diff options
| -rw-r--r-- | pkg/tcpip/transport/tcp/tcp_test.go | 122 | ||||
| -rw-r--r-- | pkg/tcpip/transport/tcp/testing/context/context.go | 6 |
2 files changed, 127 insertions, 1 deletions
diff --git a/pkg/tcpip/transport/tcp/tcp_test.go b/pkg/tcpip/transport/tcp/tcp_test.go index c4b45aa6f..50829ae27 100644 --- a/pkg/tcpip/transport/tcp/tcp_test.go +++ b/pkg/tcpip/transport/tcp/tcp_test.go @@ -792,6 +792,82 @@ func TestSendRstOnListenerRxSynAckV6(t *testing.T) { checker.SeqNum(200))) } +// TestTCPAckBeforeAcceptV4 tests that once the 3-way handshake is complete, +// peers can send data and expect a response within a reasonable ammount of time +// without calling Accept on the listening endpoint first. +// +// This test uses IPv4. +func TestTCPAckBeforeAcceptV4(t *testing.T) { + c := context.New(t, defaultMTU) + defer c.Cleanup() + + c.Create(-1) + + if err := c.EP.Bind(tcpip.FullAddress{Port: context.StackPort}); err != nil { + t.Fatal("Bind failed:", err) + } + + if err := c.EP.Listen(10); err != nil { + t.Fatal("Listen failed:", err) + } + + irs, iss := executeHandshake(t, c, context.TestPort, false /* synCookiesInUse */) + + // Send data before accepting the connection. + c.SendPacket([]byte{1, 2, 3, 4}, &context.Headers{ + SrcPort: context.TestPort, + DstPort: context.StackPort, + Flags: header.TCPFlagAck, + SeqNum: irs + 1, + AckNum: iss + 1, + }) + + // Receive ACK for the data we sent. + checker.IPv4(t, c.GetPacket(), checker.TCP( + checker.DstPort(context.TestPort), + checker.TCPFlags(header.TCPFlagAck), + checker.SeqNum(uint32(iss+1)), + checker.AckNum(uint32(irs+5)))) +} + +// TestTCPAckBeforeAcceptV6 tests that once the 3-way handshake is complete, +// peers can send data and expect a response within a reasonable ammount of time +// without calling Accept on the listening endpoint first. +// +// This test uses IPv6. +func TestTCPAckBeforeAcceptV6(t *testing.T) { + c := context.New(t, defaultMTU) + defer c.Cleanup() + + c.CreateV6Endpoint(true) + + if err := c.EP.Bind(tcpip.FullAddress{Port: context.StackPort}); err != nil { + t.Fatal("Bind failed:", err) + } + + if err := c.EP.Listen(10); err != nil { + t.Fatal("Listen failed:", err) + } + + irs, iss := executeV6Handshake(t, c, context.TestPort, false /* synCookiesInUse */) + + // Send data before accepting the connection. + c.SendV6Packet([]byte{1, 2, 3, 4}, &context.Headers{ + SrcPort: context.TestPort, + DstPort: context.StackPort, + Flags: header.TCPFlagAck, + SeqNum: irs + 1, + AckNum: iss + 1, + }) + + // Receive ACK for the data we sent. + checker.IPv6(t, c.GetV6Packet(), checker.TCP( + checker.DstPort(context.TestPort), + checker.TCPFlags(header.TCPFlagAck), + checker.SeqNum(uint32(iss+1)), + checker.AckNum(uint32(irs+5)))) +} + func TestSendRstOnListenerRxAckV4(t *testing.T) { c := context.New(t, defaultMTU) defer c.Cleanup() @@ -4303,7 +4379,7 @@ func executeHandshake(t *testing.T, c *context.Context, srcPort uint16, synCooki RcvWnd: 30000, }) - // Receive the SYN-ACK reply.w + // Receive the SYN-ACK reply. b := c.GetPacket() tcp := header.TCP(header.IPv4(b).Payload()) iss = seqnum.Value(tcp.SequenceNumber()) @@ -4336,6 +4412,50 @@ func executeHandshake(t *testing.T, c *context.Context, srcPort uint16, synCooki return irs, iss } +func executeV6Handshake(t *testing.T, c *context.Context, srcPort uint16, synCookieInUse bool) (irs, iss seqnum.Value) { + // Send a SYN request. + irs = seqnum.Value(789) + c.SendV6Packet(nil, &context.Headers{ + SrcPort: srcPort, + DstPort: context.StackPort, + Flags: header.TCPFlagSyn, + SeqNum: irs, + RcvWnd: 30000, + }) + + // Receive the SYN-ACK reply. + b := c.GetV6Packet() + tcp := header.TCP(header.IPv6(b).Payload()) + iss = seqnum.Value(tcp.SequenceNumber()) + tcpCheckers := []checker.TransportChecker{ + checker.SrcPort(context.StackPort), + checker.DstPort(srcPort), + checker.TCPFlags(header.TCPFlagAck | header.TCPFlagSyn), + checker.AckNum(uint32(irs) + 1), + } + + if synCookieInUse { + // When cookies are in use window scaling is disabled. + tcpCheckers = append(tcpCheckers, checker.TCPSynOptions(header.TCPSynOptions{ + WS: -1, + MSS: c.MSSWithoutOptionsV6(), + })) + } + + checker.IPv6(t, b, checker.TCP(tcpCheckers...)) + + // Send ACK. + c.SendV6Packet(nil, &context.Headers{ + SrcPort: srcPort, + DstPort: context.StackPort, + Flags: header.TCPFlagAck, + SeqNum: irs + 1, + AckNum: iss + 1, + RcvWnd: 30000, + }) + return irs, iss +} + // TestListenBacklogFull tests that netstack does not complete handshakes if the // listen backlog for the endpoint is full. func TestListenBacklogFull(t *testing.T) { diff --git a/pkg/tcpip/transport/tcp/testing/context/context.go b/pkg/tcpip/transport/tcp/testing/context/context.go index 04fdaaed1..6cb66c1af 100644 --- a/pkg/tcpip/transport/tcp/testing/context/context.go +++ b/pkg/tcpip/transport/tcp/testing/context/context.go @@ -1089,3 +1089,9 @@ func (c *Context) SetGSOEnabled(enable bool) { func (c *Context) MSSWithoutOptions() uint16 { return uint16(c.linkEP.MTU() - header.IPv4MinimumSize - header.TCPMinimumSize) } + +// MSSWithoutOptionsV6 returns the value for the MSS used by the stack when no +// options are in use for IPv6 packets. +func (c *Context) MSSWithoutOptionsV6() uint16 { + return uint16(c.linkEP.MTU() - header.IPv6MinimumSize - header.TCPMinimumSize) +} |