xref: /openbsd-src/sys/nfs/nfs_socket.c (revision 810390e339a5425391477d5d41c78d7cab2424ac)
1 /*	$OpenBSD: nfs_socket.c,v 1.144 2023/08/03 09:49:09 mvs 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/protosw.h>
50 #include <sys/signalvar.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/nfs_var.h>
69 
70 /* External data, mostly RPC constants in XDR form. */
71 extern u_int32_t rpc_reply, rpc_msgdenied, rpc_mismatch, rpc_vers,
72 	rpc_auth_unix, rpc_msgaccepted, rpc_call, rpc_autherr;
73 extern u_int32_t nfs_prog;
74 extern struct nfsstats nfsstats;
75 extern int nfsv3_procid[NFS_NPROCS];
76 extern int nfs_ticks;
77 
78 extern struct pool nfsrv_descript_pl;
79 
80 /*
81  * There is a congestion window for outstanding rpcs maintained per mount
82  * point. The cwnd size is adjusted in roughly the way that:
83  * Van Jacobson, Congestion avoidance and Control, In "Proceedings of
84  * SIGCOMM '88". ACM, August 1988.
85  * describes for TCP. The cwnd size is chopped in half on a retransmit timeout
86  * and incremented by 1/cwnd when each rpc reply is received and a full cwnd
87  * of rpcs is in progress.
88  * (The sent count and cwnd are scaled for integer arith.)
89  * Variants of "slow start" were tried and were found to be too much of a
90  * performance hit (ave. rtt 3 times larger),
91  * I suspect due to the large rtt that nfs rpcs have.
92  */
93 #define	NFS_CWNDSCALE	256
94 #define	NFS_MAXCWND	(NFS_CWNDSCALE * 32)
95 int nfs_backoff[8] = { 2, 4, 8, 16, 32, 64, 128, 256 };
96 
97 /* RTT estimator */
98 enum nfs_rto_timers nfs_ptimers[NFS_NPROCS] = {
99 	NFS_DEFAULT_TIMER,	/* NULL */
100 	NFS_GETATTR_TIMER,	/* GETATTR */
101 	NFS_DEFAULT_TIMER,	/* SETATTR */
102 	NFS_LOOKUP_TIMER,	/* LOOKUP */
103 	NFS_GETATTR_TIMER,	/* ACCESS */
104 	NFS_READ_TIMER,		/* READLINK */
105 	NFS_READ_TIMER,		/* READ */
106 	NFS_WRITE_TIMER,	/* WRITE */
107 	NFS_DEFAULT_TIMER,	/* CREATE */
108 	NFS_DEFAULT_TIMER,	/* MKDIR */
109 	NFS_DEFAULT_TIMER,	/* SYMLINK */
110 	NFS_DEFAULT_TIMER,	/* MKNOD */
111 	NFS_DEFAULT_TIMER,	/* REMOVE */
112 	NFS_DEFAULT_TIMER,	/* RMDIR */
113 	NFS_DEFAULT_TIMER,	/* RENAME */
114 	NFS_DEFAULT_TIMER,	/* LINK */
115 	NFS_READ_TIMER,		/* READDIR */
116 	NFS_READ_TIMER,		/* READDIRPLUS */
117 	NFS_DEFAULT_TIMER,	/* FSSTAT */
118 	NFS_DEFAULT_TIMER,	/* FSINFO */
119 	NFS_DEFAULT_TIMER,	/* PATHCONF */
120 	NFS_DEFAULT_TIMER,	/* COMMIT */
121 	NFS_DEFAULT_TIMER,	/* NOOP */
122 };
123 
124 void nfs_init_rtt(struct nfsmount *);
125 void nfs_update_rtt(struct nfsreq *);
126 int  nfs_estimate_rto(struct nfsmount *, u_int32_t procnum);
127 
128 void nfs_realign(struct mbuf **, int);
129 void nfs_realign_fixup(struct mbuf *, struct mbuf *, unsigned int *);
130 
131 int nfs_rcvlock(struct nfsreq *);
132 int nfs_receive(struct nfsreq *, struct mbuf **, struct mbuf **);
133 int nfs_reconnect(struct nfsreq *);
134 int nfs_reply(struct nfsreq *);
135 void nfs_msg(struct nfsreq *, char *);
136 void nfs_rcvunlock(int *);
137 
138 int nfsrv_getstream(struct nfssvc_sock *, int);
139 
140 unsigned int nfs_realign_test = 0;
141 unsigned int nfs_realign_count = 0;
142 
143 /* Initialize the RTT estimator state for a new mount point. */
144 void
145 nfs_init_rtt(struct nfsmount *nmp)
146 {
147 	int i;
148 
149 	for (i = 0; i < NFS_MAX_TIMER; i++)
150 		nmp->nm_srtt[i] = NFS_INITRTT;
151 	for (i = 0; i < NFS_MAX_TIMER; i++)
152 		nmp->nm_sdrtt[i] = 0;
153 }
154 
155 /*
156  * Update a mount point's RTT estimator state using data from the
157  * passed-in request.
158  *
159  * Use a gain of 0.125 on the mean and a gain of 0.25 on the deviation.
160  *
161  * NB: Since the timer resolution of NFS_HZ is so course, it can often
162  * result in r_rtt == 0. Since r_rtt == N means that the actual RTT is
163  * between N + dt and N + 2 - dt ticks, add 1 before calculating the
164  * update values.
165  */
166 void
167 nfs_update_rtt(struct nfsreq *rep)
168 {
169 	int t1 = rep->r_rtt + 1;
170 	int index = nfs_ptimers[rep->r_procnum] - 1;
171 	int *srtt = &rep->r_nmp->nm_srtt[index];
172 	int *sdrtt = &rep->r_nmp->nm_sdrtt[index];
173 
174 	t1 -= *srtt >> 3;
175 	*srtt += t1;
176 	if (t1 < 0)
177 		t1 = -t1;
178 	t1 -= *sdrtt >> 2;
179 	*sdrtt += t1;
180 }
181 
182 /*
183  * Estimate RTO for an NFS RPC sent via an unreliable datagram.
184  *
185  * Use the mean and mean deviation of RTT for the appropriate type
186  * of RPC for the frequent RPCs and a default for the others.
187  * The justification for doing "other" this way is that these RPCs
188  * happen so infrequently that timer est. would probably be stale.
189  * Also, since many of these RPCs are non-idempotent, a conservative
190  * timeout is desired.
191  *
192  * getattr, lookup - A+2D
193  * read, write     - A+4D
194  * other           - nm_timeo
195  */
196 int
197 nfs_estimate_rto(struct nfsmount *nmp, u_int32_t procnum)
198 {
199 	enum nfs_rto_timers timer = nfs_ptimers[procnum];
200 	int index = timer - 1;
201 	int rto;
202 
203 	switch (timer) {
204 	case NFS_GETATTR_TIMER:
205 	case NFS_LOOKUP_TIMER:
206 		rto = ((nmp->nm_srtt[index] + 3) >> 2) +
207 				((nmp->nm_sdrtt[index] + 1) >> 1);
208 		break;
209 	case NFS_READ_TIMER:
210 	case NFS_WRITE_TIMER:
211 		rto = ((nmp->nm_srtt[index] + 7) >> 3) +
212 				(nmp->nm_sdrtt[index] + 1);
213 		break;
214 	default:
215 		rto = nmp->nm_timeo;
216 		return (rto);
217 	}
218 
219 	if (rto < NFS_MINRTO)
220 		rto = NFS_MINRTO;
221 	else if (rto > NFS_MAXRTO)
222 		rto = NFS_MAXRTO;
223 
224 	return (rto);
225 }
226 
227 
228 
229 /*
230  * Initialize sockets and congestion for a new NFS connection.
231  * We do not free the sockaddr if error.
232  */
233 int
234 nfs_connect(struct nfsmount *nmp, struct nfsreq *rep)
235 {
236 	struct socket *so;
237 	int error, rcvreserve, sndreserve;
238 	struct sockaddr *saddr;
239 	struct sockaddr_in *sin;
240 	struct mbuf *nam = NULL, *mopt = NULL;
241 
242 	if (!(nmp->nm_sotype == SOCK_DGRAM || nmp->nm_sotype == SOCK_STREAM))
243 		return (EINVAL);
244 
245 	nmp->nm_so = NULL;
246 	saddr = mtod(nmp->nm_nam, struct sockaddr *);
247 	error = socreate(saddr->sa_family, &nmp->nm_so, nmp->nm_sotype,
248 	    nmp->nm_soproto);
249 	if (error) {
250 		nfs_disconnect(nmp);
251 		return (error);
252 	}
253 
254 	/* Allocate mbufs possibly waiting before grabbing the socket lock. */
255 	if (nmp->nm_sotype == SOCK_STREAM || saddr->sa_family == AF_INET)
256 		MGET(mopt, M_WAIT, MT_SOOPTS);
257 	if (saddr->sa_family == AF_INET)
258 		MGET(nam, M_WAIT, MT_SONAME);
259 
260 	so = nmp->nm_so;
261 	nmp->nm_soflags = so->so_proto->pr_flags;
262 
263 	/*
264 	 * Some servers require that the client port be a reserved port number.
265 	 * We always allocate a reserved port, as this prevents filehandle
266 	 * disclosure through UDP port capture.
267 	 */
268 	if (saddr->sa_family == AF_INET) {
269 		int *ip;
270 
271 		mopt->m_len = sizeof(int);
272 		ip = mtod(mopt, int *);
273 		*ip = IP_PORTRANGE_LOW;
274 		error = sosetopt(so, IPPROTO_IP, IP_PORTRANGE, mopt);
275 		if (error)
276 			goto bad;
277 
278 		sin = mtod(nam, struct sockaddr_in *);
279 		memset(sin, 0, sizeof(*sin));
280 		sin->sin_len = nam->m_len = sizeof(struct sockaddr_in);
281 		sin->sin_family = AF_INET;
282 		sin->sin_addr.s_addr = INADDR_ANY;
283 		sin->sin_port = htons(0);
284 		solock(so);
285 		error = sobind(so, nam, &proc0);
286 		sounlock(so);
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 	solock(so);
299 	/*
300 	 * Protocols that do not require connections may be optionally left
301 	 * unconnected for servers that reply from a port other than NFS_PORT.
302 	 */
303 	if (nmp->nm_flag & NFSMNT_NOCONN) {
304 		if (nmp->nm_soflags & PR_CONNREQUIRED) {
305 			error = ENOTCONN;
306 			goto bad_locked;
307 		}
308 	} else {
309 		error = soconnect(so, nmp->nm_nam);
310 		if (error)
311 			goto bad_locked;
312 
313 		/*
314 		 * Wait for the connection to complete. Cribbed from the
315 		 * connect system call but with the wait timing out so
316 		 * that interruptible mounts don't hang here for a long time.
317 		 */
318 		while ((so->so_state & SS_ISCONNECTING) && so->so_error == 0) {
319 			sosleep_nsec(so, &so->so_timeo, PSOCK, "nfscon",
320 			    SEC_TO_NSEC(2));
321 			if ((so->so_state & SS_ISCONNECTING) &&
322 			    so->so_error == 0 && rep &&
323 			    (error = nfs_sigintr(nmp, rep, rep->r_procp)) != 0){
324 				so->so_state &= ~SS_ISCONNECTING;
325 				goto bad_locked;
326 			}
327 		}
328 		if (so->so_error) {
329 			error = so->so_error;
330 			so->so_error = 0;
331 			goto bad_locked;
332 		}
333 	}
334 	/*
335 	 * Always set receive timeout to detect server crash and reconnect.
336 	 * Otherwise, we can get stuck in soreceive forever.
337 	 */
338 	so->so_rcv.sb_timeo_nsecs = SEC_TO_NSEC(5);
339 	if (nmp->nm_flag & (NFSMNT_SOFT | NFSMNT_INT))
340 		so->so_snd.sb_timeo_nsecs = SEC_TO_NSEC(5);
341 	else
342 		so->so_snd.sb_timeo_nsecs = INFSLP;
343 	sounlock(so);
344 	if (nmp->nm_sotype == SOCK_DGRAM) {
345 		sndreserve = nmp->nm_wsize + NFS_MAXPKTHDR;
346 		rcvreserve = (max(nmp->nm_rsize, nmp->nm_readdirsize) +
347 		    NFS_MAXPKTHDR) * 2;
348 	} else if (nmp->nm_sotype == SOCK_STREAM) {
349 		if (so->so_proto->pr_flags & PR_CONNREQUIRED) {
350 			*mtod(mopt, int32_t *) = 1;
351 			mopt->m_len = sizeof(int32_t);
352 			sosetopt(so, SOL_SOCKET, SO_KEEPALIVE, mopt);
353 		}
354 		if (so->so_proto->pr_protocol == IPPROTO_TCP) {
355 			*mtod(mopt, int32_t *) = 1;
356 			mopt->m_len = sizeof(int32_t);
357 			sosetopt(so, IPPROTO_TCP, TCP_NODELAY, mopt);
358 		}
359 		sndreserve = (nmp->nm_wsize + NFS_MAXPKTHDR +
360 		    sizeof (u_int32_t)) * 2;
361 		rcvreserve = (nmp->nm_rsize + NFS_MAXPKTHDR +
362 		    sizeof (u_int32_t)) * 2;
363 	} else {
364 		panic("%s: nm_sotype %d", __func__, nmp->nm_sotype);
365 	}
366 	solock(so);
367 	error = soreserve(so, sndreserve, rcvreserve);
368 	if (error)
369 		goto bad_locked;
370 	so->so_rcv.sb_flags |= SB_NOINTR;
371 	so->so_snd.sb_flags |= SB_NOINTR;
372 	sounlock(so);
373 
374 	m_freem(mopt);
375 	m_freem(nam);
376 
377 	/* Initialize other non-zero congestion variables */
378 	nfs_init_rtt(nmp);
379 	nmp->nm_cwnd = NFS_MAXCWND / 2;	    /* Initial send window */
380 	nmp->nm_sent = 0;
381 	nmp->nm_timeouts = 0;
382 	return (0);
383 
384 bad_locked:
385 	sounlock(so);
386 bad:
387 
388 	m_freem(mopt);
389 	m_freem(nam);
390 
391 	nfs_disconnect(nmp);
392 	return (error);
393 }
394 
395 /*
396  * Reconnect routine:
397  * Called when a connection is broken on a reliable protocol.
398  * - clean up the old socket
399  * - nfs_connect() again
400  * - set R_MUSTRESEND for all outstanding requests on mount point
401  * If this fails the mount point is DEAD!
402  * nb: Must be called with the nfs_sndlock() set on the mount point.
403  */
404 int
405 nfs_reconnect(struct nfsreq *rep)
406 {
407 	struct nfsreq *rp;
408 	struct nfsmount *nmp = rep->r_nmp;
409 	int error;
410 
411 	nfs_disconnect(nmp);
412 	while ((error = nfs_connect(nmp, rep)) != 0) {
413 		if (error == EINTR || error == ERESTART)
414 			return (EINTR);
415 		tsleep_nsec(&nowake, PSOCK, "nfsrecon", SEC_TO_NSEC(1));
416 	}
417 
418 	/*
419 	 * Loop through outstanding request list and fix up all requests
420 	 * on old socket.
421 	 */
422 	TAILQ_FOREACH(rp, &nmp->nm_reqsq, r_chain) {
423 		rp->r_flags |= R_MUSTRESEND;
424 		rp->r_rexmit = 0;
425 	}
426 	return (0);
427 }
428 
429 /*
430  * NFS disconnect. Clean up and unlink.
431  */
432 void
433 nfs_disconnect(struct nfsmount *nmp)
434 {
435 	struct socket *so;
436 
437 	if (nmp->nm_so) {
438 		so = nmp->nm_so;
439 		nmp->nm_so = NULL;
440 		soshutdown(so, SHUT_RDWR);
441 		soclose(so, 0);
442 	}
443 }
444 
445 /*
446  * This is the nfs send routine. For connection based socket types, it
447  * must be called with an nfs_sndlock() on the socket.
448  * "rep == NULL" indicates that it has been called from a server.
449  * For the client side:
450  * - return EINTR if the RPC is terminated, 0 otherwise
451  * - set R_MUSTRESEND if the send fails for any reason
452  * - do any cleanup required by recoverable socket errors (???)
453  * For the server side:
454  * - return EINTR or ERESTART if interrupted by a signal
455  * - return EPIPE if a connection is lost for connection based sockets (TCP...)
456  * - do any cleanup required by recoverable socket errors (???)
457  */
458 int
459 nfs_send(struct socket *so, struct mbuf *nam, struct mbuf *top,
460     struct nfsreq *rep)
461 {
462 	struct mbuf *sendnam;
463 	int error, soflags, flags;
464 
465 	if (rep) {
466 		if (rep->r_flags & R_SOFTTERM) {
467 			m_freem(top);
468 			return (EINTR);
469 		}
470 		if ((so = rep->r_nmp->nm_so) == NULL) {
471 			rep->r_flags |= R_MUSTRESEND;
472 			m_freem(top);
473 			return (0);
474 		}
475 		rep->r_flags &= ~R_MUSTRESEND;
476 		soflags = rep->r_nmp->nm_soflags;
477 	} else
478 		soflags = so->so_proto->pr_flags;
479 	if ((soflags & PR_CONNREQUIRED) || (so->so_state & SS_ISCONNECTED))
480 		sendnam = NULL;
481 	else
482 		sendnam = nam;
483 	flags = 0;
484 
485 	error = sosend(so, sendnam, NULL, top, NULL, flags);
486 	if (error) {
487 		if (rep) {
488 			/*
489 			 * Deal with errors for the client side.
490 			 */
491 			if (rep->r_flags & R_SOFTTERM)
492 				error = EINTR;
493 			else
494 				rep->r_flags |= R_MUSTRESEND;
495 		}
496 
497 		/*
498 		 * Handle any recoverable (soft) socket errors here. (???)
499 		 */
500 		if (error != EINTR && error != ERESTART &&
501 		    error != EWOULDBLOCK && error != EPIPE)
502 			error = 0;
503 	}
504 	return (error);
505 }
506 
507 #ifdef NFSCLIENT
508 /*
509  * Receive a Sun RPC Request/Reply. For SOCK_DGRAM, the work is all
510  * done by soreceive(), but for SOCK_STREAM we must deal with the Record
511  * Mark and consolidate the data into a new mbuf list.
512  * nb: Sometimes TCP passes the data up to soreceive() in long lists of
513  *     small mbufs.
514  * For SOCK_STREAM we must be very careful to read an entire record once
515  * we have read any of it, even if the system call has been interrupted.
516  */
517 int
518 nfs_receive(struct nfsreq *rep, struct mbuf **aname, struct mbuf **mp)
519 {
520 	struct socket *so;
521 	struct uio auio;
522 	struct iovec aio;
523 	struct mbuf *m;
524 	struct mbuf *control;
525 	u_int32_t len;
526 	struct mbuf **getnam;
527 	int error, sotype, rcvflg;
528 	struct proc *p = curproc;	/* XXX */
529 
530 	/*
531 	 * Set up arguments for soreceive()
532 	 */
533 	*mp = NULL;
534 	*aname = NULL;
535 	sotype = rep->r_nmp->nm_sotype;
536 
537 	/*
538 	 * For reliable protocols, lock against other senders/receivers
539 	 * in case a reconnect is necessary.
540 	 * For SOCK_STREAM, first get the Record Mark to find out how much
541 	 * more there is to get.
542 	 * We must lock the socket against other receivers
543 	 * until we have an entire rpc request/reply.
544 	 */
545 	if (sotype != SOCK_DGRAM) {
546 		error = nfs_sndlock(&rep->r_nmp->nm_flag, rep);
547 		if (error)
548 			return (error);
549 tryagain:
550 		/*
551 		 * Check for fatal errors and resending request.
552 		 */
553 		/*
554 		 * Ugh: If a reconnect attempt just happened, nm_so
555 		 * would have changed. NULL indicates a failed
556 		 * attempt that has essentially shut down this
557 		 * mount point.
558 		 */
559 		if (rep->r_mrep || (rep->r_flags & R_SOFTTERM)) {
560 			nfs_sndunlock(&rep->r_nmp->nm_flag);
561 			return (EINTR);
562 		}
563 		so = rep->r_nmp->nm_so;
564 		if (!so) {
565 			error = nfs_reconnect(rep);
566 			if (error) {
567 				nfs_sndunlock(&rep->r_nmp->nm_flag);
568 				return (error);
569 			}
570 			goto tryagain;
571 		}
572 		while (rep->r_flags & R_MUSTRESEND) {
573 			m = m_copym(rep->r_mreq, 0, M_COPYALL, M_WAIT);
574 			nfsstats.rpcretries++;
575 			rep->r_rtt = 0;
576 			rep->r_flags &= ~R_TIMING;
577 			error = nfs_send(so, rep->r_nmp->nm_nam, m, rep);
578 			if (error) {
579 				if (error == EINTR || error == ERESTART ||
580 				    (error = nfs_reconnect(rep)) != 0) {
581 					nfs_sndunlock(&rep->r_nmp->nm_flag);
582 					return (error);
583 				}
584 				goto tryagain;
585 			}
586 		}
587 		nfs_sndunlock(&rep->r_nmp->nm_flag);
588 		if (sotype == SOCK_STREAM) {
589 			aio.iov_base = (caddr_t) &len;
590 			aio.iov_len = sizeof(u_int32_t);
591 			auio.uio_iov = &aio;
592 			auio.uio_iovcnt = 1;
593 			auio.uio_segflg = UIO_SYSSPACE;
594 			auio.uio_rw = UIO_READ;
595 			auio.uio_offset = 0;
596 			auio.uio_resid = sizeof(u_int32_t);
597 			auio.uio_procp = p;
598 			do {
599 				rcvflg = MSG_WAITALL;
600 				error = soreceive(so, NULL, &auio, NULL, NULL,
601 				    &rcvflg, 0);
602 				if (error == EWOULDBLOCK && rep) {
603 					if (rep->r_flags & R_SOFTTERM)
604 						return (EINTR);
605 					/*
606 					 * looks like the server died after it
607 					 * received the request, make sure
608 					 * that we will retransmit and we
609 					 * don't get stuck here forever.
610 					 */
611 					if (rep->r_rexmit >=
612 					    rep->r_nmp->nm_retry) {
613 						nfsstats.rpctimeouts++;
614 						error = EPIPE;
615 					}
616 				}
617 			} while (error == EWOULDBLOCK);
618 			if (!error && auio.uio_resid > 0) {
619 			    log(LOG_INFO,
620 				 "short receive (%zu/%zu) from nfs server %s\n",
621 				 sizeof(u_int32_t) - auio.uio_resid,
622 				 sizeof(u_int32_t),
623 				 rep->r_nmp->nm_mountp->mnt_stat.f_mntfromname);
624 			    error = EPIPE;
625 			}
626 			if (error)
627 				goto errout;
628 
629 			len = ntohl(len) & ~0x80000000;
630 			/*
631 			 * This is SERIOUS! We are out of sync with the sender
632 			 * and forcing a disconnect/reconnect is all I can do.
633 			 */
634 			if (len > NFS_MAXPACKET) {
635 			    log(LOG_ERR, "%s (%u) from nfs server %s\n",
636 				"impossible packet length",
637 				len,
638 				rep->r_nmp->nm_mountp->mnt_stat.f_mntfromname);
639 			    error = EFBIG;
640 			    goto errout;
641 			}
642 			auio.uio_resid = len;
643 			do {
644 			    rcvflg = MSG_WAITALL;
645 			    error =  soreceive(so, NULL, &auio, mp, NULL,
646 			        &rcvflg, 0);
647 			} while (error == EWOULDBLOCK || error == EINTR ||
648 			    error == ERESTART);
649 			if (!error && auio.uio_resid > 0) {
650 				log(LOG_INFO, "short receive (%zu/%u) from "
651 				    "nfs server %s\n", len - auio.uio_resid,
652 				    len, rep->r_nmp->nm_mountp->
653 				    mnt_stat.f_mntfromname);
654 				error = EPIPE;
655 			}
656 		} else {
657 			/*
658 			 * NB: Since uio_resid is big, MSG_WAITALL is ignored
659 			 * and soreceive() will return when it has either a
660 			 * control msg or a data msg.
661 			 * We have no use for control msg., but must grab them
662 			 * and then throw them away so we know what is going
663 			 * on.
664 			 */
665 			auio.uio_resid = len = 100000000; /* Anything Big */
666 			auio.uio_procp = p;
667 			do {
668 				rcvflg = 0;
669 				error = soreceive(so, NULL, &auio, mp, &control,
670 				    &rcvflg, 0);
671 				m_freem(control);
672 				if (error == EWOULDBLOCK && rep) {
673 					if (rep->r_flags & R_SOFTTERM)
674 						return (EINTR);
675 				}
676 			} while (error == EWOULDBLOCK ||
677 			    (!error && *mp == NULL && control));
678 			if ((rcvflg & MSG_EOR) == 0)
679 				printf("Egad!!\n");
680 			if (!error && *mp == NULL)
681 				error = EPIPE;
682 			len -= auio.uio_resid;
683 		}
684 errout:
685 		if (error && error != EINTR && error != ERESTART) {
686 			m_freemp(mp);
687 			if (error != EPIPE)
688 				log(LOG_INFO,
689 				    "receive error %d from nfs server %s\n",
690 				    error,
691 				 rep->r_nmp->nm_mountp->mnt_stat.f_mntfromname);
692 			error = nfs_sndlock(&rep->r_nmp->nm_flag, rep);
693 			if (!error) {
694 				error = nfs_reconnect(rep);
695 				if (!error)
696 					goto tryagain;
697 				nfs_sndunlock(&rep->r_nmp->nm_flag);
698 			}
699 		}
700 	} else {
701 		if ((so = rep->r_nmp->nm_so) == NULL)
702 			return (EACCES);
703 		if (so->so_state & SS_ISCONNECTED)
704 			getnam = NULL;
705 		else
706 			getnam = aname;
707 		auio.uio_resid = len = 1000000;
708 		auio.uio_procp = p;
709 		do {
710 			rcvflg = 0;
711 			error = soreceive(so, getnam, &auio, mp, NULL,
712 			    &rcvflg, 0);
713 			if (error == EWOULDBLOCK &&
714 			    (rep->r_flags & R_SOFTTERM))
715 				return (EINTR);
716 		} while (error == EWOULDBLOCK);
717 		len -= auio.uio_resid;
718 	}
719 	if (error)
720 		m_freemp(mp);
721 	/*
722 	 * Search for any mbufs that are not a multiple of 4 bytes long
723 	 * or with m_data not longword aligned.
724 	 * These could cause pointer alignment problems, so copy them to
725 	 * well aligned mbufs.
726 	 */
727 	nfs_realign(mp, 5 * NFSX_UNSIGNED);
728 	return (error);
729 }
730 
731 /*
732  * Implement receipt of reply on a socket.
733  * We must search through the list of received datagrams matching them
734  * with outstanding requests using the xid, until ours is found.
735  */
736 int
737 nfs_reply(struct nfsreq *myrep)
738 {
739 	struct nfsreq *rep;
740 	struct nfsmount *nmp = myrep->r_nmp;
741 	struct nfsm_info	info;
742 	struct mbuf *nam;
743 	u_int32_t rxid, *tl, t1;
744 	caddr_t cp2;
745 	int error;
746 
747 	/*
748 	 * Loop around until we get our own reply
749 	 */
750 	for (;;) {
751 		/*
752 		 * Lock against other receivers so that I don't get stuck in
753 		 * sbwait() after someone else has received my reply for me.
754 		 * Also necessary for connection based protocols to avoid
755 		 * race conditions during a reconnect.
756 		 */
757 		error = nfs_rcvlock(myrep);
758 		if (error)
759 			return (error == EALREADY ? 0 : error);
760 
761 		/*
762 		 * Get the next Rpc reply off the socket
763 		 */
764 		error = nfs_receive(myrep, &nam, &info.nmi_mrep);
765 		nfs_rcvunlock(&nmp->nm_flag);
766 		if (error) {
767 
768 			/*
769 			 * Ignore routing errors on connectionless protocols??
770 			 */
771 			if (NFSIGNORE_SOERROR(nmp->nm_soflags, error)) {
772 				if (nmp->nm_so)
773 					nmp->nm_so->so_error = 0;
774 				continue;
775 			}
776 			return (error);
777 		}
778 		m_freem(nam);
779 
780 		/*
781 		 * Get the xid and check that it is an rpc reply
782 		 */
783 		info.nmi_md = info.nmi_mrep;
784 		info.nmi_dpos = mtod(info.nmi_md, caddr_t);
785 		nfsm_dissect(tl, u_int32_t *, 2 * NFSX_UNSIGNED);
786 		rxid = *tl++;
787 		if (*tl != rpc_reply) {
788 			nfsstats.rpcinvalid++;
789 			m_freem(info.nmi_mrep);
790 nfsmout:
791 			continue;
792 		}
793 
794 		/*
795 		 * Loop through the request list to match up the reply
796 		 * Iff no match, just drop the datagram
797 		 */
798 		TAILQ_FOREACH(rep, &nmp->nm_reqsq, r_chain) {
799 			if (rep->r_mrep == NULL && rxid == rep->r_xid) {
800 				/* Found it.. */
801 				rep->r_mrep = info.nmi_mrep;
802 				rep->r_md = info.nmi_md;
803 				rep->r_dpos = info.nmi_dpos;
804 
805 				/*
806 				 * Update congestion window.
807 				 * Do the additive increase of
808 				 * one rpc/rtt.
809 				 */
810 				if (nmp->nm_cwnd <= nmp->nm_sent) {
811 					nmp->nm_cwnd +=
812 					   (NFS_CWNDSCALE * NFS_CWNDSCALE +
813 					   (nmp->nm_cwnd >> 1)) / nmp->nm_cwnd;
814 					if (nmp->nm_cwnd > NFS_MAXCWND)
815 						nmp->nm_cwnd = NFS_MAXCWND;
816 				}
817 				rep->r_flags &= ~R_SENT;
818 				nmp->nm_sent -= NFS_CWNDSCALE;
819 
820 				if (rep->r_flags & R_TIMING)
821 					nfs_update_rtt(rep);
822 
823 				nmp->nm_timeouts = 0;
824 				break;
825 			}
826 		}
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 	caddr_t cp2;
859 	int t1, i, error = 0;
860 	int trylater_delay;
861 	struct nfsreq *rep;
862 	struct nfsm_info info;
863 
864 	rep = pool_get(&nfsreqpl, PR_WAITOK);
865 	rep->r_nmp = VFSTONFS(vp->v_mount);
866 	rep->r_vp = vp;
867 	rep->r_procp = infop->nmi_procp;
868 	rep->r_procnum = procnum;
869 
870 	/* empty mbuf for AUTH_UNIX header */
871 	rep->r_mreq = m_gethdr(M_WAIT, MT_DATA);
872 	rep->r_mreq->m_next = infop->nmi_mreq;
873 	rep->r_mreq->m_len = 0;
874 	m_calchdrlen(rep->r_mreq);
875 
876 	trylater_delay = NFS_MINTIMEO;
877 
878 	nmp = rep->r_nmp;
879 
880 	/* Get the RPC header with authorization. */
881 	nfsm_rpchead(rep, infop->nmi_cred, RPCAUTH_UNIX);
882 	m = rep->r_mreq;
883 
884 	/*
885 	 * For stream protocols, insert a Sun RPC Record Mark.
886 	 */
887 	if (nmp->nm_sotype == SOCK_STREAM) {
888 		M_PREPEND(m, NFSX_UNSIGNED, M_WAIT);
889 		*mtod(m, u_int32_t *) = htonl(0x80000000 |
890 		    (m->m_pkthdr.len - NFSX_UNSIGNED));
891 	}
892 
893 tryagain:
894 	rep->r_rtt = rep->r_rexmit = 0;
895 	if (nfs_ptimers[rep->r_procnum] != NFS_DEFAULT_TIMER)
896 		rep->r_flags = R_TIMING;
897 	else
898 		rep->r_flags = 0;
899 	rep->r_mrep = NULL;
900 
901 	/*
902 	 * Do the client side RPC.
903 	 */
904 	nfsstats.rpcrequests++;
905 	/*
906 	 * Chain request into list of outstanding requests. Be sure
907 	 * to put it LAST so timer finds oldest requests first.
908 	 */
909 	if (TAILQ_EMPTY(&nmp->nm_reqsq))
910 		timeout_add(&nmp->nm_rtimeout, nfs_ticks);
911 	TAILQ_INSERT_TAIL(&nmp->nm_reqsq, rep, r_chain);
912 
913 	/*
914 	 * If backing off another request or avoiding congestion, don't
915 	 * send this one now but let timer do it. If not timing a request,
916 	 * do it now.
917 	 */
918 	if (nmp->nm_so && (nmp->nm_sotype != SOCK_DGRAM ||
919 		(nmp->nm_flag & NFSMNT_DUMBTIMR) ||
920 		nmp->nm_sent < nmp->nm_cwnd)) {
921 		if (nmp->nm_soflags & PR_CONNREQUIRED)
922 			error = nfs_sndlock(&nmp->nm_flag, rep);
923 		if (!error) {
924 			error = nfs_send(nmp->nm_so, nmp->nm_nam,
925 			    m_copym(m, 0, M_COPYALL, M_WAIT), rep);
926 			if (nmp->nm_soflags & PR_CONNREQUIRED)
927 				nfs_sndunlock(&nmp->nm_flag);
928 		}
929 		if (!error && (rep->r_flags & R_MUSTRESEND) == 0) {
930 			nmp->nm_sent += NFS_CWNDSCALE;
931 			rep->r_flags |= R_SENT;
932 		}
933 	} else {
934 		rep->r_rtt = -1;
935 	}
936 
937 	/*
938 	 * Wait for the reply from our send or the timer's.
939 	 */
940 	if (!error || error == EPIPE)
941 		error = nfs_reply(rep);
942 
943 	/*
944 	 * RPC done, unlink the request.
945 	 */
946 	TAILQ_REMOVE(&nmp->nm_reqsq, rep, r_chain);
947 	if (TAILQ_EMPTY(&nmp->nm_reqsq))
948 		timeout_del(&nmp->nm_rtimeout);
949 
950 	/*
951 	 * Decrement the outstanding request count.
952 	 */
953 	if (rep->r_flags & R_SENT) {
954 		rep->r_flags &= ~R_SENT;	/* paranoia */
955 		nmp->nm_sent -= NFS_CWNDSCALE;
956 	}
957 
958 	/*
959 	 * If there was a successful reply and a tprintf msg.
960 	 * tprintf a response.
961 	 */
962 	if (!error && (rep->r_flags & R_TPRINTFMSG))
963 		nfs_msg(rep, "is alive again");
964 	info.nmi_mrep = rep->r_mrep;
965 	info.nmi_md = rep->r_md;
966 	info.nmi_dpos = rep->r_dpos;
967 	if (error) {
968 		infop->nmi_mrep = NULL;
969 		goto nfsmout1;
970 	}
971 
972 	/*
973 	 * break down the rpc header and check if ok
974 	 */
975 	nfsm_dissect(tl, u_int32_t *, 3 * NFSX_UNSIGNED);
976 	if (*tl++ == rpc_msgdenied) {
977 		if (*tl == rpc_mismatch)
978 			error = EOPNOTSUPP;
979 		else
980 			error = EACCES;	/* Should be EAUTH. */
981 		infop->nmi_mrep = NULL;
982 		goto nfsmout1;
983 	}
984 
985 	/*
986 	 * Since we only support RPCAUTH_UNIX atm we step over the
987 	 * reply verifer type, and in the (error) case that there really
988 	 * is any data in it, we advance over it.
989 	 */
990 	tl++;			/* Step over verifer type */
991 	i = fxdr_unsigned(int32_t, *tl);
992 	if (i > 0)
993 		nfsm_adv(nfsm_rndup(i));	/* Should not happen */
994 
995 	nfsm_dissect(tl, u_int32_t *, NFSX_UNSIGNED);
996 	/* 0 == ok */
997 	if (*tl == 0) {
998 		nfsm_dissect(tl, u_int32_t *, NFSX_UNSIGNED);
999 		if (*tl != 0) {
1000 			error = fxdr_unsigned(int, *tl);
1001 			if ((nmp->nm_flag & NFSMNT_NFSV3) &&
1002 			    error == NFSERR_TRYLATER) {
1003 				m_freem(info.nmi_mrep);
1004 				error = 0;
1005 				tsleep_nsec(&nowake, PSOCK, "nfsretry",
1006 				    SEC_TO_NSEC(trylater_delay));
1007 				trylater_delay *= NFS_TIMEOUTMUL;
1008 				if (trylater_delay > NFS_MAXTIMEO)
1009 					trylater_delay = NFS_MAXTIMEO;
1010 
1011 				goto tryagain;
1012 			}
1013 
1014 			/*
1015 			 * If the File Handle was stale, invalidate the
1016 			 * lookup cache, just in case.
1017 			 */
1018 			if (error == ESTALE)
1019 				cache_purge(rep->r_vp);
1020 		}
1021 		goto nfsmout;
1022 	}
1023 
1024 	error = EPROTONOSUPPORT;
1025 
1026 nfsmout:
1027 	infop->nmi_mrep = info.nmi_mrep;
1028 	infop->nmi_md = info.nmi_md;
1029 	infop->nmi_dpos = info.nmi_dpos;
1030 nfsmout1:
1031 	m_freem(rep->r_mreq);
1032 	pool_put(&nfsreqpl, rep);
1033 	return (error);
1034 }
1035 #endif /* NFSCLIENT */
1036 
1037 /*
1038  * Generate the rpc reply header
1039  * siz arg. is used to decide if adding a cluster is worthwhile
1040  */
1041 int
1042 nfs_rephead(int siz, struct nfsrv_descript *nd, struct nfssvc_sock *slp,
1043     int err, struct mbuf **mrq, struct mbuf **mbp)
1044 {
1045 	u_int32_t *tl;
1046 	struct mbuf *mreq;
1047 	struct mbuf *mb;
1048 
1049 	MGETHDR(mreq, M_WAIT, MT_DATA);
1050 	mb = mreq;
1051 	/*
1052 	 * If this is a big reply, use a cluster else
1053 	 * try and leave leading space for the lower level headers.
1054 	 */
1055 	siz += RPC_REPLYSIZ;
1056 	if (siz >= MHLEN - max_hdr) {
1057 		MCLGET(mreq, M_WAIT);
1058 	} else
1059 		mreq->m_data += max_hdr;
1060 	tl = mtod(mreq, u_int32_t *);
1061 	mreq->m_len = 6 * NFSX_UNSIGNED;
1062 	*tl++ = txdr_unsigned(nd->nd_retxid);
1063 	*tl++ = rpc_reply;
1064 	if (err == ERPCMISMATCH || (err & NFSERR_AUTHERR)) {
1065 		*tl++ = rpc_msgdenied;
1066 		if (err & NFSERR_AUTHERR) {
1067 			*tl++ = rpc_autherr;
1068 			*tl = txdr_unsigned(err & ~NFSERR_AUTHERR);
1069 			mreq->m_len -= NFSX_UNSIGNED;
1070 		} else {
1071 			*tl++ = rpc_mismatch;
1072 			*tl++ = txdr_unsigned(RPC_VER2);
1073 			*tl = txdr_unsigned(RPC_VER2);
1074 		}
1075 	} else {
1076 		*tl++ = rpc_msgaccepted;
1077 
1078 		/* AUTH_UNIX requires RPCAUTH_NULL. */
1079 		*tl++ = 0;
1080 		*tl++ = 0;
1081 
1082 		switch (err) {
1083 		case EPROGUNAVAIL:
1084 			*tl = txdr_unsigned(RPC_PROGUNAVAIL);
1085 			break;
1086 		case EPROGMISMATCH:
1087 			*tl = txdr_unsigned(RPC_PROGMISMATCH);
1088 			tl = nfsm_build(&mb, 2 * NFSX_UNSIGNED);
1089 			*tl++ = txdr_unsigned(NFS_VER2);
1090 			*tl = txdr_unsigned(NFS_VER3);
1091 			break;
1092 		case EPROCUNAVAIL:
1093 			*tl = txdr_unsigned(RPC_PROCUNAVAIL);
1094 			break;
1095 		case EBADRPC:
1096 			*tl = txdr_unsigned(RPC_GARBAGE);
1097 			break;
1098 		default:
1099 			*tl = 0;
1100 			if (err != NFSERR_RETVOID) {
1101 				tl = nfsm_build(&mb, NFSX_UNSIGNED);
1102 				if (err)
1103 				    *tl = txdr_unsigned(nfsrv_errmap(nd, err));
1104 				else
1105 				    *tl = 0;
1106 			}
1107 			break;
1108 		};
1109 	}
1110 
1111 	*mrq = mreq;
1112 	if (mbp != NULL)
1113 		*mbp = mb;
1114 	if (err != 0 && err != NFSERR_RETVOID)
1115 		nfsstats.srvrpc_errs++;
1116 	return (0);
1117 }
1118 
1119 /*
1120  * nfs timer routine
1121  * Scan the nfsreq list and retransmit any requests that have timed out.
1122  */
1123 void
1124 nfs_timer(void *arg)
1125 {
1126 	struct nfsmount *nmp = arg;
1127 	struct nfsreq *rep;
1128 	struct mbuf *m;
1129 	struct socket *so;
1130 	int timeo, error;
1131 
1132 	NET_LOCK();
1133 	TAILQ_FOREACH(rep, &nmp->nm_reqsq, r_chain) {
1134 		if (rep->r_mrep || (rep->r_flags & R_SOFTTERM))
1135 			continue;
1136 		if (nfs_sigintr(nmp, rep, rep->r_procp)) {
1137 			rep->r_flags |= R_SOFTTERM;
1138 			continue;
1139 		}
1140 		if (rep->r_rtt >= 0) {
1141 			rep->r_rtt++;
1142 			if (nmp->nm_flag & NFSMNT_DUMBTIMR)
1143 				timeo = nmp->nm_timeo;
1144 			else
1145 				timeo = nfs_estimate_rto(nmp, rep->r_procnum);
1146 			if (nmp->nm_timeouts > 0)
1147 				timeo *= nfs_backoff[nmp->nm_timeouts - 1];
1148 			if (rep->r_rtt <= timeo)
1149 				continue;
1150 			if (nmp->nm_timeouts < nitems(nfs_backoff))
1151 				nmp->nm_timeouts++;
1152 		}
1153 
1154 		/* Check for server not responding. */
1155 		if ((rep->r_flags & R_TPRINTFMSG) == 0 && rep->r_rexmit > 4) {
1156 			nfs_msg(rep, "not responding");
1157 			rep->r_flags |= R_TPRINTFMSG;
1158 		}
1159 		if (rep->r_rexmit >= nmp->nm_retry) {	/* too many */
1160 			nfsstats.rpctimeouts++;
1161 			rep->r_flags |= R_SOFTTERM;
1162 			continue;
1163 		}
1164 		if (nmp->nm_sotype != SOCK_DGRAM) {
1165 			if (++rep->r_rexmit > NFS_MAXREXMIT)
1166 				rep->r_rexmit = NFS_MAXREXMIT;
1167 			continue;
1168 		}
1169 
1170 		if ((so = nmp->nm_so) == NULL)
1171 			continue;
1172 
1173 		/*
1174 		 * If there is enough space and the window allows..
1175 		 *	Resend it
1176 		 * Set r_rtt to -1 in case we fail to send it now.
1177 		 */
1178 		rep->r_rtt = -1;
1179 		if (sbspace(so, &so->so_snd) >= rep->r_mreq->m_pkthdr.len &&
1180 		   ((nmp->nm_flag & NFSMNT_DUMBTIMR) ||
1181 		    (rep->r_flags & R_SENT) ||
1182 		    nmp->nm_sent < nmp->nm_cwnd) &&
1183 		   (m = m_copym(rep->r_mreq, 0, M_COPYALL, M_DONTWAIT))){
1184 			if ((nmp->nm_flag & NFSMNT_NOCONN) == 0)
1185 				error = pru_send(so, m, NULL, NULL);
1186 			else
1187 				error = pru_send(so, m, nmp->nm_nam, NULL);
1188 			if (error) {
1189 				if (NFSIGNORE_SOERROR(nmp->nm_soflags, error))
1190 					so->so_error = 0;
1191 			} else {
1192 				/*
1193 				 * Iff first send, start timing
1194 				 * else turn timing off, backoff timer
1195 				 * and divide congestion window by 2.
1196 				 */
1197 				if (rep->r_flags & R_SENT) {
1198 					rep->r_flags &= ~R_TIMING;
1199 					if (++rep->r_rexmit > NFS_MAXREXMIT)
1200 						rep->r_rexmit = NFS_MAXREXMIT;
1201 					nmp->nm_cwnd >>= 1;
1202 					if (nmp->nm_cwnd < NFS_CWNDSCALE)
1203 						nmp->nm_cwnd = NFS_CWNDSCALE;
1204 					nfsstats.rpcretries++;
1205 				} else {
1206 					rep->r_flags |= R_SENT;
1207 					nmp->nm_sent += NFS_CWNDSCALE;
1208 				}
1209 				rep->r_rtt = 0;
1210 			}
1211 		}
1212 	}
1213 	NET_UNLOCK();
1214 	timeout_add(&nmp->nm_rtimeout, nfs_ticks);
1215 }
1216 
1217 /*
1218  * Test for a termination condition pending on the process.
1219  * This is used for NFSMNT_INT mounts.
1220  */
1221 int
1222 nfs_sigintr(struct nfsmount *nmp, struct nfsreq *rep, struct proc *p)
1223 {
1224 
1225 	if (rep && (rep->r_flags & R_SOFTTERM))
1226 		return (EINTR);
1227 	if (!(nmp->nm_flag & NFSMNT_INT))
1228 		return (0);
1229 	if (p && (SIGPENDING(p) & ~p->p_p->ps_sigacts->ps_sigignore &
1230 	    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 	uint64_t slptimeo = INFSLP;
1245 	struct proc *p;
1246 	int slpflag = 0;
1247 
1248 	if (rep) {
1249 		p = rep->r_procp;
1250 		if (rep->r_nmp->nm_flag & NFSMNT_INT)
1251 			slpflag = PCATCH;
1252 	} else
1253 		p = NULL;
1254 	while (*flagp & NFSMNT_SNDLOCK) {
1255 		if (rep && nfs_sigintr(rep->r_nmp, rep, p))
1256 			return (EINTR);
1257 		*flagp |= NFSMNT_WANTSND;
1258 		tsleep_nsec(flagp, slpflag | (PZERO - 1), "nfsndlck", slptimeo);
1259 		if (slpflag == PCATCH) {
1260 			slpflag = 0;
1261 			slptimeo = SEC_TO_NSEC(2);
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 	uint64_t slptimeo = INFSLP;
1288 	int *flagp = &rep->r_nmp->nm_flag;
1289 	int slpflag;
1290 
1291 	if (*flagp & NFSMNT_INT)
1292 		slpflag = PCATCH;
1293 	else
1294 		slpflag = 0;
1295 
1296 	while (*flagp & NFSMNT_RCVLOCK) {
1297 		if (nfs_sigintr(rep->r_nmp, rep, rep->r_procp))
1298 			return (EINTR);
1299 		*flagp |= NFSMNT_WANTRCV;
1300 		tsleep_nsec(flagp, slpflag | (PZERO - 1), "nfsrcvlk", 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 = SEC_TO_NSEC(2);
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 		refcnt_init(&nd->nd_cr.cr_refcnt);
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 	KERNEL_LOCK();
1568 
1569 	if ((slp->ns_flag & SLP_VALID) == 0)
1570 		goto out;
1571 
1572 	/* Defer soreceive() to an nfsd. */
1573 	if (waitflag == M_DONTWAIT) {
1574 		slp->ns_flag |= SLP_NEEDQ;
1575 		goto dorecs;
1576 	}
1577 
1578 	auio.uio_procp = NULL;
1579 	if (so->so_type == SOCK_STREAM) {
1580 		/*
1581 		 * Do soreceive().
1582 		 */
1583 		auio.uio_resid = 1000000000;
1584 		flags = MSG_DONTWAIT;
1585 		error = soreceive(so, &nam, &auio, &mp, NULL,
1586 		    &flags, 0);
1587 		if (error || mp == NULL) {
1588 			if (error == EWOULDBLOCK)
1589 				slp->ns_flag |= SLP_NEEDQ;
1590 			else
1591 				slp->ns_flag |= SLP_DISCONN;
1592 			goto dorecs;
1593 		}
1594 		m = mp;
1595 		if (slp->ns_rawend) {
1596 			slp->ns_rawend->m_next = m;
1597 			slp->ns_cc += 1000000000 - auio.uio_resid;
1598 		} else {
1599 			slp->ns_raw = m;
1600 			slp->ns_cc = 1000000000 - auio.uio_resid;
1601 		}
1602 		while (m->m_next)
1603 			m = m->m_next;
1604 		slp->ns_rawend = m;
1605 
1606 		/*
1607 		 * Now try and parse record(s) out of the raw stream data.
1608 		 */
1609 		error = nfsrv_getstream(slp, waitflag);
1610 		if (error) {
1611 			if (error == EPERM)
1612 				slp->ns_flag |= SLP_DISCONN;
1613 			else
1614 				slp->ns_flag |= SLP_NEEDQ;
1615 		}
1616 	} else {
1617 		do {
1618 			auio.uio_resid = 1000000000;
1619 			flags = MSG_DONTWAIT;
1620 			error = soreceive(so, &nam, &auio, &mp,
1621 			    NULL, &flags, 0);
1622 			if (mp) {
1623 				if (nam) {
1624 					m = nam;
1625 					m->m_next = mp;
1626 				} else
1627 					m = mp;
1628 				if (slp->ns_recend)
1629 					slp->ns_recend->m_nextpkt = m;
1630 				else
1631 					slp->ns_rec = m;
1632 				slp->ns_recend = m;
1633 				m->m_nextpkt = NULL;
1634 			}
1635 			if (error) {
1636 				if ((so->so_proto->pr_flags & PR_CONNREQUIRED)
1637 					&& error != EWOULDBLOCK) {
1638 					slp->ns_flag |= SLP_DISCONN;
1639 					goto dorecs;
1640 				}
1641 			}
1642 		} while (mp);
1643 	}
1644 
1645 	/*
1646 	 * Now try and process the request records, non-blocking.
1647 	 */
1648 dorecs:
1649 	if (waitflag == M_DONTWAIT &&
1650 		(slp->ns_rec || (slp->ns_flag & (SLP_NEEDQ | SLP_DISCONN))))
1651 		nfsrv_wakenfsd(slp);
1652 
1653 out:
1654 	KERNEL_UNLOCK();
1655 }
1656 
1657 /*
1658  * Try and extract an RPC request from the mbuf data list received on a
1659  * stream socket. The "waitflag" argument indicates whether or not it
1660  * can sleep.
1661  */
1662 int
1663 nfsrv_getstream(struct nfssvc_sock *slp, int waitflag)
1664 {
1665 	struct mbuf *m, **mpp;
1666 	char *cp1, *cp2;
1667 	int len;
1668 	struct mbuf *om, *m2, *recm;
1669 	u_int32_t recmark;
1670 
1671 	if (slp->ns_flag & SLP_GETSTREAM)
1672 		return (0);
1673 	slp->ns_flag |= SLP_GETSTREAM;
1674 	for (;;) {
1675 		if (slp->ns_reclen == 0) {
1676 			if (slp->ns_cc < NFSX_UNSIGNED) {
1677 				slp->ns_flag &= ~SLP_GETSTREAM;
1678 				return (0);
1679 			}
1680 			m = slp->ns_raw;
1681 			if (m->m_len >= NFSX_UNSIGNED) {
1682 				bcopy(mtod(m, caddr_t), &recmark,
1683 				    NFSX_UNSIGNED);
1684 				m->m_data += NFSX_UNSIGNED;
1685 				m->m_len -= NFSX_UNSIGNED;
1686 			} else {
1687 				cp1 = (caddr_t)&recmark;
1688 				cp2 = mtod(m, caddr_t);
1689 				while (cp1 < ((caddr_t)&recmark) + NFSX_UNSIGNED) {
1690 					while (m->m_len == 0) {
1691 						m = m->m_next;
1692 						cp2 = mtod(m, caddr_t);
1693 					}
1694 					*cp1++ = *cp2++;
1695 					m->m_data++;
1696 					m->m_len--;
1697 				}
1698 			}
1699 			slp->ns_cc -= NFSX_UNSIGNED;
1700 			recmark = ntohl(recmark);
1701 			slp->ns_reclen = recmark & ~0x80000000;
1702 			if (recmark & 0x80000000)
1703 				slp->ns_flag |= SLP_LASTFRAG;
1704 			else
1705 				slp->ns_flag &= ~SLP_LASTFRAG;
1706 			if (slp->ns_reclen > NFS_MAXPACKET) {
1707 				slp->ns_flag &= ~SLP_GETSTREAM;
1708 				return (EPERM);
1709 			}
1710 		}
1711 
1712 		/*
1713 		 * Now get the record part.
1714 		 */
1715 		recm = NULL;
1716 		if (slp->ns_cc == slp->ns_reclen) {
1717 			recm = slp->ns_raw;
1718 			slp->ns_raw = slp->ns_rawend = NULL;
1719 			slp->ns_cc = slp->ns_reclen = 0;
1720 		} else if (slp->ns_cc > slp->ns_reclen) {
1721 			len = 0;
1722 			m = slp->ns_raw;
1723 			om = NULL;
1724 			while (len < slp->ns_reclen) {
1725 				if ((len + m->m_len) > slp->ns_reclen) {
1726 					m2 = m_copym(m, 0, slp->ns_reclen - len,
1727 					    waitflag);
1728 					if (m2) {
1729 						if (om) {
1730 							om->m_next = m2;
1731 							recm = slp->ns_raw;
1732 						} else
1733 							recm = m2;
1734 						m->m_data += slp->ns_reclen-len;
1735 						m->m_len -= slp->ns_reclen-len;
1736 						len = slp->ns_reclen;
1737 					} else {
1738 						slp->ns_flag &= ~SLP_GETSTREAM;
1739 						return (EWOULDBLOCK);
1740 					}
1741 				} else if ((len + m->m_len) == slp->ns_reclen) {
1742 					om = m;
1743 					len += m->m_len;
1744 					m = m->m_next;
1745 					recm = slp->ns_raw;
1746 					om->m_next = NULL;
1747 				} else {
1748 					om = m;
1749 					len += m->m_len;
1750 					m = m->m_next;
1751 				}
1752 			}
1753 			slp->ns_raw = m;
1754 			slp->ns_cc -= len;
1755 			slp->ns_reclen = 0;
1756 		} else {
1757 			slp->ns_flag &= ~SLP_GETSTREAM;
1758 			return (0);
1759 		}
1760 
1761 		/*
1762 		 * Accumulate the fragments into a record.
1763 		 */
1764 		mpp = &slp->ns_frag;
1765 		while (*mpp)
1766 			mpp = &((*mpp)->m_next);
1767 		*mpp = recm;
1768 		if (slp->ns_flag & SLP_LASTFRAG) {
1769 			if (slp->ns_recend)
1770 			    slp->ns_recend->m_nextpkt = slp->ns_frag;
1771 			else
1772 			    slp->ns_rec = slp->ns_frag;
1773 			slp->ns_recend = slp->ns_frag;
1774 			slp->ns_frag = NULL;
1775 		}
1776 	}
1777 }
1778 
1779 /*
1780  * Parse an RPC header.
1781  */
1782 int
1783 nfsrv_dorec(struct nfssvc_sock *slp, struct nfsd *nfsd,
1784     struct nfsrv_descript **ndp)
1785 {
1786 	struct mbuf *m, *nam;
1787 	struct nfsrv_descript *nd;
1788 	int error;
1789 
1790 	*ndp = NULL;
1791 	if ((slp->ns_flag & SLP_VALID) == 0 ||
1792 	    (m = slp->ns_rec) == NULL)
1793 		return (ENOBUFS);
1794 	slp->ns_rec = m->m_nextpkt;
1795 	if (slp->ns_rec)
1796 		m->m_nextpkt = NULL;
1797 	else
1798 		slp->ns_recend = NULL;
1799 	if (m->m_type == MT_SONAME) {
1800 		nam = m;
1801 		m = m->m_next;
1802 		nam->m_next = NULL;
1803 	} else
1804 		nam = NULL;
1805 	nd = pool_get(&nfsrv_descript_pl, PR_WAITOK);
1806 	nfs_realign(&m, 10 * NFSX_UNSIGNED);
1807 	nd->nd_md = nd->nd_mrep = m;
1808 	nd->nd_nam2 = nam;
1809 	nd->nd_dpos = mtod(m, caddr_t);
1810 	error = nfs_getreq(nd, nfsd, 1);
1811 	if (error) {
1812 		m_freem(nam);
1813 		pool_put(&nfsrv_descript_pl, nd);
1814 		return (error);
1815 	}
1816 	*ndp = nd;
1817 	nfsd->nfsd_nd = nd;
1818 	return (0);
1819 }
1820 
1821 
1822 /*
1823  * Search for a sleeping nfsd and wake it up.
1824  * SIDE EFFECT: If none found, set NFSD_CHECKSLP flag, so that one of the
1825  * running nfsds will go look for the work in the nfssvc_sock list.
1826  */
1827 void
1828 nfsrv_wakenfsd(struct nfssvc_sock *slp)
1829 {
1830 	struct nfsd	*nfsd;
1831 
1832 	if ((slp->ns_flag & SLP_VALID) == 0)
1833 		return;
1834 
1835 	TAILQ_FOREACH(nfsd, &nfsd_head, nfsd_chain) {
1836 		if (nfsd->nfsd_flag & NFSD_WAITING) {
1837 			nfsd->nfsd_flag &= ~NFSD_WAITING;
1838 			if (nfsd->nfsd_slp)
1839 				panic("nfsd wakeup");
1840 			slp->ns_sref++;
1841 			nfsd->nfsd_slp = slp;
1842 			wakeup_one(nfsd);
1843 			return;
1844 		}
1845 	}
1846 
1847 	slp->ns_flag |= SLP_DOREC;
1848 	nfsd_head_flag |= NFSD_CHECKSLP;
1849 }
1850 #endif /* NFSSERVER */
1851