bool LogKlog::onDataAvailable(SocketClient *cli) {
if (!initialized) {
prctl(PR_SET_NAME, "logd.klogd");
initialized = true;
enableLogging = false;
}
char buffer[LOGGER_ENTRY_MAX_PAYLOAD];
size_t len = 0;
for(;;) {
ssize_t retval = 0;
if ((sizeof(buffer) - 1 - len) > 0) {
retval = read(cli->getSocket(), buffer + len, sizeof(buffer) - 1 - len);
}
if ((retval == 0) && (len == 0)) {
break;
}
if (retval < 0) {
return false;
}
len += retval;
bool full = len == (sizeof(buffer) - 1);
char *ep = buffer + len;
*ep = '\0';
len = 0;
for(char *ptr = NULL, *tok = buffer;
((tok = log_strtok_r(tok, &ptr)));
tok = NULL) {
if (((tok + strlen(tok)) == ep) && (retval != 0) && full) {
len = strlen(tok);
memmove(buffer, tok, len);
break;
}
if (*tok) {
log(tok);
}
}
}
return true;
}
static void readDmesg(LogAudit *al, LogKlog *kl) {
if (!al && !kl) {
return;
}
int len = klogctl(KLOG_SIZE_BUFFER, NULL, 0);
if (len <= 0) {
return;
}
len += 1024; // Margin for additional input race or trailing nul
std::unique_ptr<char []> buf(new char[len]);
int rc = klogctl(KLOG_READ_ALL, buf.get(), len);
if (rc <= 0) {
return;
}
if (rc < len) {
len = rc + 1;
}
buf[len - 1] = '\0';
if (kl) {
kl->synchronize(buf.get());
}
for (char *ptr = NULL, *tok = buf.get();
(rc >= 0) && ((tok = log_strtok_r(tok, &ptr)));
tok = NULL) {
if (al) {
rc = al->log(tok);
}
if (kl) {
rc = kl->log(tok);
}
}
}
// Foreground waits for exit of the main persistent threads
// that are started here. The threads are created to manage
// UNIX domain client sockets for writing, reading and
// controlling the user space logger, and for any additional
// logging plugins like auditd and restart control. Additional
// transitory per-client threads are created for each reader.
int main(int argc, char *argv[]) {
int fdPmesg = -1;
bool klogd = property_get_bool_svelte("logd.klogd");
if (klogd) {
fdPmesg = open("/proc/kmsg", O_RDONLY | O_NDELAY);
}
fdDmesg = open("/dev/kmsg", O_WRONLY);
// issue reinit command. KISS argument parsing.
if ((argc > 1) && argv[1] && !strcmp(argv[1], "--reinit")) {
int sock = TEMP_FAILURE_RETRY(
socket_local_client("logd",
ANDROID_SOCKET_NAMESPACE_RESERVED,
SOCK_STREAM));
if (sock < 0) {
return -errno;
}
static const char reinit[] = "reinit";
ssize_t ret = TEMP_FAILURE_RETRY(write(sock, reinit, sizeof(reinit)));
if (ret < 0) {
return -errno;
}
struct pollfd p;
memset(&p, 0, sizeof(p));
p.fd = sock;
p.events = POLLIN;
ret = TEMP_FAILURE_RETRY(poll(&p, 1, 100));
if (ret < 0) {
return -errno;
}
if ((ret == 0) || !(p.revents & POLLIN)) {
return -ETIME;
}
static const char success[] = "success";
char buffer[sizeof(success) - 1];
memset(buffer, 0, sizeof(buffer));
ret = TEMP_FAILURE_RETRY(read(sock, buffer, sizeof(buffer)));
if (ret < 0) {
return -errno;
}
return strncmp(buffer, success, sizeof(success) - 1) != 0;
}
// Reinit Thread
sem_init(&reinit, 0, 0);
sem_init(&uidName, 0, 0);
sem_init(&sem_name, 0, 1);
pthread_attr_t attr;
if (!pthread_attr_init(&attr)) {
struct sched_param param;
memset(¶m, 0, sizeof(param));
pthread_attr_setschedparam(&attr, ¶m);
pthread_attr_setschedpolicy(&attr, SCHED_BATCH);
if (!pthread_attr_setdetachstate(&attr,
PTHREAD_CREATE_DETACHED)) {
pthread_t thread;
reinit_running = true;
if (pthread_create(&thread, &attr, reinit_thread_start, NULL)) {
reinit_running = false;
}
}
pthread_attr_destroy(&attr);
}
if (drop_privs() != 0) {
return -1;
}
// Serves the purpose of managing the last logs times read on a
// socket connection, and as a reader lock on a range of log
// entries.
LastLogTimes *times = new LastLogTimes();
// LogBuffer is the object which is responsible for holding all
// log entries.
logBuf = new LogBuffer(times);
signal(SIGHUP, reinit_signal_handler);
if (property_get_bool_svelte("logd.statistics")) {
logBuf->enableStatistics();
}
// LogReader listens on /dev/socket/logdr. When a client
// connects, log entries in the LogBuffer are written to the client.
LogReader *reader = new LogReader(logBuf);
if (reader->startListener()) {
exit(1);
}
// LogListener listens on /dev/socket/logdw for client
// initiated log messages. New log entries are added to LogBuffer
// and LogReader is notified to send updates to connected clients.
LogListener *swl = new LogListener(logBuf, reader);
// Backlog and /proc/sys/net/unix/max_dgram_qlen set to large value
if (swl->startListener(300)) {
exit(1);
}
// Command listener listens on /dev/socket/logd for incoming logd
// administrative commands.
CommandListener *cl = new CommandListener(logBuf, reader, swl);
if (cl->startListener()) {
exit(1);
}
// LogAudit listens on NETLINK_AUDIT socket for selinux
// initiated log messages. New log entries are added to LogBuffer
// and LogReader is notified to send updates to connected clients.
bool auditd = property_get_bool("logd.auditd", true);
LogAudit *al = NULL;
if (auditd) {
bool dmesg = property_get_bool("logd.auditd.dmesg", true);
al = new LogAudit(logBuf, reader, dmesg ? fdDmesg : -1);
}
LogKlog *kl = NULL;
if (klogd) {
kl = new LogKlog(logBuf, reader, fdDmesg, fdPmesg, al != NULL);
}
if (al || kl) {
int len = klogctl(KLOG_SIZE_BUFFER, NULL, 0);
if (len > 0) {
len++;
char buf[len];
int rc = klogctl(KLOG_READ_ALL, buf, len);
buf[len - 1] = '\0';
if ((rc >= 0) && kl) {
kl->synchronize(buf);
}
for (char *ptr = NULL, *tok = buf;
(rc >= 0) && ((tok = log_strtok_r(tok, &ptr)));
tok = NULL) {
if (al) {
rc = al->log(tok);
}
if (kl) {
rc = kl->log(tok);
}
}
}
// failure is an option ... messages are in dmesg (required by standard)
if (kl && kl->startListener()) {
delete kl;
}
if (al && al->startListener()) {
delete al;
}
}
TEMP_FAILURE_RETRY(pause());
exit(0);
}
