release/src/router/busybox/util-linux/fdisk_gpt.c

   1 #if ENABLE_FEATURE_GPT_LABEL
   2 /*
   3  * Copyright (C) 2010 Kevin Cernekee <cernekee@gmail.com>
   4  *
   5  * Licensed under GPLv2, see file LICENSE in this source tree.
   6  */
   7
   8 #define GPT_MAGIC 0x5452415020494645ULL
   9 enum {
  10         LEGACY_GPT_TYPE = 0xee,
  11         GPT_MAX_PARTS   = 256,
  12         GPT_MAX_PART_ENTRY_LEN = 4096,
  13         GUID_LEN        = 16,
  14 };
  15
  16 typedef struct {
  17         uint64_t magic;
  18         uint32_t revision;
  19         uint32_t hdr_size;
  20         uint32_t hdr_crc32;
  21         uint32_t reserved;
  22         uint64_t current_lba;
  23         uint64_t backup_lba;
  24         uint64_t first_usable_lba;
  25         uint64_t last_usable_lba;
  26         uint8_t  disk_guid[GUID_LEN];
  27         uint64_t first_part_lba;
  28         uint32_t n_parts;
  29         uint32_t part_entry_len;
  30         uint32_t part_array_crc32;
  31 } gpt_header;
  32
  33 typedef struct {
  34         uint8_t  type_guid[GUID_LEN];
  35         uint8_t  part_guid[GUID_LEN];
  36         uint64_t lba_start;
  37         uint64_t lba_end;
  38         uint64_t flags;
  39         uint16_t name[36];
  40 } gpt_partition;
  41
  42 static gpt_header *gpt_hdr;
  43
  44 static char *part_array;
  45 static unsigned int n_parts;
  46 static unsigned int part_array_len;
  47 static unsigned int part_entry_len;
  48
  49 static inline gpt_partition *
  50 gpt_part(int i)
  51 {
  52         if (i >= n_parts) {
  53                 return NULL;
  54         }
  55         return (gpt_partition *)&part_array[i * part_entry_len];
  56 }
  57
  58 static uint32_t
  59 gpt_crc32(void *buf, int len)
  60 {
  61         return ~crc32_block_endian0(0xffffffff, buf, len, global_crc32_table);
  62 }
  63
  64 static void
  65 gpt_print_guid(uint8_t *buf)
  66 {
  67         printf(
  68                 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
  69                 buf[3], buf[2], buf[1], buf[0],
  70                 buf[5], buf[4],
  71                 buf[7], buf[6],
  72                 buf[8], buf[9],
  73                 buf[10], buf[11], buf[12], buf[13], buf[14], buf[15]);
  74 }
  75
  76 /* TODO: real unicode support */
  77 static void
  78 gpt_print_wide(uint16_t *s, int max_len)
  79 {
  80         int i = 0;
  81
  82         while (i < max_len) {
  83                 if (*s == 0)
  84                         return;
  85                 fputc(*s, stdout);
  86                 s++;
  87         }
  88 }
  89
  90 static void
  91 gpt_list_table(int xtra UNUSED_PARAM)
  92 {
  93         int i;
  94         char numstr6[6];
  95
  96         numstr6[5] = '\0';
  97
  98         smart_ulltoa5((unsigned long long)total_number_of_sectors * sector_size,
  99                 numstr6, " KMGTPEZY");
 100         printf("Disk %s: %llu sectors, %s\n", disk_device,
 101                 (unsigned long long)total_number_of_sectors,
 102                 numstr6);
 103         printf("Logical sector size: %u\n", sector_size);
 104         printf("Disk identifier (GUID): ");
 105         gpt_print_guid(gpt_hdr->disk_guid);
 106         printf("\nPartition table holds up to %u entries\n",
 107                 (int)SWAP_LE32(gpt_hdr->n_parts));
 108         printf("First usable sector is %llu, last usable sector is %llu\n\n",
 109                 (unsigned long long)SWAP_LE64(gpt_hdr->first_usable_lba),
 110                 (unsigned long long)SWAP_LE64(gpt_hdr->last_usable_lba));
 111
 112         printf("Number  Start (sector)    End (sector)  Size       Code  Name\n");
 113         for (i = 0; i < n_parts; i++) {
 114                 gpt_partition *p = gpt_part(i);
 115                 if (p->lba_start) {
 116                         smart_ulltoa5((1 + SWAP_LE64(p->lba_end)
 117                                 - SWAP_LE64(p->lba_start)) * sector_size,
 118                                 numstr6, " KMGTPEZY");
 119                         printf("%4u %15llu %15llu %11s   %04x  ",
 120                                 i + 1,
 121                                 (unsigned long long)SWAP_LE64(p->lba_start),
 122                                 (unsigned long long)SWAP_LE64(p->lba_end),
 123                                 numstr6,
 124                                 0x0700 /* FIXME */);
 125                         gpt_print_wide(p->name, 18);
 126                         printf("\n");
 127                 }
 128         }
 129 }
 130
 131 static int
 132 check_gpt_label(void)
 133 {
 134         struct partition *first = pt_offset(MBRbuffer, 0);
 135         struct pte pe;
 136         uint32_t crc;
 137
 138         /* LBA 0 contains the legacy MBR */
 139
 140         if (!valid_part_table_flag(MBRbuffer)
 141          || first->sys_ind != LEGACY_GPT_TYPE
 142         ) {
 143                 current_label_type = 0;
 144                 return 0;
 145         }
 146
 147         /* LBA 1 contains the GPT header */
 148
 149         read_pte(&pe, 1);
 150         gpt_hdr = (void *)pe.sectorbuffer;
 151
 152         if (gpt_hdr->magic != SWAP_LE64(GPT_MAGIC)) {
 153                 current_label_type = 0;
 154                 return 0;
 155         }
 156
 157         if (!global_crc32_table) {
 158                 global_crc32_table = crc32_filltable(NULL, 0);
 159         }
 160
 161         crc = SWAP_LE32(gpt_hdr->hdr_crc32);
 162         gpt_hdr->hdr_crc32 = 0;
 163         if (gpt_crc32(gpt_hdr, SWAP_LE32(gpt_hdr->hdr_size)) != crc) {
 164                 /* FIXME: read the backup table */
 165                 puts("\nwarning: GPT header CRC is invalid\n");
 166         }
 167
 168         n_parts = SWAP_LE32(gpt_hdr->n_parts);
 169         part_entry_len = SWAP_LE32(gpt_hdr->part_entry_len);
 170         if (n_parts > GPT_MAX_PARTS
 171          || part_entry_len > GPT_MAX_PART_ENTRY_LEN
 172          || SWAP_LE32(gpt_hdr->hdr_size) > sector_size
 173         ) {
 174                 puts("\nwarning: unable to parse GPT disklabel\n");
 175                 current_label_type = 0;
 176                 return 0;
 177         }
 178
 179         part_array_len = n_parts * part_entry_len;
 180         part_array = xmalloc(part_array_len);
 181         seek_sector(SWAP_LE64(gpt_hdr->first_part_lba));
 182         if (full_read(dev_fd, part_array, part_array_len) != part_array_len) {
 183                 fdisk_fatal(unable_to_read);
 184         }
 185
 186         if (gpt_crc32(part_array, part_array_len) != gpt_hdr->part_array_crc32) {
 187                 /* FIXME: read the backup table */
 188                 puts("\nwarning: GPT array CRC is invalid\n");
 189         }
 190
 191         puts("Found valid GPT with protective MBR; using GPT\n");
 192
 193         current_label_type = LABEL_GPT;
 194         return 1;
 195 }
 196
 197 #endif /* GPT_LABEL */