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

DEFINITIONS

1. SEC

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/bpf.h>
   3 #include "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 bpf_map_def SEC("maps") socket_storage_map = {
  17         .type = BPF_MAP_TYPE_SK_STORAGE,
  18         .key_size = sizeof(int),
  19         .value_size = sizeof(struct tcp_rtt_storage),
  20         .map_flags = BPF_F_NO_PREALLOC,
  21 };
  22 BPF_ANNOTATE_KV_PAIR(socket_storage_map, int, struct tcp_rtt_storage);
  23 
  24 SEC("sockops")
  25 int _sockops(struct bpf_sock_ops *ctx)
  26 {
  27         struct tcp_rtt_storage *storage;
  28         struct bpf_tcp_sock *tcp_sk;
  29         int op = (int) ctx->op;
  30         struct bpf_sock *sk;
  31 
  32         sk = ctx->sk;
  33         if (!sk)
  34                 return 1;
  35 
  36         storage = bpf_sk_storage_get(&socket_storage_map, sk, 0,
  37                                      BPF_SK_STORAGE_GET_F_CREATE);
  38         if (!storage)
  39                 return 1;
  40 
  41         if (op == BPF_SOCK_OPS_TCP_CONNECT_CB) {
  42                 bpf_sock_ops_cb_flags_set(ctx, BPF_SOCK_OPS_RTT_CB_FLAG);
  43                 return 1;
  44         }
  45 
  46         if (op != BPF_SOCK_OPS_RTT_CB)
  47                 return 1;
  48 
  49         tcp_sk = bpf_tcp_sock(sk);
  50         if (!tcp_sk)
  51                 return 1;
  52 
  53         storage->invoked++;
  54 
  55         storage->dsack_dups = tcp_sk->dsack_dups;
  56         storage->delivered = tcp_sk->delivered;
  57         storage->delivered_ce = tcp_sk->delivered_ce;
  58         storage->icsk_retransmits = tcp_sk->icsk_retransmits;
  59 
  60         return 1;
  61 }