/* * Copyright (C) 2009 Gabor Juhos * * This tool was based on: * TP-Link WR941 V2 firmware checksum fixing tool. * Copyright (C) 2008,2009 Wang Jian * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 as published * by the Free Software Foundation. * */ #include #include #include #include #include /* for unlink() */ #include #include /* for getopt() */ #include #include #include #include #include #include #include #include "md5.h" #define ALIGN(x,a) ({ typeof(a) __a = (a); (((x) + __a - 1) & ~(__a - 1)); }) #define MD5SUM_LEN 16 struct file_info { char *file_name; /* name of the file */ uint32_t file_size; /* length of the file */ }; struct fw_header { uint32_t version; /* 0x00: header version */ char fw_version[48]; /* 0x04: fw version string */ uint32_t hw_id; /* 0x34: hardware id */ uint32_t hw_rev; /* 0x38: FIXME: hardware revision? */ uint32_t unk1; /* 0x3c: 0x00000000 */ uint8_t md5sum1[MD5SUM_LEN]; /* 0x40 */ uint32_t unk2; /* 0x50: 0x00000000 */ uint8_t md5sum2[MD5SUM_LEN]; /* 0x54 */ uint32_t unk3; /* 0x64: 0xffffffff */ uint32_t kernel_la; /* 0x68: kernel load address */ uint32_t kernel_ep; /* 0x6c: kernel entry point */ uint32_t fw_length; /* 0x70: total length of the image */ uint32_t kernel_ofs; /* 0x74: kernel data offset */ uint32_t kernel_len; /* 0x78: kernel data length */ uint32_t rootfs_ofs; /* 0x7c: rootfs data offset */ uint32_t rootfs_len; /* 0x80: rootfs data length */ uint32_t boot_ofs; /* 0x84: FIXME: seems to be unused */ uint32_t boot_len; /* 0x88: FIXME: seems to be unused */ uint16_t unk4; /* 0x8c: 0x55aa */ uint8_t sver_hi; /* 0x8e */ uint8_t sver_lo; /* 0x8f */ uint8_t unk5; /* 0x90: magic: 0xa5 */ uint8_t ver_hi; /* 0x91 */ uint8_t ver_mid; /* 0x92 */ uint8_t ver_lo; /* 0x93 */ uint8_t pad[364]; } __attribute__ ((packed)); struct flash_layout { char *id; uint32_t fw_max_len; uint32_t kernel_la; uint32_t kernel_ep; uint32_t rootfs_ofs; }; struct board_info { char *id; uint32_t hw_id; uint32_t hw_rev; char *layout_id; uint32_t hdr_ver; bool endian_swap; }; /* * Globals */ static char *ofname; static char *progname; static char *vendor = "TP-LINK Technologies"; static char *version = "ver. 1.0"; static char *fw_ver = "0.0.0"; static char *sver = "1.0"; static uint32_t hdr_ver = 2; static char *board_id; static struct board_info *board; static char *layout_id; static struct flash_layout *layout; static char *opt_hw_id; static uint32_t hw_id; static char *opt_hw_rev; static uint32_t hw_rev; static int fw_ver_lo; static int fw_ver_mid; static int fw_ver_hi; static int sver_lo; static int sver_hi; static struct file_info kernel_info; static uint32_t kernel_la = 0; static uint32_t kernel_ep = 0; static uint32_t kernel_len = 0; static struct file_info rootfs_info; static uint32_t rootfs_ofs = 0; static uint32_t rootfs_align; static struct file_info boot_info; static int combined; static int strip_padding; static int add_jffs2_eof; static unsigned char jffs2_eof_mark[4] = {0xde, 0xad, 0xc0, 0xde}; static struct file_info inspect_info; static int extract = 0; static bool endian_swap = false; char md5salt_normal[MD5SUM_LEN] = { 0xdc, 0xd7, 0x3a, 0xa5, 0xc3, 0x95, 0x98, 0xfb, 0xdc, 0xf9, 0xe7, 0xf4, 0x0e, 0xae, 0x47, 0x37, }; char md5salt_boot[MD5SUM_LEN] = { 0x8c, 0xef, 0x33, 0x5b, 0xd5, 0xc5, 0xce, 0xfa, 0xa7, 0x9c, 0x28, 0xda, 0xb2, 0xe9, 0x0f, 0x42, }; static struct flash_layout layouts[] = { { .id = "8Mltq", .fw_max_len = 0x7a0000, .kernel_la = 0x80002000, .kernel_ep = 0x80002000, .rootfs_ofs = 0x140000, }, { .id = "16Mltq", .fw_max_len = 0xf90000, .kernel_la = 0x80002000, .kernel_ep = 0x800061b0, .rootfs_ofs = 0x140000, }, { .id = "8Mmtk", .fw_max_len = 0x7a0000, .kernel_la = 0x80000000, .kernel_ep = 0x80000000, .rootfs_ofs = 0x140000, }, { /* terminating entry */ } }; static struct board_info boards[] = { { .id = "TD-W8970v1", .hw_id = 0x89700001, .hw_rev = 1, .layout_id = "8Mltq", }, { .id = "TD-W8980v1", .hw_id = 0x89800001, .hw_rev = 14, .layout_id = "8Mltq", }, { .id = "ArcherC20i", .hw_id = 0xc2000001, .hw_rev = 58, .layout_id = "8Mmtk", .hdr_ver = 3, .endian_swap = true, }, { .id = "ArcherVR200V", .hw_id = 0x73b70801, .hw_rev = 0x2f, .layout_id = "16Mltq", .hdr_ver = 2, }, { .id = "ArcherC50", .hw_id = 0xc7500001, .hw_rev = 69, .layout_id = "8Mmtk", .hdr_ver = 3, .endian_swap = true, }, { /* terminating entry */ } }; /* * Message macros */ #define ERR(fmt, ...) do { \ fflush(0); \ fprintf(stderr, "[%s] *** error: " fmt "\n", \ progname, ## __VA_ARGS__ ); \ } while (0) #define ERRS(fmt, ...) do { \ int save = errno; \ fflush(0); \ fprintf(stderr, "[%s] *** error: " fmt ": %s\n", \ progname, ## __VA_ARGS__, strerror(save)); \ } while (0) #define DBG(fmt, ...) do { \ fprintf(stderr, "[%s] " fmt "\n", progname, ## __VA_ARGS__ ); \ } while (0) static struct board_info *find_board(char *id) { struct board_info *ret; struct board_info *board; ret = NULL; for (board = boards; board->id != NULL; board++){ if (strcasecmp(id, board->id) == 0) { ret = board; break; } }; return ret; } static struct board_info *find_board_by_hwid(uint32_t hw_id) { struct board_info *board; for (board = boards; board->id != NULL; board++) { if (hw_id == board->hw_id) return board; }; return NULL; } static struct flash_layout *find_layout(char *id) { struct flash_layout *ret; struct flash_layout *l; ret = NULL; for (l = layouts; l->id != NULL; l++){ if (strcasecmp(id, l->id) == 0) { ret = l; break; } }; return ret; } static void usage(int status) { FILE *stream = (status != EXIT_SUCCESS) ? stderr : stdout; struct board_info *board; fprintf(stream, "Usage: %s [OPTIONS...]\n", progname); fprintf(stream, "\n" "Options:\n" " -B create image for the board specified with \n" " -c use combined kernel image\n" " -E overwrite kernel entry point with (hexval prefixed with 0x)\n" " -L overwrite kernel load address with (hexval prefixed with 0x)\n" " -H use hardware id specified with \n" " -W use hardware revision specified with \n" " -F use flash layout specified with \n" " -k read kernel image from the file \n" " -r read rootfs image from the file \n" " -a align the rootfs start on an bytes boundary\n" " -R overwrite rootfs offset with (hexval prefixed with 0x)\n" " -o write output to the file \n" " -s strip padding from the end of the image\n" " -j add jffs2 end-of-filesystem markers\n" " -V set image version to \n" " -v set firmware version to \n" " -y set secondary version to \n" " -i inspect given firmware file \n" " -x extract kernel and rootfs while inspecting (requires -i)\n" " -h show this screen\n" ); exit(status); } static int get_md5(char *data, int size, char *md5) { MD5_CTX ctx; MD5_Init(&ctx); MD5_Update(&ctx, data, size); MD5_Final(md5, &ctx); } static int get_file_stat(struct file_info *fdata) { struct stat st; int res; if (fdata->file_name == NULL) return 0; res = stat(fdata->file_name, &st); if (res){ ERRS("stat failed on %s", fdata->file_name); return res; } fdata->file_size = st.st_size; return 0; } static int read_to_buf(struct file_info *fdata, char *buf) { FILE *f; int ret = EXIT_FAILURE; f = fopen(fdata->file_name, "r"); if (f == NULL) { ERRS("could not open \"%s\" for reading", fdata->file_name); goto out; } errno = 0; fread(buf, fdata->file_size, 1, f); if (errno != 0) { ERRS("unable to read from file \"%s\"", fdata->file_name); goto out_close; } ret = EXIT_SUCCESS; out_close: fclose(f); out: return ret; } static int check_options(void) { int ret; if (inspect_info.file_name) { ret = get_file_stat(&inspect_info); if (ret) return ret; return 0; } else if (extract) { ERR("no firmware for inspection specified"); return -1; } if (board_id == NULL && opt_hw_id == NULL) { ERR("either board or hardware id must be specified"); return -1; } if (board_id) { board = find_board(board_id); if (board == NULL) { ERR("unknown/unsupported board id \"%s\"", board_id); return -1; } if (layout_id == NULL) layout_id = board->layout_id; hw_id = board->hw_id; hw_rev = board->hw_rev; if (board->hdr_ver) hdr_ver = board->hdr_ver; endian_swap = board->endian_swap; } else { if (layout_id == NULL) { ERR("flash layout is not specified"); return -1; } hw_id = strtoul(opt_hw_id, NULL, 0); if (opt_hw_rev) hw_rev = strtoul(opt_hw_rev, NULL, 0); else hw_rev = 1; } layout = find_layout(layout_id); if (layout == NULL) { ERR("unknown flash layout \"%s\"", layout_id); return -1; } if (!kernel_la) kernel_la = layout->kernel_la; if (!kernel_ep) kernel_ep = layout->kernel_ep; if (!rootfs_ofs) rootfs_ofs = layout->rootfs_ofs; if (kernel_info.file_name == NULL) { ERR("no kernel image specified"); return -1; } ret = get_file_stat(&kernel_info); if (ret) return ret; kernel_len = kernel_info.file_size; if (combined) { if (kernel_info.file_size > layout->fw_max_len - sizeof(struct fw_header)) { ERR("kernel image is too big"); return -1; } } else { if (rootfs_info.file_name == NULL) { ERR("no rootfs image specified"); return -1; } ret = get_file_stat(&rootfs_info); if (ret) return ret; if (rootfs_align) { kernel_len += sizeof(struct fw_header); kernel_len = ALIGN(kernel_len, rootfs_align); kernel_len -= sizeof(struct fw_header); DBG("kernel length aligned to %u", kernel_len); if (kernel_len + rootfs_info.file_size > layout->fw_max_len - sizeof(struct fw_header)) { ERR("images are too big"); return -1; } } else { if (kernel_info.file_size > rootfs_ofs - sizeof(struct fw_header)) { ERR("kernel image is too big"); return -1; } if (rootfs_info.file_size > (layout->fw_max_len - rootfs_ofs)) { ERR("rootfs image is too big"); return -1; } } } if (ofname == NULL) { ERR("no output file specified"); return -1; } ret = sscanf(fw_ver, "%d.%d.%d", &fw_ver_hi, &fw_ver_mid, &fw_ver_lo); if (ret != 3) { ERR("invalid firmware version '%s'", fw_ver); return -1; } ret = sscanf(sver, "%d.%d", &sver_hi, &sver_lo); if (ret != 2) { ERR("invalid secondary version '%s'", sver); return -1; } return 0; } static void fill_header(char *buf, int len) { struct fw_header *hdr = (struct fw_header *)buf; unsigned ver_len; memset(hdr, '\xff', sizeof(struct fw_header)); hdr->version = htonl(bswap_32(hdr_ver)); ver_len = strlen(version); if (ver_len > (sizeof(hdr->fw_version) - 1)) ver_len = sizeof(hdr->fw_version) - 1; memcpy(hdr->fw_version, version, ver_len); hdr->fw_version[ver_len] = 0; hdr->hw_id = htonl(hw_id); hdr->hw_rev = htonl(hw_rev); if (boot_info.file_size == 0) { memcpy(hdr->md5sum1, md5salt_normal, sizeof(hdr->md5sum1)); hdr->boot_ofs = htonl(0); hdr->boot_len = htonl(0); } else { memcpy(hdr->md5sum1, md5salt_boot, sizeof(hdr->md5sum1)); hdr->boot_ofs = htonl(rootfs_ofs + rootfs_info.file_size); hdr->boot_len = htonl(rootfs_info.file_size); } hdr->kernel_la = htonl(kernel_la); hdr->kernel_ep = htonl(kernel_ep); hdr->fw_length = htonl(layout->fw_max_len); hdr->kernel_ofs = htonl(sizeof(struct fw_header)); hdr->kernel_len = htonl(kernel_len); if (!combined) { hdr->rootfs_ofs = htonl(rootfs_ofs); hdr->rootfs_len = htonl(rootfs_info.file_size); } hdr->boot_ofs = htonl(0); hdr->boot_len = htonl(boot_info.file_size); hdr->unk1 = htonl(0); hdr->unk2 = htonl(0); hdr->unk3 = htonl(0xffffffff); hdr->unk4 = htons(0x55aa); hdr->unk5 = 0xa5; hdr->sver_hi = sver_hi; hdr->sver_lo = sver_lo; hdr->ver_hi = fw_ver_hi; hdr->ver_mid = fw_ver_mid; hdr->ver_lo = fw_ver_lo; if (endian_swap) { hdr->kernel_la = bswap_32(hdr->kernel_la); hdr->kernel_ep = bswap_32(hdr->kernel_ep); } get_md5(buf, len, hdr->md5sum1); } static int pad_jffs2(char *buf, int currlen) { int len; uint32_t pad_mask; len = currlen; pad_mask = (64 * 1024); while ((len < layout->fw_max_len) && (pad_mask != 0)) { uint32_t mask; int i; for (i = 10; i < 32; i++) { mask = 1 << i; if (pad_mask & mask) break; } len = ALIGN(len, mask); for (i = 10; i < 32; i++) { mask = 1 << i; if ((len & (mask - 1)) == 0) pad_mask &= ~mask; } for (i = 0; i < sizeof(jffs2_eof_mark); i++) buf[len + i] = jffs2_eof_mark[i]; len += sizeof(jffs2_eof_mark); } return len; } static int write_fw(char *data, int len) { FILE *f; int ret = EXIT_FAILURE; f = fopen(ofname, "w"); if (f == NULL) { ERRS("could not open \"%s\" for writing", ofname); goto out; } errno = 0; fwrite(data, len, 1, f); if (errno) { ERRS("unable to write output file"); goto out_flush; } DBG("firmware file \"%s\" completed", ofname); ret = EXIT_SUCCESS; out_flush: fflush(f); fclose(f); if (ret != EXIT_SUCCESS) { unlink(ofname); } out: return ret; } static int build_fw(void) { int buflen; char *buf; char *p; int ret = EXIT_FAILURE; int writelen = 0; buflen = layout->fw_max_len; buf = malloc(buflen); if (!buf) { ERR("no memory for buffer\n"); goto out; } memset(buf, 0xff, buflen); p = buf + sizeof(struct fw_header); ret = read_to_buf(&kernel_info, p); if (ret) goto out_free_buf; writelen = sizeof(struct fw_header) + kernel_len; if (!combined) { if (rootfs_align) p = buf + writelen; else p = buf + rootfs_ofs; ret = read_to_buf(&rootfs_info, p); if (ret) goto out_free_buf; if (rootfs_align) writelen += rootfs_info.file_size; else writelen = rootfs_ofs + rootfs_info.file_size; if (add_jffs2_eof) writelen = pad_jffs2(buf, writelen); } if (!strip_padding) writelen = buflen; fill_header(buf, writelen); ret = write_fw(buf, writelen); if (ret) goto out_free_buf; ret = EXIT_SUCCESS; out_free_buf: free(buf); out: return ret; } /* Helper functions to inspect_fw() representing different output formats */ static inline void inspect_fw_pstr(char *label, char *str) { printf("%-23s: %s\n", label, str); } static inline void inspect_fw_phex(char *label, uint32_t val) { printf("%-23s: 0x%08x\n", label, val); } static inline void inspect_fw_phexpost(char *label, uint32_t val, char *post) { printf("%-23s: 0x%08x (%s)\n", label, val, post); } static inline void inspect_fw_phexdef(char *label, uint32_t val, uint32_t defval) { printf("%-23s: 0x%08x ", label, val); if (val == defval) printf("(== OpenWrt default)\n"); else printf("(OpenWrt default: 0x%08x)\n", defval); } static inline void inspect_fw_phexexp(char *label, uint32_t val, uint32_t expval) { printf("%-23s: 0x%08x ", label, val); if (val == expval) printf("(ok)\n"); else printf("(expected: 0x%08x)\n", expval); } static inline void inspect_fw_phexdec(char *label, uint32_t val) { printf("%-23s: 0x%08x / %8u bytes\n", label, val, val); } static inline void inspect_fw_phexdecdef(char *label, uint32_t val, uint32_t defval) { printf("%-23s: 0x%08x / %8u bytes ", label, val, val); if (val == defval) printf("(== OpenWrt default)\n"); else printf("(OpenWrt default: 0x%08x)\n", defval); } static inline void inspect_fw_pmd5sum(char *label, uint8_t *val, char *text) { int i; printf("%-23s:", label); for (i=0; iversion))) { case 2: case 3: break; default: ERR("file does not seem to have V2/V3 header!\n"); goto out_free_buf; } inspect_fw_phexdec("Version 2 Header size", sizeof(struct fw_header)); if (ntohl(hdr->unk1) != 0) inspect_fw_phexdec("Unknown value 1", hdr->unk1); memcpy(md5sum, hdr->md5sum1, sizeof(md5sum)); if (ntohl(hdr->boot_len) == 0) memcpy(hdr->md5sum1, md5salt_normal, sizeof(md5sum)); else memcpy(hdr->md5sum1, md5salt_boot, sizeof(md5sum)); get_md5(buf, inspect_info.file_size, hdr->md5sum1); if (memcmp(md5sum, hdr->md5sum1, sizeof(md5sum))) { inspect_fw_pmd5sum("Header MD5Sum1", md5sum, "(*ERROR*)"); inspect_fw_pmd5sum(" --> expected", hdr->md5sum1, ""); } else { inspect_fw_pmd5sum("Header MD5Sum1", md5sum, "(ok)"); } if (ntohl(hdr->unk2) != 0) inspect_fw_phexdec("Unknown value 2", hdr->unk2); inspect_fw_pmd5sum("Header MD5Sum2", hdr->md5sum2, "(purpose yet unknown, unchecked here)"); if (ntohl(hdr->unk3) != 0xffffffff) inspect_fw_phexdec("Unknown value 3", hdr->unk3); if (ntohs(hdr->unk4) != 0x55aa) inspect_fw_phexdec("Unknown value 4", hdr->unk4); if (hdr->unk5 != 0xa5) inspect_fw_phexdec("Unknown value 5", hdr->unk5); printf("\n"); inspect_fw_pstr("Firmware version", hdr->fw_version); board = find_board_by_hwid(ntohl(hdr->hw_id)); if (board) { layout = find_layout(board->layout_id); inspect_fw_phexpost("Hardware ID", ntohl(hdr->hw_id), board->id); inspect_fw_phexexp("Hardware Revision", ntohl(hdr->hw_rev), board->hw_rev); } else { inspect_fw_phexpost("Hardware ID", ntohl(hdr->hw_id), "unknown"); inspect_fw_phex("Hardware Revision", ntohl(hdr->hw_rev)); } printf("%-23s: %d.%d.%d-%d.%d\n", "Software version", hdr->ver_hi, hdr->ver_mid, hdr->ver_lo, hdr->sver_hi, hdr->sver_lo); printf("\n"); inspect_fw_phexdec("Kernel data offset", ntohl(hdr->kernel_ofs)); inspect_fw_phexdec("Kernel data length", ntohl(hdr->kernel_len)); if (board) { inspect_fw_phexdef("Kernel load address", ntohl(hdr->kernel_la), layout ? layout->kernel_la : 0xffffffff); inspect_fw_phexdef("Kernel entry point", ntohl(hdr->kernel_ep), layout ? layout->kernel_ep : 0xffffffff); inspect_fw_phexdecdef("Rootfs data offset", ntohl(hdr->rootfs_ofs), layout ? layout->rootfs_ofs : 0xffffffff); } else { inspect_fw_phex("Kernel load address", ntohl(hdr->kernel_la)); inspect_fw_phex("Kernel entry point", ntohl(hdr->kernel_ep)); inspect_fw_phexdec("Rootfs data offset", ntohl(hdr->rootfs_ofs)); } inspect_fw_phexdec("Rootfs data length", ntohl(hdr->rootfs_len)); inspect_fw_phexdec("Boot loader data offset", ntohl(hdr->boot_ofs)); inspect_fw_phexdec("Boot loader data length", ntohl(hdr->boot_len)); inspect_fw_phexdec("Total firmware length", ntohl(hdr->fw_length)); if (extract) { FILE *fp; char *filename; printf("\n"); filename = malloc(strlen(inspect_info.file_name) + 8); sprintf(filename, "%s-kernel", inspect_info.file_name); printf("Extracting kernel to \"%s\"...\n", filename); fp = fopen(filename, "w"); if (fp) { if (!fwrite(buf + ntohl(hdr->kernel_ofs), ntohl(hdr->kernel_len), 1, fp)) { ERR("error in fwrite(): %s", strerror(errno)); } fclose(fp); } else { ERR("error in fopen(): %s", strerror(errno)); } free(filename); filename = malloc(strlen(inspect_info.file_name) + 8); sprintf(filename, "%s-rootfs", inspect_info.file_name); printf("Extracting rootfs to \"%s\"...\n", filename); fp = fopen(filename, "w"); if (fp) { if (!fwrite(buf + ntohl(hdr->rootfs_ofs), ntohl(hdr->rootfs_len), 1, fp)) { ERR("error in fwrite(): %s", strerror(errno)); } fclose(fp); } else { ERR("error in fopen(): %s", strerror(errno)); } free(filename); } out_free_buf: free(buf); out: return ret; } int main(int argc, char *argv[]) { int ret = EXIT_FAILURE; int err; FILE *outfile; progname = basename(argv[0]); while ( 1 ) { int c; c = getopt(argc, argv, "a:B:H:E:F:L:V:N:W:ci:k:r:R:o:xhsjv:y:T:e"); if (c == -1) break; switch (c) { case 'a': sscanf(optarg, "0x%x", &rootfs_align); break; case 'B': board_id = optarg; break; case 'H': opt_hw_id = optarg; break; case 'E': sscanf(optarg, "0x%x", &kernel_ep); break; case 'F': layout_id = optarg; break; case 'W': opt_hw_rev = optarg; break; case 'L': sscanf(optarg, "0x%x", &kernel_la); break; case 'V': version = optarg; break; case 'v': fw_ver = optarg; break; case 'y': sver = optarg; break; case 'N': vendor = optarg; break; case 'c': combined++; break; case 'k': kernel_info.file_name = optarg; break; case 'r': rootfs_info.file_name = optarg; break; case 'R': sscanf(optarg, "0x%x", &rootfs_ofs); break; case 'o': ofname = optarg; break; case 's': strip_padding = 1; break; case 'i': inspect_info.file_name = optarg; break; case 'j': add_jffs2_eof = 1; break; case 'x': extract = 1; break; case 'T': hdr_ver = atoi(optarg); break; case 'e': endian_swap = true; break; case 'h': usage(EXIT_SUCCESS); break; default: usage(EXIT_FAILURE); break; } } ret = check_options(); if (ret) goto out; if (!inspect_info.file_name) ret = build_fw(); else ret = inspect_fw(); out: return ret; }