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Commit e31f840a authored by Steve Muckle's avatar Steve Muckle
Browse files

libmodprobe: add support for a blacklist 

If the blacklist is enabled, blacklisted modules are treated as though
they are not present.

Change-Id: Ie8712f24298e78f92d5028b1ca3a8a3e07a9190a
parent 13700a69

libmodprobe/include/modprobe/modprobe.h

+5 −0
Original line number Diff line number Diff line
@@ -16,6 +16,7 @@ 


#pragma once



#include <set>

#include <string>

#include <unordered_map>

#include <vector>
@@ -28,6 +29,7 @@ class Modprobe { 
    bool LoadWithAliases(const std::string& module_name, bool strict,

                         const std::string& parameters = "");

    bool Remove(const std::string& module_name);

    void EnableBlacklist(bool enable);



  private:

    std::string MakeCanonical(const std::string& module_path);
@@ -42,6 +44,7 @@ class Modprobe { 
    bool ParseSoftdepCallback(const std::vector<std::string>& args);

    bool ParseLoadCallback(const std::vector<std::string>& args);

    bool ParseOptionsCallback(const std::vector<std::string>& args);

    bool ParseBlacklistCallback(const std::vector<std::string>& args);

    void ParseCfg(const std::string& cfg, std::function<bool(const std::vector<std::string>&)> f);



    std::vector<std::pair<std::string, std::string>> module_aliases_;
@@ -50,4 +53,6 @@ class Modprobe { 
    std::vector<std::pair<std::string, std::string>> module_post_softdep_;

    std::vector<std::string> module_load_;

    std::unordered_map<std::string, std::string> module_options_;

    std::set<std::string> module_blacklist_;

    bool blacklist_enabled = false;

};

libmodprobe/libmodprobe.cpp

+32 −0
Original line number Diff line number Diff line
@@ -194,6 +194,31 @@ bool Modprobe::ParseOptionsCallback(const std::vector<std::string>& args) { 
    return true;

}



bool Modprobe::ParseBlacklistCallback(const std::vector<std::string>& args) {

    auto it = args.begin();

    const std::string& type = *it++;



    if (type != "blacklist") {

        LOG(ERROR) << "non-blacklist line encountered in modules.blacklist";

        return false;

    }



    if (args.size() != 2) {

        LOG(ERROR) << "lines in modules.blacklist 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_blacklist_.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;
@@ -231,9 +256,16 @@ Modprobe::Modprobe(const std::vector<std::string>& base_paths) { 


        auto options_callback = std::bind(&Modprobe::ParseOptionsCallback, this, _1);

        ParseCfg(base_path + "/modules.options", options_callback);



        auto blacklist_callback = std::bind(&Modprobe::ParseBlacklistCallback, this, _1);

        ParseCfg(base_path + "/modules.blacklist", blacklist_callback);

    }

}



void Modprobe::EnableBlacklist(bool enable) {

    blacklist_enabled = enable;

}



std::vector<std::string> Modprobe::GetDependencies(const std::string& module) {

    auto it = module_deps_.find(module);

    if (it == module_deps_.end()) {

libmodprobe/libmodprobe_ext.cpp

+3 −0
Original line number Diff line number Diff line
@@ -65,6 +65,9 @@ bool Modprobe::Rmmod(const std::string& module_name) { 


bool Modprobe::ModuleExists(const std::string& module_name) {

    struct stat fileStat;

    if (blacklist_enabled && module_blacklist_.count(module_name)) {

        return false;

    }

    auto deps = GetDependencies(module_name);

    if (deps.empty()) {

        // missing deps can happen in the case of an alias

libmodprobe/libmodprobe_ext_test.cpp

+3 −0
Original line number Diff line number Diff line
@@ -67,6 +67,9 @@ bool Modprobe::Rmmod(const std::string& module_name) { 


bool Modprobe::ModuleExists(const std::string& module_name) {

    auto deps = GetDependencies(module_name);

    if (blacklist_enabled && module_blacklist_.count(module_name)) {

        return false;

    }

    if (deps.empty()) {

        // missing deps can happen in the case of an alias

        return false;

libmodprobe/libmodprobe_test.cpp

+21 −11
Original line number Diff line number Diff line
@@ -99,6 +99,10 @@ TEST(libmodprobe, Test) { 
            "options test9.ko param_x=1 param_y=2 param_z=3\n"

            "options test100.ko param_1=1\n";



    const std::string modules_blacklist =

            "blacklist test9.ko\n"

            "blacklist test3.ko\n";



    const std::string modules_load =

            "test4.ko\n"

            "test1.ko\n"
@@ -109,17 +113,20 @@ TEST(libmodprobe, Test) { 
            "test11.ko\n";



    TemporaryDir dir;

    ASSERT_TRUE(android::base::WriteStringToFile(

            modules_alias, std::string(dir.path) + "/modules.alias", 0600, getuid(), getgid()));



    ASSERT_TRUE(android::base::WriteStringToFile(

            modules_dep, std::string(dir.path) + "/modules.dep", 0600, getuid(), getgid()));

    ASSERT_TRUE(android::base::WriteStringToFile(

            modules_softdep, std::string(dir.path) + "/modules.softdep", 0600, getuid(), getgid()));

    ASSERT_TRUE(android::base::WriteStringToFile(

            modules_options, std::string(dir.path) + "/modules.options", 0600, getuid(), getgid()));

    ASSERT_TRUE(android::base::WriteStringToFile(

            modules_load, std::string(dir.path) + "/modules.load", 0600, getuid(), getgid()));

    auto dir_path = std::string(dir.path);

    ASSERT_TRUE(android::base::WriteStringToFile(modules_alias, dir_path + "/modules.alias", 0600,

                                                 getuid(), getgid()));



    ASSERT_TRUE(android::base::WriteStringToFile(modules_dep, dir_path + "/modules.dep", 0600,

                                                 getuid(), getgid()));

    ASSERT_TRUE(android::base::WriteStringToFile(modules_softdep, dir_path + "/modules.softdep",

                                                 0600, getuid(), getgid()));

    ASSERT_TRUE(android::base::WriteStringToFile(modules_options, dir_path + "/modules.options",

                                                 0600, getuid(), getgid()));

    ASSERT_TRUE(android::base::WriteStringToFile(modules_load, dir_path + "/modules.load", 0600,

                                                 getuid(), getgid()));

    ASSERT_TRUE(android::base::WriteStringToFile(modules_blacklist, dir_path + "/modules.blacklist",

                                                 0600, getuid(), getgid()));



    for (auto i = test_modules.begin(); i != test_modules.end(); ++i) {

        *i = dir.path + *i;
@@ -153,4 +160,7 @@ TEST(libmodprobe, Test) { 
    }



    EXPECT_TRUE(modules_loaded == expected_after_remove);



    m.EnableBlacklist(true);

    EXPECT_FALSE(m.LoadWithAliases("test4", true));

}