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 return nfs_append_addr_option(sap, salen, mi->options);
290 * Get NFS/mnt server addresses from mount options
292 * Returns 1 and fills in @nfs_saddr, @nfs_salen, @mnt_saddr, and @mnt_salen
293 * if all goes well; otherwise zero.
295 static int nfs_extract_server_addresses(struct mount_options *options,
296 struct sockaddr *nfs_saddr,
297 socklen_t *nfs_salen,
298 struct sockaddr *mnt_saddr,
299 socklen_t *mnt_salen)
303 option = po_get(options, "addr");
306 if (!nfs_string_to_sockaddr(option, strlen(option),
307 nfs_saddr, nfs_salen))
310 option = po_get(options, "mountaddr");
311 if (option == NULL) {
312 memcpy(mnt_saddr, nfs_saddr, *nfs_salen);
313 *mnt_salen = *nfs_salen;
314 } else if (!nfs_string_to_sockaddr(option, strlen(option),
315 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_mount_options()
404 * doesn't recognize are left alone.
406 * Returns a new group of mount options if successful; otherwise
407 * NULL is returned if some failure occurred.
409 static struct mount_options *nfs_rewrite_mount_options(char *str)
411 struct mount_options *options;
412 struct sockaddr_storage nfs_address;
413 struct sockaddr *nfs_saddr = (struct sockaddr *)&nfs_address;
415 struct pmap nfs_pmap;
416 struct sockaddr_storage mnt_address;
417 struct sockaddr *mnt_saddr = (struct sockaddr *)&mnt_address;
419 struct pmap mnt_pmap;
422 options = po_split(str);
429 * Skip option negotiation for proto=rdma mounts.
431 option = po_get(options, "proto");
432 if (option && strcmp(option, "rdma") == 0)
436 * Extract just the options needed to contact server.
437 * Bail now if any of these have bad values.
439 if (!nfs_extract_server_addresses(options, nfs_saddr, &nfs_salen,
440 mnt_saddr, &mnt_salen)) {
444 if (!nfs_options2pmap(options, &nfs_pmap, &mnt_pmap)) {
450 * The kernel NFS client doesn't support changing the RPC
451 * program number for these services, so force the value of
452 * these fields before probing the server's ports.
454 nfs_pmap.pm_prog = NFS_PROGRAM;
455 mnt_pmap.pm_prog = MOUNTPROG;
458 * If the server's rpcbind service isn't available, we can't
459 * negotiate. Bail now if we can't contact it.
461 if (!nfs_probe_bothports(mnt_saddr, mnt_salen, &mnt_pmap,
462 nfs_saddr, nfs_salen, &nfs_pmap)) {
467 if (!nfs_construct_new_options(options, &nfs_pmap, &mnt_pmap)) {
482 * Do the mount(2) system call.
484 * Returns 1 if successful, otherwise zero.
485 * "errno" is set to reflect the individual error.
487 static int nfs_sys_mount(const struct nfsmount_info *mi, const char *type,
492 result = mount(mi->spec, mi->node, type,
493 mi->flags & ~(MS_USER|MS_USERS), options);
494 if (verbose && result) {
496 nfs_error(_("%s: mount(2): %s"), progname, strerror(save));
503 * Retry an NFS mount that failed because the requested service isn't
504 * available on the server.
506 * Returns 1 if successful. Otherwise, returns zero.
507 * "errno" is set to reflect the individual error.
509 * Side effect: If the retry is successful, both 'options' and
510 * 'extra_opts' are updated to reflect the mount options that worked.
511 * If the retry fails, 'options' and 'extra_opts' are left unchanged.
513 static int nfs_retry_nfs23mount(struct nfsmount_info *mi)
515 struct mount_options *retry_options;
516 char *retry_str = NULL;
517 char **extra_opts = mi->extra_opts;
519 retry_options = nfs_rewrite_mount_options(*extra_opts);
523 if (po_join(retry_options, &retry_str) == PO_FAILED) {
524 po_destroy(retry_options);
530 printf(_("%s: text-based options (retry): '%s'\n"),
531 progname, retry_str);
536 if (!nfs_sys_mount(mi, "nfs", retry_str)) {
537 po_destroy(retry_options);
543 *extra_opts = retry_str;
544 po_replace(mi->options, retry_options);
549 * Attempt an NFSv2/3 mount via a mount(2) system call. If the kernel
550 * claims the requested service isn't supported on the server, probe
551 * the server to see what's supported, rewrite the mount options,
552 * and retry the request.
554 * Returns 1 if successful. Otherwise, returns zero.
555 * "errno" is set to reflect the individual error.
557 * Side effect: If the retry is successful, both 'options' and
558 * 'extra_opts' are updated to reflect the mount options that worked.
559 * If the retry fails, 'options' and 'extra_opts' are left unchanged.
561 static int nfs_try_nfs23mount(struct nfsmount_info *mi)
563 char **extra_opts = mi->extra_opts;
565 if (po_join(mi->options, extra_opts) == PO_FAILED) {
571 printf(_("%s: text-based options: '%s'\n"),
572 progname, *extra_opts);
574 return nfs_retry_nfs23mount(mi);
578 * Attempt an NFS v4 mount via a mount(2) system call.
580 * Returns 1 if successful. Otherwise, returns zero.
581 * "errno" is set to reflect the individual error.
583 static int nfs_try_nfs4mount(struct nfsmount_info *mi)
585 char **extra_opts = mi->extra_opts;
587 if (po_join(mi->options, extra_opts) == PO_FAILED) {
593 printf(_("%s: text-based options: '%s'\n"),
594 progname, *extra_opts);
599 return nfs_sys_mount(mi, "nfs4", *extra_opts);
603 * Perform either an NFSv2/3 mount, or an NFSv4 mount system call.
605 * Returns 1 if successful. Otherwise, returns zero.
606 * "errno" is set to reflect the individual error.
608 static int nfs_try_mount(struct nfsmount_info *mi)
610 if (strncmp(mi->type, "nfs4", 4) == 0)
611 return nfs_try_nfs4mount(mi);
613 return nfs_try_nfs23mount(mi);
617 * Distinguish between permanent and temporary errors.
619 * Basically, we retry if communication with the server has
620 * failed so far, but fail immediately if there is a local
621 * error (like a bad mount option).
623 * ESTALE is also a temporary error because some servers
624 * return ESTALE when a share is temporarily offline.
626 * Returns 1 if we should fail immediately, or 0 if we
629 static int nfs_is_permanent_error(int error)
635 return 0; /* temporary */
637 return 1; /* permanent */
642 * Handle "foreground" NFS mounts.
644 * Retry the mount request for as long as the 'retry=' option says.
646 * Returns a valid mount command exit code.
648 static int nfsmount_fg(struct nfsmount_info *mi)
650 unsigned int secs = 1;
653 timeout = nfs_parse_retry_option(mi->options,
654 NFS_DEF_FG_TIMEOUT_MINUTES);
656 printf(_("%s: timeout set for %s"),
657 progname, ctime(&timeout));
660 if (nfs_try_mount(mi))
663 if (nfs_is_permanent_error(errno))
666 if (time(NULL) > timeout) {
671 if (errno != ETIMEDOUT) {
680 mount_error(mi->spec, mi->node, errno);
685 * Handle "background" NFS mount [first try]
687 * Returns a valid mount command exit code.
689 * EX_BG should cause the caller to fork and invoke nfsmount_child.
691 static int nfsmount_parent(struct nfsmount_info *mi)
693 if (nfs_try_mount(mi))
696 if (nfs_is_permanent_error(errno)) {
697 mount_error(mi->spec, mi->node, errno);
701 sys_mount_errors(mi->hostname, errno, 1, 1);
706 * Handle "background" NFS mount [retry daemon]
708 * Returns a valid mount command exit code: EX_SUCCESS if successful,
709 * EX_FAIL if a failure occurred. There's nothing to catch the
710 * error return, though, so we use sys_mount_errors to log the
713 static int nfsmount_child(struct nfsmount_info *mi)
715 unsigned int secs = 1;
718 timeout = nfs_parse_retry_option(mi->options,
719 NFS_DEF_BG_TIMEOUT_MINUTES);
728 if (nfs_try_mount(mi))
731 if (nfs_is_permanent_error(errno))
734 if (time(NULL) > timeout)
737 sys_mount_errors(mi->hostname, errno, 1, 1);
740 sys_mount_errors(mi->hostname, errno, 1, 0);
745 * Handle "background" NFS mount
747 * Returns a valid mount command exit code.
749 static int nfsmount_bg(struct nfsmount_info *mi)
752 return nfsmount_parent(mi);
754 return nfsmount_child(mi);
758 * Process mount options and try a mount system call.
760 * Returns a valid mount command exit code.
762 static const char *nfs_background_opttbl[] = {
768 static int nfsmount_start(struct nfsmount_info *mi)
770 if (!nfs_validate_options(mi))
773 if (po_rightmost(mi->options, nfs_background_opttbl) == 0)
774 return nfsmount_bg(mi);
776 return nfsmount_fg(mi);
780 * nfsmount_string - Mount an NFS file system using C string options
781 * @spec: C string specifying remote share to mount ("hostname:path")
782 * @node: C string pathname of local mounted-on directory
783 * @type: C string that represents file system type ("nfs" or "nfs4")
784 * @flags: MS_ style mount flags
785 * @extra_opts: pointer to C string containing fs-specific mount options
786 * (input and output argument)
787 * @fake: flag indicating whether to carry out the whole operation
788 * @child: one if this is a mount daemon (bg)
790 int nfsmount_string(const char *spec, const char *node, const char *type,
791 int flags, char **extra_opts, int fake, int child)
793 struct nfsmount_info mi = {
797 .extra_opts = extra_opts,
802 int retval = EX_FAIL;
804 mi.options = po_split(*extra_opts);
806 retval = nfsmount_start(&mi);
807 po_destroy(mi.options);
809 nfs_error(_("%s: internal option parsing error"), progname);