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

1 files changed, 4 insertions, 131 deletions

diff --git a/init/modalias_handler.cpp b/init/modalias_handler.cpp
index a51115628..07b05d8b4 100644
--- a/init/modalias_handler.cpp
+++ b/init/modalias_handler.cpp
@@ -16,147 +16,20 @@
 
 #include "modalias_handler.h"
 
-#include <fnmatch.h>
-#include <sys/syscall.h>
-
-#include <algorithm>
-#include <functional>
 #include <string>
 #include <vector>
 
-#include <android-base/chrono_utils.h>
-#include <android-base/logging.h>
-#include <android-base/unique_fd.h>
-
-#include "parser.h"
+#include <modprobe/modprobe.h>
 
 namespace android {
 namespace init {
 
-Result<void> ModaliasHandler::ParseDepCallback(std::vector<std::string>&& args) {
-    std::vector<std::string> deps;
-
-    // Set first item as our modules path
-    std::string::size_type pos = args[0].find(':');
-    if (pos != std::string::npos) {
-        deps.emplace_back(args[0].substr(0, pos));
-    } else {
-        return 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) {
-        deps.push_back(*arg);
-    }
-
-    // Key is striped module name to match names in alias file
-    std::size_t start = args[0].find_last_of('/');
-    std::size_t end = args[0].find(".ko:");
-    if ((end - start) <= 1) return Error() << "malformed dependency line";
-    auto mod_name = args[0].substr(start + 1, (end - start) - 1);
-    // module names can have '-', but their file names will have '_'
-    std::replace(mod_name.begin(), mod_name.end(), '-', '_');
-    this->module_deps_[mod_name] = deps;
-
-    return {};
-}
-
-Result<void> ModaliasHandler::ParseAliasCallback(std::vector<std::string>&& args) {
-    auto it = args.begin();
-    const std::string& type = *it++;
-
-    if (type != "alias") {
-        return Error() << "we only handle alias lines, got: " << type;
-    }
-
-    if (args.size() != 3) {
-        return Error() << "alias lines must have 3 entries";
-    }
-
-    std::string& alias = *it++;
-    std::string& module_name = *it++;
-    this->module_aliases_.emplace_back(alias, module_name);
-
-    return {};
-}
-
-ModaliasHandler::ModaliasHandler() {
-    using namespace std::placeholders;
-
-    static const std::string base_paths[] = {
-            "/vendor/lib/modules/",
-            "/lib/modules/",
-            "/odm/lib/modules/",
-    };
-
-    Parser alias_parser;
-    auto alias_callback = std::bind(&ModaliasHandler::ParseAliasCallback, this, _1);
-    alias_parser.AddSingleLineParser("alias", alias_callback);
-    for (const auto& base_path : base_paths) alias_parser.ParseConfig(base_path + "modules.alias");
-
-    Parser dep_parser;
-    auto dep_callback = std::bind(&ModaliasHandler::ParseDepCallback, this, _1);
-    dep_parser.AddSingleLineParser("", dep_callback);
-    for (const auto& base_path : base_paths) dep_parser.ParseConfig(base_path + "modules.dep");
-}
-
-Result<void> ModaliasHandler::Insmod(const std::string& path_name, const std::string& args) {
-    base::unique_fd fd(
-            TEMP_FAILURE_RETRY(open(path_name.c_str(), O_RDONLY | O_NOFOLLOW | O_CLOEXEC)));
-    if (fd == -1) return ErrnoError() << "Could not open module '" << path_name << "'";
-
-    int ret = syscall(__NR_finit_module, fd.get(), args.c_str(), 0);
-    if (ret != 0) {
-        if (errno == EEXIST) {
-            // Module already loaded
-            return {};
-        }
-        return ErrnoError() << "Failed to insmod '" << path_name << "' with args '" << args << "'";
-    }
-
-    LOG(INFO) << "Loaded kernel module " << path_name;
-    return {};
-}
-
-Result<void> ModaliasHandler::InsmodWithDeps(const std::string& module_name,
-                                             const std::string& args) {
-    if (module_name.empty()) {
-        return Error() << "Need valid module name";
-    }
-
-    auto it = module_deps_.find(module_name);
-    if (it == module_deps_.end()) {
-        return Error() << "Module '" << module_name << "' not in dependency file";
-    }
-    auto& dependencies = it->second;
-
-    // load module dependencies in reverse order
-    for (auto dep = dependencies.rbegin(); dep != dependencies.rend() - 1; ++dep) {
-        if (auto result = Insmod(*dep, ""); !result) return result;
-    }
-
-    // load target module itself with args
-    return Insmod(dependencies[0], args);
-}
+ModaliasHandler::ModaliasHandler(const std::vector<std::string>& base_paths)
+    : modprobe_(base_paths) {}
 
 void ModaliasHandler::HandleUevent(const Uevent& uevent) {
     if (uevent.modalias.empty()) return;
-
-    for (const auto& [alias, module] : module_aliases_) {
-        if (fnmatch(alias.c_str(), uevent.modalias.c_str(), 0) != 0) continue;  // Keep looking
-
-        LOG(DEBUG) << "Loading kernel module '" << module << "' for alias '" << uevent.modalias
-                   << "'";
-
-        if (auto result = InsmodWithDeps(module, ""); !result) {
-            LOG(ERROR) << "Cannot load module: " << result.error();
-            // try another one since there may be another match
-            continue;
-        }
-
-        // loading was successful
-        return;
-    }
+    modprobe_.LoadWithAliases(uevent.modalias, true);
 }
 
 }  // namespace init