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 struct tcp_sock *tcp_sk; 88 89 if (uaddr->sa_family != AF_INET6) 90 return 0; 91 92 p = bpf_cgrp_storage_get(&socket_cookies, sock->sk->sk_cgrp_data.cgroup, 0, 0); 93 if (!p) 94 return 0; 95 96 if (p->cookie_key != bpf_get_socket_cookie(sock->sk)) 97 return 0; 98 99 p->cookie_value |= 0xF0; 100 return 0; 101 } 102