logd/LogBufferElement.cpp - android_system_core - Gitiles

 /*
  * Copyright (C) 2012-2014 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 <ctype.h>
 #include <endian.h>
 #include <fcntl.h>
 #include <stdio.h>
 #include <string.h>
 #include <time.h>
 #include <unistd.h>

 #include <private/android_logger.h>

 #include "LogBuffer.h"
 #include "LogBufferElement.h"
 #include "LogCommand.h"
 #include "LogReader.h"
 #include "LogUtils.h"

 const log_time LogBufferElement::FLUSH_ERROR((uint32_t)-1, (uint32_t)-1);
 atomic_int_fast64_t LogBufferElement::sequence(1);

 LogBufferElement::LogBufferElement(log_id_t log_id, log_time realtime,
                                    uid_t uid, pid_t pid, pid_t tid,
                                    const char* msg, uint16_t len)
     : mUid(uid),
       mPid(pid),
       mTid(tid),
       mRealTime(realtime),
       mMsgLen(len),
       mLogId(log_id),
       mDropped(false) {
     mMsg = new char[len];
     memcpy(mMsg, msg, len);
 }

 LogBufferElement::LogBufferElement(const LogBufferElement& elem)
     : mUid(elem.mUid),
       mPid(elem.mPid),
       mTid(elem.mTid),
       mRealTime(elem.mRealTime),
       mMsgLen(elem.mMsgLen),
       mLogId(elem.mLogId),
       mDropped(elem.mDropped) {
     if (mDropped) {
         if (elem.isBinary() && elem.mMsg != nullptr) {
             // for the following "len" value, refer to : setDropped(uint16_t value), getTag()
             const int len = sizeof(android_event_header_t);
             mMsg = new char[len];
             memcpy(mMsg, elem.mMsg, len);
         } else {
             mMsg = nullptr;
         }
     } else {
         mMsg = new char[mMsgLen];
         memcpy(mMsg, elem.mMsg, mMsgLen);
     }
 }

 LogBufferElement::~LogBufferElement() {
     delete[] mMsg;
 }

 uint32_t LogBufferElement::getTag() const {
     return (isBinary() &&
             ((mDropped && mMsg != nullptr) ||
              (!mDropped && mMsgLen >= sizeof(android_event_header_t))))
                ? reinterpret_cast<const android_event_header_t*>(mMsg)->tag
                : 0;
 }

 uint16_t LogBufferElement::setDropped(uint16_t value) {
     // The tag information is saved in mMsg data, if the tag is non-zero
     // save only the information needed to get the tag.
     if (getTag() != 0) {
         if (mMsgLen > sizeof(android_event_header_t)) {
             char* truncated_msg = new char[sizeof(android_event_header_t)];
             memcpy(truncated_msg, mMsg, sizeof(android_event_header_t));
             delete[] mMsg;
             mMsg = truncated_msg;
         }  // mMsgLen == sizeof(android_event_header_t), already at minimum.
     } else {
         delete[] mMsg;
         mMsg = nullptr;
     }
     mDropped = true;
     return mDroppedCount = value;
 }

 // caller must own and free character string
 char* android::tidToName(pid_t tid) {
     char* retval = nullptr;
     char buffer[256];
     snprintf(buffer, sizeof(buffer), "/proc/%u/comm", tid);
     int fd = open(buffer, O_RDONLY);
     if (fd >= 0) {
         ssize_t ret = read(fd, buffer, sizeof(buffer));
         if (ret >= (ssize_t)sizeof(buffer)) {
             ret = sizeof(buffer) - 1;
         }
         while ((ret > 0) && isspace(buffer[ret - 1])) {
             --ret;
         }
         if (ret > 0) {
             buffer[ret] = '\0';
             retval = strdup(buffer);
         }
         close(fd);
     }

     // if nothing for comm, check out cmdline
     char* name = android::pidToName(tid);
     if (!retval) {
         retval = name;
         name = nullptr;
     }

     // check if comm is truncated, see if cmdline has full representation
     if (name) {
         // impossible for retval to be NULL if name not NULL
         size_t retval_len = strlen(retval);
         size_t name_len = strlen(name);
         // KISS: ToDo: Only checks prefix truncated, not suffix, or both
         if ((retval_len < name_len) &&
             !fastcmp<strcmp>(retval, name + name_len - retval_len)) {
             free(retval);
             retval = name;
         } else {
             free(name);
         }
     }
     return retval;
 }

 // assumption: mMsg == NULL
 size_t LogBufferElement::populateDroppedMessage(char*& buffer, LogBuffer* parent,
                                                 bool lastSame) {
     static const char tag[] = "chatty";

     if (!__android_log_is_loggable_len(ANDROID_LOG_INFO, tag, strlen(tag),
                                        ANDROID_LOG_VERBOSE)) {
         return 0;
     }

     static const char format_uid[] = "uid=%u%s%s %s %u line%s";
     parent->wrlock();
     const char* name = parent->uidToName(mUid);
     parent->unlock();
     const char* commName = android::tidToName(mTid);
     if (!commName && (mTid != mPid)) {
         commName = android::tidToName(mPid);
     }
     if (!commName) {
         parent->wrlock();
         commName = parent->pidToName(mPid);
         parent->unlock();
     }
     if (name && name[0] && commName && (name[0] == commName[0])) {
         size_t len = strlen(name + 1);
         if (!strncmp(name + 1, commName + 1, len)) {
             if (commName[len + 1] == '\0') {
                 free(const_cast<char*>(commName));
                 commName = nullptr;
             } else {
                 free(const_cast<char*>(name));
                 name = nullptr;
             }
         }
     }
     if (name) {
         char* buf = nullptr;
         asprintf(&buf, "(%s)", name);
         if (buf) {
             free(const_cast<char*>(name));
             name = buf;
         }
     }
     if (commName) {
         char* buf = nullptr;
         asprintf(&buf, " %s", commName);
         if (buf) {
             free(const_cast<char*>(commName));
             commName = buf;
         }
     }
     // identical to below to calculate the buffer size required
     const char* type = lastSame ? "identical" : "expire";
     size_t len = snprintf(nullptr, 0, format_uid, mUid, name ? name : "",
                           commName ? commName : "", type, getDropped(),
                           (getDropped() > 1) ? "s" : "");

     size_t hdrLen;
     if (isBinary()) {
         hdrLen = sizeof(android_log_event_string_t);
     } else {
         hdrLen = 1 + sizeof(tag);
     }

     buffer = static_cast<char*>(calloc(1, hdrLen + len + 1));
     if (!buffer) {
         free(const_cast<char*>(name));
         free(const_cast<char*>(commName));
         return 0;
     }

     size_t retval = hdrLen + len;
     if (isBinary()) {
         android_log_event_string_t* event =
             reinterpret_cast<android_log_event_string_t*>(buffer);

         event->header.tag = htole32(CHATTY_LOG_TAG);
         event->type = EVENT_TYPE_STRING;
         event->length = htole32(len);
     } else {
         ++retval;
         buffer[0] = ANDROID_LOG_INFO;
         strcpy(buffer + 1, tag);
     }

     snprintf(buffer + hdrLen, len + 1, format_uid, mUid, name ? name : "",
              commName ? commName : "", type, getDropped(),
              (getDropped() > 1) ? "s" : "");
     free(const_cast<char*>(name));
     free(const_cast<char*>(commName));

     return retval;
 }

 log_time LogBufferElement::flushTo(SocketClient* reader, LogBuffer* parent,
                                    bool privileged, bool lastSame) {
     struct logger_entry_v4 entry;

     memset(&entry, 0, sizeof(struct logger_entry_v4));

     entry.hdr_size = privileged ? sizeof(struct logger_entry_v4)
                                 : sizeof(struct logger_entry_v3);
     entry.lid = mLogId;
     entry.pid = mPid;
     entry.tid = mTid;
     entry.uid = mUid;
     entry.sec = mRealTime.tv_sec;
     entry.nsec = mRealTime.tv_nsec;

     struct iovec iovec[2];
     iovec[0].iov_base = &entry;
     iovec[0].iov_len = entry.hdr_size;

     char* buffer = nullptr;

     if (mDropped) {
         entry.len = populateDroppedMessage(buffer, parent, lastSame);
         if (!entry.len) return mRealTime;
         iovec[1].iov_base = buffer;
     } else {
         entry.len = mMsgLen;
         iovec[1].iov_base = mMsg;
     }
     iovec[1].iov_len = entry.len;

     log_time retval = reader->sendDatav(iovec, 1 + (entry.len != 0))
                           ? FLUSH_ERROR
                           : mRealTime;

     if (buffer) free(buffer);

     return retval;
 }
	/*
	* Copyright (C) 2012-2014 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 <ctype.h>
	#include <endian.h>
	#include <fcntl.h>
	#include <stdio.h>
	#include <string.h>
	#include <time.h>
	#include <unistd.h>

	#include <private/android_logger.h>

	#include "LogBuffer.h"
	#include "LogBufferElement.h"
	#include "LogCommand.h"
	#include "LogReader.h"
	#include "LogUtils.h"

	const log_time LogBufferElement::FLUSH_ERROR((uint32_t)-1, (uint32_t)-1);
	atomic_int_fast64_t LogBufferElement::sequence(1);

	LogBufferElement::LogBufferElement(log_id_t log_id, log_time realtime,
	uid_t uid, pid_t pid, pid_t tid,
	const char* msg, uint16_t len)
	: mUid(uid),
	mPid(pid),
	mTid(tid),
	mRealTime(realtime),
	mMsgLen(len),
	mLogId(log_id),
	mDropped(false) {
	mMsg = new char[len];
	memcpy(mMsg, msg, len);
	}

	LogBufferElement::LogBufferElement(const LogBufferElement& elem)
	: mUid(elem.mUid),
	mPid(elem.mPid),
	mTid(elem.mTid),
	mRealTime(elem.mRealTime),
	mMsgLen(elem.mMsgLen),
	mLogId(elem.mLogId),
	mDropped(elem.mDropped) {
	if (mDropped) {
	if (elem.isBinary() && elem.mMsg != nullptr) {
	// for the following "len" value, refer to : setDropped(uint16_t value), getTag()
	const int len = sizeof(android_event_header_t);
	mMsg = new char[len];
	memcpy(mMsg, elem.mMsg, len);
	} else {
	mMsg = nullptr;
	}
	} else {
	mMsg = new char[mMsgLen];
	memcpy(mMsg, elem.mMsg, mMsgLen);
	}
	}

	LogBufferElement::~LogBufferElement() {
	delete[] mMsg;
	}

	uint32_t LogBufferElement::getTag() const {
	return (isBinary() &&
	((mDropped && mMsg != nullptr) \|\|
	(!mDropped && mMsgLen >= sizeof(android_event_header_t))))
	? reinterpret_cast<const android_event_header_t*>(mMsg)->tag
	: 0;
	}

	uint16_t LogBufferElement::setDropped(uint16_t value) {
	// The tag information is saved in mMsg data, if the tag is non-zero
	// save only the information needed to get the tag.
	if (getTag() != 0) {
	if (mMsgLen > sizeof(android_event_header_t)) {
	char* truncated_msg = new char[sizeof(android_event_header_t)];
	memcpy(truncated_msg, mMsg, sizeof(android_event_header_t));
	delete[] mMsg;
	mMsg = truncated_msg;
	} // mMsgLen == sizeof(android_event_header_t), already at minimum.
	} else {
	delete[] mMsg;
	mMsg = nullptr;
	}
	mDropped = true;
	return mDroppedCount = value;
	}

	// caller must own and free character string
	char* android::tidToName(pid_t tid) {
	char* retval = nullptr;
	char buffer[256];
	snprintf(buffer, sizeof(buffer), "/proc/%u/comm", tid);
	int fd = open(buffer, O_RDONLY);
	if (fd >= 0) {
	ssize_t ret = read(fd, buffer, sizeof(buffer));
	if (ret >= (ssize_t)sizeof(buffer)) {
	ret = sizeof(buffer) - 1;
	}
	while ((ret > 0) && isspace(buffer[ret - 1])) {
	--ret;
	}
	if (ret > 0) {
	buffer[ret] = '\0';
	retval = strdup(buffer);
	}
	close(fd);
	}

	// if nothing for comm, check out cmdline
	char* name = android::pidToName(tid);
	if (!retval) {
	retval = name;
	name = nullptr;
	}

	// check if comm is truncated, see if cmdline has full representation
	if (name) {
	// impossible for retval to be NULL if name not NULL
	size_t retval_len = strlen(retval);
	size_t name_len = strlen(name);
	// KISS: ToDo: Only checks prefix truncated, not suffix, or both
	if ((retval_len < name_len) &&
	!fastcmp<strcmp>(retval, name + name_len - retval_len)) {
	free(retval);
	retval = name;
	} else {
	free(name);
	}
	}
	return retval;
	}

	// assumption: mMsg == NULL
	size_t LogBufferElement::populateDroppedMessage(char& buffer, LogBuffer parent,
	bool lastSame) {
	static const char tag[] = "chatty";

	if (!__android_log_is_loggable_len(ANDROID_LOG_INFO, tag, strlen(tag),
	ANDROID_LOG_VERBOSE)) {
	return 0;
	}

	static const char format_uid[] = "uid=%u%s%s %s %u line%s";
	parent->wrlock();
	const char* name = parent->uidToName(mUid);
	parent->unlock();
	const char* commName = android::tidToName(mTid);
	if (!commName && (mTid != mPid)) {
	commName = android::tidToName(mPid);
	}
	if (!commName) {
	parent->wrlock();
	commName = parent->pidToName(mPid);
	parent->unlock();
	}
	if (name && name[0] && commName && (name[0] == commName[0])) {
	size_t len = strlen(name + 1);
	if (!strncmp(name + 1, commName + 1, len)) {
	if (commName[len + 1] == '\0') {
	free(const_cast<char*>(commName));
	commName = nullptr;
	} else {
	free(const_cast<char*>(name));
	name = nullptr;
	}
	}
	}
	if (name) {
	char* buf = nullptr;
	asprintf(&buf, "(%s)", name);
	if (buf) {
	free(const_cast<char*>(name));
	name = buf;
	}
	}
	if (commName) {
	char* buf = nullptr;
	asprintf(&buf, " %s", commName);
	if (buf) {
	free(const_cast<char*>(commName));
	commName = buf;
	}
	}
	// identical to below to calculate the buffer size required
	const char* type = lastSame ? "identical" : "expire";
	size_t len = snprintf(nullptr, 0, format_uid, mUid, name ? name : "",
	commName ? commName : "", type, getDropped(),
	(getDropped() > 1) ? "s" : "");

	size_t hdrLen;
	if (isBinary()) {
	hdrLen = sizeof(android_log_event_string_t);
	} else {
	hdrLen = 1 + sizeof(tag);
	}

	buffer = static_cast<char*>(calloc(1, hdrLen + len + 1));
	if (!buffer) {
	free(const_cast<char*>(name));
	free(const_cast<char*>(commName));
	return 0;
	}

	size_t retval = hdrLen + len;
	if (isBinary()) {
	android_log_event_string_t* event =
	reinterpret_cast<android_log_event_string_t*>(buffer);

	event->header.tag = htole32(CHATTY_LOG_TAG);
	event->type = EVENT_TYPE_STRING;
	event->length = htole32(len);
	} else {
	++retval;
	buffer[0] = ANDROID_LOG_INFO;
	strcpy(buffer + 1, tag);
	}

	snprintf(buffer + hdrLen, len + 1, format_uid, mUid, name ? name : "",
	commName ? commName : "", type, getDropped(),
	(getDropped() > 1) ? "s" : "");
	free(const_cast<char*>(name));
	free(const_cast<char*>(commName));

	return retval;
	}

	log_time LogBufferElement::flushTo(SocketClient* reader, LogBuffer* parent,
	bool privileged, bool lastSame) {
	struct logger_entry_v4 entry;

	memset(&entry, 0, sizeof(struct logger_entry_v4));

	entry.hdr_size = privileged ? sizeof(struct logger_entry_v4)
	: sizeof(struct logger_entry_v3);
	entry.lid = mLogId;
	entry.pid = mPid;
	entry.tid = mTid;
	entry.uid = mUid;
	entry.sec = mRealTime.tv_sec;
	entry.nsec = mRealTime.tv_nsec;

	struct iovec iovec[2];
	iovec[0].iov_base = &entry;
	iovec[0].iov_len = entry.hdr_size;

	char* buffer = nullptr;

	if (mDropped) {
	entry.len = populateDroppedMessage(buffer, parent, lastSame);
	if (!entry.len) return mRealTime;
	iovec[1].iov_base = buffer;
	} else {
	entry.len = mMsgLen;
	iovec[1].iov_base = mMsg;
	}
	iovec[1].iov_len = entry.len;

	log_time retval = reader->sendDatav(iovec, 1 + (entry.len != 0))
	? FLUSH_ERROR
	: mRealTime;

	if (buffer) free(buffer);

	return retval;
	}