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1// SPDX-License-Identifier: GPL-2.02#include <linux/bpf.h>3#include <bpf/bpf_helpers.h>4 5char _license[] SEC("license") = "GPL";6 7struct 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 18struct {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 25SEC("sockops")26int _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}66