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/*
FUSE: Filesystem in Userspace
Copyright (C) 2001 Miklos Szeredi (mszeredi@inf.bme.hu)
This program can be distributed under the terms of the GNU GPL.
See the file COPYING.
*/
#include "fuse.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <limits.h>
#include <signal.h>
#include <errno.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <fcntl.h>
#include <sys/wait.h>
#define FUSE_MOUNTED_ENV "_FUSE_MOUNTED"
#define FUSE_UMOUNT_CMD_ENV "_FUSE_UNMOUNT_CMD"
static void usage(char *progname)
{
fprintf(stderr,
"usage: %s mountpoint [options] \n"
"Options:\n"
" -d enable debug output\n"
" -s disable multithreaded operation\n"
" -h print help\n",
progname);
exit(1);
}
static void fuse_unmount()
{
close(0);
system(getenv(FUSE_UMOUNT_CMD_ENV));
}
static int fuse_mount_obsolete(int *argcp, char **argv)
{
char *isreexec = getenv(FUSE_MOUNTED_ENV);
if(isreexec == NULL) {
int i;
int argc = *argcp;
char *mountprog = "fusermount";
char **newargv = (char **) malloc((1 + argc + 1) * sizeof(char *));
if(argc < 2 || argv[1][0] == '-')
usage(argv[0]);
/* oldargs: "PROG MOUNTPOINT ARGS..."
newargs: "fusermount MOUNTPOINT PROG ARGS..." */
newargv[0] = mountprog;
newargv[1] = argv[1];
newargv[2] = argv[0];
for(i = 2; i < argc; i++)
newargv[i+1] = argv[i];
newargv[i+1] = NULL;
execvp(mountprog, newargv);
fprintf(stderr, "fuse: failed to exec %s: %s\n", mountprog,
strerror(errno));
return -1;
}
unsetenv(FUSE_MOUNTED_ENV);
/* The actual file descriptor is stdin */
return 0;
}
/* return value:
* >= 0 => fd
* -1 => error
*/
int receive_fd(int fd) {
struct msghdr msg;
struct iovec iov;
char buf[1];
int rv;
int connfd = -1;
char ccmsg[CMSG_SPACE(sizeof(connfd))];
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 */
fprintf(stderr, "got EOF\n");
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);
}
int fuse_mount(const char *mountpoint, const char *mount_args)
{
int fds[2], pid;
int rv, fd;
char env[10];
/* FIXME: parse mount_args (or just pass it to fusermount ???) */
mount_args = mount_args;
/* make sure the socket fds are greater than 0 */
fd = open("/dev/null",O_RDONLY);
rv = socketpair(PF_UNIX,SOCK_STREAM,0,fds);
close(fd);
if(rv) {
fprintf(stderr,"fuse: failed to socketpair()\n");
close(fd);
return -1;
}
pid = fork();
if(pid < 0) {
fprintf(stderr,"fuse: failed to fork()\n");
close(fds[0]);
close(fds[1]);
return -1;
}
if(pid == 0) {
close(fds[1]);
fcntl(fds[0],F_SETFD,0);
snprintf(env,sizeof(env),"%i",fds[0]);
setenv("_FUSE_IOSLAVE_FD",env,1);
execlp("fusermount","fusermount",mountpoint,"fuse_ioslave",NULL);
fprintf(stderr,"fuse: failed to exec fusermount\n");
exit(1);
}
fd = fds[1];
close(fds[0]);
rv = receive_fd(fd);
close(fd);
waitpid(pid,NULL,0); /* bury zombie */
return rv;
}
static void exit_handler()
{
exit(0);
}
static void set_signal_handlers()
{
struct sigaction sa;
sa.sa_handler = exit_handler;
sigemptyset(&(sa.sa_mask));
sa.sa_flags = 0;
if (sigaction(SIGHUP, &sa, NULL) == -1 ||
sigaction(SIGINT, &sa, NULL) == -1 ||
sigaction(SIGTERM, &sa, NULL) == -1) {
perror("Cannot set exit signal handlers");
exit(1);
}
sa.sa_handler = SIG_IGN;
if(sigaction(SIGPIPE, &sa, NULL) == -1) {
perror("Cannot set ignored signals");
exit(1);
}
}
void fuse_main(int argc, char *argv[], const struct fuse_operations *op)
{
int fd;
int argctr;
int flags;
int multithreaded;
struct fuse *fuse;
fd = fuse_mount_obsolete(&argc, argv);
if(fd == -1)
exit(1);
atexit(fuse_unmount);
set_signal_handlers();
argctr = 1;
flags = 0;
multithreaded = 1;
for(; argctr < argc && argv[argctr][0] == '-'; argctr ++) {
switch(argv[argctr][1]) {
case 'd':
flags |= FUSE_DEBUG;
break;
case 's':
multithreaded = 0;
break;
case 'h':
usage(argv[0]);
break;
default:
fprintf(stderr, "invalid option: %s\n", argv[argctr]);
exit(1);
}
}
if(argctr != argc) {
fprintf(stderr, "missing or surplus argument\n");
exit(1);
}
fuse = fuse_new(fd, flags, op);
if(multithreaded)
fuse_loop_mt(fuse);
else
fuse_loop(fuse);
}
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