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 __u32 _version SEC("version") = 1; 7 8 struct tcp_rtt_storage { 9 __u32 invoked; 10 __u32 dsack_dups; 11 __u32 delivered; 12 __u32 delivered_ce; 13 __u32 icsk_retransmits; 14 }; 15 16 struct { 17 __uint(type, BPF_MAP_TYPE_SK_STORAGE); 18 __uint(map_flags, BPF_F_NO_PREALLOC); 19 __type(key, int); 20 __type(value, struct tcp_rtt_storage); 21 } socket_storage_map SEC(".maps"); 22 23 SEC("sockops") 24 int _sockops(struct bpf_sock_ops *ctx) 25 { 26 struct tcp_rtt_storage *storage; 27 struct bpf_tcp_sock *tcp_sk; 28 int op = (int) ctx->op; 29 struct bpf_sock *sk; 30 31 sk = ctx->sk; 32 if (!sk) 33 return 1; 34 35 storage = bpf_sk_storage_get(&socket_storage_map, sk, 0, 36 BPF_SK_STORAGE_GET_F_CREATE); 37 if (!storage) 38 return 1; 39 40 if (op == BPF_SOCK_OPS_TCP_CONNECT_CB) { 41 bpf_sock_ops_cb_flags_set(ctx, BPF_SOCK_OPS_RTT_CB_FLAG); 42 return 1; 43 } 44 45 if (op != BPF_SOCK_OPS_RTT_CB) 46 return 1; 47 48 tcp_sk = bpf_tcp_sock(sk); 49 if (!tcp_sk) 50 return 1; 51 52 storage->invoked++; 53 54 storage->dsack_dups = tcp_sk->dsack_dups; 55 storage->delivered = tcp_sk->delivered; 56 storage->delivered_ce = tcp_sk->delivered_ce; 57 storage->icsk_retransmits = tcp_sk->icsk_retransmits; 58 59 return 1; 60 } 61