xref: /openbsd-src/sys/nfs/nfs_socket.c (revision c90a81c56dcebd6a1b73fe4aff9b03385b8e63b3)
1 /*	$OpenBSD: nfs_socket.c,v 1.132 2018/11/09 14:14:32 claudio 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/signalvar.h>
52 #include <sys/socket.h>
53 #include <sys/socketvar.h>
54 #include <sys/syslog.h>
55 #include <sys/tprintf.h>
56 #include <sys/namei.h>
57 #include <sys/pool.h>
58 #include <sys/queue.h>
59 
60 #include <netinet/in.h>
61 #include <netinet/tcp.h>
62 
63 #include <nfs/rpcv2.h>
64 #include <nfs/nfsproto.h>
65 #include <nfs/nfs.h>
66 #include <nfs/xdr_subs.h>
67 #include <nfs/nfsm_subs.h>
68 #include <nfs/nfsmount.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 
132 int nfs_rcvlock(struct nfsreq *);
133 int nfs_receive(struct nfsreq *, struct mbuf **, struct mbuf **);
134 int nfs_reconnect(struct nfsreq *);
135 int nfs_reply(struct nfsreq *);
136 void nfs_msg(struct nfsreq *, char *);
137 void nfs_rcvunlock(int *);
138 
139 int nfsrv_getstream(struct nfssvc_sock *, int);
140 
141 unsigned int nfs_realign_test = 0;
142 unsigned int nfs_realign_count = 0;
143 
144 /* Initialize the RTT estimator state for a new mount point. */
145 void
146 nfs_init_rtt(struct nfsmount *nmp)
147 {
148 	int i;
149 
150 	for (i = 0; i < NFS_MAX_TIMER; i++)
151 		nmp->nm_srtt[i] = NFS_INITRTT;
152 	for (i = 0; i < NFS_MAX_TIMER; i++)
153 		nmp->nm_sdrtt[i] = 0;
154 }
155 
156 /*
157  * Update a mount point's RTT estimator state using data from the
158  * passed-in request.
159  *
160  * Use a gain of 0.125 on the mean and a gain of 0.25 on the deviation.
161  *
162  * NB: Since the timer resolution of NFS_HZ is so course, it can often
163  * result in r_rtt == 0. Since r_rtt == N means that the actual RTT is
164  * between N + dt and N + 2 - dt ticks, add 1 before calculating the
165  * update values.
166  */
167 void
168 nfs_update_rtt(struct nfsreq *rep)
169 {
170 	int t1 = rep->r_rtt + 1;
171 	int index = nfs_ptimers[rep->r_procnum] - 1;
172 	int *srtt = &rep->r_nmp->nm_srtt[index];
173 	int *sdrtt = &rep->r_nmp->nm_sdrtt[index];
174 
175 	t1 -= *srtt >> 3;
176 	*srtt += t1;
177 	if (t1 < 0)
178 		t1 = -t1;
179 	t1 -= *sdrtt >> 2;
180 	*sdrtt += t1;
181 }
182 
183 /*
184  * Estimate RTO for an NFS RPC sent via an unreliable datagram.
185  *
186  * Use the mean and mean deviation of RTT for the appropriate type
187  * of RPC for the frequent RPCs and a default for the others.
188  * The justification for doing "other" this way is that these RPCs
189  * happen so infrequently that timer est. would probably be stale.
190  * Also, since many of these RPCs are non-idempotent, a conservative
191  * timeout is desired.
192  *
193  * getattr, lookup - A+2D
194  * read, write     - A+4D
195  * other           - nm_timeo
196  */
197 int
198 nfs_estimate_rto(struct nfsmount *nmp, u_int32_t procnum)
199 {
200 	enum nfs_rto_timers timer = nfs_ptimers[procnum];
201 	int index = timer - 1;
202 	int rto;
203 
204 	switch (timer) {
205 	case NFS_GETATTR_TIMER:
206 	case NFS_LOOKUP_TIMER:
207 		rto = ((nmp->nm_srtt[index] + 3) >> 2) +
208 				((nmp->nm_sdrtt[index] + 1) >> 1);
209 		break;
210 	case NFS_READ_TIMER:
211 	case NFS_WRITE_TIMER:
212 		rto = ((nmp->nm_srtt[index] + 7) >> 3) +
213 				(nmp->nm_sdrtt[index] + 1);
214 		break;
215 	default:
216 		rto = nmp->nm_timeo;
217 		return (rto);
218 	}
219 
220 	if (rto < NFS_MINRTO)
221 		rto = NFS_MINRTO;
222 	else if (rto > NFS_MAXRTO)
223 		rto = NFS_MAXRTO;
224 
225 	return (rto);
226 }
227 
228 
229 
230 /*
231  * Initialize sockets and congestion for a new NFS connection.
232  * We do not free the sockaddr if error.
233  */
234 int
235 nfs_connect(struct nfsmount *nmp, struct nfsreq *rep)
236 {
237 	struct socket *so;
238 	int s, error, rcvreserve, sndreserve;
239 	struct sockaddr *saddr;
240 	struct sockaddr_in *sin;
241 	struct mbuf *nam = NULL, *mopt = NULL;
242 
243 	if (!(nmp->nm_sotype == SOCK_DGRAM || nmp->nm_sotype == SOCK_STREAM))
244 		return (EINVAL);
245 
246 	nmp->nm_so = NULL;
247 	saddr = mtod(nmp->nm_nam, struct sockaddr *);
248 	error = socreate(saddr->sa_family, &nmp->nm_so, nmp->nm_sotype,
249 	    nmp->nm_soproto);
250 	if (error) {
251 		nfs_disconnect(nmp);
252 		return (error);
253 	}
254 
255 	/* Allocate mbufs possibly waiting before grabbing the socket lock. */
256 	if (nmp->nm_sotype == SOCK_STREAM || saddr->sa_family == AF_INET)
257 		MGET(mopt, M_WAIT, MT_SOOPTS);
258 	if (saddr->sa_family == AF_INET)
259 		MGET(nam, M_WAIT, MT_SONAME);
260 
261 	so = nmp->nm_so;
262 	s = solock(so);
263 	nmp->nm_soflags = so->so_proto->pr_flags;
264 
265 	/*
266 	 * Some servers require that the client port be a reserved port number.
267 	 * We always allocate a reserved port, as this prevents filehandle
268 	 * disclosure through UDP port capture.
269 	 */
270 	if (saddr->sa_family == AF_INET) {
271 		int *ip;
272 
273 		mopt->m_len = sizeof(int);
274 		ip = mtod(mopt, int *);
275 		*ip = IP_PORTRANGE_LOW;
276 		error = sosetopt(so, IPPROTO_IP, IP_PORTRANGE, mopt);
277 		if (error)
278 			goto bad;
279 
280 		sin = mtod(nam, struct sockaddr_in *);
281 		memset(sin, 0, sizeof(*sin));
282 		sin->sin_len = nam->m_len = sizeof(struct sockaddr_in);
283 		sin->sin_family = AF_INET;
284 		sin->sin_addr.s_addr = INADDR_ANY;
285 		sin->sin_port = htons(0);
286 		error = sobind(so, nam, &proc0);
287 		if (error)
288 			goto bad;
289 
290 		mopt->m_len = sizeof(int);
291 		ip = mtod(mopt, int *);
292 		*ip = IP_PORTRANGE_DEFAULT;
293 		error = sosetopt(so, IPPROTO_IP, IP_PORTRANGE, mopt);
294 		if (error)
295 			goto bad;
296 	}
297 
298 	/*
299 	 * Protocols that do not require connections may be optionally left
300 	 * unconnected for servers that reply from a port other than NFS_PORT.
301 	 */
302 	if (nmp->nm_flag & NFSMNT_NOCONN) {
303 		if (nmp->nm_soflags & PR_CONNREQUIRED) {
304 			error = ENOTCONN;
305 			goto bad;
306 		}
307 	} else {
308 		error = soconnect(so, nmp->nm_nam);
309 		if (error)
310 			goto bad;
311 
312 		/*
313 		 * Wait for the connection to complete. Cribbed from the
314 		 * connect system call but with the wait timing out so
315 		 * that interruptible mounts don't hang here for a long time.
316 		 */
317 		while ((so->so_state & SS_ISCONNECTING) && so->so_error == 0) {
318 			sosleep(so, &so->so_timeo, PSOCK, "nfscon", 2 * hz);
319 			if ((so->so_state & SS_ISCONNECTING) &&
320 			    so->so_error == 0 && rep &&
321 			    (error = nfs_sigintr(nmp, rep, rep->r_procp)) != 0){
322 				so->so_state &= ~SS_ISCONNECTING;
323 				goto bad;
324 			}
325 		}
326 		if (so->so_error) {
327 			error = so->so_error;
328 			so->so_error = 0;
329 			goto bad;
330 		}
331 	}
332 	/*
333 	 * Always set receive timeout to detect server crash and reconnect.
334 	 * Otherwise, we can get stuck in soreceive forever.
335 	 */
336 	so->so_rcv.sb_timeo = (5 * hz);
337 	if (nmp->nm_flag & (NFSMNT_SOFT | NFSMNT_INT))
338 		so->so_snd.sb_timeo = (5 * hz);
339 	else
340 		so->so_snd.sb_timeo = 0;
341 	if (nmp->nm_sotype == SOCK_DGRAM) {
342 		sndreserve = nmp->nm_wsize + NFS_MAXPKTHDR;
343 		rcvreserve = (max(nmp->nm_rsize, nmp->nm_readdirsize) +
344 		    NFS_MAXPKTHDR) * 2;
345 	} else if (nmp->nm_sotype == SOCK_STREAM) {
346 		if (so->so_proto->pr_flags & PR_CONNREQUIRED) {
347 			*mtod(mopt, int32_t *) = 1;
348 			mopt->m_len = sizeof(int32_t);
349 			sosetopt(so, SOL_SOCKET, SO_KEEPALIVE, mopt);
350 		}
351 		if (so->so_proto->pr_protocol == IPPROTO_TCP) {
352 			*mtod(mopt, int32_t *) = 1;
353 			mopt->m_len = sizeof(int32_t);
354 			sosetopt(so, IPPROTO_TCP, TCP_NODELAY, mopt);
355 		}
356 		sndreserve = (nmp->nm_wsize + NFS_MAXPKTHDR +
357 		    sizeof (u_int32_t)) * 2;
358 		rcvreserve = (nmp->nm_rsize + NFS_MAXPKTHDR +
359 		    sizeof (u_int32_t)) * 2;
360 	} else {
361 		panic("%s: nm_sotype %d", __func__, nmp->nm_sotype);
362 	}
363 	error = soreserve(so, sndreserve, rcvreserve);
364 	if (error)
365 		goto bad;
366 	so->so_rcv.sb_flags |= SB_NOINTR;
367 	so->so_snd.sb_flags |= SB_NOINTR;
368 	sounlock(so, s);
369 
370 	m_freem(mopt);
371 	m_freem(nam);
372 
373 	/* Initialize other non-zero congestion variables */
374 	nfs_init_rtt(nmp);
375 	nmp->nm_cwnd = NFS_MAXCWND / 2;	    /* Initial send window */
376 	nmp->nm_sent = 0;
377 	nmp->nm_timeouts = 0;
378 	return (0);
379 
380 bad:
381 	sounlock(so, s);
382 
383 	m_freem(mopt);
384 	m_freem(nam);
385 
386 	nfs_disconnect(nmp);
387 	return (error);
388 }
389 
390 /*
391  * Reconnect routine:
392  * Called when a connection is broken on a reliable protocol.
393  * - clean up the old socket
394  * - nfs_connect() again
395  * - set R_MUSTRESEND for all outstanding requests on mount point
396  * If this fails the mount point is DEAD!
397  * nb: Must be called with the nfs_sndlock() set on the mount point.
398  */
399 int
400 nfs_reconnect(struct nfsreq *rep)
401 {
402 	struct nfsreq *rp;
403 	struct nfsmount *nmp = rep->r_nmp;
404 	int error;
405 
406 	nfs_disconnect(nmp);
407 	while ((error = nfs_connect(nmp, rep)) != 0) {
408 		if (error == EINTR || error == ERESTART)
409 			return (EINTR);
410 		(void)tsleep((caddr_t)&lbolt, PSOCK, "nfsrecon", 0);
411 	}
412 
413 	/*
414 	 * Loop through outstanding request list and fix up all requests
415 	 * on old socket.
416 	 */
417 	TAILQ_FOREACH(rp, &nmp->nm_reqsq, r_chain) {
418 		rp->r_flags |= R_MUSTRESEND;
419 		rp->r_rexmit = 0;
420 	}
421 	return (0);
422 }
423 
424 /*
425  * NFS disconnect. Clean up and unlink.
426  */
427 void
428 nfs_disconnect(struct nfsmount *nmp)
429 {
430 	struct socket *so;
431 
432 	if (nmp->nm_so) {
433 		so = nmp->nm_so;
434 		nmp->nm_so = NULL;
435 		soshutdown(so, SHUT_RDWR);
436 		soclose(so, 0);
437 	}
438 }
439 
440 /*
441  * This is the nfs send routine. For connection based socket types, it
442  * must be called with an nfs_sndlock() on the socket.
443  * "rep == NULL" indicates that it has been called from a server.
444  * For the client side:
445  * - return EINTR if the RPC is terminated, 0 otherwise
446  * - set R_MUSTRESEND if the send fails for any reason
447  * - do any cleanup required by recoverable socket errors (???)
448  * For the server side:
449  * - return EINTR or ERESTART if interrupted by a signal
450  * - return EPIPE if a connection is lost for connection based sockets (TCP...)
451  * - do any cleanup required by recoverable socket errors (???)
452  */
453 int
454 nfs_send(struct socket *so, struct mbuf *nam, struct mbuf *top,
455     struct nfsreq *rep)
456 {
457 	struct mbuf *sendnam;
458 	int error, soflags, flags;
459 
460 	if (rep) {
461 		if (rep->r_flags & R_SOFTTERM) {
462 			m_freem(top);
463 			return (EINTR);
464 		}
465 		if ((so = rep->r_nmp->nm_so) == NULL) {
466 			rep->r_flags |= R_MUSTRESEND;
467 			m_freem(top);
468 			return (0);
469 		}
470 		rep->r_flags &= ~R_MUSTRESEND;
471 		soflags = rep->r_nmp->nm_soflags;
472 	} else
473 		soflags = so->so_proto->pr_flags;
474 	if ((soflags & PR_CONNREQUIRED) || (so->so_state & SS_ISCONNECTED))
475 		sendnam = NULL;
476 	else
477 		sendnam = nam;
478 	flags = 0;
479 
480 	error = sosend(so, sendnam, NULL, top, NULL, flags);
481 	if (error) {
482 		if (rep) {
483 			/*
484 			 * Deal with errors for the client side.
485 			 */
486 			if (rep->r_flags & R_SOFTTERM)
487 				error = EINTR;
488 			else
489 				rep->r_flags |= R_MUSTRESEND;
490 		}
491 
492 		/*
493 		 * Handle any recoverable (soft) socket errors here. (???)
494 		 */
495 		if (error != EINTR && error != ERESTART &&
496 		    error != EWOULDBLOCK && error != EPIPE)
497 			error = 0;
498 	}
499 	return (error);
500 }
501 
502 #ifdef NFSCLIENT
503 /*
504  * Receive a Sun RPC Request/Reply. For SOCK_DGRAM, the work is all
505  * done by soreceive(), but for SOCK_STREAM we must deal with the Record
506  * Mark and consolidate the data into a new mbuf list.
507  * nb: Sometimes TCP passes the data up to soreceive() in long lists of
508  *     small mbufs.
509  * For SOCK_STREAM we must be very careful to read an entire record once
510  * we have read any of it, even if the system call has been interrupted.
511  */
512 int
513 nfs_receive(struct nfsreq *rep, struct mbuf **aname, struct mbuf **mp)
514 {
515 	struct socket *so;
516 	struct uio auio;
517 	struct iovec aio;
518 	struct mbuf *m;
519 	struct mbuf *control;
520 	u_int32_t len;
521 	struct mbuf **getnam;
522 	int error, sotype, rcvflg;
523 	struct proc *p = curproc;	/* XXX */
524 
525 	/*
526 	 * Set up arguments for soreceive()
527 	 */
528 	*mp = NULL;
529 	*aname = NULL;
530 	sotype = rep->r_nmp->nm_sotype;
531 
532 	/*
533 	 * For reliable protocols, lock against other senders/receivers
534 	 * in case a reconnect is necessary.
535 	 * For SOCK_STREAM, first get the Record Mark to find out how much
536 	 * more there is to get.
537 	 * We must lock the socket against other receivers
538 	 * until we have an entire rpc request/reply.
539 	 */
540 	if (sotype != SOCK_DGRAM) {
541 		error = nfs_sndlock(&rep->r_nmp->nm_flag, rep);
542 		if (error)
543 			return (error);
544 tryagain:
545 		/*
546 		 * Check for fatal errors and resending request.
547 		 */
548 		/*
549 		 * Ugh: If a reconnect attempt just happened, nm_so
550 		 * would have changed. NULL indicates a failed
551 		 * attempt that has essentially shut down this
552 		 * mount point.
553 		 */
554 		if (rep->r_mrep || (rep->r_flags & R_SOFTTERM)) {
555 			nfs_sndunlock(&rep->r_nmp->nm_flag);
556 			return (EINTR);
557 		}
558 		so = rep->r_nmp->nm_so;
559 		if (!so) {
560 			error = nfs_reconnect(rep);
561 			if (error) {
562 				nfs_sndunlock(&rep->r_nmp->nm_flag);
563 				return (error);
564 			}
565 			goto tryagain;
566 		}
567 		while (rep->r_flags & R_MUSTRESEND) {
568 			m = m_copym(rep->r_mreq, 0, M_COPYALL, M_WAIT);
569 			nfsstats.rpcretries++;
570 			rep->r_rtt = 0;
571 			rep->r_flags &= ~R_TIMING;
572 			error = nfs_send(so, rep->r_nmp->nm_nam, m, rep);
573 			if (error) {
574 				if (error == EINTR || error == ERESTART ||
575 				    (error = nfs_reconnect(rep)) != 0) {
576 					nfs_sndunlock(&rep->r_nmp->nm_flag);
577 					return (error);
578 				}
579 				goto tryagain;
580 			}
581 		}
582 		nfs_sndunlock(&rep->r_nmp->nm_flag);
583 		if (sotype == SOCK_STREAM) {
584 			aio.iov_base = (caddr_t) &len;
585 			aio.iov_len = sizeof(u_int32_t);
586 			auio.uio_iov = &aio;
587 			auio.uio_iovcnt = 1;
588 			auio.uio_segflg = UIO_SYSSPACE;
589 			auio.uio_rw = UIO_READ;
590 			auio.uio_offset = 0;
591 			auio.uio_resid = sizeof(u_int32_t);
592 			auio.uio_procp = p;
593 			do {
594 				rcvflg = MSG_WAITALL;
595 				error = soreceive(so, NULL, &auio, NULL, NULL,
596 				    &rcvflg, 0);
597 				if (error == EWOULDBLOCK && rep) {
598 					if (rep->r_flags & R_SOFTTERM)
599 						return (EINTR);
600 					/*
601 					 * looks like the server died after it
602 					 * received the request, make sure
603 					 * that we will retransmit and we
604 					 * don't get stuck here forever.
605 					 */
606 					if (rep->r_rexmit >=
607 					    rep->r_nmp->nm_retry) {
608 						nfsstats.rpctimeouts++;
609 						error = EPIPE;
610 					}
611 				}
612 			} while (error == EWOULDBLOCK);
613 			if (!error && auio.uio_resid > 0) {
614 			    log(LOG_INFO,
615 				 "short receive (%zu/%zu) from nfs server %s\n",
616 				 sizeof(u_int32_t) - auio.uio_resid,
617 				 sizeof(u_int32_t),
618 				 rep->r_nmp->nm_mountp->mnt_stat.f_mntfromname);
619 			    error = EPIPE;
620 			}
621 			if (error)
622 				goto errout;
623 
624 			len = ntohl(len) & ~0x80000000;
625 			/*
626 			 * This is SERIOUS! We are out of sync with the sender
627 			 * and forcing a disconnect/reconnect is all I can do.
628 			 */
629 			if (len > NFS_MAXPACKET) {
630 			    log(LOG_ERR, "%s (%u) from nfs server %s\n",
631 				"impossible packet length",
632 				len,
633 				rep->r_nmp->nm_mountp->mnt_stat.f_mntfromname);
634 			    error = EFBIG;
635 			    goto errout;
636 			}
637 			auio.uio_resid = len;
638 			do {
639 			    rcvflg = MSG_WAITALL;
640 			    error =  soreceive(so, NULL, &auio, mp, NULL,
641 			        &rcvflg, 0);
642 			} while (error == EWOULDBLOCK || error == EINTR ||
643 			    error == ERESTART);
644 			if (!error && auio.uio_resid > 0) {
645 				log(LOG_INFO, "short receive (%zu/%u) from "
646 				    "nfs server %s\n", len - auio.uio_resid,
647 				    len, rep->r_nmp->nm_mountp->
648 				    mnt_stat.f_mntfromname);
649 				error = EPIPE;
650 			}
651 		} else {
652 			/*
653 			 * NB: Since uio_resid is big, MSG_WAITALL is ignored
654 			 * and soreceive() will return when it has either a
655 			 * control msg or a data msg.
656 			 * We have no use for control msg., but must grab them
657 			 * and then throw them away so we know what is going
658 			 * on.
659 			 */
660 			auio.uio_resid = len = 100000000; /* Anything Big */
661 			auio.uio_procp = p;
662 			do {
663 				rcvflg = 0;
664 				error = soreceive(so, NULL, &auio, mp, &control,
665 				    &rcvflg, 0);
666 				m_freem(control);
667 				if (error == EWOULDBLOCK && rep) {
668 					if (rep->r_flags & R_SOFTTERM)
669 						return (EINTR);
670 				}
671 			} while (error == EWOULDBLOCK ||
672 			    (!error && *mp == NULL && control));
673 			if ((rcvflg & MSG_EOR) == 0)
674 				printf("Egad!!\n");
675 			if (!error && *mp == NULL)
676 				error = EPIPE;
677 			len -= auio.uio_resid;
678 		}
679 errout:
680 		if (error && error != EINTR && error != ERESTART) {
681 			m_freemp(mp);
682 			if (error != EPIPE)
683 				log(LOG_INFO,
684 				    "receive error %d from nfs server %s\n",
685 				    error,
686 				 rep->r_nmp->nm_mountp->mnt_stat.f_mntfromname);
687 			error = nfs_sndlock(&rep->r_nmp->nm_flag, rep);
688 			if (!error) {
689 				error = nfs_reconnect(rep);
690 				if (!error)
691 					goto tryagain;
692 				nfs_sndunlock(&rep->r_nmp->nm_flag);
693 			}
694 		}
695 	} else {
696 		if ((so = rep->r_nmp->nm_so) == NULL)
697 			return (EACCES);
698 		if (so->so_state & SS_ISCONNECTED)
699 			getnam = NULL;
700 		else
701 			getnam = aname;
702 		auio.uio_resid = len = 1000000;
703 		auio.uio_procp = p;
704 		do {
705 			rcvflg = 0;
706 			error = soreceive(so, getnam, &auio, mp, NULL,
707 			    &rcvflg, 0);
708 			if (error == EWOULDBLOCK &&
709 			    (rep->r_flags & R_SOFTTERM))
710 				return (EINTR);
711 		} while (error == EWOULDBLOCK);
712 		len -= auio.uio_resid;
713 	}
714 	if (error)
715 		m_freemp(mp);
716 	/*
717 	 * Search for any mbufs that are not a multiple of 4 bytes long
718 	 * or with m_data not longword aligned.
719 	 * These could cause pointer alignment problems, so copy them to
720 	 * well aligned mbufs.
721 	 */
722 	nfs_realign(mp, 5 * NFSX_UNSIGNED);
723 	return (error);
724 }
725 
726 /*
727  * Implement receipt of reply on a socket.
728  * We must search through the list of received datagrams matching them
729  * with outstanding requests using the xid, until ours is found.
730  */
731 int
732 nfs_reply(struct nfsreq *myrep)
733 {
734 	struct nfsreq *rep;
735 	struct nfsmount *nmp = myrep->r_nmp;
736 	struct nfsm_info	info;
737 	struct mbuf *nam;
738 	u_int32_t rxid, *tl, t1;
739 	caddr_t cp2;
740 	int error;
741 
742 	/*
743 	 * Loop around until we get our own reply
744 	 */
745 	for (;;) {
746 		/*
747 		 * Lock against other receivers so that I don't get stuck in
748 		 * sbwait() after someone else has received my reply for me.
749 		 * Also necessary for connection based protocols to avoid
750 		 * race conditions during a reconnect.
751 		 */
752 		error = nfs_rcvlock(myrep);
753 		if (error)
754 			return (error == EALREADY ? 0 : error);
755 
756 		/*
757 		 * Get the next Rpc reply off the socket
758 		 */
759 		error = nfs_receive(myrep, &nam, &info.nmi_mrep);
760 		nfs_rcvunlock(&nmp->nm_flag);
761 		if (error) {
762 
763 			/*
764 			 * Ignore routing errors on connectionless protocols??
765 			 */
766 			if (NFSIGNORE_SOERROR(nmp->nm_soflags, error)) {
767 				if (nmp->nm_so)
768 					nmp->nm_so->so_error = 0;
769 				continue;
770 			}
771 			return (error);
772 		}
773 		m_freem(nam);
774 
775 		/*
776 		 * Get the xid and check that it is an rpc reply
777 		 */
778 		info.nmi_md = info.nmi_mrep;
779 		info.nmi_dpos = mtod(info.nmi_md, caddr_t);
780 		nfsm_dissect(tl, u_int32_t *, 2 * NFSX_UNSIGNED);
781 		rxid = *tl++;
782 		if (*tl != rpc_reply) {
783 			nfsstats.rpcinvalid++;
784 			m_freem(info.nmi_mrep);
785 nfsmout:
786 			continue;
787 		}
788 
789 		/*
790 		 * Loop through the request list to match up the reply
791 		 * Iff no match, just drop the datagram
792 		 */
793 		TAILQ_FOREACH(rep, &nmp->nm_reqsq, r_chain) {
794 			if (rep->r_mrep == NULL && rxid == rep->r_xid) {
795 				/* Found it.. */
796 				rep->r_mrep = info.nmi_mrep;
797 				rep->r_md = info.nmi_md;
798 				rep->r_dpos = info.nmi_dpos;
799 
800 				/*
801 				 * Update congestion window.
802 				 * Do the additive increase of
803 				 * one rpc/rtt.
804 				 */
805 				if (nmp->nm_cwnd <= nmp->nm_sent) {
806 					nmp->nm_cwnd +=
807 					   (NFS_CWNDSCALE * NFS_CWNDSCALE +
808 					   (nmp->nm_cwnd >> 1)) / nmp->nm_cwnd;
809 					if (nmp->nm_cwnd > NFS_MAXCWND)
810 						nmp->nm_cwnd = NFS_MAXCWND;
811 				}
812 				rep->r_flags &= ~R_SENT;
813 				nmp->nm_sent -= NFS_CWNDSCALE;
814 
815 				if (rep->r_flags & R_TIMING)
816 					nfs_update_rtt(rep);
817 
818 				nmp->nm_timeouts = 0;
819 				break;
820 			}
821 		}
822 		/*
823 		 * If not matched to a request, drop it.
824 		 * If it's mine, get out.
825 		 */
826 		if (rep == 0) {
827 			nfsstats.rpcunexpected++;
828 			m_freem(info.nmi_mrep);
829 		} else if (rep == myrep) {
830 			if (rep->r_mrep == NULL)
831 				panic("nfsreply nil");
832 			return (0);
833 		}
834 	}
835 }
836 
837 /*
838  * nfs_request - goes something like this
839  *	- fill in request struct
840  *	- links it into list
841  *	- calls nfs_send() for first transmit
842  *	- calls nfs_receive() to get reply
843  *	- break down rpc header and return with nfs reply pointed to
844  *	  by mrep or error
845  * nb: always frees up mreq mbuf list
846  */
847 int
848 nfs_request(struct vnode *vp, int procnum, struct nfsm_info *infop)
849 {
850 	struct mbuf *m;
851 	u_int32_t *tl;
852 	struct nfsmount *nmp;
853 	struct timeval tv;
854 	caddr_t cp2;
855 	int t1, i, error = 0;
856 	int trylater_delay;
857 	struct nfsreq *rep;
858 	struct nfsm_info info;
859 
860 	rep = pool_get(&nfsreqpl, PR_WAITOK);
861 	rep->r_nmp = VFSTONFS(vp->v_mount);
862 	rep->r_vp = vp;
863 	rep->r_procp = infop->nmi_procp;
864 	rep->r_procnum = procnum;
865 
866 	/* empty mbuf for AUTH_UNIX header */
867 	rep->r_mreq = m_gethdr(M_WAIT, MT_DATA);
868 	rep->r_mreq->m_next = infop->nmi_mreq;
869 	rep->r_mreq->m_len = 0;
870 	m_calchdrlen(rep->r_mreq);
871 
872 	trylater_delay = NFS_MINTIMEO;
873 
874 	nmp = rep->r_nmp;
875 
876 	/* Get the RPC header with authorization. */
877 	nfsm_rpchead(rep, infop->nmi_cred, RPCAUTH_UNIX);
878 	m = rep->r_mreq;
879 
880 	/*
881 	 * For stream protocols, insert a Sun RPC Record Mark.
882 	 */
883 	if (nmp->nm_sotype == SOCK_STREAM) {
884 		M_PREPEND(m, NFSX_UNSIGNED, M_WAIT);
885 		*mtod(m, u_int32_t *) = htonl(0x80000000 |
886 		    (m->m_pkthdr.len - NFSX_UNSIGNED));
887 	}
888 
889 tryagain:
890 	rep->r_rtt = rep->r_rexmit = 0;
891 	if (nfs_ptimers[rep->r_procnum] != NFS_DEFAULT_TIMER)
892 		rep->r_flags = R_TIMING;
893 	else
894 		rep->r_flags = 0;
895 	rep->r_mrep = NULL;
896 
897 	/*
898 	 * Do the client side RPC.
899 	 */
900 	nfsstats.rpcrequests++;
901 	/*
902 	 * Chain request into list of outstanding requests. Be sure
903 	 * to put it LAST so timer finds oldest requests first.
904 	 */
905 	if (TAILQ_EMPTY(&nmp->nm_reqsq))
906 		timeout_add(&nmp->nm_rtimeout, nfs_ticks);
907 	TAILQ_INSERT_TAIL(&nmp->nm_reqsq, rep, r_chain);
908 
909 	/*
910 	 * If backing off another request or avoiding congestion, don't
911 	 * send this one now but let timer do it. If not timing a request,
912 	 * do it now.
913 	 */
914 	if (nmp->nm_so && (nmp->nm_sotype != SOCK_DGRAM ||
915 		(nmp->nm_flag & NFSMNT_DUMBTIMR) ||
916 		nmp->nm_sent < nmp->nm_cwnd)) {
917 		if (nmp->nm_soflags & PR_CONNREQUIRED)
918 			error = nfs_sndlock(&nmp->nm_flag, rep);
919 		if (!error) {
920 			error = nfs_send(nmp->nm_so, nmp->nm_nam,
921 			    m_copym(m, 0, M_COPYALL, M_WAIT), rep);
922 			if (nmp->nm_soflags & PR_CONNREQUIRED)
923 				nfs_sndunlock(&nmp->nm_flag);
924 		}
925 		if (!error && (rep->r_flags & R_MUSTRESEND) == 0) {
926 			nmp->nm_sent += NFS_CWNDSCALE;
927 			rep->r_flags |= R_SENT;
928 		}
929 	} else {
930 		rep->r_rtt = -1;
931 	}
932 
933 	/*
934 	 * Wait for the reply from our send or the timer's.
935 	 */
936 	if (!error || error == EPIPE)
937 		error = nfs_reply(rep);
938 
939 	/*
940 	 * RPC done, unlink the request.
941 	 */
942 	TAILQ_REMOVE(&nmp->nm_reqsq, rep, r_chain);
943 	if (TAILQ_EMPTY(&nmp->nm_reqsq))
944 		timeout_del(&nmp->nm_rtimeout);
945 
946 	/*
947 	 * Decrement the outstanding request count.
948 	 */
949 	if (rep->r_flags & R_SENT) {
950 		rep->r_flags &= ~R_SENT;	/* paranoia */
951 		nmp->nm_sent -= NFS_CWNDSCALE;
952 	}
953 
954 	/*
955 	 * If there was a successful reply and a tprintf msg.
956 	 * tprintf a response.
957 	 */
958 	if (!error && (rep->r_flags & R_TPRINTFMSG))
959 		nfs_msg(rep, "is alive again");
960 	info.nmi_mrep = rep->r_mrep;
961 	info.nmi_md = rep->r_md;
962 	info.nmi_dpos = rep->r_dpos;
963 	if (error) {
964 		infop->nmi_mrep = NULL;
965 		goto nfsmout1;
966 	}
967 
968 	/*
969 	 * break down the rpc header and check if ok
970 	 */
971 	nfsm_dissect(tl, u_int32_t *, 3 * NFSX_UNSIGNED);
972 	if (*tl++ == rpc_msgdenied) {
973 		if (*tl == rpc_mismatch)
974 			error = EOPNOTSUPP;
975 		else
976 			error = EACCES;	/* Should be EAUTH. */
977 		infop->nmi_mrep = NULL;
978 		goto nfsmout1;
979 	}
980 
981 	/*
982 	 * Since we only support RPCAUTH_UNIX atm we step over the
983 	 * reply verifer type, and in the (error) case that there really
984 	 * is any data in it, we advance over it.
985 	 */
986 	tl++;			/* Step over verifer type */
987 	i = fxdr_unsigned(int32_t, *tl);
988 	if (i > 0)
989 		nfsm_adv(nfsm_rndup(i));	/* Should not happen */
990 
991 	nfsm_dissect(tl, u_int32_t *, NFSX_UNSIGNED);
992 	/* 0 == ok */
993 	if (*tl == 0) {
994 		nfsm_dissect(tl, u_int32_t *, NFSX_UNSIGNED);
995 		if (*tl != 0) {
996 			error = fxdr_unsigned(int, *tl);
997 			if ((nmp->nm_flag & NFSMNT_NFSV3) &&
998 			    error == NFSERR_TRYLATER) {
999 				m_freem(info.nmi_mrep);
1000 				error = 0;
1001 				tv.tv_sec = trylater_delay;
1002 				tv.tv_usec = 0;
1003 				tsleep(&tv, PSOCK, "nfsretry", tvtohz(&tv));
1004 				trylater_delay *= NFS_TIMEOUTMUL;
1005 				if (trylater_delay > NFS_MAXTIMEO)
1006 					trylater_delay = NFS_MAXTIMEO;
1007 
1008 				goto tryagain;
1009 			}
1010 
1011 			/*
1012 			 * If the File Handle was stale, invalidate the
1013 			 * lookup cache, just in case.
1014 			 */
1015 			if (error == ESTALE)
1016 				cache_purge(rep->r_vp);
1017 		}
1018 		goto nfsmout;
1019 	}
1020 
1021 	error = EPROTONOSUPPORT;
1022 
1023 nfsmout:
1024 	infop->nmi_mrep = info.nmi_mrep;
1025 	infop->nmi_md = info.nmi_md;
1026 	infop->nmi_dpos = info.nmi_dpos;
1027 nfsmout1:
1028 	m_freem(rep->r_mreq);
1029 	pool_put(&nfsreqpl, rep);
1030 	return (error);
1031 }
1032 #endif /* NFSCLIENT */
1033 
1034 /*
1035  * Generate the rpc reply header
1036  * siz arg. is used to decide if adding a cluster is worthwhile
1037  */
1038 int
1039 nfs_rephead(int siz, struct nfsrv_descript *nd, struct nfssvc_sock *slp,
1040     int err, struct mbuf **mrq, struct mbuf **mbp)
1041 {
1042 	u_int32_t *tl;
1043 	struct mbuf *mreq;
1044 	struct mbuf *mb;
1045 
1046 	MGETHDR(mreq, M_WAIT, MT_DATA);
1047 	mb = mreq;
1048 	/*
1049 	 * If this is a big reply, use a cluster else
1050 	 * try and leave leading space for the lower level headers.
1051 	 */
1052 	siz += RPC_REPLYSIZ;
1053 	if (siz >= MHLEN - max_hdr) {
1054 		MCLGET(mreq, M_WAIT);
1055 	} else
1056 		mreq->m_data += max_hdr;
1057 	tl = mtod(mreq, u_int32_t *);
1058 	mreq->m_len = 6 * NFSX_UNSIGNED;
1059 	*tl++ = txdr_unsigned(nd->nd_retxid);
1060 	*tl++ = rpc_reply;
1061 	if (err == ERPCMISMATCH || (err & NFSERR_AUTHERR)) {
1062 		*tl++ = rpc_msgdenied;
1063 		if (err & NFSERR_AUTHERR) {
1064 			*tl++ = rpc_autherr;
1065 			*tl = txdr_unsigned(err & ~NFSERR_AUTHERR);
1066 			mreq->m_len -= NFSX_UNSIGNED;
1067 		} else {
1068 			*tl++ = rpc_mismatch;
1069 			*tl++ = txdr_unsigned(RPC_VER2);
1070 			*tl = txdr_unsigned(RPC_VER2);
1071 		}
1072 	} else {
1073 		*tl++ = rpc_msgaccepted;
1074 
1075 		/* AUTH_UNIX requires RPCAUTH_NULL. */
1076 		*tl++ = 0;
1077 		*tl++ = 0;
1078 
1079 		switch (err) {
1080 		case EPROGUNAVAIL:
1081 			*tl = txdr_unsigned(RPC_PROGUNAVAIL);
1082 			break;
1083 		case EPROGMISMATCH:
1084 			*tl = txdr_unsigned(RPC_PROGMISMATCH);
1085 			tl = nfsm_build(&mb, 2 * NFSX_UNSIGNED);
1086 			*tl++ = txdr_unsigned(NFS_VER2);
1087 			*tl = txdr_unsigned(NFS_VER3);
1088 			break;
1089 		case EPROCUNAVAIL:
1090 			*tl = txdr_unsigned(RPC_PROCUNAVAIL);
1091 			break;
1092 		case EBADRPC:
1093 			*tl = txdr_unsigned(RPC_GARBAGE);
1094 			break;
1095 		default:
1096 			*tl = 0;
1097 			if (err != NFSERR_RETVOID) {
1098 				tl = nfsm_build(&mb, NFSX_UNSIGNED);
1099 				if (err)
1100 				    *tl = txdr_unsigned(nfsrv_errmap(nd, err));
1101 				else
1102 				    *tl = 0;
1103 			}
1104 			break;
1105 		};
1106 	}
1107 
1108 	*mrq = mreq;
1109 	if (mbp != NULL)
1110 		*mbp = mb;
1111 	if (err != 0 && err != NFSERR_RETVOID)
1112 		nfsstats.srvrpc_errs++;
1113 	return (0);
1114 }
1115 
1116 /*
1117  * nfs timer routine
1118  * Scan the nfsreq list and retranmit any requests that have timed out.
1119  */
1120 void
1121 nfs_timer(void *arg)
1122 {
1123 	struct nfsmount *nmp = arg;
1124 	struct nfsreq *rep;
1125 	struct mbuf *m;
1126 	struct socket *so;
1127 	int timeo, error;
1128 
1129 	NET_LOCK();
1130 	TAILQ_FOREACH(rep, &nmp->nm_reqsq, r_chain) {
1131 		if (rep->r_mrep || (rep->r_flags & R_SOFTTERM))
1132 			continue;
1133 		if (nfs_sigintr(nmp, rep, rep->r_procp)) {
1134 			rep->r_flags |= R_SOFTTERM;
1135 			continue;
1136 		}
1137 		if (rep->r_rtt >= 0) {
1138 			rep->r_rtt++;
1139 			if (nmp->nm_flag & NFSMNT_DUMBTIMR)
1140 				timeo = nmp->nm_timeo;
1141 			else
1142 				timeo = nfs_estimate_rto(nmp, rep->r_procnum);
1143 			if (nmp->nm_timeouts > 0)
1144 				timeo *= nfs_backoff[nmp->nm_timeouts - 1];
1145 			if (rep->r_rtt <= timeo)
1146 				continue;
1147 			if (nmp->nm_timeouts < nitems(nfs_backoff))
1148 				nmp->nm_timeouts++;
1149 		}
1150 
1151 		/* Check for server not responding. */
1152 		if ((rep->r_flags & R_TPRINTFMSG) == 0 && rep->r_rexmit > 4) {
1153 			nfs_msg(rep, "not responding");
1154 			rep->r_flags |= R_TPRINTFMSG;
1155 		}
1156 		if (rep->r_rexmit >= nmp->nm_retry) {	/* too many */
1157 			nfsstats.rpctimeouts++;
1158 			rep->r_flags |= R_SOFTTERM;
1159 			continue;
1160 		}
1161 		if (nmp->nm_sotype != SOCK_DGRAM) {
1162 			if (++rep->r_rexmit > NFS_MAXREXMIT)
1163 				rep->r_rexmit = NFS_MAXREXMIT;
1164 			continue;
1165 		}
1166 
1167 		if ((so = nmp->nm_so) == NULL)
1168 			continue;
1169 
1170 		/*
1171 		 * If there is enough space and the window allows..
1172 		 *	Resend it
1173 		 * Set r_rtt to -1 in case we fail to send it now.
1174 		 */
1175 		rep->r_rtt = -1;
1176 		if (sbspace(so, &so->so_snd) >= rep->r_mreq->m_pkthdr.len &&
1177 		   ((nmp->nm_flag & NFSMNT_DUMBTIMR) ||
1178 		    (rep->r_flags & R_SENT) ||
1179 		    nmp->nm_sent < nmp->nm_cwnd) &&
1180 		   (m = m_copym(rep->r_mreq, 0, M_COPYALL, M_DONTWAIT))){
1181 			if ((nmp->nm_flag & NFSMNT_NOCONN) == 0)
1182 			    	error = (*so->so_proto->pr_usrreq)(so, PRU_SEND,
1183 				    m, NULL, NULL, curproc);
1184 			else
1185 			    	error = (*so->so_proto->pr_usrreq)(so, PRU_SEND,
1186 				    m, nmp->nm_nam, NULL, curproc);
1187 			if (error) {
1188 				if (NFSIGNORE_SOERROR(nmp->nm_soflags, error))
1189 					so->so_error = 0;
1190 			} else {
1191 				/*
1192 				 * Iff first send, start timing
1193 				 * else turn timing off, backoff timer
1194 				 * and divide congestion window by 2.
1195 				 */
1196 				if (rep->r_flags & R_SENT) {
1197 					rep->r_flags &= ~R_TIMING;
1198 					if (++rep->r_rexmit > NFS_MAXREXMIT)
1199 						rep->r_rexmit = NFS_MAXREXMIT;
1200 					nmp->nm_cwnd >>= 1;
1201 					if (nmp->nm_cwnd < NFS_CWNDSCALE)
1202 						nmp->nm_cwnd = NFS_CWNDSCALE;
1203 					nfsstats.rpcretries++;
1204 				} else {
1205 					rep->r_flags |= R_SENT;
1206 					nmp->nm_sent += NFS_CWNDSCALE;
1207 				}
1208 				rep->r_rtt = 0;
1209 			}
1210 		}
1211 	}
1212 	NET_UNLOCK();
1213 	timeout_add(&nmp->nm_rtimeout, nfs_ticks);
1214 }
1215 
1216 /*
1217  * Test for a termination condition pending on the process.
1218  * This is used for NFSMNT_INT mounts.
1219  */
1220 int
1221 nfs_sigintr(struct nfsmount *nmp, struct nfsreq *rep, struct proc *p)
1222 {
1223 
1224 	if (rep && (rep->r_flags & R_SOFTTERM))
1225 		return (EINTR);
1226 	if (!(nmp->nm_flag & NFSMNT_INT))
1227 		return (0);
1228 	if (p && p->p_siglist &&
1229 	    (((p->p_siglist & ~p->p_sigmask) &
1230 	    ~p->p_p->ps_sigacts->ps_sigignore) & NFSINT_SIGMASK))
1231 		return (EINTR);
1232 	return (0);
1233 }
1234 
1235 /*
1236  * Lock a socket against others.
1237  * Necessary for STREAM sockets to ensure you get an entire rpc request/reply
1238  * and also to avoid race conditions between the processes with nfs requests
1239  * in progress when a reconnect is necessary.
1240  */
1241 int
1242 nfs_sndlock(int *flagp, struct nfsreq *rep)
1243 {
1244 	struct proc *p;
1245 	int slpflag = 0, slptimeo = 0;
1246 
1247 	if (rep) {
1248 		p = rep->r_procp;
1249 		if (rep->r_nmp->nm_flag & NFSMNT_INT)
1250 			slpflag = PCATCH;
1251 	} else
1252 		p = NULL;
1253 	while (*flagp & NFSMNT_SNDLOCK) {
1254 		if (rep && nfs_sigintr(rep->r_nmp, rep, p))
1255 			return (EINTR);
1256 		*flagp |= NFSMNT_WANTSND;
1257 		(void)tsleep((caddr_t)flagp, slpflag | (PZERO - 1), "nfsndlck",
1258 		    slptimeo);
1259 		if (slpflag == PCATCH) {
1260 			slpflag = 0;
1261 			slptimeo = 2 * hz;
1262 		}
1263 	}
1264 	*flagp |= NFSMNT_SNDLOCK;
1265 	return (0);
1266 }
1267 
1268 /*
1269  * Unlock the stream socket for others.
1270  */
1271 void
1272 nfs_sndunlock(int *flagp)
1273 {
1274 
1275 	if ((*flagp & NFSMNT_SNDLOCK) == 0)
1276 		panic("nfs sndunlock");
1277 	*flagp &= ~NFSMNT_SNDLOCK;
1278 	if (*flagp & NFSMNT_WANTSND) {
1279 		*flagp &= ~NFSMNT_WANTSND;
1280 		wakeup((caddr_t)flagp);
1281 	}
1282 }
1283 
1284 int
1285 nfs_rcvlock(struct nfsreq *rep)
1286 {
1287 	int *flagp = &rep->r_nmp->nm_flag;
1288 	int slpflag, slptimeo = 0;
1289 
1290 	if (*flagp & NFSMNT_INT)
1291 		slpflag = PCATCH;
1292 	else
1293 		slpflag = 0;
1294 
1295 	while (*flagp & NFSMNT_RCVLOCK) {
1296 		if (nfs_sigintr(rep->r_nmp, rep, rep->r_procp))
1297 			return (EINTR);
1298 		*flagp |= NFSMNT_WANTRCV;
1299 		(void)tsleep((caddr_t)flagp, slpflag | (PZERO - 1), "nfsrcvlk",
1300 		    slptimeo);
1301 		if (rep->r_mrep != NULL) {
1302 			/*
1303 			 * Don't take the lock if our reply has been received
1304 			 * while we where sleeping.
1305 			 */
1306 			 return (EALREADY);
1307 		}
1308 		if (slpflag == PCATCH) {
1309 			slpflag = 0;
1310 			slptimeo = 2 * hz;
1311 		}
1312 	}
1313 	*flagp |= NFSMNT_RCVLOCK;
1314 	return (0);
1315 }
1316 
1317 /*
1318  * Unlock the stream socket for others.
1319  */
1320 void
1321 nfs_rcvunlock(int *flagp)
1322 {
1323 
1324 	if ((*flagp & NFSMNT_RCVLOCK) == 0)
1325 		panic("nfs rcvunlock");
1326 	*flagp &= ~NFSMNT_RCVLOCK;
1327 	if (*flagp & NFSMNT_WANTRCV) {
1328 		*flagp &= ~NFSMNT_WANTRCV;
1329 		wakeup(flagp);
1330 	}
1331 }
1332 
1333 /*
1334  * Auxiliary routine to align the length of mbuf copies made with m_copyback().
1335  */
1336 void
1337 nfs_realign_fixup(struct mbuf *m, struct mbuf *n, unsigned int *off)
1338 {
1339 	size_t padding;
1340 
1341 	/*
1342 	 * The maximum number of bytes that m_copyback() places in a mbuf is
1343 	 * always an aligned quantity, so realign happens at the chain's tail.
1344 	 */
1345 	while (n->m_next != NULL)
1346 		n = n->m_next;
1347 
1348 	/*
1349 	 * Pad from the next elements in the source chain. Loop until the
1350 	 * destination chain is aligned, or the end of the source is reached.
1351 	 */
1352 	do {
1353 		m = m->m_next;
1354 		if (m == NULL)
1355 			return;
1356 
1357 		padding = min(ALIGN(n->m_len) - n->m_len, m->m_len);
1358 		if (padding > m_trailingspace(n))
1359 			panic("nfs_realign_fixup: no memory to pad to");
1360 
1361 		bcopy(mtod(m, void *), mtod(n, char *) + n->m_len, padding);
1362 
1363 		n->m_len += padding;
1364 		m_adj(m, padding);
1365 		*off += padding;
1366 
1367 	} while (!ALIGNED_POINTER(n->m_len, void *));
1368 }
1369 
1370 /*
1371  * The NFS RPC parsing code uses the data address and the length of mbuf
1372  * structures to calculate on-memory addresses. This function makes sure these
1373  * parameters are correctly aligned.
1374  */
1375 void
1376 nfs_realign(struct mbuf **pm, int hsiz)
1377 {
1378 	struct mbuf *m;
1379 	struct mbuf *n = NULL;
1380 	unsigned int off = 0;
1381 
1382 	++nfs_realign_test;
1383 	while ((m = *pm) != NULL) {
1384 		if (!ALIGNED_POINTER(m->m_data, void *) ||
1385 		    !ALIGNED_POINTER(m->m_len,  void *)) {
1386 			MGET(n, M_WAIT, MT_DATA);
1387 #define ALIGN_POINTER(n) ((u_int)(((n) + sizeof(void *)) & ~sizeof(void *)))
1388 			if (ALIGN_POINTER(m->m_len) >= MINCLSIZE) {
1389 				MCLGET(n, M_WAIT);
1390 			}
1391 			n->m_len = 0;
1392 			break;
1393 		}
1394 		pm = &m->m_next;
1395 	}
1396 	/*
1397 	 * If n is non-NULL, loop on m copying data, then replace the
1398 	 * portion of the chain that had to be realigned.
1399 	 */
1400 	if (n != NULL) {
1401 		++nfs_realign_count;
1402 		while (m) {
1403 			m_copyback(n, off, m->m_len, mtod(m, caddr_t), M_WAIT);
1404 
1405 			/*
1406 			 * If an unaligned amount of memory was copied, fix up
1407 			 * the last mbuf created by m_copyback().
1408 			 */
1409 			if (!ALIGNED_POINTER(m->m_len, void *))
1410 				nfs_realign_fixup(m, n, &off);
1411 
1412 			off += m->m_len;
1413 			m = m->m_next;
1414 		}
1415 		m_freemp(pm);
1416 		*pm = n;
1417 	}
1418 }
1419 
1420 
1421 /*
1422  * Parse an RPC request
1423  * - verify it
1424  * - fill in the cred struct.
1425  */
1426 int
1427 nfs_getreq(struct nfsrv_descript *nd, struct nfsd *nfsd, int has_header)
1428 {
1429 	int len, i;
1430 	u_int32_t *tl;
1431 	int32_t t1;
1432 	caddr_t cp2;
1433 	u_int32_t nfsvers, auth_type;
1434 	int error = 0;
1435 	struct nfsm_info info;
1436 
1437 	info.nmi_mrep = nd->nd_mrep;
1438 	info.nmi_md = nd->nd_md;
1439 	info.nmi_dpos = nd->nd_dpos;
1440 	if (has_header) {
1441 		nfsm_dissect(tl, u_int32_t *, 10 * NFSX_UNSIGNED);
1442 		nd->nd_retxid = fxdr_unsigned(u_int32_t, *tl++);
1443 		if (*tl++ != rpc_call) {
1444 			m_freem(info.nmi_mrep);
1445 			return (EBADRPC);
1446 		}
1447 	} else
1448 		nfsm_dissect(tl, u_int32_t *, 8 * NFSX_UNSIGNED);
1449 	nd->nd_repstat = 0;
1450 	nd->nd_flag = 0;
1451 	if (*tl++ != rpc_vers) {
1452 		nd->nd_repstat = ERPCMISMATCH;
1453 		nd->nd_procnum = NFSPROC_NOOP;
1454 		return (0);
1455 	}
1456 	if (*tl != nfs_prog) {
1457 		nd->nd_repstat = EPROGUNAVAIL;
1458 		nd->nd_procnum = NFSPROC_NOOP;
1459 		return (0);
1460 	}
1461 	tl++;
1462 	nfsvers = fxdr_unsigned(u_int32_t, *tl++);
1463 	if (nfsvers != NFS_VER2 && nfsvers != NFS_VER3) {
1464 		nd->nd_repstat = EPROGMISMATCH;
1465 		nd->nd_procnum = NFSPROC_NOOP;
1466 		return (0);
1467 	}
1468 	if (nfsvers == NFS_VER3)
1469 		nd->nd_flag = ND_NFSV3;
1470 	nd->nd_procnum = fxdr_unsigned(u_int32_t, *tl++);
1471 	if (nd->nd_procnum == NFSPROC_NULL)
1472 		return (0);
1473 	if (nd->nd_procnum >= NFS_NPROCS ||
1474 		(nd->nd_procnum > NFSPROC_COMMIT) ||
1475 		(!nd->nd_flag && nd->nd_procnum > NFSV2PROC_STATFS)) {
1476 		nd->nd_repstat = EPROCUNAVAIL;
1477 		nd->nd_procnum = NFSPROC_NOOP;
1478 		return (0);
1479 	}
1480 	if ((nd->nd_flag & ND_NFSV3) == 0)
1481 		nd->nd_procnum = nfsv3_procid[nd->nd_procnum];
1482 	auth_type = *tl++;
1483 	len = fxdr_unsigned(int, *tl++);
1484 	if (len < 0 || len > RPCAUTH_MAXSIZ) {
1485 		m_freem(info.nmi_mrep);
1486 		return (EBADRPC);
1487 	}
1488 
1489 	/* Handle auth_unix */
1490 	if (auth_type == rpc_auth_unix) {
1491 		len = fxdr_unsigned(int, *++tl);
1492 		if (len < 0 || len > NFS_MAXNAMLEN) {
1493 			m_freem(info.nmi_mrep);
1494 			return (EBADRPC);
1495 		}
1496 		nfsm_adv(nfsm_rndup(len));
1497 		nfsm_dissect(tl, u_int32_t *, 3 * NFSX_UNSIGNED);
1498 		memset(&nd->nd_cr, 0, sizeof (struct ucred));
1499 		nd->nd_cr.cr_ref = 1;
1500 		nd->nd_cr.cr_uid = fxdr_unsigned(uid_t, *tl++);
1501 		nd->nd_cr.cr_gid = fxdr_unsigned(gid_t, *tl++);
1502 		len = fxdr_unsigned(int, *tl);
1503 		if (len < 0 || len > RPCAUTH_UNIXGIDS) {
1504 			m_freem(info.nmi_mrep);
1505 			return (EBADRPC);
1506 		}
1507 		nfsm_dissect(tl, u_int32_t *, (len + 2) * NFSX_UNSIGNED);
1508 		for (i = 0; i < len; i++) {
1509 			if (i < NGROUPS_MAX)
1510 				nd->nd_cr.cr_groups[i] =
1511 				    fxdr_unsigned(gid_t, *tl++);
1512 			else
1513 				tl++;
1514 		}
1515 		nd->nd_cr.cr_ngroups = (len > NGROUPS_MAX) ? NGROUPS_MAX : len;
1516 		len = fxdr_unsigned(int, *++tl);
1517 		if (len < 0 || len > RPCAUTH_MAXSIZ) {
1518 			m_freem(info.nmi_mrep);
1519 			return (EBADRPC);
1520 		}
1521 		if (len > 0)
1522 			nfsm_adv(nfsm_rndup(len));
1523 	} else {
1524 		nd->nd_repstat = (NFSERR_AUTHERR | AUTH_REJECTCRED);
1525 		nd->nd_procnum = NFSPROC_NOOP;
1526 		return (0);
1527 	}
1528 
1529 	nd->nd_md = info.nmi_md;
1530 	nd->nd_dpos = info.nmi_dpos;
1531 	return (0);
1532 nfsmout:
1533 	return (error);
1534 }
1535 
1536 void
1537 nfs_msg(struct nfsreq *rep, char *msg)
1538 {
1539 	tpr_t tpr;
1540 
1541 	if (rep->r_procp)
1542 		tpr = tprintf_open(rep->r_procp);
1543 	else
1544 		tpr = NULL;
1545 
1546 	tprintf(tpr, "nfs server %s: %s\n",
1547 	    rep->r_nmp->nm_mountp->mnt_stat.f_mntfromname, msg);
1548 	tprintf_close(tpr);
1549 }
1550 
1551 #ifdef NFSSERVER
1552 /*
1553  * Socket upcall routine for the nfsd sockets.
1554  * The caddr_t arg is a pointer to the "struct nfssvc_sock".
1555  * Essentially do as much as possible non-blocking, else punt and it will
1556  * be called with M_WAIT from an nfsd.
1557  */
1558 void
1559 nfsrv_rcv(struct socket *so, caddr_t arg, int waitflag)
1560 {
1561 	struct nfssvc_sock *slp = (struct nfssvc_sock *)arg;
1562 	struct mbuf *m;
1563 	struct mbuf *mp, *nam;
1564 	struct uio auio;
1565 	int flags, error;
1566 
1567 	if ((slp->ns_flag & SLP_VALID) == 0)
1568 		return;
1569 
1570 	/* Defer soreceive() to an nfsd. */
1571 	if (waitflag == M_DONTWAIT) {
1572 		slp->ns_flag |= SLP_NEEDQ;
1573 		goto dorecs;
1574 	}
1575 
1576 	auio.uio_procp = NULL;
1577 	if (so->so_type == SOCK_STREAM) {
1578 		/*
1579 		 * Do soreceive().
1580 		 */
1581 		auio.uio_resid = 1000000000;
1582 		flags = MSG_DONTWAIT;
1583 		error = soreceive(so, &nam, &auio, &mp, NULL,
1584 		    &flags, 0);
1585 		if (error || mp == NULL) {
1586 			if (error == EWOULDBLOCK)
1587 				slp->ns_flag |= SLP_NEEDQ;
1588 			else
1589 				slp->ns_flag |= SLP_DISCONN;
1590 			goto dorecs;
1591 		}
1592 		m = mp;
1593 		if (slp->ns_rawend) {
1594 			slp->ns_rawend->m_next = m;
1595 			slp->ns_cc += 1000000000 - auio.uio_resid;
1596 		} else {
1597 			slp->ns_raw = m;
1598 			slp->ns_cc = 1000000000 - auio.uio_resid;
1599 		}
1600 		while (m->m_next)
1601 			m = m->m_next;
1602 		slp->ns_rawend = m;
1603 
1604 		/*
1605 		 * Now try and parse record(s) out of the raw stream data.
1606 		 */
1607 		error = nfsrv_getstream(slp, waitflag);
1608 		if (error) {
1609 			if (error == EPERM)
1610 				slp->ns_flag |= SLP_DISCONN;
1611 			else
1612 				slp->ns_flag |= SLP_NEEDQ;
1613 		}
1614 	} else {
1615 		do {
1616 			auio.uio_resid = 1000000000;
1617 			flags = MSG_DONTWAIT;
1618 			error = soreceive(so, &nam, &auio, &mp,
1619 			    NULL, &flags, 0);
1620 			if (mp) {
1621 				if (nam) {
1622 					m = nam;
1623 					m->m_next = mp;
1624 				} else
1625 					m = mp;
1626 				if (slp->ns_recend)
1627 					slp->ns_recend->m_nextpkt = m;
1628 				else
1629 					slp->ns_rec = m;
1630 				slp->ns_recend = m;
1631 				m->m_nextpkt = NULL;
1632 			}
1633 			if (error) {
1634 				if ((so->so_proto->pr_flags & PR_CONNREQUIRED)
1635 					&& error != EWOULDBLOCK) {
1636 					slp->ns_flag |= SLP_DISCONN;
1637 					goto dorecs;
1638 				}
1639 			}
1640 		} while (mp);
1641 	}
1642 
1643 	/*
1644 	 * Now try and process the request records, non-blocking.
1645 	 */
1646 dorecs:
1647 	if (waitflag == M_DONTWAIT &&
1648 		(slp->ns_rec || (slp->ns_flag & (SLP_NEEDQ | SLP_DISCONN))))
1649 		nfsrv_wakenfsd(slp);
1650 }
1651 
1652 /*
1653  * Try and extract an RPC request from the mbuf data list received on a
1654  * stream socket. The "waitflag" argument indicates whether or not it
1655  * can sleep.
1656  */
1657 int
1658 nfsrv_getstream(struct nfssvc_sock *slp, int waitflag)
1659 {
1660 	struct mbuf *m, **mpp;
1661 	char *cp1, *cp2;
1662 	int len;
1663 	struct mbuf *om, *m2, *recm;
1664 	u_int32_t recmark;
1665 
1666 	if (slp->ns_flag & SLP_GETSTREAM)
1667 		return (0);
1668 	slp->ns_flag |= SLP_GETSTREAM;
1669 	for (;;) {
1670 		if (slp->ns_reclen == 0) {
1671 			if (slp->ns_cc < NFSX_UNSIGNED) {
1672 				slp->ns_flag &= ~SLP_GETSTREAM;
1673 				return (0);
1674 			}
1675 			m = slp->ns_raw;
1676 			if (m->m_len >= NFSX_UNSIGNED) {
1677 				bcopy(mtod(m, caddr_t), &recmark,
1678 				    NFSX_UNSIGNED);
1679 				m->m_data += NFSX_UNSIGNED;
1680 				m->m_len -= NFSX_UNSIGNED;
1681 			} else {
1682 				cp1 = (caddr_t)&recmark;
1683 				cp2 = mtod(m, caddr_t);
1684 				while (cp1 < ((caddr_t)&recmark) + NFSX_UNSIGNED) {
1685 					while (m->m_len == 0) {
1686 						m = m->m_next;
1687 						cp2 = mtod(m, caddr_t);
1688 					}
1689 					*cp1++ = *cp2++;
1690 					m->m_data++;
1691 					m->m_len--;
1692 				}
1693 			}
1694 			slp->ns_cc -= NFSX_UNSIGNED;
1695 			recmark = ntohl(recmark);
1696 			slp->ns_reclen = recmark & ~0x80000000;
1697 			if (recmark & 0x80000000)
1698 				slp->ns_flag |= SLP_LASTFRAG;
1699 			else
1700 				slp->ns_flag &= ~SLP_LASTFRAG;
1701 			if (slp->ns_reclen > NFS_MAXPACKET) {
1702 				slp->ns_flag &= ~SLP_GETSTREAM;
1703 				return (EPERM);
1704 			}
1705 		}
1706 
1707 		/*
1708 		 * Now get the record part.
1709 		 */
1710 		recm = NULL;
1711 		if (slp->ns_cc == slp->ns_reclen) {
1712 			recm = slp->ns_raw;
1713 			slp->ns_raw = slp->ns_rawend = NULL;
1714 			slp->ns_cc = slp->ns_reclen = 0;
1715 		} else if (slp->ns_cc > slp->ns_reclen) {
1716 			len = 0;
1717 			m = slp->ns_raw;
1718 			om = NULL;
1719 			while (len < slp->ns_reclen) {
1720 				if ((len + m->m_len) > slp->ns_reclen) {
1721 					m2 = m_copym(m, 0, slp->ns_reclen - len,
1722 					    waitflag);
1723 					if (m2) {
1724 						if (om) {
1725 							om->m_next = m2;
1726 							recm = slp->ns_raw;
1727 						} else
1728 							recm = m2;
1729 						m->m_data += slp->ns_reclen-len;
1730 						m->m_len -= slp->ns_reclen-len;
1731 						len = slp->ns_reclen;
1732 					} else {
1733 						slp->ns_flag &= ~SLP_GETSTREAM;
1734 						return (EWOULDBLOCK);
1735 					}
1736 				} else if ((len + m->m_len) == slp->ns_reclen) {
1737 					om = m;
1738 					len += m->m_len;
1739 					m = m->m_next;
1740 					recm = slp->ns_raw;
1741 					om->m_next = NULL;
1742 				} else {
1743 					om = m;
1744 					len += m->m_len;
1745 					m = m->m_next;
1746 				}
1747 			}
1748 			slp->ns_raw = m;
1749 			slp->ns_cc -= len;
1750 			slp->ns_reclen = 0;
1751 		} else {
1752 			slp->ns_flag &= ~SLP_GETSTREAM;
1753 			return (0);
1754 		}
1755 
1756 		/*
1757 		 * Accumulate the fragments into a record.
1758 		 */
1759 		mpp = &slp->ns_frag;
1760 		while (*mpp)
1761 			mpp = &((*mpp)->m_next);
1762 		*mpp = recm;
1763 		if (slp->ns_flag & SLP_LASTFRAG) {
1764 			if (slp->ns_recend)
1765 			    slp->ns_recend->m_nextpkt = slp->ns_frag;
1766 			else
1767 			    slp->ns_rec = slp->ns_frag;
1768 			slp->ns_recend = slp->ns_frag;
1769 			slp->ns_frag = NULL;
1770 		}
1771 	}
1772 }
1773 
1774 /*
1775  * Parse an RPC header.
1776  */
1777 int
1778 nfsrv_dorec(struct nfssvc_sock *slp, struct nfsd *nfsd,
1779     struct nfsrv_descript **ndp)
1780 {
1781 	struct mbuf *m, *nam;
1782 	struct nfsrv_descript *nd;
1783 	int error;
1784 
1785 	*ndp = NULL;
1786 	if ((slp->ns_flag & SLP_VALID) == 0 ||
1787 	    (m = slp->ns_rec) == NULL)
1788 		return (ENOBUFS);
1789 	slp->ns_rec = m->m_nextpkt;
1790 	if (slp->ns_rec)
1791 		m->m_nextpkt = NULL;
1792 	else
1793 		slp->ns_recend = NULL;
1794 	if (m->m_type == MT_SONAME) {
1795 		nam = m;
1796 		m = m->m_next;
1797 		nam->m_next = NULL;
1798 	} else
1799 		nam = NULL;
1800 	nd = pool_get(&nfsrv_descript_pl, PR_WAITOK);
1801 	nfs_realign(&m, 10 * NFSX_UNSIGNED);
1802 	nd->nd_md = nd->nd_mrep = m;
1803 	nd->nd_nam2 = nam;
1804 	nd->nd_dpos = mtod(m, caddr_t);
1805 	error = nfs_getreq(nd, nfsd, 1);
1806 	if (error) {
1807 		m_freem(nam);
1808 		pool_put(&nfsrv_descript_pl, nd);
1809 		return (error);
1810 	}
1811 	*ndp = nd;
1812 	nfsd->nfsd_nd = nd;
1813 	return (0);
1814 }
1815 
1816 
1817 /*
1818  * Search for a sleeping nfsd and wake it up.
1819  * SIDE EFFECT: If none found, set NFSD_CHECKSLP flag, so that one of the
1820  * running nfsds will go look for the work in the nfssvc_sock list.
1821  */
1822 void
1823 nfsrv_wakenfsd(struct nfssvc_sock *slp)
1824 {
1825 	struct nfsd	*nfsd;
1826 
1827 	if ((slp->ns_flag & SLP_VALID) == 0)
1828 		return;
1829 
1830 	TAILQ_FOREACH(nfsd, &nfsd_head, nfsd_chain) {
1831 		if (nfsd->nfsd_flag & NFSD_WAITING) {
1832 			nfsd->nfsd_flag &= ~NFSD_WAITING;
1833 			if (nfsd->nfsd_slp)
1834 				panic("nfsd wakeup");
1835 			slp->ns_sref++;
1836 			nfsd->nfsd_slp = slp;
1837 			wakeup_one(nfsd);
1838 			return;
1839 		}
1840 	}
1841 
1842 	slp->ns_flag |= SLP_DOREC;
1843 	nfsd_head_flag |= NFSD_CHECKSLP;
1844 }
1845 #endif /* NFSSERVER */
1846