source: MondoRescue/branches/3.3/mindi-busybox/util-linux/volume_id/linux_swap.c@ 3621

/*
 * volume_id - reads filesystem label and uuid
 *
 * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License as published by the Free Software Foundation; either
 *  version 2.1 of the License, or (at your option) any later version.
 *
 *  This library 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
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

//kbuild:lib-$(CONFIG_FEATURE_VOLUMEID_LINUXSWAP) += linux_swap.o

//config:
//config:config FEATURE_VOLUMEID_LINUXSWAP
//config:   bool "linux swap filesystem"
//config:   default y
//config:   depends on VOLUMEID
//config:   help
//config:     TODO
//config:

#include "volume_id_internal.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;

#define LARGEST_PAGESIZE            0x4000

int FAST_FUNC volume_id_probe_linux_swap(struct volume_id *id /*,uint64_t off*/)
{
#define off ((uint64_t)0)
    struct swap_header_v1_2 *sw;
    const uint8_t *buf;
    unsigned 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) {
//              id->type_version[0] = '1';
//              id->type_version[1] = '\0';
                goto found;
            }

            if (memcmp(buf, "SWAPSPACE2", 10) == 0
             || memcmp(buf, "S1SUSPEND", 9) == 0
             || memcmp(buf, "S2SUSPEND", 9) == 0
             || memcmp(buf, "ULSUSPEND", 9) == 0
            ) {
                sw = volume_id_get_buffer(id, off, sizeof(struct swap_header_v1_2));
                if (sw == NULL)
                    return -1;
//              id->type_version[0] = '2';
//              id->type_version[1] = '\0';
//              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);
    IF_FEATURE_BLKID_TYPE(id->type = "swap";)

    return 0;
}