/*
* 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, unsigned short 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) {
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;
}
unsigned short LogBufferElement::setDropped(unsigned short 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 = NULL;
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 = NULL;
}
// 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 = NULL;
} else {
free(const_cast<char*>(name));
name = NULL;
}
}
}
if (name) {
char* buf = NULL;
asprintf(&buf, "(%s)", name);
if (buf) {
free(const_cast<char*>(name));
name = buf;
}
}
if (commName) {
char* buf = NULL;
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(NULL, 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 = NULL;
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;
}