car-bugreportd/main.cpp - platform/packages/services/Car - Git at Google

 /*
  * 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_TAG "car-bugreportd"

 #include <android-base/errors.h>
 #include <android-base/file.h>
 #include <android-base/logging.h>
 #include <android-base/macros.h>
 #include <android-base/properties.h>
 #include <android-base/stringprintf.h>
 #include <android-base/strings.h>
 #include <android-base/unique_fd.h>
 #include <cutils/sockets.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <ftw.h>
 #include <gui/SurfaceComposerClient.h>
 #include <log/log_main.h>
 #include <private/android_filesystem_config.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <sys/prctl.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <sys/wait.h>
 #include <time.h>
 #include <unistd.h>
 #include <ziparchive/zip_writer.h>

 #include <chrono>
 #include <string>
 #include <vector>

 namespace {
 // Directory used for keeping temporary files
 constexpr const char* kTempDirectory = "/data/user_de/0/com.android.shell/temp_bugreport_files";
 // Socket to write the progress information.
 constexpr const char* kCarBrProgressSocket = "car_br_progress_socket";
 // Socket to write the zipped bugreport file.
 constexpr const char* kCarBrOutputSocket = "car_br_output_socket";
 // Socket to write the extra bugreport zip file. This zip file contains data that does not exist
 // in bugreport file generated by dumpstate.
 constexpr const char* kCarBrExtraOutputSocket = "car_br_extra_output_socket";
 // The prefix used by bugreportz protocol to indicate bugreport finished successfully.
 constexpr const char* kOkPrefix = "OK:";
 // Number of connect attempts to dumpstate socket
 constexpr const int kMaxDumpstateConnectAttempts = 20;
 // Wait time between connect attempts
 constexpr const int kWaitTimeBetweenConnectAttemptsInSec = 1;
 // Wait time for dumpstate. Set a timeout so that if nothing is read in 10 minutes, we'll stop
 // reading and quit. No timeout in dumpstate is longer than 60 seconds, so this gives lots of leeway
 // in case of unforeseen time outs.
 constexpr const int kDumpstateTimeoutInSec = 600;
 // The prefix for screenshot filename in the generated zip file.
 constexpr const char* kScreenshotPrefix = "/screenshot";

 using android::OK;
 using android::PhysicalDisplayId;
 using android::status_t;
 using android::SurfaceComposerClient;

 // Returns a valid socket descriptor or -1 on failure.
 int openSocket(const char* service) {
     int s = android_get_control_socket(service);
     if (s < 0) {
         ALOGE("android_get_control_socket(%s): %s", service, strerror(errno));
         return -1;
     }
     fcntl(s, F_SETFD, FD_CLOEXEC);
     if (listen(s, 4) < 0) {
         ALOGE("listen(control socket): %s", strerror(errno));
         return -1;
     }

     struct sockaddr addr;
     socklen_t alen = sizeof(addr);
     int fd = accept(s, &addr, &alen);
     if (fd < 0) {
         ALOGE("accept(control socket): %s", strerror(errno));
         return -1;
     }
     return fd;
 }

 // Processes the given dumpstate progress protocol |line| and updates
 // |out_last_nonempty_line| when |line| is non-empty, and |out_zip_path| when
 // the bugreport is finished.
 void processLine(const std::string& line, std::string* out_zip_path,
                  std::string* out_last_nonempty_line) {
     // The protocol is documented in frameworks/native/cmds/bugreportz/readme.md
     if (line.empty()) {
         return;
     }
     *out_last_nonempty_line = line;
     if (line.find(kOkPrefix) != 0) {
         return;
     }
     *out_zip_path = line.substr(strlen(kOkPrefix));
     return;
 }

 // Sends the contents of the zip fileto |outfd|.
 // Returns true if success
 void zipFilesToFd(const std::vector<std::string>& extra_files, int outfd) {
     // pass fclose as Deleter to close the file when unique_ptr is destroyed.
     std::unique_ptr<FILE, decltype(fclose)*> outfile = {fdopen(outfd, "wb"), fclose};
     if (outfile == nullptr) {
         ALOGE("Failed to open output descriptor");
         return;
     }
     auto writer = std::make_unique<ZipWriter>(outfile.get());

     int error = 0;
     for (const auto& filepath : extra_files) {
         const auto name = android::base::Basename(filepath);

         error = writer->StartEntry(name.c_str(), 0);
         if (error) {
             ALOGE("Failed to start entry %s", writer->ErrorCodeString(error));
             return;
         }
         android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(filepath.c_str(), O_RDONLY)));
         if (fd == -1) {
             return;
         }
         while (1) {
             char buffer[65536];

             ssize_t bytes_read = TEMP_FAILURE_RETRY(read(fd, buffer, sizeof(buffer)));
             if (bytes_read == 0) {
                 break;
             }
             if (bytes_read == -1) {
                 if (errno == EAGAIN) {
                     ALOGE("timed out while reading %s", name.c_str());
                 } else {
                     ALOGE("read terminated abnormally (%s)", strerror(errno));
                 }
                 // fail immediately
                 return;
             }
             error = writer->WriteBytes(buffer, bytes_read);
             if (error) {
                 ALOGE("WriteBytes() failed %s", ZipWriter::ErrorCodeString(error));
                 // fail immediately
                 return;
             }
         }

         error = writer->FinishEntry();
         if (error) {
             ALOGE("failed to finish entry %s", writer->ErrorCodeString(error));
             continue;
         }
     }
     error = writer->Finish();
     if (error) {
         ALOGE("failed to finish zip writer %s", writer->ErrorCodeString(error));
     }
 }

 int copyTo(int fd_in, int fd_out, void* buffer, size_t buffer_len) {
     ssize_t bytes_read = TEMP_FAILURE_RETRY(read(fd_in, buffer, buffer_len));
     if (bytes_read == 0) {
         return 0;
     }
     if (bytes_read == -1) {
         // EAGAIN really means time out, so make that clear.
         if (errno == EAGAIN) {
             ALOGE("read timed out");
         } else {
             ALOGE("read terminated abnormally (%s)", strerror(errno));
         }
         return -1;
     }
     // copy all bytes to the output socket
     if (!android::base::WriteFully(fd_out, buffer, bytes_read)) {
         ALOGE("write failed");
         return -1;
     }
     return bytes_read;
 }

 bool copyFile(const std::string& zip_path, int output_socket) {
     android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(zip_path.c_str(), O_RDONLY)));
     if (fd == -1) {
         ALOGE("Failed to open zip file %s.", zip_path.c_str());
         return false;
     }
     while (1) {
         char buffer[65536];
         int bytes_copied = copyTo(fd, output_socket, buffer, sizeof(buffer));
         if (bytes_copied == 0) {
             break;
         }
         if (bytes_copied == -1) {
             ALOGE("Failed to copy zip file %s to the output_socket.", zip_path.c_str());
             return false;
         }
     }
     return true;
 }

 // Triggers a bugreport and waits until it is all collected.
 // returns false if error, true if success
 bool doBugreport(int progress_socket, size_t* out_bytes_written, std::string* zip_path) {
     // Socket will not be available until service starts.
     android::base::unique_fd s;
     for (int i = 0; i < kMaxDumpstateConnectAttempts; i++) {
         s.reset(socket_local_client("dumpstate", ANDROID_SOCKET_NAMESPACE_RESERVED, SOCK_STREAM));
         if (s != -1) break;
         sleep(kWaitTimeBetweenConnectAttemptsInSec);
     }

     if (s == -1) {
         ALOGE("failed to connect to dumpstatez service");
         return false;
     }

     // Set a timeout so that if nothing is read by the timeout, stop reading and quit
     struct timeval tv = {
         .tv_sec = kDumpstateTimeoutInSec,
         .tv_usec = 0,
     };
     if (setsockopt(s, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv)) != 0) {
         ALOGW("Cannot set socket timeout (%s)", strerror(errno));
     }

     std::string line;
     std::string last_nonempty_line;
     char buffer[65536];
     while (true) {
         ssize_t bytes_read = copyTo(s, progress_socket, buffer, sizeof(buffer));
         if (bytes_read == 0) {
             break;
         }
         if (bytes_read == -1) {
             ALOGE("Failed to copy progress to the progress_socket.");
             return false;
         }
         // Process the buffer line by line. this is needed for the filename.
         for (int i = 0; i < bytes_read; i++) {
             char c = buffer[i];
             if (c == '\n') {
                 processLine(line, zip_path, &last_nonempty_line);
                 line.clear();
             } else {
                 line.append(1, c);
             }
         }
         *out_bytes_written += bytes_read;
     }
     s.reset();
     // Process final line, in case it didn't finish with newline.
     processLine(line, zip_path, &last_nonempty_line);
     // if doBugReport finished successfully, zip path should be set.
     if (zip_path->empty()) {
         ALOGE("no zip file path was found in bugreportz progress data");
         return false;
     }
     return true;
 }

 bool waitpid_with_timeout(pid_t pid, int timeout_secs, int* status) {
     sigset_t child_mask, old_mask;
     sigemptyset(&child_mask);
     sigaddset(&child_mask, SIGCHLD);

     if (sigprocmask(SIG_BLOCK, &child_mask, &old_mask) == -1) {
         ALOGE("*** sigprocmask failed: %s\n", strerror(errno));
         return false;
     }

     timespec ts = {.tv_sec = timeout_secs, .tv_nsec = 0};
     int ret = TEMP_FAILURE_RETRY(sigtimedwait(&child_mask, nullptr, &ts));
     int saved_errno = errno;

     // Set the signals back the way they were.
     if (sigprocmask(SIG_SETMASK, &old_mask, nullptr) == -1) {
         ALOGE("*** sigprocmask failed: %s\n", strerror(errno));
         if (ret == 0) {
             return false;
         }
     }
     if (ret == -1) {
         errno = saved_errno;
         if (errno == EAGAIN) {
             errno = ETIMEDOUT;
         } else {
             ALOGE("*** sigtimedwait failed: %s\n", strerror(errno));
         }
         return false;
     }

     pid_t child_pid = waitpid(pid, status, WNOHANG);
     if (child_pid != pid) {
         if (child_pid != -1) {
             ALOGE("*** Waiting for pid %d, got pid %d instead\n", pid, child_pid);
         } else {
             ALOGE("*** waitpid failed: %s\n", strerror(errno));
         }
         return false;
     }
     return true;
 }

 // Runs the given command. Kills the command if it does not finish by timeout.
 int runCommand(int timeout_secs, const char* file, std::vector<const char*> args) {
     pid_t pid = fork();

     // handle error case
     if (pid < 0) {
         ALOGE("fork failed %s", strerror(errno));
         return pid;
     }

     // handle child case
     if (pid == 0) {
         /* make sure the child dies when parent dies */
         prctl(PR_SET_PDEATHSIG, SIGKILL);

         /* just ignore SIGPIPE, will go down with parent's */
         struct sigaction sigact;
         memset(&sigact, 0, sizeof(sigact));
         sigact.sa_handler = SIG_IGN;
         sigaction(SIGPIPE, &sigact, nullptr);

         execvp(file, (char**)args.data());
         // execvp's result will be handled after waitpid_with_timeout() below, but
         // if it failed, it's safer to exit dumpstate.
         ALOGE("execvp on command %s failed (error: %s)", file, strerror(errno));
         _exit(EXIT_FAILURE);
     }

     // handle parent case
     int status;
     bool ret = waitpid_with_timeout(pid, timeout_secs, &status);

     if (!ret) {
         if (errno == ETIMEDOUT) {
             ALOGE("command %s timed out (killing pid %d)", file, pid);
         } else {
             ALOGE("command %s: Error (killing pid %d)\n", file, pid);
         }
         kill(pid, SIGTERM);
         if (!waitpid_with_timeout(pid, 5, nullptr)) {
             kill(pid, SIGKILL);
             if (!waitpid_with_timeout(pid, 5, nullptr)) {
                 ALOGE("could not kill command '%s' (pid %d) even with SIGKILL.\n", file, pid);
             }
         }
         return -1;
     }

     if (WIFSIGNALED(status)) {
         ALOGE("command '%s' failed: killed by signal %d\n", file, WTERMSIG(status));
     } else if (WIFEXITED(status) && WEXITSTATUS(status) > 0) {
         status = WEXITSTATUS(status);
         ALOGE("command '%s' failed: exit code %d\n", file, status);
     }

     return status;
 }

 void takeScreenshotForDisplayId(PhysicalDisplayId id, const char* tmp_dir,
         std::vector<std::string>* extra_files) {
     std::string id_as_string = std::to_string(id);
     std::string filename = std::string(tmp_dir) + kScreenshotPrefix + id_as_string + ".png";
     std::vector<const char*> args { "-p", "-d", id_as_string.c_str(), filename.c_str(), nullptr };
     ALOGI("capturing screen for display (%s) as %s", id_as_string.c_str(), filename.c_str());
     int status = runCommand(10, "/system/bin/screencap", args);
     if (status == 0) {
         LOG(INFO) << "Screenshot saved for display:" << id_as_string;
     }
     // add the file regardless of the exit status of the screencap util.
     extra_files->push_back(filename);

     LOG(ERROR) << "Failed to take screenshot for display:" << id_as_string;
 }

 void takeScreenshot(const char* tmp_dir, std::vector<std::string>* extra_files) {
     // Now send the screencaptures
     std::vector<PhysicalDisplayId> ids = SurfaceComposerClient::getPhysicalDisplayIds();

     for (PhysicalDisplayId display_id : ids) {
         takeScreenshotForDisplayId(display_id, tmp_dir, extra_files);
     }
 }

 bool recursiveRemoveDir(const std::string& path) {
     auto callback = [](const char* child, const struct stat*, int file_type, struct FTW*) -> int {
         if (file_type == FTW_DP) {
             if (rmdir(child) == -1) {
                 ALOGE("rmdir(%s): %s", child, strerror(errno));
                 return -1;
             }
         } else if (file_type == FTW_F) {
             if (unlink(child) == -1) {
                 ALOGE("unlink(%s): %s", child, strerror(errno));
                 return -1;
             }
         }
         return 0;
     };
     // do a file tree walk with a sufficiently large depth.
     return nftw(path.c_str(), callback, 128, FTW_DEPTH) == 0;
 }

 status_t createTempDir(const char* dir) {
     struct stat sb;
     if (TEMP_FAILURE_RETRY(stat(dir, &sb)) == 0) {
         if (!recursiveRemoveDir(dir)) {
             return -errno;
         }
     } else if (errno != ENOENT) {
         ALOGE("Failed to stat %s ", dir);
         return -errno;
     }
     if (TEMP_FAILURE_RETRY(mkdir(dir, 0700)) == -1) {
         ALOGE("Failed to mkdir %s", dir);
         return -errno;
     }
     return OK;
 }

 // Removes bugreport
 void cleanupBugreportFile(const std::string& zip_path) {
     if (unlink(zip_path.c_str()) != 0) {
         ALOGE("Could not unlink %s (%s)", zip_path.c_str(), strerror(errno));
     }
 }

 }  // namespace

 int main(void) {
     ALOGI("Starting bugreport collecting service");

     auto t0 = std::chrono::steady_clock::now();

     std::vector<std::string> extra_files;
     if (createTempDir(kTempDirectory) == OK) {
         // take screenshots of the physical displays as early as possible
         takeScreenshot(kTempDirectory, &extra_files);
     }

     // Start the dumpstatez service.
     android::base::SetProperty("ctl.start", "car-dumpstatez");

     size_t bytes_written = 0;

     std::string zip_path;
     int progress_socket = openSocket(kCarBrProgressSocket);
     if (progress_socket < 0) {
         // early out. in this case we will not print the final message, but that is ok.
         android::base::SetProperty("ctl.stop", "car-dumpstatez");
         return EXIT_FAILURE;
     }
     bool ret_val = doBugreport(progress_socket, &bytes_written, &zip_path);
     close(progress_socket);

     if (ret_val) {
         int output_socket = openSocket(kCarBrOutputSocket);
         if (output_socket != -1) {
             ret_val = copyFile(zip_path, output_socket);
             close(output_socket);
         }
     }

     int extra_output_socket = openSocket(kCarBrExtraOutputSocket);
     if (extra_output_socket != -1 && ret_val) {
         zipFilesToFd(extra_files, extra_output_socket);
     }
     if (extra_output_socket != -1) {
         close(extra_output_socket);
     }

     auto delta = std::chrono::duration_cast<std::chrono::duration<double>>(
                      std::chrono::steady_clock::now() - t0)
                      .count();

     std::string result = ret_val ? "success" : "failed";
     ALOGI("bugreport %s in %.02fs, %zu bytes written", result.c_str(), delta, bytes_written);
     cleanupBugreportFile(zip_path);

     recursiveRemoveDir(kTempDirectory);

     // No matter how doBugreport() finished, let's try to explicitly stop
     // car-dumpstatez in case it stalled.
     android::base::SetProperty("ctl.stop", "car-dumpstatez");

     return ret_val ? EXIT_SUCCESS : EXIT_FAILURE;
 }
	/*
	* 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_TAG "car-bugreportd"

	#include <android-base/errors.h>
	#include <android-base/file.h>
	#include <android-base/logging.h>
	#include <android-base/macros.h>
	#include <android-base/properties.h>
	#include <android-base/stringprintf.h>
	#include <android-base/strings.h>
	#include <android-base/unique_fd.h>
	#include <cutils/sockets.h>
	#include <errno.h>
	#include <fcntl.h>
	#include <ftw.h>
	#include <gui/SurfaceComposerClient.h>
	#include <log/log_main.h>
	#include <private/android_filesystem_config.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <sys/prctl.h>
	#include <sys/stat.h>
	#include <sys/types.h>
	#include <sys/wait.h>
	#include <time.h>
	#include <unistd.h>
	#include <ziparchive/zip_writer.h>

	#include <chrono>
	#include <string>
	#include <vector>

	namespace {
	// Directory used for keeping temporary files
	constexpr const char* kTempDirectory = "/data/user_de/0/com.android.shell/temp_bugreport_files";
	// Socket to write the progress information.
	constexpr const char* kCarBrProgressSocket = "car_br_progress_socket";
	// Socket to write the zipped bugreport file.
	constexpr const char* kCarBrOutputSocket = "car_br_output_socket";
	// Socket to write the extra bugreport zip file. This zip file contains data that does not exist
	// in bugreport file generated by dumpstate.
	constexpr const char* kCarBrExtraOutputSocket = "car_br_extra_output_socket";
	// The prefix used by bugreportz protocol to indicate bugreport finished successfully.
	constexpr const char* kOkPrefix = "OK:";
	// Number of connect attempts to dumpstate socket
	constexpr const int kMaxDumpstateConnectAttempts = 20;
	// Wait time between connect attempts
	constexpr const int kWaitTimeBetweenConnectAttemptsInSec = 1;
	// Wait time for dumpstate. Set a timeout so that if nothing is read in 10 minutes, we'll stop
	// reading and quit. No timeout in dumpstate is longer than 60 seconds, so this gives lots of leeway
	// in case of unforeseen time outs.
	constexpr const int kDumpstateTimeoutInSec = 600;
	// The prefix for screenshot filename in the generated zip file.
	constexpr const char* kScreenshotPrefix = "/screenshot";

	using android::OK;
	using android::PhysicalDisplayId;
	using android::status_t;
	using android::SurfaceComposerClient;

	// Returns a valid socket descriptor or -1 on failure.
	int openSocket(const char* service) {
	int s = android_get_control_socket(service);
	if (s < 0) {
	ALOGE("android_get_control_socket(%s): %s", service, strerror(errno));
	return -1;
	}
	fcntl(s, F_SETFD, FD_CLOEXEC);
	if (listen(s, 4) < 0) {
	ALOGE("listen(control socket): %s", strerror(errno));
	return -1;
	}

	struct sockaddr addr;
	socklen_t alen = sizeof(addr);
	int fd = accept(s, &addr, &alen);
	if (fd < 0) {
	ALOGE("accept(control socket): %s", strerror(errno));
	return -1;
	}
	return fd;
	}

	// Processes the given dumpstate progress protocol \|line\| and updates
	// \|out_last_nonempty_line\| when \|line\| is non-empty, and \|out_zip_path\| when
	// the bugreport is finished.
	void processLine(const std::string& line, std::string* out_zip_path,
	std::string* out_last_nonempty_line) {
	// The protocol is documented in frameworks/native/cmds/bugreportz/readme.md
	if (line.empty()) {
	return;
	}
	*out_last_nonempty_line = line;
	if (line.find(kOkPrefix) != 0) {
	return;
	}
	*out_zip_path = line.substr(strlen(kOkPrefix));
	return;
	}

	// Sends the contents of the zip fileto \|outfd\|.
	// Returns true if success
	void zipFilesToFd(const std::vector<std::string>& extra_files, int outfd) {
	// pass fclose as Deleter to close the file when unique_ptr is destroyed.
	std::unique_ptr<FILE, decltype(fclose)*> outfile = {fdopen(outfd, "wb"), fclose};
	if (outfile == nullptr) {
	ALOGE("Failed to open output descriptor");
	return;
	}
	auto writer = std::make_unique<ZipWriter>(outfile.get());

	int error = 0;
	for (const auto& filepath : extra_files) {
	const auto name = android::base::Basename(filepath);

	error = writer->StartEntry(name.c_str(), 0);
	if (error) {
	ALOGE("Failed to start entry %s", writer->ErrorCodeString(error));
	return;
	}
	android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(filepath.c_str(), O_RDONLY)));
	if (fd == -1) {
	return;
	}
	while (1) {
	char buffer[65536];

	ssize_t bytes_read = TEMP_FAILURE_RETRY(read(fd, buffer, sizeof(buffer)));
	if (bytes_read == 0) {
	break;
	}
	if (bytes_read == -1) {
	if (errno == EAGAIN) {
	ALOGE("timed out while reading %s", name.c_str());
	} else {
	ALOGE("read terminated abnormally (%s)", strerror(errno));
	}
	// fail immediately
	return;
	}
	error = writer->WriteBytes(buffer, bytes_read);
	if (error) {
	ALOGE("WriteBytes() failed %s", ZipWriter::ErrorCodeString(error));
	// fail immediately
	return;
	}
	}

	error = writer->FinishEntry();
	if (error) {
	ALOGE("failed to finish entry %s", writer->ErrorCodeString(error));
	continue;
	}
	}
	error = writer->Finish();
	if (error) {
	ALOGE("failed to finish zip writer %s", writer->ErrorCodeString(error));
	}
	}

	int copyTo(int fd_in, int fd_out, void* buffer, size_t buffer_len) {
	ssize_t bytes_read = TEMP_FAILURE_RETRY(read(fd_in, buffer, buffer_len));
	if (bytes_read == 0) {
	return 0;
	}
	if (bytes_read == -1) {
	// EAGAIN really means time out, so make that clear.
	if (errno == EAGAIN) {
	ALOGE("read timed out");
	} else {
	ALOGE("read terminated abnormally (%s)", strerror(errno));
	}
	return -1;
	}
	// copy all bytes to the output socket
	if (!android::base::WriteFully(fd_out, buffer, bytes_read)) {
	ALOGE("write failed");
	return -1;
	}
	return bytes_read;
	}

	bool copyFile(const std::string& zip_path, int output_socket) {
	android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(zip_path.c_str(), O_RDONLY)));
	if (fd == -1) {
	ALOGE("Failed to open zip file %s.", zip_path.c_str());
	return false;
	}
	while (1) {
	char buffer[65536];
	int bytes_copied = copyTo(fd, output_socket, buffer, sizeof(buffer));
	if (bytes_copied == 0) {
	break;
	}
	if (bytes_copied == -1) {
	ALOGE("Failed to copy zip file %s to the output_socket.", zip_path.c_str());
	return false;
	}
	}
	return true;
	}

	// Triggers a bugreport and waits until it is all collected.
	// returns false if error, true if success
	bool doBugreport(int progress_socket, size_t* out_bytes_written, std::string* zip_path) {
	// Socket will not be available until service starts.
	android::base::unique_fd s;
	for (int i = 0; i < kMaxDumpstateConnectAttempts; i++) {
	s.reset(socket_local_client("dumpstate", ANDROID_SOCKET_NAMESPACE_RESERVED, SOCK_STREAM));
	if (s != -1) break;
	sleep(kWaitTimeBetweenConnectAttemptsInSec);
	}

	if (s == -1) {
	ALOGE("failed to connect to dumpstatez service");
	return false;
	}

	// Set a timeout so that if nothing is read by the timeout, stop reading and quit
	struct timeval tv = {
	.tv_sec = kDumpstateTimeoutInSec,
	.tv_usec = 0,
	};
	if (setsockopt(s, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv)) != 0) {
	ALOGW("Cannot set socket timeout (%s)", strerror(errno));
	}

	std::string line;
	std::string last_nonempty_line;
	char buffer[65536];
	while (true) {
	ssize_t bytes_read = copyTo(s, progress_socket, buffer, sizeof(buffer));
	if (bytes_read == 0) {
	break;
	}
	if (bytes_read == -1) {
	ALOGE("Failed to copy progress to the progress_socket.");
	return false;
	}
	// Process the buffer line by line. this is needed for the filename.
	for (int i = 0; i < bytes_read; i++) {
	char c = buffer[i];
	if (c == '\n') {
	processLine(line, zip_path, &last_nonempty_line);
	line.clear();
	} else {
	line.append(1, c);
	}
	}
	*out_bytes_written += bytes_read;
	}
	s.reset();
	// Process final line, in case it didn't finish with newline.
	processLine(line, zip_path, &last_nonempty_line);
	// if doBugReport finished successfully, zip path should be set.
	if (zip_path->empty()) {
	ALOGE("no zip file path was found in bugreportz progress data");
	return false;
	}
	return true;
	}

	bool waitpid_with_timeout(pid_t pid, int timeout_secs, int* status) {
	sigset_t child_mask, old_mask;
	sigemptyset(&child_mask);
	sigaddset(&child_mask, SIGCHLD);

	if (sigprocmask(SIG_BLOCK, &child_mask, &old_mask) == -1) {
	ALOGE("*** sigprocmask failed: %s\n", strerror(errno));
	return false;
	}

	timespec ts = {.tv_sec = timeout_secs, .tv_nsec = 0};
	int ret = TEMP_FAILURE_RETRY(sigtimedwait(&child_mask, nullptr, &ts));
	int saved_errno = errno;

	// Set the signals back the way they were.
	if (sigprocmask(SIG_SETMASK, &old_mask, nullptr) == -1) {
	ALOGE("*** sigprocmask failed: %s\n", strerror(errno));
	if (ret == 0) {
	return false;
	}
	}
	if (ret == -1) {
	errno = saved_errno;
	if (errno == EAGAIN) {
	errno = ETIMEDOUT;
	} else {
	ALOGE("*** sigtimedwait failed: %s\n", strerror(errno));
	}
	return false;
	}

	pid_t child_pid = waitpid(pid, status, WNOHANG);
	if (child_pid != pid) {
	if (child_pid != -1) {
	ALOGE("*** Waiting for pid %d, got pid %d instead\n", pid, child_pid);
	} else {
	ALOGE("*** waitpid failed: %s\n", strerror(errno));
	}
	return false;
	}
	return true;
	}

	// Runs the given command. Kills the command if it does not finish by timeout.
	int runCommand(int timeout_secs, const char* file, std::vector<const char*> args) {
	pid_t pid = fork();

	// handle error case
	if (pid < 0) {
	ALOGE("fork failed %s", strerror(errno));
	return pid;
	}

	// handle child case
	if (pid == 0) {
	/* make sure the child dies when parent dies */
	prctl(PR_SET_PDEATHSIG, SIGKILL);

	/* just ignore SIGPIPE, will go down with parent's */
	struct sigaction sigact;
	memset(&sigact, 0, sizeof(sigact));
	sigact.sa_handler = SIG_IGN;
	sigaction(SIGPIPE, &sigact, nullptr);

	execvp(file, (char**)args.data());
	// execvp's result will be handled after waitpid_with_timeout() below, but
	// if it failed, it's safer to exit dumpstate.
	ALOGE("execvp on command %s failed (error: %s)", file, strerror(errno));
	_exit(EXIT_FAILURE);
	}

	// handle parent case
	int status;
	bool ret = waitpid_with_timeout(pid, timeout_secs, &status);

	if (!ret) {
	if (errno == ETIMEDOUT) {
	ALOGE("command %s timed out (killing pid %d)", file, pid);
	} else {
	ALOGE("command %s: Error (killing pid %d)\n", file, pid);
	}
	kill(pid, SIGTERM);
	if (!waitpid_with_timeout(pid, 5, nullptr)) {
	kill(pid, SIGKILL);
	if (!waitpid_with_timeout(pid, 5, nullptr)) {
	ALOGE("could not kill command '%s' (pid %d) even with SIGKILL.\n", file, pid);
	}
	}
	return -1;
	}

	if (WIFSIGNALED(status)) {
	ALOGE("command '%s' failed: killed by signal %d\n", file, WTERMSIG(status));
	} else if (WIFEXITED(status) && WEXITSTATUS(status) > 0) {
	status = WEXITSTATUS(status);
	ALOGE("command '%s' failed: exit code %d\n", file, status);
	}

	return status;
	}

	void takeScreenshotForDisplayId(PhysicalDisplayId id, const char* tmp_dir,
	std::vector<std::string>* extra_files) {
	std::string id_as_string = std::to_string(id);
	std::string filename = std::string(tmp_dir) + kScreenshotPrefix + id_as_string + ".png";
	std::vector<const char*> args { "-p", "-d", id_as_string.c_str(), filename.c_str(), nullptr };
	ALOGI("capturing screen for display (%s) as %s", id_as_string.c_str(), filename.c_str());
	int status = runCommand(10, "/system/bin/screencap", args);
	if (status == 0) {
	LOG(INFO) << "Screenshot saved for display:" << id_as_string;
	}
	// add the file regardless of the exit status of the screencap util.
	extra_files->push_back(filename);

	LOG(ERROR) << "Failed to take screenshot for display:" << id_as_string;
	}

	void takeScreenshot(const char* tmp_dir, std::vector<std::string>* extra_files) {
	// Now send the screencaptures
	std::vector<PhysicalDisplayId> ids = SurfaceComposerClient::getPhysicalDisplayIds();

	for (PhysicalDisplayId display_id : ids) {
	takeScreenshotForDisplayId(display_id, tmp_dir, extra_files);
	}
	}

	bool recursiveRemoveDir(const std::string& path) {
	auto callback = [](const char* child, const struct stat, int file_type, struct FTW) -> int {
	if (file_type == FTW_DP) {
	if (rmdir(child) == -1) {
	ALOGE("rmdir(%s): %s", child, strerror(errno));
	return -1;
	}
	} else if (file_type == FTW_F) {
	if (unlink(child) == -1) {
	ALOGE("unlink(%s): %s", child, strerror(errno));
	return -1;
	}
	}
	return 0;
	};
	// do a file tree walk with a sufficiently large depth.
	return nftw(path.c_str(), callback, 128, FTW_DEPTH) == 0;
	}

	status_t createTempDir(const char* dir) {
	struct stat sb;
	if (TEMP_FAILURE_RETRY(stat(dir, &sb)) == 0) {
	if (!recursiveRemoveDir(dir)) {
	return -errno;
	}
	} else if (errno != ENOENT) {
	ALOGE("Failed to stat %s ", dir);
	return -errno;
	}
	if (TEMP_FAILURE_RETRY(mkdir(dir, 0700)) == -1) {
	ALOGE("Failed to mkdir %s", dir);
	return -errno;
	}
	return OK;
	}

	// Removes bugreport
	void cleanupBugreportFile(const std::string& zip_path) {
	if (unlink(zip_path.c_str()) != 0) {
	ALOGE("Could not unlink %s (%s)", zip_path.c_str(), strerror(errno));
	}
	}

	} // namespace

	int main(void) {
	ALOGI("Starting bugreport collecting service");

	auto t0 = std::chrono::steady_clock::now();

	std::vector<std::string> extra_files;
	if (createTempDir(kTempDirectory) == OK) {
	// take screenshots of the physical displays as early as possible
	takeScreenshot(kTempDirectory, &extra_files);
	}

	// Start the dumpstatez service.
	android::base::SetProperty("ctl.start", "car-dumpstatez");

	size_t bytes_written = 0;

	std::string zip_path;
	int progress_socket = openSocket(kCarBrProgressSocket);
	if (progress_socket < 0) {
	// early out. in this case we will not print the final message, but that is ok.
	android::base::SetProperty("ctl.stop", "car-dumpstatez");
	return EXIT_FAILURE;
	}
	bool ret_val = doBugreport(progress_socket, &bytes_written, &zip_path);
	close(progress_socket);

	if (ret_val) {
	int output_socket = openSocket(kCarBrOutputSocket);
	if (output_socket != -1) {
	ret_val = copyFile(zip_path, output_socket);
	close(output_socket);
	}
	}

	int extra_output_socket = openSocket(kCarBrExtraOutputSocket);
	if (extra_output_socket != -1 && ret_val) {
	zipFilesToFd(extra_files, extra_output_socket);
	}
	if (extra_output_socket != -1) {
	close(extra_output_socket);
	}

	auto delta = std::chrono::duration_cast<std::chrono::duration<double>>(
	std::chrono::steady_clock::now() - t0)
	.count();

	std::string result = ret_val ? "success" : "failed";
	ALOGI("bugreport %s in %.02fs, %zu bytes written", result.c_str(), delta, bytes_written);
	cleanupBugreportFile(zip_path);

	recursiveRemoveDir(kTempDirectory);

	// No matter how doBugreport() finished, let's try to explicitly stop
	// car-dumpstatez in case it stalled.
	android::base::SetProperty("ctl.stop", "car-dumpstatez");

	return ret_val ? EXIT_SUCCESS : EXIT_FAILURE;
	}