1 // SPDX-License-Identifier: GPL-2.0 2 // Copyright (c) 2018 Facebook 3 4 #include <linux/bpf.h> 5 #include <sys/socket.h> 6 7 #include "bpf_helpers.h" 8 #include "bpf_endian.h" 9 10 struct socket_cookie { 11 __u64 cookie_key; 12 __u32 cookie_value; 13 }; 14 15 struct { 16 __u32 type; 17 __u32 map_flags; 18 int *key; 19 struct socket_cookie *value; 20 } socket_cookies SEC(".maps") = { 21 .type = BPF_MAP_TYPE_SK_STORAGE, 22 .map_flags = BPF_F_NO_PREALLOC, 23 }; 24 25 SEC("cgroup/connect6") 26 int set_cookie(struct bpf_sock_addr *ctx) 27 { 28 struct socket_cookie *p; 29 30 if (ctx->family != AF_INET6 || ctx->user_family != AF_INET6) 31 return 1; 32 33 p = bpf_sk_storage_get(&socket_cookies, ctx->sk, 0, 34 BPF_SK_STORAGE_GET_F_CREATE); 35 if (!p) 36 return 1; 37 38 p->cookie_value = 0xFF; 39 p->cookie_key = bpf_get_socket_cookie(ctx); 40 41 return 1; 42 } 43 44 SEC("sockops") 45 int update_cookie(struct bpf_sock_ops *ctx) 46 { 47 struct bpf_sock *sk; 48 struct socket_cookie *p; 49 50 if (ctx->family != AF_INET6) 51 return 1; 52 53 if (ctx->op != BPF_SOCK_OPS_TCP_CONNECT_CB) 54 return 1; 55 56 if (!ctx->sk) 57 return 1; 58 59 p = bpf_sk_storage_get(&socket_cookies, ctx->sk, 0, 0); 60 if (!p) 61 return 1; 62 63 if (p->cookie_key != bpf_get_socket_cookie(ctx)) 64 return 1; 65 66 p->cookie_value = (ctx->local_port << 8) | p->cookie_value; 67 68 return 1; 69 } 70 71 int _version SEC("version") = 1; 72 73 char _license[] SEC("license") = "GPL"; 74