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/*
* Copyright (C) 2020 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 "linkerconfig/apex.h"
#include <algorithm>
#include <cstring>
#include <regex>
#include <set>
#include <string>
#include <string_view>
#include <vector>
#include <android-base/file.h>
#include <android-base/result.h>
#include <android-base/strings.h>
#include <apexutil.h>
#include <unistd.h>
#include "linkerconfig/configparser.h"
#include "linkerconfig/environment.h"
#include "linkerconfig/log.h"
#include "linkerconfig/stringutil.h"
// include after log.h to avoid macro redefinition error
#include "com_android_apex.h"
using android::base::ErrnoError;
using android::base::Error;
using android::base::ReadFileToString;
using android::base::Result;
using android::base::StartsWith;
namespace {
bool PathExists(const std::string& path) {
return access(path.c_str(), F_OK) == 0;
}
Result<std::set<std::string>> ReadPublicLibraries(const std::string& filepath) {
std::string file_content;
if (!android::base::ReadFileToString(filepath, &file_content)) {
return ErrnoError();
}
std::vector<std::string> lines = android::base::Split(file_content, "\n");
std::set<std::string> sonames;
for (auto& line : lines) {
auto trimmed_line = android::base::Trim(line);
if (trimmed_line[0] == '#' || trimmed_line.empty()) {
continue;
}
std::vector<std::string> tokens = android::base::Split(trimmed_line, " ");
if (tokens.size() < 1 || tokens.size() > 3) {
return Errorf("Malformed line \"{}\"", line);
}
sonames.insert(tokens[0]);
}
return sonames;
}
std::vector<std::string> Intersect(const std::vector<std::string>& as,
const std::set<std::string>& bs) {
std::vector<std::string> intersect;
std::copy_if(as.begin(),
as.end(),
std::back_inserter(intersect),
[&bs](const auto& a) { return bs.find(a) != bs.end(); });
return intersect;
}
bool IsValidForPath(const uint_fast8_t c) {
if (c >= 'a' && c <= 'z') return true;
if (c >= 'A' && c <= 'Z') return true;
if (c >= '0' && c <= '9') return true;
if (c == '-' || c == '_' || c == '.') return true;
return false;
}
Result<void> VerifyPath(const std::string& path) {
const size_t length = path.length();
constexpr char lib_dir[] = "${LIB}";
constexpr size_t lib_dir_len = (sizeof lib_dir) - 1;
const std::string_view path_view(path);
if (length == 0) {
return Error() << "Empty path is not allowed";
}
for (size_t i = 0; i < length; i++) {
uint_fast8_t current_char = path[i];
if (current_char == '/') {
i++;
if (i >= length) {
return {};
} else if (path[i] == '/') {
return Error() << "'/' should not appear twice in " << path;
} else if (i + lib_dir_len <= length &&
path_view.substr(i, lib_dir_len) == lib_dir) {
i += lib_dir_len - 1;
} else {
for (; i < length; i++) {
current_char = path[i];
if (current_char == '/') {
i--;
break;
}
if (!IsValidForPath(current_char)) {
return Error() << "Invalid char '" << current_char << "' in "
<< path;
}
}
}
} else {
return Error() << "Invalid char '" << current_char << "' in " << path
<< " at " << i;
}
}
return {};
}
} // namespace
namespace android {
namespace linkerconfig {
namespace modules {
Result<std::map<std::string, ApexInfo>> ScanActiveApexes(const std::string& root) {
std::map<std::string, ApexInfo> apexes;
const auto apex_root = root + apex::kApexRoot;
for (const auto& [path, manifest] : apex::GetActivePackages(apex_root)) {
bool has_bin = PathExists(path + "/bin");
bool has_lib = PathExists(path + "/lib") || PathExists(path + "/lib64");
bool has_shared_lib = manifest.requiresharedapexlibs().size() != 0;
std::vector<std::string> permitted_paths;
bool visible = false;
std::string linker_config_path = path + "/etc/linker.config.pb";
if (PathExists(linker_config_path)) {
auto linker_config = ParseLinkerConfig(linker_config_path);
if (linker_config.ok()) {
permitted_paths = {linker_config->permittedpaths().begin(),
linker_config->permittedpaths().end()};
for (const std::string& path : permitted_paths) {
Result<void> verify_permitted_path = VerifyPath(path);
if (!verify_permitted_path.ok()) {
return Error() << "Failed to validate path from APEX linker config"
<< linker_config_path << " : "
<< verify_permitted_path.error();
}
}
visible = linker_config->visible();
} else {
return Error() << "Failed to read APEX linker config : "
<< linker_config.error();
}
}
ApexInfo info(manifest.name(),
TrimPrefix(path, root),
{manifest.providenativelibs().begin(),
manifest.providenativelibs().end()},
{manifest.requirenativelibs().begin(),
manifest.requirenativelibs().end()},
{manifest.jnilibs().begin(), manifest.jnilibs().end()},
std::move(permitted_paths),
has_bin,
has_lib,
visible,
has_shared_lib);
apexes.emplace(manifest.name(), std::move(info));
}
if (!apexes.empty()) {
const std::string info_list_file = apex_root + "/apex-info-list.xml";
auto info_list =
com::android::apex::readApexInfoList(info_list_file.c_str());
if (info_list.has_value()) {
for (const auto& info : info_list->getApexInfo()) {
apexes[info.getModuleName()].original_path =
info.getPreinstalledModulePath();
}
} else {
return ErrnoError() << "Can't read " << info_list_file;
}
const std::string public_libraries_file =
root + "/system/etc/public.libraries.txt";
auto public_libraries = ReadPublicLibraries(public_libraries_file);
if (public_libraries.ok()) {
for (auto& [name, apex] : apexes) {
// Only system apexes can provide public libraries.
if (!apex.InSystem()) {
continue;
}
apex.public_libs = Intersect(apex.provide_libs, *public_libraries);
}
} else {
// Do not fail when public.libraries.txt is missing for minimal Android
// environment with no ART.
LOG(WARNING) << "Can't read " << public_libraries_file << ": "
<< public_libraries.error();
}
}
return apexes;
}
bool ApexInfo::InSystem() const {
return StartsWith(original_path, "/system/apex/") ||
StartsWith(original_path, "/system_ext/apex/") ||
(!IsProductVndkVersionDefined() &&
StartsWith(original_path, "/product/apex/"));
}
bool ApexInfo::InProduct() const {
return IsProductVndkVersionDefined() &&
StartsWith(original_path, "/product/apex/");
}
bool ApexInfo::InVendor() const {
return StartsWith(original_path, "/vendor/apex/") ||
StartsWith(original_path, "/odm/apex/");
}
} // namespace modules
} // namespace linkerconfig
} // namespace android