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

File Facts

System

Linux kernel

Corpus path

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

Extension

.pkt

Size

1318 bytes

Lines

29

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.

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

Dependency Surface

• No C-style include directives detected by the generator.

Detected Declarations

• No top-level syscall, struct, function, initcall, or export declaration detected by the generator.

Annotated Snippet

// Test SACK space grab to fit AccECN option
--tcp_ts_tick_usecs=1000

`./defaults.sh
sysctl -q net.ipv4.tcp_ecn=3
`

    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 < SEWA 0:0(0) win 32792 <mss 1050,nop,nop,sackOK,nop,wscale 8>
+.002 > SW. 0:0(0) ack 1 <mss 1460,ECN e1b 1 ceb 0 e0b 1,nop,nop,nop,sackOK,nop,wscale 8>
+0.05 < [ect0] W. 1:1(0) ack 1 win 264 <ECN e0b 1 ceb 0 e1b 1,nop>
+.002 accept(3, ..., ...) = 4

+.01 < [ect1] EAP. 1001:2001(1000) ack 1 win 264
+0.002 > [ect0] EA. 1:1(0) ack 1 <ECN e1b 1001 ceb 0 e0b 1,nop,nop,nop,sack 1001:2001>
+.01 < [ect0] EAP. 3001:4001(1000) ack 1 win 264
+0.002 > [ect0] EA. 1:1(0) ack 1 <ECN e1b 1001 ceb 0 e0b 1001,nop,nop,nop,sack 3001:4001 1001:2001>
+.01 < [ce] EAP. 5001:6001(1000) ack 1 win 264
+0.002 > [ect0] WA. 1:1(0) ack 1 <ECN e1b 1001 ceb 1000 e0b 1001,nop,nop,nop,sack 5001:6001 3001:4001 1001:2001>
// DSACK works?
+.01 < [ect0] EAP. 5001:6001(1000) ack 1 win 264
+0.002 > [ect0] WA. 1:1(0) ack 1 <ECN e1b 1001 ceb 1000 e0b 2001,nop,nop,nop,sack 5001:6001 5001:6001 3001:4001>
+.01 < [ect1] EAP. 6001:7001(1000) ack 1 win 264
+0.002 > [ect0] WA. 1:1(0) ack 1 <ECN e1b 2001 ceb 1000 e0b 2001,nop,nop,nop,sack 5001:7001 3001:4001 1001:2001>

Annotation

• Atlas domain: Support Tooling And Documentation / tools.
• Implementation status: atlas-only.

Implementation Notes

• This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
• Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
• Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.