2 * stropts.c -- NFS mount using C string to pass options to kernel
4 * Copyright (C) 2007 Oracle. All rights reserved.
5 * Copyright (C) 2007 Chuck Lever <chuck.lever@oracle.com>
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public
9 * License as published by the Free Software Foundation; either
10 * version 2 of the License, or (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License for more details.
17 * You should have received a copy of the GNU General Public
18 * License along with this program; if not, write to the
19 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
20 * Boston, MA 021110-1307, USA.
36 #include <sys/socket.h>
37 #include <sys/mount.h>
42 #include "nfs_mount.h"
43 #include "mount_constants.h"
47 #include "parse_opt.h"
49 #ifdef HAVE_RPCSVC_NFS_PROT_H
50 #include <rpcsvc/nfs_prot.h>
52 #include <linux/nfs.h>
53 #define nfsstat nfs_stat
60 #ifndef NFS_MAXHOSTNAME
61 #define NFS_MAXHOSTNAME (255)
64 #ifndef NFS_MAXPATHNAME
65 #define NFS_MAXPATHNAME (1024)
68 #ifndef NFS_DEF_FG_TIMEOUT_MINUTES
69 #define NFS_DEF_FG_TIMEOUT_MINUTES (2u)
72 #ifndef NFS_DEF_BG_TIMEOUT_MINUTES
73 #define NFS_DEF_BG_TIMEOUT_MINUTES (10000u)
76 extern int nfs_mount_data_version;
77 extern char *progname;
80 static int parse_devname(const char *spec, char **hostname)
83 char *dev, *pathname, *s;
87 if (!(pathname = strchr(dev, ':'))) {
88 nfs_error(_("%s: remote share not in 'host:dir' format"),
96 * We don't need a copy of the pathname, but let's
97 * sanity check it anyway.
99 if (strlen(pathname) > NFS_MAXPATHNAME) {
100 nfs_error(_("%s: export pathname is too long"),
106 * Ignore all but first hostname in replicated mounts
107 * until they can be fully supported. (mack@sgi.com)
109 if ((s = strchr(dev, ','))) {
111 nfs_error(_("%s: warning: multiple hostnames not supported"),
113 nfs_error(_("%s: ignoring hostnames that follow the first one"),
116 *hostname = xstrdup(dev);
117 if (strlen(*hostname) > NFS_MAXHOSTNAME) {
118 nfs_error(_("%s: server hostname is too long"),
131 static int fill_ipv4_sockaddr(const char *hostname, struct sockaddr_in *addr)
134 addr->sin_family = AF_INET;
136 if (inet_aton(hostname, &addr->sin_addr))
138 if ((hp = gethostbyname(hostname)) == NULL) {
139 nfs_error(_("%s: can't get address for %s\n"),
143 if (hp->h_length > sizeof(struct in_addr)) {
144 nfs_error(_("%s: got bad hp->h_length"), progname);
145 hp->h_length = sizeof(struct in_addr);
147 memcpy(&addr->sin_addr, hp->h_addr, hp->h_length);
152 * Obtain a retry timeout value based on the value of the "retry=" option.
154 * Returns a time_t timeout timestamp, in seconds.
156 static time_t nfs_parse_retry_option(struct mount_options *options,
157 unsigned int timeout_minutes)
159 char *retry_option, *endptr;
161 retry_option = po_get(options, "retry");
166 tmp = strtol(retry_option, &endptr, 10);
167 if (errno == 0 && endptr != retry_option && tmp >= 0)
168 timeout_minutes = tmp;
170 nfs_error(_("%s: invalid retry timeout was specified; "
171 "using default timeout"), progname);
174 return time(NULL) + (time_t)(timeout_minutes * 60);
178 * Append the 'addr=' option to the options string to pass a resolved
179 * server address to the kernel. After a successful mount, this address
180 * is also added to /etc/mtab for use when unmounting.
182 * If 'addr=' is already present, we strip it out. This prevents users
183 * from setting a bogus 'addr=' option themselves, and also allows bg
184 * retries to recompute the server's address, in case it has changed.
186 * Returns 1 if 'addr=' option appended successfully;
189 static int append_addr_option(struct sockaddr_in *saddr,
190 struct mount_options *options)
194 po_remove_all(options, "addr");
196 snprintf(new_option, sizeof(new_option) - 1,
197 "addr=%s", inet_ntoa(saddr->sin_addr));
199 if (po_append(options, new_option) == PO_SUCCEEDED)
205 * Called to discover our address and append an appropriate 'clientaddr='
206 * option to the options string.
208 * Returns 1 if 'clientaddr=' option created successfully or if
209 * 'clientaddr=' option is already present; otherwise zero.
211 static int append_clientaddr_option(struct sockaddr_in *saddr,
212 struct mount_options *options)
214 struct sockaddr_in my_addr;
217 if (po_contains(options, "clientaddr") == PO_SUCCEEDED)
220 if (!get_client_address(saddr, &my_addr))
223 snprintf(new_option, sizeof(new_option) - 1,
224 "clientaddr=%s", inet_ntoa(my_addr.sin_addr));
226 if (po_append(options, new_option) == PO_SUCCEEDED)
232 * Resolve the 'mounthost=' hostname and append a new option using
233 * the resulting IPv4 address.
235 static int fix_mounthost_option(struct mount_options *options)
237 struct sockaddr_in maddr;
238 char *mounthost, new_option[32];
240 mounthost = po_get(options, "mounthost");
244 if (!fill_ipv4_sockaddr(mounthost, &maddr))
247 snprintf(new_option, sizeof(new_option) - 1,
248 "mountaddr=%s", inet_ntoa(maddr.sin_addr));
250 if (po_append(options, new_option) == PO_SUCCEEDED)
256 * Returns zero if the "lock" option is in effect, but statd
257 * can't be started. Otherwise, returns 1.
259 static int verify_lock_option(struct mount_options *options)
261 if (po_rightmost(options, "nolock", "lock") == PO_KEY1_RIGHTMOST)
264 if (!start_statd()) {
265 nfs_error(_("%s: rpc.statd is not running but is "
266 "required for remote locking."), progname);
267 nfs_error(_("%s: Either use '-o nolock' to keep "
268 "locks local, or start statd."), progname);
276 * Set up mandatory mount options.
278 * Returns 1 if successful; otherwise zero.
280 static int validate_options(const char *type,
281 struct sockaddr_in *saddr,
282 struct mount_options *options,
285 if (!append_addr_option(saddr, options))
288 if (strncmp(type, "nfs4", 4) == 0) {
289 if (!append_clientaddr_option(saddr, options))
292 if (!fix_mounthost_option(options))
294 if (!fake && !verify_lock_option(options))
302 * Distinguish between permanent and temporary errors.
304 * Returns 0 if the passed-in error is temporary, thus the
305 * mount system call should be retried; returns one if the
306 * passed-in error is permanent, thus the mount system call
307 * should not be retried.
309 static int is_permanent_error(int error)
315 return 0; /* temporary */
317 return 1; /* permanent */
322 * Reconstruct the mount option string based on a portmapper probe
323 * of the server. Returns one if the server's portmapper returned
324 * something we can use, otherwise zero.
326 * To handle version and transport protocol fallback properly, we
327 * need to parse some of the mount options in order to set up a
328 * portmap probe. Mount options that rewrite_mount_options()
329 * doesn't recognize are left alone.
331 * Returns a new group of mount options if successful; otherwise
332 * NULL is returned if some failure occurred.
334 static struct mount_options *rewrite_mount_options(char *str)
336 struct mount_options *options;
337 char *option, new_option[64];
338 clnt_addr_t mnt_server = { };
339 clnt_addr_t nfs_server = { };
342 options = po_split(str);
346 option = po_get(options, "addr");
348 nfs_server.saddr.sin_family = AF_INET;
349 if (!inet_aton((const char *)option, &nfs_server.saddr.sin_addr))
354 option = po_get(options, "mountaddr");
356 mnt_server.saddr.sin_family = AF_INET;
357 if (!inet_aton((const char *)option, &mnt_server.saddr.sin_addr))
360 memcpy(&mnt_server.saddr, &nfs_server.saddr,
361 sizeof(mnt_server.saddr));
363 option = po_get(options, "mountport");
365 mnt_server.pmap.pm_port = atoi(option);
366 mnt_server.pmap.pm_prog = MOUNTPROG;
367 option = po_get(options, "mountvers");
369 mnt_server.pmap.pm_vers = atoi(option);
371 option = po_get(options, "port");
373 nfs_server.pmap.pm_port = atoi(option);
374 po_remove_all(options, "port");
376 nfs_server.pmap.pm_prog = NFS_PROGRAM;
378 option = po_get(options, "nfsvers");
380 nfs_server.pmap.pm_vers = atoi(option);
381 po_remove_all(options, "nfsvers");
383 option = po_get(options, "vers");
385 nfs_server.pmap.pm_vers = atoi(option);
386 po_remove_all(options, "vers");
388 option = po_get(options, "proto");
390 if (strcmp(option, "tcp") == 0) {
391 nfs_server.pmap.pm_prot = IPPROTO_TCP;
392 po_remove_all(options, "proto");
394 if (strcmp(option, "udp") == 0) {
395 nfs_server.pmap.pm_prot = IPPROTO_UDP;
396 po_remove_all(options, "proto");
399 p = po_rightmost(options, "tcp", "udp");
401 case PO_KEY2_RIGHTMOST:
402 nfs_server.pmap.pm_prot = IPPROTO_UDP;
404 case PO_KEY1_RIGHTMOST:
405 nfs_server.pmap.pm_prot = IPPROTO_TCP;
408 po_remove_all(options, "tcp");
409 po_remove_all(options, "udp");
411 if (!probe_bothports(&mnt_server, &nfs_server)) {
412 rpc_mount_errors("rpcbind", 0, 0);
416 snprintf(new_option, sizeof(new_option) - 1,
417 "nfsvers=%lu", nfs_server.pmap.pm_vers);
418 if (po_append(options, new_option) == PO_FAILED)
421 if (nfs_server.pmap.pm_prot == IPPROTO_TCP)
422 snprintf(new_option, sizeof(new_option) - 1,
425 snprintf(new_option, sizeof(new_option) - 1,
427 if (po_append(options, new_option) == PO_FAILED)
430 if (nfs_server.pmap.pm_port != NFS_PORT) {
431 snprintf(new_option, sizeof(new_option) - 1,
432 "port=%lu", nfs_server.pmap.pm_port);
433 if (po_append(options, new_option) == PO_FAILED)
446 * Retry an NFS mount that failed because the requested service isn't
447 * available on the server.
449 * Returns 1 if successful. Otherwise, returns zero.
450 * "errno" is set to reflect the individual error.
452 * Side effect: If the retry is successful, both 'options' and
453 * 'extra_opts' are updated to reflect the mount options that worked.
454 * If the retry fails, 'options' and 'extra_opts' are left unchanged.
456 static int retry_nfsmount(const char *spec, const char *node,
457 int flags, struct mount_options *options,
458 int fake, char **extra_opts)
460 struct mount_options *retry_options;
461 char *retry_str = NULL;
463 retry_options = rewrite_mount_options(*extra_opts);
464 if (!retry_options) {
469 if (po_join(retry_options, &retry_str) == PO_FAILED) {
470 po_destroy(retry_options);
476 printf(_("%s: text-based options (retry): '%s'\n"),
477 progname, retry_str);
479 if (!mount(spec, node, "nfs",
480 flags & ~(MS_USER|MS_USERS), retry_str)) {
482 *extra_opts = retry_str;
483 po_replace(options, retry_options);
487 po_destroy(retry_options);
493 * Attempt an NFSv2/3 mount via a mount(2) system call. If the kernel
494 * claims the requested service isn't supported on the server, probe
495 * the server to see what's supported, rewrite the mount options,
496 * and retry the request.
498 * Returns 1 if successful. Otherwise, returns zero.
499 * "errno" is set to reflect the individual error.
501 * Side effect: If the retry is successful, both 'options' and
502 * 'extra_opts' are updated to reflect the mount options that worked.
503 * If the retry fails, 'options' and 'extra_opts' are left unchanged.
505 static int try_nfs23mount(const char *spec, const char *node,
506 int flags, struct mount_options *options,
507 int fake, char **extra_opts)
509 if (po_join(options, extra_opts) == PO_FAILED) {
515 printf(_("%s: text-based options: '%s'\n"),
516 progname, *extra_opts);
521 if (!mount(spec, node, "nfs",
522 flags & ~(MS_USER|MS_USERS), *extra_opts))
526 * The kernel returns EOPNOTSUPP if the RPC bind failed,
527 * and EPROTONOSUPPORT if the version isn't supported.
529 if (errno != EOPNOTSUPP && errno != EPROTONOSUPPORT)
532 return retry_nfsmount(spec, node, flags, options, fake, extra_opts);
536 * Attempt an NFS v4 mount via a mount(2) system call.
538 * Returns 1 if successful. Otherwise, returns zero.
539 * "errno" is set to reflect the individual error.
541 static int try_nfs4mount(const char *spec, const char *node,
542 int flags, struct mount_options *options,
543 int fake, char **extra_opts)
545 if (po_join(options, extra_opts) == PO_FAILED) {
551 printf(_("%s: text-based options: '%s'\n"),
552 progname, *extra_opts);
557 if (!mount(spec, node, "nfs4",
558 flags & ~(MS_USER|MS_USERS), *extra_opts))
564 * Try the mount(2) system call.
566 * Returns 1 if successful. Otherwise, returns zero.
567 * "errno" is set to reflect the individual error.
569 static int try_mount(const char *spec, const char *node, const char *type,
570 int flags, struct mount_options *options, int fake,
573 if (strncmp(type, "nfs4", 4) == 0)
574 return try_nfs4mount(spec, node, flags,
575 options, fake, extra_opts);
577 return try_nfs23mount(spec, node, flags,
578 options, fake, extra_opts);
582 * Handle "foreground" NFS mounts.
584 * Retry the mount request for as long as the 'retry=' option says.
586 * Returns a valid mount command exit code.
588 static int nfsmount_fg(const char *spec, const char *node,
589 const char *type, int flags,
590 struct mount_options *options, int fake,
593 unsigned int secs = 1;
596 timeout = nfs_parse_retry_option(options, NFS_DEF_FG_TIMEOUT_MINUTES);
598 printf(_("%s: timeout set for %s"),
599 progname, ctime(&timeout));
602 if (try_mount(spec, node, type, flags,
603 options, fake, extra_opts))
606 if (is_permanent_error(errno))
609 if (time(NULL) > timeout) {
614 if (errno != ETIMEDOUT) {
623 mount_error(spec, node, errno);
628 * Handle "background" NFS mount [first try]
630 * Returns a valid mount command exit code.
632 * EX_BG should cause the caller to fork and invoke nfsmount_child.
634 static int nfsmount_parent(const char *spec, const char *node,
635 const char *type, char *hostname, int flags,
636 struct mount_options *options,
637 int fake, char **extra_opts)
639 if (try_mount(spec, node, type, flags, options,
643 if (is_permanent_error(errno)) {
644 mount_error(spec, node, errno);
648 sys_mount_errors(hostname, errno, 1, 1);
653 * Handle "background" NFS mount [retry daemon]
655 * Returns a valid mount command exit code: EX_SUCCESS if successful,
656 * EX_FAIL if a failure occurred. There's nothing to catch the
657 * error return, though, so we use sys_mount_errors to log the
660 static int nfsmount_child(const char *spec, const char *node,
661 const char *type, char *hostname, int flags,
662 struct mount_options *options,
663 int fake, char **extra_opts)
665 unsigned int secs = 1;
668 timeout = nfs_parse_retry_option(options, NFS_DEF_BG_TIMEOUT_MINUTES);
677 if (try_mount(spec, node, type, flags, options,
681 if (is_permanent_error(errno))
684 if (time(NULL) > timeout)
687 sys_mount_errors(hostname, errno, 1, 1);
690 sys_mount_errors(hostname, errno, 1, 0);
695 * Handle "background" NFS mount
697 * Returns a valid mount command exit code.
699 static int nfsmount_bg(const char *spec, const char *node,
700 const char *type, char *hostname, int flags,
701 struct mount_options *options,
702 int fake, int child, char **extra_opts)
705 return nfsmount_parent(spec, node, type, hostname, flags,
706 options, fake, extra_opts);
708 return nfsmount_child(spec, node, type, hostname, flags,
709 options, fake, extra_opts);
713 * nfsmount_string - Mount an NFS file system using C string options
714 * @spec: C string specifying remote share to mount ("hostname:path")
715 * @node: C string pathname of local mounted-on directory
716 * @type: C string that represents file system type ("nfs" or "nfs4")
717 * @flags: MS_ style mount flags
718 * @extra_opts: pointer to C string containing fs-specific mount options
719 * (input and output argument)
720 * @fake: flag indicating whether to carry out the whole operation
721 * @child: one if this is a mount daemon (bg)
723 int nfsmount_string(const char *spec, const char *node, const char *type,
724 int flags, char **extra_opts, int fake, int child)
726 struct mount_options *options = NULL;
727 struct sockaddr_in saddr;
729 int retval = EX_FAIL;
731 if (!parse_devname(spec, &hostname))
733 if (!fill_ipv4_sockaddr(hostname, &saddr))
736 options = po_split(*extra_opts);
738 nfs_error(_("%s: internal option parsing error"), progname);
742 if (!validate_options(type, &saddr, options, fake))
745 if (po_rightmost(options, "bg", "fg") == PO_KEY1_RIGHTMOST)
746 retval = nfsmount_bg(spec, node, type, hostname, flags,
747 options, fake, child, extra_opts);
749 retval = nfsmount_fg(spec, node, type, flags, options,