File: load_bytes_relative.c

package info (click to toggle)
linux 6.1.8-1
  • links: PTS, VCS
  • area: main
  • in suites: bookworm
  • size: 1,488,076 kB
  • sloc: ansic: 23,401,844; asm: 266,744; sh: 108,976; makefile: 49,705; python: 36,927; perl: 36,810; cpp: 6,044; yacc: 4,904; lex: 2,722; awk: 1,440; ruby: 25; sed: 5
file content (48 lines) | stat: -rw-r--r-- 1,003 bytes parent folder | download | duplicates (20) 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
 
// SPDX-License-Identifier: GPL-2.0-only

/*
 * Copyright 2020 Google LLC.
 */

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

struct {
	__uint(type, BPF_MAP_TYPE_ARRAY);
	__uint(max_entries, 1);
	__type(key, __u32);
	__type(value, __u32);
} test_result SEC(".maps");

SEC("cgroup_skb/egress")
int load_bytes_relative(struct __sk_buff *skb)
{
	struct ethhdr eth;
	struct iphdr iph;

	__u32 map_key = 0;
	__u32 test_passed = 0;

	/* MAC header is not set by the time cgroup_skb/egress triggers */
	if (bpf_skb_load_bytes_relative(skb, 0, &eth, sizeof(eth),
					BPF_HDR_START_MAC) != -EFAULT)
		goto fail;

	if (bpf_skb_load_bytes_relative(skb, 0, &iph, sizeof(iph),
					BPF_HDR_START_NET))
		goto fail;

	if (bpf_skb_load_bytes_relative(skb, 0xffff, &iph, sizeof(iph),
					BPF_HDR_START_NET) != -EFAULT)
		goto fail;

	test_passed = 1;

fail:
	bpf_map_update_elem(&test_result, &map_key, &test_passed, BPF_ANY);

	return 1;
}