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mirror of https://github.com/systemd/systemd-stable.git synced 2024-12-25 23:21:33 +03:00
systemd-stable/extras/volume_id/libvolume_id/linux_swap.c
2006-02-21 18:44:18 +01:00

78 lines
1.8 KiB
C

/*
* volume_id - reads filesystem label and uuid
*
* Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.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 version 2 of the License.
*/
#ifndef _GNU_SOURCE
#define _GNU_SOURCE 1
#endif
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <ctype.h>
#include "volume_id.h"
#include "logging.h"
#include "util.h"
struct swap_header_v1_2 {
uint8_t bootbits[1024];
uint32_t version;
uint32_t last_page;
uint32_t nr_badpages;
uint8_t uuid[16];
uint8_t volume_name[16];
} PACKED *sw;
#define LARGEST_PAGESIZE 0x4000
int volume_id_probe_linux_swap(struct volume_id *id, uint64_t off)
{
const uint8_t *buf;
unsigned int page;
dbg("probing at offset 0x%llx", (unsigned long long) off);
/* the swap signature is at the end of the PAGE_SIZE */
for (page = 0x1000; page <= LARGEST_PAGESIZE; page <<= 1) {
buf = volume_id_get_buffer(id, off + page-10, 10);
if (buf == NULL)
return -1;
if (memcmp(buf, "SWAP-SPACE", 10) == 0) {
strcpy(id->type_version, "1");
goto found;
}
if (memcmp(buf, "SWAPSPACE2", 10) == 0) {
sw = (struct swap_header_v1_2 *) volume_id_get_buffer(id, off, sizeof(struct swap_header_v1_2));
if (sw == NULL)
return -1;
strcpy(id->type_version, "2");
volume_id_set_label_raw(id, sw->volume_name, 16);
volume_id_set_label_string(id, sw->volume_name, 16);
volume_id_set_uuid(id, sw->uuid, UUID_DCE);
goto found;
}
}
return -1;
found:
volume_id_set_usage(id, VOLUME_ID_OTHER);
id->type = "swap";
return 0;
}