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 static int SaveFileContents(const char* filename, FileContents file); 34 static int LoadPartitionContents(const char* filename, FileContents* file); 35 int ParseSha1(const char* str, uint8_t* digest); 36 static 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:" or "EMMC:" means to 46 // load the contents of a partition. 47 if (strncmp(filename, "MTD:", 4) == 0 || 48 strncmp(filename, "EMMC:", 5) == 0) { 49 return LoadPartitionContents(filename, file); 50 } 51 52 if (stat(filename, &file->st) != 0) { 53 printf("failed to stat \"%s\": %s\n", filename, strerror(errno)); 54 return -1; 55 } 56 57 file->size = file->st.st_size; 58 file->data = malloc(file->size); 59 60 FILE* f = fopen(filename, "rb"); 61 if (f == NULL) { 62 printf("failed to open \"%s\": %s\n", filename, strerror(errno)); 63 free(file->data); 64 file->data = NULL; 65 return -1; 66 } 67 68 ssize_t bytes_read = fread(file->data, 1, file->size, f); 69 if (bytes_read != file->size) { 70 printf("short read of \"%s\" (%ld bytes of %ld)\n", 71 filename, (long)bytes_read, (long)file->size); 72 free(file->data); 73 file->data = NULL; 74 return -1; 75 } 76 fclose(f); 77 78 SHA(file->data, file->size, file->sha1); 79 return 0; 80 } 81 82 static size_t* size_array; 83 // comparison function for qsort()ing an int array of indexes into 84 // size_array[]. 85 static int compare_size_indices(const void* a, const void* b) { 86 int aa = *(int*)a; 87 int bb = *(int*)b; 88 if (size_array[aa] < size_array[bb]) { 89 return -1; 90 } else if (size_array[aa] > size_array[bb]) { 91 return 1; 92 } else { 93 return 0; 94 } 95 } 96 97 void FreeFileContents(FileContents* file) { 98 if (file) free(file->data); 99 free(file); 100 } 101 102 // Load the contents of an MTD or EMMC partition into the provided 103 // FileContents. filename should be a string of the form 104 // "MTD:<partition_name>:<size_1>:<sha1_1>:<size_2>:<sha1_2>:..." (or 105 // "EMMC:<partition_device>:..."). The smallest size_n bytes for 106 // which that prefix of the partition contents has the corresponding 107 // sha1 hash will be loaded. It is acceptable for a size value to be 108 // repeated with different sha1s. Will return 0 on success. 109 // 110 // This complexity is needed because if an OTA installation is 111 // interrupted, the partition might contain either the source or the 112 // target data, which might be of different lengths. We need to know 113 // the length in order to read from a partition (there is no 114 // "end-of-file" marker), so the caller must specify the possible 115 // lengths and the hash of the data, and we'll do the load expecting 116 // to find one of those hashes. 117 enum PartitionType { MTD, EMMC }; 118 119 static int LoadPartitionContents(const char* filename, FileContents* file) { 120 char* copy = strdup(filename); 121 const char* magic = strtok(copy, ":"); 122 123 enum PartitionType type; 124 125 if (strcmp(magic, "MTD") == 0) { 126 type = MTD; 127 } else if (strcmp(magic, "EMMC") == 0) { 128 type = EMMC; 129 } else { 130 printf("LoadPartitionContents called with bad filename (%s)\n", 131 filename); 132 return -1; 133 } 134 const char* partition = strtok(NULL, ":"); 135 136 int i; 137 int colons = 0; 138 for (i = 0; filename[i] != '\0'; ++i) { 139 if (filename[i] == ':') { 140 ++colons; 141 } 142 } 143 if (colons < 3 || colons%2 == 0) { 144 printf("LoadPartitionContents called with bad filename (%s)\n", 145 filename); 146 } 147 148 int pairs = (colons-1)/2; // # of (size,sha1) pairs in filename 149 int* index = malloc(pairs * sizeof(int)); 150 size_t* size = malloc(pairs * sizeof(size_t)); 151 char** sha1sum = malloc(pairs * sizeof(char*)); 152 153 for (i = 0; i < pairs; ++i) { 154 const char* size_str = strtok(NULL, ":"); 155 size[i] = strtol(size_str, NULL, 10); 156 if (size[i] == 0) { 157 printf("LoadPartitionContents called with bad size (%s)\n", filename); 158 return -1; 159 } 160 sha1sum[i] = strtok(NULL, ":"); 161 index[i] = i; 162 } 163 164 // sort the index[] array so it indexes the pairs in order of 165 // increasing size. 166 size_array = size; 167 qsort(index, pairs, sizeof(int), compare_size_indices); 168 169 MtdReadContext* ctx = NULL; 170 FILE* dev = NULL; 171 172 switch (type) { 173 case MTD: 174 if (!mtd_partitions_scanned) { 175 mtd_scan_partitions(); 176 mtd_partitions_scanned = 1; 177 } 178 179 const MtdPartition* mtd = mtd_find_partition_by_name(partition); 180 if (mtd == NULL) { 181 printf("mtd partition \"%s\" not found (loading %s)\n", 182 partition, filename); 183 return -1; 184 } 185 186 ctx = mtd_read_partition(mtd); 187 if (ctx == NULL) { 188 printf("failed to initialize read of mtd partition \"%s\"\n", 189 partition); 190 return -1; 191 } 192 break; 193 194 case EMMC: 195 dev = fopen(partition, "rb"); 196 if (dev == NULL) { 197 printf("failed to open emmc partition \"%s\": %s\n", 198 partition, strerror(errno)); 199 return -1; 200 } 201 } 202 203 SHA_CTX sha_ctx; 204 SHA_init(&sha_ctx); 205 uint8_t parsed_sha[SHA_DIGEST_SIZE]; 206 207 // allocate enough memory to hold the largest size. 208 file->data = malloc(size[index[pairs-1]]); 209 char* p = (char*)file->data; 210 file->size = 0; // # bytes read so far 211 212 for (i = 0; i < pairs; ++i) { 213 // Read enough additional bytes to get us up to the next size 214 // (again, we're trying the possibilities in order of increasing 215 // size). 216 size_t next = size[index[i]] - file->size; 217 size_t read = 0; 218 if (next > 0) { 219 switch (type) { 220 case MTD: 221 read = mtd_read_data(ctx, p, next); 222 break; 223 224 case EMMC: 225 read = fread(p, 1, next, dev); 226 break; 227 } 228 if (next != read) { 229 printf("short read (%d bytes of %d) for partition \"%s\"\n", 230 read, next, partition); 231 free(file->data); 232 file->data = NULL; 233 return -1; 234 } 235 SHA_update(&sha_ctx, p, read); 236 file->size += read; 237 } 238 239 // Duplicate the SHA context and finalize the duplicate so we can 240 // check it against this pair's expected hash. 241 SHA_CTX temp_ctx; 242 memcpy(&temp_ctx, &sha_ctx, sizeof(SHA_CTX)); 243 const uint8_t* sha_so_far = SHA_final(&temp_ctx); 244 245 if (ParseSha1(sha1sum[index[i]], parsed_sha) != 0) { 246 printf("failed to parse sha1 %s in %s\n", 247 sha1sum[index[i]], filename); 248 free(file->data); 249 file->data = NULL; 250 return -1; 251 } 252 253 if (memcmp(sha_so_far, parsed_sha, SHA_DIGEST_SIZE) == 0) { 254 // we have a match. stop reading the partition; we'll return 255 // the data we've read so far. 256 printf("partition read matched size %d sha %s\n", 257 size[index[i]], sha1sum[index[i]]); 258 break; 259 } 260 261 p += read; 262 } 263 264 switch (type) { 265 case MTD: 266 mtd_read_close(ctx); 267 break; 268 269 case EMMC: 270 fclose(dev); 271 break; 272 } 273 274 275 if (i == pairs) { 276 // Ran off the end of the list of (size,sha1) pairs without 277 // finding a match. 278 printf("contents of partition \"%s\" didn't match %s\n", 279 partition, filename); 280 free(file->data); 281 file->data = NULL; 282 return -1; 283 } 284 285 const uint8_t* sha_final = SHA_final(&sha_ctx); 286 for (i = 0; i < SHA_DIGEST_SIZE; ++i) { 287 file->sha1[i] = sha_final[i]; 288 } 289 290 // Fake some stat() info. 291 file->st.st_mode = 0644; 292 file->st.st_uid = 0; 293 file->st.st_gid = 0; 294 295 free(copy); 296 free(index); 297 free(size); 298 free(sha1sum); 299 300 return 0; 301 } 302 303 304 // Save the contents of the given FileContents object under the given 305 // filename. Return 0 on success. 306 static int SaveFileContents(const char* filename, FileContents file) { 307 int fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC); 308 if (fd < 0) { 309 printf("failed to open \"%s\" for write: %s\n", 310 filename, strerror(errno)); 311 return -1; 312 } 313 314 ssize_t bytes_written = FileSink(file.data, file.size, &fd); 315 if (bytes_written != file.size) { 316 printf("short write of \"%s\" (%ld bytes of %ld) (%s)\n", 317 filename, (long)bytes_written, (long)file.size, 318 strerror(errno)); 319 close(fd); 320 return -1; 321 } 322 fsync(fd); 323 close(fd); 324 325 if (chmod(filename, file.st.st_mode) != 0) { 326 printf("chmod of \"%s\" failed: %s\n", filename, strerror(errno)); 327 return -1; 328 } 329 if (chown(filename, file.st.st_uid, file.st.st_gid) != 0) { 330 printf("chown of \"%s\" failed: %s\n", filename, strerror(errno)); 331 return -1; 332 } 333 334 return 0; 335 } 336 337 // Write a memory buffer to 'target' partition, a string of the form 338 // "MTD:<partition>[:...]" or "EMMC:<partition_device>:". Return 0 on 339 // success. 340 int WriteToPartition(unsigned char* data, size_t len, 341 const char* target) { 342 char* copy = strdup(target); 343 const char* magic = strtok(copy, ":"); 344 345 enum PartitionType type; 346 if (strcmp(magic, "MTD") == 0) { 347 type = MTD; 348 } else if (strcmp(magic, "EMMC") == 0) { 349 type = EMMC; 350 } else { 351 printf("WriteToPartition called with bad target (%s)\n", target); 352 return -1; 353 } 354 const char* partition = strtok(NULL, ":"); 355 356 if (partition == NULL) { 357 printf("bad partition target name \"%s\"\n", target); 358 return -1; 359 } 360 361 switch (type) { 362 case MTD: 363 if (!mtd_partitions_scanned) { 364 mtd_scan_partitions(); 365 mtd_partitions_scanned = 1; 366 } 367 368 const MtdPartition* mtd = mtd_find_partition_by_name(partition); 369 if (mtd == NULL) { 370 printf("mtd partition \"%s\" not found for writing\n", 371 partition); 372 return -1; 373 } 374 375 MtdWriteContext* ctx = mtd_write_partition(mtd); 376 if (ctx == NULL) { 377 printf("failed to init mtd partition \"%s\" for writing\n", 378 partition); 379 return -1; 380 } 381 382 size_t written = mtd_write_data(ctx, (char*)data, len); 383 if (written != len) { 384 printf("only wrote %d of %d bytes to MTD %s\n", 385 written, len, partition); 386 mtd_write_close(ctx); 387 return -1; 388 } 389 390 if (mtd_erase_blocks(ctx, -1) < 0) { 391 printf("error finishing mtd write of %s\n", partition); 392 mtd_write_close(ctx); 393 return -1; 394 } 395 396 if (mtd_write_close(ctx)) { 397 printf("error closing mtd write of %s\n", partition); 398 return -1; 399 } 400 break; 401 402 case EMMC: 403 ; 404 FILE* f = fopen(partition, "wb"); 405 if (fwrite(data, 1, len, f) != len) { 406 printf("short write writing to %s (%s)\n", 407 partition, strerror(errno)); 408 return -1; 409 } 410 if (fclose(f) != 0) { 411 printf("error closing %s (%s)\n", partition, strerror(errno)); 412 return -1; 413 } 414 break; 415 } 416 417 free(copy); 418 return 0; 419 } 420 421 422 // Take a string 'str' of 40 hex digits and parse it into the 20 423 // byte array 'digest'. 'str' may contain only the digest or be of 424 // the form "<digest>:<anything>". Return 0 on success, -1 on any 425 // error. 426 int ParseSha1(const char* str, uint8_t* digest) { 427 int i; 428 const char* ps = str; 429 uint8_t* pd = digest; 430 for (i = 0; i < SHA_DIGEST_SIZE * 2; ++i, ++ps) { 431 int digit; 432 if (*ps >= '0' && *ps <= '9') { 433 digit = *ps - '0'; 434 } else if (*ps >= 'a' && *ps <= 'f') { 435 digit = *ps - 'a' + 10; 436 } else if (*ps >= 'A' && *ps <= 'F') { 437 digit = *ps - 'A' + 10; 438 } else { 439 return -1; 440 } 441 if (i % 2 == 0) { 442 *pd = digit << 4; 443 } else { 444 *pd |= digit; 445 ++pd; 446 } 447 } 448 if (*ps != '\0') return -1; 449 return 0; 450 } 451 452 // Search an array of sha1 strings for one matching the given sha1. 453 // Return the index of the match on success, or -1 if no match is 454 // found. 455 int FindMatchingPatch(uint8_t* sha1, char** const patch_sha1_str, 456 int num_patches) { 457 int i; 458 uint8_t patch_sha1[SHA_DIGEST_SIZE]; 459 for (i = 0; i < num_patches; ++i) { 460 if (ParseSha1(patch_sha1_str[i], patch_sha1) == 0 && 461 memcmp(patch_sha1, sha1, SHA_DIGEST_SIZE) == 0) { 462 return i; 463 } 464 } 465 return -1; 466 } 467 468 // Returns 0 if the contents of the file (argv[2]) or the cached file 469 // match any of the sha1's on the command line (argv[3:]). Returns 470 // nonzero otherwise. 471 int applypatch_check(const char* filename, 472 int num_patches, char** const patch_sha1_str) { 473 FileContents file; 474 file.data = NULL; 475 476 // It's okay to specify no sha1s; the check will pass if the 477 // LoadFileContents is successful. (Useful for reading 478 // partitions, where the filename encodes the sha1s; no need to 479 // check them twice.) 480 if (LoadFileContents(filename, &file) != 0 || 481 (num_patches > 0 && 482 FindMatchingPatch(file.sha1, patch_sha1_str, num_patches) < 0)) { 483 printf("file \"%s\" doesn't have any of expected " 484 "sha1 sums; checking cache\n", filename); 485 486 free(file.data); 487 488 // If the source file is missing or corrupted, it might be because 489 // we were killed in the middle of patching it. A copy of it 490 // should have been made in CACHE_TEMP_SOURCE. If that file 491 // exists and matches the sha1 we're looking for, the check still 492 // passes. 493 494 if (LoadFileContents(CACHE_TEMP_SOURCE, &file) != 0) { 495 printf("failed to load cache file\n"); 496 return 1; 497 } 498 499 if (FindMatchingPatch(file.sha1, patch_sha1_str, num_patches) < 0) { 500 printf("cache bits don't match any sha1 for \"%s\"\n", filename); 501 free(file.data); 502 return 1; 503 } 504 } 505 506 free(file.data); 507 return 0; 508 } 509 510 int ShowLicenses() { 511 ShowBSDiffLicense(); 512 return 0; 513 } 514 515 ssize_t FileSink(unsigned char* data, ssize_t len, void* token) { 516 int fd = *(int *)token; 517 ssize_t done = 0; 518 ssize_t wrote; 519 while (done < (ssize_t) len) { 520 wrote = write(fd, data+done, len-done); 521 if (wrote <= 0) { 522 printf("error writing %d bytes: %s\n", (int)(len-done), strerror(errno)); 523 return done; 524 } 525 done += wrote; 526 } 527 return done; 528 } 529 530 typedef struct { 531 unsigned char* buffer; 532 ssize_t size; 533 ssize_t pos; 534 } MemorySinkInfo; 535 536 ssize_t MemorySink(unsigned char* data, ssize_t len, void* token) { 537 MemorySinkInfo* msi = (MemorySinkInfo*)token; 538 if (msi->size - msi->pos < len) { 539 return -1; 540 } 541 memcpy(msi->buffer + msi->pos, data, len); 542 msi->pos += len; 543 return len; 544 } 545 546 // Return the amount of free space (in bytes) on the filesystem 547 // containing filename. filename must exist. Return -1 on error. 548 size_t FreeSpaceForFile(const char* filename) { 549 struct statfs sf; 550 if (statfs(filename, &sf) != 0) { 551 printf("failed to statfs %s: %s\n", filename, strerror(errno)); 552 return -1; 553 } 554 return sf.f_bsize * sf.f_bfree; 555 } 556 557 int CacheSizeCheck(size_t bytes) { 558 if (MakeFreeSpaceOnCache(bytes) < 0) { 559 printf("unable to make %ld bytes available on /cache\n", (long)bytes); 560 return 1; 561 } else { 562 return 0; 563 } 564 } 565 566 567 // This function applies binary patches to files in a way that is safe 568 // (the original file is not touched until we have the desired 569 // replacement for it) and idempotent (it's okay to run this program 570 // multiple times). 571 // 572 // - if the sha1 hash of <target_filename> is <target_sha1_string>, 573 // does nothing and exits successfully. 574 // 575 // - otherwise, if the sha1 hash of <source_filename> is one of the 576 // entries in <patch_sha1_str>, the corresponding patch from 577 // <patch_data> (which must be a VAL_BLOB) is applied to produce a 578 // new file (the type of patch is automatically detected from the 579 // blob daat). If that new file has sha1 hash <target_sha1_str>, 580 // moves it to replace <target_filename>, and exits successfully. 581 // Note that if <source_filename> and <target_filename> are not the 582 // same, <source_filename> is NOT deleted on success. 583 // <target_filename> may be the string "-" to mean "the same as 584 // source_filename". 585 // 586 // - otherwise, or if any error is encountered, exits with non-zero 587 // status. 588 // 589 // <source_filename> may refer to a partition to read the source data. 590 // See the comments for the LoadPartition Contents() function above 591 // for the format of such a filename. 592 593 int applypatch(const char* source_filename, 594 const char* target_filename, 595 const char* target_sha1_str, 596 size_t target_size, 597 int num_patches, 598 char** const patch_sha1_str, 599 Value** patch_data) { 600 printf("\napplying patch to %s\n", source_filename); 601 602 if (target_filename[0] == '-' && 603 target_filename[1] == '\0') { 604 target_filename = source_filename; 605 } 606 607 uint8_t target_sha1[SHA_DIGEST_SIZE]; 608 if (ParseSha1(target_sha1_str, target_sha1) != 0) { 609 printf("failed to parse tgt-sha1 \"%s\"\n", target_sha1_str); 610 return 1; 611 } 612 613 FileContents copy_file; 614 FileContents source_file; 615 const Value* source_patch_value = NULL; 616 const Value* copy_patch_value = NULL; 617 int made_copy = 0; 618 619 // We try to load the target file into the source_file object. 620 if (LoadFileContents(target_filename, &source_file) == 0) { 621 if (memcmp(source_file.sha1, target_sha1, SHA_DIGEST_SIZE) == 0) { 622 // The early-exit case: the patch was already applied, this file 623 // has the desired hash, nothing for us to do. 624 printf("\"%s\" is already target; no patch needed\n", 625 target_filename); 626 return 0; 627 } 628 } 629 630 if (source_file.data == NULL || 631 (target_filename != source_filename && 632 strcmp(target_filename, source_filename) != 0)) { 633 // Need to load the source file: either we failed to load the 634 // target file, or we did but it's different from the source file. 635 free(source_file.data); 636 LoadFileContents(source_filename, &source_file); 637 } 638 639 if (source_file.data != NULL) { 640 int to_use = FindMatchingPatch(source_file.sha1, 641 patch_sha1_str, num_patches); 642 if (to_use >= 0) { 643 source_patch_value = patch_data[to_use]; 644 } 645 } 646 647 if (source_patch_value == NULL) { 648 free(source_file.data); 649 printf("source file is bad; trying copy\n"); 650 651 if (LoadFileContents(CACHE_TEMP_SOURCE, ©_file) < 0) { 652 // fail. 653 printf("failed to read copy file\n"); 654 return 1; 655 } 656 657 int to_use = FindMatchingPatch(copy_file.sha1, 658 patch_sha1_str, num_patches); 659 if (to_use >= 0) { 660 copy_patch_value = patch_data[to_use]; 661 } 662 663 if (copy_patch_value == NULL) { 664 // fail. 665 printf("copy file doesn't match source SHA-1s either\n"); 666 return 1; 667 } 668 } 669 670 int retry = 1; 671 SHA_CTX ctx; 672 int output; 673 MemorySinkInfo msi; 674 FileContents* source_to_use; 675 char* outname; 676 677 // assume that target_filename (eg "/system/app/Foo.apk") is located 678 // on the same filesystem as its top-level directory ("/system"). 679 // We need something that exists for calling statfs(). 680 char target_fs[strlen(target_filename)+1]; 681 char* slash = strchr(target_filename+1, '/'); 682 if (slash != NULL) { 683 int count = slash - target_filename; 684 strncpy(target_fs, target_filename, count); 685 target_fs[count] = '\0'; 686 } else { 687 strcpy(target_fs, target_filename); 688 } 689 690 do { 691 // Is there enough room in the target filesystem to hold the patched 692 // file? 693 694 if (strncmp(target_filename, "MTD:", 4) == 0 || 695 strncmp(target_filename, "EMMC:", 5) == 0) { 696 // If the target is a partition, we're actually going to 697 // write the output to /tmp and then copy it to the 698 // partition. statfs() always returns 0 blocks free for 699 // /tmp, so instead we'll just assume that /tmp has enough 700 // space to hold the file. 701 702 // We still write the original source to cache, in case 703 // the partition write is interrupted. 704 if (MakeFreeSpaceOnCache(source_file.size) < 0) { 705 printf("not enough free space on /cache\n"); 706 return 1; 707 } 708 if (SaveFileContents(CACHE_TEMP_SOURCE, source_file) < 0) { 709 printf("failed to back up source file\n"); 710 return 1; 711 } 712 made_copy = 1; 713 retry = 0; 714 } else { 715 int enough_space = 0; 716 if (retry > 0) { 717 size_t free_space = FreeSpaceForFile(target_fs); 718 enough_space = 719 (free_space > (256 << 10)) && // 256k (two-block) minimum 720 (free_space > (target_size * 3 / 2)); // 50% margin of error 721 printf("target %ld bytes; free space %ld bytes; retry %d; enough %d\n", 722 (long)target_size, (long)free_space, retry, enough_space); 723 } 724 725 if (!enough_space) { 726 retry = 0; 727 } 728 729 if (!enough_space && source_patch_value != NULL) { 730 // Using the original source, but not enough free space. First 731 // copy the source file to cache, then delete it from the original 732 // location. 733 734 if (strncmp(source_filename, "MTD:", 4) == 0 || 735 strncmp(source_filename, "EMMC:", 5) == 0) { 736 // It's impossible to free space on the target filesystem by 737 // deleting the source if the source is a partition. If 738 // we're ever in a state where we need to do this, fail. 739 printf("not enough free space for target but source " 740 "is partition\n"); 741 return 1; 742 } 743 744 if (MakeFreeSpaceOnCache(source_file.size) < 0) { 745 printf("not enough free space on /cache\n"); 746 return 1; 747 } 748 749 if (SaveFileContents(CACHE_TEMP_SOURCE, source_file) < 0) { 750 printf("failed to back up source file\n"); 751 return 1; 752 } 753 made_copy = 1; 754 unlink(source_filename); 755 756 size_t free_space = FreeSpaceForFile(target_fs); 757 printf("(now %ld bytes free for target)\n", (long)free_space); 758 } 759 } 760 761 const Value* patch; 762 if (source_patch_value != NULL) { 763 source_to_use = &source_file; 764 patch = source_patch_value; 765 } else { 766 source_to_use = ©_file; 767 patch = copy_patch_value; 768 } 769 770 if (patch->type != VAL_BLOB) { 771 printf("patch is not a blob\n"); 772 return 1; 773 } 774 775 SinkFn sink = NULL; 776 void* token = NULL; 777 output = -1; 778 outname = NULL; 779 if (strncmp(target_filename, "MTD:", 4) == 0 || 780 strncmp(target_filename, "EMMC:", 5) == 0) { 781 // We store the decoded output in memory. 782 msi.buffer = malloc(target_size); 783 if (msi.buffer == NULL) { 784 printf("failed to alloc %ld bytes for output\n", 785 (long)target_size); 786 return 1; 787 } 788 msi.pos = 0; 789 msi.size = target_size; 790 sink = MemorySink; 791 token = &msi; 792 } else { 793 // We write the decoded output to "<tgt-file>.patch". 794 outname = (char*)malloc(strlen(target_filename) + 10); 795 strcpy(outname, target_filename); 796 strcat(outname, ".patch"); 797 798 output = open(outname, O_WRONLY | O_CREAT | O_TRUNC); 799 if (output < 0) { 800 printf("failed to open output file %s: %s\n", 801 outname, strerror(errno)); 802 return 1; 803 } 804 sink = FileSink; 805 token = &output; 806 } 807 808 char* header = patch->data; 809 ssize_t header_bytes_read = patch->size; 810 811 SHA_init(&ctx); 812 813 int result; 814 815 if (header_bytes_read >= 8 && 816 memcmp(header, "BSDIFF40", 8) == 0) { 817 result = ApplyBSDiffPatch(source_to_use->data, source_to_use->size, 818 patch, 0, sink, token, &ctx); 819 } else if (header_bytes_read >= 8 && 820 memcmp(header, "IMGDIFF2", 8) == 0) { 821 result = ApplyImagePatch(source_to_use->data, source_to_use->size, 822 patch, sink, token, &ctx); 823 } else { 824 printf("Unknown patch file format\n"); 825 return 1; 826 } 827 828 if (output >= 0) { 829 fsync(output); 830 close(output); 831 } 832 833 if (result != 0) { 834 if (retry == 0) { 835 printf("applying patch failed\n"); 836 return result != 0; 837 } else { 838 printf("applying patch failed; retrying\n"); 839 } 840 if (outname != NULL) { 841 unlink(outname); 842 } 843 } else { 844 // succeeded; no need to retry 845 break; 846 } 847 } while (retry-- > 0); 848 849 const uint8_t* current_target_sha1 = SHA_final(&ctx); 850 if (memcmp(current_target_sha1, target_sha1, SHA_DIGEST_SIZE) != 0) { 851 printf("patch did not produce expected sha1\n"); 852 return 1; 853 } 854 855 if (output < 0) { 856 // Copy the temp file to the partition. 857 if (WriteToPartition(msi.buffer, msi.pos, target_filename) != 0) { 858 printf("write of patched data to %s failed\n", target_filename); 859 return 1; 860 } 861 free(msi.buffer); 862 } else { 863 // Give the .patch file the same owner, group, and mode of the 864 // original source file. 865 if (chmod(outname, source_to_use->st.st_mode) != 0) { 866 printf("chmod of \"%s\" failed: %s\n", outname, strerror(errno)); 867 return 1; 868 } 869 if (chown(outname, source_to_use->st.st_uid, 870 source_to_use->st.st_gid) != 0) { 871 printf("chown of \"%s\" failed: %s\n", outname, strerror(errno)); 872 return 1; 873 } 874 875 // Finally, rename the .patch file to replace the target file. 876 if (rename(outname, target_filename) != 0) { 877 printf("rename of .patch to \"%s\" failed: %s\n", 878 target_filename, strerror(errno)); 879 return 1; 880 } 881 } 882 883 // If this run of applypatch created the copy, and we're here, we 884 // can delete it. 885 if (made_copy) unlink(CACHE_TEMP_SOURCE); 886 887 // Success! 888 return 0; 889 } 890