/
githubmirror
/
efivar
Обзор
Документация
Войти
/
githubmirror
/
efivar
Код
Запросы
0
Пакеты
0
Релизы
0
Аналитика
Безопасность
39
src/gpt.c
753 строки
20 KB
Sergii Dmytruk
Don't include <asm/byteorder.h>
30 янв 2024, 02:11
30 янв 2024, 02:11
3b625ff
Код
Авторство
О чём код?
// SPDX-License-Identifier: LGPL-2.1-or-later /* * gpt.[ch] * Copyright (C) 2000-2001 Dell Computer Corporation <Matt_Domsch@dell.com> * * EFI GUID Partition Table handling * Per Intel EFI Specification v1.02 * http://developer.intel.com/technology/efi/efi.htm */ #include "fix_coverity.h" #include <errno.h> #include <fcntl.h> #include <inttypes.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <sys/mount.h> #include <sys/param.h> #include <sys/stat.h> #include <sys/utsname.h> #include <unistd.h> #include "efivar.h" #ifndef BLKGETLASTSECT #define BLKGETLASTSECT _IO(0x12,108) /* get last sector of block device */ #endif struct blkdev_ioctl_param { unsigned int block; size_t content_length; char * block_contents; }; /** * is_pmbr_valid(): test Protective MBR for validity * @mbr: pointer to a legacy mbr structure * * Description: Returns 1 if PMBR is valid, 0 otherwise. * Validity depends on two things: * 1) MSDOS magic is in the last two bytes of the MBR * 2) One partition of type 0xEE is found */ static int is_pmbr_valid(legacy_mbr *mbr) { int i, found = 0, magic = 0; if (!mbr) return 0; magic = (le16_to_cpu(mbr->magic) == MSDOS_MBR_MAGIC); for (i = 0; magic && i < 4; i++) { if (mbr->partition[i].os_type == EFI_PMBR_OSTYPE_EFI_GPT) { found = 1; break; } } return (magic && found); } /** * kernel_has_blkgetsize64() * * Returns: 0 on false, 1 on true * True means kernel is 2.4.x, x>=18, or * is 2.5.x, x>4, or * is > 2.5 */ static int kernel_has_blkgetsize64(void) { int major=0, minor=0, patch=0, parsed; int rc; struct utsname u; memset(&u, 0, sizeof(u)); rc = uname(&u); if (rc) return 0; parsed = sscanf(u.release, "%d.%d.%d", &major, &minor, &patch); /* If the kernel is 2.4.15-2.4.18 and 2.5.0-2.5.3, i.e. the problem * kernels, then this will get 3 answers. If it doesn't, it isn't. */ if (parsed != 3) return 1; if (major == 2 && minor == 5 && patch < 4) return 0; if (major == 2 && minor == 4 && patch >= 15 && patch <= 18) return 0; return 1; } /************************************************************ * _get_num_sectors * Requires: * - filedes is an open file descriptor, suitable for reading * Modifies: nothing * Returns: * Last LBA value on success * 0 on error * * Try getting BLKGETSIZE64 and BLKSSZGET first, * then BLKGETSIZE if necessary. * Kernels 2.4.15-2.4.18 and 2.5.0-2.5.3 have a broken BLKGETSIZE64 * which returns the number of 512-byte sectors, not the size of * the disk in bytes. Fixed in kernels 2.4.18-pre8 and 2.5.4-pre3. ************************************************************/ static uint64_t _get_num_sectors(int filedes) { unsigned long sectors=0; uint64_t bytes=0; int rc; if (kernel_has_blkgetsize64()) { rc = ioctl(filedes, BLKGETSIZE64, &bytes); if (!rc) return bytes / get_sector_size(filedes); } rc = ioctl(filedes, BLKGETSIZE, §ors); if (rc) return 0; return sectors; } /************************************************************ * last_lba(): return number of last logical block of device * * @fd * * Description: returns Last LBA value on success, 0 on error. * Notes: The value st_blocks gives the size of the file * in 512-byte blocks, which is OK if * EFI_BLOCK_SIZE_SHIFT == 9. ************************************************************/ static uint64_t last_lba(int filedes) { int rc; uint64_t sectors = 0; struct stat s; memset(&s, 0, sizeof (s)); rc = fstat(filedes, &s); if (rc == -1) { efi_error("last_lba() could not stat: %s", strerror(errno)); return 0; } if (S_ISBLK(s.st_mode)) { sectors = _get_num_sectors(filedes); } else { efi_error("last_lba(): I don't know how to handle files with mode %x", s.st_mode); sectors = 1; } return sectors - 1; } static ssize_t read_lastoddsector(int fd, void *buffer, size_t count) { int rc; struct blkdev_ioctl_param ioctl_param; if (!buffer) return 0; ioctl_param.block = 0; /* read the last sector */ ioctl_param.content_length = count; ioctl_param.block_contents = buffer; rc = ioctl(fd, BLKGETLASTSECT, &ioctl_param); if (rc == -1) efi_error("read failed"); return !rc; } static ssize_t read_lba(int fd, uint64_t lba, void *buffer, size_t bytes) { int sector_size = get_sector_size(fd); off_t offset = lba * sector_size; ssize_t bytesread; void *iobuf; size_t iobuf_size; int rc; off_t new_offset; iobuf_size = lcm(bytes, sector_size); rc = posix_memalign(&iobuf, sector_size, iobuf_size); if (rc) return rc; memset(iobuf, 0, bytes); new_offset = lseek(fd, offset, SEEK_SET); if (new_offset == (off_t)-1) { free(iobuf); return 0; } bytesread = read(fd, iobuf, iobuf_size); memcpy(buffer, iobuf, bytes); free(iobuf); /* Kludge. This is necessary to read/write the last block of an odd-sized disk, until Linux 2.5.x kernel fixes. This is only used by gpt.c, and only to read one sector, so we don't have to be fancy. */ if (!bytesread && !(last_lba(fd) & 1) && lba == last_lba(fd)) { bytesread = read_lastoddsector(fd, buffer, bytes); } return bytesread; } /** * alloc_read_gpt_entries(): reads partition entries from disk * @fd is an open file descriptor to the whole disk * @gpt is a buffer into which the GPT will be put * Description: Returns ptes on success, NULL on error. * Allocates space for PTEs based on information found in @gpt. * Notes: remember to free pte when you're done! */ static gpt_entry * alloc_read_gpt_entries(int fd, uint32_t nptes, uint32_t ptesz, uint64_t ptelba) { gpt_entry *pte; size_t count = nptes * ptesz; if (!count) return NULL; pte = (gpt_entry *)malloc(count); if (!pte) return NULL; memset(pte, 0, count); if (!read_lba(fd, ptelba, pte, count)) { free(pte); return NULL; } return pte; } /** * alloc_read_gpt_header(): Allocates GPT header, reads into it from disk * @fd is an open file descriptor to the whole disk * @lba is the Logical Block Address of the partition table * * Description: returns GPT header on success, NULL on error. Allocates * and fills a GPT header starting at @ from @bdev. * Note: remember to free gpt when finished with it. */ static gpt_header * alloc_read_gpt_header(int fd, uint64_t lba) { gpt_header *gpt; gpt = (gpt_header *) malloc(sizeof (gpt_header)); if (!gpt) return NULL; memset(gpt, 0, sizeof (*gpt)); if (!read_lba(fd, lba, gpt, sizeof (gpt_header))) { free(gpt); return NULL; } return gpt; } /** * validate_nptes(): Tries to ensure that nptes is a reasonable value * @first_block is the beginning LBA to bound the table * @pte_start is the starting LBA of the partition table * @last_block is the end LBA of to bound the table * @ptesz is the size of a partition table entry * @nptes is the number of entries we have. * @blksz is the block size of the device. * * Description: returns 0 if the partition table doesn't fit, 1 if it does */ static int validate_nptes(uint64_t first_block, uint64_t pte_start, uint64_t last_block, uint32_t ptesz, uint32_t nptes, uint32_t blksz) { uint32_t min_entry_size = sizeof(gpt_entry); uint32_t min_entry_size_mod = 128 - sizeof(gpt_entry) % 128; uint64_t max_blocks, max_bytes; if (min_entry_size_mod == 128) min_entry_size_mod = 0; min_entry_size += min_entry_size_mod; if (ptesz < min_entry_size) return 0; if (pte_start < first_block || pte_start > last_block) return 0; max_blocks = last_block - pte_start; if (UINT64_MAX / blksz < max_blocks) return 0; max_bytes = max_blocks * blksz; if (UINT64_MAX / ptesz < max_bytes) return 0; if (ptesz > max_bytes / nptes) return 0; if (max_bytes / ptesz < nptes) return 0; return 1; } static int check_lba(uint64_t lba, uint64_t lastlba, char *name) { if (lba > lastlba) { efi_error("Invalid %s LBA %"PRIx64" max:%"PRIx64, name, lba, lastlba); return 0; } return 1; } /** * is_gpt_valid() - tests one GPT header and PTEs for validity * @fd is an open file descriptor to the whole disk * @lba is the logical block address of the GPT header to test * @gpt is a GPT header ptr, filled on return. * @ptes is a PTEs ptr, filled on return. * * Description: returns 1 if valid, 0 on error. * If valid, returns pointers to newly allocated GPT header and PTEs. */ static int is_gpt_valid(int fd, uint64_t lba, gpt_header ** gpt, gpt_entry ** ptes, uint32_t logical_block_size) { int rc = 0; /* default to not valid */ uint32_t crc, origcrc; uint64_t max_device_lba = last_lba(fd); if (!gpt || !ptes) return 0; if (!(*gpt = alloc_read_gpt_header(fd, lba))) return 0; /* Check the GUID Partition Table magic */ if (le64_to_cpu((*gpt)->magic) != GPT_HEADER_MAGIC) { efi_error("GUID Partition Table Header magic is wrong: %"PRIx64" != %"PRIx64, (uint64_t)le64_to_cpu((*gpt)->magic), GPT_HEADER_MAGIC); free(*gpt); *gpt = NULL; return rc; } uint32_t hdrsz = le32_to_cpu((*gpt)->header_size); uint32_t hdrmin = MAX(92, sizeof(gpt_header) - sizeof((*gpt)->reserved2)); if (hdrsz < hdrmin || hdrsz > logical_block_size) { efi_error("GUID Partition Table Header size is invalid (%d < %d < %d)", hdrmin, hdrsz, logical_block_size); free (*gpt); *gpt = NULL; return rc; } /* Check the GUID Partition Table Header CRC */ origcrc = le32_to_cpu((*gpt)->header_crc32); (*gpt)->header_crc32 = 0; crc = efi_crc32(*gpt, le32_to_cpu((*gpt)->header_size)); if (crc != origcrc) { efi_error("GPTH CRC check failed, %x != %x.", origcrc, crc); (*gpt)->header_crc32 = cpu_to_le32(origcrc); free(*gpt); *gpt = NULL; return 0; } (*gpt)->header_crc32 = cpu_to_le32(origcrc); /* Check that the my_lba entry points to the LBA * that contains the GPT we read */ uint64_t mylba = le64_to_cpu((*gpt)->my_lba); uint64_t altlba = le64_to_cpu((*gpt)->alternate_lba); if (mylba != lba && altlba != lba) { efi_error("lba %"PRIx64" != lba %"PRIx64".", mylba, lba); err: free(*gpt); *gpt = NULL; return 0; } if (!check_lba(mylba, max_device_lba, "GPT")) goto err; if (!check_lba(altlba, max_device_lba, "GPT Alt")) goto err; uint64_t ptelba = le64_to_cpu((*gpt)->partition_entry_lba); uint64_t fulba = le64_to_cpu((*gpt)->first_usable_lba); uint64_t lulba = le64_to_cpu((*gpt)->last_usable_lba); uint32_t nptes = le32_to_cpu((*gpt)->num_partition_entries); uint32_t ptesz = le32_to_cpu((*gpt)->sizeof_partition_entry); if (!check_lba(ptelba, max_device_lba, "PTE")) goto err; if (!check_lba(fulba, max_device_lba, "First Usable")) goto err; if (!check_lba(lulba, max_device_lba, "Last Usable")) goto err; if (ptesz < sizeof(gpt_entry) || ptesz % 128 != 0) { efi_error("Invalid GPT entry size is %d.", ptesz); goto err; } /* There's really no good answer to maximum bounds, but this large * would be completely absurd, so... */ if (nptes > 1024) { efi_error("Not honoring insane number of Partition Table Entries 0x%"PRIx32".", nptes); goto err; } if (ptesz > 4096) { efi_error("Not honoring insane Partition Table Entry size 0x%"PRIx32".", ptesz); goto err; } uint64_t pte_blocks; uint64_t firstlba, lastlba; if (altlba > mylba) { firstlba = mylba + 1; lastlba = fulba; pte_blocks = fulba - ptelba; rc = validate_nptes(firstlba, ptelba, fulba, ptesz, nptes, logical_block_size); } else { firstlba = lulba; lastlba = mylba; pte_blocks = mylba - ptelba; rc = validate_nptes(lulba, ptelba, mylba, ptesz, nptes, logical_block_size); } if (!rc) { efi_error("%"PRIu32" partition table entries with size 0x%"PRIx32" doesn't fit in 0x%"PRIx64" blocks between 0x%"PRIx64" and 0x%"PRIx64".", nptes, ptesz, pte_blocks, firstlba, lastlba); goto err; } if (!(*ptes = alloc_read_gpt_entries(fd, nptes, ptesz, ptelba))) { free(*gpt); *gpt = NULL; return 0; } /* Check the GUID Partition Entry Array CRC */ crc = efi_crc32(*ptes, nptes * ptesz); if (crc != le32_to_cpu((*gpt)->partition_entry_array_crc32)) { efi_error("GUID Partitition Entry Array CRC check failed."); free(*gpt); *gpt = NULL; free(*ptes); *ptes = NULL; return 0; } /* We're done, all's well */ return 1; } /** * compare_gpts() - Search disk for valid GPT headers and PTEs * @pgpt is the primary GPT header * @agpt is the alternate GPT header * @lastlba is the last LBA number * Description: Returns nothing. Sanity checks pgpt and agpt fields * and prints warnings on discrepancies. * */ static void compare_gpts(gpt_header *pgpt, gpt_header *agpt, uint64_t lastlba) { int error_found = 0; if (!pgpt || !agpt) return; if (le64_to_cpu(pgpt->my_lba) != le64_to_cpu(agpt->alternate_lba)) { efi_error("GPT:Primary header LBA != Alt. header alternate_lba" "GPT:0x%" PRIx64 " != 0x%" PRIx64, (uint64_t)le64_to_cpu(pgpt->my_lba), (uint64_t)le64_to_cpu(agpt->alternate_lba)); error_found++; } if (le64_to_cpu(pgpt->alternate_lba) != le64_to_cpu(agpt->my_lba)) { efi_error("GPT:Primary header alternate_lba != Alt. header my_lba" "GPT:0x%" PRIx64 " != 0x%" PRIx64, (uint64_t)le64_to_cpu(pgpt->alternate_lba), (uint64_t)le64_to_cpu(agpt->my_lba)); error_found++; } if (le64_to_cpu(pgpt->first_usable_lba) != le64_to_cpu(agpt->first_usable_lba)) { efi_error("GPT:first_usable_lbas don't match." "GPT:0x%" PRIx64 " != 0x%" PRIx64, (uint64_t)le64_to_cpu(pgpt->first_usable_lba), (uint64_t)le64_to_cpu(agpt->first_usable_lba)); error_found++; } if (le64_to_cpu(pgpt->last_usable_lba) != le64_to_cpu(agpt->last_usable_lba)) { efi_error("GPT:last_usable_lbas don't match." "GPT:0x%" PRIx64 " != 0x%" PRIx64, (uint64_t)le64_to_cpu(pgpt->last_usable_lba), (uint64_t)le64_to_cpu(agpt->last_usable_lba)); error_found++; } if (memcmp(&pgpt->disk_guid, &agpt->disk_guid, sizeof (pgpt->disk_guid))) { efi_error("GPT:disk_guids don't match."); error_found++; } if (le32_to_cpu(pgpt->num_partition_entries) != le32_to_cpu(agpt->num_partition_entries)) { efi_error("GPT:num_partition_entries don't match: 0x%x != 0x%x", le32_to_cpu(pgpt->num_partition_entries), le32_to_cpu(agpt->num_partition_entries)); error_found++; } if (le32_to_cpu(pgpt->sizeof_partition_entry) != le32_to_cpu(agpt->sizeof_partition_entry)) { efi_error("GPT:sizeof_partition_entry values don't match: 0x%x != 0x%x", le32_to_cpu(pgpt->sizeof_partition_entry), le32_to_cpu(agpt->sizeof_partition_entry)); error_found++; } if (le32_to_cpu(pgpt->partition_entry_array_crc32) != le32_to_cpu(agpt->partition_entry_array_crc32)) { efi_error("GPT:partition_entry_array_crc32 values don't match: 0x%x != 0x%x", le32_to_cpu(pgpt->partition_entry_array_crc32), le32_to_cpu(agpt->partition_entry_array_crc32)); error_found++; } if (le64_to_cpu(pgpt->alternate_lba) != lastlba) { efi_error("GPT:Primary header thinks Alt. header is not at the end of the disk." "GPT:0x%" PRIx64 " != 0x%" PRIx64, (uint64_t)le64_to_cpu(pgpt->alternate_lba), lastlba); error_found++; } if (le64_to_cpu(agpt->my_lba) != lastlba) { efi_error("GPT:Alternate GPT header not at the end of the disk." "GPT:0x%" PRIx64 " != 0x%" PRIx64, (uint64_t)le64_to_cpu(agpt->my_lba), lastlba); error_found++; } if (error_found) efi_error("GPT: Use GNU Parted to correct GPT errors."); } /** * find_valid_gpt() - Search disk for valid GPT headers and PTEs * @fd is an open file descriptor to the whole disk * @gpt is a GPT header ptr, filled on return. * @ptes is a PTEs ptr, filled on return. * Description: Returns 1 if valid, 0 on error. * If valid, returns pointers to newly allocated GPT header and PTEs. * Validity depends on finding either the Primary GPT header and PTEs valid, * or the Alternate GPT header and PTEs valid, and the PMBR valid. */ static int find_valid_gpt(int fd, gpt_header ** gpt, gpt_entry ** ptes, int ignore_pmbr_err, int logical_block_size) { int good_pgpt = 0, good_agpt = 0, good_pmbr = 0; gpt_header *pgpt = NULL, *agpt = NULL; gpt_entry *pptes = NULL, *aptes = NULL; legacy_mbr *legacymbr = NULL; uint64_t lastlba; int ret = -1; errno = EINVAL; if (!gpt || !ptes) return -1; lastlba = last_lba(fd); good_pgpt = is_gpt_valid(fd, GPT_PRIMARY_PARTITION_TABLE_LBA, &pgpt, &pptes, logical_block_size); if (good_pgpt) { good_agpt = is_gpt_valid(fd, le64_to_cpu(pgpt->alternate_lba), &agpt, &aptes, logical_block_size); if (!good_agpt) { good_agpt = is_gpt_valid(fd, lastlba, &agpt, &aptes, logical_block_size); } } else { good_agpt = is_gpt_valid(fd, lastlba, &agpt, &aptes, logical_block_size); } /* The obviously unsuccessful case */ if (!good_pgpt && !good_agpt) { goto fail; } /* This will be added to the EFI Spec. per Intel after v1.02. */ legacymbr = malloc(sizeof (*legacymbr)); if (legacymbr) { memset(legacymbr, 0, sizeof (*legacymbr)); read_lba(fd, 0, (uint8_t *) legacymbr, sizeof (*legacymbr)); good_pmbr = is_pmbr_valid(legacymbr); free(legacymbr); legacymbr=NULL; } /* Failure due to bad PMBR */ if ((good_pgpt || good_agpt) && !good_pmbr && !ignore_pmbr_err) { efi_error("Primary GPT is invalid, using alternate GPT."); goto fail; } /* Would fail due to bad PMBR, but force GPT anyhow */ if ((good_pgpt || good_agpt) && !good_pmbr && ignore_pmbr_err) { efi_error(" Warning: Disk has a valid GPT magic but invalid PMBR.\n" " Use GNU Parted to correct disk.\n" " gpt option taken, disk treated as GPT."); } compare_gpts(pgpt, agpt, lastlba); /* The good cases */ if (good_pgpt && (good_pmbr || ignore_pmbr_err)) { *gpt = pgpt; *ptes = pptes; } else if (good_agpt && (good_pmbr || ignore_pmbr_err)) { *gpt = agpt; *ptes = aptes; } ret = 0; errno = 0; fail: if (pgpt && (pgpt != *gpt || ret < 0)) { free(pgpt); pgpt=NULL; } if (pptes && (pptes != *ptes || ret < 0)) { free(pptes); pptes=NULL; } if (agpt && (agpt != *gpt || ret < 0)) { free(agpt); agpt=NULL; } if (aptes && (aptes != *ptes || ret < 0)) { free(aptes); aptes=NULL; } if (ret < 0) { *gpt = NULL; *ptes = NULL; } return ret; } /************************************************************ * gpt_disk_get_partition_info() * Requires: * - open file descriptor fd * - start, size, signature, mbr_type, signature_type * Modifies: all these * Returns: * 0 on success * non-zero on failure * ************************************************************/ int NONNULL(3, 4, 5, 6, 7) HIDDEN gpt_disk_get_partition_info(int fd, uint32_t num, uint64_t * start, uint64_t * size, efi_guid_t *signature, uint8_t * mbr_type, uint8_t * signature_type, int ignore_pmbr_error, int logical_block_size) { gpt_header *gpt = NULL; gpt_entry *ptes = NULL, *p; int rc = 0; rc = find_valid_gpt(fd, &gpt, &ptes, ignore_pmbr_error, logical_block_size); if (rc < 0) return rc; *mbr_type = 0x02; *signature_type = 0x02; if (num > 0 && num <= le32_to_cpu(gpt->num_partition_entries)) { p = &ptes[num - 1]; *start = le64_to_cpu(p->starting_lba); *size = le64_to_cpu(p->ending_lba) - le64_to_cpu(p->starting_lba) + 1; memcpy(signature, &p->unique_partition_guid, sizeof (p->unique_partition_guid)); } else { efi_error("partition %d is not valid", num); errno = EINVAL; rc = -1; } free(ptes); free(gpt); return rc; } /* * Overrides for Emacs so that we follow Linus's tabbing style. * Emacs will notice this stuff at the end of the file and automatically * adjust the settings for this buffer only. This must remain at the end * of the file. * --------------------------------------------------------------------------- * Local variables: * c-indent-level: 4 * c-brace-imaginary-offset: 0 * c-brace-offset: -4 * c-argdecl-indent: 4 * c-label-offset: -4 * c-continued-statement-offset: 4 * c-continued-brace-offset: 0 * indent-tabs-mode: nil * tab-width: 8 * End: */ // vim:fenc=utf-8:tw=75:noet