xref: /openbsd-src/lib/libsndio/mio_rmidi.c (revision ae3cb403620ab940fbaabb3055fac045a63d56b7)
1 /*	$OpenBSD: mio_rmidi.c,v 1.25 2017/11/04 09:35:56 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) {
85 		DPRINTF("mio_rmidi_getfd: %s: number expected after '/'\n", str);
86 		return -1;
87 	}
88 	if (*p != '\0') {
89 		DPRINTF("mio_rmidi_getfd: junk at end of string: %s\n", p);
90 		return -1;
91 	}
92 	snprintf(path, sizeof(path), DEVPATH_PREFIX "%u", devnum);
93 	if (mode == (MIO_IN | MIO_OUT))
94 		flags = O_RDWR;
95 	else
96 		flags = (mode & MIO_OUT) ? O_WRONLY : O_RDONLY;
97 	while ((fd = open(path, flags | O_NONBLOCK | O_CLOEXEC)) < 0) {
98 		if (errno == EINTR)
99 			continue;
100 		DPERROR(path);
101 		return -1;
102 	}
103 	return fd;
104 }
105 
106 struct mio_hdl *
107 mio_rmidi_fdopen(int fd, unsigned int mode, int nbio)
108 {
109 	struct mio_rmidi_hdl *hdl;
110 
111 #ifdef DEBUG
112 	_sndio_debug_init();
113 #endif
114 	hdl = malloc(sizeof(struct mio_rmidi_hdl));
115 	if (hdl == NULL)
116 		return NULL;
117 	_mio_create(&hdl->mio, &mio_rmidi_ops, mode, nbio);
118 	hdl->fd = fd;
119 	return (struct mio_hdl *)hdl;
120 }
121 
122 struct mio_hdl *
123 _mio_rmidi_open(const char *str, unsigned int mode, int nbio)
124 {
125 	struct mio_hdl *hdl;
126 	int fd;
127 
128 	fd = mio_rmidi_getfd(str, mode, nbio);
129 	if (fd < 0)
130 		return NULL;
131 	hdl = mio_rmidi_fdopen(fd, mode, nbio);
132 	if (hdl != NULL)
133 		return hdl;
134 	while (close(fd) < 0 && errno == EINTR)
135 		; /* retry */
136 	return NULL;
137 }
138 
139 static void
140 mio_rmidi_close(struct mio_hdl *sh)
141 {
142 	struct mio_rmidi_hdl *hdl = (struct mio_rmidi_hdl *)sh;
143 	int rc;
144 
145 	do {
146 		rc = close(hdl->fd);
147 	} while (rc < 0 && errno == EINTR);
148 	free(hdl);
149 }
150 
151 static size_t
152 mio_rmidi_read(struct mio_hdl *sh, void *buf, size_t len)
153 {
154 	struct mio_rmidi_hdl *hdl = (struct mio_rmidi_hdl *)sh;
155 	ssize_t n;
156 
157 	while ((n = read(hdl->fd, buf, len)) < 0) {
158 		if (errno == EINTR)
159 			continue;
160 		if (errno != EAGAIN) {
161 			DPERROR("mio_rmidi_read: read");
162 			hdl->mio.eof = 1;
163 		}
164 		return 0;
165 	}
166 	if (n == 0) {
167 		DPRINTF("mio_rmidi_read: eof\n");
168 		hdl->mio.eof = 1;
169 		return 0;
170 	}
171 	return n;
172 }
173 
174 static size_t
175 mio_rmidi_write(struct mio_hdl *sh, const void *buf, size_t len)
176 {
177 	struct mio_rmidi_hdl *hdl = (struct mio_rmidi_hdl *)sh;
178 	ssize_t n;
179 
180 	while ((n = write(hdl->fd, buf, len)) < 0) {
181 		if (errno == EINTR)
182 			continue;
183 		if (errno != EAGAIN) {
184 			DPERROR("mio_rmidi_write: write");
185 			hdl->mio.eof = 1;
186 		}
187 		return 0;
188 	}
189 	return n;
190 }
191 
192 static int
193 mio_rmidi_nfds(struct mio_hdl *sh)
194 {
195 	return 1;
196 }
197 
198 static int
199 mio_rmidi_pollfd(struct mio_hdl *sh, struct pollfd *pfd, int events)
200 {
201 	struct mio_rmidi_hdl *hdl = (struct mio_rmidi_hdl *)sh;
202 
203 	pfd->fd = hdl->fd;
204 	pfd->events = events;
205 	return 1;
206 }
207 
208 static int
209 mio_rmidi_revents(struct mio_hdl *sh, struct pollfd *pfd)
210 {
211 	return pfd->revents;
212 }
213