ntfs-3g/libfuse-lite/mount.c

258 lines
7.0 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 <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>
#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;
int blkdev;
char *fsname;
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[] = {
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),
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
};
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},
{"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},
{NULL, 0, 0}
};
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);
case KEY_MTAB_OPT:
return fuse_opt_add_opt(&mo->mtab_opts, arg);
case KEY_HELP:
mo->ishelp = 1;
break;
case KEY_VERSION:
mo->ishelp = 1;
break;
}
return 1;
}
void fuse_kern_unmount(const char *mountpoint, int fd)
{
int res;
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;
}
close(fd);
fusermount(1, 0, 1, "", mountpoint);
}
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;
memset(&mo, 0, sizeof(mo));
if (getuid())
mo.flags = MS_NOSUID | MS_NODEV;
if (args &&
fuse_opt_parse(args, &mo, fuse_mount_opts, fuse_mount_opt_proc) == -1)
return -1;
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;
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);
out:
free(mnt_opts);
free(mo.fsname);
free(mo.fusermount_opts);
free(mo.kernel_opts);
free(mo.mtab_opts);
return res;
}