tools/testing/selftests/bpf/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 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";