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 __u32 mrtt_us; /* args[0] */ 15 __u32 srtt; /* args[1] */ 16 }; 17 18 struct { 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 25 SEC("sockops") 26 int _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