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 __u32 _version SEC("version") = 1;
   7
   8 struct tcp_rtt_storage {
   9         __u32 invoked;
  10         __u32 dsack_dups;
  11         __u32 delivered;
  12         __u32 delivered_ce;
  13         __u32 icsk_retransmits;
  14 };
  15
  16 struct {
  17         __uint(type, BPF_MAP_TYPE_SK_STORAGE);
  18         __uint(map_flags, BPF_F_NO_PREALLOC);
  19         __type(key, int);
  20         __type(value, struct tcp_rtt_storage);
  21 } socket_storage_map SEC(".maps");
  22
  23 SEC("sockops")
  24 int _sockops(struct bpf_sock_ops *ctx)
  25 {
  26         struct tcp_rtt_storage *storage;
  27         struct bpf_tcp_sock *tcp_sk;
  28         int op = (int) ctx->op;
  29         struct bpf_sock *sk;
  30
  31         sk = ctx->sk;
  32         if (!sk)
  33                 return 1;
  34
  35         storage = bpf_sk_storage_get(&socket_storage_map, sk, 0,
  36                                      BPF_SK_STORAGE_GET_F_CREATE);
  37         if (!storage)
  38                 return 1;
  39
  40         if (op == BPF_SOCK_OPS_TCP_CONNECT_CB) {
  41                 bpf_sock_ops_cb_flags_set(ctx, BPF_SOCK_OPS_RTT_CB_FLAG);
  42                 return 1;
  43         }
  44
  45         if (op != BPF_SOCK_OPS_RTT_CB)
  46                 return 1;
  47
  48         tcp_sk = bpf_tcp_sock(sk);
  49         if (!tcp_sk)
  50                 return 1;
  51
  52         storage->invoked++;
  53
  54         storage->dsack_dups = tcp_sk->dsack_dups;
  55         storage->delivered = tcp_sk->delivered;
  56         storage->delivered_ce = tcp_sk->delivered_ce;
  57         storage->icsk_retransmits = tcp_sk->icsk_retransmits;
  58
  59         return 1;
  60 }