test_tcpnotify_kern.c

 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	__type(key, int);
27	__type(value, __u32);
28} perf_event_map SEC(".maps");
29
30SEC("sockops")
31int bpf_testcb(struct bpf_sock_ops *skops)
32{
33	int rv = -1;
34	int op;
35
36	op = (int) skops->op;
37
38	if (bpf_ntohl(skops->remote_port) != TESTPORT) {
39		skops->reply = -1;
40		return 0;
41	}
42
43	switch (op) {
44	case BPF_SOCK_OPS_TIMEOUT_INIT:
45	case BPF_SOCK_OPS_RWND_INIT:
46	case BPF_SOCK_OPS_NEEDS_ECN:
47	case BPF_SOCK_OPS_BASE_RTT:
48	case BPF_SOCK_OPS_RTO_CB:
49		rv = 1;
50		break;
51
52	case BPF_SOCK_OPS_TCP_CONNECT_CB:
53	case BPF_SOCK_OPS_TCP_LISTEN_CB:
54	case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB:
55	case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB:
56		bpf_sock_ops_cb_flags_set(skops, (BPF_SOCK_OPS_RETRANS_CB_FLAG|
57					  BPF_SOCK_OPS_RTO_CB_FLAG));
58		rv = 1;
59		break;
60	case BPF_SOCK_OPS_RETRANS_CB: {
61			__u32 key = 0;
62			struct tcpnotify_globals g, *gp;
63			struct tcp_notifier msg = {
64				.type = 0xde,
65				.subtype = 0xad,
66				.source = 0xbe,
67				.hash = 0xef,
68			};
69
70			rv = 1;
71
72			/* Update results */
73			gp = bpf_map_lookup_elem(&global_map, &key);
74			if (!gp)
75				break;
76			g = *gp;
77			g.total_retrans = skops->total_retrans;
78			g.ncalls++;
79			bpf_map_update_elem(&global_map, &key, &g,
80					    BPF_ANY);
81			bpf_perf_event_output(skops, &perf_event_map,
82					      BPF_F_CURRENT_CPU,
83					      &msg, sizeof(msg));
84		}
85		break;
86	default:
87		rv = -1;
88	}
89	skops->reply = rv;
90	return 1;
91}
92char _license[] SEC("license") = "GPL";