/*
FUSE: Filesystem in Userspace
Copyright (C) 2005-2008 Csaba Henk <csaba.henk@creo.hu>
This program can be distributed under the terms of the GNU LGPLv2.
See the file COPYING.LIB.
*/
#include "fuse_i.h"
#include "fuse_misc.h"
#include "fuse_opt.h"
#include <sys/stat.h>
#include <sys/wait.h>
#include <sys/sysctl.h>
#include <sys/user.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <stddef.h>
#include <fcntl.h>
#include <errno.h>
#include <string.h>
#include <paths.h>
#include <limits.h>
#define FUSERMOUNT_PROG "mount_fusefs"
#define FUSE_DEV_TRUNK "/dev/fuse"
enum {
KEY_ALLOW_ROOT,
KEY_RO,
KEY_HELP,
KEY_VERSION,
KEY_KERN
};
struct mount_opts {
int allow_other;
int allow_root;
int ishelp;
char *kernel_opts;
};
#define FUSE_DUAL_OPT_KEY(templ, key) \
FUSE_OPT_KEY(templ, key), FUSE_OPT_KEY("no" templ, key)
static const struct fuse_opt fuse_mount_opts[] = {
{ "allow_other", offsetof(struct mount_opts, allow_other), 1 },
{ "allow_root", offsetof(struct mount_opts, allow_root), 1 },
FUSE_OPT_KEY("allow_root", KEY_ALLOW_ROOT),
FUSE_OPT_KEY("-r", KEY_RO),
FUSE_OPT_KEY("-h", KEY_HELP),
FUSE_OPT_KEY("--help", KEY_HELP),
FUSE_OPT_KEY("-V", KEY_VERSION),
FUSE_OPT_KEY("--version", KEY_VERSION),
/* standard FreeBSD mount options */
FUSE_DUAL_OPT_KEY("dev", KEY_KERN),
FUSE_DUAL_OPT_KEY("async", KEY_KERN),
FUSE_DUAL_OPT_KEY("atime", KEY_KERN),
FUSE_DUAL_OPT_KEY("dev", KEY_KERN),
FUSE_DUAL_OPT_KEY("exec", KEY_KERN),
FUSE_DUAL_OPT_KEY("suid", KEY_KERN),
FUSE_DUAL_OPT_KEY("symfollow", KEY_KERN),
FUSE_DUAL_OPT_KEY("rdonly", KEY_KERN),
FUSE_DUAL_OPT_KEY("sync", KEY_KERN),
FUSE_DUAL_OPT_KEY("union", KEY_KERN),
FUSE_DUAL_OPT_KEY("userquota", KEY_KERN),
FUSE_DUAL_OPT_KEY("groupquota", KEY_KERN),
FUSE_DUAL_OPT_KEY("clusterr", KEY_KERN),
FUSE_DUAL_OPT_KEY("clusterw", KEY_KERN),
FUSE_DUAL_OPT_KEY("suiddir", KEY_KERN),
FUSE_DUAL_OPT_KEY("snapshot", KEY_KERN),
FUSE_DUAL_OPT_KEY("multilabel", KEY_KERN),
FUSE_DUAL_OPT_KEY("acls", KEY_KERN),
FUSE_DUAL_OPT_KEY("force", KEY_KERN),
FUSE_DUAL_OPT_KEY("update", KEY_KERN),
FUSE_DUAL_OPT_KEY("ro", KEY_KERN),
FUSE_DUAL_OPT_KEY("rw", KEY_KERN),
FUSE_DUAL_OPT_KEY("auto", KEY_KERN),
/* options supported under both Linux and FBSD */
FUSE_DUAL_OPT_KEY("allow_other", KEY_KERN),
FUSE_DUAL_OPT_KEY("default_permissions",KEY_KERN),
FUSE_OPT_KEY("max_read=", KEY_KERN),
FUSE_OPT_KEY("subtype=", KEY_KERN),
/* FBSD FUSE specific mount options */
FUSE_DUAL_OPT_KEY("private", KEY_KERN),
FUSE_DUAL_OPT_KEY("neglect_shares", KEY_KERN),
FUSE_DUAL_OPT_KEY("push_symlinks_in", KEY_KERN),
FUSE_OPT_KEY("nosync_unmount", KEY_KERN),
/* stock FBSD mountopt parsing routine lets anything be negated... */
/*
* Linux specific mount options, but let just the mount util
* handle them
*/
FUSE_OPT_KEY("fsname=", KEY_KERN),
FUSE_OPT_KEY("nonempty", KEY_KERN),
FUSE_OPT_KEY("large_read", KEY_KERN),
FUSE_OPT_END
};
static void mount_help(void)
{
fprintf(stderr,
" -o allow_root allow access to root\n"
);
system(FUSERMOUNT_PROG " --help");
fputc('\n', stderr);
}
static void mount_version(void)
{
system(FUSERMOUNT_PROG " --version");
}
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:
return fuse_opt_add_opt(&mo->kernel_opts, arg);
case KEY_HELP:
mount_help();
mo->ishelp = 1;
break;
case KEY_VERSION:
mount_version();
mo->ishelp = 1;
break;
}
return 1;
}
void fuse_unmount_compat22(const char *mountpoint)
{
char dev[128];
char *ssc, *umount_cmd;
FILE *sf;
int rv;
char seekscript[] =
/* error message is annoying in help output */
"exec 2>/dev/null; "
"/usr/bin/fstat " FUSE_DEV_TRUNK "* | "
"/usr/bin/awk 'BEGIN{ getline; if (! ($3 == \"PID\" && $10 == \"NAME\")) exit 1; }; "
" { if ($3 == %d) print $10; }' | "
"/usr/bin/sort | "
"/usr/bin/uniq | "
"/usr/bin/awk '{ i += 1; if (i > 1){ exit 1; }; printf; }; END{ if (i == 0) exit 1; }'";
(void) mountpoint;
/*
* If we don't know the fd, we have to resort to the scripted
* solution -- iterating over the fd-s is unpractical, as we
* don't know how many of open files we have. (This could be
* looked up in procfs -- however, that's optional on FBSD; or
* read out from the kmem -- however, that's bound to
* privileges (in fact, that's what happens when we call the
* setgid kmem fstat(1) utility).
*/
if (asprintf(&ssc, seekscript, getpid()) == -1)
return;
errno = 0;
sf = popen(ssc, "r");
free(ssc);
if (! sf)
return;
fgets(dev, sizeof(dev), sf);
rv = pclose(sf);
if (rv)
return;
if (asprintf(&umount_cmd, "/sbin/umount %s", dev) == -1)
return;
system(umount_cmd);
free(umount_cmd);
}
static void do_unmount(char *dev, int fd)
{
char device_path[SPECNAMELEN + 12];
const char *argv[4];
const char umount_cmd[] = "/sbin/umount";
pid_t pid;
snprintf(device_path, SPECNAMELEN + 12, _PATH_DEV "%s", dev);
argv[0] = umount_cmd;
argv[1] = "-f";
argv[2] = device_path;
argv[3] = NULL;
pid = fork();
if (pid == -1)
return;
if (pid == 0) {
close(fd);
execvp(umount_cmd, (char **)argv);
exit(1);
}
waitpid(pid, NULL, 0);
}
void fuse_kern_unmount(const char *mountpoint, int fd)
{
char *ep, dev[128];
struct stat sbuf;
(void)mountpoint;
if (fstat(fd, &sbuf) == -1)
goto out;
devname_r(sbuf.st_rdev, S_IFCHR, dev, 128);
if (strncmp(dev, "fuse", 4))
goto out;
strtol(dev + 4, &ep, 10);
if (*ep != '\0')
goto out;
do_unmount(dev, fd);
out:
close(fd);
}
/* Check if kernel is doing init in background */
static int init_backgrounded(void)
{
unsigned ibg, len;
len = sizeof(ibg);
if (sysctlbyname("vfs.fuse.init_backgrounded", &ibg, &len, NULL, 0))
return 0;
return ibg;
}
static int fuse_mount_core(const char *mountpoint, const char *opts)
{
const char *mountprog = FUSERMOUNT_PROG;
int fd;
char *fdnam, *dev;
pid_t pid, cpid;
int status;
fdnam = getenv("FUSE_DEV_FD");
if (fdnam) {
char *ep;
fd = strtol(fdnam, &ep, 10);
if (*ep != '\0') {
fprintf(stderr, "invalid value given in FUSE_DEV_FD\n");
return -1;
}
if (fd < 0)
return -1;
goto mount;
}
dev = getenv("FUSE_DEV_NAME");
if (! dev)
dev = (char *)FUSE_DEV_TRUNK;
if ((fd = open(dev, O_RDWR)) < 0) {
perror("fuse: failed to open fuse device");
return -1;
}
mount:
if (getenv("FUSE_NO_MOUNT") || ! mountpoint)
goto out;
pid = fork();
cpid = pid;
if (pid == -1) {
perror("fuse: fork() failed");
close(fd);
return -1;
}
if (pid == 0) {
if (! init_backgrounded()) {
/*
* If init is not backgrounded, we have to
* call the mount util backgrounded, to avoid
* deadlock.
*/
pid = fork();
if (pid == -1) {
perror("fuse: fork() failed");
close(fd);
exit(1);
}
}
if (pid == 0) {
const char *argv[32];
int a = 0;
if (! fdnam && asprintf(&fdnam, "%d", fd) == -1) {
perror("fuse: failed to assemble mount arguments");
exit(1);
}
argv[a++] = mountprog;
if (opts) {
argv[a++] = "-o";
argv[a++] = opts;
}
argv[a++] = fdnam;
argv[a++] = mountpoint;
argv[a++] = NULL;
execvp(mountprog, (char **) argv);
perror("fuse: failed to exec mount program");
exit(1);
}
exit(0);
}
if (waitpid(cpid, &status, 0) == -1 || WEXITSTATUS(status) != 0) {
perror("fuse: failed to mount file system");
close(fd);
return -1;
}
out:
return fd;
}
int fuse_kern_mount(const char *mountpoint, struct fuse_args *args)
{
struct mount_opts mo;
int res = -1;
memset(&mo, 0, sizeof(mo));
/* mount util should not try to spawn the daemon */
setenv("MOUNT_FUSEFS_SAFE", "1", 1);
/* to notify the mount util it's called from lib */
setenv("MOUNT_FUSEFS_CALL_BY_LIB", "1", 1);
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;
}
if (mo.ishelp)
return 0;
res = fuse_mount_core(mountpoint, mo.kernel_opts);
out:
free(mo.kernel_opts);
return res;
}
FUSE_SYMVER(".symver fuse_unmount_compat22,fuse_unmount@FUSE_2.2");
