libblkid-tiny/swap.c

   1 /*
   2  * Copyright (C) 1999 by Andries Brouwer
   3  * Copyright (C) 1999, 2000, 2003 by Theodore Ts'o
   4  * Copyright (C) 2001 by Andreas Dilger
   5  * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
   6  * Copyright (C) 2008 Karel Zak <kzak@redhat.com>
   7  *
   8  * This file may be redistributed under the terms of the
   9  * GNU Lesser General Public License.
  10  */
  11 #include <stdio.h>
  12 #include <stdlib.h>
  13 #include <unistd.h>
  14 #include <string.h>
  15 #include <errno.h>
  16 #include <ctype.h>
  17 #include <stdint.h>
  18
  19 #include "superblocks.h"
  20
  21 /* linux-2.6/include/linux/swap.h */
  22 struct swap_header_v1_2 {
  23      /* char            bootbits[1024]; */ /* Space for disklabel etc. */
  24         uint32_t        version;
  25         uint32_t        lastpage;
  26         uint32_t        nr_badpages;
  27         unsigned char   uuid[16];
  28         unsigned char   volume[16];
  29         uint32_t        padding[117];
  30         uint32_t        badpages[1];
  31 } __attribute__((packed));
  32
  33 #define PAGESIZE_MIN    0xff6   /* 4086 (arm, i386, ...) */
  34 #define PAGESIZE_MAX    0xfff6  /* 65526 (ia64) */
  35
  36 #define TOI_MAGIC_STRING        "\xed\xc3\x02\xe9\x98\x56\xe5\x0c"
  37 #define TOI_MAGIC_STRLEN        (sizeof(TOI_MAGIC_STRING) - 1)
  38
  39 static int swap_set_info(blkid_probe pr, const char *version)
  40 {
  41         struct swap_header_v1_2 *hdr;
  42
  43         /* Swap header always located at offset of 1024 bytes */
  44         hdr = (struct swap_header_v1_2 *) blkid_probe_get_buffer(pr, 1024,
  45                                 sizeof(struct swap_header_v1_2));
  46         if (!hdr)
  47                 return -1;
  48
  49         /* SWAPSPACE2 - check for wrong version or zeroed pagecount */
  50         if (strcmp(version, "2") == 0 &&
  51                 ((hdr->version != 1 && swab32(hdr->version) != 1) || hdr->lastpage == 0))
  52                 return -1;
  53
  54         /* arbitrary sanity check.. is there any garbage down there? */
  55         if (hdr->padding[32] == 0 && hdr->padding[33] == 0) {
  56                 if (hdr->volume[0] && blkid_probe_set_label(pr, hdr->volume,
  57                                 sizeof(hdr->volume)) < 0)
  58                         return -1;
  59                 if (blkid_probe_set_uuid(pr, hdr->uuid) < 0)
  60                         return -1;
  61         }
  62
  63         blkid_probe_set_version(pr, version);
  64         return 0;
  65 }
  66
  67 static int probe_swap(blkid_probe pr, const struct blkid_idmag *mag)
  68 {
  69         unsigned char *buf;
  70
  71         if (!mag)
  72                 return -1;
  73
  74         /* TuxOnIce keeps valid swap header at the end of the 1st page */
  75         buf = blkid_probe_get_buffer(pr, 0, TOI_MAGIC_STRLEN);
  76         if (!buf)
  77                 return -1;
  78
  79         if (memcmp(buf, TOI_MAGIC_STRING, TOI_MAGIC_STRLEN) == 0)
  80                 return 1;       /* Ignore swap signature, it's TuxOnIce */
  81
  82         if (!memcmp(mag->magic, "SWAP-SPACE", mag->len)) {
  83                 /* swap v0 doesn't support LABEL or UUID */
  84                 blkid_probe_set_version(pr, "1");
  85                 return 0;
  86
  87         } else if (!memcmp(mag->magic, "SWAPSPACE2", mag->len))
  88                 return swap_set_info(pr, "2");
  89
  90         return -1;
  91 }
  92
  93 static int probe_swsuspend(blkid_probe pr, const struct blkid_idmag *mag)
  94 {
  95         if (!mag)
  96                 return -1;
  97         if (!memcmp(mag->magic, "S1SUSPEND", mag->len))
  98                 return swap_set_info(pr, "s1suspend");
  99         if (!memcmp(mag->magic, "S2SUSPEND", mag->len))
 100                 return swap_set_info(pr, "s2suspend");
 101         if (!memcmp(mag->magic, "ULSUSPEND", mag->len))
 102                 return swap_set_info(pr, "ulsuspend");
 103         if (!memcmp(mag->magic, TOI_MAGIC_STRING, mag->len))
 104                 return swap_set_info(pr, "tuxonice");
 105         if (!memcmp(mag->magic, "LINHIB0001", mag->len))
 106                 return swap_set_info(pr, "linhib0001");
 107
 108         return -1;      /* no signature detected */
 109 }
 110
 111 const struct blkid_idinfo swap_idinfo =
 112 {
 113         .name           = "swap",
 114         .usage          = BLKID_USAGE_OTHER,
 115         .probefunc      = probe_swap,
 116         .minsz          = 10 * 4096,    /* 10 pages */
 117         .magics         =
 118         {
 119                 { "SWAP-SPACE", 10, 0,  0xff6 },
 120                 { "SWAPSPACE2", 10, 0,  0xff6 },
 121                 { "SWAP-SPACE", 10, 0, 0x1ff6 },
 122                 { "SWAPSPACE2", 10, 0, 0x1ff6 },
 123                 { "SWAP-SPACE", 10, 0, 0x3ff6 },
 124                 { "SWAPSPACE2", 10, 0, 0x3ff6 },
 125                 { "SWAP-SPACE", 10, 0, 0x7ff6 },
 126                 { "SWAPSPACE2", 10, 0, 0x7ff6 },
 127                 { "SWAP-SPACE", 10, 0, 0xfff6 },
 128                 { "SWAPSPACE2", 10, 0, 0xfff6 },
 129                 { NULL }
 130         }
 131 };
 132
 133
 134 const struct blkid_idinfo swsuspend_idinfo =
 135 {
 136         .name           = "swsuspend",
 137         .usage          = BLKID_USAGE_OTHER,
 138         .probefunc      = probe_swsuspend,
 139         .minsz          = 10 * 4096,    /* 10 pages */
 140         .magics         =
 141         {
 142                 { TOI_MAGIC_STRING, TOI_MAGIC_STRLEN, 0, 0 },
 143                 { "S1SUSPEND", 9, 0, 0xff6 },
 144                 { "S2SUSPEND", 9, 0, 0xff6 },
 145                 { "ULSUSPEND", 9, 0, 0xff6 },
 146                 { "LINHIB0001",10,0, 0xff6 },
 147
 148                 { "S1SUSPEND", 9, 0, 0x1ff6 },
 149                 { "S2SUSPEND", 9, 0, 0x1ff6 },
 150                 { "ULSUSPEND", 9, 0, 0x1ff6 },
 151                 { "LINHIB0001",10,0, 0x1ff6 },
 152
 153                 { "S1SUSPEND", 9, 0, 0x3ff6 },
 154                 { "S2SUSPEND", 9, 0, 0x3ff6 },
 155                 { "ULSUSPEND", 9, 0, 0x3ff6 },
 156                 { "LINHIB0001",10,0, 0x3ff6 },
 157
 158                 { "S1SUSPEND", 9, 0, 0x7ff6 },
 159                 { "S2SUSPEND", 9, 0, 0x7ff6 },
 160                 { "ULSUSPEND", 9, 0, 0x7ff6 },
 161                 { "LINHIB0001",10,0, 0x7ff6 },
 162
 163                 { "S1SUSPEND", 9, 0, 0xfff6 },
 164                 { "S2SUSPEND", 9, 0, 0xfff6 },
 165                 { "ULSUSPEND", 9, 0, 0xfff6 },
 166                 { "LINHIB0001",10,0, 0xfff6 },
 167
 168                 { NULL }
 169         }
 170 };
 171