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 bpf_map_def SEC("maps") socket_cookies = { 11 .type = BPF_MAP_TYPE_HASH, 12 .key_size = sizeof(__u64), 13 .value_size = sizeof(__u32), 14 .max_entries = 1 << 8, 15 }; 16 17 SEC("cgroup/connect6") 18 int set_cookie(struct bpf_sock_addr *ctx) 19 { 20 __u32 cookie_value = 0xFF; 21 __u64 cookie_key; 22 23 if (ctx->family != AF_INET6 || ctx->user_family != AF_INET6) 24 return 1; 25 26 cookie_key = bpf_get_socket_cookie(ctx); 27 if (bpf_map_update_elem(&socket_cookies, &cookie_key, &cookie_value, 0)) 28 return 0; 29 30 return 1; 31 } 32 33 SEC("sockops") 34 int update_cookie(struct bpf_sock_ops *ctx) 35 { 36 __u32 new_cookie_value; 37 __u32 *cookie_value; 38 __u64 cookie_key; 39 40 if (ctx->family != AF_INET6) 41 return 1; 42 43 if (ctx->op != BPF_SOCK_OPS_TCP_CONNECT_CB) 44 return 1; 45 46 cookie_key = bpf_get_socket_cookie(ctx); 47 48 cookie_value = bpf_map_lookup_elem(&socket_cookies, &cookie_key); 49 if (!cookie_value) 50 return 1; 51 52 new_cookie_value = (ctx->local_port << 8) | *cookie_value; 53 bpf_map_update_elem(&socket_cookies, &cookie_key, &new_cookie_value, 0); 54 55 return 1; 56 } 57 58 int _version SEC("version") = 1; 59 60 char _license[] SEC("license") = "GPL"; 61