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1 /*
2  * Copyright (C) 2011 The Android Open Source 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 "common_time"
18 #include <utils/Log.h>
19 
20 #include <fcntl.h>
21 #include <linux/in.h>
22 #include <linux/tcp.h>
23 #include <poll.h>
24 #include <sys/socket.h>
25 #include <sys/types.h>
26 #include <unistd.h>
27 #include <utils/Errors.h>
28 #include <utils/misc.h>
29 
30 #include <common_time/local_clock.h>
31 
32 #include "common_clock.h"
33 #include "diag_thread.h"
34 
35 #define kMaxEvents 16
36 #define kListenPort 9876
37 
setNonblocking(int fd)38 static bool setNonblocking(int fd) {
39     int flags = fcntl(fd, F_GETFL);
40     if (fcntl(fd, F_SETFL, flags | O_NONBLOCK) < 0) {
41         ALOGE("Failed to set socket (%d) to non-blocking mode (errno %d)",
42              fd, errno);
43         return false;
44     }
45 
46     return true;
47 }
48 
setNodelay(int fd)49 static bool setNodelay(int fd) {
50     int tmp = 1;
51     if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &tmp, sizeof(tmp)) < 0) {
52         ALOGE("Failed to set socket (%d) to no-delay mode (errno %d)",
53              fd, errno);
54         return false;
55     }
56 
57     return true;
58 }
59 
60 namespace android {
61 
DiagThread(CommonClock * common_clock,LocalClock * local_clock)62 DiagThread::DiagThread(CommonClock* common_clock, LocalClock* local_clock) {
63     common_clock_ = common_clock;
64     local_clock_ = local_clock;
65     listen_fd_ = -1;
66     data_fd_ = -1;
67     kernel_logID_basis_known_ = false;
68     discipline_log_ID_ = 0;
69 }
70 
~DiagThread()71 DiagThread::~DiagThread() {
72 }
73 
startWorkThread()74 status_t DiagThread::startWorkThread() {
75     status_t res;
76     stopWorkThread();
77     res = run("Diag");
78 
79     if (res != OK)
80         ALOGE("Failed to start work thread (res = %d)", res);
81 
82     return res;
83 }
84 
stopWorkThread()85 void DiagThread::stopWorkThread() {
86     status_t res;
87     res = requestExitAndWait(); // block until thread exit.
88     if (res != OK)
89         ALOGE("Failed to stop work thread (res = %d)", res);
90 }
91 
openListenSocket()92 bool DiagThread::openListenSocket() {
93     bool ret = false;
94     int flags;
95     cleanupListenSocket();
96 
97     if ((listen_fd_ = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0) {
98         ALOGE("Socket failed.");
99         goto bailout;
100     }
101 
102     // Set non-blocking operation
103     if (!setNonblocking(listen_fd_))
104         goto bailout;
105 
106     struct sockaddr_in addr;
107     memset(&addr, 0, sizeof(addr));
108     addr.sin_family = AF_INET;
109     addr.sin_addr.s_addr = INADDR_ANY;
110     addr.sin_port = htons(kListenPort);
111 
112     if (bind(listen_fd_, (struct sockaddr*)&addr, sizeof(addr)) < 0) {
113         ALOGE("Bind failed.");
114         goto bailout;
115     }
116 
117     if (listen(listen_fd_, 1) < 0) {
118         ALOGE("Listen failed.");
119         goto bailout;
120     }
121 
122     ret = true;
123 bailout:
124     if (!ret)
125         cleanupListenSocket();
126 
127     return ret;
128 }
129 
cleanupListenSocket()130 void DiagThread::cleanupListenSocket() {
131     if (listen_fd_ >= 0) {
132         int res;
133 
134         struct linger l;
135         l.l_onoff  = 1;
136         l.l_linger = 0;
137 
138         setsockopt(listen_fd_, SOL_SOCKET, SO_LINGER, &l, sizeof(l));
139         shutdown(listen_fd_, SHUT_RDWR);
140         close(listen_fd_);
141         listen_fd_ = -1;
142     }
143 }
144 
cleanupDataSocket()145 void DiagThread::cleanupDataSocket() {
146     if (data_fd_ >= 0) {
147         int res;
148 
149         struct linger l;
150         l.l_onoff  = 1;
151         l.l_linger = 0;
152 
153         setsockopt(data_fd_, SOL_SOCKET, SO_LINGER, &l, sizeof(l));
154         shutdown(data_fd_, SHUT_RDWR);
155         close(data_fd_);
156         data_fd_ = -1;
157     }
158 }
159 
resetLogIDs()160 void DiagThread::resetLogIDs() {
161     // Drain and discard all of the events from the kernel
162     struct local_time_debug_event events[kMaxEvents];
163     while(local_clock_->getDebugLog(events, kMaxEvents) > 0)
164         ;
165 
166     {
167         Mutex::Autolock lock(&discipline_log_lock_);
168         discipline_log_.clear();
169         discipline_log_ID_ = 0;
170     }
171 
172     kernel_logID_basis_known_ = false;
173 }
174 
pushDisciplineEvent(int64_t observed_local_time,int64_t observed_common_time,int64_t nominal_common_time,int32_t total_correction,int32_t rtt)175 void DiagThread::pushDisciplineEvent(int64_t observed_local_time,
176                                      int64_t observed_common_time,
177                                      int64_t nominal_common_time,
178                                      int32_t total_correction,
179                                      int32_t rtt) {
180     Mutex::Autolock lock(&discipline_log_lock_);
181 
182     DisciplineEventRecord evt;
183 
184     evt.event_id = discipline_log_ID_++;
185 
186     evt.action_local_time = local_clock_->getLocalTime();
187     common_clock_->localToCommon(evt.action_local_time,
188             &evt.action_common_time);
189 
190     evt.observed_local_time  = observed_local_time;
191     evt.observed_common_time = observed_common_time;
192     evt.nominal_common_time  = nominal_common_time;
193     evt.total_correction     = total_correction;
194     evt.rtt                  = rtt;
195 
196     discipline_log_.push_back(evt);
197     while (discipline_log_.size() > kMaxDisciplineLogSize)
198         discipline_log_.erase(discipline_log_.begin());
199 }
200 
threadLoop()201 bool DiagThread::threadLoop() {
202     struct pollfd poll_fds[1];
203 
204     if (!openListenSocket()) {
205         ALOGE("Failed to open listen socket");
206         goto bailout;
207     }
208 
209     while (!exitPending()) {
210         memset(&poll_fds, 0, sizeof(poll_fds));
211 
212         if (data_fd_ < 0) {
213             poll_fds[0].fd     = listen_fd_;
214             poll_fds[0].events = POLLIN;
215         } else {
216             poll_fds[0].fd     = data_fd_;
217             poll_fds[0].events = POLLRDHUP | POLLIN;
218         }
219 
220         int poll_res = poll(poll_fds, NELEM(poll_fds), 50);
221         if (poll_res < 0) {
222             ALOGE("Fatal error (%d,%d) while waiting on events",
223                  poll_res, errno);
224             goto bailout;
225         }
226 
227         if (exitPending())
228             break;
229 
230         if (poll_fds[0].revents) {
231             if (poll_fds[0].fd == listen_fd_) {
232                 data_fd_ = accept(listen_fd_, NULL, NULL);
233 
234                 if (data_fd_ < 0) {
235                     ALOGW("Failed accept on socket %d with err %d",
236                          listen_fd_, errno);
237                 } else {
238                     if (!setNonblocking(data_fd_))
239                         cleanupDataSocket();
240                     if (!setNodelay(data_fd_))
241                         cleanupDataSocket();
242                 }
243             } else
244                 if (poll_fds[0].fd == data_fd_) {
245                     if (poll_fds[0].revents & POLLRDHUP) {
246                         // Connection hung up; time to clean up.
247                         cleanupDataSocket();
248                     } else
249                         if (poll_fds[0].revents & POLLIN) {
250                             uint8_t cmd;
251                             if (read(data_fd_, &cmd, sizeof(cmd)) > 0) {
252                                 switch(cmd) {
253                                     case 'r':
254                                     case 'R':
255                                         resetLogIDs();
256                                         break;
257                                 }
258                             }
259                         }
260                 }
261         }
262 
263         struct local_time_debug_event events[kMaxEvents];
264         int amt = local_clock_->getDebugLog(events, kMaxEvents);
265 
266         if (amt > 0) {
267             for (int i = 0; i < amt; i++) {
268                 struct local_time_debug_event& e = events[i];
269 
270                 if (!kernel_logID_basis_known_) {
271                     kernel_logID_basis_ = e.local_timesync_event_id;
272                     kernel_logID_basis_known_ = true;
273                 }
274 
275                 char buf[1024];
276                 int64_t common_time;
277                 status_t res = common_clock_->localToCommon(e.local_time,
278                                                             &common_time);
279                 snprintf(buf, sizeof(buf), "E,%lld,%lld,%lld,%d\n",
280                          e.local_timesync_event_id - kernel_logID_basis_,
281                          e.local_time,
282                          common_time,
283                          (OK == res) ? 1 : 0);
284                 buf[sizeof(buf) - 1] = 0;
285 
286                 if (data_fd_ >= 0)
287                     write(data_fd_, buf, strlen(buf));
288             }
289         }
290 
291         { // scope for autolock pattern
292             Mutex::Autolock lock(&discipline_log_lock_);
293 
294             while (discipline_log_.size() > 0) {
295                 char buf[1024];
296                 DisciplineEventRecord& e = *discipline_log_.begin();
297                 snprintf(buf, sizeof(buf),
298                          "D,%lld,%lld,%lld,%lld,%lld,%lld,%d,%d\n",
299                          e.event_id,
300                          e.action_local_time,
301                          e.action_common_time,
302                          e.observed_local_time,
303                          e.observed_common_time,
304                          e.nominal_common_time,
305                          e.total_correction,
306                          e.rtt);
307                 buf[sizeof(buf) - 1] = 0;
308 
309                 if (data_fd_ >= 0)
310                     write(data_fd_, buf, strlen(buf));
311 
312                 discipline_log_.erase(discipline_log_.begin());
313             }
314         }
315     }
316 
317 bailout:
318     cleanupDataSocket();
319     cleanupListenSocket();
320     return false;
321 }
322 
323 }  // namespace android
324