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.
32 #include <sys/socket.h>
33 #include <sys/mount.h>
38 #include "nfs_mount.h"
39 #include "mount_constants.h"
43 #include "parse_opt.h"
45 #ifdef HAVE_RPCSVC_NFS_PROT_H
46 #include <rpcsvc/nfs_prot.h>
48 #include <linux/nfs.h>
49 #define nfsstat nfs_stat
56 #ifndef NFS_MAXHOSTNAME
57 #define NFS_MAXHOSTNAME (255)
60 #ifndef NFS_MAXPATHNAME
61 #define NFS_MAXPATHNAME (1024)
64 extern int nfs_mount_data_version;
65 extern char *progname;
68 static int parse_devname(const char *spec, char **hostname)
71 char *dev, *pathname, *s;
75 if (!(pathname = strchr(dev, ':'))) {
76 nfs_error(_("%s: remote share not in 'host:dir' format"),
84 * We don't need a copy of the pathname, but let's
85 * sanity check it anyway.
87 if (strlen(pathname) > NFS_MAXPATHNAME) {
88 nfs_error(_("%s: export pathname is too long"),
94 * Ignore all but first hostname in replicated mounts
95 * until they can be fully supported. (mack@sgi.com)
97 if ((s = strchr(dev, ','))) {
99 nfs_error(_("%s: warning: multiple hostnames not supported"),
101 nfs_error(_("%s: ignoring hostnames that follow the first one"),
104 *hostname = xstrdup(dev);
105 if (strlen(*hostname) > NFS_MAXHOSTNAME) {
106 nfs_error(_("%s: server hostname is too long"),
119 static int fill_ipv4_sockaddr(const char *hostname, struct sockaddr_in *addr)
122 addr->sin_family = AF_INET;
124 if (inet_aton(hostname, &addr->sin_addr))
126 if ((hp = gethostbyname(hostname)) == NULL) {
127 nfs_error(_("%s: can't get address for %s\n"),
131 if (hp->h_length > sizeof(struct in_addr)) {
132 nfs_error(_("%s: got bad hp->h_length"), progname);
133 hp->h_length = sizeof(struct in_addr);
135 memcpy(&addr->sin_addr, hp->h_addr, hp->h_length);
140 * Append the 'addr=' option to the options string to pass a resolved
141 * server address to the kernel. After a successful mount, this address
142 * is also added to /etc/mtab for use when unmounting.
144 * If 'addr=' is already present, we strip it out. This prevents users
145 * from setting a bogus 'addr=' option themselves, and also allows bg
146 * retries to recompute the server's address, in case it has changed.
148 * Returns 1 if 'addr=' option appended successfully;
151 static int append_addr_option(struct sockaddr_in *saddr,
152 struct mount_options *options)
156 po_remove_all(options, "addr");
158 snprintf(new_option, sizeof(new_option) - 1,
159 "addr=%s", inet_ntoa(saddr->sin_addr));
161 if (po_append(options, new_option) == PO_SUCCEEDED)
167 * Called to discover our address and append an appropriate 'clientaddr='
168 * option to the options string.
170 * Returns 1 if 'clientaddr=' option created successfully or if
171 * 'clientaddr=' option is already present; otherwise zero.
173 static int append_clientaddr_option(struct sockaddr_in *saddr,
174 struct mount_options *options)
176 struct sockaddr_in my_addr;
179 if (po_contains(options, "clientaddr") == PO_SUCCEEDED)
182 if (!get_client_address(saddr, &my_addr))
185 snprintf(new_option, sizeof(new_option) - 1,
186 "clientaddr=%s", inet_ntoa(my_addr.sin_addr));
188 if (po_append(options, new_option) == PO_SUCCEEDED)
194 * Resolve the 'mounthost=' hostname and append a new option using
195 * the resulting IPv4 address.
197 static int fix_mounthost_option(struct mount_options *options)
199 struct sockaddr_in maddr;
200 char *mounthost, new_option[32];
202 mounthost = po_get(options, "mounthost");
206 if (!fill_ipv4_sockaddr(mounthost, &maddr))
209 snprintf(new_option, sizeof(new_option) - 1,
210 "mountaddr=%s", inet_ntoa(maddr.sin_addr));
212 if (po_append(options, new_option) == PO_SUCCEEDED)
218 * Set up mandatory mount options.
220 * Returns 1 if successful; otherwise zero.
222 static int set_mandatory_options(const char *type,
223 struct sockaddr_in *saddr,
224 struct mount_options *options)
226 if (!append_addr_option(saddr, options))
229 if (strncmp(type, "nfs4", 4) == 0) {
230 if (!append_clientaddr_option(saddr, options))
233 if (!fix_mounthost_option(options))
241 * Reconstruct the mount option string based on a portmapper probe
242 * of the server. Returns one if the server's portmapper returned
243 * something we can use, otherwise zero.
245 * To handle version and transport protocol fallback properly, we
246 * need to parse some of the mount options in order to set up a
247 * portmap probe. Mount options that rewrite_mount_options()
248 * doesn't recognize are left alone.
250 * Returns a new group of mount options if successful; otherwise
251 * NULL is returned if some failure occurred.
253 static struct mount_options *rewrite_mount_options(char *str)
255 struct mount_options *options;
256 char *option, new_option[64];
257 clnt_addr_t mnt_server = { };
258 clnt_addr_t nfs_server = { };
261 options = po_split(str);
265 option = po_get(options, "addr");
267 nfs_server.saddr.sin_family = AF_INET;
268 if (!inet_aton((const char *)option, &nfs_server.saddr.sin_addr))
273 option = po_get(options, "mountaddr");
275 mnt_server.saddr.sin_family = AF_INET;
276 if (!inet_aton((const char *)option, &mnt_server.saddr.sin_addr))
279 memcpy(&mnt_server.saddr, &nfs_server.saddr,
280 sizeof(mnt_server.saddr));
282 option = po_get(options, "mountport");
284 mnt_server.pmap.pm_port = atoi(option);
285 mnt_server.pmap.pm_prog = MOUNTPROG;
286 option = po_get(options, "mountprog");
288 mnt_server.pmap.pm_prog = atoi(option);
289 option = po_get(options, "mountvers");
291 mnt_server.pmap.pm_vers = atoi(option);
293 option = po_get(options, "port");
295 nfs_server.pmap.pm_port = atoi(option);
296 po_remove_all(options, "port");
298 nfs_server.pmap.pm_prog = NFS_PROGRAM;
299 option = po_get(options, "nfsprog");
301 nfs_server.pmap.pm_prog = atoi(option);
303 option = po_get(options, "nfsvers");
305 nfs_server.pmap.pm_vers = atoi(option);
306 po_remove_all(options, "nfsvers");
308 option = po_get(options, "vers");
310 nfs_server.pmap.pm_vers = atoi(option);
311 po_remove_all(options, "vers");
313 option = po_get(options, "proto");
315 if (strcmp(option, "tcp") == 0) {
316 nfs_server.pmap.pm_prot = IPPROTO_TCP;
317 po_remove_all(options, "proto");
319 if (strcmp(option, "udp") == 0) {
320 nfs_server.pmap.pm_prot = IPPROTO_UDP;
321 po_remove_all(options, "proto");
324 p = po_rightmost(options, "tcp", "udp");
326 case PO_KEY2_RIGHTMOST:
327 nfs_server.pmap.pm_prot = IPPROTO_UDP;
329 case PO_KEY1_RIGHTMOST:
330 nfs_server.pmap.pm_prot = IPPROTO_TCP;
333 po_remove_all(options, "tcp");
334 po_remove_all(options, "udp");
336 if (!probe_bothports(&mnt_server, &nfs_server)) {
337 rpc_mount_errors("rpcbind", 0, 0);
341 snprintf(new_option, sizeof(new_option) - 1,
342 "nfsvers=%lu", nfs_server.pmap.pm_vers);
343 if (po_append(options, new_option) == PO_FAILED)
346 if (nfs_server.pmap.pm_prot == IPPROTO_TCP)
347 snprintf(new_option, sizeof(new_option) - 1,
350 snprintf(new_option, sizeof(new_option) - 1,
352 if (po_append(options, new_option) == PO_FAILED)
355 if (nfs_server.pmap.pm_port != NFS_PORT) {
356 snprintf(new_option, sizeof(new_option) - 1,
357 "port=%lu", nfs_server.pmap.pm_port);
358 if (po_append(options, new_option) == PO_FAILED)
371 * Retry an NFS mount that failed because the requested service isn't
372 * available on the server.
374 * Returns 1 if successful. Otherwise, returns zero.
375 * "errno" is set to reflect the individual error.
377 * Side effect: If the retry is successful, both 'options' and
378 * 'extra_opts' are updated to reflect the mount options that worked.
379 * If the retry fails, 'options' and 'extra_opts' are left unchanged.
381 static int retry_nfsmount(const char *spec, const char *node,
382 int flags, struct mount_options *options,
383 int fake, char **extra_opts)
385 struct mount_options *retry_options;
386 char *retry_str = NULL;
388 retry_options = rewrite_mount_options(*extra_opts);
389 if (!retry_options) {
394 if (po_join(retry_options, &retry_str) == PO_FAILED) {
395 po_destroy(retry_options);
401 printf(_("%s: text-based options (retry): '%s'\n"),
402 progname, retry_str);
404 if (!mount(spec, node, "nfs",
405 flags & ~(MS_USER|MS_USERS), retry_str)) {
407 *extra_opts = retry_str;
408 po_replace(options, retry_options);
412 po_destroy(retry_options);
418 * Attempt an NFSv2/3 mount via a mount(2) system call. If the kernel
419 * claims the requested service isn't supported on the server, probe
420 * the server to see what's supported, rewrite the mount options,
421 * and retry the request.
423 * Returns 1 if successful. Otherwise, returns zero.
424 * "errno" is set to reflect the individual error.
426 * Side effect: If the retry is successful, both 'options' and
427 * 'extra_opts' are updated to reflect the mount options that worked.
428 * If the retry fails, 'options' and 'extra_opts' are left unchanged.
430 static int try_nfs23mount(const char *spec, const char *node,
431 int flags, struct mount_options *options,
432 int fake, char **extra_opts)
434 if (po_join(options, extra_opts) == PO_FAILED) {
440 printf(_("%s: text-based options: '%s'\n"),
441 progname, *extra_opts);
446 if (!mount(spec, node, "nfs",
447 flags & ~(MS_USER|MS_USERS), *extra_opts))
451 * The kernel returns EOPNOTSUPP if the RPC bind failed,
452 * and EPROTONOSUPPORT if the version isn't supported.
454 if (errno != EOPNOTSUPP && errno != EPROTONOSUPPORT)
457 return retry_nfsmount(spec, node, flags, options, fake, extra_opts);
461 * Attempt an NFS v4 mount via a mount(2) system call.
463 * Returns 1 if successful. Otherwise, returns zero.
464 * "errno" is set to reflect the individual error.
466 static int try_nfs4mount(const char *spec, const char *node,
467 int flags, struct mount_options *options,
468 int fake, char **extra_opts)
470 if (po_join(options, extra_opts) == PO_FAILED) {
476 printf(_("%s: text-based options: '%s'\n"),
477 progname, *extra_opts);
482 if (!mount(spec, node, "nfs4",
483 flags & ~(MS_USER|MS_USERS), *extra_opts))
489 * Try the mount(2) system call.
491 * Returns 1 if successful. Otherwise, returns zero.
492 * "errno" is set to reflect the individual error.
494 static int try_mount(const char *spec, const char *node, const char *type,
495 int flags, struct mount_options *options, int fake,
498 if (strncmp(type, "nfs4", 4) == 0)
499 return try_nfs4mount(spec, node, flags,
500 options, fake, extra_opts);
502 return try_nfs23mount(spec, node, flags,
503 options, fake, extra_opts);
507 * nfsmount_string - Mount an NFS file system using C string options
508 * @spec: C string specifying remote share to mount ("hostname:path")
509 * @node: C string pathname of local mounted-on directory
510 * @type: C string that represents file system type ("nfs" or "nfs4")
511 * @flags: MS_ style mount flags
512 * @extra_opts: pointer to C string containing fs-specific mount options
513 * (input and output argument)
514 * @fake: flag indicating whether to carry out the whole operation
515 * @child: one if this is a mount daemon (bg)
517 int nfsmount_string(const char *spec, const char *node, const char *type,
518 int flags, char **extra_opts, int fake, int child)
520 struct mount_options *options = NULL;
521 struct sockaddr_in saddr;
523 int err, retval = EX_FAIL;
525 if (!parse_devname(spec, &hostname))
527 err = fill_ipv4_sockaddr(hostname, &saddr);
532 options = po_split(*extra_opts);
534 nfs_error(_("%s: internal option parsing error"), progname);
538 if (!set_mandatory_options(type, &saddr, options))
541 if (po_join(options, extra_opts) == PO_FAILED) {
542 nfs_error(_("%s: internal option parsing error"), progname);
547 printf(_("%s: text-based options: '%s'\n"),
548 progname, *extra_opts);
551 if (mount(spec, node, type,
552 flags & ~(MS_USER|MS_USERS), *extra_opts)) {
553 mount_error(spec, node, errno);