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/*
* Guillaume Cottenceau (gc)
*
* Copyright 2000 Mandriva
*
* This software may be freely redistributed under the terms of the GNU
* public license.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
/* This code comes from util-linux-2.10n (mount/lomount.c)
* (this is a simplified version of this code)
*/
#include <sys/types.h>
#include <sys/mount.h>
#include <sys/ioctl.h>
#include <sys/mount.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include "stage1.h"
#include "frontend.h"
#include "log.h"
#include "mount.h"
#include "modules.h"
#include "lomount.h"
#define LO_NAME_SIZE 64
#define LO_KEY_SIZE 32
struct loop_info
{
int lo_number; /* ioctl r/o */
dev_t lo_device; /* ioctl r/o */
unsigned long lo_inode; /* ioctl r/o */
dev_t lo_rdevice; /* ioctl r/o */
int lo_offset;
int lo_encrypt_type;
int lo_encrypt_key_size; /* ioctl w/o */
int lo_flags; /* ioctl r/o */
char lo_name[LO_NAME_SIZE];
unsigned char lo_encrypt_key[LO_KEY_SIZE]; /* ioctl w/o */
unsigned long lo_init[2];
char reserved[4];
};
#define LOOP_SET_FD 0x4C00
#define LOOP_CLR_FD 0x4C01
#define LOOP_SET_STATUS 0x4C02
#define LOOP_GET_STATUS 0x4C03
int
set_loop (const char *device, const char *file)
{
struct loop_info loopinfo;
int fd, ffd, mode;
mode = O_RDONLY;
if ((ffd = open (file, mode)) < 0)
return 1;
if ((fd = open (device, mode)) < 0) {
close(ffd);
return 1;
}
memset(&loopinfo, 0, sizeof (loopinfo));
strncpy(loopinfo.lo_name, file, LO_NAME_SIZE);
loopinfo.lo_name[LO_NAME_SIZE - 1] = 0;
loopinfo.lo_offset = 0;
#ifdef MCL_FUTURE
/*
* Oh-oh, sensitive data coming up. Better lock into memory to prevent
* passwd etc being swapped out and left somewhere on disk.
*/
if(mlockall(MCL_CURRENT|MCL_FUTURE)) {
log_message("CRITICAL Couldn't lock into memory! %s (memlock)", strerror(errno));
return 1;
}
#endif
if (ioctl(fd, LOOP_SET_FD, ffd) < 0) {
close(fd);
close(ffd);
return 1;
}
if (ioctl(fd, LOOP_SET_STATUS, &loopinfo) < 0) {
(void) ioctl (fd, LOOP_CLR_FD, 0);
close(fd);
close(ffd);
return 1;
}
close(fd);
close(ffd);
return 0;
}
char* find_free_loop()
{
struct loop_info loopinfo;
int i;
for (i=0; i<256; i++) {
int fd;
char ldev[100];
sprintf(ldev, "/dev/loop%d", i);
ensure_dev_exists(ldev);
fd = open(ldev, O_RDONLY);
if (!ioctl(fd, LOOP_GET_STATUS, &loopinfo)) {
close(fd);
continue;
}
if (errno == ENXIO) {
log_message("%s is available", ldev);
close(fd);
return strdup(ldev);
} else {
log_perror("LOOP_GET_STATUS(unexpected error)");
close(fd);
continue;
}
}
return NULL;
}
void
del_loop(char * loopdev)
{
int fd;
if (!loopdev)
return;
if ((fd = open (loopdev, O_RDONLY)) < 0)
return;
if (ioctl (fd, LOOP_CLR_FD, 0) < 0)
return;
close (fd);
}
int
lomount(char *loopfile, char *where, char **dev, int compressed)
{
long int flag;
char * loopdev;
flag = MS_MGC_VAL;
flag |= MS_RDONLY;
my_modprobe("loop", ANY_DRIVER_TYPE, "max_loop=256");
if (compressed) {
my_modprobe("squashfs", ANY_DRIVER_TYPE, NULL);
}
if (!(loopdev = find_free_loop())) {
log_message("could not find a free loop");
return 1;
}
if (dev)
*dev = loopdev;
if (set_loop(loopdev, loopfile)) {
log_message("set_loop failed on %s (%s)", loopdev, strerror(errno));
return 1;
}
if (my_mount(loopdev, where, compressed ? "squashfs" : "iso9660", 0)) {
del_loop(loopdev);
return 1;
}
log_message("lomount succeeded for %s on %s", loopfile, where);
return 0;
}
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