tools/testing/selftests/bpf/progs/socket_cookie_prog.c

   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         __uint(type, BPF_MAP_TYPE_SK_STORAGE);
  17         __uint(map_flags, BPF_F_NO_PREALLOC);
  18         __type(key, int);
  19         __type(value, struct socket_cookie);
  20 } socket_cookies SEC(".maps");
  21
  22 SEC("cgroup/connect6")
  23 int set_cookie(struct bpf_sock_addr *ctx)
  24 {
  25         struct socket_cookie *p;
  26
  27         if (ctx->family != AF_INET6 || ctx->user_family != AF_INET6)
  28                 return 1;
  29
  30         p = bpf_sk_storage_get(&socket_cookies, ctx->sk, 0,
  31                                BPF_SK_STORAGE_GET_F_CREATE);
  32         if (!p)
  33                 return 1;
  34
  35         p->cookie_value = 0xFF;
  36         p->cookie_key = bpf_get_socket_cookie(ctx);
  37
  38         return 1;
  39 }
  40
  41 SEC("sockops")
  42 int update_cookie(struct bpf_sock_ops *ctx)
  43 {
  44         struct bpf_sock *sk;
  45         struct socket_cookie *p;
  46
  47         if (ctx->family != AF_INET6)
  48                 return 1;
  49
  50         if (ctx->op != BPF_SOCK_OPS_TCP_CONNECT_CB)
  51                 return 1;
  52
  53         if (!ctx->sk)
  54                 return 1;
  55
  56         p = bpf_sk_storage_get(&socket_cookies, ctx->sk, 0, 0);
  57         if (!p)
  58                 return 1;
  59
  60         if (p->cookie_key != bpf_get_socket_cookie(ctx))
  61                 return 1;
  62
  63         p->cookie_value = (ctx->local_port << 8) | p->cookie_value;
  64
  65         return 1;
  66 }
  67
  68 int _version SEC("version") = 1;
  69
  70 char _license[] SEC("license") = "GPL";