| /* | 
 |  * 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 ':'"; | 
 |         return false; | 
 |     } | 
 |  | 
 |     // 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; | 
 | } | 
 |  | 
 | bool Modprobe::ParseBlocklistCallback(const std::vector<std::string>& args) { | 
 |     auto it = args.begin(); | 
 |     const std::string& type = *it++; | 
 |  | 
 |     if (type != "blocklist") { | 
 |         LOG(ERROR) << "non-blocklist line encountered in modules.blocklist"; | 
 |         return false; | 
 |     } | 
 |  | 
 |     if (args.size() != 2) { | 
 |         LOG(ERROR) << "lines in modules.blocklist must have exactly 2 entries, not " << args.size(); | 
 |         return false; | 
 |     } | 
 |  | 
 |     const std::string& module = *it++; | 
 |  | 
 |     const std::string& canonical_name = MakeCanonical(module); | 
 |     if (canonical_name.empty()) { | 
 |         return false; | 
 |     } | 
 |     this->module_blocklist_.emplace(canonical_name); | 
 |  | 
 |     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; | 
 | } | 
 |  | 
 | void Modprobe::AddOption(const std::string& module_name, const std::string& option_name, | 
 |                          const std::string& value) { | 
 |     auto canonical_name = MakeCanonical(module_name); | 
 |     auto options_iter = module_options_.find(canonical_name); | 
 |     auto option_str = option_name + "=" + value; | 
 |     if (options_iter != module_options_.end()) { | 
 |         options_iter->second = options_iter->second + " " + option_str; | 
 |     } else { | 
 |         module_options_.emplace(canonical_name, option_str); | 
 |     } | 
 | } | 
 |  | 
 | void Modprobe::ParseKernelCmdlineOptions(void) { | 
 |     std::string cmdline = GetKernelCmdline(); | 
 |     std::string module_name = ""; | 
 |     std::string option_name = ""; | 
 |     std::string value = ""; | 
 |     bool in_module = true; | 
 |     bool in_option = false; | 
 |     bool in_value = false; | 
 |     bool in_quotes = false; | 
 |     int start = 0; | 
 |  | 
 |     for (int i = 0; i < cmdline.size(); i++) { | 
 |         if (cmdline[i] == '"') { | 
 |             in_quotes = !in_quotes; | 
 |         } | 
 |  | 
 |         if (in_quotes) continue; | 
 |  | 
 |         if (cmdline[i] == ' ') { | 
 |             if (in_value) { | 
 |                 value = cmdline.substr(start, i - start); | 
 |                 if (!module_name.empty() && !option_name.empty()) { | 
 |                     AddOption(module_name, option_name, value); | 
 |                 } | 
 |             } | 
 |             module_name = ""; | 
 |             option_name = ""; | 
 |             value = ""; | 
 |             in_value = false; | 
 |             start = i + 1; | 
 |             in_module = true; | 
 |             continue; | 
 |         } | 
 |  | 
 |         if (cmdline[i] == '.') { | 
 |             if (in_module) { | 
 |                 module_name = cmdline.substr(start, i - start); | 
 |                 start = i + 1; | 
 |                 in_module = false; | 
 |             } | 
 |             in_option = true; | 
 |             continue; | 
 |         } | 
 |  | 
 |         if (cmdline[i] == '=') { | 
 |             if (in_option) { | 
 |                 option_name = cmdline.substr(start, i - start); | 
 |                 start = i + 1; | 
 |                 in_option = false; | 
 |             } | 
 |             in_value = true; | 
 |             continue; | 
 |         } | 
 |     } | 
 |     if (in_value && !in_quotes) { | 
 |         value = cmdline.substr(start, cmdline.size() - start); | 
 |         if (!module_name.empty() && !option_name.empty()) { | 
 |             AddOption(module_name, option_name, value); | 
 |         } | 
 |     } | 
 | } | 
 |  | 
 | Modprobe::Modprobe(const std::vector<std::string>& base_paths, const std::string load_file, | 
 |                    bool use_blocklist) | 
 |     : blocklist_enabled(use_blocklist) { | 
 |     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 + "/" + load_file, load_callback); | 
 |  | 
 |         auto options_callback = std::bind(&Modprobe::ParseOptionsCallback, this, _1); | 
 |         ParseCfg(base_path + "/modules.options", options_callback); | 
 |  | 
 |         auto blocklist_callback = std::bind(&Modprobe::ParseBlocklistCallback, this, _1); | 
 |         ParseCfg(base_path + "/modules.blocklist", blocklist_callback); | 
 |     } | 
 |  | 
 |     ParseKernelCmdlineOptions(); | 
 | } | 
 |  | 
 | 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, const std::string& parameters) { | 
 |     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) { | 
 |         LOG(VERBOSE) << "Loading hard dep for '" << module_name << "': " << *dep; | 
 |         if (!LoadWithAliases(*dep, true)) { | 
 |             return false; | 
 |         } | 
 |     } | 
 |  | 
 |     // try to load soft pre-dependencies | 
 |     for (const auto& [module, softdep] : module_pre_softdep_) { | 
 |         if (module_name == module) { | 
 |             LOG(VERBOSE) << "Loading soft pre-dep for '" << module << "': " << softdep; | 
 |             LoadWithAliases(softdep, false); | 
 |         } | 
 |     } | 
 |  | 
 |     // load target module itself with args | 
 |     if (!Insmod(dependencies[0], parameters)) { | 
 |         return false; | 
 |     } | 
 |  | 
 |     // try to load soft post-dependencies | 
 |     for (const auto& [module, softdep] : module_post_softdep_) { | 
 |         if (module_name == module) { | 
 |             LOG(VERBOSE) << "Loading soft post-dep for '" << module << "': " << softdep; | 
 |             LoadWithAliases(softdep, false); | 
 |         } | 
 |     } | 
 |  | 
 |     return true; | 
 | } | 
 |  | 
 | bool Modprobe::LoadWithAliases(const std::string& module_name, bool strict, | 
 |                                const std::string& parameters) { | 
 |     auto canonical_name = MakeCanonical(module_name); | 
 |     if (module_loaded_.count(canonical_name)) { | 
 |         return true; | 
 |     } | 
 |  | 
 |     std::set<std::string> modules_to_load = {canonical_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; | 
 |         LOG(VERBOSE) << "Found alias for '" << module_name << "': '" << aliased_module; | 
 |         if (module_loaded_.count(MakeCanonical(aliased_module))) 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, parameters)) module_loaded = true; | 
 |     } | 
 |  | 
 |     if (strict && !module_loaded) { | 
 |         LOG(ERROR) << "LoadWithAliases was unable to load " << module_name; | 
 |         return false; | 
 |     } | 
 |     return true; | 
 | } | 
 |  | 
 | bool Modprobe::IsBlocklisted(const std::string& module_name) { | 
 |     if (!blocklist_enabled) return false; | 
 |  | 
 |     auto canonical_name = MakeCanonical(module_name); | 
 |     auto dependencies = GetDependencies(canonical_name); | 
 |     for (auto dep = dependencies.begin(); dep != dependencies.end(); ++dep) { | 
 |         if (module_blocklist_.count(MakeCanonical(*dep))) return true; | 
 |     } | 
 |  | 
 |     return module_blocklist_.count(canonical_name) > 0; | 
 | } | 
 |  | 
 | bool Modprobe::LoadListedModules(bool strict) { | 
 |     auto ret = true; | 
 |     for (const auto& module : module_load_) { | 
 |         if (!LoadWithAliases(module, true)) { | 
 |             if (IsBlocklisted(module)) continue; | 
 |             ret = false; | 
 |             if (strict) break; | 
 |         } | 
 |     } | 
 |     return ret; | 
 | } | 
 |  | 
 | bool Modprobe::Remove(const std::string& module_name) { | 
 |     auto dependencies = GetDependencies(MakeCanonical(module_name)); | 
 |     for (auto dep = dependencies.begin(); dep != dependencies.end(); ++dep) { | 
 |         Rmmod(*dep); | 
 |     } | 
 |     Rmmod(module_name); | 
 |     return true; | 
 | } | 
 |  | 
 | std::vector<std::string> Modprobe::ListModules(const std::string& pattern) { | 
 |     std::vector<std::string> rv; | 
 |     for (const auto& [module, deps] : module_deps_) { | 
 |         // Attempt to match both the canonical module name and the module filename. | 
 |         if (!fnmatch(pattern.c_str(), module.c_str(), 0)) { | 
 |             rv.emplace_back(module); | 
 |         } else if (!fnmatch(pattern.c_str(), basename(deps[0].c_str()), 0)) { | 
 |             rv.emplace_back(deps[0]); | 
 |         } | 
 |     } | 
 |     return rv; | 
 | } | 
 |  | 
 | bool Modprobe::GetAllDependencies(const std::string& module, | 
 |                                   std::vector<std::string>* pre_dependencies, | 
 |                                   std::vector<std::string>* dependencies, | 
 |                                   std::vector<std::string>* post_dependencies) { | 
 |     std::string canonical_name = MakeCanonical(module); | 
 |     if (pre_dependencies) { | 
 |         pre_dependencies->clear(); | 
 |         for (const auto& [it_module, it_softdep] : module_pre_softdep_) { | 
 |             if (canonical_name == it_module) { | 
 |                 pre_dependencies->emplace_back(it_softdep); | 
 |             } | 
 |         } | 
 |     } | 
 |     if (dependencies) { | 
 |         dependencies->clear(); | 
 |         auto hard_deps = GetDependencies(canonical_name); | 
 |         if (hard_deps.empty()) { | 
 |             return false; | 
 |         } | 
 |         for (auto dep = hard_deps.rbegin(); dep != hard_deps.rend(); dep++) { | 
 |             dependencies->emplace_back(*dep); | 
 |         } | 
 |     } | 
 |     if (post_dependencies) { | 
 |         for (const auto& [it_module, it_softdep] : module_post_softdep_) { | 
 |             if (canonical_name == it_module) { | 
 |                 post_dependencies->emplace_back(it_softdep); | 
 |             } | 
 |         } | 
 |     } | 
 |     return true; | 
 | } |