xref: /dragonfly/sys/vfs/nfs/nfs_socket.c (revision 23265324)
1 /*
2  * Copyright (c) 1989, 1991, 1993, 1995
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * Rick Macklem at The University of Guelph.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by the University of
19  *	California, Berkeley and its contributors.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  *
36  *	@(#)nfs_socket.c	8.5 (Berkeley) 3/30/95
37  * $FreeBSD: src/sys/nfs/nfs_socket.c,v 1.60.2.6 2003/03/26 01:44:46 alfred Exp $
38  * $DragonFly: src/sys/vfs/nfs/nfs_socket.c,v 1.40 2007/02/03 17:05:59 corecode Exp $
39  */
40 
41 /*
42  * Socket operations for use by nfs
43  */
44 
45 #include <sys/param.h>
46 #include <sys/systm.h>
47 #include <sys/proc.h>
48 #include <sys/malloc.h>
49 #include <sys/mount.h>
50 #include <sys/kernel.h>
51 #include <sys/mbuf.h>
52 #include <sys/vnode.h>
53 #include <sys/fcntl.h>
54 #include <sys/protosw.h>
55 #include <sys/resourcevar.h>
56 #include <sys/socket.h>
57 #include <sys/socketvar.h>
58 #include <sys/socketops.h>
59 #include <sys/syslog.h>
60 #include <sys/thread.h>
61 #include <sys/tprintf.h>
62 #include <sys/sysctl.h>
63 #include <sys/signalvar.h>
64 
65 #include <netinet/in.h>
66 #include <netinet/tcp.h>
67 #include <sys/thread2.h>
68 
69 #include "rpcv2.h"
70 #include "nfsproto.h"
71 #include "nfs.h"
72 #include "xdr_subs.h"
73 #include "nfsm_subs.h"
74 #include "nfsmount.h"
75 #include "nfsnode.h"
76 #include "nfsrtt.h"
77 
78 #define	TRUE	1
79 #define	FALSE	0
80 
81 /*
82  * Estimate rto for an nfs rpc sent via. an unreliable datagram.
83  * Use the mean and mean deviation of rtt for the appropriate type of rpc
84  * for the frequent rpcs and a default for the others.
85  * The justification for doing "other" this way is that these rpcs
86  * happen so infrequently that timer est. would probably be stale.
87  * Also, since many of these rpcs are
88  * non-idempotent, a conservative timeout is desired.
89  * getattr, lookup - A+2D
90  * read, write     - A+4D
91  * other           - nm_timeo
92  */
93 #define	NFS_RTO(n, t) \
94 	((t) == 0 ? (n)->nm_timeo : \
95 	 ((t) < 3 ? \
96 	  (((((n)->nm_srtt[t-1] + 3) >> 2) + (n)->nm_sdrtt[t-1] + 1) >> 1) : \
97 	  ((((n)->nm_srtt[t-1] + 7) >> 3) + (n)->nm_sdrtt[t-1] + 1)))
98 #define	NFS_SRTT(r)	(r)->r_nmp->nm_srtt[proct[(r)->r_procnum] - 1]
99 #define	NFS_SDRTT(r)	(r)->r_nmp->nm_sdrtt[proct[(r)->r_procnum] - 1]
100 /*
101  * External data, mostly RPC constants in XDR form
102  */
103 extern u_int32_t rpc_reply, rpc_msgdenied, rpc_mismatch, rpc_vers,
104 	rpc_auth_unix, rpc_msgaccepted, rpc_call, rpc_autherr,
105 	rpc_auth_kerb;
106 extern u_int32_t nfs_prog;
107 extern struct nfsstats nfsstats;
108 extern int nfsv3_procid[NFS_NPROCS];
109 extern int nfs_ticks;
110 
111 /*
112  * Defines which timer to use for the procnum.
113  * 0 - default
114  * 1 - getattr
115  * 2 - lookup
116  * 3 - read
117  * 4 - write
118  */
119 static int proct[NFS_NPROCS] = {
120 	0, 1, 0, 2, 1, 3, 3, 4, 0, 0, 0, 0, 0, 0, 0, 0, 3, 3, 0, 0, 0, 0, 0,
121 	0, 0, 0,
122 };
123 
124 static int nfs_realign_test;
125 static int nfs_realign_count;
126 static int nfs_bufpackets = 4;
127 static int nfs_timer_raced;
128 
129 SYSCTL_DECL(_vfs_nfs);
130 
131 SYSCTL_INT(_vfs_nfs, OID_AUTO, realign_test, CTLFLAG_RW, &nfs_realign_test, 0, "");
132 SYSCTL_INT(_vfs_nfs, OID_AUTO, realign_count, CTLFLAG_RW, &nfs_realign_count, 0, "");
133 SYSCTL_INT(_vfs_nfs, OID_AUTO, bufpackets, CTLFLAG_RW, &nfs_bufpackets, 0, "");
134 
135 
136 /*
137  * There is a congestion window for outstanding rpcs maintained per mount
138  * point. The cwnd size is adjusted in roughly the way that:
139  * Van Jacobson, Congestion avoidance and Control, In "Proceedings of
140  * SIGCOMM '88". ACM, August 1988.
141  * describes for TCP. The cwnd size is chopped in half on a retransmit timeout
142  * and incremented by 1/cwnd when each rpc reply is received and a full cwnd
143  * of rpcs is in progress.
144  * (The sent count and cwnd are scaled for integer arith.)
145  * Variants of "slow start" were tried and were found to be too much of a
146  * performance hit (ave. rtt 3 times larger),
147  * I suspect due to the large rtt that nfs rpcs have.
148  */
149 #define	NFS_CWNDSCALE	256
150 #define	NFS_MAXCWND	(NFS_CWNDSCALE * 32)
151 static int nfs_backoff[8] = { 2, 4, 8, 16, 32, 64, 128, 256, };
152 int nfsrtton = 0;
153 struct nfsrtt nfsrtt;
154 struct callout	nfs_timer_handle;
155 
156 static int	nfs_msg (struct thread *,char *,char *);
157 static int	nfs_rcvlock (struct nfsreq *);
158 static void	nfs_rcvunlock (struct nfsreq *);
159 static void	nfs_realign (struct mbuf **pm, int hsiz);
160 static int	nfs_receive (struct nfsreq *rep, struct sockaddr **aname,
161 				 struct mbuf **mp);
162 static void	nfs_softterm (struct nfsreq *rep);
163 static int	nfs_reconnect (struct nfsreq *rep);
164 #ifndef NFS_NOSERVER
165 static int	nfsrv_getstream (struct nfssvc_sock *, int, int *);
166 
167 int (*nfsrv3_procs[NFS_NPROCS]) (struct nfsrv_descript *nd,
168 				    struct nfssvc_sock *slp,
169 				    struct thread *td,
170 				    struct mbuf **mreqp) = {
171 	nfsrv_null,
172 	nfsrv_getattr,
173 	nfsrv_setattr,
174 	nfsrv_lookup,
175 	nfsrv3_access,
176 	nfsrv_readlink,
177 	nfsrv_read,
178 	nfsrv_write,
179 	nfsrv_create,
180 	nfsrv_mkdir,
181 	nfsrv_symlink,
182 	nfsrv_mknod,
183 	nfsrv_remove,
184 	nfsrv_rmdir,
185 	nfsrv_rename,
186 	nfsrv_link,
187 	nfsrv_readdir,
188 	nfsrv_readdirplus,
189 	nfsrv_statfs,
190 	nfsrv_fsinfo,
191 	nfsrv_pathconf,
192 	nfsrv_commit,
193 	nfsrv_noop,
194 	nfsrv_noop,
195 	nfsrv_noop,
196 	nfsrv_noop
197 };
198 #endif /* NFS_NOSERVER */
199 
200 /*
201  * Initialize sockets and congestion for a new NFS connection.
202  * We do not free the sockaddr if error.
203  */
204 int
205 nfs_connect(struct nfsmount *nmp, struct nfsreq *rep)
206 {
207 	struct socket *so;
208 	int error, rcvreserve, sndreserve;
209 	int pktscale;
210 	struct sockaddr *saddr;
211 	struct sockaddr_in *sin;
212 	struct thread *td = &thread0; /* only used for socreate and sobind */
213 
214 	nmp->nm_so = (struct socket *)0;
215 	saddr = nmp->nm_nam;
216 	error = socreate(saddr->sa_family, &nmp->nm_so, nmp->nm_sotype,
217 		nmp->nm_soproto, td);
218 	if (error)
219 		goto bad;
220 	so = nmp->nm_so;
221 	nmp->nm_soflags = so->so_proto->pr_flags;
222 
223 	/*
224 	 * Some servers require that the client port be a reserved port number.
225 	 */
226 	if (saddr->sa_family == AF_INET && (nmp->nm_flag & NFSMNT_RESVPORT)) {
227 		struct sockopt sopt;
228 		int ip;
229 		struct sockaddr_in ssin;
230 
231 		bzero(&sopt, sizeof sopt);
232 		ip = IP_PORTRANGE_LOW;
233 		sopt.sopt_level = IPPROTO_IP;
234 		sopt.sopt_name = IP_PORTRANGE;
235 		sopt.sopt_val = (void *)&ip;
236 		sopt.sopt_valsize = sizeof(ip);
237 		sopt.sopt_td = NULL;
238 		error = sosetopt(so, &sopt);
239 		if (error)
240 			goto bad;
241 		bzero(&ssin, sizeof ssin);
242 		sin = &ssin;
243 		sin->sin_len = sizeof (struct sockaddr_in);
244 		sin->sin_family = AF_INET;
245 		sin->sin_addr.s_addr = INADDR_ANY;
246 		sin->sin_port = htons(0);
247 		error = sobind(so, (struct sockaddr *)sin, td);
248 		if (error)
249 			goto bad;
250 		bzero(&sopt, sizeof sopt);
251 		ip = IP_PORTRANGE_DEFAULT;
252 		sopt.sopt_level = IPPROTO_IP;
253 		sopt.sopt_name = IP_PORTRANGE;
254 		sopt.sopt_val = (void *)&ip;
255 		sopt.sopt_valsize = sizeof(ip);
256 		sopt.sopt_td = NULL;
257 		error = sosetopt(so, &sopt);
258 		if (error)
259 			goto bad;
260 	}
261 
262 	/*
263 	 * Protocols that do not require connections may be optionally left
264 	 * unconnected for servers that reply from a port other than NFS_PORT.
265 	 */
266 	if (nmp->nm_flag & NFSMNT_NOCONN) {
267 		if (nmp->nm_soflags & PR_CONNREQUIRED) {
268 			error = ENOTCONN;
269 			goto bad;
270 		}
271 	} else {
272 		error = soconnect(so, nmp->nm_nam, td);
273 		if (error)
274 			goto bad;
275 
276 		/*
277 		 * Wait for the connection to complete. Cribbed from the
278 		 * connect system call but with the wait timing out so
279 		 * that interruptible mounts don't hang here for a long time.
280 		 */
281 		crit_enter();
282 		while ((so->so_state & SS_ISCONNECTING) && so->so_error == 0) {
283 			(void) tsleep((caddr_t)&so->so_timeo, 0,
284 				"nfscon", 2 * hz);
285 			if ((so->so_state & SS_ISCONNECTING) &&
286 			    so->so_error == 0 && rep &&
287 			    (error = nfs_sigintr(nmp, rep, rep->r_td)) != 0){
288 				so->so_state &= ~SS_ISCONNECTING;
289 				crit_exit();
290 				goto bad;
291 			}
292 		}
293 		if (so->so_error) {
294 			error = so->so_error;
295 			so->so_error = 0;
296 			crit_exit();
297 			goto bad;
298 		}
299 		crit_exit();
300 	}
301 	so->so_rcv.sb_timeo = (5 * hz);
302 	so->so_snd.sb_timeo = (5 * hz);
303 
304 	/*
305 	 * Get buffer reservation size from sysctl, but impose reasonable
306 	 * limits.
307 	 */
308 	pktscale = nfs_bufpackets;
309 	if (pktscale < 2)
310 		pktscale = 2;
311 	if (pktscale > 64)
312 		pktscale = 64;
313 
314 	if (nmp->nm_sotype == SOCK_DGRAM) {
315 		sndreserve = (nmp->nm_wsize + NFS_MAXPKTHDR) * pktscale;
316 		rcvreserve = (max(nmp->nm_rsize, nmp->nm_readdirsize) +
317 		    NFS_MAXPKTHDR) * pktscale;
318 	} else if (nmp->nm_sotype == SOCK_SEQPACKET) {
319 		sndreserve = (nmp->nm_wsize + NFS_MAXPKTHDR) * pktscale;
320 		rcvreserve = (max(nmp->nm_rsize, nmp->nm_readdirsize) +
321 		    NFS_MAXPKTHDR) * pktscale;
322 	} else {
323 		if (nmp->nm_sotype != SOCK_STREAM)
324 			panic("nfscon sotype");
325 		if (so->so_proto->pr_flags & PR_CONNREQUIRED) {
326 			struct sockopt sopt;
327 			int val;
328 
329 			bzero(&sopt, sizeof sopt);
330 			sopt.sopt_level = SOL_SOCKET;
331 			sopt.sopt_name = SO_KEEPALIVE;
332 			sopt.sopt_val = &val;
333 			sopt.sopt_valsize = sizeof val;
334 			val = 1;
335 			sosetopt(so, &sopt);
336 		}
337 		if (so->so_proto->pr_protocol == IPPROTO_TCP) {
338 			struct sockopt sopt;
339 			int val;
340 
341 			bzero(&sopt, sizeof sopt);
342 			sopt.sopt_level = IPPROTO_TCP;
343 			sopt.sopt_name = TCP_NODELAY;
344 			sopt.sopt_val = &val;
345 			sopt.sopt_valsize = sizeof val;
346 			val = 1;
347 			sosetopt(so, &sopt);
348 		}
349 		sndreserve = (nmp->nm_wsize + NFS_MAXPKTHDR +
350 		    sizeof (u_int32_t)) * pktscale;
351 		rcvreserve = (nmp->nm_rsize + NFS_MAXPKTHDR +
352 		    sizeof (u_int32_t)) * pktscale;
353 	}
354 	error = soreserve(so, sndreserve, rcvreserve,
355 			  &td->td_proc->p_rlimit[RLIMIT_SBSIZE]);
356 	if (error)
357 		goto bad;
358 	so->so_rcv.sb_flags |= SB_NOINTR;
359 	so->so_snd.sb_flags |= SB_NOINTR;
360 
361 	/* Initialize other non-zero congestion variables */
362 	nmp->nm_srtt[0] = nmp->nm_srtt[1] = nmp->nm_srtt[2] =
363 		nmp->nm_srtt[3] = (NFS_TIMEO << 3);
364 	nmp->nm_sdrtt[0] = nmp->nm_sdrtt[1] = nmp->nm_sdrtt[2] =
365 		nmp->nm_sdrtt[3] = 0;
366 	nmp->nm_cwnd = NFS_MAXCWND / 2;	    /* Initial send window */
367 	nmp->nm_sent = 0;
368 	nmp->nm_timeouts = 0;
369 	return (0);
370 
371 bad:
372 	nfs_disconnect(nmp);
373 	return (error);
374 }
375 
376 /*
377  * Reconnect routine:
378  * Called when a connection is broken on a reliable protocol.
379  * - clean up the old socket
380  * - nfs_connect() again
381  * - set R_MUSTRESEND for all outstanding requests on mount point
382  * If this fails the mount point is DEAD!
383  * nb: Must be called with the nfs_sndlock() set on the mount point.
384  */
385 static int
386 nfs_reconnect(struct nfsreq *rep)
387 {
388 	struct nfsreq *rp;
389 	struct nfsmount *nmp = rep->r_nmp;
390 	int error;
391 
392 	nfs_disconnect(nmp);
393 	while ((error = nfs_connect(nmp, rep)) != 0) {
394 		if (error == EINTR || error == ERESTART)
395 			return (EINTR);
396 		(void) tsleep((caddr_t)&lbolt, 0, "nfscon", 0);
397 	}
398 
399 	/*
400 	 * Loop through outstanding request list and fix up all requests
401 	 * on old socket.
402 	 */
403 	crit_enter();
404 	TAILQ_FOREACH(rp, &nfs_reqq, r_chain) {
405 		if (rp->r_nmp == nmp)
406 			rp->r_flags |= R_MUSTRESEND;
407 	}
408 	crit_exit();
409 	return (0);
410 }
411 
412 /*
413  * NFS disconnect. Clean up and unlink.
414  */
415 void
416 nfs_disconnect(struct nfsmount *nmp)
417 {
418 	struct socket *so;
419 
420 	if (nmp->nm_so) {
421 		so = nmp->nm_so;
422 		nmp->nm_so = (struct socket *)0;
423 		soshutdown(so, 2);
424 		soclose(so, FNONBLOCK);
425 	}
426 }
427 
428 void
429 nfs_safedisconnect(struct nfsmount *nmp)
430 {
431 	struct nfsreq dummyreq;
432 
433 	bzero(&dummyreq, sizeof(dummyreq));
434 	dummyreq.r_nmp = nmp;
435 	dummyreq.r_td = NULL;
436 	nfs_rcvlock(&dummyreq);
437 	nfs_disconnect(nmp);
438 	nfs_rcvunlock(&dummyreq);
439 }
440 
441 /*
442  * This is the nfs send routine. For connection based socket types, it
443  * must be called with an nfs_sndlock() on the socket.
444  * "rep == NULL" indicates that it has been called from a server.
445  * For the client side:
446  * - return EINTR if the RPC is terminated, 0 otherwise
447  * - set R_MUSTRESEND if the send fails for any reason
448  * - do any cleanup required by recoverable socket errors (?)
449  * For the server side:
450  * - return EINTR or ERESTART if interrupted by a signal
451  * - return EPIPE if a connection is lost for connection based sockets (TCP...)
452  * - do any cleanup required by recoverable socket errors (?)
453  */
454 int
455 nfs_send(struct socket *so, struct sockaddr *nam, struct mbuf *top,
456 	 struct nfsreq *rep)
457 {
458 	struct sockaddr *sendnam;
459 	int error, soflags, flags;
460 
461 	if (rep) {
462 		if (rep->r_flags & R_SOFTTERM) {
463 			m_freem(top);
464 			return (EINTR);
465 		}
466 		if ((so = rep->r_nmp->nm_so) == NULL) {
467 			rep->r_flags |= R_MUSTRESEND;
468 			m_freem(top);
469 			return (0);
470 		}
471 		rep->r_flags &= ~R_MUSTRESEND;
472 		soflags = rep->r_nmp->nm_soflags;
473 	} else
474 		soflags = so->so_proto->pr_flags;
475 	if ((soflags & PR_CONNREQUIRED) || (so->so_state & SS_ISCONNECTED))
476 		sendnam = (struct sockaddr *)0;
477 	else
478 		sendnam = nam;
479 	if (so->so_type == SOCK_SEQPACKET)
480 		flags = MSG_EOR;
481 	else
482 		flags = 0;
483 
484 	error = so_pru_sosend(so, sendnam, NULL, top, NULL, flags,
485 	    curthread /*XXX*/);
486 	/*
487 	 * ENOBUFS for dgram sockets is transient and non fatal.
488 	 * No need to log, and no need to break a soft mount.
489 	 */
490 	if (error == ENOBUFS && so->so_type == SOCK_DGRAM) {
491 		error = 0;
492 		if (rep)		/* do backoff retransmit on client */
493 			rep->r_flags |= R_MUSTRESEND;
494 	}
495 
496 	if (error) {
497 		if (rep) {
498 			log(LOG_INFO, "nfs send error %d for server %s\n",error,
499 			    rep->r_nmp->nm_mountp->mnt_stat.f_mntfromname);
500 			/*
501 			 * Deal with errors for the client side.
502 			 */
503 			if (rep->r_flags & R_SOFTTERM)
504 				error = EINTR;
505 			else
506 				rep->r_flags |= R_MUSTRESEND;
507 		} else
508 			log(LOG_INFO, "nfsd send error %d\n", error);
509 
510 		/*
511 		 * Handle any recoverable (soft) socket errors here. (?)
512 		 */
513 		if (error != EINTR && error != ERESTART &&
514 			error != EWOULDBLOCK && error != EPIPE)
515 			error = 0;
516 	}
517 	return (error);
518 }
519 
520 /*
521  * Receive a Sun RPC Request/Reply. For SOCK_DGRAM, the work is all
522  * done by soreceive(), but for SOCK_STREAM we must deal with the Record
523  * Mark and consolidate the data into a new mbuf list.
524  * nb: Sometimes TCP passes the data up to soreceive() in long lists of
525  *     small mbufs.
526  * For SOCK_STREAM we must be very careful to read an entire record once
527  * we have read any of it, even if the system call has been interrupted.
528  */
529 static int
530 nfs_receive(struct nfsreq *rep, struct sockaddr **aname, struct mbuf **mp)
531 {
532 	struct socket *so;
533 	struct uio auio;
534 	struct iovec aio;
535 	struct mbuf *m;
536 	struct mbuf *control;
537 	u_int32_t len;
538 	struct sockaddr **getnam;
539 	int error, sotype, rcvflg;
540 	struct thread *td = curthread;	/* XXX */
541 
542 	/*
543 	 * Set up arguments for soreceive()
544 	 */
545 	*mp = (struct mbuf *)0;
546 	*aname = (struct sockaddr *)0;
547 	sotype = rep->r_nmp->nm_sotype;
548 
549 	/*
550 	 * For reliable protocols, lock against other senders/receivers
551 	 * in case a reconnect is necessary.
552 	 * For SOCK_STREAM, first get the Record Mark to find out how much
553 	 * more there is to get.
554 	 * We must lock the socket against other receivers
555 	 * until we have an entire rpc request/reply.
556 	 */
557 	if (sotype != SOCK_DGRAM) {
558 		error = nfs_sndlock(rep);
559 		if (error)
560 			return (error);
561 tryagain:
562 		/*
563 		 * Check for fatal errors and resending request.
564 		 */
565 		/*
566 		 * Ugh: If a reconnect attempt just happened, nm_so
567 		 * would have changed. NULL indicates a failed
568 		 * attempt that has essentially shut down this
569 		 * mount point.
570 		 */
571 		if (rep->r_mrep || (rep->r_flags & R_SOFTTERM)) {
572 			nfs_sndunlock(rep);
573 			return (EINTR);
574 		}
575 		so = rep->r_nmp->nm_so;
576 		if (!so) {
577 			error = nfs_reconnect(rep);
578 			if (error) {
579 				nfs_sndunlock(rep);
580 				return (error);
581 			}
582 			goto tryagain;
583 		}
584 		while (rep->r_flags & R_MUSTRESEND) {
585 			m = m_copym(rep->r_mreq, 0, M_COPYALL, MB_WAIT);
586 			nfsstats.rpcretries++;
587 			error = nfs_send(so, rep->r_nmp->nm_nam, m, rep);
588 			if (error) {
589 				if (error == EINTR || error == ERESTART ||
590 				    (error = nfs_reconnect(rep)) != 0) {
591 					nfs_sndunlock(rep);
592 					return (error);
593 				}
594 				goto tryagain;
595 			}
596 		}
597 		nfs_sndunlock(rep);
598 		if (sotype == SOCK_STREAM) {
599 			aio.iov_base = (caddr_t) &len;
600 			aio.iov_len = sizeof(u_int32_t);
601 			auio.uio_iov = &aio;
602 			auio.uio_iovcnt = 1;
603 			auio.uio_segflg = UIO_SYSSPACE;
604 			auio.uio_rw = UIO_READ;
605 			auio.uio_offset = 0;
606 			auio.uio_resid = sizeof(u_int32_t);
607 			auio.uio_td = td;
608 			do {
609 			   rcvflg = MSG_WAITALL;
610 			   error = so_pru_soreceive(so, NULL, &auio, NULL,
611 			       NULL, &rcvflg);
612 			   if (error == EWOULDBLOCK && rep) {
613 				if (rep->r_flags & R_SOFTTERM)
614 					return (EINTR);
615 			   }
616 			} while (error == EWOULDBLOCK);
617 			if (!error && auio.uio_resid > 0) {
618 			    /*
619 			     * Don't log a 0 byte receive; it means
620 			     * that the socket has been closed, and
621 			     * can happen during normal operation
622 			     * (forcible unmount or Solaris server).
623 			     */
624 			    if (auio.uio_resid != sizeof (u_int32_t))
625 			    log(LOG_INFO,
626 				 "short receive (%d/%d) from nfs server %s\n",
627 				 (int)(sizeof(u_int32_t) - auio.uio_resid),
628 				 (int)sizeof(u_int32_t),
629 				 rep->r_nmp->nm_mountp->mnt_stat.f_mntfromname);
630 			    error = EPIPE;
631 			}
632 			if (error)
633 				goto errout;
634 			len = ntohl(len) & ~0x80000000;
635 			/*
636 			 * This is SERIOUS! We are out of sync with the sender
637 			 * and forcing a disconnect/reconnect is all I can do.
638 			 */
639 			if (len > NFS_MAXPACKET) {
640 			    log(LOG_ERR, "%s (%d) from nfs server %s\n",
641 				"impossible packet length",
642 				len,
643 				rep->r_nmp->nm_mountp->mnt_stat.f_mntfromname);
644 			    error = EFBIG;
645 			    goto errout;
646 			}
647 			auio.uio_resid = len;
648 			do {
649 			    rcvflg = MSG_WAITALL;
650 			    error =  so_pru_soreceive(so, NULL, &auio, mp,
651 			        NULL, &rcvflg);
652 			} while (error == EWOULDBLOCK || error == EINTR ||
653 				 error == ERESTART);
654 			if (!error && auio.uio_resid > 0) {
655 			    if (len != auio.uio_resid)
656 			    log(LOG_INFO,
657 				"short receive (%d/%d) from nfs server %s\n",
658 				len - auio.uio_resid, len,
659 				rep->r_nmp->nm_mountp->mnt_stat.f_mntfromname);
660 			    error = EPIPE;
661 			}
662 		} else {
663 			/*
664 			 * NB: Since uio_resid is big, MSG_WAITALL is ignored
665 			 * and soreceive() will return when it has either a
666 			 * control msg or a data msg.
667 			 * We have no use for control msg., but must grab them
668 			 * and then throw them away so we know what is going
669 			 * on.
670 			 */
671 			auio.uio_resid = len = 100000000; /* Anything Big */
672 			auio.uio_td = td;
673 			do {
674 			    rcvflg = 0;
675 			    error =  so_pru_soreceive(so, NULL, &auio, mp,
676 			        &control, &rcvflg);
677 			    if (control)
678 				m_freem(control);
679 			    if (error == EWOULDBLOCK && rep) {
680 				if (rep->r_flags & R_SOFTTERM)
681 					return (EINTR);
682 			    }
683 			} while (error == EWOULDBLOCK ||
684 				 (!error && *mp == NULL && control));
685 			if ((rcvflg & MSG_EOR) == 0)
686 				kprintf("Egad!!\n");
687 			if (!error && *mp == NULL)
688 				error = EPIPE;
689 			len -= auio.uio_resid;
690 		}
691 errout:
692 		if (error && error != EINTR && error != ERESTART) {
693 			m_freem(*mp);
694 			*mp = (struct mbuf *)0;
695 			if (error != EPIPE)
696 				log(LOG_INFO,
697 				    "receive error %d from nfs server %s\n",
698 				    error,
699 				 rep->r_nmp->nm_mountp->mnt_stat.f_mntfromname);
700 			error = nfs_sndlock(rep);
701 			if (!error) {
702 				error = nfs_reconnect(rep);
703 				if (!error)
704 					goto tryagain;
705 				else
706 					nfs_sndunlock(rep);
707 			}
708 		}
709 	} else {
710 		if ((so = rep->r_nmp->nm_so) == NULL)
711 			return (EACCES);
712 		if (so->so_state & SS_ISCONNECTED)
713 			getnam = (struct sockaddr **)0;
714 		else
715 			getnam = aname;
716 		auio.uio_resid = len = 1000000;
717 		auio.uio_td = td;
718 		do {
719 			rcvflg = 0;
720 			error =  so_pru_soreceive(so, getnam, &auio, mp, NULL,
721 			    &rcvflg);
722 			if (error == EWOULDBLOCK &&
723 			    (rep->r_flags & R_SOFTTERM))
724 				return (EINTR);
725 		} while (error == EWOULDBLOCK);
726 		len -= auio.uio_resid;
727 	}
728 	if (error) {
729 		m_freem(*mp);
730 		*mp = (struct mbuf *)0;
731 	}
732 	/*
733 	 * Search for any mbufs that are not a multiple of 4 bytes long
734 	 * or with m_data not longword aligned.
735 	 * These could cause pointer alignment problems, so copy them to
736 	 * well aligned mbufs.
737 	 */
738 	nfs_realign(mp, 5 * NFSX_UNSIGNED);
739 	return (error);
740 }
741 
742 /*
743  * Implement receipt of reply on a socket.
744  * We must search through the list of received datagrams matching them
745  * with outstanding requests using the xid, until ours is found.
746  */
747 /* ARGSUSED */
748 int
749 nfs_reply(struct nfsreq *myrep)
750 {
751 	struct nfsreq *rep;
752 	struct nfsmount *nmp = myrep->r_nmp;
753 	int32_t t1;
754 	struct mbuf *mrep, *md;
755 	struct sockaddr *nam;
756 	u_int32_t rxid, *tl;
757 	caddr_t dpos, cp2;
758 	int error;
759 
760 	/*
761 	 * Loop around until we get our own reply
762 	 */
763 	for (;;) {
764 		/*
765 		 * Lock against other receivers so that I don't get stuck in
766 		 * sbwait() after someone else has received my reply for me.
767 		 * Also necessary for connection based protocols to avoid
768 		 * race conditions during a reconnect.
769 		 * If nfs_rcvlock() returns EALREADY, that means that
770 		 * the reply has already been recieved by another
771 		 * process and we can return immediately.  In this
772 		 * case, the lock is not taken to avoid races with
773 		 * other processes.
774 		 */
775 		error = nfs_rcvlock(myrep);
776 		if (error == EALREADY)
777 			return (0);
778 		if (error)
779 			return (error);
780 		/*
781 		 * Get the next Rpc reply off the socket
782 		 */
783 		error = nfs_receive(myrep, &nam, &mrep);
784 		nfs_rcvunlock(myrep);
785 		if (error) {
786 			/*
787 			 * Ignore routing errors on connectionless protocols??
788 			 */
789 			if (NFSIGNORE_SOERROR(nmp->nm_soflags, error)) {
790 				nmp->nm_so->so_error = 0;
791 				if (myrep->r_flags & R_GETONEREP)
792 					return (0);
793 				continue;
794 			}
795 			return (error);
796 		}
797 		if (nam)
798 			FREE(nam, M_SONAME);
799 
800 		/*
801 		 * Get the xid and check that it is an rpc reply
802 		 */
803 		md = mrep;
804 		dpos = mtod(md, caddr_t);
805 		nfsm_dissect(tl, u_int32_t *, 2*NFSX_UNSIGNED);
806 		rxid = *tl++;
807 		if (*tl != rpc_reply) {
808 			nfsstats.rpcinvalid++;
809 			m_freem(mrep);
810 nfsmout:
811 			if (myrep->r_flags & R_GETONEREP)
812 				return (0);
813 			continue;
814 		}
815 
816 		/*
817 		 * Loop through the request list to match up the reply
818 		 * Iff no match, just drop the datagram.  On match, set
819 		 * r_mrep atomically to prevent the timer from messing
820 		 * around with the request after we have exited the critical
821 		 * section.
822 		 */
823 		crit_enter();
824 		TAILQ_FOREACH(rep, &nfs_reqq, r_chain) {
825 			if (rep->r_mrep == NULL && rxid == rep->r_xid) {
826 				rep->r_mrep = mrep;
827 				break;
828 			}
829 		}
830 		crit_exit();
831 
832 		/*
833 		 * Fill in the rest of the reply if we found a match.
834 		 */
835 		if (rep) {
836 			rep->r_md = md;
837 			rep->r_dpos = dpos;
838 			if (nfsrtton) {
839 				struct rttl *rt;
840 
841 				rt = &nfsrtt.rttl[nfsrtt.pos];
842 				rt->proc = rep->r_procnum;
843 				rt->rto = NFS_RTO(nmp, proct[rep->r_procnum]);
844 				rt->sent = nmp->nm_sent;
845 				rt->cwnd = nmp->nm_cwnd;
846 				rt->srtt = nmp->nm_srtt[proct[rep->r_procnum] - 1];
847 				rt->sdrtt = nmp->nm_sdrtt[proct[rep->r_procnum] - 1];
848 				rt->fsid = nmp->nm_mountp->mnt_stat.f_fsid;
849 				getmicrotime(&rt->tstamp);
850 				if (rep->r_flags & R_TIMING)
851 					rt->rtt = rep->r_rtt;
852 				else
853 					rt->rtt = 1000000;
854 				nfsrtt.pos = (nfsrtt.pos + 1) % NFSRTTLOGSIZ;
855 			}
856 			/*
857 			 * Update congestion window.
858 			 * Do the additive increase of
859 			 * one rpc/rtt.
860 			 */
861 			if (nmp->nm_cwnd <= nmp->nm_sent) {
862 				nmp->nm_cwnd +=
863 				   (NFS_CWNDSCALE * NFS_CWNDSCALE +
864 				   (nmp->nm_cwnd >> 1)) / nmp->nm_cwnd;
865 				if (nmp->nm_cwnd > NFS_MAXCWND)
866 					nmp->nm_cwnd = NFS_MAXCWND;
867 			}
868 			crit_enter();	/* nfs_timer interlock for nm_sent */
869 			if (rep->r_flags & R_SENT) {
870 				rep->r_flags &= ~R_SENT;
871 				nmp->nm_sent -= NFS_CWNDSCALE;
872 			}
873 			crit_exit();
874 			/*
875 			 * Update rtt using a gain of 0.125 on the mean
876 			 * and a gain of 0.25 on the deviation.
877 			 */
878 			if (rep->r_flags & R_TIMING) {
879 				/*
880 				 * Since the timer resolution of
881 				 * NFS_HZ is so course, it can often
882 				 * result in r_rtt == 0. Since
883 				 * r_rtt == N means that the actual
884 				 * rtt is between N+dt and N+2-dt ticks,
885 				 * add 1.
886 				 */
887 				t1 = rep->r_rtt + 1;
888 				t1 -= (NFS_SRTT(rep) >> 3);
889 				NFS_SRTT(rep) += t1;
890 				if (t1 < 0)
891 					t1 = -t1;
892 				t1 -= (NFS_SDRTT(rep) >> 2);
893 				NFS_SDRTT(rep) += t1;
894 			}
895 			nmp->nm_timeouts = 0;
896 		}
897 		/*
898 		 * If not matched to a request, drop it.
899 		 * If it's mine, get out.
900 		 */
901 		if (rep == NULL) {
902 			nfsstats.rpcunexpected++;
903 			m_freem(mrep);
904 		} else if (rep == myrep) {
905 			if (rep->r_mrep == NULL)
906 				panic("nfsreply nil");
907 			return (0);
908 		}
909 		if (myrep->r_flags & R_GETONEREP)
910 			return (0);
911 	}
912 }
913 
914 /*
915  * nfs_request - goes something like this
916  *	- fill in request struct
917  *	- links it into list
918  *	- calls nfs_send() for first transmit
919  *	- calls nfs_receive() to get reply
920  *	- break down rpc header and return with nfs reply pointed to
921  *	  by mrep or error
922  * nb: always frees up mreq mbuf list
923  */
924 int
925 nfs_request(struct vnode *vp, struct mbuf *mrest, int procnum,
926 	    struct thread *td, struct ucred *cred, struct mbuf **mrp,
927 	    struct mbuf **mdp, caddr_t *dposp)
928 {
929 	struct mbuf *mrep, *m2;
930 	struct nfsreq *rep;
931 	u_int32_t *tl;
932 	int i;
933 	struct nfsmount *nmp;
934 	struct mbuf *m, *md, *mheadend;
935 	char nickv[RPCX_NICKVERF];
936 	time_t waituntil;
937 	caddr_t dpos, cp2;
938 	int t1, error = 0, mrest_len, auth_len, auth_type;
939 	int trylater_delay = 15, trylater_cnt = 0, failed_auth = 0;
940 	int verf_len, verf_type;
941 	u_int32_t xid;
942 	char *auth_str, *verf_str;
943 	NFSKERBKEY_T key;		/* save session key */
944 
945 	/* Reject requests while attempting a forced unmount. */
946 	if (vp->v_mount->mnt_kern_flag & MNTK_UNMOUNTF) {
947 		m_freem(mrest);
948 		return (ESTALE);
949 	}
950 	nmp = VFSTONFS(vp->v_mount);
951 	MALLOC(rep, struct nfsreq *, sizeof(struct nfsreq), M_NFSREQ, M_WAITOK);
952 	rep->r_nmp = nmp;
953 	rep->r_vp = vp;
954 	rep->r_td = td;
955 	rep->r_procnum = procnum;
956 	rep->r_mreq = NULL;
957 	i = 0;
958 	m = mrest;
959 	while (m) {
960 		i += m->m_len;
961 		m = m->m_next;
962 	}
963 	mrest_len = i;
964 
965 	/*
966 	 * Get the RPC header with authorization.
967 	 */
968 kerbauth:
969 	verf_str = auth_str = (char *)0;
970 	if (nmp->nm_flag & NFSMNT_KERB) {
971 		verf_str = nickv;
972 		verf_len = sizeof (nickv);
973 		auth_type = RPCAUTH_KERB4;
974 		bzero((caddr_t)key, sizeof (key));
975 		if (failed_auth || nfs_getnickauth(nmp, cred, &auth_str,
976 			&auth_len, verf_str, verf_len)) {
977 			error = nfs_getauth(nmp, rep, cred, &auth_str,
978 				&auth_len, verf_str, &verf_len, key);
979 			if (error) {
980 				kfree((caddr_t)rep, M_NFSREQ);
981 				m_freem(mrest);
982 				return (error);
983 			}
984 		}
985 	} else {
986 		auth_type = RPCAUTH_UNIX;
987 		if (cred->cr_ngroups < 1)
988 			panic("nfsreq nogrps");
989 		auth_len = ((((cred->cr_ngroups - 1) > nmp->nm_numgrps) ?
990 			nmp->nm_numgrps : (cred->cr_ngroups - 1)) << 2) +
991 			5 * NFSX_UNSIGNED;
992 	}
993 	m = nfsm_rpchead(cred, nmp->nm_flag, procnum, auth_type, auth_len,
994 	     auth_str, verf_len, verf_str, mrest, mrest_len, &mheadend, &xid);
995 	if (auth_str)
996 		kfree(auth_str, M_TEMP);
997 
998 	/*
999 	 * For stream protocols, insert a Sun RPC Record Mark.
1000 	 */
1001 	if (nmp->nm_sotype == SOCK_STREAM) {
1002 		M_PREPEND(m, NFSX_UNSIGNED, MB_WAIT);
1003 		if (m == NULL) {
1004 			kfree(rep, M_NFSREQ);
1005 			return (ENOBUFS);
1006 		}
1007 		*mtod(m, u_int32_t *) = htonl(0x80000000 |
1008 			 (m->m_pkthdr.len - NFSX_UNSIGNED));
1009 	}
1010 	rep->r_mreq = m;
1011 	rep->r_xid = xid;
1012 tryagain:
1013 	if (nmp->nm_flag & NFSMNT_SOFT)
1014 		rep->r_retry = nmp->nm_retry;
1015 	else
1016 		rep->r_retry = NFS_MAXREXMIT + 1;	/* past clip limit */
1017 	rep->r_rtt = rep->r_rexmit = 0;
1018 	if (proct[procnum] > 0)
1019 		rep->r_flags = R_TIMING | R_MASKTIMER;
1020 	else
1021 		rep->r_flags = R_MASKTIMER;
1022 	rep->r_mrep = NULL;
1023 
1024 	/*
1025 	 * Do the client side RPC.
1026 	 */
1027 	nfsstats.rpcrequests++;
1028 
1029 	/*
1030 	 * Chain request into list of outstanding requests. Be sure
1031 	 * to put it LAST so timer finds oldest requests first.  Note
1032 	 * that R_MASKTIMER is set at the moment to prevent any timer
1033 	 * action on this request while we are still doing processing on
1034 	 * it below.  splsoftclock() primarily protects nm_sent.  Note
1035 	 * that we may block in this code so there is no atomicy guarentee.
1036 	 */
1037 	crit_enter();
1038 	TAILQ_INSERT_TAIL(&nfs_reqq, rep, r_chain);
1039 
1040 	/*
1041 	 * If backing off another request or avoiding congestion, don't
1042 	 * send this one now but let timer do it.  If not timing a request,
1043 	 * do it now.
1044 	 *
1045 	 * Even though the timer will not mess with our request there is
1046 	 * still the possibility that we will race a reply (which clears
1047 	 * R_SENT), especially on localhost connections, so be very careful
1048 	 * when setting R_SENT.  We could set R_SENT prior to calling
1049 	 * nfs_send() but why bother if the response occurs that quickly?
1050 	 */
1051 	if (nmp->nm_so && (nmp->nm_sotype != SOCK_DGRAM ||
1052 	    (nmp->nm_flag & NFSMNT_DUMBTIMR) ||
1053 	    nmp->nm_sent < nmp->nm_cwnd)) {
1054 		if (nmp->nm_soflags & PR_CONNREQUIRED)
1055 			error = nfs_sndlock(rep);
1056 		if (!error) {
1057 			m2 = m_copym(m, 0, M_COPYALL, MB_WAIT);
1058 			error = nfs_send(nmp->nm_so, nmp->nm_nam, m2, rep);
1059 			if (nmp->nm_soflags & PR_CONNREQUIRED)
1060 				nfs_sndunlock(rep);
1061 		}
1062 		if (!error && (rep->r_flags & R_MUSTRESEND) == 0 &&
1063 		    rep->r_mrep == NULL) {
1064 			KASSERT((rep->r_flags & R_SENT) == 0,
1065 				("R_SENT ASSERT %p", rep));
1066 			nmp->nm_sent += NFS_CWNDSCALE;
1067 			rep->r_flags |= R_SENT;
1068 		}
1069 	} else {
1070 		rep->r_rtt = -1;
1071 	}
1072 
1073 	/*
1074 	 * Let the timer do what it will with the request, then
1075 	 * wait for the reply from our send or the timer's.
1076 	 */
1077 	if (!error || error == EPIPE) {
1078 		rep->r_flags &= ~R_MASKTIMER;
1079 		crit_exit();
1080 		error = nfs_reply(rep);
1081 		crit_enter();
1082 	}
1083 
1084 	/*
1085 	 * RPC done, unlink the request, but don't rip it out from under
1086 	 * the callout timer.
1087 	 */
1088 	while (rep->r_flags & R_LOCKED) {
1089 		nfs_timer_raced = 1;
1090 		tsleep(&nfs_timer_raced, 0, "nfstrac", 0);
1091 	}
1092 	TAILQ_REMOVE(&nfs_reqq, rep, r_chain);
1093 
1094 	/*
1095 	 * Decrement the outstanding request count.
1096 	 */
1097 	if (rep->r_flags & R_SENT) {
1098 		rep->r_flags &= ~R_SENT;
1099 		nmp->nm_sent -= NFS_CWNDSCALE;
1100 	}
1101 	crit_exit();
1102 
1103 	/*
1104 	 * If there was a successful reply and a tprintf msg.
1105 	 * tprintf a response.
1106 	 */
1107 	if (!error && (rep->r_flags & R_TPRINTFMSG))
1108 		nfs_msg(rep->r_td, nmp->nm_mountp->mnt_stat.f_mntfromname,
1109 		    "is alive again");
1110 	mrep = rep->r_mrep;
1111 	md = rep->r_md;
1112 	dpos = rep->r_dpos;
1113 	if (error) {
1114 		m_freem(rep->r_mreq);
1115 		kfree((caddr_t)rep, M_NFSREQ);
1116 		return (error);
1117 	}
1118 
1119 	/*
1120 	 * break down the rpc header and check if ok
1121 	 */
1122 	nfsm_dissect(tl, u_int32_t *, 3 * NFSX_UNSIGNED);
1123 	if (*tl++ == rpc_msgdenied) {
1124 		if (*tl == rpc_mismatch)
1125 			error = EOPNOTSUPP;
1126 		else if ((nmp->nm_flag & NFSMNT_KERB) && *tl++ == rpc_autherr) {
1127 			if (!failed_auth) {
1128 				failed_auth++;
1129 				mheadend->m_next = (struct mbuf *)0;
1130 				m_freem(mrep);
1131 				m_freem(rep->r_mreq);
1132 				goto kerbauth;
1133 			} else
1134 				error = EAUTH;
1135 		} else
1136 			error = EACCES;
1137 		m_freem(mrep);
1138 		m_freem(rep->r_mreq);
1139 		kfree((caddr_t)rep, M_NFSREQ);
1140 		return (error);
1141 	}
1142 
1143 	/*
1144 	 * Grab any Kerberos verifier, otherwise just throw it away.
1145 	 */
1146 	verf_type = fxdr_unsigned(int, *tl++);
1147 	i = fxdr_unsigned(int32_t, *tl);
1148 	if ((nmp->nm_flag & NFSMNT_KERB) && verf_type == RPCAUTH_KERB4) {
1149 		error = nfs_savenickauth(nmp, cred, i, key, &md, &dpos, mrep);
1150 		if (error)
1151 			goto nfsmout;
1152 	} else if (i > 0)
1153 		nfsm_adv(nfsm_rndup(i));
1154 	nfsm_dissect(tl, u_int32_t *, NFSX_UNSIGNED);
1155 	/* 0 == ok */
1156 	if (*tl == 0) {
1157 		nfsm_dissect(tl, u_int32_t *, NFSX_UNSIGNED);
1158 		if (*tl != 0) {
1159 			error = fxdr_unsigned(int, *tl);
1160 			if ((nmp->nm_flag & NFSMNT_NFSV3) &&
1161 				error == NFSERR_TRYLATER) {
1162 				m_freem(mrep);
1163 				error = 0;
1164 				waituntil = time_second + trylater_delay;
1165 				while (time_second < waituntil)
1166 					(void) tsleep((caddr_t)&lbolt,
1167 						0, "nqnfstry", 0);
1168 				trylater_delay *= nfs_backoff[trylater_cnt];
1169 				if (trylater_cnt < 7)
1170 					trylater_cnt++;
1171 				goto tryagain;
1172 			}
1173 
1174 			/*
1175 			 * If the File Handle was stale, invalidate the
1176 			 * lookup cache, just in case.
1177 			 *
1178 			 * To avoid namecache<->vnode deadlocks we must
1179 			 * release the vnode lock if we hold it.
1180 			 */
1181 			if (error == ESTALE) {
1182 				int ltype;
1183 
1184 				ltype = lockstatus(&vp->v_lock, curthread);
1185 				if (ltype == LK_EXCLUSIVE || ltype == LK_SHARED)
1186 					lockmgr(&vp->v_lock, LK_RELEASE);
1187 				cache_inval_vp(vp, CINV_CHILDREN);
1188 				if (ltype == LK_EXCLUSIVE || ltype == LK_SHARED)
1189 					lockmgr(&vp->v_lock, ltype);
1190 			}
1191 			if (nmp->nm_flag & NFSMNT_NFSV3) {
1192 				*mrp = mrep;
1193 				*mdp = md;
1194 				*dposp = dpos;
1195 				error |= NFSERR_RETERR;
1196 			} else
1197 				m_freem(mrep);
1198 			m_freem(rep->r_mreq);
1199 			kfree((caddr_t)rep, M_NFSREQ);
1200 			return (error);
1201 		}
1202 
1203 		*mrp = mrep;
1204 		*mdp = md;
1205 		*dposp = dpos;
1206 		m_freem(rep->r_mreq);
1207 		FREE((caddr_t)rep, M_NFSREQ);
1208 		return (0);
1209 	}
1210 	m_freem(mrep);
1211 	error = EPROTONOSUPPORT;
1212 nfsmout:
1213 	m_freem(rep->r_mreq);
1214 	kfree((caddr_t)rep, M_NFSREQ);
1215 	return (error);
1216 }
1217 
1218 #ifndef NFS_NOSERVER
1219 /*
1220  * Generate the rpc reply header
1221  * siz arg. is used to decide if adding a cluster is worthwhile
1222  */
1223 int
1224 nfs_rephead(int siz, struct nfsrv_descript *nd, struct nfssvc_sock *slp,
1225 	    int err, struct mbuf **mrq, struct mbuf **mbp, caddr_t *bposp)
1226 {
1227 	u_int32_t *tl;
1228 	struct mbuf *mreq;
1229 	caddr_t bpos;
1230 	struct mbuf *mb, *mb2;
1231 
1232 	siz += RPC_REPLYSIZ;
1233 	mb = mreq = m_getl(max_hdr + siz, MB_WAIT, MT_DATA, M_PKTHDR, NULL);
1234 	mreq->m_pkthdr.len = 0;
1235 	/*
1236 	 * If this is not a cluster, try and leave leading space
1237 	 * for the lower level headers.
1238 	 */
1239 	if ((max_hdr + siz) < MINCLSIZE)
1240 		mreq->m_data += max_hdr;
1241 	tl = mtod(mreq, u_int32_t *);
1242 	mreq->m_len = 6 * NFSX_UNSIGNED;
1243 	bpos = ((caddr_t)tl) + mreq->m_len;
1244 	*tl++ = txdr_unsigned(nd->nd_retxid);
1245 	*tl++ = rpc_reply;
1246 	if (err == ERPCMISMATCH || (err & NFSERR_AUTHERR)) {
1247 		*tl++ = rpc_msgdenied;
1248 		if (err & NFSERR_AUTHERR) {
1249 			*tl++ = rpc_autherr;
1250 			*tl = txdr_unsigned(err & ~NFSERR_AUTHERR);
1251 			mreq->m_len -= NFSX_UNSIGNED;
1252 			bpos -= NFSX_UNSIGNED;
1253 		} else {
1254 			*tl++ = rpc_mismatch;
1255 			*tl++ = txdr_unsigned(RPC_VER2);
1256 			*tl = txdr_unsigned(RPC_VER2);
1257 		}
1258 	} else {
1259 		*tl++ = rpc_msgaccepted;
1260 
1261 		/*
1262 		 * For Kerberos authentication, we must send the nickname
1263 		 * verifier back, otherwise just RPCAUTH_NULL.
1264 		 */
1265 		if (nd->nd_flag & ND_KERBFULL) {
1266 		    struct nfsuid *nuidp;
1267 		    struct timeval ktvin, ktvout;
1268 
1269 		    for (nuidp = NUIDHASH(slp, nd->nd_cr.cr_uid)->lh_first;
1270 			nuidp != 0; nuidp = nuidp->nu_hash.le_next) {
1271 			if (nuidp->nu_cr.cr_uid == nd->nd_cr.cr_uid &&
1272 			    (!nd->nd_nam2 || netaddr_match(NU_NETFAM(nuidp),
1273 			     &nuidp->nu_haddr, nd->nd_nam2)))
1274 			    break;
1275 		    }
1276 		    if (nuidp) {
1277 			ktvin.tv_sec =
1278 			    txdr_unsigned(nuidp->nu_timestamp.tv_sec - 1);
1279 			ktvin.tv_usec =
1280 			    txdr_unsigned(nuidp->nu_timestamp.tv_usec);
1281 
1282 			/*
1283 			 * Encrypt the timestamp in ecb mode using the
1284 			 * session key.
1285 			 */
1286 #ifdef NFSKERB
1287 			XXX
1288 #endif
1289 
1290 			*tl++ = rpc_auth_kerb;
1291 			*tl++ = txdr_unsigned(3 * NFSX_UNSIGNED);
1292 			*tl = ktvout.tv_sec;
1293 			nfsm_build(tl, u_int32_t *, 3 * NFSX_UNSIGNED);
1294 			*tl++ = ktvout.tv_usec;
1295 			*tl++ = txdr_unsigned(nuidp->nu_cr.cr_uid);
1296 		    } else {
1297 			*tl++ = 0;
1298 			*tl++ = 0;
1299 		    }
1300 		} else {
1301 			*tl++ = 0;
1302 			*tl++ = 0;
1303 		}
1304 		switch (err) {
1305 		case EPROGUNAVAIL:
1306 			*tl = txdr_unsigned(RPC_PROGUNAVAIL);
1307 			break;
1308 		case EPROGMISMATCH:
1309 			*tl = txdr_unsigned(RPC_PROGMISMATCH);
1310 			nfsm_build(tl, u_int32_t *, 2 * NFSX_UNSIGNED);
1311 			*tl++ = txdr_unsigned(2);
1312 			*tl = txdr_unsigned(3);
1313 			break;
1314 		case EPROCUNAVAIL:
1315 			*tl = txdr_unsigned(RPC_PROCUNAVAIL);
1316 			break;
1317 		case EBADRPC:
1318 			*tl = txdr_unsigned(RPC_GARBAGE);
1319 			break;
1320 		default:
1321 			*tl = 0;
1322 			if (err != NFSERR_RETVOID) {
1323 				nfsm_build(tl, u_int32_t *, NFSX_UNSIGNED);
1324 				if (err)
1325 				    *tl = txdr_unsigned(nfsrv_errmap(nd, err));
1326 				else
1327 				    *tl = 0;
1328 			}
1329 			break;
1330 		};
1331 	}
1332 
1333 	if (mrq != NULL)
1334 	    *mrq = mreq;
1335 	*mbp = mb;
1336 	*bposp = bpos;
1337 	if (err != 0 && err != NFSERR_RETVOID)
1338 		nfsstats.srvrpc_errs++;
1339 	return (0);
1340 }
1341 
1342 
1343 #endif /* NFS_NOSERVER */
1344 /*
1345  * Nfs timer routine
1346  * Scan the nfsreq list and retranmit any requests that have timed out
1347  * To avoid retransmission attempts on STREAM sockets (in the future) make
1348  * sure to set the r_retry field to 0 (implies nm_retry == 0).
1349  */
1350 void
1351 nfs_timer(void *arg /* never used */)
1352 {
1353 	struct nfsreq *rep;
1354 	struct mbuf *m;
1355 	struct socket *so;
1356 	struct nfsmount *nmp;
1357 	int timeo;
1358 	int error;
1359 #ifndef NFS_NOSERVER
1360 	struct nfssvc_sock *slp;
1361 	u_quad_t cur_usec;
1362 #endif /* NFS_NOSERVER */
1363 	struct thread *td = &thread0; /* XXX for credentials, will break if sleep */
1364 
1365 	crit_enter();
1366 	TAILQ_FOREACH(rep, &nfs_reqq, r_chain) {
1367 		nmp = rep->r_nmp;
1368 		if (rep->r_mrep || (rep->r_flags & (R_SOFTTERM|R_MASKTIMER)))
1369 			continue;
1370 		rep->r_flags |= R_LOCKED;
1371 		if (nfs_sigintr(nmp, rep, rep->r_td)) {
1372 			nfs_softterm(rep);
1373 			goto skip;
1374 		}
1375 		if (rep->r_rtt >= 0) {
1376 			rep->r_rtt++;
1377 			if (nmp->nm_flag & NFSMNT_DUMBTIMR)
1378 				timeo = nmp->nm_timeo;
1379 			else
1380 				timeo = NFS_RTO(nmp, proct[rep->r_procnum]);
1381 			if (nmp->nm_timeouts > 0)
1382 				timeo *= nfs_backoff[nmp->nm_timeouts - 1];
1383 			if (rep->r_rtt <= timeo)
1384 				goto skip;
1385 			if (nmp->nm_timeouts < 8)
1386 				nmp->nm_timeouts++;
1387 		}
1388 		/*
1389 		 * Check for server not responding
1390 		 */
1391 		if ((rep->r_flags & R_TPRINTFMSG) == 0 &&
1392 		     rep->r_rexmit > nmp->nm_deadthresh) {
1393 			nfs_msg(rep->r_td,
1394 			    nmp->nm_mountp->mnt_stat.f_mntfromname,
1395 			    "not responding");
1396 			rep->r_flags |= R_TPRINTFMSG;
1397 		}
1398 		if (rep->r_rexmit >= rep->r_retry) {	/* too many */
1399 			nfsstats.rpctimeouts++;
1400 			nfs_softterm(rep);
1401 			goto skip;
1402 		}
1403 		if (nmp->nm_sotype != SOCK_DGRAM) {
1404 			if (++rep->r_rexmit > NFS_MAXREXMIT)
1405 				rep->r_rexmit = NFS_MAXREXMIT;
1406 			goto skip;
1407 		}
1408 		if ((so = nmp->nm_so) == NULL)
1409 			goto skip;
1410 
1411 		/*
1412 		 * If there is enough space and the window allows..
1413 		 *	Resend it
1414 		 * Set r_rtt to -1 in case we fail to send it now.
1415 		 */
1416 		rep->r_rtt = -1;
1417 		if (sbspace(&so->so_snd) >= rep->r_mreq->m_pkthdr.len &&
1418 		   ((nmp->nm_flag & NFSMNT_DUMBTIMR) ||
1419 		    (rep->r_flags & R_SENT) ||
1420 		    nmp->nm_sent < nmp->nm_cwnd) &&
1421 		   (m = m_copym(rep->r_mreq, 0, M_COPYALL, MB_DONTWAIT))){
1422 			if ((nmp->nm_flag & NFSMNT_NOCONN) == 0)
1423 			    error = so_pru_send(so, 0, m, (struct sockaddr *)0,
1424 				     (struct mbuf *)0, td);
1425 			else
1426 			    error = so_pru_send(so, 0, m, nmp->nm_nam,
1427 			        (struct mbuf *)0, td);
1428 			if (error) {
1429 				if (NFSIGNORE_SOERROR(nmp->nm_soflags, error))
1430 					so->so_error = 0;
1431 			} else if (rep->r_mrep == NULL) {
1432 				/*
1433 				 * Iff first send, start timing
1434 				 * else turn timing off, backoff timer
1435 				 * and divide congestion window by 2.
1436 				 *
1437 				 * It is possible for the so_pru_send() to
1438 				 * block and for us to race a reply so we
1439 				 * only do this if the reply field has not
1440 				 * been filled in.  R_LOCKED will prevent
1441 				 * the request from being ripped out from under
1442 				 * us entirely.
1443 				 */
1444 				if (rep->r_flags & R_SENT) {
1445 					rep->r_flags &= ~R_TIMING;
1446 					if (++rep->r_rexmit > NFS_MAXREXMIT)
1447 						rep->r_rexmit = NFS_MAXREXMIT;
1448 					nmp->nm_cwnd >>= 1;
1449 					if (nmp->nm_cwnd < NFS_CWNDSCALE)
1450 						nmp->nm_cwnd = NFS_CWNDSCALE;
1451 					nfsstats.rpcretries++;
1452 				} else {
1453 					rep->r_flags |= R_SENT;
1454 					nmp->nm_sent += NFS_CWNDSCALE;
1455 				}
1456 				rep->r_rtt = 0;
1457 			}
1458 		}
1459 skip:
1460 		rep->r_flags &= ~R_LOCKED;
1461 	}
1462 #ifndef NFS_NOSERVER
1463 
1464 	/*
1465 	 * Scan the write gathering queues for writes that need to be
1466 	 * completed now.
1467 	 */
1468 	cur_usec = nfs_curusec();
1469 	TAILQ_FOREACH(slp, &nfssvc_sockhead, ns_chain) {
1470 	    if (slp->ns_tq.lh_first && slp->ns_tq.lh_first->nd_time<=cur_usec)
1471 		nfsrv_wakenfsd(slp, 1);
1472 	}
1473 #endif /* NFS_NOSERVER */
1474 
1475 	/*
1476 	 * Due to possible blocking, a client operation may be waiting for
1477 	 * us to finish processing this request so it can remove it.
1478 	 */
1479 	if (nfs_timer_raced) {
1480 		nfs_timer_raced = 0;
1481 		wakeup(&nfs_timer_raced);
1482 	}
1483 	crit_exit();
1484 	callout_reset(&nfs_timer_handle, nfs_ticks, nfs_timer, NULL);
1485 }
1486 
1487 /*
1488  * Mark all of an nfs mount's outstanding requests with R_SOFTTERM and
1489  * wait for all requests to complete. This is used by forced unmounts
1490  * to terminate any outstanding RPCs.
1491  */
1492 int
1493 nfs_nmcancelreqs(struct nfsmount *nmp)
1494 {
1495 	struct nfsreq *req;
1496 	int i;
1497 
1498 	crit_enter();
1499 	TAILQ_FOREACH(req, &nfs_reqq, r_chain) {
1500 		if (nmp != req->r_nmp || req->r_mrep != NULL ||
1501 		    (req->r_flags & R_SOFTTERM)) {
1502 			continue;
1503 		}
1504 		nfs_softterm(req);
1505 	}
1506 	crit_exit();
1507 
1508 	for (i = 0; i < 30; i++) {
1509 		crit_enter();
1510 		TAILQ_FOREACH(req, &nfs_reqq, r_chain) {
1511 			if (nmp == req->r_nmp)
1512 				break;
1513 		}
1514 		crit_exit();
1515 		if (req == NULL)
1516 			return (0);
1517 		tsleep(&lbolt, 0, "nfscancel", 0);
1518 	}
1519 	return (EBUSY);
1520 }
1521 
1522 /*
1523  * Flag a request as being about to terminate (due to NFSMNT_INT/NFSMNT_SOFT).
1524  * The nm_send count is decremented now to avoid deadlocks when the process in
1525  * soreceive() hasn't yet managed to send its own request.
1526  *
1527  * This routine must be called at splsoftclock() to protect r_flags and
1528  * nm_sent.
1529  */
1530 
1531 static void
1532 nfs_softterm(struct nfsreq *rep)
1533 {
1534 	rep->r_flags |= R_SOFTTERM;
1535 
1536 	if (rep->r_flags & R_SENT) {
1537 		rep->r_nmp->nm_sent -= NFS_CWNDSCALE;
1538 		rep->r_flags &= ~R_SENT;
1539 	}
1540 }
1541 
1542 /*
1543  * Test for a termination condition pending on the process.
1544  * This is used for NFSMNT_INT mounts.
1545  */
1546 int
1547 nfs_sigintr(struct nfsmount *nmp, struct nfsreq *rep, struct thread *td)
1548 {
1549 	sigset_t tmpset;
1550 	struct proc *p;
1551 	struct lwp *lp;
1552 
1553 	if (rep && (rep->r_flags & R_SOFTTERM))
1554 		return (EINTR);
1555 	/* Terminate all requests while attempting a forced unmount. */
1556 	if (nmp->nm_mountp->mnt_kern_flag & MNTK_UNMOUNTF)
1557 		return (EINTR);
1558 	if (!(nmp->nm_flag & NFSMNT_INT))
1559 		return (0);
1560 	/* td might be NULL YYY */
1561 	if (td == NULL || (p = td->td_proc) == NULL)
1562 		return (0);
1563 
1564 	lp = td->td_lwp;
1565 	tmpset = lp->lwp_siglist;
1566 	SIGSETOR(tmpset, p->p_siglist);
1567 	SIGSETNAND(tmpset, lp->lwp_sigmask);
1568 	SIGSETNAND(tmpset, p->p_sigignore);
1569 	if (SIGNOTEMPTY(tmpset) && NFSINT_SIGMASK(tmpset))
1570 		return (EINTR);
1571 
1572 	return (0);
1573 }
1574 
1575 /*
1576  * Lock a socket against others.
1577  * Necessary for STREAM sockets to ensure you get an entire rpc request/reply
1578  * and also to avoid race conditions between the processes with nfs requests
1579  * in progress when a reconnect is necessary.
1580  */
1581 int
1582 nfs_sndlock(struct nfsreq *rep)
1583 {
1584 	int *statep = &rep->r_nmp->nm_state;
1585 	struct thread *td;
1586 	int slptimeo;
1587 	int slpflag;
1588 	int error;
1589 
1590 	slpflag = 0;
1591 	slptimeo = 0;
1592 	td = rep->r_td;
1593 	if (rep->r_nmp->nm_flag & NFSMNT_INT)
1594 		slpflag = PCATCH;
1595 
1596 	error = 0;
1597 	crit_enter();
1598 	while (*statep & NFSSTA_SNDLOCK) {
1599 		*statep |= NFSSTA_WANTSND;
1600 		if (nfs_sigintr(rep->r_nmp, rep, td)) {
1601 			error = EINTR;
1602 			break;
1603 		}
1604 		tsleep((caddr_t)statep, slpflag, "nfsndlck", slptimeo);
1605 		if (slpflag == PCATCH) {
1606 			slpflag = 0;
1607 			slptimeo = 2 * hz;
1608 		}
1609 	}
1610 	/* Always fail if our request has been cancelled. */
1611 	if ((rep->r_flags & R_SOFTTERM))
1612 		error = EINTR;
1613 	if (error == 0)
1614 		*statep |= NFSSTA_SNDLOCK;
1615 	crit_exit();
1616 	return (error);
1617 }
1618 
1619 /*
1620  * Unlock the stream socket for others.
1621  */
1622 void
1623 nfs_sndunlock(struct nfsreq *rep)
1624 {
1625 	int *statep = &rep->r_nmp->nm_state;
1626 
1627 	if ((*statep & NFSSTA_SNDLOCK) == 0)
1628 		panic("nfs sndunlock");
1629 	crit_enter();
1630 	*statep &= ~NFSSTA_SNDLOCK;
1631 	if (*statep & NFSSTA_WANTSND) {
1632 		*statep &= ~NFSSTA_WANTSND;
1633 		wakeup((caddr_t)statep);
1634 	}
1635 	crit_exit();
1636 }
1637 
1638 static int
1639 nfs_rcvlock(struct nfsreq *rep)
1640 {
1641 	int *statep = &rep->r_nmp->nm_state;
1642 	int slpflag;
1643 	int slptimeo;
1644 	int error;
1645 
1646 	/*
1647 	 * Unconditionally check for completion in case another nfsiod
1648 	 * get the packet while the caller was blocked, before the caller
1649 	 * called us.  Packet reception is handled by mainline code which
1650 	 * is protected by the BGL at the moment.
1651 	 *
1652 	 * We do not strictly need the second check just before the
1653 	 * tsleep(), but it's good defensive programming.
1654 	 */
1655 	if (rep->r_mrep != NULL)
1656 		return (EALREADY);
1657 
1658 	if (rep->r_nmp->nm_flag & NFSMNT_INT)
1659 		slpflag = PCATCH;
1660 	else
1661 		slpflag = 0;
1662 	slptimeo = 0;
1663 	error = 0;
1664 	crit_enter();
1665 	while (*statep & NFSSTA_RCVLOCK) {
1666 		if (nfs_sigintr(rep->r_nmp, rep, rep->r_td)) {
1667 			error = EINTR;
1668 			break;
1669 		}
1670 		if (rep->r_mrep != NULL) {
1671 			error = EALREADY;
1672 			break;
1673 		}
1674 		*statep |= NFSSTA_WANTRCV;
1675 		tsleep((caddr_t)statep, slpflag, "nfsrcvlk", slptimeo);
1676 		/*
1677 		 * If our reply was recieved while we were sleeping,
1678 		 * then just return without taking the lock to avoid a
1679 		 * situation where a single iod could 'capture' the
1680 		 * recieve lock.
1681 		 */
1682 		if (rep->r_mrep != NULL) {
1683 			error = EALREADY;
1684 			break;
1685 		}
1686 		if (slpflag == PCATCH) {
1687 			slpflag = 0;
1688 			slptimeo = 2 * hz;
1689 		}
1690 	}
1691 	if (error == 0) {
1692 		*statep |= NFSSTA_RCVLOCK;
1693 		rep->r_nmp->nm_rcvlock_td = curthread;	/* DEBUGGING */
1694 	}
1695 	crit_exit();
1696 	return (error);
1697 }
1698 
1699 /*
1700  * Unlock the stream socket for others.
1701  */
1702 static void
1703 nfs_rcvunlock(struct nfsreq *rep)
1704 {
1705 	int *statep = &rep->r_nmp->nm_state;
1706 
1707 	if ((*statep & NFSSTA_RCVLOCK) == 0)
1708 		panic("nfs rcvunlock");
1709 	crit_enter();
1710 	rep->r_nmp->nm_rcvlock_td = (void *)-1;	/* DEBUGGING */
1711 	*statep &= ~NFSSTA_RCVLOCK;
1712 	if (*statep & NFSSTA_WANTRCV) {
1713 		*statep &= ~NFSSTA_WANTRCV;
1714 		wakeup((caddr_t)statep);
1715 	}
1716 	crit_exit();
1717 }
1718 
1719 /*
1720  *	nfs_realign:
1721  *
1722  *	Check for badly aligned mbuf data and realign by copying the unaligned
1723  *	portion of the data into a new mbuf chain and freeing the portions
1724  *	of the old chain that were replaced.
1725  *
1726  *	We cannot simply realign the data within the existing mbuf chain
1727  *	because the underlying buffers may contain other rpc commands and
1728  *	we cannot afford to overwrite them.
1729  *
1730  *	We would prefer to avoid this situation entirely.  The situation does
1731  *	not occur with NFS/UDP and is supposed to only occassionally occur
1732  *	with TCP.  Use vfs.nfs.realign_count and realign_test to check this.
1733  */
1734 static void
1735 nfs_realign(struct mbuf **pm, int hsiz)
1736 {
1737 	struct mbuf *m;
1738 	struct mbuf *n = NULL;
1739 	int off = 0;
1740 
1741 	++nfs_realign_test;
1742 
1743 	while ((m = *pm) != NULL) {
1744 		if ((m->m_len & 0x3) || (mtod(m, intptr_t) & 0x3)) {
1745 			n = m_getl(m->m_len, MB_WAIT, MT_DATA, 0, NULL);
1746 			n->m_len = 0;
1747 			break;
1748 		}
1749 		pm = &m->m_next;
1750 	}
1751 
1752 	/*
1753 	 * If n is non-NULL, loop on m copying data, then replace the
1754 	 * portion of the chain that had to be realigned.
1755 	 */
1756 	if (n != NULL) {
1757 		++nfs_realign_count;
1758 		while (m) {
1759 			m_copyback(n, off, m->m_len, mtod(m, caddr_t));
1760 			off += m->m_len;
1761 			m = m->m_next;
1762 		}
1763 		m_freem(*pm);
1764 		*pm = n;
1765 	}
1766 }
1767 
1768 #ifndef NFS_NOSERVER
1769 
1770 /*
1771  * Parse an RPC request
1772  * - verify it
1773  * - fill in the cred struct.
1774  */
1775 int
1776 nfs_getreq(struct nfsrv_descript *nd, struct nfsd *nfsd, int has_header)
1777 {
1778 	int len, i;
1779 	u_int32_t *tl;
1780 	int32_t t1;
1781 	struct uio uio;
1782 	struct iovec iov;
1783 	caddr_t dpos, cp2, cp;
1784 	u_int32_t nfsvers, auth_type;
1785 	uid_t nickuid;
1786 	int error = 0, ticklen;
1787 	struct mbuf *mrep, *md;
1788 	struct nfsuid *nuidp;
1789 	struct timeval tvin, tvout;
1790 #if 0				/* until encrypted keys are implemented */
1791 	NFSKERBKEYSCHED_T keys;	/* stores key schedule */
1792 #endif
1793 
1794 	mrep = nd->nd_mrep;
1795 	md = nd->nd_md;
1796 	dpos = nd->nd_dpos;
1797 	if (has_header) {
1798 		nfsm_dissect(tl, u_int32_t *, 10 * NFSX_UNSIGNED);
1799 		nd->nd_retxid = fxdr_unsigned(u_int32_t, *tl++);
1800 		if (*tl++ != rpc_call) {
1801 			m_freem(mrep);
1802 			return (EBADRPC);
1803 		}
1804 	} else
1805 		nfsm_dissect(tl, u_int32_t *, 8 * NFSX_UNSIGNED);
1806 	nd->nd_repstat = 0;
1807 	nd->nd_flag = 0;
1808 	if (*tl++ != rpc_vers) {
1809 		nd->nd_repstat = ERPCMISMATCH;
1810 		nd->nd_procnum = NFSPROC_NOOP;
1811 		return (0);
1812 	}
1813 	if (*tl != nfs_prog) {
1814 		nd->nd_repstat = EPROGUNAVAIL;
1815 		nd->nd_procnum = NFSPROC_NOOP;
1816 		return (0);
1817 	}
1818 	tl++;
1819 	nfsvers = fxdr_unsigned(u_int32_t, *tl++);
1820 	if (nfsvers < NFS_VER2 || nfsvers > NFS_VER3) {
1821 		nd->nd_repstat = EPROGMISMATCH;
1822 		nd->nd_procnum = NFSPROC_NOOP;
1823 		return (0);
1824 	}
1825 	if (nfsvers == NFS_VER3)
1826 		nd->nd_flag = ND_NFSV3;
1827 	nd->nd_procnum = fxdr_unsigned(u_int32_t, *tl++);
1828 	if (nd->nd_procnum == NFSPROC_NULL)
1829 		return (0);
1830 	if (nd->nd_procnum >= NFS_NPROCS ||
1831 		(nd->nd_procnum >= NQNFSPROC_GETLEASE) ||
1832 		(!nd->nd_flag && nd->nd_procnum > NFSV2PROC_STATFS)) {
1833 		nd->nd_repstat = EPROCUNAVAIL;
1834 		nd->nd_procnum = NFSPROC_NOOP;
1835 		return (0);
1836 	}
1837 	if ((nd->nd_flag & ND_NFSV3) == 0)
1838 		nd->nd_procnum = nfsv3_procid[nd->nd_procnum];
1839 	auth_type = *tl++;
1840 	len = fxdr_unsigned(int, *tl++);
1841 	if (len < 0 || len > RPCAUTH_MAXSIZ) {
1842 		m_freem(mrep);
1843 		return (EBADRPC);
1844 	}
1845 
1846 	nd->nd_flag &= ~ND_KERBAUTH;
1847 	/*
1848 	 * Handle auth_unix or auth_kerb.
1849 	 */
1850 	if (auth_type == rpc_auth_unix) {
1851 		len = fxdr_unsigned(int, *++tl);
1852 		if (len < 0 || len > NFS_MAXNAMLEN) {
1853 			m_freem(mrep);
1854 			return (EBADRPC);
1855 		}
1856 		nfsm_adv(nfsm_rndup(len));
1857 		nfsm_dissect(tl, u_int32_t *, 3 * NFSX_UNSIGNED);
1858 		bzero((caddr_t)&nd->nd_cr, sizeof (struct ucred));
1859 		nd->nd_cr.cr_ref = 1;
1860 		nd->nd_cr.cr_uid = fxdr_unsigned(uid_t, *tl++);
1861 		nd->nd_cr.cr_gid = fxdr_unsigned(gid_t, *tl++);
1862 		len = fxdr_unsigned(int, *tl);
1863 		if (len < 0 || len > RPCAUTH_UNIXGIDS) {
1864 			m_freem(mrep);
1865 			return (EBADRPC);
1866 		}
1867 		nfsm_dissect(tl, u_int32_t *, (len + 2) * NFSX_UNSIGNED);
1868 		for (i = 1; i <= len; i++)
1869 		    if (i < NGROUPS)
1870 			nd->nd_cr.cr_groups[i] = fxdr_unsigned(gid_t, *tl++);
1871 		    else
1872 			tl++;
1873 		nd->nd_cr.cr_ngroups = (len >= NGROUPS) ? NGROUPS : (len + 1);
1874 		if (nd->nd_cr.cr_ngroups > 1)
1875 		    nfsrvw_sort(nd->nd_cr.cr_groups, nd->nd_cr.cr_ngroups);
1876 		len = fxdr_unsigned(int, *++tl);
1877 		if (len < 0 || len > RPCAUTH_MAXSIZ) {
1878 			m_freem(mrep);
1879 			return (EBADRPC);
1880 		}
1881 		if (len > 0)
1882 			nfsm_adv(nfsm_rndup(len));
1883 	} else if (auth_type == rpc_auth_kerb) {
1884 		switch (fxdr_unsigned(int, *tl++)) {
1885 		case RPCAKN_FULLNAME:
1886 			ticklen = fxdr_unsigned(int, *tl);
1887 			*((u_int32_t *)nfsd->nfsd_authstr) = *tl;
1888 			uio.uio_resid = nfsm_rndup(ticklen) + NFSX_UNSIGNED;
1889 			nfsd->nfsd_authlen = uio.uio_resid + NFSX_UNSIGNED;
1890 			if (uio.uio_resid > (len - 2 * NFSX_UNSIGNED)) {
1891 				m_freem(mrep);
1892 				return (EBADRPC);
1893 			}
1894 			uio.uio_offset = 0;
1895 			uio.uio_iov = &iov;
1896 			uio.uio_iovcnt = 1;
1897 			uio.uio_segflg = UIO_SYSSPACE;
1898 			iov.iov_base = (caddr_t)&nfsd->nfsd_authstr[4];
1899 			iov.iov_len = RPCAUTH_MAXSIZ - 4;
1900 			nfsm_mtouio(&uio, uio.uio_resid);
1901 			nfsm_dissect(tl, u_int32_t *, 2 * NFSX_UNSIGNED);
1902 			if (*tl++ != rpc_auth_kerb ||
1903 				fxdr_unsigned(int, *tl) != 4 * NFSX_UNSIGNED) {
1904 				kprintf("Bad kerb verifier\n");
1905 				nd->nd_repstat = (NFSERR_AUTHERR|AUTH_BADVERF);
1906 				nd->nd_procnum = NFSPROC_NOOP;
1907 				return (0);
1908 			}
1909 			nfsm_dissect(cp, caddr_t, 4 * NFSX_UNSIGNED);
1910 			tl = (u_int32_t *)cp;
1911 			if (fxdr_unsigned(int, *tl) != RPCAKN_FULLNAME) {
1912 				kprintf("Not fullname kerb verifier\n");
1913 				nd->nd_repstat = (NFSERR_AUTHERR|AUTH_BADVERF);
1914 				nd->nd_procnum = NFSPROC_NOOP;
1915 				return (0);
1916 			}
1917 			cp += NFSX_UNSIGNED;
1918 			bcopy(cp, nfsd->nfsd_verfstr, 3 * NFSX_UNSIGNED);
1919 			nfsd->nfsd_verflen = 3 * NFSX_UNSIGNED;
1920 			nd->nd_flag |= ND_KERBFULL;
1921 			nfsd->nfsd_flag |= NFSD_NEEDAUTH;
1922 			break;
1923 		case RPCAKN_NICKNAME:
1924 			if (len != 2 * NFSX_UNSIGNED) {
1925 				kprintf("Kerb nickname short\n");
1926 				nd->nd_repstat = (NFSERR_AUTHERR|AUTH_BADCRED);
1927 				nd->nd_procnum = NFSPROC_NOOP;
1928 				return (0);
1929 			}
1930 			nickuid = fxdr_unsigned(uid_t, *tl);
1931 			nfsm_dissect(tl, u_int32_t *, 2 * NFSX_UNSIGNED);
1932 			if (*tl++ != rpc_auth_kerb ||
1933 				fxdr_unsigned(int, *tl) != 3 * NFSX_UNSIGNED) {
1934 				kprintf("Kerb nick verifier bad\n");
1935 				nd->nd_repstat = (NFSERR_AUTHERR|AUTH_BADVERF);
1936 				nd->nd_procnum = NFSPROC_NOOP;
1937 				return (0);
1938 			}
1939 			nfsm_dissect(tl, u_int32_t *, 3 * NFSX_UNSIGNED);
1940 			tvin.tv_sec = *tl++;
1941 			tvin.tv_usec = *tl;
1942 
1943 			for (nuidp = NUIDHASH(nfsd->nfsd_slp,nickuid)->lh_first;
1944 			    nuidp != 0; nuidp = nuidp->nu_hash.le_next) {
1945 				if (nuidp->nu_cr.cr_uid == nickuid &&
1946 				    (!nd->nd_nam2 ||
1947 				     netaddr_match(NU_NETFAM(nuidp),
1948 				      &nuidp->nu_haddr, nd->nd_nam2)))
1949 					break;
1950 			}
1951 			if (!nuidp) {
1952 				nd->nd_repstat =
1953 					(NFSERR_AUTHERR|AUTH_REJECTCRED);
1954 				nd->nd_procnum = NFSPROC_NOOP;
1955 				return (0);
1956 			}
1957 
1958 			/*
1959 			 * Now, decrypt the timestamp using the session key
1960 			 * and validate it.
1961 			 */
1962 #ifdef NFSKERB
1963 			XXX
1964 #endif
1965 
1966 			tvout.tv_sec = fxdr_unsigned(long, tvout.tv_sec);
1967 			tvout.tv_usec = fxdr_unsigned(long, tvout.tv_usec);
1968 			if (nuidp->nu_expire < time_second ||
1969 			    nuidp->nu_timestamp.tv_sec > tvout.tv_sec ||
1970 			    (nuidp->nu_timestamp.tv_sec == tvout.tv_sec &&
1971 			     nuidp->nu_timestamp.tv_usec > tvout.tv_usec)) {
1972 				nuidp->nu_expire = 0;
1973 				nd->nd_repstat =
1974 				    (NFSERR_AUTHERR|AUTH_REJECTVERF);
1975 				nd->nd_procnum = NFSPROC_NOOP;
1976 				return (0);
1977 			}
1978 			nfsrv_setcred(&nuidp->nu_cr, &nd->nd_cr);
1979 			nd->nd_flag |= ND_KERBNICK;
1980 		};
1981 	} else {
1982 		nd->nd_repstat = (NFSERR_AUTHERR | AUTH_REJECTCRED);
1983 		nd->nd_procnum = NFSPROC_NOOP;
1984 		return (0);
1985 	}
1986 
1987 	nd->nd_md = md;
1988 	nd->nd_dpos = dpos;
1989 	return (0);
1990 nfsmout:
1991 	return (error);
1992 }
1993 
1994 #endif
1995 
1996 /*
1997  * Send a message to the originating process's terminal.  The thread and/or
1998  * process may be NULL.  YYY the thread should not be NULL but there may
1999  * still be some uio_td's that are still being passed as NULL through to
2000  * nfsm_request().
2001  */
2002 static int
2003 nfs_msg(struct thread *td, char *server, char *msg)
2004 {
2005 	tpr_t tpr;
2006 
2007 	if (td && td->td_proc)
2008 		tpr = tprintf_open(td->td_proc);
2009 	else
2010 		tpr = NULL;
2011 	tprintf(tpr, "nfs server %s: %s\n", server, msg);
2012 	tprintf_close(tpr);
2013 	return (0);
2014 }
2015 
2016 #ifndef NFS_NOSERVER
2017 /*
2018  * Socket upcall routine for the nfsd sockets.
2019  * The caddr_t arg is a pointer to the "struct nfssvc_sock".
2020  * Essentially do as much as possible non-blocking, else punt and it will
2021  * be called with MB_WAIT from an nfsd.
2022  */
2023 void
2024 nfsrv_rcv(struct socket *so, void *arg, int waitflag)
2025 {
2026 	struct nfssvc_sock *slp = (struct nfssvc_sock *)arg;
2027 	struct mbuf *m;
2028 	struct mbuf *mp;
2029 	struct sockaddr *nam;
2030 	struct uio auio;
2031 	int flags, error;
2032 	int nparallel_wakeup = 0;
2033 
2034 	if ((slp->ns_flag & SLP_VALID) == 0)
2035 		return;
2036 
2037 	/*
2038 	 * Do not allow an infinite number of completed RPC records to build
2039 	 * up before we stop reading data from the socket.  Otherwise we could
2040 	 * end up holding onto an unreasonable number of mbufs for requests
2041 	 * waiting for service.
2042 	 *
2043 	 * This should give pretty good feedback to the TCP
2044 	 * layer and prevents a memory crunch for other protocols.
2045 	 *
2046 	 * Note that the same service socket can be dispatched to several
2047 	 * nfs servers simultaniously.
2048 	 *
2049 	 * the tcp protocol callback calls us with MB_DONTWAIT.
2050 	 * nfsd calls us with MB_WAIT (typically).
2051 	 */
2052 	if (waitflag == MB_DONTWAIT && slp->ns_numrec >= nfsd_waiting / 2 + 1) {
2053 		slp->ns_flag |= SLP_NEEDQ;
2054 		goto dorecs;
2055 	}
2056 
2057 	/*
2058 	 * Handle protocol specifics to parse an RPC request.  We always
2059 	 * pull from the socket using non-blocking I/O.
2060 	 */
2061 	auio.uio_td = NULL;
2062 	if (so->so_type == SOCK_STREAM) {
2063 		/*
2064 		 * The data has to be read in an orderly fashion from a TCP
2065 		 * stream, unlike a UDP socket.  It is possible for soreceive
2066 		 * and/or nfsrv_getstream() to block, so make sure only one
2067 		 * entity is messing around with the TCP stream at any given
2068 		 * moment.  The receive sockbuf's lock in soreceive is not
2069 		 * sufficient.
2070 		 *
2071 		 * Note that this procedure can be called from any number of
2072 		 * NFS severs *OR* can be upcalled directly from a TCP
2073 		 * protocol thread.
2074 		 */
2075 		if (slp->ns_flag & SLP_GETSTREAM) {
2076 			slp->ns_flag |= SLP_NEEDQ;
2077 			goto dorecs;
2078 		}
2079 		slp->ns_flag |= SLP_GETSTREAM;
2080 
2081 		/*
2082 		 * Do soreceive().
2083 		 */
2084 		auio.uio_resid = 1000000000;
2085 		flags = MSG_DONTWAIT;
2086 		error = so_pru_soreceive(so, &nam, &auio, &mp, NULL, &flags);
2087 		if (error || mp == (struct mbuf *)0) {
2088 			if (error == EWOULDBLOCK)
2089 				slp->ns_flag |= SLP_NEEDQ;
2090 			else
2091 				slp->ns_flag |= SLP_DISCONN;
2092 			slp->ns_flag &= ~SLP_GETSTREAM;
2093 			goto dorecs;
2094 		}
2095 		m = mp;
2096 		if (slp->ns_rawend) {
2097 			slp->ns_rawend->m_next = m;
2098 			slp->ns_cc += 1000000000 - auio.uio_resid;
2099 		} else {
2100 			slp->ns_raw = m;
2101 			slp->ns_cc = 1000000000 - auio.uio_resid;
2102 		}
2103 		while (m->m_next)
2104 			m = m->m_next;
2105 		slp->ns_rawend = m;
2106 
2107 		/*
2108 		 * Now try and parse as many record(s) as we can out of the
2109 		 * raw stream data.
2110 		 */
2111 		error = nfsrv_getstream(slp, waitflag, &nparallel_wakeup);
2112 		if (error) {
2113 			if (error == EPERM)
2114 				slp->ns_flag |= SLP_DISCONN;
2115 			else
2116 				slp->ns_flag |= SLP_NEEDQ;
2117 		}
2118 		slp->ns_flag &= ~SLP_GETSTREAM;
2119 	} else {
2120 		/*
2121 		 * For UDP soreceive typically pulls just one packet, loop
2122 		 * to get the whole batch.
2123 		 */
2124 		do {
2125 			auio.uio_resid = 1000000000;
2126 			flags = MSG_DONTWAIT;
2127 			error = so_pru_soreceive(so, &nam, &auio, &mp, NULL,
2128 			    &flags);
2129 			if (mp) {
2130 				struct nfsrv_rec *rec;
2131 				int mf = (waitflag & MB_DONTWAIT) ?
2132 					    M_NOWAIT : M_WAITOK;
2133 				rec = kmalloc(sizeof(struct nfsrv_rec),
2134 					     M_NFSRVDESC, mf);
2135 				if (!rec) {
2136 					if (nam)
2137 						FREE(nam, M_SONAME);
2138 					m_freem(mp);
2139 					continue;
2140 				}
2141 				nfs_realign(&mp, 10 * NFSX_UNSIGNED);
2142 				rec->nr_address = nam;
2143 				rec->nr_packet = mp;
2144 				STAILQ_INSERT_TAIL(&slp->ns_rec, rec, nr_link);
2145 				++slp->ns_numrec;
2146 				++nparallel_wakeup;
2147 			}
2148 			if (error) {
2149 				if ((so->so_proto->pr_flags & PR_CONNREQUIRED)
2150 					&& error != EWOULDBLOCK) {
2151 					slp->ns_flag |= SLP_DISCONN;
2152 					goto dorecs;
2153 				}
2154 			}
2155 		} while (mp);
2156 	}
2157 
2158 	/*
2159 	 * If we were upcalled from the tcp protocol layer and we have
2160 	 * fully parsed records ready to go, or there is new data pending,
2161 	 * or something went wrong, try to wake up an nfsd thread to deal
2162 	 * with it.
2163 	 */
2164 dorecs:
2165 	if (waitflag == MB_DONTWAIT && (slp->ns_numrec > 0
2166 	     || (slp->ns_flag & (SLP_NEEDQ | SLP_DISCONN)))) {
2167 		nfsrv_wakenfsd(slp, nparallel_wakeup);
2168 	}
2169 }
2170 
2171 /*
2172  * Try and extract an RPC request from the mbuf data list received on a
2173  * stream socket. The "waitflag" argument indicates whether or not it
2174  * can sleep.
2175  */
2176 static int
2177 nfsrv_getstream(struct nfssvc_sock *slp, int waitflag, int *countp)
2178 {
2179 	struct mbuf *m, **mpp;
2180 	char *cp1, *cp2;
2181 	int len;
2182 	struct mbuf *om, *m2, *recm;
2183 	u_int32_t recmark;
2184 
2185 	for (;;) {
2186 	    if (slp->ns_reclen == 0) {
2187 		if (slp->ns_cc < NFSX_UNSIGNED)
2188 			return (0);
2189 		m = slp->ns_raw;
2190 		if (m->m_len >= NFSX_UNSIGNED) {
2191 			bcopy(mtod(m, caddr_t), (caddr_t)&recmark, NFSX_UNSIGNED);
2192 			m->m_data += NFSX_UNSIGNED;
2193 			m->m_len -= NFSX_UNSIGNED;
2194 		} else {
2195 			cp1 = (caddr_t)&recmark;
2196 			cp2 = mtod(m, caddr_t);
2197 			while (cp1 < ((caddr_t)&recmark) + NFSX_UNSIGNED) {
2198 				while (m->m_len == 0) {
2199 					m = m->m_next;
2200 					cp2 = mtod(m, caddr_t);
2201 				}
2202 				*cp1++ = *cp2++;
2203 				m->m_data++;
2204 				m->m_len--;
2205 			}
2206 		}
2207 		slp->ns_cc -= NFSX_UNSIGNED;
2208 		recmark = ntohl(recmark);
2209 		slp->ns_reclen = recmark & ~0x80000000;
2210 		if (recmark & 0x80000000)
2211 			slp->ns_flag |= SLP_LASTFRAG;
2212 		else
2213 			slp->ns_flag &= ~SLP_LASTFRAG;
2214 		if (slp->ns_reclen > NFS_MAXPACKET || slp->ns_reclen <= 0) {
2215 			log(LOG_ERR, "%s (%d) from nfs client\n",
2216 			    "impossible packet length",
2217 			    slp->ns_reclen);
2218 			return (EPERM);
2219 		}
2220 	    }
2221 
2222 	    /*
2223 	     * Now get the record part.
2224 	     *
2225 	     * Note that slp->ns_reclen may be 0.  Linux sometimes
2226 	     * generates 0-length RPCs
2227 	     */
2228 	    recm = NULL;
2229 	    if (slp->ns_cc == slp->ns_reclen) {
2230 		recm = slp->ns_raw;
2231 		slp->ns_raw = slp->ns_rawend = (struct mbuf *)0;
2232 		slp->ns_cc = slp->ns_reclen = 0;
2233 	    } else if (slp->ns_cc > slp->ns_reclen) {
2234 		len = 0;
2235 		m = slp->ns_raw;
2236 		om = (struct mbuf *)0;
2237 
2238 		while (len < slp->ns_reclen) {
2239 			if ((len + m->m_len) > slp->ns_reclen) {
2240 				m2 = m_copym(m, 0, slp->ns_reclen - len,
2241 					waitflag);
2242 				if (m2) {
2243 					if (om) {
2244 						om->m_next = m2;
2245 						recm = slp->ns_raw;
2246 					} else
2247 						recm = m2;
2248 					m->m_data += slp->ns_reclen - len;
2249 					m->m_len -= slp->ns_reclen - len;
2250 					len = slp->ns_reclen;
2251 				} else {
2252 					return (EWOULDBLOCK);
2253 				}
2254 			} else if ((len + m->m_len) == slp->ns_reclen) {
2255 				om = m;
2256 				len += m->m_len;
2257 				m = m->m_next;
2258 				recm = slp->ns_raw;
2259 				om->m_next = (struct mbuf *)0;
2260 			} else {
2261 				om = m;
2262 				len += m->m_len;
2263 				m = m->m_next;
2264 			}
2265 		}
2266 		slp->ns_raw = m;
2267 		slp->ns_cc -= len;
2268 		slp->ns_reclen = 0;
2269 	    } else {
2270 		return (0);
2271 	    }
2272 
2273 	    /*
2274 	     * Accumulate the fragments into a record.
2275 	     */
2276 	    mpp = &slp->ns_frag;
2277 	    while (*mpp)
2278 		mpp = &((*mpp)->m_next);
2279 	    *mpp = recm;
2280 	    if (slp->ns_flag & SLP_LASTFRAG) {
2281 		struct nfsrv_rec *rec;
2282 		int mf = (waitflag & MB_DONTWAIT) ? M_NOWAIT : M_WAITOK;
2283 		rec = kmalloc(sizeof(struct nfsrv_rec), M_NFSRVDESC, mf);
2284 		if (!rec) {
2285 		    m_freem(slp->ns_frag);
2286 		} else {
2287 		    nfs_realign(&slp->ns_frag, 10 * NFSX_UNSIGNED);
2288 		    rec->nr_address = (struct sockaddr *)0;
2289 		    rec->nr_packet = slp->ns_frag;
2290 		    STAILQ_INSERT_TAIL(&slp->ns_rec, rec, nr_link);
2291 		    ++slp->ns_numrec;
2292 		    ++*countp;
2293 		}
2294 		slp->ns_frag = (struct mbuf *)0;
2295 	    }
2296 	}
2297 }
2298 
2299 /*
2300  * Parse an RPC header.
2301  */
2302 int
2303 nfsrv_dorec(struct nfssvc_sock *slp, struct nfsd *nfsd,
2304 	    struct nfsrv_descript **ndp)
2305 {
2306 	struct nfsrv_rec *rec;
2307 	struct mbuf *m;
2308 	struct sockaddr *nam;
2309 	struct nfsrv_descript *nd;
2310 	int error;
2311 
2312 	*ndp = NULL;
2313 	if ((slp->ns_flag & SLP_VALID) == 0 || !STAILQ_FIRST(&slp->ns_rec))
2314 		return (ENOBUFS);
2315 	rec = STAILQ_FIRST(&slp->ns_rec);
2316 	STAILQ_REMOVE_HEAD(&slp->ns_rec, nr_link);
2317 	KKASSERT(slp->ns_numrec > 0);
2318 	--slp->ns_numrec;
2319 	nam = rec->nr_address;
2320 	m = rec->nr_packet;
2321 	kfree(rec, M_NFSRVDESC);
2322 	MALLOC(nd, struct nfsrv_descript *, sizeof (struct nfsrv_descript),
2323 		M_NFSRVDESC, M_WAITOK);
2324 	nd->nd_md = nd->nd_mrep = m;
2325 	nd->nd_nam2 = nam;
2326 	nd->nd_dpos = mtod(m, caddr_t);
2327 	error = nfs_getreq(nd, nfsd, TRUE);
2328 	if (error) {
2329 		if (nam) {
2330 			FREE(nam, M_SONAME);
2331 		}
2332 		kfree((caddr_t)nd, M_NFSRVDESC);
2333 		return (error);
2334 	}
2335 	*ndp = nd;
2336 	nfsd->nfsd_nd = nd;
2337 	return (0);
2338 }
2339 
2340 /*
2341  * Try to assign service sockets to nfsd threads based on the number
2342  * of new rpc requests that have been queued on the service socket.
2343  *
2344  * If no nfsd's are available or additonal requests are pending, set the
2345  * NFSD_CHECKSLP flag so that one of the running nfsds will go look for
2346  * the work in the nfssvc_sock list when it is finished processing its
2347  * current work.  This flag is only cleared when an nfsd can not find
2348  * any new work to perform.
2349  */
2350 void
2351 nfsrv_wakenfsd(struct nfssvc_sock *slp, int nparallel)
2352 {
2353 	struct nfsd *nd;
2354 
2355 	if ((slp->ns_flag & SLP_VALID) == 0)
2356 		return;
2357 	if (nparallel <= 1)
2358 		nparallel = 1;
2359 	TAILQ_FOREACH(nd, &nfsd_head, nfsd_chain) {
2360 		if (nd->nfsd_flag & NFSD_WAITING) {
2361 			nd->nfsd_flag &= ~NFSD_WAITING;
2362 			if (nd->nfsd_slp)
2363 				panic("nfsd wakeup");
2364 			slp->ns_sref++;
2365 			nd->nfsd_slp = slp;
2366 			wakeup((caddr_t)nd);
2367 			if (--nparallel == 0)
2368 				break;
2369 		}
2370 	}
2371 	if (nparallel) {
2372 		slp->ns_flag |= SLP_DOREC;
2373 		nfsd_head_flag |= NFSD_CHECKSLP;
2374 	}
2375 }
2376 #endif /* NFS_NOSERVER */
2377