1 /* 2 * Copyright (C) 2008 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #include <errno.h> 18 #include <libgen.h> 19 #include <stdio.h> 20 #include <stdlib.h> 21 #include <string.h> 22 #include <sys/stat.h> 23 #include <sys/statfs.h> 24 #include <sys/types.h> 25 #include <fcntl.h> 26 #include <unistd.h> 27 28 #include "mincrypt/sha.h" 29 #include "applypatch.h" 30 #include "mtdutils/mtdutils.h" 31 #include "edify/expr.h" 32 33 int SaveFileContents(const char* filename, FileContents file); 34 int LoadMTDContents(const char* filename, FileContents* file); 35 int ParseSha1(const char* str, uint8_t* digest); 36 ssize_t FileSink(unsigned char* data, ssize_t len, void* token); 37 38 static int mtd_partitions_scanned = 0; 39 40 // Read a file into memory; store it and its associated metadata in 41 // *file. Return 0 on success. 42 int LoadFileContents(const char* filename, FileContents* file) { 43 file->data = NULL; 44 45 // A special 'filename' beginning with "MTD:" means to load the 46 // contents of an MTD partition. 47 if (strncmp(filename, "MTD:", 4) == 0) { 48 return LoadMTDContents(filename, file); 49 } 50 51 if (stat(filename, &file->st) != 0) { 52 printf("failed to stat \"%s\": %s\n", filename, strerror(errno)); 53 return -1; 54 } 55 56 file->size = file->st.st_size; 57 file->data = malloc(file->size); 58 59 FILE* f = fopen(filename, "rb"); 60 if (f == NULL) { 61 printf("failed to open \"%s\": %s\n", filename, strerror(errno)); 62 free(file->data); 63 file->data = NULL; 64 return -1; 65 } 66 67 ssize_t bytes_read = fread(file->data, 1, file->size, f); 68 if (bytes_read != file->size) { 69 printf("short read of \"%s\" (%ld bytes of %ld)\n", 70 filename, (long)bytes_read, (long)file->size); 71 free(file->data); 72 file->data = NULL; 73 return -1; 74 } 75 fclose(f); 76 77 SHA(file->data, file->size, file->sha1); 78 return 0; 79 } 80 81 static size_t* size_array; 82 // comparison function for qsort()ing an int array of indexes into 83 // size_array[]. 84 static int compare_size_indices(const void* a, const void* b) { 85 int aa = *(int*)a; 86 int bb = *(int*)b; 87 if (size_array[aa] < size_array[bb]) { 88 return -1; 89 } else if (size_array[aa] > size_array[bb]) { 90 return 1; 91 } else { 92 return 0; 93 } 94 } 95 96 void FreeFileContents(FileContents* file) { 97 if (file) free(file->data); 98 free(file); 99 } 100 101 // Load the contents of an MTD partition into the provided 102 // FileContents. filename should be a string of the form 103 // "MTD:<partition_name>:<size_1>:<sha1_1>:<size_2>:<sha1_2>:...". 104 // The smallest size_n bytes for which that prefix of the mtd contents 105 // has the corresponding sha1 hash will be loaded. It is acceptable 106 // for a size value to be repeated with different sha1s. Will return 107 // 0 on success. 108 // 109 // This complexity is needed because if an OTA installation is 110 // interrupted, the partition might contain either the source or the 111 // target data, which might be of different lengths. We need to know 112 // the length in order to read from MTD (there is no "end-of-file" 113 // marker), so the caller must specify the possible lengths and the 114 // hash of the data, and we'll do the load expecting to find one of 115 // those hashes. 116 int LoadMTDContents(const char* filename, FileContents* file) { 117 char* copy = strdup(filename); 118 const char* magic = strtok(copy, ":"); 119 if (strcmp(magic, "MTD") != 0) { 120 printf("LoadMTDContents called with bad filename (%s)\n", 121 filename); 122 return -1; 123 } 124 const char* partition = strtok(NULL, ":"); 125 126 int i; 127 int colons = 0; 128 for (i = 0; filename[i] != '\0'; ++i) { 129 if (filename[i] == ':') { 130 ++colons; 131 } 132 } 133 if (colons < 3 || colons%2 == 0) { 134 printf("LoadMTDContents called with bad filename (%s)\n", 135 filename); 136 } 137 138 int pairs = (colons-1)/2; // # of (size,sha1) pairs in filename 139 int* index = malloc(pairs * sizeof(int)); 140 size_t* size = malloc(pairs * sizeof(size_t)); 141 char** sha1sum = malloc(pairs * sizeof(char*)); 142 143 for (i = 0; i < pairs; ++i) { 144 const char* size_str = strtok(NULL, ":"); 145 size[i] = strtol(size_str, NULL, 10); 146 if (size[i] == 0) { 147 printf("LoadMTDContents called with bad size (%s)\n", filename); 148 return -1; 149 } 150 sha1sum[i] = strtok(NULL, ":"); 151 index[i] = i; 152 } 153 154 // sort the index[] array so it indexes the pairs in order of 155 // increasing size. 156 size_array = size; 157 qsort(index, pairs, sizeof(int), compare_size_indices); 158 159 if (!mtd_partitions_scanned) { 160 mtd_scan_partitions(); 161 mtd_partitions_scanned = 1; 162 } 163 164 const MtdPartition* mtd = mtd_find_partition_by_name(partition); 165 if (mtd == NULL) { 166 printf("mtd partition \"%s\" not found (loading %s)\n", 167 partition, filename); 168 return -1; 169 } 170 171 MtdReadContext* ctx = mtd_read_partition(mtd); 172 if (ctx == NULL) { 173 printf("failed to initialize read of mtd partition \"%s\"\n", 174 partition); 175 return -1; 176 } 177 178 SHA_CTX sha_ctx; 179 SHA_init(&sha_ctx); 180 uint8_t parsed_sha[SHA_DIGEST_SIZE]; 181 182 // allocate enough memory to hold the largest size. 183 file->data = malloc(size[index[pairs-1]]); 184 char* p = (char*)file->data; 185 file->size = 0; // # bytes read so far 186 187 for (i = 0; i < pairs; ++i) { 188 // Read enough additional bytes to get us up to the next size 189 // (again, we're trying the possibilities in order of increasing 190 // size). 191 size_t next = size[index[i]] - file->size; 192 size_t read = 0; 193 if (next > 0) { 194 read = mtd_read_data(ctx, p, next); 195 if (next != read) { 196 printf("short read (%d bytes of %d) for partition \"%s\"\n", 197 read, next, partition); 198 free(file->data); 199 file->data = NULL; 200 return -1; 201 } 202 SHA_update(&sha_ctx, p, read); 203 file->size += read; 204 } 205 206 // Duplicate the SHA context and finalize the duplicate so we can 207 // check it against this pair's expected hash. 208 SHA_CTX temp_ctx; 209 memcpy(&temp_ctx, &sha_ctx, sizeof(SHA_CTX)); 210 const uint8_t* sha_so_far = SHA_final(&temp_ctx); 211 212 if (ParseSha1(sha1sum[index[i]], parsed_sha) != 0) { 213 printf("failed to parse sha1 %s in %s\n", 214 sha1sum[index[i]], filename); 215 free(file->data); 216 file->data = NULL; 217 return -1; 218 } 219 220 if (memcmp(sha_so_far, parsed_sha, SHA_DIGEST_SIZE) == 0) { 221 // we have a match. stop reading the partition; we'll return 222 // the data we've read so far. 223 printf("mtd read matched size %d sha %s\n", 224 size[index[i]], sha1sum[index[i]]); 225 break; 226 } 227 228 p += read; 229 } 230 231 mtd_read_close(ctx); 232 233 if (i == pairs) { 234 // Ran off the end of the list of (size,sha1) pairs without 235 // finding a match. 236 printf("contents of MTD partition \"%s\" didn't match %s\n", 237 partition, filename); 238 free(file->data); 239 file->data = NULL; 240 return -1; 241 } 242 243 const uint8_t* sha_final = SHA_final(&sha_ctx); 244 for (i = 0; i < SHA_DIGEST_SIZE; ++i) { 245 file->sha1[i] = sha_final[i]; 246 } 247 248 // Fake some stat() info. 249 file->st.st_mode = 0644; 250 file->st.st_uid = 0; 251 file->st.st_gid = 0; 252 253 free(copy); 254 free(index); 255 free(size); 256 free(sha1sum); 257 258 return 0; 259 } 260 261 262 // Save the contents of the given FileContents object under the given 263 // filename. Return 0 on success. 264 int SaveFileContents(const char* filename, FileContents file) { 265 int fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC); 266 if (fd < 0) { 267 printf("failed to open \"%s\" for write: %s\n", 268 filename, strerror(errno)); 269 return -1; 270 } 271 272 ssize_t bytes_written = FileSink(file.data, file.size, &fd); 273 if (bytes_written != file.size) { 274 printf("short write of \"%s\" (%ld bytes of %ld) (%s)\n", 275 filename, (long)bytes_written, (long)file.size, 276 strerror(errno)); 277 close(fd); 278 return -1; 279 } 280 fsync(fd); 281 close(fd); 282 283 if (chmod(filename, file.st.st_mode) != 0) { 284 printf("chmod of \"%s\" failed: %s\n", filename, strerror(errno)); 285 return -1; 286 } 287 if (chown(filename, file.st.st_uid, file.st.st_gid) != 0) { 288 printf("chown of \"%s\" failed: %s\n", filename, strerror(errno)); 289 return -1; 290 } 291 292 return 0; 293 } 294 295 // Write a memory buffer to target_mtd partition, a string of the form 296 // "MTD:<partition>[:...]". Return 0 on success. 297 int WriteToMTDPartition(unsigned char* data, size_t len, 298 const char* target_mtd) { 299 char* partition = strchr(target_mtd, ':'); 300 if (partition == NULL) { 301 printf("bad MTD target name \"%s\"\n", target_mtd); 302 return -1; 303 } 304 ++partition; 305 // Trim off anything after a colon, eg "MTD:boot:blah:blah:blah...". 306 // We want just the partition name "boot". 307 partition = strdup(partition); 308 char* end = strchr(partition, ':'); 309 if (end != NULL) 310 *end = '\0'; 311 312 if (!mtd_partitions_scanned) { 313 mtd_scan_partitions(); 314 mtd_partitions_scanned = 1; 315 } 316 317 const MtdPartition* mtd = mtd_find_partition_by_name(partition); 318 if (mtd == NULL) { 319 printf("mtd partition \"%s\" not found for writing\n", partition); 320 return -1; 321 } 322 323 MtdWriteContext* ctx = mtd_write_partition(mtd); 324 if (ctx == NULL) { 325 printf("failed to init mtd partition \"%s\" for writing\n", 326 partition); 327 return -1; 328 } 329 330 size_t written = mtd_write_data(ctx, (char*)data, len); 331 if (written != len) { 332 printf("only wrote %d of %d bytes to MTD %s\n", 333 written, len, partition); 334 mtd_write_close(ctx); 335 return -1; 336 } 337 338 if (mtd_erase_blocks(ctx, -1) < 0) { 339 printf("error finishing mtd write of %s\n", partition); 340 mtd_write_close(ctx); 341 return -1; 342 } 343 344 if (mtd_write_close(ctx)) { 345 printf("error closing mtd write of %s\n", partition); 346 return -1; 347 } 348 349 free(partition); 350 return 0; 351 } 352 353 354 // Take a string 'str' of 40 hex digits and parse it into the 20 355 // byte array 'digest'. 'str' may contain only the digest or be of 356 // the form "<digest>:<anything>". Return 0 on success, -1 on any 357 // error. 358 int ParseSha1(const char* str, uint8_t* digest) { 359 int i; 360 const char* ps = str; 361 uint8_t* pd = digest; 362 for (i = 0; i < SHA_DIGEST_SIZE * 2; ++i, ++ps) { 363 int digit; 364 if (*ps >= '0' && *ps <= '9') { 365 digit = *ps - '0'; 366 } else if (*ps >= 'a' && *ps <= 'f') { 367 digit = *ps - 'a' + 10; 368 } else if (*ps >= 'A' && *ps <= 'F') { 369 digit = *ps - 'A' + 10; 370 } else { 371 return -1; 372 } 373 if (i % 2 == 0) { 374 *pd = digit << 4; 375 } else { 376 *pd |= digit; 377 ++pd; 378 } 379 } 380 if (*ps != '\0') return -1; 381 return 0; 382 } 383 384 // Search an array of sha1 strings for one matching the given sha1. 385 // Return the index of the match on success, or -1 if no match is 386 // found. 387 int FindMatchingPatch(uint8_t* sha1, char** const patch_sha1_str, 388 int num_patches) { 389 int i; 390 uint8_t patch_sha1[SHA_DIGEST_SIZE]; 391 for (i = 0; i < num_patches; ++i) { 392 if (ParseSha1(patch_sha1_str[i], patch_sha1) == 0 && 393 memcmp(patch_sha1, sha1, SHA_DIGEST_SIZE) == 0) { 394 return i; 395 } 396 } 397 return -1; 398 } 399 400 // Returns 0 if the contents of the file (argv[2]) or the cached file 401 // match any of the sha1's on the command line (argv[3:]). Returns 402 // nonzero otherwise. 403 int applypatch_check(const char* filename, 404 int num_patches, char** const patch_sha1_str) { 405 FileContents file; 406 file.data = NULL; 407 408 // It's okay to specify no sha1s; the check will pass if the 409 // LoadFileContents is successful. (Useful for reading MTD 410 // partitions, where the filename encodes the sha1s; no need to 411 // check them twice.) 412 if (LoadFileContents(filename, &file) != 0 || 413 (num_patches > 0 && 414 FindMatchingPatch(file.sha1, patch_sha1_str, num_patches) < 0)) { 415 printf("file \"%s\" doesn't have any of expected " 416 "sha1 sums; checking cache\n", filename); 417 418 free(file.data); 419 420 // If the source file is missing or corrupted, it might be because 421 // we were killed in the middle of patching it. A copy of it 422 // should have been made in CACHE_TEMP_SOURCE. If that file 423 // exists and matches the sha1 we're looking for, the check still 424 // passes. 425 426 if (LoadFileContents(CACHE_TEMP_SOURCE, &file) != 0) { 427 printf("failed to load cache file\n"); 428 return 1; 429 } 430 431 if (FindMatchingPatch(file.sha1, patch_sha1_str, num_patches) < 0) { 432 printf("cache bits don't match any sha1 for \"%s\"\n", filename); 433 free(file.data); 434 return 1; 435 } 436 } 437 438 free(file.data); 439 return 0; 440 } 441 442 int ShowLicenses() { 443 ShowBSDiffLicense(); 444 return 0; 445 } 446 447 ssize_t FileSink(unsigned char* data, ssize_t len, void* token) { 448 int fd = *(int *)token; 449 ssize_t done = 0; 450 ssize_t wrote; 451 while (done < (ssize_t) len) { 452 wrote = write(fd, data+done, len-done); 453 if (wrote <= 0) { 454 printf("error writing %d bytes: %s\n", (int)(len-done), strerror(errno)); 455 return done; 456 } 457 done += wrote; 458 } 459 return done; 460 } 461 462 typedef struct { 463 unsigned char* buffer; 464 ssize_t size; 465 ssize_t pos; 466 } MemorySinkInfo; 467 468 ssize_t MemorySink(unsigned char* data, ssize_t len, void* token) { 469 MemorySinkInfo* msi = (MemorySinkInfo*)token; 470 if (msi->size - msi->pos < len) { 471 return -1; 472 } 473 memcpy(msi->buffer + msi->pos, data, len); 474 msi->pos += len; 475 return len; 476 } 477 478 // Return the amount of free space (in bytes) on the filesystem 479 // containing filename. filename must exist. Return -1 on error. 480 size_t FreeSpaceForFile(const char* filename) { 481 struct statfs sf; 482 if (statfs(filename, &sf) != 0) { 483 printf("failed to statfs %s: %s\n", filename, strerror(errno)); 484 return -1; 485 } 486 return sf.f_bsize * sf.f_bfree; 487 } 488 489 int CacheSizeCheck(size_t bytes) { 490 if (MakeFreeSpaceOnCache(bytes) < 0) { 491 printf("unable to make %ld bytes available on /cache\n", (long)bytes); 492 return 1; 493 } else { 494 return 0; 495 } 496 } 497 498 499 // This function applies binary patches to files in a way that is safe 500 // (the original file is not touched until we have the desired 501 // replacement for it) and idempotent (it's okay to run this program 502 // multiple times). 503 // 504 // - if the sha1 hash of <target_filename> is <target_sha1_string>, 505 // does nothing and exits successfully. 506 // 507 // - otherwise, if the sha1 hash of <source_filename> is one of the 508 // entries in <patch_sha1_str>, the corresponding patch from 509 // <patch_data> (which must be a VAL_BLOB) is applied to produce a 510 // new file (the type of patch is automatically detected from the 511 // blob daat). If that new file has sha1 hash <target_sha1_str>, 512 // moves it to replace <target_filename>, and exits successfully. 513 // Note that if <source_filename> and <target_filename> are not the 514 // same, <source_filename> is NOT deleted on success. 515 // <target_filename> may be the string "-" to mean "the same as 516 // source_filename". 517 // 518 // - otherwise, or if any error is encountered, exits with non-zero 519 // status. 520 // 521 // <source_filename> may refer to an MTD partition to read the source 522 // data. See the comments for the LoadMTDContents() function above 523 // for the format of such a filename. 524 525 int applypatch(const char* source_filename, 526 const char* target_filename, 527 const char* target_sha1_str, 528 size_t target_size, 529 int num_patches, 530 char** const patch_sha1_str, 531 Value** patch_data) { 532 printf("\napplying patch to %s\n", source_filename); 533 534 if (target_filename[0] == '-' && 535 target_filename[1] == '\0') { 536 target_filename = source_filename; 537 } 538 539 uint8_t target_sha1[SHA_DIGEST_SIZE]; 540 if (ParseSha1(target_sha1_str, target_sha1) != 0) { 541 printf("failed to parse tgt-sha1 \"%s\"\n", target_sha1_str); 542 return 1; 543 } 544 545 FileContents copy_file; 546 FileContents source_file; 547 const Value* source_patch_value = NULL; 548 const Value* copy_patch_value = NULL; 549 int made_copy = 0; 550 551 // We try to load the target file into the source_file object. 552 if (LoadFileContents(target_filename, &source_file) == 0) { 553 if (memcmp(source_file.sha1, target_sha1, SHA_DIGEST_SIZE) == 0) { 554 // The early-exit case: the patch was already applied, this file 555 // has the desired hash, nothing for us to do. 556 printf("\"%s\" is already target; no patch needed\n", 557 target_filename); 558 return 0; 559 } 560 } 561 562 if (source_file.data == NULL || 563 (target_filename != source_filename && 564 strcmp(target_filename, source_filename) != 0)) { 565 // Need to load the source file: either we failed to load the 566 // target file, or we did but it's different from the source file. 567 free(source_file.data); 568 LoadFileContents(source_filename, &source_file); 569 } 570 571 if (source_file.data != NULL) { 572 int to_use = FindMatchingPatch(source_file.sha1, 573 patch_sha1_str, num_patches); 574 if (to_use >= 0) { 575 source_patch_value = patch_data[to_use]; 576 } 577 } 578 579 if (source_patch_value == NULL) { 580 free(source_file.data); 581 printf("source file is bad; trying copy\n"); 582 583 if (LoadFileContents(CACHE_TEMP_SOURCE, ©_file) < 0) { 584 // fail. 585 printf("failed to read copy file\n"); 586 return 1; 587 } 588 589 int to_use = FindMatchingPatch(copy_file.sha1, 590 patch_sha1_str, num_patches); 591 if (to_use > 0) { 592 copy_patch_value = patch_data[to_use]; 593 } 594 595 if (copy_patch_value == NULL) { 596 // fail. 597 printf("copy file doesn't match source SHA-1s either\n"); 598 return 1; 599 } 600 } 601 602 int retry = 1; 603 SHA_CTX ctx; 604 int output; 605 MemorySinkInfo msi; 606 FileContents* source_to_use; 607 char* outname; 608 609 // assume that target_filename (eg "/system/app/Foo.apk") is located 610 // on the same filesystem as its top-level directory ("/system"). 611 // We need something that exists for calling statfs(). 612 char target_fs[strlen(target_filename)+1]; 613 char* slash = strchr(target_filename+1, '/'); 614 if (slash != NULL) { 615 int count = slash - target_filename; 616 strncpy(target_fs, target_filename, count); 617 target_fs[count] = '\0'; 618 } else { 619 strcpy(target_fs, target_filename); 620 } 621 622 do { 623 // Is there enough room in the target filesystem to hold the patched 624 // file? 625 626 if (strncmp(target_filename, "MTD:", 4) == 0) { 627 // If the target is an MTD partition, we're actually going to 628 // write the output to /tmp and then copy it to the partition. 629 // statfs() always returns 0 blocks free for /tmp, so instead 630 // we'll just assume that /tmp has enough space to hold the file. 631 632 // We still write the original source to cache, in case the MTD 633 // write is interrupted. 634 if (MakeFreeSpaceOnCache(source_file.size) < 0) { 635 printf("not enough free space on /cache\n"); 636 return 1; 637 } 638 if (SaveFileContents(CACHE_TEMP_SOURCE, source_file) < 0) { 639 printf("failed to back up source file\n"); 640 return 1; 641 } 642 made_copy = 1; 643 retry = 0; 644 } else { 645 int enough_space = 0; 646 if (retry > 0) { 647 size_t free_space = FreeSpaceForFile(target_fs); 648 int enough_space = 649 (free_space > (target_size * 3 / 2)); // 50% margin of error 650 printf("target %ld bytes; free space %ld bytes; retry %d; enough %d\n", 651 (long)target_size, (long)free_space, retry, enough_space); 652 } 653 654 if (!enough_space) { 655 retry = 0; 656 } 657 658 if (!enough_space && source_patch_value != NULL) { 659 // Using the original source, but not enough free space. First 660 // copy the source file to cache, then delete it from the original 661 // location. 662 663 if (strncmp(source_filename, "MTD:", 4) == 0) { 664 // It's impossible to free space on the target filesystem by 665 // deleting the source if the source is an MTD partition. If 666 // we're ever in a state where we need to do this, fail. 667 printf("not enough free space for target but source is MTD\n"); 668 return 1; 669 } 670 671 if (MakeFreeSpaceOnCache(source_file.size) < 0) { 672 printf("not enough free space on /cache\n"); 673 return 1; 674 } 675 676 if (SaveFileContents(CACHE_TEMP_SOURCE, source_file) < 0) { 677 printf("failed to back up source file\n"); 678 return 1; 679 } 680 made_copy = 1; 681 unlink(source_filename); 682 683 size_t free_space = FreeSpaceForFile(target_fs); 684 printf("(now %ld bytes free for target)\n", (long)free_space); 685 } 686 } 687 688 const Value* patch; 689 if (source_patch_value != NULL) { 690 source_to_use = &source_file; 691 patch = source_patch_value; 692 } else { 693 source_to_use = ©_file; 694 patch = copy_patch_value; 695 } 696 697 if (patch->type != VAL_BLOB) { 698 printf("patch is not a blob\n"); 699 return 1; 700 } 701 702 SinkFn sink = NULL; 703 void* token = NULL; 704 output = -1; 705 outname = NULL; 706 if (strncmp(target_filename, "MTD:", 4) == 0) { 707 // We store the decoded output in memory. 708 msi.buffer = malloc(target_size); 709 if (msi.buffer == NULL) { 710 printf("failed to alloc %ld bytes for output\n", 711 (long)target_size); 712 return 1; 713 } 714 msi.pos = 0; 715 msi.size = target_size; 716 sink = MemorySink; 717 token = &msi; 718 } else { 719 // We write the decoded output to "<tgt-file>.patch". 720 outname = (char*)malloc(strlen(target_filename) + 10); 721 strcpy(outname, target_filename); 722 strcat(outname, ".patch"); 723 724 output = open(outname, O_WRONLY | O_CREAT | O_TRUNC); 725 if (output < 0) { 726 printf("failed to open output file %s: %s\n", 727 outname, strerror(errno)); 728 return 1; 729 } 730 sink = FileSink; 731 token = &output; 732 } 733 734 char* header = patch->data; 735 ssize_t header_bytes_read = patch->size; 736 737 SHA_init(&ctx); 738 739 int result; 740 741 if (header_bytes_read >= 8 && 742 memcmp(header, "BSDIFF40", 8) == 0) { 743 result = ApplyBSDiffPatch(source_to_use->data, source_to_use->size, 744 patch, 0, sink, token, &ctx); 745 } else if (header_bytes_read >= 8 && 746 memcmp(header, "IMGDIFF2", 8) == 0) { 747 result = ApplyImagePatch(source_to_use->data, source_to_use->size, 748 patch, sink, token, &ctx); 749 } else { 750 printf("Unknown patch file format\n"); 751 return 1; 752 } 753 754 if (output >= 0) { 755 fsync(output); 756 close(output); 757 } 758 759 if (result != 0) { 760 if (retry == 0) { 761 printf("applying patch failed\n"); 762 return result != 0; 763 } else { 764 printf("applying patch failed; retrying\n"); 765 } 766 if (outname != NULL) { 767 unlink(outname); 768 } 769 } else { 770 // succeeded; no need to retry 771 break; 772 } 773 } while (retry-- > 0); 774 775 const uint8_t* current_target_sha1 = SHA_final(&ctx); 776 if (memcmp(current_target_sha1, target_sha1, SHA_DIGEST_SIZE) != 0) { 777 printf("patch did not produce expected sha1\n"); 778 return 1; 779 } 780 781 if (output < 0) { 782 // Copy the temp file to the MTD partition. 783 if (WriteToMTDPartition(msi.buffer, msi.pos, target_filename) != 0) { 784 printf("write of patched data to %s failed\n", target_filename); 785 return 1; 786 } 787 free(msi.buffer); 788 } else { 789 // Give the .patch file the same owner, group, and mode of the 790 // original source file. 791 if (chmod(outname, source_to_use->st.st_mode) != 0) { 792 printf("chmod of \"%s\" failed: %s\n", outname, strerror(errno)); 793 return 1; 794 } 795 if (chown(outname, source_to_use->st.st_uid, 796 source_to_use->st.st_gid) != 0) { 797 printf("chown of \"%s\" failed: %s\n", outname, strerror(errno)); 798 return 1; 799 } 800 801 // Finally, rename the .patch file to replace the target file. 802 if (rename(outname, target_filename) != 0) { 803 printf("rename of .patch to \"%s\" failed: %s\n", 804 target_filename, strerror(errno)); 805 return 1; 806 } 807 } 808 809 // If this run of applypatch created the copy, and we're here, we 810 // can delete it. 811 if (made_copy) unlink(CACHE_TEMP_SOURCE); 812 813 // Success! 814 return 0; 815 } 816