1 // SPDX-License-Identifier: GPL-2.0 2 // Copyright (c) 2018 Facebook 3 4 #include "vmlinux.h" 5 6 #include <bpf/bpf_helpers.h> 7 #include <bpf/bpf_endian.h> 8 #include <bpf/bpf_tracing.h> 9 10 #define AF_INET6 10 11 12 struct socket_cookie { 13 __u64 cookie_key; 14 __u32 cookie_value; 15 }; 16 17 struct { 18 __uint(type, BPF_MAP_TYPE_SK_STORAGE); 19 __uint(map_flags, BPF_F_NO_PREALLOC); 20 __type(key, int); 21 __type(value, struct socket_cookie); 22 } socket_cookies SEC(".maps"); 23 24 /* 25 * These three programs get executed in a row on connect() syscalls. The 26 * userspace side of the test creates a client socket, issues a connect() on it 27 * and then checks that the local storage associated with this socket has: 28 * cookie_value == local_port << 8 | 0xFF 29 * The different parts of this cookie_value are appended by those hooks if they 30 * all agree on the output of bpf_get_socket_cookie(). 31 */ 32 SEC("cgroup/connect6") 33 int set_cookie(struct bpf_sock_addr *ctx) 34 { 35 struct socket_cookie *p; 36 37 if (ctx->family != AF_INET6 || ctx->user_family != AF_INET6) 38 return 1; 39 40 p = bpf_sk_storage_get(&socket_cookies, ctx->sk, 0, 41 BPF_SK_STORAGE_GET_F_CREATE); 42 if (!p) 43 return 1; 44 45 p->cookie_value = 0xF; 46 p->cookie_key = bpf_get_socket_cookie(ctx); 47 48 return 1; 49 } 50 51 SEC("sockops") 52 int update_cookie_sockops(struct bpf_sock_ops *ctx) 53 { 54 struct bpf_sock *sk = ctx->sk; 55 struct socket_cookie *p; 56 57 if (ctx->family != AF_INET6) 58 return 1; 59 60 if (ctx->op != BPF_SOCK_OPS_TCP_CONNECT_CB) 61 return 1; 62 63 if (!sk) 64 return 1; 65 66 p = bpf_sk_storage_get(&socket_cookies, sk, 0, 0); 67 if (!p) 68 return 1; 69 70 if (p->cookie_key != bpf_get_socket_cookie(ctx)) 71 return 1; 72 73 p->cookie_value |= (ctx->local_port << 8); 74 75 return 1; 76 } 77 78 SEC("fexit/inet_stream_connect") 79 int BPF_PROG(update_cookie_tracing, struct socket *sock, 80 struct sockaddr *uaddr, int addr_len, int flags) 81 { 82 struct socket_cookie *p; 83 84 if (uaddr->sa_family != AF_INET6) 85 return 0; 86 87 p = bpf_sk_storage_get(&socket_cookies, sock->sk, 0, 0); 88 if (!p) 89 return 0; 90 91 if (p->cookie_key != bpf_get_socket_cookie(sock->sk)) 92 return 0; 93 94 p->cookie_value |= 0xF0; 95 96 return 0; 97 } 98 99 char _license[] SEC("license") = "GPL"; 100