summaryrefslogtreecommitdiffstats
path: root/tools/testing/selftests/net/tcp_fastopen_backup_key.c
blob: 9c55ec44fc43580ef81e365e432f5db435b8f5b4 (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
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
// SPDX-License-Identifier: GPL-2.0

/*
 * Test key rotation for TFO.
 * New keys are 'rotated' in two steps:
 * 1) Add new key as the 'backup' key 'behind' the primary key
 * 2) Make new key the primary by swapping the backup and primary keys
 *
 * The rotation is done in stages using multiple sockets bound
 * to the same port via SO_REUSEPORT. This simulates key rotation
 * behind say a load balancer. We verify that across the rotation
 * there are no cases in which a cookie is not accepted by verifying
 * that TcpExtTCPFastOpenPassiveFail remains 0.
 */
#define _GNU_SOURCE
#include <arpa/inet.h>
#include <errno.h>
#include <error.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/epoll.h>
#include <unistd.h>
#include <netinet/tcp.h>
#include <fcntl.h>
#include <time.h>

#ifndef TCP_FASTOPEN_KEY
#define TCP_FASTOPEN_KEY 33
#endif

#define N_LISTEN 10
#define PROC_FASTOPEN_KEY "/proc/sys/net/ipv4/tcp_fastopen_key"
#define KEY_LENGTH 16

#ifndef ARRAY_SIZE
#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
#endif

static bool do_ipv6;
static bool do_sockopt;
static bool do_rotate;
static int key_len = KEY_LENGTH;
static int rcv_fds[N_LISTEN];
static int proc_fd;
static const char *IP4_ADDR = "127.0.0.1";
static const char *IP6_ADDR = "::1";
static const int PORT = 8891;

static void get_keys(int fd, uint32_t *keys)
{
	char buf[128];
	socklen_t len = KEY_LENGTH * 2;

	if (do_sockopt) {
		if (getsockopt(fd, SOL_TCP, TCP_FASTOPEN_KEY, keys, &len))
			error(1, errno, "Unable to get key");
		return;
	}
	lseek(proc_fd, 0, SEEK_SET);
	if (read(proc_fd, buf, sizeof(buf)) <= 0)
		error(1, errno, "Unable to read %s", PROC_FASTOPEN_KEY);
	if (sscanf(buf, "%x-%x-%x-%x,%x-%x-%x-%x", keys, keys + 1, keys + 2,
	    keys + 3, keys + 4, keys + 5, keys + 6, keys + 7) != 8)
		error(1, 0, "Unable to parse %s", PROC_FASTOPEN_KEY);
}

static void set_keys(int fd, uint32_t *keys)
{
	char buf[128];

	if (do_sockopt) {
		if (setsockopt(fd, SOL_TCP, TCP_FASTOPEN_KEY, keys,
		    key_len))
			error(1, errno, "Unable to set key");
		return;
	}
	if (do_rotate)
		snprintf(buf, 128, "%08x-%08x-%08x-%08x,%08x-%08x-%08x-%08x",
			 keys[0], keys[1], keys[2], keys[3], keys[4], keys[5],
			 keys[6], keys[7]);
	else
		snprintf(buf, 128, "%08x-%08x-%08x-%08x",
			 keys[0], keys[1], keys[2], keys[3]);
	lseek(proc_fd, 0, SEEK_SET);
	if (write(proc_fd, buf, sizeof(buf)) <= 0)
		error(1, errno, "Unable to write %s", PROC_FASTOPEN_KEY);
}

static void build_rcv_fd(int family, int proto, int *rcv_fds)
{
	struct sockaddr_in  addr4 = {0};
	struct sockaddr_in6 addr6 = {0};
	struct sockaddr *addr;
	int opt = 1, i, sz;
	int qlen = 100;
	uint32_t keys[8];

	switch (family) {
	case AF_INET:
		addr4.sin_family = family;
		addr4.sin_addr.s_addr = htonl(INADDR_ANY);
		addr4.sin_port = htons(PORT);
		sz = sizeof(addr4);
		addr = (struct sockaddr *)&addr4;
		break;
	case AF_INET6:
		addr6.sin6_family = AF_INET6;
		addr6.sin6_addr = in6addr_any;
		addr6.sin6_port = htons(PORT);
		sz = sizeof(addr6);
		addr = (struct sockaddr *)&addr6;
		break;
	default:
		error(1, 0, "Unsupported family %d", family);
		/* clang does not recognize error() above as terminating
		 * the program, so it complains that saddr, sz are
		 * not initialized when this code path is taken. Silence it.
		 */
		return;
	}
	for (i = 0; i < ARRAY_SIZE(keys); i++)
		keys[i] = rand();
	for (i = 0; i < N_LISTEN; i++) {
		rcv_fds[i] = socket(family, proto, 0);
		if (rcv_fds[i] < 0)
			error(1, errno, "failed to create receive socket");
		if (setsockopt(rcv_fds[i], SOL_SOCKET, SO_REUSEPORT, &opt,
			       sizeof(opt)))
			error(1, errno, "failed to set SO_REUSEPORT");
		if (bind(rcv_fds[i], addr, sz))
			error(1, errno, "failed to bind receive socket");
		if (setsockopt(rcv_fds[i], SOL_TCP, TCP_FASTOPEN, &qlen,
			       sizeof(qlen)))
			error(1, errno, "failed to set TCP_FASTOPEN");
		set_keys(rcv_fds[i], keys);
		if (proto == SOCK_STREAM && listen(rcv_fds[i], 10))
			error(1, errno, "failed to listen on receive port");
	}
}

static int connect_and_send(int family, int proto)
{
	struct sockaddr_in  saddr4 = {0};
	struct sockaddr_in  daddr4 = {0};
	struct sockaddr_in6 saddr6 = {0};
	struct sockaddr_in6 daddr6 = {0};
	struct sockaddr *saddr, *daddr;
	int fd, sz, ret;
	char data[1];

	switch (family) {
	case AF_INET:
		saddr4.sin_family = AF_INET;
		saddr4.sin_addr.s_addr = htonl(INADDR_ANY);
		saddr4.sin_port = 0;

		daddr4.sin_family = AF_INET;
		if (!inet_pton(family, IP4_ADDR, &daddr4.sin_addr.s_addr))
			error(1, errno, "inet_pton failed: %s", IP4_ADDR);
		daddr4.sin_port = htons(PORT);

		sz = sizeof(saddr4);
		saddr = (struct sockaddr *)&saddr4;
		daddr = (struct sockaddr *)&daddr4;
		break;
	case AF_INET6:
		saddr6.sin6_family = AF_INET6;
		saddr6.sin6_addr = in6addr_any;

		daddr6.sin6_family = AF_INET6;
		if (!inet_pton(family, IP6_ADDR, &daddr6.sin6_addr))
			error(1, errno, "inet_pton failed: %s", IP6_ADDR);
		daddr6.sin6_port = htons(PORT);

		sz = sizeof(saddr6);
		saddr = (struct sockaddr *)&saddr6;
		daddr = (struct sockaddr *)&daddr6;
		break;
	default:
		error(1, 0, "Unsupported family %d", family);
		/* clang does not recognize error() above as terminating
		 * the program, so it complains that saddr, daddr, sz are
		 * not initialized when this code path is taken. Silence it.
		 */
		return -1;
	}
	fd = socket(family, proto, 0);
	if (fd < 0)
		error(1, errno, "failed to create send socket");
	if (bind(fd, saddr, sz))
		error(1, errno, "failed to bind send socket");
	data[0] = 'a';
	ret = sendto(fd, data, 1, MSG_FASTOPEN, daddr, sz);
	if (ret != 1)
		error(1, errno, "failed to sendto");

	return fd;
}

static bool is_listen_fd(int fd)
{
	int i;

	for (i = 0; i < N_LISTEN; i++) {
		if (rcv_fds[i] == fd)
			return true;
	}
	return false;
}

static void rotate_key(int fd)
{
	static int iter;
	static uint32_t new_key[4];
	uint32_t keys[8];
	uint32_t tmp_key[4];
	int i;

	if (iter < N_LISTEN) {
		/* first set new key as backups */
		if (iter == 0) {
			for (i = 0; i < ARRAY_SIZE(new_key); i++)
				new_key[i] = rand();
		}
		get_keys(fd, keys);
		memcpy(keys + 4, new_key, KEY_LENGTH);
		set_keys(fd, keys);
	} else {
		/* swap the keys */
		get_keys(fd, keys);
		memcpy(tmp_key, keys + 4, KEY_LENGTH);
		memcpy(keys + 4, keys, KEY_LENGTH);
		memcpy(keys, tmp_key, KEY_LENGTH);
		set_keys(fd, keys);
	}
	if (++iter >= (N_LISTEN * 2))
		iter = 0;
}

static void run_one_test(int family)
{
	struct epoll_event ev;
	int i, send_fd;
	int n_loops = 10000;
	int rotate_key_fd = 0;
	int key_rotate_interval = 50;
	int fd, epfd;
	char buf[1];

	build_rcv_fd(family, SOCK_STREAM, rcv_fds);
	epfd = epoll_create(1);
	if (epfd < 0)
		error(1, errno, "failed to create epoll");
	ev.events = EPOLLIN;
	for (i = 0; i < N_LISTEN; i++) {
		ev.data.fd = rcv_fds[i];
		if (epoll_ctl(epfd, EPOLL_CTL_ADD, rcv_fds[i], &ev))
			error(1, errno, "failed to register sock epoll");
	}
	while (n_loops--) {
		send_fd = connect_and_send(family, SOCK_STREAM);
		if (do_rotate && ((n_loops % key_rotate_interval) == 0)) {
			rotate_key(rcv_fds[rotate_key_fd]);
			if (++rotate_key_fd >= N_LISTEN)
				rotate_key_fd = 0;
		}
		while (1) {
			i = epoll_wait(epfd, &ev, 1, -1);
			if (i < 0)
				error(1, errno, "epoll_wait failed");
			if (is_listen_fd(ev.data.fd)) {
				fd = accept(ev.data.fd, NULL, NULL);
				if (fd < 0)
					error(1, errno, "failed to accept");
				ev.data.fd = fd;
				if (epoll_ctl(epfd, EPOLL_CTL_ADD, fd, &ev))
					error(1, errno, "failed epoll add");
				continue;
			}
			i = recv(ev.data.fd, buf, sizeof(buf), 0);
			if (i != 1)
				error(1, errno, "failed recv data");
			if (epoll_ctl(epfd, EPOLL_CTL_DEL, ev.data.fd, NULL))
				error(1, errno, "failed epoll del");
			close(ev.data.fd);
			break;
		}
		close(send_fd);
	}
	for (i = 0; i < N_LISTEN; i++)
		close(rcv_fds[i]);
}

static void parse_opts(int argc, char **argv)
{
	int c;

	while ((c = getopt(argc, argv, "46sr")) != -1) {
		switch (c) {
		case '4':
			do_ipv6 = false;
			break;
		case '6':
			do_ipv6 = true;
			break;
		case 's':
			do_sockopt = true;
			break;
		case 'r':
			do_rotate = true;
			key_len = KEY_LENGTH * 2;
			break;
		default:
			error(1, 0, "%s: parse error", argv[0]);
		}
	}
}

int main(int argc, char **argv)
{
	parse_opts(argc, argv);
	proc_fd = open(PROC_FASTOPEN_KEY, O_RDWR);
	if (proc_fd < 0)
		error(1, errno, "Unable to open %s", PROC_FASTOPEN_KEY);
	srand(time(NULL));
	if (do_ipv6)
		run_one_test(AF_INET6);
	else
		run_one_test(AF_INET);
	close(proc_fd);
	fprintf(stderr, "PASS\n");
	return 0;
}