1 /* 2 * Copyright (C) 2012 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 /* 18 * A service that exchanges time synchronization information between 19 * a master that defines a timeline and clients that follow the timeline. 20 */ 21 22 #define LOG_TAG "common_time" 23 #include <utils/Log.h> 24 25 #include <arpa/inet.h> 26 #include <assert.h> 27 #include <fcntl.h> 28 #include <linux/if_ether.h> 29 #include <net/if.h> 30 #include <net/if_arp.h> 31 #include <netinet/ip.h> 32 #include <poll.h> 33 #include <stdio.h> 34 #include <sys/eventfd.h> 35 #include <sys/ioctl.h> 36 #include <sys/stat.h> 37 #include <sys/types.h> 38 #include <sys/socket.h> 39 40 #include <common_time/local_clock.h> 41 #include <binder/IPCThreadState.h> 42 #include <binder/ProcessState.h> 43 #include <utils/Timers.h> 44 45 #include "common_clock_service.h" 46 #include "common_time_config_service.h" 47 #include "common_time_server.h" 48 #include "common_time_server_packets.h" 49 #include "clock_recovery.h" 50 #include "common_clock.h" 51 52 #define MAX_INT ((int)0x7FFFFFFF) 53 54 namespace android { 55 56 const char* CommonTimeServer::kDefaultMasterElectionAddr = "255.255.255.255"; 57 const uint16_t CommonTimeServer::kDefaultMasterElectionPort = 8886; 58 const uint64_t CommonTimeServer::kDefaultSyncGroupID = 1; 59 const uint8_t CommonTimeServer::kDefaultMasterPriority = 1; 60 const uint32_t CommonTimeServer::kDefaultMasterAnnounceIntervalMs = 10000; 61 const uint32_t CommonTimeServer::kDefaultSyncRequestIntervalMs = 1000; 62 const uint32_t CommonTimeServer::kDefaultPanicThresholdUsec = 50000; 63 const bool CommonTimeServer::kDefaultAutoDisable = true; 64 const int CommonTimeServer::kSetupRetryTimeoutMs = 30000; 65 const int64_t CommonTimeServer::kNoGoodDataPanicThresholdUsec = 600000000ll; 66 const uint32_t CommonTimeServer::kRTTDiscardPanicThreshMultiplier = 5; 67 68 // timeout value representing an infinite timeout 69 const int CommonTimeServer::kInfiniteTimeout = -1; 70 71 /*** Initial state constants ***/ 72 73 // number of WhoIsMaster attempts sent before giving up 74 const int CommonTimeServer::kInitial_NumWhoIsMasterRetries = 6; 75 76 // timeout used when waiting for a response to a WhoIsMaster request 77 const int CommonTimeServer::kInitial_WhoIsMasterTimeoutMs = 500; 78 79 /*** Client state constants ***/ 80 81 // number of sync requests that can fail before a client assumes its master 82 // is dead 83 const int CommonTimeServer::kClient_NumSyncRequestRetries = 10; 84 85 /*** Master state constants ***/ 86 87 /*** Ronin state constants ***/ 88 89 // number of WhoIsMaster attempts sent before declaring ourselves master 90 const int CommonTimeServer::kRonin_NumWhoIsMasterRetries = 20; 91 92 // timeout used when waiting for a response to a WhoIsMaster request 93 const int CommonTimeServer::kRonin_WhoIsMasterTimeoutMs = 500; 94 95 /*** WaitForElection state constants ***/ 96 97 // how long do we wait for an announcement from a master before 98 // trying another election? 99 const int CommonTimeServer::kWaitForElection_TimeoutMs = 12500; 100 101 CommonTimeServer::CommonTimeServer() 102 : Thread(false) 103 , mState(ICommonClock::STATE_INITIAL) 104 , mClockRecovery(&mLocalClock, &mCommonClock) 105 , mSocket(-1) 106 , mLastPacketRxLocalTime(0) 107 , mTimelineID(ICommonClock::kInvalidTimelineID) 108 , mClockSynced(false) 109 , mCommonClockHasClients(false) 110 , mStateChangeLog("Recent State Change Events", 30) 111 , mElectionLog("Recent Master Election Traffic", 30) 112 , mBadPktLog("Recent Bad Packet RX Info", 8) 113 , mInitial_WhoIsMasterRequestTimeouts(0) 114 , mClient_MasterDeviceID(0) 115 , mClient_MasterDevicePriority(0) 116 , mRonin_WhoIsMasterRequestTimeouts(0) { 117 // zero out sync stats 118 resetSyncStats(); 119 120 // Setup the master election endpoint to use the default. 121 struct sockaddr_in* meep = 122 reinterpret_cast<struct sockaddr_in*>(&mMasterElectionEP); 123 memset(&mMasterElectionEP, 0, sizeof(mMasterElectionEP)); 124 inet_aton(kDefaultMasterElectionAddr, &meep->sin_addr); 125 meep->sin_family = AF_INET; 126 meep->sin_port = htons(kDefaultMasterElectionPort); 127 128 // Zero out the master endpoint. 129 memset(&mMasterEP, 0, sizeof(mMasterEP)); 130 mMasterEPValid = false; 131 mBindIfaceValid = false; 132 setForceLowPriority(false); 133 134 // Set all remaining configuration parameters to their defaults. 135 mDeviceID = 0; 136 mSyncGroupID = kDefaultSyncGroupID; 137 mMasterPriority = kDefaultMasterPriority; 138 mMasterAnnounceIntervalMs = kDefaultMasterAnnounceIntervalMs; 139 mSyncRequestIntervalMs = kDefaultSyncRequestIntervalMs; 140 mPanicThresholdUsec = kDefaultPanicThresholdUsec; 141 mAutoDisable = kDefaultAutoDisable; 142 143 // Create the eventfd we will use to signal our thread to wake up when 144 // needed. 145 mWakeupThreadFD = eventfd(0, EFD_NONBLOCK); 146 147 // seed the random number generator (used to generated timeline IDs) 148 srand48(static_cast<unsigned int>(systemTime())); 149 } 150 151 CommonTimeServer::~CommonTimeServer() { 152 shutdownThread(); 153 154 // No need to grab the lock here. We are in the destructor; if the the user 155 // has a thread in any of the APIs while the destructor is being called, 156 // there is a threading problem a the application level we cannot reasonably 157 // do anything about. 158 cleanupSocket_l(); 159 160 if (mWakeupThreadFD >= 0) { 161 close(mWakeupThreadFD); 162 mWakeupThreadFD = -1; 163 } 164 } 165 166 bool CommonTimeServer::startServices() { 167 // start the ICommonClock service 168 mICommonClock = CommonClockService::instantiate(*this); 169 if (mICommonClock == NULL) 170 return false; 171 172 // start the ICommonTimeConfig service 173 mICommonTimeConfig = CommonTimeConfigService::instantiate(*this); 174 if (mICommonTimeConfig == NULL) 175 return false; 176 177 return true; 178 } 179 180 bool CommonTimeServer::threadLoop() { 181 // Register our service interfaces. 182 if (!startServices()) 183 return false; 184 185 // Hold the lock while we are in the main thread loop. It will release the 186 // lock when it blocks, and hold the lock at all other times. 187 mLock.lock(); 188 runStateMachine_l(); 189 mLock.unlock(); 190 191 IPCThreadState::self()->stopProcess(); 192 return false; 193 } 194 195 bool CommonTimeServer::runStateMachine_l() { 196 if (!mLocalClock.initCheck()) 197 return false; 198 199 if (!mCommonClock.init(mLocalClock.getLocalFreq())) 200 return false; 201 202 // Enter the initial state. 203 becomeInitial("startup"); 204 205 // run the state machine 206 while (!exitPending()) { 207 struct pollfd pfds[2]; 208 int rc, timeout; 209 int eventCnt = 0; 210 int64_t wakeupTime; 211 uint32_t t1, t2; 212 bool needHandleTimeout = false; 213 214 // We are always interested in our wakeup FD. 215 pfds[eventCnt].fd = mWakeupThreadFD; 216 pfds[eventCnt].events = POLLIN; 217 pfds[eventCnt].revents = 0; 218 eventCnt++; 219 220 // If we have a valid socket, then we are interested in what it has to 221 // say as well. 222 if (mSocket >= 0) { 223 pfds[eventCnt].fd = mSocket; 224 pfds[eventCnt].events = POLLIN; 225 pfds[eventCnt].revents = 0; 226 eventCnt++; 227 } 228 229 t1 = static_cast<uint32_t>(mCurTimeout.msecTillTimeout()); 230 t2 = static_cast<uint32_t>(mClockRecovery.applyRateLimitedSlew()); 231 timeout = static_cast<int>(t1 < t2 ? t1 : t2); 232 233 // Note, we were holding mLock when this function was called. We 234 // release it only while we are blocking and hold it at all other times. 235 mLock.unlock(); 236 rc = poll(pfds, eventCnt, timeout); 237 wakeupTime = mLocalClock.getLocalTime(); 238 mLock.lock(); 239 240 // Is it time to shutdown? If so, don't hesitate... just do it. 241 if (exitPending()) 242 break; 243 244 // Did the poll fail? This should never happen and is fatal if it does. 245 if (rc < 0) { 246 ALOGE("%s:%d poll failed", __PRETTY_FUNCTION__, __LINE__); 247 return false; 248 } 249 250 if (rc == 0) { 251 needHandleTimeout = !mCurTimeout.msecTillTimeout(); 252 if (needHandleTimeout) 253 mCurTimeout.setTimeout(kInfiniteTimeout); 254 } 255 256 // Were we woken up on purpose? If so, clear the eventfd with a read. 257 if (pfds[0].revents) 258 clearPendingWakeupEvents_l(); 259 260 // Is out bind address dirty? If so, clean up our socket (if any). 261 // Alternatively, do we have an active socket but should be auto 262 // disabled? If so, release the socket and enter the proper sync state. 263 bool droppedSocket = false; 264 if (mBindIfaceDirty || ((mSocket >= 0) && shouldAutoDisable())) { 265 cleanupSocket_l(); 266 mBindIfaceDirty = false; 267 droppedSocket = true; 268 } 269 270 // Do we not have a socket but should have one? If so, try to set one 271 // up. 272 if ((mSocket < 0) && mBindIfaceValid && !shouldAutoDisable()) { 273 if (setupSocket_l()) { 274 // Success! We are now joining a new network (either coming 275 // from no network, or coming from a potentially different 276 // network). Force our priority to be lower so that we defer to 277 // any other masters which may already be on the network we are 278 // joining. Later, when we enter either the client or the 279 // master state, we will clear this flag and go back to our 280 // normal election priority. 281 setForceLowPriority(true); 282 switch (mState) { 283 // If we were in initial (whether we had a immediately 284 // before this network or not) we want to simply reset the 285 // system and start again. Forcing a transition from 286 // INITIAL to INITIAL should do the job. 287 case CommonClockService::STATE_INITIAL: 288 becomeInitial("bound interface"); 289 break; 290 291 // If we were in the master state, then either we were the 292 // master in a no-network situation, or we were the master 293 // of a different network and have moved to a new interface. 294 // In either case, immediately transition to Ronin at low 295 // priority. If there is no one in the network we just 296 // joined, we will become master soon enough. If there is, 297 // we want to be certain to defer master status to the 298 // existing timeline currently running on the network. 299 // 300 case CommonClockService::STATE_MASTER: 301 becomeRonin("leaving networkless mode"); 302 break; 303 304 // If we were in any other state (CLIENT, RONIN, or 305 // WAIT_FOR_ELECTION) then we must be moving from one 306 // network to another. We have lost our old master; 307 // transition to RONIN in an attempt to find a new master. 308 // If there are none out there, we will just assume 309 // responsibility for the timeline we used to be a client 310 // of. 311 default: 312 becomeRonin("bound interface"); 313 break; 314 } 315 } else { 316 // That's odd... we failed to set up our socket. This could be 317 // due to some transient network change which will work itself 318 // out shortly; schedule a retry attempt in the near future. 319 mCurTimeout.setTimeout(kSetupRetryTimeoutMs); 320 } 321 322 // One way or the other, we don't have any data to process at this 323 // point (since we just tried to bulid a new socket). Loop back 324 // around and wait for the next thing to do. 325 continue; 326 } else if (droppedSocket) { 327 // We just lost our socket, and for whatever reason (either no 328 // config, or auto disable engaged) we are not supposed to rebuild 329 // one at this time. We are not going to rebuild our socket until 330 // something about our config/auto-disabled status changes, so we 331 // are basically in network-less mode. If we are already in either 332 // INITIAL or MASTER, just stay there until something changes. If 333 // we are in any other state (CLIENT, RONIN or WAIT_FOR_ELECTION), 334 // then transition to either INITIAL or MASTER depending on whether 335 // or not our timeline is valid. 336 mStateChangeLog.log(ANDROID_LOG_INFO, LOG_TAG, 337 "Entering networkless mode interface is %s, " 338 "shouldAutoDisable = %s", 339 mBindIfaceValid ? "valid" : "invalid", 340 shouldAutoDisable() ? "true" : "false"); 341 if ((mState != ICommonClock::STATE_INITIAL) && 342 (mState != ICommonClock::STATE_MASTER)) { 343 if (mTimelineID == ICommonClock::kInvalidTimelineID) 344 becomeInitial("network-less mode"); 345 else 346 becomeMaster("network-less mode"); 347 } 348 349 continue; 350 } 351 352 // Time to handle the timeouts? 353 if (needHandleTimeout) { 354 if (!handleTimeout()) 355 ALOGE("handleTimeout failed"); 356 continue; 357 } 358 359 // Does our socket have data for us (assuming we still have one, we 360 // may have RXed a packet at the same time as a config change telling us 361 // to shut our socket down)? If so, process its data. 362 if ((mSocket >= 0) && (eventCnt > 1) && (pfds[1].revents)) { 363 mLastPacketRxLocalTime = wakeupTime; 364 if (!handlePacket()) 365 ALOGE("handlePacket failed"); 366 } 367 } 368 369 cleanupSocket_l(); 370 return true; 371 } 372 373 void CommonTimeServer::clearPendingWakeupEvents_l() { 374 int64_t tmp; 375 read(mWakeupThreadFD, &tmp, sizeof(tmp)); 376 } 377 378 void CommonTimeServer::wakeupThread_l() { 379 int64_t tmp = 1; 380 write(mWakeupThreadFD, &tmp, sizeof(tmp)); 381 } 382 383 void CommonTimeServer::cleanupSocket_l() { 384 if (mSocket >= 0) { 385 close(mSocket); 386 mSocket = -1; 387 } 388 } 389 390 void CommonTimeServer::shutdownThread() { 391 // Flag the work thread for shutdown. 392 this->requestExit(); 393 394 // Signal the thread in case its sleeping. 395 mLock.lock(); 396 wakeupThread_l(); 397 mLock.unlock(); 398 399 // Wait for the thread to exit. 400 this->join(); 401 } 402 403 bool CommonTimeServer::setupSocket_l() { 404 int rc; 405 bool ret_val = false; 406 struct sockaddr_in* ipv4_addr = NULL; 407 char masterElectionEPStr[64]; 408 const int one = 1; 409 410 // This should never be needed, but if we happened to have an old socket 411 // lying around, be sure to not leak it before proceeding. 412 cleanupSocket_l(); 413 414 // If we don't have a valid endpoint to bind to, then how did we get here in 415 // the first place? Regardless, we know that we are going to fail to bind, 416 // so don't even try. 417 if (!mBindIfaceValid) 418 return false; 419 420 sockaddrToString(mMasterElectionEP, true, masterElectionEPStr, 421 sizeof(masterElectionEPStr)); 422 mStateChangeLog.log(ANDROID_LOG_INFO, LOG_TAG, 423 "Building socket :: bind = %s master election = %s", 424 mBindIface.string(), masterElectionEPStr); 425 426 // TODO: add proper support for IPv6. Right now, we block IPv6 addresses at 427 // the configuration interface level. 428 if (AF_INET != mMasterElectionEP.ss_family) { 429 mStateChangeLog.log(ANDROID_LOG_WARN, LOG_TAG, 430 "TODO: add proper IPv6 support"); 431 goto bailout; 432 } 433 434 // open a UDP socket for the timeline serivce 435 mSocket = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP); 436 if (mSocket < 0) { 437 mStateChangeLog.log(ANDROID_LOG_ERROR, LOG_TAG, 438 "Failed to create socket (errno = %d)", errno); 439 goto bailout; 440 } 441 442 // Bind to the selected interface using Linux's spiffy SO_BINDTODEVICE. 443 struct ifreq ifr; 444 memset(&ifr, 0, sizeof(ifr)); 445 snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s", mBindIface.string()); 446 ifr.ifr_name[sizeof(ifr.ifr_name) - 1] = 0; 447 rc = setsockopt(mSocket, SOL_SOCKET, SO_BINDTODEVICE, 448 (void *)&ifr, sizeof(ifr)); 449 if (rc) { 450 mStateChangeLog.log(ANDROID_LOG_ERROR, LOG_TAG, 451 "Failed to bind socket at to interface %s " 452 "(errno = %d)", ifr.ifr_name, errno); 453 goto bailout; 454 } 455 456 // Bind our socket to INADDR_ANY and the master election port. The 457 // interface binding we made using SO_BINDTODEVICE should limit us to 458 // traffic only on the interface we are interested in. We need to bind to 459 // INADDR_ANY and the specific master election port in order to be able to 460 // receive both unicast traffic and master election multicast traffic with 461 // just a single socket. 462 struct sockaddr_in bindAddr; 463 ipv4_addr = reinterpret_cast<struct sockaddr_in*>(&mMasterElectionEP); 464 memcpy(&bindAddr, ipv4_addr, sizeof(bindAddr)); 465 bindAddr.sin_addr.s_addr = INADDR_ANY; 466 rc = bind(mSocket, 467 reinterpret_cast<const sockaddr *>(&bindAddr), 468 sizeof(bindAddr)); 469 if (rc) { 470 mStateChangeLog.log(ANDROID_LOG_ERROR, LOG_TAG, 471 "Failed to bind socket to port %hu (errno = %d)", 472 ntohs(bindAddr.sin_port), errno); 473 goto bailout; 474 } 475 476 if (0xE0000000 == (ntohl(ipv4_addr->sin_addr.s_addr) & 0xF0000000)) { 477 // If our master election endpoint is a multicast address, be sure to join 478 // the multicast group. 479 struct ip_mreq mreq; 480 mreq.imr_multiaddr = ipv4_addr->sin_addr; 481 mreq.imr_interface.s_addr = htonl(INADDR_ANY); 482 rc = setsockopt(mSocket, IPPROTO_IP, IP_ADD_MEMBERSHIP, 483 &mreq, sizeof(mreq)); 484 if (rc == -1) { 485 ALOGE("Failed to join multicast group at %s. (errno = %d)", 486 masterElectionEPStr, errno); 487 goto bailout; 488 } 489 490 // disable loopback of multicast packets 491 const int zero = 0; 492 rc = setsockopt(mSocket, IPPROTO_IP, IP_MULTICAST_LOOP, 493 &zero, sizeof(zero)); 494 if (rc == -1) { 495 mStateChangeLog.log(ANDROID_LOG_ERROR, LOG_TAG, 496 "Failed to disable multicast loopback " 497 "(errno = %d)", errno); 498 goto bailout; 499 } 500 } else 501 if (ntohl(ipv4_addr->sin_addr.s_addr) == 0xFFFFFFFF) { 502 // If the master election address is the broadcast address, then enable 503 // the broadcast socket option 504 rc = setsockopt(mSocket, SOL_SOCKET, SO_BROADCAST, &one, sizeof(one)); 505 if (rc == -1) { 506 mStateChangeLog.log(ANDROID_LOG_ERROR, LOG_TAG, 507 "Failed to enable broadcast (errno = %d)", 508 errno); 509 goto bailout; 510 } 511 } else { 512 // If the master election address is neither broadcast, nor multicast, 513 // then we are misconfigured. The config API layer should prevent this 514 // from ever happening. 515 goto bailout; 516 } 517 518 // Set the TTL of sent packets to 1. (Time protocol sync should never leave 519 // the local subnet) 520 rc = setsockopt(mSocket, IPPROTO_IP, IP_TTL, &one, sizeof(one)); 521 if (rc == -1) { 522 mStateChangeLog.log(ANDROID_LOG_ERROR, LOG_TAG, 523 "Failed to set TTL to %d (errno = %d)", one, errno); 524 goto bailout; 525 } 526 527 // get the device's unique ID 528 if (!assignDeviceID()) 529 goto bailout; 530 531 ret_val = true; 532 533 bailout: 534 if (!ret_val) 535 cleanupSocket_l(); 536 return ret_val; 537 } 538 539 // generate a unique device ID that can be used for arbitration 540 bool CommonTimeServer::assignDeviceID() { 541 if (!mBindIfaceValid) 542 return false; 543 544 struct ifreq ifr; 545 memset(&ifr, 0, sizeof(ifr)); 546 ifr.ifr_addr.sa_family = AF_INET; 547 strlcpy(ifr.ifr_name, mBindIface.string(), IFNAMSIZ); 548 549 int rc = ioctl(mSocket, SIOCGIFHWADDR, &ifr); 550 if (rc) { 551 ALOGE("%s:%d ioctl failed", __PRETTY_FUNCTION__, __LINE__); 552 return false; 553 } 554 555 if (ifr.ifr_addr.sa_family != ARPHRD_ETHER) { 556 ALOGE("%s:%d got non-Ethernet address", __PRETTY_FUNCTION__, __LINE__); 557 return false; 558 } 559 560 mDeviceID = 0; 561 for (int i = 0; i < ETH_ALEN; i++) { 562 mDeviceID = (mDeviceID << 8) | ifr.ifr_hwaddr.sa_data[i]; 563 } 564 565 return true; 566 } 567 568 // generate a new timeline ID 569 void CommonTimeServer::assignTimelineID() { 570 do { 571 mTimelineID = (static_cast<uint64_t>(lrand48()) << 32) 572 | static_cast<uint64_t>(lrand48()); 573 } while (mTimelineID == ICommonClock::kInvalidTimelineID); 574 } 575 576 // Select a preference between the device IDs of two potential masters. 577 // Returns true if the first ID wins, or false if the second ID wins. 578 bool CommonTimeServer::arbitrateMaster( 579 uint64_t deviceID1, uint8_t devicePrio1, 580 uint64_t deviceID2, uint8_t devicePrio2) { 581 return ((devicePrio1 > devicePrio2) || 582 ((devicePrio1 == devicePrio2) && (deviceID1 > deviceID2))); 583 } 584 585 static void hexDumpToString(const uint8_t* src, size_t src_len, 586 char* dst, size_t dst_len) { 587 size_t offset = 0; 588 size_t i; 589 590 for (i = 0; (i < src_len) && (offset < dst_len); ++i) { 591 int res; 592 if (0 == (i % 16)) { 593 res = snprintf(dst + offset, dst_len - offset, "\n%04zx :", i); 594 if (res < 0) 595 break; 596 offset += res; 597 if (offset >= dst_len) 598 break; 599 } 600 601 res = snprintf(dst + offset, dst_len - offset, " %02x", src[i]); 602 if (res < 0) 603 break; 604 offset += res; 605 } 606 607 dst[dst_len - 1] = 0; 608 } 609 610 bool CommonTimeServer::handlePacket() { 611 uint8_t buf[256]; 612 struct sockaddr_storage srcAddr; 613 socklen_t srcAddrLen = sizeof(srcAddr); 614 615 ssize_t recvBytes = recvfrom( 616 mSocket, buf, sizeof(buf), 0, 617 reinterpret_cast<const sockaddr *>(&srcAddr), &srcAddrLen); 618 619 if (recvBytes < 0) { 620 mBadPktLog.log(ANDROID_LOG_ERROR, LOG_TAG, 621 "recvfrom failed (res %d, errno %d)", 622 recvBytes, errno); 623 return false; 624 } 625 626 UniversalTimeServicePacket pkt; 627 if (pkt.deserializePacket(buf, recvBytes, mSyncGroupID) < 0) { 628 char hex[256]; 629 char srcEPStr[64]; 630 631 hexDumpToString(buf, static_cast<size_t>(recvBytes), hex, sizeof(hex)); 632 sockaddrToString(srcAddr, true, srcEPStr, sizeof(srcEPStr)); 633 634 mBadPktLog.log("Failed to parse %d byte packet from %s.%s", 635 recvBytes, srcEPStr, hex); 636 return false; 637 } 638 639 bool result; 640 switch (pkt.packetType) { 641 case TIME_PACKET_WHO_IS_MASTER_REQUEST: 642 result = handleWhoIsMasterRequest(&pkt.p.who_is_master_request, 643 srcAddr); 644 break; 645 646 case TIME_PACKET_WHO_IS_MASTER_RESPONSE: 647 result = handleWhoIsMasterResponse(&pkt.p.who_is_master_response, 648 srcAddr); 649 break; 650 651 case TIME_PACKET_SYNC_REQUEST: 652 result = handleSyncRequest(&pkt.p.sync_request, srcAddr); 653 break; 654 655 case TIME_PACKET_SYNC_RESPONSE: 656 result = handleSyncResponse(&pkt.p.sync_response, srcAddr); 657 break; 658 659 case TIME_PACKET_MASTER_ANNOUNCEMENT: 660 result = handleMasterAnnouncement(&pkt.p.master_announcement, 661 srcAddr); 662 break; 663 664 default: { 665 char srcEPStr[64]; 666 sockaddrToString(srcAddr, true, srcEPStr, sizeof(srcEPStr)); 667 668 mBadPktLog.log(ANDROID_LOG_WARN, LOG_TAG, 669 "unknown packet type (%d) from %s", 670 pkt.packetType, srcEPStr); 671 672 result = false; 673 } break; 674 } 675 676 return result; 677 } 678 679 bool CommonTimeServer::handleTimeout() { 680 // If we have no socket, then this must be a timeout to retry socket setup. 681 if (mSocket < 0) 682 return true; 683 684 switch (mState) { 685 case ICommonClock::STATE_INITIAL: 686 return handleTimeoutInitial(); 687 case ICommonClock::STATE_CLIENT: 688 return handleTimeoutClient(); 689 case ICommonClock::STATE_MASTER: 690 return handleTimeoutMaster(); 691 case ICommonClock::STATE_RONIN: 692 return handleTimeoutRonin(); 693 case ICommonClock::STATE_WAIT_FOR_ELECTION: 694 return handleTimeoutWaitForElection(); 695 } 696 697 return false; 698 } 699 700 bool CommonTimeServer::handleTimeoutInitial() { 701 if (++mInitial_WhoIsMasterRequestTimeouts == 702 kInitial_NumWhoIsMasterRetries) { 703 // none of our attempts to discover a master succeeded, so make 704 // this device the master 705 return becomeMaster("initial timeout"); 706 } else { 707 // retry the WhoIsMaster request 708 return sendWhoIsMasterRequest(); 709 } 710 } 711 712 bool CommonTimeServer::handleTimeoutClient() { 713 if (shouldPanicNotGettingGoodData()) 714 return becomeInitial("timeout panic, no good data"); 715 716 if (mClient_SyncRequestPending) { 717 mClient_SyncRequestPending = false; 718 719 if (++mClient_SyncRequestTimeouts < kClient_NumSyncRequestRetries) { 720 // a sync request has timed out, so retry 721 return sendSyncRequest(); 722 } else { 723 // The master has failed to respond to a sync request for too many 724 // times in a row. Assume the master is dead and start electing 725 // a new master. 726 return becomeRonin("master not responding"); 727 } 728 } else { 729 // initiate the next sync request 730 return sendSyncRequest(); 731 } 732 } 733 734 bool CommonTimeServer::handleTimeoutMaster() { 735 // send another announcement from the master 736 return sendMasterAnnouncement(); 737 } 738 739 bool CommonTimeServer::handleTimeoutRonin() { 740 if (++mRonin_WhoIsMasterRequestTimeouts == kRonin_NumWhoIsMasterRetries) { 741 // no other master is out there, so we won the election 742 return becomeMaster("no better masters detected"); 743 } else { 744 return sendWhoIsMasterRequest(); 745 } 746 } 747 748 bool CommonTimeServer::handleTimeoutWaitForElection() { 749 return becomeRonin("timeout waiting for election conclusion"); 750 } 751 752 bool CommonTimeServer::handleWhoIsMasterRequest( 753 const WhoIsMasterRequestPacket* request, 754 const sockaddr_storage& srcAddr) { 755 // Skip our own messages which come back via broadcast loopback. 756 if (request->senderDeviceID == mDeviceID) 757 return true; 758 759 char srcEPStr[64]; 760 sockaddrToString(srcAddr, true, srcEPStr, sizeof(srcEPStr)); 761 mElectionLog.log("RXed WhoIs master request while in state %s. " 762 "src %s reqTID %016llx ourTID %016llx", 763 stateToString(mState), srcEPStr, 764 request->timelineID, mTimelineID); 765 766 if (mState == ICommonClock::STATE_MASTER) { 767 // is this request related to this master's timeline? 768 if (request->timelineID != ICommonClock::kInvalidTimelineID && 769 request->timelineID != mTimelineID) 770 return true; 771 772 WhoIsMasterResponsePacket pkt; 773 pkt.initHeader(mTimelineID, mSyncGroupID); 774 pkt.deviceID = mDeviceID; 775 pkt.devicePriority = effectivePriority(); 776 777 mElectionLog.log("TXing WhoIs master resp to %s while in state %s. " 778 "ourTID %016llx ourGID %016llx ourDID %016llx " 779 "ourPrio %u", 780 srcEPStr, stateToString(mState), 781 mTimelineID, mSyncGroupID, 782 pkt.deviceID, pkt.devicePriority); 783 784 uint8_t buf[256]; 785 ssize_t bufSz = pkt.serializePacket(buf, sizeof(buf)); 786 if (bufSz < 0) 787 return false; 788 789 ssize_t sendBytes = sendto( 790 mSocket, buf, bufSz, 0, 791 reinterpret_cast<const sockaddr *>(&srcAddr), 792 sizeof(srcAddr)); 793 if (sendBytes == -1) { 794 ALOGE("%s:%d sendto failed", __PRETTY_FUNCTION__, __LINE__); 795 return false; 796 } 797 } else if (mState == ICommonClock::STATE_RONIN) { 798 // if we hear a WhoIsMaster request from another device following 799 // the same timeline and that device wins arbitration, then we will stop 800 // trying to elect ourselves master and will instead wait for an 801 // announcement from the election winner 802 if (request->timelineID != mTimelineID) 803 return true; 804 805 if (arbitrateMaster(request->senderDeviceID, 806 request->senderDevicePriority, 807 mDeviceID, 808 effectivePriority())) 809 return becomeWaitForElection("would lose election"); 810 811 return true; 812 } else if (mState == ICommonClock::STATE_INITIAL) { 813 // If a group of devices booted simultaneously (e.g. after a power 814 // outage) and all of them are in the initial state and there is no 815 // master, then each device may time out and declare itself master at 816 // the same time. To avoid this, listen for 817 // WhoIsMaster(InvalidTimeline) requests from peers. If we would lose 818 // arbitration against that peer, reset our timeout count so that the 819 // peer has a chance to become master before we time out. 820 if (request->timelineID == ICommonClock::kInvalidTimelineID && 821 arbitrateMaster(request->senderDeviceID, 822 request->senderDevicePriority, 823 mDeviceID, 824 effectivePriority())) { 825 mInitial_WhoIsMasterRequestTimeouts = 0; 826 } 827 } 828 829 return true; 830 } 831 832 bool CommonTimeServer::handleWhoIsMasterResponse( 833 const WhoIsMasterResponsePacket* response, 834 const sockaddr_storage& srcAddr) { 835 // Skip our own messages which come back via broadcast loopback. 836 if (response->deviceID == mDeviceID) 837 return true; 838 839 char srcEPStr[64]; 840 sockaddrToString(srcAddr, true, srcEPStr, sizeof(srcEPStr)); 841 mElectionLog.log("RXed WhoIs master response while in state %s. " 842 "src %s respTID %016llx respDID %016llx respPrio %u " 843 "ourTID %016llx", 844 stateToString(mState), srcEPStr, 845 response->timelineID, 846 response->deviceID, 847 static_cast<uint32_t>(response->devicePriority), 848 mTimelineID); 849 850 if (mState == ICommonClock::STATE_INITIAL || mState == ICommonClock::STATE_RONIN) { 851 return becomeClient(srcAddr, 852 response->deviceID, 853 response->devicePriority, 854 response->timelineID, 855 "heard whois response"); 856 } else if (mState == ICommonClock::STATE_CLIENT) { 857 // if we get multiple responses because there are multiple devices 858 // who believe that they are master, then follow the master that 859 // wins arbitration 860 if (arbitrateMaster(response->deviceID, 861 response->devicePriority, 862 mClient_MasterDeviceID, 863 mClient_MasterDevicePriority)) { 864 return becomeClient(srcAddr, 865 response->deviceID, 866 response->devicePriority, 867 response->timelineID, 868 "heard whois response"); 869 } 870 } 871 872 return true; 873 } 874 875 bool CommonTimeServer::handleSyncRequest(const SyncRequestPacket* request, 876 const sockaddr_storage& srcAddr) { 877 SyncResponsePacket pkt; 878 pkt.initHeader(mTimelineID, mSyncGroupID); 879 880 if ((mState == ICommonClock::STATE_MASTER) && 881 (mTimelineID == request->timelineID)) { 882 int64_t rxLocalTime = mLastPacketRxLocalTime; 883 int64_t rxCommonTime; 884 885 // If we are master on an actual network and have actual clients, then 886 // we are no longer low priority. 887 setForceLowPriority(false); 888 889 if (OK != mCommonClock.localToCommon(rxLocalTime, &rxCommonTime)) { 890 return false; 891 } 892 893 int64_t txLocalTime = mLocalClock.getLocalTime();; 894 int64_t txCommonTime; 895 if (OK != mCommonClock.localToCommon(txLocalTime, &txCommonTime)) { 896 return false; 897 } 898 899 pkt.nak = 0; 900 pkt.clientTxLocalTime = request->clientTxLocalTime; 901 pkt.masterRxCommonTime = rxCommonTime; 902 pkt.masterTxCommonTime = txCommonTime; 903 } else { 904 pkt.nak = 1; 905 pkt.clientTxLocalTime = 0; 906 pkt.masterRxCommonTime = 0; 907 pkt.masterTxCommonTime = 0; 908 } 909 910 uint8_t buf[256]; 911 ssize_t bufSz = pkt.serializePacket(buf, sizeof(buf)); 912 if (bufSz < 0) 913 return false; 914 915 ssize_t sendBytes = sendto( 916 mSocket, &buf, bufSz, 0, 917 reinterpret_cast<const sockaddr *>(&srcAddr), 918 sizeof(srcAddr)); 919 if (sendBytes == -1) { 920 ALOGE("%s:%d sendto failed", __PRETTY_FUNCTION__, __LINE__); 921 return false; 922 } 923 924 return true; 925 } 926 927 bool CommonTimeServer::handleSyncResponse( 928 const SyncResponsePacket* response, 929 const sockaddr_storage& srcAddr) { 930 if (mState != ICommonClock::STATE_CLIENT) 931 return true; 932 933 assert(mMasterEPValid); 934 if (!sockaddrMatch(srcAddr, mMasterEP, true)) { 935 char srcEP[64], expectedEP[64]; 936 sockaddrToString(srcAddr, true, srcEP, sizeof(srcEP)); 937 sockaddrToString(mMasterEP, true, expectedEP, sizeof(expectedEP)); 938 ALOGI("Dropping sync response from unexpected address." 939 " Expected %s Got %s", expectedEP, srcEP); 940 return true; 941 } 942 943 if (response->nak) { 944 // if our master is no longer accepting requests, then we need to find 945 // a new master 946 return becomeRonin("master NAK'ed"); 947 } 948 949 mClient_SyncRequestPending = 0; 950 mClient_SyncRequestTimeouts = 0; 951 mClient_PacketRTTLog.logRX(response->clientTxLocalTime, 952 mLastPacketRxLocalTime); 953 954 bool result; 955 if (!(mClient_SyncRespsRXedFromCurMaster++)) { 956 // the first request/response exchange between a client and a master 957 // may take unusually long due to ARP, so discard it. 958 result = true; 959 } else { 960 int64_t clientTxLocalTime = response->clientTxLocalTime; 961 int64_t clientRxLocalTime = mLastPacketRxLocalTime; 962 int64_t masterTxCommonTime = response->masterTxCommonTime; 963 int64_t masterRxCommonTime = response->masterRxCommonTime; 964 965 int64_t rtt = (clientRxLocalTime - clientTxLocalTime); 966 int64_t avgLocal = (clientTxLocalTime + clientRxLocalTime) >> 1; 967 int64_t avgCommon = (masterTxCommonTime + masterRxCommonTime) >> 1; 968 969 // if the RTT of the packet is significantly larger than the panic 970 // threshold, we should simply discard it. Its better to do nothing 971 // than to take cues from a packet like that. 972 int rttCommon = mCommonClock.localDurationToCommonDuration(rtt); 973 if (rttCommon > (static_cast<int64_t>(mPanicThresholdUsec) * 974 kRTTDiscardPanicThreshMultiplier)) { 975 ALOGV("Dropping sync response with RTT of %lld uSec", rttCommon); 976 mClient_ExpiredSyncRespsRXedFromCurMaster++; 977 if (shouldPanicNotGettingGoodData()) 978 return becomeInitial("RX panic, no good data"); 979 } else { 980 result = mClockRecovery.pushDisciplineEvent(avgLocal, avgCommon, rttCommon); 981 mClient_LastGoodSyncRX = clientRxLocalTime; 982 983 if (result) { 984 // indicate to listeners that we've synced to the common timeline 985 notifyClockSync(); 986 } else { 987 ALOGE("Panic! Observed clock sync error is too high to tolerate," 988 " resetting state machine and starting over."); 989 notifyClockSyncLoss(); 990 return becomeInitial("panic"); 991 } 992 } 993 } 994 995 mCurTimeout.setTimeout(mSyncRequestIntervalMs); 996 return result; 997 } 998 999 bool CommonTimeServer::handleMasterAnnouncement( 1000 const MasterAnnouncementPacket* packet, 1001 const sockaddr_storage& srcAddr) { 1002 uint64_t newDeviceID = packet->deviceID; 1003 uint8_t newDevicePrio = packet->devicePriority; 1004 uint64_t newTimelineID = packet->timelineID; 1005 1006 // Skip our own messages which come back via broadcast loopback. 1007 if (newDeviceID == mDeviceID) 1008 return true; 1009 1010 char srcEPStr[64]; 1011 sockaddrToString(srcAddr, true, srcEPStr, sizeof(srcEPStr)); 1012 mElectionLog.log("RXed master announcement while in state %s. " 1013 "src %s srcDevID %lld srcPrio %u srcTID %016llx", 1014 stateToString(mState), srcEPStr, 1015 newDeviceID, static_cast<uint32_t>(newDevicePrio), 1016 newTimelineID); 1017 1018 if (mState == ICommonClock::STATE_INITIAL || 1019 mState == ICommonClock::STATE_RONIN || 1020 mState == ICommonClock::STATE_WAIT_FOR_ELECTION) { 1021 // if we aren't currently following a master, then start following 1022 // this new master 1023 return becomeClient(srcAddr, 1024 newDeviceID, 1025 newDevicePrio, 1026 newTimelineID, 1027 "heard master announcement"); 1028 } else if (mState == ICommonClock::STATE_CLIENT) { 1029 // if the new master wins arbitration against our current master, 1030 // then become a client of the new master 1031 if (arbitrateMaster(newDeviceID, 1032 newDevicePrio, 1033 mClient_MasterDeviceID, 1034 mClient_MasterDevicePriority)) 1035 return becomeClient(srcAddr, 1036 newDeviceID, 1037 newDevicePrio, 1038 newTimelineID, 1039 "heard master announcement"); 1040 } else if (mState == ICommonClock::STATE_MASTER) { 1041 // two masters are competing - if the new one wins arbitration, then 1042 // cease acting as master 1043 if (arbitrateMaster(newDeviceID, newDevicePrio, 1044 mDeviceID, effectivePriority())) 1045 return becomeClient(srcAddr, newDeviceID, 1046 newDevicePrio, newTimelineID, 1047 "heard master announcement"); 1048 } 1049 1050 return true; 1051 } 1052 1053 bool CommonTimeServer::sendWhoIsMasterRequest() { 1054 assert(mState == ICommonClock::STATE_INITIAL || mState == ICommonClock::STATE_RONIN); 1055 1056 // If we have no socket, then we must be in the unconfigured initial state. 1057 // Don't report any errors, just don't try to send the initial who-is-master 1058 // query. Eventually, our network will either become configured, or we will 1059 // be forced into network-less master mode by higher level code. 1060 if (mSocket < 0) { 1061 assert(mState == ICommonClock::STATE_INITIAL); 1062 return true; 1063 } 1064 1065 bool ret = false; 1066 WhoIsMasterRequestPacket pkt; 1067 pkt.initHeader(mSyncGroupID); 1068 pkt.senderDeviceID = mDeviceID; 1069 pkt.senderDevicePriority = effectivePriority(); 1070 1071 uint8_t buf[256]; 1072 ssize_t bufSz = pkt.serializePacket(buf, sizeof(buf)); 1073 if (bufSz >= 0) { 1074 char dstEPStr[64]; 1075 sockaddrToString(mMasterElectionEP, true, dstEPStr, sizeof(dstEPStr)); 1076 mElectionLog.log("TXing WhoIs master request to %s while in state %s. " 1077 "ourTID %016llx ourGID %016llx ourDID %016llx " 1078 "ourPrio %u", 1079 dstEPStr, stateToString(mState), 1080 mTimelineID, mSyncGroupID, 1081 pkt.senderDeviceID, pkt.senderDevicePriority); 1082 1083 ssize_t sendBytes = sendto( 1084 mSocket, buf, bufSz, 0, 1085 reinterpret_cast<const sockaddr *>(&mMasterElectionEP), 1086 sizeof(mMasterElectionEP)); 1087 if (sendBytes < 0) 1088 ALOGE("WhoIsMaster sendto failed (errno %d)", errno); 1089 ret = true; 1090 } 1091 1092 if (mState == ICommonClock::STATE_INITIAL) { 1093 mCurTimeout.setTimeout(kInitial_WhoIsMasterTimeoutMs); 1094 } else { 1095 mCurTimeout.setTimeout(kRonin_WhoIsMasterTimeoutMs); 1096 } 1097 1098 return ret; 1099 } 1100 1101 bool CommonTimeServer::sendSyncRequest() { 1102 // If we are sending sync requests, then we must be in the client state and 1103 // we must have a socket (when we have no network, we are only supposed to 1104 // be in INITIAL or MASTER) 1105 assert(mState == ICommonClock::STATE_CLIENT); 1106 assert(mSocket >= 0); 1107 1108 bool ret = false; 1109 SyncRequestPacket pkt; 1110 pkt.initHeader(mTimelineID, mSyncGroupID); 1111 pkt.clientTxLocalTime = mLocalClock.getLocalTime(); 1112 1113 if (!mClient_FirstSyncTX) 1114 mClient_FirstSyncTX = pkt.clientTxLocalTime; 1115 1116 mClient_PacketRTTLog.logTX(pkt.clientTxLocalTime); 1117 1118 uint8_t buf[256]; 1119 ssize_t bufSz = pkt.serializePacket(buf, sizeof(buf)); 1120 if (bufSz >= 0) { 1121 ssize_t sendBytes = sendto( 1122 mSocket, buf, bufSz, 0, 1123 reinterpret_cast<const sockaddr *>(&mMasterEP), 1124 sizeof(mMasterEP)); 1125 if (sendBytes < 0) 1126 ALOGE("SyncRequest sendto failed (errno %d)", errno); 1127 ret = true; 1128 } 1129 1130 mClient_SyncsSentToCurMaster++; 1131 mCurTimeout.setTimeout(mSyncRequestIntervalMs); 1132 mClient_SyncRequestPending = true; 1133 1134 return ret; 1135 } 1136 1137 bool CommonTimeServer::sendMasterAnnouncement() { 1138 bool ret = false; 1139 assert(mState == ICommonClock::STATE_MASTER); 1140 1141 // If we are being asked to send a master announcement, but we have no 1142 // socket, we must be in network-less master mode. Don't bother to send the 1143 // announcement, and don't bother to schedule a timeout. When the network 1144 // comes up, the work thread will get poked and start the process of 1145 // figuring out who the current master should be. 1146 if (mSocket < 0) { 1147 mCurTimeout.setTimeout(kInfiniteTimeout); 1148 return true; 1149 } 1150 1151 MasterAnnouncementPacket pkt; 1152 pkt.initHeader(mTimelineID, mSyncGroupID); 1153 pkt.deviceID = mDeviceID; 1154 pkt.devicePriority = effectivePriority(); 1155 1156 uint8_t buf[256]; 1157 ssize_t bufSz = pkt.serializePacket(buf, sizeof(buf)); 1158 if (bufSz >= 0) { 1159 char dstEPStr[64]; 1160 sockaddrToString(mMasterElectionEP, true, dstEPStr, sizeof(dstEPStr)); 1161 mElectionLog.log("TXing Master announcement to %s while in state %s. " 1162 "ourTID %016llx ourGID %016llx ourDID %016llx " 1163 "ourPrio %u", 1164 dstEPStr, stateToString(mState), 1165 mTimelineID, mSyncGroupID, 1166 pkt.deviceID, pkt.devicePriority); 1167 1168 ssize_t sendBytes = sendto( 1169 mSocket, buf, bufSz, 0, 1170 reinterpret_cast<const sockaddr *>(&mMasterElectionEP), 1171 sizeof(mMasterElectionEP)); 1172 if (sendBytes < 0) 1173 ALOGE("MasterAnnouncement sendto failed (errno %d)", errno); 1174 ret = true; 1175 } 1176 1177 mCurTimeout.setTimeout(mMasterAnnounceIntervalMs); 1178 return ret; 1179 } 1180 1181 bool CommonTimeServer::becomeClient(const sockaddr_storage& masterEP, 1182 uint64_t masterDeviceID, 1183 uint8_t masterDevicePriority, 1184 uint64_t timelineID, 1185 const char* cause) { 1186 char newEPStr[64], oldEPStr[64]; 1187 sockaddrToString(masterEP, true, newEPStr, sizeof(newEPStr)); 1188 sockaddrToString(mMasterEP, mMasterEPValid, oldEPStr, sizeof(oldEPStr)); 1189 1190 mStateChangeLog.log(ANDROID_LOG_INFO, LOG_TAG, 1191 "%s --> CLIENT (%s) :%s" 1192 " OldMaster: %02x-%014llx::%016llx::%s" 1193 " NewMaster: %02x-%014llx::%016llx::%s", 1194 stateToString(mState), cause, 1195 (mTimelineID != timelineID) ? " (new timeline)" : "", 1196 mClient_MasterDevicePriority, mClient_MasterDeviceID, 1197 mTimelineID, oldEPStr, 1198 masterDevicePriority, masterDeviceID, 1199 timelineID, newEPStr); 1200 1201 if (mTimelineID != timelineID) { 1202 // start following a new timeline 1203 mTimelineID = timelineID; 1204 mClockRecovery.reset(true, true); 1205 notifyClockSyncLoss(); 1206 } else { 1207 // start following a new master on the existing timeline 1208 mClockRecovery.reset(false, true); 1209 } 1210 1211 mMasterEP = masterEP; 1212 mMasterEPValid = true; 1213 1214 // If we are on a real network as a client of a real master, then we should 1215 // no longer force low priority. If our master disappears, we should have 1216 // the high priority bit set during the election to replace the master 1217 // because this group was a real group and not a singleton created in 1218 // networkless mode. 1219 setForceLowPriority(false); 1220 1221 mClient_MasterDeviceID = masterDeviceID; 1222 mClient_MasterDevicePriority = masterDevicePriority; 1223 resetSyncStats(); 1224 1225 setState(ICommonClock::STATE_CLIENT); 1226 1227 // add some jitter to when the various clients send their requests 1228 // in order to reduce the likelihood that a group of clients overload 1229 // the master after receiving a master announcement 1230 usleep((lrand48() % 100) * 1000); 1231 1232 return sendSyncRequest(); 1233 } 1234 1235 bool CommonTimeServer::becomeMaster(const char* cause) { 1236 uint64_t oldTimelineID = mTimelineID; 1237 if (mTimelineID == ICommonClock::kInvalidTimelineID) { 1238 // this device has not been following any existing timeline, 1239 // so it will create a new timeline and declare itself master 1240 assert(!mCommonClock.isValid()); 1241 1242 // set the common time basis 1243 mCommonClock.setBasis(mLocalClock.getLocalTime(), 0); 1244 1245 // assign an arbitrary timeline iD 1246 assignTimelineID(); 1247 1248 // notify listeners that we've created a common timeline 1249 notifyClockSync(); 1250 } 1251 1252 mStateChangeLog.log(ANDROID_LOG_INFO, LOG_TAG, 1253 "%s --> MASTER (%s) : %s timeline %016llx", 1254 stateToString(mState), cause, 1255 (oldTimelineID == mTimelineID) ? "taking ownership of" 1256 : "creating new", 1257 mTimelineID); 1258 1259 memset(&mMasterEP, 0, sizeof(mMasterEP)); 1260 mMasterEPValid = false; 1261 mClient_MasterDevicePriority = effectivePriority(); 1262 mClient_MasterDeviceID = mDeviceID; 1263 mClockRecovery.reset(false, true); 1264 resetSyncStats(); 1265 1266 setState(ICommonClock::STATE_MASTER); 1267 return sendMasterAnnouncement(); 1268 } 1269 1270 bool CommonTimeServer::becomeRonin(const char* cause) { 1271 // If we were the client of a given timeline, but had never received even a 1272 // single time sync packet, then we transition back to Initial instead of 1273 // Ronin. If we transition to Ronin and end up becoming the new Master, we 1274 // will be unable to service requests for other clients because we never 1275 // actually knew what time it was. By going to initial, we ensure that 1276 // other clients who know what time it is, but would lose master arbitration 1277 // in the Ronin case, will step up and become the proper new master of the 1278 // old timeline. 1279 1280 char oldEPStr[64]; 1281 sockaddrToString(mMasterEP, mMasterEPValid, oldEPStr, sizeof(oldEPStr)); 1282 memset(&mMasterEP, 0, sizeof(mMasterEP)); 1283 mMasterEPValid = false; 1284 1285 if (mCommonClock.isValid()) { 1286 mStateChangeLog.log(ANDROID_LOG_INFO, LOG_TAG, 1287 "%s --> RONIN (%s) : lost track of previously valid timeline " 1288 "%02x-%014llx::%016llx::%s (%d TXed %d RXed %d RXExpired)", 1289 stateToString(mState), cause, 1290 mClient_MasterDevicePriority, mClient_MasterDeviceID, 1291 mTimelineID, oldEPStr, 1292 mClient_SyncsSentToCurMaster, 1293 mClient_SyncRespsRXedFromCurMaster, 1294 mClient_ExpiredSyncRespsRXedFromCurMaster); 1295 1296 mRonin_WhoIsMasterRequestTimeouts = 0; 1297 setState(ICommonClock::STATE_RONIN); 1298 return sendWhoIsMasterRequest(); 1299 } else { 1300 mStateChangeLog.log(ANDROID_LOG_INFO, LOG_TAG, 1301 "%s --> INITIAL (%s) : never synced timeline " 1302 "%02x-%014llx::%016llx::%s (%d TXed %d RXed %d RXExpired)", 1303 stateToString(mState), cause, 1304 mClient_MasterDevicePriority, mClient_MasterDeviceID, 1305 mTimelineID, oldEPStr, 1306 mClient_SyncsSentToCurMaster, 1307 mClient_SyncRespsRXedFromCurMaster, 1308 mClient_ExpiredSyncRespsRXedFromCurMaster); 1309 1310 return becomeInitial("ronin, no timeline"); 1311 } 1312 } 1313 1314 bool CommonTimeServer::becomeWaitForElection(const char* cause) { 1315 mStateChangeLog.log(ANDROID_LOG_INFO, LOG_TAG, 1316 "%s --> WAIT_FOR_ELECTION (%s) : dropping out of election," 1317 " waiting %d mSec for completion.", 1318 stateToString(mState), cause, kWaitForElection_TimeoutMs); 1319 1320 setState(ICommonClock::STATE_WAIT_FOR_ELECTION); 1321 mCurTimeout.setTimeout(kWaitForElection_TimeoutMs); 1322 return true; 1323 } 1324 1325 bool CommonTimeServer::becomeInitial(const char* cause) { 1326 mStateChangeLog.log(ANDROID_LOG_INFO, LOG_TAG, 1327 "Entering INITIAL (%s), total reset.", 1328 cause); 1329 1330 setState(ICommonClock::STATE_INITIAL); 1331 1332 // reset clock recovery 1333 mClockRecovery.reset(true, true); 1334 1335 // reset internal state bookkeeping. 1336 mCurTimeout.setTimeout(kInfiniteTimeout); 1337 memset(&mMasterEP, 0, sizeof(mMasterEP)); 1338 mMasterEPValid = false; 1339 mLastPacketRxLocalTime = 0; 1340 mTimelineID = ICommonClock::kInvalidTimelineID; 1341 mClockSynced = false; 1342 mInitial_WhoIsMasterRequestTimeouts = 0; 1343 mClient_MasterDeviceID = 0; 1344 mClient_MasterDevicePriority = 0; 1345 mRonin_WhoIsMasterRequestTimeouts = 0; 1346 resetSyncStats(); 1347 1348 // send the first request to discover the master 1349 return sendWhoIsMasterRequest(); 1350 } 1351 1352 void CommonTimeServer::notifyClockSync() { 1353 if (!mClockSynced) { 1354 mClockSynced = true; 1355 mICommonClock->notifyOnTimelineChanged(mTimelineID); 1356 } 1357 } 1358 1359 void CommonTimeServer::notifyClockSyncLoss() { 1360 if (mClockSynced) { 1361 mClockSynced = false; 1362 mICommonClock->notifyOnTimelineChanged( 1363 ICommonClock::kInvalidTimelineID); 1364 } 1365 } 1366 1367 void CommonTimeServer::setState(ICommonClock::State s) { 1368 mState = s; 1369 } 1370 1371 const char* CommonTimeServer::stateToString(ICommonClock::State s) { 1372 switch(s) { 1373 case ICommonClock::STATE_INITIAL: 1374 return "INITIAL"; 1375 case ICommonClock::STATE_CLIENT: 1376 return "CLIENT"; 1377 case ICommonClock::STATE_MASTER: 1378 return "MASTER"; 1379 case ICommonClock::STATE_RONIN: 1380 return "RONIN"; 1381 case ICommonClock::STATE_WAIT_FOR_ELECTION: 1382 return "WAIT_FOR_ELECTION"; 1383 default: 1384 return "unknown"; 1385 } 1386 } 1387 1388 void CommonTimeServer::sockaddrToString(const sockaddr_storage& addr, 1389 bool addrValid, 1390 char* buf, size_t bufLen) { 1391 if (!bufLen || !buf) 1392 return; 1393 1394 if (addrValid) { 1395 switch (addr.ss_family) { 1396 case AF_INET: { 1397 const struct sockaddr_in* sa = 1398 reinterpret_cast<const struct sockaddr_in*>(&addr); 1399 unsigned long a = ntohl(sa->sin_addr.s_addr); 1400 uint16_t p = ntohs(sa->sin_port); 1401 snprintf(buf, bufLen, "%lu.%lu.%lu.%lu:%hu", 1402 ((a >> 24) & 0xFF), ((a >> 16) & 0xFF), 1403 ((a >> 8) & 0xFF), (a & 0xFF), p); 1404 } break; 1405 1406 case AF_INET6: { 1407 const struct sockaddr_in6* sa = 1408 reinterpret_cast<const struct sockaddr_in6*>(&addr); 1409 const uint8_t* a = sa->sin6_addr.s6_addr; 1410 uint16_t p = ntohs(sa->sin6_port); 1411 snprintf(buf, bufLen, 1412 "%02X%02X:%02X%02X:%02X%02X:%02X%02X:" 1413 "%02X%02X:%02X%02X:%02X%02X:%02X%02X port %hd", 1414 a[0], a[1], a[ 2], a[ 3], a[ 4], a[ 5], a[ 6], a[ 7], 1415 a[8], a[9], a[10], a[11], a[12], a[13], a[14], a[15], 1416 p); 1417 } break; 1418 1419 default: 1420 snprintf(buf, bufLen, 1421 "<unknown sockaddr family %d>", addr.ss_family); 1422 break; 1423 } 1424 } else { 1425 snprintf(buf, bufLen, "<none>"); 1426 } 1427 1428 buf[bufLen - 1] = 0; 1429 } 1430 1431 bool CommonTimeServer::sockaddrMatch(const sockaddr_storage& a1, 1432 const sockaddr_storage& a2, 1433 bool matchAddressOnly) { 1434 if (a1.ss_family != a2.ss_family) 1435 return false; 1436 1437 switch (a1.ss_family) { 1438 case AF_INET: { 1439 const struct sockaddr_in* sa1 = 1440 reinterpret_cast<const struct sockaddr_in*>(&a1); 1441 const struct sockaddr_in* sa2 = 1442 reinterpret_cast<const struct sockaddr_in*>(&a2); 1443 1444 if (sa1->sin_addr.s_addr != sa2->sin_addr.s_addr) 1445 return false; 1446 1447 return (matchAddressOnly || (sa1->sin_port == sa2->sin_port)); 1448 } break; 1449 1450 case AF_INET6: { 1451 const struct sockaddr_in6* sa1 = 1452 reinterpret_cast<const struct sockaddr_in6*>(&a1); 1453 const struct sockaddr_in6* sa2 = 1454 reinterpret_cast<const struct sockaddr_in6*>(&a2); 1455 1456 if (memcmp(&sa1->sin6_addr, &sa2->sin6_addr, sizeof(sa2->sin6_addr))) 1457 return false; 1458 1459 return (matchAddressOnly || (sa1->sin6_port == sa2->sin6_port)); 1460 } break; 1461 1462 // Huh? We don't deal in non-IPv[46] addresses. Not sure how we got 1463 // here, but we don't know how to comapre these addresses and simply 1464 // default to a no-match decision. 1465 default: return false; 1466 } 1467 } 1468 1469 bool CommonTimeServer::shouldPanicNotGettingGoodData() { 1470 if (mClient_FirstSyncTX) { 1471 int64_t now = mLocalClock.getLocalTime(); 1472 int64_t delta = now - (mClient_LastGoodSyncRX 1473 ? mClient_LastGoodSyncRX 1474 : mClient_FirstSyncTX); 1475 int64_t deltaUsec = mCommonClock.localDurationToCommonDuration(delta); 1476 1477 if (deltaUsec >= kNoGoodDataPanicThresholdUsec) 1478 return true; 1479 } 1480 1481 return false; 1482 } 1483 1484 void CommonTimeServer::PacketRTTLog::logTX(int64_t txTime) { 1485 txTimes[wrPtr] = txTime; 1486 rxTimes[wrPtr] = 0; 1487 wrPtr = (wrPtr + 1) % RTT_LOG_SIZE; 1488 if (!wrPtr) 1489 logFull = true; 1490 } 1491 1492 void CommonTimeServer::PacketRTTLog::logRX(int64_t txTime, int64_t rxTime) { 1493 if (!logFull && !wrPtr) 1494 return; 1495 1496 uint32_t i = logFull ? wrPtr : 0; 1497 do { 1498 if (txTimes[i] == txTime) { 1499 rxTimes[i] = rxTime; 1500 break; 1501 } 1502 i = (i + 1) % RTT_LOG_SIZE; 1503 } while (i != wrPtr); 1504 } 1505 1506 } // namespace android 1507
