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];
135 if (!nfs_present_sockaddr(sap, salen, address, sizeof(address)))
138 len = snprintf(new_option, sizeof(new_option), "%s=%s",
140 if (len < 0 || (size_t)len >= sizeof(new_option))
143 if (po_append(options, new_option) != PO_SUCCEEDED)
149 nfs_error(_("%s: failed to construct %s option"), progname, keyword);
154 * Append the 'addr=' option to the options string to pass a resolved
155 * server address to the kernel. After a successful mount, this address
156 * is also added to /etc/mtab for use when unmounting.
158 * If 'addr=' is already present, we strip it out. This prevents users
159 * from setting a bogus 'addr=' option themselves, and also allows bg
160 * retries to recompute the server's address, in case it has changed.
162 * Returns 1 if 'addr=' option appended successfully;
165 static int nfs_append_addr_option(const struct sockaddr *sap,
167 struct mount_options *options)
169 po_remove_all(options, "addr");
170 return nfs_append_generic_address_option(sap, salen, "addr", options);
174 * Called to discover our address and append an appropriate 'clientaddr='
175 * option to the options string.
177 * Returns 1 if 'clientaddr=' option created successfully or if
178 * 'clientaddr=' option is already present; otherwise zero.
180 static int nfs_append_clientaddr_option(const struct sockaddr *sap,
182 struct mount_options *options)
184 struct sockaddr_storage dummy;
185 struct sockaddr *my_addr = (struct sockaddr *)&dummy;
186 socklen_t my_len = sizeof(dummy);
188 if (po_contains(options, "clientaddr") == PO_FOUND)
191 nfs_callback_address(sap, salen, my_addr, &my_len);
193 return nfs_append_generic_address_option(my_addr, my_len,
194 "clientaddr", options);
198 * Resolve the 'mounthost=' hostname and append a new option using
199 * the resulting address.
201 static int nfs_fix_mounthost_option(struct mount_options *options)
203 struct sockaddr_storage dummy;
204 struct sockaddr *sap = (struct sockaddr *)&dummy;
205 socklen_t salen = sizeof(dummy);
208 mounthost = po_get(options, "mounthost");
212 if (!nfs_name_to_address(mounthost, sap, &salen)) {
213 nfs_error(_("%s: unable to determine mount server's address"),
218 return nfs_append_generic_address_option(sap, salen,
219 "mountaddr", options);
223 * Returns zero if the "lock" option is in effect, but statd
224 * can't be started. Otherwise, returns 1.
226 static const char *nfs_lock_opttbl[] = {
232 static int nfs_verify_lock_option(struct mount_options *options)
234 if (po_rightmost(options, nfs_lock_opttbl) == 0)
237 if (!start_statd()) {
238 nfs_error(_("%s: rpc.statd is not running but is "
239 "required for remote locking."), progname);
240 nfs_error(_("%s: Either use '-o nolock' to keep "
241 "locks local, or start statd."), progname);
248 static int nfs_append_sloppy_option(struct mount_options *options)
250 if (!sloppy || linux_version_code() < MAKE_VERSION(2, 6, 27))
253 if (po_append(options, "sloppy") == PO_FAILED)
259 * Set up mandatory NFS mount options.
261 * Returns 1 if successful; otherwise zero.
263 static int nfs_validate_options(struct nfsmount_info *mi)
265 struct sockaddr_storage dummy;
266 struct sockaddr *sap = (struct sockaddr *)&dummy;
267 socklen_t salen = sizeof(dummy);
269 if (!nfs_parse_devname(mi->spec, &mi->hostname, NULL))
272 if (!nfs_name_to_address(mi->hostname, sap, &salen))
275 if (strncmp(mi->type, "nfs4", 4) == 0) {
276 if (!nfs_append_clientaddr_option(sap, salen, mi->options))
279 if (!nfs_fix_mounthost_option(mi->options))
281 if (!mi->fake && !nfs_verify_lock_option(mi->options))
285 if (!nfs_append_sloppy_option(mi->options))
288 if (!nfs_append_addr_option(sap, salen, mi->options))
292 * Update option string to be recorded in /etc/mnttab
294 if (po_join(mi->options, mi->extra_opts) == PO_FAILED)
301 * Get NFS/mnt server addresses from mount options
303 * Returns 1 and fills in @nfs_saddr, @nfs_salen, @mnt_saddr, and @mnt_salen
304 * if all goes well; otherwise zero.
306 static int nfs_extract_server_addresses(struct mount_options *options,
307 struct sockaddr *nfs_saddr,
308 socklen_t *nfs_salen,
309 struct sockaddr *mnt_saddr,
310 socklen_t *mnt_salen)
314 option = po_get(options, "addr");
317 if (!nfs_string_to_sockaddr(option, nfs_saddr, nfs_salen))
320 option = po_get(options, "mountaddr");
321 if (option == NULL) {
322 memcpy(mnt_saddr, nfs_saddr, *nfs_salen);
323 *mnt_salen = *nfs_salen;
324 } else if (!nfs_string_to_sockaddr(option, mnt_saddr, mnt_salen))
330 static int nfs_construct_new_options(struct mount_options *options,
331 struct pmap *nfs_pmap,
332 struct pmap *mnt_pmap)
336 po_remove_all(options, "nfsprog");
337 po_remove_all(options, "mountprog");
339 po_remove_all(options, "v2");
340 po_remove_all(options, "v3");
341 po_remove_all(options, "vers");
342 po_remove_all(options, "nfsvers");
343 snprintf(new_option, sizeof(new_option) - 1,
344 "vers=%lu", nfs_pmap->pm_vers);
345 if (po_append(options, new_option) == PO_FAILED)
348 po_remove_all(options, "proto");
349 po_remove_all(options, "udp");
350 po_remove_all(options, "tcp");
351 switch (nfs_pmap->pm_prot) {
353 snprintf(new_option, sizeof(new_option) - 1,
355 if (po_append(options, new_option) == PO_FAILED)
359 snprintf(new_option, sizeof(new_option) - 1,
361 if (po_append(options, new_option) == PO_FAILED)
366 po_remove_all(options, "port");
367 if (nfs_pmap->pm_port != NFS_PORT) {
368 snprintf(new_option, sizeof(new_option) - 1,
369 "port=%lu", nfs_pmap->pm_port);
370 if (po_append(options, new_option) == PO_FAILED)
374 po_remove_all(options, "mountvers");
375 snprintf(new_option, sizeof(new_option) - 1,
376 "mountvers=%lu", mnt_pmap->pm_vers);
377 if (po_append(options, new_option) == PO_FAILED)
380 po_remove_all(options, "mountproto");
381 switch (mnt_pmap->pm_prot) {
383 snprintf(new_option, sizeof(new_option) - 1,
385 if (po_append(options, new_option) == PO_FAILED)
389 snprintf(new_option, sizeof(new_option) - 1,
391 if (po_append(options, new_option) == PO_FAILED)
396 po_remove_all(options, "mountport");
397 snprintf(new_option, sizeof(new_option) - 1,
398 "mountport=%lu", mnt_pmap->pm_port);
399 if (po_append(options, new_option) == PO_FAILED)
406 * Reconstruct the mount option string based on a portmapper probe
407 * of the server. Returns one if the server's portmapper returned
408 * something we can use, otherwise zero.
410 * To handle version and transport protocol fallback properly, we
411 * need to parse some of the mount options in order to set up a
412 * portmap probe. Mount options that nfs_rewrite_pmap_mount_options()
413 * doesn't recognize are left alone.
415 * Returns TRUE if rewriting was successful; otherwise
416 * FALSE is returned if some failure occurred.
419 nfs_rewrite_pmap_mount_options(struct mount_options *options)
421 struct sockaddr_storage nfs_address;
422 struct sockaddr *nfs_saddr = (struct sockaddr *)&nfs_address;
423 socklen_t nfs_salen = sizeof(nfs_address);
424 struct pmap nfs_pmap;
425 struct sockaddr_storage mnt_address;
426 struct sockaddr *mnt_saddr = (struct sockaddr *)&mnt_address;
427 socklen_t mnt_salen = sizeof(mnt_address);
428 struct pmap mnt_pmap;
432 * Skip option negotiation for proto=rdma mounts.
434 option = po_get(options, "proto");
435 if (option && strcmp(option, "rdma") == 0)
439 * Extract just the options needed to contact server.
440 * Bail now if any of these have bad values.
442 if (!nfs_extract_server_addresses(options, nfs_saddr, &nfs_salen,
443 mnt_saddr, &mnt_salen)) {
447 if (!nfs_options2pmap(options, &nfs_pmap, &mnt_pmap)) {
453 * The kernel NFS client doesn't support changing the RPC
454 * program number for these services, so force the value of
455 * these fields before probing the server's ports.
457 nfs_pmap.pm_prog = NFS_PROGRAM;
458 mnt_pmap.pm_prog = MOUNTPROG;
461 * If the server's rpcbind service isn't available, we can't
462 * negotiate. Bail now if we can't contact it.
464 if (!nfs_probe_bothports(mnt_saddr, mnt_salen, &mnt_pmap,
465 nfs_saddr, nfs_salen, &nfs_pmap)) {
470 if (!nfs_construct_new_options(options, &nfs_pmap, &mnt_pmap)) {
481 * Do the mount(2) system call.
483 * Returns TRUE if successful, otherwise FALSE.
484 * "errno" is set to reflect the individual error.
486 static int nfs_try_mount(struct nfsmount_info *mi)
488 char *options = NULL;
491 if (strncmp(mi->type, "nfs4", 4) != 0) {
492 if (!nfs_rewrite_pmap_mount_options(mi->options))
496 if (po_join(mi->options, &options) == PO_FAILED) {
502 printf(_("%s: trying text-based options '%s'\n"),
508 result = mount(mi->spec, mi->node, mi->type,
509 mi->flags & ~(MS_USER|MS_USERS), options);
510 if (verbose && result) {
512 nfs_error(_("%s: mount(2): %s"), progname, strerror(save));
519 * Distinguish between permanent and temporary errors.
521 * Basically, we retry if communication with the server has
522 * failed so far, but fail immediately if there is a local
523 * error (like a bad mount option).
525 * ESTALE is also a temporary error because some servers
526 * return ESTALE when a share is temporarily offline.
528 * Returns 1 if we should fail immediately, or 0 if we
531 static int nfs_is_permanent_error(int error)
537 return 0; /* temporary */
539 return 1; /* permanent */
544 * Handle "foreground" NFS mounts.
546 * Retry the mount request for as long as the 'retry=' option says.
548 * Returns a valid mount command exit code.
550 static int nfsmount_fg(struct nfsmount_info *mi)
552 unsigned int secs = 1;
555 timeout = nfs_parse_retry_option(mi->options,
556 NFS_DEF_FG_TIMEOUT_MINUTES);
558 printf(_("%s: timeout set for %s"),
559 progname, ctime(&timeout));
562 if (nfs_try_mount(mi))
565 if (nfs_is_permanent_error(errno))
568 if (time(NULL) > timeout) {
573 if (errno != ETIMEDOUT) {
582 mount_error(mi->spec, mi->node, errno);
587 * Handle "background" NFS mount [first try]
589 * Returns a valid mount command exit code.
591 * EX_BG should cause the caller to fork and invoke nfsmount_child.
593 static int nfsmount_parent(struct nfsmount_info *mi)
595 if (nfs_try_mount(mi))
598 if (nfs_is_permanent_error(errno)) {
599 mount_error(mi->spec, mi->node, errno);
603 sys_mount_errors(mi->hostname, errno, 1, 1);
608 * Handle "background" NFS mount [retry daemon]
610 * Returns a valid mount command exit code: EX_SUCCESS if successful,
611 * EX_FAIL if a failure occurred. There's nothing to catch the
612 * error return, though, so we use sys_mount_errors to log the
615 static int nfsmount_child(struct nfsmount_info *mi)
617 unsigned int secs = 1;
620 timeout = nfs_parse_retry_option(mi->options,
621 NFS_DEF_BG_TIMEOUT_MINUTES);
630 if (nfs_try_mount(mi))
633 if (nfs_is_permanent_error(errno))
636 if (time(NULL) > timeout)
639 sys_mount_errors(mi->hostname, errno, 1, 1);
642 sys_mount_errors(mi->hostname, errno, 1, 0);
647 * Handle "background" NFS mount
649 * Returns a valid mount command exit code.
651 static int nfsmount_bg(struct nfsmount_info *mi)
654 return nfsmount_parent(mi);
656 return nfsmount_child(mi);
660 * Process mount options and try a mount system call.
662 * Returns a valid mount command exit code.
664 static const char *nfs_background_opttbl[] = {
670 static int nfsmount_start(struct nfsmount_info *mi)
672 if (!nfs_validate_options(mi))
675 if (po_rightmost(mi->options, nfs_background_opttbl) == 0)
676 return nfsmount_bg(mi);
678 return nfsmount_fg(mi);
682 * nfsmount_string - Mount an NFS file system using C string options
683 * @spec: C string specifying remote share to mount ("hostname:path")
684 * @node: C string pathname of local mounted-on directory
685 * @type: C string that represents file system type ("nfs" or "nfs4")
686 * @flags: MS_ style mount flags
687 * @extra_opts: pointer to C string containing fs-specific mount options
688 * (input and output argument)
689 * @fake: flag indicating whether to carry out the whole operation
690 * @child: one if this is a mount daemon (bg)
692 int nfsmount_string(const char *spec, const char *node, const char *type,
693 int flags, char **extra_opts, int fake, int child)
695 struct nfsmount_info mi = {
699 .extra_opts = extra_opts,
704 int retval = EX_FAIL;
706 mi.options = po_split(*extra_opts);
708 retval = nfsmount_start(&mi);
709 po_destroy(mi.options);
711 nfs_error(_("%s: internal option parsing error"), progname);