTDIS) |
4454 			    RD_PROTDAT);
4455 			break;
4456 
4457 		case RPROTDIS:
4458 			stp->sd_read_opt = ((stp->sd_read_opt & ~RD_PROTDAT) |
4459 			    RD_PROTDIS);
4460 			break;
4461 		}
4462 		mutex_exit(&stp->sd_lock);
4463 		return (0);
4464 
4465 	case I_GRDOPT:
4466 		/*
4467 		 * Get read option and return the value
4468 		 * to spot pointed to by arg
4469 		 */
4470 	{
4471 		int rdopt;
4472 
4473 		rdopt = ((stp->sd_read_opt & RD_MSGDIS) ? RMSGD :
4474 		    ((stp->sd_read_opt & RD_MSGNODIS) ? RMSGN : RNORM));
4475 		rdopt |= ((stp->sd_read_opt & RD_PROTDAT) ? RPROTDAT :
4476 		    ((stp->sd_read_opt & RD_PROTDIS) ? RPROTDIS : RPROTNORM));
4477 
4478 		return (strcopyout(&rdopt, (void *)arg, sizeof (int),
4479 		    copyflag));
4480 	}
4481 
4482 	case I_SERROPT:
4483 		/*
4484 		 * Set error options
4485 		 *
4486 		 * RERRNORM - persistent read errors
4487 		 * RERRNONPERSIST - non-persistent read errors
4488 		 * WERRNORM - persistent write errors
4489 		 * WERRNONPERSIST - non-persistent write errors
4490 		 */
4491 		if (arg & ~(RERRMASK | WERRMASK))
4492 			return (EINVAL);
4493 
4494 		mutex_enter(&stp->sd_lock);
4495 		switch (arg & RERRMASK) {
4496 		case RERRNORM:
4497 			stp->sd_flag &= ~STRDERRNONPERSIST;
4498 			break;
4499 		case RERRNONPERSIST:
4500 			stp->sd_flag |= STRDERRNONPERSIST;
4501 			break;
4502 		}
4503 		switch (arg & WERRMASK) {
4504 		case WERRNORM:
4505 			stp->sd_flag &= ~STWRERRNONPERSIST;
4506 			break;
4507 		case WERRNONPERSIST:
4508 			stp->sd_flag |= STWRERRNONPERSIST;
4509 			break;
4510 		}
4511 		mutex_exit(&stp->sd_lock);
4512 		return (0);
4513 
4514 	case I_GERROPT:
4515 		/*
4516 		 * Get error option and return the value
4517 		 * to spot pointed to by arg
4518 		 */
4519 	{
4520 		int erropt = 0;
4521 
4522 		erropt |= (stp->sd_flag & STRDERRNONPERSIST) ? RERRNONPERSIST :
4523 		    RERRNORM;
4524 		erropt |= (stp->sd_flag & STWRERRNONPERSIST) ? WERRNONPERSIST :
4525 		    WERRNORM;
4526 		return (strcopyout(&erropt, (void *)arg, sizeof (int),
4527 		    copyflag));
4528 	}
4529 
4530 	case I_SETSIG:
4531 		/*
4532 		 * Register the calling proc to receive the SIGPOLL
4533 		 * signal based on the events given in arg.  If
4534 		 * arg is zero, remove the proc from register list.
4535 		 */
4536 	{
4537 		strsig_t *ssp, *pssp;
4538 		struct pid *pidp;
4539 
4540 		pssp = NULL;
4541 		pidp = curproc->p_pidp;
4542 		/*
4543 		 * Hold sd_lock to prevent traversal of sd_siglist while
4544 		 * it is modified.
4545 		 */
4546 		mutex_enter(&stp->sd_lock);
4547 		for (ssp = stp->sd_siglist; ssp && (ssp->ss_pidp != pidp);
4548 		    pssp = ssp, ssp = ssp->ss_next)
4549 			;
4550 
4551 		if (arg) {
4552 			if (arg & ~(S_INPUT|S_HIPRI|S_MSG|S_HANGUP|S_ERROR|
4553 			    S_RDNORM|S_WRNORM|S_RDBAND|S_WRBAND|S_BANDURG)) {
4554 				mutex_exit(&stp->sd_lock);
4555 				return (EINVAL);
4556 			}
4557 			if ((arg & S_BANDURG) && !(arg & S_RDBAND)) {
4558 				mutex_exit(&stp->sd_lock);
4559 				return (EINVAL);
4560 			}
4561 
4562 			/*
4563 			 * If proc not already registered, add it
4564 			 * to list.
4565 			 */
4566 			if (!ssp) {
4567 				ssp = kmem_alloc(sizeof (strsig_t), KM_SLEEP);
4568 				ssp->ss_pidp = pidp;
4569 				ssp->ss_pid = pidp->pid_id;
4570 				ssp->ss_next = NULL;
4571 				if (pssp)
4572 					pssp->ss_next = ssp;
4573 				else
4574 					stp->sd_siglist = ssp;
4575 				mutex_enter(&pidlock);
4576 				PID_HOLD(pidp);
4577 				mutex_exit(&pidlock);
4578 			}
4579 
4580 			/*
4581 			 * Set events.
4582 			 */
4583 			ssp->ss_events = (int)arg;
4584 		} else {
4585 			/*
4586 			 * Remove proc from register list.
4587 			 */
4588 			if (ssp) {
4589 				mutex_enter(&pidlock);
4590 				PID_RELE(pidp);
4591 				mutex_exit(&pidlock);
4592 				if (pssp)
4593 					pssp->ss_next = ssp->ss_next;
4594 				else
4595 					stp->sd_siglist = ssp->ss_next;
4596 				kmem_free(ssp, sizeof (strsig_t));
4597 			} else {
4598 				mutex_exit(&stp->sd_lock);
4599 				return (EINVAL);
4600 			}
4601 		}
4602 
4603 		/*
4604 		 * Recalculate OR of sig events.
4605 		 */
4606 		stp->sd_sigflags = 0;
4607 		for (ssp = stp->sd_siglist; ssp; ssp = ssp->ss_next)
4608 			stp->sd_sigflags |= ssp->ss_events;
4609 		mutex_exit(&stp->sd_lock);
4610 		return (0);
4611 	}
4612 
4613 	case I_GETSIG:
4614 		/*
4615 		 * Return (in arg) the current registration of events
4616 		 * for which the calling proc is to be signaled.
4617 		 */
4618 	{
4619 		struct strsig *ssp;
4620 		struct pid  *pidp;
4621 
4622 		pidp = curproc->p_pidp;
4623 		mutex_enter(&stp->sd_lock);
4624 		for (ssp = stp->sd_siglist; ssp; ssp = ssp->ss_next)
4625 			if (ssp->ss_pidp == pidp) {
4626 				error = strcopyout(&ssp->ss_events, (void *)arg,
4627 				    sizeof (int), copyflag);
4628 				mutex_exit(&stp->sd_lock);
4629 				return (error);
4630 			}
4631 		mutex_exit(&stp->sd_lock);
4632 		return (EINVAL);
4633 	}
4634 
4635 	case I_ESETSIG:
4636 		/*
4637 		 * Register the ss_pid to receive the SIGPOLL
4638 		 * signal based on the events is ss_events arg.  If
4639 		 * ss_events is zero, remove the proc from register list.
4640 		 */
4641 	{
4642 		struct strsig *ssp, *pssp;
4643 		struct proc *proc;
4644 		struct pid  *pidp;
4645 		pid_t pid;
4646 		struct strsigset ss;
4647 
4648 		error = strcopyin((void *)arg, &ss, sizeof (ss), copyflag);
4649 		if (error)
4650 			return (error);
4651 
4652 		pid = ss.ss_pid;
4653 
4654 		if (ss.ss_events != 0) {
4655 			/*
4656 			 * Permissions check by sending signal 0.
4657 			 * Note that when kill fails it does a set_errno
4658 			 * causing the system call to fail.
4659 			 */
4660 			error = kill(pid, 0);
4661 			if (error) {
4662 				return (error);
4663 			}
4664 		}
4665 		mutex_enter(&pidlock);
4666 		if (pid == 0)
4667 			proc = curproc;
4668 		else if (pid < 0)
4669 			proc = pgfind(-pid);
4670 		else
4671 			proc = prfind(pid);
4672 		if (proc == NULL) {
4673 			mutex_exit(&pidlock);
4674 			return (ESRCH);
4675 		}
4676 		if (pid < 0)
4677 			pidp = proc->p_pgidp;
4678 		else
4679 			pidp = proc->p_pidp;
4680 		ASSERT(pidp);
4681 		/*
4682 		 * Get a hold on the pid structure while referencing it.
4683 		 * There is a separate PID_HOLD should it be inserted
4684 		 * in the list below.
4685 		 */
4686 		PID_HOLD(pidp);
4687 		mutex_exit(&pidlock);
4688 
4689 		pssp = NULL;
4690 		/*
4691 		 * Hold sd_lock to prevent traversal of sd_siglist while
4692 		 * it is modified.
4693 		 */
4694 		mutex_enter(&stp->sd_lock);
4695 		for (ssp = stp->sd_siglist; ssp && (ssp->ss_pid != pid);
4696 		    pssp = ssp, ssp = ssp->ss_next)
4697 			;
4698 
4699 		if (ss.ss_events) {
4700 			if (ss.ss_events &
4701 			    ~(S_INPUT|S_HIPRI|S_MSG|S_HANGUP|S_ERROR|
4702 			    S_RDNORM|S_WRNORM|S_RDBAND|S_WRBAND|S_BANDURG)) {
4703 				mutex_exit(&stp->sd_lock);
4704 				mutex_enter(&pidlock);
4705 				PID_RELE(pidp);
4706 				mutex_exit(&pidlock);
4707 				return (EINVAL);
4708 			}
4709 			if ((ss.ss_events & S_BANDURG) &&
4710 			    !(ss.ss_events & S_RDBAND)) {
4711 				mutex_exit(&stp->sd_lock);
4712 				mutex_enter(&pidlock);
4713 				PID_RELE(pidp);
4714 				mutex_exit(&pidlock);
4715 				return (EINVAL);
4716 			}
4717 
4718 			/*
4719 			 * If proc not already registered, add it
4720 			 * to list.
4721 			 */
4722 			if (!ssp) {
4723 				ssp = kmem_alloc(sizeof (strsig_t), KM_SLEEP);
4724 				ssp->ss_pidp = pidp;
4725 				ssp->ss_pid = pid;
4726 				ssp->ss_next = NULL;
4727 				if (pssp)
4728 					pssp->ss_next = ssp;
4729 				else
4730 					stp->sd_siglist = ssp;
4731 				mutex_enter(&pidlock);
4732 				PID_HOLD(pidp);
4733 				mutex_exit(&pidlock);
4734 			}
4735 
4736 			/*
4737 			 * Set events.
4738 			 */
4739 			ssp->ss_events = ss.ss_events;
4740 		} else {
4741 			/*
4742 			 * Remove proc from register list.
4743 			 */
4744 			if (ssp) {
4745 				mutex_enter(&pidlock);
4746 				PID_RELE(pidp);
4747 				mutex_exit(&pidlock);
4748 				if (pssp)
4749 					pssp->ss_next = ssp->ss_next;
4750 				else
4751 					stp->sd_siglist = ssp->ss_next;
4752 				kmem_free(ssp, sizeof (strsig_t));
4753 			} else {
4754 				mutex_exit(&stp->sd_lock);
4755 				mutex_enter(&pidlock);
4756 				PID_RELE(pidp);
4757 				mutex_exit(&pidlock);
4758 				return (EINVAL);
4759 			}
4760 		}
4761 
4762 		/*
4763 		 * Recalculate OR of sig events.
4764 		 */
4765 		stp->sd_sigflags = 0;
4766 		for (ssp = stp->sd_siglist; ssp; ssp = ssp->ss_next)
4767 			stp->sd_sigflags |= ssp->ss_events;
4768 		mutex_exit(&stp->sd_lock);
4769 		mutex_enter(&pidlock);
4770 		PID_RELE(pidp);
4771 		mutex_exit(&pidlock);
4772 		return (0);
4773 	}
4774 
4775 	case I_EGETSIG:
4776 		/*
4777 		 * Return (in arg) the current registration of events
4778 		 * for which the calling proc is to be signaled.
4779 		 */
4780 	{
4781 		struct strsig *ssp;
4782 		struct proc *proc;
4783 		pid_t pid;
4784 		struct pid  *pidp;
4785 		struct strsigset ss;
4786 
4787 		error = strcopyin((void *)arg, &ss, sizeof (ss), copyflag);
4788 		if (error)
4789 			return (error);
4790 
4791 		pid = ss.ss_pid;
4792 		mutex_enter(&pidlock);
4793 		if (pid == 0)
4794 			proc = curproc;
4795 		else if (pid < 0)
4796 			proc = pgfind(-pid);
4797 		else
4798 			proc = prfind(pid);
4799 		if (proc == NULL) {
4800 			mutex_exit(&pidlock);
4801 			return (ESRCH);
4802 		}
4803 		if (pid < 0)
4804 			pidp = proc->p_pgidp;
4805 		else
4806 			pidp = proc->p_pidp;
4807 
4808 		/* Prevent the pidp from being reassigned */
4809 		PID_HOLD(pidp);
4810 		mutex_exit(&pidlock);
4811 
4812 		mutex_enter(&stp->sd_lock);
4813 		for (ssp = stp->sd_siglist; ssp; ssp = ssp->ss_next)
4814 			if (ssp->ss_pid == pid) {
4815 				ss.ss_pid = ssp->ss_pid;
4816 				ss.ss_events = ssp->ss_events;
4817 				error = strcopyout(&ss, (void *)arg,
4818 				    sizeof (struct strsigset), copyflag);
4819 				mutex_exit(&stp->sd_lock);
4820 				mutex_enter(&pidlock);
4821 				PID_RELE(pidp);
4822 				mutex_exit(&pidlock);
4823 				return (error);
4824 			}
4825 		mutex_exit(&stp->sd_lock);
4826 		mutex_enter(&pidlock);
4827 		PID_RELE(pidp);
4828 		mutex_exit(&pidlock);
4829 		return (EINVAL);
4830 	}
4831 
4832 	case I_PEEK:
4833 	{
4834 		STRUCT_DECL(strpeek, strpeek);
4835 		size_t n;
4836 		mblk_t *fmp, *tmp_mp = NULL;
4837 
4838 		STRUCT_INIT(strpeek, flag);
4839 
4840 		error = strcopyin((void *)arg, STRUCT_BUF(strpeek),
4841 		    STRUCT_SIZE(strpeek), copyflag);
4842 		if (error)
4843 			return (error);
4844 
4845 		mutex_enter(QLOCK(rdq));
4846 		/*
4847 		 * Skip the invalid messages
4848 		 */
4849 		for (mp = rdq->q_first; mp != NULL; mp = mp->b_next)
4850 			if (mp->b_datap->db_type != M_SIG)
4851 				break;
4852 
4853 		/*
4854 		 * If user has requested to peek at a high priority message
4855 		 * and first message is not, return 0
4856 		 */
4857 		if (mp != NULL) {
4858 			if ((STRUCT_FGET(strpeek, flags) & RS_HIPRI) &&
4859 			    queclass(mp) == QNORM) {
4860 				*rvalp = 0;
4861 				mutex_exit(QLOCK(rdq));
4862 				return (0);
4863 			}
4864 		} else if (stp->sd_struiordq == NULL ||
4865 		    (STRUCT_FGET(strpeek, flags) & RS_HIPRI)) {
4866 			/*
4867 			 * No mblks to look at at the streamhead and
4868 			 * 1). This isn't a synch stream or
4869 			 * 2). This is a synch stream but caller wants high
4870 			 *	priority messages which is not supported by
4871 			 *	the synch stream. (it only supports QNORM)
4872 			 */
4873 			*rvalp = 0;
4874 			mutex_exit(QLOCK(rdq));
4875 			return (0);
4876 		}
4877 
4878 		fmp = mp;
4879 
4880 		if (mp && mp->b_datap->db_type == M_PASSFP) {
4881 			mutex_exit(QLOCK(rdq));
4882 			return (EBADMSG);
4883 		}
4884 
4885 		ASSERT(mp == NULL || mp->b_datap->db_type == M_PCPROTO ||
4886 		    mp->b_datap->db_type == M_PROTO ||
4887 		    mp->b_datap->db_type == M_DATA);
4888 
4889 		if (mp && mp->b_datap->db_type == M_PCPROTO) {
4890 			STRUCT_FSET(strpeek, flags, RS_HIPRI);
4891 		} else {
4892 			STRUCT_FSET(strpeek, flags, 0);
4893 		}
4894 
4895 
4896 		if (mp && ((tmp_mp = dupmsg(mp)) == NULL)) {
4897 			mutex_exit(QLOCK(rdq));
4898 			return (ENOSR);
4899 		}
4900 		mutex_exit(QLOCK(rdq));
4901 
4902 		/*
4903 		 * set mp = tmp_mp, so that I_PEEK processing can continue.
4904 		 * tmp_mp is used to free the dup'd message.
4905 		 */
4906 		mp = tmp_mp;
4907 
4908 		uio.uio_fmode = 0;
4909 		uio.uio_extflg = UIO_COPY_CACHED;
4910 		uio.uio_segflg = (copyflag == U_TO_K) ? UIO_USERSPACE :
4911 		    UIO_SYSSPACE;
4912 		uio.uio_limit = 0;
4913 		/*
4914 		 * First process PROTO blocks, if any.
4915 		 * If user doesn't want to get ctl info by setting maxlen <= 0,
4916 		 * then set len to -1/0 and skip control blocks part.
4917 		 */
4918 		if (STRUCT_FGET(strpeek, ctlbuf.maxlen) < 0)
4919 			STRUCT_FSET(strpeek, ctlbuf.len, -1);
4920 		else if (STRUCT_FGET(strpeek, ctlbuf.maxlen) == 0)
4921 			STRUCT_FSET(strpeek, ctlbuf.len, 0);
4922 		else {
4923 			int	ctl_part = 0;
4924 
4925 			iov.iov_base = STRUCT_FGETP(strpeek, ctlbuf.buf);
4926 			iov.iov_len = STRUCT_FGET(strpeek, ctlbuf.maxlen);
4927 			uio.uio_iov = &iov;
4928 			uio.uio_resid = iov.iov_len;
4929 			uio.uio_loffset = 0;
4930 			uio.uio_iovcnt = 1;
4931 			while (mp && mp->b_datap->db_type != M_DATA &&
4932 			    uio.uio_resid >= 0) {
4933 				ASSERT(STRUCT_FGET(strpeek, flags) == 0 ?
4934 				    mp->b_datap->db_type == M_PROTO :
4935 				    mp->b_datap->db_type == M_PCPROTO);
4936 
4937 				if ((n = MIN(uio.uio_resid,
4938 				    mp->b_wptr - mp->b_rptr)) != 0 &&
4939 				    (error = uiomove((char *)mp->b_rptr, n,
4940 				    UIO_READ, &uio)) != 0) {
4941 					freemsg(tmp_mp);
4942 					return (error);
4943 				}
4944 				ctl_part = 1;
4945 				mp = mp->b_cont;
4946 			}
4947 			/* No ctl message */
4948 			if (ctl_part == 0)
4949 				STRUCT_FSET(strpeek, ctlbuf.len, -1);
4950 			else
4951 				STRUCT_FSET(strpeek, ctlbuf.len,
4952 				    STRUCT_FGET(strpeek, ctlbuf.maxlen) -
4953 				    uio.uio_resid);
4954 		}
4955 
4956 		/*
4957 		 * Now process DATA blocks, if any.
4958 		 * If user doesn't want to get data info by setting maxlen <= 0,
4959 		 * then set len to -1/0 and skip data blocks part.
4960 		 */
4961 		if (STRUCT_FGET(strpeek, databuf.maxlen) < 0)
4962 			STRUCT_FSET(strpeek, databuf.len, -1);
4963 		else if (STRUCT_FGET(strpeek, databuf.maxlen) == 0)
4964 			STRUCT_FSET(strpeek, databuf.len, 0);
4965 		else {
4966 			int	data_part = 0;
4967 
4968 			iov.iov_base = STRUCT_FGETP(strpeek, databuf.buf);
4969 			iov.iov_len = STRUCT_FGET(strpeek, databuf.maxlen);
4970 			uio.uio_iov = &iov;
4971 			uio.uio_resid = iov.iov_len;
4972 			uio.uio_loffset = 0;
4973 			uio.uio_iovcnt = 1;
4974 			while (mp && uio.uio_resid) {
4975 				if (mp->b_datap->db_type == M_DATA) {
4976 					if ((n = MIN(uio.uio_resid,
4977 					    mp->b_wptr - mp->b_rptr)) != 0 &&
4978 					    (error = uiomove((char *)mp->b_rptr,
4979 					    n, UIO_READ, &uio)) != 0) {
4980 						freemsg(tmp_mp);
4981 						return (error);
4982 					}
4983 					data_part = 1;
4984 				}
4985 				ASSERT(data_part == 0 ||
4986 				    mp->b_datap->db_type == M_DATA);
4987 				mp = mp->b_cont;
4988 			}
4989 			/* No data message */
4990 			if (data_part == 0)
4991 				STRUCT_FSET(strpeek, databuf.len, -1);
4992 			else
4993 				STRUCT_FSET(strpeek, databuf.len,
4994 				    STRUCT_FGET(strpeek, databuf.maxlen) -
4995 				    uio.uio_resid);
4996 		}
4997 		freemsg(tmp_mp);
4998 
4999 		/*
5000 		 * It is a synch stream and user wants to get
5001 		 * data (maxlen > 0).
5002 		 * uio setup is done by the codes that process DATA
5003 		 * blocks above.
5004 		 */
5005 		if ((fmp == NULL) && STRUCT_FGET(strpeek, databuf.maxlen) > 0) {
5006 			infod_t infod;
5007 
5008 			infod.d_cmd = INFOD_COPYOUT;
5009 			infod.d_res = 0;
5010 			infod.d_uiop = &uio;
5011 			error = infonext(rdq, &infod);
5012 			if (error == EINVAL || error == EBUSY)
5013 				error = 0;
5014 			if (error)
5015 				return (error);
5016 			STRUCT_FSET(strpeek, databuf.len, STRUCT_FGET(strpeek,
5017 			    databuf.maxlen) - uio.uio_resid);
5018 			if (STRUCT_FGET(strpeek, databuf.len) == 0) {
5019 				/*
5020 				 * No data found by the infonext().
5021 				 */
5022 				STRUCT_FSET(strpeek, databuf.len, -1);
5023 			}
5024 		}
5025 		error = strcopyout(STRUCT_BUF(strpeek), (void *)arg,
5026 		    STRUCT_SIZE(strpeek), copyflag);
5027 		if (error) {
5028 			return (error);
5029 		}
5030 		/*
5031 		 * If there is no message retrieved, set return code to 0
5032 		 * otherwise, set it to 1.
5033 		 */
5034 		if (STRUCT_FGET(strpeek, ctlbuf.len) == -1 &&
5035 		    STRUCT_FGET(strpeek, databuf.len) == -1)
5036 			*rvalp = 0;
5037 		else
5038 			*rvalp = 1;
5039 		return (0);
5040 	}
5041 
5042 	case I_FDINSERT:
5043 	{
5044 		STRUCT_DECL(strfdinsert, strfdinsert);
5045 		struct file *resftp;
5046 		struct stdata *resstp;
5047 		t_uscalar_t	ival;
5048 		ssize_t msgsize;
5049 		struct strbuf mctl;
5050 
5051 		STRUCT_INIT(strfdinsert, flag);
5052 		if (stp->sd_flag & STRHUP)
5053 			return (ENXIO);
5054 		/*
5055 		 * STRDERR, STWRERR and STPLEX tested above.
5056 		 */
5057 		error = strcopyin((void *)arg, STRUCT_BUF(strfdinsert),
5058 		    STRUCT_SIZE(strfdinsert), copyflag);
5059 		if (error)
5060 			return (error);
5061 
5062 		if (STRUCT_FGET(strfdinsert, offset) < 0 ||
5063 		    (STRUCT_FGET(strfdinsert, offset) %
5064 		    sizeof (t_uscalar_t)) != 0)
5065 			return (EINVAL);
5066 		if ((resftp = getf(STRUCT_FGET(strfdinsert, fildes))) != NULL) {
5067 			if ((resstp = resftp->f_vnode->v_stream) == NULL) {
5068 				releasef(STRUCT_FGET(strfdinsert, fildes));
5069 				return (EINVAL);
5070 			}
5071 		} else
5072 			return (EINVAL);
5073 
5074 		mutex_enter(&resstp->sd_lock);
5075 		if (resstp->sd_flag & (STRDERR|STWRERR|STRHUP|STPLEX)) {
5076 			error = strgeterr(resstp,
5077 			    STRDERR|STWRERR|STRHUP|STPLEX, 0);
5078 			if (error != 0) {
5079 				mutex_exit(&resstp->sd_lock);
5080 				releasef(STRUCT_FGET(strfdinsert, fildes));
5081 				return (error);
5082 			}
5083 		}
5084 		mutex_exit(&resstp->sd_lock);
5085 
5086 #ifdef	_ILP32
5087 		{
5088 			queue_t	*q;
5089 			queue_t	*mate = NULL;
5090 
5091 			/* get read queue of stream terminus */
5092 			claimstr(resstp->sd_wrq);
5093 			for (q = resstp->sd_wrq->q_next; q->q_next != NULL;
5094 			    q = q->q_next)
5095 				if (!STRMATED(resstp) && STREAM(q) != resstp &&
5096 				    mate == NULL) {
5097 					ASSERT(q->q_qinfo->qi_srvp);
5098 					ASSERT(_OTHERQ(q)->q_qinfo->qi_srvp);
5099 					claimstr(q);
5100 					mate = q;
5101 				}
5102 			q = _RD(q);
5103 			if (mate)
5104 				releasestr(mate);
5105 			releasestr(resstp->sd_wrq);
5106 			ival = (t_uscalar_t)q;
5107 		}
5108 #else
5109 		ival = (t_uscalar_t)getminor(resftp->f_vnode->v_rdev);
5110 #endif	/* _ILP32 */
5111 
5112 		if (STRUCT_FGET(strfdinsert, ctlbuf.len) <
5113 		    STRUCT_FGET(strfdinsert, offset) + sizeof (t_uscalar_t)) {
5114 			releasef(STRUCT_FGET(strfdinsert, fildes));
5115 			return (EINVAL);
5116 		}
5117 
5118 		/*
5119 		 * Check for legal flag value.
5120 		 */
5121 		if (STRUCT_FGET(strfdinsert, flags) & ~RS_HIPRI) {
5122 			releasef(STRUCT_FGET(strfdinsert, fildes));
5123 			return (EINVAL);
5124 		}
5125 
5126 		/* get these values from those cached in the stream head */
5127 		mutex_enter(QLOCK(stp->sd_wrq));
5128 		rmin = stp->sd_qn_minpsz;
5129 		rmax = stp->sd_qn_maxpsz;
5130 		mutex_exit(QLOCK(stp->sd_wrq));
5131 
5132 		/*
5133 		 * Make sure ctl and data sizes together fall within
5134 		 * the limits of the max and min receive packet sizes
5135 		 * and do not exceed system limit.  A negative data
5136 		 * length means that no data part is to be sent.
5137 		 */
5138 		ASSERT((rmax >= 0) || (rmax == INFPSZ));
5139 		if (rmax == 0) {
5140 			releasef(STRUCT_FGET(strfdinsert, fildes));
5141 			return (ERANGE);
5142 		}
5143 		if ((msgsize = STRUCT_FGET(strfdinsert, databuf.len)) < 0)
5144 			msgsize = 0;
5145 		if ((msgsize < rmin) ||
5146 		    ((msgsize > rmax) && (rmax != INFPSZ)) ||
5147 		    (STRUCT_FGET(strfdinsert, ctlbuf.len) > strctlsz)) {
5148 			releasef(STRUCT_FGET(strfdinsert, fildes));
5149 			return (ERANGE);
5150 		}
5151 
5152 		mutex_enter(&stp->sd_lock);
5153 		while (!(STRUCT_FGET(strfdinsert, flags) & RS_HIPRI) &&
5154 		    !canputnext(stp->sd_wrq)) {
5155 			if ((error = strwaitq(stp, WRITEWAIT, (ssize_t)0,
5156 			    flag, -1, &done)) != 0 || done) {
5157 				mutex_exit(&stp->sd_lock);
5158 				releasef(STRUCT_FGET(strfdinsert, fildes));
5159 				return (error);
5160 			}
5161 			if ((error = i_straccess(stp, access)) != 0) {
5162 				mutex_exit(&stp->sd_lock);
5163 				releasef(
5164 				    STRUCT_FGET(strfdinsert, fildes));
5165 				return (error);
5166 			}
5167 		}
5168 		mutex_exit(&stp->sd_lock);
5169 
5170 		/*
5171 		 * Copy strfdinsert.ctlbuf into native form of
5172 		 * ctlbuf to pass down into strmakemsg().
5173 		 */
5174 		mctl.maxlen = STRUCT_FGET(strfdinsert, ctlbuf.maxlen);
5175 		mctl.len = STRUCT_FGET(strfdinsert, ctlbuf.len);
5176 		mctl.buf = STRUCT_FGETP(strfdinsert, ctlbuf.buf);
5177 
5178 		iov.iov_base = STRUCT_FGETP(strfdinsert, databuf.buf);
5179 		iov.iov_len = STRUCT_FGET(strfdinsert, databuf.len);
5180 		uio.uio_iov = &iov;
5181 		uio.uio_iovcnt = 1;
5182 		uio.uio_loffset = 0;
5183 		uio.uio_segflg = (copyflag == U_TO_K) ? UIO_USERSPACE :
5184 		    UIO_SYSSPACE;
5185 		uio.uio_fmode = 0;
5186 		uio.uio_extflg = UIO_COPY_CACHED;
5187 		uio.uio_resid = iov.iov_len;
5188 		if ((error = strmakemsg(&mctl,
5189 		    &msgsize, &uio, stp,
5190 		    STRUCT_FGET(strfdinsert, flags), &mp)) != 0 || !mp) {
5191 			STRUCT_FSET(strfdinsert, databuf.len, msgsize);
5192 			releasef(STRUCT_FGET(strfdinsert, fildes));
5193 			return (error);
5194 		}
5195 
5196 		STRUCT_FSET(strfdinsert, databuf.len, msgsize);
5197 
5198 		/*
5199 		 * Place the possibly reencoded queue pointer 'offset' bytes
5200 		 * from the start of the control portion of the message.
5201 		 */
5202 		*((t_uscalar_t *)(mp->b_rptr +
5203 		    STRUCT_FGET(strfdinsert, offset))) = ival;
5204 
5205 		/*
5206 		 * Put message downstream.
5207 		 */
5208 		stream_willservice(stp);
5209 		putnext(stp->sd_wrq, mp);
5210 		stream_runservice(stp);
5211 		releasef(STRUCT_FGET(strfdinsert, fildes));
5212 		return (error);
5213 	}
5214 
5215 	case I_SENDFD:
5216 	{
5217 		struct file *fp;
5218 
5219 		if ((fp = getf((int)arg)) == NULL)
5220 			return (EBADF);
5221 		error = do_sendfp(stp, fp, crp);
5222 		if (audit_active) {
5223 			audit_fdsend((int)arg, fp, error);
5224 		}
5225 		releasef((int)arg);
5226 		return (error);
5227 	}
5228 
5229 	case I_RECVFD:
5230 	case I_E_RECVFD:
5231 	{
5232 		struct k_strrecvfd *srf;
5233 		int i, fd;
5234 
5235 		mutex_enter(&stp->sd_lock);
5236 		while (!(mp = getq(rdq))) {
5237 			if (stp->sd_flag & (STRHUP|STREOF)) {
5238 				mutex_exit(&stp->sd_lock);
5239 				return (ENXIO);
5240 			}
5241 			if ((error = strwaitq(stp, GETWAIT, (ssize_t)0,
5242 			    flag, -1, &done)) != 0 || done) {
5243 				mutex_exit(&stp->sd_lock);
5244 				return (error);
5245 			}
5246 			if ((error = i_straccess(stp, access)) != 0) {
5247 				mutex_exit(&stp->sd_lock);
5248 				return (error);
5249 			}
5250 		}
5251 		if (mp->b_datap->db_type != M_PASSFP) {
5252 			putback(stp, rdq, mp, mp->b_band);
5253 			mutex_exit(&stp->sd_lock);
5254 			return (EBADMSG);
5255 		}
5256 		mutex_exit(&stp->sd_lock);
5257 
5258 		srf = (struct k_strrecvfd *)mp->b_rptr;
5259 		if ((fd = ufalloc(0)) == -1) {
5260 			mutex_enter(&stp->sd_lock);
5261 			putback(stp, rdq, mp, mp->b_band);
5262 			mutex_exit(&stp->sd_lock);
5263 			return (EMFILE);
5264 		}
5265 		if (cmd == I_RECVFD) {
5266 			struct o_strrecvfd	ostrfd;
5267 
5268 			/* check to see if uid/gid values are too large. */
5269 
5270 			if (srf->uid > (o_uid_t)USHRT_MAX ||
5271 			    srf->gid > (o_gid_t)USHRT_MAX) {
5272 				mutex_enter(&stp->sd_lock);
5273 				putback(stp, rdq, mp, mp->b_band);
5274 				mutex_exit(&stp->sd_lock);
5275 				setf(fd, NULL);	/* release fd entry */
5276 				return (EOVERFLOW);
5277 			}
5278 
5279 			ostrfd.fd = fd;
5280 			ostrfd.uid = (o_uid_t)srf->uid;
5281 			ostrfd.gid = (o_gid_t)srf->gid;
5282 
5283 			/* Null the filler bits */
5284 			for (i = 0; i < 8; i++)
5285 				ostrfd.fill[i] = 0;
5286 
5287 			error = strcopyout(&ostrfd, (void *)arg,
5288 			    sizeof (struct o_strrecvfd), copyflag);
5289 		} else {		/* I_E_RECVFD */
5290 			struct strrecvfd	strfd;
5291 
5292 			strfd.fd = fd;
5293 			strfd.uid = srf->uid;
5294 			strfd.gid = srf->gid;
5295 
5296 			/* null the filler bits */
5297 			for (i = 0; i < 8; i++)
5298 				strfd.fill[i] = 0;
5299 
5300 			error = strcopyout(&strfd, (void *)arg,
5301 			    sizeof (struct strrecvfd), copyflag);
5302 		}
5303 
5304 		if (error) {
5305 			setf(fd, NULL);	/* release fd entry */
5306 			mutex_enter(&stp->sd_lock);
5307 			putback(stp, rdq, mp, mp->b_band);
5308 			mutex_exit(&stp->sd_lock);
5309 			return (error);
5310 		}
5311 		if (audit_active) {
5312 			audit_fdrecv(fd, srf->fp);
5313 		}
5314 
5315 		/*
5316 		 * Always increment f_count since the freemsg() below will
5317 		 * always call free_passfp() which performs a closef().
5318 		 */
5319 		mutex_enter(&srf->fp->f_tlock);
5320 		srf->fp->f_count++;
5321 		mutex_exit(&srf->fp->f_tlock);
5322 		setf(fd, srf->fp);
5323 		freemsg(mp);
5324 		return (0);
5325 	}
5326 
5327 	case I_SWROPT:
5328 		/*
5329 		 * Set/clear the write options. arg is a bit
5330 		 * mask with any of the following bits set...
5331 		 * 	SNDZERO - send zero length message
5332 		 *	SNDPIPE - send sigpipe to process if
5333 		 *		sd_werror is set and process is
5334 		 *		doing a write or putmsg.
5335 		 * The new stream head write options should reflect
5336 		 * what is in arg.
5337 		 */
5338 		if (arg & ~(SNDZERO|SNDPIPE))
5339 			return (EINVAL);
5340 
5341 		mutex_enter(&stp->sd_lock);
5342 		stp->sd_wput_opt &= ~(SW_SIGPIPE|SW_SNDZERO);
5343 		if (arg & SNDZERO)
5344 			stp->sd_wput_opt |= SW_SNDZERO;
5345 		if (arg & SNDPIPE)
5346 			stp->sd_wput_opt |= SW_SIGPIPE;
5347 		mutex_exit(&stp->sd_lock);
5348 		return (0);
5349 
5350 	case I_GWROPT:
5351 	{
5352 		int wropt = 0;
5353 
5354 		if (stp->sd_wput_opt & SW_SNDZERO)
5355 			wropt |= SNDZERO;
5356 		if (stp->sd_wput_opt & SW_SIGPIPE)
5357 			wropt |= SNDPIPE;
5358 		return (strcopyout(&wropt, (void *)arg, sizeof (wropt),
5359 		    copyflag));
5360 	}
5361 
5362 	case I_LIST:
5363 		/*
5364 		 * Returns all the modules found on this stream,
5365 		 * upto the driver. If argument is NULL, return the
5366 		 * number of modules (including driver). If argument
5367 		 * is not NULL, copy the names into the structure
5368 		 * provided.
5369 		 */
5370 
5371 	{
5372 		queue_t *q;
5373 		int num_modules, space_allocated;
5374 		STRUCT_DECL(str_list, strlist);
5375 		struct str_mlist *mlist_ptr;
5376 
5377 		if (arg == NULL) { /* Return number of modules plus driver */
5378 			q = stp->sd_wrq;
5379 			if (stp->sd_vnode->v_type == VFIFO) {
5380 				*rvalp = stp->sd_pushcnt;
5381 			} else {
5382 				*rvalp = stp->sd_pushcnt + 1;
5383 			}
5384 		} else {
5385 			STRUCT_INIT(strlist, flag);
5386 
5387 			error = strcopyin((void *)arg, STRUCT_BUF(strlist),
5388 			    STRUCT_SIZE(strlist), copyflag);
5389 			if (error)
5390 				return (error);
5391 
5392 			space_allocated = STRUCT_FGET(strlist, sl_nmods);
5393 			if ((space_allocated) <= 0)
5394 				return (EINVAL);
5395 			claimstr(stp->sd_wrq);
5396 			q = stp->sd_wrq;
5397 			num_modules = 0;
5398 			while (_SAMESTR(q) && (space_allocated != 0)) {
5399 				char *name =
5400 				    q->q_next->q_qinfo->qi_minfo->mi_idname;
5401 
5402 				mlist_ptr = STRUCT_FGETP(strlist, sl_modlist);
5403 
5404 				error = strcopyout(name, mlist_ptr,
5405 				    strlen(name) + 1, copyflag);
5406 
5407 				if (error) {
5408 					releasestr(stp->sd_wrq);
5409 					return (error);
5410 				}
5411 				q = q->q_next;
5412 				space_allocated--;
5413 				num_modules++;
5414 				mlist_ptr =
5415 				    (struct str_mlist *)((uintptr_t)mlist_ptr +
5416 				    sizeof (struct str_mlist));
5417 				STRUCT_FSETP(strlist, sl_modlist, mlist_ptr);
5418 			}
5419 			releasestr(stp->sd_wrq);
5420 			error = strcopyout(&num_modules, (void *)arg,
5421 			    sizeof (int), copyflag);
5422 		}
5423 		return (error);
5424 	}
5425 
5426 	case I_CKBAND:
5427 	{
5428 		queue_t *q;
5429 		qband_t *qbp;
5430 
5431 		if ((arg < 0) || (arg >= NBAND))
5432 			return (EINVAL);
5433 		q = _RD(stp->sd_wrq);
5434 		mutex_enter(QLOCK(q));
5435 		if (arg > (int)q->q_nband) {
5436 			*rvalp = 0;
5437 		} else {
5438 			if (arg == 0) {
5439 				if (q->q_first)
5440 					*rvalp = 1;
5441 				else
5442 					*rvalp = 0;
5443 			} else {
5444 				qbp = q->q_bandp;
5445 				while (--arg > 0)
5446 					qbp = qbp->qb_next;
5447 				if (qbp->qb_first)
5448 					*rvalp = 1;
5449 				else
5450 					*rvalp = 0;
5451 			}
5452 		}
5453 		mutex_exit(QLOCK(q));
5454 		return (0);
5455 	}
5456 
5457 	case I_GETBAND:
5458 	{
5459 		int intpri;
5460 		queue_t *q;
5461 
5462 		q = _RD(stp->sd_wrq);
5463 		mutex_enter(QLOCK(q));
5464 		mp = q->q_first;
5465 		if (!mp) {
5466 			mutex_exit(QLOCK(q));
5467 			return (ENODATA);
5468 		}
5469 		intpri = (int)mp->b_band;
5470 		error = strcopyout(&intpri, (void *)arg, sizeof (int),
5471 		    copyflag);
5472 		mutex_exit(QLOCK(q));
5473 		return (error);
5474 	}
5475 
5476 	case I_ATMARK:
5477 	{
5478 		queue_t *q;
5479 
5480 		if (arg & ~(ANYMARK|LASTMARK))
5481 			return (EINVAL);
5482 		q = _RD(stp->sd_wrq);
5483 		mutex_enter(&stp->sd_lock);
5484 		if ((stp->sd_flag & STRATMARK) && (arg == ANYMARK)) {
5485 			*rvalp = 1;
5486 		} else {
5487 			mutex_enter(QLOCK(q));
5488 			mp = q->q_first;
5489 
5490 			if (mp == NULL)
5491 				*rvalp = 0;
5492 			else if ((arg == ANYMARK) && (mp->b_flag & MSGMARK))
5493 				*rvalp = 1;
5494 			else if ((arg == LASTMARK) && (mp == stp->sd_mark))
5495 				*rvalp = 1;
5496 			else
5497 				*rvalp = 0;
5498 			mutex_exit(QLOCK(q));
5499 		}
5500 		mutex_exit(&stp->sd_lock);
5501 		return (0);
5502 	}
5503 
5504 	case I_CANPUT:
5505 	{
5506 		char band;
5507 
5508 		if ((arg < 0) || (arg >= NBAND))
5509 			return (EINVAL);
5510 		band = (char)arg;
5511 		*rvalp = bcanputnext(stp->sd_wrq, band);
5512 		return (0);
5513 	}
5514 
5515 	case I_SETCLTIME:
5516 	{
5517 		int closetime;
5518 
5519 		error = strcopyin((void *)arg, &closetime, sizeof (int),
5520 		    copyflag);
5521 		if (error)
5522 			return (error);
5523 		if (closetime < 0)
5524 			return (EINVAL);
5525 
5526 		stp->sd_closetime = closetime;
5527 		return (0);
5528 	}
5529 
5530 	case I_GETCLTIME:
5531 	{
5532 		int closetime;
5533 
5534 		closetime = stp->sd_closetime;
5535 		return (strcopyout(&closetime, (void *)arg, sizeof (int),
5536 		    copyflag));
5537 	}
5538 
5539 	case TIOCGSID:
5540 	{
5541 		pid_t sid;
5542 
5543 		mutex_enter(&stp->sd_lock);
5544 		if (stp->sd_sidp == NULL) {
5545 			mutex_exit(&stp->sd_lock);
5546 			return (ENOTTY);
5547 		}
5548 		sid = stp->sd_sidp->pid_id;
5549 		mutex_exit(&stp->sd_lock);
5550 		return (strcopyout(&sid, (void *)arg, sizeof (pid_t),
5551 		    copyflag));
5552 	}
5553 
5554 	case TIOCSPGRP:
5555 	{
5556 		pid_t pgrp;
5557 		proc_t *q;
5558 		pid_t	sid, fg_pgid, bg_pgid;
5559 
5560 		if (error = strcopyin((void *)arg, &pgrp, sizeof (pid_t),
5561 		    copyflag))
5562 			return (error);
5563 		mutex_enter(&stp->sd_lock);
5564 		mutex_enter(&pidlock);
5565 		if (stp->sd_sidp != ttoproc(curthread)->p_sessp->s_sidp) {
5566 			mutex_exit(&pidlock);
5567 			mutex_exit(&stp->sd_lock);
5568 			return (ENOTTY);
5569 		}
5570 		if (pgrp == stp->sd_pgidp->pid_id) {
5571 			mutex_exit(&pidlock);
5572 			mutex_exit(&stp->sd_lock);
5573 			return (0);
5574 		}
5575 		if (pgrp <= 0 || pgrp >= maxpid) {
5576 			mutex_exit(&pidlock);
5577 			mutex_exit(&stp->sd_lock);
5578 			return (EINVAL);
5579 		}
5580 		if ((q = pgfind(pgrp)) == NULL ||
5581 		    q->p_sessp != ttoproc(curthread)->p_sessp) {
5582 			mutex_exit(&pidlock);
5583 			mutex_exit(&stp->sd_lock);
5584 			return (EPERM);
5585 		}
5586 		sid = stp->sd_sidp->pid_id;
5587 		fg_pgid = q->p_pgrp;
5588 		bg_pgid = stp->sd_pgidp->pid_id;
5589 		CL_SET_PROCESS_GROUP(curthread, sid, bg_pgid, fg_pgid);
5590 		PID_RELE(stp->sd_pgidp);
5591 		ctty_clear_sighuped();
5592 		stp->sd_pgidp = q->p_pgidp;
5593 		PID_HOLD(stp->sd_pgidp);
5594 		mutex_exit(&pidlock);
5595 		mutex_exit(&stp->sd_lock);
5596 		return (0);
5597 	}
5598 
5599 	case TIOCGPGRP:
5600 	{
5601 		pid_t pgrp;
5602 
5603 		mutex_enter(&stp->sd_lock);
5604 		if (stp->sd_sidp == NULL) {
5605 			mutex_exit(&stp->sd_lock);
5606 			return (ENOTTY);
5607 		}
5608 		pgrp = stp->sd_pgidp->pid_id;
5609 		mutex_exit(&stp->sd_lock);
5610 		return (strcopyout(&pgrp, (void *)arg, sizeof (pid_t),
5611 		    copyflag));
5612 	}
5613 
5614 	case TIOCSCTTY:
5615 	{
5616 		return (strctty(stp));
5617 	}
5618 
5619 	case TIOCNOTTY:
5620 	{
5621 		/* freectty() always assumes curproc. */
5622 		if (freectty(B_FALSE) != 0)
5623 			return (0);
5624 		return (ENOTTY);
5625 	}
5626 
5627 	case FIONBIO:
5628 	case FIOASYNC:
5629 		return (0);	/* handled by the upper layer */
5630 	}
5631 }
5632 
5633 /*
5634  * Custom free routine used for M_PASSFP messages.
5635  */
5636 static void
5637 free_passfp(struct k_strrecvfd *srf)
5638 {
5639 	(void) closef(srf->fp);
5640 	kmem_free(srf, sizeof (struct k_strrecvfd) + sizeof (frtn_t));
5641 }
5642 
5643 /* ARGSUSED */
5644 int
5645 do_sendfp(struct stdata *stp, struct file *fp, struct cred *cr)
5646 {
5647 	queue_t *qp, *nextqp;
5648 	struct k_strrecvfd *srf;
5649 	mblk_t *mp;
5650 	frtn_t *frtnp;
5651 	size_t bufsize;
5652 	queue_t	*mate = NULL;
5653 	syncq_t	*sq = NULL;
5654 	int retval = 0;
5655 
5656 	if (stp->sd_flag & STRHUP)
5657 		return (ENXIO);
5658 
5659 	claimstr(stp->sd_wrq);
5660 
5661 	/* Fastpath, we have a pipe, and we are already mated, use it. */
5662 	if (STRMATED(stp)) {
5663 		qp = _RD(stp->sd_mate->sd_wrq);
5664 		claimstr(qp);
5665 		mate = qp;
5666 	} else { /* Not already mated. */
5667 
5668 		/*
5669 		 * Walk the stream to the end of this one.
5670 		 * assumes that the claimstr() will prevent
5671 		 * plumbing between the stream head and the
5672 		 * driver from changing
5673 		 */
5674 		qp = stp->sd_wrq;
5675 
5676 		/*
5677 		 * Loop until we reach the end of this stream.
5678 		 * On completion, qp points to the write queue
5679 		 * at the end of the stream, or the read queue
5680 		 * at the stream head if this is a fifo.
5681 		 */
5682 		while (((qp = qp->q_next) != NULL) && _SAMESTR(qp))
5683 			;
5684 
5685 		/*
5686 		 * Just in case we get a q_next which is NULL, but
5687 		 * not at the end of the stream.  This is actually
5688 		 * broken, so we set an assert to catch it in
5689 		 * debug, and set an error and return if not debug.
5690 		 */
5691 		ASSERT(qp);
5692 		if (qp == NULL) {
5693 			releasestr(stp->sd_wrq);
5694 			return (EINVAL);
5695 		}
5696 
5697 		/*
5698 		 * Enter the syncq for the driver, so (hopefully)
5699 		 * the queue values will not change on us.
5700 		 * XXXX - This will only prevent the race IFF only
5701 		 *   the write side modifies the q_next member, and
5702 		 *   the put procedure is protected by at least
5703 		 *   MT_PERQ.
5704 		 */
5705 		if ((sq = qp->q_syncq) != NULL)
5706 			entersq(sq, SQ_PUT);
5707 
5708 		/* Now get the q_next value from this qp. */
5709 		nextqp = qp->q_next;
5710 
5711 		/*
5712 		 * If nextqp exists and the other stream is different
5713 		 * from this one claim the stream, set the mate, and
5714 		 * get the read queue at the stream head of the other
5715 		 * stream.  Assumes that nextqp was at least valid when
5716 		 * we got it.  Hopefully the entersq of the driver
5717 		 * will prevent it from changing on us.
5718 		 */
5719 		if ((nextqp != NULL) && (STREAM(nextqp) != stp)) {
5720 			ASSERT(qp->q_qinfo->qi_srvp);
5721 			ASSERT(_OTHERQ(qp)->q_qinfo->qi_srvp);
5722 			ASSERT(_OTHERQ(qp->q_next)->q_qinfo->qi_srvp);
5723 			claimstr(nextqp);
5724 
5725 			/* Make sure we still have a q_next */
5726 			if (nextqp != qp->q_next) {
5727 				releasestr(stp->sd_wrq);
5728 				releasestr(nextqp);
5729 				return (EINVAL);
5730 			}
5731 
5732 			qp = _RD(STREAM(nextqp)->sd_wrq);
5733 			mate = qp;
5734 		}
5735 		/* If we entered the synq above, leave it. */
5736 		if (sq != NULL)
5737 			leavesq(sq, SQ_PUT);
5738 	} /*  STRMATED(STP)  */
5739 
5740 	/* XXX prevents substitution of the ops vector */
5741 	if (qp->q_qinfo != &strdata && qp->q_qinfo != &fifo_strdata) {
5742 		retval = EINVAL;
5743 		goto out;
5744 	}
5745 
5746 	if (qp->q_flag & QFULL) {
5747 		retval = EAGAIN;
5748 		goto out;
5749 	}
5750 
5751 	/*
5752 	 * Since M_PASSFP messages include a file descriptor, we use
5753 	 * esballoc() and specify a custom free routine (free_passfp()) that
5754 	 * will close the descriptor as part of freeing the message.  For
5755 	 * convenience, we stash the frtn_t right after the data block.
5756 	 */
5757 	bufsize = sizeof (struct k_strrecvfd) + sizeof (frtn_t);
5758 	srf = kmem_alloc(bufsize, KM_NOSLEEP);
5759 	if (srf == NULL) {
5760 		retval = EAGAIN;
5761 		goto out;
5762 	}
5763 
5764 	frtnp = (frtn_t *)(srf + 1);
5765 	frtnp->free_arg = (caddr_t)srf;
5766 	frtnp->free_func = free_passfp;
5767 
5768 	mp = esballoc((uchar_t *)srf, bufsize, BPRI_MED, frtnp);
5769 	if (mp == NULL) {
5770 		kmem_free(srf, bufsize);
5771 		retval = EAGAIN;
5772 		goto out;
5773 	}
5774 	mp->b_wptr += sizeof (struct k_strrecvfd);
5775 	mp->b_datap->db_type = M_PASSFP;
5776 
5777 	srf->fp = fp;
5778 	srf->uid = crgetuid(curthread->t_cred);
5779 	srf->gid = crgetgid(curthread->t_cred);
5780 	mutex_enter(&fp->f_tlock);
5781 	fp->f_count++;
5782 	mutex_exit(&fp->f_tlock);
5783 
5784 	put(qp, mp);
5785 out:
5786 	releasestr(stp->sd_wrq);
5787 	if (mate)
5788 		releasestr(mate);
5789 	return (retval);
5790 }
5791 
5792 /*
5793  * Send an ioctl message downstream and wait for acknowledgement.
5794  * flags may be set to either U_TO_K or K_TO_K and a combination
5795  * of STR_NOERROR or STR_NOSIG
5796  * STR_NOSIG: Signals are essentially ignored or held and have
5797  *	no effect for the duration of the call.
5798  * STR_NOERROR: Ignores stream head read, write and hup errors.
5799  *	Additionally, if an existing ioctl times out, it is assumed
5800  *	lost and and this ioctl will continue as if the previous ioctl had
5801  *	finished.  ETIME may be returned if this ioctl times out (i.e.
5802  *	ic_timout is not INFTIM).  Non-stream head errors may be returned if
5803  *	the ioc_error indicates that the driver/module had problems,
5804  *	an EFAULT was found when accessing user data, a lack of
5805  * 	resources, etc.
5806  */
5807 int
5808 strdoioctl(
5809 	struct stdata *stp,
5810 	struct strioctl *strioc,
5811 	int fflags,		/* file flags with model info */
5812 	int flag,
5813 	cred_t *crp,
5814 	int *rvalp)
5815 {
5816 	mblk_t *bp;
5817 	struct iocblk *iocbp;
5818 	struct copyreq *reqp;
5819 	struct copyresp *resp;
5820 	int id;
5821 	int transparent = 0;
5822 	int error = 0;
5823 	int len = 0;
5824 	caddr_t taddr;
5825 	int copyflag = (flag & (U_TO_K | K_TO_K));
5826 	int sigflag = (flag & STR_NOSIG);
5827 	int errs;
5828 	uint_t waitflags;
5829 
5830 	ASSERT(copyflag == U_TO_K || copyflag == K_TO_K);
5831 	ASSERT((fflags & FMODELS) != 0);
5832 
5833 	TRACE_2(TR_FAC_STREAMS_FR,
5834 	    TR_STRDOIOCTL,
5835 	    "strdoioctl:stp %p strioc %p", stp, strioc);
5836 	if (strioc->ic_len == TRANSPARENT) {	/* send arg in M_DATA block */
5837 		transparent = 1;
5838 		strioc->ic_len = sizeof (intptr_t);
5839 	}
5840 
5841 	if (strioc->ic_len < 0 || (strmsgsz > 0 && strioc->ic_len > strmsgsz))
5842 		return (EINVAL);
5843 
5844 	if ((bp = allocb_cred_wait(sizeof (union ioctypes), sigflag, &error,
5845 	    crp)) == NULL)
5846 			return (error);
5847 
5848 	bzero(bp->b_wptr, sizeof (union ioctypes));
5849 
5850 	iocbp = (struct iocblk *)bp->b_wptr;
5851 	iocbp->ioc_count = strioc->ic_len;
5852 	iocbp->ioc_cmd = strioc->ic_cmd;
5853 	iocbp->ioc_flag = (fflags & FMODELS);
5854 
5855 	crhold(crp);
5856 	iocbp->ioc_cr = crp;
5857 	DB_TYPE(bp) = M_IOCTL;
5858 	DB_CPID(bp) = curproc->p_pid;
5859 	bp->b_wptr += sizeof (struct iocblk);
5860 
5861 	if (flag & STR_NOERROR)
5862 		errs = STPLEX;
5863 	else
5864 		errs = STRHUP|STRDERR|STWRERR|STPLEX;
5865 
5866 	/*
5867 	 * If there is data to copy into ioctl block, do so.
5868 	 */
5869 	if (iocbp->ioc_count > 0) {
5870 		if (transparent)
5871 			/*
5872 			 * Note: STR_NOERROR does not have an effect
5873 			 * in putiocd()
5874 			 */
5875 			id = K_TO_K | sigflag;
5876 		else
5877 			id = flag;
5878 		if ((error = putiocd(bp, strioc->ic_dp, id, crp)) != 0) {
5879 			freemsg(bp);
5880 			crfree(crp);
5881 			return (error);
5882 		}
5883 
5884 		/*
5885 		 * We could have slept copying in user pages.
5886 		 * Recheck the stream head state (the other end
5887 		 * of a pipe could have gone away).
5888 		 */
5889 		if (stp->sd_flag & errs) {
5890 			mutex_enter(&stp->sd_lock);
5891 			error = strgeterr(stp, errs, 0);
5892 			mutex_exit(&stp->sd_lock);
5893 			if (error != 0) {
5894 				freemsg(bp);
5895 				crfree(crp);
5896 				return (error);
5897 			}
5898 		}
5899 	}
5900 	if (transparent)
5901 		iocbp->ioc_count = TRANSPARENT;
5902 
5903 	/*
5904 	 * Block for up to STRTIMOUT milliseconds if there is an outstanding
5905 	 * ioctl for this stream already running.  All processes
5906 	 * sleeping here will be awakened as a result of an ACK
5907 	 * or NAK being received for the outstanding ioctl, or
5908 	 * as a result of the timer expiring on the outstanding
5909 	 * ioctl (a failure), or as a result of any waiting
5910 	 * process's timer expiring (also a failure).
5911 	 */
5912 
5913 	error = 0;
5914 	mutex_enter(&stp->sd_lock);
5915 	while (stp->sd_flag & (IOCWAIT | IOCWAITNE)) {
5916 		clock_t cv_rval;
5917 
5918 		TRACE_0(TR_FAC_STREAMS_FR,
5919 		    TR_STRDOIOCTL_WAIT,
5920 		    "strdoioctl sleeps - IOCWAIT");
5921 		cv_rval = str_cv_wait(&stp->sd_iocmonitor, &stp->sd_lock,
5922 		    STRTIMOUT, sigflag);
5923 		if (cv_rval <= 0) {
5924 			if (cv_rval == 0) {
5925 				error = EINTR;
5926 			} else {
5927 				if (flag & STR_NOERROR) {
5928 					/*
5929 					 * Terminating current ioctl in
5930 					 * progress -- assume it got lost and
5931 					 * wake up the other thread so that the
5932 					 * operation completes.
5933 					 */
5934 					if (!(stp->sd_flag & IOCWAITNE)) {
5935 						stp->sd_flag |= IOCWAITNE;
5936 						cv_broadcast(&stp->sd_monitor);
5937 					}
5938 					/*
5939 					 * Otherwise, there's a running
5940 					 * STR_NOERROR -- we have no choice
5941 					 * here but to wait forever (or until
5942 					 * interrupted).
5943 					 */
5944 				} else {
5945 					/*
5946 					 * pending ioctl has caused
5947 					 * us to time out
5948 					 */
5949 					error = ETIME;
5950 				}
5951 			}
5952 		} else if ((stp->sd_flag & errs)) {
5953 			error = strgeterr(stp, errs, 0);
5954 		}
5955 		if (error) {
5956 			mutex_exit(&stp->sd_lock);
5957 			freemsg(bp);
5958 			crfree(crp);
5959 			return (error);
5960 		}
5961 	}
5962 
5963 	/*
5964 	 * Have control of ioctl mechanism.
5965 	 * Send down ioctl packet and wait for response.
5966 	 */
5967 	if (stp->sd_iocblk != (mblk_t *)-1) {
5968 		freemsg(stp->sd_iocblk);
5969 	}
5970 	stp->sd_iocblk = NULL;
5971 
5972 	/*
5973 	 * If this is marked with 'noerror' (internal; mostly
5974 	 * I_{P,}{UN,}LINK), then make sure nobody else is able to get
5975 	 * in here by setting IOCWAITNE.
5976 	 */
5977 	waitflags = IOCWAIT;
5978 	if (flag & STR_NOERROR)
5979 		waitflags |= IOCWAITNE;
5980 
5981 	stp->sd_flag |= waitflags;
5982 
5983 	/*
5984 	 * Assign sequence number.
5985 	 */
5986 	iocbp->ioc_id = stp->sd_iocid = getiocseqno();
5987 
5988 	mutex_exit(&stp->sd_lock);
5989 
5990 	TRACE_1(TR_FAC_STREAMS_FR,
5991 	    TR_STRDOIOCTL_PUT, "strdoioctl put: stp %p", stp);
5992 	stream_willservice(stp);
5993 	putnext(stp->sd_wrq, bp);
5994 	stream_runservice(stp);
5995 
5996 	/*
5997 	 * Timed wait for acknowledgment.  The wait time is limited by the
5998 	 * timeout value, which must be a positive integer (number of
5999 	 * milliseconds) to wait, or 0 (use default value of STRTIMOUT
6000 	 * milliseconds), or -1 (wait forever).  This will be awakened
6001 	 * either by an ACK/NAK message arriving, the timer expiring, or
6002 	 * the timer expiring on another ioctl waiting for control of the
6003 	 * mechanism.
6004 	 */
6005 waitioc:
6006 	mutex_enter(&stp->sd_lock);
6007 
6008 
6009 	/*
6010 	 * If the reply has already arrived, don't sleep.  If awakened from
6011 	 * the sleep, fail only if the reply has not arrived by then.
6012 	 * Otherwise, process the reply.
6013 	 */
6014 	while (!stp->sd_iocblk) {
6015 		clock_t cv_rval;
6016 
6017 		if (stp->sd_flag & errs) {
6018 			error = strgeterr(stp, errs, 0);
6019 			if (error != 0) {
6020 				stp->sd_flag &= ~waitflags;
6021 				cv_broadcast(&stp->sd_iocmonitor);
6022 				mutex_exit(&stp->sd_lock);
6023 				crfree(crp);
6024 				return (error);
6025 			}
6026 		}
6027 
6028 		TRACE_0(TR_FAC_STREAMS_FR,
6029 		    TR_STRDOIOCTL_WAIT2,
6030 		    "strdoioctl sleeps awaiting reply");
6031 		ASSERT(error == 0);
6032 
6033 		cv_rval = str_cv_wait(&stp->sd_monitor, &stp->sd_lock,
6034 		    (strioc->ic_timout ?
6035 		    strioc->ic_timout * 1000 : STRTIMOUT), sigflag);
6036 
6037 		/*
6038 		 * There are four possible cases here: interrupt, timeout,
6039 		 * wakeup by IOCWAITNE (above), or wakeup by strrput_nondata (a
6040 		 * valid M_IOCTL reply).
6041 		 *
6042 		 * If we've been awakened by a STR_NOERROR ioctl on some other
6043 		 * thread, then sd_iocblk will still be NULL, and IOCWAITNE
6044 		 * will be set.  Pretend as if we just timed out.  Note that
6045 		 * this other thread waited at least STRTIMOUT before trying to
6046 		 * awaken our thread, so this is indistinguishable (even for
6047 		 * INFTIM) from the case where we failed with ETIME waiting on
6048 		 * IOCWAIT in the prior loop.
6049 		 */
6050 		if (cv_rval > 0 && !(flag & STR_NOERROR) &&
6051 		    stp->sd_iocblk == NULL && (stp->sd_flag & IOCWAITNE)) {
6052 			cv_rval = -1;
6053 		}
6054 
6055 		/*
6056 		 * note: STR_NOERROR does not protect
6057 		 * us here.. use ic_timout < 0
6058 		 */
6059 		if (cv_rval <= 0) {
6060 			if (cv_rval == 0) {
6061 				error = EINTR;
6062 			} else {
6063 				error =  ETIME;
6064 			}
6065 			/*
6066 			 * A message could have come in after we were scheduled
6067 			 * but before we were actually run.
6068 			 */
6069 			bp = stp->sd_iocblk;
6070 			stp->sd_iocblk = NULL;
6071 			if (bp != NULL) {
6072 				if ((bp->b_datap->db_type == M_COPYIN) ||
6073 				    (bp->b_datap->db_type == M_COPYOUT)) {
6074 					mutex_exit(&stp->sd_lock);
6075 					if (bp->b_cont) {
6076 						freemsg(bp->b_cont);
6077 						bp->b_cont = NULL;
6078 					}
6079 					bp->b_datap->db_type = M_IOCDATA;
6080 					bp->b_wptr = bp->b_rptr +
6081 					    sizeof (struct copyresp);
6082 					resp = (struct copyresp *)bp->b_rptr;
6083 					resp->cp_rval =
6084 					    (caddr_t)1; /* failure */
6085 					stream_willservice(stp);
6086 					putnext(stp->sd_wrq, bp);
6087 					stream_runservice(stp);
6088 					mutex_enter(&stp->sd_lock);
6089 				} else {
6090 					freemsg(bp);
6091 				}
6092 			}
6093 			stp->sd_flag &= ~waitflags;
6094 			cv_broadcast(&stp->sd_iocmonitor);
6095 			mutex_exit(&stp->sd_lock);
6096 			crfree(crp);
6097 			return (error);
6098 		}
6099 	}
6100 	bp = stp->sd_iocblk;
6101 	/*
6102 	 * Note: it is strictly impossible to get here with sd_iocblk set to
6103 	 * -1.  This is because the initial loop above doesn't allow any new
6104 	 * ioctls into the fray until all others have passed this point.
6105 	 */
6106 	ASSERT(bp != NULL && bp != (mblk_t *)-1);
6107 	TRACE_1(TR_FAC_STREAMS_FR,
6108 	    TR_STRDOIOCTL_ACK, "strdoioctl got reply: bp %p", bp);
6109 	if ((bp->b_datap->db_type == M_IOCACK) ||
6110 	    (bp->b_datap->db_type == M_IOCNAK)) {
6111 		/* for detection of duplicate ioctl replies */
6112 		stp->sd_iocblk = (mblk_t *)-1;
6113 		stp->sd_flag &= ~waitflags;
6114 		cv_broadcast(&stp->sd_iocmonitor);
6115 		mutex_exit(&stp->sd_lock);
6116 	} else {
6117 		/*
6118 		 * flags not cleared here because we're still doing
6119 		 * copy in/out for ioctl.
6120 		 */
6121 		stp->sd_iocblk = NULL;
6122 		mutex_exit(&stp->sd_lock);
6123 	}
6124 
6125 
6126 	/*
6127 	 * Have received acknowledgment.
6128 	 */
6129 
6130 	switch (bp->b_datap->db_type) {
6131 	case M_IOCACK:
6132 		/*
6133 		 * Positive ack.
6134 		 */
6135 		iocbp = (struct iocblk *)bp->b_rptr;
6136 
6137 		/*
6138 		 * Set error if indicated.
6139 		 */
6140 		if (iocbp->ioc_error) {
6141 			error = iocbp->ioc_error;
6142 			break;
6143 		}
6144 
6145 		/*
6146 		 * Set return value.
6147 		 */
6148 		*rvalp = iocbp->ioc_rval;
6149 
6150 		/*
6151 		 * Data may have been returned in ACK message (ioc_count > 0).
6152 		 * If so, copy it out to the user's buffer.
6153 		 */
6154 		if (iocbp->ioc_count && !transparent) {
6155 			if (error = getiocd(bp, strioc->ic_dp, copyflag))
6156 				break;
6157 		}
6158 		if (!transparent) {
6159 			if (len)	/* an M_COPYOUT was used with I_STR */
6160 				strioc->ic_len = len;
6161 			else
6162 				strioc->ic_len = (int)iocbp->ioc_count;
6163 		}
6164 		break;
6165 
6166 	case M_IOCNAK:
6167 		/*
6168 		 * Negative ack.
6169 		 *
6170 		 * The only thing to do is set error as specified
6171 		 * in neg ack packet.
6172 		 */
6173 		iocbp = (struct iocblk *)bp->b_rptr;
6174 
6175 		error = (iocbp->ioc_error ? iocbp->ioc_error : EINVAL);
6176 		break;
6177 
6178 	case M_COPYIN:
6179 		/*
6180 		 * Driver or module has requested user ioctl data.
6181 		 */
6182 		reqp = (struct copyreq *)bp->b_rptr;
6183 
6184 		/*
6185 		 * M_COPYIN should *never* have a message attached, though
6186 		 * it's harmless if it does -- thus, panic on a DEBUG
6187 		 * kernel and just free it on a non-DEBUG build.
6188 		 */
6189 		ASSERT(bp->b_cont == NULL);
6190 		if (bp->b_cont != NULL) {
6191 			freemsg(bp->b_cont);
6192 			bp->b_cont = NULL;
6193 		}
6194 
6195 		error = putiocd(bp, reqp->cq_addr, flag, crp);
6196 		if (error && bp->b_cont) {
6197 			freemsg(bp->b_cont);
6198 			bp->b_cont = NULL;
6199 		}
6200 
6201 		bp->b_wptr = bp->b_rptr + sizeof (struct copyresp);
6202 		bp->b_datap->db_type = M_IOCDATA;
6203 
6204 		mblk_setcred(bp, crp);
6205 		DB_CPID(bp) = curproc->p_pid;
6206 		resp = (struct copyresp *)bp->b_rptr;
6207 		resp->cp_rval = (caddr_t)(uintptr_t)error;
6208 		resp->cp_flag = (fflags & FMODELS);
6209 
6210 		stream_willservice(stp);
6211 		putnext(stp->sd_wrq, bp);
6212 		stream_runservice(stp);
6213 
6214 		if (error) {
6215 			mutex_enter(&stp->sd_lock);
6216 			stp->sd_flag &= ~waitflags;
6217 			cv_broadcast(&stp->sd_iocmonitor);
6218 			mutex_exit(&stp->sd_lock);
6219 			crfree(crp);
6220 			return (error);
6221 		}
6222 
6223 		goto waitioc;
6224 
6225 	case M_COPYOUT:
6226 		/*
6227 		 * Driver or module has ioctl data for a user.
6228 		 */
6229 		reqp = (struct copyreq *)bp->b_rptr;
6230 		ASSERT(bp->b_cont != NULL);
6231 
6232 		/*
6233 		 * Always (transparent or non-transparent )
6234 		 * use the address specified in the request
6235 		 */
6236 		taddr = reqp->cq_addr;
6237 		if (!transparent)
6238 			len = (int)reqp->cq_size;
6239 
6240 		/* copyout data to the provided address */
6241 		error = getiocd(bp, taddr, copyflag);
6242 
6243 		freemsg(bp->b_cont);
6244 		bp->b_cont = NULL;
6245 
6246 		bp->b_wptr = bp->b_rptr + sizeof (struct copyresp);
6247 		bp->b_datap->db_type = M_IOCDATA;
6248 
6249 		mblk_setcred(bp, crp);
6250 		DB_CPID(bp) = curproc->p_pid;
6251 		resp = (struct copyresp *)bp->b_rptr;
6252 		resp->cp_rval = (caddr_t)(uintptr_t)error;
6253 		resp->cp_flag = (fflags & FMODELS);
6254 
6255 		stream_willservice(stp);
6256 		putnext(stp->sd_wrq, bp);
6257 		stream_runservice(stp);
6258 
6259 		if (error) {
6260 			mutex_enter(&stp->sd_lock);
6261 			stp->sd_flag &= ~waitflags;
6262 			cv_broadcast(&stp->sd_iocmonitor);
6263 			mutex_exit(&stp->sd_lock);
6264 			crfree(crp);
6265 			return (error);
6266 		}
6267 		goto waitioc;
6268 
6269 	default:
6270 		ASSERT(0);
6271 		mutex_enter(&stp->sd_lock);
6272 		stp->sd_flag &= ~waitflags;
6273 		cv_broadcast(&stp->sd_iocmonitor);
6274 		mutex_exit(&stp->sd_lock);
6275 		break;
6276 	}
6277 
6278 	freemsg(bp);
6279 	crfree(crp);
6280 	return (error);
6281 }
6282 
6283 /*
6284  * For the SunOS keyboard driver.
6285  * Return the next available "ioctl" sequence number.
6286  * Exported, so that streams modules can send "ioctl" messages
6287  * downstream from their open routine.
6288  */
6289 int
6290 getiocseqno(void)
6291 {
6292 	int	i;
6293 
6294 	mutex_enter(&strresources);
6295 	i = ++ioc_id;
6296 	mutex_exit(&strresources);
6297 	return (i);
6298 }
6299 
6300 /*
6301  * Get the next message from the read queue.  If the message is
6302  * priority, STRPRI will have been set by strrput().  This flag
6303  * should be reset only when the entire message at the front of the
6304  * queue as been consumed.
6305  *
6306  * NOTE: strgetmsg and kstrgetmsg have much of the logic in common.
6307  */
6308 int
6309 strgetmsg(
6310 	struct vnode *vp,
6311 	struct strbuf *mctl,
6312 	struct strbuf *mdata,
6313 	unsigned char *prip,
6314 	int *flagsp,
6315 	int fmode,
6316 	rval_t *rvp)
6317 {
6318 	struct stdata *stp;
6319 	mblk_t *bp, *nbp;
6320 	mblk_t *savemp = NULL;
6321 	mblk_t *savemptail = NULL;
6322 	uint_t old_sd_flag;
6323 	int flg;
6324 	int more = 0;
6325 	int error = 0;
6326 	char first = 1;
6327 	uint_t mark;		/* Contains MSG*MARK and _LASTMARK */
6328 #define	_LASTMARK	0x8000	/* Distinct from MSG*MARK */
6329 	unsigned char pri = 0;
6330 	queue_t *q;
6331 	int	pr = 0;			/* Partial read successful */
6332 	struct uio uios;
6333 	struct uio *uiop = &uios;
6334 	struct iovec iovs;
6335 	unsigned char type;
6336 
6337 	TRACE_1(TR_FAC_STREAMS_FR, TR_STRGETMSG_ENTER,
6338 	    "strgetmsg:%p", vp);
6339 
6340 	ASSERT(vp->v_stream);
6341 	stp = vp->v_stream;
6342 	rvp->r_val1 = 0;
6343 
6344 	mutex_enter(&stp->sd_lock);
6345 
6346 	if ((error = i_straccess(stp, JCREAD)) != 0) {
6347 		mutex_exit(&stp->sd_lock);
6348 		return (error);
6349 	}
6350 
6351 	if (stp->sd_flag & (STRDERR|STPLEX)) {
6352 		error = strgeterr(stp, STRDERR|STPLEX, 0);
6353 		if (error != 0) {
6354 			mutex_exit(&stp->sd_lock);
6355 			return (error);
6356 		}
6357 	}
6358 	mutex_exit(&stp->sd_lock);
6359 
6360 	switch (*flagsp) {
6361 	case MSG_HIPRI:
6362 		if (*prip != 0)
6363 			return (EINVAL);
6364 		break;
6365 
6366 	case MSG_ANY:
6367 	case MSG_BAND:
6368 		break;
6369 
6370 	default:
6371 		return (EINVAL);
6372 	}
6373 	/*
6374 	 * Setup uio and iov for data part
6375 	 */
6376 	iovs.iov_base = mdata->buf;
6377 	iovs.iov_len = mdata->maxlen;
6378 	uios.uio_iov = &iovs;
6379 	uios.uio_iovcnt = 1;
6380 	uios.uio_loffset = 0;
6381 	uios.uio_segflg = UIO_USERSPACE;
6382 	uios.uio_fmode = 0;
6383 	uios.uio_extflg = UIO_COPY_CACHED;
6384 	uios.uio_resid = mdata->maxlen;
6385 	uios.uio_offset = 0;
6386 
6387 	q = _RD(stp->sd_wrq);
6388 	mutex_enter(&stp->sd_lock);
6389 	old_sd_flag = stp->sd_flag;
6390 	mark = 0;
6391 	for (;;) {
6392 		int done = 0;
6393 		mblk_t *q_first = q->q_first;
6394 
6395 		/*
6396 		 * Get the next message of appropriate priority
6397 		 * from the stream head.  If the caller is interested
6398 		 * in band or hipri messages, then they should already
6399 		 * be enqueued at the stream head.  On the other hand
6400 		 * if the caller wants normal (band 0) messages, they
6401 		 * might be deferred in a synchronous stream and they
6402 		 * will need to be pulled up.
6403 		 *
6404 		 * After we have dequeued a message, we might find that
6405 		 * it was a deferred M_SIG that was enqueued at the
6406 		 * stream head.  It must now be posted as part of the
6407 		 * read by calling strsignal_nolock().
6408 		 *
6409 		 * Also note that strrput does not enqueue an M_PCSIG,
6410 		 * and there cannot be more than one hipri message,
6411 		 * so there was no need to have the M_PCSIG case.
6412 		 *
6413 		 * At some time it might be nice to try and wrap the
6414 		 * functionality of kstrgetmsg() and strgetmsg() into
6415 		 * a common routine so to reduce the amount of replicated
6416 		 * code (since they are extremely similar).
6417 		 */
6418 		if (!(*flagsp & (MSG_HIPRI|MSG_BAND))) {
6419 			/* Asking for normal, band0 data */
6420 			bp = strget(stp, q, uiop, first, &error);
6421 			ASSERT(MUTEX_HELD(&stp->sd_lock));
6422 			if (bp != NULL) {
6423 				if (bp->b_datap->db_type == M_SIG) {
6424 					strsignal_nolock(stp, *bp->b_rptr,
6425 					    (int32_t)bp->b_band);
6426 					continue;
6427 				} else {
6428 					break;
6429 				}
6430 			}
6431 			if (error != 0) {
6432 				goto getmout;
6433 			}
6434 
6435 		/*
6436 		 * We can't depend on the value of STRPRI here because
6437 		 * the stream head may be in transit. Therefore, we
6438 		 * must look at the type of the first message to
6439 		 * determine if a high priority messages is waiting
6440 		 */
6441 		} else if ((*flagsp & MSG_HIPRI) && q_first != NULL &&
6442 		    q_first->b_datap->db_type >= QPCTL &&
6443 		    (bp = getq_noenab(q)) != NULL) {
6444 			/* Asked for HIPRI and got one */
6445 			ASSERT(bp->b_datap->db_type >= QPCTL);
6446 			break;
6447 		} else if ((*flagsp & MSG_BAND) && q_first != NULL &&
6448 		    ((q_first->b_band >= *prip) ||
6449 		    q_first->b_datap->db_type >= QPCTL) &&
6450 		    (bp = getq_noenab(q)) != NULL) {
6451 			/*
6452 			 * Asked for at least band "prip" and got either at
6453 			 * least that band or a hipri message.
6454 			 */
6455 			ASSERT(bp->b_band >= *prip ||
6456 			    bp->b_datap->db_type >= QPCTL);
6457 			if (bp->b_datap->db_type == M_SIG) {
6458 				strsignal_nolock(stp, *bp->b_rptr,
6459 				    (int32_t)bp->b_band);
6460 				continue;
6461 			} else {
6462 				break;
6463 			}
6464 		}
6465 
6466 		/* No data. Time to sleep? */
6467 		qbackenable(q, 0);
6468 
6469 		/*
6470 		 * If STRHUP or STREOF, return 0 length control and data.
6471 		 * If resid is 0, then a read(fd,buf,0) was done. Do not
6472 		 * sleep to satisfy this request because by default we have
6473 		 * zero bytes to return.
6474 		 */
6475 		if ((stp->sd_flag & (STRHUP|STREOF)) || (mctl->maxlen == 0 &&
6476 		    mdata->maxlen == 0)) {
6477 			mctl->len = mdata->len = 0;
6478 			*flagsp = 0;
6479 			mutex_exit(&stp->sd_lock);
6480 			return (0);
6481 		}
6482 		TRACE_2(TR_FAC_STREAMS_FR, TR_STRGETMSG_WAIT,
6483 		    "strgetmsg calls strwaitq:%p, %p",
6484 		    vp, uiop);
6485 		if (((error = strwaitq(stp, GETWAIT, (ssize_t)0, fmode, -1,
6486 		    &done)) != 0) || done) {
6487 			TRACE_2(TR_FAC_STREAMS_FR, TR_STRGETMSG_DONE,
6488 			    "strgetmsg error or done:%p, %p",
6489 			    vp, uiop);
6490 			mutex_exit(&stp->sd_lock);
6491 			return (error);
6492 		}
6493 		TRACE_2(TR_FAC_STREAMS_FR, TR_STRGETMSG_AWAKE,
6494 		    "strgetmsg awakes:%p, %p", vp, uiop);
6495 		if ((error = i_straccess(stp, JCREAD)) != 0) {
6496 			mutex_exit(&stp->sd_lock);
6497 			return (error);
6498 		}
6499 		first = 0;
6500 	}
6501 	ASSERT(bp != NULL);
6502 	/*
6503 	 * Extract any mark information. If the message is not completely
6504 	 * consumed this information will be put in the mblk
6505 	 * that is putback.
6506 	 * If MSGMARKNEXT is set and the message is completely consumed
6507 	 * the STRATMARK flag will be set below. Likewise, if
6508 	 * MSGNOTMARKNEXT is set and the message is
6509 	 * completely consumed STRNOTATMARK will be set.
6510 	 */
6511 	mark = bp->b_flag & (MSGMARK | MSGMARKNEXT | MSGNOTMARKNEXT);
6512 	ASSERT((mark & (MSGMARKNEXT|MSGNOTMARKNEXT)) !=
6513 	    (MSGMARKNEXT|MSGNOTMARKNEXT));
6514 	if (mark != 0 && bp == stp->sd_mark) {
6515 		mark |= _LASTMARK;
6516 		stp->sd_mark = NULL;
6517 	}
6518 	/*
6519 	 * keep track of the original message type and priority
6520 	 */
6521 	pri = bp->b_band;
6522 	type = bp->b_datap->db_type;
6523 	if (type == M_PASSFP) {
6524 		if ((mark & _LASTMARK) && (stp->sd_mark == NULL))
6525 			stp->sd_mark = bp;
6526 		bp->b_flag |= mark & ~_LASTMARK;
6527 		putback(stp, q, bp, pri);
6528 		qbackenable(q, pri);
6529 		mutex_exit(&stp->sd_lock);
6530 		return (EBADMSG);
6531 	}
6532 	ASSERT(type != M_SIG);
6533 
6534 	/*
6535 	 * Set this flag so strrput will not generate signals. Need to
6536 	 * make sure this flag is cleared before leaving this routine
6537 	 * else signals will stop being sent.
6538 	 */
6539 	stp->sd_flag |= STRGETINPROG;
6540 	mutex_exit(&stp->sd_lock);
6541 
6542 	if (STREAM_NEEDSERVICE(stp))
6543 		stream_runservice(stp);
6544 
6545 	/*
6546 	 * Set HIPRI flag if message is priority.
6547 	 */
6548 	if (type >= QPCTL)
6549 		flg = MSG_HIPRI;
6550 	else
6551 		flg = MSG_BAND;
6552 
6553 	/*
6554 	 * First process PROTO or PCPROTO blocks, if any.
6555 	 */
6556 	if (mctl->maxlen >= 0 && type != M_DATA) {
6557 		size_t	n, bcnt;
6558 		char	*ubuf;
6559 
6560 		bcnt = mctl->maxlen;
6561 		ubuf = mctl->buf;
6562 		while (bp != NULL && bp->b_datap->db_type != M_DATA) {
6563 			if ((n = MIN(bcnt, bp->b_wptr - bp->b_rptr)) != 0 &&
6564 			    copyout(bp->b_rptr, ubuf, n)) {
6565 				error = EFAULT;
6566 				mutex_enter(&stp->sd_lock);
6567 				/*
6568 				 * clear stream head pri flag based on
6569 				 * first message type
6570 				 */
6571 				if (type >= QPCTL) {
6572 					ASSERT(type == M_PCPROTO);
6573 					stp->sd_flag &= ~STRPRI;
6574 				}
6575 				more = 0;
6576 				freemsg(bp);
6577 				goto getmout;
6578 			}
6579 			ubuf += n;
6580 			bp->b_rptr += n;
6581 			if (bp->b_rptr >= bp->b_wptr) {
6582 				nbp = bp;
6583 				bp = bp->b_cont;
6584 				freeb(nbp);
6585 			}
6586 			ASSERT(n <= bcnt);
6587 			bcnt -= n;
6588 			if (bcnt == 0)
6589 				break;
6590 		}
6591 		mctl->len = mctl->maxlen - bcnt;
6592 	} else
6593 		mctl->len = -1;
6594 
6595 	if (bp && bp->b_datap->db_type != M_DATA) {
6596 		/*
6597 		 * More PROTO blocks in msg.
6598 		 */
6599 		more |= MORECTL;
6600 		savemp = bp;
6601 		while (bp && bp->b_datap->db_type != M_DATA) {
6602 			savemptail = bp;
6603 			bp = bp->b_cont;
6604 		}
6605 		savemptail->b_cont = NULL;
6606 	}
6607 
6608 	/*
6609 	 * Now process DATA blocks, if any.
6610 	 */
6611 	if (mdata->maxlen >= 0 && bp) {
6612 		/*
6613 		 * struiocopyout will consume a potential zero-length
6614 		 * M_DATA even if uio_resid is zero.
6615 		 */
6616 		size_t oldresid = uiop->uio_resid;
6617 
6618 		bp = struiocopyout(bp, uiop, &error);
6619 		if (error != 0) {
6620 			mutex_enter(&stp->sd_lock);
6621 			/*
6622 			 * clear stream head hi pri flag based on
6623 			 * first message
6624 			 */
6625 			if (type >= QPCTL) {
6626 				ASSERT(type == M_PCPROTO);
6627 				stp->sd_flag &= ~STRPRI;
6628 			}
6629 			more = 0;
6630 			freemsg(savemp);
6631 			goto getmout;
6632 		}
6633 		/*
6634 		 * (pr == 1) indicates a partial read.
6635 		 */
6636 		if (oldresid > uiop->uio_resid)
6637 			pr = 1;
6638 		mdata->len = mdata->maxlen - uiop->uio_resid;
6639 	} else
6640 		mdata->len = -1;
6641 
6642 	if (bp) {			/* more data blocks in msg */
6643 		more |= MOREDATA;
6644 		if (savemp)
6645 			savemptail->b_cont = bp;
6646 		else
6647 			savemp = bp;
6648 	}
6649 
6650 	mutex_enter(&stp->sd_lock);
6651 	if (savemp) {
6652 		if (pr && (savemp->b_datap->db_type == M_DATA) &&
6653 		    msgnodata(savemp)) {
6654 			/*
6655 			 * Avoid queuing a zero-length tail part of
6656 			 * a message. pr=1 indicates that we read some of
6657 			 * the message.
6658 			 */
6659 			freemsg(savemp);
6660 			more &= ~MOREDATA;
6661 			/*
6662 			 * clear stream head hi pri flag based on
6663 			 * first message
6664 			 */
6665 			if (type >= QPCTL) {
6666 				ASSERT(type == M_PCPROTO);
6667 				stp->sd_flag &= ~STRPRI;
6668 			}
6669 		} else {
6670 			savemp->b_band = pri;
6671 			/*
6672 			 * If the first message was HIPRI and the one we're
6673 			 * putting back isn't, then clear STRPRI, otherwise
6674 			 * set STRPRI again.  Note that we must set STRPRI
6675 			 * again since the flush logic in strrput_nondata()
6676 			 * may have cleared it while we had sd_lock dropped.
6677 			 */
6678 			if (type >= QPCTL) {
6679 				ASSERT(type == M_PCPROTO);
6680 				if (queclass(savemp) < QPCTL)
6681 					stp->sd_flag &= ~STRPRI;
6682 				else
6683 					stp->sd_flag |= STRPRI;
6684 			} else if (queclass(savemp) >= QPCTL) {
6685 				/*
6686 				 * The first message was not a HIPRI message,
6687 				 * but the one we are about to putback is.
6688 				 * For simplicitly, we do not allow for HIPRI
6689 				 * messages to be embedded in the message
6690 				 * body, so just force it to same type as
6691 				 * first message.
6692 				 */
6693 				ASSERT(type == M_DATA || type == M_PROTO);
6694 				ASSERT(savemp->b_datap->db_type == M_PCPROTO);
6695 				savemp->b_datap->db_type = type;
6696 			}
6697 			if (mark != 0) {
6698 				savemp->b_flag |= mark & ~_LASTMARK;
6699 				if ((mark & _LASTMARK) &&
6700 				    (stp->sd_mark == NULL)) {
6701 					/*
6702 					 * If another marked message arrived
6703 					 * while sd_lock was not held sd_mark
6704 					 * would be non-NULL.
6705 					 */
6706 					stp->sd_mark = savemp;
6707 				}
6708 			}
6709 			putback(stp, q, savemp, pri);
6710 		}
6711 	} else {
6712 		/*
6713 		 * The complete message was consumed.
6714 		 *
6715 		 * If another M_PCPROTO arrived while sd_lock was not held
6716 		 * it would have been discarded since STRPRI was still set.
6717 		 *
6718 		 * Move the MSG*MARKNEXT information
6719 		 * to the stream head just in case
6720 		 * the read queue becomes empty.
6721 		 * clear stream head hi pri flag based on
6722 		 * first message
6723 		 *
6724 		 * If the stream head was at the mark
6725 		 * (STRATMARK) before we dropped sd_lock above
6726 		 * and some data was consumed then we have
6727 		 * moved past the mark thus STRATMARK is
6728 		 * cleared. However, if a message arrived in
6729 		 * strrput during the copyout above causing
6730 		 * STRATMARK to be set we can not clear that
6731 		 * flag.
6732 		 */
6733 		if (type >= QPCTL) {
6734 			ASSERT(type == M_PCPROTO);
6735 			stp->sd_flag &= ~STRPRI;
6736 		}
6737 		if (mark & (MSGMARKNEXT|MSGNOTMARKNEXT|MSGMARK)) {
6738 			if (mark & MSGMARKNEXT) {
6739 				stp->sd_flag &= ~STRNOTATMARK;
6740 				stp->sd_flag |= STRATMARK;
6741 			} else if (mark & MSGNOTMARKNEXT) {
6742 				stp->sd_flag &= ~STRATMARK;
6743 				stp->sd_flag |= STRNOTATMARK;
6744 			} else {
6745 				stp->sd_flag &= ~(STRATMARK|STRNOTATMARK);
6746 			}
6747 		} else if (pr && (old_sd_flag & STRATMARK)) {
6748 			stp->sd_flag &= ~STRATMARK;
6749 		}
6750 	}
6751 
6752 	*flagsp = flg;
6753 	*prip = pri;
6754 
6755 	/*
6756 	 * Getmsg cleanup processing - if the state of the queue has changed
6757 	 * some signals may need to be sent and/or poll awakened.
6758 	 */
6759 getmout:
6760 	qbackenable(q, pri);
6761 
6762 	/*
6763 	 * We dropped the stream head lock above. Send all M_SIG messages
6764 	 * before processing stream head for SIGPOLL messages.
6765 	 */
6766 	ASSERT(MUTEX_HELD(&stp->sd_lock));
6767 	while ((bp = q->q_first) != NULL &&
6768 	    (bp->b_datap->db_type == M_SIG)) {
6769 		/*
6770 		 * sd_lock is held so the content of the read queue can not
6771 		 * change.
6772 		 */
6773 		bp = getq(q);
6774 		ASSERT(bp != NULL && bp->b_datap->db_type == M_SIG);
6775 
6776 		strsignal_nolock(stp, *bp->b_rptr, (int32_t)bp->b_band);
6777 		mutex_exit(&stp->sd_lock);
6778 		freemsg(bp);
6779 		if (STREAM_NEEDSERVICE(stp))
6780 			stream_runservice(stp);
6781 		mutex_enter(&stp->sd_lock);
6782 	}
6783 
6784 	/*
6785 	 * stream head cannot change while we make the determination
6786 	 * whether or not to send a signal. Drop the flag to allow strrput
6787 	 * to send firstmsgsigs again.
6788 	 */
6789 	stp->sd_flag &= ~STRGETINPROG;
6790 
6791 	/*
6792 	 * If the type of message at the front of the queue changed
6793 	 * due to the receive the appropriate signals and pollwakeup events
6794 	 * are generated. The type of changes are:
6795 	 *	Processed a hipri message, q_first is not hipri.
6796 	 *	Processed a band X message, and q_first is band Y.
6797 	 * The generated signals and pollwakeups are identical to what
6798 	 * strrput() generates should the message that is now on q_first
6799 	 * arrive to an empty read queue.
6800 	 *
6801 	 * Note: only strrput will send a signal for a hipri message.
6802 	 */
6803 	if ((bp = q->q_first) != NULL && !(stp->sd_flag & STRPRI)) {
6804 		strsigset_t signals = 0;
6805 		strpollset_t pollwakeups = 0;
6806 
6807 		if (flg & MSG_HIPRI) {
6808 			/*
6809 			 * Removed a hipri message. Regular data at
6810 			 * the front of  the queue.
6811 			 */
6812 			if (bp->b_band == 0) {
6813 				signals = S_INPUT | S_RDNORM;
6814 				pollwakeups = POLLIN | POLLRDNORM;
6815 			} else {
6816 				signals = S_INPUT | S_RDBAND;
6817 				pollwakeups = POLLIN | POLLRDBAND;
6818 			}
6819 		} else if (pri != bp->b_band) {
6820 			/*
6821 			 * The band is different for the new q_first.
6822 			 */
6823 			if (bp->b_band == 0) {
6824 				signals = S_RDNORM;
6825 				pollwakeups = POLLIN | POLLRDNORM;
6826 			} else {
6827 				signals = S_RDBAND;
6828 				pollwakeups = POLLIN | POLLRDBAND;
6829 			}
6830 		}
6831 
6832 		if (pollwakeups != 0) {
6833 			if (pollwakeups == (POLLIN | POLLRDNORM)) {
6834 				if (!(stp->sd_rput_opt & SR_POLLIN))
6835 					goto no_pollwake;
6836 				stp->sd_rput_opt &= ~SR_POLLIN;
6837 			}
6838 			mutex_exit(&stp->sd_lock);
6839 			pollwakeup(&stp->sd_pollist, pollwakeups);
6840 			mutex_enter(&stp->sd_lock);
6841 		}
6842 no_pollwake:
6843 
6844 		if (stp->sd_sigflags & signals)
6845 			strsendsig(stp->sd_siglist, signals, bp->b_band, 0);
6846 	}
6847 	mutex_exit(&stp->sd_lock);
6848 
6849 	rvp->r_val1 = more;
6850 	return (error);
6851 #undef	_LASTMARK
6852 }
6853 
6854 /*
6855  * Get the next message from the read queue.  If the message is
6856  * priority, STRPRI will have been set by strrput().  This flag
6857  * should be reset only when the entire message at the front of the
6858  * queue as been consumed.
6859  *
6860  * If uiop is NULL all data is returned in mctlp.
6861  * Note that a NULL uiop implies that FNDELAY and FNONBLOCK are assumed
6862  * not enabled.
6863  * The timeout parameter is in milliseconds; -1 for infinity.
6864  * This routine handles the consolidation private flags:
6865  *	MSG_IGNERROR	Ignore any stream head error except STPLEX.
6866  *	MSG_DELAYERROR	Defer the error check until the queue is empty.
6867  *	MSG_HOLDSIG	Hold signals while waiting for data.
6868  *	MSG_IPEEK	Only peek at messages.
6869  *	MSG_DISCARDTAIL	Discard the tail M_DATA part of the message
6870  *			that doesn't fit.
6871  *	MSG_NOMARK	If the message is marked leave it on the queue.
6872  *
6873  * NOTE: strgetmsg and kstrgetmsg have much of the logic in common.
6874  */
6875 int
6876 kstrgetmsg(
6877 	struct vnode *vp,
6878 	mblk_t **mctlp,
6879 	struct uio *uiop,
6880 	unsigned char *prip,
6881 	int *flagsp,
6882 	clock_t timout,
6883 	rval_t *rvp)
6884 {
6885 	struct stdata *stp;
6886 	mblk_t *bp, *nbp;
6887 	mblk_t *savemp = NULL;
6888 	mblk_t *savemptail = NULL;
6889 	int flags;
6890 	uint_t old_sd_flag;
6891 	int flg;
6892 	int more = 0;
6893 	int error = 0;
6894 	char first = 1;
6895 	uint_t mark;		/* Contains MSG*MARK and _LASTMARK */
6896 #define	_LASTMARK	0x8000	/* Distinct from MSG*MARK */
6897 	unsigned char pri = 0;
6898 	queue_t *q;
6899 	int	pr = 0;			/* Partial read successful */
6900 	unsigned char type;
6901 
6902 	TRACE_1(TR_FAC_STREAMS_FR, TR_KSTRGETMSG_ENTER,
6903 	    "kstrgetmsg:%p", vp);
6904 
6905 	ASSERT(vp->v_stream);
6906 	stp = vp->v_stream;
6907 	rvp->r_val1 = 0;
6908 
6909 	mutex_enter(&stp->sd_lock);
6910 
6911 	if ((error = i_straccess(stp, JCREAD)) != 0) {
6912 		mutex_exit(&stp->sd_lock);
6913 		return (error);
6914 	}
6915 
6916 	flags = *flagsp;
6917 	if (stp->sd_flag & (STRDERR|STPLEX)) {
6918 		if ((stp->sd_flag & STPLEX) ||
6919 		    (flags & (MSG_IGNERROR|MSG_DELAYERROR)) == 0) {
6920 			error = strgeterr(stp, STRDERR|STPLEX,
6921 			    (flags & MSG_IPEEK));
6922 			if (error != 0) {
6923 				mutex_exit(&stp->sd_lock);
6924 				return (error);
6925 			}
6926 		}
6927 	}
6928 	mutex_exit(&stp->sd_lock);
6929 
6930 	switch (flags & (MSG_HIPRI|MSG_ANY|MSG_BAND)) {
6931 	case MSG_HIPRI:
6932 		if (*prip != 0)
6933 			return (EINVAL);
6934 		break;
6935 
6936 	case MSG_ANY:
6937 	case MSG_BAND:
6938 		break;
6939 
6940 	default:
6941 		return (EINVAL);
6942 	}
6943 
6944 retry:
6945 	q = _RD(stp->sd_wrq);
6946 	mutex_enter(&stp->sd_lock);
6947 	old_sd_flag = stp->sd_flag;
6948 	mark = 0;
6949 	for (;;) {
6950 		int done = 0;
6951 		int waitflag;
6952 		int fmode;
6953 		mblk_t *q_first = q->q_first;
6954 
6955 		/*
6956 		 * This section of the code operates just like the code
6957 		 * in strgetmsg().  There is a comment there about what
6958 		 * is going on here.
6959 		 */
6960 		if (!(flags & (MSG_HIPRI|MSG_BAND))) {
6961 			/* Asking for normal, band0 data */
6962 			bp = strget(stp, q, uiop, first, &error);
6963 			ASSERT(MUTEX_HELD(&stp->sd_lock));
6964 			if (bp != NULL) {
6965 				if (bp->b_datap->db_type == M_SIG) {
6966 					strsignal_nolock(stp, *bp->b_rptr,
6967 					    (int32_t)bp->b_band);
6968 					continue;
6969 				} else {
6970 					break;
6971 				}
6972 			}
6973 			if (error != 0) {
6974 				goto getmout;
6975 			}
6976 		/*
6977 		 * We can't depend on the value of STRPRI here because
6978 		 * the stream head may be in transit. Therefore, we
6979 		 * must look at the type of the first message to
6980 		 * determine if a high priority messages is waiting
6981 		 */
6982 		} else if ((flags & MSG_HIPRI) && q_first != NULL &&
6983 		    q_first->b_datap->db_type >= QPCTL &&
6984 		    (bp = getq_noenab(q)) != NULL) {
6985 			ASSERT(bp->b_datap->db_type >= QPCTL);
6986 			break;
6987 		} else if ((flags & MSG_BAND) && q_first != NULL &&
6988 		    ((q_first->b_band >= *prip) ||
6989 		    q_first->b_datap->db_type >= QPCTL) &&
6990 		    (bp = getq_noenab(q)) != NULL) {
6991 			/*
6992 			 * Asked for at least band "prip" and got either at
6993 			 * least that band or a hipri message.
6994 			 */
6995 			ASSERT(bp->b_band >= *prip ||
6996 			    bp->b_datap->db_type >= QPCTL);
6997 			if (bp->b_datap->db_type == M_SIG) {
6998 				strsignal_nolock(stp, *bp->b_rptr,
6999 				    (int32_t)bp->b_band);
7000 				continue;
7001 			} else {
7002 				break;
7003 			}
7004 		}
7005 
7006 		/* No data. Time to sleep? */
7007 		qbackenable(q, 0);
7008 
7009 		/*
7010 		 * Delayed error notification?
7011 		 */
7012 		if ((stp->sd_flag & (STRDERR|STPLEX)) &&
7013 		    (flags & (MSG_IGNERROR|MSG_DELAYERROR)) == MSG_DELAYERROR) {
7014 			error = strgeterr(stp, STRDERR|STPLEX,
7015 			    (flags & MSG_IPEEK));
7016 			if (error != 0) {
7017 				mutex_exit(&stp->sd_lock);
7018 				return (error);
7019 			}
7020 		}
7021 
7022 		/*
7023 		 * If STRHUP or STREOF, return 0 length control and data.
7024 		 * If a read(fd,buf,0) has been done, do not sleep, just
7025 		 * return.
7026 		 *
7027 		 * If mctlp == NULL and uiop == NULL, then the code will
7028 		 * do the strwaitq. This is an understood way of saying
7029 		 * sleep "polling" until a message is received.
7030 		 */
7031 		if ((stp->sd_flag & (STRHUP|STREOF)) ||
7032 		    (uiop != NULL && uiop->uio_resid == 0)) {
7033 			if (mctlp != NULL)
7034 				*mctlp = NULL;
7035 			*flagsp = 0;
7036 			mutex_exit(&stp->sd_lock);
7037 			return (0);
7038 		}
7039 
7040 		waitflag = GETWAIT;
7041 		if (flags &
7042 		    (MSG_HOLDSIG|MSG_IGNERROR|MSG_IPEEK|MSG_DELAYERROR)) {
7043 			if (flags & MSG_HOLDSIG)
7044 				waitflag |= STR_NOSIG;
7045 			if (flags & MSG_IGNERROR)
7046 				waitflag |= STR_NOERROR;
7047 			if (flags & MSG_IPEEK)
7048 				waitflag |= STR_PEEK;
7049 			if (flags & MSG_DELAYERROR)
7050 				waitflag |= STR_DELAYERR;
7051 		}
7052 		if (uiop != NULL)
7053 			fmode = uiop->uio_fmode;
7054 		else
7055 			fmode = 0;
7056 
7057 		TRACE_2(TR_FAC_STREAMS_FR, TR_KSTRGETMSG_WAIT,
7058 		    "kstrgetmsg calls strwaitq:%p, %p",
7059 		    vp, uiop);
7060 		if (((error = strwaitq(stp, waitflag, (ssize_t)0,
7061 		    fmode, timout, &done)) != 0) || done) {
7062 			TRACE_2(TR_FAC_STREAMS_FR, TR_KSTRGETMSG_DONE,
7063 			    "kstrgetmsg error or done:%p, %p",
7064 			    vp, uiop);
7065 			mutex_exit(&stp->sd_lock);
7066 			return (error);
7067 		}
7068 		TRACE_2(TR_FAC_STREAMS_FR, TR_KSTRGETMSG_AWAKE,
7069 		    "kstrgetmsg awakes:%p, %p", vp, uiop);
7070 		if ((error = i_straccess(stp, JCREAD)) != 0) {
7071 			mutex_exit(&stp->sd_lock);
7072 			return (error);
7073 		}
7074 		first = 0;
7075 	}
7076 	ASSERT(bp != NULL);
7077 	/*
7078 	 * Extract any mark information. If the message is not completely
7079 	 * consumed this information will be put in the mblk
7080 	 * that is putback.
7081 	 * If MSGMARKNEXT is set and the message is completely consumed
7082 	 * the STRATMARK flag will be set below. Likewise, if
7083 	 * MSGNOTMARKNEXT is set and the message is
7084 	 * completely consumed STRNOTATMARK will be set.
7085 	 */
7086 	mark = bp->b_flag & (MSGMARK | MSGMARKNEXT | MSGNOTMARKNEXT);
7087 	ASSERT((mark & (MSGMARKNEXT|MSGNOTMARKNEXT)) !=
7088 	    (MSGMARKNEXT|MSGNOTMARKNEXT));
7089 	pri = bp->b_band;
7090 	if (mark != 0) {
7091 		/*
7092 		 * If the caller doesn't want the mark return.
7093 		 * Used to implement MSG_WAITALL in sockets.
7094 		 */
7095 		if (flags & MSG_NOMARK) {
7096 			putback(stp, q, bp, pri);
7097 			qbackenable(q, pri);
7098 			mutex_exit(&stp->sd_lock);
7099 			return (EWOULDBLOCK);
7100 		}
7101 		if (bp == stp->sd_mark) {
7102 			mark |= _LASTMARK;
7103 			stp->sd_mark = NULL;
7104 		}
7105 	}
7106 
7107 	/*
7108 	 * keep track of the first message type
7109 	 */
7110 	type = bp->b_datap->db_type;
7111 
7112 	if (bp->b_datap->db_type == M_PASSFP) {
7113 		if ((mark & _LASTMARK) && (stp->sd_mark == NULL))
7114 			stp->sd_mark = bp;
7115 		bp->b_flag |= mark & ~_LASTMARK;
7116 		putback(stp, q, bp, pri);
7117 		qbackenable(q, pri);
7118 		mutex_exit(&stp->sd_lock);
7119 		return (EBADMSG);
7120 	}
7121 	ASSERT(type != M_SIG);
7122 
7123 	if (flags & MSG_IPEEK) {
7124 		/*
7125 		 * Clear any struioflag - we do the uiomove over again
7126 		 * when peeking since it simplifies the code.
7127 		 *
7128 		 * Dup the message and put the original back on the queue.
7129 		 * If dupmsg() fails, try again with copymsg() to see if
7130 		 * there is indeed a shortage of memory.  dupmsg() may fail
7131 		 * if db_ref in any of the messages reaches its limit.
7132 		 */
7133 		if ((nbp = dupmsg(bp)) == NULL && (nbp = copymsg(bp)) == NULL) {
7134 			/*
7135 			 * Restore the state of the stream head since we
7136 			 * need to drop sd_lock (strwaitbuf is sleeping).
7137 			 */
7138 			size_t size = msgdsize(bp);
7139 
7140 			if ((mark & _LASTMARK) && (stp->sd_mark == NULL))
7141 				stp->sd_mark = bp;
7142 			bp->b_flag |= mark & ~_LASTMARK;
7143 			putback(stp, q, bp, pri);
7144 			mutex_exit(&stp->sd_lock);
7145 			error = strwaitbuf(size, BPRI_HI);
7146 			if (error) {
7147 				/*
7148 				 * There is no net change to the queue thus
7149 				 * no need to qbackenable.
7150 				 */
7151 				return (error);
7152 			}
7153 			goto retry;
7154 		}
7155 
7156 		if ((mark & _LASTMARK) && (stp->sd_mark == NULL))
7157 			stp->sd_mark = bp;
7158 		bp->b_flag |= mark & ~_LASTMARK;
7159 		putback(stp, q, bp, pri);
7160 		bp = nbp;
7161 	}
7162 
7163 	/*
7164 	 * Set this flag so strrput will not generate signals. Need to
7165 	 * make sure this flag is cleared before leaving this routine
7166 	 * else signals will stop being sent.
7167 	 */
7168 	stp->sd_flag |= STRGETINPROG;
7169 	mutex_exit(&stp->sd_lock);
7170 
7171 	if ((stp->sd_rputdatafunc != NULL) && (DB_TYPE(bp) == M_DATA) &&
7172 	    (!(DB_FLAGS(bp) & DBLK_COOKED))) {
7173 
7174 		bp = (stp->sd_rputdatafunc)(
7175 		    stp->sd_vnode, bp, NULL,
7176 		    NULL, NULL, NULL);
7177 
7178 		if (bp == NULL)
7179 			goto retry;
7180 
7181 		DB_FLAGS(bp) |= DBLK_COOKED;
7182 	}
7183 
7184 	if (STREAM_NEEDSERVICE(stp))
7185 		stream_runservice(stp);
7186 
7187 	/*
7188 	 * Set HIPRI flag if message is priority.
7189 	 */
7190 	if (type >= QPCTL)
7191 		flg = MSG_HIPRI;
7192 	else
7193 		flg = MSG_BAND;
7194 
7195 	/*
7196 	 * First process PROTO or PCPROTO blocks, if any.
7197 	 */
7198 	if (mctlp != NULL && type != M_DATA) {
7199 		mblk_t *nbp;
7200 
7201 		*mctlp = bp;
7202 		while (bp->b_cont && bp->b_cont->b_datap->db_type != M_DATA)
7203 			bp = bp->b_cont;
7204 		nbp = bp->b_cont;
7205 		bp->b_cont = NULL;
7206 		bp = nbp;
7207 	}
7208 
7209 	if (bp && bp->b_datap->db_type != M_DATA) {
7210 		/*
7211 		 * More PROTO blocks in msg. Will only happen if mctlp is NULL.
7212 		 */
7213 		more |= MORECTL;
7214 		savemp = bp;
7215 		while (bp && bp->b_datap->db_type != M_DATA) {
7216 			savemptail = bp;
7217 			bp = bp->b_cont;
7218 		}
7219 		savemptail->b_cont = NULL;
7220 	}
7221 
7222 	/*
7223 	 * Now process DATA blocks, if any.
7224 	 */
7225 	if (uiop == NULL) {
7226 		/* Append data to tail of mctlp */
7227 		if (mctlp != NULL) {
7228 			mblk_t **mpp = mctlp;
7229 
7230 			while (*mpp != NULL)
7231 				mpp = &((*mpp)->b_cont);
7232 			*mpp = bp;
7233 			bp = NULL;
7234 		}
7235 	} else if (uiop->uio_resid >= 0 && bp) {
7236 		size_t oldresid = uiop->uio_resid;
7237 
7238 		/*
7239 		 * If a streams message is likely to consist
7240 		 * of many small mblks, it is pulled up into
7241 		 * one continuous chunk of memory.
7242 		 * see longer comment at top of page
7243 		 * by mblk_pull_len declaration.
7244 		 */
7245 
7246 		if (MBLKL(bp) < mblk_pull_len) {
7247 			(void) pullupmsg(bp, -1);
7248 		}
7249 
7250 		bp = struiocopyout(bp, uiop, &error);
7251 		if (error != 0) {
7252 			if (mctlp != NULL) {
7253 				freemsg(*mctlp);
7254 				*mctlp = NULL;
7255 			} else
7256 				freemsg(savemp);
7257 			mutex_enter(&stp->sd_lock);
7258 			/*
7259 			 * clear stream head hi pri flag based on
7260 			 * first message
7261 			 */
7262 			if (!(flags & MSG_IPEEK) && (type >= QPCTL)) {
7263 				ASSERT(type == M_PCPROTO);
7264 				stp->sd_flag &= ~STRPRI;
7265 			}
7266 			more = 0;
7267 			goto getmout;
7268 		}
7269 		/*
7270 		 * (pr == 1) indicates a partial read.
7271 		 */
7272 		if (oldresid > uiop->uio_resid)
7273 			pr = 1;
7274 	}
7275 
7276 	if (bp) {			/* more data blocks in msg */
7277 		more |= MOREDATA;
7278 		if (savemp)
7279 			savemptail->b_cont = bp;
7280 		else
7281 			savemp = bp;
7282 	}
7283 
7284 	mutex_enter(&stp->sd_lock);
7285 	if (savemp) {
7286 		if (flags & (MSG_IPEEK|MSG_DISCARDTAIL)) {
7287 			/*
7288 			 * When MSG_DISCARDTAIL is set or
7289 			 * when peeking discard any tail. When peeking this
7290 			 * is the tail of the dup that was copied out - the
7291 			 * message has already been putback on the queue.
7292 			 * Return MOREDATA to the caller even though the data
7293 			 * is discarded. This is used by sockets (to
7294 			 * set MSG_TRUNC).
7295 			 */
7296 			freemsg(savemp);
7297 			if (!(flags & MSG_IPEEK) && (type >= QPCTL)) {
7298 				ASSERT(type == M_PCPROTO);
7299 				stp->sd_flag &= ~STRPRI;
7300 			}
7301 		} else if (pr && (savemp->b_datap->db_type == M_DATA) &&
7302 		    msgnodata(savemp)) {
7303 			/*
7304 			 * Avoid queuing a zero-length tail part of
7305 			 * a message. pr=1 indicates that we read some of
7306 			 * the message.
7307 			 */
7308 			freemsg(savemp);
7309 			more &= ~MOREDATA;
7310 			if (type >= QPCTL) {
7311 				ASSERT(type == M_PCPROTO);
7312 				stp->sd_flag &= ~STRPRI;
7313 			}
7314 		} else {
7315 			savemp->b_band = pri;
7316 			/*
7317 			 * If the first message was HIPRI and the one we're
7318 			 * putting back isn't, then clear STRPRI, otherwise
7319 			 * set STRPRI again.  Note that we must set STRPRI
7320 			 * again since the flush logic in strrput_nondata()
7321 			 * may have cleared it while we had sd_lock dropped.
7322 			 */
7323 			if (type >= QPCTL) {
7324 				ASSERT(type == M_PCPROTO);
7325 				if (queclass(savemp) < QPCTL)
7326 					stp->sd_flag &= ~STRPRI;
7327 				else
7328 					stp->sd_flag |= STRPRI;
7329 			} else if (queclass(savemp) >= QPCTL) {
7330 				/*
7331 				 * The first message was not a HIPRI message,
7332 				 * but the one we are about to putback is.
7333 				 * For simplicitly, we do not allow for HIPRI
7334 				 * messages to be embedded in the message
7335 				 * body, so just force it to same type as
7336 				 * first message.
7337 				 */
7338 				ASSERT(type == M_DATA || type == M_PROTO);
7339 				ASSERT(savemp->b_datap->db_type == M_PCPROTO);
7340 				savemp->b_datap->db_type = type;
7341 			}
7342 			if (mark != 0) {
7343 				if ((mark & _LASTMARK) &&
7344 				    (stp->sd_mark == NULL)) {
7345 					/*
7346 					 * If another marked message arrived
7347 					 * while sd_lock was not held sd_mark
7348 					 * would be non-NULL.
7349 					 */
7350 					stp->sd_mark = savemp;
7351 				}
7352 				savemp->b_flag |= mark & ~_LASTMARK;
7353 			}
7354 			putback(stp, q, savemp, pri);
7355 		}
7356 	} else if (!(flags & MSG_IPEEK)) {
7357 		/*
7358 		 * The complete message was consumed.
7359 		 *
7360 		 * If another M_PCPROTO arrived while sd_lock was not held
7361 		 * it would have been discarded since STRPRI was still set.
7362 		 *
7363 		 * Move the MSG*MARKNEXT information
7364 		 * to the stream head just in case
7365 		 * the read queue becomes empty.
7366 		 * clear stream head hi pri flag based on
7367 		 * first message
7368 		 *
7369 		 * If the stream head was at the mark
7370 		 * (STRATMARK) before we dropped sd_lock above
7371 		 * and some data was consumed then we have
7372 		 * moved past the mark thus STRATMARK is
7373 		 * cleared. However, if a message arrived in
7374 		 * strrput during the copyout above causing
7375 		 * STRATMARK to be set we can not clear that
7376 		 * flag.
7377 		 * XXX A "perimeter" would help by single-threading strrput,
7378 		 * strread, strgetmsg and kstrgetmsg.
7379 		 */
7380 		if (type >= QPCTL) {
7381 			ASSERT(type == M_PCPROTO);
7382 			stp->sd_flag &= ~STRPRI;
7383 		}
7384 		if (mark & (MSGMARKNEXT|MSGNOTMARKNEXT|MSGMARK)) {
7385 			if (mark & MSGMARKNEXT) {
7386 				stp->sd_flag &= ~STRNOTATMARK;
7387 				stp->sd_flag |= STRATMARK;
7388 			} else if (mark & MSGNOTMARKNEXT) {
7389 				stp->sd_flag &= ~STRATMARK;
7390 				stp->sd_flag |= STRNOTATMARK;
7391 			} else {
7392 				stp->sd_flag &= ~(STRATMARK|STRNOTATMARK);
7393 			}
7394 		} else if (pr && (old_sd_flag & STRATMARK)) {
7395 			stp->sd_flag &= ~STRATMARK;
7396 		}
7397 	}
7398 
7399 	*flagsp = flg;
7400 	*prip = pri;
7401 
7402 	/*
7403 	 * Getmsg cleanup processing - if the state of the queue has changed
7404 	 * some signals may need to be sent and/or poll awakened.
7405 	 */
7406 getmout:
7407 	qbackenable(q, pri);
7408 
7409 	/*
7410 	 * We dropped the stream head lock above. Send all M_SIG messages
7411 	 * before processing stream head for SIGPOLL messages.
7412 	 */
7413 	ASSERT(MUTEX_HELD(&stp->sd_lock));
7414 	while ((bp = q->q_first) != NULL &&
7415 	    (bp->b_datap->db_type == M_SIG)) {
7416 		/*
7417 		 * sd_lock is held so the content of the read queue can not
7418 		 * change.
7419 		 */
7420 		bp = getq(q);
7421 		ASSERT(bp != NULL && bp->b_datap->db_type == M_SIG);
7422 
7423 		strsignal_nolock(stp, *bp->b_rptr, (int32_t)bp->b_band);
7424 		mutex_exit(&stp->sd_lock);
7425 		freemsg(bp);
7426 		if (STREAM_NEEDSERVICE(stp))
7427 			stream_runservice(stp);
7428 		mutex_enter(&stp->sd_lock);
7429 	}
7430 
7431 	/*
7432 	 * stream head cannot change while we make the determination
7433 	 * whether or not to send a signal. Drop the flag to allow strrput
7434 	 * to send firstmsgsigs again.
7435 	 */
7436 	stp->sd_flag &= ~STRGETINPROG;
7437 
7438 	/*
7439 	 * If the type of message at the front of the queue changed
7440 	 * due to the receive the appropriate signals and pollwakeup events
7441 	 * are generated. The type of changes are:
7442 	 *	Processed a hipri message, q_first is not hipri.
7443 	 *	Processed a band X message, and q_first is band Y.
7444 	 * The generated signals and pollwakeups are identical to what
7445 	 * strrput() generates should the message that is now on q_first
7446 	 * arrive to an empty read queue.
7447 	 *
7448 	 * Note: only strrput will send a signal for a hipri message.
7449 	 */
7450 	if ((bp = q->q_first) != NULL && !(stp->sd_flag & STRPRI)) {
7451 		strsigset_t signals = 0;
7452 		strpollset_t pollwakeups = 0;
7453 
7454 		if (flg & MSG_HIPRI) {
7455 			/*
7456 			 * Removed a hipri message. Regular data at
7457 			 * the front of  the queue.
7458 			 */
7459 			if (bp->b_band == 0) {
7460 				signals = S_INPUT | S_RDNORM;
7461 				pollwakeups = POLLIN | POLLRDNORM;
7462 			} else {
7463 				signals = S_INPUT | S_RDBAND;
7464 				pollwakeups = POLLIN | POLLRDBAND;
7465 			}
7466 		} else if (pri != bp->b_band) {
7467 			/*
7468 			 * The band is different for the new q_first.
7469 			 */
7470 			if (bp->b_band == 0) {
7471 				signals = S_RDNORM;
7472 				pollwakeups = POLLIN | POLLRDNORM;
7473 			} else {
7474 				signals = S_RDBAND;
7475 				pollwakeups = POLLIN | POLLRDBAND;
7476 			}
7477 		}
7478 
7479 		if (pollwakeups != 0) {
7480 			if (pollwakeups == (POLLIN | POLLRDNORM)) {
7481 				if (!(stp->sd_rput_opt & SR_POLLIN))
7482 					goto no_pollwake;
7483 				stp->sd_rput_opt &= ~SR_POLLIN;
7484 			}
7485 			mutex_exit(&stp->sd_lock);
7486 			pollwakeup(&stp->sd_pollist, pollwakeups);
7487 			mutex_enter(&stp->sd_lock);
7488 		}
7489 no_pollwake:
7490 
7491 		if (stp->sd_sigflags & signals)
7492 			strsendsig(stp->sd_siglist, signals, bp->b_band, 0);
7493 	}
7494 	mutex_exit(&stp->sd_lock);
7495 
7496 	rvp->r_val1 = more;
7497 	return (error);
7498 #undef	_LASTMARK
7499 }
7500 
7501 /*
7502  * Put a message downstream.
7503  *
7504  * NOTE: strputmsg and kstrputmsg have much of the logic in common.
7505  */
7506 int
7507 strputmsg(
7508 	struct vnode *vp,
7509 	struct strbuf *mctl,
7510 	struct strbuf *mdata,
7511 	unsigned char pri,
7512 	int flag,
7513 	int fmode)
7514 {
7515 	struct stdata *stp;
7516 	queue_t *wqp;
7517 	mblk_t *mp;
7518 	ssize_t msgsize;
7519 	ssize_t rmin, rmax;
7520 	int error;
7521 	struct uio uios;
7522 	struct uio *uiop = &uios;
7523 	struct iovec iovs;
7524 	int xpg4 = 0;
7525 
7526 	ASSERT(vp->v_stream);
7527 	stp = vp->v_stream;
7528 	wqp = stp->sd_wrq;
7529 
7530 	/*
7531 	 * If it is an XPG4 application, we need to send
7532 	 * SIGPIPE below
7533 	 */
7534 
7535 	xpg4 = (flag & MSG_XPG4) ? 1 : 0;
7536 	flag &= ~MSG_XPG4;
7537 
7538 	if (audit_active)
7539 		audit_strputmsg(vp, mctl, mdata, pri, flag, fmode);
7540 
7541 	mutex_enter(&stp->sd_lock);
7542 
7543 	if ((error = i_straccess(stp, JCWRITE)) != 0) {
7544 		mutex_exit(&stp->sd_lock);
7545 		return (error);
7546 	}
7547 
7548 	if (stp->sd_flag & (STWRERR|STRHUP|STPLEX)) {
7549 		error = strwriteable(stp, B_FALSE, xpg4);
7550 		if (error != 0) {
7551 			mutex_exit(&stp->sd_lock);
7552 			return (error);
7553 		}
7554 	}
7555 
7556 	mutex_exit(&stp->sd_lock);
7557 
7558 	/*
7559 	 * Check for legal flag value.
7560 	 */
7561 	switch (flag) {
7562 	case MSG_HIPRI:
7563 		if ((mctl->len < 0) || (pri != 0))
7564 			return (EINVAL);
7565 		break;
7566 	case MSG_BAND:
7567 		break;
7568 
7569 	default:
7570 		return (EINVAL);
7571 	}
7572 
7573 	TRACE_1(TR_FAC_STREAMS_FR, TR_STRPUTMSG_IN,
7574 	    "strputmsg in:stp %p", stp);
7575 
7576 	/* get these values from those cached in the stream head */
7577 	rmin = stp->sd_qn_minpsz;
7578 	rmax = stp->sd_qn_maxpsz;
7579 
7580 	/*
7581 	 * Make sure ctl and data sizes together fall within the
7582 	 * limits of the max and min receive packet sizes and do
7583 	 * not exceed system limit.
7584 	 */
7585 	ASSERT((rmax >= 0) || (rmax == INFPSZ));
7586 	if (rmax == 0) {
7587 		return (ERANGE);
7588 	}
7589 	/*
7590 	 * Use the MAXIMUM of sd_maxblk and q_maxpsz.
7591 	 * Needed to prevent partial failures in the strmakedata loop.
7592 	 */
7593 	if (stp->sd_maxblk != INFPSZ && rmax != INFPSZ && rmax < stp->sd_maxblk)
7594 		rmax = stp->sd_maxblk;
7595 
7596 	if ((msgsize = mdata->len) < 0) {
7597 		msgsize = 0;
7598 		rmin = 0;	/* no range check for NULL data part */
7599 	}
7600 	if ((msgsize < rmin) ||
7601 	    ((msgsize > rmax) && (rmax != INFPSZ)) ||
7602 	    (mctl->len > strctlsz)) {
7603 		return (ERANGE);
7604 	}
7605 
7606 	/*
7607 	 * Setup uio and iov for data part
7608 	 */
7609 	iovs.iov_base = mdata->buf;
7610 	iovs.iov_len = msgsize;
7611 	uios.uio_iov = &iovs;
7612 	uios.uio_iovcnt = 1;
7613 	uios.uio_loffset = 0;
7614 	uios.uio_segflg = UIO_USERSPACE;
7615 	uios.uio_fmode = fmode;
7616 	uios.uio_extflg = UIO_COPY_DEFAULT;
7617 	uios.uio_resid = msgsize;
7618 	uios.uio_offset = 0;
7619 
7620 	/* Ignore flow control in strput for HIPRI */
7621 	if (flag & MSG_HIPRI)
7622 		flag |= MSG_IGNFLOW;
7623 
7624 	for (;;) {
7625 		int done = 0;
7626 
7627 		/*
7628 		 * strput will always free the ctl mblk - even when strput
7629 		 * fails.
7630 		 */
7631 		if ((error = strmakectl(mctl, flag, fmode, &mp)) != 0) {
7632 			TRACE_3(TR_FAC_STREAMS_FR, TR_STRPUTMSG_OUT,
7633 			    "strputmsg out:stp %p out %d error %d",
7634 			    stp, 1, error);
7635 			return (error);
7636 		}
7637 		/*
7638 		 * Verify that the whole message can be transferred by
7639 		 * strput.
7640 		 */
7641 		ASSERT(stp->sd_maxblk == INFPSZ ||
7642 		    stp->sd_maxblk >= mdata->len);
7643 
7644 		msgsize = mdata->len;
7645 		error = strput(stp, mp, uiop, &msgsize, 0, pri, flag);
7646 		mdata->len = msgsize;
7647 
7648 		if (error == 0)
7649 			break;
7650 
7651 		if (error != EWOULDBLOCK)
7652 			goto out;
7653 
7654 		mutex_enter(&stp->sd_lock);
7655 		/*
7656 		 * Check for a missed wakeup.
7657 		 * Needed since strput did not hold sd_lock across
7658 		 * the canputnext.
7659 		 */
7660 		if (bcanputnext(wqp, pri)) {
7661 			/* Try again */
7662 			mutex_exit(&stp->sd_lock);
7663 			continue;
7664 		}
7665 		TRACE_2(TR_FAC_STREAMS_FR, TR_STRPUTMSG_WAIT,
7666 		    "strputmsg wait:stp %p waits pri %d", stp, pri);
7667 		if (((error = strwaitq(stp, WRITEWAIT, (ssize_t)0, fmode, -1,
7668 		    &done)) != 0) || done) {
7669 			mutex_exit(&stp->sd_lock);
7670 			TRACE_3(TR_FAC_STREAMS_FR, TR_STRPUTMSG_OUT,
7671 			    "strputmsg out:q %p out %d error %d",
7672 			    stp, 0, error);
7673 			return (error);
7674 		}
7675 		TRACE_1(TR_FAC_STREAMS_FR, TR_STRPUTMSG_WAKE,
7676 		    "strputmsg wake:stp %p wakes", stp);
7677 		if ((error = i_straccess(stp, JCWRITE)) != 0) {
7678 			mutex_exit(&stp->sd_lock);
7679 			return (error);
7680 		}
7681 		mutex_exit(&stp->sd_lock);
7682 	}
7683 out:
7684 	/*
7685 	 * For historic reasons, applications expect EAGAIN
7686 	 * when data mblk could not be allocated. so change
7687 	 * ENOMEM back to EAGAIN
7688 	 */
7689 	if (error == ENOMEM)
7690 		error = EAGAIN;
7691 	TRACE_3(TR_FAC_STREAMS_FR, TR_STRPUTMSG_OUT,
7692 	    "strputmsg out:stp %p out %d error %d", stp, 2, error);
7693 	return (error);
7694 }
7695 
7696 /*
7697  * Put a message downstream.
7698  * Can send only an M_PROTO/M_PCPROTO by passing in a NULL uiop.
7699  * The fmode flag (NDELAY, NONBLOCK) is the or of the flags in the uio
7700  * and the fmode parameter.
7701  *
7702  * This routine handles the consolidation private flags:
7703  *	MSG_IGNERROR	Ignore any stream head error except STPLEX.
7704  *	MSG_HOLDSIG	Hold signals while waiting for data.
7705  *	MSG_IGNFLOW	Don't check streams flow control.
7706  *
7707  * NOTE: strputmsg and kstrputmsg have much of the logic in common.
7708  */
7709 int
7710 kstrputmsg(
7711 	struct vnode *vp,
7712 	mblk_t *mctl,
7713 	struct uio *uiop,
7714 	ssize_t msgsize,
7715 	unsigned char pri,
7716 	int flag,
7717 	int fmode)
7718 {
7719 	struct stdata *stp;
7720 	queue_t *wqp;
7721 	ssize_t rmin, rmax;
7722 	int error;
7723 
7724 	ASSERT(vp->v_stream);
7725 	stp = vp->v_stream;
7726 	wqp = stp->sd_wrq;
7727 	if (audit_active)
7728 		audit_strputmsg(vp, NULL, NULL, pri, flag, fmode);
7729 	if (mctl == NULL)
7730 		return (EINVAL);
7731 
7732 	mutex_enter(&stp->sd_lock);
7733 
7734 	if ((error = i_straccess(stp, JCWRITE)) != 0) {
7735 		mutex_exit(&stp->sd_lock);
7736 		freemsg(mctl);
7737 		return (error);
7738 	}
7739 
7740 	if ((stp->sd_flag & STPLEX) || !(flag & MSG_IGNERROR)) {
7741 		if (stp->sd_flag & (STWRERR|STRHUP|STPLEX)) {
7742 			error = strwriteable(stp, B_FALSE, B_TRUE);
7743 			if (error != 0) {
7744 				mutex_exit(&stp->sd_lock);
7745 				freemsg(mctl);
7746 				return (error);
7747 			}
7748 		}
7749 	}
7750 
7751 	mutex_exit(&stp->sd_lock);
7752 
7753 	/*
7754 	 * Check for legal flag value.
7755 	 */
7756 	switch (flag & (MSG_HIPRI|MSG_BAND|MSG_ANY)) {
7757 	case MSG_HIPRI:
7758 		if (pri != 0) {
7759 			freemsg(mctl);
7760 			return (EINVAL);
7761 		}
7762 		break;
7763 	case MSG_BAND:
7764 		break;
7765 	default:
7766 		freemsg(mctl);
7767 		return (EINVAL);
7768 	}
7769 
7770 	TRACE_1(TR_FAC_STREAMS_FR, TR_KSTRPUTMSG_IN,
7771 	    "kstrputmsg in:stp %p", stp);
7772 
7773 	/* get these values from those cached in the stream head */
7774 	rmin = stp->sd_qn_minpsz;
7775 	rmax = stp->sd_qn_maxpsz;
7776 
7777 	/*
7778 	 * Make sure ctl and data sizes together fall within the
7779 	 * limits of the max and min receive packet sizes and do
7780 	 * not exceed system limit.
7781 	 */
7782 	ASSERT((rmax >= 0) || (rmax == INFPSZ));
7783 	if (rmax == 0) {
7784 		freemsg(mctl);
7785 		return (ERANGE);
7786 	}
7787 	/*
7788 	 * Use the MAXIMUM of sd_maxblk and q_maxpsz.
7789 	 * Needed to prevent partial failures in the strmakedata loop.
7790 	 */
7791 	if (stp->sd_maxblk != INFPSZ && rmax != INFPSZ && rmax < stp->sd_maxblk)
7792 		rmax = stp->sd_maxblk;
7793 
7794 	if (uiop == NULL) {
7795 		msgsize = -1;
7796 		rmin = -1;	/* no range check for NULL data part */
7797 	} else {
7798 		/* Use uio flags as well as the fmode parameter flags */
7799 		fmode |= uiop->uio_fmode;
7800 
7801 		if ((msgsize < rmin) ||
7802 		    ((msgsize > rmax) && (rmax != INFPSZ))) {
7803 			freemsg(mctl);
7804 			return (ERANGE);
7805 		}
7806 	}
7807 
7808 	/* Ignore flow control in strput for HIPRI */
7809 	if (flag & MSG_HIPRI)
7810 		flag |= MSG_IGNFLOW;
7811 
7812 	for (;;) {
7813 		int done = 0;
7814 		int waitflag;
7815 		mblk_t *mp;
7816 
7817 		/*
7818 		 * strput will always free the ctl mblk - even when strput
7819 		 * fails. If MSG_IGNFLOW is set then any error returned
7820 		 * will cause us to break the loop, so we don't need a copy
7821 		 * of the message. If MSG_IGNFLOW is not set, then we can
7822 		 * get hit by flow control and be forced to try again. In
7823 		 * this case we need to have a copy of the message. We
7824 		 * do this using copymsg since the message may get modified
7825 		 * by something below us.
7826 		 *
7827 		 * We've observed that many TPI providers do not check db_ref
7828 		 * on the control messages but blindly reuse them for the
7829 		 * T_OK_ACK/T_ERROR_ACK. Thus using copymsg is more
7830 		 * friendly to such providers than using dupmsg. Also, note
7831 		 * that sockfs uses MSG_IGNFLOW for all TPI control messages.
7832 		 * Only data messages are subject to flow control, hence
7833 		 * subject to this copymsg.
7834 		 */
7835 		if (flag & MSG_IGNFLOW) {
7836 			mp = mctl;
7837 			mctl = NULL;
7838 		} else {
7839 			do {
7840 				/*
7841 				 * If a message has a free pointer, the message
7842 				 * must be dupmsg to maintain this pointer.
7843 				 * Code using this facility must be sure
7844 				 * that modules below will not change the
7845 				 * contents of the dblk without checking db_ref
7846 				 * first. If db_ref is > 1, then the module
7847 				 * needs to do a copymsg first. Otherwise,
7848 				 * the contents of the dblk may become
7849 				 * inconsistent because the freesmg/freeb below
7850 				 * may end up calling atomic_add_32_nv.
7851 				 * The atomic_add_32_nv in freeb (accessing
7852 				 * all of db_ref, db_type, db_flags, and
7853 				 * db_struioflag) does not prevent other threads
7854 				 * from concurrently trying to modify e.g.
7855 				 * db_type.
7856 				 */
7857 				if (mctl->b_datap->db_frtnp != NULL)
7858 					mp = dupmsg(mctl);
7859 				else
7860 					mp = copymsg(mctl);
7861 
7862 				if (mp != NULL)
7863 					break;
7864 
7865 				error = strwaitbuf(msgdsize(mctl), BPRI_MED);
7866 				if (error) {
7867 					freemsg(mctl);
7868 					return (error);
7869 				}
7870 			} while (mp == NULL);
7871 		}
7872 		/*
7873 		 * Verify that all of msgsize can be transferred by
7874 		 * strput.
7875 		 */
7876 		ASSERT(stp->sd_maxblk == INFPSZ || stp->sd_maxblk >= msgsize);
7877 		error = strput(stp, mp, uiop, &msgsize, 0, pri, flag);
7878 		if (error == 0)
7879 			break;
7880 
7881 		if (error != EWOULDBLOCK)
7882 			goto out;
7883 
7884 		/*
7885 		 * IF MSG_IGNFLOW is set we should have broken out of loop
7886 		 * above.
7887 		 */
7888 		ASSERT(!(flag & MSG_IGNFLOW));
7889 		mutex_enter(&stp->sd_lock);
7890 		/*
7891 		 * Check for a missed wakeup.
7892 		 * Needed since strput did not hold sd_lock across
7893 		 * the canputnext.
7894 		 */
7895 		if (bcanputnext(wqp, pri)) {
7896 			/* Try again */
7897 			mutex_exit(&stp->sd_lock);
7898 			continue;
7899 		}
7900 		TRACE_2(TR_FAC_STREAMS_FR, TR_KSTRPUTMSG_WAIT,
7901 		    "kstrputmsg wait:stp %p waits pri %d", stp, pri);
7902 
7903 		waitflag = WRITEWAIT;
7904 		if (flag & (MSG_HOLDSIG|MSG_IGNERROR)) {
7905 			if (flag & MSG_HOLDSIG)
7906 				waitflag |= STR_NOSIG;
7907 			if (flag & MSG_IGNERROR)
7908 				waitflag |= STR_NOERROR;
7909 		}
7910 		if (((error = strwaitq(stp, waitflag,
7911 		    (ssize_t)0, fmode, -1, &done)) != 0) || done) {
7912 			mutex_exit(&stp->sd_lock);
7913 			TRACE_3(TR_FAC_STREAMS_FR, TR_KSTRPUTMSG_OUT,
7914 			    "kstrputmsg out:stp %p out %d error %d",
7915 			    stp, 0, error);
7916 			freemsg(mctl);
7917 			return (error);
7918 		}
7919 		TRACE_1(TR_FAC_STREAMS_FR, TR_KSTRPUTMSG_WAKE,
7920 		    "kstrputmsg wake:stp %p wakes", stp);
7921 		if ((error = i_straccess(stp, JCWRITE)) != 0) {
7922 			mutex_exit(&stp->sd_lock);
7923 			freemsg(mctl);
7924 			return (error);
7925 		}
7926 		mutex_exit(&stp->sd_lock);
7927 	}
7928 out:
7929 	freemsg(mctl);
7930 	/*
7931 	 * For historic reasons, applications expect EAGAIN
7932 	 * when data mblk could not be allocated. so change
7933 	 * ENOMEM back to EAGAIN
7934 	 */
7935 	if (error == ENOMEM)
7936 		error = EAGAIN;
7937 	TRACE_3(TR_FAC_STREAMS_FR, TR_KSTRPUTMSG_OUT,
7938 	    "kstrputmsg out:stp %p out %d error %d", stp, 2, error);
7939 	return (error);
7940 }
7941 
7942 /*
7943  * Determines whether the necessary conditions are set on a stream
7944  * for it to be readable, writeable, or have exceptions.
7945  *
7946  * strpoll handles the consolidation private events:
7947  *	POLLNOERR	Do not return POLLERR even if there are stream
7948  *			head errors.
7949  *			Used by sockfs.
7950  *	POLLRDDATA	Do not return POLLIN unless at least one message on
7951  *			the queue contains one or more M_DATA mblks. Thus
7952  *			when this flag is set a queue with only
7953  *			M_PROTO/M_PCPROTO mblks does not return POLLIN.
7954  *			Used by sockfs to ignore T_EXDATA_IND messages.
7955  *
7956  * Note: POLLRDDATA assumes that synch streams only return messages with
7957  * an M_DATA attached (i.e. not messages consisting of only
7958  * an M_PROTO/M_PCPROTO part).
7959  */
7960 int
7961 strpoll(
7962 	struct stdata *stp,
7963 	short events_arg,
7964 	int anyyet,
7965 	short *reventsp,
7966 	struct pollhead **phpp)
7967 {
7968 	int events = (ushort_t)events_arg;
7969 	int retevents = 0;
7970 	mblk_t *mp;
7971 	qband_t *qbp;
7972 	long sd_flags = stp->sd_flag;
7973 	int headlocked = 0;
7974 
7975 	/*
7976 	 * For performance, a single 'if' tests for most possible edge
7977 	 * conditions in one shot
7978 	 */
7979 	if (sd_flags & (STPLEX | STRDERR | STWRERR)) {
7980 		if (sd_flags & STPLEX) {
7981 			*reventsp = POLLNVAL;
7982 			return (EINVAL);
7983 		}
7984 		if (((events & (POLLIN | POLLRDNORM | POLLRDBAND | POLLPRI)) &&
7985 		    (sd_flags & STRDERR)) ||
7986 		    ((events & (POLLOUT | POLLWRNORM | POLLWRBAND)) &&
7987 		    (sd_flags & STWRERR))) {
7988 			if (!(events & POLLNOERR)) {
7989 				*reventsp = POLLERR;
7990 				return (0);
7991 			}
7992 		}
7993 	}
7994 	if (sd_flags & STRHUP) {
7995 		retevents |= POLLHUP;
7996 	} else if (events & (POLLWRNORM | POLLWRBAND)) {
7997 		queue_t *tq;
7998 		queue_t	*qp = stp->sd_wrq;
7999 
8000 		claimstr(qp);
8001 		/* Find next module forward that has a service procedure */
8002 		tq = qp->q_next->q_nfsrv;
8003 		ASSERT(tq != NULL);
8004 
8005 		polllock(&stp->sd_pollist, QLOCK(tq));
8006 		if (events & POLLWRNORM) {
8007 			queue_t *sqp;
8008 
8009 			if (tq->q_flag & QFULL)
8010 				/* ensure backq svc procedure runs */
8011 				tq->q_flag |= QWANTW;
8012 			else if ((sqp = stp->sd_struiowrq) != NULL) {
8013 				/* Check sync stream barrier write q */
8014 				mutex_exit(QLOCK(tq));
8015 				polllock(&stp->sd_pollist, QLOCK(sqp));
8016 				if (sqp->q_flag & QFULL)
8017 					/* ensure pollwakeup() is done */
8018 					sqp->q_flag |= QWANTWSYNC;
8019 				else
8020 					retevents |= POLLOUT;
8021 				/* More write events to process ??? */
8022 				if (! (events & POLLWRBAND)) {
8023 					mutex_exit(QLOCK(sqp));
8024 					releasestr(qp);
8025 					goto chkrd;
8026 				}
8027 				mutex_exit(QLOCK(sqp));
8028 				polllock(&stp->sd_pollist, QLOCK(tq));
8029 			} else
8030 				retevents |= POLLOUT;
8031 		}
8032 		if (events & POLLWRBAND) {
8033 			qbp = tq->q_bandp;
8034 			if (qbp) {
8035 				while (qbp) {
8036 					if (qbp->qb_flag & QB_FULL)
8037 						qbp->qb_flag |= QB_WANTW;
8038 					else
8039 						retevents |= POLLWRBAND;
8040 					qbp = qbp->qb_next;
8041 				}
8042 			} else {
8043 				retevents |= POLLWRBAND;
8044 			}
8045 		}
8046 		mutex_exit(QLOCK(tq));
8047 		releasestr(qp);
8048 	}
8049 chkrd:
8050 	if (sd_flags & STRPRI) {
8051 		retevents |= (events & POLLPRI);
8052 	} else if (events & (POLLRDNORM | POLLRDBAND | POLLIN)) {
8053 		queue_t	*qp = _RD(stp->sd_wrq);
8054 		int normevents = (events & (POLLIN | POLLRDNORM));
8055 
8056 		/*
8057 		 * Note: Need to do polllock() here since ps_lock may be
8058 		 * held. See bug 4191544.
8059 		 */
8060 		polllock(&stp->sd_pollist, &stp->sd_lock);
8061 		headlocked = 1;
8062 		mp = qp->q_first;
8063 		while (mp) {
8064 			/*
8065 			 * For POLLRDDATA we scan b_cont and b_next until we
8066 			 * find an M_DATA.
8067 			 */
8068 			if ((events & POLLRDDATA) &&
8069 			    mp->b_datap->db_type != M_DATA) {
8070 				mblk_t *nmp = mp->b_cont;
8071 
8072 				while (nmp != NULL &&
8073 				    nmp->b_datap->db_type != M_DATA)
8074 					nmp = nmp->b_cont;
8075 				if (nmp == NULL) {
8076 					mp = mp->b_next;
8077 					continue;
8078 				}
8079 			}
8080 			if (mp->b_band == 0)
8081 				retevents |= normevents;
8082 			else
8083 				retevents |= (events & (POLLIN | POLLRDBAND));
8084 			break;
8085 		}
8086 		if (! (retevents & normevents) &&
8087 		    (stp->sd_wakeq & RSLEEP)) {
8088 			/*
8089 			 * Sync stream barrier read queue has data.
8090 			 */
8091 			retevents |= normevents;
8092 		}
8093 		/* Treat eof as normal data */
8094 		if (sd_flags & STREOF)
8095 			retevents |= normevents;
8096 	}
8097 
8098 	*reventsp = (short)retevents;
8099 	if (retevents) {
8100 		if (headlocked)
8101 			mutex_exit(&stp->sd_lock);
8102 		return (0);
8103 	}
8104 
8105 	/*
8106 	 * If poll() has not found any events yet, set up event cell
8107 	 * to wake up the poll if a requested event occurs on this
8108 	 * stream.  Check for collisions with outstanding poll requests.
8109 	 */
8110 	if (!anyyet) {
8111 		*phpp = &stp->sd_pollist;
8112 		if (headlocked == 0) {
8113 			polllock(&stp->sd_pollist, &stp->sd_lock);
8114 			headlocked = 1;
8115 		}
8116 		stp->sd_rput_opt |= SR_POLLIN;
8117 	}
8118 	if (headlocked)
8119 		mutex_exit(&stp->sd_lock);
8120 	return (0);
8121 }
8122 
8123 /*
8124  * The purpose of putback() is to assure sleeping polls/reads
8125  * are awakened when there are no new messages arriving at the,
8126  * stream head, and a message is placed back on the read queue.
8127  *
8128  * sd_lock must be held when messages are placed back on stream
8129  * head.  (getq() holds sd_lock when it removes messages from
8130  * the queue)
8131  */
8132 
8133 static void
8134 putback(struct stdata *stp, queue_t *q, mblk_t *bp, int band)
8135 {
8136 	mblk_t	*qfirst = q->q_first;
8137 	ASSERT(MUTEX_HELD(&stp->sd_lock));
8138 
8139 	if ((stp->sd_rput_opt & SR_CONSOL_DATA) &&
8140 	    (qfirst != NULL) &&
8141 	    (qfirst->b_datap->db_type == M_DATA) &&
8142 	    ((qfirst->b_flag & (MSGMARK|MSGDELIM)) == 0)) {
8143 		/*
8144 		 * We use the same logic as defined in strrput()
8145 		 * but in reverse as we are putting back onto the
8146 		 * queue and want to retain byte ordering.
8147 		 * Consolidate an M_DATA message onto an M_DATA,
8148 		 * M_PROTO, or M_PCPROTO by merging it with q_first.
8149 		 * The consolidation does not take place if the message
8150 		 * we are returning to the queue is marked with either
8151 		 * of the marks or the delim flag or if q_first
8152 		 * is marked with MSGMARK. The MSGMARK check is needed to
8153 		 * handle the odd semantics of MSGMARK where essentially
8154 		 * the whole message is to be treated as marked.
8155 		 * Carry any MSGMARKNEXT and MSGNOTMARKNEXT from q_first
8156 		 * to the front of the b_cont chain.
8157 		 */
8158 		unsigned char db_type = bp->b_datap->db_type;
8159 
8160 		if ((db_type == M_DATA || db_type == M_PROTO ||
8161 		    db_type == M_PCPROTO) &&
8162 		    !(bp->b_flag & (MSGMARK|MSGDELIM|MSGMARKNEXT))) {
8163 			rmvq_noenab(q, qfirst);
8164 			/*
8165 			 * The first message in the b_cont list
8166 			 * tracks MSGMARKNEXT and MSGNOTMARKNEXT.
8167 			 * We need to handle the case where we
8168 			 * are appending:
8169 			 *
8170 			 * 1) a MSGMARKNEXT to a MSGNOTMARKNEXT.
8171 			 * 2) a MSGMARKNEXT to a plain message.
8172 			 * 3) a MSGNOTMARKNEXT to a plain message
8173 			 * 4) a MSGNOTMARKNEXT to a MSGNOTMARKNEXT
8174 			 *    message.
8175 			 *
8176 			 * Thus we never append a MSGMARKNEXT or
8177 			 * MSGNOTMARKNEXT to a MSGMARKNEXT message.
8178 			 */
8179 			if (qfirst->b_flag & MSGMARKNEXT) {
8180 				bp->b_flag |= MSGMARKNEXT;
8181 				bp->b_flag &= ~MSGNOTMARKNEXT;
8182 				qfirst->b_flag &= ~MSGMARKNEXT;
8183 			} else if (qfirst->b_flag & MSGNOTMARKNEXT) {
8184 				bp->b_flag |= MSGNOTMARKNEXT;
8185 				qfirst->b_flag &= ~MSGNOTMARKNEXT;
8186 			}
8187 
8188 			linkb(bp, qfirst);
8189 		}
8190 	}
8191 	(void) putbq(q, bp);
8192 
8193 	/*
8194 	 * A message may have come in when the sd_lock was dropped in the
8195 	 * calling routine. If this is the case and STR*ATMARK info was
8196 	 * received, need to move that from the stream head to the q_last
8197 	 * so that SIOCATMARK can return the proper value.
8198 	 */
8199 	if (stp->sd_flag & (STRATMARK | STRNOTATMARK)) {
8200 		unsigned short *flagp = &q->q_last->b_flag;
8201 		uint_t b_flag = (uint_t)*flagp;
8202 
8203 		if (stp->sd_flag & STRATMARK) {
8204 			b_flag &= ~MSGNOTMARKNEXT;
8205 			b_flag |= MSGMARKNEXT;
8206 			stp->sd_flag &= ~STRATMARK;
8207 		} else {
8208 			b_flag &= ~MSGMARKNEXT;
8209 			b_flag |= MSGNOTMARKNEXT;
8210 			stp->sd_flag &= ~STRNOTATMARK;
8211 		}
8212 		*flagp = (unsigned short) b_flag;
8213 	}
8214 
8215 #ifdef	DEBUG
8216 	/*
8217 	 * Make sure that the flags are not messed up.
8218 	 */
8219 	{
8220 		mblk_t *mp;
8221 		mp = q->q_last;
8222 		while (mp != NULL) {
8223 			ASSERT((mp->b_flag & (MSGMARKNEXT|MSGNOTMARKNEXT)) !=
8224 			    (MSGMARKNEXT|MSGNOTMARKNEXT));
8225 			mp = mp->b_cont;
8226 		}
8227 	}
8228 #endif
8229 	if (q->q_first == bp) {
8230 		short pollevents;
8231 
8232 		if (stp->sd_flag & RSLEEP) {
8233 			stp->sd_flag &= ~RSLEEP;
8234 			cv_broadcast(&q->q_wait);
8235 		}
8236 		if (stp->sd_flag & STRPRI) {
8237 			pollevents = POLLPRI;
8238 		} else {
8239 			if (band == 0) {
8240 				if (!(stp->sd_rput_opt & SR_POLLIN))
8241 					return;
8242 				stp->sd_rput_opt &= ~SR_POLLIN;
8243 				pollevents = POLLIN | POLLRDNORM;
8244 			} else {
8245 				pollevents = POLLIN | POLLRDBAND;
8246 			}
8247 		}
8248 		mutex_exit(&stp->sd_lock);
8249 		pollwakeup(&stp->sd_pollist, pollevents);
8250 		mutex_enter(&stp->sd_lock);
8251 	}
8252 }
8253 
8254 /*
8255  * Return the held vnode attached to the stream head of a
8256  * given queue
8257  * It is the responsibility of the calling routine to ensure
8258  * that the queue does not go away (e.g. pop).
8259  */
8260 vnode_t *
8261 strq2vp(queue_t *qp)
8262 {
8263 	vnode_t *vp;
8264 	vp = STREAM(qp)->sd_vnode;
8265 	ASSERT(vp != NULL);
8266 	VN_HOLD(vp);
8267 	return (vp);
8268 }
8269 
8270 /*
8271  * return the stream head write queue for the given vp
8272  * It is the responsibility of the calling routine to ensure
8273  * that the stream or vnode do not close.
8274  */
8275 queue_t *
8276 strvp2wq(vnode_t *vp)
8277 {
8278 	ASSERT(vp->v_stream != NULL);
8279 	return (vp->v_stream->sd_wrq);
8280 }
8281 
8282 /*
8283  * pollwakeup stream head
8284  * It is the responsibility of the calling routine to ensure
8285  * that the stream or vnode do not close.
8286  */
8287 void
8288 strpollwakeup(vnode_t *vp, short event)
8289 {
8290 	ASSERT(vp->v_stream);
8291 	pollwakeup(&vp->v_stream->sd_pollist, event);
8292 }
8293 
8294 /*
8295  * Mate the stream heads of two vnodes together. If the two vnodes are the
8296  * same, we just make the write-side point at the read-side -- otherwise,
8297  * we do a full mate.  Only works on vnodes associated with streams that are
8298  * still being built and thus have only a stream head.
8299  */
8300 void
8301 strmate(vnode_t *vp1, vnode_t *vp2)
8302 {
8303 	queue_t *wrq1 = strvp2wq(vp1);
8304 	queue_t *wrq2 = strvp2wq(vp2);
8305 
8306 	/*
8307 	 * Verify that there are no modules on the stream yet.  We also
8308 	 * rely on the stream head always having a service procedure to
8309 	 * avoid tweaking q_nfsrv.
8310 	 */
8311 	ASSERT(wrq1->q_next == NULL && wrq2->q_next == NULL);
8312 	ASSERT(wrq1->q_qinfo->qi_srvp != NULL);
8313 	ASSERT(wrq2->q_qinfo->qi_srvp != NULL);
8314 
8315 	/*
8316 	 * If the queues are the same, just twist; otherwise do a full mate.
8317 	 */
8318 	if (wrq1 == wrq2) {
8319 		wrq1->q_next = _RD(wrq1);
8320 	} else {
8321 		wrq1->q_next = _RD(wrq2);
8322 		wrq2->q_next = _RD(wrq1);
8323 		STREAM(wrq1)->sd_mate = STREAM(wrq2);
8324 		STREAM(wrq1)->sd_flag |= STRMATE;
8325 		STREAM(wrq2)->sd_mate = STREAM(wrq1);
8326 		STREAM(wrq2)->sd_flag |= STRMATE;
8327 	}
8328 }
8329 
8330 /*
8331  * XXX will go away when console is correctly fixed.
8332  * Clean up the console PIDS, from previous I_SETSIG,
8333  * called only for cnopen which never calls strclean().
8334  */
8335 void
8336 str_cn_clean(struct vnode *vp)
8337 {
8338 	strsig_t *ssp, *pssp, *tssp;
8339 	struct stdata *stp;
8340 	struct pid  *pidp;
8341 	int update = 0;
8342 
8343 	ASSERT(vp->v_stream);
8344 	stp = vp->v_stream;
8345 	pssp = NULL;
8346 	mutex_enter(&stp->sd_lock);
8347 	ssp = stp->sd_siglist;
8348 	while (ssp) {
8349 		mutex_enter(&pidlock);
8350 		pidp = ssp->ss_pidp;
8351 		/*
8352 		 * Get rid of PID if the proc is gone.
8353 		 */
8354 		if (pidp->pid_prinactive) {
8355 			tssp = ssp->ss_next;
8356 			if (pssp)
8357 				pssp->ss_next = tssp;
8358 			else
8359 				stp->sd_siglist = tssp;
8360 			ASSERT(pidp->pid_ref <= 1);
8361 			PID_RELE(ssp->ss_pidp);
8362 			mutex_exit(&pidlock);
8363 			kmem_free(ssp, sizeof (strsig_t));
8364 			update = 1;
8365 			ssp = tssp;
8366 			continue;
8367 		} else
8368 			mutex_exit(&pidlock);
8369 		pssp = ssp;
8370 		ssp = ssp->ss_next;
8371 	}
8372 	if (update) {
8373 		stp->sd_sigflags = 0;
8374 		for (ssp = stp->sd_siglist; ssp; ssp = ssp->ss_next)
8375 			stp->sd_sigflags |= ssp->ss_events;
8376 	}
8377 	mutex_exit(&stp->sd_lock);
8378 }
8379 
8380 /*
8381  * Return B_TRUE if there is data in the message, B_FALSE otherwise.
8382  */
8383 static boolean_t
8384 msghasdata(mblk_t *bp)
8385 {
8386 	for (; bp; bp = bp->b_cont)
8387 		if (bp->b_datap->db_type == M_DATA) {
8388 			ASSERT(bp->b_wptr >= bp->b_rptr);
8389 			if (bp->b_wptr > bp->b_rptr)
8390 				return (B_TRUE);
8391 		}
8392 	return (B_FALSE);
8393 }
8394