xref: /freebsd/tests/sys/kern/pipe/pipe_reverse_test.c (revision 4d293dd8dcde59fc9842a0ce1125fef8fcf83a8c)
1 /*
2 Copyright (C) 2004 Michael J. Silbersack. All rights reserved.
3 
4 Redistribution and use in source and binary forms, with or without
5 modification, are permitted provided that the following conditions
6 are met:
7 1. Redistributions of source code must retain the above copyright
8    notice, this list of conditions and the following disclaimer.
9 2. 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 
13 THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14 ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16 ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
17 FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18 DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19 OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20 HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21 LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22 OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23 SUCH 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  * $FreeBSD$
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 
45 int
46 main(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