tools/testing/selftests/bpf/progs/cgroup_getset_retval_getsockopt.c

File Facts

System

Linux kernel

Corpus path

tools/testing/selftests/bpf/progs/cgroup_getset_retval_getsockopt.c

Extension

.c

Size

1106 bytes

Lines

59

Domain

Support Tooling And Documentation

Bucket

tools

Inferred role

Support Tooling And Documentation: implementation source

Status

source 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 uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

• errno.h
• linux/bpf.h
• bpf/bpf_helpers.h

Detected Declarations

• function get_retval
• function set_eisconn
• function clear_retval

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0-only

/*
 * Copyright 2021 Google LLC.
 */

#include <errno.h>
#include <linux/bpf.h>
#include <bpf/bpf_helpers.h>

__u32 invocations = 0;
__u32 assertion_error = 0;
__u32 retval_value = 0;
__u32 ctx_retval_value = 0;
__u32 page_size = 0;

SEC("cgroup/getsockopt")
int get_retval(struct bpf_sockopt *ctx)
{
	retval_value = bpf_get_retval();
	ctx_retval_value = ctx->retval;
	__sync_fetch_and_add(&invocations, 1);

	/* optval larger than PAGE_SIZE use kernel's buffer. */
	if (ctx->optlen > page_size)
		ctx->optlen = 0;

	return 1;
}

SEC("cgroup/getsockopt")
int set_eisconn(struct bpf_sockopt *ctx)
{
	__sync_fetch_and_add(&invocations, 1);

	if (bpf_set_retval(-EISCONN))
		assertion_error = 1;

	/* optval larger than PAGE_SIZE use kernel's buffer. */
	if (ctx->optlen > page_size)
		ctx->optlen = 0;

	return 1;
}

SEC("cgroup/getsockopt")
int clear_retval(struct bpf_sockopt *ctx)
{
	__sync_fetch_and_add(&invocations, 1);

	ctx->retval = 0;

	/* optval larger than PAGE_SIZE use kernel's buffer. */
	if (ctx->optlen > page_size)
		ctx->optlen = 0;

	return 1;
}

Annotation

• Immediate include surface: `errno.h`, `linux/bpf.h`, `bpf/bpf_helpers.h`.
• Detected declarations: `function get_retval`, `function set_eisconn`, `function clear_retval`.
• Atlas domain: Support Tooling And Documentation / tools.
• Implementation status: source 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.