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| author | Ghanan Gowripalan <ghanan@google.com> | 2019-11-06 10:42:00 -0800 |
|---|---|---|
| committer | gVisor bot <gvisor-bot@google.com> | 2019-11-06 10:44:20 -0800 |
| commit | d0d89ceeddd21f1f22e818d78dc3b07d3669dbb5 (patch) | |
| tree | 86cd1ee8da9365b358ff5e8a5392dcbadcf3544d /pkg/tcpip/transport/tcp/segment.go | |
| parent | a824b48ceac4e2e3bacd23d63e72881c76d669c8 (diff) | |
Send a TCP RST in response to a TCP SYN-ACK on a listening endpoint
This change better follows what is outlined in RFC 793 section 3.4 figure 12
where a listening socket should not accept a SYN-ACK segment in response to a
(potentially) old SYN segment.
Tests: Test that checks the TCP RST segment sent in response to a TCP SYN-ACK
segment received on a listening TCP endpoint.
PiperOrigin-RevId: 278893114
Diffstat (limited to 'pkg/tcpip/transport/tcp/segment.go')
| -rw-r--r-- | pkg/tcpip/transport/tcp/segment.go | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/pkg/tcpip/transport/tcp/segment.go b/pkg/tcpip/transport/tcp/segment.go index ea725d513..c4a89525e 100644 --- a/pkg/tcpip/transport/tcp/segment.go +++ b/pkg/tcpip/transport/tcp/segment.go @@ -99,8 +99,14 @@ func (s *segment) clone() *segment { return t } -func (s *segment) flagIsSet(flag uint8) bool { - return (s.flags & flag) != 0 +// flagIsSet checks if at least one flag in flags is set in s.flags. +func (s *segment) flagIsSet(flags uint8) bool { + return s.flags&flags != 0 +} + +// flagsAreSet checks if all flags in flags are set in s.flags. +func (s *segment) flagsAreSet(flags uint8) bool { + return s.flags&flags == flags } func (s *segment) decRef() { |