Bug 250363 - [tcp] data in syn_ack should be ignored
Summary: [tcp] data in syn_ack should be ignored
Status: New
Alias: None
Product: Base System
Classification: Unclassified
Component: kern (show other bugs)
Version: Unspecified
Hardware: Any Any
: --- Affects Some People
Assignee: Michael Tuexen
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2020-10-15 09:57 UTC by Yong-Hao Zou
Modified: 2020-10-18 10:35 UTC (History)
2 users (show)

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Description Yong-Hao Zou 2020-10-15 09:57:22 UTC
data in syn_ack should be ignored as the following packetdrill script shows:

```
0.000 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
0.000 fcntl(3, F_GETFL) = 0x2 (flags O_RDWR)
0.000 fcntl(3, F_SETFL, O_RDWR|O_NONBLOCK) = 0

// Establish connection and verify that there was no error.
0.100 connect(3, ..., ...) = -1
0.100 > S 0:0(0) <...>

+0.1 < S. 1:513(512) ack 1 win 19712 
// f-stack/FreeBSD ack 513, Linux ack 1
+0.1 > . 1:1(0) ack 1

```