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
12 int _version SEC("version") = 1;
13 char _license[] SEC("license") = "GPL";
14
15 struct {
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
25 SEC("sockops")
26 int _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
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