netns_cookie_prog.c

  1// SPDX-License-Identifier: GPL-2.0
  2
  3#include "vmlinux.h"
  4
  5#include <bpf/bpf_helpers.h>
  6
  7#define AF_INET6 10
  8
  9struct {
 10	__uint(type, BPF_MAP_TYPE_SK_STORAGE);
 11	__uint(map_flags, BPF_F_NO_PREALLOC);
 12	__type(key, int);
 13	__type(value, int);
 14} sockops_netns_cookies SEC(".maps");
 15
 16struct {
 17	__uint(type, BPF_MAP_TYPE_SK_STORAGE);
 18	__uint(map_flags, BPF_F_NO_PREALLOC);
 19	__type(key, int);
 20	__type(value, int);
 21} sk_msg_netns_cookies SEC(".maps");
 22
 23struct {
 24	__uint(type, BPF_MAP_TYPE_SOCKMAP);
 25	__uint(max_entries, 2);
 26	__type(key, __u32);
 27	__type(value, __u64);
 28} sock_map SEC(".maps");
 29
 30int tcx_init_netns_cookie, tcx_netns_cookie;
 31int cgroup_skb_init_netns_cookie, cgroup_skb_netns_cookie;
 32
 33SEC("sockops")
 34int get_netns_cookie_sockops(struct bpf_sock_ops *ctx)
 35{
 36	struct bpf_sock *sk = ctx->sk;
 37	int *cookie;
 38	__u32 key = 0;
 39
 40	if (ctx->family != AF_INET6)
 41		return 1;
 42
 43	if (!sk)
 44		return 1;
 45
 46	switch (ctx->op) {
 47	case BPF_SOCK_OPS_TCP_CONNECT_CB:
 48		cookie = bpf_sk_storage_get(&sockops_netns_cookies, sk, 0,
 49					    BPF_SK_STORAGE_GET_F_CREATE);
 50		if (!cookie)
 51			return 1;
 52
 53		*cookie = bpf_get_netns_cookie(ctx);
 54		break;
 55	case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB:
 56		bpf_sock_map_update(ctx, &sock_map, &key, BPF_NOEXIST);
 57		break;
 58	default:
 59		break;
 60	}
 61
 62	return 1;
 63}
 64
 65SEC("sk_msg")
 66int get_netns_cookie_sk_msg(struct sk_msg_md *msg)
 67{
 68	struct bpf_sock *sk = msg->sk;
 69	int *cookie;
 70
 71	if (msg->family != AF_INET6)
 72		return 1;
 73
 74	if (!sk)
 75		return 1;
 76
 77	cookie = bpf_sk_storage_get(&sk_msg_netns_cookies, sk, 0,
 78				    BPF_SK_STORAGE_GET_F_CREATE);
 79	if (!cookie)
 80		return 1;
 81
 82	*cookie = bpf_get_netns_cookie(msg);
 83
 84	return 1;
 85}
 86
 87SEC("tcx/ingress")
 88int get_netns_cookie_tcx(struct __sk_buff *skb)
 89{
 90	tcx_init_netns_cookie = bpf_get_netns_cookie(NULL);
 91	tcx_netns_cookie = bpf_get_netns_cookie(skb);
 92	return TCX_PASS;
 93}
 94
 95SEC("cgroup_skb/ingress")
 96int get_netns_cookie_cgroup_skb(struct __sk_buff *skb)
 97{
 98	cgroup_skb_init_netns_cookie = bpf_get_netns_cookie(NULL);
 99	cgroup_skb_netns_cookie = bpf_get_netns_cookie(skb);
100	return SK_PASS;
101}
102
103char _license[] SEC("license") = "GPL";