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

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/bpf.h>
   3 #include <bpf/bpf_helpers.h>
   4
   5 char _license[] SEC("license") = "GPL";
   6
   7 struct tcp_rtt_storage {
   8         __u32 invoked;
   9         __u32 dsack_dups;
  10         __u32 delivered;
  11         __u32 delivered_ce;
  12         __u32 icsk_retransmits;
  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 tcp_rtt_storage);
  20 } socket_storage_map SEC(".maps");
  21
  22 SEC("sockops")
  23 int _sockops(struct bpf_sock_ops *ctx)
  24 {
  25         struct tcp_rtt_storage *storage;
  26         struct bpf_tcp_sock *tcp_sk;
  27         int op = (int) ctx->op;
  28         struct bpf_sock *sk;
  29
  30         sk = ctx->sk;
  31         if (!sk)
  32                 return 1;
  33
  34         storage = bpf_sk_storage_get(&socket_storage_map, sk, 0,
  35                                      BPF_SK_STORAGE_GET_F_CREATE);
  36         if (!storage)
  37                 return 1;
  38
  39         if (op == BPF_SOCK_OPS_TCP_CONNECT_CB) {
  40                 bpf_sock_ops_cb_flags_set(ctx, BPF_SOCK_OPS_RTT_CB_FLAG);
  41                 return 1;
  42         }
  43
  44         if (op != BPF_SOCK_OPS_RTT_CB)
  45                 return 1;
  46
  47         tcp_sk = bpf_tcp_sock(sk);
  48         if (!tcp_sk)
  49                 return 1;
  50
  51         storage->invoked++;
  52
  53         storage->dsack_dups = tcp_sk->dsack_dups;
  54         storage->delivered = tcp_sk->delivered;
  55         storage->delivered_ce = tcp_sk->delivered_ce;
  56         storage->icsk_retransmits = tcp_sk->icsk_retransmits;
  57
  58         return 1;
  59 }