xref: /openbsd/lib/libsndio/amsg.h (revision 264ca280)
1 /*	$OpenBSD: amsg.h,v 1.10 2016/01/09 08:27:24 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 #ifndef AMSG_H
18 #define AMSG_H
19 
20 #include <stdint.h>
21 
22 /*
23  * unix-domain socket name is:
24  *
25  * DIR [ '-' UID ] '/' FILE UNIT
26  *
27  * example: "/tmp/aucat-1000/aucat0"
28  *
29  */
30 #define SOCKPATH_DIR	"/tmp/aucat"
31 #define SOCKPATH_FILE	"aucat"
32 #define SOCKPATH_MAX	(1 +		\
33 	sizeof(SOCKPATH_DIR) - 1 +	\
34 	sizeof(char) +			\
35 	sizeof(int) * 3 +		\
36 	sizeof(char) +			\
37 	sizeof(SOCKPATH_FILE) - 1 +	\
38 	sizeof(int) * 3)
39 
40 /*
41  * server TCP base port number
42  */
43 #define AUCAT_PORT		11025
44 
45 /*
46  * WARNING: since the protocol may be simultaneously used by static
47  * binaries or by different versions of a shared library, we are not
48  * allowed to change the packet binary representation in a backward
49  * incompatible way.
50  *
51  * Especially, make sure the amsg_xxx structures are not larger
52  * than 32 bytes.
53  */
54 struct amsg {
55 #define AMSG_ACK	0	/* ack for START/STOP */
56 #define AMSG_GETPAR	1	/* get the current parameters */
57 #define AMSG_SETPAR	2	/* set the current parameters */
58 #define AMSG_START	3	/* request the server to start the stream */
59 #define AMSG_STOP	4	/* request the server to stop the stream */
60 #define AMSG_DATA	5	/* data block */
61 #define AMSG_FLOWCTL	6	/* feedback about buffer usage */
62 #define AMSG_MOVE	7	/* position changed */
63 #define AMSG_SETVOL	9	/* set volume */
64 #define AMSG_HELLO	10	/* say hello, check versions and so ... */
65 #define AMSG_BYE	11	/* ask server to drop connection */
66 #define AMSG_AUTH	12	/* send authentication cookie */
67 	uint32_t cmd;
68 	uint32_t __pad;
69 	union {
70 		struct amsg_par {
71 			uint8_t legacy_mode;	/* compat for old libs */
72 			uint8_t xrun;		/* one of above */
73 			uint8_t bps;		/* bytes per sample */
74 			uint8_t bits;		/* actually used bits */
75 			uint8_t msb;		/* 1 if MSB justified */
76 			uint8_t le;		/* 1 if little endian */
77 			uint8_t sig;		/* 1 if signed */
78 			uint8_t __pad1;
79 			uint16_t pchan;		/* play channels */
80 			uint16_t rchan;		/* record channels */
81 			uint32_t rate;		/* frames per second */
82 			uint32_t bufsz;		/* total buffered frames */
83 			uint32_t round;
84 			uint32_t appbufsz;	/* client side bufsz */
85 			uint32_t _reserved[1];	/* for future use */
86 		} par;
87 		struct amsg_data {
88 #define AMSG_DATAMAX	0x1000
89 			uint32_t size;
90 		} data;
91 		struct amsg_ts {
92 			int32_t delta;
93 		} ts;
94 		struct amsg_vol {
95 			uint32_t ctl;
96 		} vol;
97 		struct amsg_hello {
98 			uint16_t mode;		/* bitmap of MODE_XXX */
99 #define AMSG_VERSION	7
100 			uint8_t version;	/* protocol version */
101 			uint8_t devnum;		/* device number */
102 			uint32_t _reserved[1];	/* for future use */
103 #define AMSG_OPTMAX	12
104 			char opt[AMSG_OPTMAX];	/* profile name */
105 			char who[12];		/* hint for leases */
106 		} hello;
107 		struct amsg_auth {
108 #define AMSG_COOKIELEN	16
109 			uint8_t cookie[AMSG_COOKIELEN];
110 		} auth;
111 	} u;
112 };
113 
114 /*
115  * Initialize an amsg structure: fill all fields with 0xff, so the read
116  * can test which fields were set.
117  */
118 #define AMSG_INIT(m) do { memset((m), 0xff, sizeof(struct amsg)); } while (0)
119 
120 /*
121  * Since the structure is memset to 0xff, the MSB can be used to check
122  * if any field was set.
123  */
124 #define AMSG_ISSET(x) (((x) & (1 << (8 * sizeof(x) - 1))) == 0)
125 
126 #endif /* !defined(AMSG_H) */
127