blob: 336860cb974bb8423be3fe0a4900548777549102 [file] [log] [blame]
/*
* 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 "applypatch/applypatch.h"
#include <errno.h>
#include <fcntl.h>
#include <libgen.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include <algorithm>
#include <functional>
#include <memory>
#include <string>
#include <utility>
#include <vector>
#include <android-base/file.h>
#include <android-base/logging.h>
#include <android-base/parseint.h>
#include <android-base/strings.h>
#include <android-base/unique_fd.h>
#include <openssl/sha.h>
#include "edify/expr.h"
#include "otautil/paths.h"
#include "otautil/print_sha1.h"
using namespace std::string_literals;
static bool GenerateTarget(const Partition& target, const FileContents& source_file,
const Value& patch, const Value* bonus_data, bool backup_source);
bool LoadFileContents(const std::string& filename, FileContents* file) {
// No longer allow loading contents from eMMC partitions.
if (android::base::StartsWith(filename, "EMMC:")) {
return false;
}
std::string data;
if (!android::base::ReadFileToString(filename, &data)) {
PLOG(ERROR) << "Failed to read \"" << filename << "\"";
return false;
}
file->data = std::vector<unsigned char>(data.begin(), data.end());
SHA1(file->data.data(), file->data.size(), file->sha1);
return true;
}
// Reads the contents of a Partition to the given FileContents buffer.
static bool ReadPartitionToBuffer(const Partition& partition, FileContents* out,
bool check_backup) {
uint8_t expected_sha1[SHA_DIGEST_LENGTH];
if (ParseSha1(partition.hash, expected_sha1) != 0) {
LOG(ERROR) << "Failed to parse target hash \"" << partition.hash << "\"";
return false;
}
android::base::unique_fd dev(open(partition.name.c_str(), O_RDONLY));
if (dev == -1) {
PLOG(ERROR) << "Failed to open eMMC partition \"" << partition << "\"";
} else {
std::vector<unsigned char> buffer(partition.size);
if (!android::base::ReadFully(dev, buffer.data(), buffer.size())) {
PLOG(ERROR) << "Failed to read " << buffer.size() << " bytes of data for partition "
<< partition;
} else {
SHA1(buffer.data(), buffer.size(), out->sha1);
if (memcmp(out->sha1, expected_sha1, SHA_DIGEST_LENGTH) == 0) {
out->data = std::move(buffer);
return true;
}
}
}
if (!check_backup) {
LOG(ERROR) << "Partition contents don't have the expected checksum";
return false;
}
if (LoadFileContents(Paths::Get().cache_temp_source(), out) &&
memcmp(out->sha1, expected_sha1, SHA_DIGEST_LENGTH) == 0) {
return true;
}
LOG(ERROR) << "Both of partition contents and backup don't have the expected checksum";
return false;
}
bool SaveFileContents(const std::string& filename, const FileContents* file) {
android::base::unique_fd fd(
open(filename.c_str(), O_WRONLY | O_CREAT | O_TRUNC | O_SYNC, S_IRUSR | S_IWUSR));
if (fd == -1) {
PLOG(ERROR) << "Failed to open \"" << filename << "\" for write";
return false;
}
if (!android::base::WriteFully(fd, file->data.data(), file->data.size())) {
PLOG(ERROR) << "Failed to write " << file->data.size() << " bytes of data to " << filename;
return false;
}
if (fsync(fd) != 0) {
PLOG(ERROR) << "Failed to fsync \"" << filename << "\"";
return false;
}
if (close(fd.release()) != 0) {
PLOG(ERROR) << "Failed to close \"" << filename << "\"";
return false;
}
return true;
}
// Writes a memory buffer to 'target' Partition.
static bool WriteBufferToPartition(const FileContents& file_contents, const Partition& partition) {
const unsigned char* data = file_contents.data.data();
size_t len = file_contents.data.size();
size_t start = 0;
bool success = false;
for (size_t attempt = 0; attempt < 2; ++attempt) {
android::base::unique_fd fd(open(partition.name.c_str(), O_RDWR));
if (fd == -1) {
PLOG(ERROR) << "Failed to open \"" << partition << "\"";
return false;
}
if (TEMP_FAILURE_RETRY(lseek(fd, start, SEEK_SET)) == -1) {
PLOG(ERROR) << "Failed to seek to " << start << " on \"" << partition << "\"";
return false;
}
if (!android::base::WriteFully(fd, data + start, len - start)) {
PLOG(ERROR) << "Failed to write " << len - start << " bytes to \"" << partition << "\"";
return false;
}
if (fsync(fd) != 0) {
PLOG(ERROR) << "Failed to sync \"" << partition << "\"";
return false;
}
if (close(fd.release()) != 0) {
PLOG(ERROR) << "Failed to close \"" << partition << "\"";
return false;
}
fd.reset(open(partition.name.c_str(), O_RDONLY));
if (fd == -1) {
PLOG(ERROR) << "Failed to reopen \"" << partition << "\" for verification";
return false;
}
// Drop caches so our subsequent verification read won't just be reading the cache.
sync();
std::string drop_cache = "/proc/sys/vm/drop_caches";
if (!android::base::WriteStringToFile("3\n", drop_cache)) {
PLOG(ERROR) << "Failed to write to " << drop_cache;
} else {
LOG(INFO) << " caches dropped";
}
sleep(1);
// Verify.
if (TEMP_FAILURE_RETRY(lseek(fd, 0, SEEK_SET)) == -1) {
PLOG(ERROR) << "Failed to seek to 0 on " << partition;
return false;
}
unsigned char buffer[4096];
start = len;
for (size_t p = 0; p < len; p += sizeof(buffer)) {
size_t to_read = len - p;
if (to_read > sizeof(buffer)) {
to_read = sizeof(buffer);
}
if (!android::base::ReadFully(fd, buffer, to_read)) {
PLOG(ERROR) << "Failed to verify-read " << partition << " at " << p;
return false;
}
if (memcmp(buffer, data + p, to_read) != 0) {
LOG(ERROR) << "Verification failed starting at " << p;
start = p;
break;
}
}
if (start == len) {
LOG(INFO) << "Verification read succeeded (attempt " << attempt + 1 << ")";
success = true;
break;
}
if (close(fd.release()) != 0) {
PLOG(ERROR) << "Failed to close " << partition;
return false;
}
}
if (!success) {
LOG(ERROR) << "Failed to verify after all attempts";
return false;
}
sync();
return true;
}
int ParseSha1(const std::string& str, uint8_t* digest) {
const char* ps = str.c_str();
uint8_t* pd = digest;
for (int i = 0; i < SHA_DIGEST_LENGTH * 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') return -1;
return 0;
}
bool PatchPartitionCheck(const Partition& target, const Partition& source) {
FileContents target_file;
FileContents source_file;
return (ReadPartitionToBuffer(target, &target_file, false) ||
ReadPartitionToBuffer(source, &source_file, true));
}
int ShowLicenses() {
ShowBSDiffLicense();
return 0;
}
bool PatchPartition(const Partition& target, const Partition& source, const Value& patch,
const Value* bonus, bool backup_source) {
LOG(INFO) << "Patching " << target.name;
// We try to load and check against the target hash first.
FileContents target_file;
if (ReadPartitionToBuffer(target, &target_file, false)) {
// The early-exit case: the patch was already applied, this file has the desired hash, nothing
// for us to do.
LOG(INFO) << " already " << target.hash.substr(0, 8);
return true;
}
FileContents source_file;
if (ReadPartitionToBuffer(source, &source_file, true)) {
return GenerateTarget(target, source_file, patch, bonus, backup_source);
}
LOG(ERROR) << "Failed to find any match";
return false;
}
bool FlashPartition(const Partition& partition, const std::string& source_filename) {
LOG(INFO) << "Flashing " << partition;
// We try to load and check against the target hash first.
FileContents target_file;
if (ReadPartitionToBuffer(partition, &target_file, false)) {
// The early-exit case: the patch was already applied, this file has the desired hash, nothing
// for us to do.
LOG(INFO) << " already " << partition.hash.substr(0, 8);
return true;
}
FileContents source_file;
if (!LoadFileContents(source_filename, &source_file)) {
LOG(ERROR) << "Failed to load source file";
return false;
}
uint8_t expected_sha1[SHA_DIGEST_LENGTH];
if (ParseSha1(partition.hash, expected_sha1) != 0) {
LOG(ERROR) << "Failed to parse source hash \"" << partition.hash << "\"";
return false;
}
if (memcmp(source_file.sha1, expected_sha1, SHA_DIGEST_LENGTH) != 0) {
// The source doesn't have desired checksum.
LOG(ERROR) << "source \"" << source_filename << "\" doesn't have expected SHA-1 sum";
LOG(ERROR) << "expected: " << partition.hash.substr(0, 8)
<< ", found: " << short_sha1(source_file.sha1);
return false;
}
if (!WriteBufferToPartition(source_file, partition)) {
LOG(ERROR) << "Failed to write to " << partition;
return false;
}
return true;
}
static bool GenerateTarget(const Partition& target, const FileContents& source_file,
const Value& patch, const Value* bonus_data, bool backup_source) {
uint8_t expected_sha1[SHA_DIGEST_LENGTH];
if (ParseSha1(target.hash, expected_sha1) != 0) {
LOG(ERROR) << "Failed to parse target hash \"" << target.hash << "\"";
return false;
}
if (patch.type != Value::Type::BLOB) {
LOG(ERROR) << "patch is not a blob";
return false;
}
const char* header = patch.data.data();
size_t header_bytes_read = patch.data.size();
bool use_bsdiff = false;
if (header_bytes_read >= 8 && memcmp(header, "BSDIFF40", 8) == 0) {
use_bsdiff = true;
} else if (header_bytes_read >= 8 && memcmp(header, "IMGDIFF2", 8) == 0) {
use_bsdiff = false;
} else {
LOG(ERROR) << "Unknown patch file format";
return false;
}
// We write the original source to cache, in case the partition write is interrupted.
if (backup_source && !CheckAndFreeSpaceOnCache(source_file.data.size())) {
LOG(ERROR) << "Not enough free space on /cache";
return false;
}
if (backup_source && !SaveFileContents(Paths::Get().cache_temp_source(), &source_file)) {
LOG(ERROR) << "Failed to back up source file";
return false;
}
// We store the decoded output in memory.
FileContents patched;
SHA_CTX ctx;
SHA1_Init(&ctx);
SinkFn sink = [&patched, &ctx](const unsigned char* data, size_t len) {
SHA1_Update(&ctx, data, len);
patched.data.insert(patched.data.end(), data, data + len);
return len;
};
int result;
if (use_bsdiff) {
result = ApplyBSDiffPatch(source_file.data.data(), source_file.data.size(), patch, 0, sink);
} else {
result =
ApplyImagePatch(source_file.data.data(), source_file.data.size(), patch, sink, bonus_data);
}
if (result != 0) {
LOG(ERROR) << "Failed to apply the patch: " << result;
return false;
}
SHA1_Final(patched.sha1, &ctx);
if (memcmp(patched.sha1, expected_sha1, SHA_DIGEST_LENGTH) != 0) {
LOG(ERROR) << "Patching did not produce the expected SHA-1 of " << short_sha1(expected_sha1);
LOG(ERROR) << "target size " << patched.data.size() << " SHA-1 " << short_sha1(patched.sha1);
LOG(ERROR) << "source size " << source_file.data.size() << " SHA-1 "
<< short_sha1(source_file.sha1);
uint8_t patch_digest[SHA_DIGEST_LENGTH];
SHA1(reinterpret_cast<const uint8_t*>(patch.data.data()), patch.data.size(), patch_digest);
LOG(ERROR) << "patch size " << patch.data.size() << " SHA-1 " << short_sha1(patch_digest);
if (bonus_data != nullptr) {
uint8_t bonus_digest[SHA_DIGEST_LENGTH];
SHA1(reinterpret_cast<const uint8_t*>(bonus_data->data.data()), bonus_data->data.size(),
bonus_digest);
LOG(ERROR) << "bonus size " << bonus_data->data.size() << " SHA-1 "
<< short_sha1(bonus_digest);
}
return false;
}
LOG(INFO) << " now " << short_sha1(expected_sha1);
// Write back the temp file to the partition.
if (!WriteBufferToPartition(patched, target)) {
LOG(ERROR) << "Failed to write patched data to " << target.name;
return false;
}
// Delete the backup copy of the source.
if (backup_source) {
unlink(Paths::Get().cache_temp_source().c_str());
}
// Success!
return true;
}
bool CheckPartition(const Partition& partition) {
FileContents target_file;
return ReadPartitionToBuffer(partition, &target_file, false);
}
Partition Partition::Parse(const std::string& input_str, std::string* err) {
std::vector<std::string> pieces = android::base::Split(input_str, ":");
if (pieces.size() != 4 || pieces[0] != "EMMC") {
*err = "Invalid number of tokens or non-eMMC target";
return {};
}
size_t size;
if (!android::base::ParseUint(pieces[2], &size) || size == 0) {
*err = "Failed to parse \"" + pieces[2] + "\" as byte count";
return {};
}
return Partition(pieces[1], size, pieces[3]);
}
std::string Partition::ToString() const {
if (*this) {
return "EMMC:"s + name + ":" + std::to_string(size) + ":" + hash;
}
return "<invalid-partition>";
}
std::ostream& operator<<(std::ostream& os, const Partition& partition) {
os << partition.ToString();
return os;
}