pipe_reverse_test.c revision 290914 
1/*
2Copyright (C) 2004 Michael J. Silbersack. All rights reserved.
3
4Redistribution and use in source and binary forms, with or without
5modification, are permitted provided that the following conditions
6are met:
71. Redistributions of source code must retain the above copyright
8   notice, this list of conditions and the following disclaimer.
92. Redistributions in binary form must reproduce the above copyright
10   notice, this list of conditions and the following disclaimer in the
11   documentation and/or other materials provided with the distribution.
12
13THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
17FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23SUCH DAMAGE.
24*/
25
26#include <sys/types.h>
27#include <sys/stat.h>
28#include <sys/wait.h>
29#include <assert.h>
30#include <err.h>
31#include <errno.h>
32#include <stdio.h>
33#include <stdlib.h>
34#include <string.h>
35#include <unistd.h>
36
37/*
38 * $FreeBSD: head/tests/sys/kern/pipe/pipe_reverse_test.c 290914 2015-11-16 05:38:40Z ngie $
39 * This program simply tests writing through the reverse direction of
40 * a pipe.  Nothing too fancy, it's only needed because most pipe-using
41 * programs never touch the reverse direction (it doesn't exist on
42 * Linux.)
43 */
44
45int
46main(void)
47{
48	char buffer[65535], buffer2[65535], go[] = "go", go2[] = "go2";
49	int desc[2], ipc_coord[2];
50	size_t i;
51	ssize_t total;
52	int buggy, error;
53	pid_t new_pid;
54
55	buggy = 0;
56	total = 0;
57
58	error = pipe(desc);
59	if (error == -1)
60		err(1, "Couldn't allocate data pipe");
61
62	error = pipe(ipc_coord);
63	if (error == -1)
64		err(1, "Couldn't allocate IPC coordination pipe");
65
66	buffer[0] = 'A';
67
68	for (i = 1; i < (int)sizeof(buffer); i++) {
69		buffer[i] = buffer[i - 1] + 1;
70		if (buffer[i] > 'Z')
71			buffer[i] = 'A';
72	}
73
74	new_pid = fork();
75	assert(new_pid != -1);
76
77#define	SYNC_R(i, _buf) do {	\
78	int _error = errno; \
79	warnx("%d: waiting for synchronization", __LINE__); \
80	if (read(ipc_coord[i], &_buf, sizeof(_buf)) != sizeof(_buf)) \
81		err(1, "failed to synchronize (%s)", (i == 0 ? "parent" : "child")); \
82	errno = _error; \
83	} while(0)
84
85#define	SYNC_W(i, _buf) do {	\
86	int _error = errno; \
87	warnx("%d: sending synchronization", __LINE__); \
88	if (write(ipc_coord[i], &_buf, sizeof(_buf)) != sizeof(_buf)) \
89		err(1, "failed to synchronize (%s)", (i == 0 ? "child" : "parent")); \
90	errno = _error; \
91	} while(0)
92
93#define	WRITE(s) do { 							\
94	ssize_t _size; 							\
95	if ((_size = write(desc[1], &buffer[total], s)) != s)		\
96		warn("short write; wrote %zd, expected %d", _size, s);	\
97	total += _size;							\
98	} while(0)
99
100	if (new_pid == 0) {
101		SYNC_R(0, go);
102		for (i = 0; i < 8; i++)
103			WRITE(4096);
104
105		SYNC_W(0, go2);
106		SYNC_R(0, go);
107
108		for (i = 0; i < 2; i++)
109			WRITE(4096);
110
111		SYNC_W(0, go2);
112
113		_exit(0);
114	}
115
116	SYNC_W(1, go);
117	SYNC_R(1, go2);
118
119	error = read(desc[0], &buffer2, 8 * 4096);
120	total += error;
121	printf("Read %d bytes\n", error);
122
123	SYNC_W(1, go);
124	SYNC_R(1, go2);
125
126	error = read(desc[0], &buffer2[total], 2 * 4096);
127	total += error;
128	printf("Read %d bytes, done\n", error);
129
130	if (memcmp(buffer, buffer2, total) != 0) {
131		for (i = 0; i < (size_t)total; i++) {
132			if (buffer[i] != buffer2[i]) {
133				buggy = 1;
134				printf("Location %zu input: %hhx "
135				    "output: %hhx\n",
136				    i, buffer[i], buffer2[i]);
137			}
138		}
139	}
140
141	waitpid(new_pid, NULL, 0);
142
143	if ((buggy == 1) || (total != 10 * 4096))
144		errx(1, "FAILED");
145	else
146		printf("SUCCESS\n");
147
148	exit(0);
149}
150