netwerk/protocol/http/nsHttpConnection.cpp
author Bevis Tseng <btseng@mozilla.com>
Wed, 14 Jun 2017 09:27:17 +0800
changeset 364864 89963ba78c353b23feab0042ebe264049f8d4533
parent 361907 d0a62851c33d0ca77d986654d1d9aa201eb8852a
child 364866 9846de3bd9545fb2c2b803a36af85568ccf2473b
permissions -rw-r--r--
Bug 1372453 - Part 2: Name the caller of ProxyReleaseEvent. r=billm MozReview-Commit-ID: LYhSWnZkq0i

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* vim:set ts=4 sw=4 sts=4 et cin: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

// HttpLog.h should generally be included first
#include "HttpLog.h"

// Log on level :5, instead of default :4.
#undef LOG
#define LOG(args) LOG5(args)
#undef LOG_ENABLED
#define LOG_ENABLED() LOG5_ENABLED()

#define TLS_EARLY_DATA_NOT_AVAILABLE 0
#define TLS_EARLY_DATA_AVAILABLE_BUT_NOT_USED 1
#define TLS_EARLY_DATA_AVAILABLE_AND_USED 2

#include "ASpdySession.h"
#include "mozilla/ChaosMode.h"
#include "mozilla/Telemetry.h"
#include "nsHttpConnection.h"
#include "nsHttpHandler.h"
#include "nsHttpRequestHead.h"
#include "nsHttpResponseHead.h"
#include "nsIOService.h"
#include "nsISocketTransport.h"
#include "nsSocketTransportService2.h"
#include "nsISSLSocketControl.h"
#include "nsISupportsPriority.h"
#include "nsPreloadedStream.h"
#include "nsProxyRelease.h"
#include "nsSocketTransport2.h"
#include "nsStringStream.h"
#include "sslt.h"
#include "TunnelUtils.h"
#include "TCPFastOpenLayer.h"

namespace mozilla {
namespace net {

//-----------------------------------------------------------------------------
// nsHttpConnection <public>
//-----------------------------------------------------------------------------

nsHttpConnection::nsHttpConnection()
    : mTransaction(nullptr)
    , mHttpHandler(gHttpHandler)
    , mCallbacksLock("nsHttpConnection::mCallbacksLock")
    , mConsiderReusedAfterInterval(0)
    , mConsiderReusedAfterEpoch(0)
    , mCurrentBytesRead(0)
    , mMaxBytesRead(0)
    , mTotalBytesRead(0)
    , mTotalBytesWritten(0)
    , mContentBytesWritten(0)
    , mConnectedTransport(false)
    , mKeepAlive(true) // assume to keep-alive by default
    , mKeepAliveMask(true)
    , mDontReuse(false)
    , mIsReused(false)
    , mCompletedProxyConnect(false)
    , mLastTransactionExpectedNoContent(false)
    , mIdleMonitoring(false)
    , mProxyConnectInProgress(false)
    , mExperienced(false)
    , mInSpdyTunnel(false)
    , mForcePlainText(false)
    , mTrafficStamp(false)
    , mHttp1xTransactionCount(0)
    , mRemainingConnectionUses(0xffffffff)
    , mNPNComplete(false)
    , mSetupSSLCalled(false)
    , mUsingSpdyVersion(0)
    , mPriority(nsISupportsPriority::PRIORITY_NORMAL)
    , mReportedSpdy(false)
    , mEverUsedSpdy(false)
    , mLastHttpResponseVersion(NS_HTTP_VERSION_1_1)
    , mTransactionCaps(0)
    , mResponseTimeoutEnabled(false)
    , mTCPKeepaliveConfig(kTCPKeepaliveDisabled)
    , mForceSendPending(false)
    , m0RTTChecked(false)
    , mWaitingFor0RTTResponse(false)
    , mContentBytesWritten0RTT(0)
    , mEarlyDataNegotiated(false)
    , mDid0RTTSpdy(false)
    , mFastOpen(false)
    , mFastOpenStatus(TFO_NOT_TRIED)
    , mForceSendDuringFastOpenPending(false)
    , mReceivedSocketWouldBlockDuringFastOpen(false)
{
    LOG(("Creating nsHttpConnection @%p\n", this));

    // the default timeout is for when this connection has not yet processed a
    // transaction
    static const PRIntervalTime k5Sec = PR_SecondsToInterval(5);
    mIdleTimeout =
        (k5Sec < gHttpHandler->IdleTimeout()) ? k5Sec : gHttpHandler->IdleTimeout();
}

nsHttpConnection::~nsHttpConnection()
{
    LOG(("Destroying nsHttpConnection @%p\n", this));

    if (!mEverUsedSpdy) {
        LOG(("nsHttpConnection %p performed %d HTTP/1.x transactions\n",
             this, mHttp1xTransactionCount));
        Telemetry::Accumulate(Telemetry::HTTP_REQUEST_PER_CONN,
                              mHttp1xTransactionCount);
    }

    if (mTotalBytesRead) {
        uint32_t totalKBRead = static_cast<uint32_t>(mTotalBytesRead >> 10);
        LOG(("nsHttpConnection %p read %dkb on connection spdy=%d\n",
             this, totalKBRead, mEverUsedSpdy));
        Telemetry::Accumulate(mEverUsedSpdy ?
                              Telemetry::SPDY_KBREAD_PER_CONN :
                              Telemetry::HTTP_KBREAD_PER_CONN,
                              totalKBRead);
    }
    if (mForceSendTimer) {
        mForceSendTimer->Cancel();
        mForceSendTimer = nullptr;
    }

    Telemetry::Accumulate(Telemetry::TCP_FAST_OPEN, mFastOpenStatus);
}

nsresult
nsHttpConnection::Init(nsHttpConnectionInfo *info,
                       uint16_t maxHangTime,
                       nsISocketTransport *transport,
                       nsIAsyncInputStream *instream,
                       nsIAsyncOutputStream *outstream,
                       bool connectedTransport,
                       nsIInterfaceRequestor *callbacks,
                       PRIntervalTime rtt)
{
    LOG(("nsHttpConnection::Init this=%p", this));
    NS_ENSURE_ARG_POINTER(info);
    NS_ENSURE_TRUE(!mConnInfo, NS_ERROR_ALREADY_INITIALIZED);

    mConnectedTransport = connectedTransport;
    mConnInfo = info;
    mLastWriteTime = mLastReadTime = PR_IntervalNow();
    mRtt = rtt;
    mMaxHangTime = PR_SecondsToInterval(maxHangTime);

    mSocketTransport = transport;
    mSocketIn = instream;
    mSocketOut = outstream;

    // See explanation for non-strictness of this operation in SetSecurityCallbacks.
    mCallbacks = new nsMainThreadPtrHolder<nsIInterfaceRequestor>(
      "nsHttpConnection::mCallbacks", callbacks, false);

    mSocketTransport->SetEventSink(this, nullptr);
    mSocketTransport->SetSecurityCallbacks(this);

    return NS_OK;
}

nsresult
nsHttpConnection::TryTakeSubTransactions(nsTArray<RefPtr<nsAHttpTransaction> > &list)
{
    nsresult rv = mTransaction->TakeSubTransactions(list);

    if (rv == NS_ERROR_ALREADY_OPENED) {
        // Has the interface for TakeSubTransactions() changed?
        LOG(("TakeSubTransactions somehow called after "
             "nsAHttpTransaction began processing\n"));
        MOZ_ASSERT(false,
                   "TakeSubTransactions somehow called after "
                   "nsAHttpTransaction began processing");
        mTransaction->Close(NS_ERROR_ABORT);
        return rv;
    }

    if (NS_FAILED(rv) && rv != NS_ERROR_NOT_IMPLEMENTED) {
        // Has the interface for TakeSubTransactions() changed?
        LOG(("unexpected rv from nnsAHttpTransaction::TakeSubTransactions()"));
        MOZ_ASSERT(false,
                   "unexpected result from "
                   "nsAHttpTransaction::TakeSubTransactions()");
        mTransaction->Close(NS_ERROR_ABORT);
        return rv;
    }

    return rv;
}

nsresult
nsHttpConnection::MoveTransactionsToSpdy(nsresult status, nsTArray<RefPtr<nsAHttpTransaction> > &list)
{
    if (NS_FAILED(status)) { // includes NS_ERROR_NOT_IMPLEMENTED
        MOZ_ASSERT(list.IsEmpty(), "sub transaction list not empty");

        // This is ok - treat mTransaction as a single real request.
        // Wrap the old http transaction into the new spdy session
        // as the first stream.
        LOG(("nsHttpConnection::MoveTransactionsToSpdy moves single transaction %p "
             "into SpdySession %p\n", mTransaction.get(), mSpdySession.get()));
        nsresult rv = AddTransaction(mTransaction, mPriority);
        if (NS_FAILED(rv)) {
            return rv;
        }
    } else {
        int32_t count = list.Length();

        LOG(("nsHttpConnection::MoveTransactionsToSpdy moving transaction list len=%d "
             "into SpdySession %p\n", count, mSpdySession.get()));

        if (!count) {
            mTransaction->Close(NS_ERROR_ABORT);
            return NS_ERROR_ABORT;
        }

        for (int32_t index = 0; index < count; ++index) {
            nsresult rv = AddTransaction(list[index], mPriority);
            if (NS_FAILED(rv)) {
                return rv;
            }
        }
    }

    return NS_OK;
}

void
nsHttpConnection::Start0RTTSpdy(uint8_t spdyVersion)
{
    LOG(("nsHttpConnection::Start0RTTSpdy [this=%p]", this));
    mDid0RTTSpdy = true;
    mUsingSpdyVersion = spdyVersion;
    mSpdySession = ASpdySession::NewSpdySession(spdyVersion, mSocketTransport,
                                                true);

    nsTArray<RefPtr<nsAHttpTransaction> > list;
    nsresult rv = TryTakeSubTransactions(list);
    if (NS_FAILED(rv) && rv != NS_ERROR_NOT_IMPLEMENTED) {
        LOG(("nsHttpConnection::Start0RTTSpdy [this=%p] failed taking "
             "subtransactions rv=%" PRIx32 , this, static_cast<uint32_t>(rv)));
        return;
    }

    rv = MoveTransactionsToSpdy(rv, list);
    if (NS_FAILED(rv)) {
        LOG(("nsHttpConnection::Start0RTTSpdy [this=%p] failed moving "
             "transactions rv=%" PRIx32 , this, static_cast<uint32_t>(rv)));
        return;
    }

    mTransaction = mSpdySession;
}

void
nsHttpConnection::StartSpdy(uint8_t spdyVersion)
{
    LOG(("nsHttpConnection::StartSpdy [this=%p, mDid0RTTSpdy=%d]\n", this, mDid0RTTSpdy));

    MOZ_ASSERT(!mSpdySession || mDid0RTTSpdy);

    mUsingSpdyVersion = spdyVersion;
    mEverUsedSpdy = true;

    if (!mDid0RTTSpdy) {
        mSpdySession = ASpdySession::NewSpdySession(spdyVersion, mSocketTransport,
                                                    false);
    }

    if (!mReportedSpdy) {
        mReportedSpdy = true;
        gHttpHandler->ConnMgr()->ReportSpdyConnection(this, true);
    }

    // Setting the connection as reused allows some transactions that fail
    // with NS_ERROR_NET_RESET to be restarted and SPDY uses that code
    // to handle clean rejections (such as those that arrived after
    // a server goaway was generated).
    mIsReused = true;

    // If mTransaction is a muxed object it might represent
    // several requests. If so, we need to unpack that and
    // pack them all into a new spdy session.

    nsTArray<RefPtr<nsAHttpTransaction> > list;
    nsresult rv = NS_OK;
    if (!mDid0RTTSpdy) {
        rv = TryTakeSubTransactions(list);

        if (NS_FAILED(rv) && rv != NS_ERROR_NOT_IMPLEMENTED) {
            return;
        }
    }

    if (NeedSpdyTunnel()) {
        LOG3(("nsHttpConnection::StartSpdy %p Connecting To a HTTP/2 "
              "Proxy and Need Connect", this));
        MOZ_ASSERT(mProxyConnectStream);

        mProxyConnectStream = nullptr;
        mCompletedProxyConnect = true;
        mProxyConnectInProgress = false;
    }

    bool spdyProxy = mConnInfo->UsingHttpsProxy() && !mTLSFilter;
    if (spdyProxy) {
        RefPtr<nsHttpConnectionInfo> wildCardProxyCi;
        rv = mConnInfo->CreateWildCard(getter_AddRefs(wildCardProxyCi));
        MOZ_ASSERT(NS_SUCCEEDED(rv));
        gHttpHandler->ConnMgr()->MoveToWildCardConnEntry(mConnInfo,
                                                         wildCardProxyCi, this);
        mConnInfo = wildCardProxyCi;
    }

    if (!mDid0RTTSpdy) {
        rv = MoveTransactionsToSpdy(rv, list);
        if (NS_FAILED(rv)) {
            return;
        }
    }

    // Disable TCP Keepalives - use SPDY ping instead.
    rv = DisableTCPKeepalives();
    if (NS_FAILED(rv)) {
        LOG(("nsHttpConnection::StartSpdy [%p] DisableTCPKeepalives failed "
             "rv[0x%" PRIx32 "]", this, static_cast<uint32_t>(rv)));
    }

    mIdleTimeout = gHttpHandler->SpdyTimeout();

    if (!mTLSFilter) {
        mTransaction = mSpdySession;
    } else {
        rv = mTLSFilter->SetProxiedTransaction(mSpdySession);
        if (NS_FAILED(rv)) {
            LOG(("nsHttpConnection::StartSpdy [%p] SetProxiedTransaction failed"
                 " rv[0x%x]", this, static_cast<uint32_t>(rv)));
        }
    }
    if (mDontReuse) {
        mSpdySession->DontReuse();
    }
}

bool
nsHttpConnection::EnsureNPNComplete(nsresult &aOut0RTTWriteHandshakeValue,
                                    uint32_t &aOut0RTTBytesWritten)
{
    // If for some reason the components to check on NPN aren't available,
    // this function will just return true to continue on and disable SPDY

    aOut0RTTWriteHandshakeValue = NS_OK;
    aOut0RTTBytesWritten = 0;

    MOZ_ASSERT(mSocketTransport);
    if (!mSocketTransport) {
        // this cannot happen
        mNPNComplete = true;
        return true;
    }

    if (mNPNComplete) {
        return true;
    }

    nsresult rv;
    nsCOMPtr<nsISupports> securityInfo;
    nsCOMPtr<nsISSLSocketControl> ssl;
    nsAutoCString negotiatedNPN;

    GetSecurityInfo(getter_AddRefs(securityInfo));
    if (!securityInfo) {
        goto npnComplete;
    }

    ssl = do_QueryInterface(securityInfo, &rv);
    if (NS_FAILED(rv))
        goto npnComplete;

    if (!m0RTTChecked) {
        // We reuse m0RTTChecked. We want to send this status only once.
        mTransaction->OnTransportStatus(mSocketTransport,
                                        NS_NET_STATUS_TLS_HANDSHAKE_STARTING,
                                        0);
    }

    rv = ssl->GetNegotiatedNPN(negotiatedNPN);
    if (!m0RTTChecked && (rv == NS_ERROR_NOT_CONNECTED) &&
        !mConnInfo->UsingProxy()) {
        // There is no ALPN info (yet!). We need to consider doing 0RTT. We
        // will do so if there is ALPN information from a previous session
        // (AlpnEarlySelection), we are using HTTP/1, and the request data can
        // be safely retried.
        m0RTTChecked = true;
        nsresult rvEarlyAlpn = ssl->GetAlpnEarlySelection(mEarlyNegotiatedALPN);
        if (NS_FAILED(rvEarlyAlpn)) {
            // if ssl->DriveHandshake() has never been called the value
            // for AlpnEarlySelection is still not set. So call it here and
            // check again.
            LOG(("nsHttpConnection::EnsureNPNComplete %p - "
                 "early selected alpn not available, we will try one more time.",
                 this));
            // Let's do DriveHandshake again.
            rv = ssl->DriveHandshake();
            if (NS_FAILED(rv) && rv != NS_BASE_STREAM_WOULD_BLOCK) {
                goto npnComplete;
            }

            // Check NegotiatedNPN first.
            rv = ssl->GetNegotiatedNPN(negotiatedNPN);
            if (rv == NS_ERROR_NOT_CONNECTED) {
                rvEarlyAlpn = ssl->GetAlpnEarlySelection(mEarlyNegotiatedALPN);
            }
        }

        if (NS_FAILED(rvEarlyAlpn)) {
            LOG(("nsHttpConnection::EnsureNPNComplete %p - "
                 "early selected alpn not available", this));
            mEarlyDataNegotiated = false;
        } else {
            LOG(("nsHttpConnection::EnsureNPNComplete %p -"
                 "early selected alpn: %s", this, mEarlyNegotiatedALPN.get()));
            uint32_t infoIndex;
            const SpdyInformation *info = gHttpHandler->SpdyInfo();
            if (NS_FAILED(info->GetNPNIndex(mEarlyNegotiatedALPN, &infoIndex))) {
                // This is the HTTP/1 case.
                // Check if early-data is allowed for this transaction.
                if (mTransaction->Do0RTT()) {
                    LOG(("nsHttpConnection::EnsureNPNComplete [this=%p] - We "
                         "can do 0RTT (http/1)!", this));
                    mWaitingFor0RTTResponse = true;
                }
            } else {
                // We have h2, we can at least 0-RTT the preamble and opening
                // SETTINGS, etc, and maybe some of the first request
                LOG(("nsHttpConnection::EnsureNPNComplete [this=%p] - Starting "
                     "0RTT for h2!", this));
                mWaitingFor0RTTResponse = true;
                Start0RTTSpdy(info->Version[infoIndex]);
            }
            mEarlyDataNegotiated = true;
        }
    }

    if (rv == NS_ERROR_NOT_CONNECTED) {
        if (mWaitingFor0RTTResponse) {
            aOut0RTTWriteHandshakeValue = mTransaction->ReadSegments(this,
                nsIOService::gDefaultSegmentSize, &aOut0RTTBytesWritten);
            if (NS_FAILED(aOut0RTTWriteHandshakeValue) &&
                aOut0RTTWriteHandshakeValue != NS_BASE_STREAM_WOULD_BLOCK) {
                goto npnComplete;
            }
            LOG(("nsHttpConnection::EnsureNPNComplete [this=%p] - written %d "
                 "bytes during 0RTT", this, aOut0RTTBytesWritten));
            mContentBytesWritten0RTT += aOut0RTTBytesWritten;
            if (mSocketOutCondition == NS_BASE_STREAM_WOULD_BLOCK) {
                mReceivedSocketWouldBlockDuringFastOpen = true;
            }
        }

        rv = ssl->DriveHandshake();
        if (NS_FAILED(rv) && rv != NS_BASE_STREAM_WOULD_BLOCK) {
            goto npnComplete;
        }

        return false;
    }

    if (NS_SUCCEEDED(rv)) {
        LOG(("nsHttpConnection::EnsureNPNComplete %p [%s] negotiated to '%s'%s\n",
             this, mConnInfo->HashKey().get(), negotiatedNPN.get(),
             mTLSFilter ? " [Double Tunnel]" : ""));

        bool earlyDataAccepted = false;
        if (mWaitingFor0RTTResponse) {
            // Check if early data has been accepted.
            rv = ssl->GetEarlyDataAccepted(&earlyDataAccepted);
            LOG(("nsHttpConnection::EnsureNPNComplete [this=%p] - early data "
                 "that was sent during 0RTT %s been accepted [rv=%" PRIx32 "].",
                 this, earlyDataAccepted ? "has" : "has not", static_cast<uint32_t>(rv)));

            if (NS_FAILED(rv) ||
                NS_FAILED(mTransaction->Finish0RTT(!earlyDataAccepted, negotiatedNPN != mEarlyNegotiatedALPN))) {
                LOG(("nsHttpConection::EnsureNPNComplete [this=%p] closing transaction %p", this, mTransaction.get()));
                mTransaction->Close(NS_ERROR_NET_RESET);
                goto npnComplete;
            }
        }

        int16_t tlsVersion;
        ssl->GetSSLVersionUsed(&tlsVersion);
        // Send the 0RTT telemetry only for tls1.3
        if (tlsVersion > nsISSLSocketControl::TLS_VERSION_1_2) {
            Telemetry::Accumulate(Telemetry::TLS_EARLY_DATA_NEGOTIATED,
                (!mEarlyDataNegotiated) ? TLS_EARLY_DATA_NOT_AVAILABLE
                    : ((mWaitingFor0RTTResponse) ? TLS_EARLY_DATA_AVAILABLE_AND_USED
                                                 : TLS_EARLY_DATA_AVAILABLE_BUT_NOT_USED));
            if (mWaitingFor0RTTResponse) {
                Telemetry::Accumulate(Telemetry::TLS_EARLY_DATA_ACCEPTED,
                                      earlyDataAccepted);
            }
            if (earlyDataAccepted) {
                Telemetry::Accumulate(Telemetry::TLS_EARLY_DATA_BYTES_WRITTEN,
                                      mContentBytesWritten0RTT);
            }
        }
        mWaitingFor0RTTResponse = false;

        if (!earlyDataAccepted) {
            LOG(("nsHttpConnection::EnsureNPNComplete [this=%p] early data not accepted", this));
            uint32_t infoIndex;
            const SpdyInformation *info = gHttpHandler->SpdyInfo();
            if (NS_SUCCEEDED(info->GetNPNIndex(negotiatedNPN, &infoIndex))) {
                StartSpdy(info->Version[infoIndex]);
            }
        } else {
          LOG(("nsHttpConnection::EnsureNPNComplete [this=%p] - %" PRId64 " bytes "
               "has been sent during 0RTT.", this, mContentBytesWritten0RTT));
          mContentBytesWritten = mContentBytesWritten0RTT;
          if (mSpdySession) {
              // We had already started 0RTT-spdy, now we need to fully set up
              // spdy, since we know we're sticking with it.
              LOG(("nsHttpConnection::EnsureNPNComplete [this=%p] - finishing "
                   "StartSpdy for 0rtt spdy session %p", this, mSpdySession.get()));
              StartSpdy(mSpdySession->SpdyVersion());
          }
        }

        Telemetry::Accumulate(Telemetry::SPDY_NPN_CONNECT, UsingSpdy());
    }

npnComplete:
    LOG(("nsHttpConnection::EnsureNPNComplete [this=%p] setting complete to true", this));
    mNPNComplete = true;

    mTransaction->OnTransportStatus(mSocketTransport,
                                    NS_NET_STATUS_TLS_HANDSHAKE_ENDED,
                                    0);
    if (mWaitingFor0RTTResponse) {
        // Didn't get 0RTT OK, back out of the "attempting 0RTT" state
        mWaitingFor0RTTResponse = false;
        LOG(("nsHttpConnection::EnsureNPNComplete [this=%p] 0rtt failed", this));
        if (NS_FAILED(mTransaction->Finish0RTT(true, negotiatedNPN != mEarlyNegotiatedALPN))) {
            mTransaction->Close(NS_ERROR_NET_RESET);
        }
        mContentBytesWritten0RTT = 0;
    }

    if (mDid0RTTSpdy && negotiatedNPN != mEarlyNegotiatedALPN) {
        // Reset the work done by Start0RTTSpdy
        LOG(("nsHttpConnection::EnsureNPNComplete [this=%p] resetting Start0RTTSpdy", this));
        mUsingSpdyVersion = 0;
        mTransaction = nullptr;
        mSpdySession = nullptr;
        // We have to reset this here, just in case we end up starting spdy again,
        // so it can actually do everything it needs to do.
        mDid0RTTSpdy = false;
    }
    return true;
}

void
nsHttpConnection::OnTunnelNudged(TLSFilterTransaction *trans)
{
    MOZ_ASSERT(OnSocketThread(), "not on socket thread");
    LOG(("nsHttpConnection::OnTunnelNudged %p\n", this));
    if (trans != mTLSFilter) {
        return;
    }
    LOG(("nsHttpConnection::OnTunnelNudged %p Calling OnSocketWritable\n", this));
    Unused << OnSocketWritable();
}

// called on the socket thread
nsresult
nsHttpConnection::Activate(nsAHttpTransaction *trans, uint32_t caps, int32_t pri)
{
    MOZ_ASSERT(OnSocketThread(), "not on socket thread");
    LOG(("nsHttpConnection::Activate [this=%p trans=%p caps=%x]\n",
         this, trans, caps));

    if (!trans->IsNullTransaction() && !mFastOpen)
        mExperienced = true;

    mTransactionCaps = caps;
    mPriority = pri;
    if (mTransaction && mUsingSpdyVersion) {
        return AddTransaction(trans, pri);
    }

    NS_ENSURE_ARG_POINTER(trans);
    NS_ENSURE_TRUE(!mTransaction, NS_ERROR_IN_PROGRESS);

    // reset the read timers to wash away any idle time
    mLastWriteTime = mLastReadTime = PR_IntervalNow();

    // Connection failures are Activated() just like regular transacions.
    // If we don't have a confirmation of a connected socket then test it
    // with a write() to get relevant error code.
    if (!mConnectedTransport) {
        uint32_t count;
        mSocketOutCondition = NS_ERROR_FAILURE;
        if (mSocketOut) {
            mSocketOutCondition = mSocketOut->Write("", 0, &count);
        }
        if (NS_FAILED(mSocketOutCondition) &&
            mSocketOutCondition != NS_BASE_STREAM_WOULD_BLOCK) {
            LOG(("nsHttpConnection::Activate [this=%p] Bad Socket %" PRIx32 "\n",
                 this, static_cast<uint32_t>(mSocketOutCondition)));
            mSocketOut->AsyncWait(nullptr, 0, 0, nullptr);
            mTransaction = trans;
            CloseTransaction(mTransaction, mSocketOutCondition);
            return mSocketOutCondition;
        }
    }

    // Update security callbacks
    nsCOMPtr<nsIInterfaceRequestor> callbacks;
    trans->GetSecurityCallbacks(getter_AddRefs(callbacks));
    SetSecurityCallbacks(callbacks);
    SetupSSL();

    // take ownership of the transaction
    mTransaction = trans;

    MOZ_ASSERT(!mIdleMonitoring, "Activating a connection with an Idle Monitor");
    mIdleMonitoring = false;

    // set mKeepAlive according to what will be requested
    mKeepAliveMask = mKeepAlive = (caps & NS_HTTP_ALLOW_KEEPALIVE);

    // need to handle HTTP CONNECT tunnels if this is the first time if
    // we are tunneling through a proxy
    nsresult rv = NS_OK;
    if (mTransaction->ConnectionInfo()->UsingConnect() && !mCompletedProxyConnect) {
        rv = SetupProxyConnect();
        if (NS_FAILED(rv))
            goto failed_activation;
        mProxyConnectInProgress = true;
    }

    // Clear the per activation counter
    mCurrentBytesRead = 0;

    // The overflow state is not needed between activations
    mInputOverflow = nullptr;

    mResponseTimeoutEnabled = gHttpHandler->ResponseTimeoutEnabled() &&
                              mTransaction->ResponseTimeout() > 0 &&
                              mTransaction->ResponseTimeoutEnabled();

    rv = StartShortLivedTCPKeepalives();
    if (NS_FAILED(rv)) {
        LOG(("nsHttpConnection::Activate [%p] "
             "StartShortLivedTCPKeepalives failed rv[0x%" PRIx32 "]",
             this, static_cast<uint32_t>(rv)));
    }

    if (mTLSFilter) {
        rv = mTLSFilter->SetProxiedTransaction(trans);
        NS_ENSURE_SUCCESS(rv, rv);
        mTransaction = mTLSFilter;
    }

    trans->OnActivated(false);

    rv = OnOutputStreamReady(mSocketOut);

failed_activation:
    if (NS_FAILED(rv)) {
        mTransaction = nullptr;
    }

    return rv;
}

void
nsHttpConnection::SetupSSL()
{
    LOG(("nsHttpConnection::SetupSSL %p caps=0x%X %s\n",
         this, mTransactionCaps, mConnInfo->HashKey().get()));

    if (mSetupSSLCalled) // do only once
        return;
    mSetupSSLCalled = true;

    if (mNPNComplete)
        return;

    // we flip this back to false if SetNPNList succeeds at the end
    // of this function
    mNPNComplete = true;

    if (!mConnInfo->FirstHopSSL() || mForcePlainText) {
        return;
    }

    // if we are connected to the proxy with TLS, start the TLS
    // flow immediately without waiting for a CONNECT sequence.
    DebugOnly<nsresult> rv;
    if (mInSpdyTunnel) {
        rv = InitSSLParams(false, true);
    } else {
        bool usingHttpsProxy = mConnInfo->UsingHttpsProxy();
        rv = InitSSLParams(usingHttpsProxy, usingHttpsProxy);
    }
    MOZ_ASSERT(NS_SUCCEEDED(rv));
}

// The naming of NPN is historical - this function creates the basic
// offer list for both NPN and ALPN. ALPN validation callbacks are made
// now before the handshake is complete, and NPN validation callbacks
// are made during the handshake.
nsresult
nsHttpConnection::SetupNPNList(nsISSLSocketControl *ssl, uint32_t caps)
{
    nsTArray<nsCString> protocolArray;

    nsCString npnToken = mConnInfo->GetNPNToken();
    if (npnToken.IsEmpty()) {
        // The first protocol is used as the fallback if none of the
        // protocols supported overlap with the server's list.
        // When using ALPN the advertised preferences are protocolArray indicies
        // {1, .., N, 0} in decreasing order.
        // For NPN, In the case of overlap, matching priority is driven by
        // the order of the server's advertisement - with index 0 used when
        // there is no match.
        protocolArray.AppendElement(NS_LITERAL_CSTRING("http/1.1"));

        if (gHttpHandler->IsSpdyEnabled() &&
            !(caps & NS_HTTP_DISALLOW_SPDY)) {
            LOG(("nsHttpConnection::SetupSSL Allow SPDY NPN selection"));
            const SpdyInformation *info = gHttpHandler->SpdyInfo();
            for (uint32_t index = SpdyInformation::kCount; index > 0; --index) {
                if (info->ProtocolEnabled(index - 1) &&
                    info->ALPNCallbacks[index - 1](ssl)) {
                    protocolArray.AppendElement(info->VersionString[index - 1]);
                }
            }
        }
    } else {
        LOG(("nsHttpConnection::SetupSSL limiting NPN selection to %s",
             npnToken.get()));
        protocolArray.AppendElement(npnToken);
    }

    nsresult rv = ssl->SetNPNList(protocolArray);
    LOG(("nsHttpConnection::SetupNPNList %p %" PRIx32 "\n",
         this, static_cast<uint32_t>(rv)));
    return rv;
}

nsresult
nsHttpConnection::AddTransaction(nsAHttpTransaction *httpTransaction,
                                 int32_t priority)
{
    MOZ_ASSERT(OnSocketThread(), "not on socket thread");
    MOZ_ASSERT(mSpdySession && mUsingSpdyVersion,
               "AddTransaction to live http connection without spdy");

    // If this is a wild card nshttpconnection (i.e. a spdy proxy) then
    // it is important to start the stream using the specific connection
    // info of the transaction to ensure it is routed on the right tunnel

    nsHttpConnectionInfo *transCI = httpTransaction->ConnectionInfo();

    bool needTunnel = transCI->UsingHttpsProxy();
    needTunnel = needTunnel && !mTLSFilter;
    needTunnel = needTunnel && transCI->UsingConnect();
    needTunnel = needTunnel && httpTransaction->QueryHttpTransaction();

    LOG(("nsHttpConnection::AddTransaction for SPDY%s",
         needTunnel ? " over tunnel" : ""));

    if (!mSpdySession->AddStream(httpTransaction, priority,
                                 needTunnel, mCallbacks)) {
        MOZ_ASSERT(false); // this cannot happen!
        httpTransaction->Close(NS_ERROR_ABORT);
        return NS_ERROR_FAILURE;
    }

    Unused << ResumeSend();
    return NS_OK;
}

void
nsHttpConnection::Close(nsresult reason, bool aIsShutdown)
{
    LOG(("nsHttpConnection::Close [this=%p reason=%" PRIx32 "]\n",
         this, static_cast<uint32_t>(reason)));

    MOZ_ASSERT(OnSocketThread(), "not on socket thread");

    // Ensure TCP keepalive timer is stopped.
    if (mTCPKeepaliveTransitionTimer) {
        mTCPKeepaliveTransitionTimer->Cancel();
        mTCPKeepaliveTransitionTimer = nullptr;
    }
    if (mForceSendTimer) {
        mForceSendTimer->Cancel();
        mForceSendTimer = nullptr;
    }

    if (NS_FAILED(reason)) {
        if (mIdleMonitoring)
            EndIdleMonitoring();

        mTLSFilter = nullptr;

        // The connection and security errors clear out alt-svc mappings
        // in case any previously validated ones are now invalid
        if (((reason == NS_ERROR_NET_RESET) ||
             (NS_ERROR_GET_MODULE(reason) == NS_ERROR_MODULE_SECURITY))
            && mConnInfo && !(mTransactionCaps & NS_HTTP_ERROR_SOFTLY)) {
            gHttpHandler->ConnMgr()->ClearHostMapping(mConnInfo);
        }

        if (mSocketTransport) {
            mSocketTransport->SetEventSink(nullptr, nullptr);

            // If there are bytes sitting in the input queue then read them
            // into a junk buffer to avoid generating a tcp rst by closing a
            // socket with data pending. TLS is a classic case of this where
            // a Alert record might be superfulous to a clean HTTP/SPDY shutdown.
            // Never block to do this and limit it to a small amount of data.
            // During shutdown just be fast!
            if (mSocketIn && !aIsShutdown) {
                char buffer[4000];
                uint32_t count, total = 0;
                nsresult rv;
                do {
                    rv = mSocketIn->Read(buffer, 4000, &count);
                    if (NS_SUCCEEDED(rv))
                        total += count;
                }
                while (NS_SUCCEEDED(rv) && count > 0 && total < 64000);
                LOG(("nsHttpConnection::Close drained %d bytes\n", total));
            }

            mSocketTransport->SetSecurityCallbacks(nullptr);
            mSocketTransport->Close(reason);
            if (mSocketOut)
                mSocketOut->AsyncWait(nullptr, 0, 0, nullptr);
        }
        mKeepAlive = false;
    }
}

// called on the socket thread
nsresult
nsHttpConnection::InitSSLParams(bool connectingToProxy, bool proxyStartSSL)
{
    LOG(("nsHttpConnection::InitSSLParams [this=%p] connectingToProxy=%d\n",
         this, connectingToProxy));
    MOZ_ASSERT(OnSocketThread(), "not on socket thread");

    nsresult rv;
    nsCOMPtr<nsISupports> securityInfo;
    GetSecurityInfo(getter_AddRefs(securityInfo));
    if (!securityInfo) {
        return NS_ERROR_FAILURE;
    }

    nsCOMPtr<nsISSLSocketControl> ssl = do_QueryInterface(securityInfo, &rv);
    if (NS_FAILED(rv)){
        return rv;
    }

    if (proxyStartSSL) {
        rv = ssl->ProxyStartSSL();
        if (NS_FAILED(rv)){
            return rv;
        }
    }

    if (NS_SUCCEEDED(SetupNPNList(ssl, mTransactionCaps))) {
        LOG(("InitSSLParams Setting up SPDY Negotiation OK"));
        mNPNComplete = false;
    }

    return NS_OK;
}

void
nsHttpConnection::DontReuse()
{
    LOG(("nsHttpConnection::DontReuse %p spdysession=%p\n", this, mSpdySession.get()));
    mKeepAliveMask = false;
    mKeepAlive = false;
    mDontReuse = true;
    mIdleTimeout = 0;
    if (mSpdySession)
        mSpdySession->DontReuse();
}

bool
nsHttpConnection::TestJoinConnection(const nsACString &hostname, int32_t port)
{
    if (mSpdySession && CanDirectlyActivate()) {
        return mSpdySession->TestJoinConnection(hostname, port);
    }
    return false;
}

bool
nsHttpConnection::JoinConnection(const nsACString &hostname, int32_t port)
{
    if (mSpdySession && CanDirectlyActivate()) {
        return mSpdySession->JoinConnection(hostname, port);
    }
    return false;
}

bool
nsHttpConnection::CanReuse()
{
    if (mDontReuse || !mRemainingConnectionUses) {
        return false;
    }

    if ((mTransaction ? (mTransaction->IsDone() ? 0U : 1U) : 0U) >=
        mRemainingConnectionUses) {
        return false;
    }

    bool canReuse;
    if (mSpdySession) {
        canReuse = mSpdySession->CanReuse();
    } else {
        canReuse = IsKeepAlive();
    }
    canReuse = canReuse && (IdleTime() < mIdleTimeout) && IsAlive();

    // An idle persistent connection should not have data waiting to be read
    // before a request is sent. Data here is likely a 408 timeout response
    // which we would deal with later on through the restart logic, but that
    // path is more expensive than just closing the socket now.

    uint64_t dataSize;
    if (canReuse && mSocketIn && !mUsingSpdyVersion && mHttp1xTransactionCount &&
        NS_SUCCEEDED(mSocketIn->Available(&dataSize)) && dataSize) {
        LOG(("nsHttpConnection::CanReuse %p %s"
             "Socket not reusable because read data pending (%" PRIu64 ") on it.\n",
             this, mConnInfo->Origin(), dataSize));
        canReuse = false;
    }
    return canReuse;
}

bool
nsHttpConnection::CanDirectlyActivate()
{
    // return true if a new transaction can be addded to ths connection at any
    // time through Activate(). In practice this means this is a healthy SPDY
    // connection with room for more concurrent streams.

    return UsingSpdy() && CanReuse() &&
        mSpdySession && mSpdySession->RoomForMoreStreams();
}

PRIntervalTime
nsHttpConnection::IdleTime()
{
    return mSpdySession ?
        mSpdySession->IdleTime() : (PR_IntervalNow() - mLastReadTime);
}

// returns the number of seconds left before the allowable idle period
// expires, or 0 if the period has already expied.
uint32_t
nsHttpConnection::TimeToLive()
{
    if (IdleTime() >= mIdleTimeout)
        return 0;
    uint32_t timeToLive = PR_IntervalToSeconds(mIdleTimeout - IdleTime());

    // a positive amount of time can be rounded to 0. Because 0 is used
    // as the expiration signal, round all values from 0 to 1 up to 1.
    if (!timeToLive)
        timeToLive = 1;
    return timeToLive;
}

bool
nsHttpConnection::IsAlive()
{
    if (!mSocketTransport || !mConnectedTransport)
        return false;

    // SocketTransport::IsAlive can run the SSL state machine, so make sure
    // the NPN options are set before that happens.
    SetupSSL();

    bool alive;
    nsresult rv = mSocketTransport->IsAlive(&alive);
    if (NS_FAILED(rv))
        alive = false;

//#define TEST_RESTART_LOGIC
#ifdef TEST_RESTART_LOGIC
    if (!alive) {
        LOG(("pretending socket is still alive to test restart logic\n"));
        alive = true;
    }
#endif

    return alive;
}

//----------------------------------------------------------------------------
// nsHttpConnection::nsAHttpConnection compatible methods
//----------------------------------------------------------------------------

nsresult
nsHttpConnection::OnHeadersAvailable(nsAHttpTransaction *trans,
                                     nsHttpRequestHead *requestHead,
                                     nsHttpResponseHead *responseHead,
                                     bool *reset)
{
    LOG(("nsHttpConnection::OnHeadersAvailable [this=%p trans=%p response-head=%p]\n",
        this, trans, responseHead));

    MOZ_ASSERT(OnSocketThread(), "not on socket thread");
    NS_ENSURE_ARG_POINTER(trans);
    MOZ_ASSERT(responseHead, "No response head?");

    if (mInSpdyTunnel) {
        DebugOnly<nsresult> rv =
            responseHead->SetHeader(nsHttp::X_Firefox_Spdy_Proxy,
                                    NS_LITERAL_CSTRING("true"));
        MOZ_ASSERT(NS_SUCCEEDED(rv));
    }

    // we won't change our keep-alive policy unless the server has explicitly
    // told us to do so.

    // inspect the connection headers for keep-alive info provided the
    // transaction completed successfully. In the case of a non-sensical close
    // and keep-alive favor the close out of conservatism.

    bool explicitKeepAlive = false;
    bool explicitClose = responseHead->HasHeaderValue(nsHttp::Connection, "close") ||
        responseHead->HasHeaderValue(nsHttp::Proxy_Connection, "close");
    if (!explicitClose)
        explicitKeepAlive = responseHead->HasHeaderValue(nsHttp::Connection, "keep-alive") ||
            responseHead->HasHeaderValue(nsHttp::Proxy_Connection, "keep-alive");

    // deal with 408 Server Timeouts
    uint16_t responseStatus = responseHead->Status();
    static const PRIntervalTime k1000ms  = PR_MillisecondsToInterval(1000);
    if (responseStatus == 408) {
        // If this error could be due to a persistent connection reuse then
        // we pass an error code of NS_ERROR_NET_RESET to
        // trigger the transaction 'restart' mechanism.  We tell it to reset its
        // response headers so that it will be ready to receive the new response.
        if (mIsReused && ((PR_IntervalNow() - mLastWriteTime) < k1000ms)) {
            Close(NS_ERROR_NET_RESET);
            *reset = true;
            return NS_OK;
        }

        // timeouts that are not caused by persistent connection reuse should
        // not be retried for browser compatibility reasons. bug 907800. The
        // server driven close is implicit in the 408.
        explicitClose = true;
        explicitKeepAlive = false;
    }

    if ((responseHead->Version() < NS_HTTP_VERSION_1_1) ||
        (requestHead->Version() < NS_HTTP_VERSION_1_1)) {
        // HTTP/1.0 connections are by default NOT persistent
        if (explicitKeepAlive)
            mKeepAlive = true;
        else
            mKeepAlive = false;
    }
    else {
        // HTTP/1.1 connections are by default persistent
        mKeepAlive = !explicitClose;
    }
    mKeepAliveMask = mKeepAlive;

    // if this connection is persistent, then the server may send a "Keep-Alive"
    // header specifying the maximum number of times the connection can be
    // reused as well as the maximum amount of time the connection can be idle
    // before the server will close it.  we ignore the max reuse count, because
    // a "keep-alive" connection is by definition capable of being reused, and
    // we only care about being able to reuse it once.  if a timeout is not
    // specified then we use our advertized timeout value.
    bool foundKeepAliveMax = false;
    if (mKeepAlive) {
        nsAutoCString keepAlive;
        Unused << responseHead->GetHeader(nsHttp::Keep_Alive, keepAlive);

        if (!mUsingSpdyVersion) {
            const char *cp = PL_strcasestr(keepAlive.get(), "timeout=");
            if (cp)
                mIdleTimeout = PR_SecondsToInterval((uint32_t) atoi(cp + 8));
            else
                mIdleTimeout = gHttpHandler->IdleTimeout();

            cp = PL_strcasestr(keepAlive.get(), "max=");
            if (cp) {
                int maxUses = atoi(cp + 4);
                if (maxUses > 0) {
                    foundKeepAliveMax = true;
                    mRemainingConnectionUses = static_cast<uint32_t>(maxUses);
                }
            }
        }
        else {
            mIdleTimeout = gHttpHandler->SpdyTimeout();
        }

        LOG(("Connection can be reused [this=%p idle-timeout=%usec]\n",
             this, PR_IntervalToSeconds(mIdleTimeout)));
    }

    if (!foundKeepAliveMax && mRemainingConnectionUses && !mUsingSpdyVersion)
        --mRemainingConnectionUses;

    // If we're doing a proxy connect, we need to check whether or not
    // it was successful.  If so, we have to reset the transaction and step-up
    // the socket connection if using SSL. Finally, we have to wake up the
    // socket write request.
    if (mProxyConnectStream) {
        MOZ_ASSERT(!mUsingSpdyVersion,
                   "SPDY NPN Complete while using proxy connect stream");
        mProxyConnectStream = nullptr;
        bool isHttps =
            mTransaction ? mTransaction->ConnectionInfo()->EndToEndSSL() :
            mConnInfo->EndToEndSSL();

        if (responseStatus == 200) {
            LOG(("proxy CONNECT succeeded! endtoendssl=%d\n", isHttps));
            *reset = true;
            nsresult rv;
            if (isHttps) {
                if (mConnInfo->UsingHttpsProxy()) {
                    LOG(("%p new TLSFilterTransaction %s %d\n",
                         this, mConnInfo->Origin(), mConnInfo->OriginPort()));
                    SetupSecondaryTLS();
                }

                rv = InitSSLParams(false, true);
                LOG(("InitSSLParams [rv=%" PRIx32 "]\n", static_cast<uint32_t>(rv)));
            }
            mCompletedProxyConnect = true;
            mProxyConnectInProgress = false;
            rv = mSocketOut->AsyncWait(this, 0, 0, nullptr);
            // XXX what if this fails -- need to handle this error
            MOZ_ASSERT(NS_SUCCEEDED(rv), "mSocketOut->AsyncWait failed");
        }
        else {
            LOG(("proxy CONNECT failed! endtoendssl=%d\n", isHttps));
            mTransaction->SetProxyConnectFailed();
        }
    }

    nsAutoCString upgradeReq;
    bool hasUpgradeReq = NS_SUCCEEDED(requestHead->GetHeader(nsHttp::Upgrade,
                                                             upgradeReq));
    // Don't use persistent connection for Upgrade unless there's an auth failure:
    // some proxies expect to see auth response on persistent connection.
    if (hasUpgradeReq && responseStatus != 401 && responseStatus != 407) {
        LOG(("HTTP Upgrade in play - disable keepalive\n"));
        DontReuse();
    }

    if (responseStatus == 101) {
        nsAutoCString upgradeResp;
        bool hasUpgradeResp = NS_SUCCEEDED(responseHead->GetHeader(
                                                nsHttp::Upgrade,
                                                upgradeResp));
        if (!hasUpgradeReq || !hasUpgradeResp ||
            !nsHttp::FindToken(upgradeResp.get(), upgradeReq.get(),
                               HTTP_HEADER_VALUE_SEPS)) {
            LOG(("HTTP 101 Upgrade header mismatch req = %s, resp = %s\n",
                 upgradeReq.get(),
                 !upgradeResp.IsEmpty() ? upgradeResp.get() :
                     "RESPONSE's nsHttp::Upgrade is empty"));
            Close(NS_ERROR_ABORT);
        }
        else {
            LOG(("HTTP Upgrade Response to %s\n", upgradeResp.get()));
        }
    }

    mLastHttpResponseVersion = responseHead->Version();

    return NS_OK;
}

bool
nsHttpConnection::IsReused()
{
    if (mIsReused)
        return true;
    if (!mConsiderReusedAfterInterval)
        return false;

    // ReusedAfter allows a socket to be consider reused only after a certain
    // interval of time has passed
    return (PR_IntervalNow() - mConsiderReusedAfterEpoch) >=
        mConsiderReusedAfterInterval;
}

void
nsHttpConnection::SetIsReusedAfter(uint32_t afterMilliseconds)
{
    mConsiderReusedAfterEpoch = PR_IntervalNow();
    mConsiderReusedAfterInterval = PR_MillisecondsToInterval(afterMilliseconds);
}

nsresult
nsHttpConnection::TakeTransport(nsISocketTransport  **aTransport,
                                nsIAsyncInputStream **aInputStream,
                                nsIAsyncOutputStream **aOutputStream)
{
    if (mUsingSpdyVersion)
        return NS_ERROR_FAILURE;
    if (mTransaction && !mTransaction->IsDone())
        return NS_ERROR_IN_PROGRESS;
    if (!(mSocketTransport && mSocketIn && mSocketOut))
        return NS_ERROR_NOT_INITIALIZED;

    if (mInputOverflow)
        mSocketIn = mInputOverflow.forget();

    // Change TCP Keepalive frequency to long-lived if currently short-lived.
    if (mTCPKeepaliveConfig == kTCPKeepaliveShortLivedConfig) {
        if (mTCPKeepaliveTransitionTimer) {
            mTCPKeepaliveTransitionTimer->Cancel();
            mTCPKeepaliveTransitionTimer = nullptr;
        }
        nsresult rv = StartLongLivedTCPKeepalives();
        LOG(("nsHttpConnection::TakeTransport [%p] calling "
             "StartLongLivedTCPKeepalives", this));
        if (NS_FAILED(rv)) {
            LOG(("nsHttpConnection::TakeTransport [%p] "
                 "StartLongLivedTCPKeepalives failed rv[0x%" PRIx32 "]",
                 this, static_cast<uint32_t>(rv)));
        }
    }

    mSocketTransport->SetSecurityCallbacks(nullptr);
    mSocketTransport->SetEventSink(nullptr, nullptr);

    // The nsHttpConnection will go away soon, so if there is a TLS Filter
    // being used (e.g. for wss CONNECT tunnel from a proxy connected to
    // via https) that filter needs to take direct control of the
    // streams
    if (mTLSFilter) {
        nsCOMPtr<nsIAsyncInputStream>  ref1(mSocketIn);
        nsCOMPtr<nsIAsyncOutputStream> ref2(mSocketOut);
        mTLSFilter->newIODriver(ref1, ref2,
                                getter_AddRefs(mSocketIn),
                                getter_AddRefs(mSocketOut));
        mTLSFilter = nullptr;
    }

    mSocketTransport.forget(aTransport);
    mSocketIn.forget(aInputStream);
    mSocketOut.forget(aOutputStream);

    return NS_OK;
}

uint32_t
nsHttpConnection::ReadTimeoutTick(PRIntervalTime now)
{
    MOZ_ASSERT(OnSocketThread(), "not on socket thread");

    // make sure timer didn't tick before Activate()
    if (!mTransaction)
        return UINT32_MAX;

    // Spdy implements some timeout handling using the SPDY ping frame.
    if (mSpdySession) {
        return mSpdySession->ReadTimeoutTick(now);
    }

    uint32_t nextTickAfter = UINT32_MAX;
    // Timeout if the response is taking too long to arrive.
    if (mResponseTimeoutEnabled) {
        NS_WARNING_ASSERTION(
            gHttpHandler->ResponseTimeoutEnabled(),
            "Timing out a response, but response timeout is disabled!");

        PRIntervalTime initialResponseDelta = now - mLastWriteTime;

        if (initialResponseDelta > mTransaction->ResponseTimeout()) {
            LOG(("canceling transaction: no response for %ums: timeout is %dms\n",
                 PR_IntervalToMilliseconds(initialResponseDelta),
                 PR_IntervalToMilliseconds(mTransaction->ResponseTimeout())));

            mResponseTimeoutEnabled = false;

            // This will also close the connection
            CloseTransaction(mTransaction, NS_ERROR_NET_TIMEOUT);
            return UINT32_MAX;
        }
        nextTickAfter = PR_IntervalToSeconds(mTransaction->ResponseTimeout()) -
                        PR_IntervalToSeconds(initialResponseDelta);
        nextTickAfter = std::max(nextTickAfter, 1U);
    }

    return nextTickAfter;
}

void
nsHttpConnection::UpdateTCPKeepalive(nsITimer *aTimer, void *aClosure)
{
    MOZ_ASSERT(aTimer);
    MOZ_ASSERT(aClosure);

    nsHttpConnection *self = static_cast<nsHttpConnection*>(aClosure);

    if (NS_WARN_IF(self->mUsingSpdyVersion)) {
        return;
    }

    // Do not reduce keepalive probe frequency for idle connections.
    if (self->mIdleMonitoring) {
        return;
    }

    nsresult rv = self->StartLongLivedTCPKeepalives();
    if (NS_FAILED(rv)) {
        LOG(("nsHttpConnection::UpdateTCPKeepalive [%p] "
             "StartLongLivedTCPKeepalives failed rv[0x%" PRIx32 "]",
             self, static_cast<uint32_t>(rv)));
    }
}

void
nsHttpConnection::GetSecurityInfo(nsISupports **secinfo)
{
    MOZ_ASSERT(OnSocketThread(), "not on socket thread");
    LOG(("nsHttpConnection::GetSecurityInfo trans=%p tlsfilter=%p socket=%p\n",
         mTransaction.get(), mTLSFilter.get(), mSocketTransport.get()));

    if (mTransaction &&
        NS_SUCCEEDED(mTransaction->GetTransactionSecurityInfo(secinfo))) {
        return;
    }

    if (mTLSFilter &&
        NS_SUCCEEDED(mTLSFilter->GetTransactionSecurityInfo(secinfo))) {
        return;
    }

    if (mSocketTransport &&
        NS_SUCCEEDED(mSocketTransport->GetSecurityInfo(secinfo))) {
        return;
    }

    *secinfo = nullptr;
}

void
nsHttpConnection::SetSecurityCallbacks(nsIInterfaceRequestor* aCallbacks)
{
    MutexAutoLock lock(mCallbacksLock);
    // This is called both on and off the main thread. For JS-implemented
    // callbacks, we requires that the call happen on the main thread, but
    // for C++-implemented callbacks we don't care. Use a pointer holder with
    // strict checking disabled.
    mCallbacks = new nsMainThreadPtrHolder<nsIInterfaceRequestor>(
      "nsHttpConnection::mCallbacks", aCallbacks, false);
}

nsresult
nsHttpConnection::PushBack(const char *data, uint32_t length)
{
    LOG(("nsHttpConnection::PushBack [this=%p, length=%d]\n", this, length));

    if (mInputOverflow) {
        NS_ERROR("nsHttpConnection::PushBack only one buffer supported");
        return NS_ERROR_UNEXPECTED;
    }

    mInputOverflow = new nsPreloadedStream(mSocketIn, data, length);
    return NS_OK;
}

class HttpConnectionForceIO : public Runnable
{
public:
  HttpConnectionForceIO(nsHttpConnection *aConn, bool doRecv,
                        bool isFastOpenForce)
     : mConn(aConn)
     , mDoRecv(doRecv)
     , mIsFastOpenForce(isFastOpenForce)
    {}

    NS_IMETHOD Run() override
    {
        MOZ_ASSERT(OnSocketThread(), "not on socket thread");

        if (mDoRecv) {
            if (!mConn->mSocketIn)
                return NS_OK;
            return mConn->OnInputStreamReady(mConn->mSocketIn);
        }

        // This runnable will be called when the ForceIO timer expires
        // (mIsFastOpenForce==false) or during the TCP Fast Open to force
        // writes (mIsFastOpenForce==true).
        if (mIsFastOpenForce && !mConn->mWaitingFor0RTTResponse) {
            // If we have exit the TCP Fast Open in the meantime we can skip
            // this.
            return NS_OK;
        }
        if (!mIsFastOpenForce) {
            MOZ_ASSERT(mConn->mForceSendPending);
            mConn->mForceSendPending = false;
        }

        if (!mConn->mSocketOut) {
            return NS_OK;
        }
        return mConn->OnOutputStreamReady(mConn->mSocketOut);
    }
private:
    RefPtr<nsHttpConnection> mConn;
    bool mDoRecv;
    bool mIsFastOpenForce;
};

nsresult
nsHttpConnection::ResumeSend()
{
    LOG(("nsHttpConnection::ResumeSend [this=%p]\n", this));

    MOZ_ASSERT(OnSocketThread(), "not on socket thread");

    if (mSocketOut) {
        nsresult rv = mSocketOut->AsyncWait(this, 0, 0, nullptr);
        LOG(("nsHttpConnection::ResumeSend [this=%p] "
             "mWaitingFor0RTTResponse=%d mForceSendDuringFastOpenPending=%d "
             "mReceivedSocketWouldBlockDuringFastOpen=%d\n",
             this, mWaitingFor0RTTResponse, mForceSendDuringFastOpenPending,
             mReceivedSocketWouldBlockDuringFastOpen));
        if (mWaitingFor0RTTResponse && !mForceSendDuringFastOpenPending &&
            !mReceivedSocketWouldBlockDuringFastOpen &&
            NS_SUCCEEDED(rv)) {
            // During TCP Fast Open, poll does not work properly so we will
            // trigger writes manually.
            mForceSendDuringFastOpenPending = true;
            NS_DispatchToCurrentThread(new HttpConnectionForceIO(this, false, true));
        }
        return rv;
    }

    NS_NOTREACHED("no socket output stream");
    return NS_ERROR_UNEXPECTED;
}

nsresult
nsHttpConnection::ResumeRecv()
{
    LOG(("nsHttpConnection::ResumeRecv [this=%p]\n", this));

    MOZ_ASSERT(OnSocketThread(), "not on socket thread");

    if (mFastOpen) {
        LOG(("nsHttpConnection::ResumeRecv - do not waiting for read during "
             "fast open! [this=%p]\n", this));
        return NS_OK;
    }

    // the mLastReadTime timestamp is used for finding slowish readers
    // and can be pretty sensitive. For that reason we actually reset it
    // when we ask to read (resume recv()) so that when we get called back
    // with actual read data in OnSocketReadable() we are only measuring
    // the latency between those two acts and not all the processing that
    // may get done before the ResumeRecv() call
    mLastReadTime = PR_IntervalNow();

    if (mSocketIn)
        return mSocketIn->AsyncWait(this, 0, 0, nullptr);

    NS_NOTREACHED("no socket input stream");
    return NS_ERROR_UNEXPECTED;
}

void
nsHttpConnection::ForceSendIO(nsITimer *aTimer, void *aClosure)
{
    MOZ_ASSERT(OnSocketThread(), "not on socket thread");
    nsHttpConnection *self = static_cast<nsHttpConnection *>(aClosure);
    MOZ_ASSERT(aTimer == self->mForceSendTimer);
    self->mForceSendTimer = nullptr;
    NS_DispatchToCurrentThread(new HttpConnectionForceIO(self, false, false));
}

nsresult
nsHttpConnection::MaybeForceSendIO()
{
    MOZ_ASSERT(OnSocketThread(), "not on socket thread");
    // due to bug 1213084 sometimes real I/O events do not get serviced when
    // NSPR derived I/O events are ready and this can cause a deadlock with
    // https over https proxying. Normally we would expect the write callback to
    // be invoked before this timer goes off, but set it at the old windows
    // tick interval (kForceDelay) as a backup for those circumstances.
    static const uint32_t kForceDelay = 17; //ms

    if (mForceSendPending) {
        return NS_OK;
    }
    MOZ_ASSERT(!mForceSendTimer);
    mForceSendPending = true;
    mForceSendTimer = do_CreateInstance("@mozilla.org/timer;1");
    return mForceSendTimer->InitWithFuncCallback(
        nsHttpConnection::ForceSendIO, this, kForceDelay, nsITimer::TYPE_ONE_SHOT);
}

// trigger an asynchronous read
nsresult
nsHttpConnection::ForceRecv()
{
    LOG(("nsHttpConnection::ForceRecv [this=%p]\n", this));
    MOZ_ASSERT(OnSocketThread(), "not on socket thread");

    return NS_DispatchToCurrentThread(new HttpConnectionForceIO(this, true, false));
}

// trigger an asynchronous write
nsresult
nsHttpConnection::ForceSend()
{
    LOG(("nsHttpConnection::ForceSend [this=%p]\n", this));
    MOZ_ASSERT(OnSocketThread(), "not on socket thread");

    if (mTLSFilter) {
        return mTLSFilter->NudgeTunnel(this);
    }
    return MaybeForceSendIO();
}

void
nsHttpConnection::BeginIdleMonitoring()
{
    LOG(("nsHttpConnection::BeginIdleMonitoring [this=%p]\n", this));
    MOZ_ASSERT(OnSocketThread(), "not on socket thread");
    MOZ_ASSERT(!mTransaction, "BeginIdleMonitoring() while active");
    MOZ_ASSERT(!mUsingSpdyVersion, "Idle monitoring of spdy not allowed");

    LOG(("Entering Idle Monitoring Mode [this=%p]", this));
    mIdleMonitoring = true;
    if (mSocketIn)
        mSocketIn->AsyncWait(this, 0, 0, nullptr);
}

void
nsHttpConnection::EndIdleMonitoring()
{
    LOG(("nsHttpConnection::EndIdleMonitoring [this=%p]\n", this));
    MOZ_ASSERT(OnSocketThread(), "not on socket thread");
    MOZ_ASSERT(!mTransaction, "EndIdleMonitoring() while active");

    if (mIdleMonitoring) {
        LOG(("Leaving Idle Monitoring Mode [this=%p]", this));
        mIdleMonitoring = false;
        if (mSocketIn)
            mSocketIn->AsyncWait(nullptr, 0, 0, nullptr);
    }
}

uint32_t
nsHttpConnection::Version()
{
    return mUsingSpdyVersion  ? mUsingSpdyVersion : mLastHttpResponseVersion;
}

//-----------------------------------------------------------------------------
// nsHttpConnection <private>
//-----------------------------------------------------------------------------

void
nsHttpConnection::CloseTransaction(nsAHttpTransaction *trans, nsresult reason,
                                   bool aIsShutdown)
{
    LOG(("nsHttpConnection::CloseTransaction[this=%p trans=%p reason=%" PRIx32 "]\n",
         this, trans, static_cast<uint32_t>(reason)));

    MOZ_ASSERT((trans == mTransaction) ||
               (mTLSFilter && mTLSFilter->Transaction() == trans));
    MOZ_ASSERT(OnSocketThread(), "not on socket thread");

    if (mCurrentBytesRead > mMaxBytesRead)
        mMaxBytesRead = mCurrentBytesRead;

    // mask this error code because its not a real error.
    if (reason == NS_BASE_STREAM_CLOSED)
        reason = NS_OK;

    if (mUsingSpdyVersion) {
        DontReuse();
        // if !mSpdySession then mUsingSpdyVersion must be false for canreuse()
        mUsingSpdyVersion = 0;
        mSpdySession = nullptr;
    }

    if (mTransaction) {
        mHttp1xTransactionCount += mTransaction->Http1xTransactionCount();

        mTransaction->Close(reason);
        mTransaction = nullptr;
    }

    {
        MutexAutoLock lock(mCallbacksLock);
        mCallbacks = nullptr;
    }

    if (NS_FAILED(reason) && (reason != NS_BINDING_RETARGETED)) {
        Close(reason, aIsShutdown);
    }

    // flag the connection as reused here for convenience sake.  certainly
    // it might be going away instead ;-)
    mIsReused = true;
}

nsresult
nsHttpConnection::ReadFromStream(nsIInputStream *input,
                                 void *closure,
                                 const char *buf,
                                 uint32_t offset,
                                 uint32_t count,
                                 uint32_t *countRead)
{
    // thunk for nsIInputStream instance
    nsHttpConnection *conn = (nsHttpConnection *) closure;
    return conn->OnReadSegment(buf, count, countRead);
}

nsresult
nsHttpConnection::OnReadSegment(const char *buf,
                                uint32_t count,
                                uint32_t *countRead)
{
    if (count == 0) {
        // some ReadSegments implementations will erroneously call the writer
        // to consume 0 bytes worth of data.  we must protect against this case
        // or else we'd end up closing the socket prematurely.
        NS_ERROR("bad ReadSegments implementation");
        return NS_ERROR_FAILURE; // stop iterating
    }

    nsresult rv = mSocketOut->Write(buf, count, countRead);
    if (NS_FAILED(rv))
        mSocketOutCondition = rv;
    else if (*countRead == 0)
        mSocketOutCondition = NS_BASE_STREAM_CLOSED;
    else {
        mLastWriteTime = PR_IntervalNow();
        mSocketOutCondition = NS_OK; // reset condition
        if (!mProxyConnectInProgress)
            mTotalBytesWritten += *countRead;
    }

    return mSocketOutCondition;
}

nsresult
nsHttpConnection::OnSocketWritable()
{
    LOG(("nsHttpConnection::OnSocketWritable [this=%p] host=%s\n",
         this, mConnInfo->Origin()));

    nsresult rv;
    uint32_t transactionBytes;
    bool again = true;

    // Prevent STS thread from being blocked by single OnOutputStreamReady callback.
    const uint32_t maxWriteAttempts = 128;
    uint32_t writeAttempts = 0;

    mForceSendDuringFastOpenPending = false;

    do {
        ++writeAttempts;
        rv = mSocketOutCondition = NS_OK;
        transactionBytes = 0;

        // The SSL handshake must be completed before the transaction->readsegments()
        // processing can proceed because we need to know how to format the
        // request differently for http/1, http/2, spdy, etc.. and that is
        // negotiated with NPN/ALPN in the SSL handshake.

        if (mConnInfo->UsingHttpsProxy() &&
            !EnsureNPNComplete(rv, transactionBytes)) {
            MOZ_ASSERT(!transactionBytes);
            mSocketOutCondition = NS_BASE_STREAM_WOULD_BLOCK;
        } else if (mProxyConnectStream) {
            // If we're need an HTTP/1 CONNECT tunnel through a proxy
            // send it before doing the SSL handshake
            LOG(("  writing CONNECT request stream\n"));
            rv = mProxyConnectStream->ReadSegments(ReadFromStream, this,
                                                   nsIOService::gDefaultSegmentSize,
                                                   &transactionBytes);
        } else if (!EnsureNPNComplete(rv, transactionBytes)) {
            if (NS_SUCCEEDED(rv) && !transactionBytes &&
                NS_SUCCEEDED(mSocketOutCondition)) {
                mSocketOutCondition = NS_BASE_STREAM_WOULD_BLOCK;
            }
        } else if (!mTransaction) {
            rv = NS_ERROR_FAILURE;
            LOG(("  No Transaction In OnSocketWritable\n"));
        } else if (NS_SUCCEEDED(rv)) {

            // for non spdy sessions let the connection manager know
            if (!mReportedSpdy) {
                mReportedSpdy = true;
                MOZ_ASSERT(!mEverUsedSpdy);
                gHttpHandler->ConnMgr()->ReportSpdyConnection(this, false);
            }

            LOG(("  writing transaction request stream\n"));
            mProxyConnectInProgress = false;
            rv = mTransaction->ReadSegmentsAgain(this, nsIOService::gDefaultSegmentSize,
                                                 &transactionBytes, &again);
            mContentBytesWritten += transactionBytes;
        }

        LOG(("nsHttpConnection::OnSocketWritable %p "
             "ReadSegments returned [rv=%" PRIx32 " read=%u "
             "sock-cond=%" PRIx32 " again=%d]\n",
             this, static_cast<uint32_t>(rv), transactionBytes,
             static_cast<uint32_t>(mSocketOutCondition), again));

        // XXX some streams return NS_BASE_STREAM_CLOSED to indicate EOF.
        if (rv == NS_BASE_STREAM_CLOSED && !mTransaction->IsDone()) {
            rv = NS_OK;
            transactionBytes = 0;
        }

        if (!again && (mFastOpen || mWaitingFor0RTTResponse)) {
            // Continue waiting;
            rv = mSocketOut->AsyncWait(this, 0, 0, nullptr);
        }
        if (NS_FAILED(rv)) {
            // if the transaction didn't want to write any more data, then
            // wait for the transaction to call ResumeSend.
            if (rv == NS_BASE_STREAM_WOULD_BLOCK) {
                rv = NS_OK;
                if (mFastOpen || mWaitingFor0RTTResponse) {
                    // Continue waiting;
                    rv = mSocketOut->AsyncWait(this, 0, 0, nullptr);
                }
            }
            again = false;
        } else if (NS_FAILED(mSocketOutCondition)) {
            if (mSocketOutCondition == NS_BASE_STREAM_WOULD_BLOCK) {
                if (mTLSFilter) {
                    LOG(("  blocked tunnel (handshake?)\n"));
                    rv = mTLSFilter->NudgeTunnel(this);
                } else {
                    rv = mSocketOut->AsyncWait(this, 0, 0, nullptr); // continue writing
                }
            } else {
                rv = mSocketOutCondition;
            }
            again = false;
        } else if (!transactionBytes) {
            rv = NS_OK;

            if (mWaitingFor0RTTResponse || mFastOpen) {
                // Wait for tls handshake to finish or waiting for connect.
                rv = mSocketOut->AsyncWait(this, 0, 0, nullptr);
            } else if (mTransaction) { // in case the ReadSegments stack called CloseTransaction()
                //
                // at this point we've written out the entire transaction, and now we
                // must wait for the server's response.  we manufacture a status message
                // here to reflect the fact that we are waiting.  this message will be
                // trumped (overwritten) if the server responds quickly.
                //
                mTransaction->OnTransportStatus(mSocketTransport,
                                                NS_NET_STATUS_WAITING_FOR,
                                                0);

                rv = ResumeRecv(); // start reading
            }
            again = false;
        } else if (writeAttempts >= maxWriteAttempts) {
            LOG(("  yield for other transactions\n"));
            rv = mSocketOut->AsyncWait(this, 0, 0, nullptr); // continue writing
            again = false;
        }
        // write more to the socket until error or end-of-request...
    } while (again && gHttpHandler->Active());

    return rv;
}

nsresult
nsHttpConnection::OnWriteSegment(char *buf,
                                 uint32_t count,
                                 uint32_t *countWritten)
{
    if (count == 0) {
        // some WriteSegments implementations will erroneously call the reader
        // to provide 0 bytes worth of data.  we must protect against this case
        // or else we'd end up closing the socket prematurely.
        NS_ERROR("bad WriteSegments implementation");
        return NS_ERROR_FAILURE; // stop iterating
    }

    if (ChaosMode::isActive(ChaosFeature::IOAmounts) &&
        ChaosMode::randomUint32LessThan(2)) {
        // read 1...count bytes
        count = ChaosMode::randomUint32LessThan(count) + 1;
    }

    nsresult rv = mSocketIn->Read(buf, count, countWritten);
    if (NS_FAILED(rv))
        mSocketInCondition = rv;
    else if (*countWritten == 0)
        mSocketInCondition = NS_BASE_STREAM_CLOSED;
    else
        mSocketInCondition = NS_OK; // reset condition

    return mSocketInCondition;
}

nsresult
nsHttpConnection::OnSocketReadable()
{
    LOG(("nsHttpConnection::OnSocketReadable [this=%p]\n", this));

    PRIntervalTime now = PR_IntervalNow();
    PRIntervalTime delta = now - mLastReadTime;

    // Reset mResponseTimeoutEnabled to stop response timeout checks.
    mResponseTimeoutEnabled = false;

    if (mKeepAliveMask && (delta >= mMaxHangTime)) {
        LOG(("max hang time exceeded!\n"));
        // give the handler a chance to create a new persistent connection to
        // this host if we've been busy for too long.
        mKeepAliveMask = false;
        Unused << gHttpHandler->ProcessPendingQ(mConnInfo);
    }

    // Reduce the estimate of the time since last read by up to 1 RTT to
    // accommodate exhausted sender TCP congestion windows or minor I/O delays.
    mLastReadTime = now;

    nsresult rv;
    uint32_t n;
    bool again = true;

    do {
        if (!mProxyConnectInProgress && !mNPNComplete) {
            // Unless we are setting up a tunnel via CONNECT, prevent reading
            // from the socket until the results of NPN
            // negotiation are known (which is determined from the write path).
            // If the server speaks SPDY it is likely the readable data here is
            // a spdy settings frame and without NPN it would be misinterpreted
            // as HTTP/*

            LOG(("nsHttpConnection::OnSocketReadable %p return due to inactive "
                 "tunnel setup but incomplete NPN state\n", this));
            rv = NS_OK;
            break;
        }

        mSocketInCondition = NS_OK;
        rv = mTransaction->
            WriteSegmentsAgain(this, nsIOService::gDefaultSegmentSize, &n, &again);
        LOG(("nsHttpConnection::OnSocketReadable %p trans->ws rv=%" PRIx32
             " n=%d socketin=%" PRIx32 "\n",
             this, static_cast<uint32_t>(rv), n, static_cast<uint32_t>(mSocketInCondition)));
        if (NS_FAILED(rv)) {
            // if the transaction didn't want to take any more data, then
            // wait for the transaction to call ResumeRecv.
            if (rv == NS_BASE_STREAM_WOULD_BLOCK) {
                rv = NS_OK;
            }
            again = false;
        } else {
            mCurrentBytesRead += n;
            mTotalBytesRead += n;
            if (NS_FAILED(mSocketInCondition)) {
                // continue waiting for the socket if necessary...
                if (mSocketInCondition == NS_BASE_STREAM_WOULD_BLOCK) {
                    rv = ResumeRecv();
                } else {
                    rv = mSocketInCondition;
                }
                again = false;
            }
        }
        // read more from the socket until error...
    } while (again && gHttpHandler->Active());

    return rv;
}

void
nsHttpConnection::SetupSecondaryTLS()
{
    MOZ_ASSERT(OnSocketThread(), "not on socket thread");
    MOZ_ASSERT(!mTLSFilter);
    LOG(("nsHttpConnection %p SetupSecondaryTLS %s %d\n",
         this, mConnInfo->Origin(), mConnInfo->OriginPort()));

    nsHttpConnectionInfo *ci = nullptr;
    if (mTransaction) {
        ci = mTransaction->ConnectionInfo();
    }
    if (!ci) {
        ci = mConnInfo;
    }
    MOZ_ASSERT(ci);

    mTLSFilter = new TLSFilterTransaction(mTransaction,
                                          ci->Origin(), ci->OriginPort(), this, this);

    if (mTransaction) {
        mTransaction = mTLSFilter;
    }
}

void
nsHttpConnection::SetInSpdyTunnel(bool arg)
{
    MOZ_ASSERT(mTLSFilter);
    mInSpdyTunnel = arg;

    // don't setup another tunnel :)
    mProxyConnectStream = nullptr;
    mCompletedProxyConnect = true;
    mProxyConnectInProgress = false;
}

nsresult
nsHttpConnection::MakeConnectString(nsAHttpTransaction *trans,
                                    nsHttpRequestHead *request,
                                    nsACString &result)
{
    result.Truncate();
    if (!trans->ConnectionInfo()) {
        return NS_ERROR_NOT_INITIALIZED;
    }

    DebugOnly<nsresult> rv;

    rv = nsHttpHandler::GenerateHostPort(
            nsDependentCString(trans->ConnectionInfo()->Origin()),
                               trans->ConnectionInfo()->OriginPort(), result);
    MOZ_ASSERT(NS_SUCCEEDED(rv));

    // CONNECT host:port HTTP/1.1
    request->SetMethod(NS_LITERAL_CSTRING("CONNECT"));
    request->SetVersion(gHttpHandler->HttpVersion());
    request->SetRequestURI(result);
    rv = request->SetHeader(nsHttp::User_Agent, gHttpHandler->UserAgent());
    MOZ_ASSERT(NS_SUCCEEDED(rv));

    // a CONNECT is always persistent
    rv = request->SetHeader(nsHttp::Proxy_Connection, NS_LITERAL_CSTRING("keep-alive"));
    MOZ_ASSERT(NS_SUCCEEDED(rv));
    rv = request->SetHeader(nsHttp::Connection, NS_LITERAL_CSTRING("keep-alive"));
    MOZ_ASSERT(NS_SUCCEEDED(rv));

    // all HTTP/1.1 requests must include a Host header (even though it
    // may seem redundant in this case; see bug 82388).
    rv = request->SetHeader(nsHttp::Host, result);
    MOZ_ASSERT(NS_SUCCEEDED(rv));

    nsAutoCString val;
    if (NS_SUCCEEDED(trans->RequestHead()->GetHeader(
                         nsHttp::Proxy_Authorization,
                         val))) {
        // we don't know for sure if this authorization is intended for the
        // SSL proxy, so we add it just in case.
        rv = request->SetHeader(nsHttp::Proxy_Authorization, val);
        MOZ_ASSERT(NS_SUCCEEDED(rv));
    }

    result.Truncate();
    request->Flatten(result, false);
    result.AppendLiteral("\r\n");
    return NS_OK;
}

nsresult
nsHttpConnection::SetupProxyConnect()
{
    LOG(("nsHttpConnection::SetupProxyConnect [this=%p]\n", this));
    NS_ENSURE_TRUE(!mProxyConnectStream, NS_ERROR_ALREADY_INITIALIZED);
    MOZ_ASSERT(!mUsingSpdyVersion,
               "SPDY NPN Complete while using proxy connect stream");

    nsAutoCString buf;
    nsHttpRequestHead request;
    nsresult rv = MakeConnectString(mTransaction, &request, buf);
    if (NS_FAILED(rv)) {
        return rv;
    }
    return NS_NewCStringInputStream(getter_AddRefs(mProxyConnectStream), buf);
}

nsresult
nsHttpConnection::StartShortLivedTCPKeepalives()
{
    if (mUsingSpdyVersion) {
        return NS_OK;
    }
    MOZ_ASSERT(mSocketTransport);
    if (!mSocketTransport) {
        return NS_ERROR_NOT_INITIALIZED;
    }

    nsresult rv = NS_OK;
    int32_t idleTimeS = -1;
    int32_t retryIntervalS = -1;
    if (gHttpHandler->TCPKeepaliveEnabledForShortLivedConns()) {
        // Set the idle time.
        idleTimeS = gHttpHandler->GetTCPKeepaliveShortLivedIdleTime();
        LOG(("nsHttpConnection::StartShortLivedTCPKeepalives[%p] "
             "idle time[%ds].", this, idleTimeS));

        retryIntervalS =
            std::max<int32_t>((int32_t)PR_IntervalToSeconds(mRtt), 1);
        rv = mSocketTransport->SetKeepaliveVals(idleTimeS, retryIntervalS);
        if (NS_FAILED(rv)) {
            return rv;
        }
        rv = mSocketTransport->SetKeepaliveEnabled(true);
        mTCPKeepaliveConfig = kTCPKeepaliveShortLivedConfig;
    } else {
        rv = mSocketTransport->SetKeepaliveEnabled(false);
        mTCPKeepaliveConfig = kTCPKeepaliveDisabled;
    }
    if (NS_FAILED(rv)) {
        return rv;
    }

    // Start a timer to move to long-lived keepalive config.
    if(!mTCPKeepaliveTransitionTimer) {
        mTCPKeepaliveTransitionTimer =
            do_CreateInstance("@mozilla.org/timer;1");
    }

    if (mTCPKeepaliveTransitionTimer) {
        int32_t time = gHttpHandler->GetTCPKeepaliveShortLivedTime();

        // Adjust |time| to ensure a full set of keepalive probes can be sent
        // at the end of the short-lived phase.
        if (gHttpHandler->TCPKeepaliveEnabledForShortLivedConns()) {
            if (NS_WARN_IF(!gSocketTransportService)) {
                return NS_ERROR_NOT_INITIALIZED;
            }
            int32_t probeCount = -1;
            rv = gSocketTransportService->GetKeepaliveProbeCount(&probeCount);
            if (NS_WARN_IF(NS_FAILED(rv))) {
                return rv;
            }
            if (NS_WARN_IF(probeCount <= 0)) {
                return NS_ERROR_UNEXPECTED;
            }
            // Add time for final keepalive probes, and 2 seconds for a buffer.
            time += ((probeCount) * retryIntervalS) - (time % idleTimeS) + 2;
        }
        mTCPKeepaliveTransitionTimer->InitWithFuncCallback(
                                          nsHttpConnection::UpdateTCPKeepalive,
                                          this,
                                          (uint32_t)time*1000,
                                          nsITimer::TYPE_ONE_SHOT);
    } else {
        NS_WARNING("nsHttpConnection::StartShortLivedTCPKeepalives failed to "
                   "create timer.");
    }

    return NS_OK;
}

nsresult
nsHttpConnection::StartLongLivedTCPKeepalives()
{
    MOZ_ASSERT(!mUsingSpdyVersion, "Don't use TCP Keepalive with SPDY!");
    if (NS_WARN_IF(mUsingSpdyVersion)) {
        return NS_OK;
    }
    MOZ_ASSERT(mSocketTransport);
    if (!mSocketTransport) {
        return NS_ERROR_NOT_INITIALIZED;
    }

    nsresult rv = NS_OK;
    if (gHttpHandler->TCPKeepaliveEnabledForLongLivedConns()) {
        // Increase the idle time.
        int32_t idleTimeS = gHttpHandler->GetTCPKeepaliveLongLivedIdleTime();
        LOG(("nsHttpConnection::StartLongLivedTCPKeepalives[%p] idle time[%ds]",
             this, idleTimeS));

        int32_t retryIntervalS =
            std::max<int32_t>((int32_t)PR_IntervalToSeconds(mRtt), 1);
        rv = mSocketTransport->SetKeepaliveVals(idleTimeS, retryIntervalS);
        if (NS_FAILED(rv)) {
            return rv;
        }

        // Ensure keepalive is enabled, if current status is disabled.
        if (mTCPKeepaliveConfig == kTCPKeepaliveDisabled) {
            rv = mSocketTransport->SetKeepaliveEnabled(true);
            if (NS_FAILED(rv)) {
                return rv;
            }
        }
        mTCPKeepaliveConfig = kTCPKeepaliveLongLivedConfig;
    } else {
        rv = mSocketTransport->SetKeepaliveEnabled(false);
        mTCPKeepaliveConfig = kTCPKeepaliveDisabled;
    }

    if (NS_FAILED(rv)) {
        return rv;
    }
    return NS_OK;
}

nsresult
nsHttpConnection::DisableTCPKeepalives()
{
    MOZ_ASSERT(mSocketTransport);
    if (!mSocketTransport) {
        return NS_ERROR_NOT_INITIALIZED;
    }

    LOG(("nsHttpConnection::DisableTCPKeepalives [%p]", this));
    if (mTCPKeepaliveConfig != kTCPKeepaliveDisabled) {
        nsresult rv = mSocketTransport->SetKeepaliveEnabled(false);
        if (NS_FAILED(rv)) {
            return rv;
        }
        mTCPKeepaliveConfig = kTCPKeepaliveDisabled;
    }
    if (mTCPKeepaliveTransitionTimer) {
        mTCPKeepaliveTransitionTimer->Cancel();
        mTCPKeepaliveTransitionTimer = nullptr;
    }
    return NS_OK;
}

//-----------------------------------------------------------------------------
// nsHttpConnection::nsISupports
//-----------------------------------------------------------------------------

NS_IMPL_ADDREF(nsHttpConnection)
NS_IMPL_RELEASE(nsHttpConnection)

NS_INTERFACE_MAP_BEGIN(nsHttpConnection)
    NS_INTERFACE_MAP_ENTRY(nsISupportsWeakReference)
    NS_INTERFACE_MAP_ENTRY(nsIInputStreamCallback)
    NS_INTERFACE_MAP_ENTRY(nsIOutputStreamCallback)
    NS_INTERFACE_MAP_ENTRY(nsITransportEventSink)
    NS_INTERFACE_MAP_ENTRY(nsIInterfaceRequestor)
    // we have no macro that covers this case.
    if (aIID.Equals(NS_GET_IID(nsHttpConnection)) ) {
        AddRef();
        *aInstancePtr = this;
        return NS_OK;
    } else
NS_INTERFACE_MAP_END

//-----------------------------------------------------------------------------
// nsHttpConnection::nsIInputStreamCallback
//-----------------------------------------------------------------------------

// called on the socket transport thread
NS_IMETHODIMP
nsHttpConnection::OnInputStreamReady(nsIAsyncInputStream *in)
{
    MOZ_ASSERT(in == mSocketIn, "unexpected stream");
    MOZ_ASSERT(OnSocketThread(), "not on socket thread");

    if (mIdleMonitoring) {
        MOZ_ASSERT(!mTransaction, "Idle Input Event While Active");

        // The only read event that is protocol compliant for an idle connection
        // is an EOF, which we check for with CanReuse(). If the data is
        // something else then just ignore it and suspend checking for EOF -
        // our normal timers or protocol stack are the place to deal with
        // any exception logic.

        if (!CanReuse()) {
            LOG(("Server initiated close of idle conn %p\n", this));
            Unused << gHttpHandler->ConnMgr()->CloseIdleConnection(this);
            return NS_OK;
        }

        LOG(("Input data on idle conn %p, but not closing yet\n", this));
        return NS_OK;
    }

    // if the transaction was dropped...
    if (!mTransaction) {
        LOG(("  no transaction; ignoring event\n"));
        return NS_OK;
    }

    nsresult rv = OnSocketReadable();
    if (NS_FAILED(rv))
        CloseTransaction(mTransaction, rv);

    return NS_OK;
}

//-----------------------------------------------------------------------------
// nsHttpConnection::nsIOutputStreamCallback
//-----------------------------------------------------------------------------

NS_IMETHODIMP
nsHttpConnection::OnOutputStreamReady(nsIAsyncOutputStream *out)
{
    MOZ_ASSERT(OnSocketThread(), "not on socket thread");
    MOZ_ASSERT(out == mSocketOut, "unexpected socket");
    // if the transaction was dropped...
    if (!mTransaction) {
        LOG(("  no transaction; ignoring event\n"));
        return NS_OK;
    }

    nsresult rv = OnSocketWritable();
    if (NS_FAILED(rv))
        CloseTransaction(mTransaction, rv);

    return NS_OK;
}

//-----------------------------------------------------------------------------
// nsHttpConnection::nsITransportEventSink
//-----------------------------------------------------------------------------

NS_IMETHODIMP
nsHttpConnection::OnTransportStatus(nsITransport *trans,
                                    nsresult status,
                                    int64_t progress,
                                    int64_t progressMax)
{
    if (mTransaction)
        mTransaction->OnTransportStatus(trans, status, progress);
    return NS_OK;
}

//-----------------------------------------------------------------------------
// nsHttpConnection::nsIInterfaceRequestor
//-----------------------------------------------------------------------------

// not called on the socket transport thread
NS_IMETHODIMP
nsHttpConnection::GetInterface(const nsIID &iid, void **result)
{
    // NOTE: This function is only called on the UI thread via sync proxy from
    //       the socket transport thread.  If that weren't the case, then we'd
    //       have to worry about the possibility of mTransaction going away
    //       part-way through this function call.  See CloseTransaction.

    // NOTE - there is a bug here, the call to getinterface is proxied off the
    // nss thread, not the ui thread as the above comment says. So there is
    // indeed a chance of mTransaction going away. bug 615342

    MOZ_ASSERT(!OnSocketThread(), "on socket thread");

    nsCOMPtr<nsIInterfaceRequestor> callbacks;
    {
        MutexAutoLock lock(mCallbacksLock);
        callbacks = mCallbacks;
    }
    if (callbacks)
        return callbacks->GetInterface(iid, result);
    return NS_ERROR_NO_INTERFACE;
}

void
nsHttpConnection::CheckForTraffic(bool check)
{
    if (check) {
        LOG((" CheckForTraffic conn %p\n", this));
        if (mSpdySession) {
            if (PR_IntervalToMilliseconds(IdleTime()) >= 500) {
                // Send a ping to verify it is still alive if it has been idle
                // more than half a second, the network changed events are
                // rate-limited to one per 1000 ms.
                LOG((" SendPing\n"));
                mSpdySession->SendPing();
            } else {
                LOG((" SendPing skipped due to network activity\n"));
            }
        } else {
            // If not SPDY, Store snapshot amount of data right now
            mTrafficCount = mTotalBytesWritten + mTotalBytesRead;
            mTrafficStamp = true;
        }
    } else {
        // mark it as not checked
        mTrafficStamp = false;
    }
}

nsAHttpTransaction *
nsHttpConnection::CloseConnectionFastOpenTakesTooLongOrError(bool aCloseSocketTransport)
{
    MOZ_ASSERT(!mCurrentBytesRead);

    mFastOpenStatus = TFO_FAILED;
    RefPtr<nsAHttpTransaction> trans;

    DontReuse();

    if (mUsingSpdyVersion) {
        // If we have a http2 connection just restart it as if 0rtt failed.
        // For http2 we do not need to do similar thing as for http1 because
        // backup connection will pick immediately all this transaction anyway.
        mUsingSpdyVersion = 0;
        if (mSpdySession) {
            mTransaction->SetFastOpenStatus(TFO_FAILED);
            Unused << mSpdySession->Finish0RTT(true, true);
        }
        mSpdySession = nullptr;
    } else {
        // For http1 we want to make this transaction an absolute priority to
        // get the backup connection so we will return it from here.
        if (NS_SUCCEEDED(mTransaction->RestartOnFastOpenError())) {
            trans = mTransaction;
        }
        mTransaction->SetConnection(nullptr);
    }

    {
        MutexAutoLock lock(mCallbacksLock);
        mCallbacks = nullptr;
    }

    if (mSocketIn) {
        mSocketIn->AsyncWait(nullptr, 0, 0, nullptr);
    }

    mTransaction = nullptr;
    if (!aCloseSocketTransport) {
        if (mSocketOut) {
            mSocketOut->AsyncWait(nullptr, 0, 0, nullptr);
        }
        mSocketTransport->SetEventSink(nullptr, nullptr);
        mSocketTransport->SetSecurityCallbacks(nullptr);
        mSocketTransport = nullptr;
    }
    Close(NS_ERROR_NET_RESET);
    return trans;
}

void
nsHttpConnection::SetFastOpen(bool aFastOpen)
{
    mFastOpen = aFastOpen;
    if (!mFastOpen &&
        mTransaction &&
        !mTransaction->IsNullTransaction()) {
        mExperienced = true;
    }
}

} // namespace net
} // namespace mozilla