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 <inttypes.h> 29 #include <linux/if_ether.h> 30 #include <net/if.h> 31 #include <net/if_arp.h> 32 #include <netinet/ip.h> 33 #include <poll.h> 34 #include <stdio.h> 35 #include <sys/eventfd.h> 36 #include <sys/ioctl.h> 37 #include <sys/stat.h> 38 #include <sys/types.h> 39 #include <sys/socket.h> 40 41 #include <common_time/local_clock.h> 42 #include <binder/IPCThreadState.h> 43 #include <binder/ProcessState.h> 44 #include <utils/Timers.h> 45 46 #include "common_clock_service.h" 47 #include "common_time_config_service.h" 48 #include "common_time_server.h" 49 #include "common_time_server_packets.h" 50 #include "clock_recovery.h" 51 #include "common_clock.h" 52 53 #define MAX_INT ((int)0x7FFFFFFF) 54 55 namespace android { 56 57 const char* CommonTimeServer::kDefaultMasterElectionAddr = "255.255.255.255"; 58 const uint16_t CommonTimeServer::kDefaultMasterElectionPort = 8886; 59 const uint64_t CommonTimeServer::kDefaultSyncGroupID = 1; 60 const uint8_t CommonTimeServer::kDefaultMasterPriority = 1; 61 const uint32_t CommonTimeServer::kDefaultMasterAnnounceIntervalMs = 10000; 62 const uint32_t CommonTimeServer::kDefaultSyncRequestIntervalMs = 1000; 63 const uint32_t CommonTimeServer::kDefaultPanicThresholdUsec = 50000; 64 const bool CommonTimeServer::kDefaultAutoDisable = true; 65 const int CommonTimeServer::kSetupRetryTimeoutMs = 30000; 66 const int64_t CommonTimeServer::kNoGoodDataPanicThresholdUsec = 600000000ll; 67 const uint32_t CommonTimeServer::kRTTDiscardPanicThreshMultiplier = 5; 68 69 // timeout value representing an infinite timeout 70 const int CommonTimeServer::kInfiniteTimeout = -1; 71 72 /*** Initial state constants ***/ 73 74 // number of WhoIsMaster attempts sent before giving up 75 const int CommonTimeServer::kInitial_NumWhoIsMasterRetries = 6; 76 77 // timeout used when waiting for a response to a WhoIsMaster request 78 const int CommonTimeServer::kInitial_WhoIsMasterTimeoutMs = 500; 79 80 /*** Client state constants ***/ 81 82 // number of sync requests that can fail before a client assumes its master 83 // is dead 84 const int CommonTimeServer::kClient_NumSyncRequestRetries = 10; 85 86 /*** Master state constants ***/ 87 88 /*** Ronin state constants ***/ 89 90 // number of WhoIsMaster attempts sent before declaring ourselves master 91 const int CommonTimeServer::kRonin_NumWhoIsMasterRetries = 20; 92 93 // timeout used when waiting for a response to a WhoIsMaster request 94 const int CommonTimeServer::kRonin_WhoIsMasterTimeoutMs = 500; 95 96 /*** WaitForElection state constants ***/ 97 98 // how long do we wait for an announcement from a master before 99 // trying another election? 100 const int CommonTimeServer::kWaitForElection_TimeoutMs = 12500; 101 102 CommonTimeServer::CommonTimeServer() 103 : Thread(false) 104 , mState(ICommonClock::STATE_INITIAL) 105 , mClockRecovery(&mLocalClock, &mCommonClock) 106 , mSocket(-1) 107 , mLastPacketRxLocalTime(0) 108 , mTimelineID(ICommonClock::kInvalidTimelineID) 109 , mClockSynced(false) 110 , mCommonClockHasClients(false) 111 , mStateChangeLog("Recent State Change Events", 30) 112 , mElectionLog("Recent Master Election Traffic", 30) 113 , mBadPktLog("Recent Bad Packet RX Info", 8) 114 , mInitial_WhoIsMasterRequestTimeouts(0) 115 , mClient_MasterDeviceID(0) 116 , mClient_MasterDevicePriority(0) 117 , mRonin_WhoIsMasterRequestTimeouts(0) { 118 // zero out sync stats 119 resetSyncStats(); 120 121 // Setup the master election endpoint to use the default. 122 struct sockaddr_in* meep = 123 reinterpret_cast<struct sockaddr_in*>(&mMasterElectionEP); 124 memset(&mMasterElectionEP, 0, sizeof(mMasterElectionEP)); 125 inet_aton(kDefaultMasterElectionAddr, &meep->sin_addr); 126 meep->sin_family = AF_INET; 127 meep->sin_port = htons(kDefaultMasterElectionPort); 128 129 // Zero out the master endpoint. 130 memset(&mMasterEP, 0, sizeof(mMasterEP)); 131 mMasterEPValid = false; 132 mBindIfaceValid = false; 133 setForceLowPriority(false); 134 135 // Set all remaining configuration parameters to their defaults. 136 mDeviceID = 0; 137 mSyncGroupID = kDefaultSyncGroupID; 138 mMasterPriority = kDefaultMasterPriority; 139 mMasterAnnounceIntervalMs = kDefaultMasterAnnounceIntervalMs; 140 mSyncRequestIntervalMs = kDefaultSyncRequestIntervalMs; 141 mPanicThresholdUsec = kDefaultPanicThresholdUsec; 142 mAutoDisable = kDefaultAutoDisable; 143 144 // Create the eventfd we will use to signal our thread to wake up when 145 // needed. 146 mWakeupThreadFD = eventfd(0, EFD_NONBLOCK | EFD_CLOEXEC); 147 148 // seed the random number generator (used to generated timeline IDs) 149 srand48(static_cast<unsigned int>(systemTime())); 150 } 151 152 CommonTimeServer::~CommonTimeServer() { 153 shutdownThread(); 154 155 // No need to grab the lock here. We are in the destructor; if the the user 156 // has a thread in any of the APIs while the destructor is being called, 157 // there is a threading problem a the application level we cannot reasonably 158 // do anything about. 159 cleanupSocket_l(); 160 161 if (mWakeupThreadFD >= 0) { 162 close(mWakeupThreadFD); 163 mWakeupThreadFD = -1; 164 } 165 } 166 167 bool CommonTimeServer::startServices() { 168 // start the ICommonClock service 169 mICommonClock = CommonClockService::instantiate(*this); 170 if (mICommonClock == NULL) 171 return false; 172 173 // start the ICommonTimeConfig service 174 mICommonTimeConfig = CommonTimeConfigService::instantiate(*this); 175 if (mICommonTimeConfig == NULL) 176 return false; 177 178 return true; 179 } 180 181 bool CommonTimeServer::threadLoop() { 182 // Register our service interfaces. 183 if (!startServices()) 184 return false; 185 186 // Hold the lock while we are in the main thread loop. It will release the 187 // lock when it blocks, and hold the lock at all other times. 188 mLock.lock(); 189 runStateMachine_l(); 190 mLock.unlock(); 191 192 IPCThreadState::self()->stopProcess(); 193 return false; 194 } 195 196 bool CommonTimeServer::runStateMachine_l() { 197 if (!mLocalClock.initCheck()) 198 return false; 199 200 if (!mCommonClock.init(mLocalClock.getLocalFreq())) 201 return false; 202 203 // Enter the initial state. 204 becomeInitial("startup"); 205 206 // run the state machine 207 while (!exitPending()) { 208 struct pollfd pfds[2]; 209 int rc, timeout; 210 int eventCnt = 0; 211 int64_t wakeupTime; 212 uint32_t t1, t2; 213 bool needHandleTimeout = false; 214 215 // We are always interested in our wakeup FD. 216 pfds[eventCnt].fd = mWakeupThreadFD; 217 pfds[eventCnt].events = POLLIN; 218 pfds[eventCnt].revents = 0; 219 eventCnt++; 220 221 // If we have a valid socket, then we are interested in what it has to 222 // say as well. 223 if (mSocket >= 0) { 224 pfds[eventCnt].fd = mSocket; 225 pfds[eventCnt].events = POLLIN; 226 pfds[eventCnt].revents = 0; 227 eventCnt++; 228 } 229 230 t1 = static_cast<uint32_t>(mCurTimeout.msecTillTimeout()); 231 t2 = static_cast<uint32_t>(mClockRecovery.applyRateLimitedSlew()); 232 timeout = static_cast<int>(t1 < t2 ? t1 : t2); 233 234 // Note, we were holding mLock when this function was called. We 235 // release it only while we are blocking and hold it at all other times. 236 mLock.unlock(); 237 rc = poll(pfds, eventCnt, timeout); 238 wakeupTime = mLocalClock.getLocalTime(); 239 mLock.lock(); 240 241 // Is it time to shutdown? If so, don't hesitate... just do it. 242 if (exitPending()) 243 break; 244 245 // Did the poll fail? This should never happen and is fatal if it does. 246 if (rc < 0) { 247 ALOGE("%s:%d poll failed", __PRETTY_FUNCTION__, __LINE__); 248 return false; 249 } 250 251 if (rc == 0) { 252 needHandleTimeout = !mCurTimeout.msecTillTimeout(); 253 if (needHandleTimeout) 254 mCurTimeout.setTimeout(kInfiniteTimeout); 255 } 256 257 // Were we woken up on purpose? If so, clear the eventfd with a read. 258 if (pfds[0].revents) 259 clearPendingWakeupEvents_l(); 260 261 // Is out bind address dirty? If so, clean up our socket (if any). 262 // Alternatively, do we have an active socket but should be auto 263 // disabled? If so, release the socket and enter the proper sync state. 264 bool droppedSocket = false; 265 if (mBindIfaceDirty || ((mSocket >= 0) && shouldAutoDisable())) { 266 cleanupSocket_l(); 267 mBindIfaceDirty = false; 268 droppedSocket = true; 269 } 270 271 // Do we not have a socket but should have one? If so, try to set one 272 // up. 273 if ((mSocket < 0) && mBindIfaceValid && !shouldAutoDisable()) { 274 if (setupSocket_l()) { 275 // Success! We are now joining a new network (either coming 276 // from no network, or coming from a potentially different 277 // network). Force our priority to be lower so that we defer to 278 // any other masters which may already be on the network we are 279 // joining. Later, when we enter either the client or the 280 // master state, we will clear this flag and go back to our 281 // normal election priority. 282 setForceLowPriority(true); 283 switch (mState) { 284 // If we were in initial (whether we had a immediately 285 // before this network or not) we want to simply reset the 286 // system and start again. Forcing a transition from 287 // INITIAL to INITIAL should do the job. 288 case CommonClockService::STATE_INITIAL: 289 becomeInitial("bound interface"); 290 break; 291 292 // If we were in the master state, then either we were the 293 // master in a no-network situation, or we were the master 294 // of a different network and have moved to a new interface. 295 // In either case, immediately transition to Ronin at low 296 // priority. If there is no one in the network we just 297 // joined, we will become master soon enough. If there is, 298 // we want to be certain to defer master status to the 299 // existing timeline currently running on the network. 300 // 301 case CommonClockService::STATE_MASTER: 302 becomeRonin("leaving networkless mode"); 303 break; 304 305 // If we were in any other state (CLIENT, RONIN, or 306 // WAIT_FOR_ELECTION) then we must be moving from one 307 // network to another. We have lost our old master; 308 // transition to RONIN in an attempt to find a new master. 309 // If there are none out there, we will just assume 310 // responsibility for the timeline we used to be a client 311 // of. 312 default: 313 becomeRonin("bound interface"); 314 break; 315 } 316 } else { 317 // That's odd... we failed to set up our socket. This could be 318 // due to some transient network change which will work itself 319 // out shortly; schedule a retry attempt in the near future. 320 mCurTimeout.setTimeout(kSetupRetryTimeoutMs); 321 } 322 323 // One way or the other, we don't have any data to process at this 324 // point (since we just tried to bulid a new socket). Loop back 325 // around and wait for the next thing to do. 326 continue; 327 } else if (droppedSocket) { 328 // We just lost our socket, and for whatever reason (either no 329 // config, or auto disable engaged) we are not supposed to rebuild 330 // one at this time. We are not going to rebuild our socket until 331 // something about our config/auto-disabled status changes, so we 332 // are basically in network-less mode. If we are already in either 333 // INITIAL or MASTER, just stay there until something changes. If 334 // we are in any other state (CLIENT, RONIN or WAIT_FOR_ELECTION), 335 // then transition to either INITIAL or MASTER depending on whether 336 // or not our timeline is valid. 337 mStateChangeLog.log(ANDROID_LOG_INFO, LOG_TAG, 338 "Entering networkless mode interface is %s, " 339 "shouldAutoDisable = %s", 340 mBindIfaceValid ? "valid" : "invalid", 341 shouldAutoDisable() ? "true" : "false"); 342 if ((mState != ICommonClock::STATE_INITIAL) && 343 (mState != ICommonClock::STATE_MASTER)) { 344 if (mTimelineID == ICommonClock::kInvalidTimelineID) 345 becomeInitial("network-less mode"); 346 else 347 becomeMaster("network-less mode"); 348 } 349 350 continue; 351 } 352 353 // Time to handle the timeouts? 354 if (needHandleTimeout) { 355 if (!handleTimeout()) 356 ALOGE("handleTimeout failed"); 357 continue; 358 } 359 360 // Does our socket have data for us (assuming we still have one, we 361 // may have RXed a packet at the same time as a config change telling us 362 // to shut our socket down)? If so, process its data. 363 if ((mSocket >= 0) && (eventCnt > 1) && (pfds[1].revents)) { 364 mLastPacketRxLocalTime = wakeupTime; 365 if (!handlePacket()) 366 ALOGE("handlePacket failed"); 367 } 368 } 369 370 cleanupSocket_l(); 371 return true; 372 } 373 374 void CommonTimeServer::clearPendingWakeupEvents_l() { 375 int64_t tmp; 376 read(mWakeupThreadFD, &tmp, sizeof(tmp)); 377 } 378 379 void CommonTimeServer::wakeupThread_l() { 380 int64_t tmp = 1; 381 write(mWakeupThreadFD, &tmp, sizeof(tmp)); 382 } 383 384 void CommonTimeServer::cleanupSocket_l() { 385 if (mSocket >= 0) { 386 close(mSocket); 387 mSocket = -1; 388 } 389 } 390 391 void CommonTimeServer::shutdownThread() { 392 // Flag the work thread for shutdown. 393 this->requestExit(); 394 395 // Signal the thread in case its sleeping. 396 mLock.lock(); 397 wakeupThread_l(); 398 mLock.unlock(); 399 400 // Wait for the thread to exit. 401 this->join(); 402 } 403 404 bool CommonTimeServer::setupSocket_l() { 405 int rc; 406 bool ret_val = false; 407 struct sockaddr_in* ipv4_addr = NULL; 408 char masterElectionEPStr[64]; 409 const int one = 1; 410 411 // This should never be needed, but if we happened to have an old socket 412 // lying around, be sure to not leak it before proceeding. 413 cleanupSocket_l(); 414 415 // If we don't have a valid endpoint to bind to, then how did we get here in 416 // the first place? Regardless, we know that we are going to fail to bind, 417 // so don't even try. 418 if (!mBindIfaceValid) 419 return false; 420 421 sockaddrToString(mMasterElectionEP, true, masterElectionEPStr, 422 sizeof(masterElectionEPStr)); 423 mStateChangeLog.log(ANDROID_LOG_INFO, LOG_TAG, 424 "Building socket :: bind = %s master election = %s", 425 mBindIface.string(), masterElectionEPStr); 426 427 // TODO: add proper support for IPv6. Right now, we block IPv6 addresses at 428 // the configuration interface level. 429 if (AF_INET != mMasterElectionEP.ss_family) { 430 mStateChangeLog.log(ANDROID_LOG_WARN, LOG_TAG, 431 "TODO: add proper IPv6 support"); 432 goto bailout; 433 } 434 435 // open a UDP socket for the timeline serivce 436 mSocket = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP); 437 if (mSocket < 0) { 438 mStateChangeLog.log(ANDROID_LOG_ERROR, LOG_TAG, 439 "Failed to create socket (errno = %d)", errno); 440 goto bailout; 441 } 442 443 // Bind to the selected interface using Linux's spiffy SO_BINDTODEVICE. 444 struct ifreq ifr; 445 memset(&ifr, 0, sizeof(ifr)); 446 snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s", mBindIface.string()); 447 ifr.ifr_name[sizeof(ifr.ifr_name) - 1] = 0; 448 rc = setsockopt(mSocket, SOL_SOCKET, SO_BINDTODEVICE, 449 (void *)&ifr, sizeof(ifr)); 450 if (rc) { 451 mStateChangeLog.log(ANDROID_LOG_ERROR, LOG_TAG, 452 "Failed to bind socket at to interface %s " 453 "(errno = %d)", ifr.ifr_name, errno); 454 goto bailout; 455 } 456 457 // Bind our socket to INADDR_ANY and the master election port. The 458 // interface binding we made using SO_BINDTODEVICE should limit us to 459 // traffic only on the interface we are interested in. We need to bind to 460 // INADDR_ANY and the specific master election port in order to be able to 461 // receive both unicast traffic and master election multicast traffic with 462 // just a single socket. 463 struct sockaddr_in bindAddr; 464 ipv4_addr = reinterpret_cast<struct sockaddr_in*>(&mMasterElectionEP); 465 memcpy(&bindAddr, ipv4_addr, sizeof(bindAddr)); 466 bindAddr.sin_addr.s_addr = INADDR_ANY; 467 rc = bind(mSocket, 468 reinterpret_cast<const sockaddr *>(&bindAddr), 469 sizeof(bindAddr)); 470 if (rc) { 471 mStateChangeLog.log(ANDROID_LOG_ERROR, LOG_TAG, 472 "Failed to bind socket to port %hu (errno = %d)", 473 ntohs(bindAddr.sin_port), errno); 474 goto bailout; 475 } 476 477 if (0xE0000000 == (ntohl(ipv4_addr->sin_addr.s_addr) & 0xF0000000)) { 478 // If our master election endpoint is a multicast address, be sure to join 479 // the multicast group. 480 struct ip_mreq mreq; 481 mreq.imr_multiaddr = ipv4_addr->sin_addr; 482 mreq.imr_interface.s_addr = htonl(INADDR_ANY); 483 rc = setsockopt(mSocket, IPPROTO_IP, IP_ADD_MEMBERSHIP, 484 &mreq, sizeof(mreq)); 485 if (rc == -1) { 486 ALOGE("Failed to join multicast group at %s. (errno = %d)", 487 masterElectionEPStr, errno); 488 goto bailout; 489 } 490 491 // disable loopback of multicast packets 492 const int zero = 0; 493 rc = setsockopt(mSocket, IPPROTO_IP, IP_MULTICAST_LOOP, 494 &zero, sizeof(zero)); 495 if (rc == -1) { 496 mStateChangeLog.log(ANDROID_LOG_ERROR, LOG_TAG, 497 "Failed to disable multicast loopback " 498 "(errno = %d)", errno); 499 goto bailout; 500 } 501 } else 502 if (ntohl(ipv4_addr->sin_addr.s_addr) == 0xFFFFFFFF) { 503 // If the master election address is the broadcast address, then enable 504 // the broadcast socket option 505 rc = setsockopt(mSocket, SOL_SOCKET, SO_BROADCAST, &one, sizeof(one)); 506 if (rc == -1) { 507 mStateChangeLog.log(ANDROID_LOG_ERROR, LOG_TAG, 508 "Failed to enable broadcast (errno = %d)", 509 errno); 510 goto bailout; 511 } 512 } else { 513 // If the master election address is neither broadcast, nor multicast, 514 // then we are misconfigured. The config API layer should prevent this 515 // from ever happening. 516 goto bailout; 517 } 518 519 // Set the TTL of sent packets to 1. (Time protocol sync should never leave 520 // the local subnet) 521 rc = setsockopt(mSocket, IPPROTO_IP, IP_TTL, &one, sizeof(one)); 522 if (rc == -1) { 523 mStateChangeLog.log(ANDROID_LOG_ERROR, LOG_TAG, 524 "Failed to set TTL to %d (errno = %d)", one, errno); 525 goto bailout; 526 } 527 528 // get the device's unique ID 529 if (!assignDeviceID()) 530 goto bailout; 531 532 ret_val = true; 533 534 bailout: 535 if (!ret_val) 536 cleanupSocket_l(); 537 return ret_val; 538 } 539 540 // generate a unique device ID that can be used for arbitration 541 bool CommonTimeServer::assignDeviceID() { 542 if (!mBindIfaceValid) 543 return false; 544 545 struct ifreq ifr; 546 memset(&ifr, 0, sizeof(ifr)); 547 ifr.ifr_addr.sa_family = AF_INET; 548 strlcpy(ifr.ifr_name, mBindIface.string(), IFNAMSIZ); 549 550 int rc = ioctl(mSocket, SIOCGIFHWADDR, &ifr); 551 if (rc) { 552 ALOGE("%s:%d ioctl failed", __PRETTY_FUNCTION__, __LINE__); 553 return false; 554 } 555 556 if (ifr.ifr_addr.sa_family != ARPHRD_ETHER) { 557 ALOGE("%s:%d got non-Ethernet address", __PRETTY_FUNCTION__, __LINE__); 558 return false; 559 } 560 561 mDeviceID = 0; 562 for (int i = 0; i < ETH_ALEN; i++) { 563 mDeviceID = (mDeviceID << 8) | ifr.ifr_hwaddr.sa_data[i]; 564 } 565 566 return true; 567 } 568 569 // generate a new timeline ID 570 void CommonTimeServer::assignTimelineID() { 571 do { 572 mTimelineID = (static_cast<uint64_t>(lrand48()) << 32) 573 | static_cast<uint64_t>(lrand48()); 574 } while (mTimelineID == ICommonClock::kInvalidTimelineID); 575 } 576 577 // Select a preference between the device IDs of two potential masters. 578 // Returns true if the first ID wins, or false if the second ID wins. 579 bool CommonTimeServer::arbitrateMaster( 580 uint64_t deviceID1, uint8_t devicePrio1, 581 uint64_t deviceID2, uint8_t devicePrio2) { 582 return ((devicePrio1 > devicePrio2) || 583 ((devicePrio1 == devicePrio2) && (deviceID1 > deviceID2))); 584 } 585 586 static void hexDumpToString(const uint8_t* src, size_t src_len, 587 char* dst, size_t dst_len) { 588 size_t offset = 0; 589 size_t i; 590 591 for (i = 0; (i < src_len) && (offset < dst_len); ++i) { 592 int res; 593 if (0 == (i % 16)) { 594 res = snprintf(dst + offset, dst_len - offset, "\n%04zx :", i); 595 if (res < 0) 596 break; 597 offset += res; 598 if (offset >= dst_len) 599 break; 600 } 601 602 res = snprintf(dst + offset, dst_len - offset, " %02x", src[i]); 603 if (res < 0) 604 break; 605 offset += res; 606 } 607 608 dst[dst_len - 1] = 0; 609 } 610 611 bool CommonTimeServer::handlePacket() { 612 uint8_t buf[256]; 613 struct sockaddr_storage srcAddr; 614 socklen_t srcAddrLen = sizeof(srcAddr); 615 616 ssize_t recvBytes = recvfrom( 617 mSocket, buf, sizeof(buf), 0, 618 reinterpret_cast<sockaddr *>(&srcAddr), &srcAddrLen); 619 620 if (recvBytes < 0) { 621 mBadPktLog.log(ANDROID_LOG_ERROR, LOG_TAG, "recvfrom failed (%s)", 622 strerror(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 int64_t rttCommon = mCommonClock.localDurationToCommonDuration(rtt); 973 if (rttCommon > (static_cast<int64_t>(mPanicThresholdUsec) * 974 kRTTDiscardPanicThreshMultiplier)) { 975 ALOGV("Dropping sync response with RTT of %" PRId64 " uSec", rttCommon); 976 mClient_ExpiredSyncRespsRXedFromCurMaster++; 977 if (shouldPanicNotGettingGoodData()) 978 return becomeInitial("RX panic, no good data"); 979 return true; 980 } else { 981 result = mClockRecovery.pushDisciplineEvent(avgLocal, avgCommon, rttCommon); 982 mClient_LastGoodSyncRX = clientRxLocalTime; 983 984 if (result) { 985 // indicate to listeners that we've synced to the common timeline 986 notifyClockSync(); 987 } else { 988 ALOGE("Panic! Observed clock sync error is too high to tolerate," 989 " resetting state machine and starting over."); 990 notifyClockSyncLoss(); 991 return becomeInitial("panic"); 992 } 993 } 994 } 995 996 mCurTimeout.setTimeout(mSyncRequestIntervalMs); 997 return result; 998 } 999 1000 bool CommonTimeServer::handleMasterAnnouncement( 1001 const MasterAnnouncementPacket* packet, 1002 const sockaddr_storage& srcAddr) { 1003 uint64_t newDeviceID = packet->deviceID; 1004 uint8_t newDevicePrio = packet->devicePriority; 1005 uint64_t newTimelineID = packet->timelineID; 1006 1007 // Skip our own messages which come back via broadcast loopback. 1008 if (newDeviceID == mDeviceID) 1009 return true; 1010 1011 char srcEPStr[64]; 1012 sockaddrToString(srcAddr, true, srcEPStr, sizeof(srcEPStr)); 1013 mElectionLog.log("RXed master announcement while in state %s. " 1014 "src %s srcDevID %lld srcPrio %u srcTID %016llx", 1015 stateToString(mState), srcEPStr, 1016 newDeviceID, static_cast<uint32_t>(newDevicePrio), 1017 newTimelineID); 1018 1019 if (mState == ICommonClock::STATE_INITIAL || 1020 mState == ICommonClock::STATE_RONIN || 1021 mState == ICommonClock::STATE_WAIT_FOR_ELECTION) { 1022 // if we aren't currently following a master, then start following 1023 // this new master 1024 return becomeClient(srcAddr, 1025 newDeviceID, 1026 newDevicePrio, 1027 newTimelineID, 1028 "heard master announcement"); 1029 } else if (mState == ICommonClock::STATE_CLIENT) { 1030 // if the new master wins arbitration against our current master, 1031 // then become a client of the new master 1032 if (arbitrateMaster(newDeviceID, 1033 newDevicePrio, 1034 mClient_MasterDeviceID, 1035 mClient_MasterDevicePriority)) 1036 return becomeClient(srcAddr, 1037 newDeviceID, 1038 newDevicePrio, 1039 newTimelineID, 1040 "heard master announcement"); 1041 } else if (mState == ICommonClock::STATE_MASTER) { 1042 // two masters are competing - if the new one wins arbitration, then 1043 // cease acting as master 1044 if (arbitrateMaster(newDeviceID, newDevicePrio, 1045 mDeviceID, effectivePriority())) 1046 return becomeClient(srcAddr, newDeviceID, 1047 newDevicePrio, newTimelineID, 1048 "heard master announcement"); 1049 } 1050 1051 return true; 1052 } 1053 1054 bool CommonTimeServer::sendWhoIsMasterRequest() { 1055 assert(mState == ICommonClock::STATE_INITIAL || mState == ICommonClock::STATE_RONIN); 1056 1057 // If we have no socket, then we must be in the unconfigured initial state. 1058 // Don't report any errors, just don't try to send the initial who-is-master 1059 // query. Eventually, our network will either become configured, or we will 1060 // be forced into network-less master mode by higher level code. 1061 if (mSocket < 0) { 1062 assert(mState == ICommonClock::STATE_INITIAL); 1063 return true; 1064 } 1065 1066 bool ret = false; 1067 WhoIsMasterRequestPacket pkt; 1068 pkt.initHeader(mSyncGroupID); 1069 pkt.senderDeviceID = mDeviceID; 1070 pkt.senderDevicePriority = effectivePriority(); 1071 1072 uint8_t buf[256]; 1073 ssize_t bufSz = pkt.serializePacket(buf, sizeof(buf)); 1074 if (bufSz >= 0) { 1075 char dstEPStr[64]; 1076 sockaddrToString(mMasterElectionEP, true, dstEPStr, sizeof(dstEPStr)); 1077 mElectionLog.log("TXing WhoIs master request to %s while in state %s. " 1078 "ourTID %016llx ourGID %016llx ourDID %016llx " 1079 "ourPrio %u", 1080 dstEPStr, stateToString(mState), 1081 mTimelineID, mSyncGroupID, 1082 pkt.senderDeviceID, pkt.senderDevicePriority); 1083 1084 ssize_t sendBytes = sendto( 1085 mSocket, buf, bufSz, 0, 1086 reinterpret_cast<const sockaddr *>(&mMasterElectionEP), 1087 sizeof(mMasterElectionEP)); 1088 if (sendBytes < 0) 1089 ALOGE("WhoIsMaster sendto failed (errno %d)", errno); 1090 ret = true; 1091 } 1092 1093 if (mState == ICommonClock::STATE_INITIAL) { 1094 mCurTimeout.setTimeout(kInitial_WhoIsMasterTimeoutMs); 1095 } else { 1096 mCurTimeout.setTimeout(kRonin_WhoIsMasterTimeoutMs); 1097 } 1098 1099 return ret; 1100 } 1101 1102 bool CommonTimeServer::sendSyncRequest() { 1103 // If we are sending sync requests, then we must be in the client state and 1104 // we must have a socket (when we have no network, we are only supposed to 1105 // be in INITIAL or MASTER) 1106 assert(mState == ICommonClock::STATE_CLIENT); 1107 assert(mSocket >= 0); 1108 1109 bool ret = false; 1110 SyncRequestPacket pkt; 1111 pkt.initHeader(mTimelineID, mSyncGroupID); 1112 pkt.clientTxLocalTime = mLocalClock.getLocalTime(); 1113 1114 if (!mClient_FirstSyncTX) 1115 mClient_FirstSyncTX = pkt.clientTxLocalTime; 1116 1117 mClient_PacketRTTLog.logTX(pkt.clientTxLocalTime); 1118 1119 uint8_t buf[256]; 1120 ssize_t bufSz = pkt.serializePacket(buf, sizeof(buf)); 1121 if (bufSz >= 0) { 1122 ssize_t sendBytes = sendto( 1123 mSocket, buf, bufSz, 0, 1124 reinterpret_cast<const sockaddr *>(&mMasterEP), 1125 sizeof(mMasterEP)); 1126 if (sendBytes < 0) 1127 ALOGE("SyncRequest sendto failed (errno %d)", errno); 1128 ret = true; 1129 } 1130 1131 mClient_SyncsSentToCurMaster++; 1132 mCurTimeout.setTimeout(mSyncRequestIntervalMs); 1133 mClient_SyncRequestPending = true; 1134 1135 return ret; 1136 } 1137 1138 bool CommonTimeServer::sendMasterAnnouncement() { 1139 bool ret = false; 1140 assert(mState == ICommonClock::STATE_MASTER); 1141 1142 // If we are being asked to send a master announcement, but we have no 1143 // socket, we must be in network-less master mode. Don't bother to send the 1144 // announcement, and don't bother to schedule a timeout. When the network 1145 // comes up, the work thread will get poked and start the process of 1146 // figuring out who the current master should be. 1147 if (mSocket < 0) { 1148 mCurTimeout.setTimeout(kInfiniteTimeout); 1149 return true; 1150 } 1151 1152 MasterAnnouncementPacket pkt; 1153 pkt.initHeader(mTimelineID, mSyncGroupID); 1154 pkt.deviceID = mDeviceID; 1155 pkt.devicePriority = effectivePriority(); 1156 1157 uint8_t buf[256]; 1158 ssize_t bufSz = pkt.serializePacket(buf, sizeof(buf)); 1159 if (bufSz >= 0) { 1160 char dstEPStr[64]; 1161 sockaddrToString(mMasterElectionEP, true, dstEPStr, sizeof(dstEPStr)); 1162 mElectionLog.log("TXing Master announcement to %s while in state %s. " 1163 "ourTID %016llx ourGID %016llx ourDID %016llx " 1164 "ourPrio %u", 1165 dstEPStr, stateToString(mState), 1166 mTimelineID, mSyncGroupID, 1167 pkt.deviceID, pkt.devicePriority); 1168 1169 ssize_t sendBytes = sendto( 1170 mSocket, buf, bufSz, 0, 1171 reinterpret_cast<const sockaddr *>(&mMasterElectionEP), 1172 sizeof(mMasterElectionEP)); 1173 if (sendBytes < 0) 1174 ALOGE("MasterAnnouncement sendto failed (errno %d)", errno); 1175 ret = true; 1176 } 1177 1178 mCurTimeout.setTimeout(mMasterAnnounceIntervalMs); 1179 return ret; 1180 } 1181 1182 bool CommonTimeServer::becomeClient(const sockaddr_storage& masterEP, 1183 uint64_t masterDeviceID, 1184 uint8_t masterDevicePriority, 1185 uint64_t timelineID, 1186 const char* cause) { 1187 char newEPStr[64], oldEPStr[64]; 1188 sockaddrToString(masterEP, true, newEPStr, sizeof(newEPStr)); 1189 sockaddrToString(mMasterEP, mMasterEPValid, oldEPStr, sizeof(oldEPStr)); 1190 1191 mStateChangeLog.log(ANDROID_LOG_INFO, LOG_TAG, 1192 "%s --> CLIENT (%s) :%s" 1193 " OldMaster: %02x-%014llx::%016llx::%s" 1194 " NewMaster: %02x-%014llx::%016llx::%s", 1195 stateToString(mState), cause, 1196 (mTimelineID != timelineID) ? " (new timeline)" : "", 1197 mClient_MasterDevicePriority, mClient_MasterDeviceID, 1198 mTimelineID, oldEPStr, 1199 masterDevicePriority, masterDeviceID, 1200 timelineID, newEPStr); 1201 1202 if (mTimelineID != timelineID) { 1203 // start following a new timeline 1204 mTimelineID = timelineID; 1205 mClockRecovery.reset(true, true); 1206 notifyClockSyncLoss(); 1207 } else { 1208 // start following a new master on the existing timeline 1209 mClockRecovery.reset(false, true); 1210 } 1211 1212 mMasterEP = masterEP; 1213 mMasterEPValid = true; 1214 1215 // If we are on a real network as a client of a real master, then we should 1216 // no longer force low priority. If our master disappears, we should have 1217 // the high priority bit set during the election to replace the master 1218 // because this group was a real group and not a singleton created in 1219 // networkless mode. 1220 setForceLowPriority(false); 1221 1222 mClient_MasterDeviceID = masterDeviceID; 1223 mClient_MasterDevicePriority = masterDevicePriority; 1224 resetSyncStats(); 1225 1226 setState(ICommonClock::STATE_CLIENT); 1227 1228 // add some jitter to when the various clients send their requests 1229 // in order to reduce the likelihood that a group of clients overload 1230 // the master after receiving a master announcement 1231 usleep((lrand48() % 100) * 1000); 1232 1233 return sendSyncRequest(); 1234 } 1235 1236 bool CommonTimeServer::becomeMaster(const char* cause) { 1237 uint64_t oldTimelineID = mTimelineID; 1238 if (mTimelineID == ICommonClock::kInvalidTimelineID) { 1239 // this device has not been following any existing timeline, 1240 // so it will create a new timeline and declare itself master 1241 assert(!mCommonClock.isValid()); 1242 1243 // set the common time basis 1244 mCommonClock.setBasis(mLocalClock.getLocalTime(), 0); 1245 1246 // assign an arbitrary timeline iD 1247 assignTimelineID(); 1248 1249 // notify listeners that we've created a common timeline 1250 notifyClockSync(); 1251 } 1252 1253 mStateChangeLog.log(ANDROID_LOG_INFO, LOG_TAG, 1254 "%s --> MASTER (%s) : %s timeline %016llx", 1255 stateToString(mState), cause, 1256 (oldTimelineID == mTimelineID) ? "taking ownership of" 1257 : "creating new", 1258 mTimelineID); 1259 1260 memset(&mMasterEP, 0, sizeof(mMasterEP)); 1261 mMasterEPValid = false; 1262 mClient_MasterDevicePriority = effectivePriority(); 1263 mClient_MasterDeviceID = mDeviceID; 1264 mClockRecovery.reset(false, true); 1265 resetSyncStats(); 1266 1267 setState(ICommonClock::STATE_MASTER); 1268 return sendMasterAnnouncement(); 1269 } 1270 1271 bool CommonTimeServer::becomeRonin(const char* cause) { 1272 // If we were the client of a given timeline, but had never received even a 1273 // single time sync packet, then we transition back to Initial instead of 1274 // Ronin. If we transition to Ronin and end up becoming the new Master, we 1275 // will be unable to service requests for other clients because we never 1276 // actually knew what time it was. By going to initial, we ensure that 1277 // other clients who know what time it is, but would lose master arbitration 1278 // in the Ronin case, will step up and become the proper new master of the 1279 // old timeline. 1280 1281 char oldEPStr[64]; 1282 sockaddrToString(mMasterEP, mMasterEPValid, oldEPStr, sizeof(oldEPStr)); 1283 memset(&mMasterEP, 0, sizeof(mMasterEP)); 1284 mMasterEPValid = false; 1285 1286 if (mCommonClock.isValid()) { 1287 mStateChangeLog.log(ANDROID_LOG_INFO, LOG_TAG, 1288 "%s --> RONIN (%s) : lost track of previously valid timeline " 1289 "%02x-%014llx::%016llx::%s (%d TXed %d RXed %d RXExpired)", 1290 stateToString(mState), cause, 1291 mClient_MasterDevicePriority, mClient_MasterDeviceID, 1292 mTimelineID, oldEPStr, 1293 mClient_SyncsSentToCurMaster, 1294 mClient_SyncRespsRXedFromCurMaster, 1295 mClient_ExpiredSyncRespsRXedFromCurMaster); 1296 1297 mRonin_WhoIsMasterRequestTimeouts = 0; 1298 setState(ICommonClock::STATE_RONIN); 1299 return sendWhoIsMasterRequest(); 1300 } else { 1301 mStateChangeLog.log(ANDROID_LOG_INFO, LOG_TAG, 1302 "%s --> INITIAL (%s) : never synced timeline " 1303 "%02x-%014llx::%016llx::%s (%d TXed %d RXed %d RXExpired)", 1304 stateToString(mState), cause, 1305 mClient_MasterDevicePriority, mClient_MasterDeviceID, 1306 mTimelineID, oldEPStr, 1307 mClient_SyncsSentToCurMaster, 1308 mClient_SyncRespsRXedFromCurMaster, 1309 mClient_ExpiredSyncRespsRXedFromCurMaster); 1310 1311 return becomeInitial("ronin, no timeline"); 1312 } 1313 } 1314 1315 bool CommonTimeServer::becomeWaitForElection(const char* cause) { 1316 mStateChangeLog.log(ANDROID_LOG_INFO, LOG_TAG, 1317 "%s --> WAIT_FOR_ELECTION (%s) : dropping out of election," 1318 " waiting %d mSec for completion.", 1319 stateToString(mState), cause, kWaitForElection_TimeoutMs); 1320 1321 setState(ICommonClock::STATE_WAIT_FOR_ELECTION); 1322 mCurTimeout.setTimeout(kWaitForElection_TimeoutMs); 1323 return true; 1324 } 1325 1326 bool CommonTimeServer::becomeInitial(const char* cause) { 1327 mStateChangeLog.log(ANDROID_LOG_INFO, LOG_TAG, 1328 "Entering INITIAL (%s), total reset.", 1329 cause); 1330 1331 setState(ICommonClock::STATE_INITIAL); 1332 1333 // reset clock recovery 1334 mClockRecovery.reset(true, true); 1335 1336 // reset internal state bookkeeping. 1337 mCurTimeout.setTimeout(kInfiniteTimeout); 1338 memset(&mMasterEP, 0, sizeof(mMasterEP)); 1339 mMasterEPValid = false; 1340 mLastPacketRxLocalTime = 0; 1341 mTimelineID = ICommonClock::kInvalidTimelineID; 1342 mClockSynced = false; 1343 mInitial_WhoIsMasterRequestTimeouts = 0; 1344 mClient_MasterDeviceID = 0; 1345 mClient_MasterDevicePriority = 0; 1346 mRonin_WhoIsMasterRequestTimeouts = 0; 1347 resetSyncStats(); 1348 1349 // send the first request to discover the master 1350 return sendWhoIsMasterRequest(); 1351 } 1352 1353 void CommonTimeServer::notifyClockSync() { 1354 if (!mClockSynced) { 1355 mClockSynced = true; 1356 mICommonClock->notifyOnTimelineChanged(mTimelineID); 1357 } 1358 } 1359 1360 void CommonTimeServer::notifyClockSyncLoss() { 1361 if (mClockSynced) { 1362 mClockSynced = false; 1363 mICommonClock->notifyOnTimelineChanged( 1364 ICommonClock::kInvalidTimelineID); 1365 } 1366 } 1367 1368 void CommonTimeServer::setState(ICommonClock::State s) { 1369 mState = s; 1370 } 1371 1372 const char* CommonTimeServer::stateToString(ICommonClock::State s) { 1373 switch(s) { 1374 case ICommonClock::STATE_INITIAL: 1375 return "INITIAL"; 1376 case ICommonClock::STATE_CLIENT: 1377 return "CLIENT"; 1378 case ICommonClock::STATE_MASTER: 1379 return "MASTER"; 1380 case ICommonClock::STATE_RONIN: 1381 return "RONIN"; 1382 case ICommonClock::STATE_WAIT_FOR_ELECTION: 1383 return "WAIT_FOR_ELECTION"; 1384 default: 1385 return "unknown"; 1386 } 1387 } 1388 1389 void CommonTimeServer::sockaddrToString(const sockaddr_storage& addr, 1390 bool addrValid, 1391 char* buf, size_t bufLen) { 1392 if (!bufLen || !buf) 1393 return; 1394 1395 if (addrValid) { 1396 switch (addr.ss_family) { 1397 case AF_INET: { 1398 const struct sockaddr_in* sa = 1399 reinterpret_cast<const struct sockaddr_in*>(&addr); 1400 unsigned long a = ntohl(sa->sin_addr.s_addr); 1401 uint16_t p = ntohs(sa->sin_port); 1402 snprintf(buf, bufLen, "%lu.%lu.%lu.%lu:%hu", 1403 ((a >> 24) & 0xFF), ((a >> 16) & 0xFF), 1404 ((a >> 8) & 0xFF), (a & 0xFF), p); 1405 } break; 1406 1407 case AF_INET6: { 1408 const struct sockaddr_in6* sa = 1409 reinterpret_cast<const struct sockaddr_in6*>(&addr); 1410 const uint8_t* a = sa->sin6_addr.s6_addr; 1411 uint16_t p = ntohs(sa->sin6_port); 1412 snprintf(buf, bufLen, 1413 "%02X%02X:%02X%02X:%02X%02X:%02X%02X:" 1414 "%02X%02X:%02X%02X:%02X%02X:%02X%02X port %hd", 1415 a[0], a[1], a[ 2], a[ 3], a[ 4], a[ 5], a[ 6], a[ 7], 1416 a[8], a[9], a[10], a[11], a[12], a[13], a[14], a[15], 1417 p); 1418 } break; 1419 1420 default: 1421 snprintf(buf, bufLen, 1422 "<unknown sockaddr family %d>", addr.ss_family); 1423 break; 1424 } 1425 } else { 1426 snprintf(buf, bufLen, "<none>"); 1427 } 1428 1429 buf[bufLen - 1] = 0; 1430 } 1431 1432 bool CommonTimeServer::sockaddrMatch(const sockaddr_storage& a1, 1433 const sockaddr_storage& a2, 1434 bool matchAddressOnly) { 1435 if (a1.ss_family != a2.ss_family) 1436 return false; 1437 1438 switch (a1.ss_family) { 1439 case AF_INET: { 1440 const struct sockaddr_in* sa1 = 1441 reinterpret_cast<const struct sockaddr_in*>(&a1); 1442 const struct sockaddr_in* sa2 = 1443 reinterpret_cast<const struct sockaddr_in*>(&a2); 1444 1445 if (sa1->sin_addr.s_addr != sa2->sin_addr.s_addr) 1446 return false; 1447 1448 return (matchAddressOnly || (sa1->sin_port == sa2->sin_port)); 1449 } break; 1450 1451 case AF_INET6: { 1452 const struct sockaddr_in6* sa1 = 1453 reinterpret_cast<const struct sockaddr_in6*>(&a1); 1454 const struct sockaddr_in6* sa2 = 1455 reinterpret_cast<const struct sockaddr_in6*>(&a2); 1456 1457 if (memcmp(&sa1->sin6_addr, &sa2->sin6_addr, sizeof(sa2->sin6_addr))) 1458 return false; 1459 1460 return (matchAddressOnly || (sa1->sin6_port == sa2->sin6_port)); 1461 } break; 1462 1463 // Huh? We don't deal in non-IPv[46] addresses. Not sure how we got 1464 // here, but we don't know how to comapre these addresses and simply 1465 // default to a no-match decision. 1466 default: return false; 1467 } 1468 } 1469 1470 bool CommonTimeServer::shouldPanicNotGettingGoodData() { 1471 if (mClient_FirstSyncTX) { 1472 int64_t now = mLocalClock.getLocalTime(); 1473 int64_t delta = now - (mClient_LastGoodSyncRX 1474 ? mClient_LastGoodSyncRX 1475 : mClient_FirstSyncTX); 1476 int64_t deltaUsec = mCommonClock.localDurationToCommonDuration(delta); 1477 1478 if (deltaUsec >= kNoGoodDataPanicThresholdUsec) 1479 return true; 1480 } 1481 1482 return false; 1483 } 1484 1485 void CommonTimeServer::PacketRTTLog::logTX(int64_t txTime) { 1486 txTimes[wrPtr] = txTime; 1487 rxTimes[wrPtr] = 0; 1488 wrPtr = (wrPtr + 1) % RTT_LOG_SIZE; 1489 if (!wrPtr) 1490 logFull = true; 1491 } 1492 1493 void CommonTimeServer::PacketRTTLog::logRX(int64_t txTime, int64_t rxTime) { 1494 if (!logFull && !wrPtr) 1495 return; 1496 1497 uint32_t i = logFull ? wrPtr : 0; 1498 do { 1499 if (txTimes[i] == txTime) { 1500 rxTimes[i] = rxTime; 1501 break; 1502 } 1503 i = (i + 1) % RTT_LOG_SIZE; 1504 } while (i != wrPtr); 1505 } 1506 1507 } // namespace android 1508
