1// SPDX-License-Identifier: GPL-2.0
2#include <stddef.h>
3#include <string.h>
4#include <netinet/in.h>
5#include <linux/bpf.h>
6#include <linux/if_ether.h>
7#include <linux/if_packet.h>
8#include <linux/ip.h>
9#include <linux/ipv6.h>
10#include <linux/types.h>
11#include <linux/socket.h>
12#include <linux/tcp.h>
13#include <bpf/bpf_helpers.h>
14#include <bpf/bpf_endian.h>
15#include "test_tcpnotify.h"
16
17struct {
18	__uint(type, BPF_MAP_TYPE_ARRAY);
19	__uint(max_entries, 4);
20	__type(key, __u32);
21	__type(value, struct tcpnotify_globals);
22} global_map SEC(".maps");
23
24struct {
25	__uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
26	__uint(max_entries, 2);
27	__type(key, int);
28	__type(value, __u32);
29} perf_event_map SEC(".maps");
30
31SEC("sockops")
32int bpf_testcb(struct bpf_sock_ops *skops)
33{
34	int rv = -1;
35	int op;
36
37	op = (int) skops->op;
38
39	if (bpf_ntohl(skops->remote_port) != TESTPORT) {
40		skops->reply = -1;
41		return 0;
42	}
43
44	switch (op) {
45	case BPF_SOCK_OPS_TIMEOUT_INIT:
46	case BPF_SOCK_OPS_RWND_INIT:
47	case BPF_SOCK_OPS_NEEDS_ECN:
48	case BPF_SOCK_OPS_BASE_RTT:
49	case BPF_SOCK_OPS_RTO_CB:
50		rv = 1;
51		break;
52
53	case BPF_SOCK_OPS_TCP_CONNECT_CB:
54	case BPF_SOCK_OPS_TCP_LISTEN_CB:
55	case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB:
56	case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB:
57		bpf_sock_ops_cb_flags_set(skops, (BPF_SOCK_OPS_RETRANS_CB_FLAG|
58					  BPF_SOCK_OPS_RTO_CB_FLAG));
59		rv = 1;
60		break;
61	case BPF_SOCK_OPS_RETRANS_CB: {
62			__u32 key = 0;
63			struct tcpnotify_globals g, *gp;
64			struct tcp_notifier msg = {
65				.type = 0xde,
66				.subtype = 0xad,
67				.source = 0xbe,
68				.hash = 0xef,
69			};
70
71			rv = 1;
72
73			/* Update results */
74			gp = bpf_map_lookup_elem(&global_map, &key);
75			if (!gp)
76				break;
77			g = *gp;
78			g.total_retrans = skops->total_retrans;
79			g.ncalls++;
80			bpf_map_update_elem(&global_map, &key, &g,
81					    BPF_ANY);
82			bpf_perf_event_output(skops, &perf_event_map,
83					      BPF_F_CURRENT_CPU,
84					      &msg, sizeof(msg));
85		}
86		break;
87	default:
88		rv = -1;
89	}
90	skops->reply = rv;
91	return 1;
92}
93char _license[] SEC("license") = "GPL";
94