#include <stdio.h> #include <stdlib.h> #include <stdint.h> #include <string.h> #include <unistd.h> #include <fcntl.h> #define LOGICAL_BLOCK_SIZE 512 typedef char *PSTR; typedef const char *PCSTR; typedef struct { char signature[8]; int revision; int header_size; uint32_t crc_header; int reserved; uint64_t lba_current; uint64_t lba_backup; uint64_t lba_first_usable; uint64_t lba_last_usable; uint8_t disk_guid[16]; uint64_t lba_entry_start; int entry_count; int entry_size; uint32_t crc_entries; int reserved1[105]; }__attribute__ ((packed)) gpt_header; typedef struct { uint8_t type_guid[16]; uint8_t unique_guid[16]; uint64_t lba_first; uint64_t lba_last; uint64_t attribute; uint16_t name[36]; }__attribute__ ((packed)) partition_entry; typedef struct { uint8_t status; uint8_t start_head; uint16_t start_sector; uint8_t part_type; uint8_t end_head; uint16_t end_sector; uint32_t first_abs_sector; uint32_t sector_count; }__attribute__ ((packed)) mbr_part_entry; typedef struct { uint8_t boot_code[440]; int unique_mbr_signature; short unknown; mbr_part_entry partition_record[4]; uint16_t signature; }__attribute__ ((packed)) legacy_mbr; static const uint32_t crc32_tab[] = { 0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L, 0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L, 0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L, 0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL, 0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L, 0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L, 0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L, 0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL, 0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L, 0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL, 0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L, 0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L, 0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L, 0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL, 0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL, 0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L, 0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL, 0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L, 0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L, 0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L, 0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL, 0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L, 0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L, 0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL, 0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L, 0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L, 0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L, 0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L, 0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L, 0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL, 0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL, 0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L, 0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L, 0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL, 0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL, 0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L, 0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL, 0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L, 0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL, 0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L, 0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL, 0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L, 0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L, 0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL, 0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L, 0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L, 0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L, 0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L, 0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L, 0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L, 0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL, 0x2d02ef8dL }; static uint32_t __efi_crc32(const void *buf, int len, uint32_t seed) { int i; register uint32_t crc32val; const unsigned char *s = buf; crc32val = seed; for (i = 0; i < len; i++) { crc32val = crc32_tab[(crc32val ^ s[i]) & 0xff] ^ (crc32val >> 8); } return crc32val; } uint32_t crc32(const void *buf, int len) { return (__efi_crc32(buf, len, ~0L) ^ ~0L); } PSTR uuid_to_str(uint8_t *data) { PSTR buf = (PSTR) malloc(37); PCSTR hex = "0123456789ABCDEF"; PSTR p = buf; uint32_t num = *((uint32_t *) data); p += sprintf(p, "%08X-", num); data += 4; uint16_t num2 = *((uint16_t *) data); p += sprintf(p, "%04hX-", num2); data += 2; num2 = *((uint16_t *) data); p += sprintf(p, "%04hX-", num2); data += 2; int i; for (i = 0; i < 8; i++) { if (i == 2) *p++ = ‘-‘; *p++ = hex[data[i] >> 4]; *p++ = hex[data[i] & 0xF]; } buf[36] = ‘\0‘; return buf; } wchar_t *utf16_to_wchar(uint16_t *str, int len) { int i = 0; wchar_t *buf = (wchar_t *) malloc((len + 1) * sizeof(wchar_t)); for (; i < len; i++) buf[i] = (wchar_t) str[i]; buf[len] = L‘\0‘; return buf; } int print_legacy_mbr(int fd) { legacy_mbr mbr; memset(&mbr, 0, sizeof(legacy_mbr)); if (read(fd, &mbr, sizeof(legacy_mbr)) == -1) { perror("read file error"); return -1; } mbr_part_entry empty; memset(&empty, 0, sizeof(mbr_part_entry)); mbr_part_entry *p; int i = 0; for (; i < 4; i++) { p = &mbr.partition_record[i]; if (!memcmp(p, &empty, sizeof(mbr_part_entry))) continue; printf("status=%hhu\tstart_head=%hhu\tstart_sector=%hu\tpart_type=0x%hhx\t" "end_head=%hhu\tend_sector=%hu\tfirst_abs_sector=%u\tsector_count=%u\n", p->status, p->start_head, p->start_sector, p->part_type, p->end_head, p->end_sector, p->first_abs_sector, p->sector_count); } printf("signature=0x%hX\n", mbr.signature); return 0; } int print_gpt_header(int fd, gpt_header *gpt) { memset(gpt, 0, sizeof(gpt_header)); if (read(fd, gpt, sizeof(gpt_header)) == -1) { perror("read file error"); return -1; } char sz[9]; memcpy(sz, gpt->signature, 8); sz[8] = ‘\0‘; printf("signature=%s\n", sz); printf("revision=%d\n", gpt->revision); printf("header_size=%d\n", gpt->header_size); printf("crc_header=0x%X\n", gpt->crc_header); printf("lba_current=%lu\n", gpt->lba_current); printf("lba_backup=%lu\n", gpt->lba_backup); printf("lba_first_usable=%lu\n", gpt->lba_first_usable); printf("lba_last_usable=%lu\n", gpt->lba_last_usable); PSTR buf = uuid_to_str(gpt->disk_guid); printf("disk_guid=%s\n", buf); free(buf); printf("lba_entry_start=%lu\n", gpt->lba_entry_start); printf("entry_count=%d\n", gpt->entry_count); printf("entry_size=%d\n", gpt->entry_size); printf("crc_entries=0x%X\n", gpt->crc_entries); uint32_t oldcrc = gpt->crc_header; gpt->crc_header = 0; if (crc32(gpt, gpt->header_size) != oldcrc) fputs("Bad crc_header.\n", stderr); gpt->crc_header = oldcrc; return 0; } int print_gpt_partitions(int fd, const gpt_header *gpt) { int entries_size = gpt->entry_count * gpt->entry_size; PSTR buf = (PSTR) malloc(entries_size); if (read(fd, buf, entries_size) == -1) { perror("read file error"); return -1; } wchar_t *gpt_entry_name; partition_entry *gentry = (partition_entry *) buf; partition_entry gentry_empty; memset(&gentry_empty, 0, sizeof(partition_entry)); PSTR tmp; int i = 0; for (; i < gpt->entry_count; i++) { if (!memcmp(gentry, &gentry_empty, sizeof(partition_entry))) continue; gpt_entry_name = utf16_to_wchar(gentry->name, 36); tmp = uuid_to_str(gentry->type_guid); printf("type_guid=%s\t", tmp); free(tmp); tmp = uuid_to_str(gentry->unique_guid); printf("unique_guid=%s\t", tmp); free(tmp); printf("lba_first=%lu\tlba_last=%lu\tattribute=%lu\tname=%ls\n", gentry->lba_first, gentry->lba_last, gentry->attribute, gpt_entry_name); free(gpt_entry_name); gentry++; } if (crc32(buf, entries_size) != gpt->crc_entries) fputs("Bad crc_entries.\n", stderr); free(buf); return 0; } /* * Usage1: Show primary GPT header and entries * <app> /dev/sda * Usage2: Show secondary GPT header and entries * <app> /dev/sda alternate */ int main(int argc, PCSTR argv[]) { int exitCode = EXIT_SUCCESS; PCSTR filename; int isAlternate = 0; if (argc < 2) { fputs("Missing argument.\n", stderr); return EXIT_FAILURE; } else { filename = argv[1]; if (argc > 2) isAlternate = 1; } int fd = open(filename, O_RDONLY); if (fd == -1) { perror("Can‘t open device"); return EXIT_FAILURE; } if (isAlternate) { if (lseek(fd, -1 * LOGICAL_BLOCK_SIZE, SEEK_END) == -1) { perror("Can‘t lseek"); exitCode = EXIT_FAILURE; goto END; } } else { if (print_legacy_mbr(fd)) { exitCode = EXIT_FAILURE; goto END; } putchar(‘\n‘); } gpt_header header; if (print_gpt_header(fd, &header)) { exitCode = EXIT_FAILURE; goto END; } putchar(‘\n‘); if (isAlternate) { if (lseek(fd, -1 * (header.entry_count * header.entry_size + LOGICAL_BLOCK_SIZE), SEEK_END) == -1) { perror("Can‘t lseek"); exitCode = EXIT_FAILURE; goto END; } } else if (lseek(fd, LOGICAL_BLOCK_SIZE * header.lba_entry_start, SEEK_SET) == -1) { perror("Can‘t lseek"); exitCode = EXIT_FAILURE; goto END; } print_gpt_partitions(fd, &header); END: close(fd); return exitCode; }