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-rw-r--r--libs/common_time/common_time_server.cpp1506
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diff --git a/libs/common_time/common_time_server.cpp b/libs/common_time/common_time_server.cpp
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+++ b/libs/common_time/common_time_server.cpp
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+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/*
+ * A service that exchanges time synchronization information between
+ * a master that defines a timeline and clients that follow the timeline.
+ */
+
+#define LOG_TAG "common_time"
+#include <utils/Log.h>
+
+#include <arpa/inet.h>
+#include <assert.h>
+#include <fcntl.h>
+#include <linux/if_ether.h>
+#include <net/if.h>
+#include <net/if_arp.h>
+#include <netinet/ip.h>
+#include <poll.h>
+#include <stdio.h>
+#include <sys/eventfd.h>
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+
+#include <common_time/local_clock.h>
+#include <binder/IPCThreadState.h>
+#include <binder/ProcessState.h>
+#include <utils/Timers.h>
+
+#include "common_clock_service.h"
+#include "common_time_config_service.h"
+#include "common_time_server.h"
+#include "common_time_server_packets.h"
+#include "clock_recovery.h"
+#include "common_clock.h"
+
+#define MAX_INT ((int)0x7FFFFFFF)
+
+namespace android {
+
+const char* CommonTimeServer::kDefaultMasterElectionAddr = "255.255.255.255";
+const uint16_t CommonTimeServer::kDefaultMasterElectionPort = 8886;
+const uint64_t CommonTimeServer::kDefaultSyncGroupID = 1;
+const uint8_t CommonTimeServer::kDefaultMasterPriority = 1;
+const uint32_t CommonTimeServer::kDefaultMasterAnnounceIntervalMs = 10000;
+const uint32_t CommonTimeServer::kDefaultSyncRequestIntervalMs = 1000;
+const uint32_t CommonTimeServer::kDefaultPanicThresholdUsec = 50000;
+const bool CommonTimeServer::kDefaultAutoDisable = true;
+const int CommonTimeServer::kSetupRetryTimeoutMs = 30000;
+const int64_t CommonTimeServer::kNoGoodDataPanicThresholdUsec = 600000000ll;
+const uint32_t CommonTimeServer::kRTTDiscardPanicThreshMultiplier = 5;
+
+// timeout value representing an infinite timeout
+const int CommonTimeServer::kInfiniteTimeout = -1;
+
+/*** Initial state constants ***/
+
+// number of WhoIsMaster attempts sent before giving up
+const int CommonTimeServer::kInitial_NumWhoIsMasterRetries = 6;
+
+// timeout used when waiting for a response to a WhoIsMaster request
+const int CommonTimeServer::kInitial_WhoIsMasterTimeoutMs = 500;
+
+/*** Client state constants ***/
+
+// number of sync requests that can fail before a client assumes its master
+// is dead
+const int CommonTimeServer::kClient_NumSyncRequestRetries = 10;
+
+/*** Master state constants ***/
+
+/*** Ronin state constants ***/
+
+// number of WhoIsMaster attempts sent before declaring ourselves master
+const int CommonTimeServer::kRonin_NumWhoIsMasterRetries = 20;
+
+// timeout used when waiting for a response to a WhoIsMaster request
+const int CommonTimeServer::kRonin_WhoIsMasterTimeoutMs = 500;
+
+/*** WaitForElection state constants ***/
+
+// how long do we wait for an announcement from a master before
+// trying another election?
+const int CommonTimeServer::kWaitForElection_TimeoutMs = 12500;
+
+CommonTimeServer::CommonTimeServer()
+ : Thread(false)
+ , mState(ICommonClock::STATE_INITIAL)
+ , mClockRecovery(&mLocalClock, &mCommonClock)
+ , mSocket(-1)
+ , mLastPacketRxLocalTime(0)
+ , mTimelineID(ICommonClock::kInvalidTimelineID)
+ , mClockSynced(false)
+ , mCommonClockHasClients(false)
+ , mStateChangeLog("Recent State Change Events", 30)
+ , mElectionLog("Recent Master Election Traffic", 30)
+ , mBadPktLog("Recent Bad Packet RX Info", 8)
+ , mInitial_WhoIsMasterRequestTimeouts(0)
+ , mClient_MasterDeviceID(0)
+ , mClient_MasterDevicePriority(0)
+ , mRonin_WhoIsMasterRequestTimeouts(0) {
+ // zero out sync stats
+ resetSyncStats();
+
+ // Setup the master election endpoint to use the default.
+ struct sockaddr_in* meep =
+ reinterpret_cast<struct sockaddr_in*>(&mMasterElectionEP);
+ memset(&mMasterElectionEP, 0, sizeof(mMasterElectionEP));
+ inet_aton(kDefaultMasterElectionAddr, &meep->sin_addr);
+ meep->sin_family = AF_INET;
+ meep->sin_port = htons(kDefaultMasterElectionPort);
+
+ // Zero out the master endpoint.
+ memset(&mMasterEP, 0, sizeof(mMasterEP));
+ mMasterEPValid = false;
+ mBindIfaceValid = false;
+ setForceLowPriority(false);
+
+ // Set all remaining configuration parameters to their defaults.
+ mDeviceID = 0;
+ mSyncGroupID = kDefaultSyncGroupID;
+ mMasterPriority = kDefaultMasterPriority;
+ mMasterAnnounceIntervalMs = kDefaultMasterAnnounceIntervalMs;
+ mSyncRequestIntervalMs = kDefaultSyncRequestIntervalMs;
+ mPanicThresholdUsec = kDefaultPanicThresholdUsec;
+ mAutoDisable = kDefaultAutoDisable;
+
+ // Create the eventfd we will use to signal our thread to wake up when
+ // needed.
+ mWakeupThreadFD = eventfd(0, EFD_NONBLOCK);
+
+ // seed the random number generator (used to generated timeline IDs)
+ srand48(static_cast<unsigned int>(systemTime()));
+}
+
+CommonTimeServer::~CommonTimeServer() {
+ shutdownThread();
+
+ // No need to grab the lock here. We are in the destructor; if the the user
+ // has a thread in any of the APIs while the destructor is being called,
+ // there is a threading problem a the application level we cannot reasonably
+ // do anything about.
+ cleanupSocket_l();
+
+ if (mWakeupThreadFD >= 0) {
+ close(mWakeupThreadFD);
+ mWakeupThreadFD = -1;
+ }
+}
+
+bool CommonTimeServer::startServices() {
+ // start the ICommonClock service
+ mICommonClock = CommonClockService::instantiate(*this);
+ if (mICommonClock == NULL)
+ return false;
+
+ // start the ICommonTimeConfig service
+ mICommonTimeConfig = CommonTimeConfigService::instantiate(*this);
+ if (mICommonTimeConfig == NULL)
+ return false;
+
+ return true;
+}
+
+bool CommonTimeServer::threadLoop() {
+ // Register our service interfaces.
+ if (!startServices())
+ return false;
+
+ // Hold the lock while we are in the main thread loop. It will release the
+ // lock when it blocks, and hold the lock at all other times.
+ mLock.lock();
+ runStateMachine_l();
+ mLock.unlock();
+
+ IPCThreadState::self()->stopProcess();
+ return false;
+}
+
+bool CommonTimeServer::runStateMachine_l() {
+ if (!mLocalClock.initCheck())
+ return false;
+
+ if (!mCommonClock.init(mLocalClock.getLocalFreq()))
+ return false;
+
+ // Enter the initial state.
+ becomeInitial("startup");
+
+ // run the state machine
+ while (!exitPending()) {
+ struct pollfd pfds[2];
+ int rc, timeout;
+ int eventCnt = 0;
+ int64_t wakeupTime;
+ uint32_t t1, t2;
+ bool needHandleTimeout = false;
+
+ // We are always interested in our wakeup FD.
+ pfds[eventCnt].fd = mWakeupThreadFD;
+ pfds[eventCnt].events = POLLIN;
+ pfds[eventCnt].revents = 0;
+ eventCnt++;
+
+ // If we have a valid socket, then we are interested in what it has to
+ // say as well.
+ if (mSocket >= 0) {
+ pfds[eventCnt].fd = mSocket;
+ pfds[eventCnt].events = POLLIN;
+ pfds[eventCnt].revents = 0;
+ eventCnt++;
+ }
+
+ t1 = static_cast<uint32_t>(mCurTimeout.msecTillTimeout());
+ t2 = static_cast<uint32_t>(mClockRecovery.applyRateLimitedSlew());
+ timeout = static_cast<int>(t1 < t2 ? t1 : t2);
+
+ // Note, we were holding mLock when this function was called. We
+ // release it only while we are blocking and hold it at all other times.
+ mLock.unlock();
+ rc = poll(pfds, eventCnt, timeout);
+ wakeupTime = mLocalClock.getLocalTime();
+ mLock.lock();
+
+ // Is it time to shutdown? If so, don't hesitate... just do it.
+ if (exitPending())
+ break;
+
+ // Did the poll fail? This should never happen and is fatal if it does.
+ if (rc < 0) {
+ ALOGE("%s:%d poll failed", __PRETTY_FUNCTION__, __LINE__);
+ return false;
+ }
+
+ if (rc == 0) {
+ needHandleTimeout = !mCurTimeout.msecTillTimeout();
+ if (needHandleTimeout)
+ mCurTimeout.setTimeout(kInfiniteTimeout);
+ }
+
+ // Were we woken up on purpose? If so, clear the eventfd with a read.
+ if (pfds[0].revents)
+ clearPendingWakeupEvents_l();
+
+ // Is out bind address dirty? If so, clean up our socket (if any).
+ // Alternatively, do we have an active socket but should be auto
+ // disabled? If so, release the socket and enter the proper sync state.
+ bool droppedSocket = false;
+ if (mBindIfaceDirty || ((mSocket >= 0) && shouldAutoDisable())) {
+ cleanupSocket_l();
+ mBindIfaceDirty = false;
+ droppedSocket = true;
+ }
+
+ // Do we not have a socket but should have one? If so, try to set one
+ // up.
+ if ((mSocket < 0) && mBindIfaceValid && !shouldAutoDisable()) {
+ if (setupSocket_l()) {
+ // Success! We are now joining a new network (either coming
+ // from no network, or coming from a potentially different
+ // network). Force our priority to be lower so that we defer to
+ // any other masters which may already be on the network we are
+ // joining. Later, when we enter either the client or the
+ // master state, we will clear this flag and go back to our
+ // normal election priority.
+ setForceLowPriority(true);
+ switch (mState) {
+ // If we were in initial (whether we had a immediately
+ // before this network or not) we want to simply reset the
+ // system and start again. Forcing a transition from
+ // INITIAL to INITIAL should do the job.
+ case CommonClockService::STATE_INITIAL:
+ becomeInitial("bound interface");
+ break;
+
+ // If we were in the master state, then either we were the
+ // master in a no-network situation, or we were the master
+ // of a different network and have moved to a new interface.
+ // In either case, immediately transition to Ronin at low
+ // priority. If there is no one in the network we just
+ // joined, we will become master soon enough. If there is,
+ // we want to be certain to defer master status to the
+ // existing timeline currently running on the network.
+ //
+ case CommonClockService::STATE_MASTER:
+ becomeRonin("leaving networkless mode");
+ break;
+
+ // If we were in any other state (CLIENT, RONIN, or
+ // WAIT_FOR_ELECTION) then we must be moving from one
+ // network to another. We have lost our old master;
+ // transition to RONIN in an attempt to find a new master.
+ // If there are none out there, we will just assume
+ // responsibility for the timeline we used to be a client
+ // of.
+ default:
+ becomeRonin("bound interface");
+ break;
+ }
+ } else {
+ // That's odd... we failed to set up our socket. This could be
+ // due to some transient network change which will work itself
+ // out shortly; schedule a retry attempt in the near future.
+ mCurTimeout.setTimeout(kSetupRetryTimeoutMs);
+ }
+
+ // One way or the other, we don't have any data to process at this
+ // point (since we just tried to bulid a new socket). Loop back
+ // around and wait for the next thing to do.
+ continue;
+ } else if (droppedSocket) {
+ // We just lost our socket, and for whatever reason (either no
+ // config, or auto disable engaged) we are not supposed to rebuild
+ // one at this time. We are not going to rebuild our socket until
+ // something about our config/auto-disabled status changes, so we
+ // are basically in network-less mode. If we are already in either
+ // INITIAL or MASTER, just stay there until something changes. If
+ // we are in any other state (CLIENT, RONIN or WAIT_FOR_ELECTION),
+ // then transition to either INITIAL or MASTER depending on whether
+ // or not our timeline is valid.
+ mStateChangeLog.log(ANDROID_LOG_INFO, LOG_TAG,
+ "Entering networkless mode interface is %s, "
+ "shouldAutoDisable = %s",
+ mBindIfaceValid ? "valid" : "invalid",
+ shouldAutoDisable() ? "true" : "false");
+ if ((mState != ICommonClock::STATE_INITIAL) &&
+ (mState != ICommonClock::STATE_MASTER)) {
+ if (mTimelineID == ICommonClock::kInvalidTimelineID)
+ becomeInitial("network-less mode");
+ else
+ becomeMaster("network-less mode");
+ }
+
+ continue;
+ }
+
+ // Time to handle the timeouts?
+ if (needHandleTimeout) {
+ if (!handleTimeout())
+ ALOGE("handleTimeout failed");
+ continue;
+ }
+
+ // Does our socket have data for us (assuming we still have one, we
+ // may have RXed a packet at the same time as a config change telling us
+ // to shut our socket down)? If so, process its data.
+ if ((mSocket >= 0) && (eventCnt > 1) && (pfds[1].revents)) {
+ mLastPacketRxLocalTime = wakeupTime;
+ if (!handlePacket())
+ ALOGE("handlePacket failed");
+ }
+ }
+
+ cleanupSocket_l();
+ return true;
+}
+
+void CommonTimeServer::clearPendingWakeupEvents_l() {
+ int64_t tmp;
+ read(mWakeupThreadFD, &tmp, sizeof(tmp));
+}
+
+void CommonTimeServer::wakeupThread_l() {
+ int64_t tmp = 1;
+ write(mWakeupThreadFD, &tmp, sizeof(tmp));
+}
+
+void CommonTimeServer::cleanupSocket_l() {
+ if (mSocket >= 0) {
+ close(mSocket);
+ mSocket = -1;
+ }
+}
+
+void CommonTimeServer::shutdownThread() {
+ // Flag the work thread for shutdown.
+ this->requestExit();
+
+ // Signal the thread in case its sleeping.
+ mLock.lock();
+ wakeupThread_l();
+ mLock.unlock();
+
+ // Wait for the thread to exit.
+ this->join();
+}
+
+bool CommonTimeServer::setupSocket_l() {
+ int rc;
+ bool ret_val = false;
+ struct sockaddr_in* ipv4_addr = NULL;
+ char masterElectionEPStr[64];
+ const int one = 1;
+
+ // This should never be needed, but if we happened to have an old socket
+ // lying around, be sure to not leak it before proceeding.
+ cleanupSocket_l();
+
+ // If we don't have a valid endpoint to bind to, then how did we get here in
+ // the first place? Regardless, we know that we are going to fail to bind,
+ // so don't even try.
+ if (!mBindIfaceValid)
+ return false;
+
+ sockaddrToString(mMasterElectionEP, true, masterElectionEPStr,
+ sizeof(masterElectionEPStr));
+ mStateChangeLog.log(ANDROID_LOG_INFO, LOG_TAG,
+ "Building socket :: bind = %s master election = %s",
+ mBindIface.string(), masterElectionEPStr);
+
+ // TODO: add proper support for IPv6. Right now, we block IPv6 addresses at
+ // the configuration interface level.
+ if (AF_INET != mMasterElectionEP.ss_family) {
+ mStateChangeLog.log(ANDROID_LOG_WARN, LOG_TAG,
+ "TODO: add proper IPv6 support");
+ goto bailout;
+ }
+
+ // open a UDP socket for the timeline serivce
+ mSocket = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
+ if (mSocket < 0) {
+ mStateChangeLog.log(ANDROID_LOG_ERROR, LOG_TAG,
+ "Failed to create socket (errno = %d)", errno);
+ goto bailout;
+ }
+
+ // Bind to the selected interface using Linux's spiffy SO_BINDTODEVICE.
+ struct ifreq ifr;
+ memset(&ifr, 0, sizeof(ifr));
+ snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s", mBindIface.string());
+ ifr.ifr_name[sizeof(ifr.ifr_name) - 1] = 0;
+ rc = setsockopt(mSocket, SOL_SOCKET, SO_BINDTODEVICE,
+ (void *)&ifr, sizeof(ifr));
+ if (rc) {
+ mStateChangeLog.log(ANDROID_LOG_ERROR, LOG_TAG,
+ "Failed to bind socket at to interface %s "
+ "(errno = %d)", ifr.ifr_name, errno);
+ goto bailout;
+ }
+
+ // Bind our socket to INADDR_ANY and the master election port. The
+ // interface binding we made using SO_BINDTODEVICE should limit us to
+ // traffic only on the interface we are interested in. We need to bind to
+ // INADDR_ANY and the specific master election port in order to be able to
+ // receive both unicast traffic and master election multicast traffic with
+ // just a single socket.
+ struct sockaddr_in bindAddr;
+ ipv4_addr = reinterpret_cast<struct sockaddr_in*>(&mMasterElectionEP);
+ memcpy(&bindAddr, ipv4_addr, sizeof(bindAddr));
+ bindAddr.sin_addr.s_addr = INADDR_ANY;
+ rc = bind(mSocket,
+ reinterpret_cast<const sockaddr *>(&bindAddr),
+ sizeof(bindAddr));
+ if (rc) {
+ mStateChangeLog.log(ANDROID_LOG_ERROR, LOG_TAG,
+ "Failed to bind socket to port %hu (errno = %d)",
+ ntohs(bindAddr.sin_port), errno);
+ goto bailout;
+ }
+
+ if (0xE0000000 == (ntohl(ipv4_addr->sin_addr.s_addr) & 0xF0000000)) {
+ // If our master election endpoint is a multicast address, be sure to join
+ // the multicast group.
+ struct ip_mreq mreq;
+ mreq.imr_multiaddr = ipv4_addr->sin_addr;
+ mreq.imr_interface.s_addr = htonl(INADDR_ANY);
+ rc = setsockopt(mSocket, IPPROTO_IP, IP_ADD_MEMBERSHIP,
+ &mreq, sizeof(mreq));
+ if (rc == -1) {
+ ALOGE("Failed to join multicast group at %s. (errno = %d)",
+ masterElectionEPStr, errno);
+ goto bailout;
+ }
+
+ // disable loopback of multicast packets
+ const int zero = 0;
+ rc = setsockopt(mSocket, IPPROTO_IP, IP_MULTICAST_LOOP,
+ &zero, sizeof(zero));
+ if (rc == -1) {
+ mStateChangeLog.log(ANDROID_LOG_ERROR, LOG_TAG,
+ "Failed to disable multicast loopback "
+ "(errno = %d)", errno);
+ goto bailout;
+ }
+ } else
+ if (ntohl(ipv4_addr->sin_addr.s_addr) == 0xFFFFFFFF) {
+ // If the master election address is the broadcast address, then enable
+ // the broadcast socket option
+ rc = setsockopt(mSocket, SOL_SOCKET, SO_BROADCAST, &one, sizeof(one));
+ if (rc == -1) {
+ mStateChangeLog.log(ANDROID_LOG_ERROR, LOG_TAG,
+ "Failed to enable broadcast (errno = %d)",
+ errno);
+ goto bailout;
+ }
+ } else {
+ // If the master election address is neither broadcast, nor multicast,
+ // then we are misconfigured. The config API layer should prevent this
+ // from ever happening.
+ goto bailout;
+ }
+
+ // Set the TTL of sent packets to 1. (Time protocol sync should never leave
+ // the local subnet)
+ rc = setsockopt(mSocket, IPPROTO_IP, IP_TTL, &one, sizeof(one));
+ if (rc == -1) {
+ mStateChangeLog.log(ANDROID_LOG_ERROR, LOG_TAG,
+ "Failed to set TTL to %d (errno = %d)", one, errno);
+ goto bailout;
+ }
+
+ // get the device's unique ID
+ if (!assignDeviceID())
+ goto bailout;
+
+ ret_val = true;
+
+bailout:
+ if (!ret_val)
+ cleanupSocket_l();
+ return ret_val;
+}
+
+// generate a unique device ID that can be used for arbitration
+bool CommonTimeServer::assignDeviceID() {
+ if (!mBindIfaceValid)
+ return false;
+
+ struct ifreq ifr;
+ memset(&ifr, 0, sizeof(ifr));
+ ifr.ifr_addr.sa_family = AF_INET;
+ strlcpy(ifr.ifr_name, mBindIface.string(), IFNAMSIZ);
+
+ int rc = ioctl(mSocket, SIOCGIFHWADDR, &ifr);
+ if (rc) {
+ ALOGE("%s:%d ioctl failed", __PRETTY_FUNCTION__, __LINE__);
+ return false;
+ }
+
+ if (ifr.ifr_addr.sa_family != ARPHRD_ETHER) {
+ ALOGE("%s:%d got non-Ethernet address", __PRETTY_FUNCTION__, __LINE__);
+ return false;
+ }
+
+ mDeviceID = 0;
+ for (int i = 0; i < ETH_ALEN; i++) {
+ mDeviceID = (mDeviceID << 8) | ifr.ifr_hwaddr.sa_data[i];
+ }
+
+ return true;
+}
+
+// generate a new timeline ID
+void CommonTimeServer::assignTimelineID() {
+ do {
+ mTimelineID = (static_cast<uint64_t>(lrand48()) << 32)
+ | static_cast<uint64_t>(lrand48());
+ } while (mTimelineID == ICommonClock::kInvalidTimelineID);
+}
+
+// Select a preference between the device IDs of two potential masters.
+// Returns true if the first ID wins, or false if the second ID wins.
+bool CommonTimeServer::arbitrateMaster(
+ uint64_t deviceID1, uint8_t devicePrio1,
+ uint64_t deviceID2, uint8_t devicePrio2) {
+ return ((devicePrio1 > devicePrio2) ||
+ ((devicePrio1 == devicePrio2) && (deviceID1 > deviceID2)));
+}
+
+static void hexDumpToString(const uint8_t* src, size_t src_len,
+ char* dst, size_t dst_len) {
+ size_t offset = 0;
+ size_t i;
+
+ for (i = 0; (i < src_len) && (offset < dst_len); ++i) {
+ int res;
+ if (0 == (i % 16)) {
+ res = snprintf(dst + offset, dst_len - offset, "\n%04x :", i);
+ if (res < 0)
+ break;
+ offset += res;
+ if (offset >= dst_len)
+ break;
+ }
+
+ res = snprintf(dst + offset, dst_len - offset, " %02x", src[i]);
+ if (res < 0)
+ break;
+ offset += res;
+ }
+
+ dst[dst_len - 1] = 0;
+}
+
+bool CommonTimeServer::handlePacket() {
+ uint8_t buf[256];
+ struct sockaddr_storage srcAddr;
+ socklen_t srcAddrLen = sizeof(srcAddr);
+
+ ssize_t recvBytes = recvfrom(
+ mSocket, buf, sizeof(buf), 0,
+ reinterpret_cast<const sockaddr *>(&srcAddr), &srcAddrLen);
+
+ if (recvBytes < 0) {
+ mBadPktLog.log(ANDROID_LOG_ERROR, LOG_TAG,
+ "recvfrom failed (res %d, errno %d)",
+ recvBytes, errno);
+ return false;
+ }
+
+ UniversalTimeServicePacket pkt;
+ if (pkt.deserializePacket(buf, recvBytes, mSyncGroupID) < 0) {
+ char hex[256];
+ char srcEPStr[64];
+
+ hexDumpToString(buf, static_cast<size_t>(recvBytes), hex, sizeof(hex));
+ sockaddrToString(srcAddr, true, srcEPStr, sizeof(srcEPStr));
+
+ mBadPktLog.log("Failed to parse %d byte packet from %s.%s",
+ recvBytes, srcEPStr, hex);
+ return false;
+ }
+
+ bool result;
+ switch (pkt.packetType) {
+ case TIME_PACKET_WHO_IS_MASTER_REQUEST:
+ result = handleWhoIsMasterRequest(&pkt.p.who_is_master_request,
+ srcAddr);
+ break;
+
+ case TIME_PACKET_WHO_IS_MASTER_RESPONSE:
+ result = handleWhoIsMasterResponse(&pkt.p.who_is_master_response,
+ srcAddr);
+ break;
+
+ case TIME_PACKET_SYNC_REQUEST:
+ result = handleSyncRequest(&pkt.p.sync_request, srcAddr);
+ break;
+
+ case TIME_PACKET_SYNC_RESPONSE:
+ result = handleSyncResponse(&pkt.p.sync_response, srcAddr);
+ break;
+
+ case TIME_PACKET_MASTER_ANNOUNCEMENT:
+ result = handleMasterAnnouncement(&pkt.p.master_announcement,
+ srcAddr);
+ break;
+
+ default: {
+ char srcEPStr[64];
+ sockaddrToString(srcAddr, true, srcEPStr, sizeof(srcEPStr));
+
+ mBadPktLog.log(ANDROID_LOG_WARN, LOG_TAG,
+ "unknown packet type (%d) from %s",
+ pkt.packetType, srcEPStr);
+
+ result = false;
+ } break;
+ }
+
+ return result;
+}
+
+bool CommonTimeServer::handleTimeout() {
+ // If we have no socket, then this must be a timeout to retry socket setup.
+ if (mSocket < 0)
+ return true;
+
+ switch (mState) {
+ case ICommonClock::STATE_INITIAL:
+ return handleTimeoutInitial();
+ case ICommonClock::STATE_CLIENT:
+ return handleTimeoutClient();
+ case ICommonClock::STATE_MASTER:
+ return handleTimeoutMaster();
+ case ICommonClock::STATE_RONIN:
+ return handleTimeoutRonin();
+ case ICommonClock::STATE_WAIT_FOR_ELECTION:
+ return handleTimeoutWaitForElection();
+ }
+
+ return false;
+}
+
+bool CommonTimeServer::handleTimeoutInitial() {
+ if (++mInitial_WhoIsMasterRequestTimeouts ==
+ kInitial_NumWhoIsMasterRetries) {
+ // none of our attempts to discover a master succeeded, so make
+ // this device the master
+ return becomeMaster("initial timeout");
+ } else {
+ // retry the WhoIsMaster request
+ return sendWhoIsMasterRequest();
+ }
+}
+
+bool CommonTimeServer::handleTimeoutClient() {
+ if (shouldPanicNotGettingGoodData())
+ return becomeInitial("timeout panic, no good data");
+
+ if (mClient_SyncRequestPending) {
+ mClient_SyncRequestPending = false;
+
+ if (++mClient_SyncRequestTimeouts < kClient_NumSyncRequestRetries) {
+ // a sync request has timed out, so retry
+ return sendSyncRequest();
+ } else {
+ // The master has failed to respond to a sync request for too many
+ // times in a row. Assume the master is dead and start electing
+ // a new master.
+ return becomeRonin("master not responding");
+ }
+ } else {
+ // initiate the next sync request
+ return sendSyncRequest();
+ }
+}
+
+bool CommonTimeServer::handleTimeoutMaster() {
+ // send another announcement from the master
+ return sendMasterAnnouncement();
+}
+
+bool CommonTimeServer::handleTimeoutRonin() {
+ if (++mRonin_WhoIsMasterRequestTimeouts == kRonin_NumWhoIsMasterRetries) {
+ // no other master is out there, so we won the election
+ return becomeMaster("no better masters detected");
+ } else {
+ return sendWhoIsMasterRequest();
+ }
+}
+
+bool CommonTimeServer::handleTimeoutWaitForElection() {
+ return becomeRonin("timeout waiting for election conclusion");
+}
+
+bool CommonTimeServer::handleWhoIsMasterRequest(
+ const WhoIsMasterRequestPacket* request,
+ const sockaddr_storage& srcAddr) {
+ // Skip our own messages which come back via broadcast loopback.
+ if (request->senderDeviceID == mDeviceID)
+ return true;
+
+ char srcEPStr[64];
+ sockaddrToString(srcAddr, true, srcEPStr, sizeof(srcEPStr));
+ mElectionLog.log("RXed WhoIs master request while in state %s. "
+ "src %s reqTID %016llx ourTID %016llx",
+ stateToString(mState), srcEPStr,
+ request->timelineID, mTimelineID);
+
+ if (mState == ICommonClock::STATE_MASTER) {
+ // is this request related to this master's timeline?
+ if (request->timelineID != ICommonClock::kInvalidTimelineID &&
+ request->timelineID != mTimelineID)
+ return true;
+
+ WhoIsMasterResponsePacket pkt;
+ pkt.initHeader(mTimelineID, mSyncGroupID);
+ pkt.deviceID = mDeviceID;
+ pkt.devicePriority = effectivePriority();
+
+ mElectionLog.log("TXing WhoIs master resp to %s while in state %s. "
+ "ourTID %016llx ourGID %016llx ourDID %016llx "
+ "ourPrio %u",
+ srcEPStr, stateToString(mState),
+ mTimelineID, mSyncGroupID,
+ pkt.deviceID, pkt.devicePriority);
+
+ uint8_t buf[256];
+ ssize_t bufSz = pkt.serializePacket(buf, sizeof(buf));
+ if (bufSz < 0)
+ return false;
+
+ ssize_t sendBytes = sendto(
+ mSocket, buf, bufSz, 0,
+ reinterpret_cast<const sockaddr *>(&srcAddr),
+ sizeof(srcAddr));
+ if (sendBytes == -1) {
+ ALOGE("%s:%d sendto failed", __PRETTY_FUNCTION__, __LINE__);
+ return false;
+ }
+ } else if (mState == ICommonClock::STATE_RONIN) {
+ // if we hear a WhoIsMaster request from another device following
+ // the same timeline and that device wins arbitration, then we will stop
+ // trying to elect ourselves master and will instead wait for an
+ // announcement from the election winner
+ if (request->timelineID != mTimelineID)
+ return true;
+
+ if (arbitrateMaster(request->senderDeviceID,
+ request->senderDevicePriority,
+ mDeviceID,
+ effectivePriority()))
+ return becomeWaitForElection("would lose election");
+
+ return true;
+ } else if (mState == ICommonClock::STATE_INITIAL) {
+ // If a group of devices booted simultaneously (e.g. after a power
+ // outage) and all of them are in the initial state and there is no
+ // master, then each device may time out and declare itself master at
+ // the same time. To avoid this, listen for
+ // WhoIsMaster(InvalidTimeline) requests from peers. If we would lose
+ // arbitration against that peer, reset our timeout count so that the
+ // peer has a chance to become master before we time out.
+ if (request->timelineID == ICommonClock::kInvalidTimelineID &&
+ arbitrateMaster(request->senderDeviceID,
+ request->senderDevicePriority,
+ mDeviceID,
+ effectivePriority())) {
+ mInitial_WhoIsMasterRequestTimeouts = 0;
+ }
+ }
+
+ return true;
+}
+
+bool CommonTimeServer::handleWhoIsMasterResponse(
+ const WhoIsMasterResponsePacket* response,
+ const sockaddr_storage& srcAddr) {
+ // Skip our own messages which come back via broadcast loopback.
+ if (response->deviceID == mDeviceID)
+ return true;
+
+ char srcEPStr[64];
+ sockaddrToString(srcAddr, true, srcEPStr, sizeof(srcEPStr));
+ mElectionLog.log("RXed WhoIs master response while in state %s. "
+ "src %s respTID %016llx respDID %016llx respPrio %u "
+ "ourTID %016llx",
+ stateToString(mState), srcEPStr,
+ response->timelineID,
+ response->deviceID,
+ static_cast<uint32_t>(response->devicePriority),
+ mTimelineID);
+
+ if (mState == ICommonClock::STATE_INITIAL || mState == ICommonClock::STATE_RONIN) {
+ return becomeClient(srcAddr,
+ response->deviceID,
+ response->devicePriority,
+ response->timelineID,
+ "heard whois response");
+ } else if (mState == ICommonClock::STATE_CLIENT) {
+ // if we get multiple responses because there are multiple devices
+ // who believe that they are master, then follow the master that
+ // wins arbitration
+ if (arbitrateMaster(response->deviceID,
+ response->devicePriority,
+ mClient_MasterDeviceID,
+ mClient_MasterDevicePriority)) {
+ return becomeClient(srcAddr,
+ response->deviceID,
+ response->devicePriority,
+ response->timelineID,
+ "heard whois response");
+ }
+ }
+
+ return true;
+}
+
+bool CommonTimeServer::handleSyncRequest(const SyncRequestPacket* request,
+ const sockaddr_storage& srcAddr) {
+ SyncResponsePacket pkt;
+ pkt.initHeader(mTimelineID, mSyncGroupID);
+
+ if ((mState == ICommonClock::STATE_MASTER) &&
+ (mTimelineID == request->timelineID)) {
+ int64_t rxLocalTime = mLastPacketRxLocalTime;
+ int64_t rxCommonTime;
+
+ // If we are master on an actual network and have actual clients, then
+ // we are no longer low priority.
+ setForceLowPriority(false);
+
+ if (OK != mCommonClock.localToCommon(rxLocalTime, &rxCommonTime)) {
+ return false;
+ }
+
+ int64_t txLocalTime = mLocalClock.getLocalTime();;
+ int64_t txCommonTime;
+ if (OK != mCommonClock.localToCommon(txLocalTime, &txCommonTime)) {
+ return false;
+ }
+
+ pkt.nak = 0;
+ pkt.clientTxLocalTime = request->clientTxLocalTime;
+ pkt.masterRxCommonTime = rxCommonTime;
+ pkt.masterTxCommonTime = txCommonTime;
+ } else {
+ pkt.nak = 1;
+ pkt.clientTxLocalTime = 0;
+ pkt.masterRxCommonTime = 0;
+ pkt.masterTxCommonTime = 0;
+ }
+
+ uint8_t buf[256];
+ ssize_t bufSz = pkt.serializePacket(buf, sizeof(buf));
+ if (bufSz < 0)
+ return false;
+
+ ssize_t sendBytes = sendto(
+ mSocket, &buf, bufSz, 0,
+ reinterpret_cast<const sockaddr *>(&srcAddr),
+ sizeof(srcAddr));
+ if (sendBytes == -1) {
+ ALOGE("%s:%d sendto failed", __PRETTY_FUNCTION__, __LINE__);
+ return false;
+ }
+
+ return true;
+}
+
+bool CommonTimeServer::handleSyncResponse(
+ const SyncResponsePacket* response,
+ const sockaddr_storage& srcAddr) {
+ if (mState != ICommonClock::STATE_CLIENT)
+ return true;
+
+ assert(mMasterEPValid);
+ if (!sockaddrMatch(srcAddr, mMasterEP, true)) {
+ char srcEP[64], expectedEP[64];
+ sockaddrToString(srcAddr, true, srcEP, sizeof(srcEP));
+ sockaddrToString(mMasterEP, true, expectedEP, sizeof(expectedEP));
+ ALOGI("Dropping sync response from unexpected address."
+ " Expected %s Got %s", expectedEP, srcEP);
+ return true;
+ }
+
+ if (response->nak) {
+ // if our master is no longer accepting requests, then we need to find
+ // a new master
+ return becomeRonin("master NAK'ed");
+ }
+
+ mClient_SyncRequestPending = 0;
+ mClient_SyncRequestTimeouts = 0;
+ mClient_PacketRTTLog.logRX(response->clientTxLocalTime,
+ mLastPacketRxLocalTime);
+
+ bool result;
+ if (!(mClient_SyncRespsRXedFromCurMaster++)) {
+ // the first request/response exchange between a client and a master
+ // may take unusually long due to ARP, so discard it.
+ result = true;
+ } else {
+ int64_t clientTxLocalTime = response->clientTxLocalTime;
+ int64_t clientRxLocalTime = mLastPacketRxLocalTime;
+ int64_t masterTxCommonTime = response->masterTxCommonTime;
+ int64_t masterRxCommonTime = response->masterRxCommonTime;
+
+ int64_t rtt = (clientRxLocalTime - clientTxLocalTime);
+ int64_t avgLocal = (clientTxLocalTime + clientRxLocalTime) >> 1;
+ int64_t avgCommon = (masterTxCommonTime + masterRxCommonTime) >> 1;
+
+ // if the RTT of the packet is significantly larger than the panic
+ // threshold, we should simply discard it. Its better to do nothing
+ // than to take cues from a packet like that.
+ int rttCommon = mCommonClock.localDurationToCommonDuration(rtt);
+ if (rttCommon > (static_cast<int64_t>(mPanicThresholdUsec) *
+ kRTTDiscardPanicThreshMultiplier)) {
+ ALOGV("Dropping sync response with RTT of %lld uSec", rttCommon);
+ mClient_ExpiredSyncRespsRXedFromCurMaster++;
+ if (shouldPanicNotGettingGoodData())
+ return becomeInitial("RX panic, no good data");
+ } else {
+ result = mClockRecovery.pushDisciplineEvent(avgLocal, avgCommon, rttCommon);
+ mClient_LastGoodSyncRX = clientRxLocalTime;
+
+ if (result) {
+ // indicate to listeners that we've synced to the common timeline
+ notifyClockSync();
+ } else {
+ ALOGE("Panic! Observed clock sync error is too high to tolerate,"
+ " resetting state machine and starting over.");
+ notifyClockSyncLoss();
+ return becomeInitial("panic");
+ }
+ }
+ }
+
+ mCurTimeout.setTimeout(mSyncRequestIntervalMs);
+ return result;
+}
+
+bool CommonTimeServer::handleMasterAnnouncement(
+ const MasterAnnouncementPacket* packet,
+ const sockaddr_storage& srcAddr) {
+ uint64_t newDeviceID = packet->deviceID;
+ uint8_t newDevicePrio = packet->devicePriority;
+ uint64_t newTimelineID = packet->timelineID;
+
+ // Skip our own messages which come back via broadcast loopback.
+ if (newDeviceID == mDeviceID)
+ return true;
+
+ char srcEPStr[64];
+ sockaddrToString(srcAddr, true, srcEPStr, sizeof(srcEPStr));
+ mElectionLog.log("RXed master announcement while in state %s. "
+ "src %s srcDevID %lld srcPrio %u srcTID %016llx",
+ stateToString(mState), srcEPStr,
+ newDeviceID, static_cast<uint32_t>(newDevicePrio),
+ newTimelineID);
+
+ if (mState == ICommonClock::STATE_INITIAL ||
+ mState == ICommonClock::STATE_RONIN ||
+ mState == ICommonClock::STATE_WAIT_FOR_ELECTION) {
+ // if we aren't currently following a master, then start following
+ // this new master
+ return becomeClient(srcAddr,
+ newDeviceID,
+ newDevicePrio,
+ newTimelineID,
+ "heard master announcement");
+ } else if (mState == ICommonClock::STATE_CLIENT) {
+ // if the new master wins arbitration against our current master,
+ // then become a client of the new master
+ if (arbitrateMaster(newDeviceID,
+ newDevicePrio,
+ mClient_MasterDeviceID,
+ mClient_MasterDevicePriority))
+ return becomeClient(srcAddr,
+ newDeviceID,
+ newDevicePrio,
+ newTimelineID,
+ "heard master announcement");
+ } else if (mState == ICommonClock::STATE_MASTER) {
+ // two masters are competing - if the new one wins arbitration, then
+ // cease acting as master
+ if (arbitrateMaster(newDeviceID, newDevicePrio,
+ mDeviceID, effectivePriority()))
+ return becomeClient(srcAddr, newDeviceID,
+ newDevicePrio, newTimelineID,
+ "heard master announcement");
+ }
+
+ return true;
+}
+
+bool CommonTimeServer::sendWhoIsMasterRequest() {
+ assert(mState == ICommonClock::STATE_INITIAL || mState == ICommonClock::STATE_RONIN);
+
+ // If we have no socket, then we must be in the unconfigured initial state.
+ // Don't report any errors, just don't try to send the initial who-is-master
+ // query. Eventually, our network will either become configured, or we will
+ // be forced into network-less master mode by higher level code.
+ if (mSocket < 0) {
+ assert(mState == ICommonClock::STATE_INITIAL);
+ return true;
+ }
+
+ bool ret = false;
+ WhoIsMasterRequestPacket pkt;
+ pkt.initHeader(mSyncGroupID);
+ pkt.senderDeviceID = mDeviceID;
+ pkt.senderDevicePriority = effectivePriority();
+
+ uint8_t buf[256];
+ ssize_t bufSz = pkt.serializePacket(buf, sizeof(buf));
+ if (bufSz >= 0) {
+ char dstEPStr[64];
+ sockaddrToString(mMasterElectionEP, true, dstEPStr, sizeof(dstEPStr));
+ mElectionLog.log("TXing WhoIs master request to %s while in state %s. "
+ "ourTID %016llx ourGID %016llx ourDID %016llx "
+ "ourPrio %u",
+ dstEPStr, stateToString(mState),
+ mTimelineID, mSyncGroupID,
+ pkt.senderDeviceID, pkt.senderDevicePriority);
+
+ ssize_t sendBytes = sendto(
+ mSocket, buf, bufSz, 0,
+ reinterpret_cast<const sockaddr *>(&mMasterElectionEP),
+ sizeof(mMasterElectionEP));
+ if (sendBytes < 0)
+ ALOGE("WhoIsMaster sendto failed (errno %d)", errno);
+ ret = true;
+ }
+
+ if (mState == ICommonClock::STATE_INITIAL) {
+ mCurTimeout.setTimeout(kInitial_WhoIsMasterTimeoutMs);
+ } else {
+ mCurTimeout.setTimeout(kRonin_WhoIsMasterTimeoutMs);
+ }
+
+ return ret;
+}
+
+bool CommonTimeServer::sendSyncRequest() {
+ // If we are sending sync requests, then we must be in the client state and
+ // we must have a socket (when we have no network, we are only supposed to
+ // be in INITIAL or MASTER)
+ assert(mState == ICommonClock::STATE_CLIENT);
+ assert(mSocket >= 0);
+
+ bool ret = false;
+ SyncRequestPacket pkt;
+ pkt.initHeader(mTimelineID, mSyncGroupID);
+ pkt.clientTxLocalTime = mLocalClock.getLocalTime();
+
+ if (!mClient_FirstSyncTX)
+ mClient_FirstSyncTX = pkt.clientTxLocalTime;
+
+ mClient_PacketRTTLog.logTX(pkt.clientTxLocalTime);
+
+ uint8_t buf[256];
+ ssize_t bufSz = pkt.serializePacket(buf, sizeof(buf));
+ if (bufSz >= 0) {
+ ssize_t sendBytes = sendto(
+ mSocket, buf, bufSz, 0,
+ reinterpret_cast<const sockaddr *>(&mMasterEP),
+ sizeof(mMasterEP));
+ if (sendBytes < 0)
+ ALOGE("SyncRequest sendto failed (errno %d)", errno);
+ ret = true;
+ }
+
+ mClient_SyncsSentToCurMaster++;
+ mCurTimeout.setTimeout(mSyncRequestIntervalMs);
+ mClient_SyncRequestPending = true;
+
+ return ret;
+}
+
+bool CommonTimeServer::sendMasterAnnouncement() {
+ bool ret = false;
+ assert(mState == ICommonClock::STATE_MASTER);
+
+ // If we are being asked to send a master announcement, but we have no
+ // socket, we must be in network-less master mode. Don't bother to send the
+ // announcement, and don't bother to schedule a timeout. When the network
+ // comes up, the work thread will get poked and start the process of
+ // figuring out who the current master should be.
+ if (mSocket < 0) {
+ mCurTimeout.setTimeout(kInfiniteTimeout);
+ return true;
+ }
+
+ MasterAnnouncementPacket pkt;
+ pkt.initHeader(mTimelineID, mSyncGroupID);
+ pkt.deviceID = mDeviceID;
+ pkt.devicePriority = effectivePriority();
+
+ uint8_t buf[256];
+ ssize_t bufSz = pkt.serializePacket(buf, sizeof(buf));
+ if (bufSz >= 0) {
+ char dstEPStr[64];
+ sockaddrToString(mMasterElectionEP, true, dstEPStr, sizeof(dstEPStr));
+ mElectionLog.log("TXing Master announcement to %s while in state %s. "
+ "ourTID %016llx ourGID %016llx ourDID %016llx "
+ "ourPrio %u",
+ dstEPStr, stateToString(mState),
+ mTimelineID, mSyncGroupID,
+ pkt.deviceID, pkt.devicePriority);
+
+ ssize_t sendBytes = sendto(
+ mSocket, buf, bufSz, 0,
+ reinterpret_cast<const sockaddr *>(&mMasterElectionEP),
+ sizeof(mMasterElectionEP));
+ if (sendBytes < 0)
+ ALOGE("MasterAnnouncement sendto failed (errno %d)", errno);
+ ret = true;
+ }
+
+ mCurTimeout.setTimeout(mMasterAnnounceIntervalMs);
+ return ret;
+}
+
+bool CommonTimeServer::becomeClient(const sockaddr_storage& masterEP,
+ uint64_t masterDeviceID,
+ uint8_t masterDevicePriority,
+ uint64_t timelineID,
+ const char* cause) {
+ char newEPStr[64], oldEPStr[64];
+ sockaddrToString(masterEP, true, newEPStr, sizeof(newEPStr));
+ sockaddrToString(mMasterEP, mMasterEPValid, oldEPStr, sizeof(oldEPStr));
+
+ mStateChangeLog.log(ANDROID_LOG_INFO, LOG_TAG,
+ "%s --> CLIENT (%s) :%s"
+ " OldMaster: %02x-%014llx::%016llx::%s"
+ " NewMaster: %02x-%014llx::%016llx::%s",
+ stateToString(mState), cause,
+ (mTimelineID != timelineID) ? " (new timeline)" : "",
+ mClient_MasterDevicePriority, mClient_MasterDeviceID,
+ mTimelineID, oldEPStr,
+ masterDevicePriority, masterDeviceID,
+ timelineID, newEPStr);
+
+ if (mTimelineID != timelineID) {
+ // start following a new timeline
+ mTimelineID = timelineID;
+ mClockRecovery.reset(true, true);
+ notifyClockSyncLoss();
+ } else {
+ // start following a new master on the existing timeline
+ mClockRecovery.reset(false, true);
+ }
+
+ mMasterEP = masterEP;
+ mMasterEPValid = true;
+
+ // If we are on a real network as a client of a real master, then we should
+ // no longer force low priority. If our master disappears, we should have
+ // the high priority bit set during the election to replace the master
+ // because this group was a real group and not a singleton created in
+ // networkless mode.
+ setForceLowPriority(false);
+
+ mClient_MasterDeviceID = masterDeviceID;
+ mClient_MasterDevicePriority = masterDevicePriority;
+ resetSyncStats();
+
+ setState(ICommonClock::STATE_CLIENT);
+
+ // add some jitter to when the various clients send their requests
+ // in order to reduce the likelihood that a group of clients overload
+ // the master after receiving a master announcement
+ usleep((lrand48() % 100) * 1000);
+
+ return sendSyncRequest();
+}
+
+bool CommonTimeServer::becomeMaster(const char* cause) {
+ uint64_t oldTimelineID = mTimelineID;
+ if (mTimelineID == ICommonClock::kInvalidTimelineID) {
+ // this device has not been following any existing timeline,
+ // so it will create a new timeline and declare itself master
+ assert(!mCommonClock.isValid());
+
+ // set the common time basis
+ mCommonClock.setBasis(mLocalClock.getLocalTime(), 0);
+
+ // assign an arbitrary timeline iD
+ assignTimelineID();
+
+ // notify listeners that we've created a common timeline
+ notifyClockSync();
+ }
+
+ mStateChangeLog.log(ANDROID_LOG_INFO, LOG_TAG,
+ "%s --> MASTER (%s) : %s timeline %016llx",
+ stateToString(mState), cause,
+ (oldTimelineID == mTimelineID) ? "taking ownership of"
+ : "creating new",
+ mTimelineID);
+
+ memset(&mMasterEP, 0, sizeof(mMasterEP));
+ mMasterEPValid = false;
+ mClient_MasterDevicePriority = effectivePriority();
+ mClient_MasterDeviceID = mDeviceID;
+ mClockRecovery.reset(false, true);
+ resetSyncStats();
+
+ setState(ICommonClock::STATE_MASTER);
+ return sendMasterAnnouncement();
+}
+
+bool CommonTimeServer::becomeRonin(const char* cause) {
+ // If we were the client of a given timeline, but had never received even a
+ // single time sync packet, then we transition back to Initial instead of
+ // Ronin. If we transition to Ronin and end up becoming the new Master, we
+ // will be unable to service requests for other clients because we never
+ // actually knew what time it was. By going to initial, we ensure that
+ // other clients who know what time it is, but would lose master arbitration
+ // in the Ronin case, will step up and become the proper new master of the
+ // old timeline.
+
+ char oldEPStr[64];
+ sockaddrToString(mMasterEP, mMasterEPValid, oldEPStr, sizeof(oldEPStr));
+ memset(&mMasterEP, 0, sizeof(mMasterEP));
+ mMasterEPValid = false;
+
+ if (mCommonClock.isValid()) {
+ mStateChangeLog.log(ANDROID_LOG_INFO, LOG_TAG,
+ "%s --> RONIN (%s) : lost track of previously valid timeline "
+ "%02x-%014llx::%016llx::%s (%d TXed %d RXed %d RXExpired)",
+ stateToString(mState), cause,
+ mClient_MasterDevicePriority, mClient_MasterDeviceID,
+ mTimelineID, oldEPStr,
+ mClient_SyncsSentToCurMaster,
+ mClient_SyncRespsRXedFromCurMaster,
+ mClient_ExpiredSyncRespsRXedFromCurMaster);
+
+ mRonin_WhoIsMasterRequestTimeouts = 0;
+ setState(ICommonClock::STATE_RONIN);
+ return sendWhoIsMasterRequest();
+ } else {
+ mStateChangeLog.log(ANDROID_LOG_INFO, LOG_TAG,
+ "%s --> INITIAL (%s) : never synced timeline "
+ "%02x-%014llx::%016llx::%s (%d TXed %d RXed %d RXExpired)",
+ stateToString(mState), cause,
+ mClient_MasterDevicePriority, mClient_MasterDeviceID,
+ mTimelineID, oldEPStr,
+ mClient_SyncsSentToCurMaster,
+ mClient_SyncRespsRXedFromCurMaster,
+ mClient_ExpiredSyncRespsRXedFromCurMaster);
+
+ return becomeInitial("ronin, no timeline");
+ }
+}
+
+bool CommonTimeServer::becomeWaitForElection(const char* cause) {
+ mStateChangeLog.log(ANDROID_LOG_INFO, LOG_TAG,
+ "%s --> WAIT_FOR_ELECTION (%s) : dropping out of election,"
+ " waiting %d mSec for completion.",
+ stateToString(mState), cause, kWaitForElection_TimeoutMs);
+
+ setState(ICommonClock::STATE_WAIT_FOR_ELECTION);
+ mCurTimeout.setTimeout(kWaitForElection_TimeoutMs);
+ return true;
+}
+
+bool CommonTimeServer::becomeInitial(const char* cause) {
+ mStateChangeLog.log(ANDROID_LOG_INFO, LOG_TAG,
+ "Entering INITIAL (%s), total reset.",
+ cause);
+
+ setState(ICommonClock::STATE_INITIAL);
+
+ // reset clock recovery
+ mClockRecovery.reset(true, true);
+
+ // reset internal state bookkeeping.
+ mCurTimeout.setTimeout(kInfiniteTimeout);
+ memset(&mMasterEP, 0, sizeof(mMasterEP));
+ mMasterEPValid = false;
+ mLastPacketRxLocalTime = 0;
+ mTimelineID = ICommonClock::kInvalidTimelineID;
+ mClockSynced = false;
+ mInitial_WhoIsMasterRequestTimeouts = 0;
+ mClient_MasterDeviceID = 0;
+ mClient_MasterDevicePriority = 0;
+ mRonin_WhoIsMasterRequestTimeouts = 0;
+ resetSyncStats();
+
+ // send the first request to discover the master
+ return sendWhoIsMasterRequest();
+}
+
+void CommonTimeServer::notifyClockSync() {
+ if (!mClockSynced) {
+ mClockSynced = true;
+ mICommonClock->notifyOnTimelineChanged(mTimelineID);
+ }
+}
+
+void CommonTimeServer::notifyClockSyncLoss() {
+ if (mClockSynced) {
+ mClockSynced = false;
+ mICommonClock->notifyOnTimelineChanged(
+ ICommonClock::kInvalidTimelineID);
+ }
+}
+
+void CommonTimeServer::setState(ICommonClock::State s) {
+ mState = s;
+}
+
+const char* CommonTimeServer::stateToString(ICommonClock::State s) {
+ switch(s) {
+ case ICommonClock::STATE_INITIAL:
+ return "INITIAL";
+ case ICommonClock::STATE_CLIENT:
+ return "CLIENT";
+ case ICommonClock::STATE_MASTER:
+ return "MASTER";
+ case ICommonClock::STATE_RONIN:
+ return "RONIN";
+ case ICommonClock::STATE_WAIT_FOR_ELECTION:
+ return "WAIT_FOR_ELECTION";
+ default:
+ return "unknown";
+ }
+}
+
+void CommonTimeServer::sockaddrToString(const sockaddr_storage& addr,
+ bool addrValid,
+ char* buf, size_t bufLen) {
+ if (!bufLen || !buf)
+ return;
+
+ if (addrValid) {
+ switch (addr.ss_family) {
+ case AF_INET: {
+ const struct sockaddr_in* sa =
+ reinterpret_cast<const struct sockaddr_in*>(&addr);
+ unsigned long a = ntohl(sa->sin_addr.s_addr);
+ uint16_t p = ntohs(sa->sin_port);
+ snprintf(buf, bufLen, "%lu.%lu.%lu.%lu:%hu",
+ ((a >> 24) & 0xFF), ((a >> 16) & 0xFF),
+ ((a >> 8) & 0xFF), (a & 0xFF), p);
+ } break;
+
+ case AF_INET6: {
+ const struct sockaddr_in6* sa =
+ reinterpret_cast<const struct sockaddr_in6*>(&addr);
+ const uint8_t* a = sa->sin6_addr.s6_addr;
+ uint16_t p = ntohs(sa->sin6_port);
+ snprintf(buf, bufLen,
+ "%02X%02X:%02X%02X:%02X%02X:%02X%02X:"
+ "%02X%02X:%02X%02X:%02X%02X:%02X%02X port %hd",
+ a[0], a[1], a[ 2], a[ 3], a[ 4], a[ 5], a[ 6], a[ 7],
+ a[8], a[9], a[10], a[11], a[12], a[13], a[14], a[15],
+ p);
+ } break;
+
+ default:
+ snprintf(buf, bufLen,
+ "<unknown sockaddr family %d>", addr.ss_family);
+ break;
+ }
+ } else {
+ snprintf(buf, bufLen, "<none>");
+ }
+
+ buf[bufLen - 1] = 0;
+}
+
+bool CommonTimeServer::sockaddrMatch(const sockaddr_storage& a1,
+ const sockaddr_storage& a2,
+ bool matchAddressOnly) {
+ if (a1.ss_family != a2.ss_family)
+ return false;
+
+ switch (a1.ss_family) {
+ case AF_INET: {
+ const struct sockaddr_in* sa1 =
+ reinterpret_cast<const struct sockaddr_in*>(&a1);
+ const struct sockaddr_in* sa2 =
+ reinterpret_cast<const struct sockaddr_in*>(&a2);
+
+ if (sa1->sin_addr.s_addr != sa2->sin_addr.s_addr)
+ return false;
+
+ return (matchAddressOnly || (sa1->sin_port == sa2->sin_port));
+ } break;
+
+ case AF_INET6: {
+ const struct sockaddr_in6* sa1 =
+ reinterpret_cast<const struct sockaddr_in6*>(&a1);
+ const struct sockaddr_in6* sa2 =
+ reinterpret_cast<const struct sockaddr_in6*>(&a2);
+
+ if (memcmp(&sa1->sin6_addr, &sa2->sin6_addr, sizeof(sa2->sin6_addr)))
+ return false;
+
+ return (matchAddressOnly || (sa1->sin6_port == sa2->sin6_port));
+ } break;
+
+ // Huh? We don't deal in non-IPv[46] addresses. Not sure how we got
+ // here, but we don't know how to comapre these addresses and simply
+ // default to a no-match decision.
+ default: return false;
+ }
+}
+
+bool CommonTimeServer::shouldPanicNotGettingGoodData() {
+ if (mClient_FirstSyncTX) {
+ int64_t now = mLocalClock.getLocalTime();
+ int64_t delta = now - (mClient_LastGoodSyncRX
+ ? mClient_LastGoodSyncRX
+ : mClient_FirstSyncTX);
+ int64_t deltaUsec = mCommonClock.localDurationToCommonDuration(delta);
+
+ if (deltaUsec >= kNoGoodDataPanicThresholdUsec)
+ return true;
+ }
+
+ return false;
+}
+
+void CommonTimeServer::PacketRTTLog::logTX(int64_t txTime) {
+ txTimes[wrPtr] = txTime;
+ rxTimes[wrPtr] = 0;
+ wrPtr = (wrPtr + 1) % RTT_LOG_SIZE;
+ if (!wrPtr)
+ logFull = true;
+}
+
+void CommonTimeServer::PacketRTTLog::logRX(int64_t txTime, int64_t rxTime) {
+ if (!logFull && !wrPtr)
+ return;
+
+ uint32_t i = logFull ? wrPtr : 0;
+ do {
+ if (txTimes[i] == txTime) {
+ rxTimes[i] = rxTime;
+ break;
+ }
+ i = (i + 1) % RTT_LOG_SIZE;
+ } while (i != wrPtr);
+}
+
+} // namespace android
generated by cgit v1.1 at 2025-08-15 14:45:29 +0000