test_sockmap_redir.c

 1// SPDX-License-Identifier: GPL-2.0
 2
 3#include <linux/bpf.h>
 4#include <bpf/bpf_helpers.h>
 5#include "bpf_misc.h"
 6
 7SEC(".maps") struct {
 8	__uint(type, BPF_MAP_TYPE_SOCKMAP);
 9	__uint(max_entries, 1);
10	__type(key, __u32);
11	__type(value, __u64);
12} nop_map, sock_map;
13
14SEC(".maps") struct {
15	__uint(type, BPF_MAP_TYPE_SOCKHASH);
16	__uint(max_entries, 1);
17	__type(key, __u32);
18	__type(value, __u64);
19} nop_hash, sock_hash;
20
21SEC(".maps") struct {
22	__uint(type, BPF_MAP_TYPE_ARRAY);
23	__uint(max_entries, 2);
24	__type(key, int);
25	__type(value, unsigned int);
26} verdict_map;
27
28/* Set by user space */
29int redirect_type;
30int redirect_flags;
31
32#define redirect_map(__data)                                                   \
33	_Generic((__data),                                                     \
34		 struct __sk_buff * : bpf_sk_redirect_map,                     \
35		 struct sk_msg_md * : bpf_msg_redirect_map                     \
36	)((__data), &sock_map, (__u32){0}, redirect_flags)
37
38#define redirect_hash(__data)                                                  \
39	_Generic((__data),                                                     \
40		 struct __sk_buff * : bpf_sk_redirect_hash,                    \
41		 struct sk_msg_md * : bpf_msg_redirect_hash                    \
42	)((__data), &sock_hash, &(__u32){0}, redirect_flags)
43
44#define DEFINE_PROG(__type, __param)                                           \
45SEC("sk_" XSTR(__type))                                                        \
46int prog_ ## __type ## _verdict(__param data)                                  \
47{                                                                              \
48	unsigned int *count;                                                   \
49	int verdict;                                                           \
50									       \
51	if (redirect_type == BPF_MAP_TYPE_SOCKMAP)                             \
52		verdict = redirect_map(data);                                  \
53	else if (redirect_type == BPF_MAP_TYPE_SOCKHASH)                       \
54		verdict = redirect_hash(data);                                 \
55	else                                                                   \
56		verdict = redirect_type - __MAX_BPF_MAP_TYPE;                  \
57									       \
58	count = bpf_map_lookup_elem(&verdict_map, &verdict);                   \
59	if (count)                                                             \
60		(*count)++;                                                    \
61									       \
62	return verdict;                                                        \
63}
64
65DEFINE_PROG(skb, struct __sk_buff *);
66DEFINE_PROG(msg, struct sk_msg_md *);
67
68char _license[] SEC("license") = "GPL";