1 // SPDX-License-Identifier: GPL-2.0 2 /* Refer to samples/bpf/tcp_bpf.readme for the instructions on 3 * how to run this sample program. 4 */ 5 #include <linux/bpf.h> 6 7 #include "bpf_helpers.h" 8 #include "bpf_endian.h" 9 10 #define INTERVAL 1000000000ULL 11 12 int _version SEC("version") = 1; 13 char _license[] SEC("license") = "GPL"; 14 15 struct { 16 __u32 type; 17 __u32 map_flags; 18 int *key; 19 __u64 *value; 20 } bpf_next_dump SEC(".maps") = { 21 .type = BPF_MAP_TYPE_SK_STORAGE, 22 .map_flags = BPF_F_NO_PREALLOC, 23 }; 24 25 SEC("sockops") 26 int _sockops(struct bpf_sock_ops *ctx) 27 { 28 struct bpf_tcp_sock *tcp_sk; 29 struct bpf_sock *sk; 30 __u64 *next_dump; 31 __u64 now; 32 33 switch (ctx->op) { 34 case BPF_SOCK_OPS_TCP_CONNECT_CB: 35 bpf_sock_ops_cb_flags_set(ctx, BPF_SOCK_OPS_RTT_CB_FLAG); 36 return 1; 37 case BPF_SOCK_OPS_RTT_CB: 38 break; 39 default: 40 return 1; 41 } 42 43 sk = ctx->sk; 44 if (!sk) 45 return 1; 46 47 next_dump = bpf_sk_storage_get(&bpf_next_dump, sk, 0, 48 BPF_SK_STORAGE_GET_F_CREATE); 49 if (!next_dump) 50 return 1; 51 52 now = bpf_ktime_get_ns(); 53 if (now < *next_dump) 54 return 1; 55 56 tcp_sk = bpf_tcp_sock(sk); 57 if (!tcp_sk) 58 return 1; 59 60 *next_dump = now + INTERVAL; 61 62 bpf_printk("dsack_dups=%u delivered=%u\n", 63 tcp_sk->dsack_dups, tcp_sk->delivered); 64 bpf_printk("delivered_ce=%u icsk_retransmits=%u\n", 65 tcp_sk->delivered_ce, tcp_sk->icsk_retransmits); 66 67 return 1; 68 } 69