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Retain only mutually supported TCP options after simultaneous SYN
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Authored by rscheff on Jan 26 2020, 6:38 PM.
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Details

Summary

When receiving a parallel SYN in SYN-SENT state, remove all the
options only we supported locally before sending the SYN,ACK.

This addresses a consistency issue on parallel opens.

Also, on such a parallel open, the stack could be coaxed into
running with timestamps enabled, even if administratively disabled.

Test Plan

see tcp-testsuite/snippets/syn-rcvd-via-syn-sent-ipv4.pkt

Diff Detail

Lint
Lint Passed
Unit
No Test Coverage
Build Status
Buildable 30966
Build 28675: arc lint + arc unit

Event Timeline

sys/netinet/tcp_stacks/bbr.c
11605

why this change?

sys/netinet/tcp_input.c
1635

undo style change.

This revision is now accepted and ready to land.May 21 2020, 1:55 PM