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129 lines
3.0 KiB
C
129 lines
3.0 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) tons of folks. Tracking down who wrote what
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* isn't something I'm going to worry about... If you wrote something
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* here, please feel free to acknowledge your work.
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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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* Based in part on code from sash, Copyright (c) 1999 by David I. Bell
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* Permission has been granted to redistribute this code under the GPL.
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*
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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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#include "loop.h" /* Pull in loop device support */
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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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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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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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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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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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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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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, "/dev/loop%d", 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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