xref: /dflybsd-src/sys/vfs/nfs/nfs_socket.c (revision 3e82b46c18bc48fdb3c1d60729c7661b3a0bf6bf)
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 = NULL;
199 	saddr = nmp->nm_nam;
200 	error = socreate(saddr->sa_family, &nmp->nm_so, nmp->nm_sotype,
201 		nmp->nm_soproto, td);
202 	if (error)
203 		goto bad;
204 	so = nmp->nm_so;
205 	nmp->nm_soflags = so->so_proto->pr_flags;
206 
207 	/*
208 	 * Some servers require that the client port be a reserved port number.
209 	 */
210 	if (saddr->sa_family == AF_INET && (nmp->nm_flag & NFSMNT_RESVPORT)) {
211 		struct sockopt sopt;
212 		int ip;
213 		struct sockaddr_in ssin;
214 
215 		bzero(&sopt, sizeof sopt);
216 		ip = IP_PORTRANGE_LOW;
217 		sopt.sopt_level = IPPROTO_IP;
218 		sopt.sopt_name = IP_PORTRANGE;
219 		sopt.sopt_val = (void *)&ip;
220 		sopt.sopt_valsize = sizeof(ip);
221 		sopt.sopt_td = NULL;
222 		error = sosetopt(so, &sopt);
223 		if (error)
224 			goto bad;
225 		bzero(&ssin, sizeof ssin);
226 		sin = &ssin;
227 		sin->sin_len = sizeof (struct sockaddr_in);
228 		sin->sin_family = AF_INET;
229 		sin->sin_addr.s_addr = INADDR_ANY;
230 		sin->sin_port = htons(0);
231 		error = sobind(so, (struct sockaddr *)sin, td);
232 		if (error)
233 			goto bad;
234 		bzero(&sopt, sizeof sopt);
235 		ip = IP_PORTRANGE_DEFAULT;
236 		sopt.sopt_level = IPPROTO_IP;
237 		sopt.sopt_name = IP_PORTRANGE;
238 		sopt.sopt_val = (void *)&ip;
239 		sopt.sopt_valsize = sizeof(ip);
240 		sopt.sopt_td = NULL;
241 		error = sosetopt(so, &sopt);
242 		if (error)
243 			goto bad;
244 	}
245 
246 	/*
247 	 * Protocols that do not require connections may be optionally left
248 	 * unconnected for servers that reply from a port other than NFS_PORT.
249 	 */
250 	if (nmp->nm_flag & NFSMNT_NOCONN) {
251 		if (nmp->nm_soflags & PR_CONNREQUIRED) {
252 			error = ENOTCONN;
253 			goto bad;
254 		}
255 	} else {
256 		error = soconnect(so, nmp->nm_nam, td);
257 		if (error)
258 			goto bad;
259 
260 		/*
261 		 * Wait for the connection to complete. Cribbed from the
262 		 * connect system call but with the wait timing out so
263 		 * that interruptible mounts don't hang here for a long time.
264 		 */
265 		crit_enter();
266 		while ((so->so_state & SS_ISCONNECTING) && so->so_error == 0) {
267 			(void) tsleep((caddr_t)&so->so_timeo, 0,
268 				"nfscon", 2 * hz);
269 			if ((so->so_state & SS_ISCONNECTING) &&
270 			    so->so_error == 0 && rep &&
271 			    (error = nfs_sigintr(nmp, rep, rep->r_td)) != 0){
272 				so->so_state &= ~SS_ISCONNECTING;
273 				crit_exit();
274 				goto bad;
275 			}
276 		}
277 		if (so->so_error) {
278 			error = so->so_error;
279 			so->so_error = 0;
280 			crit_exit();
281 			goto bad;
282 		}
283 		crit_exit();
284 	}
285 	so->so_rcv.ssb_timeo = (5 * hz);
286 	so->so_snd.ssb_timeo = (5 * hz);
287 
288 	/*
289 	 * Get buffer reservation size from sysctl, but impose reasonable
290 	 * limits.
291 	 */
292 	if (nmp->nm_sotype == SOCK_STREAM) {
293 		if (so->so_proto->pr_flags & PR_CONNREQUIRED) {
294 			struct sockopt sopt;
295 			int val;
296 
297 			bzero(&sopt, sizeof sopt);
298 			sopt.sopt_level = SOL_SOCKET;
299 			sopt.sopt_name = SO_KEEPALIVE;
300 			sopt.sopt_val = &val;
301 			sopt.sopt_valsize = sizeof val;
302 			val = 1;
303 			sosetopt(so, &sopt);
304 		}
305 		if (so->so_proto->pr_protocol == IPPROTO_TCP) {
306 			struct sockopt sopt;
307 			int val;
308 
309 			bzero(&sopt, sizeof sopt);
310 			sopt.sopt_level = IPPROTO_TCP;
311 			sopt.sopt_name = TCP_NODELAY;
312 			sopt.sopt_val = &val;
313 			sopt.sopt_valsize = sizeof val;
314 			val = 1;
315 			sosetopt(so, &sopt);
316 		}
317 	}
318 	error = soreserve(so, nfs_soreserve, nfs_soreserve, NULL);
319 	if (error)
320 		goto bad;
321 	so->so_rcv.ssb_flags |= SSB_NOINTR;
322 	so->so_snd.ssb_flags |= SSB_NOINTR;
323 
324 	/* Initialize other non-zero congestion variables */
325 	nmp->nm_srtt[0] = nmp->nm_srtt[1] = nmp->nm_srtt[2] =
326 		nmp->nm_srtt[3] = (NFS_TIMEO << NFS_RTT_SCALE_BITS);
327 	nmp->nm_sdrtt[0] = nmp->nm_sdrtt[1] = nmp->nm_sdrtt[2] =
328 		nmp->nm_sdrtt[3] = 0;
329 	nmp->nm_maxasync_scaled = NFS_MINASYNC_SCALED;
330 	nmp->nm_timeouts = 0;
331 	return (0);
332 
333 bad:
334 	nfs_disconnect(nmp);
335 	return (error);
336 }
337 
338 /*
339  * Reconnect routine:
340  * Called when a connection is broken on a reliable protocol.
341  * - clean up the old socket
342  * - nfs_connect() again
343  * - set R_NEEDSXMIT for all outstanding requests on mount point
344  * If this fails the mount point is DEAD!
345  * nb: Must be called with the nfs_sndlock() set on the mount point.
346  */
347 static int
348 nfs_reconnect(struct nfsmount *nmp, struct nfsreq *rep)
349 {
350 	struct nfsreq *req;
351 	int error;
352 
353 	nfs_disconnect(nmp);
354 	while ((error = nfs_connect(nmp, rep)) != 0) {
355 		if (error == EINTR || error == ERESTART)
356 			return (EINTR);
357 		(void) tsleep((caddr_t)&lbolt, 0, "nfscon", 0);
358 	}
359 
360 	/*
361 	 * Loop through outstanding request list and fix up all requests
362 	 * on old socket.
363 	 */
364 	crit_enter();
365 	TAILQ_FOREACH(req, &nmp->nm_reqq, r_chain) {
366 		KKASSERT(req->r_nmp == nmp);
367 		req->r_flags |= R_NEEDSXMIT;
368 	}
369 	crit_exit();
370 	return (0);
371 }
372 
373 /*
374  * NFS disconnect. Clean up and unlink.
375  */
376 void
377 nfs_disconnect(struct nfsmount *nmp)
378 {
379 	struct socket *so;
380 
381 	if (nmp->nm_so) {
382 		so = nmp->nm_so;
383 		nmp->nm_so = NULL;
384 		soshutdown(so, SHUT_RDWR);
385 		soclose(so, FNONBLOCK);
386 	}
387 }
388 
389 void
390 nfs_safedisconnect(struct nfsmount *nmp)
391 {
392 	nfs_rcvlock(nmp, NULL);
393 	nfs_disconnect(nmp);
394 	nfs_rcvunlock(nmp);
395 }
396 
397 /*
398  * This is the nfs send routine. For connection based socket types, it
399  * must be called with an nfs_sndlock() on the socket.
400  * "rep == NULL" indicates that it has been called from a server.
401  * For the client side:
402  * - return EINTR if the RPC is terminated, 0 otherwise
403  * - set R_NEEDSXMIT if the send fails for any reason
404  * - do any cleanup required by recoverable socket errors (?)
405  * For the server side:
406  * - return EINTR or ERESTART if interrupted by a signal
407  * - return EPIPE if a connection is lost for connection based sockets (TCP...)
408  * - do any cleanup required by recoverable socket errors (?)
409  */
410 int
411 nfs_send(struct socket *so, struct sockaddr *nam, struct mbuf *top,
412 	 struct nfsreq *rep)
413 {
414 	struct sockaddr *sendnam;
415 	int error, soflags, flags;
416 
417 	if (rep) {
418 		if (rep->r_flags & R_SOFTTERM) {
419 			m_freem(top);
420 			return (EINTR);
421 		}
422 		if ((so = rep->r_nmp->nm_so) == NULL) {
423 			rep->r_flags |= R_NEEDSXMIT;
424 			m_freem(top);
425 			return (0);
426 		}
427 		rep->r_flags &= ~R_NEEDSXMIT;
428 		soflags = rep->r_nmp->nm_soflags;
429 	} else {
430 		soflags = so->so_proto->pr_flags;
431 	}
432 	if ((soflags & PR_CONNREQUIRED) || (so->so_state & SS_ISCONNECTED))
433 		sendnam = NULL;
434 	else
435 		sendnam = nam;
436 	if (so->so_type == SOCK_SEQPACKET)
437 		flags = MSG_EOR;
438 	else
439 		flags = 0;
440 
441 	error = so_pru_sosend(so, sendnam, NULL, top, NULL, flags,
442 	    curthread /*XXX*/);
443 	/*
444 	 * ENOBUFS for dgram sockets is transient and non fatal.
445 	 * No need to log, and no need to break a soft mount.
446 	 */
447 	if (error == ENOBUFS && so->so_type == SOCK_DGRAM) {
448 		error = 0;
449 		/*
450 		 * do backoff retransmit on client
451 		 */
452 		if (rep) {
453 			if ((rep->r_nmp->nm_state & NFSSTA_SENDSPACE) == 0) {
454 				rep->r_nmp->nm_state |= NFSSTA_SENDSPACE;
455 				kprintf("Warning: NFS: Insufficient sendspace "
456 					"(%lu),\n"
457 					"\t You must increase vfs.nfs.soreserve"
458 					"or decrease vfs.nfs.maxasyncbio\n",
459 					so->so_snd.ssb_hiwat);
460 			}
461 			rep->r_flags |= R_NEEDSXMIT;
462 		}
463 	}
464 
465 	if (error) {
466 		if (rep) {
467 			log(LOG_INFO, "nfs send error %d for server %s\n",error,
468 			    rep->r_nmp->nm_mountp->mnt_stat.f_mntfromname);
469 			/*
470 			 * Deal with errors for the client side.
471 			 */
472 			if (rep->r_flags & R_SOFTTERM)
473 				error = EINTR;
474 			else
475 				rep->r_flags |= R_NEEDSXMIT;
476 		} else {
477 			log(LOG_INFO, "nfsd send error %d\n", error);
478 		}
479 
480 		/*
481 		 * Handle any recoverable (soft) socket errors here. (?)
482 		 */
483 		if (error != EINTR && error != ERESTART &&
484 			error != EWOULDBLOCK && error != EPIPE)
485 			error = 0;
486 	}
487 	return (error);
488 }
489 
490 /*
491  * Receive a Sun RPC Request/Reply. For SOCK_DGRAM, the work is all
492  * done by soreceive(), but for SOCK_STREAM we must deal with the Record
493  * Mark and consolidate the data into a new mbuf list.
494  * nb: Sometimes TCP passes the data up to soreceive() in long lists of
495  *     small mbufs.
496  * For SOCK_STREAM we must be very careful to read an entire record once
497  * we have read any of it, even if the system call has been interrupted.
498  */
499 static int
500 nfs_receive(struct nfsmount *nmp, struct nfsreq *rep,
501 	    struct sockaddr **aname, struct mbuf **mp)
502 {
503 	struct socket *so;
504 	struct sockbuf sio;
505 	struct uio auio;
506 	struct iovec aio;
507 	struct mbuf *m;
508 	struct mbuf *control;
509 	u_int32_t len;
510 	struct sockaddr **getnam;
511 	int error, sotype, rcvflg;
512 	struct thread *td = curthread;	/* XXX */
513 
514 	/*
515 	 * Set up arguments for soreceive()
516 	 */
517 	*mp = NULL;
518 	*aname = NULL;
519 	sotype = nmp->nm_sotype;
520 
521 	/*
522 	 * For reliable protocols, lock against other senders/receivers
523 	 * in case a reconnect is necessary.
524 	 * For SOCK_STREAM, first get the Record Mark to find out how much
525 	 * more there is to get.
526 	 * We must lock the socket against other receivers
527 	 * until we have an entire rpc request/reply.
528 	 */
529 	if (sotype != SOCK_DGRAM) {
530 		error = nfs_sndlock(nmp, rep);
531 		if (error)
532 			return (error);
533 tryagain:
534 		/*
535 		 * Check for fatal errors and resending request.
536 		 */
537 		/*
538 		 * Ugh: If a reconnect attempt just happened, nm_so
539 		 * would have changed. NULL indicates a failed
540 		 * attempt that has essentially shut down this
541 		 * mount point.
542 		 */
543 		if (rep && (rep->r_mrep || (rep->r_flags & R_SOFTTERM))) {
544 			nfs_sndunlock(nmp);
545 			return (EINTR);
546 		}
547 		so = nmp->nm_so;
548 		if (so == NULL) {
549 			error = nfs_reconnect(nmp, rep);
550 			if (error) {
551 				nfs_sndunlock(nmp);
552 				return (error);
553 			}
554 			goto tryagain;
555 		}
556 		while (rep && (rep->r_flags & R_NEEDSXMIT)) {
557 			m = m_copym(rep->r_mreq, 0, M_COPYALL, MB_WAIT);
558 			nfsstats.rpcretries++;
559 			error = nfs_send(so, rep->r_nmp->nm_nam, m, rep);
560 			if (error) {
561 				if (error == EINTR || error == ERESTART ||
562 				    (error = nfs_reconnect(nmp, rep)) != 0) {
563 					nfs_sndunlock(nmp);
564 					return (error);
565 				}
566 				goto tryagain;
567 			}
568 		}
569 		nfs_sndunlock(nmp);
570 		if (sotype == SOCK_STREAM) {
571 			/*
572 			 * Get the length marker from the stream
573 			 */
574 			aio.iov_base = (caddr_t)&len;
575 			aio.iov_len = sizeof(u_int32_t);
576 			auio.uio_iov = &aio;
577 			auio.uio_iovcnt = 1;
578 			auio.uio_segflg = UIO_SYSSPACE;
579 			auio.uio_rw = UIO_READ;
580 			auio.uio_offset = 0;
581 			auio.uio_resid = sizeof(u_int32_t);
582 			auio.uio_td = td;
583 			do {
584 			   rcvflg = MSG_WAITALL;
585 			   error = so_pru_soreceive(so, NULL, &auio, NULL,
586 						    NULL, &rcvflg);
587 			   if (error == EWOULDBLOCK && rep) {
588 				if (rep->r_flags & R_SOFTTERM)
589 					return (EINTR);
590 			   }
591 			} while (error == EWOULDBLOCK);
592 
593 			if (error == 0 && auio.uio_resid > 0) {
594 			    /*
595 			     * Only log short packets if not EOF
596 			     */
597 			    if (auio.uio_resid != sizeof(u_int32_t))
598 			    log(LOG_INFO,
599 				 "short receive (%d/%d) from nfs server %s\n",
600 				 (int)(sizeof(u_int32_t) - auio.uio_resid),
601 				 (int)sizeof(u_int32_t),
602 				 nmp->nm_mountp->mnt_stat.f_mntfromname);
603 			    error = EPIPE;
604 			}
605 			if (error)
606 				goto errout;
607 			len = ntohl(len) & ~0x80000000;
608 			/*
609 			 * This is SERIOUS! We are out of sync with the sender
610 			 * and forcing a disconnect/reconnect is all I can do.
611 			 */
612 			if (len > NFS_MAXPACKET) {
613 			    log(LOG_ERR, "%s (%d) from nfs server %s\n",
614 				"impossible packet length",
615 				len,
616 				nmp->nm_mountp->mnt_stat.f_mntfromname);
617 			    error = EFBIG;
618 			    goto errout;
619 			}
620 
621 			/*
622 			 * Get the rest of the packet as an mbuf chain
623 			 */
624 			sbinit(&sio, len);
625 			do {
626 			    rcvflg = MSG_WAITALL;
627 			    error = so_pru_soreceive(so, NULL, NULL, &sio,
628 						     NULL, &rcvflg);
629 			} while (error == EWOULDBLOCK || error == EINTR ||
630 				 error == ERESTART);
631 			if (error == 0 && sio.sb_cc != len) {
632 			    if (sio.sb_cc != 0)
633 			    log(LOG_INFO,
634 				"short receive (%d/%d) from nfs server %s\n",
635 				len - auio.uio_resid, len,
636 				nmp->nm_mountp->mnt_stat.f_mntfromname);
637 			    error = EPIPE;
638 			}
639 			*mp = sio.sb_mb;
640 		} else {
641 			/*
642 			 * Non-stream, so get the whole packet by not
643 			 * specifying MSG_WAITALL and by specifying a large
644 			 * length.
645 			 *
646 			 * We have no use for control msg., but must grab them
647 			 * and then throw them away so we know what is going
648 			 * on.
649 			 */
650 			sbinit(&sio, 100000000);
651 			do {
652 			    rcvflg = 0;
653 			    error =  so_pru_soreceive(so, NULL, NULL, &sio,
654 						      &control, &rcvflg);
655 			    if (control)
656 				m_freem(control);
657 			    if (error == EWOULDBLOCK && rep) {
658 				if (rep->r_flags & R_SOFTTERM) {
659 					m_freem(sio.sb_mb);
660 					return (EINTR);
661 				}
662 			    }
663 			} while (error == EWOULDBLOCK ||
664 				 (error == 0 && sio.sb_mb == NULL && control));
665 			if ((rcvflg & MSG_EOR) == 0)
666 				kprintf("Egad!!\n");
667 			if (error == 0 && sio.sb_mb == NULL)
668 				error = EPIPE;
669 			len = sio.sb_cc;
670 			*mp = sio.sb_mb;
671 		}
672 errout:
673 		if (error && error != EINTR && error != ERESTART) {
674 			m_freem(*mp);
675 			*mp = NULL;
676 			if (error != EPIPE) {
677 				log(LOG_INFO,
678 				    "receive error %d from nfs server %s\n",
679 				    error,
680 				 nmp->nm_mountp->mnt_stat.f_mntfromname);
681 			}
682 			error = nfs_sndlock(nmp, rep);
683 			if (!error) {
684 				error = nfs_reconnect(nmp, rep);
685 				if (!error)
686 					goto tryagain;
687 				else
688 					nfs_sndunlock(nmp);
689 			}
690 		}
691 	} else {
692 		if ((so = nmp->nm_so) == NULL)
693 			return (EACCES);
694 		if (so->so_state & SS_ISCONNECTED)
695 			getnam = NULL;
696 		else
697 			getnam = aname;
698 		sbinit(&sio, 100000000);
699 		do {
700 			rcvflg = 0;
701 			error =  so_pru_soreceive(so, getnam, NULL, &sio,
702 						  NULL, &rcvflg);
703 			if (error == EWOULDBLOCK && rep &&
704 			    (rep->r_flags & R_SOFTTERM)) {
705 				m_freem(sio.sb_mb);
706 				return (EINTR);
707 			}
708 		} while (error == EWOULDBLOCK);
709 
710 		len = sio.sb_cc;
711 		*mp = sio.sb_mb;
712 
713 		/*
714 		 * A shutdown may result in no error and no mbuf.
715 		 * Convert to EPIPE.
716 		 */
717 		if (*mp == NULL && error == 0)
718 			error = EPIPE;
719 	}
720 	if (error) {
721 		m_freem(*mp);
722 		*mp = NULL;
723 	}
724 
725 	/*
726 	 * Search for any mbufs that are not a multiple of 4 bytes long
727 	 * or with m_data not longword aligned.
728 	 * These could cause pointer alignment problems, so copy them to
729 	 * well aligned mbufs.
730 	 */
731 	nfs_realign(mp, 5 * NFSX_UNSIGNED);
732 	return (error);
733 }
734 
735 /*
736  * Implement receipt of reply on a socket.
737  *
738  * We must search through the list of received datagrams matching them
739  * with outstanding requests using the xid, until ours is found.
740  *
741  * If myrep is NULL we process packets on the socket until
742  * interrupted or until nm_reqrxq is non-empty.
743  */
744 /* ARGSUSED */
745 int
746 nfs_reply(struct nfsmount *nmp, struct nfsreq *myrep)
747 {
748 	struct nfsreq *rep;
749 	struct sockaddr *nam;
750 	u_int32_t rxid;
751 	u_int32_t *tl;
752 	int error;
753 	struct nfsm_info info;
754 
755 	/*
756 	 * Loop around until we get our own reply
757 	 */
758 	for (;;) {
759 		/*
760 		 * Lock against other receivers so that I don't get stuck in
761 		 * sbwait() after someone else has received my reply for me.
762 		 * Also necessary for connection based protocols to avoid
763 		 * race conditions during a reconnect.
764 		 *
765 		 * If nfs_rcvlock() returns EALREADY, that means that
766 		 * the reply has already been recieved by another
767 		 * process and we can return immediately.  In this
768 		 * case, the lock is not taken to avoid races with
769 		 * other processes.
770 		 */
771 		info.mrep = NULL;
772 
773 		error = nfs_rcvlock(nmp, myrep);
774 		if (error == EALREADY)
775 			return (0);
776 		if (error)
777 			return (error);
778 
779 		/*
780 		 * If myrep is NULL we are the receiver helper thread.
781 		 * Stop waiting for incoming replies if there are
782 		 * messages sitting on reqrxq that we need to process,
783 		 * or if a shutdown request is pending.
784 		 */
785 		if (myrep == NULL && (TAILQ_FIRST(&nmp->nm_reqrxq) ||
786 		    nmp->nm_rxstate > NFSSVC_PENDING)) {
787 			nfs_rcvunlock(nmp);
788 			return(EWOULDBLOCK);
789 		}
790 
791 		/*
792 		 * Get the next Rpc reply off the socket
793 		 *
794 		 * We cannot release the receive lock until we've
795 		 * filled in rep->r_mrep, otherwise a waiting
796 		 * thread may deadlock in soreceive with no incoming
797 		 * packets expected.
798 		 */
799 		error = nfs_receive(nmp, myrep, &nam, &info.mrep);
800 		if (error) {
801 			/*
802 			 * Ignore routing errors on connectionless protocols??
803 			 */
804 			nfs_rcvunlock(nmp);
805 			if (NFSIGNORE_SOERROR(nmp->nm_soflags, error)) {
806 				if (nmp->nm_so == NULL)
807 					return (error);
808 				nmp->nm_so->so_error = 0;
809 				continue;
810 			}
811 			return (error);
812 		}
813 		if (nam)
814 			FREE(nam, M_SONAME);
815 
816 		/*
817 		 * Get the xid and check that it is an rpc reply
818 		 */
819 		info.md = info.mrep;
820 		info.dpos = mtod(info.md, caddr_t);
821 		NULLOUT(tl = nfsm_dissect(&info, 2*NFSX_UNSIGNED));
822 		rxid = *tl++;
823 		if (*tl != rpc_reply) {
824 			nfsstats.rpcinvalid++;
825 			m_freem(info.mrep);
826 			info.mrep = NULL;
827 nfsmout:
828 			nfs_rcvunlock(nmp);
829 			continue;
830 		}
831 
832 		/*
833 		 * Loop through the request list to match up the reply
834 		 * Iff no match, just drop the datagram.  On match, set
835 		 * r_mrep atomically to prevent the timer from messing
836 		 * around with the request after we have exited the critical
837 		 * section.
838 		 */
839 		crit_enter();
840 		TAILQ_FOREACH(rep, &nmp->nm_reqq, r_chain) {
841 			if (rep->r_mrep == NULL && rxid == rep->r_xid)
842 				break;
843 		}
844 
845 		/*
846 		 * Fill in the rest of the reply if we found a match.
847 		 *
848 		 * Deal with duplicate responses if there was no match.
849 		 */
850 		if (rep) {
851 			rep->r_md = info.md;
852 			rep->r_dpos = info.dpos;
853 			if (nfsrtton) {
854 				struct rttl *rt;
855 
856 				rt = &nfsrtt.rttl[nfsrtt.pos];
857 				rt->proc = rep->r_procnum;
858 				rt->rto = 0;
859 				rt->sent = 0;
860 				rt->cwnd = nmp->nm_maxasync_scaled;
861 				rt->srtt = nmp->nm_srtt[proct[rep->r_procnum] - 1];
862 				rt->sdrtt = nmp->nm_sdrtt[proct[rep->r_procnum] - 1];
863 				rt->fsid = nmp->nm_mountp->mnt_stat.f_fsid;
864 				getmicrotime(&rt->tstamp);
865 				if (rep->r_flags & R_TIMING)
866 					rt->rtt = rep->r_rtt;
867 				else
868 					rt->rtt = 1000000;
869 				nfsrtt.pos = (nfsrtt.pos + 1) % NFSRTTLOGSIZ;
870 			}
871 
872 			/*
873 			 * New congestion control is based only on async
874 			 * requests.
875 			 */
876 			if (nmp->nm_maxasync_scaled < NFS_MAXASYNC_SCALED)
877 				++nmp->nm_maxasync_scaled;
878 			if (rep->r_flags & R_SENT) {
879 				rep->r_flags &= ~R_SENT;
880 			}
881 			/*
882 			 * Update rtt using a gain of 0.125 on the mean
883 			 * and a gain of 0.25 on the deviation.
884 			 *
885 			 * NOTE SRTT/SDRTT are only good if R_TIMING is set.
886 			 */
887 			if ((rep->r_flags & R_TIMING) && rep->r_rexmit == 0) {
888 				/*
889 				 * Since the timer resolution of
890 				 * NFS_HZ is so course, it can often
891 				 * result in r_rtt == 0. Since
892 				 * r_rtt == N means that the actual
893 				 * rtt is between N+dt and N+2-dt ticks,
894 				 * add 1.
895 				 */
896 				int n;
897 				int d;
898 
899 #define NFSRSB	NFS_RTT_SCALE_BITS
900 				n = ((NFS_SRTT(rep) * 7) +
901 				     (rep->r_rtt << NFSRSB)) >> 3;
902 				d = n - NFS_SRTT(rep);
903 				NFS_SRTT(rep) = n;
904 
905 				/*
906 				 * Don't let the jitter calculation decay
907 				 * too quickly, but we want a fast rampup.
908 				 */
909 				if (d < 0)
910 					d = -d;
911 				d <<= NFSRSB;
912 				if (d < NFS_SDRTT(rep))
913 					n = ((NFS_SDRTT(rep) * 15) + d) >> 4;
914 				else
915 					n = ((NFS_SDRTT(rep) * 3) + d) >> 2;
916 				NFS_SDRTT(rep) = n;
917 #undef NFSRSB
918 			}
919 			nmp->nm_timeouts = 0;
920 			rep->r_mrep = info.mrep;
921 			nfs_hardterm(rep, 0);
922 		} else {
923 			/*
924 			 * Extract vers, prog, nfsver, procnum.  A duplicate
925 			 * response means we didn't wait long enough so
926 			 * we increase the SRTT to avoid future spurious
927 			 * timeouts.
928 			 */
929 			u_int procnum = nmp->nm_lastreprocnum;
930 			int n;
931 
932 			if (procnum < NFS_NPROCS && proct[procnum]) {
933 				if (nfs_showrexmit)
934 					kprintf("D");
935 				n = nmp->nm_srtt[proct[procnum]];
936 				n += NFS_ASYSCALE * NFS_HZ;
937 				if (n < NFS_ASYSCALE * NFS_HZ * 10)
938 					n = NFS_ASYSCALE * NFS_HZ * 10;
939 				nmp->nm_srtt[proct[procnum]] = n;
940 			}
941 		}
942 		nfs_rcvunlock(nmp);
943 		crit_exit();
944 
945 		/*
946 		 * If not matched to a request, drop it.
947 		 * If it's mine, get out.
948 		 */
949 		if (rep == NULL) {
950 			nfsstats.rpcunexpected++;
951 			m_freem(info.mrep);
952 			info.mrep = NULL;
953 		} else if (rep == myrep) {
954 			if (rep->r_mrep == NULL)
955 				panic("nfsreply nil");
956 			return (0);
957 		}
958 	}
959 }
960 
961 /*
962  * Run the request state machine until the target state is reached
963  * or a fatal error occurs.  The target state is not run.  Specifying
964  * a target of NFSM_STATE_DONE runs the state machine until the rpc
965  * is complete.
966  *
967  * EINPROGRESS is returned for all states other then the DONE state,
968  * indicating that the rpc is still in progress.
969  */
970 int
971 nfs_request(struct nfsm_info *info, nfsm_state_t bstate, nfsm_state_t estate)
972 {
973 	struct nfsreq *req;
974 
975 	while (info->state >= bstate && info->state < estate) {
976 		switch(info->state) {
977 		case NFSM_STATE_SETUP:
978 			/*
979 			 * Setup the nfsreq.  Any error which occurs during
980 			 * this state is fatal.
981 			 */
982 			info->error = nfs_request_setup(info);
983 			if (info->error) {
984 				info->state = NFSM_STATE_DONE;
985 				return (info->error);
986 			} else {
987 				req = info->req;
988 				req->r_mrp = &info->mrep;
989 				req->r_mdp = &info->md;
990 				req->r_dposp = &info->dpos;
991 				info->state = NFSM_STATE_AUTH;
992 			}
993 			break;
994 		case NFSM_STATE_AUTH:
995 			/*
996 			 * Authenticate the nfsreq.  Any error which occurs
997 			 * during this state is fatal.
998 			 */
999 			info->error = nfs_request_auth(info->req);
1000 			if (info->error) {
1001 				info->state = NFSM_STATE_DONE;
1002 				return (info->error);
1003 			} else {
1004 				info->state = NFSM_STATE_TRY;
1005 			}
1006 			break;
1007 		case NFSM_STATE_TRY:
1008 			/*
1009 			 * Transmit or retransmit attempt.  An error in this
1010 			 * state is ignored and we always move on to the
1011 			 * next state.
1012 			 *
1013 			 * This can trivially race the receiver if the
1014 			 * request is asynchronous.  nfs_request_try()
1015 			 * will thus set the state for us and we
1016 			 * must also return immediately if we are
1017 			 * running an async state machine, because
1018 			 * info can become invalid due to races after
1019 			 * try() returns.
1020 			 */
1021 			if (info->req->r_flags & R_ASYNC) {
1022 				nfs_request_try(info->req);
1023 				if (estate == NFSM_STATE_WAITREPLY)
1024 					return (EINPROGRESS);
1025 			} else {
1026 				nfs_request_try(info->req);
1027 				info->state = NFSM_STATE_WAITREPLY;
1028 			}
1029 			break;
1030 		case NFSM_STATE_WAITREPLY:
1031 			/*
1032 			 * Wait for a reply or timeout and move on to the
1033 			 * next state.  The error returned by this state
1034 			 * is passed to the processing code in the next
1035 			 * state.
1036 			 */
1037 			info->error = nfs_request_waitreply(info->req);
1038 			info->state = NFSM_STATE_PROCESSREPLY;
1039 			break;
1040 		case NFSM_STATE_PROCESSREPLY:
1041 			/*
1042 			 * Process the reply or timeout.  Errors which occur
1043 			 * in this state may cause the state machine to
1044 			 * go back to an earlier state, and are fatal
1045 			 * otherwise.
1046 			 */
1047 			info->error = nfs_request_processreply(info,
1048 							       info->error);
1049 			switch(info->error) {
1050 			case ENEEDAUTH:
1051 				info->state = NFSM_STATE_AUTH;
1052 				break;
1053 			case EAGAIN:
1054 				info->state = NFSM_STATE_TRY;
1055 				break;
1056 			default:
1057 				/*
1058 				 * Operation complete, with or without an
1059 				 * error.  We are done.
1060 				 */
1061 				info->req = NULL;
1062 				info->state = NFSM_STATE_DONE;
1063 				return (info->error);
1064 			}
1065 			break;
1066 		case NFSM_STATE_DONE:
1067 			/*
1068 			 * Shouldn't be reached
1069 			 */
1070 			return (info->error);
1071 			/* NOT REACHED */
1072 		}
1073 	}
1074 
1075 	/*
1076 	 * If we are done return the error code (if any).
1077 	 * Otherwise return EINPROGRESS.
1078 	 */
1079 	if (info->state == NFSM_STATE_DONE)
1080 		return (info->error);
1081 	return (EINPROGRESS);
1082 }
1083 
1084 /*
1085  * nfs_request - goes something like this
1086  *	- fill in request struct
1087  *	- links it into list
1088  *	- calls nfs_send() for first transmit
1089  *	- calls nfs_receive() to get reply
1090  *	- break down rpc header and return with nfs reply pointed to
1091  *	  by mrep or error
1092  * nb: always frees up mreq mbuf list
1093  */
1094 static int
1095 nfs_request_setup(nfsm_info_t info)
1096 {
1097 	struct nfsreq *req;
1098 	struct nfsmount *nmp;
1099 	struct mbuf *m;
1100 	int i;
1101 
1102 	/*
1103 	 * Reject requests while attempting a forced unmount.
1104 	 */
1105 	if (info->vp->v_mount->mnt_kern_flag & MNTK_UNMOUNTF) {
1106 		m_freem(info->mreq);
1107 		info->mreq = NULL;
1108 		return (ESTALE);
1109 	}
1110 	nmp = VFSTONFS(info->vp->v_mount);
1111 	req = kmalloc(sizeof(struct nfsreq), M_NFSREQ, M_WAITOK);
1112 	req->r_nmp = nmp;
1113 	req->r_vp = info->vp;
1114 	req->r_td = info->td;
1115 	req->r_procnum = info->procnum;
1116 	req->r_mreq = NULL;
1117 	req->r_cred = info->cred;
1118 
1119 	i = 0;
1120 	m = info->mreq;
1121 	while (m) {
1122 		i += m->m_len;
1123 		m = m->m_next;
1124 	}
1125 	req->r_mrest = info->mreq;
1126 	req->r_mrest_len = i;
1127 
1128 	/*
1129 	 * The presence of a non-NULL r_info in req indicates
1130 	 * async completion via our helper threads.  See the receiver
1131 	 * code.
1132 	 */
1133 	if (info->bio) {
1134 		req->r_info = info;
1135 		req->r_flags = R_ASYNC;
1136 	} else {
1137 		req->r_info = NULL;
1138 		req->r_flags = 0;
1139 	}
1140 	info->req = req;
1141 	return(0);
1142 }
1143 
1144 static int
1145 nfs_request_auth(struct nfsreq *rep)
1146 {
1147 	struct nfsmount *nmp = rep->r_nmp;
1148 	struct mbuf *m;
1149 	char nickv[RPCX_NICKVERF];
1150 	int error = 0, auth_len, auth_type;
1151 	int verf_len;
1152 	u_int32_t xid;
1153 	char *auth_str, *verf_str;
1154 	struct ucred *cred;
1155 
1156 	cred = rep->r_cred;
1157 	rep->r_failed_auth = 0;
1158 
1159 	/*
1160 	 * Get the RPC header with authorization.
1161 	 */
1162 	verf_str = auth_str = NULL;
1163 	if (nmp->nm_flag & NFSMNT_KERB) {
1164 		verf_str = nickv;
1165 		verf_len = sizeof (nickv);
1166 		auth_type = RPCAUTH_KERB4;
1167 		bzero((caddr_t)rep->r_key, sizeof(rep->r_key));
1168 		if (rep->r_failed_auth ||
1169 		    nfs_getnickauth(nmp, cred, &auth_str, &auth_len,
1170 				    verf_str, verf_len)) {
1171 			error = nfs_getauth(nmp, rep, cred, &auth_str,
1172 				&auth_len, verf_str, &verf_len, rep->r_key);
1173 			if (error) {
1174 				m_freem(rep->r_mrest);
1175 				rep->r_mrest = NULL;
1176 				kfree((caddr_t)rep, M_NFSREQ);
1177 				return (error);
1178 			}
1179 		}
1180 	} else {
1181 		auth_type = RPCAUTH_UNIX;
1182 		if (cred->cr_ngroups < 1)
1183 			panic("nfsreq nogrps");
1184 		auth_len = ((((cred->cr_ngroups - 1) > nmp->nm_numgrps) ?
1185 			nmp->nm_numgrps : (cred->cr_ngroups - 1)) << 2) +
1186 			5 * NFSX_UNSIGNED;
1187 	}
1188 	m = nfsm_rpchead(cred, nmp->nm_flag, rep->r_procnum, auth_type,
1189 			auth_len, auth_str, verf_len, verf_str,
1190 			rep->r_mrest, rep->r_mrest_len, &rep->r_mheadend, &xid);
1191 	rep->r_mrest = NULL;
1192 	if (auth_str)
1193 		kfree(auth_str, M_TEMP);
1194 
1195 	/*
1196 	 * For stream protocols, insert a Sun RPC Record Mark.
1197 	 */
1198 	if (nmp->nm_sotype == SOCK_STREAM) {
1199 		M_PREPEND(m, NFSX_UNSIGNED, MB_WAIT);
1200 		if (m == NULL) {
1201 			kfree(rep, M_NFSREQ);
1202 			return (ENOBUFS);
1203 		}
1204 		*mtod(m, u_int32_t *) = htonl(0x80000000 |
1205 			 (m->m_pkthdr.len - NFSX_UNSIGNED));
1206 	}
1207 	rep->r_mreq = m;
1208 	rep->r_xid = xid;
1209 	return (0);
1210 }
1211 
1212 static int
1213 nfs_request_try(struct nfsreq *rep)
1214 {
1215 	struct nfsmount *nmp = rep->r_nmp;
1216 	struct mbuf *m2;
1217 	int error;
1218 
1219 	/*
1220 	 * Request is not on any queue, only the owner has access to it
1221 	 * so it should not be locked by anyone atm.
1222 	 *
1223 	 * Interlock to prevent races.  While locked the only remote
1224 	 * action possible is for r_mrep to be set (once we enqueue it).
1225 	 */
1226 	if (rep->r_flags == 0xdeadc0de) {
1227 		print_backtrace();
1228 		panic("flags nbad\n");
1229 	}
1230 	KKASSERT((rep->r_flags & (R_LOCKED | R_ONREQQ)) == 0);
1231 	if (nmp->nm_flag & NFSMNT_SOFT)
1232 		rep->r_retry = nmp->nm_retry;
1233 	else
1234 		rep->r_retry = NFS_MAXREXMIT + 1;	/* past clip limit */
1235 	rep->r_rtt = rep->r_rexmit = 0;
1236 	if (proct[rep->r_procnum] > 0)
1237 		rep->r_flags |= R_TIMING | R_LOCKED;
1238 	else
1239 		rep->r_flags |= R_LOCKED;
1240 	rep->r_mrep = NULL;
1241 
1242 	/*
1243 	 * Do the client side RPC.
1244 	 */
1245 	nfsstats.rpcrequests++;
1246 
1247 	/*
1248 	 * Chain request into list of outstanding requests. Be sure
1249 	 * to put it LAST so timer finds oldest requests first.  Note
1250 	 * that our control of R_LOCKED prevents the request from
1251 	 * getting ripped out from under us or transmitted by the
1252 	 * timer code.
1253 	 *
1254 	 * For requests with info structures we must atomically set the
1255 	 * info's state because the structure could become invalid upon
1256 	 * return due to races (i.e., if async)
1257 	 */
1258 	crit_enter();
1259 	mtx_link_init(&rep->r_link);
1260 	TAILQ_INSERT_TAIL(&nmp->nm_reqq, rep, r_chain);
1261 	rep->r_flags |= R_ONREQQ;
1262 	++nmp->nm_reqqlen;
1263 	if (rep->r_flags & R_ASYNC)
1264 		rep->r_info->state = NFSM_STATE_WAITREPLY;
1265 	crit_exit();
1266 
1267 	error = 0;
1268 
1269 	/*
1270 	 * Send if we can.  Congestion control is not handled here any more
1271 	 * becausing trying to defer the initial send based on the nfs_timer
1272 	 * requires having a very fast nfs_timer, which is silly.
1273 	 */
1274 	if (nmp->nm_so) {
1275 		if (nmp->nm_soflags & PR_CONNREQUIRED)
1276 			error = nfs_sndlock(nmp, rep);
1277 		if (error == 0) {
1278 			m2 = m_copym(rep->r_mreq, 0, M_COPYALL, MB_WAIT);
1279 			error = nfs_send(nmp->nm_so, nmp->nm_nam, m2, rep);
1280 			if (nmp->nm_soflags & PR_CONNREQUIRED)
1281 				nfs_sndunlock(nmp);
1282 			rep->r_flags &= ~R_NEEDSXMIT;
1283 			if ((rep->r_flags & R_SENT) == 0) {
1284 				rep->r_flags |= R_SENT;
1285 			}
1286 		} else {
1287 			rep->r_flags |= R_NEEDSXMIT;
1288 		}
1289 	} else {
1290 		rep->r_flags |= R_NEEDSXMIT;
1291 		rep->r_rtt = -1;
1292 	}
1293 	if (error == EPIPE)
1294 		error = 0;
1295 
1296 	/*
1297 	 * Release the lock.  The only remote action that may have occurred
1298 	 * would have been the setting of rep->r_mrep.  If this occured
1299 	 * and the request was async we have to move it to the reader
1300 	 * thread's queue for action.
1301 	 *
1302 	 * For async requests also make sure the reader is woken up so
1303 	 * it gets on the socket to read responses.
1304 	 */
1305 	crit_enter();
1306 	if (rep->r_flags & R_ASYNC) {
1307 		if (rep->r_mrep)
1308 			nfs_hardterm(rep, 1);
1309 		rep->r_flags &= ~R_LOCKED;
1310 		nfssvc_iod_reader_wakeup(nmp);
1311 	} else {
1312 		rep->r_flags &= ~R_LOCKED;
1313 	}
1314 	if (rep->r_flags & R_WANTED) {
1315 		rep->r_flags &= ~R_WANTED;
1316 		wakeup(rep);
1317 	}
1318 	crit_exit();
1319 	return (error);
1320 }
1321 
1322 /*
1323  * This code is only called for synchronous requests.  Completed synchronous
1324  * requests are left on reqq and we remove them before moving on to the
1325  * processing state.
1326  */
1327 static int
1328 nfs_request_waitreply(struct nfsreq *rep)
1329 {
1330 	struct nfsmount *nmp = rep->r_nmp;
1331 	int error;
1332 
1333 	KKASSERT((rep->r_flags & R_ASYNC) == 0);
1334 
1335 	/*
1336 	 * Wait until the request is finished.
1337 	 */
1338 	error = nfs_reply(nmp, rep);
1339 
1340 	/*
1341 	 * RPC done, unlink the request, but don't rip it out from under
1342 	 * the callout timer.
1343 	 *
1344 	 * Once unlinked no other receiver or the timer will have
1345 	 * visibility, so we do not have to set R_LOCKED.
1346 	 */
1347 	crit_enter();
1348 	while (rep->r_flags & R_LOCKED) {
1349 		rep->r_flags |= R_WANTED;
1350 		tsleep(rep, 0, "nfstrac", 0);
1351 	}
1352 	KKASSERT(rep->r_flags & R_ONREQQ);
1353 	TAILQ_REMOVE(&nmp->nm_reqq, rep, r_chain);
1354 	rep->r_flags &= ~R_ONREQQ;
1355 	--nmp->nm_reqqlen;
1356 	if (TAILQ_FIRST(&nmp->nm_bioq) &&
1357 	    nmp->nm_reqqlen == NFS_MAXASYNCBIO * 2 / 3) {
1358 		nfssvc_iod_writer_wakeup(nmp);
1359 	}
1360 	crit_exit();
1361 
1362 	/*
1363 	 * Decrement the outstanding request count.
1364 	 */
1365 	if (rep->r_flags & R_SENT) {
1366 		rep->r_flags &= ~R_SENT;
1367 	}
1368 	return (error);
1369 }
1370 
1371 /*
1372  * Process reply with error returned from nfs_requet_waitreply().
1373  *
1374  * Returns EAGAIN if it wants us to loop up to nfs_request_try() again.
1375  * Returns ENEEDAUTH if it wants us to loop up to nfs_request_auth() again.
1376  */
1377 static int
1378 nfs_request_processreply(nfsm_info_t info, int error)
1379 {
1380 	struct nfsreq *req = info->req;
1381 	struct nfsmount *nmp = req->r_nmp;
1382 	u_int32_t *tl;
1383 	int verf_type;
1384 	int i;
1385 
1386 	/*
1387 	 * If there was a successful reply and a tprintf msg.
1388 	 * tprintf a response.
1389 	 */
1390 	if (error == 0 && (req->r_flags & R_TPRINTFMSG)) {
1391 		nfs_msg(req->r_td, nmp->nm_mountp->mnt_stat.f_mntfromname,
1392 		    "is alive again");
1393 	}
1394 	info->mrep = req->r_mrep;
1395 	info->md = req->r_md;
1396 	info->dpos = req->r_dpos;
1397 	if (error) {
1398 		m_freem(req->r_mreq);
1399 		req->r_mreq = NULL;
1400 		kfree(req, M_NFSREQ);
1401 		info->req = NULL;
1402 		return (error);
1403 	}
1404 
1405 	/*
1406 	 * break down the rpc header and check if ok
1407 	 */
1408 	NULLOUT(tl = nfsm_dissect(info, 3 * NFSX_UNSIGNED));
1409 	if (*tl++ == rpc_msgdenied) {
1410 		if (*tl == rpc_mismatch) {
1411 			error = EOPNOTSUPP;
1412 		} else if ((nmp->nm_flag & NFSMNT_KERB) &&
1413 			   *tl++ == rpc_autherr) {
1414 			if (req->r_failed_auth == 0) {
1415 				req->r_failed_auth++;
1416 				req->r_mheadend->m_next = NULL;
1417 				m_freem(info->mrep);
1418 				info->mrep = NULL;
1419 				m_freem(req->r_mreq);
1420 				return (ENEEDAUTH);
1421 			} else {
1422 				error = EAUTH;
1423 			}
1424 		} else {
1425 			error = EACCES;
1426 		}
1427 		m_freem(info->mrep);
1428 		info->mrep = NULL;
1429 		m_freem(req->r_mreq);
1430 		req->r_mreq = NULL;
1431 		kfree(req, M_NFSREQ);
1432 		info->req = NULL;
1433 		return (error);
1434 	}
1435 
1436 	/*
1437 	 * Grab any Kerberos verifier, otherwise just throw it away.
1438 	 */
1439 	verf_type = fxdr_unsigned(int, *tl++);
1440 	i = fxdr_unsigned(int32_t, *tl);
1441 	if ((nmp->nm_flag & NFSMNT_KERB) && verf_type == RPCAUTH_KERB4) {
1442 		error = nfs_savenickauth(nmp, req->r_cred, i, req->r_key,
1443 					 &info->md, &info->dpos, info->mrep);
1444 		if (error)
1445 			goto nfsmout;
1446 	} else if (i > 0) {
1447 		ERROROUT(nfsm_adv(info, nfsm_rndup(i)));
1448 	}
1449 	NULLOUT(tl = nfsm_dissect(info, NFSX_UNSIGNED));
1450 	/* 0 == ok */
1451 	if (*tl == 0) {
1452 		NULLOUT(tl = nfsm_dissect(info, NFSX_UNSIGNED));
1453 		if (*tl != 0) {
1454 			error = fxdr_unsigned(int, *tl);
1455 
1456 			/*
1457 			 * Does anyone even implement this?  Just impose
1458 			 * a 1-second delay.
1459 			 */
1460 			if ((nmp->nm_flag & NFSMNT_NFSV3) &&
1461 				error == NFSERR_TRYLATER) {
1462 				m_freem(info->mrep);
1463 				info->mrep = NULL;
1464 				error = 0;
1465 
1466 				tsleep((caddr_t)&lbolt, 0, "nqnfstry", 0);
1467 				return (EAGAIN);	/* goto tryagain */
1468 			}
1469 
1470 			/*
1471 			 * If the File Handle was stale, invalidate the
1472 			 * lookup cache, just in case.
1473 			 *
1474 			 * To avoid namecache<->vnode deadlocks we must
1475 			 * release the vnode lock if we hold it.
1476 			 */
1477 			if (error == ESTALE) {
1478 				struct vnode *vp = req->r_vp;
1479 				int ltype;
1480 
1481 				ltype = lockstatus(&vp->v_lock, curthread);
1482 				if (ltype == LK_EXCLUSIVE || ltype == LK_SHARED)
1483 					lockmgr(&vp->v_lock, LK_RELEASE);
1484 				cache_inval_vp(vp, CINV_CHILDREN);
1485 				if (ltype == LK_EXCLUSIVE || ltype == LK_SHARED)
1486 					lockmgr(&vp->v_lock, ltype);
1487 			}
1488 			if (nmp->nm_flag & NFSMNT_NFSV3) {
1489 				KKASSERT(*req->r_mrp == info->mrep);
1490 				KKASSERT(*req->r_mdp == info->md);
1491 				KKASSERT(*req->r_dposp == info->dpos);
1492 				error |= NFSERR_RETERR;
1493 			} else {
1494 				m_freem(info->mrep);
1495 				info->mrep = NULL;
1496 			}
1497 			m_freem(req->r_mreq);
1498 			req->r_mreq = NULL;
1499 			kfree(req, M_NFSREQ);
1500 			info->req = NULL;
1501 			return (error);
1502 		}
1503 
1504 		KKASSERT(*req->r_mrp == info->mrep);
1505 		KKASSERT(*req->r_mdp == info->md);
1506 		KKASSERT(*req->r_dposp == info->dpos);
1507 		m_freem(req->r_mreq);
1508 		req->r_mreq = NULL;
1509 		FREE(req, M_NFSREQ);
1510 		return (0);
1511 	}
1512 	m_freem(info->mrep);
1513 	info->mrep = NULL;
1514 	error = EPROTONOSUPPORT;
1515 nfsmout:
1516 	m_freem(req->r_mreq);
1517 	req->r_mreq = NULL;
1518 	kfree(req, M_NFSREQ);
1519 	info->req = NULL;
1520 	return (error);
1521 }
1522 
1523 #ifndef NFS_NOSERVER
1524 /*
1525  * Generate the rpc reply header
1526  * siz arg. is used to decide if adding a cluster is worthwhile
1527  */
1528 int
1529 nfs_rephead(int siz, struct nfsrv_descript *nd, struct nfssvc_sock *slp,
1530 	    int err, struct mbuf **mrq, struct mbuf **mbp, caddr_t *bposp)
1531 {
1532 	u_int32_t *tl;
1533 	struct nfsm_info info;
1534 
1535 	siz += RPC_REPLYSIZ;
1536 	info.mb = m_getl(max_hdr + siz, MB_WAIT, MT_DATA, M_PKTHDR, NULL);
1537 	info.mreq = info.mb;
1538 	info.mreq->m_pkthdr.len = 0;
1539 	/*
1540 	 * If this is not a cluster, try and leave leading space
1541 	 * for the lower level headers.
1542 	 */
1543 	if ((max_hdr + siz) < MINCLSIZE)
1544 		info.mreq->m_data += max_hdr;
1545 	tl = mtod(info.mreq, u_int32_t *);
1546 	info.mreq->m_len = 6 * NFSX_UNSIGNED;
1547 	info.bpos = ((caddr_t)tl) + info.mreq->m_len;
1548 	*tl++ = txdr_unsigned(nd->nd_retxid);
1549 	*tl++ = rpc_reply;
1550 	if (err == ERPCMISMATCH || (err & NFSERR_AUTHERR)) {
1551 		*tl++ = rpc_msgdenied;
1552 		if (err & NFSERR_AUTHERR) {
1553 			*tl++ = rpc_autherr;
1554 			*tl = txdr_unsigned(err & ~NFSERR_AUTHERR);
1555 			info.mreq->m_len -= NFSX_UNSIGNED;
1556 			info.bpos -= NFSX_UNSIGNED;
1557 		} else {
1558 			*tl++ = rpc_mismatch;
1559 			*tl++ = txdr_unsigned(RPC_VER2);
1560 			*tl = txdr_unsigned(RPC_VER2);
1561 		}
1562 	} else {
1563 		*tl++ = rpc_msgaccepted;
1564 
1565 		/*
1566 		 * For Kerberos authentication, we must send the nickname
1567 		 * verifier back, otherwise just RPCAUTH_NULL.
1568 		 */
1569 		if (nd->nd_flag & ND_KERBFULL) {
1570 		    struct nfsuid *nuidp;
1571 		    struct timeval ktvin, ktvout;
1572 
1573 		    for (nuidp = NUIDHASH(slp, nd->nd_cr.cr_uid)->lh_first;
1574 			nuidp != 0; nuidp = nuidp->nu_hash.le_next) {
1575 			if (nuidp->nu_cr.cr_uid == nd->nd_cr.cr_uid &&
1576 			    (!nd->nd_nam2 || netaddr_match(NU_NETFAM(nuidp),
1577 			     &nuidp->nu_haddr, nd->nd_nam2)))
1578 			    break;
1579 		    }
1580 		    if (nuidp) {
1581 			ktvin.tv_sec =
1582 			    txdr_unsigned(nuidp->nu_timestamp.tv_sec - 1);
1583 			ktvin.tv_usec =
1584 			    txdr_unsigned(nuidp->nu_timestamp.tv_usec);
1585 
1586 			/*
1587 			 * Encrypt the timestamp in ecb mode using the
1588 			 * session key.
1589 			 */
1590 #ifdef NFSKERB
1591 			XXX
1592 #endif
1593 
1594 			*tl++ = rpc_auth_kerb;
1595 			*tl++ = txdr_unsigned(3 * NFSX_UNSIGNED);
1596 			*tl = ktvout.tv_sec;
1597 			tl = nfsm_build(&info, 3 * NFSX_UNSIGNED);
1598 			*tl++ = ktvout.tv_usec;
1599 			*tl++ = txdr_unsigned(nuidp->nu_cr.cr_uid);
1600 		    } else {
1601 			*tl++ = 0;
1602 			*tl++ = 0;
1603 		    }
1604 		} else {
1605 			*tl++ = 0;
1606 			*tl++ = 0;
1607 		}
1608 		switch (err) {
1609 		case EPROGUNAVAIL:
1610 			*tl = txdr_unsigned(RPC_PROGUNAVAIL);
1611 			break;
1612 		case EPROGMISMATCH:
1613 			*tl = txdr_unsigned(RPC_PROGMISMATCH);
1614 			tl = nfsm_build(&info, 2 * NFSX_UNSIGNED);
1615 			*tl++ = txdr_unsigned(2);
1616 			*tl = txdr_unsigned(3);
1617 			break;
1618 		case EPROCUNAVAIL:
1619 			*tl = txdr_unsigned(RPC_PROCUNAVAIL);
1620 			break;
1621 		case EBADRPC:
1622 			*tl = txdr_unsigned(RPC_GARBAGE);
1623 			break;
1624 		default:
1625 			*tl = 0;
1626 			if (err != NFSERR_RETVOID) {
1627 				tl = nfsm_build(&info, NFSX_UNSIGNED);
1628 				if (err)
1629 				    *tl = txdr_unsigned(nfsrv_errmap(nd, err));
1630 				else
1631 				    *tl = 0;
1632 			}
1633 			break;
1634 		};
1635 	}
1636 
1637 	if (mrq != NULL)
1638 	    *mrq = info.mreq;
1639 	*mbp = info.mb;
1640 	*bposp = info.bpos;
1641 	if (err != 0 && err != NFSERR_RETVOID)
1642 		nfsstats.srvrpc_errs++;
1643 	return (0);
1644 }
1645 
1646 
1647 #endif /* NFS_NOSERVER */
1648 
1649 /*
1650  * Nfs timer routine.
1651  *
1652  * Scan the nfsreq list and retranmit any requests that have timed out
1653  * To avoid retransmission attempts on STREAM sockets (in the future) make
1654  * sure to set the r_retry field to 0 (implies nm_retry == 0).
1655  *
1656  * Requests with attached responses, terminated requests, and
1657  * locked requests are ignored.  Locked requests will be picked up
1658  * in a later timer call.
1659  */
1660 void
1661 nfs_timer(void *arg /* never used */)
1662 {
1663 	struct nfsmount *nmp;
1664 	struct nfsreq *req;
1665 #ifndef NFS_NOSERVER
1666 	struct nfssvc_sock *slp;
1667 	u_quad_t cur_usec;
1668 #endif /* NFS_NOSERVER */
1669 
1670 	crit_enter();
1671 	TAILQ_FOREACH(nmp, &nfs_mountq, nm_entry) {
1672 		TAILQ_FOREACH(req, &nmp->nm_reqq, r_chain) {
1673 			KKASSERT(nmp == req->r_nmp);
1674 			if (req->r_mrep)
1675 				continue;
1676 			if (req->r_flags & (R_SOFTTERM | R_LOCKED))
1677 				continue;
1678 			req->r_flags |= R_LOCKED;
1679 			if (nfs_sigintr(nmp, req, req->r_td)) {
1680 				nfs_softterm(req, 1);
1681 			} else {
1682 				nfs_timer_req(req);
1683 			}
1684 			req->r_flags &= ~R_LOCKED;
1685 			if (req->r_flags & R_WANTED) {
1686 				req->r_flags &= ~R_WANTED;
1687 				wakeup(req);
1688 			}
1689 		}
1690 	}
1691 #ifndef NFS_NOSERVER
1692 
1693 	/*
1694 	 * Scan the write gathering queues for writes that need to be
1695 	 * completed now.
1696 	 */
1697 	cur_usec = nfs_curusec();
1698 	TAILQ_FOREACH(slp, &nfssvc_sockhead, ns_chain) {
1699 	    if (slp->ns_tq.lh_first && slp->ns_tq.lh_first->nd_time<=cur_usec)
1700 		nfsrv_wakenfsd(slp, 1);
1701 	}
1702 #endif /* NFS_NOSERVER */
1703 	crit_exit();
1704 	callout_reset(&nfs_timer_handle, nfs_ticks, nfs_timer, NULL);
1705 }
1706 
1707 static
1708 void
1709 nfs_timer_req(struct nfsreq *req)
1710 {
1711 	struct thread *td = &thread0; /* XXX for creds, will break if sleep */
1712 	struct nfsmount *nmp = req->r_nmp;
1713 	struct mbuf *m;
1714 	struct socket *so;
1715 	int timeo;
1716 	int error;
1717 
1718 	/*
1719 	 * rtt ticks and timeout calculation.  Return if the timeout
1720 	 * has not been reached yet, unless the packet is flagged
1721 	 * for an immediate send.
1722 	 *
1723 	 * The mean rtt doesn't help when we get random I/Os, we have
1724 	 * to multiply by fairly large numbers.
1725 	 */
1726 	if (req->r_rtt >= 0) {
1727 		/*
1728 		 * Calculate the timeout to test against.
1729 		 */
1730 		req->r_rtt++;
1731 		if (nmp->nm_flag & NFSMNT_DUMBTIMR) {
1732 			timeo = nmp->nm_timeo << NFS_RTT_SCALE_BITS;
1733 		} else if (req->r_flags & R_TIMING) {
1734 			timeo = NFS_SRTT(req) + NFS_SDRTT(req);
1735 		} else {
1736 			timeo = nmp->nm_timeo << NFS_RTT_SCALE_BITS;
1737 		}
1738 		timeo *= multt[req->r_procnum];
1739 		/* timeo is still scaled by SCALE_BITS */
1740 
1741 #define NFSFS	(NFS_RTT_SCALE * NFS_HZ)
1742 		if (req->r_flags & R_TIMING) {
1743 			static long last_time;
1744 			if (nfs_showrtt && last_time != time_second) {
1745 				kprintf("rpccmd %d NFS SRTT %d SDRTT %d "
1746 					"timeo %d.%03d\n",
1747 					proct[req->r_procnum],
1748 					NFS_SRTT(req), NFS_SDRTT(req),
1749 					timeo / NFSFS,
1750 					timeo % NFSFS * 1000 /  NFSFS);
1751 				last_time = time_second;
1752 			}
1753 		}
1754 #undef NFSFS
1755 
1756 		/*
1757 		 * deal with nfs_timer jitter.
1758 		 */
1759 		timeo = (timeo >> NFS_RTT_SCALE_BITS) + 1;
1760 		if (timeo < 2)
1761 			timeo = 2;
1762 
1763 		if (nmp->nm_timeouts > 0)
1764 			timeo *= nfs_backoff[nmp->nm_timeouts - 1];
1765 		if (timeo > NFS_MAXTIMEO)
1766 			timeo = NFS_MAXTIMEO;
1767 		if (req->r_rtt <= timeo) {
1768 			if ((req->r_flags & R_NEEDSXMIT) == 0)
1769 				return;
1770 		} else if (nmp->nm_timeouts < 8) {
1771 			nmp->nm_timeouts++;
1772 		}
1773 	}
1774 
1775 	/*
1776 	 * Check for server not responding
1777 	 */
1778 	if ((req->r_flags & R_TPRINTFMSG) == 0 &&
1779 	     req->r_rexmit > nmp->nm_deadthresh) {
1780 		nfs_msg(req->r_td, nmp->nm_mountp->mnt_stat.f_mntfromname,
1781 			"not responding");
1782 		req->r_flags |= R_TPRINTFMSG;
1783 	}
1784 	if (req->r_rexmit >= req->r_retry) {	/* too many */
1785 		nfsstats.rpctimeouts++;
1786 		nfs_softterm(req, 1);
1787 		return;
1788 	}
1789 
1790 	/*
1791 	 * Generally disable retransmission on reliable sockets,
1792 	 * unless the request is flagged for immediate send.
1793 	 */
1794 	if (nmp->nm_sotype != SOCK_DGRAM) {
1795 		if (++req->r_rexmit > NFS_MAXREXMIT)
1796 			req->r_rexmit = NFS_MAXREXMIT;
1797 		if ((req->r_flags & R_NEEDSXMIT) == 0)
1798 			return;
1799 	}
1800 
1801 	/*
1802 	 * Stop here if we do not have a socket!
1803 	 */
1804 	if ((so = nmp->nm_so) == NULL)
1805 		return;
1806 
1807 	/*
1808 	 * If there is enough space and the window allows.. resend it.
1809 	 *
1810 	 * r_rtt is left intact in case we get an answer after the
1811 	 * retry that was a reply to the original packet.
1812 	 */
1813 	if (ssb_space(&so->so_snd) >= req->r_mreq->m_pkthdr.len &&
1814 	    (req->r_flags & (R_SENT | R_NEEDSXMIT)) &&
1815 	   (m = m_copym(req->r_mreq, 0, M_COPYALL, MB_DONTWAIT))){
1816 		if ((nmp->nm_flag & NFSMNT_NOCONN) == 0)
1817 		    error = so_pru_send(so, 0, m, NULL, NULL, td);
1818 		else
1819 		    error = so_pru_send(so, 0, m, nmp->nm_nam,
1820 			NULL, td);
1821 		if (error) {
1822 			if (NFSIGNORE_SOERROR(nmp->nm_soflags, error))
1823 				so->so_error = 0;
1824 			req->r_flags |= R_NEEDSXMIT;
1825 		} else if (req->r_mrep == NULL) {
1826 			/*
1827 			 * Iff first send, start timing
1828 			 * else turn timing off, backoff timer
1829 			 * and divide congestion window by 2.
1830 			 *
1831 			 * It is possible for the so_pru_send() to
1832 			 * block and for us to race a reply so we
1833 			 * only do this if the reply field has not
1834 			 * been filled in.  R_LOCKED will prevent
1835 			 * the request from being ripped out from under
1836 			 * us entirely.
1837 			 *
1838 			 * Record the last resent procnum to aid us
1839 			 * in duplicate detection on receive.
1840 			 */
1841 			if ((req->r_flags & R_NEEDSXMIT) == 0) {
1842 				if (nfs_showrexmit)
1843 					kprintf("X");
1844 				if (++req->r_rexmit > NFS_MAXREXMIT)
1845 					req->r_rexmit = NFS_MAXREXMIT;
1846 				nmp->nm_maxasync_scaled >>= 1;
1847 				if (nmp->nm_maxasync_scaled < NFS_MINASYNC_SCALED)
1848 					nmp->nm_maxasync_scaled = NFS_MINASYNC_SCALED;
1849 				nfsstats.rpcretries++;
1850 				nmp->nm_lastreprocnum = req->r_procnum;
1851 			} else {
1852 				req->r_flags |= R_SENT;
1853 				req->r_flags &= ~R_NEEDSXMIT;
1854 			}
1855 		}
1856 	}
1857 }
1858 
1859 /*
1860  * Mark all of an nfs mount's outstanding requests with R_SOFTTERM and
1861  * wait for all requests to complete. This is used by forced unmounts
1862  * to terminate any outstanding RPCs.
1863  *
1864  * Locked requests cannot be canceled but will be marked for
1865  * soft-termination.
1866  */
1867 int
1868 nfs_nmcancelreqs(struct nfsmount *nmp)
1869 {
1870 	struct nfsreq *req;
1871 	int i;
1872 
1873 	crit_enter();
1874 	TAILQ_FOREACH(req, &nmp->nm_reqq, r_chain) {
1875 		if (req->r_mrep != NULL || (req->r_flags & R_SOFTTERM))
1876 			continue;
1877 		nfs_softterm(req, 0);
1878 	}
1879 	/* XXX  the other two queues as well */
1880 	crit_exit();
1881 
1882 	for (i = 0; i < 30; i++) {
1883 		crit_enter();
1884 		TAILQ_FOREACH(req, &nmp->nm_reqq, r_chain) {
1885 			if (nmp == req->r_nmp)
1886 				break;
1887 		}
1888 		crit_exit();
1889 		if (req == NULL)
1890 			return (0);
1891 		tsleep(&lbolt, 0, "nfscancel", 0);
1892 	}
1893 	return (EBUSY);
1894 }
1895 
1896 /*
1897  * Soft-terminate a request, effectively marking it as failed.
1898  *
1899  * Must be called from within a critical section.
1900  */
1901 static void
1902 nfs_softterm(struct nfsreq *rep, int islocked)
1903 {
1904 	rep->r_flags |= R_SOFTTERM;
1905 	nfs_hardterm(rep, islocked);
1906 }
1907 
1908 /*
1909  * Hard-terminate a request, typically after getting a response.
1910  *
1911  * The state machine can still decide to re-issue it later if necessary.
1912  *
1913  * Must be called from within a critical section.
1914  */
1915 static void
1916 nfs_hardterm(struct nfsreq *rep, int islocked)
1917 {
1918 	struct nfsmount *nmp = rep->r_nmp;
1919 
1920 	/*
1921 	 * The nm_send count is decremented now to avoid deadlocks
1922 	 * when the process in soreceive() hasn't yet managed to send
1923 	 * its own request.
1924 	 */
1925 	if (rep->r_flags & R_SENT) {
1926 		rep->r_flags &= ~R_SENT;
1927 	}
1928 
1929 	/*
1930 	 * If we locked the request or nobody else has locked the request,
1931 	 * and the request is async, we can move it to the reader thread's
1932 	 * queue now and fix up the state.
1933 	 *
1934 	 * If we locked the request or nobody else has locked the request,
1935 	 * we can wake up anyone blocked waiting for a response on the
1936 	 * request.
1937 	 */
1938 	if (islocked || (rep->r_flags & R_LOCKED) == 0) {
1939 		if ((rep->r_flags & (R_ONREQQ | R_ASYNC)) ==
1940 		    (R_ONREQQ | R_ASYNC)) {
1941 			rep->r_flags &= ~R_ONREQQ;
1942 			TAILQ_REMOVE(&nmp->nm_reqq, rep, r_chain);
1943 			--nmp->nm_reqqlen;
1944 			TAILQ_INSERT_TAIL(&nmp->nm_reqrxq, rep, r_chain);
1945 			KKASSERT(rep->r_info->state == NFSM_STATE_TRY ||
1946 				 rep->r_info->state == NFSM_STATE_WAITREPLY);
1947 			rep->r_info->state = NFSM_STATE_PROCESSREPLY;
1948 			nfssvc_iod_reader_wakeup(nmp);
1949 			if (TAILQ_FIRST(&nmp->nm_bioq) &&
1950 			    nmp->nm_reqqlen == NFS_MAXASYNCBIO * 2 / 3) {
1951 				nfssvc_iod_writer_wakeup(nmp);
1952 			}
1953 		}
1954 		mtx_abort_ex_link(&nmp->nm_rxlock, &rep->r_link);
1955 	}
1956 }
1957 
1958 /*
1959  * Test for a termination condition pending on the process.
1960  * This is used for NFSMNT_INT mounts.
1961  */
1962 int
1963 nfs_sigintr(struct nfsmount *nmp, struct nfsreq *rep, struct thread *td)
1964 {
1965 	sigset_t tmpset;
1966 	struct proc *p;
1967 	struct lwp *lp;
1968 
1969 	if (rep && (rep->r_flags & R_SOFTTERM))
1970 		return (EINTR);
1971 	/* Terminate all requests while attempting a forced unmount. */
1972 	if (nmp->nm_mountp->mnt_kern_flag & MNTK_UNMOUNTF)
1973 		return (EINTR);
1974 	if (!(nmp->nm_flag & NFSMNT_INT))
1975 		return (0);
1976 	/* td might be NULL YYY */
1977 	if (td == NULL || (p = td->td_proc) == NULL)
1978 		return (0);
1979 
1980 	lp = td->td_lwp;
1981 	tmpset = lwp_sigpend(lp);
1982 	SIGSETNAND(tmpset, lp->lwp_sigmask);
1983 	SIGSETNAND(tmpset, p->p_sigignore);
1984 	if (SIGNOTEMPTY(tmpset) && NFSINT_SIGMASK(tmpset))
1985 		return (EINTR);
1986 
1987 	return (0);
1988 }
1989 
1990 /*
1991  * Lock a socket against others.
1992  * Necessary for STREAM sockets to ensure you get an entire rpc request/reply
1993  * and also to avoid race conditions between the processes with nfs requests
1994  * in progress when a reconnect is necessary.
1995  */
1996 int
1997 nfs_sndlock(struct nfsmount *nmp, struct nfsreq *rep)
1998 {
1999 	mtx_t mtx = &nmp->nm_txlock;
2000 	struct thread *td;
2001 	int slptimeo;
2002 	int slpflag;
2003 	int error;
2004 
2005 	slpflag = 0;
2006 	slptimeo = 0;
2007 	td = rep ? rep->r_td : NULL;
2008 	if (nmp->nm_flag & NFSMNT_INT)
2009 		slpflag = PCATCH;
2010 
2011 	while ((error = mtx_lock_ex_try(mtx)) != 0) {
2012 		if (nfs_sigintr(nmp, rep, td)) {
2013 			error = EINTR;
2014 			break;
2015 		}
2016 		error = mtx_lock_ex(mtx, "nfsndlck", slpflag, slptimeo);
2017 		if (error == 0)
2018 			break;
2019 		if (slpflag == PCATCH) {
2020 			slpflag = 0;
2021 			slptimeo = 2 * hz;
2022 		}
2023 	}
2024 	/* Always fail if our request has been cancelled. */
2025 	if (rep && (rep->r_flags & R_SOFTTERM)) {
2026 		if (error == 0)
2027 			mtx_unlock(mtx);
2028 		error = EINTR;
2029 	}
2030 	return (error);
2031 }
2032 
2033 /*
2034  * Unlock the stream socket for others.
2035  */
2036 void
2037 nfs_sndunlock(struct nfsmount *nmp)
2038 {
2039 	mtx_unlock(&nmp->nm_txlock);
2040 }
2041 
2042 /*
2043  * Lock the receiver side of the socket.
2044  *
2045  * rep may be NULL.
2046  */
2047 static int
2048 nfs_rcvlock(struct nfsmount *nmp, struct nfsreq *rep)
2049 {
2050 	mtx_t mtx = &nmp->nm_rxlock;
2051 	int slpflag;
2052 	int slptimeo;
2053 	int error;
2054 
2055 	/*
2056 	 * Unconditionally check for completion in case another nfsiod
2057 	 * get the packet while the caller was blocked, before the caller
2058 	 * called us.  Packet reception is handled by mainline code which
2059 	 * is protected by the BGL at the moment.
2060 	 *
2061 	 * We do not strictly need the second check just before the
2062 	 * tsleep(), but it's good defensive programming.
2063 	 */
2064 	if (rep && rep->r_mrep != NULL)
2065 		return (EALREADY);
2066 
2067 	if (nmp->nm_flag & NFSMNT_INT)
2068 		slpflag = PCATCH;
2069 	else
2070 		slpflag = 0;
2071 	slptimeo = 0;
2072 
2073 	while ((error = mtx_lock_ex_try(mtx)) != 0) {
2074 		if (nfs_sigintr(nmp, rep, (rep ? rep->r_td : NULL))) {
2075 			error = EINTR;
2076 			break;
2077 		}
2078 		if (rep && rep->r_mrep != NULL) {
2079 			error = EALREADY;
2080 			break;
2081 		}
2082 
2083 		/*
2084 		 * NOTE: can return ENOLCK, but in that case rep->r_mrep
2085 		 *       will already be set.
2086 		 */
2087 		if (rep) {
2088 			error = mtx_lock_ex_link(mtx, &rep->r_link,
2089 						 "nfsrcvlk",
2090 						 slpflag, slptimeo);
2091 		} else {
2092 			error = mtx_lock_ex(mtx, "nfsrcvlk", slpflag, slptimeo);
2093 		}
2094 		if (error == 0)
2095 			break;
2096 
2097 		/*
2098 		 * If our reply was recieved while we were sleeping,
2099 		 * then just return without taking the lock to avoid a
2100 		 * situation where a single iod could 'capture' the
2101 		 * recieve lock.
2102 		 */
2103 		if (rep && rep->r_mrep != NULL) {
2104 			error = EALREADY;
2105 			break;
2106 		}
2107 		if (slpflag == PCATCH) {
2108 			slpflag = 0;
2109 			slptimeo = 2 * hz;
2110 		}
2111 	}
2112 	if (error == 0) {
2113 		if (rep && rep->r_mrep != NULL) {
2114 			error = EALREADY;
2115 			mtx_unlock(mtx);
2116 		}
2117 	}
2118 	return (error);
2119 }
2120 
2121 /*
2122  * Unlock the stream socket for others.
2123  */
2124 static void
2125 nfs_rcvunlock(struct nfsmount *nmp)
2126 {
2127 	mtx_unlock(&nmp->nm_rxlock);
2128 }
2129 
2130 /*
2131  *	nfs_realign:
2132  *
2133  *	Check for badly aligned mbuf data and realign by copying the unaligned
2134  *	portion of the data into a new mbuf chain and freeing the portions
2135  *	of the old chain that were replaced.
2136  *
2137  *	We cannot simply realign the data within the existing mbuf chain
2138  *	because the underlying buffers may contain other rpc commands and
2139  *	we cannot afford to overwrite them.
2140  *
2141  *	We would prefer to avoid this situation entirely.  The situation does
2142  *	not occur with NFS/UDP and is supposed to only occassionally occur
2143  *	with TCP.  Use vfs.nfs.realign_count and realign_test to check this.
2144  */
2145 static void
2146 nfs_realign(struct mbuf **pm, int hsiz)
2147 {
2148 	struct mbuf *m;
2149 	struct mbuf *n = NULL;
2150 	int off = 0;
2151 
2152 	++nfs_realign_test;
2153 
2154 	while ((m = *pm) != NULL) {
2155 		if ((m->m_len & 0x3) || (mtod(m, intptr_t) & 0x3)) {
2156 			n = m_getl(m->m_len, MB_WAIT, MT_DATA, 0, NULL);
2157 			n->m_len = 0;
2158 			break;
2159 		}
2160 		pm = &m->m_next;
2161 	}
2162 
2163 	/*
2164 	 * If n is non-NULL, loop on m copying data, then replace the
2165 	 * portion of the chain that had to be realigned.
2166 	 */
2167 	if (n != NULL) {
2168 		++nfs_realign_count;
2169 		while (m) {
2170 			m_copyback(n, off, m->m_len, mtod(m, caddr_t));
2171 			off += m->m_len;
2172 			m = m->m_next;
2173 		}
2174 		m_freem(*pm);
2175 		*pm = n;
2176 	}
2177 }
2178 
2179 #ifndef NFS_NOSERVER
2180 
2181 /*
2182  * Parse an RPC request
2183  * - verify it
2184  * - fill in the cred struct.
2185  */
2186 int
2187 nfs_getreq(struct nfsrv_descript *nd, struct nfsd *nfsd, int has_header)
2188 {
2189 	int len, i;
2190 	u_int32_t *tl;
2191 	struct uio uio;
2192 	struct iovec iov;
2193 	caddr_t cp;
2194 	u_int32_t nfsvers, auth_type;
2195 	uid_t nickuid;
2196 	int error = 0, ticklen;
2197 	struct nfsuid *nuidp;
2198 	struct timeval tvin, tvout;
2199 	struct nfsm_info info;
2200 #if 0				/* until encrypted keys are implemented */
2201 	NFSKERBKEYSCHED_T keys;	/* stores key schedule */
2202 #endif
2203 
2204 	info.mrep = nd->nd_mrep;
2205 	info.md = nd->nd_md;
2206 	info.dpos = nd->nd_dpos;
2207 
2208 	if (has_header) {
2209 		NULLOUT(tl = nfsm_dissect(&info, 10 * NFSX_UNSIGNED));
2210 		nd->nd_retxid = fxdr_unsigned(u_int32_t, *tl++);
2211 		if (*tl++ != rpc_call) {
2212 			m_freem(info.mrep);
2213 			return (EBADRPC);
2214 		}
2215 	} else {
2216 		NULLOUT(tl = nfsm_dissect(&info, 8 * NFSX_UNSIGNED));
2217 	}
2218 	nd->nd_repstat = 0;
2219 	nd->nd_flag = 0;
2220 	if (*tl++ != rpc_vers) {
2221 		nd->nd_repstat = ERPCMISMATCH;
2222 		nd->nd_procnum = NFSPROC_NOOP;
2223 		return (0);
2224 	}
2225 	if (*tl != nfs_prog) {
2226 		nd->nd_repstat = EPROGUNAVAIL;
2227 		nd->nd_procnum = NFSPROC_NOOP;
2228 		return (0);
2229 	}
2230 	tl++;
2231 	nfsvers = fxdr_unsigned(u_int32_t, *tl++);
2232 	if (nfsvers < NFS_VER2 || nfsvers > NFS_VER3) {
2233 		nd->nd_repstat = EPROGMISMATCH;
2234 		nd->nd_procnum = NFSPROC_NOOP;
2235 		return (0);
2236 	}
2237 	if (nfsvers == NFS_VER3)
2238 		nd->nd_flag = ND_NFSV3;
2239 	nd->nd_procnum = fxdr_unsigned(u_int32_t, *tl++);
2240 	if (nd->nd_procnum == NFSPROC_NULL)
2241 		return (0);
2242 	if (nd->nd_procnum >= NFS_NPROCS ||
2243 		(nd->nd_procnum >= NQNFSPROC_GETLEASE) ||
2244 		(!nd->nd_flag && nd->nd_procnum > NFSV2PROC_STATFS)) {
2245 		nd->nd_repstat = EPROCUNAVAIL;
2246 		nd->nd_procnum = NFSPROC_NOOP;
2247 		return (0);
2248 	}
2249 	if ((nd->nd_flag & ND_NFSV3) == 0)
2250 		nd->nd_procnum = nfsv3_procid[nd->nd_procnum];
2251 	auth_type = *tl++;
2252 	len = fxdr_unsigned(int, *tl++);
2253 	if (len < 0 || len > RPCAUTH_MAXSIZ) {
2254 		m_freem(info.mrep);
2255 		return (EBADRPC);
2256 	}
2257 
2258 	nd->nd_flag &= ~ND_KERBAUTH;
2259 	/*
2260 	 * Handle auth_unix or auth_kerb.
2261 	 */
2262 	if (auth_type == rpc_auth_unix) {
2263 		len = fxdr_unsigned(int, *++tl);
2264 		if (len < 0 || len > NFS_MAXNAMLEN) {
2265 			m_freem(info.mrep);
2266 			return (EBADRPC);
2267 		}
2268 		ERROROUT(nfsm_adv(&info, nfsm_rndup(len)));
2269 		NULLOUT(tl = nfsm_dissect(&info, 3 * NFSX_UNSIGNED));
2270 		bzero((caddr_t)&nd->nd_cr, sizeof (struct ucred));
2271 		nd->nd_cr.cr_ref = 1;
2272 		nd->nd_cr.cr_uid = fxdr_unsigned(uid_t, *tl++);
2273 		nd->nd_cr.cr_gid = fxdr_unsigned(gid_t, *tl++);
2274 		len = fxdr_unsigned(int, *tl);
2275 		if (len < 0 || len > RPCAUTH_UNIXGIDS) {
2276 			m_freem(info.mrep);
2277 			return (EBADRPC);
2278 		}
2279 		NULLOUT(tl = nfsm_dissect(&info, (len + 2) * NFSX_UNSIGNED));
2280 		for (i = 1; i <= len; i++)
2281 		    if (i < NGROUPS)
2282 			nd->nd_cr.cr_groups[i] = fxdr_unsigned(gid_t, *tl++);
2283 		    else
2284 			tl++;
2285 		nd->nd_cr.cr_ngroups = (len >= NGROUPS) ? NGROUPS : (len + 1);
2286 		if (nd->nd_cr.cr_ngroups > 1)
2287 		    nfsrvw_sort(nd->nd_cr.cr_groups, nd->nd_cr.cr_ngroups);
2288 		len = fxdr_unsigned(int, *++tl);
2289 		if (len < 0 || len > RPCAUTH_MAXSIZ) {
2290 			m_freem(info.mrep);
2291 			return (EBADRPC);
2292 		}
2293 		if (len > 0) {
2294 			ERROROUT(nfsm_adv(&info, nfsm_rndup(len)));
2295 		}
2296 	} else if (auth_type == rpc_auth_kerb) {
2297 		switch (fxdr_unsigned(int, *tl++)) {
2298 		case RPCAKN_FULLNAME:
2299 			ticklen = fxdr_unsigned(int, *tl);
2300 			*((u_int32_t *)nfsd->nfsd_authstr) = *tl;
2301 			uio.uio_resid = nfsm_rndup(ticklen) + NFSX_UNSIGNED;
2302 			nfsd->nfsd_authlen = uio.uio_resid + NFSX_UNSIGNED;
2303 			if (uio.uio_resid > (len - 2 * NFSX_UNSIGNED)) {
2304 				m_freem(info.mrep);
2305 				return (EBADRPC);
2306 			}
2307 			uio.uio_offset = 0;
2308 			uio.uio_iov = &iov;
2309 			uio.uio_iovcnt = 1;
2310 			uio.uio_segflg = UIO_SYSSPACE;
2311 			iov.iov_base = (caddr_t)&nfsd->nfsd_authstr[4];
2312 			iov.iov_len = RPCAUTH_MAXSIZ - 4;
2313 			ERROROUT(nfsm_mtouio(&info, &uio, uio.uio_resid));
2314 			NULLOUT(tl = nfsm_dissect(&info, 2 * NFSX_UNSIGNED));
2315 			if (*tl++ != rpc_auth_kerb ||
2316 				fxdr_unsigned(int, *tl) != 4 * NFSX_UNSIGNED) {
2317 				kprintf("Bad kerb verifier\n");
2318 				nd->nd_repstat = (NFSERR_AUTHERR|AUTH_BADVERF);
2319 				nd->nd_procnum = NFSPROC_NOOP;
2320 				return (0);
2321 			}
2322 			NULLOUT(cp = nfsm_dissect(&info, 4 * NFSX_UNSIGNED));
2323 			tl = (u_int32_t *)cp;
2324 			if (fxdr_unsigned(int, *tl) != RPCAKN_FULLNAME) {
2325 				kprintf("Not fullname kerb verifier\n");
2326 				nd->nd_repstat = (NFSERR_AUTHERR|AUTH_BADVERF);
2327 				nd->nd_procnum = NFSPROC_NOOP;
2328 				return (0);
2329 			}
2330 			cp += NFSX_UNSIGNED;
2331 			bcopy(cp, nfsd->nfsd_verfstr, 3 * NFSX_UNSIGNED);
2332 			nfsd->nfsd_verflen = 3 * NFSX_UNSIGNED;
2333 			nd->nd_flag |= ND_KERBFULL;
2334 			nfsd->nfsd_flag |= NFSD_NEEDAUTH;
2335 			break;
2336 		case RPCAKN_NICKNAME:
2337 			if (len != 2 * NFSX_UNSIGNED) {
2338 				kprintf("Kerb nickname short\n");
2339 				nd->nd_repstat = (NFSERR_AUTHERR|AUTH_BADCRED);
2340 				nd->nd_procnum = NFSPROC_NOOP;
2341 				return (0);
2342 			}
2343 			nickuid = fxdr_unsigned(uid_t, *tl);
2344 			NULLOUT(tl = nfsm_dissect(&info, 2 * NFSX_UNSIGNED));
2345 			if (*tl++ != rpc_auth_kerb ||
2346 				fxdr_unsigned(int, *tl) != 3 * NFSX_UNSIGNED) {
2347 				kprintf("Kerb nick verifier bad\n");
2348 				nd->nd_repstat = (NFSERR_AUTHERR|AUTH_BADVERF);
2349 				nd->nd_procnum = NFSPROC_NOOP;
2350 				return (0);
2351 			}
2352 			NULLOUT(tl = nfsm_dissect(&info, 3 * NFSX_UNSIGNED));
2353 			tvin.tv_sec = *tl++;
2354 			tvin.tv_usec = *tl;
2355 
2356 			for (nuidp = NUIDHASH(nfsd->nfsd_slp,nickuid)->lh_first;
2357 			    nuidp != 0; nuidp = nuidp->nu_hash.le_next) {
2358 				if (nuidp->nu_cr.cr_uid == nickuid &&
2359 				    (!nd->nd_nam2 ||
2360 				     netaddr_match(NU_NETFAM(nuidp),
2361 				      &nuidp->nu_haddr, nd->nd_nam2)))
2362 					break;
2363 			}
2364 			if (!nuidp) {
2365 				nd->nd_repstat =
2366 					(NFSERR_AUTHERR|AUTH_REJECTCRED);
2367 				nd->nd_procnum = NFSPROC_NOOP;
2368 				return (0);
2369 			}
2370 
2371 			/*
2372 			 * Now, decrypt the timestamp using the session key
2373 			 * and validate it.
2374 			 */
2375 #ifdef NFSKERB
2376 			XXX
2377 #endif
2378 
2379 			tvout.tv_sec = fxdr_unsigned(long, tvout.tv_sec);
2380 			tvout.tv_usec = fxdr_unsigned(long, tvout.tv_usec);
2381 			if (nuidp->nu_expire < time_second ||
2382 			    nuidp->nu_timestamp.tv_sec > tvout.tv_sec ||
2383 			    (nuidp->nu_timestamp.tv_sec == tvout.tv_sec &&
2384 			     nuidp->nu_timestamp.tv_usec > tvout.tv_usec)) {
2385 				nuidp->nu_expire = 0;
2386 				nd->nd_repstat =
2387 				    (NFSERR_AUTHERR|AUTH_REJECTVERF);
2388 				nd->nd_procnum = NFSPROC_NOOP;
2389 				return (0);
2390 			}
2391 			nfsrv_setcred(&nuidp->nu_cr, &nd->nd_cr);
2392 			nd->nd_flag |= ND_KERBNICK;
2393 		};
2394 	} else {
2395 		nd->nd_repstat = (NFSERR_AUTHERR | AUTH_REJECTCRED);
2396 		nd->nd_procnum = NFSPROC_NOOP;
2397 		return (0);
2398 	}
2399 
2400 	nd->nd_md = info.md;
2401 	nd->nd_dpos = info.dpos;
2402 	return (0);
2403 nfsmout:
2404 	return (error);
2405 }
2406 
2407 #endif
2408 
2409 /*
2410  * Send a message to the originating process's terminal.  The thread and/or
2411  * process may be NULL.  YYY the thread should not be NULL but there may
2412  * still be some uio_td's that are still being passed as NULL through to
2413  * nfsm_request().
2414  */
2415 static int
2416 nfs_msg(struct thread *td, char *server, char *msg)
2417 {
2418 	tpr_t tpr;
2419 
2420 	if (td && td->td_proc)
2421 		tpr = tprintf_open(td->td_proc);
2422 	else
2423 		tpr = NULL;
2424 	tprintf(tpr, "nfs server %s: %s\n", server, msg);
2425 	tprintf_close(tpr);
2426 	return (0);
2427 }
2428 
2429 #ifndef NFS_NOSERVER
2430 /*
2431  * Socket upcall routine for the nfsd sockets.
2432  * The caddr_t arg is a pointer to the "struct nfssvc_sock".
2433  * Essentially do as much as possible non-blocking, else punt and it will
2434  * be called with MB_WAIT from an nfsd.
2435  */
2436 void
2437 nfsrv_rcv(struct socket *so, void *arg, int waitflag)
2438 {
2439 	struct nfssvc_sock *slp = (struct nfssvc_sock *)arg;
2440 	struct mbuf *m;
2441 	struct sockaddr *nam;
2442 	struct sockbuf sio;
2443 	int flags, error;
2444 	int nparallel_wakeup = 0;
2445 
2446 	if ((slp->ns_flag & SLP_VALID) == 0)
2447 		return;
2448 
2449 	/*
2450 	 * Do not allow an infinite number of completed RPC records to build
2451 	 * up before we stop reading data from the socket.  Otherwise we could
2452 	 * end up holding onto an unreasonable number of mbufs for requests
2453 	 * waiting for service.
2454 	 *
2455 	 * This should give pretty good feedback to the TCP
2456 	 * layer and prevents a memory crunch for other protocols.
2457 	 *
2458 	 * Note that the same service socket can be dispatched to several
2459 	 * nfs servers simultaniously.
2460 	 *
2461 	 * the tcp protocol callback calls us with MB_DONTWAIT.
2462 	 * nfsd calls us with MB_WAIT (typically).
2463 	 */
2464 	if (waitflag == MB_DONTWAIT && slp->ns_numrec >= nfsd_waiting / 2 + 1) {
2465 		slp->ns_flag |= SLP_NEEDQ;
2466 		goto dorecs;
2467 	}
2468 
2469 	/*
2470 	 * Handle protocol specifics to parse an RPC request.  We always
2471 	 * pull from the socket using non-blocking I/O.
2472 	 */
2473 	if (so->so_type == SOCK_STREAM) {
2474 		/*
2475 		 * The data has to be read in an orderly fashion from a TCP
2476 		 * stream, unlike a UDP socket.  It is possible for soreceive
2477 		 * and/or nfsrv_getstream() to block, so make sure only one
2478 		 * entity is messing around with the TCP stream at any given
2479 		 * moment.  The receive sockbuf's lock in soreceive is not
2480 		 * sufficient.
2481 		 *
2482 		 * Note that this procedure can be called from any number of
2483 		 * NFS severs *OR* can be upcalled directly from a TCP
2484 		 * protocol thread.
2485 		 */
2486 		if (slp->ns_flag & SLP_GETSTREAM) {
2487 			slp->ns_flag |= SLP_NEEDQ;
2488 			goto dorecs;
2489 		}
2490 		slp->ns_flag |= SLP_GETSTREAM;
2491 
2492 		/*
2493 		 * Do soreceive().  Pull out as much data as possible without
2494 		 * blocking.
2495 		 */
2496 		sbinit(&sio, 1000000000);
2497 		flags = MSG_DONTWAIT;
2498 		error = so_pru_soreceive(so, &nam, NULL, &sio, NULL, &flags);
2499 		if (error || sio.sb_mb == NULL) {
2500 			if (error == EWOULDBLOCK)
2501 				slp->ns_flag |= SLP_NEEDQ;
2502 			else
2503 				slp->ns_flag |= SLP_DISCONN;
2504 			slp->ns_flag &= ~SLP_GETSTREAM;
2505 			goto dorecs;
2506 		}
2507 		m = sio.sb_mb;
2508 		if (slp->ns_rawend) {
2509 			slp->ns_rawend->m_next = m;
2510 			slp->ns_cc += sio.sb_cc;
2511 		} else {
2512 			slp->ns_raw = m;
2513 			slp->ns_cc = sio.sb_cc;
2514 		}
2515 		while (m->m_next)
2516 			m = m->m_next;
2517 		slp->ns_rawend = m;
2518 
2519 		/*
2520 		 * Now try and parse as many record(s) as we can out of the
2521 		 * raw stream data.
2522 		 */
2523 		error = nfsrv_getstream(slp, waitflag, &nparallel_wakeup);
2524 		if (error) {
2525 			if (error == EPERM)
2526 				slp->ns_flag |= SLP_DISCONN;
2527 			else
2528 				slp->ns_flag |= SLP_NEEDQ;
2529 		}
2530 		slp->ns_flag &= ~SLP_GETSTREAM;
2531 	} else {
2532 		/*
2533 		 * For UDP soreceive typically pulls just one packet, loop
2534 		 * to get the whole batch.
2535 		 */
2536 		do {
2537 			sbinit(&sio, 1000000000);
2538 			flags = MSG_DONTWAIT;
2539 			error = so_pru_soreceive(so, &nam, NULL, &sio,
2540 						 NULL, &flags);
2541 			if (sio.sb_mb) {
2542 				struct nfsrv_rec *rec;
2543 				int mf = (waitflag & MB_DONTWAIT) ?
2544 					    M_NOWAIT : M_WAITOK;
2545 				rec = kmalloc(sizeof(struct nfsrv_rec),
2546 					     M_NFSRVDESC, mf);
2547 				if (!rec) {
2548 					if (nam)
2549 						FREE(nam, M_SONAME);
2550 					m_freem(sio.sb_mb);
2551 					continue;
2552 				}
2553 				nfs_realign(&sio.sb_mb, 10 * NFSX_UNSIGNED);
2554 				rec->nr_address = nam;
2555 				rec->nr_packet = sio.sb_mb;
2556 				STAILQ_INSERT_TAIL(&slp->ns_rec, rec, nr_link);
2557 				++slp->ns_numrec;
2558 				++nparallel_wakeup;
2559 			}
2560 			if (error) {
2561 				if ((so->so_proto->pr_flags & PR_CONNREQUIRED)
2562 					&& error != EWOULDBLOCK) {
2563 					slp->ns_flag |= SLP_DISCONN;
2564 					goto dorecs;
2565 				}
2566 			}
2567 		} while (sio.sb_mb);
2568 	}
2569 
2570 	/*
2571 	 * If we were upcalled from the tcp protocol layer and we have
2572 	 * fully parsed records ready to go, or there is new data pending,
2573 	 * or something went wrong, try to wake up an nfsd thread to deal
2574 	 * with it.
2575 	 */
2576 dorecs:
2577 	if (waitflag == MB_DONTWAIT && (slp->ns_numrec > 0
2578 	     || (slp->ns_flag & (SLP_NEEDQ | SLP_DISCONN)))) {
2579 		nfsrv_wakenfsd(slp, nparallel_wakeup);
2580 	}
2581 }
2582 
2583 /*
2584  * Try and extract an RPC request from the mbuf data list received on a
2585  * stream socket. The "waitflag" argument indicates whether or not it
2586  * can sleep.
2587  */
2588 static int
2589 nfsrv_getstream(struct nfssvc_sock *slp, int waitflag, int *countp)
2590 {
2591 	struct mbuf *m, **mpp;
2592 	char *cp1, *cp2;
2593 	int len;
2594 	struct mbuf *om, *m2, *recm;
2595 	u_int32_t recmark;
2596 
2597 	for (;;) {
2598 	    if (slp->ns_reclen == 0) {
2599 		if (slp->ns_cc < NFSX_UNSIGNED)
2600 			return (0);
2601 		m = slp->ns_raw;
2602 		if (m->m_len >= NFSX_UNSIGNED) {
2603 			bcopy(mtod(m, caddr_t), (caddr_t)&recmark, NFSX_UNSIGNED);
2604 			m->m_data += NFSX_UNSIGNED;
2605 			m->m_len -= NFSX_UNSIGNED;
2606 		} else {
2607 			cp1 = (caddr_t)&recmark;
2608 			cp2 = mtod(m, caddr_t);
2609 			while (cp1 < ((caddr_t)&recmark) + NFSX_UNSIGNED) {
2610 				while (m->m_len == 0) {
2611 					m = m->m_next;
2612 					cp2 = mtod(m, caddr_t);
2613 				}
2614 				*cp1++ = *cp2++;
2615 				m->m_data++;
2616 				m->m_len--;
2617 			}
2618 		}
2619 		slp->ns_cc -= NFSX_UNSIGNED;
2620 		recmark = ntohl(recmark);
2621 		slp->ns_reclen = recmark & ~0x80000000;
2622 		if (recmark & 0x80000000)
2623 			slp->ns_flag |= SLP_LASTFRAG;
2624 		else
2625 			slp->ns_flag &= ~SLP_LASTFRAG;
2626 		if (slp->ns_reclen > NFS_MAXPACKET || slp->ns_reclen <= 0) {
2627 			log(LOG_ERR, "%s (%d) from nfs client\n",
2628 			    "impossible packet length",
2629 			    slp->ns_reclen);
2630 			return (EPERM);
2631 		}
2632 	    }
2633 
2634 	    /*
2635 	     * Now get the record part.
2636 	     *
2637 	     * Note that slp->ns_reclen may be 0.  Linux sometimes
2638 	     * generates 0-length RPCs
2639 	     */
2640 	    recm = NULL;
2641 	    if (slp->ns_cc == slp->ns_reclen) {
2642 		recm = slp->ns_raw;
2643 		slp->ns_raw = slp->ns_rawend = NULL;
2644 		slp->ns_cc = slp->ns_reclen = 0;
2645 	    } else if (slp->ns_cc > slp->ns_reclen) {
2646 		len = 0;
2647 		m = slp->ns_raw;
2648 		om = NULL;
2649 
2650 		while (len < slp->ns_reclen) {
2651 			if ((len + m->m_len) > slp->ns_reclen) {
2652 				m2 = m_copym(m, 0, slp->ns_reclen - len,
2653 					waitflag);
2654 				if (m2) {
2655 					if (om) {
2656 						om->m_next = m2;
2657 						recm = slp->ns_raw;
2658 					} else
2659 						recm = m2;
2660 					m->m_data += slp->ns_reclen - len;
2661 					m->m_len -= slp->ns_reclen - len;
2662 					len = slp->ns_reclen;
2663 				} else {
2664 					return (EWOULDBLOCK);
2665 				}
2666 			} else if ((len + m->m_len) == slp->ns_reclen) {
2667 				om = m;
2668 				len += m->m_len;
2669 				m = m->m_next;
2670 				recm = slp->ns_raw;
2671 				om->m_next = NULL;
2672 			} else {
2673 				om = m;
2674 				len += m->m_len;
2675 				m = m->m_next;
2676 			}
2677 		}
2678 		slp->ns_raw = m;
2679 		slp->ns_cc -= len;
2680 		slp->ns_reclen = 0;
2681 	    } else {
2682 		return (0);
2683 	    }
2684 
2685 	    /*
2686 	     * Accumulate the fragments into a record.
2687 	     */
2688 	    mpp = &slp->ns_frag;
2689 	    while (*mpp)
2690 		mpp = &((*mpp)->m_next);
2691 	    *mpp = recm;
2692 	    if (slp->ns_flag & SLP_LASTFRAG) {
2693 		struct nfsrv_rec *rec;
2694 		int mf = (waitflag & MB_DONTWAIT) ? M_NOWAIT : M_WAITOK;
2695 		rec = kmalloc(sizeof(struct nfsrv_rec), M_NFSRVDESC, mf);
2696 		if (!rec) {
2697 		    m_freem(slp->ns_frag);
2698 		} else {
2699 		    nfs_realign(&slp->ns_frag, 10 * NFSX_UNSIGNED);
2700 		    rec->nr_address = NULL;
2701 		    rec->nr_packet = slp->ns_frag;
2702 		    STAILQ_INSERT_TAIL(&slp->ns_rec, rec, nr_link);
2703 		    ++slp->ns_numrec;
2704 		    ++*countp;
2705 		}
2706 		slp->ns_frag = NULL;
2707 	    }
2708 	}
2709 }
2710 
2711 /*
2712  * Parse an RPC header.
2713  */
2714 int
2715 nfsrv_dorec(struct nfssvc_sock *slp, struct nfsd *nfsd,
2716 	    struct nfsrv_descript **ndp)
2717 {
2718 	struct nfsrv_rec *rec;
2719 	struct mbuf *m;
2720 	struct sockaddr *nam;
2721 	struct nfsrv_descript *nd;
2722 	int error;
2723 
2724 	*ndp = NULL;
2725 	if ((slp->ns_flag & SLP_VALID) == 0 || !STAILQ_FIRST(&slp->ns_rec))
2726 		return (ENOBUFS);
2727 	rec = STAILQ_FIRST(&slp->ns_rec);
2728 	STAILQ_REMOVE_HEAD(&slp->ns_rec, nr_link);
2729 	KKASSERT(slp->ns_numrec > 0);
2730 	--slp->ns_numrec;
2731 	nam = rec->nr_address;
2732 	m = rec->nr_packet;
2733 	kfree(rec, M_NFSRVDESC);
2734 	MALLOC(nd, struct nfsrv_descript *, sizeof (struct nfsrv_descript),
2735 		M_NFSRVDESC, M_WAITOK);
2736 	nd->nd_md = nd->nd_mrep = m;
2737 	nd->nd_nam2 = nam;
2738 	nd->nd_dpos = mtod(m, caddr_t);
2739 	error = nfs_getreq(nd, nfsd, TRUE);
2740 	if (error) {
2741 		if (nam) {
2742 			FREE(nam, M_SONAME);
2743 		}
2744 		kfree((caddr_t)nd, M_NFSRVDESC);
2745 		return (error);
2746 	}
2747 	*ndp = nd;
2748 	nfsd->nfsd_nd = nd;
2749 	return (0);
2750 }
2751 
2752 /*
2753  * Try to assign service sockets to nfsd threads based on the number
2754  * of new rpc requests that have been queued on the service socket.
2755  *
2756  * If no nfsd's are available or additonal requests are pending, set the
2757  * NFSD_CHECKSLP flag so that one of the running nfsds will go look for
2758  * the work in the nfssvc_sock list when it is finished processing its
2759  * current work.  This flag is only cleared when an nfsd can not find
2760  * any new work to perform.
2761  */
2762 void
2763 nfsrv_wakenfsd(struct nfssvc_sock *slp, int nparallel)
2764 {
2765 	struct nfsd *nd;
2766 
2767 	if ((slp->ns_flag & SLP_VALID) == 0)
2768 		return;
2769 	if (nparallel <= 1)
2770 		nparallel = 1;
2771 	TAILQ_FOREACH(nd, &nfsd_head, nfsd_chain) {
2772 		if (nd->nfsd_flag & NFSD_WAITING) {
2773 			nd->nfsd_flag &= ~NFSD_WAITING;
2774 			if (nd->nfsd_slp)
2775 				panic("nfsd wakeup");
2776 			slp->ns_sref++;
2777 			nd->nfsd_slp = slp;
2778 			wakeup((caddr_t)nd);
2779 			if (--nparallel == 0)
2780 				break;
2781 		}
2782 	}
2783 	if (nparallel) {
2784 		slp->ns_flag |= SLP_DOREC;
2785 		nfsd_head_flag |= NFSD_CHECKSLP;
2786 	}
2787 }
2788 #endif /* NFS_NOSERVER */
2789