xfrm_info.c

 1// SPDX-License-Identifier: GPL-2.0
 2#define BPF_NO_KFUNC_PROTOTYPES
 3#include "vmlinux.h"
 4#include "bpf_tracing_net.h"
 5#include <bpf/bpf_helpers.h>
 6
 7struct bpf_xfrm_info___local {
 8	u32 if_id;
 9	int link;
10} __attribute__((preserve_access_index));
11
12__u32 req_if_id;
13__u32 resp_if_id;
14
15int bpf_skb_set_xfrm_info(struct __sk_buff *skb_ctx,
16			  const struct bpf_xfrm_info___local *from) __ksym;
17int bpf_skb_get_xfrm_info(struct __sk_buff *skb_ctx,
18			  struct bpf_xfrm_info___local *to) __ksym;
19
20SEC("tc")
21int set_xfrm_info(struct __sk_buff *skb)
22{
23	struct bpf_xfrm_info___local info = { .if_id = req_if_id };
24
25	return bpf_skb_set_xfrm_info(skb, &info) ? TC_ACT_SHOT : TC_ACT_UNSPEC;
26}
27
28SEC("tc")
29int get_xfrm_info(struct __sk_buff *skb)
30{
31	struct bpf_xfrm_info___local info = {};
32
33	if (bpf_skb_get_xfrm_info(skb, &info) < 0)
34		return TC_ACT_SHOT;
35
36	resp_if_id = info.if_id;
37
38	return TC_ACT_UNSPEC;
39}
40
41char _license[] SEC("license") = "GPL";