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1// SPDX-License-Identifier: GPL-2.02/* Refer to samples/bpf/tcp_bpf.readme for the instructions on3 * 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 1000000000ULL11 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