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

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

File Facts

System
Linux kernel
Corpus path
tools/testing/selftests/net/packetdrill/tcp_rto_synack_rto_max.pkt
Extension
.pkt
Size
1606 bytes
Lines
55
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
//
// Test SYN+ACK RTX with 1s RTO.
//
`./defaults.sh
 ./set_sysctls.py /proc/sys/net/ipv4/tcp_rto_max_ms=1000`

//
// Test 1: TFO SYN+ACK
//
    0 socket(..., SOCK_STREAM|SOCK_NONBLOCK, IPPROTO_TCP) = 3
   +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
   +0 bind(3, ..., ...) = 0
   +0 listen(3, 1) = 0
   +0 setsockopt(3, SOL_TCP, TCP_FASTOPEN, [1], 4) = 0

   +0 < S 0:10(10) win 1000 <mss 1460,sackOK,nop,nop,FO TFO_COOKIE,nop,nop>
   +0 > S. 0:0(0) ack 11 <mss 1460,nop,nop,sackOK>

// RTO must be capped to 1s
   +1 > S. 0:0(0) ack 11 <mss 1460,nop,nop,sackOK>
   +1 > S. 0:0(0) ack 11 <mss 1460,nop,nop,sackOK>
   +1 > S. 0:0(0) ack 11 <mss 1460,nop,nop,sackOK>

   +0 < . 11:11(0) ack 1 win 1000 <mss 1460,nop,nop,sackOK>
   +0 accept(3, ..., ...) = 4
   +0 %{ assert (tcpi_options & TCPI_OPT_SYN_DATA) != 0, tcpi_options }%

   +0 close(4) = 0
   +0 close(3) = 0


//
// Test 2: non-TFO SYN+ACK
//
   +0 socket(..., SOCK_STREAM|SOCK_NONBLOCK, 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 1000 <mss 1460,sackOK,nop,nop>
   +0 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK>

// RTO must be capped to 1s
   +1 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK>
   +1 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK>
   +1 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK>

   +0 < . 1:1(0) ack 1 win 1000 <mss 1460,nop,nop,sackOK>
   +0 accept(3, ..., ...) = 4
   +0 %{ assert (tcpi_options & TCPI_OPT_SYN_DATA) == 0, tcpi_options }%

   +0 close(4) = 0
   +0 close(3) = 0

Annotation

Implementation Notes