android log丢失（三）动态切换logd机制和kernel机制

之前我们分析了如何修改版本使log机制变成kernel的log机制。这篇博客我们继续修改可以动态切换，这样方便平时log丢失时调试。

我们先来看liblog库的编译mk文件，这个文件中主要修改了对使用使用logd 使用不同文件进行编译这块做了修改，增加了log_write_common.c 和log_read_common.c两个通用文件。

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#
# Copyright (C) 2008-2014 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.
#
LOCAL_PATH := $(my-dir)
include $(CLEAR_VARS)
# This is what we want to do:
# liblog_cflags := $(shell \
# sed -n \
# 's/^ [0−9]∗ [ \t]*liblog[ \t].*/-DLIBLOG_LOG_TAG=\1/p' \
# $(LOCAL_PATH)/event.logtags)
# so make sure we do not regret hard-coding it as follows:
liblog_cflags := -DLIBLOG_LOG_TAG=1005
#ifneq ($(TARGET_USES_LOGD),false)//注释了不需要区分使用使用logd
#liblog_sources := logd_write.c log_event_write.c
#else
#liblog_sources := logd_write_kern.c log_event_write.c
#endif
liblog_sources := log_write_common.c log_event_write.c//增加log_write_common.c
# some files must not be compiled when building against Mingw
# they correspond to features not used by our host development tools
# which are also hard or even impossible to port to native Win32
ifeq ($(strip $(USE_MINGW)),)
liblog_sources += \
event_tag_map.c
else
liblog_sources += \
uio.c
endif
liblog_host_sources := $(liblog_sources) fake_log_device.c event.logtags
liblog_target_sources := $(liblog_sources) log_time.cpp log_is_loggable.c
ifeq ($(strip $(USE_MINGW)),)
liblog_target_sources += logprint.c
endif
#ifneq ($(TARGET_USES_LOGD),false)//注释了，不用区分是否使用logd
#liblog_target_sources += log_read.c
#else
#liblog_target_sources += log_read_kern.c
#endif
liblog_target_sources += log_read_common.c//增加log_read_common.c
# Shared and static library for host
# ========================================================
LOCAL_MODULE := liblog
LOCAL_SRC_FILES := $(liblog_host_sources)
LOCAL_CFLAGS := -DFAKE_LOG_DEVICE=1 -Werror $(liblog_cflags)
LOCAL_MULTILIB := both
include $(BUILD_HOST_STATIC_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := liblog
LOCAL_WHOLE_STATIC_LIBRARIES := liblog
ifeq ($(strip $(HOST_OS)),linux)
LOCAL_LDLIBS := -lrt
endif
LOCAL_MULTILIB := both
include $(BUILD_HOST_SHARED_LIBRARY)
# Shared and static library for target
# ========================================================
include $(CLEAR_VARS)
LOCAL_MODULE := liblog
LOCAL_SRC_FILES := $(liblog_target_sources)
LOCAL_CFLAGS := -Werror $(liblog_cflags)
include $(BUILD_STATIC_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := liblog
LOCAL_WHOLE_STATIC_LIBRARIES := liblog
LOCAL_CFLAGS := -Werror $(liblog_cflags)
# TODO: This is to work around b/19059885. Remove after root cause is fixed
LOCAL_LDFLAGS_arm := -Wl,--hash-style=both
include $(BUILD_SHARED_LIBRARY)
include $(call first-makefiles-under,$(LOCAL_PATH))

我们先来看log_read_common.c文件，这样主要就是将原来的logd_write.c 和logd_write_kern.c 文件进行合并。一些对外的接口，统一使用use_logd这个全局变量来控制，选择logd的函数，还是kernel的函数（logd的函数和kernel的函数就是static函数了，不用对外）。另外在__write_to_log_init函数中，第一次初始化的使用，先看system/etc/disable_logd是否有这样一个文件，有就将use_logd为0，代表使用kernel机制。

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/*
* Copyright (C) 2007-2014 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.
*/
#if (FAKE_LOG_DEVICE == 0)
#include
#endif
#include
#include
#if !defined(_WIN32)
#include
#endif
#include
#include
#include
#include
#include
#include
#include
#if (FAKE_LOG_DEVICE == 0)
#include
#include
#endif
#include
#include
#ifdef __BIONIC__
#include
#endif
#include
#include
#include
#include
#include
#include
#define LOGGER_LOG_MAIN "log/main"
#define LOGGER_LOG_RADIO "log/radio"
#define LOGGER_LOG_EVENTS "log/events"
#define LOGGER_LOG_SYSTEM "log/system"
#define LOG_BUF_SIZE 1024
#if FAKE_LOG_DEVICE
/* This will be defined when building for the host. */
#include "fake_log_device.h"
#endif
#define log_open(pathname, flags) open(pathname, (flags) | O_CLOEXEC)
#define log_writev(filedes, vector, count) writev(filedes, vector, count)
#define log_close(filedes) close(filedes)
static int __write_to_log_init(log_id_t, struct iovec *vec, size_t nr);
static int (*write_to_log)(log_id_t, struct iovec *vec, size_t nr) = __write_to_log_init;
#if !defined(_WIN32)
static pthread_mutex_t log_init_lock = PTHREAD_MUTEX_INITIALIZER;
#endif
#ifndef __unused
#define __unused __attribute__((__unused__))
#endif
static int8_t use_logd = 1;//做区分
#if FAKE_LOG_DEVICE
static int log_fds_fake[(int)LOG_ID_MAX] = { -1, -1, -1, -1, -1 };
#else
static int logd_fd = -1;
static int pstore_fd = -1;
#endif
static int log_fds_kernel[(int)LOG_ID_MAX] = { -1, -1, -1, -1 };
/*
* This is used by the C++ code to decide if it should write logs through
* the C code. Basically, if /dev/socket/logd is available, we're running in
* the simulator rather than a desktop tool and want to use the device.
*/
static enum {
kLogUninitialized, kLogNotAvailable, kLogAvailable
} g_log_status = kLogUninitialized;
static int __android_log_dev_available_logd(void)
{
if (g_log_status == kLogUninitialized) {
if (access("/dev/socket/logdw", W_OK) == 0)
g_log_status = kLogAvailable;
else
g_log_status = kLogNotAvailable;
}
return (g_log_status == kLogAvailable);
}
static int __android_log_dev_available_kernel(void)
{
if (g_log_status == kLogUninitialized) {
if (access("/dev/"LOGGER_LOG_MAIN, W_OK) == 0)
g_log_status = kLogAvailable;
else
g_log_status = kLogNotAvailable;
}
return (g_log_status == kLogAvailable);
}
int __android_log_dev_available(void)
{
if (use_logd) {
return __android_log_dev_available_logd();
} else {
return __android_log_dev_available_kernel();
}
}
/* log_init_lock assumed */
static int __write_to_log_initialize()
{
int i, ret = 0;
#if FAKE_LOG_DEVICE
for (i = 0; i < LOG_ID_MAX; i++) {
char buf[sizeof("/dev/log_system")];
snprintf(buf, sizeof(buf), "/dev/log_%s", android_log_id_to_name(i));
log_fds_fake[i] = fakeLogOpen(buf, O_WRONLY);
}
#else
if (pstore_fd < 0) {
pstore_fd = TEMP_FAILURE_RETRY(open("/dev/pmsg0", O_WRONLY));
}
if (logd_fd < 0) {
i = TEMP_FAILURE_RETRY(socket(PF_UNIX, SOCK_DGRAM | SOCK_CLOEXEC, 0));
if (i < 0) {
ret = -errno;
} else if (TEMP_FAILURE_RETRY(fcntl(i, F_SETFL, O_NONBLOCK)) < 0) {
ret = -errno;
close(i);
} else {
struct sockaddr_un un;
memset(&un, 0, sizeof(struct sockaddr_un));
un.sun_family = AF_UNIX;
strcpy(un.sun_path, "/dev/socket/logdw");
if (TEMP_FAILURE_RETRY(connect(i, (struct sockaddr *)&un,
sizeof(struct sockaddr_un))) < 0) {
ret = -errno;
close(i);
} else {
logd_fd = i;
}
}
}
#endif
return ret;
}
static int __write_to_log_daemon(log_id_t log_id, struct iovec *vec, size_t nr)
{
ssize_t ret;
#if FAKE_LOG_DEVICE
int log_fd;
if (/*(int)log_id >= 0 &&*/ (int)log_id < (int)LOG_ID_MAX) {
log_fd = log_fds_fake[(int)log_id];
} else {
return -EBADF;
}
do {
ret = fakeLogWritev(log_fd, vec, nr);
if (ret < 0) {
ret = -errno;
}
} while (ret == -EINTR);
#else
static const unsigned header_length = 2;
struct iovec newVec[nr + header_length];
android_log_header_t header;
android_pmsg_log_header_t pmsg_header;
struct timespec ts;
size_t i, payload_size;
static uid_t last_uid = AID_ROOT; /* logd *always* starts up as AID_ROOT */
static pid_t last_pid = (pid_t) -1;
static atomic_int_fast32_t dropped;
if (!nr) {
return -EINVAL;
}
if (last_uid == AID_ROOT) { /* have we called to get the UID yet? */
last_uid = getuid();
}
if (last_pid == (pid_t) -1) {
last_pid = getpid();
}
/*
* struct {
* // what we provide to pstore
* android_pmsg_log_header_t pmsg_header;
* // what we provide to socket
* android_log_header_t header;
* // caller provides
* union {
* struct {
* char prio;
* char payload[];
* } string;
* struct {
* uint32_t tag
* char payload[];
* } binary;
* };
* };
*/
clock_gettime(CLOCK_REALTIME, &ts);
pmsg_header.magic = LOGGER_MAGIC;
pmsg_header.len = sizeof(pmsg_header) + sizeof(header);
pmsg_header.uid = last_uid;
pmsg_header.pid = last_pid;
header.tid = gettid();
header.realtime.tv_sec = ts.tv_sec;
header.realtime.tv_nsec = ts.tv_nsec;
newVec[0].iov_base = (unsigned char *) &pmsg_header;
newVec[0].iov_len = sizeof(pmsg_header);
newVec[1].iov_base = (unsigned char *) &header;
newVec[1].iov_len = sizeof(header);
if (logd_fd > 0) {
int32_t snapshot = atomic_exchange_explicit(&dropped, 0, memory_order_relaxed);
if (snapshot) {
android_log_event_int_t buffer;
header.id = LOG_ID_EVENTS;
buffer.header.tag = htole32(LIBLOG_LOG_TAG);
buffer.payload.type = EVENT_TYPE_INT;
buffer.payload.data = htole32(snapshot);
newVec[2].iov_base = &buffer;
newVec[2].iov_len = sizeof(buffer);
ret = TEMP_FAILURE_RETRY(writev(logd_fd, newVec + 1, 2));
if (ret != (ssize_t)(sizeof(header) + sizeof(buffer))) {
atomic_fetch_add_explicit(&dropped, snapshot, memory_order_relaxed);
}
}
}
header.id = log_id;
for (payload_size = 0, i = header_length; i < nr + header_length; i++) {
newVec[i].iov_base = vec[i - header_length].iov_base;
payload_size += newVec[i].iov_len = vec[i - header_length].iov_len;
if (payload_size > LOGGER_ENTRY_MAX_PAYLOAD) {
newVec[i].iov_len -= payload_size - LOGGER_ENTRY_MAX_PAYLOAD;
if (newVec[i].iov_len) {
++i;
}
payload_size = LOGGER_ENTRY_MAX_PAYLOAD;
break;
}
}
pmsg_header.len += payload_size;
if (pstore_fd >= 0) {
TEMP_FAILURE_RETRY(writev(pstore_fd, newVec, i));
}
if (last_uid == AID_LOGD) { /* logd, after initialization and priv drop */
/*
* ignore log messages we send to ourself (logd).
* Such log messages are often generated by libraries we depend on
* which use standard Android logging.
*/
return 0;
}
if (logd_fd < 0) {
return -EBADF;
}
/*
* The write below could be lost, but will never block.
*
* To logd, we drop the pmsg_header
*
* ENOTCONN occurs if logd dies.
* EAGAIN occurs if logd is overloaded.
*/
ret = TEMP_FAILURE_RETRY(writev(logd_fd, newVec + 1, i - 1));
if (ret < 0) {
ret = -errno;
if (ret == -ENOTCONN) {
#if !defined(_WIN32)
pthread_mutex_lock(&log_init_lock);
#endif
close(logd_fd);
logd_fd = -1;
ret = __write_to_log_initialize();
#if !defined(_WIN32)
pthread_mutex_unlock(&log_init_lock);
#endif
if (ret < 0) {
return ret;
}
ret = TEMP_FAILURE_RETRY(writev(logd_fd, newVec + 1, i - 1));
if (ret < 0) {
ret = -errno;
}
}
}
if (ret > (ssize_t)sizeof(header)) {
ret -= sizeof(header);
} else if (ret == -EAGAIN) {
atomic_fetch_add_explicit(&dropped, 1, memory_order_relaxed);
}
#endif
return ret;
}
#if FAKE_LOG_DEVICE
static const char *LOG_NAME[LOG_ID_MAX] = {
[LOG_ID_MAIN] = "main",
[LOG_ID_RADIO] = "radio",
[LOG_ID_EVENTS] = "events",
[LOG_ID_SYSTEM] = "system",
[LOG_ID_CRASH] = "crash",
[LOG_ID_KERNEL] = "kernel",
};
const char *android_log_id_to_name(log_id_t log_id)
{
if (log_id >= LOG_ID_MAX) {
log_id = LOG_ID_MAIN;
}
return LOG_NAME[log_id];
}
#endif
static int __write_to_log_init_logd(log_id_t log_id, struct iovec *vec, size_t nr)
{
#if !defined(_WIN32)
pthread_mutex_lock(&log_init_lock);
#endif
if (write_to_log == __write_to_log_init) {
int ret;
ret = __write_to_log_initialize();
if (ret < 0) {
#if !defined(_WIN32)
pthread_mutex_unlock(&log_init_lock);
#endif
#if (FAKE_LOG_DEVICE == 0)
if (pstore_fd >= 0) {
__write_to_log_daemon(log_id, vec, nr);
}
#endif
return ret;
}
write_to_log = __write_to_log_daemon;
}
#if !defined(_WIN32)
pthread_mutex_unlock(&log_init_lock);
#endif
return write_to_log(log_id, vec, nr);
}
static int __write_to_log_null(log_id_t log_fd __unused, struct iovec *vec __unused,
size_t nr __unused)
{
return -1;
}
static int __write_to_log_kernel(log_id_t log_id, struct iovec *vec, size_t nr)
{
ssize_t ret;
int log_fd;
if (/*(int)log_id >= 0 &&*/ (int)log_id < (int)LOG_ID_MAX) {
if (log_id == LOG_ID_CRASH) {
log_id = LOG_ID_MAIN;
}
log_fd = log_fds_kernel[(int)log_id];
} else {
return -EBADF;
}
do {
ret = log_writev(log_fd, vec, nr);
if (ret < 0) {
ret = -errno;
}
} while (ret == -EINTR);
return ret;
}
static int __write_to_log_init_kernel(log_id_t log_id, struct iovec *vec, size_t nr)
{
pthread_mutex_lock(&log_init_lock);
if (write_to_log == __write_to_log_init) {
log_fds_kernel[LOG_ID_MAIN] = log_open("/dev/"LOGGER_LOG_MAIN, O_WRONLY);
log_fds_kernel[LOG_ID_RADIO] = log_open("/dev/"LOGGER_LOG_RADIO, O_WRONLY);
log_fds_kernel[LOG_ID_EVENTS] = log_open("/dev/"LOGGER_LOG_EVENTS, O_WRONLY);
log_fds_kernel[LOG_ID_SYSTEM] = log_open("/dev/"LOGGER_LOG_SYSTEM, O_WRONLY);
write_to_log = __write_to_log_kernel;
if (log_fds_kernel[LOG_ID_MAIN] < 0 || log_fds_kernel[LOG_ID_RADIO] < 0 ||
log_fds_kernel[LOG_ID_EVENTS] < 0) {
log_close(log_fds_kernel[LOG_ID_MAIN]);
log_close(log_fds_kernel[LOG_ID_RADIO]);
log_close(log_fds_kernel[LOG_ID_EVENTS]);
log_fds_kernel[LOG_ID_MAIN] = -1;
log_fds_kernel[LOG_ID_RADIO] = -1;
log_fds_kernel[LOG_ID_EVENTS] = -1;
write_to_log = __write_to_log_null;
}
if (log_fds_kernel[LOG_ID_SYSTEM] < 0) {
log_fds_kernel[LOG_ID_SYSTEM] = log_fds_kernel[LOG_ID_MAIN];
}
}
pthread_mutex_unlock(&log_init_lock);
return write_to_log(log_id, vec, nr);
}
static int __write_to_log_init(log_id_t log_id, struct iovec *vec, size_t nr) {
#if (FAKE_LOG_DEVICE == 0)
int fd;
fd = open("system/etc/disable_logd", O_RDONLY);//是否有disable_logd文件
if (fd > 0) {
use_logd = 0;
close(fd);
}
#endif
if(use_logd) {
return __write_to_log_init_logd(log_id, vec, nr);
} else {
return __write_to_log_init_kernel(log_id, vec, nr);
}
}
int __android_log_write(int prio, const char *tag, const char *msg)
{
return __android_log_buf_write(LOG_ID_MAIN, prio, tag, msg);
}
int __android_log_buf_write(int bufID, int prio, const char *tag, const char *msg)
{
struct iovec vec[3];
char tmp_tag[32];
if (!tag)
tag = "";
/* XXX: This needs to go! */
if ((bufID != LOG_ID_RADIO) &&
(!strcmp(tag, "HTC_RIL") ||
!strncmp(tag, "RIL", 3) || /* Any log tag with "RIL" as the prefix */
!strncmp(tag, "IMS", 3) || /* Any log tag with "IMS" as the prefix */
!strcmp(tag, "AT") ||
!strcmp(tag, "GSM") ||
!strcmp(tag, "STK") ||
!strcmp(tag, "CDMA") ||
!strcmp(tag, "PHONE") ||
!strcmp(tag, "SMS"))) {
bufID = LOG_ID_RADIO;
/* Inform third party apps/ril/radio.. to use Rlog or RLOG */
snprintf(tmp_tag, sizeof(tmp_tag), "use-Rlog/RLOG-%s", tag);
tag = tmp_tag;
}
#if __BIONIC__
if (prio == ANDROID_LOG_FATAL) {
android_set_abort_message(msg);
}
#endif
vec[0].iov_base = (unsigned char *) &prio;
vec[0].iov_len = 1;
vec[1].iov_base = (void *) tag;
vec[1].iov_len = strlen(tag) + 1;
vec[2].iov_base = (void *) msg;
vec[2].iov_len = strlen(msg) + 1;
return write_to_log(bufID, vec, 3);
}
int __android_log_vprint(int prio, const char *tag, const char *fmt, va_list ap)
{
char buf[LOG_BUF_SIZE];
vsnprintf(buf, LOG_BUF_SIZE, fmt, ap);
return __android_log_write(prio, tag, buf);
}
int __android_log_print(int prio, const char *tag, const char *fmt, ...)
{
va_list ap;
char buf[LOG_BUF_SIZE];
va_start(ap, fmt);
vsnprintf(buf, LOG_BUF_SIZE, fmt, ap);
va_end(ap);
return __android_log_write(prio, tag, buf);
}
int __android_log_buf_print(int bufID, int prio, const char *tag, const char *fmt, ...)
{
va_list ap;
char buf[LOG_BUF_SIZE];
va_start(ap, fmt);
vsnprintf(buf, LOG_BUF_SIZE, fmt, ap);
va_end(ap);
return __android_log_buf_write(bufID, prio, tag, buf);
}
void __android_log_assert(const char *cond, const char *tag,
const char *fmt, ...)
{
char buf[LOG_BUF_SIZE];
if (fmt) {
va_list ap;
va_start(ap, fmt);
vsnprintf(buf, LOG_BUF_SIZE, fmt, ap);
va_end(ap);
} else {
/* Msg not provided, log condition. N.B. Do not use cond directly as
* format string as it could contain spurious '%' syntax (e.g.
* "%d" in "blocks%devs == 0").
*/
if (cond)
snprintf(buf, LOG_BUF_SIZE, "Assertion failed: %s", cond);
else
strcpy(buf, "Unspecified assertion failed");
}
__android_log_write(ANDROID_LOG_FATAL, tag, buf);
abort(); /* abort so we have a chance to debug the situation */
/* NOTREACHED */
}
int __android_log_bwrite(int32_t tag, const void *payload, size_t len)
{
struct iovec vec[2];
vec[0].iov_base = &tag;
vec[0].iov_len = sizeof(tag);
vec[1].iov_base = (void*)payload;
vec[1].iov_len = len;
return write_to_log(LOG_ID_EVENTS, vec, 2);
}
/*
* Like __android_log_bwrite, but takes the type as well. Doesn't work
* for the general case where we're generating lists of stuff, but very
* handy if we just want to dump an integer into the log.
*/
int __android_log_btwrite(int32_t tag, char type, const void *payload,
size_t len)
{
struct iovec vec[3];
vec[0].iov_base = &tag;
vec[0].iov_len = sizeof(tag);
vec[1].iov_base = &type;
vec[1].iov_len = sizeof(type);
vec[2].iov_base = (void*)payload;
vec[2].iov_len = len;
return write_to_log(LOG_ID_EVENTS, vec, 3);
}
/*
* Like __android_log_bwrite, but used for writing strings to the
* event log.
*/
int __android_log_bswrite(int32_t tag, const char *payload)
{
struct iovec vec[4];
char type = EVENT_TYPE_STRING;
uint32_t len = strlen(payload);
vec[0].iov_base = &tag;
vec[0].iov_len = sizeof(tag);
vec[1].iov_base = &type;
vec[1].iov_len = sizeof(type);
vec[2].iov_base = &len;
vec[2].iov_len = sizeof(len);
vec[3].iov_base = (void*)payload;
vec[3].iov_len = len;
return write_to_log(LOG_ID_EVENTS, vec, 4);
}

另外一个就是log_read_common.c文件，将log_read.c和log_read_kern.c合并。这样文件稍微复杂一点，因为在log_read.c和log_read_kern.c中都使用了struct logger_list 和struct logger结构体而且不一样，这样我们将共同部分做了一个基类的struct logger_list 和struct logger结构体。而在合并文件中定义了struct logger_list_logd struct logger_list_kernel结构体，将其基类放在第一个变量base中。而使用指针时，对外返回的指针强制转成基类，进入的指针强制转到相关的子类。因为基类的数据结构在子类结构体中是第一个，因此子类指针强转成父类，也是能正确调用到父类的变量的。

还有我们也是用use_logd这个全局变量来控制log机制的，并且定义了一个对外的函数set_uselogd. 因为使用read这块是在logcat进程中使用的，我们需要在logcat中调用。

[cpp] view plain copy

/*
**
** 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 _GNU_SOURCE /* asprintf for x86 host */
#include
#include
#include
#include
#include
#include
#include
#define NOMINMAX /* for windows to suppress definition of min in stdlib.h */
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#define __LOGGERIO 0xAE
#define LOGGER_GET_LOG_BUF_SIZE _IO(__LOGGERIO, 1) /* size of log */
#define LOGGER_GET_LOG_LEN _IO(__LOGGERIO, 2) /* used log len */
#define LOGGER_GET_NEXT_ENTRY_LEN _IO(__LOGGERIO, 3) /* next entry len */
#define LOGGER_FLUSH_LOG _IO(__LOGGERIO, 4) /* flush log */
#define LOGGER_GET_VERSION _IO(__LOGGERIO, 5) /* abi version */
#define LOGGER_SET_VERSION _IO(__LOGGERIO, 6) /* abi version */
#define LOG_FILE_DIR "/dev/log/"
/* timeout in milliseconds */
#define LOG_TIMEOUT_FLUSH 5
#define LOG_TIMEOUT_NEVER -1
/* branchless on many architectures. */
#define min(x,y) ((y) ^ (((x) ^ (y)) & -((x) < (y))))
#if (defined(USE_MINGW) || defined(HAVE_WINSOCK))
#define WEAK static
#else
#define WEAK __attribute__((weak))
#endif
#ifndef __unused
#define __unused __attribute__((unused))
#endif
static int8_t use_logd = 1;//版本控制
void set_uselogd(int8_t uselogd) {//对外函数
use_logd = uselogd;
}
/* Private copy of ../libcutils/socket_local_client.c prevent library loops */
#ifdef HAVE_WINSOCK
int WEAK socket_local_client(const char *name, int namespaceId, int type)
{
errno = ENOSYS;
return -ENOSYS;
}
#else /* !HAVE_WINSOCK */
#include
#include
#include
#include
/* Private copy of ../libcutils/socket_local.h prevent library loops */
#define FILESYSTEM_SOCKET_PREFIX "/tmp/"
#define ANDROID_RESERVED_SOCKET_PREFIX "/dev/socket/"
/* End of ../libcutils/socket_local.h */
#define LISTEN_BACKLOG 4
/* Documented in header file. */
int WEAK socket_make_sockaddr_un(const char *name, int namespaceId,
struct sockaddr_un *p_addr, socklen_t *alen)
{
memset (p_addr, 0, sizeof (*p_addr));
size_t namelen;
switch (namespaceId) {
case ANDROID_SOCKET_NAMESPACE_ABSTRACT:
#if defined(__linux__)
namelen = strlen(name);
/* Test with length +1 for the *initial* '\0'. */
if ((namelen + 1) > sizeof(p_addr->sun_path)) {
goto error;
}
/*
* Note: The path in this case is *not* supposed to be
* '\0'-terminated. ("man 7 unix" for the gory details.)
*/
p_addr->sun_path[0] = 0;
memcpy(p_addr->sun_path + 1, name, namelen);
#else
/* this OS doesn't have the Linux abstract namespace */
namelen = strlen(name) + strlen(FILESYSTEM_SOCKET_PREFIX);
/* unix_path_max appears to be missing on linux */
if (namelen > sizeof(*p_addr)
- offsetof(struct sockaddr_un, sun_path) - 1) {
goto error;
}
strcpy(p_addr->sun_path, FILESYSTEM_SOCKET_PREFIX);
strcat(p_addr->sun_path, name);
#endif
break;
case ANDROID_SOCKET_NAMESPACE_RESERVED:
namelen = strlen(name) + strlen(ANDROID_RESERVED_SOCKET_PREFIX);
/* unix_path_max appears to be missing on linux */
if (namelen > sizeof(*p_addr)
- offsetof(struct sockaddr_un, sun_path) - 1) {
goto error;
}
strcpy(p_addr->sun_path, ANDROID_RESERVED_SOCKET_PREFIX);
strcat(p_addr->sun_path, name);
break;
case ANDROID_SOCKET_NAMESPACE_FILESYSTEM:
namelen = strlen(name);
/* unix_path_max appears to be missing on linux */
if (namelen > sizeof(*p_addr)
- offsetof(struct sockaddr_un, sun_path) - 1) {
goto error;
}
strcpy(p_addr->sun_path, name);
break;
default:
/* invalid namespace id */
return -1;
}
p_addr->sun_family = AF_LOCAL;
*alen = namelen + offsetof(struct sockaddr_un, sun_path) + 1;
return 0;
error:
return -1;
}
/**
* connect to peer named "name" on fd
* returns same fd or -1 on error.
* fd is not closed on error. that's your job.
*
* Used by AndroidSocketImpl
*/
int WEAK socket_local_client_connect(int fd, const char *name, int namespaceId,
int type __unused)
{
struct sockaddr_un addr;
socklen_t alen;
int err;
err = socket_make_sockaddr_un(name, namespaceId, &addr, &alen);
if (err < 0) {
goto error;
}
if(connect(fd, (struct sockaddr *) &addr, alen) < 0) {
goto error;
}
return fd;
error:
return -1;
}
/**
* connect to peer named "name"
* returns fd or -1 on error
*/
int WEAK socket_local_client(const char *name, int namespaceId, int type)
{
int s;
s = socket(AF_LOCAL, type, 0);
if(s < 0) return -1;
if ( 0 > socket_local_client_connect(s, name, namespaceId, type)) {
close(s);
return -1;
}
return s;
}
#endif /* !HAVE_WINSOCK */
/* End of ../libcutils/socket_local_client.c */
#define logger_for_each(logger, logger_list) \
for (logger = node_to_item((logger_list)->node.next, struct logger, node); \
logger != node_to_item(&(logger_list)->node, struct logger, node); \
logger = node_to_item((logger)->node.next, struct logger, node))
#ifndef __unused
#define __unused __attribute__((unused))
#endif
/* In the future, we would like to make this list extensible */
static const char *LOG_NAME[LOG_ID_MAX] = {
[LOG_ID_MAIN] = "main",
[LOG_ID_RADIO] = "radio",
[LOG_ID_EVENTS] = "events",
[LOG_ID_SYSTEM] = "system",
[LOG_ID_CRASH] = "crash",
[LOG_ID_KERNEL] = "kernel",
};
const char *android_log_id_to_name(log_id_t log_id)
{
if (log_id >= LOG_ID_MAX) {
log_id = LOG_ID_MAIN;
}
return LOG_NAME[log_id];
}
static int accessmode(int mode)
{
if ((mode & ANDROID_LOG_ACCMODE) == ANDROID_LOG_WRONLY) {
return W_OK;
}
if ((mode & ANDROID_LOG_ACCMODE) == ANDROID_LOG_RDWR) {
return R_OK | W_OK;
}
return R_OK;
}
/* repeated fragment */

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