xref: /dragonfly/sys/vfs/nfs/nfs_socket.c (revision dca3c15d)
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 1.45 2007/05/18 17:05:13 dillon 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 #include <sys/mutex.h>
65 
66 #include <sys/signal2.h>
67 #include <sys/mutex2.h>
68 
69 #include <netinet/in.h>
70 #include <netinet/tcp.h>
71 #include <sys/thread2.h>
72 
73 #include "rpcv2.h"
74 #include "nfsproto.h"
75 #include "nfs.h"
76 #include "xdr_subs.h"
77 #include "nfsm_subs.h"
78 #include "nfsmount.h"
79 #include "nfsnode.h"
80 #include "nfsrtt.h"
81 
82 #define	TRUE	1
83 #define	FALSE	0
84 
85 /*
86  * RTT calculations are scaled by 256 (8 bits).  A proper fractional
87  * RTT will still be calculated even with a slow NFS timer.
88  */
89 #define	NFS_SRTT(r)	(r)->r_nmp->nm_srtt[proct[(r)->r_procnum]]
90 #define	NFS_SDRTT(r)	(r)->r_nmp->nm_sdrtt[proct[(r)->r_procnum]]
91 #define NFS_RTT_SCALE_BITS	8	/* bits */
92 #define NFS_RTT_SCALE		256	/* value */
93 
94 /*
95  * Defines which timer to use for the procnum.
96  * 0 - default
97  * 1 - getattr
98  * 2 - lookup
99  * 3 - read
100  * 4 - write
101  */
102 static int proct[NFS_NPROCS] = {
103 	0, 1, 0, 2, 1, 3, 3, 4, 0, 0,	/* 00-09	*/
104 	0, 0, 0, 0, 0, 0, 3, 3, 0, 0,	/* 10-19	*/
105 	0, 5, 0, 0, 0, 0,		/* 20-29	*/
106 };
107 
108 static int multt[NFS_NPROCS] = {
109 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1,	/* 00-09	*/
110 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1,	/* 10-19	*/
111 	1, 2, 1, 1, 1, 1,		/* 20-29	*/
112 };
113 
114 static int nfs_backoff[8] = { 2, 3, 5, 8, 13, 21, 34, 55 };
115 static int nfs_realign_test;
116 static int nfs_realign_count;
117 static int nfs_showrtt;
118 static int nfs_showrexmit;
119 int nfs_maxasyncbio = NFS_MAXASYNCBIO;
120 
121 SYSCTL_DECL(_vfs_nfs);
122 
123 SYSCTL_INT(_vfs_nfs, OID_AUTO, realign_test, CTLFLAG_RW, &nfs_realign_test, 0, "");
124 SYSCTL_INT(_vfs_nfs, OID_AUTO, realign_count, CTLFLAG_RW, &nfs_realign_count, 0, "");
125 SYSCTL_INT(_vfs_nfs, OID_AUTO, showrtt, CTLFLAG_RW, &nfs_showrtt, 0, "");
126 SYSCTL_INT(_vfs_nfs, OID_AUTO, showrexmit, CTLFLAG_RW, &nfs_showrexmit, 0, "");
127 SYSCTL_INT(_vfs_nfs, OID_AUTO, maxasyncbio, CTLFLAG_RW, &nfs_maxasyncbio, 0, "");
128 
129 static int nfs_request_setup(nfsm_info_t info);
130 static int nfs_request_auth(struct nfsreq *rep);
131 static int nfs_request_try(struct nfsreq *rep);
132 static int nfs_request_waitreply(struct nfsreq *rep);
133 static int nfs_request_processreply(nfsm_info_t info, int);
134 
135 int nfsrtton = 0;
136 struct nfsrtt nfsrtt;
137 struct callout	nfs_timer_handle;
138 
139 static int	nfs_msg (struct thread *,char *,char *);
140 static int	nfs_rcvlock (struct nfsmount *nmp, struct nfsreq *myreq);
141 static void	nfs_rcvunlock (struct nfsmount *nmp);
142 static void	nfs_realign (struct mbuf **pm, int hsiz);
143 static int	nfs_receive (struct nfsmount *nmp, struct nfsreq *rep,
144 				struct sockaddr **aname, struct mbuf **mp);
145 static void	nfs_softterm (struct nfsreq *rep, int islocked);
146 static void	nfs_hardterm (struct nfsreq *rep, int islocked);
147 static int	nfs_reconnect (struct nfsmount *nmp, struct nfsreq *rep);
148 #ifndef NFS_NOSERVER
149 static int	nfsrv_getstream (struct nfssvc_sock *, int, int *);
150 static void	nfs_timer_req(struct nfsreq *req);
151 
152 int (*nfsrv3_procs[NFS_NPROCS]) (struct nfsrv_descript *nd,
153 				    struct nfssvc_sock *slp,
154 				    struct thread *td,
155 				    struct mbuf **mreqp) = {
156 	nfsrv_null,
157 	nfsrv_getattr,
158 	nfsrv_setattr,
159 	nfsrv_lookup,
160 	nfsrv3_access,
161 	nfsrv_readlink,
162 	nfsrv_read,
163 	nfsrv_write,
164 	nfsrv_create,
165 	nfsrv_mkdir,
166 	nfsrv_symlink,
167 	nfsrv_mknod,
168 	nfsrv_remove,
169 	nfsrv_rmdir,
170 	nfsrv_rename,
171 	nfsrv_link,
172 	nfsrv_readdir,
173 	nfsrv_readdirplus,
174 	nfsrv_statfs,
175 	nfsrv_fsinfo,
176 	nfsrv_pathconf,
177 	nfsrv_commit,
178 	nfsrv_noop,
179 	nfsrv_noop,
180 	nfsrv_noop,
181 	nfsrv_noop
182 };
183 #endif /* NFS_NOSERVER */
184 
185 /*
186  * Initialize sockets and congestion for a new NFS connection.
187  * We do not free the sockaddr if error.
188  */
189 int
190 nfs_connect(struct nfsmount *nmp, struct nfsreq *rep)
191 {
192 	struct socket *so;
193 	int error;
194 	struct sockaddr *saddr;
195 	struct sockaddr_in *sin;
196 	struct thread *td = &thread0; /* only used for socreate and sobind */
197 
198 	nmp->nm_so = so = NULL;
199 	if (nmp->nm_flag & NFSMNT_FORCE)
200 		return (EINVAL);
201 	saddr = nmp->nm_nam;
202 	error = socreate(saddr->sa_family, &so, nmp->nm_sotype,
203 		nmp->nm_soproto, td);
204 	if (error)
205 		goto bad;
206 	nmp->nm_soflags = so->so_proto->pr_flags;
207 
208 	/*
209 	 * Some servers require that the client port be a reserved port number.
210 	 */
211 	if (saddr->sa_family == AF_INET && (nmp->nm_flag & NFSMNT_RESVPORT)) {
212 		struct sockopt sopt;
213 		int ip;
214 		struct sockaddr_in ssin;
215 
216 		bzero(&sopt, sizeof sopt);
217 		ip = IP_PORTRANGE_LOW;
218 		sopt.sopt_level = IPPROTO_IP;
219 		sopt.sopt_name = IP_PORTRANGE;
220 		sopt.sopt_val = (void *)&ip;
221 		sopt.sopt_valsize = sizeof(ip);
222 		sopt.sopt_td = NULL;
223 		error = sosetopt(so, &sopt);
224 		if (error)
225 			goto bad;
226 		bzero(&ssin, sizeof ssin);
227 		sin = &ssin;
228 		sin->sin_len = sizeof (struct sockaddr_in);
229 		sin->sin_family = AF_INET;
230 		sin->sin_addr.s_addr = INADDR_ANY;
231 		sin->sin_port = htons(0);
232 		error = sobind(so, (struct sockaddr *)sin, td);
233 		if (error)
234 			goto bad;
235 		bzero(&sopt, sizeof sopt);
236 		ip = IP_PORTRANGE_DEFAULT;
237 		sopt.sopt_level = IPPROTO_IP;
238 		sopt.sopt_name = IP_PORTRANGE;
239 		sopt.sopt_val = (void *)&ip;
240 		sopt.sopt_valsize = sizeof(ip);
241 		sopt.sopt_td = NULL;
242 		error = sosetopt(so, &sopt);
243 		if (error)
244 			goto bad;
245 	}
246 
247 	/*
248 	 * Protocols that do not require connections may be optionally left
249 	 * unconnected for servers that reply from a port other than NFS_PORT.
250 	 */
251 	if (nmp->nm_flag & NFSMNT_NOCONN) {
252 		if (nmp->nm_soflags & PR_CONNREQUIRED) {
253 			error = ENOTCONN;
254 			goto bad;
255 		}
256 	} else {
257 		error = soconnect(so, nmp->nm_nam, td);
258 		if (error)
259 			goto bad;
260 
261 		/*
262 		 * Wait for the connection to complete. Cribbed from the
263 		 * connect system call but with the wait timing out so
264 		 * that interruptible mounts don't hang here for a long time.
265 		 */
266 		crit_enter();
267 		while ((so->so_state & SS_ISCONNECTING) && so->so_error == 0) {
268 			(void) tsleep((caddr_t)&so->so_timeo, 0,
269 				"nfscon", 2 * hz);
270 			if ((so->so_state & SS_ISCONNECTING) &&
271 			    so->so_error == 0 && rep &&
272 			    (error = nfs_sigintr(nmp, rep, rep->r_td)) != 0){
273 				so->so_state &= ~SS_ISCONNECTING;
274 				crit_exit();
275 				goto bad;
276 			}
277 		}
278 		if (so->so_error) {
279 			error = so->so_error;
280 			so->so_error = 0;
281 			crit_exit();
282 			goto bad;
283 		}
284 		crit_exit();
285 	}
286 	so->so_rcv.ssb_timeo = (5 * hz);
287 	so->so_snd.ssb_timeo = (5 * hz);
288 
289 	/*
290 	 * Get buffer reservation size from sysctl, but impose reasonable
291 	 * limits.
292 	 */
293 	if (nmp->nm_sotype == SOCK_STREAM) {
294 		if (so->so_proto->pr_flags & PR_CONNREQUIRED) {
295 			struct sockopt sopt;
296 			int val;
297 
298 			bzero(&sopt, sizeof sopt);
299 			sopt.sopt_level = SOL_SOCKET;
300 			sopt.sopt_name = SO_KEEPALIVE;
301 			sopt.sopt_val = &val;
302 			sopt.sopt_valsize = sizeof val;
303 			val = 1;
304 			sosetopt(so, &sopt);
305 		}
306 		if (so->so_proto->pr_protocol == IPPROTO_TCP) {
307 			struct sockopt sopt;
308 			int val;
309 
310 			bzero(&sopt, sizeof sopt);
311 			sopt.sopt_level = IPPROTO_TCP;
312 			sopt.sopt_name = TCP_NODELAY;
313 			sopt.sopt_val = &val;
314 			sopt.sopt_valsize = sizeof val;
315 			val = 1;
316 			sosetopt(so, &sopt);
317 		}
318 	}
319 	error = soreserve(so, nfs_soreserve, nfs_soreserve, NULL);
320 	if (error)
321 		goto bad;
322 	so->so_rcv.ssb_flags |= SSB_NOINTR;
323 	so->so_snd.ssb_flags |= SSB_NOINTR;
324 
325 	/* Initialize other non-zero congestion variables */
326 	nmp->nm_srtt[0] = nmp->nm_srtt[1] = nmp->nm_srtt[2] =
327 		nmp->nm_srtt[3] = (NFS_TIMEO << NFS_RTT_SCALE_BITS);
328 	nmp->nm_sdrtt[0] = nmp->nm_sdrtt[1] = nmp->nm_sdrtt[2] =
329 		nmp->nm_sdrtt[3] = 0;
330 	nmp->nm_maxasync_scaled = NFS_MINASYNC_SCALED;
331 	nmp->nm_timeouts = 0;
332 
333 	/*
334 	 * Assign nm_so last.  The moment nm_so is assigned the nfs_timer()
335 	 * can mess with the socket.
336 	 */
337 	nmp->nm_so = so;
338 	return (0);
339 
340 bad:
341 	if (so) {
342 		soshutdown(so, SHUT_RDWR);
343 		soclose(so, FNONBLOCK);
344 	}
345 	return (error);
346 }
347 
348 /*
349  * Reconnect routine:
350  * Called when a connection is broken on a reliable protocol.
351  * - clean up the old socket
352  * - nfs_connect() again
353  * - set R_NEEDSXMIT for all outstanding requests on mount point
354  * If this fails the mount point is DEAD!
355  * nb: Must be called with the nfs_sndlock() set on the mount point.
356  */
357 static int
358 nfs_reconnect(struct nfsmount *nmp, struct nfsreq *rep)
359 {
360 	struct nfsreq *req;
361 	int error;
362 
363 	nfs_disconnect(nmp);
364 	if (nmp->nm_rxstate >= NFSSVC_STOPPING)
365 		return (EINTR);
366 	while ((error = nfs_connect(nmp, rep)) != 0) {
367 		if (error == EINTR || error == ERESTART)
368 			return (EINTR);
369 		if (error == EINVAL)
370 			return (error);
371 		if (nmp->nm_rxstate >= NFSSVC_STOPPING)
372 			return (EINTR);
373 		(void) tsleep((caddr_t)&lbolt, 0, "nfscon", 0);
374 	}
375 
376 	/*
377 	 * Loop through outstanding request list and fix up all requests
378 	 * on old socket.
379 	 */
380 	crit_enter();
381 	TAILQ_FOREACH(req, &nmp->nm_reqq, r_chain) {
382 		KKASSERT(req->r_nmp == nmp);
383 		req->r_flags |= R_NEEDSXMIT;
384 	}
385 	crit_exit();
386 	return (0);
387 }
388 
389 /*
390  * NFS disconnect. Clean up and unlink.
391  */
392 void
393 nfs_disconnect(struct nfsmount *nmp)
394 {
395 	struct socket *so;
396 
397 	if (nmp->nm_so) {
398 		so = nmp->nm_so;
399 		nmp->nm_so = NULL;
400 		soshutdown(so, SHUT_RDWR);
401 		soclose(so, FNONBLOCK);
402 	}
403 }
404 
405 void
406 nfs_safedisconnect(struct nfsmount *nmp)
407 {
408 	nfs_rcvlock(nmp, NULL);
409 	nfs_disconnect(nmp);
410 	nfs_rcvunlock(nmp);
411 }
412 
413 /*
414  * This is the nfs send routine. For connection based socket types, it
415  * must be called with an nfs_sndlock() on the socket.
416  * "rep == NULL" indicates that it has been called from a server.
417  * For the client side:
418  * - return EINTR if the RPC is terminated, 0 otherwise
419  * - set R_NEEDSXMIT if the send fails for any reason
420  * - do any cleanup required by recoverable socket errors (?)
421  * For the server side:
422  * - return EINTR or ERESTART if interrupted by a signal
423  * - return EPIPE if a connection is lost for connection based sockets (TCP...)
424  * - do any cleanup required by recoverable socket errors (?)
425  */
426 int
427 nfs_send(struct socket *so, struct sockaddr *nam, struct mbuf *top,
428 	 struct nfsreq *rep)
429 {
430 	struct sockaddr *sendnam;
431 	int error, soflags, flags;
432 
433 	if (rep) {
434 		if (rep->r_flags & R_SOFTTERM) {
435 			m_freem(top);
436 			return (EINTR);
437 		}
438 		if ((so = rep->r_nmp->nm_so) == NULL) {
439 			rep->r_flags |= R_NEEDSXMIT;
440 			m_freem(top);
441 			return (0);
442 		}
443 		rep->r_flags &= ~R_NEEDSXMIT;
444 		soflags = rep->r_nmp->nm_soflags;
445 	} else {
446 		soflags = so->so_proto->pr_flags;
447 	}
448 	if ((soflags & PR_CONNREQUIRED) || (so->so_state & SS_ISCONNECTED))
449 		sendnam = NULL;
450 	else
451 		sendnam = nam;
452 	if (so->so_type == SOCK_SEQPACKET)
453 		flags = MSG_EOR;
454 	else
455 		flags = 0;
456 
457 	error = so_pru_sosend(so, sendnam, NULL, top, NULL, flags,
458 	    curthread /*XXX*/);
459 	/*
460 	 * ENOBUFS for dgram sockets is transient and non fatal.
461 	 * No need to log, and no need to break a soft mount.
462 	 */
463 	if (error == ENOBUFS && so->so_type == SOCK_DGRAM) {
464 		error = 0;
465 		/*
466 		 * do backoff retransmit on client
467 		 */
468 		if (rep) {
469 			if ((rep->r_nmp->nm_state & NFSSTA_SENDSPACE) == 0) {
470 				rep->r_nmp->nm_state |= NFSSTA_SENDSPACE;
471 				kprintf("Warning: NFS: Insufficient sendspace "
472 					"(%lu),\n"
473 					"\t You must increase vfs.nfs.soreserve"
474 					"or decrease vfs.nfs.maxasyncbio\n",
475 					so->so_snd.ssb_hiwat);
476 			}
477 			rep->r_flags |= R_NEEDSXMIT;
478 		}
479 	}
480 
481 	if (error) {
482 		if (rep) {
483 			log(LOG_INFO, "nfs send error %d for server %s\n",error,
484 			    rep->r_nmp->nm_mountp->mnt_stat.f_mntfromname);
485 			/*
486 			 * Deal with errors for the client side.
487 			 */
488 			if (rep->r_flags & R_SOFTTERM)
489 				error = EINTR;
490 			else
491 				rep->r_flags |= R_NEEDSXMIT;
492 		} else {
493 			log(LOG_INFO, "nfsd send error %d\n", error);
494 		}
495 
496 		/*
497 		 * Handle any recoverable (soft) socket errors here. (?)
498 		 */
499 		if (error != EINTR && error != ERESTART &&
500 			error != EWOULDBLOCK && error != EPIPE)
501 			error = 0;
502 	}
503 	return (error);
504 }
505 
506 /*
507  * Receive a Sun RPC Request/Reply. For SOCK_DGRAM, the work is all
508  * done by soreceive(), but for SOCK_STREAM we must deal with the Record
509  * Mark and consolidate the data into a new mbuf list.
510  * nb: Sometimes TCP passes the data up to soreceive() in long lists of
511  *     small mbufs.
512  * For SOCK_STREAM we must be very careful to read an entire record once
513  * we have read any of it, even if the system call has been interrupted.
514  */
515 static int
516 nfs_receive(struct nfsmount *nmp, struct nfsreq *rep,
517 	    struct sockaddr **aname, struct mbuf **mp)
518 {
519 	struct socket *so;
520 	struct sockbuf sio;
521 	struct uio auio;
522 	struct iovec aio;
523 	struct mbuf *m;
524 	struct mbuf *control;
525 	u_int32_t len;
526 	struct sockaddr **getnam;
527 	int error, sotype, rcvflg;
528 	struct thread *td = curthread;	/* XXX */
529 
530 	/*
531 	 * Set up arguments for soreceive()
532 	 */
533 	*mp = NULL;
534 	*aname = NULL;
535 	sotype = nmp->nm_sotype;
536 
537 	/*
538 	 * For reliable protocols, lock against other senders/receivers
539 	 * in case a reconnect is necessary.
540 	 * For SOCK_STREAM, first get the Record Mark to find out how much
541 	 * more there is to get.
542 	 * We must lock the socket against other receivers
543 	 * until we have an entire rpc request/reply.
544 	 */
545 	if (sotype != SOCK_DGRAM) {
546 		error = nfs_sndlock(nmp, rep);
547 		if (error)
548 			return (error);
549 tryagain:
550 		/*
551 		 * Check for fatal errors and resending request.
552 		 */
553 		/*
554 		 * Ugh: If a reconnect attempt just happened, nm_so
555 		 * would have changed. NULL indicates a failed
556 		 * attempt that has essentially shut down this
557 		 * mount point.
558 		 */
559 		if (rep && (rep->r_mrep || (rep->r_flags & R_SOFTTERM))) {
560 			nfs_sndunlock(nmp);
561 			return (EINTR);
562 		}
563 		so = nmp->nm_so;
564 		if (so == NULL) {
565 			error = nfs_reconnect(nmp, rep);
566 			if (error) {
567 				nfs_sndunlock(nmp);
568 				return (error);
569 			}
570 			goto tryagain;
571 		}
572 		while (rep && (rep->r_flags & R_NEEDSXMIT)) {
573 			m = m_copym(rep->r_mreq, 0, M_COPYALL, MB_WAIT);
574 			nfsstats.rpcretries++;
575 			error = nfs_send(so, rep->r_nmp->nm_nam, m, rep);
576 			if (error) {
577 				if (error == EINTR || error == ERESTART ||
578 				    (error = nfs_reconnect(nmp, rep)) != 0) {
579 					nfs_sndunlock(nmp);
580 					return (error);
581 				}
582 				goto tryagain;
583 			}
584 		}
585 		nfs_sndunlock(nmp);
586 		if (sotype == SOCK_STREAM) {
587 			/*
588 			 * Get the length marker from the stream
589 			 */
590 			aio.iov_base = (caddr_t)&len;
591 			aio.iov_len = sizeof(u_int32_t);
592 			auio.uio_iov = &aio;
593 			auio.uio_iovcnt = 1;
594 			auio.uio_segflg = UIO_SYSSPACE;
595 			auio.uio_rw = UIO_READ;
596 			auio.uio_offset = 0;
597 			auio.uio_resid = sizeof(u_int32_t);
598 			auio.uio_td = td;
599 			do {
600 			   rcvflg = MSG_WAITALL;
601 			   error = so_pru_soreceive(so, NULL, &auio, NULL,
602 						    NULL, &rcvflg);
603 			   if (error == EWOULDBLOCK && rep) {
604 				if (rep->r_flags & R_SOFTTERM)
605 					return (EINTR);
606 			   }
607 			} while (error == EWOULDBLOCK);
608 
609 			if (error == 0 && auio.uio_resid > 0) {
610 			    /*
611 			     * Only log short packets if not EOF
612 			     */
613 			    if (auio.uio_resid != sizeof(u_int32_t))
614 			    log(LOG_INFO,
615 				 "short receive (%d/%d) from nfs server %s\n",
616 				 (int)(sizeof(u_int32_t) - auio.uio_resid),
617 				 (int)sizeof(u_int32_t),
618 				 nmp->nm_mountp->mnt_stat.f_mntfromname);
619 			    error = EPIPE;
620 			}
621 			if (error)
622 				goto errout;
623 			len = ntohl(len) & ~0x80000000;
624 			/*
625 			 * This is SERIOUS! We are out of sync with the sender
626 			 * and forcing a disconnect/reconnect is all I can do.
627 			 */
628 			if (len > NFS_MAXPACKET) {
629 			    log(LOG_ERR, "%s (%d) from nfs server %s\n",
630 				"impossible packet length",
631 				len,
632 				nmp->nm_mountp->mnt_stat.f_mntfromname);
633 			    error = EFBIG;
634 			    goto errout;
635 			}
636 
637 			/*
638 			 * Get the rest of the packet as an mbuf chain
639 			 */
640 			sbinit(&sio, len);
641 			do {
642 			    rcvflg = MSG_WAITALL;
643 			    error = so_pru_soreceive(so, NULL, NULL, &sio,
644 						     NULL, &rcvflg);
645 			} while (error == EWOULDBLOCK || error == EINTR ||
646 				 error == ERESTART);
647 			if (error == 0 && sio.sb_cc != len) {
648 			    if (sio.sb_cc != 0)
649 			    log(LOG_INFO,
650 				"short receive (%zu/%d) from nfs server %s\n",
651 				(size_t)len - auio.uio_resid, len,
652 				nmp->nm_mountp->mnt_stat.f_mntfromname);
653 			    error = EPIPE;
654 			}
655 			*mp = sio.sb_mb;
656 		} else {
657 			/*
658 			 * Non-stream, so get the whole packet by not
659 			 * specifying MSG_WAITALL and by specifying a large
660 			 * length.
661 			 *
662 			 * We have no use for control msg., but must grab them
663 			 * and then throw them away so we know what is going
664 			 * on.
665 			 */
666 			sbinit(&sio, 100000000);
667 			do {
668 			    rcvflg = 0;
669 			    error =  so_pru_soreceive(so, NULL, NULL, &sio,
670 						      &control, &rcvflg);
671 			    if (control)
672 				m_freem(control);
673 			    if (error == EWOULDBLOCK && rep) {
674 				if (rep->r_flags & R_SOFTTERM) {
675 					m_freem(sio.sb_mb);
676 					return (EINTR);
677 				}
678 			    }
679 			} while (error == EWOULDBLOCK ||
680 				 (error == 0 && sio.sb_mb == NULL && control));
681 			if ((rcvflg & MSG_EOR) == 0)
682 				kprintf("Egad!!\n");
683 			if (error == 0 && sio.sb_mb == NULL)
684 				error = EPIPE;
685 			len = sio.sb_cc;
686 			*mp = sio.sb_mb;
687 		}
688 errout:
689 		if (error && error != EINTR && error != ERESTART) {
690 			m_freem(*mp);
691 			*mp = NULL;
692 			if (error != EPIPE) {
693 				log(LOG_INFO,
694 				    "receive error %d from nfs server %s\n",
695 				    error,
696 				 nmp->nm_mountp->mnt_stat.f_mntfromname);
697 			}
698 			error = nfs_sndlock(nmp, rep);
699 			if (!error) {
700 				error = nfs_reconnect(nmp, rep);
701 				if (!error)
702 					goto tryagain;
703 				else
704 					nfs_sndunlock(nmp);
705 			}
706 		}
707 	} else {
708 		if ((so = nmp->nm_so) == NULL)
709 			return (EACCES);
710 		if (so->so_state & SS_ISCONNECTED)
711 			getnam = NULL;
712 		else
713 			getnam = aname;
714 		sbinit(&sio, 100000000);
715 		do {
716 			rcvflg = 0;
717 			error =  so_pru_soreceive(so, getnam, NULL, &sio,
718 						  NULL, &rcvflg);
719 			if (error == EWOULDBLOCK && rep &&
720 			    (rep->r_flags & R_SOFTTERM)) {
721 				m_freem(sio.sb_mb);
722 				return (EINTR);
723 			}
724 		} while (error == EWOULDBLOCK);
725 
726 		len = sio.sb_cc;
727 		*mp = sio.sb_mb;
728 
729 		/*
730 		 * A shutdown may result in no error and no mbuf.
731 		 * Convert to EPIPE.
732 		 */
733 		if (*mp == NULL && error == 0)
734 			error = EPIPE;
735 	}
736 	if (error) {
737 		m_freem(*mp);
738 		*mp = NULL;
739 	}
740 
741 	/*
742 	 * Search for any mbufs that are not a multiple of 4 bytes long
743 	 * or with m_data not longword aligned.
744 	 * These could cause pointer alignment problems, so copy them to
745 	 * well aligned mbufs.
746 	 */
747 	nfs_realign(mp, 5 * NFSX_UNSIGNED);
748 	return (error);
749 }
750 
751 /*
752  * Implement receipt of reply on a socket.
753  *
754  * We must search through the list of received datagrams matching them
755  * with outstanding requests using the xid, until ours is found.
756  *
757  * If myrep is NULL we process packets on the socket until
758  * interrupted or until nm_reqrxq is non-empty.
759  */
760 /* ARGSUSED */
761 int
762 nfs_reply(struct nfsmount *nmp, struct nfsreq *myrep)
763 {
764 	struct nfsreq *rep;
765 	struct sockaddr *nam;
766 	u_int32_t rxid;
767 	u_int32_t *tl;
768 	int error;
769 	struct nfsm_info info;
770 
771 	/*
772 	 * Loop around until we get our own reply
773 	 */
774 	for (;;) {
775 		/*
776 		 * Lock against other receivers so that I don't get stuck in
777 		 * sbwait() after someone else has received my reply for me.
778 		 * Also necessary for connection based protocols to avoid
779 		 * race conditions during a reconnect.
780 		 *
781 		 * If nfs_rcvlock() returns EALREADY, that means that
782 		 * the reply has already been recieved by another
783 		 * process and we can return immediately.  In this
784 		 * case, the lock is not taken to avoid races with
785 		 * other processes.
786 		 */
787 		info.mrep = NULL;
788 
789 		error = nfs_rcvlock(nmp, myrep);
790 		if (error == EALREADY)
791 			return (0);
792 		if (error)
793 			return (error);
794 
795 		/*
796 		 * If myrep is NULL we are the receiver helper thread.
797 		 * Stop waiting for incoming replies if there are
798 		 * messages sitting on reqrxq that we need to process,
799 		 * or if a shutdown request is pending.
800 		 */
801 		if (myrep == NULL && (TAILQ_FIRST(&nmp->nm_reqrxq) ||
802 		    nmp->nm_rxstate > NFSSVC_PENDING)) {
803 			nfs_rcvunlock(nmp);
804 			return(EWOULDBLOCK);
805 		}
806 
807 		/*
808 		 * Get the next Rpc reply off the socket
809 		 *
810 		 * We cannot release the receive lock until we've
811 		 * filled in rep->r_mrep, otherwise a waiting
812 		 * thread may deadlock in soreceive with no incoming
813 		 * packets expected.
814 		 */
815 		error = nfs_receive(nmp, myrep, &nam, &info.mrep);
816 		if (error) {
817 			/*
818 			 * Ignore routing errors on connectionless protocols??
819 			 */
820 			nfs_rcvunlock(nmp);
821 			if (NFSIGNORE_SOERROR(nmp->nm_soflags, error)) {
822 				if (nmp->nm_so == NULL)
823 					return (error);
824 				nmp->nm_so->so_error = 0;
825 				continue;
826 			}
827 			return (error);
828 		}
829 		if (nam)
830 			FREE(nam, M_SONAME);
831 
832 		/*
833 		 * Get the xid and check that it is an rpc reply
834 		 */
835 		info.md = info.mrep;
836 		info.dpos = mtod(info.md, caddr_t);
837 		NULLOUT(tl = nfsm_dissect(&info, 2*NFSX_UNSIGNED));
838 		rxid = *tl++;
839 		if (*tl != rpc_reply) {
840 			nfsstats.rpcinvalid++;
841 			m_freem(info.mrep);
842 			info.mrep = NULL;
843 nfsmout:
844 			nfs_rcvunlock(nmp);
845 			continue;
846 		}
847 
848 		/*
849 		 * Loop through the request list to match up the reply
850 		 * Iff no match, just drop the datagram.  On match, set
851 		 * r_mrep atomically to prevent the timer from messing
852 		 * around with the request after we have exited the critical
853 		 * section.
854 		 */
855 		crit_enter();
856 		TAILQ_FOREACH(rep, &nmp->nm_reqq, r_chain) {
857 			if (rep->r_mrep == NULL && rxid == rep->r_xid)
858 				break;
859 		}
860 
861 		/*
862 		 * Fill in the rest of the reply if we found a match.
863 		 *
864 		 * Deal with duplicate responses if there was no match.
865 		 */
866 		if (rep) {
867 			rep->r_md = info.md;
868 			rep->r_dpos = info.dpos;
869 			if (nfsrtton) {
870 				struct rttl *rt;
871 
872 				rt = &nfsrtt.rttl[nfsrtt.pos];
873 				rt->proc = rep->r_procnum;
874 				rt->rto = 0;
875 				rt->sent = 0;
876 				rt->cwnd = nmp->nm_maxasync_scaled;
877 				rt->srtt = nmp->nm_srtt[proct[rep->r_procnum] - 1];
878 				rt->sdrtt = nmp->nm_sdrtt[proct[rep->r_procnum] - 1];
879 				rt->fsid = nmp->nm_mountp->mnt_stat.f_fsid;
880 				getmicrotime(&rt->tstamp);
881 				if (rep->r_flags & R_TIMING)
882 					rt->rtt = rep->r_rtt;
883 				else
884 					rt->rtt = 1000000;
885 				nfsrtt.pos = (nfsrtt.pos + 1) % NFSRTTLOGSIZ;
886 			}
887 
888 			/*
889 			 * New congestion control is based only on async
890 			 * requests.
891 			 */
892 			if (nmp->nm_maxasync_scaled < NFS_MAXASYNC_SCALED)
893 				++nmp->nm_maxasync_scaled;
894 			if (rep->r_flags & R_SENT) {
895 				rep->r_flags &= ~R_SENT;
896 			}
897 			/*
898 			 * Update rtt using a gain of 0.125 on the mean
899 			 * and a gain of 0.25 on the deviation.
900 			 *
901 			 * NOTE SRTT/SDRTT are only good if R_TIMING is set.
902 			 */
903 			if ((rep->r_flags & R_TIMING) && rep->r_rexmit == 0) {
904 				/*
905 				 * Since the timer resolution of
906 				 * NFS_HZ is so course, it can often
907 				 * result in r_rtt == 0. Since
908 				 * r_rtt == N means that the actual
909 				 * rtt is between N+dt and N+2-dt ticks,
910 				 * add 1.
911 				 */
912 				int n;
913 				int d;
914 
915 #define NFSRSB	NFS_RTT_SCALE_BITS
916 				n = ((NFS_SRTT(rep) * 7) +
917 				     (rep->r_rtt << NFSRSB)) >> 3;
918 				d = n - NFS_SRTT(rep);
919 				NFS_SRTT(rep) = n;
920 
921 				/*
922 				 * Don't let the jitter calculation decay
923 				 * too quickly, but we want a fast rampup.
924 				 */
925 				if (d < 0)
926 					d = -d;
927 				d <<= NFSRSB;
928 				if (d < NFS_SDRTT(rep))
929 					n = ((NFS_SDRTT(rep) * 15) + d) >> 4;
930 				else
931 					n = ((NFS_SDRTT(rep) * 3) + d) >> 2;
932 				NFS_SDRTT(rep) = n;
933 #undef NFSRSB
934 			}
935 			nmp->nm_timeouts = 0;
936 			rep->r_mrep = info.mrep;
937 			nfs_hardterm(rep, 0);
938 		} else {
939 			/*
940 			 * Extract vers, prog, nfsver, procnum.  A duplicate
941 			 * response means we didn't wait long enough so
942 			 * we increase the SRTT to avoid future spurious
943 			 * timeouts.
944 			 */
945 			u_int procnum = nmp->nm_lastreprocnum;
946 			int n;
947 
948 			if (procnum < NFS_NPROCS && proct[procnum]) {
949 				if (nfs_showrexmit)
950 					kprintf("D");
951 				n = nmp->nm_srtt[proct[procnum]];
952 				n += NFS_ASYSCALE * NFS_HZ;
953 				if (n < NFS_ASYSCALE * NFS_HZ * 10)
954 					n = NFS_ASYSCALE * NFS_HZ * 10;
955 				nmp->nm_srtt[proct[procnum]] = n;
956 			}
957 		}
958 		nfs_rcvunlock(nmp);
959 		crit_exit();
960 
961 		/*
962 		 * If not matched to a request, drop it.
963 		 * If it's mine, get out.
964 		 */
965 		if (rep == NULL) {
966 			nfsstats.rpcunexpected++;
967 			m_freem(info.mrep);
968 			info.mrep = NULL;
969 		} else if (rep == myrep) {
970 			if (rep->r_mrep == NULL)
971 				panic("nfsreply nil");
972 			return (0);
973 		}
974 	}
975 }
976 
977 /*
978  * Run the request state machine until the target state is reached
979  * or a fatal error occurs.  The target state is not run.  Specifying
980  * a target of NFSM_STATE_DONE runs the state machine until the rpc
981  * is complete.
982  *
983  * EINPROGRESS is returned for all states other then the DONE state,
984  * indicating that the rpc is still in progress.
985  */
986 int
987 nfs_request(struct nfsm_info *info, nfsm_state_t bstate, nfsm_state_t estate)
988 {
989 	struct nfsreq *req;
990 
991 	while (info->state >= bstate && info->state < estate) {
992 		switch(info->state) {
993 		case NFSM_STATE_SETUP:
994 			/*
995 			 * Setup the nfsreq.  Any error which occurs during
996 			 * this state is fatal.
997 			 */
998 			info->error = nfs_request_setup(info);
999 			if (info->error) {
1000 				info->state = NFSM_STATE_DONE;
1001 				return (info->error);
1002 			} else {
1003 				req = info->req;
1004 				req->r_mrp = &info->mrep;
1005 				req->r_mdp = &info->md;
1006 				req->r_dposp = &info->dpos;
1007 				info->state = NFSM_STATE_AUTH;
1008 			}
1009 			break;
1010 		case NFSM_STATE_AUTH:
1011 			/*
1012 			 * Authenticate the nfsreq.  Any error which occurs
1013 			 * during this state is fatal.
1014 			 */
1015 			info->error = nfs_request_auth(info->req);
1016 			if (info->error) {
1017 				info->state = NFSM_STATE_DONE;
1018 				return (info->error);
1019 			} else {
1020 				info->state = NFSM_STATE_TRY;
1021 			}
1022 			break;
1023 		case NFSM_STATE_TRY:
1024 			/*
1025 			 * Transmit or retransmit attempt.  An error in this
1026 			 * state is ignored and we always move on to the
1027 			 * next state.
1028 			 *
1029 			 * This can trivially race the receiver if the
1030 			 * request is asynchronous.  nfs_request_try()
1031 			 * will thus set the state for us and we
1032 			 * must also return immediately if we are
1033 			 * running an async state machine, because
1034 			 * info can become invalid due to races after
1035 			 * try() returns.
1036 			 */
1037 			if (info->req->r_flags & R_ASYNC) {
1038 				nfs_request_try(info->req);
1039 				if (estate == NFSM_STATE_WAITREPLY)
1040 					return (EINPROGRESS);
1041 			} else {
1042 				nfs_request_try(info->req);
1043 				info->state = NFSM_STATE_WAITREPLY;
1044 			}
1045 			break;
1046 		case NFSM_STATE_WAITREPLY:
1047 			/*
1048 			 * Wait for a reply or timeout and move on to the
1049 			 * next state.  The error returned by this state
1050 			 * is passed to the processing code in the next
1051 			 * state.
1052 			 */
1053 			info->error = nfs_request_waitreply(info->req);
1054 			info->state = NFSM_STATE_PROCESSREPLY;
1055 			break;
1056 		case NFSM_STATE_PROCESSREPLY:
1057 			/*
1058 			 * Process the reply or timeout.  Errors which occur
1059 			 * in this state may cause the state machine to
1060 			 * go back to an earlier state, and are fatal
1061 			 * otherwise.
1062 			 */
1063 			info->error = nfs_request_processreply(info,
1064 							       info->error);
1065 			switch(info->error) {
1066 			case ENEEDAUTH:
1067 				info->state = NFSM_STATE_AUTH;
1068 				break;
1069 			case EAGAIN:
1070 				info->state = NFSM_STATE_TRY;
1071 				break;
1072 			default:
1073 				/*
1074 				 * Operation complete, with or without an
1075 				 * error.  We are done.
1076 				 */
1077 				info->req = NULL;
1078 				info->state = NFSM_STATE_DONE;
1079 				return (info->error);
1080 			}
1081 			break;
1082 		case NFSM_STATE_DONE:
1083 			/*
1084 			 * Shouldn't be reached
1085 			 */
1086 			return (info->error);
1087 			/* NOT REACHED */
1088 		}
1089 	}
1090 
1091 	/*
1092 	 * If we are done return the error code (if any).
1093 	 * Otherwise return EINPROGRESS.
1094 	 */
1095 	if (info->state == NFSM_STATE_DONE)
1096 		return (info->error);
1097 	return (EINPROGRESS);
1098 }
1099 
1100 /*
1101  * nfs_request - goes something like this
1102  *	- fill in request struct
1103  *	- links it into list
1104  *	- calls nfs_send() for first transmit
1105  *	- calls nfs_receive() to get reply
1106  *	- break down rpc header and return with nfs reply pointed to
1107  *	  by mrep or error
1108  * nb: always frees up mreq mbuf list
1109  */
1110 static int
1111 nfs_request_setup(nfsm_info_t info)
1112 {
1113 	struct nfsreq *req;
1114 	struct nfsmount *nmp;
1115 	struct mbuf *m;
1116 	int i;
1117 
1118 	/*
1119 	 * Reject requests while attempting a forced unmount.
1120 	 */
1121 	if (info->vp->v_mount->mnt_kern_flag & MNTK_UNMOUNTF) {
1122 		m_freem(info->mreq);
1123 		info->mreq = NULL;
1124 		return (ESTALE);
1125 	}
1126 	nmp = VFSTONFS(info->vp->v_mount);
1127 	req = kmalloc(sizeof(struct nfsreq), M_NFSREQ, M_WAITOK);
1128 	req->r_nmp = nmp;
1129 	req->r_vp = info->vp;
1130 	req->r_td = info->td;
1131 	req->r_procnum = info->procnum;
1132 	req->r_mreq = NULL;
1133 	req->r_cred = info->cred;
1134 
1135 	i = 0;
1136 	m = info->mreq;
1137 	while (m) {
1138 		i += m->m_len;
1139 		m = m->m_next;
1140 	}
1141 	req->r_mrest = info->mreq;
1142 	req->r_mrest_len = i;
1143 
1144 	/*
1145 	 * The presence of a non-NULL r_info in req indicates
1146 	 * async completion via our helper threads.  See the receiver
1147 	 * code.
1148 	 */
1149 	if (info->bio) {
1150 		req->r_info = info;
1151 		req->r_flags = R_ASYNC;
1152 	} else {
1153 		req->r_info = NULL;
1154 		req->r_flags = 0;
1155 	}
1156 	info->req = req;
1157 	return(0);
1158 }
1159 
1160 static int
1161 nfs_request_auth(struct nfsreq *rep)
1162 {
1163 	struct nfsmount *nmp = rep->r_nmp;
1164 	struct mbuf *m;
1165 	char nickv[RPCX_NICKVERF];
1166 	int error = 0, auth_len, auth_type;
1167 	int verf_len;
1168 	u_int32_t xid;
1169 	char *auth_str, *verf_str;
1170 	struct ucred *cred;
1171 
1172 	cred = rep->r_cred;
1173 	rep->r_failed_auth = 0;
1174 
1175 	/*
1176 	 * Get the RPC header with authorization.
1177 	 */
1178 	verf_str = auth_str = NULL;
1179 	if (nmp->nm_flag & NFSMNT_KERB) {
1180 		verf_str = nickv;
1181 		verf_len = sizeof (nickv);
1182 		auth_type = RPCAUTH_KERB4;
1183 		bzero((caddr_t)rep->r_key, sizeof(rep->r_key));
1184 		if (rep->r_failed_auth ||
1185 		    nfs_getnickauth(nmp, cred, &auth_str, &auth_len,
1186 				    verf_str, verf_len)) {
1187 			error = nfs_getauth(nmp, rep, cred, &auth_str,
1188 				&auth_len, verf_str, &verf_len, rep->r_key);
1189 			if (error) {
1190 				m_freem(rep->r_mrest);
1191 				rep->r_mrest = NULL;
1192 				kfree((caddr_t)rep, M_NFSREQ);
1193 				return (error);
1194 			}
1195 		}
1196 	} else {
1197 		auth_type = RPCAUTH_UNIX;
1198 		if (cred->cr_ngroups < 1)
1199 			panic("nfsreq nogrps");
1200 		auth_len = ((((cred->cr_ngroups - 1) > nmp->nm_numgrps) ?
1201 			nmp->nm_numgrps : (cred->cr_ngroups - 1)) << 2) +
1202 			5 * NFSX_UNSIGNED;
1203 	}
1204 	m = nfsm_rpchead(cred, nmp->nm_flag, rep->r_procnum, auth_type,
1205 			auth_len, auth_str, verf_len, verf_str,
1206 			rep->r_mrest, rep->r_mrest_len, &rep->r_mheadend, &xid);
1207 	rep->r_mrest = NULL;
1208 	if (auth_str)
1209 		kfree(auth_str, M_TEMP);
1210 
1211 	/*
1212 	 * For stream protocols, insert a Sun RPC Record Mark.
1213 	 */
1214 	if (nmp->nm_sotype == SOCK_STREAM) {
1215 		M_PREPEND(m, NFSX_UNSIGNED, MB_WAIT);
1216 		if (m == NULL) {
1217 			kfree(rep, M_NFSREQ);
1218 			return (ENOBUFS);
1219 		}
1220 		*mtod(m, u_int32_t *) = htonl(0x80000000 |
1221 			 (m->m_pkthdr.len - NFSX_UNSIGNED));
1222 	}
1223 	rep->r_mreq = m;
1224 	rep->r_xid = xid;
1225 	return (0);
1226 }
1227 
1228 static int
1229 nfs_request_try(struct nfsreq *rep)
1230 {
1231 	struct nfsmount *nmp = rep->r_nmp;
1232 	struct mbuf *m2;
1233 	int error;
1234 
1235 	/*
1236 	 * Request is not on any queue, only the owner has access to it
1237 	 * so it should not be locked by anyone atm.
1238 	 *
1239 	 * Interlock to prevent races.  While locked the only remote
1240 	 * action possible is for r_mrep to be set (once we enqueue it).
1241 	 */
1242 	if (rep->r_flags == 0xdeadc0de) {
1243 		print_backtrace();
1244 		panic("flags nbad\n");
1245 	}
1246 	KKASSERT((rep->r_flags & (R_LOCKED | R_ONREQQ)) == 0);
1247 	if (nmp->nm_flag & NFSMNT_SOFT)
1248 		rep->r_retry = nmp->nm_retry;
1249 	else
1250 		rep->r_retry = NFS_MAXREXMIT + 1;	/* past clip limit */
1251 	rep->r_rtt = rep->r_rexmit = 0;
1252 	if (proct[rep->r_procnum] > 0)
1253 		rep->r_flags |= R_TIMING | R_LOCKED;
1254 	else
1255 		rep->r_flags |= R_LOCKED;
1256 	rep->r_mrep = NULL;
1257 
1258 	/*
1259 	 * Do the client side RPC.
1260 	 */
1261 	nfsstats.rpcrequests++;
1262 
1263 	if (nmp->nm_flag & NFSMNT_FORCE) {
1264 		rep->r_flags |= R_SOFTTERM;
1265 		rep->r_flags &= ~R_LOCKED;
1266 		return (0);
1267 	}
1268 
1269 	/*
1270 	 * Chain request into list of outstanding requests. Be sure
1271 	 * to put it LAST so timer finds oldest requests first.  Note
1272 	 * that our control of R_LOCKED prevents the request from
1273 	 * getting ripped out from under us or transmitted by the
1274 	 * timer code.
1275 	 *
1276 	 * For requests with info structures we must atomically set the
1277 	 * info's state because the structure could become invalid upon
1278 	 * return due to races (i.e., if async)
1279 	 */
1280 	crit_enter();
1281 	mtx_link_init(&rep->r_link);
1282 	TAILQ_INSERT_TAIL(&nmp->nm_reqq, rep, r_chain);
1283 	rep->r_flags |= R_ONREQQ;
1284 	++nmp->nm_reqqlen;
1285 	if (rep->r_flags & R_ASYNC)
1286 		rep->r_info->state = NFSM_STATE_WAITREPLY;
1287 	crit_exit();
1288 
1289 	error = 0;
1290 
1291 	/*
1292 	 * Send if we can.  Congestion control is not handled here any more
1293 	 * becausing trying to defer the initial send based on the nfs_timer
1294 	 * requires having a very fast nfs_timer, which is silly.
1295 	 */
1296 	if (nmp->nm_so) {
1297 		if (nmp->nm_soflags & PR_CONNREQUIRED)
1298 			error = nfs_sndlock(nmp, rep);
1299 		if (error == 0) {
1300 			m2 = m_copym(rep->r_mreq, 0, M_COPYALL, MB_WAIT);
1301 			error = nfs_send(nmp->nm_so, nmp->nm_nam, m2, rep);
1302 			if (nmp->nm_soflags & PR_CONNREQUIRED)
1303 				nfs_sndunlock(nmp);
1304 			rep->r_flags &= ~R_NEEDSXMIT;
1305 			if ((rep->r_flags & R_SENT) == 0) {
1306 				rep->r_flags |= R_SENT;
1307 			}
1308 		} else {
1309 			rep->r_flags |= R_NEEDSXMIT;
1310 		}
1311 	} else {
1312 		rep->r_flags |= R_NEEDSXMIT;
1313 		rep->r_rtt = -1;
1314 	}
1315 	if (error == EPIPE)
1316 		error = 0;
1317 
1318 	/*
1319 	 * Release the lock.  The only remote action that may have occurred
1320 	 * would have been the setting of rep->r_mrep.  If this occured
1321 	 * and the request was async we have to move it to the reader
1322 	 * thread's queue for action.
1323 	 *
1324 	 * For async requests also make sure the reader is woken up so
1325 	 * it gets on the socket to read responses.
1326 	 */
1327 	crit_enter();
1328 	if (rep->r_flags & R_ASYNC) {
1329 		if (rep->r_mrep)
1330 			nfs_hardterm(rep, 1);
1331 		rep->r_flags &= ~R_LOCKED;
1332 		nfssvc_iod_reader_wakeup(nmp);
1333 	} else {
1334 		rep->r_flags &= ~R_LOCKED;
1335 	}
1336 	if (rep->r_flags & R_WANTED) {
1337 		rep->r_flags &= ~R_WANTED;
1338 		wakeup(rep);
1339 	}
1340 	crit_exit();
1341 	return (error);
1342 }
1343 
1344 /*
1345  * This code is only called for synchronous requests.  Completed synchronous
1346  * requests are left on reqq and we remove them before moving on to the
1347  * processing state.
1348  */
1349 static int
1350 nfs_request_waitreply(struct nfsreq *rep)
1351 {
1352 	struct nfsmount *nmp = rep->r_nmp;
1353 	int error;
1354 
1355 	KKASSERT((rep->r_flags & R_ASYNC) == 0);
1356 
1357 	/*
1358 	 * Wait until the request is finished.
1359 	 */
1360 	error = nfs_reply(nmp, rep);
1361 
1362 	/*
1363 	 * RPC done, unlink the request, but don't rip it out from under
1364 	 * the callout timer.
1365 	 *
1366 	 * Once unlinked no other receiver or the timer will have
1367 	 * visibility, so we do not have to set R_LOCKED.
1368 	 */
1369 	crit_enter();
1370 	while (rep->r_flags & R_LOCKED) {
1371 		rep->r_flags |= R_WANTED;
1372 		tsleep(rep, 0, "nfstrac", 0);
1373 	}
1374 	KKASSERT(rep->r_flags & R_ONREQQ);
1375 	TAILQ_REMOVE(&nmp->nm_reqq, rep, r_chain);
1376 	rep->r_flags &= ~R_ONREQQ;
1377 	--nmp->nm_reqqlen;
1378 	if (TAILQ_FIRST(&nmp->nm_bioq) &&
1379 	    nmp->nm_reqqlen <= nfs_maxasyncbio * 2 / 3) {
1380 		nfssvc_iod_writer_wakeup(nmp);
1381 	}
1382 	crit_exit();
1383 
1384 	/*
1385 	 * Decrement the outstanding request count.
1386 	 */
1387 	if (rep->r_flags & R_SENT) {
1388 		rep->r_flags &= ~R_SENT;
1389 	}
1390 	return (error);
1391 }
1392 
1393 /*
1394  * Process reply with error returned from nfs_requet_waitreply().
1395  *
1396  * Returns EAGAIN if it wants us to loop up to nfs_request_try() again.
1397  * Returns ENEEDAUTH if it wants us to loop up to nfs_request_auth() again.
1398  */
1399 static int
1400 nfs_request_processreply(nfsm_info_t info, int error)
1401 {
1402 	struct nfsreq *req = info->req;
1403 	struct nfsmount *nmp = req->r_nmp;
1404 	u_int32_t *tl;
1405 	int verf_type;
1406 	int i;
1407 
1408 	/*
1409 	 * If there was a successful reply and a tprintf msg.
1410 	 * tprintf a response.
1411 	 */
1412 	if (error == 0 && (req->r_flags & R_TPRINTFMSG)) {
1413 		nfs_msg(req->r_td, nmp->nm_mountp->mnt_stat.f_mntfromname,
1414 		    "is alive again");
1415 	}
1416 	info->mrep = req->r_mrep;
1417 	info->md = req->r_md;
1418 	info->dpos = req->r_dpos;
1419 	if (error) {
1420 		m_freem(req->r_mreq);
1421 		req->r_mreq = NULL;
1422 		kfree(req, M_NFSREQ);
1423 		info->req = NULL;
1424 		return (error);
1425 	}
1426 
1427 	/*
1428 	 * break down the rpc header and check if ok
1429 	 */
1430 	NULLOUT(tl = nfsm_dissect(info, 3 * NFSX_UNSIGNED));
1431 	if (*tl++ == rpc_msgdenied) {
1432 		if (*tl == rpc_mismatch) {
1433 			error = EOPNOTSUPP;
1434 		} else if ((nmp->nm_flag & NFSMNT_KERB) &&
1435 			   *tl++ == rpc_autherr) {
1436 			if (req->r_failed_auth == 0) {
1437 				req->r_failed_auth++;
1438 				req->r_mheadend->m_next = NULL;
1439 				m_freem(info->mrep);
1440 				info->mrep = NULL;
1441 				m_freem(req->r_mreq);
1442 				return (ENEEDAUTH);
1443 			} else {
1444 				error = EAUTH;
1445 			}
1446 		} else {
1447 			error = EACCES;
1448 		}
1449 		m_freem(info->mrep);
1450 		info->mrep = NULL;
1451 		m_freem(req->r_mreq);
1452 		req->r_mreq = NULL;
1453 		kfree(req, M_NFSREQ);
1454 		info->req = NULL;
1455 		return (error);
1456 	}
1457 
1458 	/*
1459 	 * Grab any Kerberos verifier, otherwise just throw it away.
1460 	 */
1461 	verf_type = fxdr_unsigned(int, *tl++);
1462 	i = fxdr_unsigned(int32_t, *tl);
1463 	if ((nmp->nm_flag & NFSMNT_KERB) && verf_type == RPCAUTH_KERB4) {
1464 		error = nfs_savenickauth(nmp, req->r_cred, i, req->r_key,
1465 					 &info->md, &info->dpos, info->mrep);
1466 		if (error)
1467 			goto nfsmout;
1468 	} else if (i > 0) {
1469 		ERROROUT(nfsm_adv(info, nfsm_rndup(i)));
1470 	}
1471 	NULLOUT(tl = nfsm_dissect(info, NFSX_UNSIGNED));
1472 	/* 0 == ok */
1473 	if (*tl == 0) {
1474 		NULLOUT(tl = nfsm_dissect(info, NFSX_UNSIGNED));
1475 		if (*tl != 0) {
1476 			error = fxdr_unsigned(int, *tl);
1477 
1478 			/*
1479 			 * Does anyone even implement this?  Just impose
1480 			 * a 1-second delay.
1481 			 */
1482 			if ((nmp->nm_flag & NFSMNT_NFSV3) &&
1483 				error == NFSERR_TRYLATER) {
1484 				m_freem(info->mrep);
1485 				info->mrep = NULL;
1486 				error = 0;
1487 
1488 				tsleep((caddr_t)&lbolt, 0, "nqnfstry", 0);
1489 				return (EAGAIN);	/* goto tryagain */
1490 			}
1491 
1492 			/*
1493 			 * If the File Handle was stale, invalidate the
1494 			 * lookup cache, just in case.
1495 			 *
1496 			 * To avoid namecache<->vnode deadlocks we must
1497 			 * release the vnode lock if we hold it.
1498 			 */
1499 			if (error == ESTALE) {
1500 				struct vnode *vp = req->r_vp;
1501 				int ltype;
1502 
1503 				ltype = lockstatus(&vp->v_lock, curthread);
1504 				if (ltype == LK_EXCLUSIVE || ltype == LK_SHARED)
1505 					lockmgr(&vp->v_lock, LK_RELEASE);
1506 				cache_inval_vp(vp, CINV_CHILDREN);
1507 				if (ltype == LK_EXCLUSIVE || ltype == LK_SHARED)
1508 					lockmgr(&vp->v_lock, ltype);
1509 			}
1510 			if (nmp->nm_flag & NFSMNT_NFSV3) {
1511 				KKASSERT(*req->r_mrp == info->mrep);
1512 				KKASSERT(*req->r_mdp == info->md);
1513 				KKASSERT(*req->r_dposp == info->dpos);
1514 				error |= NFSERR_RETERR;
1515 			} else {
1516 				m_freem(info->mrep);
1517 				info->mrep = NULL;
1518 			}
1519 			m_freem(req->r_mreq);
1520 			req->r_mreq = NULL;
1521 			kfree(req, M_NFSREQ);
1522 			info->req = NULL;
1523 			return (error);
1524 		}
1525 
1526 		KKASSERT(*req->r_mrp == info->mrep);
1527 		KKASSERT(*req->r_mdp == info->md);
1528 		KKASSERT(*req->r_dposp == info->dpos);
1529 		m_freem(req->r_mreq);
1530 		req->r_mreq = NULL;
1531 		FREE(req, M_NFSREQ);
1532 		return (0);
1533 	}
1534 	m_freem(info->mrep);
1535 	info->mrep = NULL;
1536 	error = EPROTONOSUPPORT;
1537 nfsmout:
1538 	m_freem(req->r_mreq);
1539 	req->r_mreq = NULL;
1540 	kfree(req, M_NFSREQ);
1541 	info->req = NULL;
1542 	return (error);
1543 }
1544 
1545 #ifndef NFS_NOSERVER
1546 /*
1547  * Generate the rpc reply header
1548  * siz arg. is used to decide if adding a cluster is worthwhile
1549  */
1550 int
1551 nfs_rephead(int siz, struct nfsrv_descript *nd, struct nfssvc_sock *slp,
1552 	    int err, struct mbuf **mrq, struct mbuf **mbp, caddr_t *bposp)
1553 {
1554 	u_int32_t *tl;
1555 	struct nfsm_info info;
1556 
1557 	siz += RPC_REPLYSIZ;
1558 	info.mb = m_getl(max_hdr + siz, MB_WAIT, MT_DATA, M_PKTHDR, NULL);
1559 	info.mreq = info.mb;
1560 	info.mreq->m_pkthdr.len = 0;
1561 	/*
1562 	 * If this is not a cluster, try and leave leading space
1563 	 * for the lower level headers.
1564 	 */
1565 	if ((max_hdr + siz) < MINCLSIZE)
1566 		info.mreq->m_data += max_hdr;
1567 	tl = mtod(info.mreq, u_int32_t *);
1568 	info.mreq->m_len = 6 * NFSX_UNSIGNED;
1569 	info.bpos = ((caddr_t)tl) + info.mreq->m_len;
1570 	*tl++ = txdr_unsigned(nd->nd_retxid);
1571 	*tl++ = rpc_reply;
1572 	if (err == ERPCMISMATCH || (err & NFSERR_AUTHERR)) {
1573 		*tl++ = rpc_msgdenied;
1574 		if (err & NFSERR_AUTHERR) {
1575 			*tl++ = rpc_autherr;
1576 			*tl = txdr_unsigned(err & ~NFSERR_AUTHERR);
1577 			info.mreq->m_len -= NFSX_UNSIGNED;
1578 			info.bpos -= NFSX_UNSIGNED;
1579 		} else {
1580 			*tl++ = rpc_mismatch;
1581 			*tl++ = txdr_unsigned(RPC_VER2);
1582 			*tl = txdr_unsigned(RPC_VER2);
1583 		}
1584 	} else {
1585 		*tl++ = rpc_msgaccepted;
1586 
1587 		/*
1588 		 * For Kerberos authentication, we must send the nickname
1589 		 * verifier back, otherwise just RPCAUTH_NULL.
1590 		 */
1591 		if (nd->nd_flag & ND_KERBFULL) {
1592 		    struct nfsuid *nuidp;
1593 		    struct timeval ktvin, ktvout;
1594 
1595 		    for (nuidp = NUIDHASH(slp, nd->nd_cr.cr_uid)->lh_first;
1596 			nuidp != 0; nuidp = nuidp->nu_hash.le_next) {
1597 			if (nuidp->nu_cr.cr_uid == nd->nd_cr.cr_uid &&
1598 			    (!nd->nd_nam2 || netaddr_match(NU_NETFAM(nuidp),
1599 			     &nuidp->nu_haddr, nd->nd_nam2)))
1600 			    break;
1601 		    }
1602 		    if (nuidp) {
1603 			ktvin.tv_sec =
1604 			    txdr_unsigned(nuidp->nu_timestamp.tv_sec - 1);
1605 			ktvin.tv_usec =
1606 			    txdr_unsigned(nuidp->nu_timestamp.tv_usec);
1607 
1608 			/*
1609 			 * Encrypt the timestamp in ecb mode using the
1610 			 * session key.
1611 			 */
1612 #ifdef NFSKERB
1613 			XXX
1614 #else
1615 			ktvout.tv_sec = 0;
1616 			ktvout.tv_usec = 0;
1617 #endif
1618 
1619 			*tl++ = rpc_auth_kerb;
1620 			*tl++ = txdr_unsigned(3 * NFSX_UNSIGNED);
1621 			*tl = ktvout.tv_sec;
1622 			tl = nfsm_build(&info, 3 * NFSX_UNSIGNED);
1623 			*tl++ = ktvout.tv_usec;
1624 			*tl++ = txdr_unsigned(nuidp->nu_cr.cr_uid);
1625 		    } else {
1626 			*tl++ = 0;
1627 			*tl++ = 0;
1628 		    }
1629 		} else {
1630 			*tl++ = 0;
1631 			*tl++ = 0;
1632 		}
1633 		switch (err) {
1634 		case EPROGUNAVAIL:
1635 			*tl = txdr_unsigned(RPC_PROGUNAVAIL);
1636 			break;
1637 		case EPROGMISMATCH:
1638 			*tl = txdr_unsigned(RPC_PROGMISMATCH);
1639 			tl = nfsm_build(&info, 2 * NFSX_UNSIGNED);
1640 			*tl++ = txdr_unsigned(2);
1641 			*tl = txdr_unsigned(3);
1642 			break;
1643 		case EPROCUNAVAIL:
1644 			*tl = txdr_unsigned(RPC_PROCUNAVAIL);
1645 			break;
1646 		case EBADRPC:
1647 			*tl = txdr_unsigned(RPC_GARBAGE);
1648 			break;
1649 		default:
1650 			*tl = 0;
1651 			if (err != NFSERR_RETVOID) {
1652 				tl = nfsm_build(&info, NFSX_UNSIGNED);
1653 				if (err)
1654 				    *tl = txdr_unsigned(nfsrv_errmap(nd, err));
1655 				else
1656 				    *tl = 0;
1657 			}
1658 			break;
1659 		};
1660 	}
1661 
1662 	if (mrq != NULL)
1663 	    *mrq = info.mreq;
1664 	*mbp = info.mb;
1665 	*bposp = info.bpos;
1666 	if (err != 0 && err != NFSERR_RETVOID)
1667 		nfsstats.srvrpc_errs++;
1668 	return (0);
1669 }
1670 
1671 
1672 #endif /* NFS_NOSERVER */
1673 
1674 /*
1675  * Nfs timer routine.
1676  *
1677  * Scan the nfsreq list and retranmit any requests that have timed out
1678  * To avoid retransmission attempts on STREAM sockets (in the future) make
1679  * sure to set the r_retry field to 0 (implies nm_retry == 0).
1680  *
1681  * Requests with attached responses, terminated requests, and
1682  * locked requests are ignored.  Locked requests will be picked up
1683  * in a later timer call.
1684  */
1685 void
1686 nfs_timer(void *arg /* never used */)
1687 {
1688 	struct nfsmount *nmp;
1689 	struct nfsreq *req;
1690 #ifndef NFS_NOSERVER
1691 	struct nfssvc_sock *slp;
1692 	u_quad_t cur_usec;
1693 #endif /* NFS_NOSERVER */
1694 
1695 	crit_enter();
1696 	TAILQ_FOREACH(nmp, &nfs_mountq, nm_entry) {
1697 		TAILQ_FOREACH(req, &nmp->nm_reqq, r_chain) {
1698 			KKASSERT(nmp == req->r_nmp);
1699 			if (req->r_mrep)
1700 				continue;
1701 			if (req->r_flags & (R_SOFTTERM | R_LOCKED))
1702 				continue;
1703 			req->r_flags |= R_LOCKED;
1704 			if (nfs_sigintr(nmp, req, req->r_td)) {
1705 				nfs_softterm(req, 1);
1706 			} else {
1707 				nfs_timer_req(req);
1708 			}
1709 			req->r_flags &= ~R_LOCKED;
1710 			if (req->r_flags & R_WANTED) {
1711 				req->r_flags &= ~R_WANTED;
1712 				wakeup(req);
1713 			}
1714 		}
1715 	}
1716 #ifndef NFS_NOSERVER
1717 
1718 	/*
1719 	 * Scan the write gathering queues for writes that need to be
1720 	 * completed now.
1721 	 */
1722 	cur_usec = nfs_curusec();
1723 	TAILQ_FOREACH(slp, &nfssvc_sockhead, ns_chain) {
1724 	    if (slp->ns_tq.lh_first && slp->ns_tq.lh_first->nd_time<=cur_usec)
1725 		nfsrv_wakenfsd(slp, 1);
1726 	}
1727 #endif /* NFS_NOSERVER */
1728 	crit_exit();
1729 	callout_reset(&nfs_timer_handle, nfs_ticks, nfs_timer, NULL);
1730 }
1731 
1732 static
1733 void
1734 nfs_timer_req(struct nfsreq *req)
1735 {
1736 	struct thread *td = &thread0; /* XXX for creds, will break if sleep */
1737 	struct nfsmount *nmp = req->r_nmp;
1738 	struct mbuf *m;
1739 	struct socket *so;
1740 	int timeo;
1741 	int error;
1742 
1743 	/*
1744 	 * rtt ticks and timeout calculation.  Return if the timeout
1745 	 * has not been reached yet, unless the packet is flagged
1746 	 * for an immediate send.
1747 	 *
1748 	 * The mean rtt doesn't help when we get random I/Os, we have
1749 	 * to multiply by fairly large numbers.
1750 	 */
1751 	if (req->r_rtt >= 0) {
1752 		/*
1753 		 * Calculate the timeout to test against.
1754 		 */
1755 		req->r_rtt++;
1756 		if (nmp->nm_flag & NFSMNT_DUMBTIMR) {
1757 			timeo = nmp->nm_timeo << NFS_RTT_SCALE_BITS;
1758 		} else if (req->r_flags & R_TIMING) {
1759 			timeo = NFS_SRTT(req) + NFS_SDRTT(req);
1760 		} else {
1761 			timeo = nmp->nm_timeo << NFS_RTT_SCALE_BITS;
1762 		}
1763 		timeo *= multt[req->r_procnum];
1764 		/* timeo is still scaled by SCALE_BITS */
1765 
1766 #define NFSFS	(NFS_RTT_SCALE * NFS_HZ)
1767 		if (req->r_flags & R_TIMING) {
1768 			static long last_time;
1769 			if (nfs_showrtt && last_time != time_second) {
1770 				kprintf("rpccmd %d NFS SRTT %d SDRTT %d "
1771 					"timeo %d.%03d\n",
1772 					proct[req->r_procnum],
1773 					NFS_SRTT(req), NFS_SDRTT(req),
1774 					timeo / NFSFS,
1775 					timeo % NFSFS * 1000 /  NFSFS);
1776 				last_time = time_second;
1777 			}
1778 		}
1779 #undef NFSFS
1780 
1781 		/*
1782 		 * deal with nfs_timer jitter.
1783 		 */
1784 		timeo = (timeo >> NFS_RTT_SCALE_BITS) + 1;
1785 		if (timeo < 2)
1786 			timeo = 2;
1787 
1788 		if (nmp->nm_timeouts > 0)
1789 			timeo *= nfs_backoff[nmp->nm_timeouts - 1];
1790 		if (timeo > NFS_MAXTIMEO)
1791 			timeo = NFS_MAXTIMEO;
1792 		if (req->r_rtt <= timeo) {
1793 			if ((req->r_flags & R_NEEDSXMIT) == 0)
1794 				return;
1795 		} else if (nmp->nm_timeouts < 8) {
1796 			nmp->nm_timeouts++;
1797 		}
1798 	}
1799 
1800 	/*
1801 	 * Check for server not responding
1802 	 */
1803 	if ((req->r_flags & R_TPRINTFMSG) == 0 &&
1804 	     req->r_rexmit > nmp->nm_deadthresh) {
1805 		nfs_msg(req->r_td, nmp->nm_mountp->mnt_stat.f_mntfromname,
1806 			"not responding");
1807 		req->r_flags |= R_TPRINTFMSG;
1808 	}
1809 	if (req->r_rexmit >= req->r_retry) {	/* too many */
1810 		nfsstats.rpctimeouts++;
1811 		nfs_softterm(req, 1);
1812 		return;
1813 	}
1814 
1815 	/*
1816 	 * Generally disable retransmission on reliable sockets,
1817 	 * unless the request is flagged for immediate send.
1818 	 */
1819 	if (nmp->nm_sotype != SOCK_DGRAM) {
1820 		if (++req->r_rexmit > NFS_MAXREXMIT)
1821 			req->r_rexmit = NFS_MAXREXMIT;
1822 		if ((req->r_flags & R_NEEDSXMIT) == 0)
1823 			return;
1824 	}
1825 
1826 	/*
1827 	 * Stop here if we do not have a socket!
1828 	 */
1829 	if ((so = nmp->nm_so) == NULL)
1830 		return;
1831 
1832 	/*
1833 	 * If there is enough space and the window allows.. resend it.
1834 	 *
1835 	 * r_rtt is left intact in case we get an answer after the
1836 	 * retry that was a reply to the original packet.
1837 	 */
1838 	if (ssb_space(&so->so_snd) >= req->r_mreq->m_pkthdr.len &&
1839 	    (req->r_flags & (R_SENT | R_NEEDSXMIT)) &&
1840 	   (m = m_copym(req->r_mreq, 0, M_COPYALL, MB_DONTWAIT))){
1841 		if ((nmp->nm_flag & NFSMNT_NOCONN) == 0)
1842 		    error = so_pru_send(so, 0, m, NULL, NULL, td);
1843 		else
1844 		    error = so_pru_send(so, 0, m, nmp->nm_nam,
1845 			NULL, td);
1846 		if (error) {
1847 			if (NFSIGNORE_SOERROR(nmp->nm_soflags, error))
1848 				so->so_error = 0;
1849 			req->r_flags |= R_NEEDSXMIT;
1850 		} else if (req->r_mrep == NULL) {
1851 			/*
1852 			 * Iff first send, start timing
1853 			 * else turn timing off, backoff timer
1854 			 * and divide congestion window by 2.
1855 			 *
1856 			 * It is possible for the so_pru_send() to
1857 			 * block and for us to race a reply so we
1858 			 * only do this if the reply field has not
1859 			 * been filled in.  R_LOCKED will prevent
1860 			 * the request from being ripped out from under
1861 			 * us entirely.
1862 			 *
1863 			 * Record the last resent procnum to aid us
1864 			 * in duplicate detection on receive.
1865 			 */
1866 			if ((req->r_flags & R_NEEDSXMIT) == 0) {
1867 				if (nfs_showrexmit)
1868 					kprintf("X");
1869 				if (++req->r_rexmit > NFS_MAXREXMIT)
1870 					req->r_rexmit = NFS_MAXREXMIT;
1871 				nmp->nm_maxasync_scaled >>= 1;
1872 				if (nmp->nm_maxasync_scaled < NFS_MINASYNC_SCALED)
1873 					nmp->nm_maxasync_scaled = NFS_MINASYNC_SCALED;
1874 				nfsstats.rpcretries++;
1875 				nmp->nm_lastreprocnum = req->r_procnum;
1876 			} else {
1877 				req->r_flags |= R_SENT;
1878 				req->r_flags &= ~R_NEEDSXMIT;
1879 			}
1880 		}
1881 	}
1882 }
1883 
1884 /*
1885  * Mark all of an nfs mount's outstanding requests with R_SOFTTERM and
1886  * wait for all requests to complete. This is used by forced unmounts
1887  * to terminate any outstanding RPCs.
1888  *
1889  * Locked requests cannot be canceled but will be marked for
1890  * soft-termination.
1891  */
1892 int
1893 nfs_nmcancelreqs(struct nfsmount *nmp)
1894 {
1895 	struct nfsreq *req;
1896 	int i;
1897 
1898 	crit_enter();
1899 	TAILQ_FOREACH(req, &nmp->nm_reqq, r_chain) {
1900 		if (req->r_mrep != NULL || (req->r_flags & R_SOFTTERM))
1901 			continue;
1902 		nfs_softterm(req, 0);
1903 	}
1904 	/* XXX  the other two queues as well */
1905 	crit_exit();
1906 
1907 	for (i = 0; i < 30; i++) {
1908 		crit_enter();
1909 		TAILQ_FOREACH(req, &nmp->nm_reqq, r_chain) {
1910 			if (nmp == req->r_nmp)
1911 				break;
1912 		}
1913 		crit_exit();
1914 		if (req == NULL)
1915 			return (0);
1916 		tsleep(&lbolt, 0, "nfscancel", 0);
1917 	}
1918 	return (EBUSY);
1919 }
1920 
1921 /*
1922  * Soft-terminate a request, effectively marking it as failed.
1923  *
1924  * Must be called from within a critical section.
1925  */
1926 static void
1927 nfs_softterm(struct nfsreq *rep, int islocked)
1928 {
1929 	rep->r_flags |= R_SOFTTERM;
1930 	nfs_hardterm(rep, islocked);
1931 }
1932 
1933 /*
1934  * Hard-terminate a request, typically after getting a response.
1935  *
1936  * The state machine can still decide to re-issue it later if necessary.
1937  *
1938  * Must be called from within a critical section.
1939  */
1940 static void
1941 nfs_hardterm(struct nfsreq *rep, int islocked)
1942 {
1943 	struct nfsmount *nmp = rep->r_nmp;
1944 
1945 	/*
1946 	 * The nm_send count is decremented now to avoid deadlocks
1947 	 * when the process in soreceive() hasn't yet managed to send
1948 	 * its own request.
1949 	 */
1950 	if (rep->r_flags & R_SENT) {
1951 		rep->r_flags &= ~R_SENT;
1952 	}
1953 
1954 	/*
1955 	 * If we locked the request or nobody else has locked the request,
1956 	 * and the request is async, we can move it to the reader thread's
1957 	 * queue now and fix up the state.
1958 	 *
1959 	 * If we locked the request or nobody else has locked the request,
1960 	 * we can wake up anyone blocked waiting for a response on the
1961 	 * request.
1962 	 */
1963 	if (islocked || (rep->r_flags & R_LOCKED) == 0) {
1964 		if ((rep->r_flags & (R_ONREQQ | R_ASYNC)) ==
1965 		    (R_ONREQQ | R_ASYNC)) {
1966 			rep->r_flags &= ~R_ONREQQ;
1967 			TAILQ_REMOVE(&nmp->nm_reqq, rep, r_chain);
1968 			--nmp->nm_reqqlen;
1969 			TAILQ_INSERT_TAIL(&nmp->nm_reqrxq, rep, r_chain);
1970 			KKASSERT(rep->r_info->state == NFSM_STATE_TRY ||
1971 				 rep->r_info->state == NFSM_STATE_WAITREPLY);
1972 			rep->r_info->state = NFSM_STATE_PROCESSREPLY;
1973 			nfssvc_iod_reader_wakeup(nmp);
1974 			if (TAILQ_FIRST(&nmp->nm_bioq) &&
1975 			    nmp->nm_reqqlen <= nfs_maxasyncbio * 2 / 3) {
1976 				nfssvc_iod_writer_wakeup(nmp);
1977 			}
1978 		}
1979 		mtx_abort_ex_link(&nmp->nm_rxlock, &rep->r_link);
1980 	}
1981 }
1982 
1983 /*
1984  * Test for a termination condition pending on the process.
1985  * This is used for NFSMNT_INT mounts.
1986  */
1987 int
1988 nfs_sigintr(struct nfsmount *nmp, struct nfsreq *rep, struct thread *td)
1989 {
1990 	sigset_t tmpset;
1991 	struct proc *p;
1992 	struct lwp *lp;
1993 
1994 	if (rep && (rep->r_flags & R_SOFTTERM))
1995 		return (EINTR);
1996 	/* Terminate all requests while attempting a forced unmount. */
1997 	if (nmp->nm_mountp->mnt_kern_flag & MNTK_UNMOUNTF)
1998 		return (EINTR);
1999 	if (!(nmp->nm_flag & NFSMNT_INT))
2000 		return (0);
2001 	/* td might be NULL YYY */
2002 	if (td == NULL || (p = td->td_proc) == NULL)
2003 		return (0);
2004 
2005 	lp = td->td_lwp;
2006 	tmpset = lwp_sigpend(lp);
2007 	SIGSETNAND(tmpset, lp->lwp_sigmask);
2008 	SIGSETNAND(tmpset, p->p_sigignore);
2009 	if (SIGNOTEMPTY(tmpset) && NFSINT_SIGMASK(tmpset))
2010 		return (EINTR);
2011 
2012 	return (0);
2013 }
2014 
2015 /*
2016  * Lock a socket against others.
2017  * Necessary for STREAM sockets to ensure you get an entire rpc request/reply
2018  * and also to avoid race conditions between the processes with nfs requests
2019  * in progress when a reconnect is necessary.
2020  */
2021 int
2022 nfs_sndlock(struct nfsmount *nmp, struct nfsreq *rep)
2023 {
2024 	mtx_t mtx = &nmp->nm_txlock;
2025 	struct thread *td;
2026 	int slptimeo;
2027 	int slpflag;
2028 	int error;
2029 
2030 	slpflag = 0;
2031 	slptimeo = 0;
2032 	td = rep ? rep->r_td : NULL;
2033 	if (nmp->nm_flag & NFSMNT_INT)
2034 		slpflag = PCATCH;
2035 
2036 	while ((error = mtx_lock_ex_try(mtx)) != 0) {
2037 		if (nfs_sigintr(nmp, rep, td)) {
2038 			error = EINTR;
2039 			break;
2040 		}
2041 		error = mtx_lock_ex(mtx, "nfsndlck", slpflag, slptimeo);
2042 		if (error == 0)
2043 			break;
2044 		if (slpflag == PCATCH) {
2045 			slpflag = 0;
2046 			slptimeo = 2 * hz;
2047 		}
2048 	}
2049 	/* Always fail if our request has been cancelled. */
2050 	if (rep && (rep->r_flags & R_SOFTTERM)) {
2051 		if (error == 0)
2052 			mtx_unlock(mtx);
2053 		error = EINTR;
2054 	}
2055 	return (error);
2056 }
2057 
2058 /*
2059  * Unlock the stream socket for others.
2060  */
2061 void
2062 nfs_sndunlock(struct nfsmount *nmp)
2063 {
2064 	mtx_unlock(&nmp->nm_txlock);
2065 }
2066 
2067 /*
2068  * Lock the receiver side of the socket.
2069  *
2070  * rep may be NULL.
2071  */
2072 static int
2073 nfs_rcvlock(struct nfsmount *nmp, struct nfsreq *rep)
2074 {
2075 	mtx_t mtx = &nmp->nm_rxlock;
2076 	int slpflag;
2077 	int slptimeo;
2078 	int error;
2079 
2080 	/*
2081 	 * Unconditionally check for completion in case another nfsiod
2082 	 * get the packet while the caller was blocked, before the caller
2083 	 * called us.  Packet reception is handled by mainline code which
2084 	 * is protected by the BGL at the moment.
2085 	 *
2086 	 * We do not strictly need the second check just before the
2087 	 * tsleep(), but it's good defensive programming.
2088 	 */
2089 	if (rep && rep->r_mrep != NULL)
2090 		return (EALREADY);
2091 
2092 	if (nmp->nm_flag & NFSMNT_INT)
2093 		slpflag = PCATCH;
2094 	else
2095 		slpflag = 0;
2096 	slptimeo = 0;
2097 
2098 	while ((error = mtx_lock_ex_try(mtx)) != 0) {
2099 		if (nfs_sigintr(nmp, rep, (rep ? rep->r_td : NULL))) {
2100 			error = EINTR;
2101 			break;
2102 		}
2103 		if (rep && rep->r_mrep != NULL) {
2104 			error = EALREADY;
2105 			break;
2106 		}
2107 
2108 		/*
2109 		 * NOTE: can return ENOLCK, but in that case rep->r_mrep
2110 		 *       will already be set.
2111 		 */
2112 		if (rep) {
2113 			error = mtx_lock_ex_link(mtx, &rep->r_link,
2114 						 "nfsrcvlk",
2115 						 slpflag, slptimeo);
2116 		} else {
2117 			error = mtx_lock_ex(mtx, "nfsrcvlk", slpflag, slptimeo);
2118 		}
2119 		if (error == 0)
2120 			break;
2121 
2122 		/*
2123 		 * If our reply was recieved while we were sleeping,
2124 		 * then just return without taking the lock to avoid a
2125 		 * situation where a single iod could 'capture' the
2126 		 * recieve lock.
2127 		 */
2128 		if (rep && rep->r_mrep != NULL) {
2129 			error = EALREADY;
2130 			break;
2131 		}
2132 		if (slpflag == PCATCH) {
2133 			slpflag = 0;
2134 			slptimeo = 2 * hz;
2135 		}
2136 	}
2137 	if (error == 0) {
2138 		if (rep && rep->r_mrep != NULL) {
2139 			error = EALREADY;
2140 			mtx_unlock(mtx);
2141 		}
2142 	}
2143 	return (error);
2144 }
2145 
2146 /*
2147  * Unlock the stream socket for others.
2148  */
2149 static void
2150 nfs_rcvunlock(struct nfsmount *nmp)
2151 {
2152 	mtx_unlock(&nmp->nm_rxlock);
2153 }
2154 
2155 /*
2156  *	nfs_realign:
2157  *
2158  *	Check for badly aligned mbuf data and realign by copying the unaligned
2159  *	portion of the data into a new mbuf chain and freeing the portions
2160  *	of the old chain that were replaced.
2161  *
2162  *	We cannot simply realign the data within the existing mbuf chain
2163  *	because the underlying buffers may contain other rpc commands and
2164  *	we cannot afford to overwrite them.
2165  *
2166  *	We would prefer to avoid this situation entirely.  The situation does
2167  *	not occur with NFS/UDP and is supposed to only occassionally occur
2168  *	with TCP.  Use vfs.nfs.realign_count and realign_test to check this.
2169  */
2170 static void
2171 nfs_realign(struct mbuf **pm, int hsiz)
2172 {
2173 	struct mbuf *m;
2174 	struct mbuf *n = NULL;
2175 	int off = 0;
2176 
2177 	++nfs_realign_test;
2178 
2179 	while ((m = *pm) != NULL) {
2180 		if ((m->m_len & 0x3) || (mtod(m, intptr_t) & 0x3)) {
2181 			n = m_getl(m->m_len, MB_WAIT, MT_DATA, 0, NULL);
2182 			n->m_len = 0;
2183 			break;
2184 		}
2185 		pm = &m->m_next;
2186 	}
2187 
2188 	/*
2189 	 * If n is non-NULL, loop on m copying data, then replace the
2190 	 * portion of the chain that had to be realigned.
2191 	 */
2192 	if (n != NULL) {
2193 		++nfs_realign_count;
2194 		while (m) {
2195 			m_copyback(n, off, m->m_len, mtod(m, caddr_t));
2196 			off += m->m_len;
2197 			m = m->m_next;
2198 		}
2199 		m_freem(*pm);
2200 		*pm = n;
2201 	}
2202 }
2203 
2204 #ifndef NFS_NOSERVER
2205 
2206 /*
2207  * Parse an RPC request
2208  * - verify it
2209  * - fill in the cred struct.
2210  */
2211 int
2212 nfs_getreq(struct nfsrv_descript *nd, struct nfsd *nfsd, int has_header)
2213 {
2214 	int len, i;
2215 	u_int32_t *tl;
2216 	struct uio uio;
2217 	struct iovec iov;
2218 	caddr_t cp;
2219 	u_int32_t nfsvers, auth_type;
2220 	uid_t nickuid;
2221 	int error = 0, ticklen;
2222 	struct nfsuid *nuidp;
2223 	struct timeval tvin, tvout;
2224 	struct nfsm_info info;
2225 #if 0				/* until encrypted keys are implemented */
2226 	NFSKERBKEYSCHED_T keys;	/* stores key schedule */
2227 #endif
2228 
2229 	info.mrep = nd->nd_mrep;
2230 	info.md = nd->nd_md;
2231 	info.dpos = nd->nd_dpos;
2232 
2233 	if (has_header) {
2234 		NULLOUT(tl = nfsm_dissect(&info, 10 * NFSX_UNSIGNED));
2235 		nd->nd_retxid = fxdr_unsigned(u_int32_t, *tl++);
2236 		if (*tl++ != rpc_call) {
2237 			m_freem(info.mrep);
2238 			return (EBADRPC);
2239 		}
2240 	} else {
2241 		NULLOUT(tl = nfsm_dissect(&info, 8 * NFSX_UNSIGNED));
2242 	}
2243 	nd->nd_repstat = 0;
2244 	nd->nd_flag = 0;
2245 	if (*tl++ != rpc_vers) {
2246 		nd->nd_repstat = ERPCMISMATCH;
2247 		nd->nd_procnum = NFSPROC_NOOP;
2248 		return (0);
2249 	}
2250 	if (*tl != nfs_prog) {
2251 		nd->nd_repstat = EPROGUNAVAIL;
2252 		nd->nd_procnum = NFSPROC_NOOP;
2253 		return (0);
2254 	}
2255 	tl++;
2256 	nfsvers = fxdr_unsigned(u_int32_t, *tl++);
2257 	if (nfsvers < NFS_VER2 || nfsvers > NFS_VER3) {
2258 		nd->nd_repstat = EPROGMISMATCH;
2259 		nd->nd_procnum = NFSPROC_NOOP;
2260 		return (0);
2261 	}
2262 	if (nfsvers == NFS_VER3)
2263 		nd->nd_flag = ND_NFSV3;
2264 	nd->nd_procnum = fxdr_unsigned(u_int32_t, *tl++);
2265 	if (nd->nd_procnum == NFSPROC_NULL)
2266 		return (0);
2267 	if (nd->nd_procnum >= NFS_NPROCS ||
2268 		(nd->nd_procnum >= NQNFSPROC_GETLEASE) ||
2269 		(!nd->nd_flag && nd->nd_procnum > NFSV2PROC_STATFS)) {
2270 		nd->nd_repstat = EPROCUNAVAIL;
2271 		nd->nd_procnum = NFSPROC_NOOP;
2272 		return (0);
2273 	}
2274 	if ((nd->nd_flag & ND_NFSV3) == 0)
2275 		nd->nd_procnum = nfsv3_procid[nd->nd_procnum];
2276 	auth_type = *tl++;
2277 	len = fxdr_unsigned(int, *tl++);
2278 	if (len < 0 || len > RPCAUTH_MAXSIZ) {
2279 		m_freem(info.mrep);
2280 		return (EBADRPC);
2281 	}
2282 
2283 	nd->nd_flag &= ~ND_KERBAUTH;
2284 	/*
2285 	 * Handle auth_unix or auth_kerb.
2286 	 */
2287 	if (auth_type == rpc_auth_unix) {
2288 		len = fxdr_unsigned(int, *++tl);
2289 		if (len < 0 || len > NFS_MAXNAMLEN) {
2290 			m_freem(info.mrep);
2291 			return (EBADRPC);
2292 		}
2293 		ERROROUT(nfsm_adv(&info, nfsm_rndup(len)));
2294 		NULLOUT(tl = nfsm_dissect(&info, 3 * NFSX_UNSIGNED));
2295 		bzero((caddr_t)&nd->nd_cr, sizeof (struct ucred));
2296 		nd->nd_cr.cr_ref = 1;
2297 		nd->nd_cr.cr_uid = fxdr_unsigned(uid_t, *tl++);
2298 		nd->nd_cr.cr_ruid = nd->nd_cr.cr_svuid = nd->nd_cr.cr_uid;
2299 		nd->nd_cr.cr_gid = fxdr_unsigned(gid_t, *tl++);
2300 		nd->nd_cr.cr_rgid = nd->nd_cr.cr_svgid = nd->nd_cr.cr_gid;
2301 		len = fxdr_unsigned(int, *tl);
2302 		if (len < 0 || len > RPCAUTH_UNIXGIDS) {
2303 			m_freem(info.mrep);
2304 			return (EBADRPC);
2305 		}
2306 		NULLOUT(tl = nfsm_dissect(&info, (len + 2) * NFSX_UNSIGNED));
2307 		for (i = 1; i <= len; i++)
2308 		    if (i < NGROUPS)
2309 			nd->nd_cr.cr_groups[i] = fxdr_unsigned(gid_t, *tl++);
2310 		    else
2311 			tl++;
2312 		nd->nd_cr.cr_ngroups = (len >= NGROUPS) ? NGROUPS : (len + 1);
2313 		if (nd->nd_cr.cr_ngroups > 1)
2314 		    nfsrvw_sort(nd->nd_cr.cr_groups, nd->nd_cr.cr_ngroups);
2315 		len = fxdr_unsigned(int, *++tl);
2316 		if (len < 0 || len > RPCAUTH_MAXSIZ) {
2317 			m_freem(info.mrep);
2318 			return (EBADRPC);
2319 		}
2320 		if (len > 0) {
2321 			ERROROUT(nfsm_adv(&info, nfsm_rndup(len)));
2322 		}
2323 	} else if (auth_type == rpc_auth_kerb) {
2324 		switch (fxdr_unsigned(int, *tl++)) {
2325 		case RPCAKN_FULLNAME:
2326 			ticklen = fxdr_unsigned(int, *tl);
2327 			*((u_int32_t *)nfsd->nfsd_authstr) = *tl;
2328 			uio.uio_resid = nfsm_rndup(ticklen) + NFSX_UNSIGNED;
2329 			nfsd->nfsd_authlen = uio.uio_resid + NFSX_UNSIGNED;
2330 			if (uio.uio_resid > (len - 2 * NFSX_UNSIGNED)) {
2331 				m_freem(info.mrep);
2332 				return (EBADRPC);
2333 			}
2334 			uio.uio_offset = 0;
2335 			uio.uio_iov = &iov;
2336 			uio.uio_iovcnt = 1;
2337 			uio.uio_segflg = UIO_SYSSPACE;
2338 			iov.iov_base = (caddr_t)&nfsd->nfsd_authstr[4];
2339 			iov.iov_len = RPCAUTH_MAXSIZ - 4;
2340 			ERROROUT(nfsm_mtouio(&info, &uio, uio.uio_resid));
2341 			NULLOUT(tl = nfsm_dissect(&info, 2 * NFSX_UNSIGNED));
2342 			if (*tl++ != rpc_auth_kerb ||
2343 				fxdr_unsigned(int, *tl) != 4 * NFSX_UNSIGNED) {
2344 				kprintf("Bad kerb verifier\n");
2345 				nd->nd_repstat = (NFSERR_AUTHERR|AUTH_BADVERF);
2346 				nd->nd_procnum = NFSPROC_NOOP;
2347 				return (0);
2348 			}
2349 			NULLOUT(cp = nfsm_dissect(&info, 4 * NFSX_UNSIGNED));
2350 			tl = (u_int32_t *)cp;
2351 			if (fxdr_unsigned(int, *tl) != RPCAKN_FULLNAME) {
2352 				kprintf("Not fullname kerb verifier\n");
2353 				nd->nd_repstat = (NFSERR_AUTHERR|AUTH_BADVERF);
2354 				nd->nd_procnum = NFSPROC_NOOP;
2355 				return (0);
2356 			}
2357 			cp += NFSX_UNSIGNED;
2358 			bcopy(cp, nfsd->nfsd_verfstr, 3 * NFSX_UNSIGNED);
2359 			nfsd->nfsd_verflen = 3 * NFSX_UNSIGNED;
2360 			nd->nd_flag |= ND_KERBFULL;
2361 			nfsd->nfsd_flag |= NFSD_NEEDAUTH;
2362 			break;
2363 		case RPCAKN_NICKNAME:
2364 			if (len != 2 * NFSX_UNSIGNED) {
2365 				kprintf("Kerb nickname short\n");
2366 				nd->nd_repstat = (NFSERR_AUTHERR|AUTH_BADCRED);
2367 				nd->nd_procnum = NFSPROC_NOOP;
2368 				return (0);
2369 			}
2370 			nickuid = fxdr_unsigned(uid_t, *tl);
2371 			NULLOUT(tl = nfsm_dissect(&info, 2 * NFSX_UNSIGNED));
2372 			if (*tl++ != rpc_auth_kerb ||
2373 				fxdr_unsigned(int, *tl) != 3 * NFSX_UNSIGNED) {
2374 				kprintf("Kerb nick verifier bad\n");
2375 				nd->nd_repstat = (NFSERR_AUTHERR|AUTH_BADVERF);
2376 				nd->nd_procnum = NFSPROC_NOOP;
2377 				return (0);
2378 			}
2379 			NULLOUT(tl = nfsm_dissect(&info, 3 * NFSX_UNSIGNED));
2380 			tvin.tv_sec = *tl++;
2381 			tvin.tv_usec = *tl;
2382 
2383 			for (nuidp = NUIDHASH(nfsd->nfsd_slp,nickuid)->lh_first;
2384 			    nuidp != 0; nuidp = nuidp->nu_hash.le_next) {
2385 				if (nuidp->nu_cr.cr_uid == nickuid &&
2386 				    (!nd->nd_nam2 ||
2387 				     netaddr_match(NU_NETFAM(nuidp),
2388 				      &nuidp->nu_haddr, nd->nd_nam2)))
2389 					break;
2390 			}
2391 			if (!nuidp) {
2392 				nd->nd_repstat =
2393 					(NFSERR_AUTHERR|AUTH_REJECTCRED);
2394 				nd->nd_procnum = NFSPROC_NOOP;
2395 				return (0);
2396 			}
2397 
2398 			/*
2399 			 * Now, decrypt the timestamp using the session key
2400 			 * and validate it.
2401 			 */
2402 #ifdef NFSKERB
2403 			XXX
2404 #else
2405 			tvout.tv_sec = 0;
2406 			tvout.tv_usec = 0;
2407 #endif
2408 
2409 			tvout.tv_sec = fxdr_unsigned(long, tvout.tv_sec);
2410 			tvout.tv_usec = fxdr_unsigned(long, tvout.tv_usec);
2411 			if (nuidp->nu_expire < time_second ||
2412 			    nuidp->nu_timestamp.tv_sec > tvout.tv_sec ||
2413 			    (nuidp->nu_timestamp.tv_sec == tvout.tv_sec &&
2414 			     nuidp->nu_timestamp.tv_usec > tvout.tv_usec)) {
2415 				nuidp->nu_expire = 0;
2416 				nd->nd_repstat =
2417 				    (NFSERR_AUTHERR|AUTH_REJECTVERF);
2418 				nd->nd_procnum = NFSPROC_NOOP;
2419 				return (0);
2420 			}
2421 			nfsrv_setcred(&nuidp->nu_cr, &nd->nd_cr);
2422 			nd->nd_flag |= ND_KERBNICK;
2423 		};
2424 	} else {
2425 		nd->nd_repstat = (NFSERR_AUTHERR | AUTH_REJECTCRED);
2426 		nd->nd_procnum = NFSPROC_NOOP;
2427 		return (0);
2428 	}
2429 
2430 	nd->nd_md = info.md;
2431 	nd->nd_dpos = info.dpos;
2432 	return (0);
2433 nfsmout:
2434 	return (error);
2435 }
2436 
2437 #endif
2438 
2439 /*
2440  * Send a message to the originating process's terminal.  The thread and/or
2441  * process may be NULL.  YYY the thread should not be NULL but there may
2442  * still be some uio_td's that are still being passed as NULL through to
2443  * nfsm_request().
2444  */
2445 static int
2446 nfs_msg(struct thread *td, char *server, char *msg)
2447 {
2448 	tpr_t tpr;
2449 
2450 	if (td && td->td_proc)
2451 		tpr = tprintf_open(td->td_proc);
2452 	else
2453 		tpr = NULL;
2454 	tprintf(tpr, "nfs server %s: %s\n", server, msg);
2455 	tprintf_close(tpr);
2456 	return (0);
2457 }
2458 
2459 #ifndef NFS_NOSERVER
2460 /*
2461  * Socket upcall routine for the nfsd sockets.
2462  * The caddr_t arg is a pointer to the "struct nfssvc_sock".
2463  * Essentially do as much as possible non-blocking, else punt and it will
2464  * be called with MB_WAIT from an nfsd.
2465  */
2466 void
2467 nfsrv_rcv(struct socket *so, void *arg, int waitflag)
2468 {
2469 	struct nfssvc_sock *slp = (struct nfssvc_sock *)arg;
2470 	struct mbuf *m;
2471 	struct sockaddr *nam;
2472 	struct sockbuf sio;
2473 	int flags, error;
2474 	int nparallel_wakeup = 0;
2475 
2476 	if ((slp->ns_flag & SLP_VALID) == 0)
2477 		return;
2478 
2479 	/*
2480 	 * Do not allow an infinite number of completed RPC records to build
2481 	 * up before we stop reading data from the socket.  Otherwise we could
2482 	 * end up holding onto an unreasonable number of mbufs for requests
2483 	 * waiting for service.
2484 	 *
2485 	 * This should give pretty good feedback to the TCP
2486 	 * layer and prevents a memory crunch for other protocols.
2487 	 *
2488 	 * Note that the same service socket can be dispatched to several
2489 	 * nfs servers simultaniously.
2490 	 *
2491 	 * the tcp protocol callback calls us with MB_DONTWAIT.
2492 	 * nfsd calls us with MB_WAIT (typically).
2493 	 */
2494 	if (waitflag == MB_DONTWAIT && slp->ns_numrec >= nfsd_waiting / 2 + 1) {
2495 		slp->ns_flag |= SLP_NEEDQ;
2496 		goto dorecs;
2497 	}
2498 
2499 	/*
2500 	 * Handle protocol specifics to parse an RPC request.  We always
2501 	 * pull from the socket using non-blocking I/O.
2502 	 */
2503 	if (so->so_type == SOCK_STREAM) {
2504 		/*
2505 		 * The data has to be read in an orderly fashion from a TCP
2506 		 * stream, unlike a UDP socket.  It is possible for soreceive
2507 		 * and/or nfsrv_getstream() to block, so make sure only one
2508 		 * entity is messing around with the TCP stream at any given
2509 		 * moment.  The receive sockbuf's lock in soreceive is not
2510 		 * sufficient.
2511 		 *
2512 		 * Note that this procedure can be called from any number of
2513 		 * NFS severs *OR* can be upcalled directly from a TCP
2514 		 * protocol thread.
2515 		 */
2516 		if (slp->ns_flag & SLP_GETSTREAM) {
2517 			slp->ns_flag |= SLP_NEEDQ;
2518 			goto dorecs;
2519 		}
2520 		slp->ns_flag |= SLP_GETSTREAM;
2521 
2522 		/*
2523 		 * Do soreceive().  Pull out as much data as possible without
2524 		 * blocking.
2525 		 */
2526 		sbinit(&sio, 1000000000);
2527 		flags = MSG_DONTWAIT;
2528 		error = so_pru_soreceive(so, &nam, NULL, &sio, NULL, &flags);
2529 		if (error || sio.sb_mb == NULL) {
2530 			if (error == EWOULDBLOCK)
2531 				slp->ns_flag |= SLP_NEEDQ;
2532 			else
2533 				slp->ns_flag |= SLP_DISCONN;
2534 			slp->ns_flag &= ~SLP_GETSTREAM;
2535 			goto dorecs;
2536 		}
2537 		m = sio.sb_mb;
2538 		if (slp->ns_rawend) {
2539 			slp->ns_rawend->m_next = m;
2540 			slp->ns_cc += sio.sb_cc;
2541 		} else {
2542 			slp->ns_raw = m;
2543 			slp->ns_cc = sio.sb_cc;
2544 		}
2545 		while (m->m_next)
2546 			m = m->m_next;
2547 		slp->ns_rawend = m;
2548 
2549 		/*
2550 		 * Now try and parse as many record(s) as we can out of the
2551 		 * raw stream data.
2552 		 */
2553 		error = nfsrv_getstream(slp, waitflag, &nparallel_wakeup);
2554 		if (error) {
2555 			if (error == EPERM)
2556 				slp->ns_flag |= SLP_DISCONN;
2557 			else
2558 				slp->ns_flag |= SLP_NEEDQ;
2559 		}
2560 		slp->ns_flag &= ~SLP_GETSTREAM;
2561 	} else {
2562 		/*
2563 		 * For UDP soreceive typically pulls just one packet, loop
2564 		 * to get the whole batch.
2565 		 */
2566 		do {
2567 			sbinit(&sio, 1000000000);
2568 			flags = MSG_DONTWAIT;
2569 			error = so_pru_soreceive(so, &nam, NULL, &sio,
2570 						 NULL, &flags);
2571 			if (sio.sb_mb) {
2572 				struct nfsrv_rec *rec;
2573 				int mf = (waitflag & MB_DONTWAIT) ?
2574 					    M_NOWAIT : M_WAITOK;
2575 				rec = kmalloc(sizeof(struct nfsrv_rec),
2576 					     M_NFSRVDESC, mf);
2577 				if (!rec) {
2578 					if (nam)
2579 						FREE(nam, M_SONAME);
2580 					m_freem(sio.sb_mb);
2581 					continue;
2582 				}
2583 				nfs_realign(&sio.sb_mb, 10 * NFSX_UNSIGNED);
2584 				rec->nr_address = nam;
2585 				rec->nr_packet = sio.sb_mb;
2586 				STAILQ_INSERT_TAIL(&slp->ns_rec, rec, nr_link);
2587 				++slp->ns_numrec;
2588 				++nparallel_wakeup;
2589 			}
2590 			if (error) {
2591 				if ((so->so_proto->pr_flags & PR_CONNREQUIRED)
2592 					&& error != EWOULDBLOCK) {
2593 					slp->ns_flag |= SLP_DISCONN;
2594 					goto dorecs;
2595 				}
2596 			}
2597 		} while (sio.sb_mb);
2598 	}
2599 
2600 	/*
2601 	 * If we were upcalled from the tcp protocol layer and we have
2602 	 * fully parsed records ready to go, or there is new data pending,
2603 	 * or something went wrong, try to wake up an nfsd thread to deal
2604 	 * with it.
2605 	 */
2606 dorecs:
2607 	if (waitflag == MB_DONTWAIT && (slp->ns_numrec > 0
2608 	     || (slp->ns_flag & (SLP_NEEDQ | SLP_DISCONN)))) {
2609 		nfsrv_wakenfsd(slp, nparallel_wakeup);
2610 	}
2611 }
2612 
2613 /*
2614  * Try and extract an RPC request from the mbuf data list received on a
2615  * stream socket. The "waitflag" argument indicates whether or not it
2616  * can sleep.
2617  */
2618 static int
2619 nfsrv_getstream(struct nfssvc_sock *slp, int waitflag, int *countp)
2620 {
2621 	struct mbuf *m, **mpp;
2622 	char *cp1, *cp2;
2623 	int len;
2624 	struct mbuf *om, *m2, *recm;
2625 	u_int32_t recmark;
2626 
2627 	for (;;) {
2628 	    if (slp->ns_reclen == 0) {
2629 		if (slp->ns_cc < NFSX_UNSIGNED)
2630 			return (0);
2631 		m = slp->ns_raw;
2632 		if (m->m_len >= NFSX_UNSIGNED) {
2633 			bcopy(mtod(m, caddr_t), (caddr_t)&recmark, NFSX_UNSIGNED);
2634 			m->m_data += NFSX_UNSIGNED;
2635 			m->m_len -= NFSX_UNSIGNED;
2636 		} else {
2637 			cp1 = (caddr_t)&recmark;
2638 			cp2 = mtod(m, caddr_t);
2639 			while (cp1 < ((caddr_t)&recmark) + NFSX_UNSIGNED) {
2640 				while (m->m_len == 0) {
2641 					m = m->m_next;
2642 					cp2 = mtod(m, caddr_t);
2643 				}
2644 				*cp1++ = *cp2++;
2645 				m->m_data++;
2646 				m->m_len--;
2647 			}
2648 		}
2649 		slp->ns_cc -= NFSX_UNSIGNED;
2650 		recmark = ntohl(recmark);
2651 		slp->ns_reclen = recmark & ~0x80000000;
2652 		if (recmark & 0x80000000)
2653 			slp->ns_flag |= SLP_LASTFRAG;
2654 		else
2655 			slp->ns_flag &= ~SLP_LASTFRAG;
2656 		if (slp->ns_reclen > NFS_MAXPACKET || slp->ns_reclen <= 0) {
2657 			log(LOG_ERR, "%s (%d) from nfs client\n",
2658 			    "impossible packet length",
2659 			    slp->ns_reclen);
2660 			return (EPERM);
2661 		}
2662 	    }
2663 
2664 	    /*
2665 	     * Now get the record part.
2666 	     *
2667 	     * Note that slp->ns_reclen may be 0.  Linux sometimes
2668 	     * generates 0-length RPCs
2669 	     */
2670 	    recm = NULL;
2671 	    if (slp->ns_cc == slp->ns_reclen) {
2672 		recm = slp->ns_raw;
2673 		slp->ns_raw = slp->ns_rawend = NULL;
2674 		slp->ns_cc = slp->ns_reclen = 0;
2675 	    } else if (slp->ns_cc > slp->ns_reclen) {
2676 		len = 0;
2677 		m = slp->ns_raw;
2678 		om = NULL;
2679 
2680 		while (len < slp->ns_reclen) {
2681 			if ((len + m->m_len) > slp->ns_reclen) {
2682 				m2 = m_copym(m, 0, slp->ns_reclen - len,
2683 					waitflag);
2684 				if (m2) {
2685 					if (om) {
2686 						om->m_next = m2;
2687 						recm = slp->ns_raw;
2688 					} else
2689 						recm = m2;
2690 					m->m_data += slp->ns_reclen - len;
2691 					m->m_len -= slp->ns_reclen - len;
2692 					len = slp->ns_reclen;
2693 				} else {
2694 					return (EWOULDBLOCK);
2695 				}
2696 			} else if ((len + m->m_len) == slp->ns_reclen) {
2697 				om = m;
2698 				len += m->m_len;
2699 				m = m->m_next;
2700 				recm = slp->ns_raw;
2701 				om->m_next = NULL;
2702 			} else {
2703 				om = m;
2704 				len += m->m_len;
2705 				m = m->m_next;
2706 			}
2707 		}
2708 		slp->ns_raw = m;
2709 		slp->ns_cc -= len;
2710 		slp->ns_reclen = 0;
2711 	    } else {
2712 		return (0);
2713 	    }
2714 
2715 	    /*
2716 	     * Accumulate the fragments into a record.
2717 	     */
2718 	    mpp = &slp->ns_frag;
2719 	    while (*mpp)
2720 		mpp = &((*mpp)->m_next);
2721 	    *mpp = recm;
2722 	    if (slp->ns_flag & SLP_LASTFRAG) {
2723 		struct nfsrv_rec *rec;
2724 		int mf = (waitflag & MB_DONTWAIT) ? M_NOWAIT : M_WAITOK;
2725 		rec = kmalloc(sizeof(struct nfsrv_rec), M_NFSRVDESC, mf);
2726 		if (!rec) {
2727 		    m_freem(slp->ns_frag);
2728 		} else {
2729 		    nfs_realign(&slp->ns_frag, 10 * NFSX_UNSIGNED);
2730 		    rec->nr_address = NULL;
2731 		    rec->nr_packet = slp->ns_frag;
2732 		    STAILQ_INSERT_TAIL(&slp->ns_rec, rec, nr_link);
2733 		    ++slp->ns_numrec;
2734 		    ++*countp;
2735 		}
2736 		slp->ns_frag = NULL;
2737 	    }
2738 	}
2739 }
2740 
2741 /*
2742  * Parse an RPC header.
2743  */
2744 int
2745 nfsrv_dorec(struct nfssvc_sock *slp, struct nfsd *nfsd,
2746 	    struct nfsrv_descript **ndp)
2747 {
2748 	struct nfsrv_rec *rec;
2749 	struct mbuf *m;
2750 	struct sockaddr *nam;
2751 	struct nfsrv_descript *nd;
2752 	int error;
2753 
2754 	*ndp = NULL;
2755 	if ((slp->ns_flag & SLP_VALID) == 0 || !STAILQ_FIRST(&slp->ns_rec))
2756 		return (ENOBUFS);
2757 	rec = STAILQ_FIRST(&slp->ns_rec);
2758 	STAILQ_REMOVE_HEAD(&slp->ns_rec, nr_link);
2759 	KKASSERT(slp->ns_numrec > 0);
2760 	--slp->ns_numrec;
2761 	nam = rec->nr_address;
2762 	m = rec->nr_packet;
2763 	kfree(rec, M_NFSRVDESC);
2764 	MALLOC(nd, struct nfsrv_descript *, sizeof (struct nfsrv_descript),
2765 		M_NFSRVDESC, M_WAITOK);
2766 	nd->nd_md = nd->nd_mrep = m;
2767 	nd->nd_nam2 = nam;
2768 	nd->nd_dpos = mtod(m, caddr_t);
2769 	error = nfs_getreq(nd, nfsd, TRUE);
2770 	if (error) {
2771 		if (nam) {
2772 			FREE(nam, M_SONAME);
2773 		}
2774 		kfree((caddr_t)nd, M_NFSRVDESC);
2775 		return (error);
2776 	}
2777 	*ndp = nd;
2778 	nfsd->nfsd_nd = nd;
2779 	return (0);
2780 }
2781 
2782 /*
2783  * Try to assign service sockets to nfsd threads based on the number
2784  * of new rpc requests that have been queued on the service socket.
2785  *
2786  * If no nfsd's are available or additonal requests are pending, set the
2787  * NFSD_CHECKSLP flag so that one of the running nfsds will go look for
2788  * the work in the nfssvc_sock list when it is finished processing its
2789  * current work.  This flag is only cleared when an nfsd can not find
2790  * any new work to perform.
2791  */
2792 void
2793 nfsrv_wakenfsd(struct nfssvc_sock *slp, int nparallel)
2794 {
2795 	struct nfsd *nd;
2796 
2797 	if ((slp->ns_flag & SLP_VALID) == 0)
2798 		return;
2799 	if (nparallel <= 1)
2800 		nparallel = 1;
2801 	TAILQ_FOREACH(nd, &nfsd_head, nfsd_chain) {
2802 		if (nd->nfsd_flag & NFSD_WAITING) {
2803 			nd->nfsd_flag &= ~NFSD_WAITING;
2804 			if (nd->nfsd_slp)
2805 				panic("nfsd wakeup");
2806 			slp->ns_sref++;
2807 			nd->nfsd_slp = slp;
2808 			wakeup((caddr_t)nd);
2809 			if (--nparallel == 0)
2810 				break;
2811 		}
2812 	}
2813 	if (nparallel) {
2814 		slp->ns_flag |= SLP_DOREC;
2815 		nfsd_head_flag |= NFSD_CHECKSLP;
2816 	}
2817 }
2818 #endif /* NFS_NOSERVER */
2819