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/*
**
** Copyright 2016, 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 "read_apk.h"
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include <memory>
#include <android-base/file.h>
#include <android-base/logging.h>
#include <android-base/strings.h>
#include <ziparchive/zip_archive.h>
#include "read_elf.h"
#include "utils.h"
std::unordered_map<std::string, ApkInspector::ApkNode> ApkInspector::embedded_elf_cache_;
EmbeddedElf* ApkInspector::FindElfInApkByOffset(const std::string& apk_path, uint64_t file_offset) {
// Already in cache?
ApkNode& node = embedded_elf_cache_[apk_path];
auto it = node.offset_map.find(file_offset);
if (it != node.offset_map.end()) {
return it->second.get();
}
std::unique_ptr<EmbeddedElf> elf = FindElfInApkByOffsetWithoutCache(apk_path, file_offset);
EmbeddedElf* result = elf.get();
node.offset_map[file_offset] = std::move(elf);
if (result != nullptr) {
node.name_map[result->entry_name()] = result;
}
return result;
}
EmbeddedElf* ApkInspector::FindElfInApkByName(const std::string& apk_path,
const std::string& entry_name) {
ApkNode& node = embedded_elf_cache_[apk_path];
auto it = node.name_map.find(entry_name);
if (it != node.name_map.end()) {
return it->second;
}
std::unique_ptr<EmbeddedElf> elf = FindElfInApkByNameWithoutCache(apk_path, entry_name);
EmbeddedElf* result = elf.get();
node.name_map[entry_name] = result;
if (result != nullptr) {
node.offset_map[result->entry_offset()] = std::move(elf);
}
return result;
}
std::unique_ptr<EmbeddedElf> ApkInspector::FindElfInApkByOffsetWithoutCache(
const std::string& apk_path, uint64_t file_offset) {
std::unique_ptr<ArchiveHelper> ahelper = ArchiveHelper::CreateInstance(apk_path);
if (!ahelper) {
return nullptr;
}
// Iterate through the zip file. Look for a zip entry corresponding
// to an uncompressed blob whose range intersects with the mmap
// offset we're interested in.
bool found = false;
ZipEntry found_entry;
std::string found_entry_name;
bool result = ahelper->IterateEntries([&](ZipEntry& entry, const std::string& name) {
if (entry.method == kCompressStored &&
file_offset >= static_cast<uint64_t>(entry.offset) &&
file_offset < static_cast<uint64_t>(entry.offset) + entry.uncompressed_length) {
found = true;
found_entry = entry;
found_entry_name = name;
return false;
}
return true;
});
if (!result || !found) {
return nullptr;
}
// We found something in the zip file at the right spot. Is it an ELF?
if (lseek(ahelper->GetFd(), found_entry.offset, SEEK_SET) != found_entry.offset) {
PLOG(ERROR) << "lseek() failed in " << apk_path << " offset " << found_entry.offset;
return nullptr;
}
if (IsValidElfFile(ahelper->GetFd()) != ElfStatus::NO_ERROR) {
// Omit files that are not ELF files.
return nullptr;
}
return std::unique_ptr<EmbeddedElf>(new EmbeddedElf(apk_path, found_entry_name,
found_entry.offset,
found_entry.uncompressed_length));
}
std::unique_ptr<EmbeddedElf> ApkInspector::FindElfInApkByNameWithoutCache(
const std::string& apk_path, const std::string& entry_name) {
std::unique_ptr<ArchiveHelper> ahelper = ArchiveHelper::CreateInstance(apk_path);
if (!ahelper) {
return nullptr;
}
ZipEntry zentry;
if (!ahelper->FindEntry(entry_name, &zentry)) {
return nullptr;
}
if (zentry.method != kCompressStored || zentry.compressed_length != zentry.uncompressed_length) {
return nullptr;
}
return std::unique_ptr<EmbeddedElf>(new EmbeddedElf(apk_path, entry_name, zentry.offset,
zentry.uncompressed_length));
}
// Refer file in apk in compliance with http://developer.android.com/reference/java/net/JarURLConnection.html.
std::string GetUrlInApk(const std::string& apk_path, const std::string& elf_filename) {
return apk_path + "!/" + elf_filename;
}
std::tuple<bool, std::string, std::string> SplitUrlInApk(const std::string& path) {
size_t pos = path.find("!/");
if (pos == std::string::npos) {
return std::make_tuple(false, "", "");
}
return std::make_tuple(true, path.substr(0, pos), path.substr(pos + 2));
}
// Parse path like "[anon:dalvik-classes.dex extracted in memory from /..base.apk] (deleted)",
// or "/dev/ashmem/dalvik-classes.dex extracted in memory from /..base.apk (deleted)" on Android P.
bool ParseExtractedInMemoryPath(const std::string& path, std::string* zip_path,
std::string* entry_name) {
const char* prefixes[2] = {"[anon:dalvik-", "/dev/ashmem/dalvik-"};
const char* key = " extracted in memory from ";
size_t pos = path.find(key);
if (pos != std::string::npos) {
for (const char* prefix : prefixes) {
if (android::base::StartsWith(path, prefix)) {
size_t entry_name_start = strlen(prefix);
size_t entry_name_end = pos;
size_t zip_path_start = pos + strlen(key);
size_t zip_path_end = path.find_first_of(" ]", zip_path_start);
if (zip_path_end == std::string::npos) {
zip_path_end = path.size();
}
if (entry_name_start < entry_name_end && zip_path_start < zip_path_end) {
*entry_name = path.substr(entry_name_start, entry_name_end - entry_name_start);
*zip_path = path.substr(zip_path_start, zip_path_end - zip_path_start);
size_t multidex_separator_pos = zip_path->find('!');
if (multidex_separator_pos != std::string::npos) {
zip_path->resize(multidex_separator_pos);
}
return true;
}
}
}
}
return false;
}
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