xref: /freebsd/tests/sys/kern/pipe/pipe_kqueue_test.c (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2020 Jan Kokemüller
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/cdefs.h>
29 __FBSDID("$FreeBSD$");
30 
31 #include <sys/param.h>
32 #include <sys/event.h>
33 #include <sys/stat.h>
34 
35 #include <errno.h>
36 #include <fcntl.h>
37 #include <limits.h>
38 #include <poll.h>
39 #include <stdio.h>
40 #include <stdlib.h>
41 #include <time.h>
42 #include <unistd.h>
43 
44 #include <atf-c.h>
45 
46 ATF_TC_WITHOUT_HEAD(pipe_kqueue__write_end);
47 ATF_TC_BODY(pipe_kqueue__write_end, tc)
48 {
49 	int p[2] = { -1, -1 };
50 
51 	ATF_REQUIRE(pipe2(p, O_CLOEXEC | O_NONBLOCK) == 0);
52 	ATF_REQUIRE(p[0] >= 0);
53 	ATF_REQUIRE(p[1] >= 0);
54 
55 	int kq = kqueue();
56 	ATF_REQUIRE(kq >= 0);
57 
58 	struct kevent kev[32];
59 	EV_SET(&kev[0], p[1], EVFILT_WRITE, EV_ADD | EV_CLEAR, 0, 0, 0);
60 
61 	ATF_REQUIRE(kevent(kq, kev, 1, NULL, 0, NULL) == 0);
62 
63 	/* Test that EVFILT_WRITE behaves sensibly on the write end. */
64 
65 	ATF_REQUIRE(kevent(kq, NULL, 0, kev, nitems(kev),
66 	    &(struct timespec) { 0, 0 }) == 1);
67 	ATF_REQUIRE(kev[0].ident == (uintptr_t)p[1]);
68 	ATF_REQUIRE(kev[0].filter == EVFILT_WRITE);
69 	ATF_REQUIRE(kev[0].flags == EV_CLEAR);
70 	ATF_REQUIRE(kev[0].fflags == 0);
71 	ATF_REQUIRE(kev[0].data == 16384);
72 	ATF_REQUIRE(kev[0].udata == 0);
73 
74 	/* Filling up the pipe should make the EVFILT_WRITE disappear. */
75 
76 	char c = 0;
77 	ssize_t r;
78 	while ((r = write(p[1], &c, 1)) == 1) {
79 	}
80 	ATF_REQUIRE(r < 0);
81 	ATF_REQUIRE(errno == EAGAIN || errno == EWOULDBLOCK);
82 
83 	ATF_REQUIRE(kevent(kq, NULL, 0, kev, nitems(kev),
84 	    &(struct timespec) { 0, 0 }) == 0);
85 
86 	/* Reading (PIPE_BUF - 1) bytes will not trigger a EVFILT_WRITE yet. */
87 
88 	for (int i = 0; i < PIPE_BUF - 1; ++i) {
89 		ATF_REQUIRE(read(p[0], &c, 1) == 1);
90 	}
91 
92 	ATF_REQUIRE(kevent(kq, NULL, 0, kev, nitems(kev),
93 	    &(struct timespec) { 0, 0 }) == 0);
94 
95 	/* Reading one additional byte triggers the EVFILT_WRITE. */
96 
97 	ATF_REQUIRE(read(p[0], &c, 1) == 1);
98 
99 	r = kevent(kq, NULL, 0, kev, nitems(kev), &(struct timespec) { 0, 0 });
100 	ATF_REQUIRE(r == 1);
101 	ATF_REQUIRE(kev[0].ident == (uintptr_t)p[1]);
102 	ATF_REQUIRE(kev[0].filter == EVFILT_WRITE);
103 	ATF_REQUIRE(kev[0].flags == EV_CLEAR);
104 	ATF_REQUIRE(kev[0].fflags == 0);
105 	ATF_REQUIRE(kev[0].data == PIPE_BUF);
106 	ATF_REQUIRE(kev[0].udata == 0);
107 
108 	/*
109 	 * Reading another byte triggers the EVFILT_WRITE again with a changed
110 	 * 'data' field.
111 	 */
112 
113 	ATF_REQUIRE(read(p[0], &c, 1) == 1);
114 
115 	ATF_REQUIRE(kevent(kq, NULL, 0, kev, nitems(kev),
116 	    &(struct timespec) { 0, 0 }) == 1);
117 	ATF_REQUIRE(kev[0].ident == (uintptr_t)p[1]);
118 	ATF_REQUIRE(kev[0].filter == EVFILT_WRITE);
119 	ATF_REQUIRE(kev[0].flags == EV_CLEAR);
120 	ATF_REQUIRE(kev[0].fflags == 0);
121 	ATF_REQUIRE(kev[0].data == PIPE_BUF + 1);
122 	ATF_REQUIRE(kev[0].udata == 0);
123 
124 	/*
125 	 * Closing the read end should make a EV_EOF appear but leave the 'data'
126 	 * field unchanged.
127 	 */
128 
129 	ATF_REQUIRE(close(p[0]) == 0);
130 
131 	ATF_REQUIRE(kevent(kq, NULL, 0, kev, nitems(kev),
132 	    &(struct timespec) { 0, 0 }) == 1);
133 	ATF_REQUIRE(kev[0].ident == (uintptr_t)p[1]);
134 	ATF_REQUIRE(kev[0].filter == EVFILT_WRITE);
135 	ATF_REQUIRE(kev[0].flags == (EV_CLEAR | EV_EOF | EV_ONESHOT));
136 	ATF_REQUIRE(kev[0].fflags == 0);
137 	ATF_REQUIRE(kev[0].data == PIPE_BUF + 1);
138 	ATF_REQUIRE(kev[0].udata == 0);
139 
140 	ATF_REQUIRE(close(kq) == 0);
141 	ATF_REQUIRE(close(p[1]) == 0);
142 }
143 
144 ATF_TC_WITHOUT_HEAD(pipe_kqueue__closed_read_end);
145 ATF_TC_BODY(pipe_kqueue__closed_read_end, tc)
146 {
147 	int p[2] = { -1, -1 };
148 
149 	ATF_REQUIRE(pipe2(p, O_CLOEXEC | O_NONBLOCK) == 0);
150 	ATF_REQUIRE(p[0] >= 0);
151 	ATF_REQUIRE(p[1] >= 0);
152 
153 	ATF_REQUIRE(close(p[0]) == 0);
154 
155 	int kq = kqueue();
156 	ATF_REQUIRE(kq >= 0);
157 
158 	struct kevent kev[32];
159 	EV_SET(&kev[0], p[1], EVFILT_READ, EV_ADD | EV_CLEAR | EV_RECEIPT, /**/
160 	    0, 0, 0);
161 	EV_SET(&kev[1], p[1], EVFILT_WRITE, EV_ADD | EV_CLEAR | EV_RECEIPT, /**/
162 	    0, 0, 0);
163 
164 	/*
165 	 * Trying to register EVFILT_WRITE when the pipe is closed leads to an
166 	 * EPIPE error.
167 	 */
168 
169 	ATF_REQUIRE(kevent(kq, kev, 2, kev, 2, NULL) == 2);
170 	ATF_REQUIRE((kev[0].flags & EV_ERROR) != 0);
171 	ATF_REQUIRE(kev[0].data == 0);
172 	ATF_REQUIRE((kev[1].flags & EV_ERROR) != 0);
173 	ATF_REQUIRE(kev[1].data == EPIPE);
174 
175 	ATF_REQUIRE(kevent(kq, NULL, 0, kev, nitems(kev),
176 	    &(struct timespec) { 0, 0 }) == 1);
177 	ATF_REQUIRE(kev[0].ident == (uintptr_t)p[1]);
178 	ATF_REQUIRE(kev[0].filter == EVFILT_READ);
179 	ATF_REQUIRE(kev[0].flags == (EV_EOF | EV_CLEAR | EV_RECEIPT));
180 	ATF_REQUIRE(kev[0].fflags == 0);
181 	ATF_REQUIRE(kev[0].data == 0);
182 	ATF_REQUIRE(kev[0].udata == 0);
183 
184 	ATF_REQUIRE(close(kq) == 0);
185 	ATF_REQUIRE(close(p[1]) == 0);
186 }
187 
188 ATF_TC_WITHOUT_HEAD(pipe_kqueue__closed_read_end_register_before_close);
189 ATF_TC_BODY(pipe_kqueue__closed_read_end_register_before_close, tc)
190 {
191 	int p[2] = { -1, -1 };
192 
193 	ATF_REQUIRE(pipe2(p, O_CLOEXEC | O_NONBLOCK) == 0);
194 	ATF_REQUIRE(p[0] >= 0);
195 	ATF_REQUIRE(p[1] >= 0);
196 
197 	int kq = kqueue();
198 	ATF_REQUIRE(kq >= 0);
199 
200 	struct kevent kev[32];
201 	EV_SET(&kev[0], p[1], EVFILT_READ, EV_ADD | EV_CLEAR | EV_RECEIPT, /**/
202 	    0, 0, 0);
203 	EV_SET(&kev[1], p[1], EVFILT_WRITE, EV_ADD | EV_CLEAR | EV_RECEIPT, /**/
204 	    0, 0, 0);
205 
206 	/*
207 	 * Registering EVFILT_WRITE before the pipe is closed leads to a
208 	 * EVFILT_WRITE event with EV_EOF set.
209 	 */
210 
211 	ATF_REQUIRE(kevent(kq, kev, 2, kev, 2, NULL) == 2);
212 	ATF_REQUIRE((kev[0].flags & EV_ERROR) != 0);
213 	ATF_REQUIRE(kev[0].data == 0);
214 	ATF_REQUIRE((kev[1].flags & EV_ERROR) != 0);
215 	ATF_REQUIRE(kev[1].data == 0);
216 
217 	ATF_REQUIRE(close(p[0]) == 0);
218 
219 	ATF_REQUIRE(kevent(kq, NULL, 0, kev, nitems(kev),
220 	    &(struct timespec) { 0, 0 }) == 2);
221 	{
222 		ATF_REQUIRE(kev[0].ident == (uintptr_t)p[1]);
223 		ATF_REQUIRE(kev[0].filter == EVFILT_WRITE);
224 		ATF_REQUIRE(kev[0].flags ==
225 		    (EV_EOF | EV_CLEAR | EV_ONESHOT | EV_RECEIPT));
226 		ATF_REQUIRE(kev[0].fflags == 0);
227 		ATF_REQUIRE(kev[0].data == 16384);
228 		ATF_REQUIRE(kev[0].udata == 0);
229 	}
230 	{
231 		ATF_REQUIRE(kev[1].ident == (uintptr_t)p[1]);
232 		ATF_REQUIRE(kev[1].filter == EVFILT_READ);
233 		ATF_REQUIRE(kev[1].flags == (EV_EOF | EV_CLEAR | EV_RECEIPT));
234 		ATF_REQUIRE(kev[1].fflags == 0);
235 		ATF_REQUIRE(kev[1].data == 0);
236 		ATF_REQUIRE(kev[1].udata == 0);
237 	}
238 
239 	ATF_REQUIRE(close(kq) == 0);
240 	ATF_REQUIRE(close(p[1]) == 0);
241 }
242 
243 ATF_TC_WITHOUT_HEAD(pipe_kqueue__closed_write_end);
244 ATF_TC_BODY(pipe_kqueue__closed_write_end, tc)
245 {
246 	struct kevent kev[32];
247 	ssize_t bytes, n;
248 	int kq, p[2];
249 	char c;
250 
251 	ATF_REQUIRE(pipe2(p, O_CLOEXEC | O_NONBLOCK) == 0);
252 	ATF_REQUIRE(p[0] >= 0);
253 	ATF_REQUIRE(p[1] >= 0);
254 
255 	bytes = 0;
256 	c = 0;
257 	while ((n = write(p[1], &c, 1)) == 1)
258 		bytes++;
259 	ATF_REQUIRE(n < 0);
260 	ATF_REQUIRE(errno == EAGAIN || errno == EWOULDBLOCK);
261 
262 	ATF_REQUIRE(close(p[1]) == 0);
263 
264 	kq = kqueue();
265 	ATF_REQUIRE(kq >= 0);
266 
267 	EV_SET(&kev[0], p[0], EVFILT_READ, EV_ADD | EV_CLEAR | EV_RECEIPT,
268 	    0, 0, 0);
269 	EV_SET(&kev[1], p[0], EVFILT_WRITE, EV_ADD | EV_CLEAR | EV_RECEIPT,
270 	    0, 0, 0);
271 
272 	/*
273 	 * Trying to register EVFILT_WRITE when the pipe is closed leads to an
274 	 * EPIPE error.
275 	 */
276 
277 	ATF_REQUIRE(kevent(kq, kev, 2, kev, 2, NULL) == 2);
278 	ATF_REQUIRE((kev[0].flags & EV_ERROR) != 0);
279 	ATF_REQUIRE(kev[0].data == 0);
280 	ATF_REQUIRE((kev[1].flags & EV_ERROR) != 0);
281 	ATF_REQUIRE(kev[1].data == EPIPE);
282 
283 	ATF_REQUIRE(kevent(kq, NULL, 0, kev, nitems(kev),
284 	    &(struct timespec) { 0, 0 }) == 1);
285 	ATF_REQUIRE(kev[0].ident == (uintptr_t)p[0]);
286 	ATF_REQUIRE(kev[0].filter == EVFILT_READ);
287 	ATF_REQUIRE(kev[0].flags == (EV_EOF | EV_CLEAR | EV_RECEIPT));
288 	ATF_REQUIRE(kev[0].fflags == 0);
289 	ATF_REQUIRE(kev[0].data == bytes);
290 	ATF_REQUIRE(kev[0].udata == 0);
291 
292 	ATF_REQUIRE(close(kq) == 0);
293 	ATF_REQUIRE(close(p[0]) == 0);
294 }
295 
296 ATF_TC_WITHOUT_HEAD(pipe_kqueue__closed_write_end_register_before_close);
297 ATF_TC_BODY(pipe_kqueue__closed_write_end_register_before_close, tc)
298 {
299 	struct kevent kev[32];
300 	ssize_t bytes, n;
301 	int kq, p[2];
302 	char c;
303 
304 	ATF_REQUIRE(pipe2(p, O_CLOEXEC | O_NONBLOCK) == 0);
305 	ATF_REQUIRE(p[0] >= 0);
306 	ATF_REQUIRE(p[1] >= 0);
307 
308 	kq = kqueue();
309 	ATF_REQUIRE(kq >= 0);
310 
311 	EV_SET(&kev[0], p[0], EVFILT_READ, EV_ADD | EV_CLEAR | EV_RECEIPT,
312 	    0, 0, 0);
313 	EV_SET(&kev[1], p[0], EVFILT_WRITE, EV_ADD | EV_CLEAR | EV_RECEIPT,
314 	    0, 0, 0);
315 
316 	/*
317 	 * Registering EVFILT_WRITE before the pipe is closed leads to a
318 	 * EVFILT_WRITE event with EV_EOF set.
319 	 */
320 
321 	ATF_REQUIRE(kevent(kq, kev, 2, kev, 2, NULL) == 2);
322 	ATF_REQUIRE((kev[0].flags & EV_ERROR) != 0);
323 	ATF_REQUIRE(kev[0].data == 0);
324 	ATF_REQUIRE((kev[1].flags & EV_ERROR) != 0);
325 	ATF_REQUIRE(kev[1].data == 0);
326 
327 	bytes = 0;
328 	c = 0;
329 	while ((n = write(p[1], &c, 1)) == 1)
330 		bytes++;
331 	ATF_REQUIRE(n < 0);
332 	ATF_REQUIRE(errno == EAGAIN || errno == EWOULDBLOCK);
333 
334 	ATF_REQUIRE(close(p[1]) == 0);
335 
336 	ATF_REQUIRE(kevent(kq, NULL, 0, kev, nitems(kev),
337 	    &(struct timespec){ 0, 0 }) == 2);
338 
339 	ATF_REQUIRE(kev[0].ident == (uintptr_t)p[0]);
340 	ATF_REQUIRE(kev[0].filter == EVFILT_WRITE);
341 	ATF_REQUIRE(kev[0].flags ==
342 	    (EV_EOF | EV_CLEAR | EV_ONESHOT | EV_RECEIPT));
343 	ATF_REQUIRE(kev[0].fflags == 0);
344 	ATF_REQUIRE(kev[0].data > 0);
345 	ATF_REQUIRE(kev[0].udata == 0);
346 
347 	ATF_REQUIRE(kev[1].ident == (uintptr_t)p[0]);
348 	ATF_REQUIRE(kev[1].filter == EVFILT_READ);
349 	ATF_REQUIRE(kev[1].flags == (EV_EOF | EV_CLEAR | EV_RECEIPT));
350 	ATF_REQUIRE(kev[1].fflags == 0);
351 	ATF_REQUIRE(kev[1].data == bytes);
352 	ATF_REQUIRE(kev[1].udata == 0);
353 
354 	ATF_REQUIRE(close(kq) == 0);
355 	ATF_REQUIRE(close(p[0]) == 0);
356 }
357 
358 ATF_TP_ADD_TCS(tp)
359 {
360 	ATF_TP_ADD_TC(tp, pipe_kqueue__write_end);
361 	ATF_TP_ADD_TC(tp, pipe_kqueue__closed_read_end);
362 	ATF_TP_ADD_TC(tp, pipe_kqueue__closed_read_end_register_before_close);
363 	ATF_TP_ADD_TC(tp, pipe_kqueue__closed_write_end);
364 	ATF_TP_ADD_TC(tp, pipe_kqueue__closed_write_end_register_before_close);
365 
366 	return atf_no_error();
367 }
368