diff options
Diffstat (limited to 'src/gpt.c')
| -rw-r--r-- | src/gpt.c | 342 |
1 files changed, 342 insertions, 0 deletions
diff --git a/src/gpt.c b/src/gpt.c new file mode 100644 index 0000000..40ac4a5 --- /dev/null +++ b/src/gpt.c @@ -0,0 +1,342 @@ +/* + * Copyright (C) 2016 Paul Kocialkowski <contact@paulk.fr> + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be usefu, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <stdlib.h> +#include <stdio.h> +#include <string.h> +#include <ctype.h> + +#include "lg-downloader.h" +#include "download.h" +#include "gpt.h" + +/* Lookup table for CRC32 with generator polynomial 0x04C11Db7. */ +static const unsigned int gpt_crc_table[] = { + 0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, + 0x706af48f, 0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4, + 0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, + 0x90bf1d91, 0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de, + 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7, 0x136c9856, + 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9, + 0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4, + 0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, + 0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, + 0x45df5c75, 0xdcd60dcf, 0xabd13d59, 0x26d930ac, 0x51de003a, + 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599, + 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924, + 0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190, + 0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, + 0x9fbfe4a5, 0xe8b8d433, 0x7807c9a2, 0x0f00f934, 0x9609a88e, + 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01, + 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed, + 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950, + 0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, + 0xfbd44c65, 0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, + 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, + 0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5, + 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa, 0xbe0b1010, + 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f, + 0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, + 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, + 0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615, + 0x73dc1683, 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8, + 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1, 0xf00f9344, + 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb, + 0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, + 0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, + 0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, + 0xa6bc5767, 0x3fb506dd, 0x48b2364b, 0xd80d2bda, 0xaf0a1b4c, + 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef, + 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236, + 0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, + 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, + 0x2cd99e8b, 0x5bdeae1d, 0x9b64c2b0, 0xec63f226, 0x756aa39c, + 0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713, + 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b, + 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242, + 0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, + 0x18b74777, 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, + 0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45, 0xa00ae278, + 0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7, + 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc, 0x40df0b66, + 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9, + 0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, + 0xcdd70693, 0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, + 0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, + 0x2d02ef8d +}; + +static unsigned int gpt_crc_step(unsigned int crc, unsigned char data) +{ + return ((crc >> 8) ^ gpt_crc_table[(crc ^ data) & 0xff]); +} + +static unsigned int gpt_crc_final(unsigned int crc) +{ + return crc ^ GPT_CRC_SEED; +} + +static void gpt_partition_name(struct gpt_partition *partition, char *name) +{ + unsigned int i; + unsigned int j; + char c; + + if (partition == NULL || name == NULL) + return; + + for (i = 0, j = 0; i < GPT_PARTITION_NAME_COUNT; i++) { + c = (char) le16toh(partition->name[i]); + + if (isprint(c)) + name[j++] = c; + } + + name[j] = '\0'; +} + +int gpt_header_verify(struct gpt_header *header) +{ + struct gpt_header header_copy; + unsigned char *p; + unsigned int crc; + unsigned int i; + + if (header == NULL) + return -1; + + if (strncmp(header->signature, GPT_SIGNATURE, sizeof(header->signature)) != 0) { + fprintf(stderr, "Verifying GPT signature failed\n"); + return -1; + } + + if (le32toh(header->version) != GPT_VERSION) { + fprintf(stderr, "Verifying GPT version failed\n"); + return -1; + } + + memcpy(&header_copy, header, sizeof(struct gpt_header)); + header_copy.crc = 0; + + crc = GPT_CRC_SEED; + p = (unsigned char *) &header_copy; + + for (i = 0; i < sizeof(struct gpt_header); i++) + crc = gpt_crc_step(crc, *p++); + + crc = gpt_crc_final(crc); + + if (le32toh(header->crc) != crc) { + fprintf(stderr, "Verifying GPT CRC failed\n"); + return -1; + } + + if (le32toh(header->partitions_size) != sizeof(struct gpt_partition)) + return -1; + + if ((GPT_BLOCK_SIZE % le32toh(header->partitions_size)) != 0) + return -1; + + if (le32toh(header->partitions_lba) == 0 || le32toh(header->partitions_count) == 0) + return -1; + + return 0; +} + +int gpt_header_read(struct context *context, struct gpt_header *header) +{ + unsigned int address; + unsigned int length; + int rc; + + address = GPT_HEADER_LBA; + length = sizeof(struct gpt_header); + + rc = download_ready_read(context, address, length); + if (rc < 0) + return -1; + + rc = download_read(context, (void *) header, length); + if (rc < 0) + return -1; + + return 0; +} + +int gpt_partition_find(struct context *context) +{ + struct gpt_header header; + struct gpt_partition *partition; + void *buffer = NULL; + char name[GPT_PARTITION_NAME_COUNT + 1]; + unsigned int address; + unsigned int length; + unsigned int count; + unsigned int index; + unsigned int i; + int rc; + + if (context == NULL || context->partition == NULL) + return -1; + + if (context->verbose) + printf("Reading GPT header\n"); + + rc = gpt_header_read(context, &header); + if (rc < 0) { + fprintf(stderr, "Reading GPT header failed\n"); + goto error; + } + + if (context->verbose) + printf("Verifying GPT header\n"); + + rc = gpt_header_verify(&header); + if (rc < 0) { + fprintf(stderr, "Verifying GPT header failed\n"); + goto error; + } + + address = le32toh(header.partitions_lba); + length = le32toh(header.partitions_size); + count = le32toh(header.partitions_count); + + buffer = calloc(1, GPT_BLOCK_SIZE); + + for (i = 0; i < count; i++) { + index = i % (GPT_BLOCK_SIZE / length); + + if (index == 0) { + rc = download_ready_read(context, address, GPT_BLOCK_SIZE); + if (rc < 0) + goto error; + + rc = download_read(context, buffer, GPT_BLOCK_SIZE); + if (rc < 0) + goto error; + + address++; + } + + partition = ((struct gpt_partition *) buffer) + index; + + gpt_partition_name(partition, (char *) &name); + + if (name[0] != '\0') { + if (context->verbose) + printf("Found GPT partition: %s\n", name); + + if (strcmp(name, context->partition) == 0) { + printf("Matched GPT partition: %s\n", name); + + context->address = (unsigned int) le64toh(partition->first_lba); + context->length = (unsigned int) (le64toh(partition->last_lba) - le64toh(partition->first_lba) + 1) * GPT_BLOCK_SIZE; + + rc = 0; + goto complete; + } + + } + } + + fprintf(stderr, "Matching GPT partition: %s failed\n", context->partition); + +error: + rc = -1; + +complete: + if (buffer != NULL) + free(buffer); + + return rc; +} + +int gpt_partitions_print(struct context *context) +{ + struct gpt_header header; + struct gpt_partition *partition; + void *buffer = NULL; + char name[GPT_PARTITION_NAME_COUNT + 1]; + unsigned int address; + unsigned int length; + unsigned int count; + unsigned int index; + unsigned int i; + int rc; + + if (context == NULL) + return -1; + + if (context->verbose) + printf("Reading GPT header\n"); + + rc = gpt_header_read(context, &header); + if (rc < 0) { + fprintf(stderr, "Reading GPT header failed\n"); + goto error; + } + + if (context->verbose) + printf("Verifying GPT header\n"); + + rc = gpt_header_verify(&header); + if (rc < 0) { + fprintf(stderr, "Verifying GPT header failed\n"); + goto error; + } + + address = le32toh(header.partitions_lba); + length = le32toh(header.partitions_size); + count = le32toh(header.partitions_count); + + buffer = calloc(1, GPT_BLOCK_SIZE); + + for (i = 0; i < count; i++) { + index = i % (GPT_BLOCK_SIZE / length); + + if (index == 0) { + rc = download_ready_read(context, address, GPT_BLOCK_SIZE); + if (rc < 0) + goto error; + + rc = download_read(context, buffer, GPT_BLOCK_SIZE); + if (rc < 0) + goto error; + + address++; + } + + partition = ((struct gpt_partition *) buffer) + index; + + gpt_partition_name(partition, (char *) &name); + + if (name[0] != '\0') + printf("Partition name: %s, size: %d bytes\n", name, (unsigned int) (le64toh(partition->last_lba) - le64toh(partition->first_lba) + 1) * GPT_BLOCK_SIZE); + } + + rc = 0; + goto complete; + +error: + rc = -1; + +complete: + if (buffer != NULL) + free(buffer); + + return rc; +} |