1// SPDX-License-Identifier: GPL-2.0
2/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */
3
4#include "vmlinux.h"
5#include <bpf/bpf_helpers.h>
6#include <bpf/bpf_tracing.h>
7#include "bpf_tracing_net.h"
8
9char _license[] SEC("license") = "GPL";
10
11struct socket_cookie {
12	__u64 cookie_key;
13	__u64 cookie_value;
14};
15
16struct {
17	__uint(type, BPF_MAP_TYPE_CGRP_STORAGE);
18	__uint(map_flags, BPF_F_NO_PREALLOC);
19	__type(key, int);
20	__type(value, struct socket_cookie);
21} socket_cookies SEC(".maps");
22
23SEC("cgroup/connect6")
24int set_cookie(struct bpf_sock_addr *ctx)
25{
26	struct socket_cookie *p;
27	struct tcp_sock *tcp_sk;
28	struct bpf_sock *sk;
29
30	if (ctx->family != AF_INET6 || ctx->user_family != AF_INET6)
31		return 1;
32
33	sk = ctx->sk;
34	if (!sk)
35		return 1;
36
37	tcp_sk = bpf_skc_to_tcp_sock(sk);
38	if (!tcp_sk)
39		return 1;
40
41	p = bpf_cgrp_storage_get(&socket_cookies,
42		tcp_sk->inet_conn.icsk_inet.sk.sk_cgrp_data.cgroup, 0,
43		BPF_LOCAL_STORAGE_GET_F_CREATE);
44	if (!p)
45		return 1;
46
47	p->cookie_value = 0xF;
48	p->cookie_key = bpf_get_socket_cookie(ctx);
49	return 1;
50}
51
52SEC("sockops")
53int update_cookie_sockops(struct bpf_sock_ops *ctx)
54{
55	struct socket_cookie *p;
56	struct tcp_sock *tcp_sk;
57	struct bpf_sock *sk;
58
59	if (ctx->family != AF_INET6 || ctx->op != BPF_SOCK_OPS_TCP_CONNECT_CB)
60		return 1;
61
62	sk = ctx->sk;
63	if (!sk)
64		return 1;
65
66	tcp_sk = bpf_skc_to_tcp_sock(sk);
67	if (!tcp_sk)
68		return 1;
69
70	p = bpf_cgrp_storage_get(&socket_cookies,
71		tcp_sk->inet_conn.icsk_inet.sk.sk_cgrp_data.cgroup, 0, 0);
72	if (!p)
73		return 1;
74
75	if (p->cookie_key != bpf_get_socket_cookie(ctx))
76		return 1;
77
78	p->cookie_value |= (ctx->local_port << 8);
79	return 1;
80}
81
82SEC("fexit/inet_stream_connect")
83int BPF_PROG(update_cookie_tracing, struct socket *sock,
84	     struct sockaddr *uaddr, int addr_len, int flags)
85{
86	struct socket_cookie *p;
87
88	if (uaddr->sa_family != AF_INET6)
89		return 0;
90
91	p = bpf_cgrp_storage_get(&socket_cookies, sock->sk->sk_cgrp_data.cgroup, 0, 0);
92	if (!p)
93		return 0;
94
95	if (p->cookie_key != bpf_get_socket_cookie(sock->sk))
96		return 0;
97
98	p->cookie_value |= 0xF0;
99	return 0;
100}
101