create libmodprobe, integrate into first_stage_init
Modprobe functionality is required both within first stage init and also
as a standalone binary. Create a library for this using and extending
the logic in modalias_handler.cpp.
First stage init will attempt to load modules from /lib/modules.
Bug: 129780532
Change-Id: Ie3582358fd839c2f64e1b386b30ed551a86aef5d
diff --git a/libmodprobe/libmodprobe.cpp b/libmodprobe/libmodprobe.cpp
new file mode 100644
index 0000000..01cf2e3
--- /dev/null
+++ b/libmodprobe/libmodprobe.cpp
@@ -0,0 +1,321 @@
+/*
+ * 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;
+}