liblog/logd_reader.cpp - android_system_core - Gitiles

 /*
  * Copyright (C) 2007-2016 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 "logd_reader.h"

 #include <errno.h>
 #include <fcntl.h>
 #include <inttypes.h>
 #include <poll.h>
 #include <stdarg.h>
 #include <stdatomic.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/param.h>
 #include <sys/socket.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <sys/un.h>
 #include <time.h>
 #include <unistd.h>

 #include <string>

 #include <private/android_logger.h>

 #include "logger.h"

 // Connects to /dev/socket/<name> and returns the associated fd or returns -1 on error.
 // O_CLOEXEC is always set.
 static int socket_local_client(const std::string& name, int type) {
   sockaddr_un addr = {.sun_family = AF_LOCAL};

   std::string path = "/dev/socket/" + name;
   if (path.size() + 1 > sizeof(addr.sun_path)) {
     return -1;
   }
   strlcpy(addr.sun_path, path.c_str(), sizeof(addr.sun_path));

   int fd = socket(AF_LOCAL, type | SOCK_CLOEXEC, 0);
   if (fd == -1) {
     return -1;
   }

   if (connect(fd, reinterpret_cast<sockaddr*>(&addr), sizeof(addr)) == -1) {
     close(fd);
     return -1;
   }

   return fd;
 }

 /* worker for sending the command to the logger */
 ssize_t SendLogdControlMessage(char* buf, size_t buf_size) {
   ssize_t ret;
   size_t len;
   char* cp;
   int errno_save = 0;
   int sock = socket_local_client("logd", SOCK_STREAM);
   if (sock < 0) {
     return sock;
   }

   len = strlen(buf) + 1;
   ret = TEMP_FAILURE_RETRY(write(sock, buf, len));
   if (ret <= 0) {
     goto done;
   }

   len = buf_size;
   cp = buf;
   while ((ret = TEMP_FAILURE_RETRY(read(sock, cp, len))) > 0) {
     struct pollfd p;

     if (((size_t)ret == len) || (buf_size < PAGE_SIZE)) {
       break;
     }

     len -= ret;
     cp += ret;

     memset(&p, 0, sizeof(p));
     p.fd = sock;
     p.events = POLLIN;

     /* Give other side 20ms to refill pipe */
     ret = TEMP_FAILURE_RETRY(poll(&p, 1, 20));

     if (ret <= 0) {
       break;
     }

     if (!(p.revents & POLLIN)) {
       ret = 0;
       break;
     }
   }

   if (ret >= 0) {
     ret += buf_size - len;
   }

 done:
   if ((ret == -1) && errno) {
     errno_save = errno;
   }
   close(sock);
   if (errno_save) {
     errno = errno_save;
   }
   return ret;
 }

 static int check_log_success(char* buf, ssize_t ret) {
   if (ret < 0) {
     return ret;
   }

   if (strncmp(buf, "success", 7)) {
     errno = EINVAL;
     return -1;
   }

   return 0;
 }

 int android_logger_clear(struct logger* logger) {
   if (!android_logger_is_logd(logger)) {
     return -EINVAL;
   }
   uint32_t log_id = android_logger_get_id(logger);
   char buf[512];
   snprintf(buf, sizeof(buf), "clear %" PRIu32, log_id);

   return check_log_success(buf, SendLogdControlMessage(buf, sizeof(buf)));
 }

 /* returns the total size of the log's ring buffer */
 long android_logger_get_log_size(struct logger* logger) {
   if (!android_logger_is_logd(logger)) {
     return -EINVAL;
   }

   uint32_t log_id = android_logger_get_id(logger);
   char buf[512];
   snprintf(buf, sizeof(buf), "getLogSize %" PRIu32, log_id);

   ssize_t ret = SendLogdControlMessage(buf, sizeof(buf));
   if (ret < 0) {
     return ret;
   }

   if ((buf[0] < '0') || ('9' < buf[0])) {
     return -1;
   }

   return atol(buf);
 }

 int android_logger_set_log_size(struct logger* logger, unsigned long size) {
   if (!android_logger_is_logd(logger)) {
     return -EINVAL;
   }

   uint32_t log_id = android_logger_get_id(logger);
   char buf[512];
   snprintf(buf, sizeof(buf), "setLogSize %" PRIu32 " %lu", log_id, size);

   return check_log_success(buf, SendLogdControlMessage(buf, sizeof(buf)));
 }

 /*
  * returns the readable size of the log's ring buffer (that is, amount of the
  * log consumed)
  */
 long android_logger_get_log_readable_size(struct logger* logger) {
   if (!android_logger_is_logd(logger)) {
     return -EINVAL;
   }

   uint32_t log_id = android_logger_get_id(logger);
   char buf[512];
   snprintf(buf, sizeof(buf), "getLogSizeUsed %" PRIu32, log_id);

   ssize_t ret = SendLogdControlMessage(buf, sizeof(buf));
   if (ret < 0) {
     return ret;
   }

   if ((buf[0] < '0') || ('9' < buf[0])) {
     return -1;
   }

   return atol(buf);
 }

 int android_logger_get_log_version(struct logger*) {
   return 4;
 }

 ssize_t android_logger_get_statistics(struct logger_list* logger_list, char* buf, size_t len) {
   if (logger_list->mode & ANDROID_LOG_PSTORE) {
     return -EINVAL;
   }

   char* cp = buf;
   size_t remaining = len;
   size_t n;

   n = snprintf(cp, remaining, "getStatistics");
   n = MIN(n, remaining);
   remaining -= n;
   cp += n;

   for (size_t log_id = 0; log_id < LOG_ID_MAX; ++log_id) {
     if ((1 << log_id) & logger_list->log_mask) {
       n = snprintf(cp, remaining, " %zu", log_id);
       n = MIN(n, remaining);
       remaining -= n;
       cp += n;
     }
   }

   if (logger_list->pid) {
     snprintf(cp, remaining, " pid=%u", logger_list->pid);
   }

   return SendLogdControlMessage(buf, len);
 }
 ssize_t android_logger_get_prune_list(struct logger_list* logger_list, char* buf, size_t len) {
   if (logger_list->mode & ANDROID_LOG_PSTORE) {
     return -EINVAL;
   }

   snprintf(buf, len, "getPruneList");
   return SendLogdControlMessage(buf, len);
 }

 int android_logger_set_prune_list(struct logger_list* logger_list, const char* buf, size_t len) {
   if (logger_list->mode & ANDROID_LOG_PSTORE) {
     return -EINVAL;
   }

   std::string cmd = "setPruneList " + std::string{buf, len};

   return check_log_success(cmd.data(), SendLogdControlMessage(cmd.data(), cmd.size()));
 }

 static int logdOpen(struct logger_list* logger_list) {
   char buffer[256], *cp, c;
   int ret, remaining, sock;

   sock = atomic_load(&logger_list->fd);
   if (sock > 0) {
     return sock;
   }

   sock = socket_local_client("logdr", SOCK_SEQPACKET);
   if (sock <= 0) {
     if ((sock == -1) && errno) {
       return -errno;
     }
     return sock;
   }

   strcpy(buffer, (logger_list->mode & ANDROID_LOG_NONBLOCK) ? "dumpAndClose" : "stream");
   cp = buffer + strlen(buffer);

   strcpy(cp, " lids");
   cp += 5;
   c = '=';
   remaining = sizeof(buffer) - (cp - buffer);

   for (size_t log_id = 0; log_id < LOG_ID_MAX; ++log_id) {
     if ((1 << log_id) & logger_list->log_mask) {
       ret = snprintf(cp, remaining, "%c%zu", c, log_id);
       ret = MIN(ret, remaining);
       remaining -= ret;
       cp += ret;
       c = ',';
     }
   }

   if (logger_list->tail) {
     ret = snprintf(cp, remaining, " tail=%u", logger_list->tail);
     ret = MIN(ret, remaining);
     remaining -= ret;
     cp += ret;
   }

   if (logger_list->start.tv_sec || logger_list->start.tv_nsec) {
     if (logger_list->mode & ANDROID_LOG_WRAP) {
       // ToDo: alternate API to allow timeout to be adjusted.
       ret = snprintf(cp, remaining, " timeout=%u", ANDROID_LOG_WRAP_DEFAULT_TIMEOUT);
       ret = MIN(ret, remaining);
       remaining -= ret;
       cp += ret;
     }
     ret = snprintf(cp, remaining, " start=%" PRIu32 ".%09" PRIu32, logger_list->start.tv_sec,
                    logger_list->start.tv_nsec);
     ret = MIN(ret, remaining);
     remaining -= ret;
     cp += ret;
   }

   if (logger_list->pid) {
     ret = snprintf(cp, remaining, " pid=%u", logger_list->pid);
     ret = MIN(ret, remaining);
     cp += ret;
   }

   ret = TEMP_FAILURE_RETRY(write(sock, buffer, cp - buffer));
   int write_errno = errno;

   if (ret <= 0) {
     close(sock);
     if (ret == -1) {
       return -write_errno;
     }
     if (ret == 0) {
       return -EIO;
     }
     return ret;
   }

   ret = atomic_exchange(&logger_list->fd, sock);
   if ((ret > 0) && (ret != sock)) {
     close(ret);
   }
   return sock;
 }

 /* Read from the selected logs */
 int LogdRead(struct logger_list* logger_list, struct log_msg* log_msg) {
   int ret = logdOpen(logger_list);
   if (ret < 0) {
     return ret;
   }

   /* NOTE: SOCK_SEQPACKET guarantees we read exactly one full entry */
   ret = TEMP_FAILURE_RETRY(recv(ret, log_msg, LOGGER_ENTRY_MAX_LEN, 0));
   if ((logger_list->mode & ANDROID_LOG_NONBLOCK) && ret == 0) {
     return -EAGAIN;
   }

   if (ret == -1) {
     return -errno;
   }
   return ret;
 }

 /* Close all the logs */
 void LogdClose(struct logger_list* logger_list) {
   int sock = atomic_exchange(&logger_list->fd, -1);
   if (sock > 0) {
     close(sock);
   }
 }
	/*
	* Copyright (C) 2007-2016 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 "logd_reader.h"

	#include <errno.h>
	#include <fcntl.h>
	#include <inttypes.h>
	#include <poll.h>
	#include <stdarg.h>
	#include <stdatomic.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <string.h>
	#include <sys/param.h>
	#include <sys/socket.h>
	#include <sys/stat.h>
	#include <sys/types.h>
	#include <sys/un.h>
	#include <time.h>
	#include <unistd.h>

	#include <string>

	#include <private/android_logger.h>

	#include "logger.h"

	// Connects to /dev/socket/<name> and returns the associated fd or returns -1 on error.
	// O_CLOEXEC is always set.
	static int socket_local_client(const std::string& name, int type) {
	sockaddr_un addr = {.sun_family = AF_LOCAL};

	std::string path = "/dev/socket/" + name;
	if (path.size() + 1 > sizeof(addr.sun_path)) {
	return -1;
	}
	strlcpy(addr.sun_path, path.c_str(), sizeof(addr.sun_path));

	int fd = socket(AF_LOCAL, type \| SOCK_CLOEXEC, 0);
	if (fd == -1) {
	return -1;
	}

	if (connect(fd, reinterpret_cast<sockaddr*>(&addr), sizeof(addr)) == -1) {
	close(fd);
	return -1;
	}

	return fd;
	}

	/* worker for sending the command to the logger */
	ssize_t SendLogdControlMessage(char* buf, size_t buf_size) {
	ssize_t ret;
	size_t len;
	char* cp;
	int errno_save = 0;
	int sock = socket_local_client("logd", SOCK_STREAM);
	if (sock < 0) {
	return sock;
	}

	len = strlen(buf) + 1;
	ret = TEMP_FAILURE_RETRY(write(sock, buf, len));
	if (ret <= 0) {
	goto done;
	}

	len = buf_size;
	cp = buf;
	while ((ret = TEMP_FAILURE_RETRY(read(sock, cp, len))) > 0) {
	struct pollfd p;

	if (((size_t)ret == len) \|\| (buf_size < PAGE_SIZE)) {
	break;
	}

	len -= ret;
	cp += ret;

	memset(&p, 0, sizeof(p));
	p.fd = sock;
	p.events = POLLIN;

	/* Give other side 20ms to refill pipe */
	ret = TEMP_FAILURE_RETRY(poll(&p, 1, 20));

	if (ret <= 0) {
	break;
	}

	if (!(p.revents & POLLIN)) {
	ret = 0;
	break;
	}
	}

	if (ret >= 0) {
	ret += buf_size - len;
	}

	done:
	if ((ret == -1) && errno) {
	errno_save = errno;
	}
	close(sock);
	if (errno_save) {
	errno = errno_save;
	}
	return ret;
	}

	static int check_log_success(char* buf, ssize_t ret) {
	if (ret < 0) {
	return ret;
	}

	if (strncmp(buf, "success", 7)) {
	errno = EINVAL;
	return -1;
	}

	return 0;
	}

	int android_logger_clear(struct logger* logger) {
	if (!android_logger_is_logd(logger)) {
	return -EINVAL;
	}
	uint32_t log_id = android_logger_get_id(logger);
	char buf[512];
	snprintf(buf, sizeof(buf), "clear %" PRIu32, log_id);

	return check_log_success(buf, SendLogdControlMessage(buf, sizeof(buf)));
	}

	/* returns the total size of the log's ring buffer */
	long android_logger_get_log_size(struct logger* logger) {
	if (!android_logger_is_logd(logger)) {
	return -EINVAL;
	}

	uint32_t log_id = android_logger_get_id(logger);
	char buf[512];
	snprintf(buf, sizeof(buf), "getLogSize %" PRIu32, log_id);

	ssize_t ret = SendLogdControlMessage(buf, sizeof(buf));
	if (ret < 0) {
	return ret;
	}

	if ((buf[0] < '0') \|\| ('9' < buf[0])) {
	return -1;
	}

	return atol(buf);
	}

	int android_logger_set_log_size(struct logger* logger, unsigned long size) {
	if (!android_logger_is_logd(logger)) {
	return -EINVAL;
	}

	uint32_t log_id = android_logger_get_id(logger);
	char buf[512];
	snprintf(buf, sizeof(buf), "setLogSize %" PRIu32 " %lu", log_id, size);

	return check_log_success(buf, SendLogdControlMessage(buf, sizeof(buf)));
	}

	/*
	* returns the readable size of the log's ring buffer (that is, amount of the
	* log consumed)
	*/
	long android_logger_get_log_readable_size(struct logger* logger) {
	if (!android_logger_is_logd(logger)) {
	return -EINVAL;
	}

	uint32_t log_id = android_logger_get_id(logger);
	char buf[512];
	snprintf(buf, sizeof(buf), "getLogSizeUsed %" PRIu32, log_id);

	ssize_t ret = SendLogdControlMessage(buf, sizeof(buf));
	if (ret < 0) {
	return ret;
	}

	if ((buf[0] < '0') \|\| ('9' < buf[0])) {
	return -1;
	}

	return atol(buf);
	}

	int android_logger_get_log_version(struct logger*) {
	return 4;
	}

	ssize_t android_logger_get_statistics(struct logger_list* logger_list, char* buf, size_t len) {
	if (logger_list->mode & ANDROID_LOG_PSTORE) {
	return -EINVAL;
	}

	char* cp = buf;
	size_t remaining = len;
	size_t n;

	n = snprintf(cp, remaining, "getStatistics");
	n = MIN(n, remaining);
	remaining -= n;
	cp += n;

	for (size_t log_id = 0; log_id < LOG_ID_MAX; ++log_id) {
	if ((1 << log_id) & logger_list->log_mask) {
	n = snprintf(cp, remaining, " %zu", log_id);
	n = MIN(n, remaining);
	remaining -= n;
	cp += n;
	}
	}

	if (logger_list->pid) {
	snprintf(cp, remaining, " pid=%u", logger_list->pid);
	}

	return SendLogdControlMessage(buf, len);
	}
	ssize_t android_logger_get_prune_list(struct logger_list* logger_list, char* buf, size_t len) {
	if (logger_list->mode & ANDROID_LOG_PSTORE) {
	return -EINVAL;
	}

	snprintf(buf, len, "getPruneList");
	return SendLogdControlMessage(buf, len);
	}

	int android_logger_set_prune_list(struct logger_list* logger_list, const char* buf, size_t len) {
	if (logger_list->mode & ANDROID_LOG_PSTORE) {
	return -EINVAL;
	}

	std::string cmd = "setPruneList " + std::string{buf, len};

	return check_log_success(cmd.data(), SendLogdControlMessage(cmd.data(), cmd.size()));
	}

	static int logdOpen(struct logger_list* logger_list) {
	char buffer[256], *cp, c;
	int ret, remaining, sock;

	sock = atomic_load(&logger_list->fd);
	if (sock > 0) {
	return sock;
	}

	sock = socket_local_client("logdr", SOCK_SEQPACKET);
	if (sock <= 0) {
	if ((sock == -1) && errno) {
	return -errno;
	}
	return sock;
	}

	strcpy(buffer, (logger_list->mode & ANDROID_LOG_NONBLOCK) ? "dumpAndClose" : "stream");
	cp = buffer + strlen(buffer);

	strcpy(cp, " lids");
	cp += 5;
	c = '=';
	remaining = sizeof(buffer) - (cp - buffer);

	for (size_t log_id = 0; log_id < LOG_ID_MAX; ++log_id) {
	if ((1 << log_id) & logger_list->log_mask) {
	ret = snprintf(cp, remaining, "%c%zu", c, log_id);
	ret = MIN(ret, remaining);
	remaining -= ret;
	cp += ret;
	c = ',';
	}
	}

	if (logger_list->tail) {
	ret = snprintf(cp, remaining, " tail=%u", logger_list->tail);
	ret = MIN(ret, remaining);
	remaining -= ret;
	cp += ret;
	}

	if (logger_list->start.tv_sec \|\| logger_list->start.tv_nsec) {
	if (logger_list->mode & ANDROID_LOG_WRAP) {
	// ToDo: alternate API to allow timeout to be adjusted.
	ret = snprintf(cp, remaining, " timeout=%u", ANDROID_LOG_WRAP_DEFAULT_TIMEOUT);
	ret = MIN(ret, remaining);
	remaining -= ret;
	cp += ret;
	}
	ret = snprintf(cp, remaining, " start=%" PRIu32 ".%09" PRIu32, logger_list->start.tv_sec,
	logger_list->start.tv_nsec);
	ret = MIN(ret, remaining);
	remaining -= ret;
	cp += ret;
	}

	if (logger_list->pid) {
	ret = snprintf(cp, remaining, " pid=%u", logger_list->pid);
	ret = MIN(ret, remaining);
	cp += ret;
	}

	ret = TEMP_FAILURE_RETRY(write(sock, buffer, cp - buffer));
	int write_errno = errno;

	if (ret <= 0) {
	close(sock);
	if (ret == -1) {
	return -write_errno;
	}
	if (ret == 0) {
	return -EIO;
	}
	return ret;
	}

	ret = atomic_exchange(&logger_list->fd, sock);
	if ((ret > 0) && (ret != sock)) {
	close(ret);
	}
	return sock;
	}

	/* Read from the selected logs */
	int LogdRead(struct logger_list* logger_list, struct log_msg* log_msg) {
	int ret = logdOpen(logger_list);
	if (ret < 0) {
	return ret;
	}

	/* NOTE: SOCK_SEQPACKET guarantees we read exactly one full entry */
	ret = TEMP_FAILURE_RETRY(recv(ret, log_msg, LOGGER_ENTRY_MAX_LEN, 0));
	if ((logger_list->mode & ANDROID_LOG_NONBLOCK) && ret == 0) {
	return -EAGAIN;
	}

	if (ret == -1) {
	return -errno;
	}
	return ret;
	}

	/* Close all the logs */
	void LogdClose(struct logger_list* logger_list) {
	int sock = atomic_exchange(&logger_list->fd, -1);
	if (sock > 0) {
	close(sock);
	}
	}