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 * 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
44int
45main(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