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

Source file repositories/reference/linux-study-clean/tools/testing/selftests/bpf/progs/test_xdp_devmap_helpers.c

File Facts

System
Linux kernel
Corpus path
tools/testing/selftests/bpf/progs/test_xdp_devmap_helpers.c
Extension
.c
Size
580 bytes
Lines
23
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.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0
/* fails to load without expected_attach_type = BPF_XDP_DEVMAP
 * because of access to egress_ifindex
 */
#include <linux/bpf.h>
#include <bpf/bpf_helpers.h>

SEC("xdp")
int xdpdm_devlog(struct xdp_md *ctx)
{
	char fmt[] = "devmap redirect: dev %u -> dev %u len %u\n";
	void *data_end = (void *)(long)ctx->data_end;
	void *data = (void *)(long)ctx->data;
	unsigned int len = data_end - data;

	bpf_trace_printk(fmt, sizeof(fmt),
			 ctx->ingress_ifindex, ctx->egress_ifindex, len);

	return XDP_PASS;
}

char _license[] SEC("license") = "GPL";

Annotation

Implementation Notes