// SPDX-License-Identifier: GPL-2.0 #include <linux/bpf.h> #include <bpf/bpf_helpers.h> char _license[] SEC("license") = "GPL"; struct tcp_rtt_storage { __u32 invoked; __u32 dsack_dups; __u32 delivered; __u32 delivered_ce; __u32 icsk_retransmits; }; struct { __uint(type, BPF_MAP_TYPE_SK_STORAGE); __uint(map_flags, BPF_F_NO_PREALLOC); __type(key, int); __type(value, struct tcp_rtt_storage); } socket_storage_map SEC(".maps"); SEC("sockops") int _sockops(struct bpf_sock_ops *ctx) { struct tcp_rtt_storage *storage; struct bpf_tcp_sock *tcp_sk; int op = (int) ctx->op; struct bpf_sock *sk; sk = ctx->sk; if (!sk) return 1; storage = bpf_sk_storage_get(&socket_storage_map, sk, 0, BPF_SK_STORAGE_GET_F_CREATE); if (!storage) return 1; if (op == BPF_SOCK_OPS_TCP_CONNECT_CB) { bpf_sock_ops_cb_flags_set(ctx, BPF_SOCK_OPS_RTT_CB_FLAG); return 1; } if (op != BPF_SOCK_OPS_RTT_CB) return 1; tcp_sk = bpf_tcp_sock(sk); if (!tcp_sk) return 1; storage->invoked++; storage->dsack_dups = tcp_sk->dsack_dups; storage->delivered = tcp_sk->delivered; storage->delivered_ce = tcp_sk->delivered_ce; storage->icsk_retransmits = tcp_sk->icsk_retransmits; return 1; }