xref: /freebsd/sys/rpc/svc_vc.c (revision 050570efa79efcc9cf5adeb545f1a679c8dc377b)
1 /*	$NetBSD: svc_vc.c,v 1.7 2000/08/03 00:01:53 fvdl Exp $	*/
2 
3 /*
4  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
5  * unrestricted use provided that this legend is included on all tape
6  * media and as a part of the software program in whole or part.  Users
7  * may copy or modify Sun RPC without charge, but are not authorized
8  * to license or distribute it to anyone else except as part of a product or
9  * program developed by the user.
10  *
11  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
12  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
13  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
14  *
15  * Sun RPC is provided with no support and without any obligation on the
16  * part of Sun Microsystems, Inc. to assist in its use, correction,
17  * modification or enhancement.
18  *
19  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
20  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
21  * OR ANY PART THEREOF.
22  *
23  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
24  * or profits or other special, indirect and consequential damages, even if
25  * Sun has been advised of the possibility of such damages.
26  *
27  * Sun Microsystems, Inc.
28  * 2550 Garcia Avenue
29  * Mountain View, California  94043
30  */
31 
32 #if defined(LIBC_SCCS) && !defined(lint)
33 static char *sccsid2 = "@(#)svc_tcp.c 1.21 87/08/11 Copyr 1984 Sun Micro";
34 static char *sccsid = "@(#)svc_tcp.c	2.2 88/08/01 4.0 RPCSRC";
35 #endif
36 #include <sys/cdefs.h>
37 __FBSDID("$FreeBSD$");
38 
39 /*
40  * svc_vc.c, Server side for Connection Oriented based RPC.
41  *
42  * Actually implements two flavors of transporter -
43  * a tcp rendezvouser (a listner and connection establisher)
44  * and a record/tcp stream.
45  */
46 
47 #include <sys/param.h>
48 #include <sys/lock.h>
49 #include <sys/kernel.h>
50 #include <sys/malloc.h>
51 #include <sys/mbuf.h>
52 #include <sys/mutex.h>
53 #include <sys/proc.h>
54 #include <sys/protosw.h>
55 #include <sys/queue.h>
56 #include <sys/socket.h>
57 #include <sys/socketvar.h>
58 #include <sys/sx.h>
59 #include <sys/systm.h>
60 #include <sys/uio.h>
61 
62 #include <net/vnet.h>
63 
64 #include <netinet/tcp.h>
65 
66 #include <rpc/rpc.h>
67 
68 #include <rpc/rpc_com.h>
69 
70 #include <security/mac/mac_framework.h>
71 
72 static bool_t svc_vc_rendezvous_recv(SVCXPRT *, struct rpc_msg *,
73     struct sockaddr **, struct mbuf **);
74 static enum xprt_stat svc_vc_rendezvous_stat(SVCXPRT *);
75 static void svc_vc_rendezvous_destroy(SVCXPRT *);
76 static bool_t svc_vc_null(void);
77 static void svc_vc_destroy(SVCXPRT *);
78 static enum xprt_stat svc_vc_stat(SVCXPRT *);
79 static bool_t svc_vc_recv(SVCXPRT *, struct rpc_msg *,
80     struct sockaddr **, struct mbuf **);
81 static bool_t svc_vc_reply(SVCXPRT *, struct rpc_msg *,
82     struct sockaddr *, struct mbuf *);
83 static bool_t svc_vc_control(SVCXPRT *xprt, const u_int rq, void *in);
84 static bool_t svc_vc_rendezvous_control (SVCXPRT *xprt, const u_int rq,
85     void *in);
86 static SVCXPRT *svc_vc_create_conn(SVCPOOL *pool, struct socket *so,
87     struct sockaddr *raddr);
88 static int svc_vc_accept(struct socket *head, struct socket **sop);
89 static int svc_vc_soupcall(struct socket *so, void *arg, int waitflag);
90 
91 static struct xp_ops svc_vc_rendezvous_ops = {
92 	.xp_recv =	svc_vc_rendezvous_recv,
93 	.xp_stat =	svc_vc_rendezvous_stat,
94 	.xp_reply =	(bool_t (*)(SVCXPRT *, struct rpc_msg *,
95 		struct sockaddr *, struct mbuf *))svc_vc_null,
96 	.xp_destroy =	svc_vc_rendezvous_destroy,
97 	.xp_control =	svc_vc_rendezvous_control
98 };
99 
100 static struct xp_ops svc_vc_ops = {
101 	.xp_recv =	svc_vc_recv,
102 	.xp_stat =	svc_vc_stat,
103 	.xp_reply =	svc_vc_reply,
104 	.xp_destroy =	svc_vc_destroy,
105 	.xp_control =	svc_vc_control
106 };
107 
108 struct cf_conn {  /* kept in xprt->xp_p1 for actual connection */
109 	enum xprt_stat strm_stat;
110 	struct mbuf *mpending;	/* unparsed data read from the socket */
111 	struct mbuf *mreq;	/* current record being built from mpending */
112 	uint32_t resid;		/* number of bytes needed for fragment */
113 	bool_t eor;		/* reading last fragment of current record */
114 };
115 
116 /*
117  * Usage:
118  *	xprt = svc_vc_create(sock, send_buf_size, recv_buf_size);
119  *
120  * Creates, registers, and returns a (rpc) tcp based transporter.
121  * Once *xprt is initialized, it is registered as a transporter
122  * see (svc.h, xprt_register).  This routine returns
123  * a NULL if a problem occurred.
124  *
125  * The filedescriptor passed in is expected to refer to a bound, but
126  * not yet connected socket.
127  *
128  * Since streams do buffered io similar to stdio, the caller can specify
129  * how big the send and receive buffers are via the second and third parms;
130  * 0 => use the system default.
131  */
132 SVCXPRT *
133 svc_vc_create(SVCPOOL *pool, struct socket *so, size_t sendsize,
134     size_t recvsize)
135 {
136 	SVCXPRT *xprt;
137 	struct sockaddr* sa;
138 	int error;
139 
140 	if (so->so_state & SS_ISCONNECTED) {
141 		error = so->so_proto->pr_usrreqs->pru_peeraddr(so, &sa);
142 		if (error)
143 			return (NULL);
144 		xprt = svc_vc_create_conn(pool, so, sa);
145 		free(sa, M_SONAME);
146 		return (xprt);
147 	}
148 
149 	xprt = svc_xprt_alloc();
150 	sx_init(&xprt->xp_lock, "xprt->xp_lock");
151 	xprt->xp_pool = pool;
152 	xprt->xp_socket = so;
153 	xprt->xp_p1 = NULL;
154 	xprt->xp_p2 = NULL;
155 	xprt->xp_ops = &svc_vc_rendezvous_ops;
156 
157 	CURVNET_SET(so->so_vnet);
158 	error = so->so_proto->pr_usrreqs->pru_sockaddr(so, &sa);
159 	if (error) {
160 		CURVNET_RESTORE();
161 		goto cleanup_svc_vc_create;
162 	}
163 
164 	memcpy(&xprt->xp_ltaddr, sa, sa->sa_len);
165 	free(sa, M_SONAME);
166 
167 	xprt_register(xprt);
168 
169 	solisten(so, SOMAXCONN, curthread);
170 	CURVNET_RESTORE();
171 
172 	SOCKBUF_LOCK(&so->so_rcv);
173 	xprt->xp_upcallset = 1;
174 	soupcall_set(so, SO_RCV, svc_vc_soupcall, xprt);
175 	SOCKBUF_UNLOCK(&so->so_rcv);
176 
177 	return (xprt);
178 cleanup_svc_vc_create:
179 	if (xprt)
180 		svc_xprt_free(xprt);
181 	return (NULL);
182 }
183 
184 /*
185  * Create a new transport for a socket optained via soaccept().
186  */
187 SVCXPRT *
188 svc_vc_create_conn(SVCPOOL *pool, struct socket *so, struct sockaddr *raddr)
189 {
190 	SVCXPRT *xprt = NULL;
191 	struct cf_conn *cd = NULL;
192 	struct sockaddr* sa = NULL;
193 	struct sockopt opt;
194 	int one = 1;
195 	int error;
196 
197 	bzero(&opt, sizeof(struct sockopt));
198 	opt.sopt_dir = SOPT_SET;
199 	opt.sopt_level = SOL_SOCKET;
200 	opt.sopt_name = SO_KEEPALIVE;
201 	opt.sopt_val = &one;
202 	opt.sopt_valsize = sizeof(one);
203 	CURVNET_SET(so->so_vnet);
204 	error = sosetopt(so, &opt);
205 	if (error) {
206 		CURVNET_RESTORE();
207 		return (NULL);
208 	}
209 
210 	if (so->so_proto->pr_protocol == IPPROTO_TCP) {
211 		bzero(&opt, sizeof(struct sockopt));
212 		opt.sopt_dir = SOPT_SET;
213 		opt.sopt_level = IPPROTO_TCP;
214 		opt.sopt_name = TCP_NODELAY;
215 		opt.sopt_val = &one;
216 		opt.sopt_valsize = sizeof(one);
217 		error = sosetopt(so, &opt);
218 		if (error) {
219 			CURVNET_RESTORE();
220 			return (NULL);
221 		}
222 	}
223 	CURVNET_RESTORE();
224 
225 	cd = mem_alloc(sizeof(*cd));
226 	cd->strm_stat = XPRT_IDLE;
227 
228 	xprt = svc_xprt_alloc();
229 	sx_init(&xprt->xp_lock, "xprt->xp_lock");
230 	xprt->xp_pool = pool;
231 	xprt->xp_socket = so;
232 	xprt->xp_p1 = cd;
233 	xprt->xp_p2 = NULL;
234 	xprt->xp_ops = &svc_vc_ops;
235 
236 	/*
237 	 * See http://www.connectathon.org/talks96/nfstcp.pdf - client
238 	 * has a 5 minute timer, server has a 6 minute timer.
239 	 */
240 	xprt->xp_idletimeout = 6 * 60;
241 
242 	memcpy(&xprt->xp_rtaddr, raddr, raddr->sa_len);
243 
244 	error = so->so_proto->pr_usrreqs->pru_sockaddr(so, &sa);
245 	if (error)
246 		goto cleanup_svc_vc_create;
247 
248 	memcpy(&xprt->xp_ltaddr, sa, sa->sa_len);
249 	free(sa, M_SONAME);
250 
251 	xprt_register(xprt);
252 
253 	SOCKBUF_LOCK(&so->so_rcv);
254 	xprt->xp_upcallset = 1;
255 	soupcall_set(so, SO_RCV, svc_vc_soupcall, xprt);
256 	SOCKBUF_UNLOCK(&so->so_rcv);
257 
258 	/*
259 	 * Throw the transport into the active list in case it already
260 	 * has some data buffered.
261 	 */
262 	sx_xlock(&xprt->xp_lock);
263 	xprt_active(xprt);
264 	sx_xunlock(&xprt->xp_lock);
265 
266 	return (xprt);
267 cleanup_svc_vc_create:
268 	if (xprt) {
269 		mem_free(xprt, sizeof(*xprt));
270 	}
271 	if (cd)
272 		mem_free(cd, sizeof(*cd));
273 	return (NULL);
274 }
275 
276 /*
277  * This does all of the accept except the final call to soaccept. The
278  * caller will call soaccept after dropping its locks (soaccept may
279  * call malloc).
280  */
281 int
282 svc_vc_accept(struct socket *head, struct socket **sop)
283 {
284 	int error = 0;
285 	struct socket *so;
286 
287 	if ((head->so_options & SO_ACCEPTCONN) == 0) {
288 		error = EINVAL;
289 		goto done;
290 	}
291 #ifdef MAC
292 	error = mac_socket_check_accept(curthread->td_ucred, head);
293 	if (error != 0)
294 		goto done;
295 #endif
296 	ACCEPT_LOCK();
297 	if (TAILQ_EMPTY(&head->so_comp)) {
298 		ACCEPT_UNLOCK();
299 		error = EWOULDBLOCK;
300 		goto done;
301 	}
302 	so = TAILQ_FIRST(&head->so_comp);
303 	KASSERT(!(so->so_qstate & SQ_INCOMP), ("svc_vc_accept: so SQ_INCOMP"));
304 	KASSERT(so->so_qstate & SQ_COMP, ("svc_vc_accept: so not SQ_COMP"));
305 
306 	/*
307 	 * Before changing the flags on the socket, we have to bump the
308 	 * reference count.  Otherwise, if the protocol calls sofree(),
309 	 * the socket will be released due to a zero refcount.
310 	 * XXX might not need soref() since this is simpler than kern_accept.
311 	 */
312 	SOCK_LOCK(so);			/* soref() and so_state update */
313 	soref(so);			/* file descriptor reference */
314 
315 	TAILQ_REMOVE(&head->so_comp, so, so_list);
316 	head->so_qlen--;
317 	so->so_state |= (head->so_state & SS_NBIO);
318 	so->so_qstate &= ~SQ_COMP;
319 	so->so_head = NULL;
320 
321 	SOCK_UNLOCK(so);
322 	ACCEPT_UNLOCK();
323 
324 	*sop = so;
325 
326 	/* connection has been removed from the listen queue */
327 	KNOTE_UNLOCKED(&head->so_rcv.sb_sel.si_note, 0);
328 done:
329 	return (error);
330 }
331 
332 /*ARGSUSED*/
333 static bool_t
334 svc_vc_rendezvous_recv(SVCXPRT *xprt, struct rpc_msg *msg,
335     struct sockaddr **addrp, struct mbuf **mp)
336 {
337 	struct socket *so = NULL;
338 	struct sockaddr *sa = NULL;
339 	int error;
340 	SVCXPRT *new_xprt;
341 
342 	/*
343 	 * The socket upcall calls xprt_active() which will eventually
344 	 * cause the server to call us here. We attempt to accept a
345 	 * connection from the socket and turn it into a new
346 	 * transport. If the accept fails, we have drained all pending
347 	 * connections so we call xprt_inactive().
348 	 */
349 	sx_xlock(&xprt->xp_lock);
350 
351 	error = svc_vc_accept(xprt->xp_socket, &so);
352 
353 	if (error == EWOULDBLOCK) {
354 		/*
355 		 * We must re-test for new connections after taking
356 		 * the lock to protect us in the case where a new
357 		 * connection arrives after our call to accept fails
358 		 * with EWOULDBLOCK. The pool lock protects us from
359 		 * racing the upcall after our TAILQ_EMPTY() call
360 		 * returns false.
361 		 */
362 		ACCEPT_LOCK();
363 		mtx_lock(&xprt->xp_pool->sp_lock);
364 		if (TAILQ_EMPTY(&xprt->xp_socket->so_comp))
365 			xprt_inactive_locked(xprt);
366 		mtx_unlock(&xprt->xp_pool->sp_lock);
367 		ACCEPT_UNLOCK();
368 		sx_xunlock(&xprt->xp_lock);
369 		return (FALSE);
370 	}
371 
372 	if (error) {
373 		SOCKBUF_LOCK(&xprt->xp_socket->so_rcv);
374 		if (xprt->xp_upcallset) {
375 			xprt->xp_upcallset = 0;
376 			soupcall_clear(xprt->xp_socket, SO_RCV);
377 		}
378 		SOCKBUF_UNLOCK(&xprt->xp_socket->so_rcv);
379 		xprt_inactive(xprt);
380 		sx_xunlock(&xprt->xp_lock);
381 		return (FALSE);
382 	}
383 
384 	sx_xunlock(&xprt->xp_lock);
385 
386 	sa = 0;
387 	error = soaccept(so, &sa);
388 
389 	if (error) {
390 		/*
391 		 * XXX not sure if I need to call sofree or soclose here.
392 		 */
393 		if (sa)
394 			free(sa, M_SONAME);
395 		return (FALSE);
396 	}
397 
398 	/*
399 	 * svc_vc_create_conn will call xprt_register - we don't need
400 	 * to do anything with the new connection except derefence it.
401 	 */
402 	new_xprt = svc_vc_create_conn(xprt->xp_pool, so, sa);
403 	if (!new_xprt) {
404 		soclose(so);
405 	} else {
406 		SVC_RELEASE(new_xprt);
407 	}
408 
409 	free(sa, M_SONAME);
410 
411 	return (FALSE); /* there is never an rpc msg to be processed */
412 }
413 
414 /*ARGSUSED*/
415 static enum xprt_stat
416 svc_vc_rendezvous_stat(SVCXPRT *xprt)
417 {
418 
419 	return (XPRT_IDLE);
420 }
421 
422 static void
423 svc_vc_destroy_common(SVCXPRT *xprt)
424 {
425 	SOCKBUF_LOCK(&xprt->xp_socket->so_rcv);
426 	if (xprt->xp_upcallset) {
427 		xprt->xp_upcallset = 0;
428 		soupcall_clear(xprt->xp_socket, SO_RCV);
429 	}
430 	SOCKBUF_UNLOCK(&xprt->xp_socket->so_rcv);
431 
432 	sx_destroy(&xprt->xp_lock);
433 	if (xprt->xp_socket)
434 		(void)soclose(xprt->xp_socket);
435 
436 	if (xprt->xp_netid)
437 		(void) mem_free(xprt->xp_netid, strlen(xprt->xp_netid) + 1);
438 	svc_xprt_free(xprt);
439 }
440 
441 static void
442 svc_vc_rendezvous_destroy(SVCXPRT *xprt)
443 {
444 
445 	svc_vc_destroy_common(xprt);
446 }
447 
448 static void
449 svc_vc_destroy(SVCXPRT *xprt)
450 {
451 	struct cf_conn *cd = (struct cf_conn *)xprt->xp_p1;
452 
453 	svc_vc_destroy_common(xprt);
454 
455 	if (cd->mreq)
456 		m_freem(cd->mreq);
457 	if (cd->mpending)
458 		m_freem(cd->mpending);
459 	mem_free(cd, sizeof(*cd));
460 }
461 
462 /*ARGSUSED*/
463 static bool_t
464 svc_vc_control(SVCXPRT *xprt, const u_int rq, void *in)
465 {
466 	return (FALSE);
467 }
468 
469 static bool_t
470 svc_vc_rendezvous_control(SVCXPRT *xprt, const u_int rq, void *in)
471 {
472 
473 	return (FALSE);
474 }
475 
476 static enum xprt_stat
477 svc_vc_stat(SVCXPRT *xprt)
478 {
479 	struct cf_conn *cd;
480 	struct mbuf *m;
481 	size_t n;
482 
483 	cd = (struct cf_conn *)(xprt->xp_p1);
484 
485 	if (cd->strm_stat == XPRT_DIED)
486 		return (XPRT_DIED);
487 
488 	/*
489 	 * Return XPRT_MOREREQS if we have buffered data and we are
490 	 * mid-record or if we have enough data for a record
491 	 * marker. Since this is only a hint, we read mpending and
492 	 * resid outside the lock. We do need to take the lock if we
493 	 * have to traverse the mbuf chain.
494 	 */
495 	if (cd->mpending) {
496 		if (cd->resid)
497 			return (XPRT_MOREREQS);
498 		n = 0;
499 		sx_xlock(&xprt->xp_lock);
500 		m = cd->mpending;
501 		while (m && n < sizeof(uint32_t)) {
502 			n += m->m_len;
503 			m = m->m_next;
504 		}
505 		sx_xunlock(&xprt->xp_lock);
506 		if (n >= sizeof(uint32_t))
507 			return (XPRT_MOREREQS);
508 	}
509 
510 	if (soreadable(xprt->xp_socket))
511 		return (XPRT_MOREREQS);
512 
513 	return (XPRT_IDLE);
514 }
515 
516 static bool_t
517 svc_vc_recv(SVCXPRT *xprt, struct rpc_msg *msg,
518     struct sockaddr **addrp, struct mbuf **mp)
519 {
520 	struct cf_conn *cd = (struct cf_conn *) xprt->xp_p1;
521 	struct uio uio;
522 	struct mbuf *m;
523 	XDR xdrs;
524 	int error, rcvflag;
525 
526 	/*
527 	 * Serialise access to the socket and our own record parsing
528 	 * state.
529 	 */
530 	sx_xlock(&xprt->xp_lock);
531 
532 	for (;;) {
533 		/*
534 		 * If we have an mbuf chain in cd->mpending, try to parse a
535 		 * record from it, leaving the result in cd->mreq. If we don't
536 		 * have a complete record, leave the partial result in
537 		 * cd->mreq and try to read more from the socket.
538 		 */
539 		if (cd->mpending) {
540 			/*
541 			 * If cd->resid is non-zero, we have part of the
542 			 * record already, otherwise we are expecting a record
543 			 * marker.
544 			 */
545 			if (!cd->resid) {
546 				/*
547 				 * See if there is enough data buffered to
548 				 * make up a record marker. Make sure we can
549 				 * handle the case where the record marker is
550 				 * split across more than one mbuf.
551 				 */
552 				size_t n = 0;
553 				uint32_t header;
554 
555 				m = cd->mpending;
556 				while (n < sizeof(uint32_t) && m) {
557 					n += m->m_len;
558 					m = m->m_next;
559 				}
560 				if (n < sizeof(uint32_t))
561 					goto readmore;
562 				m_copydata(cd->mpending, 0, sizeof(header),
563 				    (char *)&header);
564 				header = ntohl(header);
565 				cd->eor = (header & 0x80000000) != 0;
566 				cd->resid = header & 0x7fffffff;
567 				m_adj(cd->mpending, sizeof(uint32_t));
568 			}
569 
570 			/*
571 			 * Start pulling off mbufs from cd->mpending
572 			 * until we either have a complete record or
573 			 * we run out of data. We use m_split to pull
574 			 * data - it will pull as much as possible and
575 			 * split the last mbuf if necessary.
576 			 */
577 			while (cd->mpending && cd->resid) {
578 				m = cd->mpending;
579 				if (cd->mpending->m_next
580 				    || cd->mpending->m_len > cd->resid)
581 					cd->mpending = m_split(cd->mpending,
582 					    cd->resid, M_WAIT);
583 				else
584 					cd->mpending = NULL;
585 				if (cd->mreq)
586 					m_last(cd->mreq)->m_next = m;
587 				else
588 					cd->mreq = m;
589 				while (m) {
590 					cd->resid -= m->m_len;
591 					m = m->m_next;
592 				}
593 			}
594 
595 			/*
596 			 * If cd->resid is zero now, we have managed to
597 			 * receive a record fragment from the stream. Check
598 			 * for the end-of-record mark to see if we need more.
599 			 */
600 			if (cd->resid == 0) {
601 				if (!cd->eor)
602 					continue;
603 
604 				/*
605 				 * Success - we have a complete record in
606 				 * cd->mreq.
607 				 */
608 				xdrmbuf_create(&xdrs, cd->mreq, XDR_DECODE);
609 				cd->mreq = NULL;
610 				sx_xunlock(&xprt->xp_lock);
611 
612 				if (! xdr_callmsg(&xdrs, msg)) {
613 					XDR_DESTROY(&xdrs);
614 					return (FALSE);
615 				}
616 
617 				*addrp = NULL;
618 				*mp = xdrmbuf_getall(&xdrs);
619 				XDR_DESTROY(&xdrs);
620 
621 				return (TRUE);
622 			}
623 		}
624 
625 	readmore:
626 		/*
627 		 * The socket upcall calls xprt_active() which will eventually
628 		 * cause the server to call us here. We attempt to
629 		 * read as much as possible from the socket and put
630 		 * the result in cd->mpending. If the read fails,
631 		 * we have drained both cd->mpending and the socket so
632 		 * we can call xprt_inactive().
633 		 */
634 		uio.uio_resid = 1000000000;
635 		uio.uio_td = curthread;
636 		m = NULL;
637 		rcvflag = MSG_DONTWAIT;
638 		CURVNET_SET(xprt->xp_socket->so_vnet);
639 		error = soreceive(xprt->xp_socket, NULL, &uio, &m, NULL,
640 		    &rcvflag);
641 		CURVNET_RESTORE();
642 
643 		if (error == EWOULDBLOCK) {
644 			/*
645 			 * We must re-test for readability after
646 			 * taking the lock to protect us in the case
647 			 * where a new packet arrives on the socket
648 			 * after our call to soreceive fails with
649 			 * EWOULDBLOCK. The pool lock protects us from
650 			 * racing the upcall after our soreadable()
651 			 * call returns false.
652 			 */
653 			mtx_lock(&xprt->xp_pool->sp_lock);
654 			if (!soreadable(xprt->xp_socket))
655 				xprt_inactive_locked(xprt);
656 			mtx_unlock(&xprt->xp_pool->sp_lock);
657 			sx_xunlock(&xprt->xp_lock);
658 			return (FALSE);
659 		}
660 
661 		if (error) {
662 			SOCKBUF_LOCK(&xprt->xp_socket->so_rcv);
663 			if (xprt->xp_upcallset) {
664 				xprt->xp_upcallset = 0;
665 				soupcall_clear(xprt->xp_socket, SO_RCV);
666 			}
667 			SOCKBUF_UNLOCK(&xprt->xp_socket->so_rcv);
668 			xprt_inactive(xprt);
669 			cd->strm_stat = XPRT_DIED;
670 			sx_xunlock(&xprt->xp_lock);
671 			return (FALSE);
672 		}
673 
674 		if (!m) {
675 			/*
676 			 * EOF - the other end has closed the socket.
677 			 */
678 			xprt_inactive(xprt);
679 			cd->strm_stat = XPRT_DIED;
680 			sx_xunlock(&xprt->xp_lock);
681 			return (FALSE);
682 		}
683 
684 		if (cd->mpending)
685 			m_last(cd->mpending)->m_next = m;
686 		else
687 			cd->mpending = m;
688 	}
689 }
690 
691 static bool_t
692 svc_vc_reply(SVCXPRT *xprt, struct rpc_msg *msg,
693     struct sockaddr *addr, struct mbuf *m)
694 {
695 	XDR xdrs;
696 	struct mbuf *mrep;
697 	bool_t stat = TRUE;
698 	int error;
699 
700 	/*
701 	 * Leave space for record mark.
702 	 */
703 	MGETHDR(mrep, M_WAIT, MT_DATA);
704 	mrep->m_len = 0;
705 	mrep->m_data += sizeof(uint32_t);
706 
707 	xdrmbuf_create(&xdrs, mrep, XDR_ENCODE);
708 
709 	if (msg->rm_reply.rp_stat == MSG_ACCEPTED &&
710 	    msg->rm_reply.rp_acpt.ar_stat == SUCCESS) {
711 		if (!xdr_replymsg(&xdrs, msg))
712 			stat = FALSE;
713 		else
714 			xdrmbuf_append(&xdrs, m);
715 	} else {
716 		stat = xdr_replymsg(&xdrs, msg);
717 	}
718 
719 	if (stat) {
720 		m_fixhdr(mrep);
721 
722 		/*
723 		 * Prepend a record marker containing the reply length.
724 		 */
725 		M_PREPEND(mrep, sizeof(uint32_t), M_WAIT);
726 		*mtod(mrep, uint32_t *) =
727 			htonl(0x80000000 | (mrep->m_pkthdr.len
728 				- sizeof(uint32_t)));
729 		error = sosend(xprt->xp_socket, NULL, NULL, mrep, NULL,
730 		    0, curthread);
731 		if (!error) {
732 			stat = TRUE;
733 		}
734 	} else {
735 		m_freem(mrep);
736 	}
737 
738 	XDR_DESTROY(&xdrs);
739 	xprt->xp_p2 = NULL;
740 
741 	return (stat);
742 }
743 
744 static bool_t
745 svc_vc_null()
746 {
747 
748 	return (FALSE);
749 }
750 
751 static int
752 svc_vc_soupcall(struct socket *so, void *arg, int waitflag)
753 {
754 	SVCXPRT *xprt = (SVCXPRT *) arg;
755 
756 	xprt_active(xprt);
757 	return (SU_OK);
758 }
759 
760 #if 0
761 /*
762  * Get the effective UID of the sending process. Used by rpcbind, keyserv
763  * and rpc.yppasswdd on AF_LOCAL.
764  */
765 int
766 __rpc_get_local_uid(SVCXPRT *transp, uid_t *uid) {
767 	int sock, ret;
768 	gid_t egid;
769 	uid_t euid;
770 	struct sockaddr *sa;
771 
772 	sock = transp->xp_fd;
773 	sa = (struct sockaddr *)transp->xp_rtaddr;
774 	if (sa->sa_family == AF_LOCAL) {
775 		ret = getpeereid(sock, &euid, &egid);
776 		if (ret == 0)
777 			*uid = euid;
778 		return (ret);
779 	} else
780 		return (-1);
781 }
782 #endif
783