static int __write_to_log_init(log_id_t log_id, struct iovec *vec, size_t nr)
{
DECLARE_SIGSET(sigflags);
lock(&sigflags);
if (write_to_log == __write_to_log_init) {
int ret;
ret = __write_to_log_initialize();
if (ret < 0) {
unlock(&sigflags);
#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(&sigflags);
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 !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_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;
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;
* };
* };
*/
if (android_log_timestamp() == 'm') {
clock_gettime(CLOCK_MONOTONIC, &ts);
} else {
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) {
DECLARE_SIGSET(sigflags);
ret = -errno;
if (ret == -ENOTCONN) {
lock(&sigflags);
close(logd_fd);
logd_fd = -1;
ret = __write_to_log_initialize();
unlock(&sigflags);
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;
}