xref: /freebsd/sys/rpc/svc_vc.c (revision 195ebc7e9e4b129de810833791a19dfb4349d6a9)
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/sx.h>
58 #include <sys/systm.h>
59 #include <sys/uio.h>
60 #include <netinet/tcp.h>
61 
62 #include <rpc/rpc.h>
63 
64 #include <rpc/rpc_com.h>
65 
66 static bool_t svc_vc_rendezvous_recv(SVCXPRT *, struct rpc_msg *,
67     struct sockaddr **, struct mbuf **);
68 static enum xprt_stat svc_vc_rendezvous_stat(SVCXPRT *);
69 static void svc_vc_rendezvous_destroy(SVCXPRT *);
70 static bool_t svc_vc_null(void);
71 static void svc_vc_destroy(SVCXPRT *);
72 static enum xprt_stat svc_vc_stat(SVCXPRT *);
73 static bool_t svc_vc_recv(SVCXPRT *, struct rpc_msg *,
74     struct sockaddr **, struct mbuf **);
75 static bool_t svc_vc_reply(SVCXPRT *, struct rpc_msg *,
76     struct sockaddr *, struct mbuf *);
77 static bool_t svc_vc_control(SVCXPRT *xprt, const u_int rq, void *in);
78 static bool_t svc_vc_rendezvous_control (SVCXPRT *xprt, const u_int rq,
79     void *in);
80 static SVCXPRT *svc_vc_create_conn(SVCPOOL *pool, struct socket *so,
81     struct sockaddr *raddr);
82 static int svc_vc_accept(struct socket *head, struct socket **sop);
83 static int svc_vc_soupcall(struct socket *so, void *arg, int waitflag);
84 
85 static struct xp_ops svc_vc_rendezvous_ops = {
86 	.xp_recv =	svc_vc_rendezvous_recv,
87 	.xp_stat =	svc_vc_rendezvous_stat,
88 	.xp_reply =	(bool_t (*)(SVCXPRT *, struct rpc_msg *,
89 		struct sockaddr *, struct mbuf *))svc_vc_null,
90 	.xp_destroy =	svc_vc_rendezvous_destroy,
91 	.xp_control =	svc_vc_rendezvous_control
92 };
93 
94 static struct xp_ops svc_vc_ops = {
95 	.xp_recv =	svc_vc_recv,
96 	.xp_stat =	svc_vc_stat,
97 	.xp_reply =	svc_vc_reply,
98 	.xp_destroy =	svc_vc_destroy,
99 	.xp_control =	svc_vc_control
100 };
101 
102 struct cf_conn {  /* kept in xprt->xp_p1 for actual connection */
103 	enum xprt_stat strm_stat;
104 	struct mbuf *mpending;	/* unparsed data read from the socket */
105 	struct mbuf *mreq;	/* current record being built from mpending */
106 	uint32_t resid;		/* number of bytes needed for fragment */
107 	bool_t eor;		/* reading last fragment of current record */
108 };
109 
110 /*
111  * Usage:
112  *	xprt = svc_vc_create(sock, send_buf_size, recv_buf_size);
113  *
114  * Creates, registers, and returns a (rpc) tcp based transporter.
115  * Once *xprt is initialized, it is registered as a transporter
116  * see (svc.h, xprt_register).  This routine returns
117  * a NULL if a problem occurred.
118  *
119  * The filedescriptor passed in is expected to refer to a bound, but
120  * not yet connected socket.
121  *
122  * Since streams do buffered io similar to stdio, the caller can specify
123  * how big the send and receive buffers are via the second and third parms;
124  * 0 => use the system default.
125  */
126 SVCXPRT *
127 svc_vc_create(SVCPOOL *pool, struct socket *so, size_t sendsize,
128     size_t recvsize)
129 {
130 	SVCXPRT *xprt;
131 	struct sockaddr* sa;
132 	int error;
133 
134 	if (so->so_state & SS_ISCONNECTED) {
135 		error = so->so_proto->pr_usrreqs->pru_peeraddr(so, &sa);
136 		if (error)
137 			return (NULL);
138 		xprt = svc_vc_create_conn(pool, so, sa);
139 		free(sa, M_SONAME);
140 		return (xprt);
141 	}
142 
143 	xprt = svc_xprt_alloc();
144 	sx_init(&xprt->xp_lock, "xprt->xp_lock");
145 	xprt->xp_pool = pool;
146 	xprt->xp_socket = so;
147 	xprt->xp_p1 = NULL;
148 	xprt->xp_p2 = NULL;
149 	xprt->xp_ops = &svc_vc_rendezvous_ops;
150 
151 	error = so->so_proto->pr_usrreqs->pru_sockaddr(so, &sa);
152 	if (error)
153 		goto cleanup_svc_vc_create;
154 
155 	memcpy(&xprt->xp_ltaddr, sa, sa->sa_len);
156 	free(sa, M_SONAME);
157 
158 	xprt_register(xprt);
159 
160 	solisten(so, SOMAXCONN, curthread);
161 
162 	SOCKBUF_LOCK(&so->so_rcv);
163 	soupcall_set(so, SO_RCV, svc_vc_soupcall, xprt);
164 	SOCKBUF_UNLOCK(&so->so_rcv);
165 
166 	return (xprt);
167 cleanup_svc_vc_create:
168 	if (xprt)
169 		svc_xprt_free(xprt);
170 	return (NULL);
171 }
172 
173 /*
174  * Create a new transport for a socket optained via soaccept().
175  */
176 SVCXPRT *
177 svc_vc_create_conn(SVCPOOL *pool, struct socket *so, struct sockaddr *raddr)
178 {
179 	SVCXPRT *xprt = NULL;
180 	struct cf_conn *cd = NULL;
181 	struct sockaddr* sa = NULL;
182 	struct sockopt opt;
183 	int one = 1;
184 	int error;
185 
186 	bzero(&opt, sizeof(struct sockopt));
187 	opt.sopt_dir = SOPT_SET;
188 	opt.sopt_level = SOL_SOCKET;
189 	opt.sopt_name = SO_KEEPALIVE;
190 	opt.sopt_val = &one;
191 	opt.sopt_valsize = sizeof(one);
192 	error = sosetopt(so, &opt);
193 	if (error)
194 		return (NULL);
195 
196 	if (so->so_proto->pr_protocol == IPPROTO_TCP) {
197 		bzero(&opt, sizeof(struct sockopt));
198 		opt.sopt_dir = SOPT_SET;
199 		opt.sopt_level = IPPROTO_TCP;
200 		opt.sopt_name = TCP_NODELAY;
201 		opt.sopt_val = &one;
202 		opt.sopt_valsize = sizeof(one);
203 		error = sosetopt(so, &opt);
204 		if (error)
205 			return (NULL);
206 	}
207 
208 	cd = mem_alloc(sizeof(*cd));
209 	cd->strm_stat = XPRT_IDLE;
210 
211 	xprt = svc_xprt_alloc();
212 	sx_init(&xprt->xp_lock, "xprt->xp_lock");
213 	xprt->xp_pool = pool;
214 	xprt->xp_socket = so;
215 	xprt->xp_p1 = cd;
216 	xprt->xp_p2 = NULL;
217 	xprt->xp_ops = &svc_vc_ops;
218 
219 	/*
220 	 * See http://www.connectathon.org/talks96/nfstcp.pdf - client
221 	 * has a 5 minute timer, server has a 6 minute timer.
222 	 */
223 	xprt->xp_idletimeout = 6 * 60;
224 
225 	memcpy(&xprt->xp_rtaddr, raddr, raddr->sa_len);
226 
227 	error = so->so_proto->pr_usrreqs->pru_sockaddr(so, &sa);
228 	if (error)
229 		goto cleanup_svc_vc_create;
230 
231 	memcpy(&xprt->xp_ltaddr, sa, sa->sa_len);
232 	free(sa, M_SONAME);
233 
234 	xprt_register(xprt);
235 
236 	SOCKBUF_LOCK(&so->so_rcv);
237 	soupcall_set(so, SO_RCV, svc_vc_soupcall, xprt);
238 	SOCKBUF_UNLOCK(&so->so_rcv);
239 
240 	/*
241 	 * Throw the transport into the active list in case it already
242 	 * has some data buffered.
243 	 */
244 	sx_xlock(&xprt->xp_lock);
245 	xprt_active(xprt);
246 	sx_xunlock(&xprt->xp_lock);
247 
248 	return (xprt);
249 cleanup_svc_vc_create:
250 	if (xprt) {
251 		mem_free(xprt, sizeof(*xprt));
252 	}
253 	if (cd)
254 		mem_free(cd, sizeof(*cd));
255 	return (NULL);
256 }
257 
258 /*
259  * This does all of the accept except the final call to soaccept. The
260  * caller will call soaccept after dropping its locks (soaccept may
261  * call malloc).
262  */
263 int
264 svc_vc_accept(struct socket *head, struct socket **sop)
265 {
266 	int error = 0;
267 	struct socket *so;
268 
269 	if ((head->so_options & SO_ACCEPTCONN) == 0) {
270 		error = EINVAL;
271 		goto done;
272 	}
273 #ifdef MAC
274 	error = mac_socket_check_accept(td->td_ucred, head);
275 	if (error != 0)
276 		goto done;
277 #endif
278 	ACCEPT_LOCK();
279 	if (TAILQ_EMPTY(&head->so_comp)) {
280 		ACCEPT_UNLOCK();
281 		error = EWOULDBLOCK;
282 		goto done;
283 	}
284 	so = TAILQ_FIRST(&head->so_comp);
285 	KASSERT(!(so->so_qstate & SQ_INCOMP), ("svc_vc_accept: so SQ_INCOMP"));
286 	KASSERT(so->so_qstate & SQ_COMP, ("svc_vc_accept: so not SQ_COMP"));
287 
288 	/*
289 	 * Before changing the flags on the socket, we have to bump the
290 	 * reference count.  Otherwise, if the protocol calls sofree(),
291 	 * the socket will be released due to a zero refcount.
292 	 * XXX might not need soref() since this is simpler than kern_accept.
293 	 */
294 	SOCK_LOCK(so);			/* soref() and so_state update */
295 	soref(so);			/* file descriptor reference */
296 
297 	TAILQ_REMOVE(&head->so_comp, so, so_list);
298 	head->so_qlen--;
299 	so->so_state |= (head->so_state & SS_NBIO);
300 	so->so_qstate &= ~SQ_COMP;
301 	so->so_head = NULL;
302 
303 	SOCK_UNLOCK(so);
304 	ACCEPT_UNLOCK();
305 
306 	*sop = so;
307 
308 	/* connection has been removed from the listen queue */
309 	KNOTE_UNLOCKED(&head->so_rcv.sb_sel.si_note, 0);
310 done:
311 	return (error);
312 }
313 
314 /*ARGSUSED*/
315 static bool_t
316 svc_vc_rendezvous_recv(SVCXPRT *xprt, struct rpc_msg *msg,
317     struct sockaddr **addrp, struct mbuf **mp)
318 {
319 	struct socket *so = NULL;
320 	struct sockaddr *sa = NULL;
321 	int error;
322 
323 	/*
324 	 * The socket upcall calls xprt_active() which will eventually
325 	 * cause the server to call us here. We attempt to accept a
326 	 * connection from the socket and turn it into a new
327 	 * transport. If the accept fails, we have drained all pending
328 	 * connections so we call xprt_inactive().
329 	 */
330 	sx_xlock(&xprt->xp_lock);
331 
332 	error = svc_vc_accept(xprt->xp_socket, &so);
333 
334 	if (error == EWOULDBLOCK) {
335 		/*
336 		 * We must re-test for new connections after taking
337 		 * the lock to protect us in the case where a new
338 		 * connection arrives after our call to accept fails
339 		 * with EWOULDBLOCK. The pool lock protects us from
340 		 * racing the upcall after our TAILQ_EMPTY() call
341 		 * returns false.
342 		 */
343 		ACCEPT_LOCK();
344 		mtx_lock(&xprt->xp_pool->sp_lock);
345 		if (TAILQ_EMPTY(&xprt->xp_socket->so_comp))
346 			xprt_inactive_locked(xprt);
347 		mtx_unlock(&xprt->xp_pool->sp_lock);
348 		ACCEPT_UNLOCK();
349 		sx_xunlock(&xprt->xp_lock);
350 		return (FALSE);
351 	}
352 
353 	if (error) {
354 		SOCKBUF_LOCK(&xprt->xp_socket->so_rcv);
355 		soupcall_clear(xprt->xp_socket, SO_RCV);
356 		SOCKBUF_UNLOCK(&xprt->xp_socket->so_rcv);
357 		xprt_inactive(xprt);
358 		sx_xunlock(&xprt->xp_lock);
359 		return (FALSE);
360 	}
361 
362 	sx_xunlock(&xprt->xp_lock);
363 
364 	sa = 0;
365 	error = soaccept(so, &sa);
366 
367 	if (error) {
368 		/*
369 		 * XXX not sure if I need to call sofree or soclose here.
370 		 */
371 		if (sa)
372 			free(sa, M_SONAME);
373 		return (FALSE);
374 	}
375 
376 	/*
377 	 * svc_vc_create_conn will call xprt_register - we don't need
378 	 * to do anything with the new connection.
379 	 */
380 	if (!svc_vc_create_conn(xprt->xp_pool, so, sa))
381 		soclose(so);
382 
383 	free(sa, M_SONAME);
384 
385 	return (FALSE); /* there is never an rpc msg to be processed */
386 }
387 
388 /*ARGSUSED*/
389 static enum xprt_stat
390 svc_vc_rendezvous_stat(SVCXPRT *xprt)
391 {
392 
393 	return (XPRT_IDLE);
394 }
395 
396 static void
397 svc_vc_destroy_common(SVCXPRT *xprt)
398 {
399 	SOCKBUF_LOCK(&xprt->xp_socket->so_rcv);
400 	soupcall_clear(xprt->xp_socket, SO_RCV);
401 	SOCKBUF_UNLOCK(&xprt->xp_socket->so_rcv);
402 
403 	sx_destroy(&xprt->xp_lock);
404 	if (xprt->xp_socket)
405 		(void)soclose(xprt->xp_socket);
406 
407 	if (xprt->xp_netid)
408 		(void) mem_free(xprt->xp_netid, strlen(xprt->xp_netid) + 1);
409 	svc_xprt_free(xprt);
410 }
411 
412 static void
413 svc_vc_rendezvous_destroy(SVCXPRT *xprt)
414 {
415 
416 	svc_vc_destroy_common(xprt);
417 }
418 
419 static void
420 svc_vc_destroy(SVCXPRT *xprt)
421 {
422 	struct cf_conn *cd = (struct cf_conn *)xprt->xp_p1;
423 
424 	svc_vc_destroy_common(xprt);
425 
426 	if (cd->mreq)
427 		m_freem(cd->mreq);
428 	if (cd->mpending)
429 		m_freem(cd->mpending);
430 	mem_free(cd, sizeof(*cd));
431 }
432 
433 /*ARGSUSED*/
434 static bool_t
435 svc_vc_control(SVCXPRT *xprt, const u_int rq, void *in)
436 {
437 	return (FALSE);
438 }
439 
440 static bool_t
441 svc_vc_rendezvous_control(SVCXPRT *xprt, const u_int rq, void *in)
442 {
443 
444 	return (FALSE);
445 }
446 
447 static enum xprt_stat
448 svc_vc_stat(SVCXPRT *xprt)
449 {
450 	struct cf_conn *cd;
451 	struct mbuf *m;
452 	size_t n;
453 
454 	cd = (struct cf_conn *)(xprt->xp_p1);
455 
456 	if (cd->strm_stat == XPRT_DIED)
457 		return (XPRT_DIED);
458 
459 	/*
460 	 * Return XPRT_MOREREQS if we have buffered data and we are
461 	 * mid-record or if we have enough data for a record
462 	 * marker. Since this is only a hint, we read mpending and
463 	 * resid outside the lock. We do need to take the lock if we
464 	 * have to traverse the mbuf chain.
465 	 */
466 	if (cd->mpending) {
467 		if (cd->resid)
468 			return (XPRT_MOREREQS);
469 		n = 0;
470 		sx_xlock(&xprt->xp_lock);
471 		m = cd->mpending;
472 		while (m && n < sizeof(uint32_t)) {
473 			n += m->m_len;
474 			m = m->m_next;
475 		}
476 		sx_xunlock(&xprt->xp_lock);
477 		if (n >= sizeof(uint32_t))
478 			return (XPRT_MOREREQS);
479 	}
480 
481 	if (soreadable(xprt->xp_socket))
482 		return (XPRT_MOREREQS);
483 
484 	return (XPRT_IDLE);
485 }
486 
487 static bool_t
488 svc_vc_recv(SVCXPRT *xprt, struct rpc_msg *msg,
489     struct sockaddr **addrp, struct mbuf **mp)
490 {
491 	struct cf_conn *cd = (struct cf_conn *) xprt->xp_p1;
492 	struct uio uio;
493 	struct mbuf *m;
494 	XDR xdrs;
495 	int error, rcvflag;
496 
497 	/*
498 	 * Serialise access to the socket and our own record parsing
499 	 * state.
500 	 */
501 	sx_xlock(&xprt->xp_lock);
502 
503 	for (;;) {
504 		/*
505 		 * If we have an mbuf chain in cd->mpending, try to parse a
506 		 * record from it, leaving the result in cd->mreq. If we don't
507 		 * have a complete record, leave the partial result in
508 		 * cd->mreq and try to read more from the socket.
509 		 */
510 		if (cd->mpending) {
511 			/*
512 			 * If cd->resid is non-zero, we have part of the
513 			 * record already, otherwise we are expecting a record
514 			 * marker.
515 			 */
516 			if (!cd->resid) {
517 				/*
518 				 * See if there is enough data buffered to
519 				 * make up a record marker. Make sure we can
520 				 * handle the case where the record marker is
521 				 * split across more than one mbuf.
522 				 */
523 				size_t n = 0;
524 				uint32_t header;
525 
526 				m = cd->mpending;
527 				while (n < sizeof(uint32_t) && m) {
528 					n += m->m_len;
529 					m = m->m_next;
530 				}
531 				if (n < sizeof(uint32_t))
532 					goto readmore;
533 				if (cd->mpending->m_len < sizeof(uint32_t))
534 					cd->mpending = m_pullup(cd->mpending,
535 					    sizeof(uint32_t));
536 				memcpy(&header, mtod(cd->mpending, uint32_t *),
537 				    sizeof(header));
538 				header = ntohl(header);
539 				cd->eor = (header & 0x80000000) != 0;
540 				cd->resid = header & 0x7fffffff;
541 				m_adj(cd->mpending, sizeof(uint32_t));
542 			}
543 
544 			/*
545 			 * Start pulling off mbufs from cd->mpending
546 			 * until we either have a complete record or
547 			 * we run out of data. We use m_split to pull
548 			 * data - it will pull as much as possible and
549 			 * split the last mbuf if necessary.
550 			 */
551 			while (cd->mpending && cd->resid) {
552 				m = cd->mpending;
553 				if (cd->mpending->m_next
554 				    || cd->mpending->m_len > cd->resid)
555 					cd->mpending = m_split(cd->mpending,
556 					    cd->resid, M_WAIT);
557 				else
558 					cd->mpending = NULL;
559 				if (cd->mreq)
560 					m_last(cd->mreq)->m_next = m;
561 				else
562 					cd->mreq = m;
563 				while (m) {
564 					cd->resid -= m->m_len;
565 					m = m->m_next;
566 				}
567 			}
568 
569 			/*
570 			 * If cd->resid is zero now, we have managed to
571 			 * receive a record fragment from the stream. Check
572 			 * for the end-of-record mark to see if we need more.
573 			 */
574 			if (cd->resid == 0) {
575 				if (!cd->eor)
576 					continue;
577 
578 				/*
579 				 * Success - we have a complete record in
580 				 * cd->mreq.
581 				 */
582 				xdrmbuf_create(&xdrs, cd->mreq, XDR_DECODE);
583 				cd->mreq = NULL;
584 				sx_xunlock(&xprt->xp_lock);
585 
586 				if (! xdr_callmsg(&xdrs, msg)) {
587 					XDR_DESTROY(&xdrs);
588 					return (FALSE);
589 				}
590 
591 				*addrp = NULL;
592 				*mp = xdrmbuf_getall(&xdrs);
593 				XDR_DESTROY(&xdrs);
594 
595 				return (TRUE);
596 			}
597 		}
598 
599 	readmore:
600 		/*
601 		 * The socket upcall calls xprt_active() which will eventually
602 		 * cause the server to call us here. We attempt to
603 		 * read as much as possible from the socket and put
604 		 * the result in cd->mpending. If the read fails,
605 		 * we have drained both cd->mpending and the socket so
606 		 * we can call xprt_inactive().
607 		 */
608 		uio.uio_resid = 1000000000;
609 		uio.uio_td = curthread;
610 		m = NULL;
611 		rcvflag = MSG_DONTWAIT;
612 		error = soreceive(xprt->xp_socket, NULL, &uio, &m, NULL,
613 		    &rcvflag);
614 
615 		if (error == EWOULDBLOCK) {
616 			/*
617 			 * We must re-test for readability after
618 			 * taking the lock to protect us in the case
619 			 * where a new packet arrives on the socket
620 			 * after our call to soreceive fails with
621 			 * EWOULDBLOCK. The pool lock protects us from
622 			 * racing the upcall after our soreadable()
623 			 * call returns false.
624 			 */
625 			mtx_lock(&xprt->xp_pool->sp_lock);
626 			if (!soreadable(xprt->xp_socket))
627 				xprt_inactive_locked(xprt);
628 			mtx_unlock(&xprt->xp_pool->sp_lock);
629 			sx_xunlock(&xprt->xp_lock);
630 			return (FALSE);
631 		}
632 
633 		if (error) {
634 			SOCKBUF_LOCK(&xprt->xp_socket->so_rcv);
635 			soupcall_clear(xprt->xp_socket, SO_RCV);
636 			SOCKBUF_UNLOCK(&xprt->xp_socket->so_rcv);
637 			xprt_inactive(xprt);
638 			cd->strm_stat = XPRT_DIED;
639 			sx_xunlock(&xprt->xp_lock);
640 			return (FALSE);
641 		}
642 
643 		if (!m) {
644 			/*
645 			 * EOF - the other end has closed the socket.
646 			 */
647 			xprt_inactive(xprt);
648 			cd->strm_stat = XPRT_DIED;
649 			sx_xunlock(&xprt->xp_lock);
650 			return (FALSE);
651 		}
652 
653 		if (cd->mpending)
654 			m_last(cd->mpending)->m_next = m;
655 		else
656 			cd->mpending = m;
657 	}
658 }
659 
660 static bool_t
661 svc_vc_reply(SVCXPRT *xprt, struct rpc_msg *msg,
662     struct sockaddr *addr, struct mbuf *m)
663 {
664 	XDR xdrs;
665 	struct mbuf *mrep;
666 	bool_t stat = TRUE;
667 	int error;
668 
669 	/*
670 	 * Leave space for record mark.
671 	 */
672 	MGETHDR(mrep, M_WAIT, MT_DATA);
673 	mrep->m_len = 0;
674 	mrep->m_data += sizeof(uint32_t);
675 
676 	xdrmbuf_create(&xdrs, mrep, XDR_ENCODE);
677 
678 	if (msg->rm_reply.rp_stat == MSG_ACCEPTED &&
679 	    msg->rm_reply.rp_acpt.ar_stat == SUCCESS) {
680 		if (!xdr_replymsg(&xdrs, msg))
681 			stat = FALSE;
682 		else
683 			xdrmbuf_append(&xdrs, m);
684 	} else {
685 		stat = xdr_replymsg(&xdrs, msg);
686 	}
687 
688 	if (stat) {
689 		m_fixhdr(mrep);
690 
691 		/*
692 		 * Prepend a record marker containing the reply length.
693 		 */
694 		M_PREPEND(mrep, sizeof(uint32_t), M_WAIT);
695 		*mtod(mrep, uint32_t *) =
696 			htonl(0x80000000 | (mrep->m_pkthdr.len
697 				- sizeof(uint32_t)));
698 		error = sosend(xprt->xp_socket, NULL, NULL, mrep, NULL,
699 		    0, curthread);
700 		if (!error) {
701 			stat = TRUE;
702 		}
703 	} else {
704 		m_freem(mrep);
705 	}
706 
707 	XDR_DESTROY(&xdrs);
708 	xprt->xp_p2 = NULL;
709 
710 	return (stat);
711 }
712 
713 static bool_t
714 svc_vc_null()
715 {
716 
717 	return (FALSE);
718 }
719 
720 static int
721 svc_vc_soupcall(struct socket *so, void *arg, int waitflag)
722 {
723 	SVCXPRT *xprt = (SVCXPRT *) arg;
724 
725 	xprt_active(xprt);
726 	return (SU_OK);
727 }
728 
729 #if 0
730 /*
731  * Get the effective UID of the sending process. Used by rpcbind, keyserv
732  * and rpc.yppasswdd on AF_LOCAL.
733  */
734 int
735 __rpc_get_local_uid(SVCXPRT *transp, uid_t *uid) {
736 	int sock, ret;
737 	gid_t egid;
738 	uid_t euid;
739 	struct sockaddr *sa;
740 
741 	sock = transp->xp_fd;
742 	sa = (struct sockaddr *)transp->xp_rtaddr;
743 	if (sa->sa_family == AF_LOCAL) {
744 		ret = getpeereid(sock, &euid, &egid);
745 		if (ret == 0)
746 			*uid = euid;
747 		return (ret);
748 	} else
749 		return (-1);
750 }
751 #endif
752