Move libstatssocket from frameworks/base to system/core/
So that lmkd can build on PDK.
Bug: 79349329
Test: builds locally
Merged-In: I981e6ef9f9769b873640e5f169a9495ccea2f25c
Change-Id: I981e6ef9f9769b873640e5f169a9495ccea2f25c
(cherry picked from commit b13a102c0afec2c0a1fbdafb9a00e3d55450b28b)
diff --git a/libstats/statsd_writer.c b/libstats/statsd_writer.c
new file mode 100644
index 0000000..9953bba
--- /dev/null
+++ b/libstats/statsd_writer.c
@@ -0,0 +1,260 @@
+/*
+ * Copyright (C) 2018, 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 "statsd_writer.h"
+
+#include <cutils/sockets.h>
+#include <endian.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <poll.h>
+#include <private/android_filesystem_config.h>
+#include <private/android_logger.h>
+#include <stdarg.h>
+#include <stdatomic.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/un.h>
+#include <time.h>
+#include <unistd.h>
+
+/* branchless on many architectures. */
+#define min(x, y) ((y) ^ (((x) ^ (y)) & -((x) < (y))))
+
+static pthread_mutex_t log_init_lock = PTHREAD_MUTEX_INITIALIZER;
+
+void statsd_writer_init_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);
+}
+
+int statd_writer_trylock() {
+ return pthread_mutex_trylock(&log_init_lock);
+}
+
+void statsd_writer_init_unlock() {
+ pthread_mutex_unlock(&log_init_lock);
+}
+
+static int statsdAvailable();
+static int statsdOpen();
+static void statsdClose();
+static int statsdWrite(struct timespec* ts, struct iovec* vec, size_t nr);
+
+struct android_log_transport_write statsdLoggerWrite = {
+ .name = "statsd",
+ .sock = -EBADF,
+ .available = statsdAvailable,
+ .open = statsdOpen,
+ .close = statsdClose,
+ .write = statsdWrite,
+};
+
+/* log_init_lock assumed */
+static int statsdOpen() {
+ int i, ret = 0;
+
+ i = atomic_load(&statsdLoggerWrite.sock);
+ if (i < 0) {
+ int sock = TEMP_FAILURE_RETRY(socket(PF_UNIX, SOCK_DGRAM | SOCK_CLOEXEC | SOCK_NONBLOCK, 0));
+ if (sock < 0) {
+ ret = -errno;
+ } else {
+ struct sockaddr_un un;
+ memset(&un, 0, sizeof(struct sockaddr_un));
+ un.sun_family = AF_UNIX;
+ strcpy(un.sun_path, "/dev/socket/statsdw");
+
+ if (TEMP_FAILURE_RETRY(
+ connect(sock, (struct sockaddr*)&un, sizeof(struct sockaddr_un))) < 0) {
+ ret = -errno;
+ switch (ret) {
+ case -ENOTCONN:
+ case -ECONNREFUSED:
+ case -ENOENT:
+ i = atomic_exchange(&statsdLoggerWrite.sock, ret);
+ /* FALLTHRU */
+ default:
+ break;
+ }
+ close(sock);
+ } else {
+ ret = atomic_exchange(&statsdLoggerWrite.sock, sock);
+ if ((ret >= 0) && (ret != sock)) {
+ close(ret);
+ }
+ ret = 0;
+ }
+ }
+ }
+
+ return ret;
+}
+
+static void __statsdClose(int negative_errno) {
+ int sock = atomic_exchange(&statsdLoggerWrite.sock, negative_errno);
+ if (sock >= 0) {
+ close(sock);
+ }
+}
+
+static void statsdClose() {
+ __statsdClose(-EBADF);
+}
+
+static int statsdAvailable() {
+ if (atomic_load(&statsdLoggerWrite.sock) < 0) {
+ if (access("/dev/socket/statsdw", W_OK) == 0) {
+ return 0;
+ }
+ return -EBADF;
+ }
+ return 1;
+}
+
+static int statsdWrite(struct timespec* ts, struct iovec* vec, size_t nr) {
+ ssize_t ret;
+ int sock;
+ static const unsigned headerLength = 1;
+ struct iovec newVec[nr + headerLength];
+ android_log_header_t header;
+ size_t i, payloadSize;
+ static atomic_int dropped;
+
+ sock = atomic_load(&statsdLoggerWrite.sock);
+ if (sock < 0) switch (sock) {
+ case -ENOTCONN:
+ case -ECONNREFUSED:
+ case -ENOENT:
+ break;
+ default:
+ return -EBADF;
+ }
+ /*
+ * struct {
+ * // 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;
+ * };
+ * };
+ */
+
+ header.tid = gettid();
+ header.realtime.tv_sec = ts->tv_sec;
+ header.realtime.tv_nsec = ts->tv_nsec;
+
+ newVec[0].iov_base = (unsigned char*)&header;
+ newVec[0].iov_len = sizeof(header);
+
+ // If we dropped events before, try to tell statsd.
+ if (sock >= 0) {
+ int32_t snapshot = atomic_exchange_explicit(&dropped, 0, memory_order_relaxed);
+ if (snapshot) {
+ android_log_event_int_t buffer;
+ header.id = LOG_ID_STATS;
+ buffer.header.tag = htole32(LIBLOG_LOG_TAG);
+ buffer.payload.type = EVENT_TYPE_INT;
+ buffer.payload.data = htole32(snapshot);
+
+ newVec[headerLength].iov_base = &buffer;
+ newVec[headerLength].iov_len = sizeof(buffer);
+
+ ret = TEMP_FAILURE_RETRY(writev(sock, newVec, 2));
+ if (ret != (ssize_t)(sizeof(header) + sizeof(buffer))) {
+ atomic_fetch_add_explicit(&dropped, snapshot, memory_order_relaxed);
+ }
+ }
+ }
+
+ header.id = LOG_ID_STATS;
+
+ for (payloadSize = 0, i = headerLength; i < nr + headerLength; i++) {
+ newVec[i].iov_base = vec[i - headerLength].iov_base;
+ payloadSize += newVec[i].iov_len = vec[i - headerLength].iov_len;
+
+ if (payloadSize > LOGGER_ENTRY_MAX_PAYLOAD) {
+ newVec[i].iov_len -= payloadSize - LOGGER_ENTRY_MAX_PAYLOAD;
+ if (newVec[i].iov_len) {
+ ++i;
+ }
+ break;
+ }
+ }
+
+ /*
+ * The write below could be lost, but will never block.
+ *
+ * ENOTCONN occurs if statsd has died.
+ * ENOENT occurs if statsd is not running and socket is missing.
+ * ECONNREFUSED occurs if we can not reconnect to statsd.
+ * EAGAIN occurs if statsd is overloaded.
+ */
+ if (sock < 0) {
+ ret = sock;
+ } else {
+ ret = TEMP_FAILURE_RETRY(writev(sock, newVec, i));
+ if (ret < 0) {
+ ret = -errno;
+ }
+ }
+ switch (ret) {
+ case -ENOTCONN:
+ case -ECONNREFUSED:
+ case -ENOENT:
+ if (statd_writer_trylock()) {
+ return ret; /* in a signal handler? try again when less stressed
+ */
+ }
+ __statsdClose(ret);
+ ret = statsdOpen();
+ statsd_writer_init_unlock();
+
+ if (ret < 0) {
+ return ret;
+ }
+
+ ret = TEMP_FAILURE_RETRY(writev(atomic_load(&statsdLoggerWrite.sock), newVec, i));
+ if (ret < 0) {
+ ret = -errno;
+ }
+ /* FALLTHRU */
+ default:
+ break;
+ }
+
+ if (ret > (ssize_t)sizeof(header)) {
+ ret -= sizeof(header);
+ } else if (ret == -EAGAIN) {
+ atomic_fetch_add_explicit(&dropped, 1, memory_order_relaxed);
+ }
+
+ return ret;
+}