xref: /openbsd-src/lib/libsndio/mio_rmidi.c (revision bde5d16205d7fce9aa9d9c4a24abc5f43058c82b)
1 /*	$OpenBSD: mio_rmidi.c,v 1.23 2015/12/20 11:29:29 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/types.h>
19 #include <sys/stat.h>
20 
21 #include <errno.h>
22 #include <fcntl.h>
23 #include <limits.h>
24 #include <poll.h>
25 #include <stdio.h>
26 #include <stdlib.h>
27 #include <string.h>
28 #include <unistd.h>
29 
30 #include "debug.h"
31 #include "mio_priv.h"
32 
33 #define DEVPATH_PREFIX	"/dev/rmidi"
34 #define DEVPATH_MAX 	(1 +		\
35 	sizeof(DEVPATH_PREFIX) - 1 +	\
36 	sizeof(int) * 3)
37 
38 struct mio_rmidi_hdl {
39 	struct mio_hdl mio;
40 	int fd;
41 };
42 
43 static void mio_rmidi_close(struct mio_hdl *);
44 static size_t mio_rmidi_read(struct mio_hdl *, void *, size_t);
45 static size_t mio_rmidi_write(struct mio_hdl *, const void *, size_t);
46 static int mio_rmidi_nfds(struct mio_hdl *);
47 static int mio_rmidi_pollfd(struct mio_hdl *, struct pollfd *, int);
48 static int mio_rmidi_revents(struct mio_hdl *, struct pollfd *);
49 
50 static struct mio_ops mio_rmidi_ops = {
51 	mio_rmidi_close,
52 	mio_rmidi_write,
53 	mio_rmidi_read,
54 	mio_rmidi_nfds,
55 	mio_rmidi_pollfd,
56 	mio_rmidi_revents
57 };
58 
59 int
60 mio_rmidi_getfd(const char *str, unsigned int mode, int nbio)
61 {
62 	const char *p;
63 	char path[DEVPATH_MAX];
64 	unsigned int devnum;
65 	int fd, flags;
66 
67 #ifdef DEBUG
68 	_sndio_debug_init();
69 #endif
70 	p = _sndio_parsetype(str, "rmidi");
71 	if (p == NULL) {
72 		DPRINTF("mio_rmidi_getfd: %s: \"rsnd\" expected\n", str);
73 		return -1;
74 	}
75 	switch (*p) {
76 	case '/':
77 		p++;
78 		break;
79 	default:
80 		DPRINTF("mio_rmidi_getfd: %s: '/' expected\n", str);
81 		return -1;
82 	}
83 	p = _sndio_parsenum(p, &devnum, 255);
84 	if (p == NULL || *p != '\0') {
85 		DPRINTF("mio_rmidi_getfd: %s: number expected after '/'\n", str);
86 		return -1;
87 	}
88 	snprintf(path, sizeof(path), DEVPATH_PREFIX "%u", devnum);
89 	if (mode == (MIO_IN | MIO_OUT))
90 		flags = O_RDWR;
91 	else
92 		flags = (mode & MIO_OUT) ? O_WRONLY : O_RDONLY;
93 	while ((fd = open(path, flags | O_NONBLOCK | O_CLOEXEC)) < 0) {
94 		if (errno == EINTR)
95 			continue;
96 		DPERROR(path);
97 		return -1;
98 	}
99 	return fd;
100 }
101 
102 struct mio_hdl *
103 mio_rmidi_fdopen(int fd, unsigned int mode, int nbio)
104 {
105 	struct mio_rmidi_hdl *hdl;
106 
107 #ifdef DEBUG
108 	_sndio_debug_init();
109 #endif
110 	hdl = malloc(sizeof(struct mio_rmidi_hdl));
111 	if (hdl == NULL)
112 		return NULL;
113 	_mio_create(&hdl->mio, &mio_rmidi_ops, mode, nbio);
114 	hdl->fd = fd;
115 	return (struct mio_hdl *)hdl;
116 }
117 
118 struct mio_hdl *
119 _mio_rmidi_open(const char *str, unsigned int mode, int nbio)
120 {
121 	struct mio_hdl *hdl;
122 	int fd;
123 
124 	fd = mio_rmidi_getfd(str, mode, nbio);
125 	if (fd < 0)
126 		return NULL;
127 	hdl = mio_rmidi_fdopen(fd, mode, nbio);
128 	if (hdl != NULL)
129 		return hdl;
130 	while (close(fd) < 0 && errno == EINTR)
131 		; /* retry */
132 	return NULL;
133 }
134 
135 static void
136 mio_rmidi_close(struct mio_hdl *sh)
137 {
138 	struct mio_rmidi_hdl *hdl = (struct mio_rmidi_hdl *)sh;
139 	int rc;
140 
141 	do {
142 		rc = close(hdl->fd);
143 	} while (rc < 0 && errno == EINTR);
144 	free(hdl);
145 }
146 
147 static size_t
148 mio_rmidi_read(struct mio_hdl *sh, void *buf, size_t len)
149 {
150 	struct mio_rmidi_hdl *hdl = (struct mio_rmidi_hdl *)sh;
151 	ssize_t n;
152 
153 	while ((n = read(hdl->fd, buf, len)) < 0) {
154 		if (errno == EINTR)
155 			continue;
156 		if (errno != EAGAIN) {
157 			DPERROR("mio_rmidi_read: read");
158 			hdl->mio.eof = 1;
159 		}
160 		return 0;
161 	}
162 	if (n == 0) {
163 		DPRINTF("mio_rmidi_read: eof\n");
164 		hdl->mio.eof = 1;
165 		return 0;
166 	}
167 	return n;
168 }
169 
170 static size_t
171 mio_rmidi_write(struct mio_hdl *sh, const void *buf, size_t len)
172 {
173 	struct mio_rmidi_hdl *hdl = (struct mio_rmidi_hdl *)sh;
174 	ssize_t n;
175 
176 	while ((n = write(hdl->fd, buf, len)) < 0) {
177 		if (errno == EINTR)
178 			continue;
179 		if (errno != EAGAIN) {
180 			DPERROR("mio_rmidi_write: write");
181 			hdl->mio.eof = 1;
182 		}
183  		return 0;
184 	}
185 	return n;
186 }
187 
188 static int
189 mio_rmidi_nfds(struct mio_hdl *sh)
190 {
191 	return 1;
192 }
193 
194 static int
195 mio_rmidi_pollfd(struct mio_hdl *sh, struct pollfd *pfd, int events)
196 {
197 	struct mio_rmidi_hdl *hdl = (struct mio_rmidi_hdl *)sh;
198 
199 	pfd->fd = hdl->fd;
200 	pfd->events = events;
201 	return 1;
202 }
203 
204 static int
205 mio_rmidi_revents(struct mio_hdl *sh, struct pollfd *pfd)
206 {
207 	return pfd->revents;
208 }
209