xref: /freebsd/sbin/mount_nfs/mount_nfs.c (revision ee2ea5ceafed78a5bd9810beb9e3ca927180c226)
1 /*
2  * Copyright (c) 1992, 1993, 1994
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 
37 #ifndef lint
38 static const char copyright[] =
39 "@(#) Copyright (c) 1992, 1993, 1994\n\
40 	The Regents of the University of California.  All rights reserved.\n";
41 #endif /* not lint */
42 
43 #ifndef lint
44 #if 0
45 static char sccsid[] = "@(#)mount_nfs.c	8.11 (Berkeley) 5/4/95";
46 #endif
47 static const char rcsid[] =
48   "$FreeBSD$";
49 #endif /* not lint */
50 
51 #include <sys/param.h>
52 #include <sys/mount.h>
53 #include <sys/socket.h>
54 #include <sys/stat.h>
55 #include <sys/syslog.h>
56 
57 #include <rpc/rpc.h>
58 #include <rpc/pmap_clnt.h>
59 #include <rpc/pmap_prot.h>
60 
61 #include <nfs/rpcv2.h>
62 #include <nfs/nfsproto.h>
63 #include <nfsclient/nfs.h>
64 #include <nfsclient/nfsargs.h>
65 
66 #include <arpa/inet.h>
67 
68 #include <ctype.h>
69 #include <err.h>
70 #include <errno.h>
71 #include <fcntl.h>
72 #include <netdb.h>
73 #include <stdio.h>
74 #include <stdlib.h>
75 #include <strings.h>
76 #include <sysexits.h>
77 #include <unistd.h>
78 
79 #include "mntopts.h"
80 #include "mounttab.h"
81 
82 #define	ALTF_BG		0x1
83 #define ALTF_NOCONN	0x2
84 #define ALTF_DUMBTIMR	0x4
85 #define ALTF_INTR	0x8
86 #define ALTF_NFSV3	0x20
87 #define ALTF_RDIRPLUS	0x40
88 #define ALTF_MNTUDP	0x80
89 #define ALTF_RESVPORT	0x100
90 #define ALTF_SEQPACKET	0x200
91 #define ALTF_SOFT	0x800
92 #define ALTF_TCP	0x1000
93 #define ALTF_PORT	0x2000
94 #define ALTF_NFSV2	0x4000
95 #define ALTF_ACREGMIN	0x8000
96 #define ALTF_ACREGMAX	0x10000
97 #define ALTF_ACDIRMIN	0x20000
98 #define ALTF_ACDIRMAX	0x40000
99 #define ALTF_NOLOCKD	0x80000
100 
101 struct mntopt mopts[] = {
102 	MOPT_STDOPTS,
103 	MOPT_FORCE,
104 	MOPT_UPDATE,
105 	MOPT_ASYNC,
106 	{ "bg", 0, ALTF_BG, 1 },
107 	{ "conn", 1, ALTF_NOCONN, 1 },
108 	{ "dumbtimer", 0, ALTF_DUMBTIMR, 1 },
109 	{ "intr", 0, ALTF_INTR, 1 },
110 	{ "nfsv3", 0, ALTF_NFSV3, 1 },
111 	{ "rdirplus", 0, ALTF_RDIRPLUS, 1 },
112 	{ "mntudp", 0, ALTF_MNTUDP, 1 },
113 	{ "resvport", 0, ALTF_RESVPORT, 1 },
114 	{ "soft", 0, ALTF_SOFT, 1 },
115 	{ "tcp", 0, ALTF_TCP, 1 },
116 	{ "port=", 0, ALTF_PORT, 1 },
117 	{ "nfsv2", 0, ALTF_NFSV2, 1 },
118 	{ "acregmin=", 0, ALTF_ACREGMIN, 1 },
119 	{ "acregmax=", 0, ALTF_ACREGMAX, 1 },
120 	{ "acdirmin=", 0, ALTF_ACDIRMIN, 1 },
121 	{ "acdirmax=", 0, ALTF_ACDIRMAX, 1 },
122 	{ "lockd", 1, ALTF_NOLOCKD, 1 },
123 	{ NULL }
124 };
125 
126 struct nfs_args nfsdefargs = {
127 	NFS_ARGSVERSION,
128 	(struct sockaddr *)0,
129 	sizeof (struct sockaddr_in),
130 	SOCK_DGRAM,
131 	0,
132 	(u_char *)0,
133 	0,
134 	NFSMNT_RESVPORT,
135 	NFS_WSIZE,
136 	NFS_RSIZE,
137 	NFS_READDIRSIZE,
138 	10,
139 	NFS_RETRANS,
140 	NFS_MAXGRPS,
141 	NFS_DEFRAHEAD,
142 	0,			/* was: NQ_DEFLEASE */
143 	NFS_MAXDEADTHRESH,	/* was: NQ_DEADTHRESH */
144 	(char *)0,
145 	/* args version 4 */
146 	NFS_MINATTRTIMO,
147 	NFS_MAXATTRTIMO,
148 	NFS_MINDIRATTRTIMO,
149 	NFS_MAXDIRATTRTIMO,
150 };
151 
152 /* Table for af,sotype -> netid conversions. */
153 struct nc_protos {
154 	char *netid;
155 	int af;
156 	int sotype;
157 } nc_protos[] = {
158 	{"udp",		AF_INET,	SOCK_DGRAM},
159 	{"tcp",		AF_INET,	SOCK_STREAM},
160 	{"udp6",	AF_INET6,	SOCK_DGRAM},
161 	{"tcp6",	AF_INET6,	SOCK_STREAM},
162 	{NULL}
163 };
164 
165 struct nfhret {
166 	u_long		stat;
167 	long		vers;
168 	long		auth;
169 	long		fhsize;
170 	u_char		nfh[NFSX_V3FHMAX];
171 };
172 #define	BGRND	1
173 #define	ISBGRND	2
174 int retrycnt = -1;
175 int opflags = 0;
176 int nfsproto = IPPROTO_UDP;
177 int mnttcp_ok = 1;
178 char *portspec = NULL;	/* Server nfs port; NULL means look up via rpcbind. */
179 enum mountmode {
180 	ANY,
181 	V2,
182 	V3
183 } mountmode = ANY;
184 
185 /* Return codes for nfs_tryproto. */
186 enum tryret {
187 	TRYRET_SUCCESS,
188 	TRYRET_TIMEOUT,		/* No response received. */
189 	TRYRET_REMOTEERR,	/* Error received from remote server. */
190 	TRYRET_LOCALERR		/* Local failure. */
191 };
192 
193 int	getnfsargs(char *, struct nfs_args *);
194 /* void	set_rpc_maxgrouplist(int); */
195 struct netconfig *getnetconf_cached(const char *netid);
196 char	*netidbytype(int af, int sotype);
197 void	usage(void) __dead2;
198 int	xdr_dir(XDR *, char *);
199 int	xdr_fh(XDR *, struct nfhret *);
200 enum tryret nfs_tryproto(struct nfs_args *nfsargsp, struct addrinfo *ai,
201     char *hostp, char *spec, char **errstr);
202 enum tryret returncode(enum clnt_stat stat, struct rpc_err *rpcerr);
203 
204 /*
205  * Used to set mount flags with getmntopts.  Call with dir=TRUE to
206  * initialize altflags from the current mount flags.  Call with
207  * dir=FALSE to update mount flags with the new value of altflags after
208  * the call to getmntopts.
209  */
210 static void
211 set_flags(int* altflags, int* nfsflags, int dir)
212 {
213 #define F2(af, nf)					\
214 	if (dir) {					\
215 		if (*nfsflags & NFSMNT_##nf)		\
216 			*altflags |= ALTF_##af;		\
217 		else					\
218 			*altflags &= ~ALTF_##af;	\
219 	} else {					\
220 		if (*altflags & ALTF_##af)		\
221 			*nfsflags |= NFSMNT_##nf;	\
222 		else					\
223 			*nfsflags &= ~NFSMNT_##nf;	\
224 	}
225 #define F(f)	F2(f,f)
226 
227 	F(NOCONN);
228 	F(DUMBTIMR);
229 	F2(INTR, INT);
230 	F(RDIRPLUS);
231 	F(RESVPORT);
232 	F(SOFT);
233 	F(NOLOCKD);
234 
235 #undef F
236 #undef F2
237 }
238 
239 int
240 main(argc, argv)
241 	int argc;
242 	char *argv[];
243 {
244 	int c;
245 	struct nfs_args *nfsargsp;
246 	struct nfs_args nfsargs;
247 	int mntflags, altflags, nfssvc_flag, num;
248 	char *name, *p, *spec;
249 	char mntpath[MAXPATHLEN];
250 	struct vfsconf vfc;
251 	int error = 0;
252 
253 	mntflags = 0;
254 	altflags = 0;
255 	nfsargs = nfsdefargs;
256 	nfsargsp = &nfsargs;
257 	while ((c = getopt(argc, argv,
258 	    "23a:bcdD:g:I:iLl:No:PpR:r:sTt:w:x:U")) != -1)
259 		switch (c) {
260 		case '2':
261 			mountmode = V2;
262 			break;
263 		case '3':
264 			mountmode = V3;
265 			break;
266 		case 'a':
267 			num = strtol(optarg, &p, 10);
268 			if (*p || num < 0)
269 				errx(1, "illegal -a value -- %s", optarg);
270 			nfsargsp->readahead = num;
271 			nfsargsp->flags |= NFSMNT_READAHEAD;
272 			break;
273 		case 'b':
274 			opflags |= BGRND;
275 			break;
276 		case 'c':
277 			nfsargsp->flags |= NFSMNT_NOCONN;
278 			break;
279 		case 'D':
280 			num = strtol(optarg, &p, 10);
281 			if (*p || num <= 0)
282 				errx(1, "illegal -D value -- %s", optarg);
283 			nfsargsp->deadthresh = num;
284 			nfsargsp->flags |= NFSMNT_DEADTHRESH;
285 			break;
286 		case 'd':
287 			nfsargsp->flags |= NFSMNT_DUMBTIMR;
288 			break;
289 #if 0 /* XXXX */
290 		case 'g':
291 			num = strtol(optarg, &p, 10);
292 			if (*p || num <= 0)
293 				errx(1, "illegal -g value -- %s", optarg);
294 			set_rpc_maxgrouplist(num);
295 			nfsargsp->maxgrouplist = num;
296 			nfsargsp->flags |= NFSMNT_MAXGRPS;
297 			break;
298 #endif
299 		case 'I':
300 			num = strtol(optarg, &p, 10);
301 			if (*p || num <= 0)
302 				errx(1, "illegal -I value -- %s", optarg);
303 			nfsargsp->readdirsize = num;
304 			nfsargsp->flags |= NFSMNT_READDIRSIZE;
305 			break;
306 		case 'i':
307 			nfsargsp->flags |= NFSMNT_INT;
308 			break;
309 		case 'L':
310 			nfsargsp->flags |= NFSMNT_NOLOCKD;
311 			break;
312 		case 'l':
313 			nfsargsp->flags |= NFSMNT_RDIRPLUS;
314 			break;
315 		case 'N':
316 			nfsargsp->flags &= ~NFSMNT_RESVPORT;
317 			break;
318 		case 'o':
319 			altflags = 0;
320 			set_flags(&altflags, &nfsargsp->flags, TRUE);
321 			if (mountmode == V2)
322 				altflags |= ALTF_NFSV2;
323 			else if (mountmode == V3)
324 				altflags |= ALTF_NFSV3;
325 			getmntopts(optarg, mopts, &mntflags, &altflags);
326 			set_flags(&altflags, &nfsargsp->flags, FALSE);
327 			/*
328 			 * Handle altflags which don't map directly to
329 			 * mount flags.
330 			 */
331 			if(altflags & ALTF_BG)
332 				opflags |= BGRND;
333 			if(altflags & ALTF_MNTUDP)
334 				mnttcp_ok = 0;
335 			if(altflags & ALTF_TCP) {
336 				nfsargsp->sotype = SOCK_STREAM;
337 				nfsproto = IPPROTO_TCP;
338 			}
339 			if(altflags & ALTF_PORT) {
340 				/*
341 				 * XXX Converting from a string to an int
342 				 * and back again is silly, and we should
343 				 * allow /etc/services names.
344 				 */
345 				asprintf(&portspec, "%d",
346 				    atoi(strstr(optarg, "port=") + 5));
347 				if (portspec == NULL)
348 					err(1, "asprintf");
349 			}
350 			mountmode = ANY;
351 			if(altflags & ALTF_NFSV2)
352 				mountmode = V2;
353 			if(altflags & ALTF_NFSV3)
354 				mountmode = V3;
355 			if(altflags & ALTF_ACREGMIN)
356 				nfsargsp->acregmin = atoi(strstr(optarg,
357 				    "acregmin=") + 9);
358 			if(altflags & ALTF_ACREGMAX)
359 				nfsargsp->acregmax = atoi(strstr(optarg,
360 				    "acregmax=") + 9);
361 			if(altflags & ALTF_ACDIRMIN)
362 				nfsargsp->acdirmin = atoi(strstr(optarg,
363 				    "acdirmin=") + 9);
364 			if(altflags & ALTF_ACDIRMAX)
365 				nfsargsp->acdirmax = atoi(strstr(optarg,
366 				    "acdirmax=") + 9);
367 			break;
368 		case 'P':
369 			/* obsolete for NFSMNT_RESVPORT, now default */
370 			break;
371 		case 'R':
372 			num = strtol(optarg, &p, 10);
373 			if (*p || num < 0)
374 				errx(1, "illegal -R value -- %s", optarg);
375 			retrycnt = num;
376 			break;
377 		case 'r':
378 			num = strtol(optarg, &p, 10);
379 			if (*p || num <= 0)
380 				errx(1, "illegal -r value -- %s", optarg);
381 			nfsargsp->rsize = num;
382 			nfsargsp->flags |= NFSMNT_RSIZE;
383 			break;
384 		case 's':
385 			nfsargsp->flags |= NFSMNT_SOFT;
386 			break;
387 		case 'T':
388 			nfsargsp->sotype = SOCK_STREAM;
389 			nfsproto = IPPROTO_TCP;
390 			break;
391 		case 't':
392 			num = strtol(optarg, &p, 10);
393 			if (*p || num <= 0)
394 				errx(1, "illegal -t value -- %s", optarg);
395 			nfsargsp->timeo = num;
396 			nfsargsp->flags |= NFSMNT_TIMEO;
397 			break;
398 		case 'w':
399 			num = strtol(optarg, &p, 10);
400 			if (*p || num <= 0)
401 				errx(1, "illegal -w value -- %s", optarg);
402 			nfsargsp->wsize = num;
403 			nfsargsp->flags |= NFSMNT_WSIZE;
404 			break;
405 		case 'x':
406 			num = strtol(optarg, &p, 10);
407 			if (*p || num <= 0)
408 				errx(1, "illegal -x value -- %s", optarg);
409 			nfsargsp->retrans = num;
410 			nfsargsp->flags |= NFSMNT_RETRANS;
411 			break;
412 		case 'U':
413 			mnttcp_ok = 0;
414 			break;
415 		default:
416 			usage();
417 			break;
418 		}
419 	argc -= optind;
420 	argv += optind;
421 
422 	if (argc != 2) {
423 		usage();
424 		/* NOTREACHED */
425 	}
426 
427 	spec = *argv++;
428 	name = *argv;
429 
430 	if (retrycnt == -1)
431 		/* The default is to keep retrying forever. */
432 		retrycnt = 0;
433 	if (!getnfsargs(spec, nfsargsp))
434 		exit(1);
435 
436 	/* resolve the mountpoint with realpath(3) */
437 	(void)checkpath(name, mntpath);
438 
439 	error = getvfsbyname("nfs", &vfc);
440 	if (error && vfsisloadable("nfs")) {
441 		if(vfsload("nfs"))
442 			err(EX_OSERR, "vfsload(nfs)");
443 		endvfsent();	/* clear cache */
444 		error = getvfsbyname("nfs", &vfc);
445 	}
446 	if (error)
447 		errx(EX_OSERR, "nfs filesystem is not available");
448 
449 	if (mount(vfc.vfc_name, mntpath, mntflags, nfsargsp))
450 		err(1, "%s", mntpath);
451 
452 	exit(0);
453 }
454 
455 int
456 getnfsargs(spec, nfsargsp)
457 	char *spec;
458 	struct nfs_args *nfsargsp;
459 {
460 	struct addrinfo hints, *ai_nfs, *ai;
461 	enum tryret ret;
462 	int ecode, speclen, remoteerr;
463 	char *hostp, *delimp, *errstr;
464 	size_t len;
465 	static char nam[MNAMELEN + 1];
466 
467 	if ((delimp = strrchr(spec, ':')) != NULL) {
468 		hostp = spec;
469 		spec = delimp + 1;
470 	} else if ((delimp = strrchr(spec, '@')) != NULL) {
471 		warnx("path@server syntax is deprecated, use server:path");
472 		hostp = delimp + 1;
473 	} else {
474 		warnx("no <host>:<dirpath> nfs-name");
475 		return (0);
476 	}
477 	*delimp = '\0';
478 
479 	/*
480 	 * If there has been a trailing slash at mounttime it seems
481 	 * that some mountd implementations fail to remove the mount
482 	 * entries from their mountlist while unmounting.
483 	 */
484 	for (speclen = strlen(spec);
485 		speclen > 1 && spec[speclen - 1] == '/';
486 		speclen--)
487 		spec[speclen - 1] = '\0';
488 	if (strlen(hostp) + strlen(spec) + 1 > MNAMELEN) {
489 		warnx("%s:%s: %s", hostp, spec, strerror(ENAMETOOLONG));
490 		return (0);
491 	}
492 	/* Make both '@' and ':' notations equal */
493 	if (*hostp != '\0') {
494 		len = strlen(hostp);
495 		memmove(nam, hostp, len);
496 		nam[len] = ':';
497 		memmove(nam + len + 1, spec, speclen);
498 		nam[len + speclen + 1] = '\0';
499 	}
500 
501 	/*
502 	 * Handle an internet host address.
503 	 */
504 	memset(&hints, 0, sizeof hints);
505 	hints.ai_flags = AI_NUMERICHOST;
506 	hints.ai_socktype = nfsargsp->sotype;
507 	if (getaddrinfo(hostp, portspec, &hints, &ai_nfs) != 0) {
508 		hints.ai_flags = 0;
509 		if ((ecode = getaddrinfo(hostp, portspec, &hints, &ai_nfs))
510 		    != 0) {
511 			if (portspec == NULL)
512 				errx(1, "%s: %s", hostp, gai_strerror(ecode));
513 			else
514 				errx(1, "%s:%s: %s", hostp, portspec,
515 				    gai_strerror(ecode));
516 			return (0);
517 		}
518 	}
519 
520 	ret = TRYRET_LOCALERR;
521 	for (;;) {
522 		/*
523 		 * Try each entry returned by getaddrinfo(). Note the
524 		 * occurence of remote errors by setting `remoteerr'.
525 		 */
526 		remoteerr = 0;
527 		for (ai = ai_nfs; ai != NULL; ai = ai->ai_next) {
528 			ret = nfs_tryproto(nfsargsp, ai, hostp, spec, &errstr);
529 			if (ret == TRYRET_SUCCESS)
530 				break;
531 			if (ret != TRYRET_LOCALERR)
532 				remoteerr = 1;
533 			if ((opflags & ISBGRND) == 0)
534 				fprintf(stderr, "%s\n", errstr);
535 		}
536 		if (ret == TRYRET_SUCCESS)
537 			break;
538 
539 		/* Exit if all errors were local. */
540 		if (!remoteerr)
541 			exit(1);
542 
543 		/*
544 		 * If retrycnt == 0, we are to keep retrying forever.
545 		 * Otherwise decrement it, and exit if it hits zero.
546 		 */
547 		if (retrycnt != 0 && --retrycnt == 0)
548 			exit(1);
549 
550 		if ((opflags & (BGRND | ISBGRND)) == BGRND) {
551 			warnx("Cannot immediately mount %s:%s, backgrounding",
552 			    hostp, spec);
553 			opflags |= ISBGRND;
554 			if (daemon(0, 0) != 0)
555 				err(1, "daemon");
556 		}
557 		sleep(60);
558 	}
559 	freeaddrinfo(ai_nfs);
560 	nfsargsp->hostname = nam;
561 	/* Add mounted filesystem to PATH_MOUNTTAB */
562 	if (!add_mtab(hostp, spec))
563 		warnx("can't update %s for %s:%s", PATH_MOUNTTAB, hostp, spec);
564 	return (1);
565 }
566 
567 /*
568  * Try to set up the NFS arguments according to the address
569  * family, protocol (and possibly port) specified in `ai'.
570  *
571  * Returns TRYRET_SUCCESS if successful, or:
572  *   TRYRET_TIMEOUT		The server did not respond.
573  *   TRYRET_REMOTEERR		The server reported an error.
574  *   TRYRET_LOCALERR		Local failure.
575  *
576  * In all error cases, *errstr will be set to a statically-allocated string
577  * describing the error.
578  */
579 enum tryret
580 nfs_tryproto(struct nfs_args *nfsargsp, struct addrinfo *ai, char *hostp,
581     char *spec, char **errstr)
582 {
583 	static char errbuf[256];
584 	struct sockaddr_storage nfs_ss;
585 	struct netbuf nfs_nb;
586 	struct nfhret nfhret;
587 	struct timeval try;
588 	struct rpc_err rpcerr;
589 	CLIENT *clp;
590 	struct netconfig *nconf, *nconf_mnt;
591 	char *netid, *netid_mnt;
592 	int doconnect, nfsvers, mntvers;
593 	enum clnt_stat stat;
594 	enum mountmode trymntmode;
595 
596 	trymntmode = mountmode;
597 	errbuf[0] = '\0';
598 	*errstr = errbuf;
599 
600 	if ((netid = netidbytype(ai->ai_family, nfsargsp->sotype)) == NULL) {
601 		snprintf(errbuf, sizeof errbuf,
602 		    "af %d sotype %d not supported", ai->ai_family,
603 		    nfsargsp->sotype);
604 		return (TRYRET_LOCALERR);
605 	}
606 	if ((nconf = getnetconf_cached(netid)) == NULL) {
607 		snprintf(errbuf, sizeof errbuf, "%s: %s", netid, nc_sperror());
608 		return (TRYRET_LOCALERR);
609 	}
610 	/* The RPCPROG_MNT netid may be different. */
611 	if (mnttcp_ok) {
612 		netid_mnt = netid;
613 		nconf_mnt = nconf;
614 	} else {
615 		if ((netid_mnt = netidbytype(ai->ai_family, SOCK_DGRAM))
616 		     == NULL) {
617 			snprintf(errbuf, sizeof errbuf,
618 			    "af %d sotype SOCK_DGRAM not supported",
619 			     ai->ai_family);
620 			return (TRYRET_LOCALERR);
621 		}
622 		if ((nconf_mnt = getnetconf_cached(netid_mnt)) == NULL) {
623 			snprintf(errbuf, sizeof errbuf, "%s: %s", netid_mnt,
624 			    nc_sperror());
625 			return (TRYRET_LOCALERR);
626 		}
627 	}
628 
629 tryagain:
630 	if (trymntmode == V2) {
631 		nfsvers = 2;
632 		mntvers = 1;
633 	} else {
634 		nfsvers = 3;
635 		mntvers = 3;
636 	}
637 
638 	if (portspec != NULL) {
639 		/* `ai' contains the complete nfsd sockaddr. */
640 		nfs_nb.buf = ai->ai_addr;
641 		nfs_nb.len = nfs_nb.maxlen = ai->ai_addrlen;
642 	} else {
643 		/* Ask the remote rpcbind. */
644 		nfs_nb.buf = &nfs_ss;
645 		nfs_nb.len = nfs_nb.maxlen = sizeof nfs_ss;
646 
647 		if (!rpcb_getaddr(RPCPROG_NFS, nfsvers, nconf, &nfs_nb,
648 		    hostp)) {
649 			if (rpc_createerr.cf_stat == RPC_PROGVERSMISMATCH &&
650 			    trymntmode == ANY) {
651 				trymntmode = V2;
652 				goto tryagain;
653 			}
654 			snprintf(errbuf, sizeof errbuf, "[%s] %s:%s: %s",
655 			    netid, hostp, spec,
656 			    clnt_spcreateerror("RPCPROG_NFS"));
657 			return (returncode(rpc_createerr.cf_stat,
658 			    &rpc_createerr.cf_error));
659 		}
660 	}
661 
662 	/* Check that the server (nfsd) responds on the port we have chosen. */
663 	clp = clnt_tli_create(RPC_ANYFD, nconf, &nfs_nb, RPCPROG_NFS, nfsvers,
664 	    0, 0);
665 	if (clp == NULL) {
666 		snprintf(errbuf, sizeof errbuf, "[%s] %s:%s: %s", netid,
667 		    hostp, spec, clnt_spcreateerror("nfsd: RPCPROG_NFS"));
668 		return (returncode(rpc_createerr.cf_stat,
669 		    &rpc_createerr.cf_error));
670 	}
671 	if (nfsargsp->sotype == SOCK_DGRAM) {
672 		/*
673 		 * Use connect(), to match what the kernel does. This
674 		 * catches cases where the server responds from the
675 		 * wrong source address.
676 		 */
677 		doconnect = 1;
678 		if (!clnt_control(clp, CLSET_CONNECT, (char *)&doconnect)) {
679 			clnt_destroy(clp);
680 			snprintf(errbuf, sizeof errbuf,
681 			    "[%s] %s:%s: CLSET_CONNECT failed", netid, hostp,
682 			    spec);
683 			return (TRYRET_LOCALERR);
684 		}
685 	}
686 
687 	try.tv_sec = 10;
688 	try.tv_usec = 0;
689 	stat = clnt_call(clp, NFSPROC_NULL, xdr_void, NULL, xdr_void, NULL,
690 	    try);
691 	if (stat != RPC_SUCCESS) {
692 		if (stat == RPC_PROGVERSMISMATCH && trymntmode == ANY) {
693 			clnt_destroy(clp);
694 			trymntmode = V2;
695 			goto tryagain;
696 		}
697 		clnt_geterr(clp, &rpcerr);
698 		snprintf(errbuf, sizeof errbuf, "[%s] %s:%s: %s", netid,
699 		    hostp, spec, clnt_sperror(clp, "NFSPROC_NULL"));
700 		clnt_destroy(clp);
701 		return (returncode(stat, &rpcerr));
702 	}
703 	clnt_destroy(clp);
704 
705 	/* Send the RPCMNT_MOUNT RPC to get the root filehandle. */
706 	try.tv_sec = 10;
707 	try.tv_usec = 0;
708 	clp = clnt_tp_create(hostp, RPCPROG_MNT, mntvers, nconf_mnt);
709 	if (clp == NULL) {
710 		snprintf(errbuf, sizeof errbuf, "[%s] %s:%s: %s", netid_mnt,
711 		    hostp, spec, clnt_spcreateerror("RPCMNT: clnt_create"));
712 		return (returncode(rpc_createerr.cf_stat,
713 		    &rpc_createerr.cf_error));
714 	}
715 	clp->cl_auth = authsys_create_default();
716 	nfhret.auth = RPCAUTH_UNIX;
717 	nfhret.vers = mntvers;
718 	stat = clnt_call(clp, RPCMNT_MOUNT, xdr_dir, spec, xdr_fh, &nfhret,
719 	    try);
720 	auth_destroy(clp->cl_auth);
721 	if (stat != RPC_SUCCESS) {
722 		if (stat == RPC_PROGVERSMISMATCH && trymntmode == ANY) {
723 			clnt_destroy(clp);
724 			trymntmode = V2;
725 			goto tryagain;
726 		}
727 		clnt_geterr(clp, &rpcerr);
728 		snprintf(errbuf, sizeof errbuf, "[%s] %s:%s: %s", netid_mnt,
729 		    hostp, spec, clnt_sperror(clp, "RPCPROG_MNT"));
730 		clnt_destroy(clp);
731 		return (returncode(stat, &rpcerr));
732 	}
733 	clnt_destroy(clp);
734 
735 	if (nfhret.stat != 0) {
736 		snprintf(errbuf, sizeof errbuf, "[%s] %s:%s: %s", netid_mnt,
737 		    hostp, spec, strerror(nfhret.stat));
738 		return (TRYRET_REMOTEERR);
739 	}
740 
741 	/*
742 	 * Store the filehandle and server address in nfsargsp, making
743 	 * sure to copy any locally allocated structures.
744 	 */
745 	nfsargsp->addrlen = nfs_nb.len;
746 	nfsargsp->addr = malloc(nfsargsp->addrlen);
747 	nfsargsp->fhsize = nfhret.fhsize;
748 	nfsargsp->fh = malloc(nfsargsp->fhsize);
749 	if (nfsargsp->addr == NULL || nfsargsp->fh == NULL)
750 		err(1, "malloc");
751 	bcopy(nfs_nb.buf, nfsargsp->addr, nfsargsp->addrlen);
752 	bcopy(nfhret.nfh, nfsargsp->fh, nfsargsp->fhsize);
753 
754 	if (nfsvers == 3)
755 		nfsargsp->flags |= NFSMNT_NFSV3;
756 	else
757 		nfsargsp->flags &= ~NFSMNT_NFSV3;
758 
759 	return (TRYRET_SUCCESS);
760 }
761 
762 
763 /*
764  * Catagorise a RPC return status and error into an `enum tryret'
765  * return code.
766  */
767 enum tryret
768 returncode(enum clnt_stat stat, struct rpc_err *rpcerr)
769 {
770 	switch (stat) {
771 	case RPC_TIMEDOUT:
772 		return (TRYRET_TIMEOUT);
773 	case RPC_PMAPFAILURE:
774 	case RPC_PROGNOTREGISTERED:
775 	case RPC_PROGVERSMISMATCH:
776 	/* XXX, these can be local or remote. */
777 	case RPC_CANTSEND:
778 	case RPC_CANTRECV:
779 		return (TRYRET_REMOTEERR);
780 	case RPC_SYSTEMERROR:
781 		switch (rpcerr->re_errno) {
782 		case ETIMEDOUT:
783 			return (TRYRET_TIMEOUT);
784 		case ENOMEM:
785 			break;
786 		default:
787 			return (TRYRET_REMOTEERR);
788 		}
789 		/* FALLTHROUGH */
790 	default:
791 		break;
792 	}
793 	return (TRYRET_LOCALERR);
794 }
795 
796 /*
797  * Look up a netid based on an address family and socket type.
798  * `af' is the address family, and `sotype' is SOCK_DGRAM or SOCK_STREAM.
799  *
800  * XXX there should be a library function for this.
801  */
802 char *
803 netidbytype(int af, int sotype) {
804 	struct nc_protos *p;
805 
806 	for (p = nc_protos; p->netid != NULL; p++) {
807 		if (af != p->af || sotype != p->sotype)
808 			continue;
809 		return (p->netid);
810 	}
811 	return (NULL);
812 }
813 
814 /*
815  * Look up a netconfig entry based on a netid, and cache the result so
816  * that we don't need to remember to call freenetconfigent().
817  *
818  * Otherwise it behaves just like getnetconfigent(), so nc_*error()
819  * work on failure.
820  */
821 struct netconfig *
822 getnetconf_cached(const char *netid) {
823 	static struct nc_entry {
824 		struct netconfig *nconf;
825 		struct nc_entry *next;
826 	} *head;
827 	struct nc_entry *p;
828 	struct netconfig *nconf;
829 
830 	for (p = head; p != NULL; p = p->next)
831 		if (strcmp(netid, p->nconf->nc_netid) == 0)
832 			return (p->nconf);
833 
834 	if ((nconf = getnetconfigent(netid)) == NULL)
835 		return (NULL);
836 	if ((p = malloc(sizeof(*p))) == NULL)
837 		err(1, "malloc");
838 	p->nconf = nconf;
839 	p->next = head;
840 	head = p;
841 
842 	return (p->nconf);
843 }
844 
845 /*
846  * xdr routines for mount rpc's
847  */
848 int
849 xdr_dir(xdrsp, dirp)
850 	XDR *xdrsp;
851 	char *dirp;
852 {
853 	return (xdr_string(xdrsp, &dirp, RPCMNT_PATHLEN));
854 }
855 
856 int
857 xdr_fh(xdrsp, np)
858 	XDR *xdrsp;
859 	struct nfhret *np;
860 {
861 	int i;
862 	long auth, authcnt, authfnd = 0;
863 
864 	if (!xdr_u_long(xdrsp, &np->stat))
865 		return (0);
866 	if (np->stat)
867 		return (1);
868 	switch (np->vers) {
869 	case 1:
870 		np->fhsize = NFSX_V2FH;
871 		return (xdr_opaque(xdrsp, (caddr_t)np->nfh, NFSX_V2FH));
872 	case 3:
873 		if (!xdr_long(xdrsp, &np->fhsize))
874 			return (0);
875 		if (np->fhsize <= 0 || np->fhsize > NFSX_V3FHMAX)
876 			return (0);
877 		if (!xdr_opaque(xdrsp, (caddr_t)np->nfh, np->fhsize))
878 			return (0);
879 		if (!xdr_long(xdrsp, &authcnt))
880 			return (0);
881 		for (i = 0; i < authcnt; i++) {
882 			if (!xdr_long(xdrsp, &auth))
883 				return (0);
884 			if (auth == np->auth)
885 				authfnd++;
886 		}
887 		/*
888 		 * Some servers, such as DEC's OSF/1 return a nil authenticator
889 		 * list to indicate RPCAUTH_UNIX.
890 		 */
891 		if (!authfnd && (authcnt > 0 || np->auth != RPCAUTH_UNIX))
892 			np->stat = EAUTH;
893 		return (1);
894 	};
895 	return (0);
896 }
897 
898 void
899 usage()
900 {
901 	(void)fprintf(stderr, "%s\n%s\n%s\n%s\n",
902 "usage: mount_nfs [-23KNPTUbcdilqs] [-D deadthresh] [-I readdirsize]",
903 "                 [-R retrycnt] [-a maxreadahead]",
904 "                 [-g maxgroups] [-m realm] [-o options] [-r readsize]",
905 "                 [-t timeout] [-w writesize] [-x retrans] rhost:path node");
906 	exit(1);
907 }
908