e2fsprogs/misc/e2image.c

/*
 * e2image.c --- Program which writes an image file backing up
 * critical metadata for the filesystem.
 *
 * Copyright 2000, 2001 by Theodore Ts'o.
 *
 * %Begin-Header%
 * This file may be redistributed under the terms of the GNU Public
 * License.
 * %End-Header%
 */

#include <fcntl.h>
#include <grp.h>
#ifdef HAVE_GETOPT_H
#include <getopt.h>
#else
extern char *optarg;
extern int optind;
#endif
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/stat.h>
#include <sys/types.h>

#include <linux/ext2_fs.h>

#include "ext2fs/ext2fs.h"
#include "et/com_err.h"
#include "uuid/uuid.h"
#include "e2p/e2p.h"
#include "ext2fs/e2image.h"

#include "../version.h"
#include "nls-enable.h"

const char * program_name = "e2image";
char * device_name = NULL;

static void usage(void)
{
	fprintf(stderr, _("Usage: %s device file\n"), program_name);
	exit (1);
}

static void write_header(int fd, struct ext2_image_hdr *hdr, int blocksize)
{
	char *header_buf;
	int actual;

	header_buf = malloc(blocksize);
	if (!header_buf) {
		fprintf(stderr, _("Couldn't allocate header buffer\n"));
		exit(1);
	}

	if (lseek(fd, 0, SEEK_SET) < 0) {
		perror("lseek while writing header");
		exit(1);
	}
	memset(header_buf, 0, blocksize);
	
	if (hdr)
		memcpy(header_buf, hdr, sizeof(struct ext2_image_hdr));
	
	actual = write(fd, header_buf, blocksize);
	if (actual < 0) {
		perror("write header");
		exit(1);
	}
	if (actual != blocksize) {
		fprintf(stderr, _("short write (only %d bytes) for"
				  "writing image header"), actual);
		exit(1);
	}
	free(header_buf);
}


int main (int argc, char ** argv)
{
	int c;
	errcode_t retval;
	ext2_filsys fs;
	int open_flag = 0;
	int raw_flag = 0;
	int fd = 0;
	struct ext2_image_hdr hdr;
	struct stat st;

#ifdef ENABLE_NLS
	setlocale(LC_MESSAGES, "");
	bindtextdomain(NLS_CAT_NAME, LOCALEDIR);
	textdomain(NLS_CAT_NAME);
#endif
	fprintf (stderr, _("e2image %s, %s for EXT2 FS %s, %s\n"),
		 E2FSPROGS_VERSION, E2FSPROGS_DATE,
		 EXT2FS_VERSION, EXT2FS_DATE);
	if (argc && *argv)
		program_name = *argv;
	initialize_ext2_error_table();
	while ((c = getopt (argc, argv, "r")) != EOF)
		switch (c) {
		case 'r':
			raw_flag++;
			break;
		default:
			usage();
		}
	if (optind != argc - 2 )
		usage();
	device_name = argv[optind];
	retval = ext2fs_open (device_name, open_flag, 0, 0,
			      unix_io_manager, &fs);
        if (retval) {
		com_err (program_name, retval, _("while trying to open %s"),
			 device_name);
		printf(_("Couldn't find valid filesystem superblock.\n"));
		exit(1);
	}

	fd = open(argv[optind+1], O_CREAT|O_RDWR, 0600);
	if (fd < 0) {
		com_err(program_name, errno, _("while trying to open %s"),
			argv[optind+1]);
		exit(1);
	}

	write_header(fd, NULL, fs->blocksize);
	memset(&hdr, 0, sizeof(struct ext2_image_hdr));
	
	hdr.offset_super = lseek(fd, 0, SEEK_CUR);
	retval = ext2fs_image_super_write(fs, fd, 0);
	if (retval) {
		com_err(program_name, retval, _("while writing superblock"));
		exit(1);
	}
	
	hdr.offset_inode = lseek(fd, 0, SEEK_CUR);
	retval = ext2fs_image_inode_write(fs, fd, IMAGER_FLAG_SPARSEWRITE);
	if (retval) {
		com_err(program_name, retval, _("while writing inode table"));
		exit(1);
	}
	
	hdr.offset_blockmap = lseek(fd, 0, SEEK_CUR);
	retval = ext2fs_image_bitmap_write(fs, fd, 0);
	if (retval) {
		com_err(program_name, retval, _("while writing block bitmap"));
		exit(1);
	}

	hdr.offset_inodemap = lseek(fd, 0, SEEK_CUR);
	retval = ext2fs_image_bitmap_write(fs, fd, IMAGER_FLAG_INODEMAP);
	if (retval) {
		com_err(program_name, retval, _("while writing inode bitmap"));
		exit(1);
	}

	hdr.magic_number = EXT2_ET_MAGIC_E2IMAGE;
	strcpy(hdr.magic_descriptor, "Ext2 Image 1.0");
	gethostname(hdr.fs_hostname, sizeof(hdr.fs_hostname));
	strncat(hdr.fs_device_name, device_name, sizeof(hdr.fs_device_name));
	hdr.fs_device_name[sizeof(hdr.fs_device_name) - 1] = 0;
	hdr.fs_blocksize = fs->blocksize;
	
	if (stat(device_name, &st) == 0)
		hdr.fs_device = st.st_rdev;

	if (fstat(fd, &st) == 0) {
		hdr.image_device = st.st_dev;
		hdr.image_inode = st.st_ino;
	}
	memcpy(hdr.fs_uuid, fs->super->s_uuid, sizeof(hdr.fs_uuid));

	hdr.image_time = time(0);
	write_header(fd, &hdr, fs->blocksize);

	ext2fs_close (fs);
	exit (0);
}