tools/testing/selftests/net/packetdrill/tcp_syscall_bad_arg_fastopen-invalid-buf-ptr.pkt

File Facts

System

Linux kernel

Corpus path

tools/testing/selftests/net/packetdrill/tcp_syscall_bad_arg_fastopen-invalid-buf-ptr.pkt

Extension

.pkt

Size

1571 bytes

Lines

43

Domain

Support Tooling And Documentation

Bucket

tools

Inferred role

Support Tooling And Documentation: syscall or user/kernel boundary

Status

core implementation candidate

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.
• Defines or participates in a user/kernel boundary; inspect argument validation, copy_from_user/copy_to_user, credentials, and dispatch target.

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

// SPDX-License-Identifier: GPL-2.0
// Test TCP fastopen behavior with NULL as buffer pointer, but a non-zero
// buffer length.
`./defaults.sh
./set_sysctls.py /proc/sys/net/ipv4/tcp_timestamps=0`

// Cache warmup: send a Fast Open cookie request
 0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
+0 fcntl(3, F_SETFL, O_RDWR|O_NONBLOCK) = 0
+0 setsockopt(3, SOL_TCP, TCP_FASTOPEN_CONNECT, [1], 4) = 0
+0 connect(3, ..., ...) = -1 EINPROGRESS (Operation is now in progress)
+0 > S 0:0(0) <mss 1460,nop,nop,sackOK,nop,wscale 8,FO,nop,nop>
+0 < S. 123:123(0) ack 1 win 14600 <mss 1460,nop,nop,sackOK,nop,wscale 6,FO abcd1234,nop,nop>
+0 > . 1:1(0) ack 1
+0 close(3) = 0
+0 > F. 1:1(0) ack 1
+0 < F. 1:1(0) ack 2 win 92
+0 > .  2:2(0) ack 2

// Test with MSG_FASTOPEN without TCP_FASTOPEN_CONNECT.
+0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 4
+0 fcntl(4, F_SETFL, O_RDWR|O_NONBLOCK) = 0
+0 sendto(4, NULL, 1, MSG_FASTOPEN, ..., ...) = -1
+0 close(4) = 0

// Test with TCP_FASTOPEN_CONNECT without MSG_FASTOPEN.
+0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 5
+0 fcntl(5, F_SETFL, O_RDWR|O_NONBLOCK) = 0
+0 setsockopt(5, SOL_TCP, TCP_FASTOPEN_CONNECT, [1], 4) = 0
+0 connect(5, ..., ...) = 0
+0 sendto(5, NULL, 1, 0, ..., ...) = -1
+0 close(5) = 0

// Test with both TCP_FASTOPEN_CONNECT and MSG_FASTOPEN.
+0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 6
+0 fcntl(6, F_SETFL, O_RDWR|O_NONBLOCK) = 0
+0 setsockopt(6, SOL_TCP, TCP_FASTOPEN_CONNECT, [1], 4) = 0
+0 connect(6, ..., ...) = 0
+0 sendto(6, NULL, 1, MSG_FASTOPEN, ..., ...) = -1
+0 close(6) = 0

`/tmp/sysctl_restore_${PPID}.sh`

Annotation

• Atlas domain: Support Tooling And Documentation / tools.
• Implementation status: core implementation candidate.

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.