1 /* vi: set sw=4 ts=4: */
3 * Mini mount implementation for busybox
5 * Copyright (C) 1995, 1996 by Bruce Perens <bruce@pixar.com>.
6 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
7 * Copyright (C) 2005-2006 by Rob Landley <rob@landley.net>
9 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
11 // Design notes: There is no spec for mount. Remind me to write one.
13 // mount_main() calls singlemount() which calls mount_it_now().
15 // mount_main() can loop through /etc/fstab for mount -a
16 // singlemount() can loop through /etc/filesystems for fstype detection.
17 // mount_it_now() does the actual mount.
21 //config: bool "mount"
23 //config: select PLATFORM_LINUX
25 //config: All files and filesystems in Unix are arranged into one big directory
26 //config: tree. The 'mount' utility is used to graft a filesystem onto a
27 //config: particular part of the tree. A filesystem can either live on a block
28 //config: device, or it can be accessible over the network, as is the case with
29 //config: NFS filesystems. Most people using BusyBox will also want to enable
30 //config: the 'mount' utility.
32 //config:config FEATURE_MOUNT_FAKE
33 //config: bool "Support option -f"
35 //config: depends on MOUNT
37 //config: Enable support for faking a file system mount.
39 //config:config FEATURE_MOUNT_VERBOSE
40 //config: bool "Support option -v"
42 //config: depends on MOUNT
44 //config: Enable multi-level -v[vv...] verbose messages. Useful if you
45 //config: debug mount problems and want to see what is exactly passed
46 //config: to the kernel.
48 //config:config FEATURE_MOUNT_HELPERS
49 //config: bool "Support mount helpers"
51 //config: depends on MOUNT
53 //config: Enable mounting of virtual file systems via external helpers.
54 //config: E.g. "mount obexfs#-b00.11.22.33.44.55 /mnt" will in effect call
55 //config: "obexfs -b00.11.22.33.44.55 /mnt"
56 //config: Also "mount -t sometype [-o opts] fs /mnt" will try
57 //config: "sometype [-o opts] fs /mnt" if simple mount syscall fails.
58 //config: The idea is to use such virtual filesystems in /etc/fstab.
60 //config:config FEATURE_MOUNT_LABEL
61 //config: bool "Support specifying devices by label or UUID"
63 //config: depends on MOUNT
64 //config: select VOLUMEID
66 //config: This allows for specifying a device by label or uuid, rather than by
67 //config: name. This feature utilizes the same functionality as blkid/findfs.
68 //config: This also enables label or uuid support for swapon.
70 //config:config FEATURE_MOUNT_NFS
71 //config: bool "Support mounting NFS file systems on Linux < 2.6.23"
73 //config: depends on MOUNT
74 //config: select FEATURE_HAVE_RPC
75 //config: select FEATURE_SYSLOG
77 //config: Enable mounting of NFS file systems on Linux kernels prior
78 //config: to version 2.6.23. Note that in this case mounting of NFS
79 //config: over IPv6 will not be possible.
81 //config: Note that this option links in RPC support from libc,
82 //config: which is rather large (~10 kbytes on uclibc).
84 //config:config FEATURE_MOUNT_CIFS
85 //config: bool "Support mounting CIFS/SMB file systems"
87 //config: depends on MOUNT
89 //config: Enable support for samba mounts.
91 //config:config FEATURE_MOUNT_FLAGS
92 //config: depends on MOUNT
93 //config: bool "Support lots of -o flags"
96 //config: Without this, mount only supports ro/rw/remount. With this, it
97 //config: supports nosuid, suid, dev, nodev, exec, noexec, sync, async, atime,
98 //config: noatime, diratime, nodiratime, loud, bind, move, shared, slave,
99 //config: private, unbindable, rshared, rslave, rprivate, and runbindable.
101 //config:config FEATURE_MOUNT_FSTAB
102 //config: depends on MOUNT
103 //config: bool "Support /etc/fstab and -a"
106 //config: Support mount all and looking for files in /etc/fstab.
108 //config:config FEATURE_MOUNT_OTHERTAB
109 //config: depends on FEATURE_MOUNT_FSTAB
110 //config: bool "Support -T <alt_fstab>"
113 //config: Support mount -T (specifying an alternate fstab)
115 /* On full-blown systems, requires suid for user mounts.
116 * But it's not unthinkable to have it available in non-suid flavor on some systems,
117 * for viewing mount table.
118 * Therefore we use BB_SUID_MAYBE instead of BB_SUID_REQUIRE: */
119 //applet:IF_MOUNT(APPLET(mount, BB_DIR_BIN, IF_DESKTOP(BB_SUID_MAYBE) IF_NOT_DESKTOP(BB_SUID_DROP)))
121 //kbuild:lib-$(CONFIG_MOUNT) += mount.o
123 //usage:#define mount_trivial_usage
124 //usage: "[OPTIONS] [-o OPT] DEVICE NODE"
125 //usage:#define mount_full_usage "\n\n"
126 //usage: "Mount a filesystem. Filesystem autodetection requires /proc.\n"
127 //usage: "\n -a Mount all filesystems in fstab"
128 //usage: IF_FEATURE_MOUNT_FAKE(
129 //usage: IF_FEATURE_MTAB_SUPPORT(
130 //usage: "\n -f Update /etc/mtab, but don't mount"
132 //usage: IF_NOT_FEATURE_MTAB_SUPPORT(
133 //usage: "\n -f Dry run"
136 //usage: IF_FEATURE_MOUNT_HELPERS(
137 //usage: "\n -i Don't run mount helper"
139 //usage: IF_FEATURE_MTAB_SUPPORT(
140 //usage: "\n -n Don't update /etc/mtab"
142 //usage: IF_FEATURE_MOUNT_VERBOSE(
143 //usage: "\n -v Verbose"
145 ////usage: "\n -s Sloppy (ignored)"
146 //usage: "\n -r Read-only mount"
147 ////usage: "\n -w Read-write mount (default)"
148 //usage: "\n -t FSTYPE[,...] Filesystem type(s)"
149 //usage: IF_FEATURE_MOUNT_OTHERTAB(
150 //usage: "\n -T FILE Read FILE instead of /etc/fstab"
152 //usage: "\n -O OPT Mount only filesystems with option OPT (-a only)"
154 //usage: IF_FEATURE_MOUNT_LOOP(
155 //usage: "\n loop Ignored (loop devices are autodetected)"
157 //usage: IF_FEATURE_MOUNT_FLAGS(
158 //usage: "\n [a]sync Writes are [a]synchronous"
159 //usage: "\n [no]atime Disable/enable updates to inode access times"
160 //usage: "\n [no]diratime Disable/enable atime updates to directories"
161 //usage: "\n [no]relatime Disable/enable atime updates relative to modification time"
162 //usage: "\n [no]dev (Dis)allow use of special device files"
163 //usage: "\n [no]exec (Dis)allow use of executable files"
164 //usage: "\n [no]suid (Dis)allow set-user-id-root programs"
165 //usage: "\n [r]shared Convert [recursively] to a shared subtree"
166 //usage: "\n [r]slave Convert [recursively] to a slave subtree"
167 //usage: "\n [r]private Convert [recursively] to a private subtree"
168 //usage: "\n [un]bindable Make mount point [un]able to be bind mounted"
169 //usage: "\n [r]bind Bind a file or directory [recursively] to another location"
170 //usage: "\n move Relocate an existing mount point"
172 //usage: "\n remount Remount a mounted filesystem, changing flags"
173 //usage: "\n ro Same as -r"
175 //usage: "\nThere are filesystem-specific -o flags."
177 //usage:#define mount_example_usage
179 //usage: "/dev/hda3 on / type minix (rw)\n"
180 //usage: "proc on /proc type proc (rw)\n"
181 //usage: "devpts on /dev/pts type devpts (rw)\n"
182 //usage: "$ mount /dev/fd0 /mnt -t msdos -o ro\n"
183 //usage: "$ mount /tmp/diskimage /opt -t ext2 -o loop\n"
184 //usage: "$ mount cd_image.iso mydir\n"
185 //usage:#define mount_notes_usage
186 //usage: "Returns 0 for success, number of failed mounts for -a, or errno for one mount."
190 #include <sys/mount.h>
191 // Grab more as needed from util-linux's mount/mount_constants.h
193 # define MS_DIRSYNC (1 << 7) // Directory modifications are synchronous
196 # define MS_UNION (1 << 8)
199 # define MS_BIND (1 << 12)
202 # define MS_MOVE (1 << 13)
205 # define MS_RECURSIVE (1 << 14)
208 # define MS_SILENT (1 << 15)
210 // The shared subtree stuff, which went in around 2.6.15
211 #ifndef MS_UNBINDABLE
212 # define MS_UNBINDABLE (1 << 17)
215 # define MS_PRIVATE (1 << 18)
218 # define MS_SLAVE (1 << 19)
221 # define MS_SHARED (1 << 20)
224 # define MS_RELATIME (1 << 21)
226 #ifndef MS_STRICTATIME
227 # define MS_STRICTATIME (1 << 24)
230 /* Any ~MS_FOO value has this bit set: */
231 #define BB_MS_INVERTED_VALUE (1u << 31)
234 #include "common_bufsiz.h"
235 #if ENABLE_FEATURE_MOUNT_LABEL
236 # include "volume_id.h"
238 # define resolve_mount_spec(fsname) ((void)0)
241 // Needed for nfs support only
242 #include <sys/utsname.h>
245 #if ENABLE_FEATURE_MOUNT_NFS
246 /* This is just a warning of a common mistake. Possibly this should be a
247 * uclibc faq entry rather than in busybox... */
248 # if defined(__UCLIBC__) && ! defined(__UCLIBC_HAS_RPC__)
249 # error "You need to build uClibc with UCLIBC_HAS_RPC for NFS support"
251 # include <rpc/rpc.h>
252 # include <rpc/pmap_prot.h>
253 # include <rpc/pmap_clnt.h>
257 #if defined(__dietlibc__)
258 // 16.12.2006, Sampo Kellomaki (sampo@iki.fi)
259 // dietlibc-0.30 does not have implementation of getmntent_r()
260 static struct mntent *getmntent_r(FILE* stream, struct mntent* result,
261 char* buffer UNUSED_PARAM, int bufsize UNUSED_PARAM)
263 struct mntent* ment = getmntent(stream);
264 return memcpy(result, ment, sizeof(*ment));
269 // Not real flags, but we want to be able to check for this.
271 MOUNT_USERS = (1 << 27) * ENABLE_DESKTOP,
272 MOUNT_NOFAIL = (1 << 28) * ENABLE_DESKTOP,
273 MOUNT_NOAUTO = (1 << 29),
274 MOUNT_SWAP = (1 << 30),
275 MOUNT_FAKEFLAGS = MOUNT_USERS | MOUNT_NOFAIL | MOUNT_NOAUTO | MOUNT_SWAP
279 #define OPTION_STR "o:*t:rwanfvsiO:" IF_FEATURE_MOUNT_OTHERTAB("T:")
295 #if ENABLE_FEATURE_MTAB_SUPPORT
296 #define USE_MTAB (!(option_mask32 & OPT_n))
301 #if ENABLE_FEATURE_MOUNT_FAKE
302 #define FAKE_IT (option_mask32 & OPT_f)
307 #if ENABLE_FEATURE_MOUNT_HELPERS
308 #define HELPERS_ALLOWED (!(option_mask32 & OPT_i))
310 #define HELPERS_ALLOWED 0
314 // TODO: more "user" flag compatibility.
315 // "user" option (from mount manpage):
316 // Only the user that mounted a filesystem can unmount it again.
317 // If any user should be able to unmount, then use users instead of user
318 // in the fstab line. The owner option is similar to the user option,
319 // with the restriction that the user must be the owner of the special file.
320 // This may be useful e.g. for /dev/fd if a login script makes
321 // the console user owner of this device.
323 // Standard mount options (from -o options or --options),
324 // with corresponding flags
325 static const int32_t mount_options[] = {
326 // MS_FLAGS set a bit. ~MS_FLAGS disable that bit. 0 flags are NOPs.
328 IF_FEATURE_MOUNT_LOOP(
332 IF_FEATURE_MOUNT_FSTAB(
334 /* "quiet" 0 - do not filter out, vfat wants to see it */
335 /* "noauto" */ MOUNT_NOAUTO,
336 /* "sw" */ MOUNT_SWAP,
337 /* "swap" */ MOUNT_SWAP,
338 IF_DESKTOP(/* "user" */ MOUNT_USERS,)
339 IF_DESKTOP(/* "users" */ MOUNT_USERS,)
340 IF_DESKTOP(/* "nofail" */ MOUNT_NOFAIL,)
342 IF_DESKTOP(/* "comment=" */ 0,) /* systemd uses this in fstab */
345 IF_FEATURE_MOUNT_FLAGS(
347 /* "nosuid" */ MS_NOSUID,
348 /* "suid" */ ~MS_NOSUID,
349 /* "dev" */ ~MS_NODEV,
350 /* "nodev" */ MS_NODEV,
351 /* "exec" */ ~MS_NOEXEC,
352 /* "noexec" */ MS_NOEXEC,
353 /* "sync" */ MS_SYNCHRONOUS,
354 /* "dirsync" */ MS_DIRSYNC,
355 /* "async" */ ~MS_SYNCHRONOUS,
356 /* "atime" */ ~MS_NOATIME,
357 /* "noatime" */ MS_NOATIME,
358 /* "diratime" */ ~MS_NODIRATIME,
359 /* "nodiratime" */ MS_NODIRATIME,
360 /* "mand" */ MS_MANDLOCK,
361 /* "nomand" */ ~MS_MANDLOCK,
362 /* "relatime" */ MS_RELATIME,
363 /* "norelatime" */ ~MS_RELATIME,
364 /* "strictatime" */ MS_STRICTATIME,
365 /* "loud" */ ~MS_SILENT,
366 /* "rbind" */ MS_BIND|MS_RECURSIVE,
369 /* "union" */ MS_UNION,
370 /* "bind" */ MS_BIND,
371 /* "move" */ MS_MOVE,
372 /* "shared" */ MS_SHARED,
373 /* "slave" */ MS_SLAVE,
374 /* "private" */ MS_PRIVATE,
375 /* "unbindable" */ MS_UNBINDABLE,
376 /* "rshared" */ MS_SHARED|MS_RECURSIVE,
377 /* "rslave" */ MS_SLAVE|MS_RECURSIVE,
378 /* "rprivate" */ MS_PRIVATE|MS_RECURSIVE,
379 /* "runbindable" */ MS_UNBINDABLE|MS_RECURSIVE,
382 // Always understood.
383 /* "ro" */ MS_RDONLY, // vfs flag
384 /* "rw" */ ~MS_RDONLY, // vfs flag
385 /* "remount" */ MS_REMOUNT // action flag
388 static const char mount_option_str[] ALIGN1 =
389 IF_FEATURE_MOUNT_LOOP(
392 IF_FEATURE_MOUNT_FSTAB(
394 // "quiet\0" - do not filter out, vfat wants to see it
399 IF_DESKTOP("users\0")
400 IF_DESKTOP("nofail\0")
402 IF_DESKTOP("comment=\0") /* systemd uses this in fstab */
404 IF_FEATURE_MOUNT_FLAGS(
441 // Always understood.
444 "remount\0" // action flag
449 #if ENABLE_FEATURE_MOUNT_NFS
450 smalluint nfs_mount_version;
452 #if ENABLE_FEATURE_MOUNT_VERBOSE
456 char getmntent_buf[1];
458 enum { GETMNTENT_BUFSIZE = COMMON_BUFSIZE - offsetof(struct globals, getmntent_buf) };
459 #define G (*(struct globals*)bb_common_bufsiz1)
460 #define nfs_mount_version (G.nfs_mount_version)
461 #if ENABLE_FEATURE_MOUNT_VERBOSE
462 #define verbose (G.verbose )
466 #define fslist (G.fslist )
467 #define getmntent_buf (G.getmntent_buf )
468 #define INIT_G() do { setup_common_bufsiz(); } while (0)
470 #if ENABLE_FEATURE_MTAB_SUPPORT
472 * update_mtab_entry_on_move() is used to update entry in case of mount --move.
473 * we are looking for existing entries mnt_dir which is equal to mnt_fsname of
474 * input mntent and replace it by new one.
476 static void FAST_FUNC update_mtab_entry_on_move(const struct mntent *mp)
478 struct mntent *entries, *m;
482 mountTable = setmntent(bb_path_mtab_file, "r");
484 bb_perror_msg(bb_path_mtab_file);
490 while ((m = getmntent(mountTable)) != NULL) {
491 entries = xrealloc_vector(entries, 3, count);
492 entries[count].mnt_fsname = xstrdup(m->mnt_fsname);
493 entries[count].mnt_dir = xstrdup(m->mnt_dir);
494 entries[count].mnt_type = xstrdup(m->mnt_type);
495 entries[count].mnt_opts = xstrdup(m->mnt_opts);
496 entries[count].mnt_freq = m->mnt_freq;
497 entries[count].mnt_passno = m->mnt_passno;
500 endmntent(mountTable);
502 mountTable = setmntent(bb_path_mtab_file, "w");
504 for (i = 0; i < count; i++) {
505 if (strcmp(entries[i].mnt_dir, mp->mnt_fsname) != 0)
506 addmntent(mountTable, &entries[i]);
508 addmntent(mountTable, mp);
510 endmntent(mountTable);
511 } else if (errno != EROFS)
512 bb_perror_msg(bb_path_mtab_file);
514 if (ENABLE_FEATURE_CLEAN_UP) {
515 for (i = 0; i < count; i++) {
516 free(entries[i].mnt_fsname);
517 free(entries[i].mnt_dir);
518 free(entries[i].mnt_type);
519 free(entries[i].mnt_opts);
526 #if ENABLE_FEATURE_MOUNT_VERBOSE
527 static int verbose_mount(const char *source, const char *target,
528 const char *filesystemtype,
529 unsigned long mountflags, const void *data)
534 rc = mount(source, target, filesystemtype, mountflags, data);
536 bb_perror_msg("mount('%s','%s','%s',0x%08lx,'%s'):%d",
537 source, target, filesystemtype,
538 mountflags, (char*)data, rc);
542 #define verbose_mount(...) mount(__VA_ARGS__)
545 // Append mount options to string
546 static void append_mount_options(char **oldopts, const char *newopts)
548 if (*oldopts && **oldopts) {
549 // Do not insert options which are already there
552 int len = strlen(newopts);
553 p = strchr(newopts, ',');
554 if (p) len = p - newopts;
557 if (!strncmp(p, newopts, len)
558 && (p[len] == ',' || p[len] == '\0'))
564 p = xasprintf("%s,%.*s", *oldopts, len, newopts);
569 while (newopts[0] == ',') newopts++;
572 if (ENABLE_FEATURE_CLEAN_UP) free(*oldopts);
573 *oldopts = xstrdup(newopts);
577 // Use the mount_options list to parse options into flags.
578 // Also update list of unrecognized options if unrecognized != NULL
579 static unsigned long parse_mount_options(char *options, char **unrecognized)
581 unsigned long flags = MS_SILENT;
583 // Loop through options
586 char *comma = strchr(options, ',');
587 const char *option_str = mount_option_str;
589 if (comma) *comma = '\0';
591 // FIXME: use hasmntopt()
592 // Find this option in mount_options
593 for (i = 0; i < ARRAY_SIZE(mount_options); i++) {
594 unsigned opt_len = strlen(option_str);
596 if (strncasecmp(option_str, options, opt_len) == 0
597 && (options[opt_len] == '\0'
598 /* or is it "comment=" thingy in fstab? */
599 IF_FEATURE_MOUNT_FSTAB(IF_DESKTOP( || option_str[opt_len-1] == '=' ))
602 unsigned long fl = mount_options[i];
603 if (fl & BB_MS_INVERTED_VALUE)
609 option_str += opt_len + 1;
611 // We did not recognize this option.
612 // If "unrecognized" is not NULL, append option there.
613 // Note that we should not append *empty* option -
614 // in this case we want to pass NULL, not "", to "data"
615 // parameter of mount(2) syscall.
616 // This is crucial for filesystems that don't accept
617 // any arbitrary mount options, like cgroup fs:
618 // "mount -t cgroup none /mnt"
619 if (options[0] && unrecognized) {
620 // Add it to strflags, to pass on to kernel
621 char *p = *unrecognized;
622 unsigned len = p ? strlen(p) : 0;
623 *unrecognized = p = xrealloc(p, len + strlen(options) + 2);
625 // Comma separated if it's not the first one
626 if (len) p[len++] = ',';
627 strcpy(p + len, options);
632 // Advance to next option
640 // Return a list of all block device backed filesystems
641 static llist_t *get_block_backed_filesystems(void)
643 static const char filesystems[2][sizeof("/proc/filesystems")] = {
648 llist_t *list = NULL;
652 for (i = 0; i < 2; i++) {
653 f = fopen_for_read(filesystems[i]);
656 while ((buf = xmalloc_fgetline(f)) != NULL) {
657 if (is_prefixed_with(buf, "nodev") && isspace(buf[5]))
659 fs = skip_whitespace(buf);
660 if (*fs == '#' || *fs == '*' || !*fs)
663 llist_add_to_end(&list, xstrdup(fs));
667 if (ENABLE_FEATURE_CLEAN_UP) fclose(f);
673 #if ENABLE_FEATURE_CLEAN_UP
674 static void delete_block_backed_filesystems(void)
676 llist_free(fslist, free);
679 void delete_block_backed_filesystems(void);
682 // Perform actual mount of specific filesystem at specific location.
683 // NB: mp->xxx fields may be trashed on exit
684 static int mount_it_now(struct mntent *mp, unsigned long vfsflags, char *filteropts)
688 vfsflags &= ~(unsigned long)MOUNT_FAKEFLAGS;
692 bb_error_msg("would do mount('%s','%s','%s',0x%08lx,'%s')",
693 mp->mnt_fsname, mp->mnt_dir, mp->mnt_type,
694 vfsflags, filteropts);
698 // Mount, with fallback to read-only if necessary.
701 rc = verbose_mount(mp->mnt_fsname, mp->mnt_dir, mp->mnt_type,
702 vfsflags, filteropts);
704 // If mount failed, try
705 // helper program mount.<mnt_type>
706 if (HELPERS_ALLOWED && rc && mp->mnt_type) {
708 int errno_save = errno;
709 args[0] = xasprintf("mount.%s", mp->mnt_type);
712 args[rc++] = (char *)"-f";
713 if (ENABLE_FEATURE_MTAB_SUPPORT && !USE_MTAB)
714 args[rc++] = (char *)"-n";
715 args[rc++] = mp->mnt_fsname;
716 args[rc++] = mp->mnt_dir;
718 args[rc++] = (char *)"-o";
719 args[rc++] = filteropts;
722 rc = spawn_and_wait(args);
729 if (!rc || (vfsflags & MS_RDONLY) || (errno != EACCES && errno != EROFS))
731 if (!(vfsflags & MS_SILENT))
732 bb_error_msg("%s is write-protected, mounting read-only",
734 vfsflags |= MS_RDONLY;
737 // Abort entirely if permission denied.
739 if (rc && errno == EPERM)
740 bb_error_msg_and_die(bb_msg_perm_denied_are_you_root);
742 // If the mount was successful, and we're maintaining an old-style
743 // mtab file by hand, add the new entry to it now.
745 if (USE_MTAB && !rc && !(vfsflags & MS_REMOUNT)) {
747 FILE *mountTable = setmntent(bb_path_mtab_file, "a+");
748 const char *option_str = mount_option_str;
752 bb_perror_msg(bb_path_mtab_file);
756 // Add vfs string flags
757 for (i = 0; mount_options[i] != MS_REMOUNT; i++) {
758 if (mount_options[i] > 0 && (mount_options[i] & vfsflags))
759 append_mount_options(&(mp->mnt_opts), option_str);
760 option_str += strlen(option_str) + 1;
763 // Remove trailing / (if any) from directory we mounted on
764 i = strlen(mp->mnt_dir) - 1;
765 while (i > 0 && mp->mnt_dir[i] == '/')
766 mp->mnt_dir[i--] = '\0';
768 // Convert to canonical pathnames as needed
769 mp->mnt_dir = bb_simplify_path(mp->mnt_dir);
771 if (!mp->mnt_type || !*mp->mnt_type) { // bind mount
772 mp->mnt_fsname = fsname = bb_simplify_path(mp->mnt_fsname);
773 mp->mnt_type = (char*)"bind";
775 mp->mnt_freq = mp->mnt_passno = 0;
778 #if ENABLE_FEATURE_MTAB_SUPPORT
779 if (vfsflags & MS_MOVE)
780 update_mtab_entry_on_move(mp);
783 addmntent(mountTable, mp);
784 endmntent(mountTable);
786 if (ENABLE_FEATURE_CLEAN_UP) {
795 #if ENABLE_FEATURE_MOUNT_NFS
799 * Copyright (C) 1993 Rick Sladkey <jrs@world.std.com>
801 * Licensed under GPLv2, see file LICENSE in this source tree.
803 * Wed Feb 8 12:51:48 1995, biro@yggdrasil.com (Ross Biro): allow all port
804 * numbers to be specified on the command line.
806 * Fri, 8 Mar 1996 18:01:39, Swen Thuemmler <swen@uni-paderborn.de>:
807 * Omit the call to connect() for Linux version 1.3.11 or later.
809 * Wed Oct 1 23:55:28 1997: Dick Streefland <dick_streefland@tasking.com>
810 * Implemented the "bg", "fg" and "retry" mount options for NFS.
812 * 1999-02-22 Arkadiusz Mickiewicz <misiek@misiek.eu.org>
813 * - added Native Language Support
815 * Modified by Olaf Kirch and Trond Myklebust for new NFS code,
819 #define MOUNTPORT 635
820 #define MNTPATHLEN 1024
821 #define MNTNAMLEN 255
825 typedef char fhandle[FHSIZE];
828 unsigned int fhandle3_len;
840 MNT3ERR_NAMETOOLONG = 63,
841 MNT3ERR_NOTSUPP = 10004,
842 MNT3ERR_SERVERFAULT = 10006,
844 typedef enum mountstat3 mountstat3;
847 unsigned int fhs_status;
852 typedef struct fhstatus fhstatus;
854 struct mountres3_ok {
857 unsigned int auth_flavours_len;
858 char *auth_flavours_val;
861 typedef struct mountres3_ok mountres3_ok;
864 mountstat3 fhs_status;
866 mountres3_ok mountinfo;
869 typedef struct mountres3 mountres3;
871 typedef char *dirpath;
875 typedef struct mountbody *mountlist;
879 dirpath ml_directory;
882 typedef struct mountbody mountbody;
884 typedef struct groupnode *groups;
890 typedef struct groupnode groupnode;
892 typedef struct exportnode *exports;
899 typedef struct exportnode exportnode;
912 typedef struct ppathcnf ppathcnf;
914 #define MOUNTPROG 100005
917 #define MOUNTPROC_NULL 0
918 #define MOUNTPROC_MNT 1
919 #define MOUNTPROC_DUMP 2
920 #define MOUNTPROC_UMNT 3
921 #define MOUNTPROC_UMNTALL 4
922 #define MOUNTPROC_EXPORT 5
923 #define MOUNTPROC_EXPORTALL 6
925 #define MOUNTVERS_POSIX 2
927 #define MOUNTPROC_PATHCONF 7
931 #define MOUNTPROC3_NULL 0
932 #define MOUNTPROC3_MNT 1
933 #define MOUNTPROC3_DUMP 2
934 #define MOUNTPROC3_UMNT 3
935 #define MOUNTPROC3_UMNTALL 4
936 #define MOUNTPROC3_EXPORT 5
948 * We want to be able to compile mount on old kernels in such a way
949 * that the binary will work well on more recent kernels.
950 * Thus, if necessary we teach nfsmount.c the structure of new fields
951 * that will come later.
953 * Moreover, the new kernel includes conflict with glibc includes
954 * so it is easiest to ignore the kernel altogether (at compile time).
962 unsigned char data[64];
965 struct nfs_mount_data {
968 struct nfs2_fh old_root; /* 1 */
974 int acregmin; /* 1 */
975 int acregmax; /* 1 */
976 int acdirmin; /* 1 */
977 int acdirmax; /* 1 */
978 struct sockaddr_in addr; /* 1 */
979 char hostname[256]; /* 1 */
981 unsigned int bsize; /* 3 */
982 struct nfs3_fh root; /* 4 */
985 /* bits in the flags field */
987 NFS_MOUNT_SOFT = 0x0001, /* 1 */
988 NFS_MOUNT_INTR = 0x0002, /* 1 */
989 NFS_MOUNT_SECURE = 0x0004, /* 1 */
990 NFS_MOUNT_POSIX = 0x0008, /* 1 */
991 NFS_MOUNT_NOCTO = 0x0010, /* 1 */
992 NFS_MOUNT_NOAC = 0x0020, /* 1 */
993 NFS_MOUNT_TCP = 0x0040, /* 2 */
994 NFS_MOUNT_VER3 = 0x0080, /* 3 */
995 NFS_MOUNT_KERBEROS = 0x0100, /* 3 */
996 NFS_MOUNT_NONLM = 0x0200, /* 3 */
997 NFS_MOUNT_NOACL = 0x0800, /* 4 */
998 NFS_MOUNT_NORDIRPLUS = 0x4000
1003 * We need to translate between nfs status return values and
1004 * the local errno values which may not be the same.
1006 * Andreas Schwab <schwab@LS5.informatik.uni-dortmund.de>: change errno:
1007 * "after #include <errno.h> the symbol errno is reserved for any use,
1008 * it cannot even be used as a struct tag or field name".
1011 # define EDQUOT ENOSPC
1013 /* Convert each NFSERR_BLAH into EBLAH */
1014 static const uint8_t nfs_err_stat[] ALIGN1 = {
1016 19, 20, 21, 22, 27, 28,
1017 30, 63, 66, 69, 70, 71
1020 EPERM | ENOENT | EIO | ENXIO | EACCES| EEXIST | \
1021 ENODEV| ENOTDIR | EISDIR | EINVAL| EFBIG | ENOSPC | \
1022 EROFS | ENAMETOOLONG| ENOTEMPTY| EDQUOT| ESTALE| EREMOTE) < 256
1023 typedef uint8_t nfs_err_type;
1025 typedef uint16_t nfs_err_type;
1027 static const nfs_err_type nfs_err_errnum[] ALIGN2 = {
1028 EPERM , ENOENT , EIO , ENXIO , EACCES, EEXIST,
1029 ENODEV, ENOTDIR , EISDIR , EINVAL, EFBIG , ENOSPC,
1030 EROFS , ENAMETOOLONG, ENOTEMPTY, EDQUOT, ESTALE, EREMOTE
1032 static char *nfs_strerror(int status)
1036 for (i = 0; i < ARRAY_SIZE(nfs_err_stat); i++) {
1037 if (nfs_err_stat[i] == status)
1038 return strerror(nfs_err_errnum[i]);
1040 return xasprintf("unknown nfs status return value: %d", status);
1043 static bool_t xdr_fhandle(XDR *xdrs, fhandle objp)
1045 return xdr_opaque(xdrs, objp, FHSIZE);
1048 static bool_t xdr_fhstatus(XDR *xdrs, fhstatus *objp)
1050 if (!xdr_u_int(xdrs, &objp->fhs_status))
1052 if (objp->fhs_status == 0)
1053 return xdr_fhandle(xdrs, objp->fhstatus_u.fhs_fhandle);
1057 static bool_t xdr_dirpath(XDR *xdrs, dirpath *objp)
1059 return xdr_string(xdrs, objp, MNTPATHLEN);
1062 static bool_t xdr_fhandle3(XDR *xdrs, fhandle3 *objp)
1064 return xdr_bytes(xdrs, (char **)&objp->fhandle3_val,
1065 (unsigned int *) &objp->fhandle3_len,
1069 static bool_t xdr_mountres3_ok(XDR *xdrs, mountres3_ok *objp)
1071 if (!xdr_fhandle3(xdrs, &objp->fhandle))
1073 return xdr_array(xdrs, &(objp->auth_flavours.auth_flavours_val),
1074 &(objp->auth_flavours.auth_flavours_len),
1077 (xdrproc_t) xdr_int);
1080 static bool_t xdr_mountstat3(XDR *xdrs, mountstat3 *objp)
1082 return xdr_enum(xdrs, (enum_t *) objp);
1085 static bool_t xdr_mountres3(XDR *xdrs, mountres3 *objp)
1087 if (!xdr_mountstat3(xdrs, &objp->fhs_status))
1089 if (objp->fhs_status == MNT_OK)
1090 return xdr_mountres3_ok(xdrs, &objp->mountres3_u.mountinfo);
1094 #define MAX_NFSPROT ((nfs_mount_version >= 4) ? 3 : 2)
1097 * Unfortunately, the kernel prints annoying console messages
1098 * in case of an unexpected nfs mount version (instead of
1099 * just returning some error). Therefore we'll have to try
1100 * and figure out what version the kernel expects.
1103 * KERNEL_NFS_MOUNT_VERSION: kernel sources at compile time
1104 * NFS_MOUNT_VERSION: these nfsmount sources at compile time
1105 * nfs_mount_version: version this source and running kernel can handle
1108 find_kernel_nfs_mount_version(void)
1112 if (nfs_mount_version)
1115 nfs_mount_version = 4; /* default */
1117 kernel_version = get_linux_version_code();
1118 if (kernel_version) {
1119 if (kernel_version < KERNEL_VERSION(2,2,18))
1120 nfs_mount_version = 3;
1121 /* else v4 since 2.3.99pre4 */
1126 get_mountport(struct pmap *pm_mnt,
1127 struct sockaddr_in *server_addr,
1129 long unsigned version,
1130 long unsigned proto,
1133 struct pmaplist *pmap;
1135 server_addr->sin_port = PMAPPORT;
1136 /* glibc 2.4 (still) has pmap_getmaps(struct sockaddr_in *).
1137 * I understand it like "IPv6 for this is not 100% ready" */
1138 pmap = pmap_getmaps(server_addr);
1140 if (version > MAX_NFSPROT)
1141 version = MAX_NFSPROT;
1144 pm_mnt->pm_prog = prog;
1145 pm_mnt->pm_vers = version;
1146 pm_mnt->pm_prot = proto;
1147 pm_mnt->pm_port = port;
1150 if (pmap->pml_map.pm_prog != prog)
1152 if (!version && pm_mnt->pm_vers > pmap->pml_map.pm_vers)
1154 if (version > 2 && pmap->pml_map.pm_vers != version)
1156 if (version && version <= 2 && pmap->pml_map.pm_vers > 2)
1158 if (pmap->pml_map.pm_vers > MAX_NFSPROT
1159 || (proto && pm_mnt->pm_prot && pmap->pml_map.pm_prot != proto)
1160 || (port && pmap->pml_map.pm_port != port)
1164 memcpy(pm_mnt, &pmap->pml_map, sizeof(*pm_mnt));
1166 pmap = pmap->pml_next;
1168 if (!pm_mnt->pm_vers)
1169 pm_mnt->pm_vers = MOUNTVERS;
1170 if (!pm_mnt->pm_port)
1171 pm_mnt->pm_port = MOUNTPORT;
1172 if (!pm_mnt->pm_prot)
1173 pm_mnt->pm_prot = IPPROTO_TCP;
1177 static int daemonize(void)
1180 if (pid < 0) /* error */
1182 if (pid > 0) /* parent */
1186 xopen(bb_dev_null, O_RDWR);
1190 openlog(applet_name, LOG_PID, LOG_DAEMON);
1191 logmode = LOGMODE_SYSLOG;
1195 static inline int daemonize(void) { return -ENOSYS; }
1199 static inline int we_saw_this_host_before(const char *hostname UNUSED_PARAM)
1204 /* RPC strerror analogs are terminally idiotic:
1205 * *mandatory* prefix and \n at end.
1206 * This hopefully helps. Usage:
1207 * error_msg_rpc(clnt_*error*(" ")) */
1208 static void error_msg_rpc(const char *msg)
1211 while (msg[0] == ' ' || msg[0] == ':') msg++;
1213 while (len && msg[len-1] == '\n') len--;
1214 bb_error_msg("%.*s", len, msg);
1217 /* NB: mp->xxx fields may be trashed on exit */
1218 static NOINLINE int nfsmount(struct mntent *mp, unsigned long vfsflags, char *filteropts)
1224 /* prior to 2.6.23, kernel took NFS options in a form of this struct
1225 * only. 2.6.23+ looks at data->version, and if it's not 1..6,
1226 * then data pointer is interpreted as a string. */
1227 struct nfs_mount_data data;
1230 struct sockaddr_in server_addr;
1231 struct sockaddr_in mount_server_addr;
1234 struct fhstatus nfsv2;
1235 struct mountres3 nfsv3;
1253 /* these all are one-bit really. gcc 4.3.1 likes this combination: */
1264 find_kernel_nfs_mount_version();
1272 /* NB: hostname, mounthost, filteropts must be free()d prior to return */
1274 filteropts = xstrdup(filteropts); /* going to trash it later... */
1276 hostname = xstrdup(mp->mnt_fsname);
1277 /* mount_main() guarantees that ':' is there */
1278 s = strchr(hostname, ':');
1281 /* Ignore all but first hostname in replicated mounts
1282 * until they can be fully supported. (mack@sgi.com) */
1283 s = strchr(hostname, ',');
1286 bb_error_msg("warning: multiple hostnames not supported");
1289 server_addr.sin_family = AF_INET;
1290 if (!inet_aton(hostname, &server_addr.sin_addr)) {
1291 hp = gethostbyname(hostname);
1293 bb_herror_msg("%s", hostname);
1296 if (hp->h_length != (int)sizeof(struct in_addr)) {
1297 bb_error_msg_and_die("only IPv4 is supported");
1299 memcpy(&server_addr.sin_addr, hp->h_addr_list[0], sizeof(struct in_addr));
1302 memcpy(&mount_server_addr, &server_addr, sizeof(mount_server_addr));
1304 /* add IP address to mtab options for use when unmounting */
1306 if (!mp->mnt_opts) { /* TODO: actually mp->mnt_opts is never NULL */
1307 mp->mnt_opts = xasprintf("addr=%s", inet_ntoa(server_addr.sin_addr));
1309 char *tmp = xasprintf("%s%saddr=%s", mp->mnt_opts,
1310 mp->mnt_opts[0] ? "," : "",
1311 inet_ntoa(server_addr.sin_addr));
1316 /* Set default options.
1317 * rsize/wsize (and bsize, for ver >= 3) are left 0 in order to
1318 * let the kernel decide.
1319 * timeo is filled in after we know whether it'll be TCP or UDP. */
1320 memset(&data, 0, sizeof(data));
1326 data.namlen = NAME_MAX;
1336 retry = 10000; /* 10000 minutes ~ 1 week */
1337 tcp = 1; /* nfs-utils uses tcp per default */
1339 mountprog = MOUNTPROG;
1347 if (filteropts) for (opt = strtok(filteropts, ","); opt; opt = strtok(NULL, ",")) {
1348 char *opteq = strchr(opt, '=');
1351 static const char options[] ALIGN1 =
1356 /* 4 */ "acregmin\0"
1357 /* 5 */ "acregmax\0"
1358 /* 6 */ "acdirmin\0"
1359 /* 7 */ "acdirmax\0"
1363 /* 11 */ "mountport\0"
1364 /* 12 */ "mounthost\0"
1365 /* 13 */ "mountprog\0"
1366 /* 14 */ "mountvers\0"
1367 /* 15 */ "nfsprog\0"
1368 /* 16 */ "nfsvers\0"
1375 idx = index_in_strings(options, opt);
1377 case 12: // "mounthost"
1378 mounthost = xstrndup(opteq,
1379 strcspn(opteq, " \t\n\r,"));
1382 if (is_prefixed_with(opteq, "tcp"))
1384 else if (is_prefixed_with(opteq, "udp"))
1387 bb_error_msg("warning: unrecognized proto= option");
1389 case 20: // "addr" - ignore
1392 if (vfsflags & MS_REMOUNT)
1396 val = xatoi_positive(opteq);
1407 case 3: // "retrans"
1410 case 4: // "acregmin"
1411 data.acregmin = val;
1413 case 5: // "acregmax"
1414 data.acregmax = val;
1416 case 6: // "acdirmin"
1417 data.acdirmin = val;
1419 case 7: // "acdirmax"
1420 data.acdirmax = val;
1422 case 8: // "actimeo"
1423 data.acregmin = val;
1424 data.acregmax = val;
1425 data.acdirmin = val;
1426 data.acdirmax = val;
1434 case 11: // "mountport"
1437 case 13: // "mountprog"
1440 case 14: // "mountvers"
1443 case 15: // "nfsprog"
1446 case 16: // "nfsvers"
1450 case 19: // "namlen"
1451 //if (nfs_mount_version >= 2)
1454 // bb_error_msg("warning: option namlen is not supported\n");
1457 bb_error_msg("unknown nfs mount parameter: %s=%d", opt, val);
1461 else { /* not of the form opt=val */
1462 static const char options[] ALIGN1 =
1477 if (is_prefixed_with(opt, "no")) {
1481 switch (index_in_strings(options, opt)) {
1517 if (nfs_mount_version >= 3)
1520 bb_error_msg("warning: option nolock is not supported");
1529 bb_error_msg("unknown nfs mount option: %s%s", val ? "" : "no", opt);
1534 proto = (tcp) ? IPPROTO_TCP : IPPROTO_UDP;
1536 data.flags = (soft ? NFS_MOUNT_SOFT : 0)
1537 | (intr ? NFS_MOUNT_INTR : 0)
1538 | (posix ? NFS_MOUNT_POSIX : 0)
1539 | (nocto ? NFS_MOUNT_NOCTO : 0)
1540 | (noac ? NFS_MOUNT_NOAC : 0)
1541 | (nordirplus ? NFS_MOUNT_NORDIRPLUS : 0)
1542 | (noacl ? NFS_MOUNT_NOACL : 0);
1543 if (nfs_mount_version >= 2)
1544 data.flags |= (tcp ? NFS_MOUNT_TCP : 0);
1545 if (nfs_mount_version >= 3)
1546 data.flags |= (nolock ? NFS_MOUNT_NONLM : 0);
1547 if (nfsvers > MAX_NFSPROT || mountvers > MAX_NFSPROT) {
1548 bb_error_msg("NFSv%d not supported", nfsvers);
1551 if (nfsvers && !mountvers)
1552 mountvers = (nfsvers < 3) ? 1 : nfsvers;
1553 if (nfsvers && nfsvers < mountvers) {
1554 mountvers = nfsvers;
1557 /* Adjust options if none specified */
1559 data.timeo = tcp ? 70 : 7;
1561 data.version = nfs_mount_version;
1563 if (vfsflags & MS_REMOUNT)
1567 * If the previous mount operation on the same host was
1568 * backgrounded, and the "bg" for this mount is also set,
1569 * give up immediately, to avoid the initial timeout.
1571 if (bg && we_saw_this_host_before(hostname)) {
1572 daemonized = daemonize();
1573 if (daemonized <= 0) { /* parent or error */
1574 retval = -daemonized;
1579 /* Create mount daemon client */
1580 /* See if the nfs host = mount host. */
1582 if (mounthost[0] >= '0' && mounthost[0] <= '9') {
1583 mount_server_addr.sin_family = AF_INET;
1584 mount_server_addr.sin_addr.s_addr = inet_addr(hostname);
1586 hp = gethostbyname(mounthost);
1588 bb_herror_msg("%s", mounthost);
1591 if (hp->h_length != (int)sizeof(struct in_addr)) {
1592 bb_error_msg_and_die("only IPv4 is supported");
1594 mount_server_addr.sin_family = AF_INET;
1595 memcpy(&mount_server_addr.sin_addr, hp->h_addr_list[0], sizeof(struct in_addr));
1600 * The following loop implements the mount retries. When the mount
1601 * times out, and the "bg" option is set, we background ourself
1602 * and continue trying.
1604 * The case where the mount point is not present and the "bg"
1605 * option is set, is treated as a timeout. This is done to
1606 * support nested mounts.
1608 * The "retry" count specified by the user is the number of
1609 * minutes to retry before giving up.
1612 struct timeval total_timeout;
1613 struct timeval retry_timeout;
1619 retry_timeout.tv_sec = 3;
1620 retry_timeout.tv_usec = 0;
1621 total_timeout.tv_sec = 20;
1622 total_timeout.tv_usec = 0;
1623 /* FIXME: use monotonic()? */
1624 timeout = time(NULL) + 60 * retry;
1628 /* Be careful not to use too many CPU cycles */
1632 get_mountport(&pm_mnt, &mount_server_addr,
1637 nfsvers = (pm_mnt.pm_vers < 2) ? 2 : pm_mnt.pm_vers;
1639 /* contact the mount daemon via TCP */
1640 mount_server_addr.sin_port = htons(pm_mnt.pm_port);
1641 msock = RPC_ANYSOCK;
1643 switch (pm_mnt.pm_prot) {
1645 mclient = clntudp_create(&mount_server_addr,
1652 mount_server_addr.sin_port = htons(pm_mnt.pm_port);
1653 msock = RPC_ANYSOCK;
1655 mclient = clnttcp_create(&mount_server_addr,
1664 if (!daemonized && prevt == 0)
1665 error_msg_rpc(clnt_spcreateerror(" "));
1667 enum clnt_stat clnt_stat;
1669 /* Try to mount hostname:pathname */
1670 mclient->cl_auth = authunix_create_default();
1672 /* Make pointers in xdr_mountres3 NULL so
1673 * that xdr_array allocates memory for us
1675 memset(&status, 0, sizeof(status));
1677 if (pm_mnt.pm_vers == 3)
1678 clnt_stat = clnt_call(mclient, MOUNTPROC3_MNT,
1679 (xdrproc_t) xdr_dirpath,
1680 (caddr_t) &pathname,
1681 (xdrproc_t) xdr_mountres3,
1685 clnt_stat = clnt_call(mclient, MOUNTPROC_MNT,
1686 (xdrproc_t) xdr_dirpath,
1687 (caddr_t) &pathname,
1688 (xdrproc_t) xdr_fhstatus,
1692 if (clnt_stat == RPC_SUCCESS)
1693 goto prepare_kernel_data; /* we're done */
1694 if (errno != ECONNREFUSED) {
1695 error_msg_rpc(clnt_sperror(mclient, " "));
1696 goto fail; /* don't retry */
1698 /* Connection refused */
1699 if (!daemonized && prevt == 0) /* print just once */
1700 error_msg_rpc(clnt_sperror(mclient, " "));
1701 auth_destroy(mclient->cl_auth);
1702 clnt_destroy(mclient);
1708 /* Timeout. We are going to retry... maybe */
1712 daemonized = daemonize();
1713 if (daemonized <= 0) { /* parent or error */
1714 retval = -daemonized;
1721 /* TODO error message */
1727 prepare_kernel_data:
1730 if (status.nfsv2.fhs_status != 0) {
1731 bb_error_msg("%s:%s failed, reason given by server: %s",
1733 nfs_strerror(status.nfsv2.fhs_status));
1736 memcpy(data.root.data,
1737 (char *) status.nfsv2.fhstatus_u.fhs_fhandle,
1739 data.root.size = NFS_FHSIZE;
1740 memcpy(data.old_root.data,
1741 (char *) status.nfsv2.fhstatus_u.fhs_fhandle,
1744 fhandle3 *my_fhandle;
1745 if (status.nfsv3.fhs_status != 0) {
1746 bb_error_msg("%s:%s failed, reason given by server: %s",
1748 nfs_strerror(status.nfsv3.fhs_status));
1751 my_fhandle = &status.nfsv3.mountres3_u.mountinfo.fhandle;
1752 memset(data.old_root.data, 0, NFS_FHSIZE);
1753 memset(&data.root, 0, sizeof(data.root));
1754 data.root.size = my_fhandle->fhandle3_len;
1755 memcpy(data.root.data,
1756 (char *) my_fhandle->fhandle3_val,
1757 my_fhandle->fhandle3_len);
1759 data.flags |= NFS_MOUNT_VER3;
1762 /* Create nfs socket for kernel */
1764 if (nfs_mount_version < 3) {
1765 bb_error_msg("NFS over TCP is not supported");
1768 fsock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
1770 fsock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
1772 bb_perror_msg("nfs socket");
1775 if (bindresvport(fsock, 0) < 0) {
1776 bb_perror_msg("nfs bindresvport");
1780 server_addr.sin_port = PMAPPORT;
1781 port = pmap_getport(&server_addr, nfsprog, nfsvers,
1782 tcp ? IPPROTO_TCP : IPPROTO_UDP);
1786 server_addr.sin_port = htons(port);
1788 /* Prepare data structure for kernel */
1790 memcpy((char *) &data.addr, (char *) &server_addr, sizeof(data.addr));
1791 strncpy(data.hostname, hostname, sizeof(data.hostname));
1794 auth_destroy(mclient->cl_auth);
1795 clnt_destroy(mclient);
1800 /* We must wait until mount directory is available */
1801 struct stat statbuf;
1803 while (stat(mp->mnt_dir, &statbuf) == -1) {
1805 daemonized = daemonize();
1806 if (daemonized <= 0) { /* parent or error */
1807 /* FIXME: parent doesn't close fsock - ??! */
1808 retval = -daemonized;
1812 sleep(delay); /* 1, 2, 4, 8, 16, 30, ... */
1819 /* Perform actual mount */
1821 retval = mount_it_now(mp, vfsflags, (char*)&data);
1828 auth_destroy(mclient->cl_auth);
1829 clnt_destroy(mclient);
1843 #else // !ENABLE_FEATURE_MOUNT_NFS
1845 /* Linux 2.6.23+ supports nfs mounts with options passed as a string.
1846 * For older kernels, you must build busybox with ENABLE_FEATURE_MOUNT_NFS.
1847 * (However, note that then you lose any chances that NFS over IPv6 would work).
1849 static int nfsmount(struct mntent *mp, unsigned long vfsflags, char *filteropts)
1851 len_and_sockaddr *lsa;
1857 # if ENABLE_FEATURE_IPV6
1858 end = strchr(mp->mnt_fsname, ']');
1859 if (end && end[1] == ':')
1863 /* mount_main() guarantees that ':' is there */
1864 end = strchr(mp->mnt_fsname, ':');
1867 lsa = xhost2sockaddr(mp->mnt_fsname, /*port:*/ 0);
1869 dotted = xmalloc_sockaddr2dotted_noport(&lsa->u.sa);
1870 if (ENABLE_FEATURE_CLEAN_UP) free(lsa);
1871 opts = xasprintf("%s%saddr=%s",
1872 filteropts ? filteropts : "",
1873 filteropts ? "," : "",
1876 if (ENABLE_FEATURE_CLEAN_UP) free(dotted);
1877 ret = mount_it_now(mp, vfsflags, opts);
1878 if (ENABLE_FEATURE_CLEAN_UP) free(opts);
1883 #endif // !ENABLE_FEATURE_MOUNT_NFS
1885 // Mount one directory. Handles CIFS, NFS, loopback, autobind, and filesystem
1886 // type detection. Returns 0 for success, nonzero for failure.
1887 // NB: mp->xxx fields may be trashed on exit
1888 static int singlemount(struct mntent *mp, int ignore_busy)
1891 unsigned long vfsflags;
1892 char *loopFile = NULL, *filteropts = NULL;
1898 vfsflags = parse_mount_options(mp->mnt_opts, &filteropts);
1900 // Treat fstype "auto" as unspecified
1901 if (mp->mnt_type && strcmp(mp->mnt_type, "auto") == 0)
1902 mp->mnt_type = NULL;
1904 // Might this be a virtual filesystem?
1905 if (ENABLE_FEATURE_MOUNT_HELPERS && strchr(mp->mnt_fsname, '#')) {
1909 // fsname: "cmd#arg1#arg2..."
1910 // WARNING: allows execution of arbitrary commands!
1911 // Try "mount 'sh#-c#sh' bogus_dir".
1912 // It is safe ONLY because non-root
1913 // cannot use two-argument mount command
1914 // and using one-argument "mount 'sh#-c#sh'" doesn't work:
1915 // "mount: can't find sh#-c#sh in /etc/fstab"
1916 // (if /etc/fstab has it, it's ok: root sets up /etc/fstab).
1921 while (*s && n < 35 - 2) {
1922 if (*s++ == '#' && *s != '#') {
1927 args[n++] = mp->mnt_dir;
1929 rc = spawn_and_wait(args);
1933 // Might this be an CIFS filesystem?
1934 if (ENABLE_FEATURE_MOUNT_CIFS
1935 && (!mp->mnt_type || strcmp(mp->mnt_type, "cifs") == 0)
1936 && (mp->mnt_fsname[0] == '/' || mp->mnt_fsname[0] == '\\')
1937 && mp->mnt_fsname[0] == mp->mnt_fsname[1]
1941 char *hostname, *share;
1942 len_and_sockaddr *lsa;
1944 // Parse mp->mnt_fsname of the form "//hostname/share[/dir1/dir2]"
1946 hostname = mp->mnt_fsname + 2;
1947 len = strcspn(hostname, "/\\");
1948 share = hostname + len + 1;
1949 if (len == 0 // 3rd char is a [back]slash (IOW: empty hostname)
1950 || share[-1] == '\0' // no [back]slash after hostname
1951 || share[0] == '\0' // empty share name
1957 len = strcspn(share, "/\\");
1959 // "unc=\\hostname\share" option is mandatory
1960 // after CIFS option parsing was rewritten in Linux 3.4.
1961 // Must use backslashes.
1962 // If /dir1/dir2 is present, also add "prefixpath=dir1/dir2"
1964 char *unc = xasprintf(
1965 share[len] != '\0' /* "/dir1/dir2" exists? */
1966 ? "unc=\\\\%s\\%.*s,prefixpath=%s"
1967 : "unc=\\\\%s\\%.*s",
1970 share + len + 1 /* "dir1/dir2" */
1972 parse_mount_options(unc, &filteropts);
1973 if (ENABLE_FEATURE_CLEAN_UP) free(unc);
1976 lsa = host2sockaddr(hostname, 0);
1981 // If there is no "ip=..." option yet
1982 if (!is_prefixed_with(filteropts, ",ip="+1)
1983 && !strstr(filteropts, ",ip=")
1986 // Insert "ip=..." option into options
1987 dotted = xmalloc_sockaddr2dotted_noport(&lsa->u.sa);
1988 if (ENABLE_FEATURE_CLEAN_UP) free(lsa);
1989 ip = xasprintf("ip=%s", dotted);
1990 if (ENABLE_FEATURE_CLEAN_UP) free(dotted);
1991 // Note: IPv6 scoped addresses ("host%iface", see RFC 4007) should be
1992 // handled by libc in getnameinfo() (inside xmalloc_sockaddr2dotted_noport()).
1993 // Currently, glibc does not support that (has no NI_NUMERICSCOPE),
1994 // musl apparently does. This results in "ip=numericIPv6%iface_name"
1995 // (instead of _numeric_ iface_id) with glibc.
1996 // This probably should be fixed in glibc, not here.
1997 // The workaround is to manually specify correct "ip=ADDR%n" option.
1998 parse_mount_options(ip, &filteropts);
1999 if (ENABLE_FEATURE_CLEAN_UP) free(ip);
2002 mp->mnt_type = (char*)"cifs";
2003 rc = mount_it_now(mp, vfsflags, filteropts);
2008 // Might this be an NFS filesystem?
2009 if ((!mp->mnt_type || is_prefixed_with(mp->mnt_type, "nfs"))
2010 && strchr(mp->mnt_fsname, ':') != NULL
2013 mp->mnt_type = (char*)"nfs";
2014 rc = nfsmount(mp, vfsflags, filteropts);
2018 // Look at the file. (Not found isn't a failure for remount, or for
2019 // a synthetic filesystem like proc or sysfs.)
2020 // (We use stat, not lstat, in order to allow
2021 // mount symlink_to_file_or_blkdev dir)
2022 if (!stat(mp->mnt_fsname, &st)
2023 && !(vfsflags & (MS_REMOUNT | MS_BIND | MS_MOVE))
2025 // Do we need to allocate a loopback device for it?
2026 if (ENABLE_FEATURE_MOUNT_LOOP && S_ISREG(st.st_mode)) {
2027 loopFile = bb_simplify_path(mp->mnt_fsname);
2028 mp->mnt_fsname = NULL; // will receive malloced loop dev name
2029 if (set_loop(&mp->mnt_fsname, loopFile, 0, /*ro:*/ (vfsflags & MS_RDONLY)) < 0) {
2030 if (errno == EPERM || errno == EACCES)
2031 bb_error_msg(bb_msg_perm_denied_are_you_root);
2033 bb_perror_msg("can't setup loop device");
2037 // Autodetect bind mounts
2038 } else if (S_ISDIR(st.st_mode) && !mp->mnt_type)
2039 vfsflags |= MS_BIND;
2042 // If we know the fstype (or don't need to), jump straight
2043 // to the actual mount.
2044 if (mp->mnt_type || (vfsflags & (MS_REMOUNT | MS_BIND | MS_MOVE))) {
2047 next = mp->mnt_type ? strchr(mp->mnt_type, ',') : NULL;
2050 rc = mount_it_now(mp, vfsflags, filteropts);
2051 if (rc == 0 || !next)
2053 mp->mnt_type = next + 1;
2056 // Loop through filesystem types until mount succeeds
2059 // Initialize list of block backed filesystems.
2060 // This has to be done here so that during "mount -a",
2061 // mounts after /proc shows up can autodetect.
2063 fslist = get_block_backed_filesystems();
2064 if (ENABLE_FEATURE_CLEAN_UP && fslist)
2065 atexit(delete_block_backed_filesystems);
2068 for (fl = fslist; fl; fl = fl->link) {
2069 mp->mnt_type = fl->data;
2070 rc = mount_it_now(mp, vfsflags, filteropts);
2076 // If mount failed, clean up loop file (if any).
2077 if (ENABLE_FEATURE_MOUNT_LOOP && rc && loopFile) {
2078 del_loop(mp->mnt_fsname);
2079 if (ENABLE_FEATURE_CLEAN_UP) {
2081 /* No, "rc != 0" needs it: free(mp->mnt_fsname); */
2086 if (ENABLE_FEATURE_CLEAN_UP)
2089 if (errno == EBUSY && ignore_busy)
2091 if (errno == ENOENT && (vfsflags & MOUNT_NOFAIL))
2094 bb_perror_msg("mounting %s on %s failed", mp->mnt_fsname, mp->mnt_dir);
2099 // -O interprets a list of filter options which select whether a mount
2100 // point will be mounted: only mounts with options matching *all* filtering
2101 // options will be selected.
2102 // By default each -O filter option must be present in the list of mount
2103 // options, but if it is prefixed by "no" then it must be absent.
2105 // -O a,nob,c matches -o a,c but fails to match -o a,b,c
2106 // (and also fails to match -o a because -o c is absent).
2108 // It is different from -t in that each option is matched exactly; a leading
2109 // "no" at the beginning of one option does not negate the rest.
2110 static int match_opt(const char *fs_opt_in, const char *O_opt)
2116 const char *fs_opt = fs_opt_in;
2120 // If option begins with "no" then treat as an inverted match:
2121 // matching is a failure
2123 if (O_opt[0] == 'n' && O_opt[1] == 'o') {
2127 // Isolate the current O option
2128 O_len = strchrnul(O_opt, ',') - O_opt;
2129 // Check for a match against existing options
2131 if (strncmp(fs_opt, O_opt, O_len) == 0
2132 && (fs_opt[O_len] == '\0' || fs_opt[O_len] == ',')
2135 return 0; // "no" prefix, but option found
2136 match = 1; // current O option found, go check next one
2139 fs_opt = strchr(fs_opt, ',');
2145 return 0; // match wanted but not found
2146 if (O_opt[O_len] == '\0') // end?
2148 // Step to the next O option
2151 // If we get here then everything matched
2155 // Parse options, if necessary parse fstab/mtab, and call singlemount for
2156 // each directory to be mounted.
2157 int mount_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
2158 int mount_main(int argc UNUSED_PARAM, char **argv)
2160 char *cmdopts = xzalloc(1);
2161 char *fstype = NULL;
2162 char *O_optmatch = NULL;
2164 llist_t *lst_o = NULL;
2165 const char *fstabname = "/etc/fstab";
2168 int rc = EXIT_SUCCESS;
2169 unsigned long cmdopt_flags;
2171 struct mntent mtpair[2], *mtcur = mtpair;
2172 IF_NOT_DESKTOP(const int nonroot = 0;)
2174 IF_DESKTOP(int nonroot = ) sanitize_env_if_suid();
2178 // Parse long options, like --bind and --move. Note that -o option
2179 // and --option are synonymous. Yes, this means --remount,rw works.
2180 for (i = j = 1; argv[i]; i++) {
2181 if (argv[i][0] == '-' && argv[i][1] == '-')
2182 append_mount_options(&cmdopts, argv[i] + 2);
2184 argv[j++] = argv[i];
2188 // Parse remaining options
2189 // Max 2 params; -o is a list, -v is a counter
2190 opt_complementary = "?2" IF_FEATURE_MOUNT_VERBOSE("vv");
2191 opt = getopt32(argv, OPTION_STR, &lst_o, &fstype, &O_optmatch
2192 IF_FEATURE_MOUNT_OTHERTAB(, &fstabname)
2193 IF_FEATURE_MOUNT_VERBOSE(, &verbose));
2194 while (lst_o) append_mount_options(&cmdopts, llist_pop(&lst_o)); // -o
2195 if (opt & OPT_r) append_mount_options(&cmdopts, "ro"); // -r
2196 if (opt & OPT_w) append_mount_options(&cmdopts, "rw"); // -w
2199 // If we have no arguments, show currently mounted filesystems
2201 if (!(opt & OPT_a)) {
2202 FILE *mountTable = setmntent(bb_path_mtab_file, "r");
2205 bb_error_msg_and_die("no %s", bb_path_mtab_file);
2207 while (getmntent_r(mountTable, &mtpair[0], getmntent_buf,
2210 // Don't show rootfs. FIXME: why??
2211 // util-linux 2.12a happily shows rootfs...
2212 //if (strcmp(mtpair->mnt_fsname, "rootfs") == 0) continue;
2214 if (!fstype || strcmp(mtpair->mnt_type, fstype) == 0)
2215 printf("%s on %s type %s (%s)\n", mtpair->mnt_fsname,
2216 mtpair->mnt_dir, mtpair->mnt_type,
2219 if (ENABLE_FEATURE_CLEAN_UP)
2220 endmntent(mountTable);
2221 return EXIT_SUCCESS;
2223 storage_path = NULL;
2225 // When we have two arguments, the second is the directory and we can
2226 // skip looking at fstab entirely. We can always abspath() the directory
2227 // argument when we get it.
2230 bb_error_msg_and_die(bb_msg_you_must_be_root);
2231 mtpair->mnt_fsname = argv[0];
2232 mtpair->mnt_dir = argv[1];
2233 mtpair->mnt_type = fstype;
2234 mtpair->mnt_opts = cmdopts;
2235 resolve_mount_spec(&mtpair->mnt_fsname);
2236 rc = singlemount(mtpair, /*ignore_busy:*/ 0);
2239 storage_path = bb_simplify_path(argv[0]); // malloced
2242 // Past this point, we are handling either "mount -a [opts]"
2243 // or "mount [opts] single_param"
2245 cmdopt_flags = parse_mount_options(cmdopts, NULL);
2246 if (nonroot && (cmdopt_flags & ~MS_SILENT)) // Non-root users cannot specify flags
2247 bb_error_msg_and_die(bb_msg_you_must_be_root);
2249 // If we have a shared subtree flag, don't worry about fstab or mtab.
2250 if (ENABLE_FEATURE_MOUNT_FLAGS
2251 && (cmdopt_flags & (MS_SHARED | MS_PRIVATE | MS_SLAVE | MS_UNBINDABLE))
2253 // verbose_mount(source, target, type, flags, data)
2254 rc = verbose_mount("", argv[0], "", cmdopt_flags, "");
2256 bb_simple_perror_msg_and_die(argv[0]);
2260 // A malicious user could overmount /usr without this.
2261 if (ENABLE_FEATURE_MOUNT_OTHERTAB && nonroot)
2262 fstabname = "/etc/fstab";
2263 // Open either fstab or mtab
2264 if (cmdopt_flags & MS_REMOUNT) {
2265 // WARNING. I am not sure this matches util-linux's
2266 // behavior. It's possible util-linux does not
2267 // take -o opts from mtab (takes only mount source).
2268 fstabname = bb_path_mtab_file;
2270 fstab = setmntent(fstabname, "r");
2272 bb_perror_msg_and_die("can't read '%s'", fstabname);
2274 // Loop through entries until we find what we're looking for
2275 memset(mtpair, 0, sizeof(mtpair));
2277 struct mntent *mtother = (mtcur==mtpair ? mtpair+1 : mtpair);
2279 // Get next fstab entry
2280 if (!getmntent_r(fstab, mtcur, getmntent_buf
2281 + (mtcur==mtpair ? GETMNTENT_BUFSIZE/2 : 0),
2282 GETMNTENT_BUFSIZE/2)
2283 ) { // End of fstab/mtab is reached
2284 mtcur = mtother; // the thing we found last time
2288 // If we're trying to mount something specific and this isn't it,
2289 // skip it. Note we must match the exact text in fstab (ala
2290 // "proc") or a full path from root
2293 // Is this what we're looking for?
2294 if (strcmp(argv[0], mtcur->mnt_fsname) != 0
2295 && strcmp(storage_path, mtcur->mnt_fsname) != 0
2296 && strcmp(argv[0], mtcur->mnt_dir) != 0
2297 && strcmp(storage_path, mtcur->mnt_dir) != 0
2302 // Remember this entry. Something later may have
2303 // overmounted it, and we want the _last_ match.
2306 // If we're mounting all
2309 // No, mount -a won't mount anything,
2310 // even user mounts, for mere humans
2312 bb_error_msg_and_die(bb_msg_you_must_be_root);
2314 // Does type match? (NULL matches always)
2315 if (!match_fstype(mtcur, fstype))
2318 // Skip noauto and swap anyway
2319 if ((parse_mount_options(mtcur->mnt_opts, NULL) & (MOUNT_NOAUTO | MOUNT_SWAP))
2320 // swap is bogus "fstype", parse_mount_options can't check fstypes
2321 || strcasecmp(mtcur->mnt_type, "swap") == 0
2326 // Does (at least one) option match?
2327 // (NULL matches always)
2328 if (!match_opt(mtcur->mnt_opts, O_optmatch))
2331 resolve_mount_spec(&mtcur->mnt_fsname);
2333 // NFS mounts want this to be xrealloc-able
2334 mtcur->mnt_opts = xstrdup(mtcur->mnt_opts);
2336 // If nothing is mounted on this directory...
2337 // (otherwise repeated "mount -a" mounts everything again)
2338 mp = find_mount_point(mtcur->mnt_dir, /*subdir_too:*/ 0);
2339 // We do not check fsname match of found mount point -
2340 // "/" may have fsname of "/dev/root" while fstab
2341 // says "/dev/something_else".
2344 bb_error_msg("according to %s, "
2345 "%s is already mounted on %s",
2347 mp->mnt_fsname, mp->mnt_dir);
2350 // ...mount this thing
2351 if (singlemount(mtcur, /*ignore_busy:*/ 1)) {
2352 // Count number of failed mounts
2356 free(mtcur->mnt_opts);
2360 // End of fstab/mtab is reached.
2361 // Were we looking for something specific?
2362 if (argv[0]) { // yes
2365 // If we didn't find anything, complain
2366 if (!mtcur->mnt_fsname)
2367 bb_error_msg_and_die("can't find %s in %s",
2368 argv[0], fstabname);
2370 // What happens when we try to "mount swap_partition"?
2371 // (fstab containts "swap_partition swap swap defaults 0 0")
2372 // util-linux-ng 2.13.1 does this:
2373 // stat("/sbin/mount.swap", 0x7fff62a3a350) = -1 ENOENT (No such file or directory)
2374 // mount("swap_partition", "swap", "swap", MS_MGC_VAL, NULL) = -1 ENOENT (No such file or directory)
2375 // lstat("swap", 0x7fff62a3a640) = -1 ENOENT (No such file or directory)
2376 // write(2, "mount: mount point swap does not exist\n", 39) = 39
2377 // exit_group(32) = ?
2379 // In case we want to simply skip swap partitions:
2380 l = parse_mount_options(mtcur->mnt_opts, NULL);
2381 if ((l & MOUNT_SWAP)
2382 // swap is bogus "fstype", parse_mount_options can't check fstypes
2383 || strcasecmp(mtcur->mnt_type, "swap") == 0
2389 // fstab must have "users" or "user"
2390 l = parse_mount_options(mtcur->mnt_opts, NULL);
2391 if (!(l & MOUNT_USERS))
2392 bb_error_msg_and_die(bb_msg_you_must_be_root);
2395 //util-linux-2.12 does not do this check.
2396 //// If nothing is mounted on this directory...
2397 //// (otherwise repeated "mount FOO" mounts FOO again)
2398 //mp = find_mount_point(mtcur->mnt_dir, /*subdir_too:*/ 0);
2400 // bb_error_msg("according to %s, "
2401 // "%s is already mounted on %s",
2402 // bb_path_mtab_file,
2403 // mp->mnt_fsname, mp->mnt_dir);
2405 // ...mount the last thing we found
2406 mtcur->mnt_opts = xstrdup(mtcur->mnt_opts);
2407 append_mount_options(&(mtcur->mnt_opts), cmdopts);
2408 resolve_mount_spec(&mtpair->mnt_fsname);
2409 rc = singlemount(mtcur, /*ignore_busy:*/ 0);
2410 if (ENABLE_FEATURE_CLEAN_UP)
2411 free(mtcur->mnt_opts);
2416 if (ENABLE_FEATURE_CLEAN_UP)
2418 if (ENABLE_FEATURE_CLEAN_UP) {
2423 //TODO: exitcode should be ORed mask of (from "man mount"):
2425 // 1 incorrect invocation or permissions
2426 // 2 system error (out of memory, cannot fork, no more loop devices)
2427 // 4 internal mount bug or missing nfs support in mount
2429 //16 problems writing or locking /etc/mtab
2431 //64 some mount succeeded