diff options
| author | Bhasker Hariharan <bhaskerh@google.com> | 2019-02-11 10:22:42 -0800 |
|---|---|---|
| committer | Shentubot <shentubot@google.com> | 2019-02-11 10:23:43 -0800 |
| commit | efe5e737d7da48e6f99a1d9a53fe04b6d21b7511 (patch) | |
| tree | 0709c0e8448a08c8ee361cf4ad961c10f8eea25b /pkg/tcpip/transport/tcp/connect.go | |
| parent | 85d53d81d9f544277e3e86f83558cbc008ff7adb (diff) | |
Do not drop packets w/ missing TCP timestamps.
RFC7323 recommends that if the timestamp option was negotiated
then all packets should carry a TCP Timestamp and any packets that
do not should be dropped.
Netstack implemented this behaviour. Linux OTOH does not and will
accept such packets. This change makes Netstack behaviour compatible
with Linux.
Also now that we allow such packets, we do need to update RTO calculations
based on these packets even if timestamp option is enabled.
PiperOrigin-RevId: 233432268
Change-Id: I9f4742ae6b63930ac3b5e37d8c238761e6a4b29f
Diffstat (limited to 'pkg/tcpip/transport/tcp/connect.go')
| -rw-r--r-- | pkg/tcpip/transport/tcp/connect.go | 15 |
1 files changed, 3 insertions, 12 deletions
diff --git a/pkg/tcpip/transport/tcp/connect.go b/pkg/tcpip/transport/tcp/connect.go index cc34e74b2..7b80f7519 100644 --- a/pkg/tcpip/transport/tcp/connect.go +++ b/pkg/tcpip/transport/tcp/connect.go @@ -289,8 +289,9 @@ func (h *handshake) synRcvdState(s *segment) *tcpip.Error { } // Update timestamp if required. See RFC7323, section-4.3. - h.ep.updateRecentTimestamp(s.parsedOptions.TSVal, h.ackNum, s.sequenceNumber) - + if h.ep.sendTSOk && s.parsedOptions.TS { + h.ep.updateRecentTimestamp(s.parsedOptions.TSVal, h.ackNum, s.sequenceNumber) + } h.state = handshakeCompleted return nil } @@ -740,16 +741,6 @@ func (e *endpoint) handleSegments() *tcpip.Error { // send window scale. s.window <<= e.snd.sndWndScale - // If the timestamp option is negotiated and the segment - // does not carry a timestamp option then the segment - // must be dropped as per - // https://tools.ietf.org/html/rfc7323#section-3.2. - if e.sendTSOk && !s.parsedOptions.TS { - e.stack.Stats().DroppedPackets.Increment() - s.decRef() - continue - } - // RFC 793, page 41 states that "once in the ESTABLISHED // state all segments must carry current acknowledgment // information." |