diff options
Diffstat (limited to 'pkg/tcpip/transport/tcp/accept.go')
| -rw-r--r-- | pkg/tcpip/transport/tcp/accept.go | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/pkg/tcpip/transport/tcp/accept.go b/pkg/tcpip/transport/tcp/accept.go index 1dd00d026..cb0e13ebc 100644 --- a/pkg/tcpip/transport/tcp/accept.go +++ b/pkg/tcpip/transport/tcp/accept.go @@ -25,6 +25,7 @@ import ( "gvisor.dev/gvisor/pkg/rand" "gvisor.dev/gvisor/pkg/sleep" "gvisor.dev/gvisor/pkg/tcpip" + "gvisor.dev/gvisor/pkg/tcpip/buffer" "gvisor.dev/gvisor/pkg/tcpip/header" "gvisor.dev/gvisor/pkg/tcpip/seqnum" "gvisor.dev/gvisor/pkg/tcpip/stack" @@ -400,6 +401,14 @@ func (e *endpoint) acceptQueueIsFull() bool { // handleListenSegment is called when a listening endpoint receives a segment // and needs to handle it. func (e *endpoint) handleListenSegment(ctx *listenContext, s *segment) { + if s.flagsAreSet(header.TCPFlagSyn | header.TCPFlagAck) { + // RFC 793 section 3.4 page 35 (figure 12) outlines that a RST + // must be sent in response to a SYN-ACK while in the listen + // state to prevent completing a handshake from an old SYN. + e.sendTCP(&s.route, s.id, buffer.VectorisedView{}, e.ttl, e.sendTOS, header.TCPFlagRst, s.ackNumber, 0, 0, nil, nil) + return + } + // TODO(b/143300739): Use the userMSS of the listening socket // for accepted sockets. |