xref: /openbsd-src/sys/nfs/nfs_socket.c (revision a28daedfc357b214be5c701aa8ba8adb29a7f1c2)
1 /*	$OpenBSD: nfs_socket.c,v 1.78 2009/02/22 07:47:22 otto Exp $	*/
2 /*	$NetBSD: nfs_socket.c,v 1.27 1996/04/15 20:20:00 thorpej Exp $	*/
3 
4 /*
5  * Copyright (c) 1989, 1991, 1993, 1995
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * This code is derived from software contributed to Berkeley by
9  * Rick Macklem at The University of Guelph.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  *
35  *	@(#)nfs_socket.c	8.5 (Berkeley) 3/30/95
36  */
37 
38 /*
39  * Socket operations for use by nfs
40  */
41 
42 #include <sys/param.h>
43 #include <sys/systm.h>
44 #include <sys/proc.h>
45 #include <sys/mount.h>
46 #include <sys/kernel.h>
47 #include <sys/mbuf.h>
48 #include <sys/vnode.h>
49 #include <sys/domain.h>
50 #include <sys/protosw.h>
51 #include <sys/socket.h>
52 #include <sys/socketvar.h>
53 #include <sys/syslog.h>
54 #include <sys/tprintf.h>
55 #include <sys/namei.h>
56 #include <sys/pool.h>
57 #include <sys/queue.h>
58 
59 #include <netinet/in.h>
60 #include <netinet/tcp.h>
61 
62 #include <nfs/rpcv2.h>
63 #include <nfs/nfsproto.h>
64 #include <nfs/nfs.h>
65 #include <nfs/xdr_subs.h>
66 #include <nfs/nfsm_subs.h>
67 #include <nfs/nfsmount.h>
68 #include <nfs/nfsnode.h>
69 #include <nfs/nfsrtt.h>
70 #include <nfs/nfs_var.h>
71 
72 /*
73  * Estimate rto for an nfs rpc sent via. an unreliable datagram.
74  * Use the mean and mean deviation of rtt for the appropriate type of rpc
75  * for the frequent rpcs and a default for the others.
76  * The justification for doing "other" this way is that these rpcs
77  * happen so infrequently that timer est. would probably be stale.
78  * Also, since many of these rpcs are
79  * non-idempotent, a conservative timeout is desired.
80  * getattr, lookup - A+2D
81  * read, write     - A+4D
82  * other           - nm_timeo
83  */
84 #define	NFS_RTO(n, t) \
85 	((t) == 0 ? (n)->nm_timeo : \
86 	 ((t) < 3 ? \
87 	  (((((n)->nm_srtt[t-1] + 3) >> 2) + (n)->nm_sdrtt[t-1] + 1) >> 1) : \
88 	  ((((n)->nm_srtt[t-1] + 7) >> 3) + (n)->nm_sdrtt[t-1] + 1)))
89 #define	NFS_SRTT(r)	(r)->r_nmp->nm_srtt[proct[(r)->r_procnum] - 1]
90 #define	NFS_SDRTT(r)	(r)->r_nmp->nm_sdrtt[proct[(r)->r_procnum] - 1]
91 /*
92  * External data, mostly RPC constants in XDR form
93  */
94 extern u_int32_t rpc_reply, rpc_msgdenied, rpc_mismatch, rpc_vers,
95 	rpc_auth_unix, rpc_msgaccepted, rpc_call, rpc_autherr;
96 extern u_int32_t nfs_prog;
97 extern struct nfsstats nfsstats;
98 extern int nfsv3_procid[NFS_NPROCS];
99 extern int nfs_ticks;
100 
101 /*
102  * Defines which timer to use for the procnum.
103  * 0 - default
104  * 1 - getattr
105  * 2 - lookup
106  * 3 - read
107  * 4 - write
108  */
109 static int proct[NFS_NPROCS] = {
110 	0, 1, 0, 2, 1, 3, 3, 4, 0, 0, 0, 0, 0, 0, 0, 0, 3, 3, 0, 0, 0, 0, 0,
111 	0, 0, 0,
112 };
113 
114 /*
115  * There is a congestion window for outstanding rpcs maintained per mount
116  * point. The cwnd size is adjusted in roughly the way that:
117  * Van Jacobson, Congestion avoidance and Control, In "Proceedings of
118  * SIGCOMM '88". ACM, August 1988.
119  * describes for TCP. The cwnd size is chopped in half on a retransmit timeout
120  * and incremented by 1/cwnd when each rpc reply is received and a full cwnd
121  * of rpcs is in progress.
122  * (The sent count and cwnd are scaled for integer arith.)
123  * Variants of "slow start" were tried and were found to be too much of a
124  * performance hit (ave. rtt 3 times larger),
125  * I suspect due to the large rtt that nfs rpcs have.
126  */
127 #define	NFS_CWNDSCALE	256
128 #define	NFS_MAXCWND	(NFS_CWNDSCALE * 32)
129 static int nfs_backoff[8] = { 2, 4, 8, 16, 32, 64, 128, 256, };
130 int nfsrtton = 0;
131 struct nfsrtt nfsrtt;
132 
133 void nfs_realign(struct mbuf **, int);
134 void nfs_realign_fixup(struct mbuf *, struct mbuf *, unsigned int *);
135 unsigned int nfs_realign_test = 0;
136 unsigned int nfs_realign_count = 0;
137 
138 struct nfsreqhead nfs_reqq;
139 
140 /*
141  * Initialize sockets and congestion for a new NFS connection.
142  * We do not free the sockaddr if error.
143  */
144 int
145 nfs_connect(nmp, rep)
146 	struct nfsmount *nmp;
147 	struct nfsreq *rep;
148 {
149 	struct socket *so;
150 	int s, error, rcvreserve, sndreserve;
151 	struct sockaddr *saddr;
152 	struct sockaddr_in *sin;
153 	struct mbuf *m;
154 
155 	nmp->nm_so = (struct socket *)0;
156 	saddr = mtod(nmp->nm_nam, struct sockaddr *);
157 	error = socreate(saddr->sa_family, &nmp->nm_so, nmp->nm_sotype,
158 		nmp->nm_soproto);
159 	if (error)
160 		goto bad;
161 	so = nmp->nm_so;
162 	nmp->nm_soflags = so->so_proto->pr_flags;
163 
164 	/*
165 	 * Some servers require that the client port be a reserved port number.
166 	 * We always allocate a reserved port, as this prevents filehandle
167 	 * disclosure through UDP port capture.
168 	 */
169 	if (saddr->sa_family == AF_INET) {
170 		struct mbuf *mopt;
171 		int *ip;
172 
173 		MGET(mopt, M_WAIT, MT_SOOPTS);
174 		mopt->m_len = sizeof(int);
175 		ip = mtod(mopt, int *);
176 		*ip = IP_PORTRANGE_LOW;
177 		error = sosetopt(so, IPPROTO_IP, IP_PORTRANGE, mopt);
178 		if (error)
179 			goto bad;
180 
181 		MGET(m, M_WAIT, MT_SONAME);
182 		sin = mtod(m, struct sockaddr_in *);
183 		sin->sin_len = m->m_len = sizeof (struct sockaddr_in);
184 		sin->sin_family = AF_INET;
185 		sin->sin_addr.s_addr = INADDR_ANY;
186 		sin->sin_port = htons(0);
187 		error = sobind(so, m, &proc0);
188 		m_freem(m);
189 		if (error)
190 			goto bad;
191 
192 		MGET(mopt, M_WAIT, MT_SOOPTS);
193 		mopt->m_len = sizeof(int);
194 		ip = mtod(mopt, int *);
195 		*ip = IP_PORTRANGE_DEFAULT;
196 		error = sosetopt(so, IPPROTO_IP, IP_PORTRANGE, mopt);
197 		if (error)
198 			goto bad;
199 	}
200 
201 	/*
202 	 * Protocols that do not require connections may be optionally left
203 	 * unconnected for servers that reply from a port other than NFS_PORT.
204 	 */
205 	if (nmp->nm_flag & NFSMNT_NOCONN) {
206 		if (nmp->nm_soflags & PR_CONNREQUIRED) {
207 			error = ENOTCONN;
208 			goto bad;
209 		}
210 	} else {
211 		error = soconnect(so, nmp->nm_nam);
212 		if (error)
213 			goto bad;
214 
215 		/*
216 		 * Wait for the connection to complete. Cribbed from the
217 		 * connect system call but with the wait timing out so
218 		 * that interruptible mounts don't hang here for a long time.
219 		 */
220 		s = splsoftnet();
221 		while ((so->so_state & SS_ISCONNECTING) && so->so_error == 0) {
222 			(void) tsleep((caddr_t)&so->so_timeo, PSOCK,
223 				"nfscon", 2 * hz);
224 			if ((so->so_state & SS_ISCONNECTING) &&
225 			    so->so_error == 0 && rep &&
226 			    (error = nfs_sigintr(nmp, rep, rep->r_procp)) != 0){
227 				so->so_state &= ~SS_ISCONNECTING;
228 				splx(s);
229 				goto bad;
230 			}
231 		}
232 		if (so->so_error) {
233 			error = so->so_error;
234 			so->so_error = 0;
235 			splx(s);
236 			goto bad;
237 		}
238 		splx(s);
239 	}
240 	/*
241 	 * Always set receive timeout to detect server crash and reconnect.
242 	 * Otherwise, we can get stuck in soreceive forever.
243 	 */
244 	so->so_rcv.sb_timeo = (5 * hz);
245 	if (nmp->nm_flag & (NFSMNT_SOFT | NFSMNT_INT))
246 		so->so_snd.sb_timeo = (5 * hz);
247 	else
248 		so->so_snd.sb_timeo = 0;
249 	if (nmp->nm_sotype == SOCK_DGRAM) {
250 		sndreserve = nmp->nm_wsize + NFS_MAXPKTHDR;
251 		rcvreserve = (max(nmp->nm_rsize, nmp->nm_readdirsize) +
252 		    NFS_MAXPKTHDR) * 2;
253 	} else if (nmp->nm_sotype == SOCK_SEQPACKET) {
254 		sndreserve = (nmp->nm_wsize + NFS_MAXPKTHDR) * 2;
255 		rcvreserve = (max(nmp->nm_rsize, nmp->nm_readdirsize) +
256 		    NFS_MAXPKTHDR) * 2;
257 	} else {
258 		if (nmp->nm_sotype != SOCK_STREAM)
259 			panic("nfscon sotype");
260 		if (so->so_proto->pr_flags & PR_CONNREQUIRED) {
261 			MGET(m, M_WAIT, MT_SOOPTS);
262 			*mtod(m, int32_t *) = 1;
263 			m->m_len = sizeof(int32_t);
264 			sosetopt(so, SOL_SOCKET, SO_KEEPALIVE, m);
265 		}
266 		if (so->so_proto->pr_protocol == IPPROTO_TCP) {
267 			MGET(m, M_WAIT, MT_SOOPTS);
268 			*mtod(m, int32_t *) = 1;
269 			m->m_len = sizeof(int32_t);
270 			sosetopt(so, IPPROTO_TCP, TCP_NODELAY, m);
271 		}
272 		sndreserve = (nmp->nm_wsize + NFS_MAXPKTHDR +
273 		    sizeof (u_int32_t)) * 2;
274 		rcvreserve = (nmp->nm_rsize + NFS_MAXPKTHDR +
275 		    sizeof (u_int32_t)) * 2;
276 	}
277 	error = soreserve(so, sndreserve, rcvreserve);
278 	if (error)
279 		goto bad;
280 	so->so_rcv.sb_flags |= SB_NOINTR;
281 	so->so_snd.sb_flags |= SB_NOINTR;
282 
283 	/* Initialize other non-zero congestion variables */
284 	nmp->nm_srtt[0] = nmp->nm_srtt[1] = nmp->nm_srtt[2] =
285 	    nmp->nm_srtt[3] = (NFS_TIMEO << 3);
286 	nmp->nm_sdrtt[0] = nmp->nm_sdrtt[1] = nmp->nm_sdrtt[2] =
287 	    nmp->nm_sdrtt[3] = 0;
288 	nmp->nm_cwnd = NFS_MAXCWND / 2;	    /* Initial send window */
289 	nmp->nm_sent = 0;
290 	nmp->nm_timeouts = 0;
291 	return (0);
292 
293 bad:
294 	nfs_disconnect(nmp);
295 	return (error);
296 }
297 
298 /*
299  * Reconnect routine:
300  * Called when a connection is broken on a reliable protocol.
301  * - clean up the old socket
302  * - nfs_connect() again
303  * - set R_MUSTRESEND for all outstanding requests on mount point
304  * If this fails the mount point is DEAD!
305  * nb: Must be called with the nfs_sndlock() set on the mount point.
306  */
307 int
308 nfs_reconnect(rep)
309 	struct nfsreq *rep;
310 {
311 	struct nfsreq *rp;
312 	struct nfsmount *nmp = rep->r_nmp;
313 	int s, error;
314 
315 	nfs_disconnect(nmp);
316 	while ((error = nfs_connect(nmp, rep)) != 0) {
317 		if (error == EINTR || error == ERESTART)
318 			return (EINTR);
319 		(void) tsleep((caddr_t)&lbolt, PSOCK, "nfscon", 0);
320 	}
321 
322 	/*
323 	 * Loop through outstanding request list and fix up all requests
324 	 * on old socket.
325 	 */
326 	s = splsoftnet();
327 	TAILQ_FOREACH(rp, &nfs_reqq, r_chain) {
328 		if (rp->r_nmp == nmp) {
329 			rp->r_flags |= R_MUSTRESEND;
330 			rp->r_rexmit = 0;
331 		}
332 	}
333 	splx(s);
334 	return (0);
335 }
336 
337 /*
338  * NFS disconnect. Clean up and unlink.
339  */
340 void
341 nfs_disconnect(nmp)
342 	struct nfsmount *nmp;
343 {
344 	struct socket *so;
345 
346 	if (nmp->nm_so) {
347 		so = nmp->nm_so;
348 		nmp->nm_so = (struct socket *)0;
349 		soshutdown(so, SHUT_RDWR);
350 		soclose(so);
351 	}
352 }
353 
354 /*
355  * This is the nfs send routine. For connection based socket types, it
356  * must be called with an nfs_sndlock() on the socket.
357  * "rep == NULL" indicates that it has been called from a server.
358  * For the client side:
359  * - return EINTR if the RPC is terminated, 0 otherwise
360  * - set R_MUSTRESEND if the send fails for any reason
361  * - do any cleanup required by recoverable socket errors (???)
362  * For the server side:
363  * - return EINTR or ERESTART if interrupted by a signal
364  * - return EPIPE if a connection is lost for connection based sockets (TCP...)
365  * - do any cleanup required by recoverable socket errors (???)
366  */
367 int
368 nfs_send(so, nam, top, rep)
369 	struct socket *so;
370 	struct mbuf *nam;
371 	struct mbuf *top;
372 	struct nfsreq *rep;
373 {
374 	struct mbuf *sendnam;
375 	int error, soflags, flags;
376 
377 	if (rep) {
378 		if (rep->r_flags & R_SOFTTERM) {
379 			m_freem(top);
380 			return (EINTR);
381 		}
382 		if ((so = rep->r_nmp->nm_so) == NULL) {
383 			rep->r_flags |= R_MUSTRESEND;
384 			m_freem(top);
385 			return (0);
386 		}
387 		rep->r_flags &= ~R_MUSTRESEND;
388 		soflags = rep->r_nmp->nm_soflags;
389 	} else
390 		soflags = so->so_proto->pr_flags;
391 	if ((soflags & PR_CONNREQUIRED) || (so->so_state & SS_ISCONNECTED))
392 		sendnam = (struct mbuf *)0;
393 	else
394 		sendnam = nam;
395 	if (so->so_type == SOCK_SEQPACKET)
396 		flags = MSG_EOR;
397 	else
398 		flags = 0;
399 
400 	error = sosend(so, sendnam, (struct uio *)0, top,
401 		(struct mbuf *)0, flags);
402 	if (error) {
403 		if (rep) {
404 			/*
405 			 * Deal with errors for the client side.
406 			 */
407 			if (rep->r_flags & R_SOFTTERM)
408 				error = EINTR;
409 			else
410 				rep->r_flags |= R_MUSTRESEND;
411 		}
412 
413 		/*
414 		 * Handle any recoverable (soft) socket errors here. (???)
415 		 */
416 		if (error != EINTR && error != ERESTART &&
417 			error != EWOULDBLOCK && error != EPIPE)
418 			error = 0;
419 	}
420 	return (error);
421 }
422 
423 #ifdef NFSCLIENT
424 /*
425  * Receive a Sun RPC Request/Reply. For SOCK_DGRAM, the work is all
426  * done by soreceive(), but for SOCK_STREAM we must deal with the Record
427  * Mark and consolidate the data into a new mbuf list.
428  * nb: Sometimes TCP passes the data up to soreceive() in long lists of
429  *     small mbufs.
430  * For SOCK_STREAM we must be very careful to read an entire record once
431  * we have read any of it, even if the system call has been interrupted.
432  */
433 int
434 nfs_receive(rep, aname, mp)
435 	struct nfsreq *rep;
436 	struct mbuf **aname;
437 	struct mbuf **mp;
438 {
439 	struct socket *so;
440 	struct uio auio;
441 	struct iovec aio;
442 	struct mbuf *m;
443 	struct mbuf *control;
444 	u_int32_t len;
445 	struct mbuf **getnam;
446 	int error, sotype, rcvflg;
447 	struct proc *p = curproc;	/* XXX */
448 
449 	/*
450 	 * Set up arguments for soreceive()
451 	 */
452 	*mp = (struct mbuf *)0;
453 	*aname = (struct mbuf *)0;
454 	sotype = rep->r_nmp->nm_sotype;
455 
456 	/*
457 	 * For reliable protocols, lock against other senders/receivers
458 	 * in case a reconnect is necessary.
459 	 * For SOCK_STREAM, first get the Record Mark to find out how much
460 	 * more there is to get.
461 	 * We must lock the socket against other receivers
462 	 * until we have an entire rpc request/reply.
463 	 */
464 	if (sotype != SOCK_DGRAM) {
465 		error = nfs_sndlock(&rep->r_nmp->nm_flag, rep);
466 		if (error)
467 			return (error);
468 tryagain:
469 		/*
470 		 * Check for fatal errors and resending request.
471 		 */
472 		/*
473 		 * Ugh: If a reconnect attempt just happened, nm_so
474 		 * would have changed. NULL indicates a failed
475 		 * attempt that has essentially shut down this
476 		 * mount point.
477 		 */
478 		if (rep->r_mrep || (rep->r_flags & R_SOFTTERM)) {
479 			nfs_sndunlock(&rep->r_nmp->nm_flag);
480 			return (EINTR);
481 		}
482 		so = rep->r_nmp->nm_so;
483 		if (!so) {
484 			error = nfs_reconnect(rep);
485 			if (error) {
486 				nfs_sndunlock(&rep->r_nmp->nm_flag);
487 				return (error);
488 			}
489 			goto tryagain;
490 		}
491 		while (rep->r_flags & R_MUSTRESEND) {
492 			m = m_copym(rep->r_mreq, 0, M_COPYALL, M_WAIT);
493 			nfsstats.rpcretries++;
494 			rep->r_rtt = 0;
495 			rep->r_flags &= ~R_TIMING;
496 			error = nfs_send(so, rep->r_nmp->nm_nam, m, rep);
497 			if (error) {
498 				if (error == EINTR || error == ERESTART ||
499 				    (error = nfs_reconnect(rep)) != 0) {
500 					nfs_sndunlock(&rep->r_nmp->nm_flag);
501 					return (error);
502 				}
503 				goto tryagain;
504 			}
505 		}
506 		nfs_sndunlock(&rep->r_nmp->nm_flag);
507 		if (sotype == SOCK_STREAM) {
508 			aio.iov_base = (caddr_t) &len;
509 			aio.iov_len = sizeof(u_int32_t);
510 			auio.uio_iov = &aio;
511 			auio.uio_iovcnt = 1;
512 			auio.uio_segflg = UIO_SYSSPACE;
513 			auio.uio_rw = UIO_READ;
514 			auio.uio_offset = 0;
515 			auio.uio_resid = sizeof(u_int32_t);
516 			auio.uio_procp = p;
517 			do {
518 			   rcvflg = MSG_WAITALL;
519 			   error = soreceive(so, (struct mbuf **)0, &auio,
520 				(struct mbuf **)0, (struct mbuf **)0, &rcvflg,
521 				0);
522 			   if (error == EWOULDBLOCK && rep) {
523 				if (rep->r_flags & R_SOFTTERM)
524 					return (EINTR);
525 				/*
526 				 * looks like the server died after it
527 				 * received the request, make sure
528 				 * that we will retransmit and we
529 				 * don't get stuck here forever.
530 				 */
531 				if (rep->r_rexmit >= rep->r_nmp->nm_retry) {
532 					nfsstats.rpctimeouts++;
533 					error = EPIPE;
534 				}
535 			   }
536 			} while (error == EWOULDBLOCK);
537 			if (!error && auio.uio_resid > 0) {
538 			    log(LOG_INFO,
539 				 "short receive (%d/%d) from nfs server %s\n",
540 				 sizeof(u_int32_t) - auio.uio_resid,
541 				 sizeof(u_int32_t),
542 				 rep->r_nmp->nm_mountp->mnt_stat.f_mntfromname);
543 			    error = EPIPE;
544 			}
545 			if (error)
546 				goto errout;
547 
548 			len = ntohl(len) & ~0x80000000;
549 			/*
550 			 * This is SERIOUS! We are out of sync with the sender
551 			 * and forcing a disconnect/reconnect is all I can do.
552 			 */
553 			if (len > NFS_MAXPACKET) {
554 			    log(LOG_ERR, "%s (%d) from nfs server %s\n",
555 				"impossible packet length",
556 				len,
557 				rep->r_nmp->nm_mountp->mnt_stat.f_mntfromname);
558 			    error = EFBIG;
559 			    goto errout;
560 			}
561 			auio.uio_resid = len;
562 			do {
563 			    rcvflg = MSG_WAITALL;
564 			    error =  soreceive(so, (struct mbuf **)0,
565 				&auio, mp, (struct mbuf **)0, &rcvflg, 0);
566 			} while (error == EWOULDBLOCK || error == EINTR ||
567 				 error == ERESTART);
568 			if (!error && auio.uio_resid > 0) {
569 			    log(LOG_INFO,
570 				"short receive (%d/%d) from nfs server %s\n",
571 				len - auio.uio_resid, len,
572 				rep->r_nmp->nm_mountp->mnt_stat.f_mntfromname);
573 			    error = EPIPE;
574 			}
575 		} else {
576 			/*
577 			 * NB: Since uio_resid is big, MSG_WAITALL is ignored
578 			 * and soreceive() will return when it has either a
579 			 * control msg or a data msg.
580 			 * We have no use for control msg., but must grab them
581 			 * and then throw them away so we know what is going
582 			 * on.
583 			 */
584 			auio.uio_resid = len = 100000000; /* Anything Big */
585 			auio.uio_procp = p;
586 			do {
587 			    rcvflg = 0;
588 			    error =  soreceive(so, (struct mbuf **)0,
589 				&auio, mp, &control, &rcvflg, 0);
590 			    if (control)
591 				m_freem(control);
592 			    if (error == EWOULDBLOCK && rep) {
593 				if (rep->r_flags & R_SOFTTERM)
594 					return (EINTR);
595 			    }
596 			} while (error == EWOULDBLOCK ||
597 				 (!error && *mp == NULL && control));
598 			if ((rcvflg & MSG_EOR) == 0)
599 				printf("Egad!!\n");
600 			if (!error && *mp == NULL)
601 				error = EPIPE;
602 			len -= auio.uio_resid;
603 		}
604 errout:
605 		if (error && error != EINTR && error != ERESTART) {
606 			m_freem(*mp);
607 			*mp = (struct mbuf *)0;
608 			if (error != EPIPE)
609 				log(LOG_INFO,
610 				    "receive error %d from nfs server %s\n",
611 				    error,
612 				 rep->r_nmp->nm_mountp->mnt_stat.f_mntfromname);
613 			error = nfs_sndlock(&rep->r_nmp->nm_flag, rep);
614 			if (!error) {
615 				error = nfs_reconnect(rep);
616 				if (!error)
617 					goto tryagain;
618 				nfs_sndunlock(&rep->r_nmp->nm_flag);
619 			}
620 		}
621 	} else {
622 		if ((so = rep->r_nmp->nm_so) == NULL)
623 			return (EACCES);
624 		if (so->so_state & SS_ISCONNECTED)
625 			getnam = (struct mbuf **)0;
626 		else
627 			getnam = aname;
628 		auio.uio_resid = len = 1000000;
629 		auio.uio_procp = p;
630 		do {
631 			rcvflg = 0;
632 			error =  soreceive(so, getnam, &auio, mp,
633 				(struct mbuf **)0, &rcvflg, 0);
634 			if (error == EWOULDBLOCK &&
635 			    (rep->r_flags & R_SOFTTERM))
636 				return (EINTR);
637 		} while (error == EWOULDBLOCK);
638 		len -= auio.uio_resid;
639 	}
640 	if (error) {
641 		m_freem(*mp);
642 		*mp = (struct mbuf *)0;
643 	}
644 	/*
645 	 * Search for any mbufs that are not a multiple of 4 bytes long
646 	 * or with m_data not longword aligned.
647 	 * These could cause pointer alignment problems, so copy them to
648 	 * well aligned mbufs.
649 	 */
650 	nfs_realign(mp, 5 * NFSX_UNSIGNED);
651 	return (error);
652 }
653 
654 /*
655  * Implement receipt of reply on a socket.
656  * We must search through the list of received datagrams matching them
657  * with outstanding requests using the xid, until ours is found.
658  */
659 int
660 nfs_reply(myrep)
661 	struct nfsreq *myrep;
662 {
663 	struct nfsreq *rep;
664 	struct nfsmount *nmp = myrep->r_nmp;
665 	int32_t t1;
666 	struct mbuf *mrep, *nam, *md;
667 	u_int32_t rxid, *tl;
668 	caddr_t dpos, cp2;
669 	int s, error;
670 
671 	/*
672 	 * Loop around until we get our own reply
673 	 */
674 	for (;;) {
675 		/*
676 		 * Lock against other receivers so that I don't get stuck in
677 		 * sbwait() after someone else has received my reply for me.
678 		 * Also necessary for connection based protocols to avoid
679 		 * race conditions during a reconnect.
680 		 */
681 		error = nfs_rcvlock(myrep);
682 		if (error)
683 			return (error == EALREADY ? 0 : error);
684 
685 		/*
686 		 * Get the next Rpc reply off the socket
687 		 */
688 		error = nfs_receive(myrep, &nam, &mrep);
689 		nfs_rcvunlock(&nmp->nm_flag);
690 		if (error) {
691 
692 			/*
693 			 * Ignore routing errors on connectionless protocols??
694 			 */
695 			if (NFSIGNORE_SOERROR(nmp->nm_soflags, error)) {
696 				if (nmp->nm_so)
697 					nmp->nm_so->so_error = 0;
698 				continue;
699 			}
700 			return (error);
701 		}
702 		if (nam)
703 			m_freem(nam);
704 
705 		/*
706 		 * Get the xid and check that it is an rpc reply
707 		 */
708 		md = mrep;
709 		dpos = mtod(md, caddr_t);
710 		nfsm_dissect(tl, u_int32_t *, 2*NFSX_UNSIGNED);
711 		rxid = *tl++;
712 		if (*tl != rpc_reply) {
713 			nfsstats.rpcinvalid++;
714 			m_freem(mrep);
715 nfsmout:
716 			continue;
717 		}
718 
719 		/*
720 		 * Loop through the request list to match up the reply
721 		 * Iff no match, just drop the datagram
722 		 */
723 		s = splsoftnet();
724 		TAILQ_FOREACH(rep, &nfs_reqq, r_chain) {
725 			if (rep->r_mrep == NULL && rxid == rep->r_xid) {
726 				/* Found it.. */
727 				rep->r_mrep = mrep;
728 				rep->r_md = md;
729 				rep->r_dpos = dpos;
730 				if (nfsrtton) {
731 					struct rttl *rt;
732 
733 					rt = &nfsrtt.rttl[nfsrtt.pos];
734 					rt->proc = rep->r_procnum;
735 					rt->rto = NFS_RTO(nmp, proct[rep->r_procnum]);
736 					rt->sent = nmp->nm_sent;
737 					rt->cwnd = nmp->nm_cwnd;
738 					rt->srtt = nmp->nm_srtt[proct[rep->r_procnum] - 1];
739 					rt->sdrtt = nmp->nm_sdrtt[proct[rep->r_procnum] - 1];
740 					rt->fsid = nmp->nm_mountp->mnt_stat.f_fsid;
741 					getmicrotime(&rt->tstamp);
742 					if (rep->r_flags & R_TIMING)
743 						rt->rtt = rep->r_rtt;
744 					else
745 						rt->rtt = 1000000;
746 					nfsrtt.pos = (nfsrtt.pos + 1) % NFSRTTLOGSIZ;
747 				}
748 				/*
749 				 * Update congestion window.
750 				 * Do the additive increase of
751 				 * one rpc/rtt.
752 				 */
753 				if (nmp->nm_cwnd <= nmp->nm_sent) {
754 					nmp->nm_cwnd +=
755 					   (NFS_CWNDSCALE * NFS_CWNDSCALE +
756 					   (nmp->nm_cwnd >> 1)) / nmp->nm_cwnd;
757 					if (nmp->nm_cwnd > NFS_MAXCWND)
758 						nmp->nm_cwnd = NFS_MAXCWND;
759 				}
760 				rep->r_flags &= ~R_SENT;
761 				nmp->nm_sent -= NFS_CWNDSCALE;
762 				/*
763 				 * Update rtt using a gain of 0.125 on the mean
764 				 * and a gain of 0.25 on the deviation.
765 				 */
766 				if (rep->r_flags & R_TIMING) {
767 					/*
768 					 * Since the timer resolution of
769 					 * NFS_HZ is so course, it can often
770 					 * result in r_rtt == 0. Since
771 					 * r_rtt == N means that the actual
772 					 * rtt is between N+dt and N+2-dt ticks,
773 					 * add 1.
774 					 */
775 					t1 = rep->r_rtt + 1;
776 					t1 -= (NFS_SRTT(rep) >> 3);
777 					NFS_SRTT(rep) += t1;
778 					if (t1 < 0)
779 						t1 = -t1;
780 					t1 -= (NFS_SDRTT(rep) >> 2);
781 					NFS_SDRTT(rep) += t1;
782 				}
783 				nmp->nm_timeouts = 0;
784 				break;
785 			}
786 		}
787 		splx(s);
788 		/*
789 		 * If not matched to a request, drop it.
790 		 * If it's mine, get out.
791 		 */
792 		if (rep == 0) {
793 			nfsstats.rpcunexpected++;
794 			m_freem(mrep);
795 		} else if (rep == myrep) {
796 			if (rep->r_mrep == NULL)
797 				panic("nfsreply nil");
798 			return (0);
799 		}
800 	}
801 }
802 
803 /*
804  * nfs_request - goes something like this
805  *	- fill in request struct
806  *	- links it into list
807  *	- calls nfs_send() for first transmit
808  *	- calls nfs_receive() to get reply
809  *	- break down rpc header and return with nfs reply pointed to
810  *	  by mrep or error
811  * nb: always frees up mreq mbuf list
812  */
813 int
814 nfs_request(vp, mrest, procnum, procp, cred, mrp, mdp, dposp)
815 	struct vnode *vp;
816 	struct mbuf *mrest;
817 	int procnum;
818 	struct proc *procp;
819 	struct ucred *cred;
820 	struct mbuf **mrp;
821 	struct mbuf **mdp;
822 	caddr_t *dposp;
823 {
824 	struct mbuf *m;
825 	struct nfsreq *rep;
826 	int  mrest_len;
827 
828 	rep = pool_get(&nfsreqpl, PR_WAITOK);
829 	rep->r_nmp = VFSTONFS(vp->v_mount);
830 	rep->r_vp = vp;
831 	rep->r_procp = procp;
832 	rep->r_procnum = procnum;
833 
834 	mrest_len = 0;
835 	m = mrest;
836 	while (m) {
837 		mrest_len += m->m_len;
838 		m = m->m_next;
839 	}
840 
841 	/* empty mbuf for AUTH_UNIX header */
842 	rep->r_mreq = m_gethdr(M_WAIT, MT_DATA);
843 	rep->r_mreq->m_next = mrest;
844 	rep->r_mreq->m_pkthdr.len = mrest_len;
845 
846 	return (nfs_request1(rep, cred, mrp, mdp, dposp));
847 }
848 
849 int
850 nfs_request1(struct nfsreq *rep, struct ucred *cred, struct mbuf **mrp,
851     struct mbuf **mdp, caddr_t *dposp)
852 {
853 	struct mbuf *m, *mrep;
854 	u_int32_t *tl;
855 	struct nfsmount *nmp;
856 	struct mbuf *md;
857 	time_t waituntil;
858 	caddr_t dpos, cp2;
859 	int t1, i, s, error = 0;
860 	int trylater_delay;
861 
862 	trylater_delay = NFS_MINTIMEO;
863 
864 	nmp = rep->r_nmp;
865 
866 	/* Get the RPC header with authorization. */
867 	nfsm_rpchead(rep, cred, RPCAUTH_UNIX);
868 	m = rep->r_mreq;
869 
870 	/*
871 	 * For stream protocols, insert a Sun RPC Record Mark.
872 	 */
873 	if (nmp->nm_sotype == SOCK_STREAM) {
874 		M_PREPEND(m, NFSX_UNSIGNED, M_WAIT);
875 		*mtod(m, u_int32_t *) = htonl(0x80000000 |
876 			 (m->m_pkthdr.len - NFSX_UNSIGNED));
877 	}
878 
879 tryagain:
880 	if (nmp->nm_flag & NFSMNT_SOFT)
881 		rep->r_retry = nmp->nm_retry;
882 	else
883 		rep->r_retry = NFS_MAXREXMIT + 1;	/* past clip limit */
884 	rep->r_rtt = rep->r_rexmit = 0;
885 	if (proct[rep->r_procnum] > 0)
886 		rep->r_flags = R_TIMING;
887 	else
888 		rep->r_flags = 0;
889 	rep->r_mrep = NULL;
890 
891 	/*
892 	 * Do the client side RPC.
893 	 */
894 	nfsstats.rpcrequests++;
895 	/*
896 	 * Chain request into list of outstanding requests. Be sure
897 	 * to put it LAST so timer finds oldest requests first.
898 	 */
899 	s = splsoftnet();
900 	TAILQ_INSERT_TAIL(&nfs_reqq, rep, r_chain);
901 
902 	/*
903 	 * If backing off another request or avoiding congestion, don't
904 	 * send this one now but let timer do it. If not timing a request,
905 	 * do it now.
906 	 */
907 	if (nmp->nm_so && (nmp->nm_sotype != SOCK_DGRAM ||
908 		(nmp->nm_flag & NFSMNT_DUMBTIMR) ||
909 		nmp->nm_sent < nmp->nm_cwnd)) {
910 		splx(s);
911 		if (nmp->nm_soflags & PR_CONNREQUIRED)
912 			error = nfs_sndlock(&nmp->nm_flag, rep);
913 		if (!error) {
914 			error = nfs_send(nmp->nm_so, nmp->nm_nam,
915 					m_copym(m, 0, M_COPYALL, M_WAIT),
916 					rep);
917 			if (nmp->nm_soflags & PR_CONNREQUIRED)
918 				nfs_sndunlock(&nmp->nm_flag);
919 		}
920 		if (!error && (rep->r_flags & R_MUSTRESEND) == 0) {
921 			nmp->nm_sent += NFS_CWNDSCALE;
922 			rep->r_flags |= R_SENT;
923 		}
924 	} else {
925 		splx(s);
926 		rep->r_rtt = -1;
927 	}
928 
929 	/*
930 	 * Wait for the reply from our send or the timer's.
931 	 */
932 	if (!error || error == EPIPE)
933 		error = nfs_reply(rep);
934 
935 	/*
936 	 * RPC done, unlink the request.
937 	 */
938 	s = splsoftnet();
939 	TAILQ_REMOVE(&nfs_reqq, rep, r_chain);
940 	splx(s);
941 
942 	/*
943 	 * Decrement the outstanding request count.
944 	 */
945 	if (rep->r_flags & R_SENT) {
946 		rep->r_flags &= ~R_SENT;	/* paranoia */
947 		nmp->nm_sent -= NFS_CWNDSCALE;
948 	}
949 
950 	/*
951 	 * If there was a successful reply and a tprintf msg.
952 	 * tprintf a response.
953 	 */
954 	if (!error && (rep->r_flags & R_TPRINTFMSG))
955 		nfs_msg(rep, "is alive again");
956 	mrep = rep->r_mrep;
957 	md = rep->r_md;
958 	dpos = rep->r_dpos;
959 	if (error) {
960 		m_freem(rep->r_mreq);
961 		pool_put(&nfsreqpl, rep);
962 		return (error);
963 	}
964 
965 	/*
966 	 * break down the rpc header and check if ok
967 	 */
968 	nfsm_dissect(tl, u_int32_t *, 3 * NFSX_UNSIGNED);
969 	if (*tl++ == rpc_msgdenied) {
970 		if (*tl == rpc_mismatch)
971 			error = EOPNOTSUPP;
972 		else
973 			error = EACCES;
974 		m_freem(mrep);
975 		m_freem(rep->r_mreq);
976 		pool_put(&nfsreqpl, rep);
977 		return (error);
978 	}
979 
980 	/*
981 	 * Since we only support RPCAUTH_UNIX atm we step over the
982 	 * reply verifer type, and if the (error) case that there really
983 	 * is any data init, we advance over it.
984 	 */
985 	tl++;			/* Step over verifer type */
986 	i = fxdr_unsigned(int32_t, *tl);
987 	if (i > 0)
988 		nfsm_adv(nfsm_rndup(i));	/* Should not happen */
989 
990 	nfsm_dissect(tl, u_int32_t *, NFSX_UNSIGNED);
991 	/* 0 == ok */
992 	if (*tl == 0) {
993 		nfsm_dissect(tl, u_int32_t *, NFSX_UNSIGNED);
994 		if (*tl != 0) {
995 			error = fxdr_unsigned(int, *tl);
996 			if ((nmp->nm_flag & NFSMNT_NFSV3) &&
997 				error == NFSERR_TRYLATER) {
998 				m_freem(mrep);
999 				error = 0;
1000 				waituntil = time_second + trylater_delay;
1001 				while (time_second < waituntil)
1002 					(void) tsleep((caddr_t)&lbolt,
1003 						PSOCK, "nqnfstry", 0);
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 			if (nmp->nm_flag & NFSMNT_NFSV3 || error == ESTALE) {
1019 				*mrp = mrep;
1020 				*mdp = md;
1021 				*dposp = dpos;
1022 				error |= NFSERR_RETERR;
1023 			} else
1024 				m_freem(mrep);
1025 			m_freem(rep->r_mreq);
1026 			pool_put(&nfsreqpl, rep);
1027 			return (error);
1028 		}
1029 
1030 		*mrp = mrep;
1031 		*mdp = md;
1032 		*dposp = dpos;
1033 		m_freem(rep->r_mreq);
1034 		pool_put(&nfsreqpl, rep);
1035 		return (0);
1036 	}
1037 	m_freem(mrep);
1038 	error = EPROTONOSUPPORT;
1039 nfsmout:
1040 	m_freem(rep->r_mreq);
1041 	pool_put(&nfsreqpl, rep);
1042 	return (error);
1043 }
1044 #endif /* NFSCLIENT */
1045 
1046 /*
1047  * Generate the rpc reply header
1048  * siz arg. is used to decide if adding a cluster is worthwhile
1049  */
1050 int
1051 nfs_rephead(siz, nd, slp, err, mrq, mbp)
1052 	int siz;
1053 	struct nfsrv_descript *nd;
1054 	struct nfssvc_sock *slp;
1055 	int err;
1056 	struct mbuf **mrq;
1057 	struct mbuf **mbp;
1058 {
1059 	u_int32_t *tl;
1060 	struct mbuf *mreq;
1061 	struct mbuf *mb;
1062 
1063 	MGETHDR(mreq, M_WAIT, MT_DATA);
1064 	mb = mreq;
1065 	/*
1066 	 * If this is a big reply, use a cluster else
1067 	 * try and leave leading space for the lower level headers.
1068 	 */
1069 	siz += RPC_REPLYSIZ;
1070 	if (siz >= max_datalen) {
1071 		MCLGET(mreq, M_WAIT);
1072 	} else
1073 		mreq->m_data += max_hdr;
1074 	tl = mtod(mreq, u_int32_t *);
1075 	mreq->m_len = 6 * NFSX_UNSIGNED;
1076 	*tl++ = txdr_unsigned(nd->nd_retxid);
1077 	*tl++ = rpc_reply;
1078 	if (err == ERPCMISMATCH || (err & NFSERR_AUTHERR)) {
1079 		*tl++ = rpc_msgdenied;
1080 		if (err & NFSERR_AUTHERR) {
1081 			*tl++ = rpc_autherr;
1082 			*tl = txdr_unsigned(err & ~NFSERR_AUTHERR);
1083 			mreq->m_len -= NFSX_UNSIGNED;
1084 		} else {
1085 			*tl++ = rpc_mismatch;
1086 			*tl++ = txdr_unsigned(RPC_VER2);
1087 			*tl = txdr_unsigned(RPC_VER2);
1088 		}
1089 	} else {
1090 		*tl++ = rpc_msgaccepted;
1091 
1092 		/* AUTH_UNIX requires RPCAUTH_NULL. */
1093 		*tl++ = 0;
1094 		*tl++ = 0;
1095 
1096 		switch (err) {
1097 		case EPROGUNAVAIL:
1098 			*tl = txdr_unsigned(RPC_PROGUNAVAIL);
1099 			break;
1100 		case EPROGMISMATCH:
1101 			*tl = txdr_unsigned(RPC_PROGMISMATCH);
1102 			tl = nfsm_build(&mb, 2 * NFSX_UNSIGNED);
1103 			*tl++ = txdr_unsigned(NFS_VER2);
1104 			*tl = txdr_unsigned(NFS_VER3);
1105 			break;
1106 		case EPROCUNAVAIL:
1107 			*tl = txdr_unsigned(RPC_PROCUNAVAIL);
1108 			break;
1109 		case EBADRPC:
1110 			*tl = txdr_unsigned(RPC_GARBAGE);
1111 			break;
1112 		default:
1113 			*tl = 0;
1114 			if (err != NFSERR_RETVOID) {
1115 				tl = nfsm_build(&mb, NFSX_UNSIGNED);
1116 				if (err)
1117 				    *tl = txdr_unsigned(nfsrv_errmap(nd, err));
1118 				else
1119 				    *tl = 0;
1120 			}
1121 			break;
1122 		};
1123 	}
1124 
1125 	*mrq = mreq;
1126 	if (mbp != NULL)
1127 		*mbp = mb;
1128 	if (err != 0 && err != NFSERR_RETVOID)
1129 		nfsstats.srvrpc_errs++;
1130 	return (0);
1131 }
1132 
1133 /*
1134  * Nfs timer routine
1135  * Scan the nfsreq list and retranmit any requests that have timed out
1136  * To avoid retransmission attempts on STREAM sockets (in the future) make
1137  * sure to set the r_retry field to 0 (implies nm_retry == 0).
1138  */
1139 void
1140 nfs_timer(arg)
1141 	void *arg;
1142 {
1143 	struct timeout *to = (struct timeout *)arg;
1144 	struct nfsreq *rep;
1145 	struct mbuf *m;
1146 	struct socket *so;
1147 	struct nfsmount *nmp;
1148 	int timeo;
1149 	int s, error;
1150 #ifdef NFSSERVER
1151 	struct nfssvc_sock *slp;
1152 	struct timeval tv;
1153 #endif
1154 
1155 	s = splsoftnet();
1156 	TAILQ_FOREACH(rep, &nfs_reqq, r_chain) {
1157 		nmp = rep->r_nmp;
1158 		if (rep->r_mrep || (rep->r_flags & R_SOFTTERM))
1159 			continue;
1160 		if (nfs_sigintr(nmp, rep, rep->r_procp)) {
1161 			rep->r_flags |= R_SOFTTERM;
1162 			continue;
1163 		}
1164 		if (rep->r_rtt >= 0) {
1165 			rep->r_rtt++;
1166 			if (nmp->nm_flag & NFSMNT_DUMBTIMR)
1167 				timeo = nmp->nm_timeo;
1168 			else
1169 				timeo = NFS_RTO(nmp, proct[rep->r_procnum]);
1170 			if (nmp->nm_timeouts > 0)
1171 				timeo *= nfs_backoff[nmp->nm_timeouts - 1];
1172 			if (rep->r_rtt <= timeo)
1173 				continue;
1174 			if (nmp->nm_timeouts < nitems(nfs_backoff))
1175 				nmp->nm_timeouts++;
1176 		}
1177 		/*
1178 		 * Check for server not responding
1179 		 */
1180 		if ((rep->r_flags & R_TPRINTFMSG) == 0 &&
1181 		     rep->r_rexmit > nmp->nm_deadthresh) {
1182 			nfs_msg(rep, "not responding");
1183 			rep->r_flags |= R_TPRINTFMSG;
1184 		}
1185 		if (rep->r_rexmit >= rep->r_retry) {	/* too many */
1186 			nfsstats.rpctimeouts++;
1187 			rep->r_flags |= R_SOFTTERM;
1188 			continue;
1189 		}
1190 		if (nmp->nm_sotype != SOCK_DGRAM) {
1191 			if (++rep->r_rexmit > NFS_MAXREXMIT)
1192 				rep->r_rexmit = NFS_MAXREXMIT;
1193 			continue;
1194 		}
1195 		if ((so = nmp->nm_so) == NULL)
1196 			continue;
1197 
1198 		/*
1199 		 * If there is enough space and the window allows..
1200 		 *	Resend it
1201 		 * Set r_rtt to -1 in case we fail to send it now.
1202 		 */
1203 		rep->r_rtt = -1;
1204 		if (sbspace(&so->so_snd) >= rep->r_mreq->m_pkthdr.len &&
1205 		   ((nmp->nm_flag & NFSMNT_DUMBTIMR) ||
1206 		    (rep->r_flags & R_SENT) ||
1207 		    nmp->nm_sent < nmp->nm_cwnd) &&
1208 		   (m = m_copym(rep->r_mreq, 0, M_COPYALL, M_DONTWAIT))){
1209 			if ((nmp->nm_flag & NFSMNT_NOCONN) == 0)
1210 			    error = (*so->so_proto->pr_usrreq)(so, PRU_SEND, m,
1211 			    (struct mbuf *)0, (struct mbuf *)0, curproc);
1212 			else
1213 			    error = (*so->so_proto->pr_usrreq)(so, PRU_SEND, m,
1214 			    nmp->nm_nam, (struct mbuf *)0, curproc);
1215 			if (error) {
1216 				if (NFSIGNORE_SOERROR(nmp->nm_soflags, error))
1217 					so->so_error = 0;
1218 			} else {
1219 				/*
1220 				 * Iff first send, start timing
1221 				 * else turn timing off, backoff timer
1222 				 * and divide congestion window by 2.
1223 				 */
1224 				if (rep->r_flags & R_SENT) {
1225 					rep->r_flags &= ~R_TIMING;
1226 					if (++rep->r_rexmit > NFS_MAXREXMIT)
1227 						rep->r_rexmit = NFS_MAXREXMIT;
1228 					nmp->nm_cwnd >>= 1;
1229 					if (nmp->nm_cwnd < NFS_CWNDSCALE)
1230 						nmp->nm_cwnd = NFS_CWNDSCALE;
1231 					nfsstats.rpcretries++;
1232 				} else {
1233 					rep->r_flags |= R_SENT;
1234 					nmp->nm_sent += NFS_CWNDSCALE;
1235 				}
1236 				rep->r_rtt = 0;
1237 			}
1238 		}
1239 	}
1240 
1241 #ifdef NFSSERVER
1242 	/*
1243 	 * Scan the write gathering queues for writes that need to be
1244 	 * completed now.
1245 	 */
1246 	getmicrotime(&tv);
1247 	TAILQ_FOREACH(slp, &nfssvc_sockhead, ns_chain) {
1248 		if (LIST_FIRST(&slp->ns_tq) &&
1249 		    timercmp(&LIST_FIRST(&slp->ns_tq)->nd_time, &tv, <=))
1250 			nfsrv_wakenfsd(slp);
1251 	}
1252 #endif /* NFSSERVER */
1253 	splx(s);
1254 	timeout_add(to, nfs_ticks);
1255 }
1256 
1257 /*
1258  * Test for a termination condition pending on the process.
1259  * This is used for NFSMNT_INT mounts.
1260  */
1261 int
1262 nfs_sigintr(nmp, rep, p)
1263 	struct nfsmount *nmp;
1264 	struct nfsreq *rep;
1265 	struct proc *p;
1266 {
1267 
1268 	if (rep && (rep->r_flags & R_SOFTTERM))
1269 		return (EINTR);
1270 	if (!(nmp->nm_flag & NFSMNT_INT))
1271 		return (0);
1272 	if (p && p->p_siglist &&
1273 	    (((p->p_siglist & ~p->p_sigmask) & ~p->p_sigignore) &
1274 	    NFSINT_SIGMASK))
1275 		return (EINTR);
1276 	return (0);
1277 }
1278 
1279 /*
1280  * Lock a socket against others.
1281  * Necessary for STREAM sockets to ensure you get an entire rpc request/reply
1282  * and also to avoid race conditions between the processes with nfs requests
1283  * in progress when a reconnect is necessary.
1284  */
1285 int
1286 nfs_sndlock(flagp, rep)
1287 	int *flagp;
1288 	struct nfsreq *rep;
1289 {
1290 	struct proc *p;
1291 	int slpflag = 0, slptimeo = 0;
1292 
1293 	if (rep) {
1294 		p = rep->r_procp;
1295 		if (rep->r_nmp->nm_flag & NFSMNT_INT)
1296 			slpflag = PCATCH;
1297 	} else
1298 		p = (struct proc *)0;
1299 	while (*flagp & NFSMNT_SNDLOCK) {
1300 		if (rep && nfs_sigintr(rep->r_nmp, rep, p))
1301 			return (EINTR);
1302 		*flagp |= NFSMNT_WANTSND;
1303 		(void) tsleep((caddr_t)flagp, slpflag | (PZERO - 1), "nfsndlck",
1304 			slptimeo);
1305 		if (slpflag == PCATCH) {
1306 			slpflag = 0;
1307 			slptimeo = 2 * hz;
1308 		}
1309 	}
1310 	*flagp |= NFSMNT_SNDLOCK;
1311 	return (0);
1312 }
1313 
1314 /*
1315  * Unlock the stream socket for others.
1316  */
1317 void
1318 nfs_sndunlock(flagp)
1319 	int *flagp;
1320 {
1321 
1322 	if ((*flagp & NFSMNT_SNDLOCK) == 0)
1323 		panic("nfs sndunlock");
1324 	*flagp &= ~NFSMNT_SNDLOCK;
1325 	if (*flagp & NFSMNT_WANTSND) {
1326 		*flagp &= ~NFSMNT_WANTSND;
1327 		wakeup((caddr_t)flagp);
1328 	}
1329 }
1330 
1331 int
1332 nfs_rcvlock(rep)
1333 	struct nfsreq *rep;
1334 {
1335 	int *flagp = &rep->r_nmp->nm_flag;
1336 	int slpflag, slptimeo = 0;
1337 
1338 	if (*flagp & NFSMNT_INT)
1339 		slpflag = PCATCH;
1340 	else
1341 		slpflag = 0;
1342 
1343 	while (*flagp & NFSMNT_RCVLOCK) {
1344 		if (nfs_sigintr(rep->r_nmp, rep, rep->r_procp))
1345 			return (EINTR);
1346 		*flagp |= NFSMNT_WANTRCV;
1347 		(void) tsleep((caddr_t)flagp, slpflag | (PZERO - 1), "nfsrcvlk",
1348 			slptimeo);
1349 		if (rep->r_mrep != NULL) {
1350 			/*
1351 			 * Don't take the lock if our reply has been received
1352 			 * while we where sleeping.
1353 			 */
1354 			 return (EALREADY);
1355 		}
1356 		if (slpflag == PCATCH) {
1357 			slpflag = 0;
1358 			slptimeo = 2 * hz;
1359 		}
1360 	}
1361 	*flagp |= NFSMNT_RCVLOCK;
1362 	return (0);
1363 }
1364 
1365 /*
1366  * Unlock the stream socket for others.
1367  */
1368 void
1369 nfs_rcvunlock(flagp)
1370 	int *flagp;
1371 {
1372 
1373 	if ((*flagp & NFSMNT_RCVLOCK) == 0)
1374 		panic("nfs rcvunlock");
1375 	*flagp &= ~NFSMNT_RCVLOCK;
1376 	if (*flagp & NFSMNT_WANTRCV) {
1377 		*flagp &= ~NFSMNT_WANTRCV;
1378 		wakeup((caddr_t)flagp);
1379 	}
1380 }
1381 
1382 /*
1383  * Auxiliary routine to align the length of mbuf copies made with m_copyback().
1384  */
1385 void
1386 nfs_realign_fixup(struct mbuf *m, struct mbuf *n, unsigned int *off)
1387 {
1388 	size_t padding;
1389 
1390 	/*
1391 	 * The maximum number of bytes that m_copyback() places in a mbuf is
1392 	 * always an aligned quantity, so realign happens at the chain's tail.
1393 	 */
1394 	while (n->m_next != NULL)
1395 		n = n->m_next;
1396 
1397 	/*
1398 	 * Pad from the next elements in the source chain. Loop until the
1399 	 * destination chain is aligned, or the end of the source is reached.
1400 	 */
1401 	do {
1402 		m = m->m_next;
1403 		if (m == NULL)
1404 			return;
1405 
1406 		padding = min(ALIGN(n->m_len) - n->m_len, m->m_len);
1407 		if (padding > M_TRAILINGSPACE(n))
1408 			panic("nfs_realign_fixup: no memory to pad to");
1409 
1410 		bcopy(mtod(m, void *), mtod(n, char *) + n->m_len, padding);
1411 
1412 		n->m_len += padding;
1413 		m_adj(m, padding);
1414 		*off += padding;
1415 
1416 	} while (!ALIGNED_POINTER(n->m_len, void *));
1417 }
1418 
1419 /*
1420  * The NFS RPC parsing code uses the data address and the length of mbuf
1421  * structures to calculate on-memory addresses. This function makes sure these
1422  * parameters are correctly aligned.
1423  */
1424 void
1425 nfs_realign(struct mbuf **pm, int hsiz)
1426 {
1427 	struct mbuf *m;
1428 	struct mbuf *n = NULL;
1429 	unsigned int off = 0;
1430 
1431 	++nfs_realign_test;
1432 	while ((m = *pm) != NULL) {
1433 		if (!ALIGNED_POINTER(m->m_data, void *) ||
1434 		    !ALIGNED_POINTER(m->m_len,  void *)) {
1435 			MGET(n, M_WAIT, MT_DATA);
1436 			if (ALIGN(m->m_len) >= MINCLSIZE) {
1437 				MCLGET(n, M_WAIT);
1438 			}
1439 			n->m_len = 0;
1440 			break;
1441 		}
1442 		pm = &m->m_next;
1443 	}
1444 	/*
1445 	 * If n is non-NULL, loop on m copying data, then replace the
1446 	 * portion of the chain that had to be realigned.
1447 	 */
1448 	if (n != NULL) {
1449 		++nfs_realign_count;
1450 		while (m) {
1451 			m_copyback(n, off, m->m_len, mtod(m, caddr_t));
1452 
1453 			/*
1454 			 * If an unaligned amount of memory was copied, fix up
1455 			 * the last mbuf created by m_copyback().
1456 			 */
1457 			if (!ALIGNED_POINTER(m->m_len, void *))
1458 				nfs_realign_fixup(m, n, &off);
1459 
1460 			off += m->m_len;
1461 			m = m->m_next;
1462 		}
1463 		m_freem(*pm);
1464 		*pm = n;
1465 	}
1466 }
1467 
1468 
1469 /*
1470  * Parse an RPC request
1471  * - verify it
1472  * - fill in the cred struct.
1473  */
1474 int
1475 nfs_getreq(nd, nfsd, has_header)
1476 	struct nfsrv_descript *nd;
1477 	struct nfsd *nfsd;
1478 	int has_header;
1479 {
1480 	int len, i;
1481 	u_int32_t *tl;
1482 	int32_t t1;
1483 	caddr_t dpos, cp2;
1484 	u_int32_t nfsvers, auth_type;
1485 	int error = 0;
1486 	struct mbuf *mrep, *md;
1487 
1488 	mrep = nd->nd_mrep;
1489 	md = nd->nd_md;
1490 	dpos = nd->nd_dpos;
1491 	if (has_header) {
1492 		nfsm_dissect(tl, u_int32_t *, 10 * NFSX_UNSIGNED);
1493 		nd->nd_retxid = fxdr_unsigned(u_int32_t, *tl++);
1494 		if (*tl++ != rpc_call) {
1495 			m_freem(mrep);
1496 			return (EBADRPC);
1497 		}
1498 	} else
1499 		nfsm_dissect(tl, u_int32_t *, 8 * NFSX_UNSIGNED);
1500 	nd->nd_repstat = 0;
1501 	nd->nd_flag = 0;
1502 	if (*tl++ != rpc_vers) {
1503 		nd->nd_repstat = ERPCMISMATCH;
1504 		nd->nd_procnum = NFSPROC_NOOP;
1505 		return (0);
1506 	}
1507 	if (*tl != nfs_prog) {
1508 		nd->nd_repstat = EPROGUNAVAIL;
1509 		nd->nd_procnum = NFSPROC_NOOP;
1510 		return (0);
1511 	}
1512 	tl++;
1513 	nfsvers = fxdr_unsigned(u_int32_t, *tl++);
1514 	if (nfsvers != NFS_VER2 && nfsvers != NFS_VER3) {
1515 		nd->nd_repstat = EPROGMISMATCH;
1516 		nd->nd_procnum = NFSPROC_NOOP;
1517 		return (0);
1518 	}
1519 	if (nfsvers == NFS_VER3)
1520 		nd->nd_flag = ND_NFSV3;
1521 	nd->nd_procnum = fxdr_unsigned(u_int32_t, *tl++);
1522 	if (nd->nd_procnum == NFSPROC_NULL)
1523 		return (0);
1524 	if (nd->nd_procnum >= NFS_NPROCS ||
1525 		(nd->nd_procnum > NFSPROC_COMMIT) ||
1526 		(!nd->nd_flag && nd->nd_procnum > NFSV2PROC_STATFS)) {
1527 		nd->nd_repstat = EPROCUNAVAIL;
1528 		nd->nd_procnum = NFSPROC_NOOP;
1529 		return (0);
1530 	}
1531 	if ((nd->nd_flag & ND_NFSV3) == 0)
1532 		nd->nd_procnum = nfsv3_procid[nd->nd_procnum];
1533 	auth_type = *tl++;
1534 	len = fxdr_unsigned(int, *tl++);
1535 	if (len < 0 || len > RPCAUTH_MAXSIZ) {
1536 		m_freem(mrep);
1537 		return (EBADRPC);
1538 	}
1539 
1540 	/* Handle auth_unix */
1541 	if (auth_type == rpc_auth_unix) {
1542 		len = fxdr_unsigned(int, *++tl);
1543 		if (len < 0 || len > NFS_MAXNAMLEN) {
1544 			m_freem(mrep);
1545 			return (EBADRPC);
1546 		}
1547 		nfsm_adv(nfsm_rndup(len));
1548 		nfsm_dissect(tl, u_int32_t *, 3 * NFSX_UNSIGNED);
1549 		bzero((caddr_t)&nd->nd_cr, sizeof (struct ucred));
1550 		nd->nd_cr.cr_ref = 1;
1551 		nd->nd_cr.cr_uid = fxdr_unsigned(uid_t, *tl++);
1552 		nd->nd_cr.cr_gid = fxdr_unsigned(gid_t, *tl++);
1553 		len = fxdr_unsigned(int, *tl);
1554 		if (len < 0 || len > RPCAUTH_UNIXGIDS) {
1555 			m_freem(mrep);
1556 			return (EBADRPC);
1557 		}
1558 		nfsm_dissect(tl, u_int32_t *, (len + 2) * NFSX_UNSIGNED);
1559 		for (i = 0; i < len; i++)
1560 		    if (i < NGROUPS)
1561 			nd->nd_cr.cr_groups[i] = fxdr_unsigned(gid_t, *tl++);
1562 		    else
1563 			tl++;
1564 		nd->nd_cr.cr_ngroups = (len > NGROUPS) ? NGROUPS : len;
1565 		if (nd->nd_cr.cr_ngroups > 1)
1566 		    nfsrvw_sort(nd->nd_cr.cr_groups, nd->nd_cr.cr_ngroups);
1567 		len = fxdr_unsigned(int, *++tl);
1568 		if (len < 0 || len > RPCAUTH_MAXSIZ) {
1569 			m_freem(mrep);
1570 			return (EBADRPC);
1571 		}
1572 		if (len > 0)
1573 			nfsm_adv(nfsm_rndup(len));
1574 	} else {
1575 		nd->nd_repstat = (NFSERR_AUTHERR | AUTH_REJECTCRED);
1576 		nd->nd_procnum = NFSPROC_NOOP;
1577 		return (0);
1578 	}
1579 
1580 	nd->nd_md = md;
1581 	nd->nd_dpos = dpos;
1582 	return (0);
1583 nfsmout:
1584 	return (error);
1585 }
1586 
1587 void
1588 nfs_msg(struct nfsreq *rep, char *msg)
1589 {
1590 	tpr_t tpr;
1591 
1592 	if (rep->r_procp)
1593 		tpr = tprintf_open(rep->r_procp);
1594 	else
1595 		tpr = NULL;
1596 
1597 	tprintf(tpr, "nfs server %s: %s\n",
1598 	    rep->r_nmp->nm_mountp->mnt_stat.f_mntfromname, msg);
1599 	tprintf_close(tpr);
1600 }
1601 
1602 #ifdef NFSSERVER
1603 /*
1604  * Socket upcall routine for the nfsd sockets.
1605  * The caddr_t arg is a pointer to the "struct nfssvc_sock".
1606  * Essentially do as much as possible non-blocking, else punt and it will
1607  * be called with M_WAIT from an nfsd.
1608  */
1609 void
1610 nfsrv_rcv(so, arg, waitflag)
1611 	struct socket *so;
1612 	caddr_t arg;
1613 	int waitflag;
1614 {
1615 	struct nfssvc_sock *slp = (struct nfssvc_sock *)arg;
1616 	struct mbuf *m;
1617 	struct mbuf *mp, *nam;
1618 	struct uio auio;
1619 	int flags, error;
1620 
1621 	if ((slp->ns_flag & SLP_VALID) == 0)
1622 		return;
1623 #ifdef notdef
1624 	/*
1625 	 * Define this to test for nfsds handling this under heavy load.
1626 	 */
1627 	if (waitflag == M_DONTWAIT) {
1628 		slp->ns_flag |= SLP_NEEDQ; goto dorecs;
1629 	}
1630 #endif
1631 	auio.uio_procp = NULL;
1632 	if (so->so_type == SOCK_STREAM) {
1633 		/*
1634 		 * If there are already records on the queue, defer soreceive()
1635 		 * to an nfsd so that there is feedback to the TCP layer that
1636 		 * the nfs servers are heavily loaded.
1637 		 */
1638 		if (slp->ns_rec && waitflag == M_DONTWAIT) {
1639 			slp->ns_flag |= SLP_NEEDQ;
1640 			goto dorecs;
1641 		}
1642 
1643 		/*
1644 		 * Do soreceive().
1645 		 */
1646 		auio.uio_resid = 1000000000;
1647 		flags = MSG_DONTWAIT;
1648 		error = soreceive(so, &nam, &auio, &mp, (struct mbuf **)0,
1649 		    &flags, 0);
1650 		if (error || mp == (struct mbuf *)0) {
1651 			if (error == EWOULDBLOCK)
1652 				slp->ns_flag |= SLP_NEEDQ;
1653 			else
1654 				slp->ns_flag |= SLP_DISCONN;
1655 			goto dorecs;
1656 		}
1657 		m = mp;
1658 		if (slp->ns_rawend) {
1659 			slp->ns_rawend->m_next = m;
1660 			slp->ns_cc += 1000000000 - auio.uio_resid;
1661 		} else {
1662 			slp->ns_raw = m;
1663 			slp->ns_cc = 1000000000 - auio.uio_resid;
1664 		}
1665 		while (m->m_next)
1666 			m = m->m_next;
1667 		slp->ns_rawend = m;
1668 
1669 		/*
1670 		 * Now try and parse record(s) out of the raw stream data.
1671 		 */
1672 		error = nfsrv_getstream(slp, waitflag);
1673 		if (error) {
1674 			if (error == EPERM)
1675 				slp->ns_flag |= SLP_DISCONN;
1676 			else
1677 				slp->ns_flag |= SLP_NEEDQ;
1678 		}
1679 	} else {
1680 		do {
1681 			auio.uio_resid = 1000000000;
1682 			flags = MSG_DONTWAIT;
1683 			error = soreceive(so, &nam, &auio, &mp,
1684 			    (struct mbuf **)0, &flags, 0);
1685 			if (mp) {
1686 				if (nam) {
1687 					m = nam;
1688 					m->m_next = mp;
1689 				} else
1690 					m = mp;
1691 				if (slp->ns_recend)
1692 					slp->ns_recend->m_nextpkt = m;
1693 				else
1694 					slp->ns_rec = m;
1695 				slp->ns_recend = m;
1696 				m->m_nextpkt = (struct mbuf *)0;
1697 			}
1698 			if (error) {
1699 				if ((so->so_proto->pr_flags & PR_CONNREQUIRED)
1700 					&& error != EWOULDBLOCK) {
1701 					slp->ns_flag |= SLP_DISCONN;
1702 					goto dorecs;
1703 				}
1704 			}
1705 		} while (mp);
1706 	}
1707 
1708 	/*
1709 	 * Now try and process the request records, non-blocking.
1710 	 */
1711 dorecs:
1712 	if (waitflag == M_DONTWAIT &&
1713 		(slp->ns_rec || (slp->ns_flag & (SLP_NEEDQ | SLP_DISCONN))))
1714 		nfsrv_wakenfsd(slp);
1715 }
1716 
1717 /*
1718  * Try and extract an RPC request from the mbuf data list received on a
1719  * stream socket. The "waitflag" argument indicates whether or not it
1720  * can sleep.
1721  */
1722 int
1723 nfsrv_getstream(slp, waitflag)
1724 	struct nfssvc_sock *slp;
1725 	int waitflag;
1726 {
1727 	struct mbuf *m, **mpp;
1728 	char *cp1, *cp2;
1729 	int len;
1730 	struct mbuf *om, *m2, *recm;
1731 	u_int32_t recmark;
1732 
1733 	if (slp->ns_flag & SLP_GETSTREAM)
1734 		panic("nfs getstream");
1735 	slp->ns_flag |= SLP_GETSTREAM;
1736 	for (;;) {
1737 	    if (slp->ns_reclen == 0) {
1738 		if (slp->ns_cc < NFSX_UNSIGNED) {
1739 			slp->ns_flag &= ~SLP_GETSTREAM;
1740 			return (0);
1741 		}
1742 		m = slp->ns_raw;
1743 		if (m->m_len >= NFSX_UNSIGNED) {
1744 			bcopy(mtod(m, caddr_t), (caddr_t)&recmark, NFSX_UNSIGNED);
1745 			m->m_data += NFSX_UNSIGNED;
1746 			m->m_len -= NFSX_UNSIGNED;
1747 		} else {
1748 			cp1 = (caddr_t)&recmark;
1749 			cp2 = mtod(m, caddr_t);
1750 			while (cp1 < ((caddr_t)&recmark) + NFSX_UNSIGNED) {
1751 				while (m->m_len == 0) {
1752 					m = m->m_next;
1753 					cp2 = mtod(m, caddr_t);
1754 				}
1755 				*cp1++ = *cp2++;
1756 				m->m_data++;
1757 				m->m_len--;
1758 			}
1759 		}
1760 		slp->ns_cc -= NFSX_UNSIGNED;
1761 		recmark = ntohl(recmark);
1762 		slp->ns_reclen = recmark & ~0x80000000;
1763 		if (recmark & 0x80000000)
1764 			slp->ns_flag |= SLP_LASTFRAG;
1765 		else
1766 			slp->ns_flag &= ~SLP_LASTFRAG;
1767 		if (slp->ns_reclen > NFS_MAXPACKET) {
1768 			slp->ns_flag &= ~SLP_GETSTREAM;
1769 			return (EPERM);
1770 		}
1771 	    }
1772 
1773 	    /*
1774 	     * Now get the record part.
1775 	     */
1776 	    recm = NULL;
1777 	    if (slp->ns_cc == slp->ns_reclen) {
1778 		recm = slp->ns_raw;
1779 		slp->ns_raw = slp->ns_rawend = (struct mbuf *)0;
1780 		slp->ns_cc = slp->ns_reclen = 0;
1781 	    } else if (slp->ns_cc > slp->ns_reclen) {
1782 		len = 0;
1783 		m = slp->ns_raw;
1784 		om = (struct mbuf *)0;
1785 		while (len < slp->ns_reclen) {
1786 			if ((len + m->m_len) > slp->ns_reclen) {
1787 				m2 = m_copym(m, 0, slp->ns_reclen - len,
1788 					waitflag);
1789 				if (m2) {
1790 					if (om) {
1791 						om->m_next = m2;
1792 						recm = slp->ns_raw;
1793 					} else
1794 						recm = m2;
1795 					m->m_data += slp->ns_reclen - len;
1796 					m->m_len -= slp->ns_reclen - len;
1797 					len = slp->ns_reclen;
1798 				} else {
1799 					slp->ns_flag &= ~SLP_GETSTREAM;
1800 					return (EWOULDBLOCK);
1801 				}
1802 			} else if ((len + m->m_len) == slp->ns_reclen) {
1803 				om = m;
1804 				len += m->m_len;
1805 				m = m->m_next;
1806 				recm = slp->ns_raw;
1807 				om->m_next = (struct mbuf *)0;
1808 			} else {
1809 				om = m;
1810 				len += m->m_len;
1811 				m = m->m_next;
1812 			}
1813 		}
1814 		slp->ns_raw = m;
1815 		slp->ns_cc -= len;
1816 		slp->ns_reclen = 0;
1817 	    } else {
1818 		slp->ns_flag &= ~SLP_GETSTREAM;
1819 		return (0);
1820 	    }
1821 
1822 	    /*
1823 	     * Accumulate the fragments into a record.
1824 	     */
1825 	    mpp = &slp->ns_frag;
1826 	    while (*mpp)
1827 		mpp = &((*mpp)->m_next);
1828 	    *mpp = recm;
1829 	    if (slp->ns_flag & SLP_LASTFRAG) {
1830 		if (slp->ns_recend)
1831 		    slp->ns_recend->m_nextpkt = slp->ns_frag;
1832 		else
1833 		    slp->ns_rec = slp->ns_frag;
1834 		slp->ns_recend = slp->ns_frag;
1835 		slp->ns_frag = (struct mbuf *)0;
1836 	    }
1837 	}
1838 }
1839 
1840 /*
1841  * Parse an RPC header.
1842  */
1843 int
1844 nfsrv_dorec(slp, nfsd, ndp)
1845 	struct nfssvc_sock *slp;
1846 	struct nfsd *nfsd;
1847 	struct nfsrv_descript **ndp;
1848 {
1849 	struct mbuf *m, *nam;
1850 	struct nfsrv_descript *nd;
1851 	int error;
1852 
1853 	*ndp = NULL;
1854 	if ((slp->ns_flag & SLP_VALID) == 0 ||
1855 	    (m = slp->ns_rec) == (struct mbuf *)0)
1856 		return (ENOBUFS);
1857 	slp->ns_rec = m->m_nextpkt;
1858 	if (slp->ns_rec)
1859 		m->m_nextpkt = (struct mbuf *)0;
1860 	else
1861 		slp->ns_recend = (struct mbuf *)0;
1862 	if (m->m_type == MT_SONAME) {
1863 		nam = m;
1864 		m = m->m_next;
1865 		nam->m_next = NULL;
1866 	} else
1867 		nam = NULL;
1868 	nd = malloc(sizeof(struct nfsrv_descript), M_NFSRVDESC, M_WAITOK);
1869 	nfs_realign(&m, 10 * NFSX_UNSIGNED);
1870 	nd->nd_md = nd->nd_mrep = m;
1871 	nd->nd_nam2 = nam;
1872 	nd->nd_dpos = mtod(m, caddr_t);
1873 	error = nfs_getreq(nd, nfsd, 1);
1874 	if (error) {
1875 		m_freem(nam);
1876 		free(nd, M_NFSRVDESC);
1877 		return (error);
1878 	}
1879 	*ndp = nd;
1880 	nfsd->nfsd_nd = nd;
1881 	return (0);
1882 }
1883 
1884 
1885 /*
1886  * Search for a sleeping nfsd and wake it up.
1887  * SIDE EFFECT: If none found, set NFSD_CHECKSLP flag, so that one of the
1888  * running nfsds will go look for the work in the nfssvc_sock list.
1889  */
1890 void
1891 nfsrv_wakenfsd(struct nfssvc_sock *slp)
1892 {
1893 	struct nfsd	*nfsd;
1894 
1895 	if ((slp->ns_flag & SLP_VALID) == 0)
1896 		return;
1897 
1898 	TAILQ_FOREACH(nfsd, &nfsd_head, nfsd_chain) {
1899 		if (nfsd->nfsd_flag & NFSD_WAITING) {
1900 			nfsd->nfsd_flag &= ~NFSD_WAITING;
1901 			if (nfsd->nfsd_slp)
1902 				panic("nfsd wakeup");
1903 			slp->ns_sref++;
1904 			nfsd->nfsd_slp = slp;
1905 			wakeup_one(nfsd);
1906 			return;
1907 		}
1908 	}
1909 
1910 	slp->ns_flag |= SLP_DOREC;
1911 	nfsd_head_flag |= NFSD_CHECKSLP;
1912 }
1913 #endif /* NFSSERVER */
1914