tools/testing/selftests/net/packetdrill/tcp_disorder_fin_in_FIN_WAIT.pkt

Source file repositories/reference/linux-study-clean/tools/testing/selftests/net/packetdrill/tcp_disorder_fin_in_FIN_WAIT.pkt

File Facts

System
Linux kernel
Corpus path
tools/testing/selftests/net/packetdrill/tcp_disorder_fin_in_FIN_WAIT.pkt
Extension
.pkt
Size
915 bytes
Lines
34
Domain
Support Tooling And Documentation
Bucket
tools
Inferred role
Support Tooling And Documentation: tools
Status
atlas-only

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0

// Check fix in 795a7dfbc3d9 ("net: tcp: accept old ack during closing")

// Set up config.
`./defaults.sh`

// Initialize a server socket.
    0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
   +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
   +0 bind(3, ..., ...) = 0
   +0 listen(3, 1) = 0

   +0 < S  0:0(0) win 65535 <mss 1000,sackOK,nop,nop,nop,wscale 7>
   *  > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK,nop,wscale 8>
   +0 < .  1:1(0) ack 1 win 257

   +0 accept(3, ..., ...) = 4

   +0 shutdown(4, SHUT_WR) = 0
   *  > F. 1:1(0) ack 1

// We expect to receive one ACK.
// But what happens if a FIN was already in transmt and received out-of-order ?

   +0 < .  2:2(0) ack 2 win 257

// This FIN packet was sent before the prior ACK (see ack 1).
   +0 < F. 1:1(0) ack 1 win 257

// Even if the FIN is received out-of-order, we should ACK it.

   *  > .  2:2(0) ack 2

Annotation

Implementation Notes