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 * This program simply tests writing through the reverse direction of
39 * a pipe. Nothing too fancy, it's only needed because most pipe-using
40 * programs never touch the reverse direction (it doesn't exist on
41 * Linux.)
42 */
43
44 int
main(void)45 main(void)
46 {
47 char buffer[65535], buffer2[65535], go[] = "go", go2[] = "go2";
48 int desc[2], ipc_coord[2];
49 size_t i;
50 ssize_t total;
51 int buggy, error;
52 pid_t new_pid;
53
54 buggy = 0;
55 total = 0;
56
57 error = pipe(desc);
58 if (error == -1)
59 err(1, "Couldn't allocate data pipe");
60
61 error = pipe(ipc_coord);
62 if (error == -1)
63 err(1, "Couldn't allocate IPC coordination pipe");
64
65 buffer[0] = 'A';
66
67 for (i = 1; i < (int)sizeof(buffer); i++) {
68 buffer[i] = buffer[i - 1] + 1;
69 if (buffer[i] > 'Z')
70 buffer[i] = 'A';
71 }
72
73 new_pid = fork();
74 assert(new_pid != -1);
75
76 #define SYNC_R(i, _buf) do { \
77 int _error = errno; \
78 warnx("%d: waiting for synchronization", __LINE__); \
79 if (read(ipc_coord[i], &_buf, sizeof(_buf)) != sizeof(_buf)) \
80 err(1, "failed to synchronize (%s)", (i == 0 ? "parent" : "child")); \
81 errno = _error; \
82 } while(0)
83
84 #define SYNC_W(i, _buf) do { \
85 int _error = errno; \
86 warnx("%d: sending synchronization", __LINE__); \
87 if (write(ipc_coord[i], &_buf, sizeof(_buf)) != sizeof(_buf)) \
88 err(1, "failed to synchronize (%s)", (i == 0 ? "child" : "parent")); \
89 errno = _error; \
90 } while(0)
91
92 #define WRITE(s) do { \
93 ssize_t _size; \
94 if ((_size = write(desc[1], &buffer[total], s)) != s) \
95 warn("short write; wrote %zd, expected %d", _size, s); \
96 total += _size; \
97 } while(0)
98
99 if (new_pid == 0) {
100 SYNC_R(0, go);
101 for (i = 0; i < 8; i++)
102 WRITE(4096);
103
104 SYNC_W(0, go2);
105 SYNC_R(0, go);
106
107 for (i = 0; i < 2; i++)
108 WRITE(4096);
109
110 SYNC_W(0, go2);
111
112 _exit(0);
113 }
114
115 SYNC_W(1, go);
116 SYNC_R(1, go2);
117
118 error = read(desc[0], &buffer2, 8 * 4096);
119 total += error;
120 printf("Read %d bytes\n", error);
121
122 SYNC_W(1, go);
123 SYNC_R(1, go2);
124
125 error = read(desc[0], &buffer2[total], 2 * 4096);
126 total += error;
127 printf("Read %d bytes, done\n", error);
128
129 if (memcmp(buffer, buffer2, total) != 0) {
130 for (i = 0; i < (size_t)total; i++) {
131 if (buffer[i] != buffer2[i]) {
132 buggy = 1;
133 printf("Location %zu input: %hhx "
134 "output: %hhx\n",
135 i, buffer[i], buffer2[i]);
136 }
137 }
138 }
139
140 waitpid(new_pid, NULL, 0);
141
142 if ((buggy == 1) || (total != 10 * 4096))
143 errx(1, "FAILED");
144 else
145 printf("SUCCESS\n");
146
147 exit(0);
148 }
149