diff options
Diffstat (limited to 'package/system/mtd/src/wrg.c')
| -rw-r--r-- | package/system/mtd/src/wrg.c | 208 |
1 files changed, 208 insertions, 0 deletions
diff --git a/package/system/mtd/src/wrg.c b/package/system/mtd/src/wrg.c new file mode 100644 index 0000000000..879cf1bbe0 --- /dev/null +++ b/package/system/mtd/src/wrg.c @@ -0,0 +1,208 @@ +/* + * wrg.c + * + * Copyright (C) 2005 Mike Baker + * Copyright (C) 2008 Felix Fietkau <nbd@nbd.name> + * Copyright (C) 2011-2012 Gabor Juhos <juhosg@openwrt.org> + * Copyright (C) 2016 Stijn Tintel <stijn@linux-ipv6.be> + * Copyright (C) 2017 George Hopkins <george-hopkins@null.net> + * + * 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 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * 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, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + */ + +#include <byteswap.h> +#include <endian.h> +#include <stdio.h> +#include <stdlib.h> +#include <stddef.h> +#include <unistd.h> +#include <fcntl.h> +#include <sys/mman.h> +#include <sys/stat.h> +#include <string.h> +#include <errno.h> +#include <arpa/inet.h> + +#include <sys/ioctl.h> +#include <mtd/mtd-user.h> +#include "mtd.h" +#include "md5.h" + +#if !defined(__BYTE_ORDER) +#error "Unknown byte order" +#endif + +#if __BYTE_ORDER == __BIG_ENDIAN +#define cpu_to_le32(x) bswap_32(x) +#define le32_to_cpu(x) bswap_32(x) +#elif __BYTE_ORDER == __LITTLE_ENDIAN +#define cpu_to_le32(x) (x) +#define le32_to_cpu(x) (x) +#else +#error "Unsupported endianness" +#endif + +#define WRG_MAGIC 0x20040220 + +struct wrg_header { + char signature[32]; + uint32_t magic1; + uint32_t magic2; + uint32_t size; + uint32_t offset; + char devname[32]; + char digest[16]; +} __attribute__ ((packed)); + +ssize_t pread(int fd, void *buf, size_t count, off_t offset); +ssize_t pwrite(int fd, const void *buf, size_t count, off_t offset); + +int +wrg_fix_md5(struct wrg_header *shdr, int fd, size_t data_offset, size_t data_size) +{ + char *buf; + ssize_t res; + MD5_CTX ctx; + unsigned char digest[16]; + int i; + int err = 0; + + buf = malloc(data_size); + if (!buf) { + err = -ENOMEM; + goto err_out; + } + + res = pread(fd, buf, data_size, data_offset); + if (res != data_size) { + perror("pread"); + err = -EIO; + goto err_free; + } + + MD5_Init(&ctx); + MD5_Update(&ctx, (char *)&shdr->offset, sizeof(shdr->offset)); + MD5_Update(&ctx, (char *)&shdr->devname, sizeof(shdr->devname)); + MD5_Update(&ctx, buf, data_size); + MD5_Final(digest, &ctx); + + if (!memcmp(digest, shdr->digest, sizeof(digest))) { + if (quiet < 2) + fprintf(stderr, "the header is fixed already\n"); + return -1; + } + + if (quiet < 2) { + fprintf(stderr, "new size: %u, new MD5: ", data_size); + for (i = 0; i < sizeof(digest); i++) + fprintf(stderr, "%02x", digest[i]); + + fprintf(stderr, "\n"); + } + + /* update the size in the image */ + shdr->size = cpu_to_le32(data_size); + + /* update the checksum in the image */ + memcpy(shdr->digest, digest, sizeof(digest)); + +err_free: + free(buf); +err_out: + return err; +} + +int +mtd_fixwrg(const char *mtd, size_t offset, size_t data_size) +{ + int fd; + char *first_block; + ssize_t res; + size_t block_offset; + size_t data_offset; + struct wrg_header *shdr; + + if (quiet < 2) + fprintf(stderr, "Trying to fix WRG header in %s at 0x%x...\n", + mtd, offset); + + block_offset = offset & ~(erasesize - 1); + offset -= block_offset; + + fd = mtd_check_open(mtd); + if(fd < 0) { + fprintf(stderr, "Could not open mtd device: %s\n", mtd); + exit(1); + } + + if (block_offset + erasesize > mtdsize) { + fprintf(stderr, "Offset too large, device size 0x%x\n", + mtdsize); + exit(1); + } + + first_block = malloc(erasesize); + if (!first_block) { + perror("malloc"); + exit(1); + } + + res = pread(fd, first_block, erasesize, block_offset); + if (res != erasesize) { + perror("pread"); + exit(1); + } + + shdr = (struct wrg_header *)(first_block + offset); + if (le32_to_cpu(shdr->magic1) != WRG_MAGIC) { + fprintf(stderr, "No WRG header found (%08x != %08x)\n", + le32_to_cpu(shdr->magic1), WRG_MAGIC); + exit(1); + } else if (!le32_to_cpu(shdr->size)) { + fprintf(stderr, "WRG entity with empty image\n"); + exit(1); + } + + data_offset = offset + sizeof(struct wrg_header); + if (!data_size) + data_size = mtdsize - data_offset; + if (data_size > le32_to_cpu(shdr->size)) + data_size = le32_to_cpu(shdr->size); + if (wrg_fix_md5(shdr, fd, data_offset, data_size)) + goto out; + + if (mtd_erase_block(fd, block_offset)) { + fprintf(stderr, "Can't erease block at 0x%x (%s)\n", + block_offset, strerror(errno)); + exit(1); + } + + if (quiet < 2) + fprintf(stderr, "Rewriting block at 0x%x\n", block_offset); + + if (pwrite(fd, first_block, erasesize, block_offset) != erasesize) { + fprintf(stderr, "Error writing block (%s)\n", strerror(errno)); + exit(1); + } + + if (quiet < 2) + fprintf(stderr, "Done.\n"); + +out: + close (fd); + sync(); + + return 0; +} |