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.
33 #include <sys/socket.h>
34 #include <sys/mount.h>
35 #include <netinet/in.h>
36 #include <arpa/inet.h>
41 #include "mount_constants.h"
45 #include "parse_opt.h"
47 #include "parse_dev.h"
50 #define NFS_PROGRAM (100003)
54 #define NFS_PORT (2049)
57 #ifndef NFS_MAXHOSTNAME
58 #define NFS_MAXHOSTNAME (255)
61 #ifndef NFS_MAXPATHNAME
62 #define NFS_MAXPATHNAME (1024)
65 #ifndef NFS_DEF_FG_TIMEOUT_MINUTES
66 #define NFS_DEF_FG_TIMEOUT_MINUTES (2u)
69 #ifndef NFS_DEF_BG_TIMEOUT_MINUTES
70 #define NFS_DEF_BG_TIMEOUT_MINUTES (10000u)
73 extern int nfs_mount_data_version;
74 extern char *progname;
78 struct nfsmount_info {
79 const char *spec, /* server:/path */
80 *node, /* mounted-on dir */
81 *type; /* "nfs" or "nfs4" */
82 char *hostname; /* server's hostname */
84 struct mount_options *options; /* parsed mount options */
85 char **extra_opts; /* string for /etc/mtab */
87 int flags, /* MS_ flags */
88 fake, /* actually do the mount? */
89 child; /* forked bg child? */
93 * Obtain a retry timeout value based on the value of the "retry=" option.
95 * Returns a time_t timeout timestamp, in seconds.
97 static time_t nfs_parse_retry_option(struct mount_options *options,
98 unsigned int timeout_minutes)
102 switch (po_get_numeric(options, "retry", &tmp)) {
107 timeout_minutes = tmp;
112 nfs_error(_("%s: invalid retry timeout was specified; "
113 "using default timeout"), progname);
117 return time(NULL) + (time_t)(timeout_minutes * 60);
121 * Convert the passed-in sockaddr-style address to presentation
122 * format, then append an option of the form "keyword=address".
124 * Returns 1 if the option was appended successfully; otherwise zero.
126 static int nfs_append_generic_address_option(const struct sockaddr *sap,
127 const socklen_t salen,
129 struct mount_options *options)
131 char address[NI_MAXHOST];
132 char new_option[512];
134 if (!nfs_present_sockaddr(sap, salen, address, sizeof(address)))
137 if (snprintf(new_option, sizeof(new_option), "%s=%s",
138 keyword, address) >= sizeof(new_option))
141 if (po_append(options, new_option) != PO_SUCCEEDED)
147 nfs_error(_("%s: failed to construct %s option"), progname, keyword);
152 * Append the 'addr=' option to the options string to pass a resolved
153 * server address to the kernel. After a successful mount, this address
154 * is also added to /etc/mtab for use when unmounting.
156 * If 'addr=' is already present, we strip it out. This prevents users
157 * from setting a bogus 'addr=' option themselves, and also allows bg
158 * retries to recompute the server's address, in case it has changed.
160 * Returns 1 if 'addr=' option appended successfully;
163 static int nfs_append_addr_option(const struct sockaddr *sap,
165 struct mount_options *options)
167 po_remove_all(options, "addr");
168 return nfs_append_generic_address_option(sap, salen, "addr", options);
172 * Called to discover our address and append an appropriate 'clientaddr='
173 * option to the options string.
175 * Returns 1 if 'clientaddr=' option created successfully or if
176 * 'clientaddr=' option is already present; otherwise zero.
178 static int nfs_append_clientaddr_option(const struct sockaddr *sap,
180 struct mount_options *options)
182 struct sockaddr_storage dummy;
183 struct sockaddr *my_addr = (struct sockaddr *)&dummy;
184 socklen_t my_len = sizeof(dummy);
186 if (po_contains(options, "clientaddr") == PO_FOUND)
189 nfs_callback_address(sap, salen, my_addr, &my_len);
191 return nfs_append_generic_address_option(my_addr, my_len,
192 "clientaddr", options);
196 * Resolve the 'mounthost=' hostname and append a new option using
197 * the resulting address.
199 static int nfs_fix_mounthost_option(struct mount_options *options)
201 struct sockaddr_storage dummy;
202 struct sockaddr *sap = (struct sockaddr *)&dummy;
203 socklen_t salen = sizeof(dummy);
206 mounthost = po_get(options, "mounthost");
210 if (!nfs_name_to_address(mounthost, sap, &salen)) {
211 nfs_error(_("%s: unable to determine mount server's address"),
216 return nfs_append_generic_address_option(sap, salen,
217 "mountaddr", options);
221 * Returns zero if the "lock" option is in effect, but statd
222 * can't be started. Otherwise, returns 1.
224 static const char *nfs_lock_opttbl[] = {
230 static int nfs_verify_lock_option(struct mount_options *options)
232 if (po_rightmost(options, nfs_lock_opttbl) == 0)
235 if (!start_statd()) {
236 nfs_error(_("%s: rpc.statd is not running but is "
237 "required for remote locking."), progname);
238 nfs_error(_("%s: Either use '-o nolock' to keep "
239 "locks local, or start statd."), progname);
246 static int nfs_append_sloppy_option(struct mount_options *options)
248 if (!sloppy || linux_version_code() < MAKE_VERSION(2, 6, 27))
251 if (po_append(options, "sloppy") == PO_FAILED)
257 * Set up mandatory NFS mount options.
259 * Returns 1 if successful; otherwise zero.
261 static int nfs_validate_options(struct nfsmount_info *mi)
263 struct sockaddr_storage dummy;
264 struct sockaddr *sap = (struct sockaddr *)&dummy;
265 socklen_t salen = sizeof(dummy);
267 if (!nfs_parse_devname(mi->spec, &mi->hostname, NULL))
270 if (!nfs_name_to_address(mi->hostname, sap, &salen))
273 if (strncmp(mi->type, "nfs4", 4) == 0) {
274 if (!nfs_append_clientaddr_option(sap, salen, mi->options))
277 if (!nfs_fix_mounthost_option(mi->options))
279 if (!mi->fake && !nfs_verify_lock_option(mi->options))
283 if (!nfs_append_sloppy_option(mi->options))
286 if (!nfs_append_addr_option(sap, salen, mi->options))
290 * Update option string to be recorded in /etc/mnttab
292 if (po_join(mi->options, mi->extra_opts) == PO_FAILED)
299 * Get NFS/mnt server addresses from mount options
301 * Returns 1 and fills in @nfs_saddr, @nfs_salen, @mnt_saddr, and @mnt_salen
302 * if all goes well; otherwise zero.
304 static int nfs_extract_server_addresses(struct mount_options *options,
305 struct sockaddr *nfs_saddr,
306 socklen_t *nfs_salen,
307 struct sockaddr *mnt_saddr,
308 socklen_t *mnt_salen)
312 option = po_get(options, "addr");
315 if (!nfs_string_to_sockaddr(option, nfs_saddr, nfs_salen))
318 option = po_get(options, "mountaddr");
319 if (option == NULL) {
320 memcpy(mnt_saddr, nfs_saddr, *nfs_salen);
321 *mnt_salen = *nfs_salen;
322 } else if (!nfs_string_to_sockaddr(option, mnt_saddr, mnt_salen))
328 static int nfs_construct_new_options(struct mount_options *options,
329 struct pmap *nfs_pmap,
330 struct pmap *mnt_pmap)
334 po_remove_all(options, "nfsprog");
335 po_remove_all(options, "mountprog");
337 po_remove_all(options, "v2");
338 po_remove_all(options, "v3");
339 po_remove_all(options, "vers");
340 po_remove_all(options, "nfsvers");
341 snprintf(new_option, sizeof(new_option) - 1,
342 "vers=%lu", nfs_pmap->pm_vers);
343 if (po_append(options, new_option) == PO_FAILED)
346 po_remove_all(options, "proto");
347 po_remove_all(options, "udp");
348 po_remove_all(options, "tcp");
349 switch (nfs_pmap->pm_prot) {
351 snprintf(new_option, sizeof(new_option) - 1,
353 if (po_append(options, new_option) == PO_FAILED)
357 snprintf(new_option, sizeof(new_option) - 1,
359 if (po_append(options, new_option) == PO_FAILED)
364 po_remove_all(options, "port");
365 if (nfs_pmap->pm_port != NFS_PORT) {
366 snprintf(new_option, sizeof(new_option) - 1,
367 "port=%lu", nfs_pmap->pm_port);
368 if (po_append(options, new_option) == PO_FAILED)
372 po_remove_all(options, "mountvers");
373 snprintf(new_option, sizeof(new_option) - 1,
374 "mountvers=%lu", mnt_pmap->pm_vers);
375 if (po_append(options, new_option) == PO_FAILED)
378 po_remove_all(options, "mountproto");
379 switch (mnt_pmap->pm_prot) {
381 snprintf(new_option, sizeof(new_option) - 1,
383 if (po_append(options, new_option) == PO_FAILED)
387 snprintf(new_option, sizeof(new_option) - 1,
389 if (po_append(options, new_option) == PO_FAILED)
394 po_remove_all(options, "mountport");
395 snprintf(new_option, sizeof(new_option) - 1,
396 "mountport=%lu", mnt_pmap->pm_port);
397 if (po_append(options, new_option) == PO_FAILED)
404 * Reconstruct the mount option string based on a portmapper probe
405 * of the server. Returns one if the server's portmapper returned
406 * something we can use, otherwise zero.
408 * To handle version and transport protocol fallback properly, we
409 * need to parse some of the mount options in order to set up a
410 * portmap probe. Mount options that nfs_rewrite_pmap_mount_options()
411 * doesn't recognize are left alone.
413 * Returns TRUE if rewriting was successful; otherwise
414 * FALSE is returned if some failure occurred.
417 nfs_rewrite_pmap_mount_options(struct mount_options *options)
419 struct sockaddr_storage nfs_address;
420 struct sockaddr *nfs_saddr = (struct sockaddr *)&nfs_address;
422 struct pmap nfs_pmap;
423 struct sockaddr_storage mnt_address;
424 struct sockaddr *mnt_saddr = (struct sockaddr *)&mnt_address;
426 struct pmap mnt_pmap;
430 * Skip option negotiation for proto=rdma mounts.
432 option = po_get(options, "proto");
433 if (option && strcmp(option, "rdma") == 0)
437 * Extract just the options needed to contact server.
438 * Bail now if any of these have bad values.
440 if (!nfs_extract_server_addresses(options, nfs_saddr, &nfs_salen,
441 mnt_saddr, &mnt_salen)) {
445 if (!nfs_options2pmap(options, &nfs_pmap, &mnt_pmap)) {
451 * The kernel NFS client doesn't support changing the RPC
452 * program number for these services, so force the value of
453 * these fields before probing the server's ports.
455 nfs_pmap.pm_prog = NFS_PROGRAM;
456 mnt_pmap.pm_prog = MOUNTPROG;
459 * If the server's rpcbind service isn't available, we can't
460 * negotiate. Bail now if we can't contact it.
462 if (!nfs_probe_bothports(mnt_saddr, mnt_salen, &mnt_pmap,
463 nfs_saddr, nfs_salen, &nfs_pmap)) {
468 if (!nfs_construct_new_options(options, &nfs_pmap, &mnt_pmap)) {
479 * Do the mount(2) system call.
481 * Returns TRUE if successful, otherwise FALSE.
482 * "errno" is set to reflect the individual error.
484 static int nfs_try_mount(struct nfsmount_info *mi)
486 char *options = NULL;
489 if (strncmp(mi->type, "nfs4", 4) != 0) {
490 if (!nfs_rewrite_pmap_mount_options(mi->options))
494 if (po_join(mi->options, &options) == PO_FAILED) {
500 printf(_("%s: trying text-based options '%s'\n"),
506 result = mount(mi->spec, mi->node, mi->type,
507 mi->flags & ~(MS_USER|MS_USERS), options);
508 if (verbose && result) {
510 nfs_error(_("%s: mount(2): %s"), progname, strerror(save));
517 * Distinguish between permanent and temporary errors.
519 * Basically, we retry if communication with the server has
520 * failed so far, but fail immediately if there is a local
521 * error (like a bad mount option).
523 * ESTALE is also a temporary error because some servers
524 * return ESTALE when a share is temporarily offline.
526 * Returns 1 if we should fail immediately, or 0 if we
529 static int nfs_is_permanent_error(int error)
535 return 0; /* temporary */
537 return 1; /* permanent */
542 * Handle "foreground" NFS mounts.
544 * Retry the mount request for as long as the 'retry=' option says.
546 * Returns a valid mount command exit code.
548 static int nfsmount_fg(struct nfsmount_info *mi)
550 unsigned int secs = 1;
553 timeout = nfs_parse_retry_option(mi->options,
554 NFS_DEF_FG_TIMEOUT_MINUTES);
556 printf(_("%s: timeout set for %s"),
557 progname, ctime(&timeout));
560 if (nfs_try_mount(mi))
563 if (nfs_is_permanent_error(errno))
566 if (time(NULL) > timeout) {
571 if (errno != ETIMEDOUT) {
580 mount_error(mi->spec, mi->node, errno);
585 * Handle "background" NFS mount [first try]
587 * Returns a valid mount command exit code.
589 * EX_BG should cause the caller to fork and invoke nfsmount_child.
591 static int nfsmount_parent(struct nfsmount_info *mi)
593 if (nfs_try_mount(mi))
596 if (nfs_is_permanent_error(errno)) {
597 mount_error(mi->spec, mi->node, errno);
601 sys_mount_errors(mi->hostname, errno, 1, 1);
606 * Handle "background" NFS mount [retry daemon]
608 * Returns a valid mount command exit code: EX_SUCCESS if successful,
609 * EX_FAIL if a failure occurred. There's nothing to catch the
610 * error return, though, so we use sys_mount_errors to log the
613 static int nfsmount_child(struct nfsmount_info *mi)
615 unsigned int secs = 1;
618 timeout = nfs_parse_retry_option(mi->options,
619 NFS_DEF_BG_TIMEOUT_MINUTES);
628 if (nfs_try_mount(mi))
631 if (nfs_is_permanent_error(errno))
634 if (time(NULL) > timeout)
637 sys_mount_errors(mi->hostname, errno, 1, 1);
640 sys_mount_errors(mi->hostname, errno, 1, 0);
645 * Handle "background" NFS mount
647 * Returns a valid mount command exit code.
649 static int nfsmount_bg(struct nfsmount_info *mi)
652 return nfsmount_parent(mi);
654 return nfsmount_child(mi);
658 * Process mount options and try a mount system call.
660 * Returns a valid mount command exit code.
662 static const char *nfs_background_opttbl[] = {
668 static int nfsmount_start(struct nfsmount_info *mi)
670 if (!nfs_validate_options(mi))
673 if (po_rightmost(mi->options, nfs_background_opttbl) == 0)
674 return nfsmount_bg(mi);
676 return nfsmount_fg(mi);
680 * nfsmount_string - Mount an NFS file system using C string options
681 * @spec: C string specifying remote share to mount ("hostname:path")
682 * @node: C string pathname of local mounted-on directory
683 * @type: C string that represents file system type ("nfs" or "nfs4")
684 * @flags: MS_ style mount flags
685 * @extra_opts: pointer to C string containing fs-specific mount options
686 * (input and output argument)
687 * @fake: flag indicating whether to carry out the whole operation
688 * @child: one if this is a mount daemon (bg)
690 int nfsmount_string(const char *spec, const char *node, const char *type,
691 int flags, char **extra_opts, int fake, int child)
693 struct nfsmount_info mi = {
697 .extra_opts = extra_opts,
702 int retval = EX_FAIL;
704 mi.options = po_split(*extra_opts);
706 retval = nfsmount_start(&mi);
707 po_destroy(mi.options);
709 nfs_error(_("%s: internal option parsing error"), progname);