openharmony/third_party_libfuse
1
0
Fork 0
mirror of https://github.com/openharmony/third_party_libfuse.git synced 2026-07-19 13:34:16 -04:00
Code Issues Packages Projects Releases Wiki Activity

mounting fixes

Browse Source
This commit is contained in:
Miklos Szeredi
2006-12-10 00:13:53 +00:00
parent 2ad6a4bc54
commit a2ff24b600
3 changed files with 101 additions and 235 deletions
Download Patch File Download Diff File Expand all files Collapse all files
ChangeLog
+11
View File
@@ -1,3 +1,14 @@
2006-12-10 Miklos Szeredi <miklos@szeredi.hu>
* mount.fuse: add "setuid=USER" option which does a "su - USER"
for the filesystem
* fusermount: use "/bin/mount -f" to add entry to /etc/mtab, and
"/bin/umount" to remove entry from /etc/mtab. This gets rid of
the ugly code dealing with mtab, as well as a possible race
between fusermount and mount trying to modify /etc/mtab at the
same time
2006-12-04 Miklos Szeredi <miklos@szeredi.hu>
* Fix warnings with gcc-4.1 on 64bit archs. Report from
util/fusermount.c
+82 -233
View File
@@ -7,15 +7,6 @@
*/
/* This program does the mounting and unmounting of FUSE filesystems */
/*
* NOTE: This program should be part of (or be called from) /bin/mount
*
* Unless that is done, operations on /etc/mtab are not under lock, and so
* data in this file may be lost. (I will _not_ reimplement that locking,
* and anyway that should be done in libc, if possible. But probably it
* isn't).
*/
#include <config.h>
#include <stdio.h>
@@ -29,19 +20,12 @@
#include <pwd.h>
#include <mntent.h>
#include <dirent.h>
#include <sys/param.h>
#include <sys/wait.h>
#include <sys/stat.h>
#include <sys/mount.h>
#include <sys/fsuid.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <sys/utsname.h>
#include <sys/sysmacros.h>
#ifdef HAVE_SELINUX_SELINUX_H
#include <selinux/selinux.h>
#endif
#define FUSE_COMMFD_ENV "_FUSE_COMMFD"
@@ -91,239 +75,119 @@ static void restore_privs(void)
static int do_unmount(const char *mnt, int quiet, int lazy)
{
int res = umount2(mnt, lazy ? 2 : 0);
if (res == -1) {
if (!quiet)
fprintf(stderr, "%s: failed to unmount %s: %s\n",
progname, mnt, strerror(errno));
}
return res;
}
#ifndef IGNORE_MTAB
/* use a lock file so that multiple fusermount processes don't try and
modify the mtab file at once! */
static int lock_mtab(void)
{
const char *mtab_lock = _PATH_MOUNTED ".fuselock";
int mtablock;
int res;
struct stat mtab_stat;
int status;
/* /etc/mtab could be a symlink to /proc/mounts */
if (!lstat(_PATH_MOUNTED, &mtab_stat)) {
if (S_ISLNK(mtab_stat.st_mode))
return -1;
(void) quiet;
res = fork();
if (res == -1) {
perror("fork");
return -1;
}
mtablock = open(mtab_lock, O_RDWR | O_CREAT, 0600);
if (mtablock >= 0) {
res = lockf(mtablock, F_LOCK, 0);
if (res < 0)
fprintf(stderr, "%s: error getting lock", progname);
} else
fprintf(stderr, "%s: unable to open fuse lock file\n", progname);
return mtablock;
}
static void unlock_mtab(int mtablock)
{
if (mtablock >= 0) {
lockf(mtablock, F_ULOCK, 0);
close(mtablock);
if (res == 0) {
setuid(geteuid());
execl("/bin/umount", "/bin/umount", "-i", mnt, lazy ? "-l" : NULL,
NULL);
perror("execl /bin/umount");
exit(1);
}
}
/* Glibc addmntent() doesn't encode '\n', misencodes '\t' as '\n'
(version 2.3.2), and encodes '\\' differently as mount(8). So
let's not allow those characters, they are not all that usual in
filenames. */
static int check_name(const char *name)
{
const char *s;
for (s = "\n\t\\"; *s; s++) {
if (strchr(name, *s)) {
fprintf(stderr, "%s: illegal character 0x%02x in mount entry\n",
progname, *s);
return -1;
}
res = waitpid(res, &status, 0);
if (res == -1) {
perror("waitpid");
return -1;
}
if (status != 0)
return -1;
return 0;
}
#ifndef IGNORE_MTAB
static int add_mount(const char *fsname, const char *mnt, const char *type,
const char *opts)
{
int res;
const char *mtab = _PATH_MOUNTED;
struct mntent ent;
FILE *fp;
int status;
if (check_name(fsname) == -1 || check_name(mnt) == -1 ||
check_name(type) == -1 || check_name(opts) == -1)
return -1;
fp = setmntent(mtab, "a");
if (fp == NULL) {
fprintf(stderr, "%s: failed to open %s: %s\n", progname, mtab,
strerror(errno));
return -1;
}
ent.mnt_fsname = (char *) fsname;
ent.mnt_dir = (char *) mnt;
ent.mnt_type = (char *) type;
ent.mnt_opts = (char *) opts;
ent.mnt_freq = 0;
ent.mnt_passno = 0;
res = addmntent(fp, &ent);
if (res != 0) {
fprintf(stderr, "%s: failed to add entry to %s: %s\n", progname,
mtab, strerror(errno));
return -1;
}
endmntent(fp);
return 0;
}
static int unmount_rename(const char *mtab, const char *mtab_new)
{
int res;
struct stat sbuf;
if (stat(mtab, &sbuf) == 0)
chown(mtab_new, sbuf.st_uid, sbuf.st_gid);
#ifdef HAVE_LIBSELINUX
{
security_context_t filecon;
if (getfilecon(mtab, &filecon) > 0) {
setfilecon(mtab_new, filecon);
if (filecon != NULL)
freecon(filecon);
}
}
#endif
res = rename(mtab_new, mtab);
res = fork();
if (res == -1) {
fprintf(stderr, "%s: failed to rename %s to %s: %s\n", progname,
mtab_new, mtab, strerror(errno));
perror("fork");
return -1;
}
if (res == 0) {
setuid(geteuid());
execl("/bin/mount", "/bin/mount", "-i", "-f", "-t", type, "-o", opts,
fsname, mnt, NULL);
perror("execl /bin/mount");
exit(1);
}
res = waitpid(res, &status, 0);
if (res == -1) {
perror("waitpid");
return -1;
}
if (status != 0)
return -1;
return 0;
}
static int unmount_fuse(const char *mnt, int quiet, int lazy)
{
int res;
struct mntent *entp;
FILE *fp;
FILE *newfp = NULL;
const char *user = NULL;
char uidstr[32];
unsigned uidlen = 0;
int found;
int issymlink = 0;
struct stat stbuf;
const char *mtab = _PATH_MOUNTED;
const char *mtab_new = _PATH_MOUNTED "~fuse~";
if (lstat(mtab, &stbuf) != -1 && S_ISLNK(stbuf.st_mode))
issymlink = 1;
fp = setmntent(mtab, "r");
if (fp == NULL) {
fprintf(stderr, "%s: failed to open %s: %s\n", progname, mtab,
strerror(errno));
return -1;
}
if (!issymlink) {
newfp = setmntent(mtab_new, "w");
if (newfp == NULL) {
fprintf(stderr, "%s: failed to open %s: %s\n", progname, mtab_new,
strerror(errno));
endmntent(fp);
return -1;
}
}
if (getuid() != 0) {
struct mntent *entp;
FILE *fp;
const char *user = NULL;
char uidstr[32];
unsigned uidlen = 0;
int found;
const char *mtab = _PATH_MOUNTED;
user = get_user_name();
if (user == NULL)
goto err_endmntent;
return -1;
fp = setmntent(mtab, "r");
if (fp == NULL) {
fprintf(stderr, "%s: failed to open %s: %s\n", progname, mtab,
strerror(errno));
return -1;
}
uidlen = sprintf(uidstr, "%u", getuid());
}
found = 0;
while ((entp = getmntent(fp)) != NULL) {
int removed = 0;
if (!found && strcmp(entp->mnt_dir, mnt) == 0 &&
(strcmp(entp->mnt_type, "fuse") == 0 ||
strcmp(entp->mnt_type, "fuseblk") == 0)) {
if (user == NULL)
removed = 1;
else {
found = 0;
while ((entp = getmntent(fp)) != NULL) {
if (!found && strcmp(entp->mnt_dir, mnt) == 0 &&
(strcmp(entp->mnt_type, "fuse") == 0 ||
strcmp(entp->mnt_type, "fuseblk") == 0)) {
char *p = strstr(entp->mnt_opts, "user=");
if (p && (p == entp->mnt_opts || *(p-1) == ',') &&
strcmp(p + 5, user) == 0)
removed = 1;
strcmp(p + 5, user) == 0) {
found = 1;
break;
}
/* /etc/mtab is a link pointing to /proc/mounts: */
else if ((p = strstr(entp->mnt_opts, "user_id=")) &&
(p == entp->mnt_opts || *(p-1) == ',') &&
strncmp(p + 8, uidstr, uidlen) == 0 &&
(*(p+8+uidlen) == ',' || *(p+8+uidlen) == '\0'))
removed = 1;
(*(p+8+uidlen) == ',' || *(p+8+uidlen) == '\0')) {
found = 1;
break;
}
}
}
if (removed)
found = 1;
else if (!issymlink) {
res = addmntent(newfp, entp);
if (res != 0) {
fprintf(stderr, "%s: failed to add entry to %s: %s\n",
progname, mtab_new, strerror(errno));
}
endmntent(fp);
if (!found) {
if (!quiet)
fprintf(stderr, "%s: entry for %s not found in %s\n", progname,
mnt, mtab);
return -1;
}
}
endmntent(fp);
if (!issymlink)
endmntent(newfp);
if (!found) {
if (!quiet)
fprintf(stderr, "%s: entry for %s not found in %s\n", progname,
mnt, mtab);
goto err;
}
drop_privs();
res = do_unmount(mnt, quiet, lazy);
restore_privs();
if (res == -1)
goto err;
if (!issymlink) {
res = unmount_rename(mtab, mtab_new);
if (res == -1)
goto err;
}
return 0;
err_endmntent:
if (!issymlink)
endmntent(newfp);
endmntent(fp);
err:
if (!issymlink)
unlink(mtab_new);
return -1;
return do_unmount(mnt, quiet, lazy);
}
static int count_fuse_fs(void)
@@ -347,16 +211,6 @@ static int count_fuse_fs(void)
#else /* IGNORE_MTAB */
static int lock_mtab()
{
return 0;
}
static void unlock_mtab(int mtablock)
{
(void) mtablock;
}
static int count_fuse_fs()
{
return 0;
@@ -902,15 +756,11 @@ static int mount_fuse(const char *mnt, const char *opts)
const char *real_mnt = mnt;
int currdir_fd = -1;
int mountpoint_fd = -1;
int mtablock = -1;
fd = open_fuse_device(&dev);
if (fd == -1)
return -1;
if (geteuid() == 0)
mtablock = lock_mtab();
drop_privs();
read_conf();
@@ -919,7 +769,6 @@ static int mount_fuse(const char *mnt, const char *opts)
if (mount_count >= mount_max) {
fprintf(stderr, "%s: too many FUSE filesystems mounted; mount_max=N can be set in /etc/fuse.conf\n", progname);
close(fd);
unlock_mtab(mtablock);
return -1;
}
}
@@ -943,13 +792,11 @@ static int mount_fuse(const char *mnt, const char *opts)
if (res == -1) {
close(fd);
unlock_mtab(mtablock);
return -1;
}
if (geteuid() == 0) {
res = add_mount(fsname, mnt, type, mnt_opts);
unlock_mtab(mtablock);
if (res == -1) {
umount2(mnt, 2); /* lazy umount */
close(fd);
@@ -1166,12 +1013,14 @@ int main(int argc, char *argv[])
umask(033);
if (unmount) {
if (geteuid() == 0) {
int mtablock = lock_mtab();
if (geteuid() == 0)
res = unmount_fuse(mnt, quiet, lazy);
unlock_mtab(mtablock);
} else
res = do_unmount(mnt, quiet, lazy);
else {
res = umount2(mnt, lazy ? 2 : 0);
if (res == -1 && !quiet)
fprintf(stderr, "%s: failed to unmount %s: %s\n", progname,
mnt, strerror(errno));
}
if (res == -1)
exit(1);
return 0;
util/mount.fuse
+8 -2
View File
@@ -45,8 +45,14 @@ MOUNTPOINT="$2"
shift
shift
ignore_opts='\(user\|nouser\|users\|auto\|noauto\|_netdev\)'
eval `echo $@ | sed -n "s/\([^,]*,\)*setuid=\([^,]*\).*/SETUID=\2/p"`
ignore_opts='\(user\|nouser\|users\|auto\|noauto\|_netdev\|setuid=[^,]*\)'
OPTIONS=`echo $@ | sed "s/,${ignore_opts}\|${ignore_opts},//g"`
${FSTYPE} ${MOUNTPATH} ${MOUNTPOINT} ${OPTIONS}
if test -z "$SETUID"; then
${FSTYPE} ${MOUNTPATH} ${MOUNTPOINT} ${OPTIONS}
else
su - "$SETUID" -c "${FSTYPE} ${MOUNTPATH} ${MOUNTPOINT} ${OPTIONS}"
fi