From 512536a54a1a211a9f582e76cbf12850dc7d5466 Mon Sep 17 00:00:00 2001 From: Doug Zongker Date: Wed, 17 Feb 2010 16:11:44 -0800 Subject: relocate applypatch; add type system and new functions to edify - Move applypatch to this package (from build). - Add a rudimentary type system to edify: instead of just returning a char*, functions now return a Value*, which is a struct that can carry different types of value (currently just STRING and BLOB). Convert all functions to this new scheme. - Change the one-argument form of package_extract_file to return a Value of the new BLOB type. - Add read_file() to load a local file and return a blob, and sha1_check() to test a blob (or string) against a set of possible sha1s. read_file() uses the file-loading code from applypatch so it can read MTD partitions as well. This is the start of better integration between applypatch and the rest of edify. b/2361316 - VZW Issue PP628: Continuous reset to Droid logo: framework-res.apk update failed (CR LIBtt59130) Change-Id: Ibd038074749a4d515de1f115c498c6c589ee91e5 --- applypatch/applypatch.c | 900 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 900 insertions(+) create mode 100644 applypatch/applypatch.c (limited to 'applypatch/applypatch.c') diff --git a/applypatch/applypatch.c b/applypatch/applypatch.c new file mode 100644 index 000000000..daf372907 --- /dev/null +++ b/applypatch/applypatch.c @@ -0,0 +1,900 @@ +/* + * Copyright (C) 2008 The Android Open Source Project + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "mincrypt/sha.h" +#include "applypatch.h" +#include "mtdutils/mtdutils.h" + +int SaveFileContents(const char* filename, FileContents file); +int LoadMTDContents(const char* filename, FileContents* file); +int ParseSha1(const char* str, uint8_t* digest); +ssize_t FileSink(unsigned char* data, ssize_t len, void* token); + +static int mtd_partitions_scanned = 0; + +// Read a file into memory; store it and its associated metadata in +// *file. Return 0 on success. +int LoadFileContents(const char* filename, FileContents* file) { + file->data = NULL; + + // A special 'filename' beginning with "MTD:" means to load the + // contents of an MTD partition. + if (strncmp(filename, "MTD:", 4) == 0) { + return LoadMTDContents(filename, file); + } + + if (stat(filename, &file->st) != 0) { + printf("failed to stat \"%s\": %s\n", filename, strerror(errno)); + return -1; + } + + file->size = file->st.st_size; + file->data = malloc(file->size); + + FILE* f = fopen(filename, "rb"); + if (f == NULL) { + printf("failed to open \"%s\": %s\n", filename, strerror(errno)); + free(file->data); + file->data = NULL; + return -1; + } + + size_t bytes_read = fread(file->data, 1, file->size, f); + if (bytes_read != file->size) { + printf("short read of \"%s\" (%d bytes of %d)\n", + filename, bytes_read, file->size); + free(file->data); + file->data = NULL; + return -1; + } + fclose(f); + + SHA(file->data, file->size, file->sha1); + return 0; +} + +static size_t* size_array; +// comparison function for qsort()ing an int array of indexes into +// size_array[]. +static int compare_size_indices(const void* a, const void* b) { + int aa = *(int*)a; + int bb = *(int*)b; + if (size_array[aa] < size_array[bb]) { + return -1; + } else if (size_array[aa] > size_array[bb]) { + return 1; + } else { + return 0; + } +} + +void FreeFileContents(FileContents* file) { + if (file) free(file->data); + free(file); +} + +// Load the contents of an MTD partition into the provided +// FileContents. filename should be a string of the form +// "MTD::::::...". +// The smallest size_n bytes for which that prefix of the mtd contents +// has the corresponding sha1 hash will be loaded. It is acceptable +// for a size value to be repeated with different sha1s. Will return +// 0 on success. +// +// This complexity is needed because if an OTA installation is +// interrupted, the partition might contain either the source or the +// target data, which might be of different lengths. We need to know +// the length in order to read from MTD (there is no "end-of-file" +// marker), so the caller must specify the possible lengths and the +// hash of the data, and we'll do the load expecting to find one of +// those hashes. +int LoadMTDContents(const char* filename, FileContents* file) { + char* copy = strdup(filename); + const char* magic = strtok(copy, ":"); + if (strcmp(magic, "MTD") != 0) { + printf("LoadMTDContents called with bad filename (%s)\n", + filename); + return -1; + } + const char* partition = strtok(NULL, ":"); + + int i; + int colons = 0; + for (i = 0; filename[i] != '\0'; ++i) { + if (filename[i] == ':') { + ++colons; + } + } + if (colons < 3 || colons%2 == 0) { + printf("LoadMTDContents called with bad filename (%s)\n", + filename); + } + + int pairs = (colons-1)/2; // # of (size,sha1) pairs in filename + int* index = malloc(pairs * sizeof(int)); + size_t* size = malloc(pairs * sizeof(size_t)); + char** sha1sum = malloc(pairs * sizeof(char*)); + + for (i = 0; i < pairs; ++i) { + const char* size_str = strtok(NULL, ":"); + size[i] = strtol(size_str, NULL, 10); + if (size[i] == 0) { + printf("LoadMTDContents called with bad size (%s)\n", filename); + return -1; + } + sha1sum[i] = strtok(NULL, ":"); + index[i] = i; + } + + // sort the index[] array so it indexes the pairs in order of + // increasing size. + size_array = size; + qsort(index, pairs, sizeof(int), compare_size_indices); + + if (!mtd_partitions_scanned) { + mtd_scan_partitions(); + mtd_partitions_scanned = 1; + } + + const MtdPartition* mtd = mtd_find_partition_by_name(partition); + if (mtd == NULL) { + printf("mtd partition \"%s\" not found (loading %s)\n", + partition, filename); + return -1; + } + + MtdReadContext* ctx = mtd_read_partition(mtd); + if (ctx == NULL) { + printf("failed to initialize read of mtd partition \"%s\"\n", + partition); + return -1; + } + + SHA_CTX sha_ctx; + SHA_init(&sha_ctx); + uint8_t parsed_sha[SHA_DIGEST_SIZE]; + + // allocate enough memory to hold the largest size. + file->data = malloc(size[index[pairs-1]]); + char* p = (char*)file->data; + file->size = 0; // # bytes read so far + + for (i = 0; i < pairs; ++i) { + // Read enough additional bytes to get us up to the next size + // (again, we're trying the possibilities in order of increasing + // size). + size_t next = size[index[i]] - file->size; + size_t read = 0; + if (next > 0) { + read = mtd_read_data(ctx, p, next); + if (next != read) { + printf("short read (%d bytes of %d) for partition \"%s\"\n", + read, next, partition); + free(file->data); + file->data = NULL; + return -1; + } + SHA_update(&sha_ctx, p, read); + file->size += read; + } + + // Duplicate the SHA context and finalize the duplicate so we can + // check it against this pair's expected hash. + SHA_CTX temp_ctx; + memcpy(&temp_ctx, &sha_ctx, sizeof(SHA_CTX)); + const uint8_t* sha_so_far = SHA_final(&temp_ctx); + + if (ParseSha1(sha1sum[index[i]], parsed_sha) != 0) { + printf("failed to parse sha1 %s in %s\n", + sha1sum[index[i]], filename); + free(file->data); + file->data = NULL; + return -1; + } + + if (memcmp(sha_so_far, parsed_sha, SHA_DIGEST_SIZE) == 0) { + // we have a match. stop reading the partition; we'll return + // the data we've read so far. + printf("mtd read matched size %d sha %s\n", + size[index[i]], sha1sum[index[i]]); + break; + } + + p += read; + } + + mtd_read_close(ctx); + + if (i == pairs) { + // Ran off the end of the list of (size,sha1) pairs without + // finding a match. + printf("contents of MTD partition \"%s\" didn't match %s\n", + partition, filename); + free(file->data); + file->data = NULL; + return -1; + } + + const uint8_t* sha_final = SHA_final(&sha_ctx); + for (i = 0; i < SHA_DIGEST_SIZE; ++i) { + file->sha1[i] = sha_final[i]; + } + + // Fake some stat() info. + file->st.st_mode = 0644; + file->st.st_uid = 0; + file->st.st_gid = 0; + + free(copy); + free(index); + free(size); + free(sha1sum); + + return 0; +} + + +// Save the contents of the given FileContents object under the given +// filename. Return 0 on success. +int SaveFileContents(const char* filename, FileContents file) { + int fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC); + if (fd < 0) { + printf("failed to open \"%s\" for write: %s\n", + filename, strerror(errno)); + return -1; + } + + size_t bytes_written = FileSink(file.data, file.size, &fd); + if (bytes_written != file.size) { + printf("short write of \"%s\" (%d bytes of %d) (%s)\n", + filename, bytes_written, file.size, strerror(errno)); + close(fd); + return -1; + } + fsync(fd); + close(fd); + + if (chmod(filename, file.st.st_mode) != 0) { + printf("chmod of \"%s\" failed: %s\n", filename, strerror(errno)); + return -1; + } + if (chown(filename, file.st.st_uid, file.st.st_gid) != 0) { + printf("chown of \"%s\" failed: %s\n", filename, strerror(errno)); + return -1; + } + + return 0; +} + +// Write a memory buffer to target_mtd partition, a string of the form +// "MTD:[:...]". Return 0 on success. +int WriteToMTDPartition(unsigned char* data, size_t len, + const char* target_mtd) { + char* partition = strchr(target_mtd, ':'); + if (partition == NULL) { + printf("bad MTD target name \"%s\"\n", target_mtd); + return -1; + } + ++partition; + // Trim off anything after a colon, eg "MTD:boot:blah:blah:blah...". + // We want just the partition name "boot". + partition = strdup(partition); + char* end = strchr(partition, ':'); + if (end != NULL) + *end = '\0'; + + if (!mtd_partitions_scanned) { + mtd_scan_partitions(); + mtd_partitions_scanned = 1; + } + + const MtdPartition* mtd = mtd_find_partition_by_name(partition); + if (mtd == NULL) { + printf("mtd partition \"%s\" not found for writing\n", partition); + return -1; + } + + MtdWriteContext* ctx = mtd_write_partition(mtd); + if (ctx == NULL) { + printf("failed to init mtd partition \"%s\" for writing\n", + partition); + return -1; + } + + size_t written = mtd_write_data(ctx, (char*)data, len); + if (written != len) { + printf("only wrote %d of %d bytes to MTD %s\n", + written, len, partition); + mtd_write_close(ctx); + return -1; + } + + if (mtd_erase_blocks(ctx, -1) < 0) { + printf("error finishing mtd write of %s\n", partition); + mtd_write_close(ctx); + return -1; + } + + if (mtd_write_close(ctx)) { + printf("error closing mtd write of %s\n", partition); + return -1; + } + + free(partition); + return 0; +} + + +// Take a string 'str' of 40 hex digits and parse it into the 20 +// byte array 'digest'. 'str' may contain only the digest or be of +// the form ":". Return 0 on success, -1 on any +// error. +int ParseSha1(const char* str, uint8_t* digest) { + int i; + const char* ps = str; + uint8_t* pd = digest; + for (i = 0; i < SHA_DIGEST_SIZE * 2; ++i, ++ps) { + int digit; + if (*ps >= '0' && *ps <= '9') { + digit = *ps - '0'; + } else if (*ps >= 'a' && *ps <= 'f') { + digit = *ps - 'a' + 10; + } else if (*ps >= 'A' && *ps <= 'F') { + digit = *ps - 'A' + 10; + } else { + return -1; + } + if (i % 2 == 0) { + *pd = digit << 4; + } else { + *pd |= digit; + ++pd; + } + } + if (*ps != '\0' && *ps != ':') return -1; + return 0; +} + +// Parse arguments (which should be of the form "" or +// ":" into the array *patches, returning the number +// of Patch objects in *num_patches. Return 0 on success. +int ParseShaArgs(int argc, char** argv, Patch** patches, int* num_patches) { + *num_patches = argc; + *patches = malloc(*num_patches * sizeof(Patch)); + + int i; + for (i = 0; i < *num_patches; ++i) { + if (ParseSha1(argv[i], (*patches)[i].sha1) != 0) { + printf("failed to parse sha1 \"%s\"\n", argv[i]); + return -1; + } + if (argv[i][SHA_DIGEST_SIZE*2] == '\0') { + (*patches)[i].patch_filename = NULL; + } else if (argv[i][SHA_DIGEST_SIZE*2] == ':') { + (*patches)[i].patch_filename = argv[i] + (SHA_DIGEST_SIZE*2+1); + } else { + printf("failed to parse filename \"%s\"\n", argv[i]); + return -1; + } + } + + return 0; +} + +// Search an array of Patch objects for one matching the given sha1. +// Return the Patch object on success, or NULL if no match is found. +const Patch* FindMatchingPatch(uint8_t* sha1, Patch* patches, int num_patches) { + int i; + for (i = 0; i < num_patches; ++i) { + if (memcmp(patches[i].sha1, sha1, SHA_DIGEST_SIZE) == 0) { + return patches+i; + } + } + return NULL; +} + +// Returns 0 if the contents of the file (argv[2]) or the cached file +// match any of the sha1's on the command line (argv[3:]). Returns +// nonzero otherwise. +int CheckMode(int argc, char** argv) { + if (argc < 3) { + printf("no filename given\n"); + return 2; + } + + int num_patches; + Patch* patches; + if (ParseShaArgs(argc-3, argv+3, &patches, &num_patches) != 0) { return 1; } + + FileContents file; + file.data = NULL; + + // It's okay to specify no sha1s; the check will pass if the + // LoadFileContents is successful. (Useful for reading MTD + // partitions, where the filename encodes the sha1s; no need to + // check them twice.) + if (LoadFileContents(argv[2], &file) != 0 || + (num_patches > 0 && + FindMatchingPatch(file.sha1, patches, num_patches) == NULL)) { + printf("file \"%s\" doesn't have any of expected " + "sha1 sums; checking cache\n", argv[2]); + + free(file.data); + + // If the source file is missing or corrupted, it might be because + // we were killed in the middle of patching it. A copy of it + // should have been made in CACHE_TEMP_SOURCE. If that file + // exists and matches the sha1 we're looking for, the check still + // passes. + + if (LoadFileContents(CACHE_TEMP_SOURCE, &file) != 0) { + printf("failed to load cache file\n"); + return 1; + } + + if (FindMatchingPatch(file.sha1, patches, num_patches) == NULL) { + printf("cache bits don't match any sha1 for \"%s\"\n", + argv[2]); + return 1; + } + } + + free(file.data); + return 0; +} + +int ShowLicenses() { + ShowBSDiffLicense(); + return 0; +} + +ssize_t FileSink(unsigned char* data, ssize_t len, void* token) { + int fd = *(int *)token; + ssize_t done = 0; + ssize_t wrote; + while (done < (ssize_t) len) { + wrote = write(fd, data+done, len-done); + if (wrote <= 0) { + printf("error writing %d bytes: %s\n", (int)(len-done), strerror(errno)); + return done; + } + done += wrote; + } + printf("wrote %d bytes to output\n", (int)done); + return done; +} + +typedef struct { + unsigned char* buffer; + ssize_t size; + ssize_t pos; +} MemorySinkInfo; + +ssize_t MemorySink(unsigned char* data, ssize_t len, void* token) { + MemorySinkInfo* msi = (MemorySinkInfo*)token; + if (msi->size - msi->pos < len) { + return -1; + } + memcpy(msi->buffer + msi->pos, data, len); + msi->pos += len; + return len; +} + +// Return the amount of free space (in bytes) on the filesystem +// containing filename. filename must exist. Return -1 on error. +size_t FreeSpaceForFile(const char* filename) { + struct statfs sf; + if (statfs(filename, &sf) != 0) { + printf("failed to statfs %s: %s\n", filename, strerror(errno)); + return -1; + } + return sf.f_bsize * sf.f_bfree; +} + +// This program applies binary patches to files in a way that is safe +// (the original file is not touched until we have the desired +// replacement for it) and idempotent (it's okay to run this program +// multiple times). +// +// - if the sha1 hash of is , does nothing and exits +// successfully. +// +// - otherwise, if the sha1 hash of is , applies the +// bsdiff to to produce a new file (the type of patch +// is automatically detected from the file header). If that new +// file has sha1 hash , moves it to replace , and +// exits successfully. Note that if and are +// not the same, is NOT deleted on success. +// may be the string "-" to mean "the same as src-file". +// +// - otherwise, or if any error is encountered, exits with non-zero +// status. +// +// (or in check mode) may refer to an MTD partition +// to read the source data. See the comments for the +// LoadMTDContents() function above for the format of such a filename. +// +// +// As you might guess from the arguments, this function used to be +// main(); it was split out this way so applypatch could be built as a +// static library and linked into other executables as well. In the +// future only the library form will exist; we will not need to build +// this as a standalone executable. +// +// The arguments to this function are just the command-line of the +// standalone executable: +// +// [: ...] +// to apply a patch. Returns 0 on success, 1 on failure. +// +// "-c" [ ...] +// to check a file's contents against zero or more sha1s. Returns +// 0 if it matches any of them, 1 if it doesn't. +// +// "-s" +// returns 0 if enough free space is available on /cache; 1 if it +// does not. +// +// "-l" +// shows open-source license information and returns 0. +// +// This function returns 2 if the arguments are not understood (in the +// standalone executable, this causes the usage message to be +// printed). +// +// TODO: make the interface more sensible for use as a library. + +int applypatch(int argc, char** argv) { + if (argc < 2) { + return 2; + } + + if (strncmp(argv[1], "-l", 3) == 0) { + return ShowLicenses(); + } + + if (strncmp(argv[1], "-c", 3) == 0) { + return CheckMode(argc, argv); + } + + if (strncmp(argv[1], "-s", 3) == 0) { + if (argc != 3) { + return 2; + } + size_t bytes = strtol(argv[2], NULL, 10); + if (MakeFreeSpaceOnCache(bytes) < 0) { + printf("unable to make %ld bytes available on /cache\n", (long)bytes); + return 1; + } else { + return 0; + } + } + + uint8_t target_sha1[SHA_DIGEST_SIZE]; + + const char* source_filename = argv[1]; + const char* target_filename = argv[2]; + if (target_filename[0] == '-' && + target_filename[1] == '\0') { + target_filename = source_filename; + } + + printf("\napplying patch to %s\n", source_filename); + + if (ParseSha1(argv[3], target_sha1) != 0) { + printf("failed to parse tgt-sha1 \"%s\"\n", argv[3]); + return 1; + } + + unsigned long target_size = strtoul(argv[4], NULL, 0); + + int num_patches; + Patch* patches; + if (ParseShaArgs(argc-5, argv+5, &patches, &num_patches) < 0) { return 1; } + + FileContents copy_file; + FileContents source_file; + const char* source_patch_filename = NULL; + const char* copy_patch_filename = NULL; + int made_copy = 0; + + // We try to load the target file into the source_file object. + if (LoadFileContents(target_filename, &source_file) == 0) { + if (memcmp(source_file.sha1, target_sha1, SHA_DIGEST_SIZE) == 0) { + // The early-exit case: the patch was already applied, this file + // has the desired hash, nothing for us to do. + printf("\"%s\" is already target; no patch needed\n", + target_filename); + return 0; + } + } + + if (source_file.data == NULL || + (target_filename != source_filename && + strcmp(target_filename, source_filename) != 0)) { + // Need to load the source file: either we failed to load the + // target file, or we did but it's different from the source file. + free(source_file.data); + LoadFileContents(source_filename, &source_file); + } + + if (source_file.data != NULL) { + const Patch* to_use = + FindMatchingPatch(source_file.sha1, patches, num_patches); + if (to_use != NULL) { + source_patch_filename = to_use->patch_filename; + } + } + + if (source_patch_filename == NULL) { + free(source_file.data); + printf("source file is bad; trying copy\n"); + + if (LoadFileContents(CACHE_TEMP_SOURCE, ©_file) < 0) { + // fail. + printf("failed to read copy file\n"); + return 1; + } + + const Patch* to_use = + FindMatchingPatch(copy_file.sha1, patches, num_patches); + if (to_use != NULL) { + copy_patch_filename = to_use->patch_filename; + } + + if (copy_patch_filename == NULL) { + // fail. + printf("copy file doesn't match source SHA-1s either\n"); + return 1; + } + } + + int retry = 1; + SHA_CTX ctx; + int output; + MemorySinkInfo msi; + FileContents* source_to_use; + char* outname; + + // assume that target_filename (eg "/system/app/Foo.apk") is located + // on the same filesystem as its top-level directory ("/system"). + // We need something that exists for calling statfs(). + char target_fs[strlen(target_filename)+1]; + char* slash = strchr(target_filename+1, '/'); + if (slash != NULL) { + int count = slash - target_filename; + strncpy(target_fs, target_filename, count); + target_fs[count] = '\0'; + } else { + strcpy(target_fs, target_filename); + } + + do { + // Is there enough room in the target filesystem to hold the patched + // file? + + if (strncmp(target_filename, "MTD:", 4) == 0) { + // If the target is an MTD partition, we're actually going to + // write the output to /tmp and then copy it to the partition. + // statfs() always returns 0 blocks free for /tmp, so instead + // we'll just assume that /tmp has enough space to hold the file. + + // We still write the original source to cache, in case the MTD + // write is interrupted. + if (MakeFreeSpaceOnCache(source_file.size) < 0) { + printf("not enough free space on /cache\n"); + return 1; + } + if (SaveFileContents(CACHE_TEMP_SOURCE, source_file) < 0) { + printf("failed to back up source file\n"); + return 1; + } + made_copy = 1; + retry = 0; + } else { + int enough_space = 0; + if (retry > 0) { + size_t free_space = FreeSpaceForFile(target_fs); + int enough_space = + (free_space > (target_size * 3 / 2)); // 50% margin of error + printf("target %ld bytes; free space %ld bytes; retry %d; enough %d\n", + (long)target_size, (long)free_space, retry, enough_space); + } + + if (!enough_space) { + retry = 0; + } + + if (!enough_space && source_patch_filename != NULL) { + // Using the original source, but not enough free space. First + // copy the source file to cache, then delete it from the original + // location. + + if (strncmp(source_filename, "MTD:", 4) == 0) { + // It's impossible to free space on the target filesystem by + // deleting the source if the source is an MTD partition. If + // we're ever in a state where we need to do this, fail. + printf("not enough free space for target but source is MTD\n"); + return 1; + } + + if (MakeFreeSpaceOnCache(source_file.size) < 0) { + printf("not enough free space on /cache\n"); + return 1; + } + + if (SaveFileContents(CACHE_TEMP_SOURCE, source_file) < 0) { + printf("failed to back up source file\n"); + return 1; + } + made_copy = 1; + unlink(source_filename); + + size_t free_space = FreeSpaceForFile(target_fs); + printf("(now %ld bytes free for target)\n", (long)free_space); + } + } + + const char* patch_filename; + if (source_patch_filename != NULL) { + source_to_use = &source_file; + patch_filename = source_patch_filename; + } else { + source_to_use = ©_file; + patch_filename = copy_patch_filename; + } + + SinkFn sink = NULL; + void* token = NULL; + output = -1; + outname = NULL; + if (strncmp(target_filename, "MTD:", 4) == 0) { + // We store the decoded output in memory. + msi.buffer = malloc(target_size); + if (msi.buffer == NULL) { + printf("failed to alloc %ld bytes for output\n", + (long)target_size); + return 1; + } + msi.pos = 0; + msi.size = target_size; + sink = MemorySink; + token = &msi; + } else { + // We write the decoded output to ".patch". + outname = (char*)malloc(strlen(target_filename) + 10); + strcpy(outname, target_filename); + strcat(outname, ".patch"); + + output = open(outname, O_WRONLY | O_CREAT | O_TRUNC); + if (output < 0) { + printf("failed to open output file %s: %s\n", + outname, strerror(errno)); + return 1; + } + sink = FileSink; + token = &output; + } + +#define MAX_HEADER_LENGTH 8 + unsigned char header[MAX_HEADER_LENGTH]; + FILE* patchf = fopen(patch_filename, "rb"); + if (patchf == NULL) { + printf("failed to open patch file %s: %s\n", + patch_filename, strerror(errno)); + return 1; + } + int header_bytes_read = fread(header, 1, MAX_HEADER_LENGTH, patchf); + fclose(patchf); + + SHA_init(&ctx); + + int result; + + if (header_bytes_read >= 4 && + header[0] == 0xd6 && header[1] == 0xc3 && + header[2] == 0xc4 && header[3] == 0) { + // xdelta3 patches begin "VCD" (with the high bits set) followed + // by a zero byte (the version number). + printf("error: xdelta3 patches no longer supported\n"); + return 1; + } else if (header_bytes_read >= 8 && + memcmp(header, "BSDIFF40", 8) == 0) { + result = ApplyBSDiffPatch(source_to_use->data, source_to_use->size, + patch_filename, 0, sink, token, &ctx); + } else if (header_bytes_read >= 8 && + memcmp(header, "IMGDIFF", 7) == 0 && + (header[7] == '1' || header[7] == '2')) { + result = ApplyImagePatch(source_to_use->data, source_to_use->size, + patch_filename, sink, token, &ctx); + } else { + printf("Unknown patch file format\n"); + return 1; + } + + if (output >= 0) { + fsync(output); + close(output); + } + + if (result != 0) { + if (retry == 0) { + printf("applying patch failed\n"); + return result != 0; + } else { + printf("applying patch failed; retrying\n"); + } + if (outname != NULL) { + unlink(outname); + } + } else { + // succeeded; no need to retry + break; + } + } while (retry-- > 0); + + const uint8_t* current_target_sha1 = SHA_final(&ctx); + if (memcmp(current_target_sha1, target_sha1, SHA_DIGEST_SIZE) != 0) { + printf("patch did not produce expected sha1\n"); + return 1; + } + + if (output < 0) { + // Copy the temp file to the MTD partition. + if (WriteToMTDPartition(msi.buffer, msi.pos, target_filename) != 0) { + printf("write of patched data to %s failed\n", target_filename); + return 1; + } + free(msi.buffer); + } else { + // Give the .patch file the same owner, group, and mode of the + // original source file. + if (chmod(outname, source_to_use->st.st_mode) != 0) { + printf("chmod of \"%s\" failed: %s\n", outname, strerror(errno)); + return 1; + } + if (chown(outname, source_to_use->st.st_uid, + source_to_use->st.st_gid) != 0) { + printf("chown of \"%s\" failed: %s\n", outname, strerror(errno)); + return 1; + } + + // Finally, rename the .patch file to replace the target file. + if (rename(outname, target_filename) != 0) { + printf("rename of .patch to \"%s\" failed: %s\n", + target_filename, strerror(errno)); + return 1; + } + } + + // If this run of applypatch created the copy, and we're here, we + // can delete it. + if (made_copy) unlink(CACHE_TEMP_SOURCE); + + // Success! + return 0; +} -- cgit v1.2.3