xref: /openbsd-src/sys/nfs/nfs_socket.c (revision 43003dfe3ad45d1698bed8a37f2b0f5b14f20d4f)
1 /*	$OpenBSD: nfs_socket.c,v 1.95 2009/08/25 13:41:29 thib Exp $	*/
2 /*	$NetBSD: nfs_socket.c,v 1.27 1996/04/15 20:20:00 thorpej Exp $	*/
3 
4 /*
5  * Copyright (c) 1989, 1991, 1993, 1995
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * This code is derived from software contributed to Berkeley by
9  * Rick Macklem at The University of Guelph.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  *
35  *	@(#)nfs_socket.c	8.5 (Berkeley) 3/30/95
36  */
37 
38 /*
39  * Socket operations for use by nfs
40  */
41 
42 #include <sys/param.h>
43 #include <sys/systm.h>
44 #include <sys/proc.h>
45 #include <sys/mount.h>
46 #include <sys/kernel.h>
47 #include <sys/mbuf.h>
48 #include <sys/vnode.h>
49 #include <sys/domain.h>
50 #include <sys/protosw.h>
51 #include <sys/socket.h>
52 #include <sys/socketvar.h>
53 #include <sys/syslog.h>
54 #include <sys/tprintf.h>
55 #include <sys/namei.h>
56 #include <sys/pool.h>
57 #include <sys/queue.h>
58 
59 #include <netinet/in.h>
60 #include <netinet/tcp.h>
61 
62 #include <nfs/rpcv2.h>
63 #include <nfs/nfsproto.h>
64 #include <nfs/nfs.h>
65 #include <nfs/xdr_subs.h>
66 #include <nfs/nfsm_subs.h>
67 #include <nfs/nfsmount.h>
68 #include <nfs/nfsnode.h>
69 #include <nfs/nfs_var.h>
70 
71 /* External data, mostly RPC constants in XDR form. */
72 extern u_int32_t rpc_reply, rpc_msgdenied, rpc_mismatch, rpc_vers,
73 	rpc_auth_unix, rpc_msgaccepted, rpc_call, rpc_autherr;
74 extern u_int32_t nfs_prog;
75 extern struct nfsstats nfsstats;
76 extern int nfsv3_procid[NFS_NPROCS];
77 extern int nfs_ticks;
78 
79 extern struct pool nfsrv_descript_pl;
80 
81 /*
82  * There is a congestion window for outstanding rpcs maintained per mount
83  * point. The cwnd size is adjusted in roughly the way that:
84  * Van Jacobson, Congestion avoidance and Control, In "Proceedings of
85  * SIGCOMM '88". ACM, August 1988.
86  * describes for TCP. The cwnd size is chopped in half on a retransmit timeout
87  * and incremented by 1/cwnd when each rpc reply is received and a full cwnd
88  * of rpcs is in progress.
89  * (The sent count and cwnd are scaled for integer arith.)
90  * Variants of "slow start" were tried and were found to be too much of a
91  * performance hit (ave. rtt 3 times larger),
92  * I suspect due to the large rtt that nfs rpcs have.
93  */
94 #define	NFS_CWNDSCALE	256
95 #define	NFS_MAXCWND	(NFS_CWNDSCALE * 32)
96 int nfs_backoff[8] = { 2, 4, 8, 16, 32, 64, 128, 256 };
97 
98 /* RTT estimator */
99 enum nfs_rto_timers nfs_ptimers[NFS_NPROCS] = {
100 	NFS_DEFAULT_TIMER,	/* NULL */
101 	NFS_GETATTR_TIMER,	/* GETATTR */
102 	NFS_DEFAULT_TIMER,	/* SETATTR */
103 	NFS_LOOKUP_TIMER,	/* LOOKUP */
104 	NFS_GETATTR_TIMER,	/* ACCESS */
105 	NFS_READ_TIMER,		/* READLINK */
106 	NFS_READ_TIMER,		/* READ */
107 	NFS_WRITE_TIMER,	/* WRITE */
108 	NFS_DEFAULT_TIMER,	/* CREATE */
109 	NFS_DEFAULT_TIMER,	/* MKDIR */
110 	NFS_DEFAULT_TIMER,	/* SYMLINK */
111 	NFS_DEFAULT_TIMER,	/* MKNOD */
112 	NFS_DEFAULT_TIMER,	/* REMOVE */
113 	NFS_DEFAULT_TIMER,	/* RMDIR */
114 	NFS_DEFAULT_TIMER,	/* RENAME */
115 	NFS_DEFAULT_TIMER,	/* LINK */
116 	NFS_READ_TIMER,		/* READDIR */
117 	NFS_READ_TIMER,		/* READDIRPLUS */
118 	NFS_DEFAULT_TIMER,	/* FSSTAT */
119 	NFS_DEFAULT_TIMER,	/* FSINFO */
120 	NFS_DEFAULT_TIMER,	/* PATHCONF */
121 	NFS_DEFAULT_TIMER,	/* COMMIT */
122 	NFS_DEFAULT_TIMER,	/* NOOP */
123 };
124 
125 void nfs_init_rtt(struct nfsmount *);
126 void nfs_update_rtt(struct nfsreq *);
127 int  nfs_estimate_rto(struct nfsmount *, u_int32_t procnum);
128 
129 void nfs_realign(struct mbuf **, int);
130 void nfs_realign_fixup(struct mbuf *, struct mbuf *, unsigned int *);
131 unsigned int nfs_realign_test = 0;
132 unsigned int nfs_realign_count = 0;
133 
134 /* Initialize the RTT estimator state for a new mount point. */
135 void
136 nfs_init_rtt(struct nfsmount *nmp)
137 {
138 	int i;
139 
140 	for (i = 0; i < NFS_MAX_TIMER; i++)
141 		nmp->nm_srtt[i] = NFS_INITRTT;
142 	for (i = 0; i < NFS_MAX_TIMER; i++)
143 		nmp->nm_sdrtt[i] = 0;
144 }
145 
146 /*
147  * Update a mount point's RTT estimator state using data from the
148  * passed-in request.
149  *
150  * Use a gain of 0.125 on the mean and a gain of 0.25 on the deviation.
151  *
152  * NB: Since the timer resolution of NFS_HZ is so course, it can often
153  * result in r_rtt == 0. Since r_rtt == N means that the actual RTT is
154  * between N + dt and N + 2 - dt ticks, add 1 before calculating the
155  * update values.
156  */
157 void
158 nfs_update_rtt(struct nfsreq *rep)
159 {
160 	int t1 = rep->r_rtt + 1;
161 	int index = nfs_ptimers[rep->r_procnum] - 1;
162 	int *srtt = &rep->r_nmp->nm_srtt[index];
163 	int *sdrtt = &rep->r_nmp->nm_sdrtt[index];
164 
165 	t1 -= *srtt >> 3;
166 	*srtt += t1;
167 	if (t1 < 0)
168 		t1 = -t1;
169 	t1 -= *sdrtt >> 2;
170 	*sdrtt += t1;
171 }
172 
173 /*
174  * Estimate RTO for an NFS RPC sent via an unreliable datagram.
175  *
176  * Use the mean and mean deviation of RTT for the appropriate type
177  * of RPC for the frequent RPCs and a default for the others.
178  * The justification for doing "other" this way is that these RPCs
179  * happen so infrequently that timer est. would probably be stale.
180  * Also, since many of these RPCs are non-idempotent, a conservative
181  * timeout is desired.
182  *
183  * getattr, lookup - A+2D
184  * read, write     - A+4D
185  * other           - nm_timeo
186  */
187 int
188 nfs_estimate_rto(struct nfsmount *nmp, u_int32_t procnum)
189 {
190 	enum nfs_rto_timers timer = nfs_ptimers[procnum];
191 	int index = timer - 1;
192 	int rto;
193 
194 	switch (timer) {
195 	case NFS_GETATTR_TIMER:
196 	case NFS_LOOKUP_TIMER:
197 		rto = ((nmp->nm_srtt[index] + 3) >> 2) +
198 				((nmp->nm_sdrtt[index] + 1) >> 1);
199 		break;
200 	case NFS_READ_TIMER:
201 	case NFS_WRITE_TIMER:
202 		rto = ((nmp->nm_srtt[index] + 7) >> 3) +
203 				(nmp->nm_sdrtt[index] + 1);
204 		break;
205 	default:
206 		rto = nmp->nm_timeo;
207 		return (rto);
208 	}
209 
210 	if (rto < NFS_MINRTO)
211 		rto = NFS_MINRTO;
212 	else if (rto > NFS_MAXRTO)
213 		rto = NFS_MAXRTO;
214 
215 	return (rto);
216 }
217 
218 
219 
220 /*
221  * Initialize sockets and congestion for a new NFS connection.
222  * We do not free the sockaddr if error.
223  */
224 int
225 nfs_connect(nmp, rep)
226 	struct nfsmount *nmp;
227 	struct nfsreq *rep;
228 {
229 	struct socket *so;
230 	int s, error, rcvreserve, sndreserve;
231 	struct sockaddr *saddr;
232 	struct sockaddr_in *sin;
233 	struct mbuf *m;
234 
235 	nmp->nm_so = NULL;
236 	saddr = mtod(nmp->nm_nam, struct sockaddr *);
237 	error = socreate(saddr->sa_family, &nmp->nm_so, nmp->nm_sotype,
238 		nmp->nm_soproto);
239 	if (error)
240 		goto bad;
241 	so = nmp->nm_so;
242 	nmp->nm_soflags = so->so_proto->pr_flags;
243 
244 	/*
245 	 * Some servers require that the client port be a reserved port number.
246 	 * We always allocate a reserved port, as this prevents filehandle
247 	 * disclosure through UDP port capture.
248 	 */
249 	if (saddr->sa_family == AF_INET) {
250 		struct mbuf *mopt;
251 		int *ip;
252 
253 		MGET(mopt, M_WAIT, MT_SOOPTS);
254 		mopt->m_len = sizeof(int);
255 		ip = mtod(mopt, int *);
256 		*ip = IP_PORTRANGE_LOW;
257 		error = sosetopt(so, IPPROTO_IP, IP_PORTRANGE, mopt);
258 		if (error)
259 			goto bad;
260 
261 		MGET(m, M_WAIT, MT_SONAME);
262 		sin = mtod(m, struct sockaddr_in *);
263 		sin->sin_len = m->m_len = sizeof (struct sockaddr_in);
264 		sin->sin_family = AF_INET;
265 		sin->sin_addr.s_addr = INADDR_ANY;
266 		sin->sin_port = htons(0);
267 		error = sobind(so, m, &proc0);
268 		m_freem(m);
269 		if (error)
270 			goto bad;
271 
272 		MGET(mopt, M_WAIT, MT_SOOPTS);
273 		mopt->m_len = sizeof(int);
274 		ip = mtod(mopt, int *);
275 		*ip = IP_PORTRANGE_DEFAULT;
276 		error = sosetopt(so, IPPROTO_IP, IP_PORTRANGE, mopt);
277 		if (error)
278 			goto bad;
279 	}
280 
281 	/*
282 	 * Protocols that do not require connections may be optionally left
283 	 * unconnected for servers that reply from a port other than NFS_PORT.
284 	 */
285 	if (nmp->nm_flag & NFSMNT_NOCONN) {
286 		if (nmp->nm_soflags & PR_CONNREQUIRED) {
287 			error = ENOTCONN;
288 			goto bad;
289 		}
290 	} else {
291 		error = soconnect(so, nmp->nm_nam);
292 		if (error)
293 			goto bad;
294 
295 		/*
296 		 * Wait for the connection to complete. Cribbed from the
297 		 * connect system call but with the wait timing out so
298 		 * that interruptible mounts don't hang here for a long time.
299 		 */
300 		s = splsoftnet();
301 		while ((so->so_state & SS_ISCONNECTING) && so->so_error == 0) {
302 			(void) tsleep((caddr_t)&so->so_timeo, PSOCK,
303 				"nfscon", 2 * hz);
304 			if ((so->so_state & SS_ISCONNECTING) &&
305 			    so->so_error == 0 && rep &&
306 			    (error = nfs_sigintr(nmp, rep, rep->r_procp)) != 0){
307 				so->so_state &= ~SS_ISCONNECTING;
308 				splx(s);
309 				goto bad;
310 			}
311 		}
312 		if (so->so_error) {
313 			error = so->so_error;
314 			so->so_error = 0;
315 			splx(s);
316 			goto bad;
317 		}
318 		splx(s);
319 	}
320 	/*
321 	 * Always set receive timeout to detect server crash and reconnect.
322 	 * Otherwise, we can get stuck in soreceive forever.
323 	 */
324 	so->so_rcv.sb_timeo = (5 * hz);
325 	if (nmp->nm_flag & (NFSMNT_SOFT | NFSMNT_INT))
326 		so->so_snd.sb_timeo = (5 * hz);
327 	else
328 		so->so_snd.sb_timeo = 0;
329 	if (nmp->nm_sotype == SOCK_DGRAM) {
330 		sndreserve = nmp->nm_wsize + NFS_MAXPKTHDR;
331 		rcvreserve = (max(nmp->nm_rsize, nmp->nm_readdirsize) +
332 		    NFS_MAXPKTHDR) * 2;
333 	} else if (nmp->nm_sotype == SOCK_SEQPACKET) {
334 		sndreserve = (nmp->nm_wsize + NFS_MAXPKTHDR) * 2;
335 		rcvreserve = (max(nmp->nm_rsize, nmp->nm_readdirsize) +
336 		    NFS_MAXPKTHDR) * 2;
337 	} else {
338 		if (nmp->nm_sotype != SOCK_STREAM)
339 			panic("nfscon sotype");
340 		if (so->so_proto->pr_flags & PR_CONNREQUIRED) {
341 			MGET(m, M_WAIT, MT_SOOPTS);
342 			*mtod(m, int32_t *) = 1;
343 			m->m_len = sizeof(int32_t);
344 			sosetopt(so, SOL_SOCKET, SO_KEEPALIVE, m);
345 		}
346 		if (so->so_proto->pr_protocol == IPPROTO_TCP) {
347 			MGET(m, M_WAIT, MT_SOOPTS);
348 			*mtod(m, int32_t *) = 1;
349 			m->m_len = sizeof(int32_t);
350 			sosetopt(so, IPPROTO_TCP, TCP_NODELAY, m);
351 		}
352 		sndreserve = (nmp->nm_wsize + NFS_MAXPKTHDR +
353 		    sizeof (u_int32_t)) * 2;
354 		rcvreserve = (nmp->nm_rsize + NFS_MAXPKTHDR +
355 		    sizeof (u_int32_t)) * 2;
356 	}
357 	error = soreserve(so, sndreserve, rcvreserve);
358 	if (error)
359 		goto bad;
360 	so->so_rcv.sb_flags |= SB_NOINTR;
361 	so->so_snd.sb_flags |= SB_NOINTR;
362 
363 	/* Initialize other non-zero congestion variables */
364 	nfs_init_rtt(nmp);
365 	nmp->nm_cwnd = NFS_MAXCWND / 2;	    /* Initial send window */
366 	nmp->nm_sent = 0;
367 	nmp->nm_timeouts = 0;
368 	return (0);
369 
370 bad:
371 	nfs_disconnect(nmp);
372 	return (error);
373 }
374 
375 /*
376  * Reconnect routine:
377  * Called when a connection is broken on a reliable protocol.
378  * - clean up the old socket
379  * - nfs_connect() again
380  * - set R_MUSTRESEND for all outstanding requests on mount point
381  * If this fails the mount point is DEAD!
382  * nb: Must be called with the nfs_sndlock() set on the mount point.
383  */
384 int
385 nfs_reconnect(rep)
386 	struct nfsreq *rep;
387 {
388 	struct nfsreq *rp;
389 	struct nfsmount *nmp = rep->r_nmp;
390 	int s, error;
391 
392 	nfs_disconnect(nmp);
393 	while ((error = nfs_connect(nmp, rep)) != 0) {
394 		if (error == EINTR || error == ERESTART)
395 			return (EINTR);
396 		(void) tsleep((caddr_t)&lbolt, PSOCK, "nfsrecon", 0);
397 	}
398 
399 	/*
400 	 * Loop through outstanding request list and fix up all requests
401 	 * on old socket.
402 	 */
403 	s = splsoftnet();
404 	TAILQ_FOREACH(rp, &nmp->nm_reqsq, r_chain) {
405 		rp->r_flags |= R_MUSTRESEND;
406 		rp->r_rexmit = 0;
407 	}
408 	splx(s);
409 	return (0);
410 }
411 
412 /*
413  * NFS disconnect. Clean up and unlink.
414  */
415 void
416 nfs_disconnect(nmp)
417 	struct nfsmount *nmp;
418 {
419 	struct socket *so;
420 
421 	if (nmp->nm_so) {
422 		so = nmp->nm_so;
423 		nmp->nm_so = NULL;
424 		soshutdown(so, SHUT_RDWR);
425 		soclose(so);
426 	}
427 }
428 
429 /*
430  * This is the nfs send routine. For connection based socket types, it
431  * must be called with an nfs_sndlock() on the socket.
432  * "rep == NULL" indicates that it has been called from a server.
433  * For the client side:
434  * - return EINTR if the RPC is terminated, 0 otherwise
435  * - set R_MUSTRESEND if the send fails for any reason
436  * - do any cleanup required by recoverable socket errors (???)
437  * For the server side:
438  * - return EINTR or ERESTART if interrupted by a signal
439  * - return EPIPE if a connection is lost for connection based sockets (TCP...)
440  * - do any cleanup required by recoverable socket errors (???)
441  */
442 int
443 nfs_send(so, nam, top, rep)
444 	struct socket *so;
445 	struct mbuf *nam;
446 	struct mbuf *top;
447 	struct nfsreq *rep;
448 {
449 	struct mbuf *sendnam;
450 	int error, soflags, flags;
451 
452 	if (rep) {
453 		if (rep->r_flags & R_SOFTTERM) {
454 			m_freem(top);
455 			return (EINTR);
456 		}
457 		if ((so = rep->r_nmp->nm_so) == NULL) {
458 			rep->r_flags |= R_MUSTRESEND;
459 			m_freem(top);
460 			return (0);
461 		}
462 		rep->r_flags &= ~R_MUSTRESEND;
463 		soflags = rep->r_nmp->nm_soflags;
464 	} else
465 		soflags = so->so_proto->pr_flags;
466 	if ((soflags & PR_CONNREQUIRED) || (so->so_state & SS_ISCONNECTED))
467 		sendnam = NULL;
468 	else
469 		sendnam = nam;
470 	if (so->so_type == SOCK_SEQPACKET)
471 		flags = MSG_EOR;
472 	else
473 		flags = 0;
474 
475 	error = sosend(so, sendnam, NULL, top, NULL, flags);
476 	if (error) {
477 		if (rep) {
478 			/*
479 			 * Deal with errors for the client side.
480 			 */
481 			if (rep->r_flags & R_SOFTTERM)
482 				error = EINTR;
483 			else
484 				rep->r_flags |= R_MUSTRESEND;
485 		}
486 
487 		/*
488 		 * Handle any recoverable (soft) socket errors here. (???)
489 		 */
490 		if (error != EINTR && error != ERESTART &&
491 			error != EWOULDBLOCK && error != EPIPE)
492 			error = 0;
493 	}
494 	return (error);
495 }
496 
497 #ifdef NFSCLIENT
498 /*
499  * Receive a Sun RPC Request/Reply. For SOCK_DGRAM, the work is all
500  * done by soreceive(), but for SOCK_STREAM we must deal with the Record
501  * Mark and consolidate the data into a new mbuf list.
502  * nb: Sometimes TCP passes the data up to soreceive() in long lists of
503  *     small mbufs.
504  * For SOCK_STREAM we must be very careful to read an entire record once
505  * we have read any of it, even if the system call has been interrupted.
506  */
507 int
508 nfs_receive(rep, aname, mp)
509 	struct nfsreq *rep;
510 	struct mbuf **aname;
511 	struct mbuf **mp;
512 {
513 	struct socket *so;
514 	struct uio auio;
515 	struct iovec aio;
516 	struct mbuf *m;
517 	struct mbuf *control;
518 	u_int32_t len;
519 	struct mbuf **getnam;
520 	int error, sotype, rcvflg;
521 	struct proc *p = curproc;	/* XXX */
522 
523 	/*
524 	 * Set up arguments for soreceive()
525 	 */
526 	*mp = NULL;
527 	*aname = NULL;
528 	sotype = rep->r_nmp->nm_sotype;
529 
530 	/*
531 	 * For reliable protocols, lock against other senders/receivers
532 	 * in case a reconnect is necessary.
533 	 * For SOCK_STREAM, first get the Record Mark to find out how much
534 	 * more there is to get.
535 	 * We must lock the socket against other receivers
536 	 * until we have an entire rpc request/reply.
537 	 */
538 	if (sotype != SOCK_DGRAM) {
539 		error = nfs_sndlock(&rep->r_nmp->nm_flag, rep);
540 		if (error)
541 			return (error);
542 tryagain:
543 		/*
544 		 * Check for fatal errors and resending request.
545 		 */
546 		/*
547 		 * Ugh: If a reconnect attempt just happened, nm_so
548 		 * would have changed. NULL indicates a failed
549 		 * attempt that has essentially shut down this
550 		 * mount point.
551 		 */
552 		if (rep->r_mrep || (rep->r_flags & R_SOFTTERM)) {
553 			nfs_sndunlock(&rep->r_nmp->nm_flag);
554 			return (EINTR);
555 		}
556 		so = rep->r_nmp->nm_so;
557 		if (!so) {
558 			error = nfs_reconnect(rep);
559 			if (error) {
560 				nfs_sndunlock(&rep->r_nmp->nm_flag);
561 				return (error);
562 			}
563 			goto tryagain;
564 		}
565 		while (rep->r_flags & R_MUSTRESEND) {
566 			m = m_copym(rep->r_mreq, 0, M_COPYALL, M_WAIT);
567 			nfsstats.rpcretries++;
568 			rep->r_rtt = 0;
569 			rep->r_flags &= ~R_TIMING;
570 			error = nfs_send(so, rep->r_nmp->nm_nam, m, rep);
571 			if (error) {
572 				if (error == EINTR || error == ERESTART ||
573 				    (error = nfs_reconnect(rep)) != 0) {
574 					nfs_sndunlock(&rep->r_nmp->nm_flag);
575 					return (error);
576 				}
577 				goto tryagain;
578 			}
579 		}
580 		nfs_sndunlock(&rep->r_nmp->nm_flag);
581 		if (sotype == SOCK_STREAM) {
582 			aio.iov_base = (caddr_t) &len;
583 			aio.iov_len = sizeof(u_int32_t);
584 			auio.uio_iov = &aio;
585 			auio.uio_iovcnt = 1;
586 			auio.uio_segflg = UIO_SYSSPACE;
587 			auio.uio_rw = UIO_READ;
588 			auio.uio_offset = 0;
589 			auio.uio_resid = sizeof(u_int32_t);
590 			auio.uio_procp = p;
591 			do {
592 			   rcvflg = MSG_WAITALL;
593 			   error = soreceive(so, NULL, &auio, NULL, NULL,
594 			       &rcvflg, 0);
595 			   if (error == EWOULDBLOCK && rep) {
596 				if (rep->r_flags & R_SOFTTERM)
597 					return (EINTR);
598 				/*
599 				 * looks like the server died after it
600 				 * received the request, make sure
601 				 * that we will retransmit and we
602 				 * don't get stuck here forever.
603 				 */
604 				if (rep->r_rexmit >= rep->r_nmp->nm_retry) {
605 					nfsstats.rpctimeouts++;
606 					error = EPIPE;
607 				}
608 			   }
609 			} while (error == EWOULDBLOCK);
610 			if (!error && auio.uio_resid > 0) {
611 			    log(LOG_INFO,
612 				 "short receive (%d/%d) from nfs server %s\n",
613 				 sizeof(u_int32_t) - auio.uio_resid,
614 				 sizeof(u_int32_t),
615 				 rep->r_nmp->nm_mountp->mnt_stat.f_mntfromname);
616 			    error = EPIPE;
617 			}
618 			if (error)
619 				goto errout;
620 
621 			len = ntohl(len) & ~0x80000000;
622 			/*
623 			 * This is SERIOUS! We are out of sync with the sender
624 			 * and forcing a disconnect/reconnect is all I can do.
625 			 */
626 			if (len > NFS_MAXPACKET) {
627 			    log(LOG_ERR, "%s (%d) from nfs server %s\n",
628 				"impossible packet length",
629 				len,
630 				rep->r_nmp->nm_mountp->mnt_stat.f_mntfromname);
631 			    error = EFBIG;
632 			    goto errout;
633 			}
634 			auio.uio_resid = len;
635 			do {
636 			    rcvflg = MSG_WAITALL;
637 			    error =  soreceive(so, NULL, &auio, mp, NULL,
638 			        &rcvflg, 0);
639 			} while (error == EWOULDBLOCK || error == EINTR ||
640 				 error == ERESTART);
641 			if (!error && auio.uio_resid > 0) {
642 			    log(LOG_INFO,
643 				"short receive (%d/%d) from nfs server %s\n",
644 				len - auio.uio_resid, len,
645 				rep->r_nmp->nm_mountp->mnt_stat.f_mntfromname);
646 			    error = EPIPE;
647 			}
648 		} else {
649 			/*
650 			 * NB: Since uio_resid is big, MSG_WAITALL is ignored
651 			 * and soreceive() will return when it has either a
652 			 * control msg or a data msg.
653 			 * We have no use for control msg., but must grab them
654 			 * and then throw them away so we know what is going
655 			 * on.
656 			 */
657 			auio.uio_resid = len = 100000000; /* Anything Big */
658 			auio.uio_procp = p;
659 			do {
660 			    rcvflg = 0;
661 			    error =  soreceive(so, NULL, &auio, mp, &control,
662 			        &rcvflg, 0);
663 			    if (control)
664 				m_freem(control);
665 			    if (error == EWOULDBLOCK && rep) {
666 				if (rep->r_flags & R_SOFTTERM)
667 					return (EINTR);
668 			    }
669 			} while (error == EWOULDBLOCK ||
670 				 (!error && *mp == NULL && control));
671 			if ((rcvflg & MSG_EOR) == 0)
672 				printf("Egad!!\n");
673 			if (!error && *mp == NULL)
674 				error = EPIPE;
675 			len -= auio.uio_resid;
676 		}
677 errout:
678 		if (error && error != EINTR && error != ERESTART) {
679 			m_freem(*mp);
680 			*mp = NULL;
681 			if (error != EPIPE)
682 				log(LOG_INFO,
683 				    "receive error %d from nfs server %s\n",
684 				    error,
685 				 rep->r_nmp->nm_mountp->mnt_stat.f_mntfromname);
686 			error = nfs_sndlock(&rep->r_nmp->nm_flag, rep);
687 			if (!error) {
688 				error = nfs_reconnect(rep);
689 				if (!error)
690 					goto tryagain;
691 				nfs_sndunlock(&rep->r_nmp->nm_flag);
692 			}
693 		}
694 	} else {
695 		if ((so = rep->r_nmp->nm_so) == NULL)
696 			return (EACCES);
697 		if (so->so_state & SS_ISCONNECTED)
698 			getnam = NULL;
699 		else
700 			getnam = aname;
701 		auio.uio_resid = len = 1000000;
702 		auio.uio_procp = p;
703 		do {
704 			rcvflg = 0;
705 			error =  soreceive(so, getnam, &auio, mp, NULL,
706 			    &rcvflg, 0);
707 			if (error == EWOULDBLOCK &&
708 			    (rep->r_flags & R_SOFTTERM))
709 				return (EINTR);
710 		} while (error == EWOULDBLOCK);
711 		len -= auio.uio_resid;
712 	}
713 	if (error) {
714 		m_freem(*mp);
715 		*mp = NULL;
716 	}
717 	/*
718 	 * Search for any mbufs that are not a multiple of 4 bytes long
719 	 * or with m_data not longword aligned.
720 	 * These could cause pointer alignment problems, so copy them to
721 	 * well aligned mbufs.
722 	 */
723 	nfs_realign(mp, 5 * NFSX_UNSIGNED);
724 	return (error);
725 }
726 
727 /*
728  * Implement receipt of reply on a socket.
729  * We must search through the list of received datagrams matching them
730  * with outstanding requests using the xid, until ours is found.
731  */
732 int
733 nfs_reply(myrep)
734 	struct nfsreq *myrep;
735 {
736 	struct nfsreq *rep;
737 	struct nfsmount *nmp = myrep->r_nmp;
738 	struct nfsm_info	info;
739 	struct mbuf *nam;
740 	u_int32_t rxid, *tl, t1;
741 	caddr_t cp2;
742 	int s, error;
743 
744 	/*
745 	 * Loop around until we get our own reply
746 	 */
747 	for (;;) {
748 		/*
749 		 * Lock against other receivers so that I don't get stuck in
750 		 * sbwait() after someone else has received my reply for me.
751 		 * Also necessary for connection based protocols to avoid
752 		 * race conditions during a reconnect.
753 		 */
754 		error = nfs_rcvlock(myrep);
755 		if (error)
756 			return (error == EALREADY ? 0 : error);
757 
758 		/*
759 		 * Get the next Rpc reply off the socket
760 		 */
761 		error = nfs_receive(myrep, &nam, &info.nmi_mrep);
762 		nfs_rcvunlock(&nmp->nm_flag);
763 		if (error) {
764 
765 			/*
766 			 * Ignore routing errors on connectionless protocols??
767 			 */
768 			if (NFSIGNORE_SOERROR(nmp->nm_soflags, error)) {
769 				if (nmp->nm_so)
770 					nmp->nm_so->so_error = 0;
771 				continue;
772 			}
773 			return (error);
774 		}
775 		if (nam)
776 			m_freem(nam);
777 
778 		/*
779 		 * Get the xid and check that it is an rpc reply
780 		 */
781 		info.nmi_md = info.nmi_mrep;
782 		info.nmi_dpos = mtod(info.nmi_md, caddr_t);
783 		nfsm_dissect(tl, u_int32_t *, 2*NFSX_UNSIGNED);
784 		rxid = *tl++;
785 		if (*tl != rpc_reply) {
786 			nfsstats.rpcinvalid++;
787 			m_freem(info.nmi_mrep);
788 nfsmout:
789 			continue;
790 		}
791 
792 		/*
793 		 * Loop through the request list to match up the reply
794 		 * Iff no match, just drop the datagram
795 		 */
796 		s = splsoftnet();
797 		TAILQ_FOREACH(rep, &nmp->nm_reqsq, r_chain) {
798 			if (rep->r_mrep == NULL && rxid == rep->r_xid) {
799 				/* Found it.. */
800 				rep->r_mrep = info.nmi_mrep;
801 				rep->r_md = info.nmi_md;
802 				rep->r_dpos = info.nmi_dpos;
803 
804 				/*
805 				 * Update congestion window.
806 				 * Do the additive increase of
807 				 * one rpc/rtt.
808 				 */
809 				if (nmp->nm_cwnd <= nmp->nm_sent) {
810 					nmp->nm_cwnd +=
811 					   (NFS_CWNDSCALE * NFS_CWNDSCALE +
812 					   (nmp->nm_cwnd >> 1)) / nmp->nm_cwnd;
813 					if (nmp->nm_cwnd > NFS_MAXCWND)
814 						nmp->nm_cwnd = NFS_MAXCWND;
815 				}
816 				rep->r_flags &= ~R_SENT;
817 				nmp->nm_sent -= NFS_CWNDSCALE;
818 
819 				if (rep->r_flags & R_TIMING)
820 					nfs_update_rtt(rep);
821 
822 				nmp->nm_timeouts = 0;
823 				break;
824 			}
825 		}
826 		splx(s);
827 		/*
828 		 * If not matched to a request, drop it.
829 		 * If it's mine, get out.
830 		 */
831 		if (rep == 0) {
832 			nfsstats.rpcunexpected++;
833 			m_freem(info.nmi_mrep);
834 		} else if (rep == myrep) {
835 			if (rep->r_mrep == NULL)
836 				panic("nfsreply nil");
837 			return (0);
838 		}
839 	}
840 }
841 
842 /*
843  * nfs_request - goes something like this
844  *	- fill in request struct
845  *	- links it into list
846  *	- calls nfs_send() for first transmit
847  *	- calls nfs_receive() to get reply
848  *	- break down rpc header and return with nfs reply pointed to
849  *	  by mrep or error
850  * nb: always frees up mreq mbuf list
851  */
852 int
853 nfs_request(struct vnode *vp, int procnum, struct nfsm_info *infop)
854 {
855 	struct mbuf *m;
856 	u_int32_t *tl;
857 	struct nfsmount *nmp;
858 	struct timeval tv;
859 	caddr_t cp2;
860 	int t1, i, s, error = 0;
861 	int trylater_delay;
862 	struct nfsreq *rep;
863 	int  mrest_len;
864 	struct nfsm_info	info;
865 
866 	rep = pool_get(&nfsreqpl, PR_WAITOK);
867 	rep->r_nmp = VFSTONFS(vp->v_mount);
868 	rep->r_vp = vp;
869 	rep->r_procp = infop->nmi_procp;
870 	rep->r_procnum = procnum;
871 
872 	mrest_len = 0;
873 	m = infop->nmi_mreq;
874 	while (m) {
875 		mrest_len += m->m_len;
876 		m = m->m_next;
877 	}
878 
879 	/* empty mbuf for AUTH_UNIX header */
880 	rep->r_mreq = m_gethdr(M_WAIT, MT_DATA);
881 	rep->r_mreq->m_next = infop->nmi_mreq;
882 	rep->r_mreq->m_pkthdr.len = mrest_len;
883 
884 	trylater_delay = NFS_MINTIMEO;
885 
886 	nmp = rep->r_nmp;
887 
888 	/* Get the RPC header with authorization. */
889 	nfsm_rpchead(rep, infop->nmi_cred, RPCAUTH_UNIX);
890 	m = rep->r_mreq;
891 
892 	/*
893 	 * For stream protocols, insert a Sun RPC Record Mark.
894 	 */
895 	if (nmp->nm_sotype == SOCK_STREAM) {
896 		M_PREPEND(m, NFSX_UNSIGNED, M_WAIT);
897 		*mtod(m, u_int32_t *) = htonl(0x80000000 |
898 			 (m->m_pkthdr.len - NFSX_UNSIGNED));
899 	}
900 
901 tryagain:
902 	rep->r_rtt = rep->r_rexmit = 0;
903 	if (nfs_ptimers[rep->r_procnum] != NFS_DEFAULT_TIMER)
904 		rep->r_flags = R_TIMING;
905 	else
906 		rep->r_flags = 0;
907 	rep->r_mrep = NULL;
908 
909 	/*
910 	 * Do the client side RPC.
911 	 */
912 	nfsstats.rpcrequests++;
913 	/*
914 	 * Chain request into list of outstanding requests. Be sure
915 	 * to put it LAST so timer finds oldest requests first.
916 	 */
917 	s = splsoftnet();
918 	if (TAILQ_EMPTY(&nmp->nm_reqsq))
919 		timeout_add(&nmp->nm_rtimeout, nfs_ticks);
920 	TAILQ_INSERT_TAIL(&nmp->nm_reqsq, rep, r_chain);
921 
922 	/*
923 	 * If backing off another request or avoiding congestion, don't
924 	 * send this one now but let timer do it. If not timing a request,
925 	 * do it now.
926 	 */
927 	if (nmp->nm_so && (nmp->nm_sotype != SOCK_DGRAM ||
928 		(nmp->nm_flag & NFSMNT_DUMBTIMR) ||
929 		nmp->nm_sent < nmp->nm_cwnd)) {
930 		splx(s);
931 		if (nmp->nm_soflags & PR_CONNREQUIRED)
932 			error = nfs_sndlock(&nmp->nm_flag, rep);
933 		if (!error) {
934 			error = nfs_send(nmp->nm_so, nmp->nm_nam,
935 					m_copym(m, 0, M_COPYALL, M_WAIT),
936 					rep);
937 			if (nmp->nm_soflags & PR_CONNREQUIRED)
938 				nfs_sndunlock(&nmp->nm_flag);
939 		}
940 		if (!error && (rep->r_flags & R_MUSTRESEND) == 0) {
941 			nmp->nm_sent += NFS_CWNDSCALE;
942 			rep->r_flags |= R_SENT;
943 		}
944 	} else {
945 		splx(s);
946 		rep->r_rtt = -1;
947 	}
948 
949 	/*
950 	 * Wait for the reply from our send or the timer's.
951 	 */
952 	if (!error || error == EPIPE)
953 		error = nfs_reply(rep);
954 
955 	/*
956 	 * RPC done, unlink the request.
957 	 */
958 	s = splsoftnet();
959 	TAILQ_REMOVE(&nmp->nm_reqsq, rep, r_chain);
960 	if (TAILQ_EMPTY(&nmp->nm_reqsq))
961 		timeout_del(&nmp->nm_rtimeout);
962 	splx(s);
963 
964 	/*
965 	 * Decrement the outstanding request count.
966 	 */
967 	if (rep->r_flags & R_SENT) {
968 		rep->r_flags &= ~R_SENT;	/* paranoia */
969 		nmp->nm_sent -= NFS_CWNDSCALE;
970 	}
971 
972 	/*
973 	 * If there was a successful reply and a tprintf msg.
974 	 * tprintf a response.
975 	 */
976 	if (!error && (rep->r_flags & R_TPRINTFMSG))
977 		nfs_msg(rep, "is alive again");
978 	info.nmi_mrep = rep->r_mrep;
979 	info.nmi_md = rep->r_md;
980 	info.nmi_dpos = rep->r_dpos;
981 	if (error) {
982 		infop->nmi_mrep = NULL;
983 		goto nfsmout1;
984 	}
985 
986 	/*
987 	 * break down the rpc header and check if ok
988 	 */
989 	nfsm_dissect(tl, u_int32_t *, 3 * NFSX_UNSIGNED);
990 	if (*tl++ == rpc_msgdenied) {
991 		if (*tl == rpc_mismatch)
992 			error = EOPNOTSUPP;
993 		else
994 			error = EACCES;	/* Should be EAUTH. */
995 		infop->nmi_mrep = NULL;
996 		goto nfsmout1;
997 	}
998 
999 	/*
1000 	 * Since we only support RPCAUTH_UNIX atm we step over the
1001 	 * reply verifer type, and in the (error) case that there really
1002 	 * is any data in it, we advance over it.
1003 	 */
1004 	tl++;			/* Step over verifer type */
1005 	i = fxdr_unsigned(int32_t, *tl);
1006 	if (i > 0)
1007 		nfsm_adv(nfsm_rndup(i));	/* Should not happen */
1008 
1009 	nfsm_dissect(tl, u_int32_t *, NFSX_UNSIGNED);
1010 	/* 0 == ok */
1011 	if (*tl == 0) {
1012 		nfsm_dissect(tl, u_int32_t *, NFSX_UNSIGNED);
1013 		if (*tl != 0) {
1014 			error = fxdr_unsigned(int, *tl);
1015 			if ((nmp->nm_flag & NFSMNT_NFSV3) &&
1016 			    error == NFSERR_TRYLATER) {
1017 				m_freem(info.nmi_mrep);
1018 				error = 0;
1019 				tv.tv_sec = time_second + trylater_delay;
1020 				tv.tv_usec = 0;
1021 				tsleep(&tv, PSOCK, "nfsretry", hzto(&tv));
1022 				trylater_delay *= NFS_TIMEOUTMUL;
1023 				if (trylater_delay > NFS_MAXTIMEO)
1024 					trylater_delay = NFS_MAXTIMEO;
1025 
1026 				goto tryagain;
1027 			}
1028 
1029 			/*
1030 			 * If the File Handle was stale, invalidate the
1031 			 * lookup cache, just in case.
1032 			 */
1033 			if (error == ESTALE)
1034 				cache_purge(rep->r_vp);
1035 		}
1036 		goto nfsmout;
1037 	}
1038 
1039 	error = EPROTONOSUPPORT;
1040 
1041 nfsmout:
1042 	infop->nmi_mrep = info.nmi_mrep;
1043 	infop->nmi_md = info.nmi_md;
1044 	infop->nmi_dpos = info.nmi_dpos;
1045 nfsmout1:
1046 	m_freem(rep->r_mreq);
1047 	pool_put(&nfsreqpl, rep);
1048 	return (error);
1049 }
1050 #endif /* NFSCLIENT */
1051 
1052 /*
1053  * Generate the rpc reply header
1054  * siz arg. is used to decide if adding a cluster is worthwhile
1055  */
1056 int
1057 nfs_rephead(siz, nd, slp, err, mrq, mbp)
1058 	int siz;
1059 	struct nfsrv_descript *nd;
1060 	struct nfssvc_sock *slp;
1061 	int err;
1062 	struct mbuf **mrq;
1063 	struct mbuf **mbp;
1064 {
1065 	u_int32_t *tl;
1066 	struct mbuf *mreq;
1067 	struct mbuf *mb;
1068 
1069 	MGETHDR(mreq, M_WAIT, MT_DATA);
1070 	mb = mreq;
1071 	/*
1072 	 * If this is a big reply, use a cluster else
1073 	 * try and leave leading space for the lower level headers.
1074 	 */
1075 	siz += RPC_REPLYSIZ;
1076 	if (siz >= max_datalen) {
1077 		MCLGET(mreq, M_WAIT);
1078 	} else
1079 		mreq->m_data += max_hdr;
1080 	tl = mtod(mreq, u_int32_t *);
1081 	mreq->m_len = 6 * NFSX_UNSIGNED;
1082 	*tl++ = txdr_unsigned(nd->nd_retxid);
1083 	*tl++ = rpc_reply;
1084 	if (err == ERPCMISMATCH || (err & NFSERR_AUTHERR)) {
1085 		*tl++ = rpc_msgdenied;
1086 		if (err & NFSERR_AUTHERR) {
1087 			*tl++ = rpc_autherr;
1088 			*tl = txdr_unsigned(err & ~NFSERR_AUTHERR);
1089 			mreq->m_len -= NFSX_UNSIGNED;
1090 		} else {
1091 			*tl++ = rpc_mismatch;
1092 			*tl++ = txdr_unsigned(RPC_VER2);
1093 			*tl = txdr_unsigned(RPC_VER2);
1094 		}
1095 	} else {
1096 		*tl++ = rpc_msgaccepted;
1097 
1098 		/* AUTH_UNIX requires RPCAUTH_NULL. */
1099 		*tl++ = 0;
1100 		*tl++ = 0;
1101 
1102 		switch (err) {
1103 		case EPROGUNAVAIL:
1104 			*tl = txdr_unsigned(RPC_PROGUNAVAIL);
1105 			break;
1106 		case EPROGMISMATCH:
1107 			*tl = txdr_unsigned(RPC_PROGMISMATCH);
1108 			tl = nfsm_build(&mb, 2 * NFSX_UNSIGNED);
1109 			*tl++ = txdr_unsigned(NFS_VER2);
1110 			*tl = txdr_unsigned(NFS_VER3);
1111 			break;
1112 		case EPROCUNAVAIL:
1113 			*tl = txdr_unsigned(RPC_PROCUNAVAIL);
1114 			break;
1115 		case EBADRPC:
1116 			*tl = txdr_unsigned(RPC_GARBAGE);
1117 			break;
1118 		default:
1119 			*tl = 0;
1120 			if (err != NFSERR_RETVOID) {
1121 				tl = nfsm_build(&mb, NFSX_UNSIGNED);
1122 				if (err)
1123 				    *tl = txdr_unsigned(nfsrv_errmap(nd, err));
1124 				else
1125 				    *tl = 0;
1126 			}
1127 			break;
1128 		};
1129 	}
1130 
1131 	*mrq = mreq;
1132 	if (mbp != NULL)
1133 		*mbp = mb;
1134 	if (err != 0 && err != NFSERR_RETVOID)
1135 		nfsstats.srvrpc_errs++;
1136 	return (0);
1137 }
1138 
1139 /*
1140  * nfs timer routine
1141  * Scan the nfsreq list and retranmit any requests that have timed out.
1142  */
1143 void
1144 nfs_timer(void *arg)
1145 {
1146 	struct nfsmount *nmp = arg;
1147 	struct nfsreq *rep;
1148 	struct mbuf *m;
1149 	struct socket *so;
1150 	int timeo, s, error;
1151 
1152 	s = splsoftnet();
1153 	TAILQ_FOREACH(rep, &nmp->nm_reqsq, r_chain) {
1154 		if (rep->r_mrep || (rep->r_flags & R_SOFTTERM))
1155 			continue;
1156 		if (nfs_sigintr(nmp, rep, rep->r_procp)) {
1157 			rep->r_flags |= R_SOFTTERM;
1158 			continue;
1159 		}
1160 		if (rep->r_rtt >= 0) {
1161 			rep->r_rtt++;
1162 			if (nmp->nm_flag & NFSMNT_DUMBTIMR)
1163 				timeo = nmp->nm_timeo;
1164 			else
1165 				timeo = nfs_estimate_rto(nmp, rep->r_procnum);
1166 			if (nmp->nm_timeouts > 0)
1167 				timeo *= nfs_backoff[nmp->nm_timeouts - 1];
1168 			if (rep->r_rtt <= timeo)
1169 				continue;
1170 			if (nmp->nm_timeouts < nitems(nfs_backoff))
1171 				nmp->nm_timeouts++;
1172 		}
1173 
1174 		/* Check for server not responding. */
1175 		if ((rep->r_flags & R_TPRINTFMSG) == 0 && rep->r_rexmit > 4) {
1176 			nfs_msg(rep, "not responding");
1177 			rep->r_flags |= R_TPRINTFMSG;
1178 		}
1179 		if (rep->r_rexmit >= nmp->nm_retry) {	/* too many */
1180 			nfsstats.rpctimeouts++;
1181 			rep->r_flags |= R_SOFTTERM;
1182 			continue;
1183 		}
1184 		if (nmp->nm_sotype != SOCK_DGRAM) {
1185 			if (++rep->r_rexmit > NFS_MAXREXMIT)
1186 				rep->r_rexmit = NFS_MAXREXMIT;
1187 			continue;
1188 		}
1189 
1190 		if ((so = nmp->nm_so) == NULL)
1191 			continue;
1192 
1193 		/*
1194 		 * If there is enough space and the window allows..
1195 		 *	Resend it
1196 		 * Set r_rtt to -1 in case we fail to send it now.
1197 		 */
1198 		rep->r_rtt = -1;
1199 		if (sbspace(&so->so_snd) >= rep->r_mreq->m_pkthdr.len &&
1200 		   ((nmp->nm_flag & NFSMNT_DUMBTIMR) ||
1201 		    (rep->r_flags & R_SENT) ||
1202 		    nmp->nm_sent < nmp->nm_cwnd) &&
1203 		   (m = m_copym(rep->r_mreq, 0, M_COPYALL, M_DONTWAIT))){
1204 			if ((nmp->nm_flag & NFSMNT_NOCONN) == 0)
1205 			    error = (*so->so_proto->pr_usrreq)(so, PRU_SEND, m,
1206 			    NULL, NULL, curproc);
1207 			else
1208 			    error = (*so->so_proto->pr_usrreq)(so, PRU_SEND, m,
1209 			    nmp->nm_nam, NULL, curproc);
1210 			if (error) {
1211 				if (NFSIGNORE_SOERROR(nmp->nm_soflags, error))
1212 					so->so_error = 0;
1213 			} else {
1214 				/*
1215 				 * Iff first send, start timing
1216 				 * else turn timing off, backoff timer
1217 				 * and divide congestion window by 2.
1218 				 */
1219 				if (rep->r_flags & R_SENT) {
1220 					rep->r_flags &= ~R_TIMING;
1221 					if (++rep->r_rexmit > NFS_MAXREXMIT)
1222 						rep->r_rexmit = NFS_MAXREXMIT;
1223 					nmp->nm_cwnd >>= 1;
1224 					if (nmp->nm_cwnd < NFS_CWNDSCALE)
1225 						nmp->nm_cwnd = NFS_CWNDSCALE;
1226 					nfsstats.rpcretries++;
1227 				} else {
1228 					rep->r_flags |= R_SENT;
1229 					nmp->nm_sent += NFS_CWNDSCALE;
1230 				}
1231 				rep->r_rtt = 0;
1232 			}
1233 		}
1234 	}
1235 	splx(s);
1236 	timeout_add(&nmp->nm_rtimeout, nfs_ticks);
1237 }
1238 
1239 /*
1240  * Test for a termination condition pending on the process.
1241  * This is used for NFSMNT_INT mounts.
1242  */
1243 int
1244 nfs_sigintr(nmp, rep, p)
1245 	struct nfsmount *nmp;
1246 	struct nfsreq *rep;
1247 	struct proc *p;
1248 {
1249 
1250 	if (rep && (rep->r_flags & R_SOFTTERM))
1251 		return (EINTR);
1252 	if (!(nmp->nm_flag & NFSMNT_INT))
1253 		return (0);
1254 	if (p && p->p_siglist &&
1255 	    (((p->p_siglist & ~p->p_sigmask) & ~p->p_sigignore) &
1256 	    NFSINT_SIGMASK))
1257 		return (EINTR);
1258 	return (0);
1259 }
1260 
1261 /*
1262  * Lock a socket against others.
1263  * Necessary for STREAM sockets to ensure you get an entire rpc request/reply
1264  * and also to avoid race conditions between the processes with nfs requests
1265  * in progress when a reconnect is necessary.
1266  */
1267 int
1268 nfs_sndlock(flagp, rep)
1269 	int *flagp;
1270 	struct nfsreq *rep;
1271 {
1272 	struct proc *p;
1273 	int slpflag = 0, slptimeo = 0;
1274 
1275 	if (rep) {
1276 		p = rep->r_procp;
1277 		if (rep->r_nmp->nm_flag & NFSMNT_INT)
1278 			slpflag = PCATCH;
1279 	} else
1280 		p = NULL;
1281 	while (*flagp & NFSMNT_SNDLOCK) {
1282 		if (rep && nfs_sigintr(rep->r_nmp, rep, p))
1283 			return (EINTR);
1284 		*flagp |= NFSMNT_WANTSND;
1285 		(void) tsleep((caddr_t)flagp, slpflag | (PZERO - 1), "nfsndlck",
1286 			slptimeo);
1287 		if (slpflag == PCATCH) {
1288 			slpflag = 0;
1289 			slptimeo = 2 * hz;
1290 		}
1291 	}
1292 	*flagp |= NFSMNT_SNDLOCK;
1293 	return (0);
1294 }
1295 
1296 /*
1297  * Unlock the stream socket for others.
1298  */
1299 void
1300 nfs_sndunlock(flagp)
1301 	int *flagp;
1302 {
1303 
1304 	if ((*flagp & NFSMNT_SNDLOCK) == 0)
1305 		panic("nfs sndunlock");
1306 	*flagp &= ~NFSMNT_SNDLOCK;
1307 	if (*flagp & NFSMNT_WANTSND) {
1308 		*flagp &= ~NFSMNT_WANTSND;
1309 		wakeup((caddr_t)flagp);
1310 	}
1311 }
1312 
1313 int
1314 nfs_rcvlock(rep)
1315 	struct nfsreq *rep;
1316 {
1317 	int *flagp = &rep->r_nmp->nm_flag;
1318 	int slpflag, slptimeo = 0;
1319 
1320 	if (*flagp & NFSMNT_INT)
1321 		slpflag = PCATCH;
1322 	else
1323 		slpflag = 0;
1324 
1325 	while (*flagp & NFSMNT_RCVLOCK) {
1326 		if (nfs_sigintr(rep->r_nmp, rep, rep->r_procp))
1327 			return (EINTR);
1328 		*flagp |= NFSMNT_WANTRCV;
1329 		(void) tsleep((caddr_t)flagp, slpflag | (PZERO - 1), "nfsrcvlk",
1330 			slptimeo);
1331 		if (rep->r_mrep != NULL) {
1332 			/*
1333 			 * Don't take the lock if our reply has been received
1334 			 * while we where sleeping.
1335 			 */
1336 			 return (EALREADY);
1337 		}
1338 		if (slpflag == PCATCH) {
1339 			slpflag = 0;
1340 			slptimeo = 2 * hz;
1341 		}
1342 	}
1343 	*flagp |= NFSMNT_RCVLOCK;
1344 	return (0);
1345 }
1346 
1347 /*
1348  * Unlock the stream socket for others.
1349  */
1350 void
1351 nfs_rcvunlock(flagp)
1352 	int *flagp;
1353 {
1354 
1355 	if ((*flagp & NFSMNT_RCVLOCK) == 0)
1356 		panic("nfs rcvunlock");
1357 	*flagp &= ~NFSMNT_RCVLOCK;
1358 	if (*flagp & NFSMNT_WANTRCV) {
1359 		*flagp &= ~NFSMNT_WANTRCV;
1360 		wakeup((caddr_t)flagp);
1361 	}
1362 }
1363 
1364 /*
1365  * Auxiliary routine to align the length of mbuf copies made with m_copyback().
1366  */
1367 void
1368 nfs_realign_fixup(struct mbuf *m, struct mbuf *n, unsigned int *off)
1369 {
1370 	size_t padding;
1371 
1372 	/*
1373 	 * The maximum number of bytes that m_copyback() places in a mbuf is
1374 	 * always an aligned quantity, so realign happens at the chain's tail.
1375 	 */
1376 	while (n->m_next != NULL)
1377 		n = n->m_next;
1378 
1379 	/*
1380 	 * Pad from the next elements in the source chain. Loop until the
1381 	 * destination chain is aligned, or the end of the source is reached.
1382 	 */
1383 	do {
1384 		m = m->m_next;
1385 		if (m == NULL)
1386 			return;
1387 
1388 		padding = min(ALIGN(n->m_len) - n->m_len, m->m_len);
1389 		if (padding > M_TRAILINGSPACE(n))
1390 			panic("nfs_realign_fixup: no memory to pad to");
1391 
1392 		bcopy(mtod(m, void *), mtod(n, char *) + n->m_len, padding);
1393 
1394 		n->m_len += padding;
1395 		m_adj(m, padding);
1396 		*off += padding;
1397 
1398 	} while (!ALIGNED_POINTER(n->m_len, void *));
1399 }
1400 
1401 /*
1402  * The NFS RPC parsing code uses the data address and the length of mbuf
1403  * structures to calculate on-memory addresses. This function makes sure these
1404  * parameters are correctly aligned.
1405  */
1406 void
1407 nfs_realign(struct mbuf **pm, int hsiz)
1408 {
1409 	struct mbuf *m;
1410 	struct mbuf *n = NULL;
1411 	unsigned int off = 0;
1412 
1413 	++nfs_realign_test;
1414 	while ((m = *pm) != NULL) {
1415 		if (!ALIGNED_POINTER(m->m_data, void *) ||
1416 		    !ALIGNED_POINTER(m->m_len,  void *)) {
1417 			MGET(n, M_WAIT, MT_DATA);
1418 			if (ALIGN(m->m_len) >= MINCLSIZE) {
1419 				MCLGET(n, M_WAIT);
1420 			}
1421 			n->m_len = 0;
1422 			break;
1423 		}
1424 		pm = &m->m_next;
1425 	}
1426 	/*
1427 	 * If n is non-NULL, loop on m copying data, then replace the
1428 	 * portion of the chain that had to be realigned.
1429 	 */
1430 	if (n != NULL) {
1431 		++nfs_realign_count;
1432 		while (m) {
1433 			m_copyback(n, off, m->m_len, mtod(m, caddr_t));
1434 
1435 			/*
1436 			 * If an unaligned amount of memory was copied, fix up
1437 			 * the last mbuf created by m_copyback().
1438 			 */
1439 			if (!ALIGNED_POINTER(m->m_len, void *))
1440 				nfs_realign_fixup(m, n, &off);
1441 
1442 			off += m->m_len;
1443 			m = m->m_next;
1444 		}
1445 		m_freem(*pm);
1446 		*pm = n;
1447 	}
1448 }
1449 
1450 
1451 /*
1452  * Parse an RPC request
1453  * - verify it
1454  * - fill in the cred struct.
1455  */
1456 int
1457 nfs_getreq(nd, nfsd, has_header)
1458 	struct nfsrv_descript *nd;
1459 	struct nfsd *nfsd;
1460 	int has_header;
1461 {
1462 	int len, i;
1463 	u_int32_t *tl;
1464 	int32_t t1;
1465 	caddr_t cp2;
1466 	u_int32_t nfsvers, auth_type;
1467 	int error = 0;
1468 	struct nfsm_info	info;
1469 
1470 	info.nmi_mrep = nd->nd_mrep;
1471 	info.nmi_md = nd->nd_md;
1472 	info.nmi_dpos = nd->nd_dpos;
1473 	if (has_header) {
1474 		nfsm_dissect(tl, u_int32_t *, 10 * NFSX_UNSIGNED);
1475 		nd->nd_retxid = fxdr_unsigned(u_int32_t, *tl++);
1476 		if (*tl++ != rpc_call) {
1477 			m_freem(info.nmi_mrep);
1478 			return (EBADRPC);
1479 		}
1480 	} else
1481 		nfsm_dissect(tl, u_int32_t *, 8 * NFSX_UNSIGNED);
1482 	nd->nd_repstat = 0;
1483 	nd->nd_flag = 0;
1484 	if (*tl++ != rpc_vers) {
1485 		nd->nd_repstat = ERPCMISMATCH;
1486 		nd->nd_procnum = NFSPROC_NOOP;
1487 		return (0);
1488 	}
1489 	if (*tl != nfs_prog) {
1490 		nd->nd_repstat = EPROGUNAVAIL;
1491 		nd->nd_procnum = NFSPROC_NOOP;
1492 		return (0);
1493 	}
1494 	tl++;
1495 	nfsvers = fxdr_unsigned(u_int32_t, *tl++);
1496 	if (nfsvers != NFS_VER2 && nfsvers != NFS_VER3) {
1497 		nd->nd_repstat = EPROGMISMATCH;
1498 		nd->nd_procnum = NFSPROC_NOOP;
1499 		return (0);
1500 	}
1501 	if (nfsvers == NFS_VER3)
1502 		nd->nd_flag = ND_NFSV3;
1503 	nd->nd_procnum = fxdr_unsigned(u_int32_t, *tl++);
1504 	if (nd->nd_procnum == NFSPROC_NULL)
1505 		return (0);
1506 	if (nd->nd_procnum >= NFS_NPROCS ||
1507 		(nd->nd_procnum > NFSPROC_COMMIT) ||
1508 		(!nd->nd_flag && nd->nd_procnum > NFSV2PROC_STATFS)) {
1509 		nd->nd_repstat = EPROCUNAVAIL;
1510 		nd->nd_procnum = NFSPROC_NOOP;
1511 		return (0);
1512 	}
1513 	if ((nd->nd_flag & ND_NFSV3) == 0)
1514 		nd->nd_procnum = nfsv3_procid[nd->nd_procnum];
1515 	auth_type = *tl++;
1516 	len = fxdr_unsigned(int, *tl++);
1517 	if (len < 0 || len > RPCAUTH_MAXSIZ) {
1518 		m_freem(info.nmi_mrep);
1519 		return (EBADRPC);
1520 	}
1521 
1522 	/* Handle auth_unix */
1523 	if (auth_type == rpc_auth_unix) {
1524 		len = fxdr_unsigned(int, *++tl);
1525 		if (len < 0 || len > NFS_MAXNAMLEN) {
1526 			m_freem(info.nmi_mrep);
1527 			return (EBADRPC);
1528 		}
1529 		nfsm_adv(nfsm_rndup(len));
1530 		nfsm_dissect(tl, u_int32_t *, 3 * NFSX_UNSIGNED);
1531 		bzero((caddr_t)&nd->nd_cr, sizeof (struct ucred));
1532 		nd->nd_cr.cr_ref = 1;
1533 		nd->nd_cr.cr_uid = fxdr_unsigned(uid_t, *tl++);
1534 		nd->nd_cr.cr_gid = fxdr_unsigned(gid_t, *tl++);
1535 		len = fxdr_unsigned(int, *tl);
1536 		if (len < 0 || len > RPCAUTH_UNIXGIDS) {
1537 			m_freem(info.nmi_mrep);
1538 			return (EBADRPC);
1539 		}
1540 		nfsm_dissect(tl, u_int32_t *, (len + 2) * NFSX_UNSIGNED);
1541 		for (i = 0; i < len; i++)
1542 		    if (i < NGROUPS)
1543 			nd->nd_cr.cr_groups[i] = fxdr_unsigned(gid_t, *tl++);
1544 		    else
1545 			tl++;
1546 		nd->nd_cr.cr_ngroups = (len > NGROUPS) ? NGROUPS : len;
1547 		len = fxdr_unsigned(int, *++tl);
1548 		if (len < 0 || len > RPCAUTH_MAXSIZ) {
1549 			m_freem(info.nmi_mrep);
1550 			return (EBADRPC);
1551 		}
1552 		if (len > 0)
1553 			nfsm_adv(nfsm_rndup(len));
1554 	} else {
1555 		nd->nd_repstat = (NFSERR_AUTHERR | AUTH_REJECTCRED);
1556 		nd->nd_procnum = NFSPROC_NOOP;
1557 		return (0);
1558 	}
1559 
1560 	nd->nd_md = info.nmi_md;
1561 	nd->nd_dpos = info.nmi_dpos;
1562 	return (0);
1563 nfsmout:
1564 	return (error);
1565 }
1566 
1567 void
1568 nfs_msg(struct nfsreq *rep, char *msg)
1569 {
1570 	tpr_t tpr;
1571 
1572 	if (rep->r_procp)
1573 		tpr = tprintf_open(rep->r_procp);
1574 	else
1575 		tpr = NULL;
1576 
1577 	tprintf(tpr, "nfs server %s: %s\n",
1578 	    rep->r_nmp->nm_mountp->mnt_stat.f_mntfromname, msg);
1579 	tprintf_close(tpr);
1580 }
1581 
1582 #ifdef NFSSERVER
1583 /*
1584  * Socket upcall routine for the nfsd sockets.
1585  * The caddr_t arg is a pointer to the "struct nfssvc_sock".
1586  * Essentially do as much as possible non-blocking, else punt and it will
1587  * be called with M_WAIT from an nfsd.
1588  */
1589 void
1590 nfsrv_rcv(so, arg, waitflag)
1591 	struct socket *so;
1592 	caddr_t arg;
1593 	int waitflag;
1594 {
1595 	struct nfssvc_sock *slp = (struct nfssvc_sock *)arg;
1596 	struct mbuf *m;
1597 	struct mbuf *mp, *nam;
1598 	struct uio auio;
1599 	int flags, error;
1600 
1601 	if ((slp->ns_flag & SLP_VALID) == 0)
1602 		return;
1603 #ifdef notdef
1604 	/*
1605 	 * Define this to test for nfsds handling this under heavy load.
1606 	 */
1607 	if (waitflag == M_DONTWAIT) {
1608 		slp->ns_flag |= SLP_NEEDQ; goto dorecs;
1609 	}
1610 #endif
1611 	auio.uio_procp = NULL;
1612 	if (so->so_type == SOCK_STREAM) {
1613 		/*
1614 		 * If there are already records on the queue, defer soreceive()
1615 		 * to an nfsd so that there is feedback to the TCP layer that
1616 		 * the nfs servers are heavily loaded.
1617 		 */
1618 		if (slp->ns_rec && waitflag == M_DONTWAIT) {
1619 			slp->ns_flag |= SLP_NEEDQ;
1620 			goto dorecs;
1621 		}
1622 
1623 		/*
1624 		 * Do soreceive().
1625 		 */
1626 		auio.uio_resid = 1000000000;
1627 		flags = MSG_DONTWAIT;
1628 		error = soreceive(so, &nam, &auio, &mp, NULL,
1629 		    &flags, 0);
1630 		if (error || mp == NULL) {
1631 			if (error == EWOULDBLOCK)
1632 				slp->ns_flag |= SLP_NEEDQ;
1633 			else
1634 				slp->ns_flag |= SLP_DISCONN;
1635 			goto dorecs;
1636 		}
1637 		m = mp;
1638 		if (slp->ns_rawend) {
1639 			slp->ns_rawend->m_next = m;
1640 			slp->ns_cc += 1000000000 - auio.uio_resid;
1641 		} else {
1642 			slp->ns_raw = m;
1643 			slp->ns_cc = 1000000000 - auio.uio_resid;
1644 		}
1645 		while (m->m_next)
1646 			m = m->m_next;
1647 		slp->ns_rawend = m;
1648 
1649 		/*
1650 		 * Now try and parse record(s) out of the raw stream data.
1651 		 */
1652 		error = nfsrv_getstream(slp, waitflag);
1653 		if (error) {
1654 			if (error == EPERM)
1655 				slp->ns_flag |= SLP_DISCONN;
1656 			else
1657 				slp->ns_flag |= SLP_NEEDQ;
1658 		}
1659 	} else {
1660 		do {
1661 			auio.uio_resid = 1000000000;
1662 			flags = MSG_DONTWAIT;
1663 			error = soreceive(so, &nam, &auio, &mp,
1664 			    NULL, &flags, 0);
1665 			if (mp) {
1666 				if (nam) {
1667 					m = nam;
1668 					m->m_next = mp;
1669 				} else
1670 					m = mp;
1671 				if (slp->ns_recend)
1672 					slp->ns_recend->m_nextpkt = m;
1673 				else
1674 					slp->ns_rec = m;
1675 				slp->ns_recend = m;
1676 				m->m_nextpkt = NULL;
1677 			}
1678 			if (error) {
1679 				if ((so->so_proto->pr_flags & PR_CONNREQUIRED)
1680 					&& error != EWOULDBLOCK) {
1681 					slp->ns_flag |= SLP_DISCONN;
1682 					goto dorecs;
1683 				}
1684 			}
1685 		} while (mp);
1686 	}
1687 
1688 	/*
1689 	 * Now try and process the request records, non-blocking.
1690 	 */
1691 dorecs:
1692 	if (waitflag == M_DONTWAIT &&
1693 		(slp->ns_rec || (slp->ns_flag & (SLP_NEEDQ | SLP_DISCONN))))
1694 		nfsrv_wakenfsd(slp);
1695 }
1696 
1697 /*
1698  * Try and extract an RPC request from the mbuf data list received on a
1699  * stream socket. The "waitflag" argument indicates whether or not it
1700  * can sleep.
1701  */
1702 int
1703 nfsrv_getstream(slp, waitflag)
1704 	struct nfssvc_sock *slp;
1705 	int waitflag;
1706 {
1707 	struct mbuf *m, **mpp;
1708 	char *cp1, *cp2;
1709 	int len;
1710 	struct mbuf *om, *m2, *recm;
1711 	u_int32_t recmark;
1712 
1713 	if (slp->ns_flag & SLP_GETSTREAM)
1714 		panic("nfs getstream");
1715 	slp->ns_flag |= SLP_GETSTREAM;
1716 	for (;;) {
1717 	    if (slp->ns_reclen == 0) {
1718 		if (slp->ns_cc < NFSX_UNSIGNED) {
1719 			slp->ns_flag &= ~SLP_GETSTREAM;
1720 			return (0);
1721 		}
1722 		m = slp->ns_raw;
1723 		if (m->m_len >= NFSX_UNSIGNED) {
1724 			bcopy(mtod(m, caddr_t), (caddr_t)&recmark, NFSX_UNSIGNED);
1725 			m->m_data += NFSX_UNSIGNED;
1726 			m->m_len -= NFSX_UNSIGNED;
1727 		} else {
1728 			cp1 = (caddr_t)&recmark;
1729 			cp2 = mtod(m, caddr_t);
1730 			while (cp1 < ((caddr_t)&recmark) + NFSX_UNSIGNED) {
1731 				while (m->m_len == 0) {
1732 					m = m->m_next;
1733 					cp2 = mtod(m, caddr_t);
1734 				}
1735 				*cp1++ = *cp2++;
1736 				m->m_data++;
1737 				m->m_len--;
1738 			}
1739 		}
1740 		slp->ns_cc -= NFSX_UNSIGNED;
1741 		recmark = ntohl(recmark);
1742 		slp->ns_reclen = recmark & ~0x80000000;
1743 		if (recmark & 0x80000000)
1744 			slp->ns_flag |= SLP_LASTFRAG;
1745 		else
1746 			slp->ns_flag &= ~SLP_LASTFRAG;
1747 		if (slp->ns_reclen > NFS_MAXPACKET) {
1748 			slp->ns_flag &= ~SLP_GETSTREAM;
1749 			return (EPERM);
1750 		}
1751 	    }
1752 
1753 	    /*
1754 	     * Now get the record part.
1755 	     */
1756 	    recm = NULL;
1757 	    if (slp->ns_cc == slp->ns_reclen) {
1758 		recm = slp->ns_raw;
1759 		slp->ns_raw = slp->ns_rawend = NULL;
1760 		slp->ns_cc = slp->ns_reclen = 0;
1761 	    } else if (slp->ns_cc > slp->ns_reclen) {
1762 		len = 0;
1763 		m = slp->ns_raw;
1764 		om = NULL;
1765 		while (len < slp->ns_reclen) {
1766 			if ((len + m->m_len) > slp->ns_reclen) {
1767 				m2 = m_copym(m, 0, slp->ns_reclen - len,
1768 					waitflag);
1769 				if (m2) {
1770 					if (om) {
1771 						om->m_next = m2;
1772 						recm = slp->ns_raw;
1773 					} else
1774 						recm = m2;
1775 					m->m_data += slp->ns_reclen - len;
1776 					m->m_len -= slp->ns_reclen - len;
1777 					len = slp->ns_reclen;
1778 				} else {
1779 					slp->ns_flag &= ~SLP_GETSTREAM;
1780 					return (EWOULDBLOCK);
1781 				}
1782 			} else if ((len + m->m_len) == slp->ns_reclen) {
1783 				om = m;
1784 				len += m->m_len;
1785 				m = m->m_next;
1786 				recm = slp->ns_raw;
1787 				om->m_next = NULL;
1788 			} else {
1789 				om = m;
1790 				len += m->m_len;
1791 				m = m->m_next;
1792 			}
1793 		}
1794 		slp->ns_raw = m;
1795 		slp->ns_cc -= len;
1796 		slp->ns_reclen = 0;
1797 	    } else {
1798 		slp->ns_flag &= ~SLP_GETSTREAM;
1799 		return (0);
1800 	    }
1801 
1802 	    /*
1803 	     * Accumulate the fragments into a record.
1804 	     */
1805 	    mpp = &slp->ns_frag;
1806 	    while (*mpp)
1807 		mpp = &((*mpp)->m_next);
1808 	    *mpp = recm;
1809 	    if (slp->ns_flag & SLP_LASTFRAG) {
1810 		if (slp->ns_recend)
1811 		    slp->ns_recend->m_nextpkt = slp->ns_frag;
1812 		else
1813 		    slp->ns_rec = slp->ns_frag;
1814 		slp->ns_recend = slp->ns_frag;
1815 		slp->ns_frag = NULL;
1816 	    }
1817 	}
1818 }
1819 
1820 /*
1821  * Parse an RPC header.
1822  */
1823 int
1824 nfsrv_dorec(slp, nfsd, ndp)
1825 	struct nfssvc_sock *slp;
1826 	struct nfsd *nfsd;
1827 	struct nfsrv_descript **ndp;
1828 {
1829 	struct mbuf *m, *nam;
1830 	struct nfsrv_descript *nd;
1831 	int error;
1832 
1833 	*ndp = NULL;
1834 	if ((slp->ns_flag & SLP_VALID) == 0 ||
1835 	    (m = slp->ns_rec) == NULL)
1836 		return (ENOBUFS);
1837 	slp->ns_rec = m->m_nextpkt;
1838 	if (slp->ns_rec)
1839 		m->m_nextpkt = NULL;
1840 	else
1841 		slp->ns_recend = NULL;
1842 	if (m->m_type == MT_SONAME) {
1843 		nam = m;
1844 		m = m->m_next;
1845 		nam->m_next = NULL;
1846 	} else
1847 		nam = NULL;
1848 	nd = pool_get(&nfsrv_descript_pl, PR_WAITOK);
1849 	nfs_realign(&m, 10 * NFSX_UNSIGNED);
1850 	nd->nd_md = nd->nd_mrep = m;
1851 	nd->nd_nam2 = nam;
1852 	nd->nd_dpos = mtod(m, caddr_t);
1853 	error = nfs_getreq(nd, nfsd, 1);
1854 	if (error) {
1855 		m_freem(nam);
1856 		pool_put(&nfsrv_descript_pl, nd);
1857 		return (error);
1858 	}
1859 	*ndp = nd;
1860 	nfsd->nfsd_nd = nd;
1861 	return (0);
1862 }
1863 
1864 
1865 /*
1866  * Search for a sleeping nfsd and wake it up.
1867  * SIDE EFFECT: If none found, set NFSD_CHECKSLP flag, so that one of the
1868  * running nfsds will go look for the work in the nfssvc_sock list.
1869  */
1870 void
1871 nfsrv_wakenfsd(struct nfssvc_sock *slp)
1872 {
1873 	struct nfsd	*nfsd;
1874 
1875 	if ((slp->ns_flag & SLP_VALID) == 0)
1876 		return;
1877 
1878 	TAILQ_FOREACH(nfsd, &nfsd_head, nfsd_chain) {
1879 		if (nfsd->nfsd_flag & NFSD_WAITING) {
1880 			nfsd->nfsd_flag &= ~NFSD_WAITING;
1881 			if (nfsd->nfsd_slp)
1882 				panic("nfsd wakeup");
1883 			slp->ns_sref++;
1884 			nfsd->nfsd_slp = slp;
1885 			wakeup_one(nfsd);
1886 			return;
1887 		}
1888 	}
1889 
1890 	slp->ns_flag |= SLP_DOREC;
1891 	nfsd_head_flag |= NFSD_CHECKSLP;
1892 }
1893 #endif /* NFSSERVER */
1894