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/* Taken from Ted's losetup.c - Mitch <m.dsouza@mrc-apu.cam.ac.uk> */
/*
* losetup.c - setup and control loop devices
*/
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <fcntl.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <linux/fs.h>
#include "loop.h"
char *crypt_name (int);
int crypt_type (char *);
void show_loop (char *);
int del_loop (const char *);
int set_loop (const char *, const char *, int offset, char *);
int lomount (const char *, const char *, const char *, char **,
int *, char **, char **);
struct crypt_type_struct {
int id;
char *name;
} crypt_type_tbl[] = {
{
LO_CRYPT_NONE, "no"
},
{
LO_CRYPT_NONE, "none"
},
{
LO_CRYPT_XOR, "xor"
},
{
LO_CRYPT_DES, "DES"
},
{
-1, NULL
}
};
char *
crypt_name (int id)
{
int i;
for (i = 0; crypt_type_tbl[i].id != -1; i++)
if (id == crypt_type_tbl[i].id)
return crypt_type_tbl[i].name;
return "undefined";
}
int
crypt_type (char *name)
{
int i;
for (i = 0; crypt_type_tbl[i].id != -1; i++)
if (!strcasecmp (name, crypt_type_tbl[i].name))
return crypt_type_tbl[i].id;
return -1;
}
void
show_loop (char *device)
{
struct loop_info loopinfo;
int fd;
if ((fd = open (device, O_RDWR)) < 0) {
fprintf(stderr, "loop: can't open device %s: %s\n",
device, strerror (errno));
return;
}
if (ioctl (fd, LOOP_GET_STATUS, &loopinfo) < 0) {
fprintf(stderr, "loop: can't get info on device %s: %s\n",
device, strerror (errno));
close (fd);
return;
}
printf ("%s: [%04x]:%ld (%s) offset %d, %s encryption\n",
device, loopinfo.lo_device, loopinfo.lo_inode,
loopinfo.lo_name, loopinfo.lo_offset,
crypt_name (loopinfo.lo_encrypt_type));
close (fd);
}
int
set_loop (const char *device, const char *file, int offset, char *encryption)
{
struct loop_info loopinfo;
int fd,
ffd,
i;
char *pass;
if ((fd = open (device, O_RDWR)) < 0) {
perror (device);
return 1;
}
if ((ffd = open (file, O_RDWR)) < 0) {
perror (file);
return 1;
}
memset (&loopinfo, 0, sizeof (loopinfo));
strncpy (loopinfo.lo_name, file, LO_NAME_SIZE);
loopinfo.lo_name[LO_NAME_SIZE - 1] = 0;
if (encryption && (loopinfo.lo_encrypt_type = crypt_type (encryption))
< 0) {
fprintf (stderr, "Unsupported encryption type %s", encryption);
return 1;
}
loopinfo.lo_offset = offset;
switch (loopinfo.lo_encrypt_type) {
case LO_CRYPT_NONE:
loopinfo.lo_encrypt_key_size = 0;
break;
case LO_CRYPT_XOR:
pass = getpass ("Password: ");
strncpy (loopinfo.lo_encrypt_key, pass, LO_KEY_SIZE);
loopinfo.lo_encrypt_key[LO_KEY_SIZE - 1] = 0;
loopinfo.lo_encrypt_key_size = strlen (loopinfo.lo_encrypt_key);
break;
case LO_CRYPT_DES:
pass = getpass ("Password: ");
strncpy (loopinfo.lo_encrypt_key, pass, 8);
loopinfo.lo_encrypt_key[8] = 0;
loopinfo.lo_encrypt_key_size = 8;
pass = getpass ("Init (up to 16 hex digits): ");
for (i = 0; i < 16 && pass[i]; i++)
if (isxdigit (pass[i]))
loopinfo.lo_init[i >> 3] |= (pass[i] > '9' ?
(islower (pass[i]) ? toupper (pass[i]) :
pass[i]) - 'A' + 10 : pass[i] - '0') << (i & 7) * 4;
else {
fprintf (stderr, "Non-hex digit '%c'.\n", pass[i]);
return 1;
}
break;
default:
fprintf (stderr,
"Don't know how to get key for encryption system %d\n",
loopinfo.lo_encrypt_type);
return 1;
}
if (ioctl (fd, LOOP_SET_FD, ffd) < 0) {
perror ("ioctl: LOOP_SET_FD");
return 1;
}
if (ioctl (fd, LOOP_SET_STATUS, &loopinfo) < 0) {
(void) ioctl (fd, LOOP_CLR_FD, 0);
perror ("ioctl: LOOP_SET_STATUS");
return 1;
}
close (fd);
close (ffd);
return 0;
}
int
del_loop (const char *device)
{
int fd;
if ((fd = open (device, O_RDONLY)) < 0) {
fprintf(stderr, "loop: can't delete device %s: %s\n",
device, strerror (errno));
return 1;
}
if (ioctl (fd, LOOP_CLR_FD, 0) < 0) {
#if 0
perror ("ioctl: LOOP_CLR_FD");
#endif
return 1;
}
return 0;
}
int
lomount (const char *spec, const char *node, const char *device, char **type,
int *flags, char **extra_opts, char **mount_opts)
{
char *opt,
*opteq;
int val;
char *encryption = NULL, *vfs = NULL;
int offset = 0, err;
char new_opts[1024];
for (opt = strtok (*extra_opts, ","); opt; opt = strtok (NULL, ",")) {
if ((opteq = strchr (opt, '='))) {
val = atoi (opteq + 1);
*opteq = '\0';
if (!strcmp (opt, "encryption"))
encryption = strdup(opteq + 1);
else if (!strcmp (opt, "vfs"))
vfs = strdup(opteq + 1);
else if (!strcmp (opt, "offset"))
offset = val;
else {
printf ("unknown loop mount parameter: "
"%s=%d (%s)\n", opt, val, opteq+1);
return 1;
}
} else {
printf ("unknown loop mount parameter: "
"%s\n", opt);
return 1;
}
}
err = set_loop (device, spec, offset, encryption);
sprintf(new_opts, "vfs=%s,offset=%d,encryption=%s",
*type = vfs ? vfs : FSTYPE_DEFAULT, offset,
encryption=crypt_type(encryption)<0?"none":encryption);
*extra_opts=strdup(new_opts);
return err;
}
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