1 /*
2 * Copyright (C) 2021 The Android Open Sourete Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #define LOG_TAG "metrics"
18
19 #include <android-base/logging.h>
20 #include <fcntl.h>
21 #include <poll.h>
22 #include <trusty/metrics/metrics.h>
23 #include <trusty/metrics/tipc.h>
24 #include <trusty/tipc.h>
25 #include <unistd.h>
26
27 namespace android {
28 namespace trusty {
29 namespace metrics {
30
31 using android::base::ErrnoError;
32 using android::base::Error;
33
Open()34 Result<void> TrustyMetrics::Open() {
35 int fd = tipc_connect(tipc_dev_.c_str(), METRICS_PORT);
36 if (fd < 0) {
37 return ErrnoError() << "failed to connect to Trusty metrics TA";
38 }
39
40 int flags = fcntl(fd, F_GETFL, 0);
41 if (flags < 0) {
42 return ErrnoError() << "failed F_GETFL";
43 }
44
45 int rc = fcntl(fd, F_SETFL, flags | O_NONBLOCK);
46 if (rc < 0) {
47 return ErrnoError() << "failed F_SETFL";
48 }
49
50 metrics_fd_.reset(fd);
51 return {};
52 }
53
WaitForEvent(int timeout_ms)54 Result<void> TrustyMetrics::WaitForEvent(int timeout_ms) {
55 if (!metrics_fd_.ok()) {
56 return Error() << "connection to Metrics TA has not been initialized yet";
57 }
58
59 struct pollfd pfd = {
60 .fd = metrics_fd_,
61 .events = POLLIN,
62 };
63
64 int rc = poll(&pfd, 1, timeout_ms);
65 if (rc != 1) {
66 return ErrnoError() << "failed poll()";
67 }
68
69 if (!(pfd.revents & POLLIN)) {
70 return ErrnoError() << "channel not ready";
71 }
72
73 return {};
74 }
75
HandleEvent()76 Result<void> TrustyMetrics::HandleEvent() {
77 if (!metrics_fd_.ok()) {
78 return Error() << "connection to Metrics TA has not been initialized yet";
79 }
80
81 uint8_t msg[METRICS_MAX_MSG_SIZE];
82
83 auto rc = read(metrics_fd_, msg, sizeof(msg));
84 if (rc < 0) {
85 return ErrnoError() << "failed to read metrics message";
86 }
87 size_t msg_len = rc;
88
89 if (msg_len < sizeof(metrics_req)) {
90 return Error() << "message too small: " << rc;
91 }
92 auto req = reinterpret_cast<metrics_req*>(msg);
93 size_t offset = sizeof(metrics_req);
94 uint32_t status = METRICS_NO_ERROR;
95
96 switch (req->cmd) {
97 case METRICS_CMD_REPORT_CRASH: {
98 if (msg_len < offset + sizeof(metrics_report_crash_req)) {
99 return Error() << "message too small: " << rc;
100 }
101 auto crash_args = reinterpret_cast<metrics_report_crash_req*>(msg + offset);
102 offset += sizeof(metrics_report_crash_req);
103
104 if (msg_len < offset + crash_args->app_id_len) {
105 return Error() << "message too small: " << rc;
106 }
107 auto app_id_ptr = reinterpret_cast<char*>(msg + offset);
108 std::string app_id(app_id_ptr, crash_args->app_id_len);
109
110 HandleCrash(app_id);
111 break;
112 }
113
114 case METRICS_CMD_REPORT_EVENT_DROP:
115 HandleEventDrop();
116 break;
117
118 default:
119 status = METRICS_ERR_UNKNOWN_CMD;
120 break;
121 }
122
123 metrics_resp resp = {
124 .cmd = req->cmd | METRICS_CMD_RESP_BIT,
125 .status = status,
126 };
127
128 rc = write(metrics_fd_, &resp, sizeof(resp));
129 if (rc < 0) {
130 return ErrnoError() << "failed to request next metrics event";
131 }
132
133 if (rc != (int)sizeof(resp)) {
134 return Error() << "unexpected number of bytes sent event: " << rc;
135 }
136
137 return {};
138 }
139
140 } // namespace metrics
141 } // namespace trusty
142 } // namespace android
143