LXR linux/samples/bpf/tcp_dumpstats

   1// SPDX-License-Identifier: GPL-2.0
   2/* Refer to samples/bpf/tcp_bpf.readme for the instructions on
   3 * how to run this sample program.
   4 */
   5#include <linux/bpf.h>
   6
   7#include <bpf/bpf_helpers.h>
   8#include <bpf/bpf_endian.h>
   9
  10#define INTERVAL                        1000000000ULL
  11
  12int _version SEC("version") = 1;
  13char _license[] SEC("license") = "GPL";
  14
  15struct {
  16        __u32 type;
  17        __u32 map_flags;
  18        int *key;
  19        __u64 *value;
  20} bpf_next_dump SEC(".maps") = {
  21        .type = BPF_MAP_TYPE_SK_STORAGE,
  22        .map_flags = BPF_F_NO_PREALLOC,
  23};
  24
  25SEC("sockops")
  26int _sockops(struct bpf_sock_ops *ctx)
  27{
  28        struct bpf_tcp_sock *tcp_sk;
  29        struct bpf_sock *sk;
  30        __u64 *next_dump;
  31        __u64 now;
  32
  33        switch (ctx->op) {
  34        case BPF_SOCK_OPS_TCP_CONNECT_CB:
  35                bpf_sock_ops_cb_flags_set(ctx, BPF_SOCK_OPS_RTT_CB_FLAG);
  36                return 1;
  37        case BPF_SOCK_OPS_RTT_CB:
  38                break;
  39        default:
  40                return 1;
  41        }
  42
  43        sk = ctx->sk;
  44        if (!sk)
  45                return 1;
  46
  47        next_dump = bpf_sk_storage_get(&bpf_next_dump, sk, 0,
  48                                       BPF_SK_STORAGE_GET_F_CREATE);
  49        if (!next_dump)
  50                return 1;
  51
  52        now = bpf_ktime_get_ns();
  53        if (now < *next_dump)
  54                return 1;
  55
  56        tcp_sk = bpf_tcp_sock(sk);
  57        if (!tcp_sk)
  58                return 1;
  59
  60        *next_dump = now + INTERVAL;
  61
  62        bpf_printk("dsack_dups=%u delivered=%u\n",
  63                   tcp_sk->dsack_dups, tcp_sk->delivered);
  64        bpf_printk("delivered_ce=%u icsk_retransmits=%u\n",
  65                   tcp_sk->delivered_ce, tcp_sk->icsk_retransmits);
  66
  67        return 1;
  68}
  69