xref: /freebsd/tests/sys/kern/unix_dgram.c (revision bdd1243df58e60e85101c09001d9812a789b6bc4)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2022 Gleb Smirnoff <glebius@FreeBSD.org>
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #include <sys/time.h>
29 #include <sys/event.h>
30 #include <sys/ioctl.h>
31 #include <sys/select.h>
32 #include <sys/socket.h>
33 #include <sys/sysctl.h>
34 #include <sys/un.h>
35 #include <aio.h>
36 #include <errno.h>
37 #include <fcntl.h>
38 #include <signal.h>
39 #include <stdio.h>
40 #include <stdlib.h>
41 
42 #include <atf-c.h>
43 
44 static struct itimerval itv = {
45 	.it_interval = { 0, 0 },
46 	.it_value = { 1, 0 },	/* one second */
47 };
48 static sig_atomic_t timer_done = 0;
49 static void
50 sigalarm(int sig __unused)
51 {
52 
53 	timer_done = 1;
54 }
55 
56 static struct sigaction sigact = {
57 	.sa_handler = sigalarm,
58 };
59 
60 static struct sockaddr_un sun = {
61 	.sun_family = AF_LOCAL,
62 	.sun_len = sizeof(sun),
63 	.sun_path = "unix_dgram_listener",
64 };
65 
66 /*
67  * Fill socket to a state when next send(len) would fail.
68  *
69  * Note that every datagram is prepended with sender address,
70  * size of struct sockaddr.
71  */
72 static void
73 fill(int fd, void *buf, ssize_t len)
74 {
75 	unsigned long recvspace;
76 	size_t llen = sizeof(unsigned long);
77 	ssize_t sent;
78 
79 	ATF_REQUIRE(sysctlbyname("net.local.dgram.recvspace", &recvspace,
80 	    &llen, NULL, 0) == 0);
81 	for (sent = 0;
82 	    sent + len + sizeof(struct sockaddr) < recvspace;
83 	    sent += len + sizeof(struct sockaddr))
84 		ATF_REQUIRE(send(fd, buf, len, 0) == len);
85 }
86 
87 ATF_TC_WITHOUT_HEAD(basic);
88 ATF_TC_BODY(basic, tc)
89 {
90 	struct msghdr msg;
91 	struct iovec iov[1];
92 	unsigned long maxdgram;
93 	size_t llen = sizeof(unsigned long);
94 	int fd[2];
95 	char *buf;
96 
97 	/* Allocate and initialize:
98 	 * - fd[0] to send, fd[1] to receive
99 	 * - buf[maxdgram] for data
100 	 */
101 	ATF_REQUIRE(sysctlbyname("net.local.dgram.maxdgram", &maxdgram,
102 	    &llen, NULL, 0) == 0);
103 	ATF_REQUIRE(socketpair(PF_UNIX, SOCK_DGRAM, 0, fd) != -1);
104 	buf = malloc(maxdgram + 1);
105 	ATF_REQUIRE(buf);
106 	msg = (struct msghdr ){
107 		.msg_iov = iov,
108 		.msg_iovlen = 1,
109 	};
110 	iov[0] = (struct iovec ){
111 		.iov_base = buf,
112 	};
113 
114 	/* Fail to send > maxdgram. */
115 	ATF_REQUIRE(send(fd[0], buf, maxdgram + 1, 0) == -1);
116 	ATF_REQUIRE(errno == EMSGSIZE);
117 
118 	/* Send maxdgram. */
119 	ATF_REQUIRE(send(fd[0], buf, maxdgram, 0) == (ssize_t)maxdgram);
120 
121 	/* Exercise MSG_PEEK, full and truncated.. */
122 	ATF_REQUIRE(recv(fd[1], buf, maxdgram, MSG_PEEK) == (ssize_t)maxdgram);
123 	iov[0].iov_len = 42;
124 	ATF_REQUIRE(recvmsg(fd[1], &msg, MSG_PEEK) == 42);
125 	ATF_REQUIRE(msg.msg_flags == (MSG_PEEK | MSG_TRUNC));
126 
127 	/* Receive maxdgram. */
128 	iov[0].iov_len = maxdgram;
129 	ATF_REQUIRE(recvmsg(fd[1], &msg, 0) == (ssize_t)maxdgram);
130 	ATF_REQUIRE(msg.msg_flags == 0);
131 
132 	/* Receive truncated message. */
133 	ATF_REQUIRE(send(fd[0], buf, maxdgram, 0) == (ssize_t)maxdgram);
134 	iov[0].iov_len = maxdgram / 2;
135 	ATF_REQUIRE(recvmsg(fd[1], &msg, 0) == (ssize_t)maxdgram / 2);
136 	ATF_REQUIRE(msg.msg_flags == MSG_TRUNC);
137 
138 	/* Empty: block. */
139 	ATF_REQUIRE(sigaction(SIGALRM, &sigact, NULL) == 0);
140 	ATF_REQUIRE(timer_done == 0);
141 	ATF_REQUIRE(setitimer(ITIMER_REAL, &itv, NULL) == 0);
142 	ATF_REQUIRE(recv(fd[1], buf, maxdgram, 0) == -1);
143 	ATF_REQUIRE(errno == EINTR);
144 	ATF_REQUIRE(timer_done == 1);
145 
146 	/* Don't block with MSG_DONTWAIT. */
147 	ATF_REQUIRE(recv(fd[1], buf, maxdgram, MSG_DONTWAIT) == -1);
148 	ATF_REQUIRE(errno == EAGAIN);
149 
150 	/* Don't block with O_NONBLOCK. */
151 	ATF_REQUIRE(fcntl(fd[1], F_SETFL, O_NONBLOCK) != -1);
152 	ATF_REQUIRE(recv(fd[1], buf, maxdgram, 0) == -1);
153 	ATF_REQUIRE(errno == EAGAIN);
154 
155 	/* Fail with ENOBUFS on full socket. */
156 	fill(fd[0], buf, maxdgram);
157 	ATF_REQUIRE(send(fd[0], buf, maxdgram, 0) == -1);
158 	ATF_REQUIRE(errno == ENOBUFS);
159 
160 	/*
161 	 * Fail with ENOBUFS with O_NONBLOCK set, too. See 71e70c25c00
162 	 * for explanation why this behavior needs to be preserved.
163 	 */
164 	ATF_REQUIRE(fcntl(fd[0], F_SETFL, O_NONBLOCK) != -1);
165 	ATF_REQUIRE(send(fd[0], buf, maxdgram, 0) == -1);
166 	ATF_REQUIRE(errno == ENOBUFS);
167 
168 	/* Remote side closed -> ECONNRESET. */
169 	close(fd[1]);
170 	ATF_REQUIRE(send(fd[0], buf, maxdgram, 0) == -1);
171 	ATF_REQUIRE(errno == ECONNRESET);
172 }
173 
174 ATF_TC_WITHOUT_HEAD(one2many);
175 ATF_TC_BODY(one2many, tc)
176 {
177 	int one, many[3], two;
178 #define	BUFSIZE	1024
179 	char buf[BUFSIZE], goodboy[BUFSIZE], flooder[BUFSIZE], notconn[BUFSIZE];
180 
181 	/* Establish one to many connection. */
182 	ATF_REQUIRE((one = socket(PF_UNIX, SOCK_DGRAM, 0)) > 0);
183 	ATF_REQUIRE(bind(one, (struct sockaddr *)&sun, sizeof(sun)) == 0);
184 	/* listen(2) shall fail. */
185 	ATF_REQUIRE(listen(one, -1) != 0);
186 	for (int i = 0; i < 3; i++) {
187 		ATF_REQUIRE((many[i] = socket(PF_UNIX, SOCK_DGRAM, 0)) > 0);
188 		ATF_REQUIRE(connect(many[i], (struct sockaddr *)&sun,
189 		    sizeof(sun)) == 0);
190 	}
191 
192 	/* accept() on UNIX/DGRAM is invalid. */
193 	ATF_REQUIRE(accept(one, NULL, NULL) == -1);
194 	ATF_REQUIRE(errno == EINVAL);
195 
196 	/*
197 	 * Connecting a bound socket to self: a strange, useless, but
198 	 * historically existing edge case that is not explicitly described
199 	 * in SuS, neither is forbidden there. Works on FreeBSD and Linux.
200 	 */
201 	ATF_REQUIRE(connect(one, (struct sockaddr *)&sun, sizeof(sun)) == 0);
202 	ATF_REQUIRE(send(one, buf, 42, 0) == 42);
203 	ATF_REQUIRE(recv(one, buf, sizeof(buf), 0) == 42);
204 
205 	/*
206 	 * Interaction between concurrent senders. New feature in FreeBSD 14.
207 	 *
208 	 * One sender can not fill the receive side.  Other senders can
209 	 * continue operation.  Senders who don't fill their buffers are
210 	 * prioritized over flooders.  Connected senders are prioritized over
211 	 * unconnected.
212 	 *
213 	 * Disconnecting a sender that has queued data optionally preserves
214 	 * the data.  Allow the data to migrate to peers buffer only if the
215 	 * latter is empty.  Otherwise discard it, to prevent against
216 	 * connect-fill-close attack.
217 	 */
218 #define	FLOODER	13	/* for connected flooder on many[0] */
219 #define	GOODBOY	42	/* for a good boy on many[1] */
220 #define	NOTCONN	66	/* for sendto(2) via two */
221 	goodboy[0] = GOODBOY;
222 	flooder[0] = FLOODER;
223 	notconn[0] = NOTCONN;
224 
225 	/* Connected priority over sendto(2). */
226 	ATF_REQUIRE((two = socket(PF_UNIX, SOCK_DGRAM, 0)) > 0);
227 	ATF_REQUIRE(sendto(two, notconn, BUFSIZE, 0, (struct sockaddr *)&sun,
228 	    sizeof(sun)) == BUFSIZE);
229 	ATF_REQUIRE(send(many[1], goodboy, BUFSIZE, 0) == BUFSIZE);
230 	ATF_REQUIRE(recv(one, buf, sizeof(buf), 0) == sizeof(buf));
231 	ATF_REQUIRE(buf[0] == GOODBOY);	/* message from good boy comes first */
232 	ATF_REQUIRE(recv(one, buf, sizeof(buf), 0) == sizeof(buf));
233 	ATF_REQUIRE(buf[0] == NOTCONN);	/* only then message from sendto(2) */
234 
235 	/* Casual sender priority over a flooder. */
236 	fill(many[0], flooder, sizeof(flooder));
237 	ATF_REQUIRE(send(many[0], flooder, BUFSIZE, 0) == -1);
238 	ATF_REQUIRE(errno == ENOBUFS);
239 	ATF_REQUIRE(send(many[1], goodboy, BUFSIZE, 0) == BUFSIZE);
240 	ATF_REQUIRE(recv(one, buf, sizeof(buf), 0) == sizeof(buf));
241 	ATF_REQUIRE(buf[0] == GOODBOY);	/* message from good boy comes first */
242 	ATF_REQUIRE(recv(one, buf, sizeof(buf), 0) == sizeof(buf));
243 	ATF_REQUIRE(buf[0] == FLOODER);	/* only then message from flooder */
244 
245 	/* Once seen, a message can't be deprioritized by any other message. */
246 	ATF_REQUIRE(recv(one, buf, sizeof(buf), MSG_PEEK) == sizeof(buf));
247 	ATF_REQUIRE(buf[0] == FLOODER); /* message from the flooder seen */
248 	ATF_REQUIRE(send(many[1], goodboy, BUFSIZE, 0) == BUFSIZE);
249 	ATF_REQUIRE(recv(one, buf, sizeof(buf), MSG_PEEK) == sizeof(buf));
250 	ATF_REQUIRE(buf[0] == FLOODER); /* should be the same message */
251 	ATF_REQUIRE(recv(one, buf, sizeof(buf), 0) == sizeof(buf));
252 	ATF_REQUIRE(buf[0] == FLOODER); /* now we read it out... */
253 	ATF_REQUIRE(recv(one, buf, sizeof(buf), 0) == sizeof(buf));
254 	ATF_REQUIRE(buf[0] == GOODBOY); /* ... and next one is the good boy */
255 
256 	/* Disconnect in presence of data from not connected. */
257 	ATF_REQUIRE(sendto(two, notconn, BUFSIZE, 0, (struct sockaddr *)&sun,
258 	    sizeof(sun)) == BUFSIZE);
259 	close(many[0]);
260 	ATF_REQUIRE(recv(one, buf, sizeof(buf), 0) == sizeof(buf));
261 	ATF_REQUIRE(buf[0] == NOTCONN);	/* message from sendto() */
262 	ATF_REQUIRE(recv(one, buf, sizeof(buf), MSG_DONTWAIT) == -1);
263 	ATF_REQUIRE(errno == EAGAIN);	/* data from many[0] discarded */
264 
265 	/* Disconnect in absence of data from not connected. */
266 	ATF_REQUIRE(send(many[1], goodboy, BUFSIZE, 0) == BUFSIZE);
267 	close(many[1]);
268 	ATF_REQUIRE(recv(one, buf, sizeof(buf), 0) == sizeof(buf));
269 	ATF_REQUIRE(buf[0] == GOODBOY);	/* message from many[1] preserved */
270 
271 	/* Check that nothing leaks on close(2). */
272 	ATF_REQUIRE(send(many[2], buf, 42, 0) == 42);
273 	ATF_REQUIRE(send(many[2], buf, 42, 0) == 42);
274 	ATF_REQUIRE(recv(one, buf, sizeof(buf), MSG_PEEK) == 42);
275 	ATF_REQUIRE(sendto(two, notconn, 42, 0, (struct sockaddr *)&sun,
276 	    sizeof(sun)) == 42);
277 	close(one);
278 }
279 
280 /*
281  * Check that various mechanism report socket as readable and having
282  * 42 bytes of data.
283  */
284 static void
285 test42(int fd)
286 {
287 
288 	/* ioctl(FIONREAD) */
289 	int data;
290 
291 	ATF_REQUIRE(ioctl(fd, FIONREAD, &data) != -1);
292 	ATF_REQUIRE(data == 42);
293 
294 	/* select(2) */
295 	fd_set rfds;
296 
297 	FD_ZERO(&rfds);
298 	FD_SET(fd, &rfds);
299 	ATF_REQUIRE(select(fd + 1, &rfds, NULL, NULL, NULL) == 1);
300 	ATF_REQUIRE(FD_ISSET(fd, &rfds));
301 
302 	/* kevent(2) */
303 	struct kevent ev;
304 	int kq;
305 
306 	ATF_REQUIRE((kq = kqueue()) != -1);
307 	EV_SET(&ev, fd, EVFILT_READ, EV_ADD, NOTE_LOWAT, 41, NULL);
308 	ATF_REQUIRE(kevent(kq, &ev, 1, NULL, 0, NULL) == 0);
309 	ATF_REQUIRE(kevent(kq, NULL, 0, &ev, 1, NULL) == 1);
310 	ATF_REQUIRE(ev.filter == EVFILT_READ);
311 	ATF_REQUIRE(ev.data == 42);
312 
313 	/* aio(4) */
314 	char buf[50];
315 	struct aiocb aio = {
316 		.aio_nbytes = 50,
317 		.aio_fildes = fd,
318 		.aio_buf = buf,
319 	}, *aiop;
320 
321 	ATF_REQUIRE(aio_read(&aio) == 0);
322 	ATF_REQUIRE(aio_waitcomplete(&aiop, NULL) == 42);
323 	ATF_REQUIRE(aiop == &aio);
324 }
325 
326 /*
327  * Send data and control in connected & unconnected mode and check that
328  * various event mechanisms see the data, but don't count control bytes.
329  */
330 ATF_TC_WITHOUT_HEAD(event);
331 ATF_TC_BODY(event, tc)
332 {
333 	int fd[2];
334 	char buf[50];
335 	struct iovec iov = {
336 		.iov_base = buf,
337 		.iov_len = 42,
338 	};
339 	struct cmsghdr cmsg = {
340 		.cmsg_len = CMSG_LEN(0),
341 		.cmsg_level = SOL_SOCKET,
342 		.cmsg_type = SCM_TIMESTAMP,
343 	};
344 	struct msghdr msghdr = {
345 		.msg_iov = &iov,
346 		.msg_iovlen = 1,
347 		.msg_control = &cmsg,
348 		.msg_controllen = CMSG_LEN(0),
349 	};
350 
351 	/* Connected socket */
352 	ATF_REQUIRE(socketpair(PF_UNIX, SOCK_DGRAM, 0, fd) != -1);
353 	ATF_REQUIRE(sendmsg(fd[0], &msghdr, 0) == 42);
354 	test42(fd[1]);
355 	close(fd[0]);
356 	close(fd[1]);
357 
358 	/* Not-connected send */
359 	ATF_REQUIRE((fd[0] = socket(PF_UNIX, SOCK_DGRAM, 0)) > 0);
360 	ATF_REQUIRE((fd[1] = socket(PF_UNIX, SOCK_DGRAM, 0)) > 0);
361 	ATF_REQUIRE(bind(fd[0], (struct sockaddr *)&sun, sizeof(sun)) == 0);
362 	ATF_REQUIRE(sendto(fd[1], buf, 42, 0, (struct sockaddr *)&sun,
363 	    sizeof(sun)) == 42);
364 	test42(fd[0]);
365 }
366 
367 ATF_TC_WITHOUT_HEAD(selfgetpeername);
368 ATF_TC_BODY(selfgetpeername, tc)
369 {
370 	struct sockaddr_un sun;
371 	const char *name;
372 	socklen_t len;
373 	int sd;
374 
375 	name = "selfgetpeername";
376 
377 	sd = socket(PF_UNIX, SOCK_DGRAM, 0);
378 	ATF_REQUIRE(sd != -1);
379 
380 	memset(&sun, 0, sizeof(sun));
381 	sun.sun_len = sizeof(sun);
382 	sun.sun_family = AF_UNIX;
383 	snprintf(sun.sun_path, sizeof(sun.sun_path), "%s", name);
384 	ATF_REQUIRE(bind(sd, (struct sockaddr *)&sun, sizeof(sun)) == 0);
385 	ATF_REQUIRE(connect(sd, (struct sockaddr *)&sun, sizeof(sun)) == 0);
386 
387 	len = sizeof(sun);
388 	ATF_REQUIRE(getpeername(sd, (struct sockaddr *)&sun, &len) == 0);
389 	ATF_REQUIRE(strcmp(sun.sun_path, name) == 0);
390 
391 	ATF_REQUIRE(close(sd) == 0);
392 }
393 
394 ATF_TP_ADD_TCS(tp)
395 {
396 	ATF_TP_ADD_TC(tp, basic);
397 	ATF_TP_ADD_TC(tp, one2many);
398 	ATF_TP_ADD_TC(tp, event);
399 	ATF_TP_ADD_TC(tp, selfgetpeername);
400 
401 	return (atf_no_error());
402 }
403