1// SPDX-License-Identifier: GPL-2.0
 2// Copyright (c) 2018 Facebook
 3
 4#include <linux/bpf.h>
 5#include <sys/socket.h>
 6
 7#include <bpf/bpf_helpers.h>
 8#include <bpf/bpf_endian.h>
 9
10struct socket_cookie {
11	__u64 cookie_key;
12	__u32 cookie_value;
13};
14
15struct {
16	__uint(type, BPF_MAP_TYPE_SK_STORAGE);
17	__uint(map_flags, BPF_F_NO_PREALLOC);
18	__type(key, int);
19	__type(value, struct socket_cookie);
20} socket_cookies SEC(".maps");
21
22SEC("cgroup/connect6")
23int set_cookie(struct bpf_sock_addr *ctx)
24{
25	struct socket_cookie *p;
26
27	if (ctx->family != AF_INET6 || ctx->user_family != AF_INET6)
28		return 1;
29
30	p = bpf_sk_storage_get(&socket_cookies, ctx->sk, 0,
31			       BPF_SK_STORAGE_GET_F_CREATE);
32	if (!p)
33		return 1;
34
35	p->cookie_value = 0xFF;
36	p->cookie_key = bpf_get_socket_cookie(ctx);
37
38	return 1;
39}
40
41SEC("sockops")
42int update_cookie(struct bpf_sock_ops *ctx)
43{
44	struct bpf_sock *sk;
45	struct socket_cookie *p;
46
47	if (ctx->family != AF_INET6)
48		return 1;
49
50	if (ctx->op != BPF_SOCK_OPS_TCP_CONNECT_CB)
51		return 1;
52
53	if (!ctx->sk)
54		return 1;
55
56	p = bpf_sk_storage_get(&socket_cookies, ctx->sk, 0, 0);
57	if (!p)
58		return 1;
59
60	if (p->cookie_key != bpf_get_socket_cookie(ctx))
61		return 1;
62
63	p->cookie_value = (ctx->local_port << 8) | p->cookie_value;
64
65	return 1;
66}
67
68int _version SEC("version") = 1;
69
70char _license[] SEC("license") = "GPL";