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/* fusefs_fuse.c */
/* This is rewriting most of the things that occur
* in fuse_main up through fuse_loop */
#define FUSE_USE_VERSION 26
#define _FILE_OFFSET_BITS 64
#include <fuse.h>
#include <fuse/fuse_lowlevel.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <limits.h>
#include <errno.h>
#include <assert.h>
#include <stdint.h>
#include <sys/param.h>
#include <sys/uio.h>
#include <signal.h>
struct fuse *fuse_instance = NULL;
struct fuse_chan *fusech = NULL;
static char *mounted_at = NULL;
static int set_one_signal_handler(int signal, void (*handler)(int));
int fusefs_fd() {
if(fusech == NULL)
return -1;
return fuse_chan_fd(fusech);
}
int
fusefs_unmount() {
char buf[128];
if (mounted_at && fusech) {
fuse_unmount(mounted_at, fusech);
sprintf(buf, "/sbin/umount %s", mounted_at);
system(buf);
}
if (fuse_instance)
fuse_destroy(fuse_instance);
fuse_instance = NULL;
free(mounted_at);
fusech = NULL;
}
static void
fusefs_ehandler() {
if (fuse_instance != NULL) {
fusefs_unmount();
}
}
int
fusefs_setup(char *mountpoint, const struct fuse_operations *op, struct fuse_args *opts) {
fusech = NULL;
if (fuse_instance != NULL) {
return 0;
}
if (mounted_at != NULL) {
return 0;
}
/* First, mount us */
fusech = fuse_mount(mountpoint, opts);
if (fusech == NULL) return 0;
fuse_instance = fuse_new(fusech, opts, op, sizeof(*op), NULL);
if (fuse_instance == NULL)
goto err_unmount;
/* Set signal handlers */
if (set_one_signal_handler(SIGHUP, fusefs_ehandler) == -1 ||
set_one_signal_handler(SIGINT, fusefs_ehandler) == -1 ||
set_one_signal_handler(SIGTERM, fusefs_ehandler) == -1 ||
set_one_signal_handler(SIGPIPE, SIG_IGN) == -1)
return 0;
atexit(fusefs_ehandler);
/* We've initialized it! */
mounted_at = strdup(mountpoint);
return 1;
err_destroy:
fuse_destroy(fuse_instance);
err_unmount:
fuse_unmount(mountpoint, fusech);
return 0;
}
int
fusefs_uid() {
struct fuse_context *context = fuse_get_context();
if (context) return context->uid;
return -1;
}
int
fusefs_gid() {
struct fuse_context *context = fuse_get_context();
if (context) return context->gid;
return -1;
}
int
fusefs_process() {
/* This gets exactly 1 command out of fuse fd. */
/* Ideally, this is triggered after a select() returns */
if (fuse_instance != NULL) {
struct fuse_cmd *cmd;
if (fuse_exited(fuse_instance))
return 0;
cmd = fuse_read_cmd(fuse_instance);
if (cmd == NULL)
return 1;
fuse_process_cmd(fuse_instance, cmd);
}
return 1;
}
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;
}
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