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