samples/bpf/sockex1_kern.c

Source file repositories/reference/linux-study-clean/samples/bpf/sockex1_kern.c

File Facts

System
Linux kernel
Corpus path
samples/bpf/sockex1_kern.c
Extension
.c
Size
661 bytes
Lines
31
Domain
Support Tooling And Documentation
Bucket
samples
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

#include <uapi/linux/bpf.h>
#include <uapi/linux/if_ether.h>
#include <uapi/linux/if_packet.h>
#include <uapi/linux/ip.h>
#include <bpf/bpf_helpers.h>
#include "bpf_legacy.h"

struct {
	__uint(type, BPF_MAP_TYPE_ARRAY);
	__type(key, u32);
	__type(value, long);
	__uint(max_entries, 256);
} my_map SEC(".maps");

SEC("socket1")
int bpf_prog1(struct __sk_buff *skb)
{
	int index = load_byte(skb, ETH_HLEN + offsetof(struct iphdr, protocol));
	long *value;

	if (skb->pkt_type != PACKET_OUTGOING)
		return 0;

	value = bpf_map_lookup_elem(&my_map, &index);
	if (value)
		__sync_fetch_and_add(value, skb->len);

	return 0;
}
char _license[] SEC("license") = "GPL";

Annotation

Implementation Notes