platform_system_core/liblog/logger_read.c

545 lines
19 KiB
C

/*
** Copyright 2013-2014, 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 <errno.h>
#include <fcntl.h>
#include <pthread.h>
#include <sched.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <android/log.h>
#include <cutils/list.h>
#include <private/android_filesystem_config.h>
#include "config_read.h"
#include "log_portability.h"
#include "logger.h"
/* android_logger_alloc unimplemented, no use case */
/* android_logger_free not exported */
static void android_logger_free(struct logger *logger)
{
struct android_log_logger *logger_internal =
(struct android_log_logger *)logger;
if (!logger_internal) {
return;
}
list_remove(&logger_internal->node);
free(logger_internal);
}
/* android_logger_alloc unimplemented, no use case */
/* method for getting the associated sublog id */
LIBLOG_ABI_PUBLIC log_id_t android_logger_get_id(struct logger *logger)
{
return ((struct android_log_logger *)logger)->logId;
}
static int init_transport_context(struct android_log_logger_list *logger_list)
{
struct android_log_transport_read *transport;
struct listnode *node;
if (!logger_list) {
return -EINVAL;
}
if (list_empty(&logger_list->logger)) {
return -EINVAL;
}
if (!list_empty(&logger_list->transport)) {
return 0;
}
__android_log_lock();
/* mini __write_to_log_initialize() to populate transports */
if (list_empty(&__android_log_transport_read) &&
list_empty(&__android_log_persist_read)) {
__android_log_config_read();
}
__android_log_unlock();
node = (logger_list->mode & ANDROID_LOG_PSTORE) ?
&__android_log_persist_read : &__android_log_transport_read;
read_transport_for_each(transport, node) {
struct android_log_transport_context *transp;
struct android_log_logger *logger;
unsigned logMask = 0;
logger_for_each(logger, logger_list) {
log_id_t logId = logger->logId;
if ((logId == LOG_ID_SECURITY) &&
(__android_log_uid() != AID_SYSTEM)) {
continue;
}
if (transport->read &&
(!transport->available ||
(transport->available(logId) >= 0))) {
logMask |= 1 << logId;
}
}
if (!logMask) {
continue;
}
transp = calloc(1, sizeof(*transp));
if (!transp) {
return -ENOMEM;
}
transp->parent = logger_list;
transp->transport = transport;
transp->logMask = logMask;
transp->ret = 1;
list_add_tail(&logger_list->transport, &transp->node);
}
if (list_empty(&logger_list->transport)) {
return -ENODEV;
}
return 0;
}
#define LOGGER_FUNCTION(logger, def, func, args...) \
ssize_t ret = -EINVAL; \
struct android_log_transport_context *transp; \
struct android_log_logger *logger_internal = \
(struct android_log_logger *)(logger); \
\
if (!logger_internal) { \
return ret; \
} \
ret = init_transport_context(logger_internal->parent); \
if (ret < 0) { \
return ret; \
} \
\
ret = (def); \
transport_context_for_each(transp, logger_internal->parent) { \
if ((transp->logMask & (1 << logger_internal->logId)) && \
transp->transport && transp->transport->func) { \
ssize_t retval = (transp->transport->func)(logger_internal, \
transp, ## args); \
if ((ret >= 0) || (ret == (def))) { \
ret = retval; \
} \
} \
} \
return ret
LIBLOG_ABI_PUBLIC int android_logger_clear(struct logger *logger)
{
LOGGER_FUNCTION(logger, -ENODEV, clear);
}
/* returns the total size of the log's ring buffer */
LIBLOG_ABI_PUBLIC long android_logger_get_log_size(struct logger *logger)
{
LOGGER_FUNCTION(logger, -ENODEV, getSize);
}
LIBLOG_ABI_PUBLIC int android_logger_set_log_size(struct logger *logger,
unsigned long size)
{
LOGGER_FUNCTION(logger, -ENODEV, setSize, size);
}
/*
* returns the readable size of the log's ring buffer (that is, amount of the
* log consumed)
*/
LIBLOG_ABI_PUBLIC long android_logger_get_log_readable_size(
struct logger *logger)
{
LOGGER_FUNCTION(logger, -ENODEV, getReadableSize);
}
/*
* returns the logger version
*/
LIBLOG_ABI_PUBLIC int android_logger_get_log_version(struct logger *logger)
{
LOGGER_FUNCTION(logger, 4, version);
}
#define LOGGER_LIST_FUNCTION(logger_list, def, func, args...) \
struct android_log_transport_context *transp; \
struct android_log_logger_list *logger_list_internal = \
(struct android_log_logger_list *)(logger_list); \
\
ssize_t ret = init_transport_context(logger_list_internal); \
if (ret < 0) { \
return ret; \
} \
\
ret = (def); \
transport_context_for_each(transp, logger_list_internal) { \
if (transp->transport && (transp->transport->func)) { \
ssize_t retval = (transp->transport->func)(logger_list_internal, \
transp, ## args); \
if ((ret >= 0) || (ret == (def))) { \
ret = retval; \
} \
} \
} \
return ret
/*
* returns statistics
*/
LIBLOG_ABI_PUBLIC ssize_t android_logger_get_statistics(
struct logger_list *logger_list,
char *buf, size_t len)
{
LOGGER_LIST_FUNCTION(logger_list, -ENODEV, getStats, buf, len);
}
LIBLOG_ABI_PUBLIC ssize_t android_logger_get_prune_list(
struct logger_list *logger_list,
char *buf, size_t len)
{
LOGGER_LIST_FUNCTION(logger_list, -ENODEV, getPrune, buf, len);
}
LIBLOG_ABI_PUBLIC int android_logger_set_prune_list(
struct logger_list *logger_list,
char *buf, size_t len)
{
LOGGER_LIST_FUNCTION(logger_list, -ENODEV, setPrune, buf, len);
}
LIBLOG_HIDDEN struct listnode __android_log_readers =
{ &__android_log_readers, &__android_log_readers };
#if !defined(_WIN32)
LIBLOG_HIDDEN pthread_rwlock_t __android_log_readers_lock =
PTHREAD_RWLOCK_INITIALIZER;
#endif
LIBLOG_ABI_PUBLIC struct logger_list *android_logger_list_alloc(
int mode,
unsigned int tail,
pid_t pid)
{
struct android_log_logger_list *logger_list;
logger_list = calloc(1, sizeof(*logger_list));
if (!logger_list) {
return NULL;
}
list_init(&logger_list->logger);
list_init(&logger_list->transport);
logger_list->mode = mode;
logger_list->tail = tail;
logger_list->pid = pid;
logger_list_wrlock();
list_add_tail(&__android_log_readers, &logger_list->node);
logger_list_unlock();
return (struct logger_list *)logger_list;
}
LIBLOG_ABI_PUBLIC struct logger_list *android_logger_list_alloc_time(
int mode,
log_time start,
pid_t pid)
{
struct android_log_logger_list *logger_list;
logger_list = calloc(1, sizeof(*logger_list));
if (!logger_list) {
return NULL;
}
list_init(&logger_list->logger);
list_init(&logger_list->transport);
logger_list->mode = mode;
logger_list->start = start;
logger_list->pid = pid;
logger_list_wrlock();
list_add_tail(&__android_log_readers, &logger_list->node);
logger_list_unlock();
return (struct logger_list *)logger_list;
}
/* android_logger_list_register unimplemented, no use case */
/* android_logger_list_unregister unimplemented, no use case */
/* Open the named log and add it to the logger list */
LIBLOG_ABI_PUBLIC struct logger *android_logger_open(
struct logger_list *logger_list,
log_id_t logId)
{
struct android_log_logger_list *logger_list_internal =
(struct android_log_logger_list *)logger_list;
struct android_log_logger *logger;
if (!logger_list_internal || (logId >= LOG_ID_MAX)) {
goto err;
}
logger_for_each(logger, logger_list_internal) {
if (logger->logId == logId) {
goto ok;
}
}
logger = calloc(1, sizeof(*logger));
if (!logger) {
goto err;
}
logger->logId = logId;
list_add_tail(&logger_list_internal->logger, &logger->node);
logger->parent = logger_list_internal;
/* Reset known transports to re-evaluate, we just added one */
while (!list_empty(&logger_list_internal->transport)) {
struct listnode *node = list_head(&logger_list_internal->transport);
struct android_log_transport_context *transp =
node_to_item(node, struct android_log_transport_context, node);
list_remove(&transp->node);
free(transp);
}
goto ok;
err:
logger = NULL;
ok:
return (struct logger *)logger;
}
/* Open the single named log and make it part of a new logger list */
LIBLOG_ABI_PUBLIC struct logger_list *android_logger_list_open(
log_id_t logId,
int mode,
unsigned int tail,
pid_t pid)
{
struct logger_list *logger_list =
android_logger_list_alloc(mode, tail, pid);
if (!logger_list) {
return NULL;
}
if (!android_logger_open(logger_list, logId)) {
android_logger_list_free(logger_list);
return NULL;
}
return logger_list;
}
/* Validate log_msg packet, read function has already been null checked */
static int android_transport_read(struct android_log_logger_list *logger_list,
struct android_log_transport_context *transp,
struct log_msg *log_msg)
{
int ret = (*transp->transport->read)(logger_list, transp, log_msg);
if (ret > (int)sizeof(*log_msg)) {
ret = sizeof(*log_msg);
}
transp->ret = ret;
/* propagate errors, or make sure len & hdr_size members visible */
if (ret < (int)(sizeof(log_msg->entry.len) +
sizeof(log_msg->entry.hdr_size))) {
if (ret >= (int)sizeof(log_msg->entry.len)) {
log_msg->entry.len = 0;
}
return ret;
}
/* hdr_size correction (logger_entry -> logger_entry_v2+ conversion) */
if (log_msg->entry_v2.hdr_size == 0) {
log_msg->entry_v2.hdr_size = sizeof(struct logger_entry);
}
if ((log_msg->entry_v2.hdr_size < sizeof(log_msg->entry_v1)) ||
(log_msg->entry_v2.hdr_size > sizeof(log_msg->entry))) {
return -EINVAL;
}
/* len validation */
if (ret <= log_msg->entry_v2.hdr_size) {
log_msg->entry.len = 0;
} else {
log_msg->entry.len = ret - log_msg->entry_v2.hdr_size;
}
return ret;
}
/* Read from the selected logs */
LIBLOG_ABI_PUBLIC int android_logger_list_read(struct logger_list *logger_list,
struct log_msg *log_msg)
{
struct android_log_transport_context *transp;
struct android_log_logger_list *logger_list_internal =
(struct android_log_logger_list *)logger_list;
int ret = init_transport_context(logger_list_internal);
if (ret < 0) {
return ret;
}
/* at least one transport */
transp = node_to_item(logger_list_internal->transport.next,
struct android_log_transport_context, node);
/* more than one transport? */
if (transp->node.next != &logger_list_internal->transport) {
/* Poll and merge sort the entries if from multiple transports */
struct android_log_transport_context *oldest = NULL;
int ret;
int polled = 0;
do {
if (polled) {
sched_yield();
}
ret = -1000;
polled = 0;
do {
int retval = transp->ret;
if ((retval > 0) && !transp->logMsg.entry.len) {
if (!transp->transport->read) {
retval = transp->ret = 0;
} else if ((logger_list_internal->mode &
ANDROID_LOG_NONBLOCK) ||
!transp->transport->poll) {
retval = android_transport_read(
logger_list_internal,
transp,
&transp->logMsg);
} else {
int pollval = (*transp->transport->poll)(
logger_list_internal, transp);
if (pollval <= 0) {
sched_yield();
pollval = (*transp->transport->poll)(
logger_list_internal, transp);
}
polled = 1;
if (pollval < 0) {
if ((pollval == -EINTR) || (pollval == -EAGAIN)) {
return -EAGAIN;
}
retval = transp->ret = pollval;
} else if (pollval > 0) {
retval = android_transport_read(
logger_list_internal,
transp,
&transp->logMsg);
}
}
}
if (ret < retval) {
ret = retval;
}
if ((transp->ret > 0) && transp->logMsg.entry.len &&
(!oldest ||
(oldest->logMsg.entry.sec >
transp->logMsg.entry.sec) ||
((oldest->logMsg.entry.sec ==
transp->logMsg.entry.sec) &&
(oldest->logMsg.entry.nsec >
transp->logMsg.entry.nsec)))) {
oldest = transp;
}
transp = node_to_item(transp->node.next,
struct android_log_transport_context,
node);
} while (transp != node_to_item(
&logger_list_internal->transport,
struct android_log_transport_context,
node));
if (!oldest &&
(logger_list_internal->mode & ANDROID_LOG_NONBLOCK)) {
return (ret < 0) ? ret : -EAGAIN;
}
transp = node_to_item(logger_list_internal->transport.next,
struct android_log_transport_context, node);
} while (!oldest && (ret > 0));
if (!oldest) {
return ret;
}
// ret is a positive value less than sizeof(struct log_msg)
ret = oldest->ret;
if (ret < oldest->logMsg.entry.hdr_size) {
// zero truncated header fields.
memset(log_msg, 0,
(oldest->logMsg.entry.hdr_size > sizeof(oldest->logMsg) ?
sizeof(oldest->logMsg) :
oldest->logMsg.entry.hdr_size));
}
memcpy(log_msg, &oldest->logMsg, ret);
oldest->logMsg.entry.len = 0; /* Mark it as copied */
return ret;
}
/* if only one, no need to copy into transport_context and merge-sort */
return android_transport_read(logger_list_internal, transp, log_msg);
}
/* Close all the logs */
LIBLOG_ABI_PUBLIC void android_logger_list_free(struct logger_list *logger_list)
{
struct android_log_logger_list *logger_list_internal =
(struct android_log_logger_list *)logger_list;
if (logger_list_internal == NULL) {
return;
}
logger_list_wrlock();
list_remove(&logger_list_internal->node);
logger_list_unlock();
while (!list_empty(&logger_list_internal->transport)) {
struct listnode *node = list_head(&logger_list_internal->transport);
struct android_log_transport_context *transp =
node_to_item(node, struct android_log_transport_context, node);
if (transp->transport && transp->transport->close) {
(*transp->transport->close)(logger_list_internal, transp);
}
list_remove(&transp->node);
free(transp);
}
while (!list_empty(&logger_list_internal->logger)) {
struct listnode *node = list_head(&logger_list_internal->logger);
struct android_log_logger *logger =
node_to_item(node, struct android_log_logger, node);
android_logger_free((struct logger *)logger);
}
free(logger_list_internal);
}