ef8cd3be17
with 2.6.x asm/posix_types.h, which has done singularly evil thing by yanking __kernel_dev_t and renaming it. The loop interface was really poorly designed in the first place. The new 64 bit loop interface looks to be somewhat less horrible, too bad it is only present in 2.6.x kernels. -Erik
157 lines
3.8 KiB
C
157 lines
3.8 KiB
C
/* vi: set sw=4 ts=4: */
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/*
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* Utility routines.
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*
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* Copyright (C) 1999-2003 by Erik Andersen <andersen@codepoet.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include <stdio.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <string.h>
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#include <unistd.h>
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#include <sys/ioctl.h>
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#include "libbb.h"
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/* Grumble... The 2.6.x kernel breaks asm/posix_types.h
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* so we get to try and cope as best we can... */
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#include <linux/version.h>
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#include <asm/posix_types.h>
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#if LINUX_VERSION_CODE >= 132608
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#define __bb_kernel_dev_t __kernel_old_dev_t
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#elif LINUX_VERSION_CODE >= 0x20600
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#define __bb_kernel_dev_t __kernel_dev_t
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#else
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#define __bb_kernel_dev_t unsigned short
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#endif
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/* Stuff stolen from linux/loop.h */
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#define LO_NAME_SIZE 64
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#define LO_KEY_SIZE 32
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#define LOOP_SET_FD 0x4C00
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#define LOOP_CLR_FD 0x4C01
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#define LOOP_SET_STATUS 0x4C02
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#define LOOP_GET_STATUS 0x4C03
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struct loop_info {
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int lo_number;
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__bb_kernel_dev_t lo_device;
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unsigned long lo_inode;
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__bb_kernel_dev_t lo_rdevice;
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int lo_offset;
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int lo_encrypt_type;
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int lo_encrypt_key_size;
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int lo_flags;
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char lo_name[LO_NAME_SIZE];
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unsigned char lo_encrypt_key[LO_KEY_SIZE];
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unsigned long lo_init[2];
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char reserved[4];
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};
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extern int del_loop(const char *device)
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{
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int fd;
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if ((fd = open(device, O_RDONLY)) < 0) {
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bb_perror_msg("%s", device);
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return (FALSE);
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}
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if (ioctl(fd, LOOP_CLR_FD, 0) < 0) {
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close(fd);
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bb_perror_msg("ioctl: LOOP_CLR_FD");
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return (FALSE);
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}
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close(fd);
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return (TRUE);
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}
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extern int set_loop(const char *device, const char *file, int offset,
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int *loopro)
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{
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struct loop_info loopinfo;
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int fd, ffd, mode;
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mode = *loopro ? O_RDONLY : O_RDWR;
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if ((ffd = open(file, mode)) < 0 && !*loopro
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&& (errno != EROFS || (ffd = open(file, mode = O_RDONLY)) < 0)) {
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bb_perror_msg("%s", file);
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return 1;
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}
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if ((fd = open(device, mode)) < 0) {
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close(ffd);
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bb_perror_msg("%s", device);
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return 1;
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}
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*loopro = (mode == O_RDONLY);
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memset(&loopinfo, 0, sizeof(loopinfo));
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safe_strncpy(loopinfo.lo_name, file, LO_NAME_SIZE);
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loopinfo.lo_offset = offset;
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loopinfo.lo_encrypt_key_size = 0;
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if (ioctl(fd, LOOP_SET_FD, ffd) < 0) {
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bb_perror_msg("ioctl: LOOP_SET_FD");
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close(fd);
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close(ffd);
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return 1;
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}
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if (ioctl(fd, LOOP_SET_STATUS, &loopinfo) < 0) {
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(void) ioctl(fd, LOOP_CLR_FD, 0);
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bb_perror_msg("ioctl: LOOP_SET_STATUS");
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close(fd);
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close(ffd);
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return 1;
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}
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close(fd);
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close(ffd);
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return 0;
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}
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extern char *find_unused_loop_device(void)
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{
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char dev[20];
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int i, fd;
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struct stat statbuf;
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struct loop_info loopinfo;
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for (i = 0; i <= 7; i++) {
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sprintf(dev, LOOP_FORMAT, i);
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if (stat(dev, &statbuf) == 0 && S_ISBLK(statbuf.st_mode)) {
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if ((fd = open(dev, O_RDONLY)) >= 0) {
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if (ioctl(fd, LOOP_GET_STATUS, &loopinfo) != 0) {
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if (errno == ENXIO) { /* probably free */
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close(fd);
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return strdup(dev);
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}
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}
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close(fd);
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}
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}
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}
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return NULL;
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}
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/* END CODE */
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/*
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Local Variables:
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c-file-style: "linux"
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c-basic-offset: 4
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tab-width: 4
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End:
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*/
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