ntfs-3g/libfuse-lite/mount.c
Jean-Pierre André fc666cb0b9 Fixed bad test in fuse mount
Apply a fix from the full fuse library
2016-04-06 09:42:16 +02:00

733 lines
20 KiB
C

/*
FUSE: Filesystem in Userspace
Copyright (C) 2001-2007 Miklos Szeredi <miklos@szeredi.hu>
This program can be distributed under the terms of the GNU LGPLv2.
See the file COPYING.LIB.
*/
#include "config.h"
#include "fuse_i.h"
#include "fuse_opt.h"
#include "mount_util.h"
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <stddef.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/poll.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <sys/wait.h>
#include <sys/mount.h>
#ifdef __SOLARIS__
#define FUSERMOUNT_PROG "fusermount"
#define FUSE_COMMFD_ENV "_FUSE_COMMFD"
#ifndef FUSERMOUNT_DIR
#define FUSERMOUNT_DIR "/usr"
#endif /* FUSERMOUNT_DIR */
#ifndef HAVE_FORK
#define fork() vfork()
#endif
#endif /* __SOLARIS__ */
#ifndef MS_DIRSYNC
#define MS_DIRSYNC 128
#endif
enum {
KEY_KERN_FLAG,
KEY_KERN_OPT,
KEY_FUSERMOUNT_OPT,
KEY_SUBTYPE_OPT,
KEY_MTAB_OPT,
KEY_ALLOW_ROOT,
KEY_RO,
KEY_HELP,
KEY_VERSION,
};
struct mount_opts {
int allow_other;
int allow_root;
int ishelp;
int flags;
#ifdef __SOLARIS__
int nonempty;
int blkdev;
char *fsname;
char *subtype;
char *subtype_opt;
#else
int blkdev;
char *fsname;
#endif
char *mtab_opts;
char *fusermount_opts;
char *kernel_opts;
};
#define FUSE_MOUNT_OPT(t, p) { t, offsetof(struct mount_opts, p), 1 }
static const struct fuse_opt fuse_mount_opts[] = {
#ifdef __SOLARIS__
FUSE_MOUNT_OPT("allow_other", allow_other),
FUSE_MOUNT_OPT("allow_root", allow_root),
FUSE_MOUNT_OPT("nonempty", nonempty),
FUSE_MOUNT_OPT("blkdev", blkdev),
FUSE_MOUNT_OPT("fsname=%s", fsname),
FUSE_MOUNT_OPT("subtype=%s", subtype),
FUSE_OPT_KEY("allow_other", KEY_KERN_OPT),
FUSE_OPT_KEY("allow_root", KEY_ALLOW_ROOT),
FUSE_OPT_KEY("nonempty", KEY_FUSERMOUNT_OPT),
FUSE_OPT_KEY("blkdev", KEY_FUSERMOUNT_OPT),
FUSE_OPT_KEY("fsname=", KEY_FUSERMOUNT_OPT),
FUSE_OPT_KEY("subtype=", KEY_SUBTYPE_OPT),
FUSE_OPT_KEY("large_read", KEY_KERN_OPT),
FUSE_OPT_KEY("blksize=", KEY_KERN_OPT),
FUSE_OPT_KEY("default_permissions", KEY_KERN_OPT),
FUSE_OPT_KEY("max_read=", KEY_KERN_OPT),
FUSE_OPT_KEY("max_read=", FUSE_OPT_KEY_KEEP),
FUSE_OPT_KEY("user=", KEY_MTAB_OPT),
FUSE_OPT_KEY("-r", KEY_RO),
FUSE_OPT_KEY("ro", KEY_KERN_FLAG),
FUSE_OPT_KEY("rw", KEY_KERN_FLAG),
FUSE_OPT_KEY("suid", KEY_KERN_FLAG),
FUSE_OPT_KEY("nosuid", KEY_KERN_FLAG),
FUSE_OPT_KEY("-g", KEY_KERN_FLAG),
FUSE_OPT_KEY("-m", KEY_KERN_FLAG),
FUSE_OPT_KEY("-O", KEY_KERN_FLAG),
FUSE_OPT_KEY("setuid", KEY_KERN_OPT),
FUSE_OPT_KEY("nosetuid", KEY_KERN_OPT),
FUSE_OPT_KEY("devices", KEY_KERN_OPT),
FUSE_OPT_KEY("nodevices", KEY_KERN_OPT),
FUSE_OPT_KEY("exec", KEY_KERN_OPT),
FUSE_OPT_KEY("noexec", KEY_KERN_OPT),
FUSE_OPT_KEY("nbmand", KEY_KERN_OPT),
FUSE_OPT_KEY("nonbmand", KEY_KERN_OPT),
#else /* __SOLARIS__ */
FUSE_MOUNT_OPT("allow_other", allow_other),
FUSE_MOUNT_OPT("allow_root", allow_root),
FUSE_MOUNT_OPT("blkdev", blkdev),
FUSE_MOUNT_OPT("fsname=%s", fsname),
FUSE_OPT_KEY("allow_other", KEY_KERN_OPT),
FUSE_OPT_KEY("allow_root", KEY_ALLOW_ROOT),
FUSE_OPT_KEY("blkdev", KEY_FUSERMOUNT_OPT),
FUSE_OPT_KEY("fsname=", KEY_FUSERMOUNT_OPT),
FUSE_OPT_KEY("large_read", KEY_KERN_OPT),
FUSE_OPT_KEY("blksize=", KEY_KERN_OPT),
FUSE_OPT_KEY("default_permissions", KEY_KERN_OPT),
FUSE_OPT_KEY("context=", KEY_KERN_OPT),
FUSE_OPT_KEY("max_read=", KEY_KERN_OPT),
FUSE_OPT_KEY("max_read=", FUSE_OPT_KEY_KEEP),
FUSE_OPT_KEY("user=", KEY_MTAB_OPT),
FUSE_OPT_KEY("-r", KEY_RO),
FUSE_OPT_KEY("ro", KEY_KERN_FLAG),
FUSE_OPT_KEY("rw", KEY_KERN_FLAG),
FUSE_OPT_KEY("suid", KEY_KERN_FLAG),
FUSE_OPT_KEY("nosuid", KEY_KERN_FLAG),
FUSE_OPT_KEY("dev", KEY_KERN_FLAG),
FUSE_OPT_KEY("nodev", KEY_KERN_FLAG),
FUSE_OPT_KEY("exec", KEY_KERN_FLAG),
FUSE_OPT_KEY("noexec", KEY_KERN_FLAG),
FUSE_OPT_KEY("async", KEY_KERN_FLAG),
FUSE_OPT_KEY("sync", KEY_KERN_FLAG),
FUSE_OPT_KEY("dirsync", KEY_KERN_FLAG),
FUSE_OPT_KEY("atime", KEY_KERN_FLAG),
FUSE_OPT_KEY("noatime", KEY_KERN_FLAG),
#endif /* __SOLARIS__ */
FUSE_OPT_KEY("-h", KEY_HELP),
FUSE_OPT_KEY("--help", KEY_HELP),
FUSE_OPT_KEY("-V", KEY_VERSION),
FUSE_OPT_KEY("--version", KEY_VERSION),
FUSE_OPT_END
};
#ifdef __SOLARIS__
static void mount_help(void)
{
fprintf(stderr,
" -o allow_other allow access to other users\n"
" -o allow_root allow access to root\n"
" -o nonempty allow mounts over non-empty file/dir\n"
" -o default_permissions enable permission checking by kernel\n"
" -o fsname=NAME set filesystem name\n"
" -o subtype=NAME set filesystem type\n"
" -o large_read issue large read requests (2.4 only)\n"
" -o max_read=N set maximum size of read requests\n"
"\n"
);
}
static void exec_fusermount(const char *argv[])
{
execv(FUSERMOUNT_DIR "/" FUSERMOUNT_PROG, (char **) argv);
execvp(FUSERMOUNT_PROG, (char **) argv);
}
static void mount_version(void)
{
int pid = fork();
if (!pid) {
const char *argv[] = { FUSERMOUNT_PROG, "--version", NULL };
exec_fusermount(argv);
_exit(1);
} else if (pid != -1)
waitpid(pid, NULL, 0);
}
#endif /* __SOLARIS__ */
struct mount_flags {
const char *opt;
unsigned long flag;
int on;
};
static struct mount_flags mount_flags[] = {
{"rw", MS_RDONLY, 0},
{"ro", MS_RDONLY, 1},
{"suid", MS_NOSUID, 0},
{"nosuid", MS_NOSUID, 1},
#ifndef __SOLARIS__
{"dev", MS_NODEV, 0},
{"nodev", MS_NODEV, 1},
{"exec", MS_NOEXEC, 0},
{"noexec", MS_NOEXEC, 1},
{"async", MS_SYNCHRONOUS, 0},
{"sync", MS_SYNCHRONOUS, 1},
{"atime", MS_NOATIME, 0},
{"noatime", MS_NOATIME, 1},
{"dirsync", MS_DIRSYNC, 1},
#else /* __SOLARIS__ */
{"-g", MS_GLOBAL, 1}, /* 1eaf4 */
{"-m", MS_NOMNTTAB, 1}, /* 1eb00 */
{"-O", MS_OVERLAY, 1}, /* 1eb0c */
#endif /* __SOLARIS__ */
{NULL, 0, 0}
};
#ifdef __SOLARIS__
/*
* See comments in fuse_kern_mount()
*/
struct solaris_mount_opts {
int nosuid;
int setuid;
int nosetuid;
int devices;
int nodevices;
};
#define SOLARIS_MOUNT_OPT(t, p, n) \
{ t, offsetof(struct solaris_mount_opts, p), n }
static const struct fuse_opt solaris_mnt_opts[] = {
SOLARIS_MOUNT_OPT("suid", setuid, 1),
SOLARIS_MOUNT_OPT("suid", devices, 1),
SOLARIS_MOUNT_OPT("nosuid", nosuid, 1),
SOLARIS_MOUNT_OPT("setuid", setuid, 1),
SOLARIS_MOUNT_OPT("nosetuid", nosetuid, 1),
SOLARIS_MOUNT_OPT("devices", devices, 1),
SOLARIS_MOUNT_OPT("nodevices", nodevices, 1),
FUSE_OPT_END
};
#endif /* __SOLARIS__ */
static void set_mount_flag(const char *s, int *flags)
{
int i;
for (i = 0; mount_flags[i].opt != NULL; i++) {
const char *opt = mount_flags[i].opt;
if (strcmp(opt, s) == 0) {
if (mount_flags[i].on)
*flags |= mount_flags[i].flag;
else
*flags &= ~mount_flags[i].flag;
return;
}
}
fprintf(stderr, "fuse: internal error, can't find mount flag\n");
abort();
}
static int fuse_mount_opt_proc(void *data, const char *arg, int key,
struct fuse_args *outargs)
{
struct mount_opts *mo = data;
switch (key) {
case KEY_ALLOW_ROOT:
if (fuse_opt_add_opt(&mo->kernel_opts, "allow_other") == -1 ||
fuse_opt_add_arg(outargs, "-oallow_root") == -1)
return -1;
return 0;
case KEY_RO:
arg = "ro";
/* fall through */
case KEY_KERN_FLAG:
set_mount_flag(arg, &mo->flags);
return 0;
case KEY_KERN_OPT:
return fuse_opt_add_opt(&mo->kernel_opts, arg);
case KEY_FUSERMOUNT_OPT:
return fuse_opt_add_opt(&mo->fusermount_opts, arg);
#ifdef __SOLARIS__
case KEY_SUBTYPE_OPT:
return fuse_opt_add_opt(&mo->subtype_opt, arg);
#endif /* __SOLARIS__ */
case KEY_MTAB_OPT:
return fuse_opt_add_opt(&mo->mtab_opts, arg);
case KEY_HELP:
#ifdef __SOLARIS__
mount_help();
#endif /* __SOLARIS__ */
mo->ishelp = 1;
break;
case KEY_VERSION:
#ifdef __SOLARIS__
mount_version();
#endif /* __SOLARIS__ */
mo->ishelp = 1;
break;
}
return 1;
}
#ifdef __SOLARIS__
/* return value:
* >= 0 => fd
* -1 => error
*/
static int receive_fd(int fd)
{
struct msghdr msg;
struct iovec iov;
char buf[1];
int rv;
size_t ccmsg[CMSG_SPACE(sizeof(int)) / sizeof(size_t)];
struct cmsghdr *cmsg;
iov.iov_base = buf;
iov.iov_len = 1;
msg.msg_name = 0;
msg.msg_namelen = 0;
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
/* old BSD implementations should use msg_accrights instead of
* msg_control; the interface is different. */
msg.msg_control = ccmsg;
msg.msg_controllen = sizeof(ccmsg);
while(((rv = recvmsg(fd, &msg, 0)) == -1) && errno == EINTR);
if (rv == -1) {
perror("recvmsg");
return -1;
}
if(!rv) {
/* EOF */
return -1;
}
cmsg = CMSG_FIRSTHDR(&msg);
if (cmsg->cmsg_type != SCM_RIGHTS) {
fprintf(stderr, "got control message of unknown type %d\n",
cmsg->cmsg_type);
return -1;
}
return *(int*)CMSG_DATA(cmsg);
}
#endif /* __SOLARIS__ */
void fuse_kern_unmount(const char *mountpoint, int fd)
{
int res;
#ifdef __SOLARIS__
int pid;
#endif /* __SOLARIS__ */
if (!mountpoint)
return;
if (fd != -1) {
struct pollfd pfd;
pfd.fd = fd;
pfd.events = 0;
res = poll(&pfd, 1, 0);
/* If file poll returns POLLERR on the device file descriptor,
then the filesystem is already unmounted */
if (res == 1 && (pfd.revents & POLLERR))
return;
}
#ifndef __SOLARIS__
close(fd);
fusermount(1, 0, 1, "", mountpoint);
#else /* __SOLARIS__ */
if (geteuid() == 0) {
fuse_mnt_umount("fuse", mountpoint, 1);
return;
}
res = umount2(mountpoint, 2);
if (res == 0)
return;
pid = fork();
if(pid == -1)
return;
if(pid == 0) {
const char *argv[] =
{ FUSERMOUNT_PROG, "-u", "-q", "-z", "--", mountpoint, NULL };
exec_fusermount(argv);
_exit(1);
}
waitpid(pid, NULL, 0);
#endif /* __SOLARIS__ */
}
#ifdef __SOLARIS__
static int fuse_mount_fusermount(const char *mountpoint, const char *opts,
int quiet)
{
int fds[2], pid;
int res;
int rv;
if (!mountpoint) {
fprintf(stderr, "fuse: missing mountpoint\n");
return -1;
}
res = socketpair(PF_UNIX, SOCK_STREAM, 0, fds);
if(res == -1) {
perror("fuse: socketpair() failed");
return -1;
}
pid = fork();
if(pid == -1) {
perror("fuse: fork() failed");
close(fds[0]);
close(fds[1]);
return -1;
}
if(pid == 0) {
char env[10];
const char *argv[32];
int a = 0;
if (quiet) {
int fd = open("/dev/null", O_RDONLY);
dup2(fd, 1);
dup2(fd, 2);
}
argv[a++] = FUSERMOUNT_PROG;
if (opts) {
argv[a++] = "-o";
argv[a++] = opts;
}
argv[a++] = "--";
argv[a++] = mountpoint;
argv[a++] = NULL;
close(fds[1]);
fcntl(fds[0], F_SETFD, 0);
snprintf(env, sizeof(env), "%i", fds[0]);
setenv(FUSE_COMMFD_ENV, env, 1);
exec_fusermount(argv);
perror("fuse: failed to exec fusermount");
_exit(1);
}
close(fds[0]);
rv = receive_fd(fds[1]);
close(fds[1]);
waitpid(pid, NULL, 0); /* bury zombie */
return rv;
}
static int fuse_mount_sys(const char *mnt, struct mount_opts *mo,
const char *mnt_opts)
{
char tmp[128];
const char *devname = "/dev/fuse";
char *source = NULL;
char *type = NULL;
struct stat stbuf;
int fd;
int res;
if (!mnt) {
fprintf(stderr, "fuse: missing mountpoint\n");
return -1;
}
res = lstat(mnt, &stbuf);
if (res == -1) {
fprintf(stderr ,"fuse: failed to access mountpoint %s: %s\n",
mnt, strerror(errno));
return -1;
}
if (!mo->nonempty) {
res = fuse_mnt_check_empty("fuse", mnt, stbuf.st_mode, stbuf.st_size);
if (res == -1)
return -1;
}
fd = open(devname, O_RDWR);
if (fd == -1) {
if (errno == ENODEV || errno == ENOENT)
fprintf(stderr,
"fuse: device not found, try 'modprobe fuse' first\n");
else
fprintf(stderr, "fuse: failed to open %s: %s\n", devname,
strerror(errno));
return -1;
}
snprintf(tmp, sizeof(tmp), "fd=%i,rootmode=%o,user_id=%i,group_id=%i", fd,
stbuf.st_mode & S_IFMT, getuid(), getgid());
res = fuse_opt_add_opt(&mo->kernel_opts, tmp);
if (res == -1)
goto out_close;
source = malloc((mo->fsname ? strlen(mo->fsname) : 0) +
(mo->subtype ? strlen(mo->subtype) : 0) +
strlen(devname) + 32);
type = malloc((mo->subtype ? strlen(mo->subtype) : 0) + 32);
if (!type || !source) {
fprintf(stderr, "fuse: failed to allocate memory\n");
goto out_close;
}
strcpy(type, mo->blkdev ? "fuseblk" : "fuse");
if (mo->subtype) {
strcat(type, ".");
strcat(type, mo->subtype);
}
strcpy(source,
mo->fsname ? mo->fsname : (mo->subtype ? mo->subtype : devname));
/* JPA added two final zeroes */
res = mount(source, mnt, MS_OPTIONSTR|mo->flags, type, NULL, 0,
mo->kernel_opts, MAX_MNTOPT_STR, 0, 0);
if (res == -1 && errno == EINVAL && mo->subtype) {
/* Probably missing subtype support */
strcpy(type, mo->blkdev ? "fuseblk" : "fuse");
if (mo->fsname) {
if (!mo->blkdev)
sprintf(source, "%s#%s", mo->subtype, mo->fsname);
} else {
strcpy(source, type);
}
/* JPA two null args added */
res = mount(source, mnt, MS_OPTIONSTR|mo->flags, type, NULL, 0,
mo->kernel_opts, MAX_MNTOPT_STR, 0, 0);
}
if (res == -1) {
/*
* Maybe kernel doesn't support unprivileged mounts, in this
* case try falling back to fusermount
*/
if (errno == EPERM) {
res = -2;
} else {
int errno_save = errno;
if (mo->blkdev && errno == ENODEV && !fuse_mnt_check_fuseblk())
fprintf(stderr, "fuse: 'fuseblk' support missing\n");
else
fprintf(stderr, "fuse: mount failed: %s\n",
strerror(errno_save));
}
goto out_close;
}
return fd;
out_umount:
umount2(mnt, 2); /* lazy umount */
out_close:
free(type);
free(source);
close(fd);
return res;
}
#endif /* __SOLARIS__ */
static int get_mnt_flag_opts(char **mnt_optsp, int flags)
{
int i;
if (!(flags & MS_RDONLY) && fuse_opt_add_opt(mnt_optsp, "rw") == -1)
return -1;
for (i = 0; mount_flags[i].opt != NULL; i++) {
if (mount_flags[i].on && (flags & mount_flags[i].flag) &&
fuse_opt_add_opt(mnt_optsp, mount_flags[i].opt) == -1)
return -1;
}
return 0;
}
int fuse_kern_mount(const char *mountpoint, struct fuse_args *args)
{
struct mount_opts mo;
int res = -1;
char *mnt_opts = NULL;
#ifdef __SOLARIS__
struct solaris_mount_opts smo;
struct fuse_args sa = FUSE_ARGS_INIT(0, NULL);
#endif /* __SOLARIS__ */
memset(&mo, 0, sizeof(mo));
#ifndef __SOLARIS__
if (getuid())
mo.flags = MS_NOSUID | MS_NODEV;
#else /* __SOLARIS__ */
mo.flags = 0;
memset(&smo, 0, sizeof(smo));
if (args != NULL) {
while (args->argv[sa.argc] != NULL)
fuse_opt_add_arg(&sa, args->argv[sa.argc]);
}
#endif /* __SOLARIS__ */
if (args &&
fuse_opt_parse(args, &mo, fuse_mount_opts, fuse_mount_opt_proc) == -1)
#ifndef __SOLARIS__
return -1;
#else /* __SOLARIS__ */
goto out; /* if SOLARIS, clean up 'sa' */
/*
* In Solaris, nosuid is equivalent to nosetuid + nodevices. We only
* have MS_NOSUID for mount flags (no MS_(NO)SETUID, etc.). But if
* we set that as a default, it restricts specifying just nosetuid
* or nodevices; there is no way for the user to specify setuid +
* nodevices or vice-verse. So we parse the existing options, then
* add restrictive defaults if needed.
*/
if (fuse_opt_parse(&sa, &smo, solaris_mnt_opts, NULL) == -1)
goto out;
if (smo.nosuid || (!smo.nodevices && !smo.devices
&& !smo.nosetuid && !smo.setuid)) {
mo.flags |= MS_NOSUID;
} else {
/*
* Defaults; if neither nodevices|devices,nosetuid|setuid has
* been specified, add the default negative option string. If
* both have been specified (i.e., -osuid,nosuid), leave them
* alone; the last option will have precedence.
*/
if (!smo.nodevices && !smo.devices)
if (fuse_opt_add_opt(&mo.kernel_opts, "nodevices") == -1)
goto out;
if (!smo.nosetuid && !smo.setuid)
if (fuse_opt_add_opt(&mo.kernel_opts, "nosetuid") == -1)
goto out;
}
#endif /* __SOLARIS__ */
if (mo.allow_other && mo.allow_root) {
fprintf(stderr, "fuse: 'allow_other' and 'allow_root' options are mutually exclusive\n");
goto out;
}
res = 0;
if (mo.ishelp)
goto out;
res = -1;
if (get_mnt_flag_opts(&mnt_opts, mo.flags) == -1)
goto out;
#ifndef __SOLARIS__
if (!(mo.flags & MS_NODEV) && fuse_opt_add_opt(&mnt_opts, "dev") == -1)
goto out;
if (!(mo.flags & MS_NOSUID) && fuse_opt_add_opt(&mnt_opts, "suid") == -1)
goto out;
if (mo.kernel_opts && fuse_opt_add_opt(&mnt_opts, mo.kernel_opts) == -1)
goto out;
if (mo.mtab_opts && fuse_opt_add_opt(&mnt_opts, mo.mtab_opts) == -1)
goto out;
if (mo.fusermount_opts && fuse_opt_add_opt(&mnt_opts, mo.fusermount_opts) < 0)
goto out;
res = fusermount(0, 0, 0, mnt_opts ? mnt_opts : "", mountpoint);
#else /* __SOLARIS__ */
if (mo.kernel_opts && fuse_opt_add_opt(&mnt_opts, mo.kernel_opts) == -1)
goto out;
if (mo.mtab_opts && fuse_opt_add_opt(&mnt_opts, mo.mtab_opts) == -1)
goto out;
res = fuse_mount_sys(mountpoint, &mo, mnt_opts);
if (res == -2) {
if (mo.fusermount_opts &&
fuse_opt_add_opt(&mnt_opts, mo.fusermount_opts) == -1)
goto out;
if (mo.subtype) {
char *tmp_opts = NULL;
res = -1;
if (fuse_opt_add_opt(&tmp_opts, mnt_opts) == -1 ||
fuse_opt_add_opt(&tmp_opts, mo.subtype_opt) == -1) {
free(tmp_opts);
goto out;
}
res = fuse_mount_fusermount(mountpoint, tmp_opts, 1);
free(tmp_opts);
if (res == -1)
res = fuse_mount_fusermount(mountpoint, mnt_opts, 0);
} else {
res = fuse_mount_fusermount(mountpoint, mnt_opts, 0);
}
}
#endif /* __SOLARIS__ */
out:
free(mnt_opts);
#ifdef __SOLARIS__
fuse_opt_free_args(&sa);
free(mo.subtype);
free(mo.subtype_opt);
#endif /* __SOLARIS__ */
free(mo.fsname);
free(mo.fusermount_opts);
free(mo.kernel_opts);
free(mo.mtab_opts);
return res;
}