platform_system_core/logd/LogBufferElement.cpp

136 lines
3.7 KiB
C++

/*
* 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 <endian.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <log/logger.h>
#include <private/android_logger.h>
#include "LogBufferElement.h"
#include "LogCommand.h"
#include "LogReader.h"
const uint64_t LogBufferElement::FLUSH_ERROR(0);
atomic_int_fast64_t LogBufferElement::sequence;
LogBufferElement::LogBufferElement(log_id_t log_id, log_time realtime,
uid_t uid, pid_t pid, pid_t tid,
const char *msg, unsigned short len)
: mLogId(log_id)
, mUid(uid)
, mPid(pid)
, mTid(tid)
, mMsgLen(len)
, mSequence(sequence.fetch_add(1, memory_order_relaxed))
, mRealTime(realtime) {
mMsg = new char[len];
memcpy(mMsg, msg, len);
}
LogBufferElement::~LogBufferElement() {
delete [] mMsg;
}
// assumption: mMsg == NULL
size_t LogBufferElement::populateDroppedMessage(char *&buffer, bool privileged) {
static const char format_uid[] = "uid=%u dropped=%u";
static const size_t unprivileged_offset = 7;
static const char tag[] = "logd";
size_t len;
if (privileged) {
len = snprintf(NULL, 0, format_uid, mUid, mDropped);
} else {
len = snprintf(NULL, 0, format_uid + unprivileged_offset, mDropped);
}
size_t hdrLen;
if (mLogId == LOG_ID_EVENTS) {
hdrLen = sizeof(android_log_event_string_t);
} else {
hdrLen = 1 + sizeof(tag);
}
buffer = static_cast<char *>(calloc(1, hdrLen + len + 1));
if (!buffer) {
return 0;
}
size_t retval = hdrLen + len;
if (mLogId == LOG_ID_EVENTS) {
android_log_event_string_t *e = reinterpret_cast<android_log_event_string_t *>(buffer);
e->header.tag = htole32(LOGD_LOG_TAG);
e->type = EVENT_TYPE_STRING;
e->length = htole32(len);
} else {
++retval;
buffer[0] = ANDROID_LOG_INFO;
strcpy(buffer + 1, tag);
}
if (privileged) {
snprintf(buffer + hdrLen, len + 1, format_uid, mUid, mDropped);
} else {
snprintf(buffer + hdrLen, len + 1, format_uid + unprivileged_offset, mDropped);
}
return retval;
}
uint64_t LogBufferElement::flushTo(SocketClient *reader) {
struct logger_entry_v3 entry;
memset(&entry, 0, sizeof(struct logger_entry_v3));
entry.hdr_size = sizeof(struct logger_entry_v3);
entry.lid = mLogId;
entry.pid = mPid;
entry.tid = mTid;
entry.sec = mRealTime.tv_sec;
entry.nsec = mRealTime.tv_nsec;
struct iovec iovec[2];
iovec[0].iov_base = &entry;
iovec[0].iov_len = sizeof(struct logger_entry_v3);
char *buffer = NULL;
if (!mMsg) {
entry.len = populateDroppedMessage(buffer, clientHasLogCredentials(reader));
if (!entry.len) {
return mSequence;
}
iovec[1].iov_base = buffer;
} else {
entry.len = mMsgLen;
iovec[1].iov_base = mMsg;
}
iovec[1].iov_len = entry.len;
uint64_t retval = reader->sendDatav(iovec, 2) ? FLUSH_ERROR : mSequence;
if (buffer) {
free(buffer);
}
return retval;
}