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         __u32 mrtt_us;  /* args[0] */
  15         __u32 srtt;     /* args[1] */
  16 };
  17
  18 struct {
  19         __uint(type, BPF_MAP_TYPE_SK_STORAGE);
  20         __uint(map_flags, BPF_F_NO_PREALLOC);
  21         __type(key, int);
  22         __type(value, struct tcp_rtt_storage);
  23 } socket_storage_map SEC(".maps");
  24
  25 SEC("sockops")
  26 int _sockops(struct bpf_sock_ops *ctx)
  27 {
  28         struct tcp_rtt_storage *storage;
  29         struct bpf_tcp_sock *tcp_sk;
  30         int op = (int) ctx->op;
  31         struct bpf_sock *sk;
  32
  33         sk = ctx->sk;
  34         if (!sk)
  35                 return 1;
  36
  37         storage = bpf_sk_storage_get(&socket_storage_map, sk, 0,
  38                                      BPF_SK_STORAGE_GET_F_CREATE);
  39         if (!storage)
  40                 return 1;
  41
  42         if (op == BPF_SOCK_OPS_TCP_CONNECT_CB) {
  43                 bpf_sock_ops_cb_flags_set(ctx, BPF_SOCK_OPS_RTT_CB_FLAG);
  44                 return 1;
  45         }
  46
  47         if (op != BPF_SOCK_OPS_RTT_CB)
  48                 return 1;
  49
  50         tcp_sk = bpf_tcp_sock(sk);
  51         if (!tcp_sk)
  52                 return 1;
  53
  54         storage->invoked++;
  55
  56         storage->dsack_dups = tcp_sk->dsack_dups;
  57         storage->delivered = tcp_sk->delivered;
  58         storage->delivered_ce = tcp_sk->delivered_ce;
  59         storage->icsk_retransmits = tcp_sk->icsk_retransmits;
  60
  61         storage->mrtt_us = ctx->args[0];
  62         storage->srtt = ctx->args[1];
  63
  64         return 1;
  65 }