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/* vi: set sw=4 ts=4: */
/*
* Utility routines.
*
* Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <stdio.h>
#include <errno.h>
#include <fcntl.h>
#include <string.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include "libbb.h"
/* Grumble... The 2.6.x kernel breaks asm/posix_types.h
* so we get to try and cope as best we can... */
#include <linux/version.h>
#include <asm/posix_types.h>
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
#define __bb_kernel_dev_t __kernel_old_dev_t
#elif LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
#define __bb_kernel_dev_t __kernel_dev_t
#else
#define __bb_kernel_dev_t unsigned short
#endif
/* Stuff stolen from linux/loop.h */
#define LO_NAME_SIZE 64
#define LO_KEY_SIZE 32
#define LOOP_SET_FD 0x4C00
#define LOOP_CLR_FD 0x4C01
#define LOOP_SET_STATUS 0x4C02
#define LOOP_GET_STATUS 0x4C03
struct loop_info {
int lo_number;
__bb_kernel_dev_t lo_device;
unsigned long lo_inode;
__bb_kernel_dev_t lo_rdevice;
int lo_offset;
int lo_encrypt_type;
int lo_encrypt_key_size;
int lo_flags;
char lo_name[LO_NAME_SIZE];
unsigned char lo_encrypt_key[LO_KEY_SIZE];
unsigned long lo_init[2];
char reserved[4];
};
extern int del_loop(const char *device)
{
int fd;
if ((fd = open(device, O_RDONLY)) < 0) {
bb_perror_msg("%s", device);
return (FALSE);
}
if (ioctl(fd, LOOP_CLR_FD, 0) < 0) {
close(fd);
bb_perror_msg("ioctl: LOOP_CLR_FD");
return (FALSE);
}
close(fd);
return (TRUE);
}
extern int set_loop(const char *device, const char *file, int offset,
int *loopro)
{
struct loop_info loopinfo;
int fd, ffd, mode;
mode = *loopro ? O_RDONLY : O_RDWR;
if ((ffd = open(file, mode)) < 0 && !*loopro
&& (errno != EROFS || (ffd = open(file, mode = O_RDONLY)) < 0)) {
bb_perror_msg("%s", file);
return 1;
}
if ((fd = open(device, mode)) < 0) {
close(ffd);
bb_perror_msg("%s", device);
return 1;
}
*loopro = (mode == O_RDONLY);
memset(&loopinfo, 0, sizeof(loopinfo));
safe_strncpy(loopinfo.lo_name, file, LO_NAME_SIZE);
loopinfo.lo_offset = offset;
loopinfo.lo_encrypt_key_size = 0;
if (ioctl(fd, LOOP_SET_FD, ffd) < 0) {
bb_perror_msg("ioctl: LOOP_SET_FD");
close(fd);
close(ffd);
return 1;
}
if (ioctl(fd, LOOP_SET_STATUS, &loopinfo) < 0) {
(void) ioctl(fd, LOOP_CLR_FD, 0);
bb_perror_msg("ioctl: LOOP_SET_STATUS");
close(fd);
close(ffd);
return 1;
}
close(fd);
close(ffd);
return 0;
}
extern char *find_unused_loop_device(void)
{
char dev[20];
int i, fd;
struct stat statbuf;
struct loop_info loopinfo;
for (i = 0; i <= 7; i++) {
sprintf(dev, LOOP_FORMAT, i);
if (stat(dev, &statbuf) == 0 && S_ISBLK(statbuf.st_mode)) {
if ((fd = open(dev, O_RDONLY)) >= 0) {
if (ioctl(fd, LOOP_GET_STATUS, &loopinfo) != 0) {
if (errno == ENXIO) { /* probably free */
close(fd);
return strdup(dev);
}
}
close(fd);
}
}
}
return NULL;
}
/* END CODE */
/*
Local Variables:
c-file-style: "linux"
c-basic-offset: 4
tab-width: 4
End:
*/
|
