summaryrefslogtreecommitdiffstats
path: root/tools/testing/selftests/net/reuseport_bpf_cpu.c
blob: 2d646174729f9251c1780e0437180183c1ac5f31 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
// SPDX-License-Identifier: GPL-2.0
/*
 * Test functionality of BPF filters with SO_REUSEPORT.  This program creates
 * an SO_REUSEPORT receiver group containing one socket per CPU core. It then
 * creates a BPF program that will select a socket from this group based
 * on the core id that receives the packet.  The sending code artificially
 * moves itself to run on different core ids and sends one message from
 * each core.  Since these packets are delivered over loopback, they should
 * arrive on the same core that sent them.  The receiving code then ensures
 * that the packet was received on the socket for the corresponding core id.
 * This entire process is done for several different core id permutations
 * and for each IPv4/IPv6 and TCP/UDP combination.
 */

#define _GNU_SOURCE

#include <arpa/inet.h>
#include <errno.h>
#include <error.h>
#include <linux/filter.h>
#include <linux/in.h>
#include <linux/unistd.h>
#include <sched.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/epoll.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <unistd.h>

static const int PORT = 8888;

static void build_rcv_group(int *rcv_fd, size_t len, int family, int proto)
{
	struct sockaddr_storage addr;
	struct sockaddr_in  *addr4;
	struct sockaddr_in6 *addr6;
	size_t i;
	int opt;

	switch (family) {
	case AF_INET:
		addr4 = (struct sockaddr_in *)&addr;
		addr4->sin_family = AF_INET;
		addr4->sin_addr.s_addr = htonl(INADDR_ANY);
		addr4->sin_port = htons(PORT);
		break;
	case AF_INET6:
		addr6 = (struct sockaddr_in6 *)&addr;
		addr6->sin6_family = AF_INET6;
		addr6->sin6_addr = in6addr_any;
		addr6->sin6_port = htons(PORT);
		break;
	default:
		error(1, 0, "Unsupported family %d", family);
	}

	for (i = 0; i < len; ++i) {
		rcv_fd[i] = socket(family, proto, 0);
		if (rcv_fd[i] < 0)
			error(1, errno, "failed to create receive socket");

		opt = 1;
		if (setsockopt(rcv_fd[i], SOL_SOCKET, SO_REUSEPORT, &opt,
			       sizeof(opt)))
			error(1, errno, "failed to set SO_REUSEPORT");

		if (bind(rcv_fd[i], (struct sockaddr *)&addr, sizeof(addr)))
			error(1, errno, "failed to bind receive socket");

		if (proto == SOCK_STREAM && listen(rcv_fd[i], len * 10))
			error(1, errno, "failed to listen on receive port");
	}
}

static void attach_bpf(int fd)
{
	struct sock_filter code[] = {
		/* A = raw_smp_processor_id() */
		{ BPF_LD  | BPF_W | BPF_ABS, 0, 0, SKF_AD_OFF + SKF_AD_CPU },
		/* return A */
		{ BPF_RET | BPF_A, 0, 0, 0 },
	};
	struct sock_fprog p = {
		.len = 2,
		.filter = code,
	};

	if (setsockopt(fd, SOL_SOCKET, SO_ATTACH_REUSEPORT_CBPF, &p, sizeof(p)))
		error(1, errno, "failed to set SO_ATTACH_REUSEPORT_CBPF");
}

static void send_from_cpu(int cpu_id, int family, int proto)
{
	struct sockaddr_storage saddr, daddr;
	struct sockaddr_in  *saddr4, *daddr4;
	struct sockaddr_in6 *saddr6, *daddr6;
	cpu_set_t cpu_set;
	int fd;

	switch (family) {
	case AF_INET:
		saddr4 = (struct sockaddr_in *)&saddr;
		saddr4->sin_family = AF_INET;
		saddr4->sin_addr.s_addr = htonl(INADDR_ANY);
		saddr4->sin_port = 0;

		daddr4 = (struct sockaddr_in *)&daddr;
		daddr4->sin_family = AF_INET;
		daddr4->sin_addr.s_addr = htonl(INADDR_LOOPBACK);
		daddr4->sin_port = htons(PORT);
		break;
	case AF_INET6:
		saddr6 = (struct sockaddr_in6 *)&saddr;
		saddr6->sin6_family = AF_INET6;
		saddr6->sin6_addr = in6addr_any;
		saddr6->sin6_port = 0;

		daddr6 = (struct sockaddr_in6 *)&daddr;
		daddr6->sin6_family = AF_INET6;
		daddr6->sin6_addr = in6addr_loopback;
		daddr6->sin6_port = htons(PORT);
		break;
	default:
		error(1, 0, "Unsupported family %d", family);
	}

	memset(&cpu_set, 0, sizeof(cpu_set));
	CPU_SET(cpu_id, &cpu_set);
	if (sched_setaffinity(0, sizeof(cpu_set), &cpu_set) < 0)
		error(1, errno, "failed to pin to cpu");

	fd = socket(family, proto, 0);
	if (fd < 0)
		error(1, errno, "failed to create send socket");

	if (bind(fd, (struct sockaddr *)&saddr, sizeof(saddr)))
		error(1, errno, "failed to bind send socket");

	if (connect(fd, (struct sockaddr *)&daddr, sizeof(daddr)))
		error(1, errno, "failed to connect send socket");

	if (send(fd, "a", 1, 0) < 0)
		error(1, errno, "failed to send message");

	close(fd);
}

static
void receive_on_cpu(int *rcv_fd, int len, int epfd, int cpu_id, int proto)
{
	struct epoll_event ev;
	int i, fd;
	char buf[8];

	i = epoll_wait(epfd, &ev, 1, -1);
	if (i < 0)
		error(1, errno, "epoll_wait failed");

	if (proto == SOCK_STREAM) {
		fd = accept(ev.data.fd, NULL, NULL);
		if (fd < 0)
			error(1, errno, "failed to accept");
		i = recv(fd, buf, sizeof(buf), 0);
		close(fd);
	} else {
		i = recv(ev.data.fd, buf, sizeof(buf), 0);
	}

	if (i < 0)
		error(1, errno, "failed to recv");

	for (i = 0; i < len; ++i)
		if (ev.data.fd == rcv_fd[i])
			break;
	if (i == len)
		error(1, 0, "failed to find socket");
	fprintf(stderr, "send cpu %d, receive socket %d\n", cpu_id, i);
	if (cpu_id != i)
		error(1, 0, "cpu id/receive socket mismatch");
}

static void test(int *rcv_fd, int len, int family, int proto)
{
	struct epoll_event ev;
	int epfd, cpu;

	build_rcv_group(rcv_fd, len, family, proto);
	attach_bpf(rcv_fd[0]);

	epfd = epoll_create(1);
	if (epfd < 0)
		error(1, errno, "failed to create epoll");
	for (cpu = 0; cpu < len; ++cpu) {
		ev.events = EPOLLIN;
		ev.data.fd = rcv_fd[cpu];
		if (epoll_ctl(epfd, EPOLL_CTL_ADD, rcv_fd[cpu], &ev))
			error(1, errno, "failed to register sock epoll");
	}

	/* Forward iterate */
	for (cpu = 0; cpu < len; ++cpu) {
		send_from_cpu(cpu, family, proto);
		receive_on_cpu(rcv_fd, len, epfd, cpu, proto);
	}

	/* Reverse iterate */
	for (cpu = len - 1; cpu >= 0; --cpu) {
		send_from_cpu(cpu, family, proto);
		receive_on_cpu(rcv_fd, len, epfd, cpu, proto);
	}

	/* Even cores */
	for (cpu = 0; cpu < len; cpu += 2) {
		send_from_cpu(cpu, family, proto);
		receive_on_cpu(rcv_fd, len, epfd, cpu, proto);
	}

	/* Odd cores */
	for (cpu = 1; cpu < len; cpu += 2) {
		send_from_cpu(cpu, family, proto);
		receive_on_cpu(rcv_fd, len, epfd, cpu, proto);
	}

	close(epfd);
	for (cpu = 0; cpu < len; ++cpu)
		close(rcv_fd[cpu]);
}

int main(void)
{
	int *rcv_fd, cpus;

	cpus = sysconf(_SC_NPROCESSORS_ONLN);
	if (cpus <= 0)
		error(1, errno, "failed counting cpus");

	rcv_fd = calloc(cpus, sizeof(int));
	if (!rcv_fd)
		error(1, 0, "failed to allocate array");

	fprintf(stderr, "---- IPv4 UDP ----\n");
	test(rcv_fd, cpus, AF_INET, SOCK_DGRAM);

	fprintf(stderr, "---- IPv6 UDP ----\n");
	test(rcv_fd, cpus, AF_INET6, SOCK_DGRAM);

	fprintf(stderr, "---- IPv4 TCP ----\n");
	test(rcv_fd, cpus, AF_INET, SOCK_STREAM);

	fprintf(stderr, "---- IPv6 TCP ----\n");
	test(rcv_fd, cpus, AF_INET6, SOCK_STREAM);

	free(rcv_fd);

	fprintf(stderr, "SUCCESS\n");
	return 0;
}