libfuse/lib/mount.c
2004-03-30 07:24:29 +00:00

137 lines
3.1 KiB
C

/*
FUSE: Filesystem in Userspace
Copyright (C) 2001 Miklos Szeredi (mszeredi@inf.bme.hu)
This program can be distributed under the terms of the GNU LGPL.
See the file COPYING.LIB.
*/
#include "fuse.h"
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <sys/wait.h>
#define FUSERMOUNT_PROG "fusermount"
#define FUSE_COMMFD_ENV "_FUSE_COMMFD"
/* return value:
* >= 0 => fd
* -1 => error
*/
static 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 */
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);
}
void fuse_unmount(const char *mountpoint)
{
const char *mountprog = FUSERMOUNT_PROG;
char umount_cmd[1024];
snprintf(umount_cmd, sizeof(umount_cmd) - 1, "%s -u -q -z %s", mountprog,
mountpoint);
umount_cmd[sizeof(umount_cmd) - 1] = '\0';
system(umount_cmd);
}
int fuse_mount(const char *mountpoint, const char *args[])
{
const char *mountprog = FUSERMOUNT_PROG;
int fds[2], pid;
int res;
int rv;
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];
char **newargv;
int numargs = 0;
int actr;
int i;
if(args != NULL)
while(args[numargs] != NULL)
numargs ++;
newargv = (char **) malloc((1 + numargs + 2) * sizeof(char *));
actr = 0;
newargv[actr++] = strdup(mountprog);
for(i = 0; i < numargs; i++)
newargv[actr++] = strdup(args[i]);
newargv[actr++] = strdup(mountpoint);
newargv[actr++] = NULL;
close(fds[1]);
fcntl(fds[0], F_SETFD, 0);
snprintf(env, sizeof(env), "%i", fds[0]);
setenv(FUSE_COMMFD_ENV, env, 1);
execvp(mountprog, newargv);
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;
}