0001
0002 #include <linux/bpf.h>
0003 #include <bpf/bpf_helpers.h>
0004
0005 char _license[] SEC("license") = "GPL";
0006
0007 struct tcp_rtt_storage {
0008 __u32 invoked;
0009 __u32 dsack_dups;
0010 __u32 delivered;
0011 __u32 delivered_ce;
0012 __u32 icsk_retransmits;
0013 };
0014
0015 struct {
0016 __uint(type, BPF_MAP_TYPE_SK_STORAGE);
0017 __uint(map_flags, BPF_F_NO_PREALLOC);
0018 __type(key, int);
0019 __type(value, struct tcp_rtt_storage);
0020 } socket_storage_map SEC(".maps");
0021
0022 SEC("sockops")
0023 int _sockops(struct bpf_sock_ops *ctx)
0024 {
0025 struct tcp_rtt_storage *storage;
0026 struct bpf_tcp_sock *tcp_sk;
0027 int op = (int) ctx->op;
0028 struct bpf_sock *sk;
0029
0030 sk = ctx->sk;
0031 if (!sk)
0032 return 1;
0033
0034 storage = bpf_sk_storage_get(&socket_storage_map, sk, 0,
0035 BPF_SK_STORAGE_GET_F_CREATE);
0036 if (!storage)
0037 return 1;
0038
0039 if (op == BPF_SOCK_OPS_TCP_CONNECT_CB) {
0040 bpf_sock_ops_cb_flags_set(ctx, BPF_SOCK_OPS_RTT_CB_FLAG);
0041 return 1;
0042 }
0043
0044 if (op != BPF_SOCK_OPS_RTT_CB)
0045 return 1;
0046
0047 tcp_sk = bpf_tcp_sock(sk);
0048 if (!tcp_sk)
0049 return 1;
0050
0051 storage->invoked++;
0052
0053 storage->dsack_dups = tcp_sk->dsack_dups;
0054 storage->delivered = tcp_sk->delivered;
0055 storage->delivered_ce = tcp_sk->delivered_ce;
0056 storage->icsk_retransmits = tcp_sk->icsk_retransmits;
0057
0058 return 1;
0059 }