1/*	$NetBSD: msg.h,v 1.1 2016/12/05 20:10:10 christos Exp $	*/
2
3/*-
4 * Copyright (c) 2016 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Christos Zoulas.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32struct msg_fds {
33	int pfd[2];
34	int cfd[2];
35};
36
37#define CLOSEFD(fd) do { \
38	if (fd != -1) { \
39		close(fd); \
40		fd = -1; \
41	} \
42} while (/*CONSTCOND*/ 0)
43
44static int
45msg_open(struct msg_fds *fds)
46{
47	if (pipe(fds->pfd) == -1)
48		return -1;
49	if (pipe(fds->cfd) == -1) {
50		close(fds->pfd[0]);
51		close(fds->pfd[1]);
52		return -1;
53	}
54	return 0;
55}
56
57static void
58msg_close(struct msg_fds *fds)
59{
60	CLOSEFD(fds->pfd[0]);
61	CLOSEFD(fds->pfd[1]);
62	CLOSEFD(fds->cfd[0]);
63	CLOSEFD(fds->cfd[1]);
64}
65
66static int
67msg_write_child(const char *info, struct msg_fds *fds, void *msg, size_t len)
68{
69	ssize_t rv;
70	CLOSEFD(fds->cfd[1]);
71	CLOSEFD(fds->pfd[0]);
72
73	printf("Send %s\n", info);
74	rv = write(fds->pfd[1], msg, len);
75	if (rv != (ssize_t)len)
76		return 1;
77//	printf("Wait %s\n", info);
78	rv = read(fds->cfd[0], msg, len);
79	if (rv != (ssize_t)len)
80		return 1;
81	return 0;
82}
83
84static int
85msg_write_parent(const char *info, struct msg_fds *fds, void *msg, size_t len)
86{
87	ssize_t rv;
88	CLOSEFD(fds->pfd[1]);
89	CLOSEFD(fds->cfd[0]);
90
91	printf("Send %s\n", info);
92	rv = write(fds->cfd[1], msg, len);
93	if (rv != (ssize_t)len)
94		return 1;
95//	printf("Wait %s\n", info);
96	rv = read(fds->pfd[0], msg, len);
97	if (rv != (ssize_t)len)
98		return 1;
99	return 0;
100}
101
102static int
103msg_read_parent(const char *info, struct msg_fds *fds, void *msg, size_t len)
104{
105	ssize_t rv;
106	CLOSEFD(fds->pfd[1]);
107	CLOSEFD(fds->cfd[0]);
108
109	printf("Wait %s\n", info);
110	rv = read(fds->pfd[0], msg, len);
111	if (rv != (ssize_t)len)
112		return 1;
113//	printf("Send %s\n", info);
114	rv = write(fds->cfd[1], msg, len);
115	if (rv != (ssize_t)len)
116		return 1;
117	return 0;
118}
119
120static int
121msg_read_child(const char *info, struct msg_fds *fds, void *msg, size_t len)
122{
123	ssize_t rv;
124	CLOSEFD(fds->cfd[1]);
125	CLOSEFD(fds->pfd[0]);
126
127	printf("Wait %s\n", info);
128	rv = read(fds->cfd[0], msg, len);
129	if (rv != (ssize_t)len)
130		return 1;
131//	printf("Send %s\n", info);
132	rv = write(fds->pfd[1], msg, len);
133	if (rv != (ssize_t)len)
134		return 1;
135	return 0;
136}
137