libfuse/lib/helper.c
2004-11-30 00:00:02 +00:00

347 lines
9.2 KiB
C

/*
FUSE: Filesystem in Userspace
Copyright (C) 2001-2004 Miklos Szeredi <miklos@szeredi.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 <string.h>
#include <limits.h>
#include <signal.h>
static struct fuse *fuse_instance;
static void usage(const char *progname)
{
fprintf(stderr,
"usage: %s mountpoint [options]\n"
"Options:\n"
" -d enable debug output (implies -f)\n"
" -f foreground operation\n"
" -s disable multithreaded operation\n"
" -r mount read only (equivalent to '-o ro')\n"
" -o opt,[opt...] mount options\n"
" -h print help\n"
"\n"
"Mount options:\n"
" default_permissions enable permission checking\n"
" allow_other allow access to other users\n"
" kernel_cache cache files in kernel\n"
" large_read issue large read requests (2.4 only)\n"
" direct_io use direct I/O\n"
" max_read=N set maximum size of read requests\n"
" hard_remove immediate removal (don't hide files)\n"
" debug enable debug output\n"
" fsname=NAME set filesystem name in mtab\n",
progname);
}
static void invalid_option(const char *argv[], int argctr)
{
fprintf(stderr, "fuse: invalid option: %s\n\n", argv[argctr]);
usage(argv[0]);
}
static void exit_handler()
{
if (fuse_instance != NULL)
fuse_exit(fuse_instance);
}
static int set_one_signal_handler(int signal, void (*handler)(int))
{
struct sigaction sa;
struct sigaction old_sa;
memset(&sa, 0, sizeof(struct sigaction));
sa.sa_handler = handler;
sigemptyset(&(sa.sa_mask));
sa.sa_flags = 0;
if (sigaction(signal, NULL, &old_sa) == -1) {
perror("FUSE: cannot get old signal handler");
return -1;
}
if (old_sa.sa_handler == SIG_DFL &&
sigaction(signal, &sa, NULL) == -1) {
perror("Cannot set signal handler");
return -1;
}
return 0;
}
static int set_signal_handlers()
{
if (set_one_signal_handler(SIGHUP, exit_handler) == -1 ||
set_one_signal_handler(SIGINT, exit_handler) == -1 ||
set_one_signal_handler(SIGTERM, exit_handler) == -1 ||
set_one_signal_handler(SIGPIPE, SIG_IGN) == -1)
return -1;
return 0;
}
static int add_option_to(const char *opt, char **optp)
{
unsigned len = strlen(opt);
if (*optp) {
unsigned oldlen = strlen(*optp);
*optp = realloc(*optp, oldlen + 1 + len + 1);
if (*optp == NULL)
return -1;
(*optp)[oldlen] = ',';
strcpy(*optp + oldlen + 1, opt);
} else {
*optp = malloc(len + 1);
if (*optp == NULL)
return -1;
strcpy(*optp, opt);
}
return 0;
}
static int add_options(char **lib_optp, char **kernel_optp, const char *opts)
{
char *xopts = strdup(opts);
char *s = xopts;
char *opt;
if (xopts == NULL) {
fprintf(stderr, "fuse: memory allocation failed\n");
return -1;
}
while((opt = strsep(&s, ",")) != NULL) {
int res;
if (fuse_is_lib_option(opt))
res = add_option_to(opt, lib_optp);
else
res = add_option_to(opt, kernel_optp);
if (res == -1) {
fprintf(stderr, "fuse: memory allocation failed\n");
return -1;
}
}
free(xopts);
return 0;
}
static int fuse_parse_cmdline(int argc, const char *argv[], char **kernel_opts,
char **lib_opts, char **mountpoint,
int *multithreaded, int *background)
{
int res;
int argctr;
const char *basename;
char *fsname_opt;
*kernel_opts = NULL;
*lib_opts = NULL;
*mountpoint = NULL;
*multithreaded = 1;
*background = 1;
basename = strrchr(argv[0], '/');
if (basename == NULL)
basename = argv[0];
else if (basename[1] != '\0')
basename++;
fsname_opt = malloc(strlen(basename) + 64);
if (fsname_opt == NULL) {
fprintf(stderr, "fuse: memory allocation failed\n");
return -1;
}
sprintf(fsname_opt, "fsname=%s", basename);
res = add_options(lib_opts, kernel_opts, fsname_opt);
free(fsname_opt);
if (res == -1)
goto err;
for (argctr = 1; argctr < argc; argctr ++) {
if (argv[argctr][0] == '-') {
if (strlen(argv[argctr]) == 2)
switch (argv[argctr][1]) {
case 'o':
if (argctr + 1 == argc || argv[argctr+1][0] == '-') {
fprintf(stderr, "missing option after -o\n\n");
usage(argv[0]);
goto err;
}
argctr ++;
res = add_options(lib_opts, kernel_opts, argv[argctr]);
if (res == -1)
goto err;
break;
case 'd':
res = add_options(lib_opts, kernel_opts, "debug");
if (res == -1)
goto err;
*background = 0;
break;
case 'r':
res = add_options(lib_opts, kernel_opts, "ro");
if (res == -1)
goto err;
break;
case 'f':
*background = 0;
break;
case 's':
*multithreaded = 0;
break;
case 'h':
usage(argv[0]);
goto err;
default:
invalid_option(argv, argctr);
goto err;
}
else {
if (argv[argctr][1] == 'o') {
res = add_options(lib_opts, kernel_opts, &argv[argctr][2]);
if (res == -1)
goto err;
}
else {
invalid_option(argv, argctr);
goto err;
}
}
} else if (*mountpoint == NULL) {
*mountpoint = strdup(argv[argctr]);
if (*mountpoint == NULL) {
fprintf(stderr, "fuse: memory allocation failed\n");
goto err;
}
}
else {
invalid_option(argv, argctr);
goto err;
}
}
if (*mountpoint == NULL) {
fprintf(stderr, "missing mountpoint\n\n");
usage(argv[0]);
goto err;
}
return 0;
err:
free(*kernel_opts);
free(*lib_opts);
free(*mountpoint);
return -1;
}
struct fuse *__fuse_setup(int argc, char *argv[],
const struct fuse_operations *op,
char **mountpoint, int *multithreaded, int *fd)
{
struct fuse *fuse;
int background;
char *kernel_opts;
char *lib_opts;
int res;
if (fuse_instance != NULL) {
fprintf(stderr, "fuse: __fuse_setup() called twice\n");
return NULL;
}
res = fuse_parse_cmdline(argc, (const char **) argv, &kernel_opts,
&lib_opts, mountpoint, multithreaded,
&background);
if (res == -1)
return NULL;
*fd = fuse_mount(*mountpoint, kernel_opts);
if (*fd == -1)
goto err_free;
fuse = fuse_new(*fd, lib_opts, op);
if (fuse == NULL)
goto err_unmount;
if (background) {
res = daemon(0, 0);
if (res == -1) {
perror("fuse: failed to daemonize program\n");
goto err_destroy;
}
}
res = set_signal_handlers();
if (res == -1)
goto err_destroy;
fuse_instance = fuse;
free(kernel_opts);
free(lib_opts);
return fuse;
err_destroy:
fuse_destroy(fuse);
err_unmount:
fuse_unmount(*mountpoint);
err_free:
free(kernel_opts);
free(lib_opts);
free(*mountpoint);
return NULL;
}
void __fuse_teardown(struct fuse *fuse, int fd, char *mountpoint)
{
if (fuse_instance != fuse)
fprintf(stderr, "fuse: __fuse_teardown() with unknown fuse object\n");
else
fuse_instance = NULL;
fuse_destroy(fuse);
close(fd);
fuse_unmount(mountpoint);
free(mountpoint);
}
int fuse_main(int argc, char *argv[], const struct fuse_operations *op)
{
struct fuse *fuse;
char *mountpoint;
int multithreaded;
int res;
int fd;
fuse = __fuse_setup(argc, argv, op, &mountpoint, &multithreaded, &fd);
if (fuse == NULL)
return 1;
if (multithreaded)
res = fuse_loop_mt(fuse);
else
res = fuse_loop(fuse);
__fuse_teardown(fuse, fd, mountpoint);
if (res == -1)
return 1;
return 0;
}