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 | |