blob: 85a4aab52165e17d7c26867d493bfb122dd551fb [file] [log] [blame]
/*
* 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 <endian.h>
#endif
#include <errno.h>
#include <fcntl.h>
#if !defined(_WIN32)
#include <pthread.h>
#endif
#include <stdarg.h>
#include <stdatomic.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#if (FAKE_LOG_DEVICE == 0)
#include <sys/socket.h>
#include <sys/un.h>
#endif
#include <time.h>
#include <unistd.h>
#ifdef __BIONIC__
#include <android/set_abort_message.h>
#endif
#include <log/event_tag_map.h>
#include <log/logd.h>
#include <log/logger.h>
#include <log/log_read.h>
#include <private/android_filesystem_config.h>
#include <private/android_logger.h>
#include "log_cdefs.h"
#define LOG_BUF_SIZE 1024
#if FAKE_LOG_DEVICE
/* This will be defined when building for the host. */
#include "fake_log_device.h"
#endif
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;
static void lock()
{
/*
* If we trigger a signal handler in the middle of locked activity and the
* signal handler logs a message, we could get into a deadlock state.
*/
pthread_mutex_lock(&log_init_lock);
}
static int trylock()
{
return pthread_mutex_trylock(&log_init_lock);
}
static void unlock()
{
pthread_mutex_unlock(&log_init_lock);
}
#else /* !defined(_WIN32) */
#define lock() ((void)0)
#define trylock() (0) /* success */
#define unlock() ((void)0)
#endif /* !defined(_WIN32) */
#if FAKE_LOG_DEVICE
static int log_fds[(int)LOG_ID_MAX] = { -1, -1, -1, -1, -1, -1 };
#else
static int logd_fd = -1;
static int pstore_fd = -1;
#endif
/*
* 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;
LIBLOG_ABI_PUBLIC int __android_log_dev_available()
{
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);
}
/* 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_security")];
snprintf(buf, sizeof(buf), "/dev/log_%s", android_log_id_to_name(i));
log_fds[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[(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;
static atomic_int_fast32_t dropped_security;
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();
}
if (log_id == LOG_ID_SECURITY) {
if (vec[0].iov_len < 4) {
return -EINVAL;
}
/* Matches clientHasLogCredentials() in logd */
if ((last_uid != AID_SYSTEM) && (last_uid != AID_ROOT) && (last_uid != AID_LOG)) {
uid_t uid = geteuid();
if ((uid != AID_SYSTEM) && (uid != AID_ROOT) && (uid != AID_LOG)) {
gid_t gid = getgid();
if ((gid != AID_SYSTEM) && (gid != AID_ROOT) && (gid != AID_LOG)) {
gid = getegid();
if ((gid != AID_SYSTEM) && (gid != AID_ROOT) && (gid != AID_LOG)) {
int num_groups;
gid_t *groups;
num_groups = getgroups(0, NULL);
if (num_groups <= 0) {
return -EPERM;
}
groups = calloc(num_groups, sizeof(gid_t));
if (!groups) {
return -ENOMEM;
}
num_groups = getgroups(num_groups, groups);
while (num_groups > 0) {
if (groups[num_groups - 1] == AID_LOG) {
break;
}
--num_groups;
}
free(groups);
if (num_groups <= 0) {
return -EPERM;
}
}
}
}
}
if (!__android_log_security()) {
atomic_store(&dropped_security, 0);
return -EPERM;
}
} else if (log_id == LOG_ID_EVENTS) {
static atomic_uintptr_t map;
int ret;
const char *tag;
EventTagMap *m, *f;
if (vec[0].iov_len < 4) {
return -EINVAL;
}
tag = NULL;
f = NULL;
m = (EventTagMap *)atomic_load(&map);
if (!m) {
ret = trylock();
m = (EventTagMap *)atomic_load(&map); /* trylock flush cache */
if (!m) {
m = android_openEventTagMap(EVENT_TAG_MAP_FILE);
if (ret) { /* trylock failed, use local copy, mark for close */
f = m;
} else {
if (!m) { /* One chance to open map file */
m = (EventTagMap *)(uintptr_t)-1LL;
}
atomic_store(&map, (uintptr_t)m);
}
}
if (!ret) { /* trylock succeeded, unlock */
unlock();
}
}
if (m && (m != (EventTagMap *)(uintptr_t)-1LL)) {
tag = android_lookupEventTag(
m,
htole32(((uint32_t *)vec[0].iov_base)[0]));
}
ret = __android_log_is_loggable(ANDROID_LOG_INFO,
tag,
ANDROID_LOG_VERBOSE);
if (f) { /* local copy marked for close */
android_closeEventTagMap(f);
}
if (!ret) {
return -EPERM;
}
} else {
/* Validate the incoming tag, tag content can not split across iovec */
char prio = ANDROID_LOG_VERBOSE;
const char *tag = vec[0].iov_base;
size_t len = vec[0].iov_len;
if (!tag) {
len = 0;
}
if (len > 0) {
prio = *tag;
if (len > 1) {
--len;
++tag;
} else {
len = vec[1].iov_len;
tag = ((const char *)vec[1].iov_base);
if (!tag) {
len = 0;
}
}
}
/* tag must be nul terminated */
if (strnlen(tag, len) >= len) {
tag = NULL;
}
if (!__android_log_is_loggable(prio, tag, ANDROID_LOG_VERBOSE)) {
return -EPERM;
}
}
/*
* 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(android_log_clockid(), &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_security, 0,
memory_order_relaxed);
if (snapshot) {
android_log_event_int_t buffer;
header.id = LOG_ID_SECURITY;
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_security, snapshot,
memory_order_relaxed);
}
}
snapshot = atomic_exchange_explicit(&dropped, 0, memory_order_relaxed);
if (snapshot && __android_log_is_loggable(ANDROID_LOG_INFO,
"liblog",
ANDROID_LOG_VERBOSE)) {
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) {
lock();
close(logd_fd);
logd_fd = -1;
ret = __write_to_log_initialize();
unlock();
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);
if (log_id == LOG_ID_SECURITY) {
atomic_fetch_add_explicit(&dropped_security, 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_SECURITY] = "security",
[LOG_ID_KERNEL] = "kernel",
};
LIBLOG_ABI_PUBLIC 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(log_id_t log_id, struct iovec *vec, size_t nr)
{
lock();
if (write_to_log == __write_to_log_init) {
int ret;
ret = __write_to_log_initialize();
if (ret < 0) {
unlock();
#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;
}
unlock();
return write_to_log(log_id, vec, nr);
}
LIBLOG_ABI_PUBLIC int __android_log_write(int prio, const char *tag,
const char *msg)
{
return __android_log_buf_write(LOG_ID_MAIN, prio, tag, msg);
}
LIBLOG_ABI_PUBLIC 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);
}
LIBLOG_ABI_PUBLIC 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);
}
LIBLOG_ABI_PUBLIC 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);
}
LIBLOG_ABI_PUBLIC 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);
}
LIBLOG_ABI_PUBLIC 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 */
}
LIBLOG_ABI_PUBLIC 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);
}
LIBLOG_ABI_PUBLIC int __android_log_security_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_SECURITY, 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.
*/
LIBLOG_ABI_PUBLIC 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.
*/
LIBLOG_ABI_PUBLIC 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);
}
/*
* Like __android_log_security_bwrite, but used for writing strings to the
* security log.
*/
LIBLOG_ABI_PUBLIC int __android_log_security_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_SECURITY, vec, 4);
}