From 3952325a90c2a6bf6b9c3ce1e87cf71c79f2531c Mon Sep 17 00:00:00 2001 From: Alexander Couzens Date: Fri, 2 Mar 2018 00:44:30 +0100 Subject: [PATCH] tplink-safeloader: add support to split & extract firmwares Split the oem firmware upgrade images into seperate files. Useful when analysing oem firmware files. Signed-off-by: Alexander Couzens --- src/tplink-safeloader.c | 280 +++++++++++++++++++++++++++++++++++++--- 1 file changed, 263 insertions(+), 17 deletions(-) diff --git a/src/tplink-safeloader.c b/src/tplink-safeloader.c index c96edb4..0a11287 100644 --- a/src/tplink-safeloader.c +++ b/src/tplink-safeloader.c @@ -46,6 +46,7 @@ #include #include +#include #include "md5.h" @@ -1379,6 +1380,9 @@ static void usage(const char *argv0) { "Usage: %s [OPTIONS...]\n" "\n" "Options:\n" + " -h show this help\n" + "\n" + "Create a new image:\n" " -B create image for the board specified with \n" " -k read kernel image from the file \n" " -r read rootfs image from the file \n" @@ -1386,7 +1390,9 @@ static void usage(const char *argv0) { " -V sets the revision number to \n" " -j add jffs2 end-of-filesystem markers\n" " -S create sysupgrade instead of factory image\n" - " -h show this help\n", + "Extract an old image:\n" + " -x extract all oem firmware partition\n" + " -d destination to extract the firmware partition\n", argv0 ); }; @@ -1403,8 +1409,232 @@ static const struct device_info *find_board(const char *id) return NULL; } +static int add_flash_partition( + struct flash_partition_entry *part_list, + size_t max_entries, + const char *name, + unsigned long base, + unsigned long size) +{ + int ptr = 0; + /* check if the list has a free entry */ + for (int ptr=0; ptrname == NULL && + part_list->base == 0 && + part_list->size == 0) + break; + } + + if (ptr == max_entries) { + error(1, 0, "No free flash part entry available."); + } + + part_list->name = calloc(1, strlen(name) + 1); + memcpy((char *)part_list->name, name, strlen(name)); + part_list->base = base; + part_list->size = size; + + return 0; +} + +/** read the partition table into struct flash_partition_entry */ +static int read_partition_table( + FILE *file, long offset, + struct flash_partition_entry *entries, size_t max_entries, + int type) +{ + char buf[2048]; + char *ptr, *end; + const char *parthdr = NULL; + const char *fwuphdr = "fwup-ptn"; + const char *flashhdr = "partition"; + + /* TODO: search for the partition table */ + + switch(type) { + case 0: + parthdr = fwuphdr; + break; + case 1: + parthdr = flashhdr; + break; + default: + error(1, 0, "Invalid partition table"); + } + + if (fseek(file, offset, SEEK_SET) < 0) + error(1, errno, "Can not seek in the firmware"); + + if (fread(buf, 1, 2048, file) < 0) + error(1, errno, "Can not read fwup-ptn from the firmware"); + + buf[2047] = '\0'; + + /* look for the partition header */ + if (memcmp(buf, parthdr, strlen(parthdr)) != 0) { + fprintf(stderr, "DEBUG: can not find fwuphdr\n"); + return 1; + } + + ptr = buf; + end = buf + sizeof(buf); + while ((ptr + strlen(parthdr)) < end && + memcmp(ptr, parthdr, strlen(parthdr)) == 0) { + char *end_part; + char *end_element; + + char name[32] = { 0 }; + int name_len = 0; + unsigned long base = 0; + unsigned long size = 0; + + end_part = memchr(ptr, '\n', (end - ptr)); + if (end_part == NULL) { + /* in theory this should never happen, because a partition always ends with 0x09, 0x0D, 0x0A */ + break; + } + + for (int i=0; i<=4; i++) { + if (end_part <= ptr) + break; + + end_element = memchr(ptr, 0x20, (end_part - ptr)); + if (end_element == NULL) { + error(1, errno, "Ignoring the rest of the partition entries."); + break; + } + + switch (i) { + /* partition header */ + case 0: + ptr = end_element + 1; + continue; + /* name */ + case 1: + name_len = (end_element - ptr) > 31 ? 31 : (end_element - ptr); + strncpy(name, ptr, name_len); + name[name_len] = '\0'; + ptr = end_element + 1; + continue; + + /* string "base" */ + case 2: + ptr = end_element + 1; + continue; + + /* actual base */ + case 3: + base = strtoul(ptr, NULL, 16); + ptr = end_element + 1; + continue; + + /* string "size" */ + case 4: + ptr = end_element + 1; + /* actual size. The last element doesn't have a sepeartor */ + size = strtoul(ptr, NULL, 16); + /* the part ends with 0x09, 0x0d, 0x0a */ + ptr = end_part + 1; + add_flash_partition(entries, max_entries, name, base, size); + continue; + } + } + } + + return 0; +} + +static void write_partition( + FILE *input_file, + size_t firmware_offset, + struct flash_partition_entry *entry, + FILE *output_file) +{ + char buf[4096]; + size_t offset; + + fseek(input_file, entry->base + firmware_offset, SEEK_SET); + + for (offset = 0; sizeof(buf) + offset <= entry->size; offset += sizeof(buf)) { + if (fread(buf, sizeof(buf), 1, input_file) < 0) + error(1, errno, "Can not read partition from input_file"); + + if (fwrite(buf, sizeof(buf), 1, output_file) < 0) + error(1, errno, "Can not write partition to output_file"); + } + /* write last chunk smaller than buffer */ + if (offset < entry->size) { + offset = entry->size - offset; + if (fread(buf, offset, 1, input_file) < 0) + error(1, errno, "Can not read partition from input_file"); + if (fwrite(buf, offset, 1, output_file) < 0) + error(1, errno, "Can not write partition to output_file"); + } +} + +static int extract_firmware_partition(FILE *input_file, size_t firmware_offset, struct flash_partition_entry *entry, const char *output_directory) +{ + FILE *output_file; + char output[PATH_MAX]; + + snprintf(output, PATH_MAX, "%s/%s", output_directory, entry->name); + output_file = fopen(output, "wb+"); + if (output_file == NULL) { + error(1, errno, "Can not open output file %s", output); + } + + write_partition(input_file, firmware_offset, entry, output_file); + + fclose(output_file); + + return 0; +} + +/** extract all partitions from the firmware file */ +static int extract_firmware(const char *input, const char *output_directory) +{ + struct flash_partition_entry entries[16] = { 0 }; + size_t max_entries = 16; + size_t firmware_offset = 0x1014; + FILE *input_file; + + struct stat statbuf; + + /* check input file */ + if (stat(input, &statbuf)) { + error(1, errno, "Can not read input firmware %s", input); + } + + /* check if output directory exists */ + if (stat(output_directory, &statbuf)) { + error(1, errno, "Failed to stat output directory %s", output_directory); + } + + if ((statbuf.st_mode & S_IFMT) != S_IFDIR) { + error(1, errno, "Given output directory is not a directory %s", output_directory); + } + + input_file = fopen(input, "rb"); + + if (read_partition_table(input_file, firmware_offset, entries, 16, 0) != 0) { + error(1, 0, "Error can not read the partition table (fwup-ptn)"); + } + + for (int i=0; i. Output directory is only valid with -x"); + if (!output_directory) + error(1, 0, "Can not extract an image without output directory. Use -d "); + extract_firmware(extract_image, output_directory); + } else { + if (!board) + error(1, 0, "no board has been specified"); + if (!kernel_image) + error(1, 0, "no kernel image has been specified"); + if (!rootfs_image) + error(1, 0, "no rootfs image has been specified"); + if (!output) + error(1, 0, "no output filename has been specified"); + + info = find_board(board); + + if (info == NULL) + error(1, 0, "unsupported board %s", board); + + build_image(output, kernel_image, rootfs_image, rev, add_jffs2_eof, sysupgrade, info); + } return 0; } -- 2.30.2