xref: /openbsd-src/lib/libsndio/mio.c (revision 43003dfe3ad45d1698bed8a37f2b0f5b14f20d4f)
1 /*	$OpenBSD: mio.c,v 1.7 2009/08/21 16:48:03 ratchov Exp $	*/
2 /*
3  * Copyright (c) 2008 Alexandre Ratchov <alex@caoua.org>
4  *
5  * Permission to use, copy, modify, and distribute this software for any
6  * purpose with or without fee is hereby granted, provided that the above
7  * copyright notice and this permission notice appear in all copies.
8  *
9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16  */
17 
18 #include <sys/param.h>
19 #include <sys/types.h>
20 #include <sys/time.h>
21 #include <sys/stat.h>
22 
23 #include <errno.h>
24 #include <fcntl.h>
25 #include <poll.h>
26 #include <stdio.h>
27 #include <stdlib.h>
28 #include <string.h>
29 #include <unistd.h>
30 
31 #include "mio_priv.h"
32 
33 #ifdef DEBUG
34 /*
35  * debug level, -1 means uninitialized
36  */
37 int mio_debug = -1;
38 #endif
39 
40 struct mio_hdl *
41 mio_open(const char *str, unsigned mode, int nbio)
42 {
43 	static char prefix_midithru[] = "midithru";
44 	static char prefix_rmidi[] = "rmidi";
45 	static char prefix_aucat[] = "aucat";
46 	struct mio_hdl *hdl;
47 	struct stat sb;
48 	char *sep, buf[4];
49 	int len;
50 #ifdef DEBUG
51 	char *dbg;
52 
53 	if (mio_debug < 0) {
54 		dbg = issetugid() ? NULL : getenv("MIO_DEBUG");
55 		if (!dbg || sscanf(dbg, "%u", &mio_debug) != 1)
56 			mio_debug = 0;
57 	}
58 #endif
59 	if ((mode & (MIO_OUT | MIO_IN)) == 0)
60 		return NULL;
61 	if (str == NULL && !issetugid())
62 		str = getenv("MIDIDEVICE");
63 	if (str == NULL) {
64 		hdl = mio_open_thru("0", mode, nbio);
65 		if (hdl != NULL)
66 			return hdl;
67 		return mio_open_rmidi("0", mode, nbio);
68 	}
69 	sep = strchr(str, ':');
70 	if (sep == NULL) {
71 		/*
72 		 * try legacy "/dev/rmidioxxx" device name
73 		 */
74 		if (stat(str, &sb) < 0 || !S_ISCHR(sb.st_mode)) {
75 			DPRINTF("mio_open: %s: missing ':' separator\n", str);
76 			return NULL;
77 		}
78 		snprintf(buf, sizeof(buf), "%u", minor(sb.st_rdev));
79 		return mio_open_rmidi(buf, mode, nbio);
80 	}
81 
82 	len = sep - str;
83 	if (len == (sizeof(prefix_midithru) - 1) &&
84 	    memcmp(str, prefix_midithru, len) == 0)
85 		return mio_open_thru(sep + 1, mode, nbio);
86 	if (len == (sizeof(prefix_aucat) - 1) &&
87 	    memcmp(str, prefix_aucat, len) == 0)
88 		return mio_open_aucat(sep + 1, mode, nbio);
89 	if (len == (sizeof(prefix_rmidi) - 1) &&
90 	    memcmp(str, prefix_rmidi, len) == 0)
91 		return mio_open_rmidi(sep + 1, mode, nbio);
92 	DPRINTF("mio_open: %s: unknown device type\n", str);
93 	return NULL;
94 }
95 
96 void
97 mio_create(struct mio_hdl *hdl, struct mio_ops *ops, unsigned mode, int nbio)
98 {
99 	hdl->ops = ops;
100 	hdl->mode = mode;
101 	hdl->nbio = nbio;
102 	hdl->eof = 0;
103 }
104 
105 void
106 mio_close(struct mio_hdl *hdl)
107 {
108 	hdl->ops->close(hdl);
109 }
110 
111 size_t
112 mio_read(struct mio_hdl *hdl, void *buf, size_t len)
113 {
114 	if (hdl->eof) {
115 		DPRINTF("mio_read: eof\n");
116 		return 0;
117 	}
118 	if (!(hdl->mode & MIO_IN)) {
119 		DPRINTF("mio_read: not input device\n");
120 		hdl->eof = 1;
121 		return 0;
122 	}
123 	if (len == 0) {
124 		DPRINTF("mio_read: zero length read ignored\n");
125 		return 0;
126 	}
127 	return hdl->ops->read(hdl, buf, len);
128 }
129 
130 size_t
131 mio_write(struct mio_hdl *hdl, const void *buf, size_t len)
132 {
133 	if (hdl->eof) {
134 		DPRINTF("mio_write: eof\n");
135 		return 0;
136 	}
137 	if (!(hdl->mode & MIO_OUT)) {
138 		DPRINTF("mio_write: not output device\n");
139 		hdl->eof = 1;
140 		return 0;
141 	}
142 	if (len == 0) {
143 		DPRINTF("mio_write: zero length write ignored\n");
144 		return 0;
145 	}
146 	return hdl->ops->write(hdl, buf, len);
147 }
148 
149 int
150 mio_nfds(struct mio_hdl *hdl)
151 {
152 	return 1;
153 }
154 
155 int
156 mio_pollfd(struct mio_hdl *hdl, struct pollfd *pfd, int events)
157 {
158 	if (hdl->eof)
159 		return 0;
160 	return hdl->ops->pollfd(hdl, pfd, events);
161 }
162 
163 int
164 mio_revents(struct mio_hdl *hdl, struct pollfd *pfd)
165 {
166 	if (hdl->eof)
167 		return POLLHUP;
168 	return hdl->ops->revents(hdl, pfd);
169 }
170 
171 int
172 mio_eof(struct mio_hdl *hdl)
173 {
174 	return hdl->eof;
175 }
176