xref: /freebsd/sys/rpc/svc_vc.c (revision 2be1a816)
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/protosw.h>
54 #include <sys/queue.h>
55 #include <sys/socket.h>
56 #include <sys/socketvar.h>
57 #include <sys/systm.h>
58 #include <sys/uio.h>
59 #include <netinet/tcp.h>
60 
61 #include <rpc/rpc.h>
62 
63 #include <rpc/rpc_com.h>
64 
65 static bool_t svc_vc_rendezvous_recv(SVCXPRT *, struct rpc_msg *);
66 static enum xprt_stat svc_vc_rendezvous_stat(SVCXPRT *);
67 static void svc_vc_rendezvous_destroy(SVCXPRT *);
68 static bool_t svc_vc_null(void);
69 static void svc_vc_destroy(SVCXPRT *);
70 static enum xprt_stat svc_vc_stat(SVCXPRT *);
71 static bool_t svc_vc_recv(SVCXPRT *, struct rpc_msg *);
72 static bool_t svc_vc_getargs(SVCXPRT *, xdrproc_t, void *);
73 static bool_t svc_vc_freeargs(SVCXPRT *, xdrproc_t, void *);
74 static bool_t svc_vc_reply(SVCXPRT *, struct rpc_msg *);
75 static bool_t svc_vc_control(SVCXPRT *xprt, const u_int rq, void *in);
76 static bool_t svc_vc_rendezvous_control (SVCXPRT *xprt, const u_int rq,
77     void *in);
78 static SVCXPRT *svc_vc_create_conn(SVCPOOL *pool, struct socket *so,
79     struct sockaddr *raddr);
80 static int svc_vc_accept(struct socket *head, struct socket **sop);
81 static void svc_vc_soupcall(struct socket *so, void *arg, int waitflag);
82 
83 static struct xp_ops svc_vc_rendezvous_ops = {
84 	.xp_recv =	svc_vc_rendezvous_recv,
85 	.xp_stat =	svc_vc_rendezvous_stat,
86 	.xp_getargs =	(bool_t (*)(SVCXPRT *, xdrproc_t, void *))svc_vc_null,
87 	.xp_reply =	(bool_t (*)(SVCXPRT *, struct rpc_msg *))svc_vc_null,
88 	.xp_freeargs =	(bool_t (*)(SVCXPRT *, xdrproc_t, void *))svc_vc_null,
89 	.xp_destroy =	svc_vc_rendezvous_destroy,
90 	.xp_control =	svc_vc_rendezvous_control
91 };
92 
93 static struct xp_ops svc_vc_ops = {
94 	.xp_recv =	svc_vc_recv,
95 	.xp_stat =	svc_vc_stat,
96 	.xp_getargs =	svc_vc_getargs,
97 	.xp_reply =	svc_vc_reply,
98 	.xp_freeargs =	svc_vc_freeargs,
99 	.xp_destroy =	svc_vc_destroy,
100 	.xp_control =	svc_vc_control
101 };
102 
103 struct cf_conn {  /* kept in xprt->xp_p1 for actual connection */
104 	enum xprt_stat strm_stat;
105 	struct mbuf *mpending;	/* unparsed data read from the socket */
106 	struct mbuf *mreq;	/* current record being built from mpending */
107 	uint32_t resid;		/* number of bytes needed for fragment */
108 	bool_t eor;		/* reading last fragment of current record */
109 };
110 
111 /*
112  * Usage:
113  *	xprt = svc_vc_create(sock, send_buf_size, recv_buf_size);
114  *
115  * Creates, registers, and returns a (rpc) tcp based transporter.
116  * Once *xprt is initialized, it is registered as a transporter
117  * see (svc.h, xprt_register).  This routine returns
118  * a NULL if a problem occurred.
119  *
120  * The filedescriptor passed in is expected to refer to a bound, but
121  * not yet connected socket.
122  *
123  * Since streams do buffered io similar to stdio, the caller can specify
124  * how big the send and receive buffers are via the second and third parms;
125  * 0 => use the system default.
126  */
127 SVCXPRT *
128 svc_vc_create(SVCPOOL *pool, struct socket *so, size_t sendsize,
129     size_t recvsize)
130 {
131 	SVCXPRT *xprt;
132 	struct sockaddr* sa;
133 	int error;
134 
135 	xprt = mem_alloc(sizeof(SVCXPRT));
136 	mtx_init(&xprt->xp_lock, "xprt->xp_lock", NULL, MTX_DEF);
137 	xprt->xp_pool = pool;
138 	xprt->xp_socket = so;
139 	xprt->xp_p1 = NULL;
140 	xprt->xp_p2 = NULL;
141 	xprt->xp_p3 = NULL;
142 	xprt->xp_verf = _null_auth;
143 	xprt->xp_ops = &svc_vc_rendezvous_ops;
144 
145 	error = so->so_proto->pr_usrreqs->pru_sockaddr(so, &sa);
146 	if (error)
147 		goto cleanup_svc_vc_create;
148 
149 	xprt->xp_ltaddr.buf = mem_alloc(sizeof (struct sockaddr_storage));
150 	xprt->xp_ltaddr.maxlen = sizeof (struct sockaddr_storage);
151 	xprt->xp_ltaddr.len = sa->sa_len;
152 	memcpy(xprt->xp_ltaddr.buf, sa, sa->sa_len);
153 	free(sa, M_SONAME);
154 
155 	xprt->xp_rtaddr.maxlen = 0;
156 
157 	xprt_register(xprt);
158 
159 	solisten(so, SOMAXCONN, curthread);
160 
161 	SOCKBUF_LOCK(&so->so_rcv);
162 	so->so_upcallarg = xprt;
163 	so->so_upcall = svc_vc_soupcall;
164 	so->so_rcv.sb_flags |= SB_UPCALL;
165 	SOCKBUF_UNLOCK(&so->so_rcv);
166 
167 	return (xprt);
168 cleanup_svc_vc_create:
169 	if (xprt)
170 		mem_free(xprt, sizeof(*xprt));
171 	return (NULL);
172 }
173 
174 /*
175  * Create a new transport for a socket optained via soaccept().
176  */
177 SVCXPRT *
178 svc_vc_create_conn(SVCPOOL *pool, struct socket *so, struct sockaddr *raddr)
179 {
180 	SVCXPRT *xprt = NULL;
181 	struct cf_conn *cd = NULL;
182 	struct sockaddr* sa = NULL;
183 	int error;
184 
185 	cd = mem_alloc(sizeof(*cd));
186 	cd->strm_stat = XPRT_IDLE;
187 
188 	xprt = mem_alloc(sizeof(SVCXPRT));
189 	mtx_init(&xprt->xp_lock, "xprt->xp_lock", NULL, MTX_DEF);
190 	xprt->xp_pool = pool;
191 	xprt->xp_socket = so;
192 	xprt->xp_p1 = cd;
193 	xprt->xp_p2 = NULL;
194 	xprt->xp_p3 = NULL;
195 	xprt->xp_verf = _null_auth;
196 	xprt->xp_ops = &svc_vc_ops;
197 
198 	xprt->xp_rtaddr.buf = mem_alloc(sizeof (struct sockaddr_storage));
199 	xprt->xp_rtaddr.maxlen = sizeof (struct sockaddr_storage);
200 	xprt->xp_rtaddr.len = raddr->sa_len;
201 	memcpy(xprt->xp_rtaddr.buf, raddr, raddr->sa_len);
202 
203 	error = so->so_proto->pr_usrreqs->pru_sockaddr(so, &sa);
204 	if (error)
205 		goto cleanup_svc_vc_create;
206 
207 	xprt->xp_ltaddr.buf = mem_alloc(sizeof (struct sockaddr_storage));
208 	xprt->xp_ltaddr.maxlen = sizeof (struct sockaddr_storage);
209 	xprt->xp_ltaddr.len = sa->sa_len;
210 	memcpy(xprt->xp_ltaddr.buf, sa, sa->sa_len);
211 	free(sa, M_SONAME);
212 
213 	xprt_register(xprt);
214 
215 	SOCKBUF_LOCK(&so->so_rcv);
216 	so->so_upcallarg = xprt;
217 	so->so_upcall = svc_vc_soupcall;
218 	so->so_rcv.sb_flags |= SB_UPCALL;
219 	SOCKBUF_UNLOCK(&so->so_rcv);
220 
221 	/*
222 	 * Throw the transport into the active list in case it already
223 	 * has some data buffered.
224 	 */
225 	mtx_lock(&xprt->xp_lock);
226 	xprt_active(xprt);
227 	mtx_unlock(&xprt->xp_lock);
228 
229 	return (xprt);
230 cleanup_svc_vc_create:
231 	if (xprt) {
232 		if (xprt->xp_ltaddr.buf)
233 			mem_free(xprt->xp_ltaddr.buf,
234 			    sizeof(struct sockaddr_storage));
235 		if (xprt->xp_rtaddr.buf)
236 			mem_free(xprt->xp_rtaddr.buf,
237 			    sizeof(struct sockaddr_storage));
238 		mem_free(xprt, sizeof(*xprt));
239 	}
240 	if (cd)
241 		mem_free(cd, sizeof(*cd));
242 	return (NULL);
243 }
244 
245 /*
246  * This does all of the accept except the final call to soaccept. The
247  * caller will call soaccept after dropping its locks (soaccept may
248  * call malloc).
249  */
250 int
251 svc_vc_accept(struct socket *head, struct socket **sop)
252 {
253 	int error = 0;
254 	struct socket *so;
255 
256 	if ((head->so_options & SO_ACCEPTCONN) == 0) {
257 		error = EINVAL;
258 		goto done;
259 	}
260 #ifdef MAC
261 	SOCK_LOCK(head);
262 	error = mac_socket_check_accept(td->td_ucred, head);
263 	SOCK_UNLOCK(head);
264 	if (error != 0)
265 		goto done;
266 #endif
267 	ACCEPT_LOCK();
268 	if (TAILQ_EMPTY(&head->so_comp)) {
269 		ACCEPT_UNLOCK();
270 		error = EWOULDBLOCK;
271 		goto done;
272 	}
273 	so = TAILQ_FIRST(&head->so_comp);
274 	KASSERT(!(so->so_qstate & SQ_INCOMP), ("svc_vc_accept: so SQ_INCOMP"));
275 	KASSERT(so->so_qstate & SQ_COMP, ("svc_vc_accept: so not SQ_COMP"));
276 
277 	/*
278 	 * Before changing the flags on the socket, we have to bump the
279 	 * reference count.  Otherwise, if the protocol calls sofree(),
280 	 * the socket will be released due to a zero refcount.
281 	 * XXX might not need soref() since this is simpler than kern_accept.
282 	 */
283 	SOCK_LOCK(so);			/* soref() and so_state update */
284 	soref(so);			/* file descriptor reference */
285 
286 	TAILQ_REMOVE(&head->so_comp, so, so_list);
287 	head->so_qlen--;
288 	so->so_state |= (head->so_state & SS_NBIO);
289 	so->so_qstate &= ~SQ_COMP;
290 	so->so_head = NULL;
291 
292 	SOCK_UNLOCK(so);
293 	ACCEPT_UNLOCK();
294 
295 	*sop = so;
296 
297 	/* connection has been removed from the listen queue */
298 	KNOTE_UNLOCKED(&head->so_rcv.sb_sel.si_note, 0);
299 done:
300 	return (error);
301 }
302 
303 /*ARGSUSED*/
304 static bool_t
305 svc_vc_rendezvous_recv(SVCXPRT *xprt, struct rpc_msg *msg)
306 {
307 	struct socket *so = NULL;
308 	struct sockaddr *sa = NULL;
309 	struct sockopt opt;
310 	int one = 1;
311 	int error;
312 
313 	/*
314 	 * The socket upcall calls xprt_active() which will eventually
315 	 * cause the server to call us here. We attempt to accept a
316 	 * connection from the socket and turn it into a new
317 	 * transport. If the accept fails, we have drained all pending
318 	 * connections so we call xprt_inactive().
319 	 *
320 	 * The lock protects us in the case where a new connection arrives
321 	 * on the socket after our call to accept fails with
322 	 * EWOULDBLOCK - the call to xprt_active() in the upcall will
323 	 * happen only after our call to xprt_inactive() which ensures
324 	 * that we will remain active. It might be possible to use
325 	 * SOCKBUF_LOCK for this - its not clear to me what locks are
326 	 * held during the upcall.
327 	 */
328 	mtx_lock(&xprt->xp_lock);
329 
330 	error = svc_vc_accept(xprt->xp_socket, &so);
331 
332 	if (error == EWOULDBLOCK) {
333 		xprt_inactive(xprt);
334 		mtx_unlock(&xprt->xp_lock);
335 		return (FALSE);
336 	}
337 
338 	if (error) {
339 		SOCKBUF_LOCK(&xprt->xp_socket->so_rcv);
340 		xprt->xp_socket->so_upcallarg = NULL;
341 		xprt->xp_socket->so_upcall = NULL;
342 		xprt->xp_socket->so_rcv.sb_flags &= ~SB_UPCALL;
343 		SOCKBUF_UNLOCK(&xprt->xp_socket->so_rcv);
344 		xprt_inactive(xprt);
345 		mtx_unlock(&xprt->xp_lock);
346 		return (FALSE);
347 	}
348 
349 	mtx_unlock(&xprt->xp_lock);
350 
351 	sa = 0;
352 	error = soaccept(so, &sa);
353 
354 	if (!error) {
355 		bzero(&opt, sizeof(struct sockopt));
356 		opt.sopt_dir = SOPT_SET;
357 		opt.sopt_level = IPPROTO_TCP;
358 		opt.sopt_name = TCP_NODELAY;
359 		opt.sopt_val = &one;
360 		opt.sopt_valsize = sizeof(one);
361 		error = sosetopt(so, &opt);
362 	}
363 
364 	if (error) {
365 		/*
366 		 * XXX not sure if I need to call sofree or soclose here.
367 		 */
368 		if (sa)
369 			free(sa, M_SONAME);
370 		return (FALSE);
371 	}
372 
373 	/*
374 	 * svc_vc_create_conn will call xprt_register - we don't need
375 	 * to do anything with the new connection.
376 	 */
377 	svc_vc_create_conn(xprt->xp_pool, so, sa);
378 	free(sa, M_SONAME);
379 
380 	return (FALSE); /* there is never an rpc msg to be processed */
381 }
382 
383 /*ARGSUSED*/
384 static enum xprt_stat
385 svc_vc_rendezvous_stat(SVCXPRT *xprt)
386 {
387 
388 	return (XPRT_IDLE);
389 }
390 
391 static void
392 svc_vc_destroy_common(SVCXPRT *xprt)
393 {
394 	SOCKBUF_LOCK(&xprt->xp_socket->so_rcv);
395 	xprt->xp_socket->so_upcallarg = NULL;
396 	xprt->xp_socket->so_upcall = NULL;
397 	xprt->xp_socket->so_rcv.sb_flags &= ~SB_UPCALL;
398 	SOCKBUF_UNLOCK(&xprt->xp_socket->so_rcv);
399 
400 	xprt_unregister(xprt);
401 
402 	mtx_destroy(&xprt->xp_lock);
403 	if (xprt->xp_socket)
404 		(void)soclose(xprt->xp_socket);
405 
406 	if (xprt->xp_rtaddr.buf)
407 		(void) mem_free(xprt->xp_rtaddr.buf, xprt->xp_rtaddr.maxlen);
408 	if (xprt->xp_ltaddr.buf)
409 		(void) mem_free(xprt->xp_ltaddr.buf, xprt->xp_ltaddr.maxlen);
410 	(void) mem_free(xprt, sizeof (SVCXPRT));
411 
412 }
413 
414 static void
415 svc_vc_rendezvous_destroy(SVCXPRT *xprt)
416 {
417 
418 	svc_vc_destroy_common(xprt);
419 }
420 
421 static void
422 svc_vc_destroy(SVCXPRT *xprt)
423 {
424 	struct cf_conn *cd = (struct cf_conn *)xprt->xp_p1;
425 
426 	svc_vc_destroy_common(xprt);
427 
428 	if (cd->mreq)
429 		m_freem(cd->mreq);
430 	if (cd->mpending)
431 		m_freem(cd->mpending);
432 	mem_free(cd, sizeof(*cd));
433 }
434 
435 /*ARGSUSED*/
436 static bool_t
437 svc_vc_control(SVCXPRT *xprt, const u_int rq, void *in)
438 {
439 	return (FALSE);
440 }
441 
442 static bool_t
443 svc_vc_rendezvous_control(SVCXPRT *xprt, const u_int rq, void *in)
444 {
445 
446 	return (FALSE);
447 }
448 
449 static enum xprt_stat
450 svc_vc_stat(SVCXPRT *xprt)
451 {
452 	struct cf_conn *cd;
453 	struct mbuf *m;
454 	size_t n;
455 
456 	cd = (struct cf_conn *)(xprt->xp_p1);
457 
458 	if (cd->strm_stat == XPRT_DIED)
459 		return (XPRT_DIED);
460 
461 	/*
462 	 * Return XPRT_MOREREQS if we have buffered data and we are
463 	 * mid-record or if we have enough data for a record marker.
464 	 */
465 	if (cd->mpending) {
466 		if (cd->resid)
467 			return (XPRT_MOREREQS);
468 		n = 0;
469 		m = cd->mpending;
470 		while (m && n < sizeof(uint32_t)) {
471 			n += m->m_len;
472 			m = m->m_next;
473 		}
474 		if (n >= sizeof(uint32_t))
475 			return (XPRT_MOREREQS);
476 	}
477 
478 	return (XPRT_IDLE);
479 }
480 
481 static bool_t
482 svc_vc_recv(SVCXPRT *xprt, struct rpc_msg *msg)
483 {
484 	struct cf_conn *cd = (struct cf_conn *) xprt->xp_p1;
485 	struct uio uio;
486 	struct mbuf *m;
487 	int error, rcvflag;
488 
489 	for (;;) {
490 		/*
491 		 * If we have an mbuf chain in cd->mpending, try to parse a
492 		 * record from it, leaving the result in cd->mreq. If we don't
493 		 * have a complete record, leave the partial result in
494 		 * cd->mreq and try to read more from the socket.
495 		 */
496 		if (cd->mpending) {
497 			/*
498 			 * If cd->resid is non-zero, we have part of the
499 			 * record already, otherwise we are expecting a record
500 			 * marker.
501 			 */
502 			if (!cd->resid) {
503 				/*
504 				 * See if there is enough data buffered to
505 				 * make up a record marker. Make sure we can
506 				 * handle the case where the record marker is
507 				 * split across more than one mbuf.
508 				 */
509 				size_t n = 0;
510 				uint32_t header;
511 
512 				m = cd->mpending;
513 				while (n < sizeof(uint32_t) && m) {
514 					n += m->m_len;
515 					m = m->m_next;
516 				}
517 				if (n < sizeof(uint32_t))
518 					goto readmore;
519 				cd->mpending = m_pullup(cd->mpending, sizeof(uint32_t));
520 				memcpy(&header, mtod(cd->mpending, uint32_t *),
521 				    sizeof(header));
522 				header = ntohl(header);
523 				cd->eor = (header & 0x80000000) != 0;
524 				cd->resid = header & 0x7fffffff;
525 				m_adj(cd->mpending, sizeof(uint32_t));
526 			}
527 
528 			/*
529 			 * Start pulling off mbufs from cd->mpending
530 			 * until we either have a complete record or
531 			 * we run out of data. We use m_split to pull
532 			 * data - it will pull as much as possible and
533 			 * split the last mbuf if necessary.
534 			 */
535 			while (cd->mpending && cd->resid) {
536 				m = cd->mpending;
537 				cd->mpending = m_split(cd->mpending, cd->resid,
538 				    M_WAIT);
539 				if (cd->mreq)
540 					m_last(cd->mreq)->m_next = m;
541 				else
542 					cd->mreq = m;
543 				while (m) {
544 					cd->resid -= m->m_len;
545 					m = m->m_next;
546 				}
547 			}
548 
549 			/*
550 			 * If cd->resid is zero now, we have managed to
551 			 * receive a record fragment from the stream. Check
552 			 * for the end-of-record mark to see if we need more.
553 			 */
554 			if (cd->resid == 0) {
555 				if (!cd->eor)
556 					continue;
557 
558 				/*
559 				 * Success - we have a complete record in
560 				 * cd->mreq.
561 				 */
562 				xdrmbuf_create(&xprt->xp_xdrreq, cd->mreq, XDR_DECODE);
563 				cd->mreq = NULL;
564 				if (! xdr_callmsg(&xprt->xp_xdrreq, msg)) {
565 					XDR_DESTROY(&xprt->xp_xdrreq);
566 					return (FALSE);
567 				}
568 				xprt->xp_xid = msg->rm_xid;
569 
570 				return (TRUE);
571 			}
572 		}
573 
574 	readmore:
575 		/*
576 		 * The socket upcall calls xprt_active() which will eventually
577 		 * cause the server to call us here. We attempt to
578 		 * read as much as possible from the socket and put
579 		 * the result in cd->mpending. If the read fails,
580 		 * we have drained both cd->mpending and the socket so
581 		 * we can call xprt_inactive().
582 		 *
583 		 * The lock protects us in the case where a new packet arrives
584 		 * on the socket after our call to soreceive fails with
585 		 * EWOULDBLOCK - the call to xprt_active() in the upcall will
586 		 * happen only after our call to xprt_inactive() which ensures
587 		 * that we will remain active. It might be possible to use
588 		 * SOCKBUF_LOCK for this - its not clear to me what locks are
589 		 * held during the upcall.
590 		 */
591 		mtx_lock(&xprt->xp_lock);
592 
593 		uio.uio_resid = 1000000000;
594 		uio.uio_td = curthread;
595 		m = NULL;
596 		rcvflag = MSG_DONTWAIT;
597 		error = soreceive(xprt->xp_socket, NULL, &uio, &m, NULL,
598 		    &rcvflag);
599 
600 		if (error == EWOULDBLOCK) {
601 			xprt_inactive(xprt);
602 			mtx_unlock(&xprt->xp_lock);
603 			return (FALSE);
604 		}
605 
606 		if (error) {
607 			SOCKBUF_LOCK(&xprt->xp_socket->so_rcv);
608 			xprt->xp_socket->so_upcallarg = NULL;
609 			xprt->xp_socket->so_upcall = NULL;
610 			xprt->xp_socket->so_rcv.sb_flags &= ~SB_UPCALL;
611 			SOCKBUF_UNLOCK(&xprt->xp_socket->so_rcv);
612 			xprt_inactive(xprt);
613 			cd->strm_stat = XPRT_DIED;
614 			mtx_unlock(&xprt->xp_lock);
615 			return (FALSE);
616 		}
617 
618 		if (!m) {
619 			/*
620 			 * EOF - the other end has closed the socket.
621 			 */
622 			cd->strm_stat = XPRT_DIED;
623 			mtx_unlock(&xprt->xp_lock);
624 			return (FALSE);
625 		}
626 
627 		if (cd->mpending)
628 			m_last(cd->mpending)->m_next = m;
629 		else
630 			cd->mpending = m;
631 
632 		mtx_unlock(&xprt->xp_lock);
633 	}
634 }
635 
636 static bool_t
637 svc_vc_getargs(SVCXPRT *xprt, xdrproc_t xdr_args, void *args_ptr)
638 {
639 
640 	return (xdr_args(&xprt->xp_xdrreq, args_ptr));
641 }
642 
643 static bool_t
644 svc_vc_freeargs(SVCXPRT *xprt, xdrproc_t xdr_args, void *args_ptr)
645 {
646 	XDR xdrs;
647 
648 	/*
649 	 * Free the request mbuf here - this allows us to handle
650 	 * protocols where not all requests have replies
651 	 * (i.e. NLM). Note that xdrmbuf_destroy handles being called
652 	 * twice correctly - the mbuf will only be freed once.
653 	 */
654 	XDR_DESTROY(&xprt->xp_xdrreq);
655 
656 	xdrs.x_op = XDR_FREE;
657 	return (xdr_args(&xdrs, args_ptr));
658 }
659 
660 static bool_t
661 svc_vc_reply(SVCXPRT *xprt, struct rpc_msg *msg)
662 {
663 	struct mbuf *mrep;
664 	bool_t stat = FALSE;
665 	int error;
666 
667 	/*
668 	 * Leave space for record mark.
669 	 */
670 	MGETHDR(mrep, M_WAIT, MT_DATA);
671 	MCLGET(mrep, M_WAIT);
672 	mrep->m_len = 0;
673 	mrep->m_data += sizeof(uint32_t);
674 
675 	xdrmbuf_create(&xprt->xp_xdrrep, mrep, XDR_ENCODE);
676 	msg->rm_xid = xprt->xp_xid;
677 	if (xdr_replymsg(&xprt->xp_xdrrep, msg)) {
678 		m_fixhdr(mrep);
679 
680 		/*
681 		 * Prepend a record marker containing the reply length.
682 		 */
683 		M_PREPEND(mrep, sizeof(uint32_t), M_WAIT);
684 		*mtod(mrep, uint32_t *) =
685 			htonl(0x80000000 | (mrep->m_pkthdr.len
686 				- sizeof(uint32_t)));
687 		error = sosend(xprt->xp_socket, NULL, NULL, mrep, NULL,
688 		    0, curthread);
689 		if (!error) {
690 			stat = TRUE;
691 		}
692 	} else {
693 		m_freem(mrep);
694 	}
695 
696 	/*
697 	 * This frees the request mbuf chain as well. The reply mbuf
698 	 * chain was consumed by sosend.
699 	 */
700 	XDR_DESTROY(&xprt->xp_xdrreq);
701 	XDR_DESTROY(&xprt->xp_xdrrep);
702 	xprt->xp_p2 = NULL;
703 
704 	return (stat);
705 }
706 
707 static bool_t
708 svc_vc_null()
709 {
710 
711 	return (FALSE);
712 }
713 
714 static void
715 svc_vc_soupcall(struct socket *so, void *arg, int waitflag)
716 {
717 	SVCXPRT *xprt = (SVCXPRT *) arg;
718 
719 	mtx_lock(&xprt->xp_lock);
720 	xprt_active(xprt);
721 	mtx_unlock(&xprt->xp_lock);
722 }
723 
724 #if 0
725 /*
726  * Get the effective UID of the sending process. Used by rpcbind, keyserv
727  * and rpc.yppasswdd on AF_LOCAL.
728  */
729 int
730 __rpc_get_local_uid(SVCXPRT *transp, uid_t *uid) {
731 	int sock, ret;
732 	gid_t egid;
733 	uid_t euid;
734 	struct sockaddr *sa;
735 
736 	sock = transp->xp_fd;
737 	sa = (struct sockaddr *)transp->xp_rtaddr.buf;
738 	if (sa->sa_family == AF_LOCAL) {
739 		ret = getpeereid(sock, &euid, &egid);
740 		if (ret == 0)
741 			*uid = euid;
742 		return (ret);
743 	} else
744 		return (-1);
745 }
746 #endif
747