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.
37 #include <sys/socket.h>
38 #include <sys/mount.h>
39 #include <netinet/in.h>
40 #include <arpa/inet.h>
45 #include "nfs_mount.h"
46 #include "mount_constants.h"
50 #include "parse_opt.h"
53 #ifdef HAVE_RPCSVC_NFS_PROT_H
54 #include <rpcsvc/nfs_prot.h>
56 #include <linux/nfs.h>
57 #define nfsstat nfs_stat
64 #ifndef NFS_MAXHOSTNAME
65 #define NFS_MAXHOSTNAME (255)
68 #ifndef NFS_MAXPATHNAME
69 #define NFS_MAXPATHNAME (1024)
72 #ifndef NFS_DEF_FG_TIMEOUT_MINUTES
73 #define NFS_DEF_FG_TIMEOUT_MINUTES (2u)
76 #ifndef NFS_DEF_BG_TIMEOUT_MINUTES
77 #define NFS_DEF_BG_TIMEOUT_MINUTES (10000u)
80 extern int nfs_mount_data_version;
81 extern char *progname;
85 struct nfsmount_info {
86 const char *spec, /* server:/path */
87 *node, /* mounted-on dir */
88 *type; /* "nfs" or "nfs4" */
89 char *hostname; /* server's hostname */
91 struct mount_options *options; /* parsed mount options */
92 char **extra_opts; /* string for /etc/mtab */
94 int flags, /* MS_ flags */
95 fake, /* actually do the mount? */
96 child; /* forked bg child? */
99 static int nfs_parse_devname(struct nfsmount_info *mi)
102 char *dev, *pathname, *s;
104 dev = xstrdup(mi->spec);
106 if (!(pathname = strchr(dev, ':'))) {
107 nfs_error(_("%s: remote share not in 'host:dir' format"),
115 * We don't need a copy of the pathname, but let's
116 * sanity check it anyway.
118 if (strlen(pathname) > NFS_MAXPATHNAME) {
119 nfs_error(_("%s: export pathname is too long"),
125 * Ignore all but first hostname in replicated mounts
126 * until they can be fully supported. (mack@sgi.com)
128 if ((s = strchr(dev, ','))) {
130 nfs_error(_("%s: warning: multiple hostnames not supported"),
132 nfs_error(_("%s: ignoring hostnames that follow the first one"),
135 mi->hostname = xstrdup(dev);
136 if (strlen(mi->hostname) > NFS_MAXHOSTNAME) {
137 nfs_error(_("%s: server hostname is too long"),
151 static int fill_ipv4_sockaddr(const char *hostname, struct sockaddr_in *addr)
154 addr->sin_family = AF_INET;
156 if (inet_aton(hostname, &addr->sin_addr))
158 if ((hp = gethostbyname(hostname)) == NULL) {
159 nfs_error(_("%s: can't get address for %s\n"),
163 if (hp->h_length > sizeof(struct in_addr)) {
164 nfs_error(_("%s: got bad hp->h_length"), progname);
165 hp->h_length = sizeof(struct in_addr);
167 memcpy(&addr->sin_addr, hp->h_addr, hp->h_length);
172 * Obtain a retry timeout value based on the value of the "retry=" option.
174 * Returns a time_t timeout timestamp, in seconds.
176 static time_t nfs_parse_retry_option(struct mount_options *options,
177 unsigned int timeout_minutes)
179 char *retry_option, *endptr;
181 retry_option = po_get(options, "retry");
186 tmp = strtol(retry_option, &endptr, 10);
187 if (errno == 0 && endptr != retry_option && tmp >= 0)
188 timeout_minutes = tmp;
190 nfs_error(_("%s: invalid retry timeout was specified; "
191 "using default timeout"), progname);
194 return time(NULL) + (time_t)(timeout_minutes * 60);
198 * Append the 'addr=' option to the options string to pass a resolved
199 * server address to the kernel. After a successful mount, this address
200 * is also added to /etc/mtab for use when unmounting.
202 * If 'addr=' is already present, we strip it out. This prevents users
203 * from setting a bogus 'addr=' option themselves, and also allows bg
204 * retries to recompute the server's address, in case it has changed.
206 * Returns 1 if 'addr=' option appended successfully;
209 static int append_addr_option(struct sockaddr_in *saddr,
210 struct mount_options *options)
214 po_remove_all(options, "addr");
216 snprintf(new_option, sizeof(new_option) - 1,
217 "addr=%s", inet_ntoa(saddr->sin_addr));
219 if (po_append(options, new_option) == PO_SUCCEEDED)
225 * Called to discover our address and append an appropriate 'clientaddr='
226 * option to the options string.
228 * Returns 1 if 'clientaddr=' option created successfully or if
229 * 'clientaddr=' option is already present; otherwise zero.
231 static int append_clientaddr_option(struct sockaddr_in *saddr,
232 struct mount_options *options)
234 struct sockaddr_in my_addr;
237 if (po_contains(options, "clientaddr") == PO_SUCCEEDED)
240 if (!get_client_address(saddr, &my_addr))
243 snprintf(new_option, sizeof(new_option) - 1,
244 "clientaddr=%s", inet_ntoa(my_addr.sin_addr));
246 if (po_append(options, new_option) == PO_SUCCEEDED)
252 * Resolve the 'mounthost=' hostname and append a new option using
253 * the resulting IPv4 address.
255 static int fix_mounthost_option(struct mount_options *options)
257 struct sockaddr_in maddr;
258 char *mounthost, new_option[32];
260 mounthost = po_get(options, "mounthost");
264 if (!fill_ipv4_sockaddr(mounthost, &maddr))
267 snprintf(new_option, sizeof(new_option) - 1,
268 "mountaddr=%s", inet_ntoa(maddr.sin_addr));
270 if (po_append(options, new_option) == PO_SUCCEEDED)
276 * Returns zero if the "lock" option is in effect, but statd
277 * can't be started. Otherwise, returns 1.
279 static int verify_lock_option(struct mount_options *options)
281 if (po_rightmost(options, "nolock", "lock") == PO_KEY1_RIGHTMOST)
284 if (!start_statd()) {
285 nfs_error(_("%s: rpc.statd is not running but is "
286 "required for remote locking."), progname);
287 nfs_error(_("%s: Either use '-o nolock' to keep "
288 "locks local, or start statd."), progname);
295 static int nfs_append_sloppy_option(struct mount_options *options)
297 if (!sloppy || linux_version_code() < MAKE_VERSION(2, 6, 27))
300 if (po_append(options, "sloppy") == PO_FAILED)
306 * Set up mandatory NFS mount options.
308 * Returns 1 if successful; otherwise zero.
310 static int nfs_validate_options(struct nfsmount_info *mi)
312 struct sockaddr_in saddr;
314 if (!fill_ipv4_sockaddr(mi->hostname, &saddr))
317 if (strncmp(mi->type, "nfs4", 4) == 0) {
318 if (!append_clientaddr_option(&saddr, mi->options))
321 if (!fix_mounthost_option(mi->options))
323 if (!mi->fake && !verify_lock_option(mi->options))
327 if (!nfs_append_sloppy_option(mi->options))
330 if (!append_addr_option(&saddr, mi->options))
337 * Distinguish between permanent and temporary errors.
339 * Returns 0 if the passed-in error is temporary, thus the
340 * mount system call should be retried; returns one if the
341 * passed-in error is permanent, thus the mount system call
342 * should not be retried.
344 static int is_permanent_error(int error)
350 return 0; /* temporary */
352 return 1; /* permanent */
357 * Reconstruct the mount option string based on a portmapper probe
358 * of the server. Returns one if the server's portmapper returned
359 * something we can use, otherwise zero.
361 * To handle version and transport protocol fallback properly, we
362 * need to parse some of the mount options in order to set up a
363 * portmap probe. Mount options that rewrite_mount_options()
364 * doesn't recognize are left alone.
366 * Returns a new group of mount options if successful; otherwise
367 * NULL is returned if some failure occurred.
369 static struct mount_options *rewrite_mount_options(char *str)
371 struct mount_options *options;
372 char *option, new_option[64];
373 clnt_addr_t mnt_server = { };
374 clnt_addr_t nfs_server = { };
377 options = po_split(str);
384 option = po_get(options, "addr");
386 nfs_server.saddr.sin_family = AF_INET;
387 if (!inet_aton((const char *)option, &nfs_server.saddr.sin_addr))
392 option = po_get(options, "mountaddr");
394 mnt_server.saddr.sin_family = AF_INET;
395 if (!inet_aton((const char *)option, &mnt_server.saddr.sin_addr))
398 memcpy(&mnt_server.saddr, &nfs_server.saddr,
399 sizeof(mnt_server.saddr));
401 option = po_get(options, "mountport");
403 mnt_server.pmap.pm_port = atoi(option);
404 mnt_server.pmap.pm_prog = MOUNTPROG;
405 option = po_get(options, "mountvers");
407 mnt_server.pmap.pm_vers = atoi(option);
409 option = po_get(options, "port");
411 nfs_server.pmap.pm_port = atoi(option);
412 po_remove_all(options, "port");
414 nfs_server.pmap.pm_prog = NFS_PROGRAM;
416 option = po_get(options, "nfsvers");
418 nfs_server.pmap.pm_vers = atoi(option);
419 po_remove_all(options, "nfsvers");
421 option = po_get(options, "vers");
423 nfs_server.pmap.pm_vers = atoi(option);
424 po_remove_all(options, "vers");
426 option = po_get(options, "proto");
428 if (strcmp(option, "tcp") == 0) {
429 nfs_server.pmap.pm_prot = IPPROTO_TCP;
430 po_remove_all(options, "proto");
432 if (strcmp(option, "udp") == 0) {
433 nfs_server.pmap.pm_prot = IPPROTO_UDP;
434 po_remove_all(options, "proto");
437 p = po_rightmost(options, "tcp", "udp");
439 case PO_KEY2_RIGHTMOST:
440 nfs_server.pmap.pm_prot = IPPROTO_UDP;
442 case PO_KEY1_RIGHTMOST:
443 nfs_server.pmap.pm_prot = IPPROTO_TCP;
446 po_remove_all(options, "tcp");
447 po_remove_all(options, "udp");
449 if (!probe_bothports(&mnt_server, &nfs_server)) {
454 snprintf(new_option, sizeof(new_option) - 1,
455 "nfsvers=%lu", nfs_server.pmap.pm_vers);
456 if (po_append(options, new_option) == PO_FAILED)
459 if (nfs_server.pmap.pm_prot == IPPROTO_TCP)
460 snprintf(new_option, sizeof(new_option) - 1,
463 snprintf(new_option, sizeof(new_option) - 1,
465 if (po_append(options, new_option) == PO_FAILED)
468 if (nfs_server.pmap.pm_port != NFS_PORT) {
469 snprintf(new_option, sizeof(new_option) - 1,
470 "port=%lu", nfs_server.pmap.pm_port);
471 if (po_append(options, new_option) == PO_FAILED)
485 * Do the mount(2) system call.
487 * Returns 1 if successful, otherwise zero.
488 * "errno" is set to reflect the individual error.
490 static int nfs_sys_mount(const struct nfsmount_info *mi, const char *type,
495 result = mount(mi->spec, mi->node, type,
496 mi->flags & ~(MS_USER|MS_USERS), options);
497 if (verbose && result) {
499 nfs_error(_("%s: mount(2): %s"), progname, strerror(save));
506 * Retry an NFS mount that failed because the requested service isn't
507 * available on the server.
509 * Returns 1 if successful. Otherwise, returns zero.
510 * "errno" is set to reflect the individual error.
512 * Side effect: If the retry is successful, both 'options' and
513 * 'extra_opts' are updated to reflect the mount options that worked.
514 * If the retry fails, 'options' and 'extra_opts' are left unchanged.
516 static int nfs_retry_nfs23mount(struct nfsmount_info *mi)
518 struct mount_options *retry_options;
519 char *retry_str = NULL;
520 char **extra_opts = mi->extra_opts;
522 retry_options = rewrite_mount_options(*extra_opts);
526 if (po_join(retry_options, &retry_str) == PO_FAILED) {
527 po_destroy(retry_options);
533 printf(_("%s: text-based options (retry): '%s'\n"),
534 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);
577 if (nfs_sys_mount(mi, "nfs", *extra_opts))
581 * The kernel returns EOPNOTSUPP if the RPC bind failed,
582 * and EPROTONOSUPPORT if the version isn't supported.
584 if (errno != EOPNOTSUPP && errno != EPROTONOSUPPORT)
587 return nfs_retry_nfs23mount(mi);
591 * Attempt an NFS v4 mount via a mount(2) system call.
593 * Returns 1 if successful. Otherwise, returns zero.
594 * "errno" is set to reflect the individual error.
596 static int nfs_try_nfs4mount(struct nfsmount_info *mi)
598 char **extra_opts = mi->extra_opts;
600 if (po_join(mi->options, extra_opts) == PO_FAILED) {
606 printf(_("%s: text-based options: '%s'\n"),
607 progname, *extra_opts);
612 return nfs_sys_mount(mi, "nfs4", *extra_opts);
616 * Perform either an NFSv2/3 mount, or an NFSv4 mount system call.
618 * Returns 1 if successful. Otherwise, returns zero.
619 * "errno" is set to reflect the individual error.
621 static int nfs_try_mount(struct nfsmount_info *mi)
623 if (strncmp(mi->type, "nfs4", 4) == 0)
624 return nfs_try_nfs4mount(mi);
626 return nfs_try_nfs23mount(mi);
630 * Handle "foreground" NFS mounts.
632 * Retry the mount request for as long as the 'retry=' option says.
634 * Returns a valid mount command exit code.
636 static int nfsmount_fg(struct nfsmount_info *mi)
638 unsigned int secs = 1;
641 timeout = nfs_parse_retry_option(mi->options,
642 NFS_DEF_FG_TIMEOUT_MINUTES);
644 printf(_("%s: timeout set for %s"),
645 progname, ctime(&timeout));
648 if (nfs_try_mount(mi))
651 if (is_permanent_error(errno))
654 if (time(NULL) > timeout) {
659 if (errno != ETIMEDOUT) {
668 mount_error(mi->spec, mi->node, errno);
673 * Handle "background" NFS mount [first try]
675 * Returns a valid mount command exit code.
677 * EX_BG should cause the caller to fork and invoke nfsmount_child.
679 static int nfsmount_parent(struct nfsmount_info *mi)
681 if (nfs_try_mount(mi))
684 if (is_permanent_error(errno)) {
685 mount_error(mi->spec, mi->node, errno);
689 sys_mount_errors(mi->hostname, errno, 1, 1);
694 * Handle "background" NFS mount [retry daemon]
696 * Returns a valid mount command exit code: EX_SUCCESS if successful,
697 * EX_FAIL if a failure occurred. There's nothing to catch the
698 * error return, though, so we use sys_mount_errors to log the
701 static int nfsmount_child(struct nfsmount_info *mi)
703 unsigned int secs = 1;
706 timeout = nfs_parse_retry_option(mi->options,
707 NFS_DEF_BG_TIMEOUT_MINUTES);
716 if (nfs_try_mount(mi))
719 if (is_permanent_error(errno))
722 if (time(NULL) > timeout)
725 sys_mount_errors(mi->hostname, errno, 1, 1);
728 sys_mount_errors(mi->hostname, errno, 1, 0);
733 * Handle "background" NFS mount
735 * Returns a valid mount command exit code.
737 static int nfsmount_bg(struct nfsmount_info *mi)
740 return nfsmount_parent(mi);
742 return nfsmount_child(mi);
746 * Process mount options and try a mount system call.
748 * Returns a valid mount command exit code.
750 static int nfsmount_start(struct nfsmount_info *mi)
752 if (!nfs_validate_options(mi))
755 if (po_rightmost(mi->options, "bg", "fg") == PO_KEY1_RIGHTMOST)
756 return nfsmount_bg(mi);
758 return nfsmount_fg(mi);
762 * nfsmount_string - Mount an NFS file system using C string options
763 * @spec: C string specifying remote share to mount ("hostname:path")
764 * @node: C string pathname of local mounted-on directory
765 * @type: C string that represents file system type ("nfs" or "nfs4")
766 * @flags: MS_ style mount flags
767 * @extra_opts: pointer to C string containing fs-specific mount options
768 * (input and output argument)
769 * @fake: flag indicating whether to carry out the whole operation
770 * @child: one if this is a mount daemon (bg)
772 int nfsmount_string(const char *spec, const char *node, const char *type,
773 int flags, char **extra_opts, int fake, int child)
775 struct nfsmount_info mi = {
779 .extra_opts = extra_opts,
784 int retval = EX_FAIL;
786 if (!nfs_parse_devname(&mi))
789 mi.options = po_split(*extra_opts);
791 retval = nfsmount_start(&mi);
792 po_destroy(mi.options);
794 nfs_error(_("%s: internal option parsing error"), progname);