trusty: Helper library for metrics
Bug: 182489121
Test: libtrusty_metrics_test
Change-Id: I7fc45ea3319185a8ac55889e56bd484d4774e928
diff --git a/trusty/metrics/metrics.cpp b/trusty/metrics/metrics.cpp
new file mode 100644
index 0000000..3ac128a
--- /dev/null
+++ b/trusty/metrics/metrics.cpp
@@ -0,0 +1,142 @@
+/*
+ * Copyright (C) 2021 The Android Open Sourete 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.
+ */
+
+#define LOG_TAG "metrics"
+
+#include <android-base/logging.h>
+#include <fcntl.h>
+#include <poll.h>
+#include <trusty/metrics/metrics.h>
+#include <trusty/metrics/tipc.h>
+#include <trusty/tipc.h>
+#include <unistd.h>
+
+namespace android {
+namespace trusty {
+namespace metrics {
+
+using android::base::ErrnoError;
+using android::base::Error;
+
+Result<void> TrustyMetrics::Open() {
+ int fd = tipc_connect(tipc_dev_.c_str(), METRICS_PORT);
+ if (fd < 0) {
+ return ErrnoError() << "failed to connect to Trusty metrics TA";
+ }
+
+ int flags = fcntl(fd, F_GETFL, 0);
+ if (flags < 0) {
+ return ErrnoError() << "failed F_GETFL";
+ }
+
+ int rc = fcntl(fd, F_SETFL, flags | O_NONBLOCK);
+ if (rc < 0) {
+ return ErrnoError() << "failed F_SETFL";
+ }
+
+ metrics_fd_.reset(fd);
+ return {};
+}
+
+Result<void> TrustyMetrics::WaitForEvent(int timeout_ms) {
+ if (!metrics_fd_.ok()) {
+ return Error() << "connection to Metrics TA has not been initialized yet";
+ }
+
+ struct pollfd pfd = {
+ .fd = metrics_fd_,
+ .events = POLLIN,
+ };
+
+ int rc = poll(&pfd, 1, timeout_ms);
+ if (rc != 1) {
+ return ErrnoError() << "failed poll()";
+ }
+
+ if (!(pfd.revents & POLLIN)) {
+ return ErrnoError() << "channel not ready";
+ }
+
+ return {};
+}
+
+Result<void> TrustyMetrics::HandleEvent() {
+ if (!metrics_fd_.ok()) {
+ return Error() << "connection to Metrics TA has not been initialized yet";
+ }
+
+ uint8_t msg[METRICS_MAX_MSG_SIZE];
+
+ auto rc = read(metrics_fd_, msg, sizeof(msg));
+ if (rc < 0) {
+ return ErrnoError() << "failed to read metrics message";
+ }
+ size_t msg_len = rc;
+
+ if (msg_len < sizeof(metrics_req)) {
+ return Error() << "message too small: " << rc;
+ }
+ auto req = reinterpret_cast<metrics_req*>(msg);
+ size_t offset = sizeof(metrics_req);
+ uint32_t status = METRICS_NO_ERROR;
+
+ switch (req->cmd) {
+ case METRICS_CMD_REPORT_CRASH: {
+ if (msg_len < offset + sizeof(metrics_report_crash_req)) {
+ return Error() << "message too small: " << rc;
+ }
+ auto crash_args = reinterpret_cast<metrics_report_crash_req*>(msg + offset);
+ offset += sizeof(metrics_report_crash_req);
+
+ if (msg_len < offset + crash_args->app_id_len) {
+ return Error() << "message too small: " << rc;
+ }
+ auto app_id_ptr = reinterpret_cast<char*>(msg + offset);
+ std::string app_id(app_id_ptr, crash_args->app_id_len);
+
+ HandleCrash(app_id);
+ break;
+ }
+
+ case METRICS_CMD_REPORT_EVENT_DROP:
+ HandleEventDrop();
+ break;
+
+ default:
+ status = METRICS_ERR_UNKNOWN_CMD;
+ break;
+ }
+
+ metrics_resp resp = {
+ .cmd = req->cmd | METRICS_CMD_RESP_BIT,
+ .status = status,
+ };
+
+ rc = write(metrics_fd_, &resp, sizeof(resp));
+ if (rc < 0) {
+ return ErrnoError() << "failed to request next metrics event";
+ }
+
+ if (rc != (int)sizeof(resp)) {
+ return Error() << "unexpected number of bytes sent event: " << rc;
+ }
+
+ return {};
+}
+
+} // namespace metrics
+} // namespace trusty
+} // namespace android