// 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;
__u32 mrtt_us; /* args[0] */
__u32 srtt; /* args[1] */
};
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;
storage->mrtt_us = ctx->args[0];
storage->srtt = ctx->args[1];
return 1;
}