diff options
Diffstat (limited to 'pkg/tcpip/transport')
-rw-r--r-- | pkg/tcpip/transport/tcp/accept.go | 91 | ||||
-rw-r--r-- | pkg/tcpip/transport/tcp/connect.go | 20 | ||||
-rw-r--r-- | pkg/tcpip/transport/tcp/dual_stack_test.go | 14 | ||||
-rw-r--r-- | pkg/tcpip/transport/tcp/endpoint.go | 14 | ||||
-rw-r--r-- | pkg/tcpip/transport/tcp/protocol.go | 77 | ||||
-rw-r--r-- | pkg/tcpip/transport/tcp/tcp_sack_test.go | 14 | ||||
-rw-r--r-- | pkg/tcpip/transport/tcp/tcp_test.go | 85 | ||||
-rw-r--r-- | pkg/tcpip/transport/tcp/tcp_timestamp_test.go | 8 |
8 files changed, 126 insertions, 197 deletions
diff --git a/pkg/tcpip/transport/tcp/accept.go b/pkg/tcpip/transport/tcp/accept.go index 025b134e2..7372ebc08 100644 --- a/pkg/tcpip/transport/tcp/accept.go +++ b/pkg/tcpip/transport/tcp/accept.go @@ -51,11 +51,6 @@ const ( // timestamp and the current timestamp. If the difference is greater // than maxTSDiff, the cookie is expired. maxTSDiff = 2 - - // SynRcvdCountThreshold is the default global maximum number of - // connections that are allowed to be in SYN-RCVD state before TCP - // starts using SYN cookies to accept connections. - SynRcvdCountThreshold uint64 = 1000 ) var ( @@ -80,9 +75,6 @@ func encodeMSS(mss uint16) uint32 { type listenContext struct { stack *stack.Stack - // synRcvdCount is a reference to the stack level synRcvdCount. - synRcvdCount *synRcvdCounter - // rcvWnd is the receive window that is sent by this listening context // in the initial SYN-ACK. rcvWnd seqnum.Size @@ -138,11 +130,6 @@ func newListenContext(stk *stack.Stack, listenEP *endpoint, rcvWnd seqnum.Size, listenEP: listenEP, pendingEndpoints: make(map[stack.TransportEndpointID]*endpoint), } - p, ok := stk.TransportProtocolInstance(ProtocolNumber).(*protocol) - if !ok { - panic(fmt.Sprintf("unable to get TCP protocol instance from stack: %+v", stk)) - } - l.synRcvdCount = p.SynRcvdCounter() rand.Read(l.nonce[0][:]) rand.Read(l.nonce[1][:]) @@ -199,6 +186,14 @@ func (l *listenContext) isCookieValid(id stack.TransportEndpointID, cookie seqnu return (v - l.cookieHash(id, cookieTS, 1)) & hashMask, true } +func (l *listenContext) useSynCookies() bool { + var alwaysUseSynCookies tcpip.TCPAlwaysUseSynCookies + if err := l.stack.TransportProtocolOption(header.TCPProtocolNumber, &alwaysUseSynCookies); err != nil { + panic(fmt.Sprintf("TransportProtocolOption(%d, %T) = %s", header.TCPProtocolNumber, alwaysUseSynCookies, err)) + } + return bool(alwaysUseSynCookies) || (l.listenEP != nil && l.listenEP.synRcvdBacklogFull()) +} + // createConnectingEndpoint creates a new endpoint in a connecting state, with // the connection parameters given by the arguments. func (l *listenContext) createConnectingEndpoint(s *segment, iss seqnum.Value, irs seqnum.Value, rcvdSynOpts *header.TCPSynOptions, queue *waiter.Queue) (*endpoint, tcpip.Error) { @@ -307,6 +302,7 @@ func (l *listenContext) startHandshake(s *segment, opts *header.TCPSynOptions, q // Initialize and start the handshake. h := ep.newPassiveHandshake(isn, irs, opts, deferAccept) + h.listenEP = l.listenEP h.start() return h, nil } @@ -485,7 +481,6 @@ func (e *endpoint) handleSynSegment(ctx *listenContext, s *segment, opts *header } go func() { - defer ctx.synRcvdCount.dec() if err := h.complete(); err != nil { e.stack.Stats().TCP.FailedConnectionAttempts.Increment() e.stats.FailedConnectionAttempts.Increment() @@ -497,24 +492,29 @@ func (e *endpoint) handleSynSegment(ctx *listenContext, s *segment, opts *header h.ep.startAcceptedLoop() e.stack.Stats().TCP.PassiveConnectionOpenings.Increment() e.deliverAccepted(h.ep, false /*withSynCookie*/) - }() // S/R-SAFE: synRcvdCount is the barrier. + }() return nil } -func (e *endpoint) incSynRcvdCount() bool { +func (e *endpoint) synRcvdBacklogFull() bool { e.acceptMu.Lock() - canInc := int(atomic.LoadInt32(&e.synRcvdCount)) < cap(e.acceptedChan) + acceptedChanCap := cap(e.acceptedChan) e.acceptMu.Unlock() - if canInc { - atomic.AddInt32(&e.synRcvdCount, 1) - } - return canInc + // The allocated accepted channel size would always be one greater than the + // listen backlog. But, the SYNRCVD connections count is always checked + // against the listen backlog value for Linux parity reason. + // https://github.com/torvalds/linux/blob/7acac4b3196/include/net/inet_connection_sock.h#L280 + // + // We maintain an equality check here as the synRcvdCount is incremented + // and compared only from a single listener context and the capacity of + // the accepted channel can only increase by a new listen call. + return int(atomic.LoadInt32(&e.synRcvdCount)) == acceptedChanCap-1 } func (e *endpoint) acceptQueueIsFull() bool { e.acceptMu.Lock() - full := len(e.acceptedChan)+int(atomic.LoadInt32(&e.synRcvdCount)) >= cap(e.acceptedChan) + full := len(e.acceptedChan) == cap(e.acceptedChan) e.acceptMu.Unlock() return full } @@ -539,17 +539,13 @@ func (e *endpoint) handleListenSegment(ctx *listenContext, s *segment) tcpip.Err switch { case s.flags == header.TCPFlagSyn: opts := parseSynSegmentOptions(s) - if ctx.synRcvdCount.inc() { - // Only handle the syn if the following conditions hold - // - accept queue is not full. - // - number of connections in synRcvd state is less than the - // backlog. - if !e.acceptQueueIsFull() && e.incSynRcvdCount() { + if !ctx.useSynCookies() { + if !e.acceptQueueIsFull() { s.incRef() + atomic.AddInt32(&e.synRcvdCount, 1) _ = e.handleSynSegment(ctx, s, &opts) return nil } - ctx.synRcvdCount.dec() e.stack.Stats().TCP.ListenOverflowSynDrop.Increment() e.stats.ReceiveErrors.ListenOverflowSynDrop.Increment() e.stack.Stats().DroppedPackets.Increment() @@ -615,25 +611,6 @@ func (e *endpoint) handleListenSegment(ctx *listenContext, s *segment) tcpip.Err return nil } - if !ctx.synRcvdCount.synCookiesInUse() { - // When not using SYN cookies, as per RFC 793, section 3.9, page 64: - // Any acknowledgment is bad if it arrives on a connection still in - // the LISTEN state. An acceptable reset segment should be formed - // for any arriving ACK-bearing segment. The RST should be - // formatted as follows: - // - // <SEQ=SEG.ACK><CTL=RST> - // - // Send a reset as this is an ACK for which there is no - // half open connections and we are not using cookies - // yet. - // - // The only time we should reach here when a connection - // was opened and closed really quickly and a delayed - // ACK was received from the sender. - return replyWithReset(e.stack, s, e.sendTOS, e.ttl) - } - iss := s.ackNumber - 1 irs := s.sequenceNumber - 1 @@ -651,7 +628,23 @@ func (e *endpoint) handleListenSegment(ctx *listenContext, s *segment) tcpip.Err if !ok || int(data) >= len(mssTable) { e.stack.Stats().TCP.ListenOverflowInvalidSynCookieRcvd.Increment() e.stack.Stats().DroppedPackets.Increment() - return nil + + // When not using SYN cookies, as per RFC 793, section 3.9, page 64: + // Any acknowledgment is bad if it arrives on a connection still in + // the LISTEN state. An acceptable reset segment should be formed + // for any arriving ACK-bearing segment. The RST should be + // formatted as follows: + // + // <SEQ=SEG.ACK><CTL=RST> + // + // Send a reset as this is an ACK for which there is no + // half open connections and we are not using cookies + // yet. + // + // The only time we should reach here when a connection + // was opened and closed really quickly and a delayed + // ACK was received from the sender. + return replyWithReset(e.stack, s, e.sendTOS, e.ttl) } e.stack.Stats().TCP.ListenOverflowSynCookieRcvd.Increment() // Create newly accepted endpoint and deliver it. diff --git a/pkg/tcpip/transport/tcp/connect.go b/pkg/tcpip/transport/tcp/connect.go index a9e978cf6..8f0f0c3e9 100644 --- a/pkg/tcpip/transport/tcp/connect.go +++ b/pkg/tcpip/transport/tcp/connect.go @@ -65,11 +65,12 @@ const ( // NOTE: handshake.ep.mu is held during handshake processing. It is released if // we are going to block and reacquired when we start processing an event. type handshake struct { - ep *endpoint - state handshakeState - active bool - flags header.TCPFlags - ackNum seqnum.Value + ep *endpoint + listenEP *endpoint + state handshakeState + active bool + flags header.TCPFlags + ackNum seqnum.Value // iss is the initial send sequence number, as defined in RFC 793. iss seqnum.Value @@ -394,6 +395,15 @@ func (h *handshake) synRcvdState(s *segment) tcpip.Error { return nil } + // Drop the ACK if the accept queue is full. + // https://github.com/torvalds/linux/blob/7acac4b3196/net/ipv4/tcp_ipv4.c#L1523 + // We could abort the connection as well with a tunable as in + // https://github.com/torvalds/linux/blob/7acac4b3196/net/ipv4/tcp_minisocks.c#L788 + if listenEP := h.listenEP; listenEP != nil && listenEP.acceptQueueIsFull() { + listenEP.stack.Stats().DroppedPackets.Increment() + return nil + } + // Update timestamp if required. See RFC7323, section-4.3. if h.ep.sendTSOk && s.parsedOptions.TS { h.ep.updateRecentTimestamp(s.parsedOptions.TSVal, h.ackNum, s.sequenceNumber) diff --git a/pkg/tcpip/transport/tcp/dual_stack_test.go b/pkg/tcpip/transport/tcp/dual_stack_test.go index f6a16f96e..d6d68f128 100644 --- a/pkg/tcpip/transport/tcp/dual_stack_test.go +++ b/pkg/tcpip/transport/tcp/dual_stack_test.go @@ -565,17 +565,15 @@ func TestV4AcceptOnV4(t *testing.T) { } func testV4ListenClose(t *testing.T, c *context.Context) { - // Set the SynRcvd threshold to zero to force a syn cookie based accept - // to happen. - var opt tcpip.TCPSynRcvdCountThresholdOption + opt := tcpip.TCPAlwaysUseSynCookies(true) if err := c.Stack().SetTransportProtocolOption(tcp.ProtocolNumber, &opt); err != nil { - t.Fatalf("setting TCPSynRcvdCountThresholdOption(%d, &%T(%d)): %s", tcp.ProtocolNumber, opt, opt, err) + t.Fatalf("SetTransportProtocolOption(%d, &%T(%t)): %s", tcp.ProtocolNumber, opt, opt, err) } - const n = uint16(32) + const n = 32 // Start listening. - if err := c.EP.Listen(int(tcp.SynRcvdCountThreshold + 1)); err != nil { + if err := c.EP.Listen(n); err != nil { t.Fatalf("Listen failed: %v", err) } @@ -591,9 +589,9 @@ func testV4ListenClose(t *testing.T, c *context.Context) { }) } - // Each of these ACK's will cause a syn-cookie based connection to be + // Each of these ACKs will cause a syn-cookie based connection to be // accepted and delivered to the listening endpoint. - for i := uint16(0); i < n; i++ { + for i := 0; i < n; i++ { b := c.GetPacket() tcp := header.TCP(header.IPv4(b).Payload()) iss := seqnum.Value(tcp.SequenceNumber()) diff --git a/pkg/tcpip/transport/tcp/endpoint.go b/pkg/tcpip/transport/tcp/endpoint.go index c5daba232..9438056f9 100644 --- a/pkg/tcpip/transport/tcp/endpoint.go +++ b/pkg/tcpip/transport/tcp/endpoint.go @@ -2474,6 +2474,20 @@ func (e *endpoint) shutdownLocked(flags tcpip.ShutdownFlags) tcpip.Error { // Listen puts the endpoint in "listen" mode, which allows it to accept // new connections. func (e *endpoint) Listen(backlog int) tcpip.Error { + if uint32(backlog) > MaxListenBacklog { + // Linux treats incoming backlog as uint with a limit defined by + // sysctl_somaxconn. + // https://github.com/torvalds/linux/blob/7acac4b3196/net/socket.c#L1666 + // + // We use the backlog to allocate a channel of that size, hence enforce + // a hard limit for the backlog. + backlog = MaxListenBacklog + } else { + // Accept one more than the configured listen backlog to keep in parity with + // Linux. Ref, because of missing equality check here: + // https://github.com/torvalds/linux/blob/7acac4b3196/include/net/sock.h#L937 + backlog++ + } err := e.listen(backlog) if err != nil { if !err.IgnoreStats() { diff --git a/pkg/tcpip/transport/tcp/protocol.go b/pkg/tcpip/transport/tcp/protocol.go index 2a4667906..230fa6ebe 100644 --- a/pkg/tcpip/transport/tcp/protocol.go +++ b/pkg/tcpip/transport/tcp/protocol.go @@ -68,6 +68,9 @@ const ( // DefaultSynRetries is the default value for the number of SYN retransmits // before a connect is aborted. DefaultSynRetries = 6 + + // MaxListenBacklog is the maximum limit of listen backlog supported. + MaxListenBacklog = 1024 ) const ( @@ -75,63 +78,6 @@ const ( ccCubic = "cubic" ) -// syncRcvdCounter tracks the number of endpoints in the SYN-RCVD state. The -// value is protected by a mutex so that we can increment only when it's -// guaranteed not to go above a threshold. -type synRcvdCounter struct { - sync.Mutex - value uint64 - pending sync.WaitGroup - threshold uint64 -} - -// inc tries to increment the global number of endpoints in SYN-RCVD state. It -// succeeds if the increment doesn't make the count go beyond the threshold, and -// fails otherwise. -func (s *synRcvdCounter) inc() bool { - s.Lock() - defer s.Unlock() - if s.value >= s.threshold { - return false - } - - s.pending.Add(1) - s.value++ - - return true -} - -// dec atomically decrements the global number of endpoints in SYN-RCVD -// state. It must only be called if a previous call to inc succeeded. -func (s *synRcvdCounter) dec() { - s.Lock() - defer s.Unlock() - s.value-- - s.pending.Done() -} - -// synCookiesInUse returns true if the synRcvdCount is greater than -// SynRcvdCountThreshold. -func (s *synRcvdCounter) synCookiesInUse() bool { - s.Lock() - defer s.Unlock() - return s.value >= s.threshold -} - -// SetThreshold sets synRcvdCounter.Threshold to ths new threshold. -func (s *synRcvdCounter) SetThreshold(threshold uint64) { - s.Lock() - defer s.Unlock() - s.threshold = threshold -} - -// Threshold returns the current value of synRcvdCounter.Threhsold. -func (s *synRcvdCounter) Threshold() uint64 { - s.Lock() - defer s.Unlock() - return s.threshold -} - type protocol struct { stack *stack.Stack @@ -139,6 +85,7 @@ type protocol struct { sackEnabled bool recovery tcpip.TCPRecovery delayEnabled bool + alwaysUseSynCookies bool sendBufferSize tcpip.TCPSendBufferSizeRangeOption recvBufferSize tcpip.TCPReceiveBufferSizeRangeOption congestionControl string @@ -150,7 +97,6 @@ type protocol struct { minRTO time.Duration maxRTO time.Duration maxRetries uint32 - synRcvdCount synRcvdCounter synRetries uint8 dispatcher dispatcher } @@ -373,9 +319,9 @@ func (p *protocol) SetOption(option tcpip.SettableTransportProtocolOption) tcpip p.mu.Unlock() return nil - case *tcpip.TCPSynRcvdCountThresholdOption: + case *tcpip.TCPAlwaysUseSynCookies: p.mu.Lock() - p.synRcvdCount.SetThreshold(uint64(*v)) + p.alwaysUseSynCookies = bool(*v) p.mu.Unlock() return nil @@ -480,9 +426,9 @@ func (p *protocol) Option(option tcpip.GettableTransportProtocolOption) tcpip.Er p.mu.RUnlock() return nil - case *tcpip.TCPSynRcvdCountThresholdOption: + case *tcpip.TCPAlwaysUseSynCookies: p.mu.RLock() - *v = tcpip.TCPSynRcvdCountThresholdOption(p.synRcvdCount.Threshold()) + *v = tcpip.TCPAlwaysUseSynCookies(p.alwaysUseSynCookies) p.mu.RUnlock() return nil @@ -507,12 +453,6 @@ func (p *protocol) Wait() { p.dispatcher.wait() } -// SynRcvdCounter returns a reference to the synRcvdCount for this protocol -// instance. -func (p *protocol) SynRcvdCounter() *synRcvdCounter { - return &p.synRcvdCount -} - // Parse implements stack.TransportProtocol.Parse. func (*protocol) Parse(pkt *stack.PacketBuffer) bool { return parse.TCP(pkt) @@ -537,7 +477,6 @@ func NewProtocol(s *stack.Stack) stack.TransportProtocol { lingerTimeout: DefaultTCPLingerTimeout, timeWaitTimeout: DefaultTCPTimeWaitTimeout, timeWaitReuse: tcpip.TCPTimeWaitReuseLoopbackOnly, - synRcvdCount: synRcvdCounter{threshold: SynRcvdCountThreshold}, synRetries: DefaultSynRetries, minRTO: MinRTO, maxRTO: MaxRTO, diff --git a/pkg/tcpip/transport/tcp/tcp_sack_test.go b/pkg/tcpip/transport/tcp/tcp_sack_test.go index 81f800cad..20c9761f2 100644 --- a/pkg/tcpip/transport/tcp/tcp_sack_test.go +++ b/pkg/tcpip/transport/tcp/tcp_sack_test.go @@ -160,12 +160,9 @@ func TestSackPermittedAccept(t *testing.T) { defer c.Cleanup() if tc.cookieEnabled { - // Set the SynRcvd threshold to - // zero to force a syn cookie - // based accept to happen. - var opt tcpip.TCPSynRcvdCountThresholdOption + opt := tcpip.TCPAlwaysUseSynCookies(true) if err := c.Stack().SetTransportProtocolOption(tcp.ProtocolNumber, &opt); err != nil { - t.Fatalf("SetTransportProtocolOption(%d, &%T(%d)): %s", tcp.ProtocolNumber, opt, opt, err) + t.Fatalf("SetTransportProtocolOption(%d, &%T(%t)): %s", tcp.ProtocolNumber, opt, opt, err) } } setStackSACKPermitted(t, c, sackEnabled) @@ -235,12 +232,9 @@ func TestSackDisabledAccept(t *testing.T) { defer c.Cleanup() if tc.cookieEnabled { - // Set the SynRcvd threshold to - // zero to force a syn cookie - // based accept to happen. - var opt tcpip.TCPSynRcvdCountThresholdOption + opt := tcpip.TCPAlwaysUseSynCookies(true) if err := c.Stack().SetTransportProtocolOption(tcp.ProtocolNumber, &opt); err != nil { - t.Fatalf("SetTransportProtocolOption(%d, &%T(%d)): %s", tcp.ProtocolNumber, opt, opt, err) + t.Fatalf("SetTransportProtocolOption(%d, &%T(%t)): %s", tcp.ProtocolNumber, opt, opt, err) } } diff --git a/pkg/tcpip/transport/tcp/tcp_test.go b/pkg/tcpip/transport/tcp/tcp_test.go index 9c23469f2..5605a4390 100644 --- a/pkg/tcpip/transport/tcp/tcp_test.go +++ b/pkg/tcpip/transport/tcp/tcp_test.go @@ -955,11 +955,7 @@ func TestUserSuppliedMSSOnConnect(t *testing.T) { // when completing the handshake for a new TCP connection from a TCP // listening socket. It should be present in the sent TCP SYN-ACK segment. func TestUserSuppliedMSSOnListenAccept(t *testing.T) { - const ( - nonSynCookieAccepts = 2 - totalAccepts = 4 - mtu = 5000 - ) + const mtu = 5000 ips := []struct { name string @@ -1033,12 +1029,6 @@ func TestUserSuppliedMSSOnListenAccept(t *testing.T) { ip.createEP(c) - // Set the SynRcvd threshold to force a syn cookie based accept to happen. - opt := tcpip.TCPSynRcvdCountThresholdOption(nonSynCookieAccepts) - if err := c.Stack().SetTransportProtocolOption(tcp.ProtocolNumber, &opt); err != nil { - t.Fatalf("SetTransportProtocolOption(%d, &%T(%d)): %s", tcp.ProtocolNumber, opt, opt, err) - } - if err := c.EP.SetSockOptInt(tcpip.MaxSegOption, int(test.setMSS)); err != nil { t.Fatalf("SetSockOptInt(MaxSegOption, %d): %s", test.setMSS, err) } @@ -1048,13 +1038,17 @@ func TestUserSuppliedMSSOnListenAccept(t *testing.T) { t.Fatalf("Bind(%+v): %s:", bindAddr, err) } - if err := c.EP.Listen(totalAccepts); err != nil { - t.Fatalf("Listen(%d): %s:", totalAccepts, err) + backlog := 5 + // Keep the number of client requests twice to the backlog + // such that half of the connections do not use syncookies + // and the other half does. + clientConnects := backlog * 2 + + if err := c.EP.Listen(backlog); err != nil { + t.Fatalf("Listen(%d): %s:", backlog, err) } - // The first nonSynCookieAccepts packets sent will trigger a gorooutine - // based accept. The rest will trigger a cookie based accept. - for i := 0; i < totalAccepts; i++ { + for i := 0; i < clientConnects; i++ { // Send a SYN requests. iss := seqnum.Value(i) srcPort := context.TestPort + uint16(i) @@ -3087,11 +3081,9 @@ func TestSynCookiePassiveSendMSSLessThanMTU(t *testing.T) { c := context.New(t, mtu) defer c.Cleanup() - // Set the SynRcvd threshold to zero to force a syn cookie based accept - // to happen. - opt := tcpip.TCPSynRcvdCountThresholdOption(0) + opt := tcpip.TCPAlwaysUseSynCookies(true) if err := c.Stack().SetTransportProtocolOption(tcp.ProtocolNumber, &opt); err != nil { - t.Fatalf("SetTransportProtocolOption(%d, &%T(%d)): %s", tcp.ProtocolNumber, opt, opt, err) + t.Fatalf("SetTransportProtocolOption(%d, &%T(%t)): %s", tcp.ProtocolNumber, opt, opt, err) } // Create EP and start listening. @@ -5363,7 +5355,7 @@ func TestListenBacklogFull(t *testing.T) { } lastPortOffset := uint16(0) - for ; int(lastPortOffset) < listenBacklog; lastPortOffset++ { + for ; int(lastPortOffset) < listenBacklog+1; lastPortOffset++ { executeHandshake(t, c, context.TestPort+lastPortOffset, false /*synCookieInUse */) } @@ -5671,15 +5663,13 @@ func TestListenSynRcvdQueueFull(t *testing.T) { } // Test acceptance. - // Start listening. - listenBacklog := 1 - if err := c.EP.Listen(listenBacklog); err != nil { + if err := c.EP.Listen(0); err != nil { t.Fatalf("Listen failed: %s", err) } // Send two SYN's the first one should get a SYN-ACK, the // second one should not get any response and is dropped as - // the synRcvd count will be equal to backlog. + // the accept queue is full. irs := seqnum.Value(context.TestInitialSequenceNumber) c.SendPacket(nil, &context.Headers{ SrcPort: context.TestPort, @@ -5701,23 +5691,7 @@ func TestListenSynRcvdQueueFull(t *testing.T) { } checker.IPv4(t, b, checker.TCP(tcpCheckers...)) - // Now execute send one more SYN. The stack should not respond as the backlog - // is full at this point. - // - // NOTE: we did not complete the handshake for the previous one so the - // accept backlog should be empty and there should be one connection in - // synRcvd state. - c.SendPacket(nil, &context.Headers{ - SrcPort: context.TestPort + 1, - DstPort: context.StackPort, - Flags: header.TCPFlagSyn, - SeqNum: seqnum.Value(889), - RcvWnd: 30000, - }) - c.CheckNoPacketTimeout("unexpected packet received", 50*time.Millisecond) - - // Now complete the previous connection and verify that there is a connection - // to accept. + // Now complete the previous connection. // Send ACK. c.SendPacket(nil, &context.Headers{ SrcPort: context.TestPort, @@ -5728,11 +5702,24 @@ func TestListenSynRcvdQueueFull(t *testing.T) { RcvWnd: 30000, }) - // Try to accept the connections in the backlog. + // Verify if that is delivered to the accept queue. we, ch := waiter.NewChannelEntry(nil) c.WQ.EventRegister(&we, waiter.ReadableEvents) defer c.WQ.EventUnregister(&we) + <-ch + + // Now execute send one more SYN. The stack should not respond as the backlog + // is full at this point. + c.SendPacket(nil, &context.Headers{ + SrcPort: context.TestPort + 1, + DstPort: context.StackPort, + Flags: header.TCPFlagSyn, + SeqNum: seqnum.Value(889), + RcvWnd: 30000, + }) + c.CheckNoPacketTimeout("unexpected packet received", 50*time.Millisecond) + // Try to accept the connections in the backlog. newEP, _, err := c.EP.Accept(nil) if _, ok := err.(*tcpip.ErrWouldBlock); ok { // Wait for connection to be established. @@ -5764,11 +5751,6 @@ func TestListenBacklogFullSynCookieInUse(t *testing.T) { c := context.New(t, defaultMTU) defer c.Cleanup() - opt := tcpip.TCPSynRcvdCountThresholdOption(1) - if err := c.Stack().SetTransportProtocolOption(tcp.ProtocolNumber, &opt); err != nil { - t.Fatalf("SetTransportProtocolOption(%d, &%T(%d)): %s", tcp.ProtocolNumber, opt, opt, err) - } - // Create TCP endpoint. var err tcpip.Error c.EP, err = c.Stack().NewEndpoint(tcp.ProtocolNumber, ipv4.ProtocolNumber, &c.WQ) @@ -5781,9 +5763,8 @@ func TestListenBacklogFullSynCookieInUse(t *testing.T) { t.Fatalf("Bind failed: %s", err) } - // Start listening. - listenBacklog := 1 - if err := c.EP.Listen(listenBacklog); err != nil { + // Test for SynCookies usage after filling up the backlog. + if err := c.EP.Listen(0); err != nil { t.Fatalf("Listen failed: %s", err) } @@ -6066,7 +6047,7 @@ func TestPassiveFailedConnectionAttemptIncrement(t *testing.T) { if err := c.EP.Bind(tcpip.FullAddress{Addr: context.StackAddr, Port: context.StackPort}); err != nil { t.Fatalf("Bind failed: %s", err) } - if err := c.EP.Listen(1); err != nil { + if err := c.EP.Listen(0); err != nil { t.Fatalf("Listen failed: %s", err) } diff --git a/pkg/tcpip/transport/tcp/tcp_timestamp_test.go b/pkg/tcpip/transport/tcp/tcp_timestamp_test.go index 2949588ce..1deb1fe4d 100644 --- a/pkg/tcpip/transport/tcp/tcp_timestamp_test.go +++ b/pkg/tcpip/transport/tcp/tcp_timestamp_test.go @@ -139,9 +139,9 @@ func timeStampEnabledAccept(t *testing.T, cookieEnabled bool, wndScale int, wndS defer c.Cleanup() if cookieEnabled { - var opt tcpip.TCPSynRcvdCountThresholdOption + opt := tcpip.TCPAlwaysUseSynCookies(true) if err := c.Stack().SetTransportProtocolOption(tcp.ProtocolNumber, &opt); err != nil { - t.Fatalf("SetTransportProtocolOption(%d, &%T(%d)): %s", tcp.ProtocolNumber, opt, opt, err) + t.Fatalf("SetTransportProtocolOption(%d, &%T(%t)): %s", tcp.ProtocolNumber, opt, opt, err) } } @@ -202,9 +202,9 @@ func timeStampDisabledAccept(t *testing.T, cookieEnabled bool, wndScale int, wnd defer c.Cleanup() if cookieEnabled { - var opt tcpip.TCPSynRcvdCountThresholdOption + opt := tcpip.TCPAlwaysUseSynCookies(true) if err := c.Stack().SetTransportProtocolOption(tcp.ProtocolNumber, &opt); err != nil { - t.Fatalf("SetTransportProtocolOption(%d, &%T(%d)): %s", tcp.ProtocolNumber, opt, opt, err) + t.Fatalf("SetTransportProtocolOption(%d, &%T(%t)): %s", tcp.ProtocolNumber, opt, opt, err) } } |