xref: /freebsd/tests/sys/kern/pipe/pipe_kqueue_test.c (revision 5ca8e32633c4ffbbcd6762e5888b6a4ba0708c6c)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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/param.h>
29 #include <sys/event.h>
30 #include <sys/stat.h>
31 
32 #include <errno.h>
33 #include <fcntl.h>
34 #include <limits.h>
35 #include <poll.h>
36 #include <stdio.h>
37 #include <stdlib.h>
38 #include <time.h>
39 #include <unistd.h>
40 
41 #include <atf-c.h>
42 
43 ATF_TC_WITHOUT_HEAD(pipe_kqueue__write_end);
44 ATF_TC_BODY(pipe_kqueue__write_end, tc)
45 {
46 	int p[2] = { -1, -1 };
47 
48 	ATF_REQUIRE(pipe2(p, O_CLOEXEC | O_NONBLOCK) == 0);
49 	ATF_REQUIRE(p[0] >= 0);
50 	ATF_REQUIRE(p[1] >= 0);
51 
52 	int kq = kqueue();
53 	ATF_REQUIRE(kq >= 0);
54 
55 	struct kevent kev[32];
56 	EV_SET(&kev[0], p[1], EVFILT_WRITE, EV_ADD | EV_CLEAR, 0, 0, 0);
57 
58 	ATF_REQUIRE(kevent(kq, kev, 1, NULL, 0, NULL) == 0);
59 
60 	/* Test that EVFILT_WRITE behaves sensibly on the write end. */
61 
62 	ATF_REQUIRE(kevent(kq, NULL, 0, kev, nitems(kev),
63 	    &(struct timespec) { 0, 0 }) == 1);
64 	ATF_REQUIRE(kev[0].ident == (uintptr_t)p[1]);
65 	ATF_REQUIRE(kev[0].filter == EVFILT_WRITE);
66 	ATF_REQUIRE(kev[0].flags == EV_CLEAR);
67 	ATF_REQUIRE(kev[0].fflags == 0);
68 	ATF_REQUIRE(kev[0].data == 16384);
69 	ATF_REQUIRE(kev[0].udata == 0);
70 
71 	/* Filling up the pipe should make the EVFILT_WRITE disappear. */
72 
73 	char c = 0;
74 	ssize_t r;
75 	while ((r = write(p[1], &c, 1)) == 1) {
76 	}
77 	ATF_REQUIRE(r < 0);
78 	ATF_REQUIRE(errno == EAGAIN || errno == EWOULDBLOCK);
79 
80 	ATF_REQUIRE(kevent(kq, NULL, 0, kev, nitems(kev),
81 	    &(struct timespec) { 0, 0 }) == 0);
82 
83 	/* Reading (PIPE_BUF - 1) bytes will not trigger a EVFILT_WRITE yet. */
84 
85 	for (int i = 0; i < PIPE_BUF - 1; ++i) {
86 		ATF_REQUIRE(read(p[0], &c, 1) == 1);
87 	}
88 
89 	ATF_REQUIRE(kevent(kq, NULL, 0, kev, nitems(kev),
90 	    &(struct timespec) { 0, 0 }) == 0);
91 
92 	/* Reading one additional byte triggers the EVFILT_WRITE. */
93 
94 	ATF_REQUIRE(read(p[0], &c, 1) == 1);
95 
96 	r = kevent(kq, NULL, 0, kev, nitems(kev), &(struct timespec) { 0, 0 });
97 	ATF_REQUIRE(r == 1);
98 	ATF_REQUIRE(kev[0].ident == (uintptr_t)p[1]);
99 	ATF_REQUIRE(kev[0].filter == EVFILT_WRITE);
100 	ATF_REQUIRE(kev[0].flags == EV_CLEAR);
101 	ATF_REQUIRE(kev[0].fflags == 0);
102 	ATF_REQUIRE(kev[0].data == PIPE_BUF);
103 	ATF_REQUIRE(kev[0].udata == 0);
104 
105 	/*
106 	 * Reading another byte triggers the EVFILT_WRITE again with a changed
107 	 * 'data' field.
108 	 */
109 
110 	ATF_REQUIRE(read(p[0], &c, 1) == 1);
111 
112 	ATF_REQUIRE(kevent(kq, NULL, 0, kev, nitems(kev),
113 	    &(struct timespec) { 0, 0 }) == 1);
114 	ATF_REQUIRE(kev[0].ident == (uintptr_t)p[1]);
115 	ATF_REQUIRE(kev[0].filter == EVFILT_WRITE);
116 	ATF_REQUIRE(kev[0].flags == EV_CLEAR);
117 	ATF_REQUIRE(kev[0].fflags == 0);
118 	ATF_REQUIRE(kev[0].data == PIPE_BUF + 1);
119 	ATF_REQUIRE(kev[0].udata == 0);
120 
121 	/*
122 	 * Closing the read end should make a EV_EOF appear but leave the 'data'
123 	 * field unchanged.
124 	 */
125 
126 	ATF_REQUIRE(close(p[0]) == 0);
127 
128 	ATF_REQUIRE(kevent(kq, NULL, 0, kev, nitems(kev),
129 	    &(struct timespec) { 0, 0 }) == 1);
130 	ATF_REQUIRE(kev[0].ident == (uintptr_t)p[1]);
131 	ATF_REQUIRE(kev[0].filter == EVFILT_WRITE);
132 	ATF_REQUIRE(kev[0].flags == (EV_CLEAR | EV_EOF | EV_ONESHOT));
133 	ATF_REQUIRE(kev[0].fflags == 0);
134 	ATF_REQUIRE(kev[0].data == PIPE_BUF + 1);
135 	ATF_REQUIRE(kev[0].udata == 0);
136 
137 	ATF_REQUIRE(close(kq) == 0);
138 	ATF_REQUIRE(close(p[1]) == 0);
139 }
140 
141 ATF_TC_WITHOUT_HEAD(pipe_kqueue__closed_read_end);
142 ATF_TC_BODY(pipe_kqueue__closed_read_end, tc)
143 {
144 	int p[2] = { -1, -1 };
145 
146 	ATF_REQUIRE(pipe2(p, O_CLOEXEC | O_NONBLOCK) == 0);
147 	ATF_REQUIRE(p[0] >= 0);
148 	ATF_REQUIRE(p[1] >= 0);
149 
150 	ATF_REQUIRE(close(p[0]) == 0);
151 
152 	int kq = kqueue();
153 	ATF_REQUIRE(kq >= 0);
154 
155 	struct kevent kev[32];
156 	EV_SET(&kev[0], p[1], EVFILT_READ, EV_ADD | EV_CLEAR | EV_RECEIPT, /**/
157 	    0, 0, 0);
158 	EV_SET(&kev[1], p[1], EVFILT_WRITE, EV_ADD | EV_CLEAR | EV_RECEIPT, /**/
159 	    0, 0, 0);
160 
161 	/*
162 	 * Trying to register EVFILT_WRITE when the pipe is closed leads to an
163 	 * EPIPE error.
164 	 */
165 
166 	ATF_REQUIRE(kevent(kq, kev, 2, kev, 2, NULL) == 2);
167 	ATF_REQUIRE((kev[0].flags & EV_ERROR) != 0);
168 	ATF_REQUIRE(kev[0].data == 0);
169 	ATF_REQUIRE((kev[1].flags & EV_ERROR) != 0);
170 	ATF_REQUIRE(kev[1].data == EPIPE);
171 
172 	ATF_REQUIRE(kevent(kq, NULL, 0, kev, nitems(kev),
173 	    &(struct timespec) { 0, 0 }) == 1);
174 	ATF_REQUIRE(kev[0].ident == (uintptr_t)p[1]);
175 	ATF_REQUIRE(kev[0].filter == EVFILT_READ);
176 	ATF_REQUIRE(kev[0].flags == (EV_EOF | EV_CLEAR | EV_RECEIPT));
177 	ATF_REQUIRE(kev[0].fflags == 0);
178 	ATF_REQUIRE(kev[0].data == 0);
179 	ATF_REQUIRE(kev[0].udata == 0);
180 
181 	ATF_REQUIRE(close(kq) == 0);
182 	ATF_REQUIRE(close(p[1]) == 0);
183 }
184 
185 ATF_TC_WITHOUT_HEAD(pipe_kqueue__closed_read_end_register_before_close);
186 ATF_TC_BODY(pipe_kqueue__closed_read_end_register_before_close, tc)
187 {
188 	int p[2] = { -1, -1 };
189 
190 	ATF_REQUIRE(pipe2(p, O_CLOEXEC | O_NONBLOCK) == 0);
191 	ATF_REQUIRE(p[0] >= 0);
192 	ATF_REQUIRE(p[1] >= 0);
193 
194 	int kq = kqueue();
195 	ATF_REQUIRE(kq >= 0);
196 
197 	struct kevent kev[32];
198 	EV_SET(&kev[0], p[1], EVFILT_READ, EV_ADD | EV_CLEAR | EV_RECEIPT, /**/
199 	    0, 0, 0);
200 	EV_SET(&kev[1], p[1], EVFILT_WRITE, EV_ADD | EV_CLEAR | EV_RECEIPT, /**/
201 	    0, 0, 0);
202 
203 	/*
204 	 * Registering EVFILT_WRITE before the pipe is closed leads to a
205 	 * EVFILT_WRITE event with EV_EOF set.
206 	 */
207 
208 	ATF_REQUIRE(kevent(kq, kev, 2, kev, 2, NULL) == 2);
209 	ATF_REQUIRE((kev[0].flags & EV_ERROR) != 0);
210 	ATF_REQUIRE(kev[0].data == 0);
211 	ATF_REQUIRE((kev[1].flags & EV_ERROR) != 0);
212 	ATF_REQUIRE(kev[1].data == 0);
213 
214 	ATF_REQUIRE(close(p[0]) == 0);
215 
216 	ATF_REQUIRE(kevent(kq, NULL, 0, kev, nitems(kev),
217 	    &(struct timespec) { 0, 0 }) == 2);
218 	{
219 		ATF_REQUIRE(kev[0].ident == (uintptr_t)p[1]);
220 		ATF_REQUIRE(kev[0].filter == EVFILT_WRITE);
221 		ATF_REQUIRE(kev[0].flags ==
222 		    (EV_EOF | EV_CLEAR | EV_ONESHOT | EV_RECEIPT));
223 		ATF_REQUIRE(kev[0].fflags == 0);
224 		ATF_REQUIRE(kev[0].data == 16384);
225 		ATF_REQUIRE(kev[0].udata == 0);
226 	}
227 	{
228 		ATF_REQUIRE(kev[1].ident == (uintptr_t)p[1]);
229 		ATF_REQUIRE(kev[1].filter == EVFILT_READ);
230 		ATF_REQUIRE(kev[1].flags == (EV_EOF | EV_CLEAR | EV_RECEIPT));
231 		ATF_REQUIRE(kev[1].fflags == 0);
232 		ATF_REQUIRE(kev[1].data == 0);
233 		ATF_REQUIRE(kev[1].udata == 0);
234 	}
235 
236 	ATF_REQUIRE(close(kq) == 0);
237 	ATF_REQUIRE(close(p[1]) == 0);
238 }
239 
240 ATF_TC_WITHOUT_HEAD(pipe_kqueue__closed_write_end);
241 ATF_TC_BODY(pipe_kqueue__closed_write_end, tc)
242 {
243 	struct kevent kev[32];
244 	ssize_t bytes, n;
245 	int kq, p[2];
246 	char c;
247 
248 	ATF_REQUIRE(pipe2(p, O_CLOEXEC | O_NONBLOCK) == 0);
249 	ATF_REQUIRE(p[0] >= 0);
250 	ATF_REQUIRE(p[1] >= 0);
251 
252 	bytes = 0;
253 	c = 0;
254 	while ((n = write(p[1], &c, 1)) == 1)
255 		bytes++;
256 	ATF_REQUIRE(n < 0);
257 	ATF_REQUIRE(errno == EAGAIN || errno == EWOULDBLOCK);
258 
259 	ATF_REQUIRE(close(p[1]) == 0);
260 
261 	kq = kqueue();
262 	ATF_REQUIRE(kq >= 0);
263 
264 	EV_SET(&kev[0], p[0], EVFILT_READ, EV_ADD | EV_CLEAR | EV_RECEIPT,
265 	    0, 0, 0);
266 	EV_SET(&kev[1], p[0], EVFILT_WRITE, EV_ADD | EV_CLEAR | EV_RECEIPT,
267 	    0, 0, 0);
268 
269 	/*
270 	 * Trying to register EVFILT_WRITE when the pipe is closed leads to an
271 	 * EPIPE error.
272 	 */
273 
274 	ATF_REQUIRE(kevent(kq, kev, 2, kev, 2, NULL) == 2);
275 	ATF_REQUIRE((kev[0].flags & EV_ERROR) != 0);
276 	ATF_REQUIRE(kev[0].data == 0);
277 	ATF_REQUIRE((kev[1].flags & EV_ERROR) != 0);
278 	ATF_REQUIRE(kev[1].data == EPIPE);
279 
280 	ATF_REQUIRE(kevent(kq, NULL, 0, kev, nitems(kev),
281 	    &(struct timespec) { 0, 0 }) == 1);
282 	ATF_REQUIRE(kev[0].ident == (uintptr_t)p[0]);
283 	ATF_REQUIRE(kev[0].filter == EVFILT_READ);
284 	ATF_REQUIRE(kev[0].flags == (EV_EOF | EV_CLEAR | EV_RECEIPT));
285 	ATF_REQUIRE(kev[0].fflags == 0);
286 	ATF_REQUIRE(kev[0].data == bytes);
287 	ATF_REQUIRE(kev[0].udata == 0);
288 
289 	ATF_REQUIRE(close(kq) == 0);
290 	ATF_REQUIRE(close(p[0]) == 0);
291 }
292 
293 ATF_TC_WITHOUT_HEAD(pipe_kqueue__closed_write_end_register_before_close);
294 ATF_TC_BODY(pipe_kqueue__closed_write_end_register_before_close, tc)
295 {
296 	struct kevent kev[32];
297 	ssize_t bytes, n;
298 	int kq, p[2];
299 	char c;
300 
301 	ATF_REQUIRE(pipe2(p, O_CLOEXEC | O_NONBLOCK) == 0);
302 	ATF_REQUIRE(p[0] >= 0);
303 	ATF_REQUIRE(p[1] >= 0);
304 
305 	kq = kqueue();
306 	ATF_REQUIRE(kq >= 0);
307 
308 	EV_SET(&kev[0], p[0], EVFILT_READ, EV_ADD | EV_CLEAR | EV_RECEIPT,
309 	    0, 0, 0);
310 	EV_SET(&kev[1], p[0], EVFILT_WRITE, EV_ADD | EV_CLEAR | EV_RECEIPT,
311 	    0, 0, 0);
312 
313 	/*
314 	 * Registering EVFILT_WRITE before the pipe is closed leads to a
315 	 * EVFILT_WRITE event with EV_EOF set.
316 	 */
317 
318 	ATF_REQUIRE(kevent(kq, kev, 2, kev, 2, NULL) == 2);
319 	ATF_REQUIRE((kev[0].flags & EV_ERROR) != 0);
320 	ATF_REQUIRE(kev[0].data == 0);
321 	ATF_REQUIRE((kev[1].flags & EV_ERROR) != 0);
322 	ATF_REQUIRE(kev[1].data == 0);
323 
324 	bytes = 0;
325 	c = 0;
326 	while ((n = write(p[1], &c, 1)) == 1)
327 		bytes++;
328 	ATF_REQUIRE(n < 0);
329 	ATF_REQUIRE(errno == EAGAIN || errno == EWOULDBLOCK);
330 
331 	ATF_REQUIRE(close(p[1]) == 0);
332 
333 	ATF_REQUIRE(kevent(kq, NULL, 0, kev, nitems(kev),
334 	    &(struct timespec){ 0, 0 }) == 2);
335 
336 	ATF_REQUIRE(kev[0].ident == (uintptr_t)p[0]);
337 	ATF_REQUIRE(kev[0].filter == EVFILT_WRITE);
338 	ATF_REQUIRE(kev[0].flags ==
339 	    (EV_EOF | EV_CLEAR | EV_ONESHOT | EV_RECEIPT));
340 	ATF_REQUIRE(kev[0].fflags == 0);
341 	ATF_REQUIRE(kev[0].data > 0);
342 	ATF_REQUIRE(kev[0].udata == 0);
343 
344 	ATF_REQUIRE(kev[1].ident == (uintptr_t)p[0]);
345 	ATF_REQUIRE(kev[1].filter == EVFILT_READ);
346 	ATF_REQUIRE(kev[1].flags == (EV_EOF | EV_CLEAR | EV_RECEIPT));
347 	ATF_REQUIRE(kev[1].fflags == 0);
348 	ATF_REQUIRE(kev[1].data == bytes);
349 	ATF_REQUIRE(kev[1].udata == 0);
350 
351 	ATF_REQUIRE(close(kq) == 0);
352 	ATF_REQUIRE(close(p[0]) == 0);
353 }
354 
355 ATF_TP_ADD_TCS(tp)
356 {
357 	ATF_TP_ADD_TC(tp, pipe_kqueue__write_end);
358 	ATF_TP_ADD_TC(tp, pipe_kqueue__closed_read_end);
359 	ATF_TP_ADD_TC(tp, pipe_kqueue__closed_read_end_register_before_close);
360 	ATF_TP_ADD_TC(tp, pipe_kqueue__closed_write_end);
361 	ATF_TP_ADD_TC(tp, pipe_kqueue__closed_write_end_register_before_close);
362 
363 	return atf_no_error();
364 }
365