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authorRob Landley <rob@landley.net>2014-08-24 23:46:23 -0500
committerRob Landley <rob@landley.net>2014-08-24 23:46:23 -0500
commite996bddf88a946a8ac8338c02e14add57e3d588c (patch)
tree0ee8e48bd53058370b0a3203610aeb131bc62d8a /toys/pending/mount.c
parent5d16faa426b641aefe2d019cbbf76a3d49c4549f (diff)
downloadtoybox-e996bddf88a946a8ac8338c02e14add57e3d588c.tar.gz
Work in progress snapshot of mount, with fallout to umount. (Not done yet.)
Diffstat (limited to 'toys/pending/mount.c')
-rw-r--r--toys/pending/mount.c131
1 files changed, 96 insertions, 35 deletions
diff --git a/toys/pending/mount.c b/toys/pending/mount.c
index fc4406c1..c816a192 100644
--- a/toys/pending/mount.c
+++ b/toys/pending/mount.c
@@ -6,7 +6,7 @@
* Note: -hV is bad spec, haven't implemented -FsLU yet
* no mtab (/proc/mounts does it) so -n is NOP.
-USE_MOUNT(NEWTOY(mount, "?>2afnrvwt:o*[-rw]", TOYFLAG_USR|TOYFLAG_BIN|TOYFLAG_STAYROOT))
+USE_MOUNT(NEWTOY(mount, "?O:afnrvwt:o*[-rw]", TOYFLAG_USR|TOYFLAG_BIN|TOYFLAG_STAYROOT))
config MOUNT
bool "mount"
@@ -18,6 +18,7 @@ config MOUNT
mounts.
-a mount all entries in /etc/fstab (with -t, only entries of that TYPE)
+ -O only mount -a entries that have this option
-f fake it (don't actually mount)
-r read only (same as -o ro)
-w read/write (default, same as -o rw)
@@ -29,7 +30,8 @@ config MOUNT
This mount autodetects loopback mounts (a file on a directory) and
bind mounts (file on file, directory on directory), so you don't need
- to say --bind or --loop.
+ to say --bind or --loop. You can also "mount -a /path" to mount everything
+ in /etc/fstab under /path, even if it's noauto.
*/
#define FOR_mount
@@ -38,14 +40,27 @@ config MOUNT
GLOBALS(
struct arg_list *optlist;
char *type;
+ char *bigO;
unsigned long flags;
char *opts;
+ int okuser;
)
-// Strip flags out of comma separated list of options.
-// Return flags,
-static long parse_opts(char *new, long flags, char **more)
+// TODO detect existing identical mount (procfs with different dev name?)
+// TODO user, users, owner, group, nofail
+// TODO -p (passfd)
+// TODO -a -t notype,type2
+// TODO --subtree
+// TODO --rbind, -R
+// TODO make "mount --bind,ro old new" work (implicit -o remount)
+// TODO mount -a
+// TODO mount -o remount
+// TODO fstab: lookup default options for mount
+// TODO implement -v
+
+// Strip flags out of comma separated list of options, return flags,.
+static long flag_opts(char *new, long flags, char **more)
{
struct {
char *name;
@@ -53,6 +68,7 @@ static long parse_opts(char *new, long flags, char **more)
} opts[] = {
// NOPs (we autodetect --loop and --bind)
{"loop", 0}, {"bind", 0}, {"defaults", 0}, {"quiet", 0},
+ {"user", 0}, {"nouser", 0}, // checked in fstab, ignored in -o
// {"noauto", 0}, {"swap", 0},
{"ro", MS_RDONLY}, {"rw", ~MS_RDONLY},
{"nosuid", MS_NOSUID}, {"suid", ~MS_NOSUID},
@@ -70,7 +86,7 @@ static long parse_opts(char *new, long flags, char **more)
// mand dirsync rec iversion strictatime
};
- for (;;) {
+ if (new) for (;;) {
char *comma = strchr(new, ',');
int i;
@@ -110,17 +126,28 @@ static void mount_filesystem(char *dev, char *dir, char *type,
if (toys.optflags & FLAG_f) return;
+ if (getuid()) {
+ if (TT.okuser) TT.okuser = 0;
+ else {
+ error_msg("'%s' not user mountable in fstab");
+ return;
+ }
+ }
+
// Autodetect bind mount or filesystem type
- if (!type) {
+ if (!type || !strcmp(type, "auto")) {
struct stat stdev, stdir;
+ // file on file or dir on dir is a --bind mount.
if (!stat(dev, &stdev) && !stat(dir, &stdir)
&& ((S_ISREG(stdev.st_mode) && S_ISREG(stdir.st_mode))
|| (S_ISDIR(stdev.st_mode) && S_ISDIR(stdir.st_mode))))
{
flags |= MS_BIND;
} else fp = xfopen("/proc/filesystems", "r");
- }
+ } else if (!strcmp(type, "ignore")) return;
+ else if (!strcmp(type, "swap"))
+ toys.exitval |= xpclose(xpopen((char *[]){"swapon", "--", dev, 0}, 0), 0);
for (;;) {
char *buf = 0;
@@ -145,15 +172,17 @@ static void mount_filesystem(char *dev, char *dir, char *type,
printf("try '%s' type '%s' on '%s'\n", dev, type, dir);
rc = mount(dev, dir, type, flags, opts);
- // Looking for bind mounts in autodetect above isn't good enough because
- // "mount -t ext2 fs.img dir" is valid, but if you _do_ accept bind mounts
- // with -t how do you tell "-t cifs" isn't looking for a block device if
- // it's not in /proc/filesystems yet because the module that won't be
- // loaded until you try the mount, and if you can't then DEVICE
- // existing as a file would cause a false positive loopback mount.
+ // Trying to autodetect loop mounts like bind mounts above (file on dir)
+ // isn't good enough because "mount -t ext2 fs.img dir" is valid, but if
+ // you _do_ accept loop mounts with -t how do you tell "-t cifs" isn't
+ // looking for a block device if it's not in /proc/filesystems yet
+ // because the module that won't be loaded until you try the mount, and
+ // if you can't then DEVICE existing as a file would cause a false
+ // positive loopback mount (so "touch servername" becomes a potential
+ // denial of service attack...)
//
- // Solution: try mount, let the kernel tell us it wanted a block device,
- // do the loopback setup and retry the mount.
+ // Solution: try the mount, let the kernel tell us it wanted a block device,
+ // then do the loopback setup and retry the mount.
if (rc && errno == ENOTBLK) {
char *losetup[] = {"losetup", "-fs", dev, 0};
int pipes[2], len;
@@ -181,39 +210,71 @@ static void mount_filesystem(char *dev, char *dir, char *type,
void mount_main(void)
{
+ char *opts = 0, *dev = 0, *dir = 0, **ss;
long flags = MS_SILENT;
struct arg_list *o;
- char *opts = 0;
-
- if (toys.optflags & FLAG_a) {
- fprintf(stderr, "not yet\n");
- return;
- }
+ struct mtab_list *mtl, *mm;
+// TODO what do mount -aw and -ar do?
+ for (o = TT.optlist; o; o = o->next) flags = flag_opts(o->arg, flags, &opts);
if (toys.optflags & FLAG_r) flags |= MS_RDONLY;
if (toys.optflags & FLAG_w) flags &= ~MS_RDONLY;
- for (o = TT.optlist; o; o = o->next)
- flags = parse_opts(o->arg, flags, &opts);
- // show mounts
- if (!toys.optc) {
- struct mtab_list *mtl = xgetmountlist(0), *m;
+ // Treat each --option as -o option
+ for (ss = toys.optargs; *ss; ss++) {
+ if ((*ss)[0] && (*ss)[1]) flags = flag_opts(2+*ss, flags, &opts);
+ else if (!dev) dev = *ss;
+ else if (!dir) dir = *ss;
+ // same message as lib/args.c ">2" which we can't use because --opts count
+ else error_exit("Max 2 arguments\n");
+ }
- for (mtl = xgetmountlist(0); mtl && (m = dlist_pop(&mtl)); free(m)) {
+ if ((toys.optflags & FLAG_a) && dir) error_exit("-a with DIR");
+
+ // Do we need to do an /etc/fstab trawl?
+ if (toys.optflags & FLAG_a || !dir || getpid()) {
+ for (mtl = xgetmountlist("/etc/fstab"); mtl && (mm = dlist_pop(&mtl));
+ free(mm))
+ {
+ char *aopts = opts ? xstrdup(opts) : 0;
+ int aflags;
+
+ if (toys.optflags & FLAG_a) {
+ if (!mountlist_istype(mtl,TT.type) || !comma_scanall(mtl->opts,TT.bigO))
+ continue;
+
+ } else {
+ if (dir && strcmp(dir, mtl->dir)) continue;
+ if (dev && strcmp(dev, mtl->device) && (dir || strcmp(dev, mtl->dir)))
+ continue;
+ }
+
+ // user only counts from fstab, not opts.
+ if (comma_scan(mtl->opts, "user", 1)) TT.okuser = 1;
+ aflags = flag_opts(mtl->opts, flags, &aopts);
+
+ mount_filesystem(mtl->device, mtl->dir, mtl->type, aflags, aopts);
+
+ free(aopts);
+ }
+ }
+
+ // show mounts
+ if (!dir) {
+ for (mtl = xgetmountlist(0); mtl && (mm = dlist_pop(&mtl)); free(mm)) {
char *s = 0;
- if (TT.type && strcmp(TT.type, m->type)) continue;
- if (*m->device == '/') s = xabspath(m->device, 0);
+ if (TT.type && strcmp(TT.type, mm->type)) continue;
+ if (*mm->device == '/') s = xabspath(mm->device, 0);
xprintf("%s on %s type %s (%s)\n",
- s ? s : m->device, m->dir, m->type, m->opts);
+ s ? s : mm->device, mm->dir, mm->type, mm->opts);
free(s);
}
// one argument: from fstab, remount, subtree
- } else if (toys.optc == 1) {
- fprintf(stderr, "not yet\n");
+ } else if (!dev) {
+ fprintf(stderr, "not yet\n"); // TODO
return;
// two arguments
- } else mount_filesystem(toys.optargs[0], toys.optargs[1], TT.type,
- flags, opts ? opts : "");
+ } else mount_filesystem(dev, dir, TT.type, flags, opts);
}