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 */
83 struct sockaddr_storage address; /* server's address */
84 socklen_t salen; /* size of server's address */
86 struct mount_options *options; /* parsed mount options */
87 char **extra_opts; /* string for /etc/mtab */
89 unsigned long version; /* NFS version */
90 int flags, /* MS_ flags */
91 fake, /* actually do the mount? */
92 child; /* forked bg child? */
96 * Obtain a retry timeout value based on the value of the "retry=" option.
98 * Returns a time_t timeout timestamp, in seconds.
100 static time_t nfs_parse_retry_option(struct mount_options *options,
101 unsigned int timeout_minutes)
105 switch (po_get_numeric(options, "retry", &tmp)) {
110 timeout_minutes = tmp;
115 nfs_error(_("%s: invalid retry timeout was specified; "
116 "using default timeout"), progname);
120 return time(NULL) + (time_t)(timeout_minutes * 60);
124 * Convert the passed-in sockaddr-style address to presentation
125 * format, then append an option of the form "keyword=address".
127 * Returns 1 if the option was appended successfully; otherwise zero.
129 static int nfs_append_generic_address_option(const struct sockaddr *sap,
130 const socklen_t salen,
132 struct mount_options *options)
134 char address[NI_MAXHOST];
135 char new_option[512];
138 if (!nfs_present_sockaddr(sap, salen, address, sizeof(address)))
141 len = snprintf(new_option, sizeof(new_option), "%s=%s",
143 if (len < 0 || (size_t)len >= sizeof(new_option))
146 if (po_append(options, new_option) != PO_SUCCEEDED)
152 nfs_error(_("%s: failed to construct %s option"), progname, keyword);
157 * Append the 'addr=' option to the options string to pass a resolved
158 * server address to the kernel. After a successful mount, this address
159 * is also added to /etc/mtab for use when unmounting.
161 * If 'addr=' is already present, we strip it out. This prevents users
162 * from setting a bogus 'addr=' option themselves, and also allows bg
163 * retries to recompute the server's address, in case it has changed.
165 * Returns 1 if 'addr=' option appended successfully;
168 static int nfs_append_addr_option(const struct sockaddr *sap,
170 struct mount_options *options)
172 po_remove_all(options, "addr");
173 return nfs_append_generic_address_option(sap, salen, "addr", options);
177 * Called to discover our address and append an appropriate 'clientaddr='
178 * option to the options string.
180 * Returns 1 if 'clientaddr=' option created successfully or if
181 * 'clientaddr=' option is already present; otherwise zero.
183 static int nfs_append_clientaddr_option(const struct sockaddr *sap,
185 struct mount_options *options)
187 struct sockaddr_storage dummy;
188 struct sockaddr *my_addr = (struct sockaddr *)&dummy;
189 socklen_t my_len = sizeof(dummy);
191 if (po_contains(options, "clientaddr") == PO_FOUND)
194 nfs_callback_address(sap, salen, my_addr, &my_len);
196 return nfs_append_generic_address_option(my_addr, my_len,
197 "clientaddr", options);
201 * Resolve the 'mounthost=' hostname and append a new option using
202 * the resulting address.
204 static int nfs_fix_mounthost_option(struct mount_options *options)
206 struct sockaddr_storage dummy;
207 struct sockaddr *sap = (struct sockaddr *)&dummy;
208 socklen_t salen = sizeof(dummy);
211 mounthost = po_get(options, "mounthost");
215 if (!nfs_name_to_address(mounthost, sap, &salen)) {
216 nfs_error(_("%s: unable to determine mount server's address"),
221 return nfs_append_generic_address_option(sap, salen,
222 "mountaddr", options);
226 * Returns zero if the "lock" option is in effect, but statd
227 * can't be started. Otherwise, returns 1.
229 static const char *nfs_lock_opttbl[] = {
235 static int nfs_verify_lock_option(struct mount_options *options)
237 if (po_rightmost(options, nfs_lock_opttbl) == 0)
240 if (!start_statd()) {
241 nfs_error(_("%s: rpc.statd is not running but is "
242 "required for remote locking."), progname);
243 nfs_error(_("%s: Either use '-o nolock' to keep "
244 "locks local, or start statd."), progname);
251 static int nfs_append_sloppy_option(struct mount_options *options)
253 if (!sloppy || linux_version_code() < MAKE_VERSION(2, 6, 27))
256 if (po_append(options, "sloppy") == PO_FAILED)
262 * Set up mandatory non-version specific NFS mount options.
264 * Returns 1 if successful; otherwise zero.
266 static int nfs_validate_options(struct nfsmount_info *mi)
268 struct sockaddr *sap = (struct sockaddr *)&mi->address;
270 if (!nfs_parse_devname(mi->spec, &mi->hostname, NULL))
273 mi->salen = sizeof(mi->address);
274 if (!nfs_name_to_address(mi->hostname, sap, &mi->salen))
277 if (!nfs_nfs_version(mi->options, &mi->version))
279 if (strncmp(mi->type, "nfs4", 4) == 0)
282 if (!nfs_append_sloppy_option(mi->options))
285 if (!nfs_append_addr_option(sap, mi->salen, mi->options))
292 * Get NFS/mnt server addresses from mount options
294 * Returns 1 and fills in @nfs_saddr, @nfs_salen, @mnt_saddr, and @mnt_salen
295 * if all goes well; otherwise zero.
297 static int nfs_extract_server_addresses(struct mount_options *options,
298 struct sockaddr *nfs_saddr,
299 socklen_t *nfs_salen,
300 struct sockaddr *mnt_saddr,
301 socklen_t *mnt_salen)
305 option = po_get(options, "addr");
308 if (!nfs_string_to_sockaddr(option, nfs_saddr, nfs_salen))
311 option = po_get(options, "mountaddr");
312 if (option == NULL) {
313 memcpy(mnt_saddr, nfs_saddr, *nfs_salen);
314 *mnt_salen = *nfs_salen;
315 } else if (!nfs_string_to_sockaddr(option, mnt_saddr, mnt_salen))
321 static int nfs_construct_new_options(struct mount_options *options,
322 struct pmap *nfs_pmap,
323 struct pmap *mnt_pmap)
327 po_remove_all(options, "nfsprog");
328 po_remove_all(options, "mountprog");
330 po_remove_all(options, "v2");
331 po_remove_all(options, "v3");
332 po_remove_all(options, "vers");
333 po_remove_all(options, "nfsvers");
334 snprintf(new_option, sizeof(new_option) - 1,
335 "vers=%lu", nfs_pmap->pm_vers);
336 if (po_append(options, new_option) == PO_FAILED)
339 po_remove_all(options, "proto");
340 po_remove_all(options, "udp");
341 po_remove_all(options, "tcp");
342 switch (nfs_pmap->pm_prot) {
344 snprintf(new_option, sizeof(new_option) - 1,
346 if (po_append(options, new_option) == PO_FAILED)
350 snprintf(new_option, sizeof(new_option) - 1,
352 if (po_append(options, new_option) == PO_FAILED)
357 po_remove_all(options, "port");
358 if (nfs_pmap->pm_port != NFS_PORT) {
359 snprintf(new_option, sizeof(new_option) - 1,
360 "port=%lu", nfs_pmap->pm_port);
361 if (po_append(options, new_option) == PO_FAILED)
365 po_remove_all(options, "mountvers");
366 snprintf(new_option, sizeof(new_option) - 1,
367 "mountvers=%lu", mnt_pmap->pm_vers);
368 if (po_append(options, new_option) == PO_FAILED)
371 po_remove_all(options, "mountproto");
372 switch (mnt_pmap->pm_prot) {
374 snprintf(new_option, sizeof(new_option) - 1,
376 if (po_append(options, new_option) == PO_FAILED)
380 snprintf(new_option, sizeof(new_option) - 1,
382 if (po_append(options, new_option) == PO_FAILED)
387 po_remove_all(options, "mountport");
388 snprintf(new_option, sizeof(new_option) - 1,
389 "mountport=%lu", mnt_pmap->pm_port);
390 if (po_append(options, new_option) == PO_FAILED)
397 * Reconstruct the mount option string based on a portmapper probe
398 * of the server. Returns one if the server's portmapper returned
399 * something we can use, otherwise zero.
401 * To handle version and transport protocol fallback properly, we
402 * need to parse some of the mount options in order to set up a
403 * portmap probe. Mount options that nfs_rewrite_pmap_mount_options()
404 * doesn't recognize are left alone.
406 * Returns TRUE if rewriting was successful; otherwise
407 * FALSE is returned if some failure occurred.
410 nfs_rewrite_pmap_mount_options(struct mount_options *options)
412 struct sockaddr_storage nfs_address;
413 struct sockaddr *nfs_saddr = (struct sockaddr *)&nfs_address;
414 socklen_t nfs_salen = sizeof(nfs_address);
415 struct pmap nfs_pmap;
416 struct sockaddr_storage mnt_address;
417 struct sockaddr *mnt_saddr = (struct sockaddr *)&mnt_address;
418 socklen_t mnt_salen = sizeof(mnt_address);
419 struct pmap mnt_pmap;
423 * Skip option negotiation for proto=rdma mounts.
425 option = po_get(options, "proto");
426 if (option && strcmp(option, "rdma") == 0)
430 * Extract just the options needed to contact server.
431 * Bail now if any of these have bad values.
433 if (!nfs_extract_server_addresses(options, nfs_saddr, &nfs_salen,
434 mnt_saddr, &mnt_salen)) {
438 if (!nfs_options2pmap(options, &nfs_pmap, &mnt_pmap)) {
444 * The kernel NFS client doesn't support changing the RPC
445 * program number for these services, so force the value of
446 * these fields before probing the server's ports.
448 nfs_pmap.pm_prog = NFS_PROGRAM;
449 mnt_pmap.pm_prog = MOUNTPROG;
452 * If the server's rpcbind service isn't available, we can't
453 * negotiate. Bail now if we can't contact it.
455 if (!nfs_probe_bothports(mnt_saddr, mnt_salen, &mnt_pmap,
456 nfs_saddr, nfs_salen, &nfs_pmap)) {
461 if (!nfs_construct_new_options(options, &nfs_pmap, &mnt_pmap)) {
472 * Do the mount(2) system call.
474 * Returns TRUE if successful, otherwise FALSE.
475 * "errno" is set to reflect the individual error.
477 static int nfs_sys_mount(struct nfsmount_info *mi, struct mount_options *opts)
479 char *options = NULL;
482 if (po_join(opts, &options) == PO_FAILED) {
488 printf(_("%s: trying text-based options '%s'\n"),
494 result = mount(mi->spec, mi->node, mi->type,
495 mi->flags & ~(MS_USER|MS_USERS), options);
496 if (verbose && result) {
498 nfs_error(_("%s: mount(2): %s"), progname, strerror(save));
505 * For "-t nfs vers=2" or "-t nfs vers=3" mounts.
507 static int nfs_try_mount_v3v2(struct nfsmount_info *mi)
509 struct mount_options *options = po_dup(mi->options);
517 if (!nfs_fix_mounthost_option(options)) {
521 if (!mi->fake && !nfs_verify_lock_option(options)) {
527 * Options we negotiate below may be stale by the time this
528 * file system is unmounted. In order to force umount.nfs
529 * to renegotiate with the server, only write the user-
530 * specified options, and not negotiated options, to /etc/mtab.
532 if (po_join(options, mi->extra_opts) == PO_FAILED) {
537 if (!nfs_rewrite_pmap_mount_options(options))
540 result = nfs_sys_mount(mi, options);
548 * For "-t nfs -o vers=4" or "-t nfs4" mounts.
550 static int nfs_try_mount_v4(struct nfsmount_info *mi)
552 struct sockaddr *sap = (struct sockaddr *)&mi->address;
553 struct mount_options *options = po_dup(mi->options);
561 if (!nfs_append_clientaddr_option(sap, mi->salen, options)) {
567 * Update option string to be recorded in /etc/mtab.
569 if (po_join(options, mi->extra_opts) == PO_FAILED) {
574 result = nfs_sys_mount(mi, options);
582 * This is a single pass through the fg/bg loop.
584 * Returns TRUE if successful, otherwise FALSE.
585 * "errno" is set to reflect the individual error.
587 static int nfs_try_mount(struct nfsmount_info *mi)
591 switch (mi->version) {
595 result = nfs_try_mount_v3v2(mi);
598 result = nfs_try_mount_v4(mi);
608 * Distinguish between permanent and temporary errors.
610 * Basically, we retry if communication with the server has
611 * failed so far, but fail immediately if there is a local
612 * error (like a bad mount option).
614 * ESTALE is also a temporary error because some servers
615 * return ESTALE when a share is temporarily offline.
617 * Returns 1 if we should fail immediately, or 0 if we
620 static int nfs_is_permanent_error(int error)
626 return 0; /* temporary */
628 return 1; /* permanent */
633 * Handle "foreground" NFS mounts.
635 * Retry the mount request for as long as the 'retry=' option says.
637 * Returns a valid mount command exit code.
639 static int nfsmount_fg(struct nfsmount_info *mi)
641 unsigned int secs = 1;
644 timeout = nfs_parse_retry_option(mi->options,
645 NFS_DEF_FG_TIMEOUT_MINUTES);
647 printf(_("%s: timeout set for %s"),
648 progname, ctime(&timeout));
651 if (nfs_try_mount(mi))
654 if (nfs_is_permanent_error(errno))
657 if (time(NULL) > timeout) {
662 if (errno != ETIMEDOUT) {
671 mount_error(mi->spec, mi->node, errno);
676 * Handle "background" NFS mount [first try]
678 * Returns a valid mount command exit code.
680 * EX_BG should cause the caller to fork and invoke nfsmount_child.
682 static int nfsmount_parent(struct nfsmount_info *mi)
684 if (nfs_try_mount(mi))
687 if (nfs_is_permanent_error(errno)) {
688 mount_error(mi->spec, mi->node, errno);
692 sys_mount_errors(mi->hostname, errno, 1, 1);
697 * Handle "background" NFS mount [retry daemon]
699 * Returns a valid mount command exit code: EX_SUCCESS if successful,
700 * EX_FAIL if a failure occurred. There's nothing to catch the
701 * error return, though, so we use sys_mount_errors to log the
704 static int nfsmount_child(struct nfsmount_info *mi)
706 unsigned int secs = 1;
709 timeout = nfs_parse_retry_option(mi->options,
710 NFS_DEF_BG_TIMEOUT_MINUTES);
719 if (nfs_try_mount(mi))
722 if (nfs_is_permanent_error(errno))
725 if (time(NULL) > timeout)
728 sys_mount_errors(mi->hostname, errno, 1, 1);
731 sys_mount_errors(mi->hostname, errno, 1, 0);
736 * Handle "background" NFS mount
738 * Returns a valid mount command exit code.
740 static int nfsmount_bg(struct nfsmount_info *mi)
743 return nfsmount_parent(mi);
745 return nfsmount_child(mi);
749 * Process mount options and try a mount system call.
751 * Returns a valid mount command exit code.
753 static const char *nfs_background_opttbl[] = {
759 static int nfsmount_start(struct nfsmount_info *mi)
761 if (!nfs_validate_options(mi))
764 if (po_rightmost(mi->options, nfs_background_opttbl) == 0)
765 return nfsmount_bg(mi);
767 return nfsmount_fg(mi);
771 * nfsmount_string - Mount an NFS file system using C string options
772 * @spec: C string specifying remote share to mount ("hostname:path")
773 * @node: C string pathname of local mounted-on directory
774 * @type: C string that represents file system type ("nfs" or "nfs4")
775 * @flags: MS_ style mount flags
776 * @extra_opts: pointer to C string containing fs-specific mount options
777 * (input and output argument)
778 * @fake: flag indicating whether to carry out the whole operation
779 * @child: one if this is a mount daemon (bg)
781 int nfsmount_string(const char *spec, const char *node, const char *type,
782 int flags, char **extra_opts, int fake, int child)
784 struct nfsmount_info mi = {
788 .extra_opts = extra_opts,
793 int retval = EX_FAIL;
795 mi.options = po_split(*extra_opts);
797 retval = nfsmount_start(&mi);
798 po_destroy(mi.options);
800 nfs_error(_("%s: internal option parsing error"), progname);