diff options
Diffstat (limited to 'applypatch')
| -rw-r--r-- | applypatch/applypatch.cpp | 386 |
1 files changed, 109 insertions, 277 deletions
diff --git a/applypatch/applypatch.cpp b/applypatch/applypatch.cpp index 500663120..7be3fdbde 100644 --- a/applypatch/applypatch.cpp +++ b/applypatch/applypatch.cpp @@ -32,6 +32,7 @@ #include <utility> #include <vector> +#include <android-base/logging.h> #include <android-base/parseint.h> #include <android-base/strings.h> #include <openssl/sha.h> @@ -42,15 +43,9 @@ static int LoadPartitionContents(const std::string& filename, FileContents* file); static ssize_t FileSink(const unsigned char* data, ssize_t len, void* token); -static int GenerateTarget(FileContents* source_file, - const Value* source_patch_value, - FileContents* copy_file, - const Value* copy_patch_value, - const char* source_filename, - const char* target_filename, - const uint8_t target_sha1[SHA_DIGEST_LENGTH], - size_t target_size, - const Value* bonus_data); +static int GenerateTarget(const FileContents& source_file, const std::unique_ptr<Value>& patch, + const std::string& target_filename, + const uint8_t target_sha1[SHA_DIGEST_LENGTH], const Value* bonus_data); // Read a file into memory; store the file contents and associated metadata in *file. // Return 0 on success. @@ -190,7 +185,6 @@ static int LoadPartitionContents(const std::string& filename, FileContents* file return 0; } - // Save the contents of the given FileContents object under the given // filename. Return 0 on success. int SaveFileContents(const char* filename, const FileContents* file) { @@ -480,108 +474,90 @@ int CacheSizeCheck(size_t bytes) { } } -// This function 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). +// This function applies binary patches to EMMC target 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 <target_filename> is <target_sha1_string>, -// does nothing and exits successfully. +// - If the SHA-1 hash of <target_filename> is <target_sha1_string>, does nothing and exits +// successfully. // -// - otherwise, if the sha1 hash of <source_filename> is one of the -// entries in <patch_sha1_str>, the corresponding patch from -// <patch_data> (which must be a VAL_BLOB) is applied to produce a -// new file (the type of patch is automatically detected from the -// blob data). If that new file has sha1 hash <target_sha1_str>, -// moves it to replace <target_filename>, and exits successfully. -// Note that if <source_filename> and <target_filename> are not the -// same, <source_filename> is NOT deleted on success. -// <target_filename> may be the string "-" to mean "the same as -// source_filename". +// - Otherwise, if the SHA-1 hash of <source_filename> is one of the entries in <patch_sha1_str>, +// the corresponding patch from <patch_data> (which must be a VAL_BLOB) is applied to produce a +// new file (the type of patch is automatically detected from the blob data). If that new file +// has SHA-1 hash <target_sha1_str>, moves it to replace <target_filename>, and exits +// successfully. Note that if <source_filename> and <target_filename> are not the same, +// <source_filename> is NOT deleted on success. <target_filename> may be the string "-" to mean +// "the same as <source_filename>". // -// - otherwise, or if any error is encountered, exits with non-zero -// status. +// - Otherwise, or if any error is encountered, exits with non-zero status. // -// <source_filename> may refer to a partition to read the source data. -// See the comments for the LoadPartitionContents() function above -// for the format of such a filename. - -int applypatch(const char* source_filename, - const char* target_filename, - const char* target_sha1_str, - size_t target_size, +// <source_filename> must refer to an EMMC partition to read the source data. See the comments for +// the LoadPartitionContents() function above for the format of such a filename. <target_size> has +// become obsolete since we have dropped the support for patching non-EMMC targets (EMMC targets +// have the size embedded in the filename). +int applypatch(const char* source_filename, const char* target_filename, + const char* target_sha1_str, size_t target_size __unused, const std::vector<std::string>& patch_sha1_str, - const std::vector<std::unique_ptr<Value>>& patch_data, - const Value* bonus_data) { - printf("patch %s: ", source_filename); + const std::vector<std::unique_ptr<Value>>& patch_data, const Value* bonus_data) { + printf("patch %s: ", source_filename); - if (target_filename[0] == '-' && target_filename[1] == '\0') { - target_filename = source_filename; - } + if (target_filename[0] == '-' && target_filename[1] == '\0') { + target_filename = source_filename; + } - uint8_t target_sha1[SHA_DIGEST_LENGTH]; - if (ParseSha1(target_sha1_str, target_sha1) != 0) { - printf("failed to parse tgt-sha1 \"%s\"\n", target_sha1_str); - return 1; - } + if (strncmp(target_filename, "EMMC:", 5) != 0) { + printf("Supporting patching EMMC targets only.\n"); + return 1; + } - FileContents source_file; - const Value* source_patch_value = nullptr; + uint8_t target_sha1[SHA_DIGEST_LENGTH]; + if (ParseSha1(target_sha1_str, target_sha1) != 0) { + printf("failed to parse tgt-sha1 \"%s\"\n", target_sha1_str); + return 1; + } - // 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_LENGTH) == 0) { - // The early-exit case: the patch was already applied, this file - // has the desired hash, nothing for us to do. - printf("already %s\n", short_sha1(target_sha1).c_str()); - return 0; - } + // We try to load the target file into the source_file object. + FileContents source_file; + if (LoadFileContents(target_filename, &source_file) == 0) { + if (memcmp(source_file.sha1, target_sha1, SHA_DIGEST_LENGTH) == 0) { + // The early-exit case: the patch was already applied, this file has the desired hash, nothing + // for us to do. + printf("already %s\n", short_sha1(target_sha1).c_str()); + return 0; } + } - if (source_file.data.empty() || - (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. - source_file.data.clear(); - LoadFileContents(source_filename, &source_file); - } + if (source_file.data.empty() || + (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 expected. + source_file.data.clear(); + LoadFileContents(source_filename, &source_file); + } - if (!source_file.data.empty()) { - int to_use = FindMatchingPatch(source_file.sha1, patch_sha1_str); - if (to_use >= 0) { - source_patch_value = patch_data[to_use].get(); - } + if (!source_file.data.empty()) { + int to_use = FindMatchingPatch(source_file.sha1, patch_sha1_str); + if (to_use != -1) { + return GenerateTarget(source_file, patch_data[to_use], target_filename, target_sha1, + bonus_data); } + } - FileContents copy_file; - const Value* copy_patch_value = nullptr; - if (source_patch_value == nullptr) { - source_file.data.clear(); - 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; - } + printf("source file is bad; trying copy\n"); - int to_use = FindMatchingPatch(copy_file.sha1, patch_sha1_str); - if (to_use >= 0) { - copy_patch_value = patch_data[to_use].get(); - } + FileContents copy_file; + if (LoadFileContents(CACHE_TEMP_SOURCE, ©_file) < 0) { + printf("failed to read copy file\n"); + return 1; + } - if (copy_patch_value == nullptr) { - // fail. - printf("copy file doesn't match source SHA-1s either\n"); - return 1; - } - } + int to_use = FindMatchingPatch(copy_file.sha1, patch_sha1_str); + if (to_use == -1) { + printf("copy file doesn't match source SHA-1s either\n"); + return 1; + } - return GenerateTarget(&source_file, source_patch_value, - ©_file, copy_patch_value, - source_filename, target_filename, - target_sha1, target_size, bonus_data); + return GenerateTarget(copy_file, patch_data[to_use], target_filename, target_sha1, bonus_data); } /* @@ -638,34 +614,9 @@ int applypatch_flash(const char* source_filename, const char* target_filename, return 0; } -static int GenerateTarget(FileContents* source_file, - const Value* source_patch_value, - FileContents* copy_file, - const Value* copy_patch_value, - const char* source_filename, - const char* target_filename, - const uint8_t target_sha1[SHA_DIGEST_LENGTH], - size_t target_size, - const Value* bonus_data) { - // 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(). - std::string target_fs = target_filename; - auto slash_pos = target_fs.find('/', 1); - if (slash_pos != std::string::npos) { - target_fs.resize(slash_pos); - } - - FileContents* source_to_use; - const Value* patch; - if (source_patch_value != nullptr) { - source_to_use = source_file; - patch = source_patch_value; - } else { - source_to_use = copy_file; - patch = copy_patch_value; - } - +static int GenerateTarget(const FileContents& source_file, const std::unique_ptr<Value>& patch, + const std::string& target_filename, + const uint8_t target_sha1[SHA_DIGEST_LENGTH], const Value* bonus_data) { if (patch->type != VAL_BLOB) { printf("patch is not a blob\n"); return 1; @@ -683,137 +634,39 @@ static int GenerateTarget(FileContents* source_file, return 1; } - bool target_is_partition = (strncmp(target_filename, "EMMC:", 5) == 0); - const std::string tmp_target_filename = std::string(target_filename) + ".patch"; - - int retry = 1; - bool made_copy = false; - SHA_CTX ctx; - std::string memory_sink_str; // Don't need to reserve space. - do { - // Is there enough room in the target filesystem to hold the patched file? - - if (target_is_partition) { - // If the target is a 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 partition write is interrupted. - if (MakeFreeSpaceOnCache(source_file->data.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 = true; - retry = 0; - } else { - bool enough_space = false; - if (retry > 0) { - size_t free_space = FreeSpaceForFile(target_fs.c_str()); - enough_space = (free_space > (256 << 10)) && // 256k (two-block) minimum - (free_space > (target_size * 3 / 2)); // 50% margin of error - if (!enough_space) { - printf("target %zu bytes; free space %zu bytes; retry %d; enough %d\n", target_size, - free_space, retry, enough_space); - } - } - - if (!enough_space) { - retry = 0; - } - - if (!enough_space && source_patch_value != nullptr) { - // 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, "EMMC:", 5) == 0) { - // It's impossible to free space on the target filesystem by - // deleting the source if the source is a 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 partition\n"); - return 1; - } + CHECK(android::base::StartsWith(target_filename, "EMMC:")); - if (MakeFreeSpaceOnCache(source_file->data.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 = true; - unlink(source_filename); - - size_t free_space = FreeSpaceForFile(target_fs.c_str()); - printf("(now %zu bytes free for target) ", free_space); - } - } - - SinkFn sink = nullptr; - void* token = nullptr; - unique_fd output_fd; - if (target_is_partition) { - // We store the decoded output in memory. - sink = MemorySink; - token = &memory_sink_str; - } else { - // We write the decoded output to "<tgt-file>.patch". - output_fd.reset(ota_open(tmp_target_filename.c_str(), O_WRONLY | O_CREAT | O_TRUNC | O_SYNC, - S_IRUSR | S_IWUSR)); - if (output_fd == -1) { - printf("failed to open output file %s: %s\n", tmp_target_filename.c_str(), strerror(errno)); - return 1; - } - sink = FileSink; - token = &output_fd; - } + // We still write the original source to cache, in case the partition write is interrupted. + if (MakeFreeSpaceOnCache(source_file.data.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; + } - SHA1_Init(&ctx); + // We store the decoded output in memory. + SinkFn sink = MemorySink; + std::string memory_sink_str; // Don't need to reserve space. + void* token = &memory_sink_str; - int result; - if (use_bsdiff) { - result = ApplyBSDiffPatch(source_to_use->data.data(), source_to_use->data.size(), patch, 0, - sink, token, &ctx); - } else { - result = ApplyImagePatch(source_to_use->data.data(), source_to_use->data.size(), patch, sink, - token, &ctx, bonus_data); - } + SHA_CTX ctx; + SHA1_Init(&ctx); - if (!target_is_partition) { - if (ota_fsync(output_fd) != 0) { - printf("failed to fsync file \"%s\": %s\n", tmp_target_filename.c_str(), strerror(errno)); - result = 1; - } - if (ota_close(output_fd) != 0) { - printf("failed to close file \"%s\": %s\n", tmp_target_filename.c_str(), strerror(errno)); - result = 1; - } - } + int result; + if (use_bsdiff) { + result = ApplyBSDiffPatch(source_file.data.data(), source_file.data.size(), patch.get(), 0, + sink, token, &ctx); + } else { + result = ApplyImagePatch(source_file.data.data(), source_file.data.size(), patch.get(), sink, + token, &ctx, bonus_data); + } - if (result != 0) { - if (retry == 0) { - printf("applying patch failed\n"); - return 1; - } else { - printf("applying patch failed; retrying\n"); - } - if (!target_is_partition) { - unlink(tmp_target_filename.c_str()); - } - } else { - // succeeded; no need to retry - break; - } - } while (retry-- > 0); + if (result != 0) { + printf("applying patch failed\n"); + return 1; + } uint8_t current_target_sha1[SHA_DIGEST_LENGTH]; SHA1_Final(current_target_sha1, &ctx); @@ -824,36 +677,15 @@ static int GenerateTarget(FileContents* source_file, printf("now %s\n", short_sha1(target_sha1).c_str()); } - if (target_is_partition) { - // Copy the temp file to the partition. - if (WriteToPartition(reinterpret_cast<const unsigned char*>(memory_sink_str.c_str()), - memory_sink_str.size(), target_filename) != 0) { - printf("write of patched data to %s failed\n", target_filename); - return 1; - } - } else { - // Give the .patch file the same owner, group, and mode of the original source file. - if (chmod(tmp_target_filename.c_str(), source_to_use->st.st_mode) != 0) { - printf("chmod of \"%s\" failed: %s\n", tmp_target_filename.c_str(), strerror(errno)); - return 1; - } - if (chown(tmp_target_filename.c_str(), source_to_use->st.st_uid, - source_to_use->st.st_gid) != 0) { - printf("chown of \"%s\" failed: %s\n", tmp_target_filename.c_str(), strerror(errno)); - return 1; - } - - // Finally, rename the .patch file to replace the target file. - if (rename(tmp_target_filename.c_str(), target_filename) != 0) { - printf("rename of .patch to \"%s\" failed: %s\n", target_filename, strerror(errno)); - return 1; - } + // Write back the temp file to the partition. + if (WriteToPartition(reinterpret_cast<const unsigned char*>(memory_sink_str.c_str()), + memory_sink_str.size(), target_filename) != 0) { + printf("write of patched data to %s failed\n", target_filename.c_str()); + 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); - } + // Delete the backup copy of the source. + unlink(CACHE_TEMP_SOURCE); // Success! return 0; |