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 extern int nfs_mount_data_version;
69 extern char *progname;
72 static int parse_devname(const char *spec, char **hostname)
75 char *dev, *pathname, *s;
79 if (!(pathname = strchr(dev, ':'))) {
80 nfs_error(_("%s: remote share not in 'host:dir' format"),
88 * We don't need a copy of the pathname, but let's
89 * sanity check it anyway.
91 if (strlen(pathname) > NFS_MAXPATHNAME) {
92 nfs_error(_("%s: export pathname is too long"),
98 * Ignore all but first hostname in replicated mounts
99 * until they can be fully supported. (mack@sgi.com)
101 if ((s = strchr(dev, ','))) {
103 nfs_error(_("%s: warning: multiple hostnames not supported"),
105 nfs_error(_("%s: ignoring hostnames that follow the first one"),
108 *hostname = xstrdup(dev);
109 if (strlen(*hostname) > NFS_MAXHOSTNAME) {
110 nfs_error(_("%s: server hostname is too long"),
123 static int fill_ipv4_sockaddr(const char *hostname, struct sockaddr_in *addr)
126 addr->sin_family = AF_INET;
128 if (inet_aton(hostname, &addr->sin_addr))
130 if ((hp = gethostbyname(hostname)) == NULL) {
131 nfs_error(_("%s: can't get address for %s\n"),
135 if (hp->h_length > sizeof(struct in_addr)) {
136 nfs_error(_("%s: got bad hp->h_length"), progname);
137 hp->h_length = sizeof(struct in_addr);
139 memcpy(&addr->sin_addr, hp->h_addr, hp->h_length);
144 * Append the 'addr=' option to the options string to pass a resolved
145 * server address to the kernel. After a successful mount, this address
146 * is also added to /etc/mtab for use when unmounting.
148 * If 'addr=' is already present, we strip it out. This prevents users
149 * from setting a bogus 'addr=' option themselves, and also allows bg
150 * retries to recompute the server's address, in case it has changed.
152 * Returns 1 if 'addr=' option appended successfully;
155 static int append_addr_option(struct sockaddr_in *saddr,
156 struct mount_options *options)
160 po_remove_all(options, "addr");
162 snprintf(new_option, sizeof(new_option) - 1,
163 "addr=%s", inet_ntoa(saddr->sin_addr));
165 if (po_append(options, new_option) == PO_SUCCEEDED)
171 * Called to discover our address and append an appropriate 'clientaddr='
172 * option to the options string.
174 * Returns 1 if 'clientaddr=' option created successfully or if
175 * 'clientaddr=' option is already present; otherwise zero.
177 static int append_clientaddr_option(struct sockaddr_in *saddr,
178 struct mount_options *options)
180 struct sockaddr_in my_addr;
183 if (po_contains(options, "clientaddr") == PO_SUCCEEDED)
186 if (!get_client_address(saddr, &my_addr))
189 snprintf(new_option, sizeof(new_option) - 1,
190 "clientaddr=%s", inet_ntoa(my_addr.sin_addr));
192 if (po_append(options, new_option) == PO_SUCCEEDED)
198 * Resolve the 'mounthost=' hostname and append a new option using
199 * the resulting IPv4 address.
201 static int fix_mounthost_option(struct mount_options *options)
203 struct sockaddr_in maddr;
204 char *mounthost, new_option[32];
206 mounthost = po_get(options, "mounthost");
210 if (!fill_ipv4_sockaddr(mounthost, &maddr))
213 snprintf(new_option, sizeof(new_option) - 1,
214 "mountaddr=%s", inet_ntoa(maddr.sin_addr));
216 if (po_append(options, new_option) == PO_SUCCEEDED)
222 * Returns zero if the "lock" option is in effect, but statd
223 * can't be started. Otherwise, returns 1.
225 static int verify_lock_option(struct mount_options *options)
227 if (po_rightmost(options, "nolock", "lock") == PO_KEY1_RIGHTMOST)
230 if (!start_statd()) {
231 nfs_error(_("%s: rpc.statd is not running but is "
232 "required for remote locking."), progname);
233 nfs_error(_("%s: Either use '-o nolock' to keep "
234 "locks local, or start statd."), progname);
242 * Set up mandatory mount options.
244 * Returns 1 if successful; otherwise zero.
246 static int validate_options(const char *type,
247 struct sockaddr_in *saddr,
248 struct mount_options *options,
251 if (!append_addr_option(saddr, options))
254 if (strncmp(type, "nfs4", 4) == 0) {
255 if (!append_clientaddr_option(saddr, options))
258 if (!fix_mounthost_option(options))
260 if (!fake && !verify_lock_option(options))
268 * Distinguish between permanent and temporary errors.
270 * Returns 0 if the passed-in error is temporary, thus the
271 * mount system call should be retried; returns one if the
272 * passed-in error is permanent, thus the mount system call
273 * should not be retried.
275 static int is_permanent_error(int error)
281 return 0; /* temporary */
283 return 1; /* permanent */
288 * Reconstruct the mount option string based on a portmapper probe
289 * of the server. Returns one if the server's portmapper returned
290 * something we can use, otherwise zero.
292 * To handle version and transport protocol fallback properly, we
293 * need to parse some of the mount options in order to set up a
294 * portmap probe. Mount options that rewrite_mount_options()
295 * doesn't recognize are left alone.
297 * Returns a new group of mount options if successful; otherwise
298 * NULL is returned if some failure occurred.
300 static struct mount_options *rewrite_mount_options(char *str)
302 struct mount_options *options;
303 char *option, new_option[64];
304 clnt_addr_t mnt_server = { };
305 clnt_addr_t nfs_server = { };
308 options = po_split(str);
312 option = po_get(options, "addr");
314 nfs_server.saddr.sin_family = AF_INET;
315 if (!inet_aton((const char *)option, &nfs_server.saddr.sin_addr))
320 option = po_get(options, "mountaddr");
322 mnt_server.saddr.sin_family = AF_INET;
323 if (!inet_aton((const char *)option, &mnt_server.saddr.sin_addr))
326 memcpy(&mnt_server.saddr, &nfs_server.saddr,
327 sizeof(mnt_server.saddr));
329 option = po_get(options, "mountport");
331 mnt_server.pmap.pm_port = atoi(option);
332 mnt_server.pmap.pm_prog = MOUNTPROG;
333 option = po_get(options, "mountvers");
335 mnt_server.pmap.pm_vers = atoi(option);
337 option = po_get(options, "port");
339 nfs_server.pmap.pm_port = atoi(option);
340 po_remove_all(options, "port");
342 nfs_server.pmap.pm_prog = NFS_PROGRAM;
344 option = po_get(options, "nfsvers");
346 nfs_server.pmap.pm_vers = atoi(option);
347 po_remove_all(options, "nfsvers");
349 option = po_get(options, "vers");
351 nfs_server.pmap.pm_vers = atoi(option);
352 po_remove_all(options, "vers");
354 option = po_get(options, "proto");
356 if (strcmp(option, "tcp") == 0) {
357 nfs_server.pmap.pm_prot = IPPROTO_TCP;
358 po_remove_all(options, "proto");
360 if (strcmp(option, "udp") == 0) {
361 nfs_server.pmap.pm_prot = IPPROTO_UDP;
362 po_remove_all(options, "proto");
365 p = po_rightmost(options, "tcp", "udp");
367 case PO_KEY2_RIGHTMOST:
368 nfs_server.pmap.pm_prot = IPPROTO_UDP;
370 case PO_KEY1_RIGHTMOST:
371 nfs_server.pmap.pm_prot = IPPROTO_TCP;
374 po_remove_all(options, "tcp");
375 po_remove_all(options, "udp");
377 if (!probe_bothports(&mnt_server, &nfs_server)) {
378 rpc_mount_errors("rpcbind", 0, 0);
382 snprintf(new_option, sizeof(new_option) - 1,
383 "nfsvers=%lu", nfs_server.pmap.pm_vers);
384 if (po_append(options, new_option) == PO_FAILED)
387 if (nfs_server.pmap.pm_prot == IPPROTO_TCP)
388 snprintf(new_option, sizeof(new_option) - 1,
391 snprintf(new_option, sizeof(new_option) - 1,
393 if (po_append(options, new_option) == PO_FAILED)
396 if (nfs_server.pmap.pm_port != NFS_PORT) {
397 snprintf(new_option, sizeof(new_option) - 1,
398 "port=%lu", nfs_server.pmap.pm_port);
399 if (po_append(options, new_option) == PO_FAILED)
412 * Retry an NFS mount that failed because the requested service isn't
413 * available on the server.
415 * Returns 1 if successful. Otherwise, returns zero.
416 * "errno" is set to reflect the individual error.
418 * Side effect: If the retry is successful, both 'options' and
419 * 'extra_opts' are updated to reflect the mount options that worked.
420 * If the retry fails, 'options' and 'extra_opts' are left unchanged.
422 static int retry_nfsmount(const char *spec, const char *node,
423 int flags, struct mount_options *options,
424 int fake, char **extra_opts)
426 struct mount_options *retry_options;
427 char *retry_str = NULL;
429 retry_options = rewrite_mount_options(*extra_opts);
430 if (!retry_options) {
435 if (po_join(retry_options, &retry_str) == PO_FAILED) {
436 po_destroy(retry_options);
442 printf(_("%s: text-based options (retry): '%s'\n"),
443 progname, retry_str);
445 if (!mount(spec, node, "nfs",
446 flags & ~(MS_USER|MS_USERS), retry_str)) {
448 *extra_opts = retry_str;
449 po_replace(options, retry_options);
453 po_destroy(retry_options);
459 * Attempt an NFSv2/3 mount via a mount(2) system call. If the kernel
460 * claims the requested service isn't supported on the server, probe
461 * the server to see what's supported, rewrite the mount options,
462 * and retry the request.
464 * Returns 1 if successful. Otherwise, returns zero.
465 * "errno" is set to reflect the individual error.
467 * Side effect: If the retry is successful, both 'options' and
468 * 'extra_opts' are updated to reflect the mount options that worked.
469 * If the retry fails, 'options' and 'extra_opts' are left unchanged.
471 static int try_nfs23mount(const char *spec, const char *node,
472 int flags, struct mount_options *options,
473 int fake, char **extra_opts)
475 if (po_join(options, extra_opts) == PO_FAILED) {
481 printf(_("%s: text-based options: '%s'\n"),
482 progname, *extra_opts);
487 if (!mount(spec, node, "nfs",
488 flags & ~(MS_USER|MS_USERS), *extra_opts))
492 * The kernel returns EOPNOTSUPP if the RPC bind failed,
493 * and EPROTONOSUPPORT if the version isn't supported.
495 if (errno != EOPNOTSUPP && errno != EPROTONOSUPPORT)
498 return retry_nfsmount(spec, node, flags, options, fake, extra_opts);
502 * Attempt an NFS v4 mount via a mount(2) system call.
504 * Returns 1 if successful. Otherwise, returns zero.
505 * "errno" is set to reflect the individual error.
507 static int try_nfs4mount(const char *spec, const char *node,
508 int flags, struct mount_options *options,
509 int fake, char **extra_opts)
511 if (po_join(options, extra_opts) == PO_FAILED) {
517 printf(_("%s: text-based options: '%s'\n"),
518 progname, *extra_opts);
523 if (!mount(spec, node, "nfs4",
524 flags & ~(MS_USER|MS_USERS), *extra_opts))
530 * Try the mount(2) system call.
532 * Returns 1 if successful. Otherwise, returns zero.
533 * "errno" is set to reflect the individual error.
535 static int try_mount(const char *spec, const char *node, const char *type,
536 int flags, struct mount_options *options, int fake,
539 if (strncmp(type, "nfs4", 4) == 0)
540 return try_nfs4mount(spec, node, flags,
541 options, fake, extra_opts);
543 return try_nfs23mount(spec, node, flags,
544 options, fake, extra_opts);
548 * Handle "foreground" NFS mounts.
550 * Retry the mount request for as long as the 'retry=' option says.
552 * Returns a valid mount command exit code.
554 static int nfsmount_fg(const char *spec, const char *node,
555 const char *type, int flags,
556 struct mount_options *options, int fake,
559 unsigned int secs = 1;
560 time_t timeout = time(NULL);
563 timeout += 60 * 2; /* default: 2 minutes */
564 retry = po_get(options, "retry");
566 timeout += 60 * atoi(retry);
569 printf(_("%s: timeout set for %s"),
570 progname, ctime(&timeout));
573 if (try_mount(spec, node, type, flags,
574 options, fake, extra_opts))
577 if (is_permanent_error(errno))
580 if (time(NULL) > timeout) {
585 if (errno != ETIMEDOUT) {
594 mount_error(spec, node, errno);
599 * Handle "background" NFS mount [first try]
601 * Returns a valid mount command exit code.
603 * EX_BG should cause the caller to fork and invoke nfsmount_child.
605 static int nfsmount_parent(const char *spec, const char *node,
606 const char *type, char *hostname, int flags,
607 struct mount_options *options,
608 int fake, char **extra_opts)
610 if (try_mount(spec, node, type, flags, options,
614 if (is_permanent_error(errno)) {
615 mount_error(spec, node, errno);
619 sys_mount_errors(hostname, errno, 1, 1);
624 * Handle "background" NFS mount [retry daemon]
626 * Returns a valid mount command exit code: EX_SUCCESS if successful,
627 * EX_FAIL if a failure occurred. There's nothing to catch the
628 * error return, though, so we use sys_mount_errors to log the
631 static int nfsmount_child(const char *spec, const char *node,
632 const char *type, char *hostname, int flags,
633 struct mount_options *options,
634 int fake, char **extra_opts)
636 unsigned int secs = 1;
637 time_t timeout = time(NULL);
640 timeout += 60 * 10000; /* default: 10,000 minutes */
641 retry = po_get(options, "retry");
643 timeout += 60 * atoi(retry);
652 if (try_mount(spec, node, type, flags, options,
656 if (is_permanent_error(errno))
659 if (time(NULL) > timeout)
662 sys_mount_errors(hostname, errno, 1, 1);
665 sys_mount_errors(hostname, errno, 1, 0);
670 * Handle "background" NFS mount
672 * Returns a valid mount command exit code.
674 static int nfsmount_bg(const char *spec, const char *node,
675 const char *type, char *hostname, int flags,
676 struct mount_options *options,
677 int fake, int child, char **extra_opts)
680 return nfsmount_parent(spec, node, type, hostname, flags,
681 options, fake, extra_opts);
683 return nfsmount_child(spec, node, type, hostname, flags,
684 options, fake, extra_opts);
688 * nfsmount_string - Mount an NFS file system using C string options
689 * @spec: C string specifying remote share to mount ("hostname:path")
690 * @node: C string pathname of local mounted-on directory
691 * @type: C string that represents file system type ("nfs" or "nfs4")
692 * @flags: MS_ style mount flags
693 * @extra_opts: pointer to C string containing fs-specific mount options
694 * (input and output argument)
695 * @fake: flag indicating whether to carry out the whole operation
696 * @child: one if this is a mount daemon (bg)
698 int nfsmount_string(const char *spec, const char *node, const char *type,
699 int flags, char **extra_opts, int fake, int child)
701 struct mount_options *options = NULL;
702 struct sockaddr_in saddr;
704 int retval = EX_FAIL;
706 if (!parse_devname(spec, &hostname))
708 if (!fill_ipv4_sockaddr(hostname, &saddr))
711 options = po_split(*extra_opts);
713 nfs_error(_("%s: internal option parsing error"), progname);
717 if (!validate_options(type, &saddr, options, fake))
720 if (po_rightmost(options, "bg", "fg") == PO_KEY1_RIGHTMOST)
721 retval = nfsmount_bg(spec, node, type, hostname, flags,
722 options, fake, child, extra_opts);
724 retval = nfsmount_fg(spec, node, type, flags, options,