/**************************************************************************** * fs/partition/fs_gpt.c * * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. The * ASF licenses this file to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance with the * License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations * under the License. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include #include #include #include #include "partition.h" /**************************************************************************** * Pre-processor Definitions ****************************************************************************/ #define GPT_BLOCK_SIZE 512 #define GPT_HEADER_SIGNATURE 0x5452415020494645ull #define GPT_PARTNAME_MAX_SIZE (72 / sizeof(uint16_t)) #define GPT_LBA_TO_BLOCK(lba, blk) ((le64toh(lba) * 512 + (blk) -1) / (blk)) /**************************************************************************** * Private Types ****************************************************************************/ struct gpt_guid_s { uint8_t b[16]; }; /* For limited backward compatibility, the space of the legacy MBR is still * reserved in the GPT specification, but it is now used in a way that * prevents MBR-based disk utilities from misrecognizing and possibly * overwriting GPT disks. This is referred to as a protective MBR. */ begin_packed_struct struct legacy_partition_s { uint8_t boot_ind; /* 0x80 - active */ uint8_t head; /* Starting head */ uint8_t sector; /* Starting sector */ uint8_t cyl; /* Starting cylinder */ uint8_t sys_ind; /* What partition type */ uint8_t end_head; /* End head */ uint8_t end_sector; /* End sector */ uint8_t end_cyl; /* End cylinder */ uint32_t start_sect; /* Starting sector counting from 0 */ uint32_t nr_sects; /* Nr of sectors in partition */ } end_packed_struct; /* The partition table header defines the usable blocks on the disk. * It also defines the number and size of the partition entries that * make up the partition table (offsets 80 and 84 in the table). */ begin_packed_struct struct gpt_header_s { uint64_t signature; /* EFI PART */ uint32_t revision; /* Revision info */ uint32_t header_size; /* Header size in little endian */ uint32_t header_crc32; /* CRC32 of header (offset +0 up to header size) */ uint32_t reserved1; /* Must be zero */ uint64_t my_lba; /* Current LBA (location of this header copy) */ uint64_t alternate_lba; /* Backup LBA (location of the other header copy) */ uint64_t first_usable_lba; /* First usable LBA for partitions primary partition table last LBA + 1 */ uint64_t last_usable_lba; /* Last usable LBA secondary partition table first LBA − 1 */ struct gpt_guid_s disk_guid; /* Disk GUID in mixed endian */ uint64_t partition_entry_lba; /* Starting LBA of array of partition entries (always 2 in primary copy) */ uint32_t num_partition_entries; /* Number of partition entries in array */ uint32_t sizeof_partition_entry; /* Size of a single partition entry */ uint32_t partition_entry_array_crc32; /* CRC32 of partition entries array in little endian */ /* The rest of the logical block is reserved by UEFI and must be zero. * EFI standard handles this by: * * uint8_t reserved2[ BlockSize - 92 ]; */ } end_packed_struct; /* After the header, the Partition Entry Array describes partitions, * using a minimum size of 128 bytes for each entry block. */ /* The 64-bit partition table attributes are shared between 48-bit * common attributes for all partition types, and 16-bit * type-specific attributes */ begin_packed_struct struct gpt_entry_attributes_s { uint64_t required_to_function:1; uint64_t reserved:47; uint64_t type_guid_specific:16; } end_packed_struct; begin_packed_struct struct gpt_entry_s { struct gpt_guid_s partition_type_guid; /* Partition type GUID */ struct gpt_guid_s unique_partition_guid; /* Unique partition GUID */ uint64_t starting_lba; /* First LBA */ uint64_t ending_lba; /* Last LBA */ struct gpt_entry_attributes_s attributes; /* Attribute flags */ uint16_t partition_name[GPT_PARTNAME_MAX_SIZE]; /* Partition name */ } end_packed_struct; begin_packed_struct struct gpt_ptable_s { uint8_t mbr[512]; union { struct gpt_header_s gpt_header; uint8_t gpt[512]; } u; } end_packed_struct; /**************************************************************************** * Private Data ****************************************************************************/ static const struct gpt_guid_s g_null_guid; /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: gpt_last_lba * * Description: * Return number of last logical block of device, 0 on error. * * Input Parameters: * state - The partition table state * * Returned Value: * Returns last LBA value on success, 0 on error. * This is stored (by sd and ide-geometry) in * the part[0] entry for this disk, and is the number of * physical sectors available on the disk. * ****************************************************************************/ static inline blkcnt_t gpt_last_lba(FAR struct partition_state_s *state) { return (((uint64_t)state->nblocks) * state->blocksize + GPT_BLOCK_SIZE - 1) / GPT_BLOCK_SIZE - 1; } /**************************************************************************** * Name: gpt_alloc_verify_entries() * * Description: * reads and verifies partition entries from disk * * Input Parameters: * state - the handle of partition state * gpt - a GPT header ptr. * * Returned Value: * 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 FAR struct gpt_entry_s * gpt_alloc_verify_entries(FAR struct partition_state_s *state, FAR struct gpt_header_s *gpt) { FAR struct gpt_entry_s *pte; unsigned long from; unsigned long size; unsigned long blk; uint32_t crc; int ret; size = le32toh(gpt->num_partition_entries) * le32toh(gpt->sizeof_partition_entry); if (!size) { return NULL; } blk = (size + (state->blocksize -1)) / state->blocksize; pte = kmm_zalloc(blk * state->blocksize); if (!pte) { return NULL; } from = GPT_LBA_TO_BLOCK(gpt->partition_entry_lba, state->blocksize); ret = read_partition_block(state, pte, from, blk); if (ret < 0) { kmm_free(pte); ferr("Read ptr from block failed:%d.\n", ret); return NULL; } /* Check the GUID Partition Table Entry Array CRC */ crc = crc32part((FAR const uint8_t *)pte, size, ~0l) ^ ~0l; if (crc != le32toh(gpt->partition_entry_array_crc32)) { ferr("GUID Partitition Entry Array CRC check failed.\n"); kmm_free(pte); return NULL; } return pte; } /**************************************************************************** * Name: gpt_header_is_valid * * Description: * tests one GPT header for validity * * Input Parameters: * state - The partition table state * gpt - is a GPT header ptr. * lba - is the logical block address of the GPT header to test * * Returned Value: * Returns 0 if valid, a negative errno returned on error. * ****************************************************************************/ static int gpt_header_is_valid(FAR struct partition_state_s *state, FAR struct gpt_header_s *gpt, blkcnt_t lba) { uint32_t crc; uint32_t origcrc; blkcnt_t lastlba; /* Check the GPT header signature */ if (le64toh(gpt->signature) != GPT_HEADER_SIGNATURE) { ferr("GUID Partition Table Header signature is wrong:" "0x%" PRIx64 " != 0x%llx\n", le64toh(gpt->signature), GPT_HEADER_SIGNATURE); return -EINVAL; } /* Check the GUID Partition Table CRC */ origcrc = gpt->header_crc32; gpt->header_crc32 = 0; crc = crc32part((FAR const uint8_t *)gpt, le32toh(gpt->header_size), ~0l) ^ ~0l; if (crc != le32toh(origcrc)) { ferr("GUID Partition Table Header CRC is wrong: %" PRIx32 " != %" PRIx32 "\n", crc, le32toh(origcrc)); return -EINVAL; } gpt->header_crc32 = origcrc; /* Check that the my_lba entry points to the LBA that contains * the GUID Partition Table */ if (le64toh(gpt->my_lba) != lba) { ferr("GPT: my_lba incorrect: %" PRIx64 " != %" PRIxOFF "\n", le64toh(gpt->my_lba), lba); return -EINVAL; } /* Check the first_usable_lba and last_usable_lba are within the disk. */ lastlba = gpt_last_lba(state); if (le64toh(gpt->first_usable_lba) > lastlba) { ferr("GPT: first_usable_lba incorrect: %" PRId64 " > %" PRIdOFF "\n", le64toh(gpt->first_usable_lba), lastlba); return -EINVAL; } if (le64toh(gpt->last_usable_lba) > lastlba) { ferr("GPT: last_usable_lba incorrect: %" PRId64 " > %" PRIdOFF "\n", le64toh(gpt->last_usable_lba), lastlba); return -EINVAL; } return OK; } /**************************************************************************** * Name: gpt_pte_is_valid() * * Description: * tests one PTE for validity * * Input Parameters: * pte is the pte to check * lastlba is last lba of the disk * * Returned Value: * Returns 1 if valid, 0 on error. * ****************************************************************************/ static inline int gpt_pte_is_valid(FAR const struct gpt_entry_s *pte, blkcnt_t lastlba) { if (!memcmp(&pte->partition_type_guid, &g_null_guid, sizeof(g_null_guid)) || le64toh(pte->starting_lba) > lastlba || le64toh(pte->ending_lba) > lastlba) { return 0; } return 1; } static void gpt_part_set_name(FAR struct gpt_entry_s *pte, FAR char *dest, size_t len) { int i; if (--len > GPT_PARTNAME_MAX_SIZE) { len = GPT_PARTNAME_MAX_SIZE; } for (i = 0; i < len; i++) { uint8_t c = pte->partition_name[i]; dest[i] = (c && !isprint(c)) ? '.' : c; } dest[i] = 0; } /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: parse_gpt_partition * * Description: * parse the gpt(EFI GUID Partition Table) partition. * * Input Parameters: * state - The partition table state * handler - The function to be called for each found partition * arg - A caller provided value to return with the handler * * Returned Value: * Zero on success; A negated errno value is returned on a failure * ****************************************************************************/ int parse_gpt_partition(FAR struct partition_state_s *state, partition_handler_t handler, FAR void *arg) { FAR struct legacy_partition_s *pmbr; FAR struct gpt_ptable_s *ptbl; FAR struct gpt_header_s *gpt; FAR struct gpt_entry_s *ptes; struct partition_s pentry; blkcnt_t lastlba; int nb_part; int count; int ret; /* Read GPT Ptable (LBA0 + LBA1) */ count = (sizeof(struct gpt_ptable_s) + (state->blocksize - 1)) / state->blocksize; ptbl = kmm_malloc(count * state->blocksize); if (!ptbl) { return -ENOMEM; } ret = read_partition_block(state, ptbl, 0, count); if (ret < 0) { goto err; } /* Verify mbr is valid */ pmbr = (FAR struct legacy_partition_s *)&ptbl->mbr[0x1be]; if (pmbr->sys_ind != 0xee) { ret = -EINVAL; goto err; } /* Verify gpt header is valid */ gpt = &(ptbl->u.gpt_header); ret = gpt_header_is_valid(state, gpt, 1); if (ret >= 0) { /* Verify gpt header is valid */ ptes = gpt_alloc_verify_entries(state, gpt); } if (ret < 0 || !ptes) { /* Read and Verify backup gpt header is valid */ finfo("Primary GPT is invalid, using alternate GPT.\n"); count = (GPT_BLOCK_SIZE + state->blocksize - 1) / state->blocksize; ret = read_partition_block(state, ptbl, GPT_LBA_TO_BLOCK(gpt->alternate_lba, state->blocksize), count); if (ret < 0) { goto err; } gpt = (FAR struct gpt_header_s *)ptbl; ret = gpt_header_is_valid(state, gpt, le64toh(gpt->alternate_lba)); if (ret >= 0) { /* Verify gpt header is valid */ ptes = gpt_alloc_verify_entries(state, gpt); } } if (ret < 0 || !ptes) { finfo("Alternate GPT is also invalid!!\n"); goto err; } lastlba = gpt_last_lba(state); nb_part = le32toh(gpt->num_partition_entries); for (pentry.index = 0; pentry.index < nb_part; pentry.index++) { /* Skip the empty or invalid entries */ if (!gpt_pte_is_valid(&ptes[pentry.index], lastlba)) { continue; } pentry.firstblock = GPT_LBA_TO_BLOCK(ptes[pentry.index].starting_lba, state->blocksize); pentry.nblocks = GPT_LBA_TO_BLOCK(ptes[pentry.index].ending_lba + 1, state->blocksize) - pentry.firstblock; pentry.blocksize = state->blocksize; gpt_part_set_name(&ptes[pentry.index], pentry.name, sizeof(pentry.name)); handler(&pentry, arg); } kmm_free(ptes); err: kmm_free(ptbl); return ret; }