libmodprobe/libmodprobe.cpp - android_system_core - Gitiles

 /*
  * Copyright (C) 2018 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 <modprobe/modprobe.h>

 #include <fnmatch.h>
 #include <sys/stat.h>
 #include <sys/syscall.h>

 #include <algorithm>
 #include <set>
 #include <string>
 #include <vector>

 #include <android-base/chrono_utils.h>
 #include <android-base/file.h>
 #include <android-base/logging.h>
 #include <android-base/strings.h>
 #include <android-base/unique_fd.h>

 std::string Modprobe::MakeCanonical(const std::string& module_path) {
     auto start = module_path.find_last_of('/');
     if (start == std::string::npos) {
         start = 0;
     } else {
         start += 1;
     }
     auto end = module_path.size();
     if (android::base::EndsWith(module_path, ".ko")) {
         end -= 3;
     }
     if ((end - start) <= 1) {
         LOG(ERROR) << "malformed module name: " << module_path;
         return "";
     }
     std::string module_name = module_path.substr(start, end - start);
     // module names can have '-', but their file names will have '_'
     std::replace(module_name.begin(), module_name.end(), '-', '_');
     return module_name;
 }

 bool Modprobe::ParseDepCallback(const std::string& base_path,
                                 const std::vector<std::string>& args) {
     std::vector<std::string> deps;
     std::string prefix = "";

     // Set first item as our modules path
     std::string::size_type pos = args[0].find(':');
     if (args[0][0] != '/') {
         prefix = base_path + "/";
     }
     if (pos != std::string::npos) {
         deps.emplace_back(prefix + args[0].substr(0, pos));
     } else {
         LOG(ERROR) << "dependency lines must start with name followed by ':'";
     }

     // Remaining items are dependencies of our module
     for (auto arg = args.begin() + 1; arg != args.end(); ++arg) {
         if ((*arg)[0] != '/') {
             prefix = base_path + "/";
         } else {
             prefix = "";
         }
         deps.push_back(prefix + *arg);
     }

     std::string canonical_name = MakeCanonical(args[0].substr(0, pos));
     if (canonical_name.empty()) {
         return false;
     }
     this->module_deps_[canonical_name] = deps;

     return true;
 }

 bool Modprobe::ParseAliasCallback(const std::vector<std::string>& args) {
     auto it = args.begin();
     const std::string& type = *it++;

     if (type != "alias") {
         LOG(ERROR) << "non-alias line encountered in modules.alias, found " << type;
         return false;
     }

     if (args.size() != 3) {
         LOG(ERROR) << "alias lines in modules.alias must have 3 entries, not " << args.size();
         return false;
     }

     const std::string& alias = *it++;
     const std::string& module_name = *it++;
     this->module_aliases_.emplace_back(alias, module_name);

     return true;
 }

 bool Modprobe::ParseSoftdepCallback(const std::vector<std::string>& args) {
     auto it = args.begin();
     const std::string& type = *it++;
     std::string state = "";

     if (type != "softdep") {
         LOG(ERROR) << "non-softdep line encountered in modules.softdep, found " << type;
         return false;
     }

     if (args.size() < 4) {
         LOG(ERROR) << "softdep lines in modules.softdep must have at least 4 entries";
         return false;
     }

     const std::string& module = *it++;
     while (it != args.end()) {
         const std::string& token = *it++;
         if (token == "pre:" || token == "post:") {
             state = token;
             continue;
         }
         if (state == "") {
             LOG(ERROR) << "malformed modules.softdep at token " << token;
             return false;
         }
         if (state == "pre:") {
             this->module_pre_softdep_.emplace_back(module, token);
         } else {
             this->module_post_softdep_.emplace_back(module, token);
         }
     }

     return true;
 }

 bool Modprobe::ParseLoadCallback(const std::vector<std::string>& args) {
     auto it = args.begin();
     const std::string& module = *it++;

     const std::string& canonical_name = MakeCanonical(module);
     if (canonical_name.empty()) {
         return false;
     }
     this->module_load_.emplace_back(canonical_name);

     return true;
 }

 bool Modprobe::ParseOptionsCallback(const std::vector<std::string>& args) {
     auto it = args.begin();
     const std::string& type = *it++;

     if (type != "options") {
         LOG(ERROR) << "non-options line encountered in modules.options";
         return false;
     }

     if (args.size() < 2) {
         LOG(ERROR) << "lines in modules.options must have at least 2 entries, not " << args.size();
         return false;
     }

     const std::string& module = *it++;
     std::string options = "";

     const std::string& canonical_name = MakeCanonical(module);
     if (canonical_name.empty()) {
         return false;
     }

     while (it != args.end()) {
         options += *it++;
         if (it != args.end()) {
             options += " ";
         }
     }

     auto [unused, inserted] = this->module_options_.emplace(canonical_name, options);
     if (!inserted) {
         LOG(ERROR) << "multiple options lines present for module " << module;
         return false;
     }
     return true;
 }

 void Modprobe::ParseCfg(const std::string& cfg,
                         std::function<bool(const std::vector<std::string>&)> f) {
     std::string cfg_contents;
     if (!android::base::ReadFileToString(cfg, &cfg_contents, false)) {
         return;
     }

     std::vector<std::string> lines = android::base::Split(cfg_contents, "\n");
     for (const std::string line : lines) {
         if (line.empty() || line[0] == '#') {
             continue;
         }
         const std::vector<std::string> args = android::base::Split(line, " ");
         if (args.empty()) continue;
         f(args);
     }
     return;
 }

 Modprobe::Modprobe(const std::vector<std::string>& base_paths) {
     using namespace std::placeholders;

     for (const auto& base_path : base_paths) {
         auto alias_callback = std::bind(&Modprobe::ParseAliasCallback, this, _1);
         ParseCfg(base_path + "/modules.alias", alias_callback);

         auto dep_callback = std::bind(&Modprobe::ParseDepCallback, this, base_path, _1);
         ParseCfg(base_path + "/modules.dep", dep_callback);

         auto softdep_callback = std::bind(&Modprobe::ParseSoftdepCallback, this, _1);
         ParseCfg(base_path + "/modules.softdep", softdep_callback);

         auto load_callback = std::bind(&Modprobe::ParseLoadCallback, this, _1);
         ParseCfg(base_path + "/modules.load", load_callback);

         auto options_callback = std::bind(&Modprobe::ParseOptionsCallback, this, _1);
         ParseCfg(base_path + "/modules.options", options_callback);
     }
 }

 std::vector<std::string> Modprobe::GetDependencies(const std::string& module) {
     auto it = module_deps_.find(module);
     if (it == module_deps_.end()) {
         return {};
     }
     return it->second;
 }

 bool Modprobe::InsmodWithDeps(const std::string& module_name) {
     if (module_name.empty()) {
         LOG(ERROR) << "Need valid module name, given: " << module_name;
         return false;
     }

     auto dependencies = GetDependencies(module_name);
     if (dependencies.empty()) {
         LOG(ERROR) << "Module " << module_name << " not in dependency file";
         return false;
     }

     // load module dependencies in reverse order
     for (auto dep = dependencies.rbegin(); dep != dependencies.rend() - 1; ++dep) {
         const std::string& canonical_name = MakeCanonical(*dep);
         if (canonical_name.empty()) {
             return false;
         }
         if (!LoadWithAliases(canonical_name, true)) {
             return false;
         }
     }

     // try to load soft pre-dependencies
     for (const auto& [module, softdep] : module_pre_softdep_) {
         if (module_name == module) {
             LoadWithAliases(softdep, false);
         }
     }

     // load target module itself with args
     if (!Insmod(dependencies[0])) {
         return false;
     }

     // try to load soft post-dependencies
     for (const auto& [module, softdep] : module_post_softdep_) {
         if (module_name == module) {
             LoadWithAliases(softdep, false);
         }
     }

     return true;
 }

 bool Modprobe::LoadWithAliases(const std::string& module_name, bool strict) {
     std::set<std::string> modules_to_load = {module_name};
     bool module_loaded = false;

     // use aliases to expand list of modules to load (multiple modules
     // may alias themselves to the requested name)
     for (const auto& [alias, aliased_module] : module_aliases_) {
         if (fnmatch(alias.c_str(), module_name.c_str(), 0) != 0) continue;
         modules_to_load.emplace(aliased_module);
     }

     // attempt to load all modules aliased to this name
     for (const auto& module : modules_to_load) {
         if (!ModuleExists(module)) continue;
         if (InsmodWithDeps(module)) module_loaded = true;
     }

     if (strict && !module_loaded) {
         LOG(ERROR) << "LoadWithAliases did not find a module for " << module_name;
         return false;
     }
     return true;
 }

 bool Modprobe::LoadListedModules() {
     for (const auto& module : module_load_) {
         if (!LoadWithAliases(module, true)) {
             return false;
         }
     }
     return true;
 }
	/*
	* Copyright (C) 2018 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 <modprobe/modprobe.h>

	#include <fnmatch.h>
	#include <sys/stat.h>
	#include <sys/syscall.h>

	#include <algorithm>
	#include <set>
	#include <string>
	#include <vector>

	#include <android-base/chrono_utils.h>
	#include <android-base/file.h>
	#include <android-base/logging.h>
	#include <android-base/strings.h>
	#include <android-base/unique_fd.h>

	std::string Modprobe::MakeCanonical(const std::string& module_path) {
	auto start = module_path.find_last_of('/');
	if (start == std::string::npos) {
	start = 0;
	} else {
	start += 1;
	}
	auto end = module_path.size();
	if (android::base::EndsWith(module_path, ".ko")) {
	end -= 3;
	}
	if ((end - start) <= 1) {
	LOG(ERROR) << "malformed module name: " << module_path;
	return "";
	}
	std::string module_name = module_path.substr(start, end - start);
	// module names can have '-', but their file names will have '_'
	std::replace(module_name.begin(), module_name.end(), '-', '_');
	return module_name;
	}

	bool Modprobe::ParseDepCallback(const std::string& base_path,
	const std::vector<std::string>& args) {
	std::vector<std::string> deps;
	std::string prefix = "";

	// Set first item as our modules path
	std::string::size_type pos = args[0].find(':');
	if (args[0][0] != '/') {
	prefix = base_path + "/";
	}
	if (pos != std::string::npos) {
	deps.emplace_back(prefix + args[0].substr(0, pos));
	} else {
	LOG(ERROR) << "dependency lines must start with name followed by ':'";
	}

	// Remaining items are dependencies of our module
	for (auto arg = args.begin() + 1; arg != args.end(); ++arg) {
	if ((*arg)[0] != '/') {
	prefix = base_path + "/";
	} else {
	prefix = "";
	}
	deps.push_back(prefix + *arg);
	}

	std::string canonical_name = MakeCanonical(args[0].substr(0, pos));
	if (canonical_name.empty()) {
	return false;
	}
	this->module_deps_[canonical_name] = deps;

	return true;
	}

	bool Modprobe::ParseAliasCallback(const std::vector<std::string>& args) {
	auto it = args.begin();
	const std::string& type = *it++;

	if (type != "alias") {
	LOG(ERROR) << "non-alias line encountered in modules.alias, found " << type;
	return false;
	}

	if (args.size() != 3) {
	LOG(ERROR) << "alias lines in modules.alias must have 3 entries, not " << args.size();
	return false;
	}

	const std::string& alias = *it++;
	const std::string& module_name = *it++;
	this->module_aliases_.emplace_back(alias, module_name);

	return true;
	}

	bool Modprobe::ParseSoftdepCallback(const std::vector<std::string>& args) {
	auto it = args.begin();
	const std::string& type = *it++;
	std::string state = "";

	if (type != "softdep") {
	LOG(ERROR) << "non-softdep line encountered in modules.softdep, found " << type;
	return false;
	}

	if (args.size() < 4) {
	LOG(ERROR) << "softdep lines in modules.softdep must have at least 4 entries";
	return false;
	}

	const std::string& module = *it++;
	while (it != args.end()) {
	const std::string& token = *it++;
	if (token == "pre:" \|\| token == "post:") {
	state = token;
	continue;
	}
	if (state == "") {
	LOG(ERROR) << "malformed modules.softdep at token " << token;
	return false;
	}
	if (state == "pre:") {
	this->module_pre_softdep_.emplace_back(module, token);
	} else {
	this->module_post_softdep_.emplace_back(module, token);
	}
	}

	return true;
	}

	bool Modprobe::ParseLoadCallback(const std::vector<std::string>& args) {
	auto it = args.begin();
	const std::string& module = *it++;

	const std::string& canonical_name = MakeCanonical(module);
	if (canonical_name.empty()) {
	return false;
	}
	this->module_load_.emplace_back(canonical_name);

	return true;
	}

	bool Modprobe::ParseOptionsCallback(const std::vector<std::string>& args) {
	auto it = args.begin();
	const std::string& type = *it++;

	if (type != "options") {
	LOG(ERROR) << "non-options line encountered in modules.options";
	return false;
	}

	if (args.size() < 2) {
	LOG(ERROR) << "lines in modules.options must have at least 2 entries, not " << args.size();
	return false;
	}

	const std::string& module = *it++;
	std::string options = "";

	const std::string& canonical_name = MakeCanonical(module);
	if (canonical_name.empty()) {
	return false;
	}

	while (it != args.end()) {
	options += *it++;
	if (it != args.end()) {
	options += " ";
	}
	}

	auto [unused, inserted] = this->module_options_.emplace(canonical_name, options);
	if (!inserted) {
	LOG(ERROR) << "multiple options lines present for module " << module;
	return false;
	}
	return true;
	}

	void Modprobe::ParseCfg(const std::string& cfg,
	std::function<bool(const std::vector<std::string>&)> f) {
	std::string cfg_contents;
	if (!android::base::ReadFileToString(cfg, &cfg_contents, false)) {
	return;
	}

	std::vector<std::string> lines = android::base::Split(cfg_contents, "\n");
	for (const std::string line : lines) {
	if (line.empty() \|\| line[0] == '#') {
	continue;
	}
	const std::vector<std::string> args = android::base::Split(line, " ");
	if (args.empty()) continue;
	f(args);
	}
	return;
	}

	Modprobe::Modprobe(const std::vector<std::string>& base_paths) {
	using namespace std::placeholders;

	for (const auto& base_path : base_paths) {
	auto alias_callback = std::bind(&Modprobe::ParseAliasCallback, this, _1);
	ParseCfg(base_path + "/modules.alias", alias_callback);

	auto dep_callback = std::bind(&Modprobe::ParseDepCallback, this, base_path, _1);
	ParseCfg(base_path + "/modules.dep", dep_callback);

	auto softdep_callback = std::bind(&Modprobe::ParseSoftdepCallback, this, _1);
	ParseCfg(base_path + "/modules.softdep", softdep_callback);

	auto load_callback = std::bind(&Modprobe::ParseLoadCallback, this, _1);
	ParseCfg(base_path + "/modules.load", load_callback);

	auto options_callback = std::bind(&Modprobe::ParseOptionsCallback, this, _1);
	ParseCfg(base_path + "/modules.options", options_callback);
	}
	}

	std::vector<std::string> Modprobe::GetDependencies(const std::string& module) {
	auto it = module_deps_.find(module);
	if (it == module_deps_.end()) {
	return {};
	}
	return it->second;
	}

	bool Modprobe::InsmodWithDeps(const std::string& module_name) {
	if (module_name.empty()) {
	LOG(ERROR) << "Need valid module name, given: " << module_name;
	return false;
	}

	auto dependencies = GetDependencies(module_name);
	if (dependencies.empty()) {
	LOG(ERROR) << "Module " << module_name << " not in dependency file";
	return false;
	}

	// load module dependencies in reverse order
	for (auto dep = dependencies.rbegin(); dep != dependencies.rend() - 1; ++dep) {
	const std::string& canonical_name = MakeCanonical(*dep);
	if (canonical_name.empty()) {
	return false;
	}
	if (!LoadWithAliases(canonical_name, true)) {
	return false;
	}
	}

	// try to load soft pre-dependencies
	for (const auto& [module, softdep] : module_pre_softdep_) {
	if (module_name == module) {
	LoadWithAliases(softdep, false);
	}
	}

	// load target module itself with args
	if (!Insmod(dependencies[0])) {
	return false;
	}

	// try to load soft post-dependencies
	for (const auto& [module, softdep] : module_post_softdep_) {
	if (module_name == module) {
	LoadWithAliases(softdep, false);
	}
	}

	return true;
	}

	bool Modprobe::LoadWithAliases(const std::string& module_name, bool strict) {
	std::set<std::string> modules_to_load = {module_name};
	bool module_loaded = false;

	// use aliases to expand list of modules to load (multiple modules
	// may alias themselves to the requested name)
	for (const auto& [alias, aliased_module] : module_aliases_) {
	if (fnmatch(alias.c_str(), module_name.c_str(), 0) != 0) continue;
	modules_to_load.emplace(aliased_module);
	}

	// attempt to load all modules aliased to this name
	for (const auto& module : modules_to_load) {
	if (!ModuleExists(module)) continue;
	if (InsmodWithDeps(module)) module_loaded = true;
	}

	if (strict && !module_loaded) {
	LOG(ERROR) << "LoadWithAliases did not find a module for " << module_name;
	return false;
	}
	return true;
	}

	bool Modprobe::LoadListedModules() {
	for (const auto& module : module_load_) {
	if (!LoadWithAliases(module, true)) {
	return false;
	}
	}
	return true;
	}