xref: /freebsd/tests/sys/netinet/ip6_v4mapped_test.c (revision 1db64f89363c97858961c4df0b7d02f3223723cf)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2022 Michael J. Karels.
5  * Copyright (c) 2020 Netflix, Inc.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions are
9  * met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in
14  *    the documentation and/or other materials provided with the
15  *    distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 /*
31  * This test is derived from tcp_connect_port_test.c.
32  */
33 
34 #include <sys/param.h>
35 #include <sys/socket.h>
36 #include <sys/stat.h>
37 #include <sys/sysctl.h>
38 
39 #include <netinet/in.h>
40 
41 #include <err.h>
42 #include <errno.h>
43 #include <fcntl.h>
44 #include <netdb.h>
45 #include <stdio.h>
46 #include <stdlib.h>
47 #include <unistd.h>
48 
49 #include <atf-c.h>
50 
51 #define	SYSCTLBAKFILE	"tmp.net.inet.ip.portrange.values"
52 
53 #define	PORT_FIRST	10000		/* normal default */
54 #define	PORT_LAST	10003
55 #define	LOOPS		10		/* 5 should be enough */
56 
57 struct portrange {
58 	int	first;
59 	int	last;
60 };
61 
62 /*
63  * Set first and last ports in the ipport range.  Save the old values
64  * of the sysctls so they can be restored later.
65  */
66 static void
67 set_portrange(void)
68 {
69 	int error, fd, first_new, last_new;
70 	struct portrange save_ports;
71 	size_t sysctlsz;
72 
73 	/*
74 	 * Pre-emptively unlink our restoration file, so we will do no
75 	 * restoration on error.
76 	 */
77 	unlink(SYSCTLBAKFILE);
78 
79 	/*
80 	 * Set the net.inet.ip.portrange.{first,last} sysctls. Save the
81 	 * old values so we can restore them.
82 	 */
83 	first_new = PORT_FIRST;
84 	sysctlsz = sizeof(save_ports.first);
85 	error = sysctlbyname("net.inet.ip.portrange.first", &save_ports.first,
86 	    &sysctlsz, &first_new, sizeof(first_new));
87 	if (error) {
88 		warn("sysctlbyname(\"net.inet.ip.portrange.first\") "
89 		    "failed");
90 		atf_tc_skip("Unable to set sysctl");
91 	}
92 	if (sysctlsz != sizeof(save_ports.first)) {
93 		fprintf(stderr, "Error: unexpected sysctl value size "
94 		    "(expected %zu, actual %zu)\n", sizeof(save_ports.first),
95 		    sysctlsz);
96 		goto restore_sysctl;
97 	}
98 
99 	last_new = PORT_LAST;
100 	sysctlsz = sizeof(save_ports.last);
101 	error = sysctlbyname("net.inet.ip.portrange.last", &save_ports.last,
102 	    &sysctlsz, &last_new, sizeof(last_new));
103 	if (error) {
104 		warn("sysctlbyname(\"net.inet.ip.portrange.last\") "
105 		    "failed");
106 		atf_tc_skip("Unable to set sysctl");
107 	}
108 	if (sysctlsz != sizeof(save_ports.last)) {
109 		fprintf(stderr, "Error: unexpected sysctl value size "
110 		    "(expected %zu, actual %zu)\n", sizeof(save_ports.last),
111 		    sysctlsz);
112 		goto restore_sysctl;
113 	}
114 
115 	/* Open the backup file, write the contents, and close it. */
116 	fd = open(SYSCTLBAKFILE, O_WRONLY|O_CREAT|O_TRUNC|O_EXCL,
117 	    S_IRUSR|S_IWUSR);
118 	if (fd < 0) {
119 		warn("error opening sysctl backup file");
120 		goto restore_sysctl;
121 	}
122 	error = write(fd, &save_ports, sizeof(save_ports));
123 	if (error < 0) {
124 		warn("error writing saved value to sysctl backup file");
125 		goto cleanup_and_restore;
126 	}
127 	if (error != (int)sizeof(save_ports)) {
128 		fprintf(stderr,
129 		    "Error writing saved value to sysctl backup file: "
130 		    "(expected %zu, actual %d)\n", sizeof(save_ports), error);
131 		goto cleanup_and_restore;
132 	}
133 	error = close(fd);
134 	if (error) {
135 		warn("error closing sysctl backup file");
136 cleanup_and_restore:
137 		(void)close(fd);
138 		(void)unlink(SYSCTLBAKFILE);
139 restore_sysctl:
140 		sysctlsz = sizeof(save_ports.first);
141 		(void)sysctlbyname("net.inet.ip.portrange.first", NULL,
142 		    NULL, &save_ports.first, sysctlsz);
143 		sysctlsz = sizeof(save_ports.last);
144 		(void)sysctlbyname("net.inet.ip.portrange.last", NULL,
145 		    NULL, &save_ports.last, sysctlsz);
146 		atf_tc_skip("Error setting sysctl");
147 	}
148 }
149 
150 /*
151  * Restore the sysctl values from the backup file and delete the backup file.
152  */
153 static void
154 restore_portrange(void)
155 {
156 	int error, fd;
157 	struct portrange save_ports;
158 
159 	/* Open the backup file, read the contents, close it, and delete it. */
160 	fd = open(SYSCTLBAKFILE, O_RDONLY);
161 	if (fd < 0) {
162 		warn("error opening sysctl backup file");
163 		return;
164 	}
165 	error = read(fd, &save_ports, sizeof(save_ports));
166 	if (error < 0) {
167 		warn("error reading saved values from sysctl backup file");
168 		return;
169 	}
170 	if (error != (int)sizeof(save_ports)) {
171 		fprintf(stderr,
172 		    "Error reading saved values from sysctl backup file: "
173 		    "(expected %zu, actual %d)\n", sizeof(save_ports), error);
174 		return;
175 	}
176 	error = close(fd);
177 	if (error)
178 		warn("error closing sysctl backup file");
179 	error = unlink(SYSCTLBAKFILE);
180 	if (error)
181 		warn("error removing sysctl backup file");
182 
183 	/* Restore the saved sysctl values. */
184 	error = sysctlbyname("net.inet.ip.portrange.first", NULL, NULL,
185 	    &save_ports.first, sizeof(save_ports.first));
186 	if (error)
187 		warn("sysctlbyname(\"net.inet.ip.portrange.first\") "
188 		    "failed while restoring value");
189 	error = sysctlbyname("net.inet.ip.portrange.last", NULL, NULL,
190 	    &save_ports.last, sizeof(save_ports.last));
191 	if (error)
192 		warn("sysctlbyname(\"net.inet.ip.portrange.last\") "
193 		    "failed while restoring value");
194 }
195 
196 ATF_TC_WITH_CLEANUP(tcp_v4mapped_bind);
197 ATF_TC_HEAD(tcp_v4mapped_bind, tc)
198 {
199 	/* root is only required for sysctls (setup and cleanup). */
200 	atf_tc_set_md_var(tc, "require.user", "root");
201 	atf_tc_set_md_var(tc, "require.config", "allow_sysctl_side_effects");
202 	atf_tc_set_md_var(tc, "descr",
203 	    "Check local port assignment with bind and mapped V4 addresses");
204 }
205 /*
206  * Create a listening IPv4 socket, then connect to it repeatedly using a
207  * bound IPv6 socket using a v4 mapped address.  With a small port range,
208  * this should fail on a bind() call with EADDRNOTAVAIL.  However, in
209  * previous systems, the bind() would succeed, binding a duplicate port,
210  * and then the connect would fail with EADDRINUSE.  Make sure we get
211  * the right error.
212  */
213 ATF_TC_BODY(tcp_v4mapped_bind, tc)
214 {
215 	union {
216 		struct sockaddr saddr;
217 		struct sockaddr_in saddr4;
218 		struct sockaddr_in6 saddr6;
219 	} su_clnt, su_srvr, su_mapped;
220 	struct addrinfo ai_hint, *aip;
221 	socklen_t salen;
222 	int csock, error, i, lsock, off = 0;
223 	bool got_bind_error = false;
224 
225 	/*
226 	 * Set the net.inet.ip.portrange.{first,last} sysctls to use a small
227 	 * range, allowing us to generate port exhaustion quickly.
228 	 */
229 	set_portrange();
230 
231 	/* Setup the listen socket. */
232 	lsock = socket(PF_INET, SOCK_STREAM, 0);
233 	ATF_REQUIRE_MSG(lsock >= 0, "socket() for listen socket failed: %s",
234 	    strerror(errno));
235 
236 	memset(&su_srvr.saddr4, 0, sizeof(su_srvr.saddr4));
237 	su_srvr.saddr4.sin_family = AF_INET;
238 	error = bind(lsock, &su_srvr.saddr, sizeof(su_srvr.saddr4));
239 	ATF_REQUIRE_MSG(error == 0, "bind() failed: %s", strerror(errno));
240 	error = listen(lsock, LOOPS + 1);
241 	ATF_REQUIRE_MSG(error == 0, "listen() failed: %s", strerror(errno));
242 
243 	/* Get the address of the listen socket. */
244 	salen = sizeof(su_srvr);
245 	error = getsockname(lsock, &su_srvr.saddr, &salen);
246 	ATF_REQUIRE_MSG(error == 0,
247 	    "getsockname() for listen socket failed: %s",
248 	    strerror(errno));
249 	ATF_REQUIRE_MSG(salen == sizeof(struct sockaddr_in),
250 	    "unexpected sockaddr size");
251 	ATF_REQUIRE_MSG(su_srvr.saddr.sa_len == sizeof(struct sockaddr_in),
252 	    "unexpected sa_len size");
253 
254 	/* Set up destination address for client sockets. */
255 	memset(&ai_hint, 0, sizeof(ai_hint));
256 	ai_hint.ai_family = AF_INET6;
257 	ai_hint.ai_flags = AI_NUMERICHOST | AI_V4MAPPED;
258 	error = getaddrinfo("127.0.0.1", NULL, &ai_hint, &aip);
259 	ATF_REQUIRE_MSG(error == 0, "getaddrinfo: %s", gai_strerror(error));
260 	memcpy(&su_mapped.saddr6, aip->ai_addr, sizeof(su_mapped.saddr6));
261 	su_mapped.saddr6.sin6_port = su_srvr.saddr4.sin_port;
262 	freeaddrinfo(aip);
263 
264 	/* Set up address to bind for client sockets (unspecified). */
265 	memset(&su_clnt.saddr6, 0, sizeof(su_clnt.saddr6));
266 	su_clnt.saddr6.sin6_family = AF_INET6;
267 
268 	/* Open connections in a loop. */
269 	for (i = 0; i < LOOPS; i++) {
270 		csock = socket(PF_INET6, SOCK_STREAM, 0);
271 		ATF_REQUIRE_MSG(csock >= 0,
272 		    "socket() for client socket %d failed: %s",
273 		    i, strerror(errno));
274 		error = setsockopt(csock, IPPROTO_IPV6, IPV6_V6ONLY, &off,
275 		    sizeof(off));
276 		ATF_REQUIRE_MSG(error == 0,
277 		    "setsockopt(IPV6_ONLY = 0) failed: %s", strerror(errno));
278 
279 		/*
280 		 * A bind would not be necessary for operation, but
281 		 * provokes the error.
282 		 */
283 		error = bind(csock, &su_clnt.saddr, sizeof(su_clnt.saddr6));
284 		if (error != 0) {
285 			if (errno == EADDRNOTAVAIL) {	/* Success, expected */
286 				got_bind_error = true;
287 				break;
288 			}
289 			ATF_REQUIRE_MSG(error == 0,
290 			    "client bind %d failed: %s", i, strerror(errno));
291 		}
292 
293 		error = connect(csock, &su_mapped.saddr, su_mapped.saddr.sa_len);
294 		if (error != 0 && errno == EADDRINUSE) {
295 			/* This is the specific error we were looking for. */
296 			atf_tc_fail("client connect %d failed, "
297 			    " client had duplicate port: %s",
298 			    i, strerror(errno));
299 		}
300 		ATF_REQUIRE_MSG(error == 0,
301 		    "connect() for client socket %d failed: %s",
302 		    i, strerror(errno));
303 
304 		/*
305 		 * We don't accept the new socket from the server socket
306 		 * or close the client socket, as we want the ports to
307 		 * remain busy.  The range is small enough that this is
308 		 * not a problem.
309 		 */
310 	}
311 	ATF_REQUIRE_MSG(i >= 1, "No successful connections");
312 	ATF_REQUIRE_MSG(got_bind_error == true, "No expected bind error");
313 
314 	ATF_REQUIRE(close(lsock) == 0);
315 }
316 ATF_TC_CLEANUP(tcp_v4mapped_bind, tc)
317 {
318 	restore_portrange();
319 }
320 
321 ATF_TC(udp_v4mapped_sendto);
322 ATF_TC_HEAD(udp_v4mapped_sendto, tc)
323 {
324 	atf_tc_set_md_var(tc, "descr",
325 	    "Validate sendto() with a v4-mapped address and a v6-only socket");
326 }
327 ATF_TC_BODY(udp_v4mapped_sendto, tc)
328 {
329 	struct addrinfo ai_hint, *aip;
330 	struct sockaddr_in sin;
331 	struct sockaddr_in6 sin6;
332 	ssize_t n;
333 	socklen_t salen;
334 	int error, ls, s, zero;
335 	short port;
336 	char ch;
337 
338 	ls = socket(PF_INET, SOCK_DGRAM, 0);
339 	ATF_REQUIRE(ls >= 0);
340 
341 	memset(&ai_hint, 0, sizeof(ai_hint));
342 	ai_hint.ai_family = AF_INET;
343 	ai_hint.ai_flags = AI_NUMERICHOST;
344 	error = getaddrinfo("127.0.0.1", NULL, &ai_hint, &aip);
345 	ATF_REQUIRE_MSG(error == 0, "getaddrinfo: %s", gai_strerror(error));
346 	memcpy(&sin, aip->ai_addr, sizeof(sin));
347 
348 	error = bind(ls, (struct sockaddr *)&sin, sizeof(sin));
349 	ATF_REQUIRE_MSG(error == 0, "bind: %s", strerror(errno));
350 	salen = sizeof(sin);
351 	error = getsockname(ls, (struct sockaddr *)&sin, &salen);
352 	ATF_REQUIRE_MSG(error == 0,
353 	    "getsockname() for listen socket failed: %s", strerror(errno));
354 	ATF_REQUIRE_MSG(salen == sizeof(struct sockaddr_in),
355 	    "unexpected sockaddr size");
356 	port = sin.sin_port;
357 
358 	s = socket(PF_INET6, SOCK_DGRAM, 0);
359 	ATF_REQUIRE(s >= 0);
360 
361 	memset(&ai_hint, 0, sizeof(ai_hint));
362 	ai_hint.ai_family = AF_INET6;
363 	ai_hint.ai_flags = AI_NUMERICHOST | AI_V4MAPPED;
364 	error = getaddrinfo("127.0.0.1", NULL, &ai_hint, &aip);
365 	ATF_REQUIRE_MSG(error == 0, "getaddrinfo: %s", gai_strerror(error));
366 	memcpy(&sin6, aip->ai_addr, sizeof(sin6));
367 	sin6.sin6_port = port;
368 	freeaddrinfo(aip);
369 
370 	ch = 0x42;
371 	n = sendto(s, &ch, 1, 0, (struct sockaddr *)&sin6, sizeof(sin6));
372 	ATF_REQUIRE_ERRNO(EINVAL, n == -1);
373 
374 	zero = 0;
375 	error = setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, &zero, sizeof(zero));
376 	ATF_REQUIRE_MSG(error == 0,
377 	    "setsockopt(IPV6_V6ONLY) failed: %s", strerror(errno));
378 
379 	ch = 0x42;
380 	n = sendto(s, &ch, 1, 0, (struct sockaddr *)&sin6, sizeof(sin6));
381 	ATF_REQUIRE_MSG(n == 1, "sendto() failed: %s", strerror(errno));
382 
383 	ch = 0;
384 	n = recv(ls, &ch, 1, 0);
385 	ATF_REQUIRE_MSG(n == 1, "recv() failed: %s", strerror(errno));
386 	ATF_REQUIRE(ch == 0x42);
387 
388 	ATF_REQUIRE(close(s) == 0);
389 	ATF_REQUIRE(close(ls) == 0);
390 }
391 
392 ATF_TP_ADD_TCS(tp)
393 {
394 	ATF_TP_ADD_TC(tp, tcp_v4mapped_bind);
395 	ATF_TP_ADD_TC(tp, udp_v4mapped_sendto);
396 
397 	return (atf_no_error());
398 }
399