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/* $OpenBSD: amsg.h,v 1.20 2011/04/16 11:24:18 ratchov Exp $ */
/*
* Copyright (c) 2008 Alexandre Ratchov <alex@caoua.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#ifndef AMSG_H
#define AMSG_H
#include <stdint.h>
#include "conf.h"
/*
* WARNING: since the protocol may be simultaneously used by static
* binaries or by different versions of a shared library, we are not
* allowed to change the packet binary representation in a backward
* incompatible way.
*
* Especially, make sure the amsg_xxx structures are not larger
* than 32 bytes.
*/
struct amsg {
#define AMSG_ACK 0 /* ack for START/STOP */
#define AMSG_GETPAR 1 /* get the current parameters */
#define AMSG_SETPAR 2 /* set the current parameters */
#define AMSG_START 3 /* request the server to start the stream */
#define AMSG_STOP 4 /* request the server to stop the stream */
#define AMSG_DATA 5 /* data block */
#define AMSG_POS 6 /* initial position */
#define AMSG_MOVE 7 /* position changed */
#define AMSG_SETVOL 9 /* set volume */
#define AMSG_HELLO 10 /* say hello, check versions and so ... */
#define AMSG_BYE 11 /* ask server to drop connection */
uint32_t cmd;
uint32_t __pad;
union {
struct amsg_par {
uint8_t legacy_mode; /* compat for old libs */
uint8_t xrun; /* one of above */
uint8_t bps; /* bytes per sample */
uint8_t bits; /* actually used bits */
uint8_t msb; /* 1 if MSB justified */
uint8_t le; /* 1 if little endian */
uint8_t sig; /* 1 if signed */
uint8_t __pad1;
uint16_t pchan; /* play channels */
uint16_t rchan; /* record channels */
uint32_t rate; /* frames per second */
uint32_t bufsz; /* total buffered frames */
uint32_t round;
uint32_t appbufsz; /* client side bufsz */
uint32_t _reserved[1]; /* for future use */
} par;
struct amsg_data {
#define AMSG_DATAMAX 0x1000
uint32_t size;
} data;
struct amsg_ts {
int32_t delta;
} ts;
struct amsg_vol {
uint32_t ctl;
} vol;
struct amsg_hello {
uint16_t mode; /* bitmap of MODE_XXX */
#define AMSG_VERSION 5
uint8_t version; /* protocol version */
uint8_t reserved1[5]; /* for future use */
char opt[12]; /* profile name */
char who[12]; /* hint for leases */
} hello;
} u;
};
/*
* Initialize an amsg structure: fill all fields with 0xff, so the read
* can test which fields were set.
*/
#define AMSG_INIT(m) do { memset((m), 0xff, sizeof(struct amsg)); } while (0)
/*
* Since the structure is memset to 0xff, the MSB can be used to check
* if any field was set.
*/
#define AMSG_ISSET(x) (((x) & (1 << (8 * sizeof(x) - 1))) == 0)
#endif /* !defined(AMSG_H) */
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