| /* |
| * Copyright (C) 2019 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. |
| */ |
| |
| //#define LOG_NDEBUG 0 |
| #define LOG_TAG "libprocessgroup" |
| |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <grp.h> |
| #include <pwd.h> |
| #include <sys/mman.h> |
| #include <sys/mount.h> |
| #include <sys/stat.h> |
| #include <sys/types.h> |
| #include <time.h> |
| #include <unistd.h> |
| |
| #include <regex> |
| |
| #include <android-base/file.h> |
| #include <android-base/logging.h> |
| #include <android-base/properties.h> |
| #include <android-base/stringprintf.h> |
| #include <android-base/strings.h> |
| #include <android-base/unique_fd.h> |
| #include <cgroup_map.h> |
| #include <json/reader.h> |
| #include <json/value.h> |
| #include <processgroup/processgroup.h> |
| |
| using android::base::GetBoolProperty; |
| using android::base::StartsWith; |
| using android::base::StringPrintf; |
| using android::base::unique_fd; |
| using android::base::WriteStringToFile; |
| |
| static constexpr const char* CGROUP_PROCS_FILE = "/cgroup.procs"; |
| static constexpr const char* CGROUP_TASKS_FILE = "/tasks"; |
| static constexpr const char* CGROUP_TASKS_FILE_V2 = "/cgroup.tasks"; |
| |
| uint32_t CgroupController::version() const { |
| CHECK(HasValue()); |
| return ACgroupController_getVersion(controller_); |
| } |
| |
| const char* CgroupController::name() const { |
| CHECK(HasValue()); |
| return ACgroupController_getName(controller_); |
| } |
| |
| const char* CgroupController::path() const { |
| CHECK(HasValue()); |
| return ACgroupController_getPath(controller_); |
| } |
| |
| bool CgroupController::HasValue() const { |
| return controller_ != nullptr; |
| } |
| |
| bool CgroupController::IsUsable() { |
| if (!HasValue()) return false; |
| |
| if (state_ == UNKNOWN) { |
| if (__builtin_available(android 30, *)) { |
| uint32_t flags = ACgroupController_getFlags(controller_); |
| state_ = (flags & CGROUPRC_CONTROLLER_FLAG_MOUNTED) != 0 ? USABLE : MISSING; |
| } else { |
| state_ = access(GetProcsFilePath("", 0, 0).c_str(), F_OK) == 0 ? USABLE : MISSING; |
| } |
| } |
| |
| return state_ == USABLE; |
| } |
| |
| std::string CgroupController::GetTasksFilePath(const std::string& rel_path) const { |
| std::string tasks_path = path(); |
| |
| if (!rel_path.empty()) { |
| tasks_path += "/" + rel_path; |
| } |
| return (version() == 1) ? tasks_path + CGROUP_TASKS_FILE : tasks_path + CGROUP_TASKS_FILE_V2; |
| } |
| |
| std::string CgroupController::GetProcsFilePath(const std::string& rel_path, uid_t uid, |
| pid_t pid) const { |
| std::string proc_path(path()); |
| proc_path.append("/").append(rel_path); |
| proc_path = regex_replace(proc_path, std::regex("<uid>"), std::to_string(uid)); |
| proc_path = regex_replace(proc_path, std::regex("<pid>"), std::to_string(pid)); |
| |
| return proc_path.append(CGROUP_PROCS_FILE); |
| } |
| |
| bool CgroupController::GetTaskGroup(int tid, std::string* group) const { |
| std::string file_name = StringPrintf("/proc/%d/cgroup", tid); |
| std::string content; |
| if (!android::base::ReadFileToString(file_name, &content)) { |
| PLOG(ERROR) << "Failed to read " << file_name; |
| return false; |
| } |
| |
| // if group is null and tid exists return early because |
| // user is not interested in cgroup membership |
| if (group == nullptr) { |
| return true; |
| } |
| |
| std::string cg_tag; |
| |
| if (version() == 2) { |
| cg_tag = "0::"; |
| } else { |
| cg_tag = StringPrintf(":%s:", name()); |
| } |
| size_t start_pos = content.find(cg_tag); |
| if (start_pos == std::string::npos) { |
| return false; |
| } |
| |
| start_pos += cg_tag.length() + 1; // skip '/' |
| size_t end_pos = content.find('\n', start_pos); |
| if (end_pos == std::string::npos) { |
| *group = content.substr(start_pos, std::string::npos); |
| } else { |
| *group = content.substr(start_pos, end_pos - start_pos); |
| } |
| |
| return true; |
| } |
| |
| CgroupMap::CgroupMap() { |
| if (!LoadRcFile()) { |
| LOG(ERROR) << "CgroupMap::LoadRcFile called for [" << getpid() << "] failed"; |
| } |
| } |
| |
| CgroupMap& CgroupMap::GetInstance() { |
| // Deliberately leak this object to avoid a race between destruction on |
| // process exit and concurrent access from another thread. |
| static auto* instance = new CgroupMap; |
| return *instance; |
| } |
| |
| bool CgroupMap::LoadRcFile() { |
| if (!loaded_) { |
| loaded_ = (ACgroupFile_getVersion() != 0); |
| } |
| return loaded_; |
| } |
| |
| void CgroupMap::Print() const { |
| if (!loaded_) { |
| LOG(ERROR) << "CgroupMap::Print called for [" << getpid() |
| << "] failed, RC file was not initialized properly"; |
| return; |
| } |
| LOG(INFO) << "File version = " << ACgroupFile_getVersion(); |
| LOG(INFO) << "File controller count = " << ACgroupFile_getControllerCount(); |
| |
| LOG(INFO) << "Mounted cgroups:"; |
| |
| auto controller_count = ACgroupFile_getControllerCount(); |
| for (uint32_t i = 0; i < controller_count; ++i) { |
| const ACgroupController* controller = ACgroupFile_getController(i); |
| if (__builtin_available(android 30, *)) { |
| LOG(INFO) << "\t" << ACgroupController_getName(controller) << " ver " |
| << ACgroupController_getVersion(controller) << " path " |
| << ACgroupController_getPath(controller) << " flags " |
| << ACgroupController_getFlags(controller); |
| } else { |
| LOG(INFO) << "\t" << ACgroupController_getName(controller) << " ver " |
| << ACgroupController_getVersion(controller) << " path " |
| << ACgroupController_getPath(controller); |
| } |
| } |
| } |
| |
| CgroupController CgroupMap::FindController(const std::string& name) const { |
| if (!loaded_) { |
| LOG(ERROR) << "CgroupMap::FindController called for [" << getpid() |
| << "] failed, RC file was not initialized properly"; |
| return CgroupController(nullptr); |
| } |
| |
| auto controller_count = ACgroupFile_getControllerCount(); |
| for (uint32_t i = 0; i < controller_count; ++i) { |
| const ACgroupController* controller = ACgroupFile_getController(i); |
| if (name == ACgroupController_getName(controller)) { |
| return CgroupController(controller); |
| } |
| } |
| |
| return CgroupController(nullptr); |
| } |
| |
| CgroupController CgroupMap::FindControllerByPath(const std::string& path) const { |
| if (!loaded_) { |
| LOG(ERROR) << "CgroupMap::FindControllerByPath called for [" << getpid() |
| << "] failed, RC file was not initialized properly"; |
| return CgroupController(nullptr); |
| } |
| |
| auto controller_count = ACgroupFile_getControllerCount(); |
| for (uint32_t i = 0; i < controller_count; ++i) { |
| const ACgroupController* controller = ACgroupFile_getController(i); |
| if (StartsWith(path, ACgroupController_getPath(controller))) { |
| return CgroupController(controller); |
| } |
| } |
| |
| return CgroupController(nullptr); |
| } |
| |
| int CgroupMap::ActivateControllers(const std::string& path) const { |
| if (__builtin_available(android 30, *)) { |
| auto controller_count = ACgroupFile_getControllerCount(); |
| for (uint32_t i = 0; i < controller_count; ++i) { |
| const ACgroupController* controller = ACgroupFile_getController(i); |
| if (ACgroupController_getFlags(controller) & |
| CGROUPRC_CONTROLLER_FLAG_NEEDS_ACTIVATION) { |
| std::string str = std::string("+") + ACgroupController_getName(controller); |
| if (!WriteStringToFile(str, path + "/cgroup.subtree_control")) { |
| return -errno; |
| } |
| } |
| } |
| return 0; |
| } |
| return -ENOSYS; |
| } |