xref: /freebsd/sbin/mount_nfs/mount_nfs.c (revision d93a896e)
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. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #if 0
34 #ifndef lint
35 static const char copyright[] =
36 "@(#) Copyright (c) 1992, 1993, 1994\n\
37 	The Regents of the University of California.  All rights reserved.\n";
38 #endif /* not lint */
39 
40 #ifndef lint
41 static char sccsid[] = "@(#)mount_nfs.c	8.11 (Berkeley) 5/4/95";
42 #endif /* not lint */
43 #endif
44 #include <sys/cdefs.h>
45 __FBSDID("$FreeBSD$");
46 
47 #include <sys/param.h>
48 #include <sys/linker.h>
49 #include <sys/module.h>
50 #include <sys/mount.h>
51 #include <sys/socket.h>
52 #include <sys/stat.h>
53 #include <sys/syslog.h>
54 #include <sys/uio.h>
55 
56 #include <rpc/rpc.h>
57 #include <rpc/pmap_clnt.h>
58 #include <rpc/pmap_prot.h>
59 #include <rpcsvc/nfs_prot.h>
60 #include <rpcsvc/mount.h>
61 
62 #include <nfsclient/nfs.h>
63 
64 #include <arpa/inet.h>
65 
66 #include <ctype.h>
67 #include <err.h>
68 #include <errno.h>
69 #include <fcntl.h>
70 #include <netdb.h>
71 #include <stdio.h>
72 #include <stdlib.h>
73 #include <string.h>
74 #include <strings.h>
75 #include <sysexits.h>
76 #include <unistd.h>
77 
78 #include "mntopts.h"
79 #include "mounttab.h"
80 
81 /* Table for af,sotype -> netid conversions. */
82 static struct nc_protos {
83 	const char *netid;
84 	int af;
85 	int sotype;
86 } nc_protos[] = {
87 	{"udp",		AF_INET,	SOCK_DGRAM},
88 	{"tcp",		AF_INET,	SOCK_STREAM},
89 	{"udp6",	AF_INET6,	SOCK_DGRAM},
90 	{"tcp6",	AF_INET6,	SOCK_STREAM},
91 	{NULL,		0,		0}
92 };
93 
94 struct nfhret {
95 	u_long		stat;
96 	long		vers;
97 	long		auth;
98 	long		fhsize;
99 	u_char		nfh[NFS3_FHSIZE];
100 };
101 #define	BGRND	1
102 #define	ISBGRND	2
103 #define	OF_NOINET4	4
104 #define	OF_NOINET6	8
105 static int retrycnt = -1;
106 static int opflags = 0;
107 static int nfsproto = IPPROTO_TCP;
108 static int mnttcp_ok = 1;
109 static int noconn = 0;
110 /* The 'portspec' is the server nfs port; NULL means look up via rpcbind. */
111 static const char *portspec = NULL;
112 static struct sockaddr *addr;
113 static int addrlen = 0;
114 static u_char *fh = NULL;
115 static int fhsize = 0;
116 static int secflavor = -1;
117 static int got_principal = 0;
118 
119 static enum mountmode {
120 	ANY,
121 	V2,
122 	V3,
123 	V4
124 } mountmode = ANY;
125 
126 /* Return codes for nfs_tryproto. */
127 enum tryret {
128 	TRYRET_SUCCESS,
129 	TRYRET_TIMEOUT,		/* No response received. */
130 	TRYRET_REMOTEERR,	/* Error received from remote server. */
131 	TRYRET_LOCALERR		/* Local failure. */
132 };
133 
134 static int	sec_name_to_num(const char *sec);
135 static const char	*sec_num_to_name(int num);
136 static int	getnfsargs(char *, struct iovec **iov, int *iovlen);
137 /* void	set_rpc_maxgrouplist(int); */
138 static struct netconfig *getnetconf_cached(const char *netid);
139 static const char	*netidbytype(int af, int sotype);
140 static void	usage(void) __dead2;
141 static int	xdr_dir(XDR *, char *);
142 static int	xdr_fh(XDR *, struct nfhret *);
143 static enum tryret nfs_tryproto(struct addrinfo *ai, char *hostp, char *spec,
144     char **errstr, struct iovec **iov, int *iovlen);
145 static enum tryret returncode(enum clnt_stat stat, struct rpc_err *rpcerr);
146 
147 int
148 main(int argc, char *argv[])
149 {
150 	int c;
151 	struct iovec *iov;
152 	int num, iovlen;
153 	char *mntname, *p, *spec, *tmp;
154 	char mntpath[MAXPATHLEN], errmsg[255];
155 	char hostname[MAXHOSTNAMELEN + 1], gssn[MAXHOSTNAMELEN + 50];
156 	const char *gssname;
157 
158 	iov = NULL;
159 	iovlen = 0;
160 	memset(errmsg, 0, sizeof(errmsg));
161 	gssname = NULL;
162 
163 	while ((c = getopt(argc, argv,
164 	    "23a:bcdD:g:I:iLlNo:PR:r:sTt:w:x:U")) != -1)
165 		switch (c) {
166 		case '2':
167 			mountmode = V2;
168 			break;
169 		case '3':
170 			mountmode = V3;
171 			break;
172 		case 'a':
173 			printf("-a deprecated, use -o readahead=<value>\n");
174 			build_iovec(&iov, &iovlen, "readahead", optarg, (size_t)-1);
175 			break;
176 		case 'b':
177 			opflags |= BGRND;
178 			break;
179 		case 'c':
180 			printf("-c deprecated, use -o noconn\n");
181 			build_iovec(&iov, &iovlen, "noconn", NULL, 0);
182 			noconn = 1;
183 			break;
184 		case 'D':
185 			printf("-D deprecated, use -o deadthresh=<value>\n");
186 			build_iovec(&iov, &iovlen, "deadthresh", optarg, (size_t)-1);
187 			break;
188 		case 'd':
189 			printf("-d deprecated, use -o dumbtimer");
190 			build_iovec(&iov, &iovlen, "dumbtimer", NULL, 0);
191 			break;
192 		case 'g':
193 			printf("-g deprecated, use -o maxgroups");
194 			num = strtol(optarg, &p, 10);
195 			if (*p || num <= 0)
196 				errx(1, "illegal -g value -- %s", optarg);
197 			//set_rpc_maxgrouplist(num);
198 			build_iovec(&iov, &iovlen, "maxgroups", optarg, (size_t)-1);
199 			break;
200 		case 'I':
201 			printf("-I deprecated, use -o readdirsize=<value>\n");
202 			build_iovec(&iov, &iovlen, "readdirsize", optarg, (size_t)-1);
203 			break;
204 		case 'i':
205 			printf("-i deprecated, use -o intr\n");
206 			build_iovec(&iov, &iovlen, "intr", NULL, 0);
207 			break;
208 		case 'L':
209 			printf("-L deprecated, use -o nolockd\n");
210 			build_iovec(&iov, &iovlen, "nolockd", NULL, 0);
211 			break;
212 		case 'l':
213 			printf("-l deprecated, -o rdirplus\n");
214 			build_iovec(&iov, &iovlen, "rdirplus", NULL, 0);
215 			break;
216 		case 'N':
217 			printf("-N deprecated, do not specify -o resvport\n");
218 			break;
219 		case 'o': {
220 			int pass_flag_to_nmount;
221 			char *opt = optarg;
222 			while (opt) {
223 				char *pval = NULL;
224 				char *pnextopt = NULL;
225 				const char *val = "";
226 				pass_flag_to_nmount = 1;
227 				pnextopt = strchr(opt, ',');
228 				if (pnextopt != NULL) {
229 					*pnextopt = '\0';
230 					pnextopt++;
231 				}
232 				pval = strchr(opt, '=');
233 				if (pval != NULL) {
234 					*pval = '\0';
235 					val = pval + 1;
236 				}
237 				if (strcmp(opt, "bg") == 0) {
238 					opflags |= BGRND;
239 					pass_flag_to_nmount=0;
240 				} else if (strcmp(opt, "fg") == 0) {
241 					/* same as not specifying -o bg */
242 					pass_flag_to_nmount=0;
243 				} else if (strcmp(opt, "gssname") == 0) {
244 					pass_flag_to_nmount = 0;
245 					gssname = val;
246 				} else if (strcmp(opt, "mntudp") == 0) {
247 					mnttcp_ok = 0;
248 					nfsproto = IPPROTO_UDP;
249 				} else if (strcmp(opt, "udp") == 0) {
250 					nfsproto = IPPROTO_UDP;
251 				} else if (strcmp(opt, "tcp") == 0) {
252 					nfsproto = IPPROTO_TCP;
253 				} else if (strcmp(opt, "noinet4") == 0) {
254 					pass_flag_to_nmount=0;
255 					opflags |= OF_NOINET4;
256 				} else if (strcmp(opt, "noinet6") == 0) {
257 					pass_flag_to_nmount=0;
258 					opflags |= OF_NOINET6;
259 				} else if (strcmp(opt, "noconn") == 0) {
260 					noconn = 1;
261 				} else if (strcmp(opt, "nfsv2") == 0) {
262 					pass_flag_to_nmount=0;
263 					mountmode = V2;
264 				} else if (strcmp(opt, "nfsv3") == 0) {
265 					mountmode = V3;
266 				} else if (strcmp(opt, "nfsv4") == 0) {
267 					pass_flag_to_nmount=0;
268 					mountmode = V4;
269 					nfsproto = IPPROTO_TCP;
270 					if (portspec == NULL)
271 						portspec = "2049";
272 				} else if (strcmp(opt, "port") == 0) {
273 					pass_flag_to_nmount=0;
274 					asprintf(&tmp, "%d", atoi(val));
275 					if (tmp == NULL)
276 						err(1, "asprintf");
277 					portspec = tmp;
278 				} else if (strcmp(opt, "principal") == 0) {
279 					got_principal = 1;
280 				} else if (strcmp(opt, "proto") == 0) {
281 					pass_flag_to_nmount=0;
282 					if (strcmp(val, "tcp") == 0) {
283 						nfsproto = IPPROTO_TCP;
284 						opflags |= OF_NOINET6;
285 						build_iovec(&iov, &iovlen,
286 						    "tcp", NULL, 0);
287 					} else if (strcmp(val, "udp") == 0) {
288 						mnttcp_ok = 0;
289 						nfsproto = IPPROTO_UDP;
290 						opflags |= OF_NOINET6;
291 						build_iovec(&iov, &iovlen,
292 						    "udp", NULL, 0);
293 					} else if (strcmp(val, "tcp6") == 0) {
294 						nfsproto = IPPROTO_TCP;
295 						opflags |= OF_NOINET4;
296 						build_iovec(&iov, &iovlen,
297 						    "tcp", NULL, 0);
298 					} else if (strcmp(val, "udp6") == 0) {
299 						mnttcp_ok = 0;
300 						nfsproto = IPPROTO_UDP;
301 						opflags |= OF_NOINET4;
302 						build_iovec(&iov, &iovlen,
303 						    "udp", NULL, 0);
304 					} else {
305 						errx(1,
306 						    "illegal proto value -- %s",
307 						    val);
308 					}
309 				} else if (strcmp(opt, "sec") == 0) {
310 					/*
311 					 * Don't add this option to
312 					 * the iovec yet - we will
313 					 * negotiate which sec flavor
314 					 * to use with the remote
315 					 * mountd.
316 					 */
317 					pass_flag_to_nmount=0;
318 					secflavor = sec_name_to_num(val);
319 					if (secflavor < 0) {
320 						errx(1,
321 						    "illegal sec value -- %s",
322 						    val);
323 					}
324 				} else if (strcmp(opt, "retrycnt") == 0) {
325 					pass_flag_to_nmount=0;
326 					num = strtol(val, &p, 10);
327 					if (*p || num < 0)
328 						errx(1, "illegal retrycnt value -- %s", val);
329 					retrycnt = num;
330 				} else if (strcmp(opt, "maxgroups") == 0) {
331 					num = strtol(val, &p, 10);
332 					if (*p || num <= 0)
333 						errx(1, "illegal maxgroups value -- %s", val);
334 					//set_rpc_maxgrouplist(num);
335 				} else if (strcmp(opt, "vers") == 0) {
336 					num = strtol(val, &p, 10);
337 					if (*p || num <= 0)
338 						errx(1, "illegal vers value -- "
339 						    "%s", val);
340 					switch (num) {
341 					case 2:
342 						mountmode = V2;
343 						break;
344 					case 3:
345 						mountmode = V3;
346 						build_iovec(&iov, &iovlen,
347 						    "nfsv3", NULL, 0);
348 						break;
349 					case 4:
350 						mountmode = V4;
351 						nfsproto = IPPROTO_TCP;
352 						if (portspec == NULL)
353 							portspec = "2049";
354 						break;
355 					default:
356 						errx(1, "illegal nfs version "
357 						    "value -- %s", val);
358 					}
359 					pass_flag_to_nmount=0;
360 				}
361 				if (pass_flag_to_nmount) {
362 					build_iovec(&iov, &iovlen, opt,
363 					    __DECONST(void *, val),
364 					    strlen(val) + 1);
365 				}
366 				opt = pnextopt;
367 			}
368 			}
369 			break;
370 		case 'P':
371 			/* obsolete for -o noresvport now default */
372 			printf("-P deprecated, use -o noresvport\n");
373 			build_iovec(&iov, &iovlen, "noresvport", NULL, 0);
374 			break;
375 		case 'R':
376 			printf("-R deprecated, use -o retrycnt=<retrycnt>\n");
377 			num = strtol(optarg, &p, 10);
378 			if (*p || num < 0)
379 				errx(1, "illegal -R value -- %s", optarg);
380 			retrycnt = num;
381 			break;
382 		case 'r':
383 			printf("-r deprecated, use -o rsize=<rsize>\n");
384 			build_iovec(&iov, &iovlen, "rsize", optarg, (size_t)-1);
385 			break;
386 		case 's':
387 			printf("-s deprecated, use -o soft\n");
388 			build_iovec(&iov, &iovlen, "soft", NULL, 0);
389 			break;
390 		case 'T':
391 			nfsproto = IPPROTO_TCP;
392 			printf("-T deprecated, use -o tcp\n");
393 			break;
394 		case 't':
395 			printf("-t deprecated, use -o timeout=<value>\n");
396 			build_iovec(&iov, &iovlen, "timeout", optarg, (size_t)-1);
397 			break;
398 		case 'w':
399 			printf("-w deprecated, use -o wsize=<value>\n");
400 			build_iovec(&iov, &iovlen, "wsize", optarg, (size_t)-1);
401 			break;
402 		case 'x':
403 			printf("-x deprecated, use -o retrans=<value>\n");
404 			build_iovec(&iov, &iovlen, "retrans", optarg, (size_t)-1);
405 			break;
406 		case 'U':
407 			printf("-U deprecated, use -o mntudp\n");
408 			mnttcp_ok = 0;
409 			nfsproto = IPPROTO_UDP;
410 			build_iovec(&iov, &iovlen, "mntudp", NULL, 0);
411 			break;
412 		default:
413 			usage();
414 			break;
415 		}
416 	argc -= optind;
417 	argv += optind;
418 
419 	if (argc != 2) {
420 		usage();
421 		/* NOTREACHED */
422 	}
423 
424 	spec = *argv++;
425 	mntname = *argv;
426 
427 	if (retrycnt == -1)
428 		/* The default is to keep retrying forever. */
429 		retrycnt = 0;
430 
431 	if (modfind("nfscl") < 0) {
432 		/* Not present in kernel, try loading it */
433 		if (kldload("nfscl") < 0 ||
434 		    modfind("nfscl") < 0)
435 			errx(1, "nfscl is not available");
436 	}
437 
438 	/*
439 	 * Add the fqdn to the gssname, as required.
440 	 */
441 	if (gssname != NULL) {
442 		if (strchr(gssname, '@') == NULL &&
443 		    gethostname(hostname, MAXHOSTNAMELEN) == 0) {
444 			snprintf(gssn, sizeof (gssn), "%s@%s", gssname,
445 			    hostname);
446 			gssname = gssn;
447 		}
448 		build_iovec(&iov, &iovlen, "gssname",
449 		    __DECONST(void *, gssname), strlen(gssname) + 1);
450 	}
451 
452 	if (!getnfsargs(spec, &iov, &iovlen))
453 		exit(1);
454 
455 	/* resolve the mountpoint with realpath(3) */
456 	if (checkpath(mntname, mntpath) != 0)
457 		err(1, "%s", mntpath);
458 
459 	build_iovec_argf(&iov, &iovlen, "fstype", "nfs");
460 	build_iovec(&iov, &iovlen, "fspath", mntpath, (size_t)-1);
461 	build_iovec(&iov, &iovlen, "errmsg", errmsg, sizeof(errmsg));
462 
463 	if (nmount(iov, iovlen, 0))
464 		err(1, "nmount: %s%s%s", mntpath, errmsg[0] ? ", " : "",
465 		    errmsg);
466 
467 	exit(0);
468 }
469 
470 static int
471 sec_name_to_num(const char *sec)
472 {
473 	if (!strcmp(sec, "krb5"))
474 		return (RPCSEC_GSS_KRB5);
475 	if (!strcmp(sec, "krb5i"))
476 		return (RPCSEC_GSS_KRB5I);
477 	if (!strcmp(sec, "krb5p"))
478 		return (RPCSEC_GSS_KRB5P);
479 	if (!strcmp(sec, "sys"))
480 		return (AUTH_SYS);
481 	return (-1);
482 }
483 
484 static const char *
485 sec_num_to_name(int flavor)
486 {
487 	switch (flavor) {
488 	case RPCSEC_GSS_KRB5:
489 		return ("krb5");
490 	case RPCSEC_GSS_KRB5I:
491 		return ("krb5i");
492 	case RPCSEC_GSS_KRB5P:
493 		return ("krb5p");
494 	case AUTH_SYS:
495 		return ("sys");
496 	}
497 	return (NULL);
498 }
499 
500 static int
501 getnfsargs(char *spec, struct iovec **iov, int *iovlen)
502 {
503 	struct addrinfo hints, *ai_nfs, *ai;
504 	enum tryret ret;
505 	int ecode, speclen, remoteerr, offset, have_bracket = 0;
506 	char *hostp, *delimp, *errstr;
507 	size_t len;
508 	static char nam[MNAMELEN + 1], pname[MAXHOSTNAMELEN + 5];
509 
510 	if (*spec == '[' && (delimp = strchr(spec + 1, ']')) != NULL &&
511 	    *(delimp + 1) == ':') {
512 		hostp = spec + 1;
513 		spec = delimp + 2;
514 		have_bracket = 1;
515 	} else if ((delimp = strrchr(spec, ':')) != NULL) {
516 		hostp = spec;
517 		spec = delimp + 1;
518 	} else if ((delimp = strrchr(spec, '@')) != NULL) {
519 		warnx("path@server syntax is deprecated, use server:path");
520 		hostp = delimp + 1;
521 	} else {
522 		warnx("no <host>:<dirpath> nfs-name");
523 		return (0);
524 	}
525 	*delimp = '\0';
526 
527 	/*
528 	 * If there has been a trailing slash at mounttime it seems
529 	 * that some mountd implementations fail to remove the mount
530 	 * entries from their mountlist while unmounting.
531 	 */
532 	for (speclen = strlen(spec);
533 		speclen > 1 && spec[speclen - 1] == '/';
534 		speclen--)
535 		spec[speclen - 1] = '\0';
536 	if (strlen(hostp) + strlen(spec) + 1 > MNAMELEN) {
537 		warnx("%s:%s: %s", hostp, spec, strerror(ENAMETOOLONG));
538 		return (0);
539 	}
540 	/* Make both '@' and ':' notations equal */
541 	if (*hostp != '\0') {
542 		len = strlen(hostp);
543 		offset = 0;
544 		if (have_bracket)
545 			nam[offset++] = '[';
546 		memmove(nam + offset, hostp, len);
547 		if (have_bracket)
548 			nam[len + offset++] = ']';
549 		nam[len + offset++] = ':';
550 		memmove(nam + len + offset, spec, speclen);
551 		nam[len + speclen + offset] = '\0';
552 	}
553 
554 	/*
555 	 * Handle an internet host address.
556 	 */
557 	memset(&hints, 0, sizeof hints);
558 	hints.ai_flags = AI_NUMERICHOST;
559 	if (nfsproto == IPPROTO_TCP)
560 		hints.ai_socktype = SOCK_STREAM;
561 	else if (nfsproto == IPPROTO_UDP)
562 		hints.ai_socktype = SOCK_DGRAM;
563 
564 	if (getaddrinfo(hostp, portspec, &hints, &ai_nfs) != 0) {
565 		hints.ai_flags = AI_CANONNAME;
566 		if ((ecode = getaddrinfo(hostp, portspec, &hints, &ai_nfs))
567 		    != 0) {
568 			if (portspec == NULL)
569 				errx(1, "%s: %s", hostp, gai_strerror(ecode));
570 			else
571 				errx(1, "%s:%s: %s", hostp, portspec,
572 				    gai_strerror(ecode));
573 			return (0);
574 		}
575 
576 		/*
577 		 * For a Kerberized nfs mount where the "principal"
578 		 * argument has not been set, add it here.
579 		 */
580 		if (got_principal == 0 && secflavor != AUTH_SYS &&
581 		    ai_nfs->ai_canonname != NULL) {
582 			snprintf(pname, sizeof (pname), "nfs@%s",
583 			    ai_nfs->ai_canonname);
584 			build_iovec(iov, iovlen, "principal", pname,
585 			    strlen(pname) + 1);
586 		}
587 	}
588 
589 	ret = TRYRET_LOCALERR;
590 	for (;;) {
591 		/*
592 		 * Try each entry returned by getaddrinfo(). Note the
593 		 * occurrence of remote errors by setting `remoteerr'.
594 		 */
595 		remoteerr = 0;
596 		for (ai = ai_nfs; ai != NULL; ai = ai->ai_next) {
597 			if ((ai->ai_family == AF_INET6) &&
598 			    (opflags & OF_NOINET6))
599 				continue;
600 			if ((ai->ai_family == AF_INET) &&
601 			    (opflags & OF_NOINET4))
602 				continue;
603 			ret = nfs_tryproto(ai, hostp, spec, &errstr, iov,
604 			    iovlen);
605 			if (ret == TRYRET_SUCCESS)
606 				break;
607 			if (ret != TRYRET_LOCALERR)
608 				remoteerr = 1;
609 			if ((opflags & ISBGRND) == 0)
610 				fprintf(stderr, "%s\n", errstr);
611 		}
612 		if (ret == TRYRET_SUCCESS)
613 			break;
614 
615 		/* Exit if all errors were local. */
616 		if (!remoteerr)
617 			exit(1);
618 
619 		/*
620 		 * If retrycnt == 0, we are to keep retrying forever.
621 		 * Otherwise decrement it, and exit if it hits zero.
622 		 */
623 		if (retrycnt != 0 && --retrycnt == 0)
624 			exit(1);
625 
626 		if ((opflags & (BGRND | ISBGRND)) == BGRND) {
627 			warnx("Cannot immediately mount %s:%s, backgrounding",
628 			    hostp, spec);
629 			opflags |= ISBGRND;
630 			if (daemon(0, 0) != 0)
631 				err(1, "daemon");
632 		}
633 		sleep(60);
634 	}
635 	freeaddrinfo(ai_nfs);
636 
637 	build_iovec(iov, iovlen, "hostname", nam, (size_t)-1);
638 	/* Add mounted file system to PATH_MOUNTTAB */
639 	if (mountmode != V4 && !add_mtab(hostp, spec))
640 		warnx("can't update %s for %s:%s", PATH_MOUNTTAB, hostp, spec);
641 	return (1);
642 }
643 
644 /*
645  * Try to set up the NFS arguments according to the address
646  * family, protocol (and possibly port) specified in `ai'.
647  *
648  * Returns TRYRET_SUCCESS if successful, or:
649  *   TRYRET_TIMEOUT		The server did not respond.
650  *   TRYRET_REMOTEERR		The server reported an error.
651  *   TRYRET_LOCALERR		Local failure.
652  *
653  * In all error cases, *errstr will be set to a statically-allocated string
654  * describing the error.
655  */
656 static enum tryret
657 nfs_tryproto(struct addrinfo *ai, char *hostp, char *spec, char **errstr,
658     struct iovec **iov, int *iovlen)
659 {
660 	static char errbuf[256];
661 	struct sockaddr_storage nfs_ss;
662 	struct netbuf nfs_nb;
663 	struct nfhret nfhret;
664 	struct timeval try;
665 	struct rpc_err rpcerr;
666 	CLIENT *clp;
667 	struct netconfig *nconf, *nconf_mnt;
668 	const char *netid, *netid_mnt, *secname;
669 	int doconnect, nfsvers, mntvers, sotype;
670 	enum clnt_stat clntstat;
671 	enum mountmode trymntmode;
672 
673 	sotype = 0;
674 	trymntmode = mountmode;
675 	errbuf[0] = '\0';
676 	*errstr = errbuf;
677 
678 	if (nfsproto == IPPROTO_TCP)
679 		sotype = SOCK_STREAM;
680 	else if (nfsproto == IPPROTO_UDP)
681 		sotype = SOCK_DGRAM;
682 
683 	if ((netid = netidbytype(ai->ai_family, sotype)) == NULL) {
684 		snprintf(errbuf, sizeof errbuf,
685 		    "af %d sotype %d not supported", ai->ai_family, sotype);
686 		return (TRYRET_LOCALERR);
687 	}
688 	if ((nconf = getnetconf_cached(netid)) == NULL) {
689 		snprintf(errbuf, sizeof errbuf, "%s: %s", netid, nc_sperror());
690 		return (TRYRET_LOCALERR);
691 	}
692 	/* The RPCPROG_MNT netid may be different. */
693 	if (mnttcp_ok) {
694 		netid_mnt = netid;
695 		nconf_mnt = nconf;
696 	} else {
697 		if ((netid_mnt = netidbytype(ai->ai_family, SOCK_DGRAM))
698 		     == NULL) {
699 			snprintf(errbuf, sizeof errbuf,
700 			    "af %d sotype SOCK_DGRAM not supported",
701 			     ai->ai_family);
702 			return (TRYRET_LOCALERR);
703 		}
704 		if ((nconf_mnt = getnetconf_cached(netid_mnt)) == NULL) {
705 			snprintf(errbuf, sizeof errbuf, "%s: %s", netid_mnt,
706 			    nc_sperror());
707 			return (TRYRET_LOCALERR);
708 		}
709 	}
710 
711 tryagain:
712 	if (trymntmode == V4) {
713 		nfsvers = 4;
714 		mntvers = 3; /* Workaround for GCC. */
715 	} else if (trymntmode == V2) {
716 		nfsvers = 2;
717 		mntvers = 1;
718 	} else {
719 		nfsvers = 3;
720 		mntvers = 3;
721 	}
722 
723 	if (portspec != NULL) {
724 		/* `ai' contains the complete nfsd sockaddr. */
725 		nfs_nb.buf = ai->ai_addr;
726 		nfs_nb.len = nfs_nb.maxlen = ai->ai_addrlen;
727 	} else {
728 		/* Ask the remote rpcbind. */
729 		nfs_nb.buf = &nfs_ss;
730 		nfs_nb.len = nfs_nb.maxlen = sizeof nfs_ss;
731 
732 		if (!rpcb_getaddr(NFS_PROGRAM, nfsvers, nconf, &nfs_nb,
733 		    hostp)) {
734 			if (rpc_createerr.cf_stat == RPC_PROGVERSMISMATCH &&
735 			    trymntmode == ANY) {
736 				trymntmode = V2;
737 				goto tryagain;
738 			}
739 			snprintf(errbuf, sizeof errbuf, "[%s] %s:%s: %s",
740 			    netid, hostp, spec,
741 			    clnt_spcreateerror("RPCPROG_NFS"));
742 			return (returncode(rpc_createerr.cf_stat,
743 			    &rpc_createerr.cf_error));
744 		}
745 	}
746 
747 	/* Check that the server (nfsd) responds on the port we have chosen. */
748 	clp = clnt_tli_create(RPC_ANYFD, nconf, &nfs_nb, NFS_PROGRAM, nfsvers,
749 	    0, 0);
750 	if (clp == NULL) {
751 		snprintf(errbuf, sizeof errbuf, "[%s] %s:%s: %s", netid,
752 		    hostp, spec, clnt_spcreateerror("nfsd: RPCPROG_NFS"));
753 		return (returncode(rpc_createerr.cf_stat,
754 		    &rpc_createerr.cf_error));
755 	}
756 	if (sotype == SOCK_DGRAM && noconn == 0) {
757 		/*
758 		 * Use connect(), to match what the kernel does. This
759 		 * catches cases where the server responds from the
760 		 * wrong source address.
761 		 */
762 		doconnect = 1;
763 		if (!clnt_control(clp, CLSET_CONNECT, (char *)&doconnect)) {
764 			clnt_destroy(clp);
765 			snprintf(errbuf, sizeof errbuf,
766 			    "[%s] %s:%s: CLSET_CONNECT failed", netid, hostp,
767 			    spec);
768 			return (TRYRET_LOCALERR);
769 		}
770 	}
771 
772 	try.tv_sec = 10;
773 	try.tv_usec = 0;
774 	clntstat = clnt_call(clp, NFSPROC_NULL, (xdrproc_t)xdr_void, NULL,
775 			 (xdrproc_t)xdr_void, NULL, try);
776 	if (clntstat != RPC_SUCCESS) {
777 		if (clntstat == RPC_PROGVERSMISMATCH && trymntmode == ANY) {
778 			clnt_destroy(clp);
779 			trymntmode = V2;
780 			goto tryagain;
781 		}
782 		clnt_geterr(clp, &rpcerr);
783 		snprintf(errbuf, sizeof errbuf, "[%s] %s:%s: %s", netid,
784 		    hostp, spec, clnt_sperror(clp, "NFSPROC_NULL"));
785 		clnt_destroy(clp);
786 		return (returncode(clntstat, &rpcerr));
787 	}
788 	clnt_destroy(clp);
789 
790 	/*
791 	 * For NFSv4, there is no mount protocol.
792 	 */
793 	if (trymntmode == V4) {
794 		/*
795 		 * Store the server address in nfsargsp, making
796 		 * sure to copy any locally allocated structures.
797 		 */
798 		addrlen = nfs_nb.len;
799 		addr = malloc(addrlen);
800 		if (addr == NULL)
801 			err(1, "malloc");
802 		bcopy(nfs_nb.buf, addr, addrlen);
803 
804 		build_iovec(iov, iovlen, "addr", addr, addrlen);
805 		secname = sec_num_to_name(secflavor);
806 		if (secname != NULL) {
807 			build_iovec(iov, iovlen, "sec",
808 			    __DECONST(void *, secname), (size_t)-1);
809 		}
810 		build_iovec(iov, iovlen, "nfsv4", NULL, 0);
811 		build_iovec(iov, iovlen, "dirpath", spec, (size_t)-1);
812 
813 		return (TRYRET_SUCCESS);
814 	}
815 
816 	/* Send the MOUNTPROC_MNT RPC to get the root filehandle. */
817 	try.tv_sec = 10;
818 	try.tv_usec = 0;
819 	clp = clnt_tp_create(hostp, MOUNTPROG, mntvers, nconf_mnt);
820 	if (clp == NULL) {
821 		snprintf(errbuf, sizeof errbuf, "[%s] %s:%s: %s", netid_mnt,
822 		    hostp, spec, clnt_spcreateerror("RPCMNT: clnt_create"));
823 		return (returncode(rpc_createerr.cf_stat,
824 		    &rpc_createerr.cf_error));
825 	}
826 	clp->cl_auth = authsys_create_default();
827 	nfhret.auth = secflavor;
828 	nfhret.vers = mntvers;
829 	clntstat = clnt_call(clp, MOUNTPROC_MNT, (xdrproc_t)xdr_dir, spec,
830 			 (xdrproc_t)xdr_fh, &nfhret,
831 	    try);
832 	auth_destroy(clp->cl_auth);
833 	if (clntstat != RPC_SUCCESS) {
834 		if (clntstat == RPC_PROGVERSMISMATCH && trymntmode == ANY) {
835 			clnt_destroy(clp);
836 			trymntmode = V2;
837 			goto tryagain;
838 		}
839 		clnt_geterr(clp, &rpcerr);
840 		snprintf(errbuf, sizeof errbuf, "[%s] %s:%s: %s", netid_mnt,
841 		    hostp, spec, clnt_sperror(clp, "RPCPROG_MNT"));
842 		clnt_destroy(clp);
843 		return (returncode(clntstat, &rpcerr));
844 	}
845 	clnt_destroy(clp);
846 
847 	if (nfhret.stat != 0) {
848 		snprintf(errbuf, sizeof errbuf, "[%s] %s:%s: %s", netid_mnt,
849 		    hostp, spec, strerror(nfhret.stat));
850 		return (TRYRET_REMOTEERR);
851 	}
852 
853 	/*
854 	 * Store the filehandle and server address in nfsargsp, making
855 	 * sure to copy any locally allocated structures.
856 	 */
857 	addrlen = nfs_nb.len;
858 	addr = malloc(addrlen);
859 	fhsize = nfhret.fhsize;
860 	fh = malloc(fhsize);
861 	if (addr == NULL || fh == NULL)
862 		err(1, "malloc");
863 	bcopy(nfs_nb.buf, addr, addrlen);
864 	bcopy(nfhret.nfh, fh, fhsize);
865 
866 	build_iovec(iov, iovlen, "addr", addr, addrlen);
867 	build_iovec(iov, iovlen, "fh", fh, fhsize);
868 	secname = sec_num_to_name(nfhret.auth);
869 	if (secname) {
870 		build_iovec(iov, iovlen, "sec",
871 		    __DECONST(void *, secname), (size_t)-1);
872 	}
873 	if (nfsvers == 3)
874 		build_iovec(iov, iovlen, "nfsv3", NULL, 0);
875 
876 	return (TRYRET_SUCCESS);
877 }
878 
879 /*
880  * Catagorise a RPC return status and error into an `enum tryret'
881  * return code.
882  */
883 static enum tryret
884 returncode(enum clnt_stat clntstat, struct rpc_err *rpcerr)
885 {
886 
887 	switch (clntstat) {
888 	case RPC_TIMEDOUT:
889 		return (TRYRET_TIMEOUT);
890 	case RPC_PMAPFAILURE:
891 	case RPC_PROGNOTREGISTERED:
892 	case RPC_PROGVERSMISMATCH:
893 	/* XXX, these can be local or remote. */
894 	case RPC_CANTSEND:
895 	case RPC_CANTRECV:
896 		return (TRYRET_REMOTEERR);
897 	case RPC_SYSTEMERROR:
898 		switch (rpcerr->re_errno) {
899 		case ETIMEDOUT:
900 			return (TRYRET_TIMEOUT);
901 		case ENOMEM:
902 			break;
903 		default:
904 			return (TRYRET_REMOTEERR);
905 		}
906 		/* FALLTHROUGH */
907 	default:
908 		break;
909 	}
910 	return (TRYRET_LOCALERR);
911 }
912 
913 /*
914  * Look up a netid based on an address family and socket type.
915  * `af' is the address family, and `sotype' is SOCK_DGRAM or SOCK_STREAM.
916  *
917  * XXX there should be a library function for this.
918  */
919 static const char *
920 netidbytype(int af, int sotype)
921 {
922 	struct nc_protos *p;
923 
924 	for (p = nc_protos; p->netid != NULL; p++) {
925 		if (af != p->af || sotype != p->sotype)
926 			continue;
927 		return (p->netid);
928 	}
929 	return (NULL);
930 }
931 
932 /*
933  * Look up a netconfig entry based on a netid, and cache the result so
934  * that we don't need to remember to call freenetconfigent().
935  *
936  * Otherwise it behaves just like getnetconfigent(), so nc_*error()
937  * work on failure.
938  */
939 static struct netconfig *
940 getnetconf_cached(const char *netid)
941 {
942 	static struct nc_entry {
943 		struct netconfig *nconf;
944 		struct nc_entry *next;
945 	} *head;
946 	struct nc_entry *p;
947 	struct netconfig *nconf;
948 
949 	for (p = head; p != NULL; p = p->next)
950 		if (strcmp(netid, p->nconf->nc_netid) == 0)
951 			return (p->nconf);
952 
953 	if ((nconf = getnetconfigent(netid)) == NULL)
954 		return (NULL);
955 	if ((p = malloc(sizeof(*p))) == NULL)
956 		err(1, "malloc");
957 	p->nconf = nconf;
958 	p->next = head;
959 	head = p;
960 
961 	return (p->nconf);
962 }
963 
964 /*
965  * xdr routines for mount rpc's
966  */
967 static int
968 xdr_dir(XDR *xdrsp, char *dirp)
969 {
970 	return (xdr_string(xdrsp, &dirp, MNTPATHLEN));
971 }
972 
973 static int
974 xdr_fh(XDR *xdrsp, struct nfhret *np)
975 {
976 	int i;
977 	long auth, authcnt, authfnd = 0;
978 
979 	if (!xdr_u_long(xdrsp, &np->stat))
980 		return (0);
981 	if (np->stat)
982 		return (1);
983 	switch (np->vers) {
984 	case 1:
985 		np->fhsize = NFS_FHSIZE;
986 		return (xdr_opaque(xdrsp, (caddr_t)np->nfh, NFS_FHSIZE));
987 	case 3:
988 		if (!xdr_long(xdrsp, &np->fhsize))
989 			return (0);
990 		if (np->fhsize <= 0 || np->fhsize > NFS3_FHSIZE)
991 			return (0);
992 		if (!xdr_opaque(xdrsp, (caddr_t)np->nfh, np->fhsize))
993 			return (0);
994 		if (!xdr_long(xdrsp, &authcnt))
995 			return (0);
996 		for (i = 0; i < authcnt; i++) {
997 			if (!xdr_long(xdrsp, &auth))
998 				return (0);
999 			if (np->auth == -1) {
1000 				np->auth = auth;
1001 				authfnd++;
1002 			} else if (auth == np->auth) {
1003 				authfnd++;
1004 			}
1005 		}
1006 		/*
1007 		 * Some servers, such as DEC's OSF/1 return a nil authenticator
1008 		 * list to indicate RPCAUTH_UNIX.
1009 		 */
1010 		if (authcnt == 0 && np->auth == -1)
1011 			np->auth = AUTH_SYS;
1012 		if (!authfnd && (authcnt > 0 || np->auth != AUTH_SYS))
1013 			np->stat = EAUTH;
1014 		return (1);
1015 	}
1016 	return (0);
1017 }
1018 
1019 static void
1020 usage(void)
1021 {
1022 	(void)fprintf(stderr, "%s\n%s\n%s\n%s\n",
1023 "usage: mount_nfs [-23bcdiLlNPsTU] [-a maxreadahead] [-D deadthresh]",
1024 "                 [-g maxgroups] [-I readdirsize] [-o options] [-R retrycnt]",
1025 "                 [-r readsize] [-t timeout] [-w writesize] [-x retrans]",
1026 "                 rhost:path node");
1027 	exit(1);
1028 }
1029