| /* |
| * Copyright (C) 2017 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 "firmware_handler.h" |
| |
| #include <fcntl.h> |
| #include <fnmatch.h> |
| #include <glob.h> |
| #include <grp.h> |
| #include <pwd.h> |
| #include <signal.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <sys/sendfile.h> |
| #include <sys/wait.h> |
| #include <unistd.h> |
| |
| #include <thread> |
| |
| #include <android-base/chrono_utils.h> |
| #include <android-base/file.h> |
| #include <android-base/logging.h> |
| #include <android-base/scopeguard.h> |
| #include <android-base/strings.h> |
| #include <android-base/unique_fd.h> |
| |
| using android::base::ReadFdToString; |
| using android::base::Socketpair; |
| using android::base::Split; |
| using android::base::Timer; |
| using android::base::Trim; |
| using android::base::unique_fd; |
| using android::base::WriteFully; |
| |
| namespace android { |
| namespace init { |
| |
| namespace { |
| bool PrefixMatch(const std::string& pattern, const std::string& path) { |
| return android::base::StartsWith(path, pattern); |
| } |
| |
| bool FnMatch(const std::string& pattern, const std::string& path) { |
| return fnmatch(pattern.c_str(), path.c_str(), 0) == 0; |
| } |
| |
| bool EqualMatch(const std::string& pattern, const std::string& path) { |
| return pattern == path; |
| } |
| } // namespace |
| |
| static void LoadFirmware(const std::string& firmware, const std::string& root, int fw_fd, |
| size_t fw_size, int loading_fd, int data_fd) { |
| // Start transfer. |
| WriteFully(loading_fd, "1", 1); |
| |
| // Copy the firmware. |
| int rc = sendfile(data_fd, fw_fd, nullptr, fw_size); |
| if (rc == -1) { |
| PLOG(ERROR) << "firmware: sendfile failed { '" << root << "', '" << firmware << "' }"; |
| } |
| |
| // Tell the firmware whether to abort or commit. |
| const char* response = (rc != -1) ? "0" : "-1"; |
| WriteFully(loading_fd, response, strlen(response)); |
| } |
| |
| static bool IsBooting() { |
| return access("/dev/.booting", F_OK) == 0; |
| } |
| |
| ExternalFirmwareHandler::ExternalFirmwareHandler(std::string devpath, uid_t uid, gid_t gid, |
| std::string handler_path) |
| : devpath(std::move(devpath)), uid(uid), gid(gid), handler_path(std::move(handler_path)) { |
| auto wildcard_position = this->devpath.find('*'); |
| if (wildcard_position != std::string::npos) { |
| if (wildcard_position == this->devpath.length() - 1) { |
| this->devpath.pop_back(); |
| match = std::bind(PrefixMatch, this->devpath, std::placeholders::_1); |
| } else { |
| match = std::bind(FnMatch, this->devpath, std::placeholders::_1); |
| } |
| } else { |
| match = std::bind(EqualMatch, this->devpath, std::placeholders::_1); |
| } |
| } |
| |
| ExternalFirmwareHandler::ExternalFirmwareHandler(std::string devpath, uid_t uid, |
| std::string handler_path) |
| : ExternalFirmwareHandler(devpath, uid, 0, handler_path) {} |
| |
| FirmwareHandler::FirmwareHandler(std::vector<std::string> firmware_directories, |
| std::vector<ExternalFirmwareHandler> external_firmware_handlers) |
| : firmware_directories_(std::move(firmware_directories)), |
| external_firmware_handlers_(std::move(external_firmware_handlers)) {} |
| |
| Result<std::string> FirmwareHandler::RunExternalHandler(const std::string& handler, uid_t uid, |
| gid_t gid, const Uevent& uevent) const { |
| unique_fd child_stdout; |
| unique_fd parent_stdout; |
| if (!Socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0, &child_stdout, &parent_stdout)) { |
| return ErrnoError() << "Socketpair() for stdout failed"; |
| } |
| |
| unique_fd child_stderr; |
| unique_fd parent_stderr; |
| if (!Socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0, &child_stderr, &parent_stderr)) { |
| return ErrnoError() << "Socketpair() for stderr failed"; |
| } |
| |
| signal(SIGCHLD, SIG_DFL); |
| |
| auto pid = fork(); |
| if (pid < 0) { |
| return ErrnoError() << "fork() failed"; |
| } |
| |
| if (pid == 0) { |
| setenv("FIRMWARE", uevent.firmware.c_str(), 1); |
| setenv("DEVPATH", uevent.path.c_str(), 1); |
| parent_stdout.reset(); |
| parent_stderr.reset(); |
| close(STDOUT_FILENO); |
| close(STDERR_FILENO); |
| dup2(child_stdout.get(), STDOUT_FILENO); |
| dup2(child_stderr.get(), STDERR_FILENO); |
| |
| auto args = Split(handler, " "); |
| std::vector<char*> c_args; |
| for (auto& arg : args) { |
| c_args.emplace_back(arg.data()); |
| } |
| c_args.emplace_back(nullptr); |
| |
| if (gid != 0) { |
| if (setgid(gid) != 0) { |
| fprintf(stderr, "setgid() failed: %s", strerror(errno)); |
| _exit(EXIT_FAILURE); |
| } |
| } |
| |
| if (setuid(uid) != 0) { |
| fprintf(stderr, "setuid() failed: %s", strerror(errno)); |
| _exit(EXIT_FAILURE); |
| } |
| |
| execv(c_args[0], c_args.data()); |
| fprintf(stderr, "exec() failed: %s", strerror(errno)); |
| _exit(EXIT_FAILURE); |
| } |
| |
| child_stdout.reset(); |
| child_stderr.reset(); |
| |
| int status; |
| pid_t waited_pid = TEMP_FAILURE_RETRY(waitpid(pid, &status, 0)); |
| if (waited_pid == -1) { |
| return ErrnoError() << "waitpid() failed"; |
| } |
| |
| std::string stdout_content; |
| if (!ReadFdToString(parent_stdout.get(), &stdout_content)) { |
| return ErrnoError() << "ReadFdToString() for stdout failed"; |
| } |
| |
| std::string stderr_content; |
| if (ReadFdToString(parent_stderr.get(), &stderr_content)) { |
| auto messages = Split(stderr_content, "\n"); |
| for (const auto& message : messages) { |
| if (!message.empty()) { |
| LOG(ERROR) << "External Firmware Handler: " << message; |
| } |
| } |
| } else { |
| LOG(ERROR) << "ReadFdToString() for stderr failed"; |
| } |
| |
| if (WIFEXITED(status)) { |
| if (WEXITSTATUS(status) == EXIT_SUCCESS) { |
| return Trim(stdout_content); |
| } else { |
| return Error() << "exited with status " << WEXITSTATUS(status); |
| } |
| } else if (WIFSIGNALED(status)) { |
| return Error() << "killed by signal " << WTERMSIG(status); |
| } |
| |
| return Error() << "unexpected exit status " << status; |
| } |
| |
| std::string FirmwareHandler::GetFirmwarePath(const Uevent& uevent) const { |
| for (const auto& external_handler : external_firmware_handlers_) { |
| if (external_handler.match(uevent.path)) { |
| LOG(INFO) << "Launching external firmware handler '" << external_handler.handler_path |
| << "' for devpath: '" << uevent.path << "' firmware: '" << uevent.firmware |
| << "'"; |
| |
| auto result = RunExternalHandler(external_handler.handler_path, external_handler.uid, |
| external_handler.gid, uevent); |
| if (!result.ok()) { |
| LOG(ERROR) << "Using default firmware; External firmware handler failed: " |
| << result.error(); |
| return uevent.firmware; |
| } |
| if (result->find("..") != std::string::npos) { |
| LOG(ERROR) << "Using default firmware; External firmware handler provided an " |
| "invalid path, '" |
| << *result << "'"; |
| return uevent.firmware; |
| } |
| LOG(INFO) << "Loading firmware '" << *result << "' in place of '" << uevent.firmware |
| << "'"; |
| return *result; |
| } |
| } |
| LOG(INFO) << "firmware: loading '" << uevent.firmware << "' for '" << uevent.path << "'"; |
| return uevent.firmware; |
| } |
| |
| void FirmwareHandler::ProcessFirmwareEvent(const std::string& root, |
| const std::string& firmware) const { |
| std::string loading = root + "/loading"; |
| std::string data = root + "/data"; |
| |
| unique_fd loading_fd(open(loading.c_str(), O_WRONLY | O_CLOEXEC)); |
| if (loading_fd == -1) { |
| PLOG(ERROR) << "couldn't open firmware loading fd for " << firmware; |
| return; |
| } |
| |
| unique_fd data_fd(open(data.c_str(), O_WRONLY | O_CLOEXEC)); |
| if (data_fd == -1) { |
| PLOG(ERROR) << "couldn't open firmware data fd for " << firmware; |
| return; |
| } |
| |
| std::vector<std::string> attempted_paths_and_errors; |
| auto TryLoadFirmware = [&](const std::string& firmware_directory) { |
| std::string file = firmware_directory + firmware; |
| unique_fd fw_fd(open(file.c_str(), O_RDONLY | O_CLOEXEC)); |
| if (fw_fd == -1) { |
| attempted_paths_and_errors.emplace_back("firmware: attempted " + file + |
| ", open failed: " + strerror(errno)); |
| return false; |
| } |
| struct stat sb; |
| if (fstat(fw_fd, &sb) == -1) { |
| attempted_paths_and_errors.emplace_back("firmware: attempted " + file + |
| ", fstat failed: " + strerror(errno)); |
| return false; |
| } |
| LoadFirmware(firmware, root, fw_fd, sb.st_size, loading_fd, data_fd); |
| return true; |
| }; |
| |
| int booting = IsBooting(); |
| try_loading_again: |
| attempted_paths_and_errors.clear(); |
| if (ForEachFirmwareDirectory(TryLoadFirmware)) { |
| return; |
| } |
| |
| if (booting) { |
| // If we're not fully booted, we may be missing |
| // filesystems needed for firmware, wait and retry. |
| std::this_thread::sleep_for(100ms); |
| booting = IsBooting(); |
| goto try_loading_again; |
| } |
| |
| LOG(ERROR) << "firmware: could not find firmware for " << firmware; |
| for (const auto& message : attempted_paths_and_errors) { |
| LOG(ERROR) << message; |
| } |
| |
| // Write "-1" as our response to the kernel's firmware request, since we have nothing for it. |
| write(loading_fd, "-1", 2); |
| } |
| |
| bool FirmwareHandler::ForEachFirmwareDirectory( |
| std::function<bool(const std::string&)> handler) const { |
| for (const std::string& firmware_directory : firmware_directories_) { |
| if (std::invoke(handler, firmware_directory)) { |
| return true; |
| } |
| } |
| |
| glob_t glob_result; |
| glob("/apex/*/etc/firmware/", GLOB_MARK, nullptr, &glob_result); |
| auto free_glob = android::base::make_scope_guard(std::bind(&globfree, &glob_result)); |
| for (size_t i = 0; i < glob_result.gl_pathc; i++) { |
| char* apex_firmware_directory = glob_result.gl_pathv[i]; |
| // Filter-out /apex/<name>@<ver> paths. The paths are bind-mounted to |
| // /apex/<name> paths, so unless we filter them out, we will look into the |
| // same apex twice. |
| if (strchr(apex_firmware_directory, '@')) { |
| continue; |
| } |
| if (std::invoke(handler, apex_firmware_directory)) { |
| return true; |
| } |
| } |
| |
| return false; |
| } |
| |
| void FirmwareHandler::HandleUevent(const Uevent& uevent) { |
| if (uevent.subsystem != "firmware" || uevent.action != "add") return; |
| |
| // Loading the firmware in a child means we can do that in parallel... |
| auto pid = fork(); |
| if (pid == -1) { |
| PLOG(ERROR) << "could not fork to process firmware event for " << uevent.firmware; |
| } |
| if (pid == 0) { |
| Timer t; |
| auto firmware = GetFirmwarePath(uevent); |
| ProcessFirmwareEvent("/sys" + uevent.path, firmware); |
| LOG(INFO) << "loading " << uevent.path << " took " << t; |
| _exit(EXIT_SUCCESS); |
| } |
| } |
| |
| } // namespace init |
| } // namespace android |