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
9 char _license[] SEC("license") = "GPL";
10
11 struct socket_cookie {
12 __u64 cookie_key;
13 __u64 cookie_value;
14 };
15
16 struct {
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
23 SEC("cgroup/connect6")
24 int 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
52 SEC("sockops")
53 int 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
82 SEC("fexit/inet_stream_connect")
83 int 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
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