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Diffstat (limited to '')
-rw-r--r-- | libblkid/gpt.c | 412 |
1 files changed, 0 insertions, 412 deletions
diff --git a/libblkid/gpt.c b/libblkid/gpt.c deleted file mode 100644 index 7288d683e..000000000 --- a/libblkid/gpt.c +++ /dev/null @@ -1,412 +0,0 @@ -/* - * EFI GPT partition parsing code - * - * Copyright (C) 2009 Karel Zak <kzak@redhat.com> - * - * This file may be redistributed under the terms of the - * GNU Lesser General Public License. - * - * This code is not copy & past from any other implementation. - * - * For more information about GPT start your study at: - * http://en.wikipedia.org/wiki/GUID_Partition_Table - * http://technet.microsoft.com/en-us/library/cc739412(WS.10).aspx - */ -#include <stdio.h> -#include <string.h> -#include <stdlib.h> -#include <stdint.h> -#include <stddef.h> - -#include "partitions.h" -#include "crc32.h" -#include "dos.h" - -#define GPT_PRIMARY_LBA 1 - -/* Signature - “EFI PART” */ -#define GPT_HEADER_SIGNATURE 0x5452415020494645ULL -#define GPT_HEADER_SIGNATURE_STR "EFI PART" - -/* basic types */ -typedef uint16_t efi_char16_t; - -/* UUID */ -typedef struct { - uint32_t time_low; - uint16_t time_mid; - uint16_t time_hi_and_version; - uint8_t clock_seq_hi; - uint8_t clock_seq_low; - uint8_t node[6]; -} efi_guid_t; - - -#define GPT_UNUSED_ENTRY_GUID \ - ((efi_guid_t) { 0x00000000, 0x0000, 0x0000, 0x00, 0x00, \ - { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }}) -struct gpt_header { - uint64_t signature; /* "EFI PART" */ - uint32_t revision; - uint32_t header_size; /* usually 92 bytes */ - uint32_t header_crc32; /* checksum of header with this - * field zeroed during calculation */ - uint32_t reserved1; - - uint64_t my_lba; /* location of this header copy */ - uint64_t alternate_lba; /* location of the other header copy */ - uint64_t first_usable_lba; /* lirst usable LBA for partitions */ - uint64_t last_usable_lba; /* last usable LBA for partitions */ - - efi_guid_t disk_guid; /* disk UUID */ - - uint64_t partition_entries_lba; /* always 2 in primary header copy */ - uint32_t num_partition_entries; - uint32_t sizeof_partition_entry; - uint32_t partition_entry_array_crc32; - - /* - * The rest of the block is reserved by UEFI and must be zero. EFI - * standard handles this by: - * - * uint8_t reserved2[ BLKSSZGET - 92 ]; - * - * This definition is useless in practice. It is necessary to read - * whole block from the device rather than sizeof(struct gpt_header) - * only. - */ -} __attribute__ ((packed)); - -/*** not used -struct gpt_entry_attributes { - uint64_t required_to_function:1; - uint64_t reserved:47; - uint64_t type_guid_specific:16; -} __attribute__ ((packed)); -***/ - -struct gpt_entry { - efi_guid_t partition_type_guid; /* type UUID */ - efi_guid_t unique_partition_guid; /* partition UUID */ - uint64_t starting_lba; - uint64_t ending_lba; - - /*struct gpt_entry_attributes attributes;*/ - - uint64_t attributes; - - efi_char16_t partition_name[72 / sizeof(efi_char16_t)]; /* UTF-16LE string*/ -} __attribute__ ((packed)); - - -/* - * EFI uses crc32 with ~0 seed and xor's with ~0 at the end. - */ -static inline uint32_t count_crc32(const unsigned char *buf, size_t len) -{ - return (crc32(~0L, buf, len) ^ ~0L); -} - -static inline unsigned char *get_lba_buffer(blkid_probe pr, - uint64_t lba, size_t bytes) -{ - return blkid_probe_get_buffer(pr, - blkid_probe_get_sectorsize(pr) * lba, bytes); -} - -static inline int guidcmp(efi_guid_t left, efi_guid_t right) -{ - return memcmp(&left, &right, sizeof (efi_guid_t)); -} - -/* - * UUID is traditionally 16 byte big-endian array, except Intel EFI - * specification where the UUID is a structure of little-endian fields. - */ -static void swap_efi_guid(efi_guid_t *uid) -{ - uid->time_low = swab32(uid->time_low); - uid->time_mid = swab16(uid->time_mid); - uid->time_hi_and_version = swab16(uid->time_hi_and_version); -} - -static int last_lba(blkid_probe pr, uint64_t *lba) -{ - blkid_loff_t sz = blkid_probe_get_size(pr); - unsigned int ssz = blkid_probe_get_sectorsize(pr); - - if (sz < ssz) - return -1; - - *lba = (sz / ssz) - 1ULL; - return 0; -} - -/* - * Protective (legacy) MBR. - * - * This MBR contains standard DOS partition table with a single partition, type - * of 0xEE. The partition usually encompassing the entire GPT drive - or 2TiB - * for large disks. - * - * Note that Apple uses GPT/MBR hybrid disks, where the DOS partition table is - * synchronized with GPT. This synchronization has many restriction of course - * (due DOS PT limitations). - * - * Note that the PMBR detection is optional (enabled by default) and could be - * disabled by BLKID_PARTS_FOPCE_GPT flag (see also blkid_paertitions_set_flags()). - */ -static int is_pmbr_valid(blkid_probe pr) -{ - int flags = blkid_partitions_get_flags(pr); - unsigned char *data; - struct dos_partition *p; - int i; - - if (flags & BLKID_PARTS_FORCE_GPT) - goto ok; /* skip PMBR check */ - - data = blkid_probe_get_sector(pr, 0); - if (!data) - goto failed; - - if (!is_valid_mbr_signature(data)) - goto failed; - - p = (struct dos_partition *) (data + BLKID_MSDOS_PT_OFFSET); - - for (i = 0; i < 4; i++, p++) { - if (p->sys_type == BLKID_GPT_PARTITION) - goto ok; - } -failed: - return 0; -ok: - return 1; -} - -/* - * Reads GPT header to @hdr and returns a pointer to @hdr or NULL in case of - * error. The function also returns GPT entries in @ents. - * - * Note, this function does not allocate any memory. The GPT header has fixed - * size so we use stack, and @ents returns memory from libblkid buffer (so the - * next blkid_probe_get_buffer() will overwrite this buffer). - * - * This function checks validity of header and entries array. A corrupted - * header is not returned. - */ -static struct gpt_header *get_gpt_header( - blkid_probe pr, struct gpt_header *hdr, - struct gpt_entry **ents, uint64_t lba, - uint64_t lastlba) -{ - struct gpt_header *h; - uint32_t crc, orgcrc; - uint64_t lu, fu; - size_t esz; - uint32_t hsz, ssz; - - ssz = blkid_probe_get_sectorsize(pr); - - /* whole sector is allocated for GPT header */ - h = (struct gpt_header *) get_lba_buffer(pr, lba, ssz); - if (!h) - return NULL; - - if (le64_to_cpu(h->signature) != GPT_HEADER_SIGNATURE) - return NULL; - - hsz = le32_to_cpu(h->header_size); - - /* EFI: The HeaderSize must be greater than 92 and must be less - * than or equal to the logical block size. - */ - if (hsz > ssz || hsz < sizeof(*h)) - return NULL; - - /* Header has to be verified when header_crc32 is zero */ - orgcrc = h->header_crc32; - h->header_crc32 = 0; - crc = count_crc32((unsigned char *) h, hsz); - h->header_crc32 = orgcrc; - - if (crc != le32_to_cpu(orgcrc)) { - DBG(DEBUG_LOWPROBE, printf("GPT header corrupted\n")); - return NULL; - } - - /* Valid header has to be at MyLBA */ - if (le64_to_cpu(h->my_lba) != lba) { - DBG(DEBUG_LOWPROBE, printf( - "GPT->MyLBA mismatch with real position\n")); - return NULL; - } - - fu = le64_to_cpu(h->first_usable_lba); - lu = le64_to_cpu(h->last_usable_lba); - - /* Check if First and Last usable LBA makes sense */ - if (lu < fu || fu > lastlba || lu > lastlba) { - DBG(DEBUG_LOWPROBE, printf( - "GPT->{First,Last}UsableLBA out of range\n")); - return NULL; - } - - /* The header has to be outside usable range */ - if (fu < lba && lba < lu) { - DBG(DEBUG_LOWPROBE, printf("GPT header is inside usable area\n")); - return NULL; - } - - /* Size of blocks with GPT entries */ - esz = le32_to_cpu(h->num_partition_entries) * - le32_to_cpu(h->sizeof_partition_entry); - if (!esz) { - DBG(DEBUG_LOWPROBE, printf("GPT entries undefined\n")); - return NULL; - } - - /* The header seems valid, save it - * (we don't care about zeros in hdr->reserved2 area) */ - memcpy(hdr, h, sizeof(*h)); - h = hdr; - - /* Read GPT entries */ - *ents = (struct gpt_entry *) get_lba_buffer(pr, - le64_to_cpu(h->partition_entries_lba), esz); - if (!*ents) { - DBG(DEBUG_LOWPROBE, printf("GPT entries unreadable\n")); - return NULL; - } - - /* Validate entries */ - crc = count_crc32((unsigned char *) *ents, esz); - if (crc != le32_to_cpu(h->partition_entry_array_crc32)) { - DBG(DEBUG_LOWPROBE, printf("GPT entries corrupted\n")); - return NULL; - } - - return h; -} - -static int probe_gpt_pt(blkid_probe pr, - const struct blkid_idmag *mag __attribute__((__unused__))) -{ - uint64_t lastlba = 0, lba; - struct gpt_header hdr, *h; - struct gpt_entry *e; - blkid_parttable tab = NULL; - blkid_partlist ls; - uint64_t fu, lu; - uint32_t ssf, i; - efi_guid_t guid; - - if (last_lba(pr, &lastlba)) - goto nothing; - - if (!is_pmbr_valid(pr)) - goto nothing; - - h = get_gpt_header(pr, &hdr, &e, (lba = GPT_PRIMARY_LBA), lastlba); - if (!h) - h = get_gpt_header(pr, &hdr, &e, (lba = lastlba), lastlba); - - if (!h) - goto nothing; - - blkid_probe_use_wiper(pr, lba * blkid_probe_get_size(pr), 8); - - if (blkid_probe_set_magic(pr, lba << 9, - sizeof(GPT_HEADER_SIGNATURE_STR) - 1, - (unsigned char *) GPT_HEADER_SIGNATURE_STR)) - goto err; - - if (blkid_partitions_need_typeonly(pr)) - /* caller does not ask for details about partitions */ - return 0; - - ls = blkid_probe_get_partlist(pr); - if (!ls) - goto err; - - tab = blkid_partlist_new_parttable(ls, "gpt", lba << 9); - if (!tab) - goto err; - - guid = h->disk_guid; - swap_efi_guid(&guid); - blkid_parttable_set_id(tab, (const unsigned char *) &guid); - - ssf = blkid_probe_get_sectorsize(pr) / 512; - - fu = le64_to_cpu(h->first_usable_lba); - lu = le64_to_cpu(h->last_usable_lba); - - for (i = 0; i < le32_to_cpu(h->num_partition_entries); i++, e++) { - - blkid_partition par; - uint64_t start = le64_to_cpu(e->starting_lba); - uint64_t size = le64_to_cpu(e->ending_lba) - - le64_to_cpu(e->starting_lba) + 1ULL; - - /* 00000000-0000-0000-0000-000000000000 entry */ - if (!guidcmp(e->partition_type_guid, GPT_UNUSED_ENTRY_GUID)) { - blkid_partlist_increment_partno(ls); - continue; - } - /* the partition has to inside usable range */ - if (start < fu || start + size - 1 > lu) { - DBG(DEBUG_LOWPROBE, printf( - "GPT entry[%d] overflows usable area - ignore\n", - i)); - blkid_partlist_increment_partno(ls); - continue; - } - - par = blkid_partlist_add_partition(ls, tab, - start * ssf, size * ssf); - if (!par) - goto err; - - blkid_partition_set_utf8name(par, - (unsigned char *) e->partition_name, - sizeof(e->partition_name), BLKID_ENC_UTF16LE); - - guid = e->unique_partition_guid; - swap_efi_guid(&guid); - blkid_partition_set_uuid(par, (const unsigned char *) &guid); - - guid = e->partition_type_guid; - swap_efi_guid(&guid); - blkid_partition_set_type_uuid(par, (const unsigned char *) &guid); - - blkid_partition_set_flags(par, e->attributes); - } - - return 0; - -nothing: - return 1; -err: - return -1; -} - - -const struct blkid_idinfo gpt_pt_idinfo = -{ - .name = "gpt", - .probefunc = probe_gpt_pt, - .minsz = 1024 * 1440 + 1, /* ignore floppies */ - - /* - * It would be possible to check for DOS signature (0xAA55), but - * unfortunately almost all EFI GPT implemenations allow to optionaly - * skip the legacy MBR. We follows this behavior and MBR is optional. - * See is_valid_pmbr(). - * - * It means we have to always call probe_gpt_pt(). - */ - .magics = BLKID_NONE_MAGIC -}; - |