/**
* @brief Receive an AppleMIDI command.
* Receive a datagram and decompose the message into the message structure.
* @private @memberof MIDIDriverAppleMIDI
* @param driver The driver.
* @param fd The file descriptor to use for communication.
* @param command The command.
* @retval 0 On success.
* @retval >0 If the packet could not be sent.
*/
static int _applemidi_recv_command( struct MIDIDriverAppleMIDI * driver, int fd, struct AppleMIDICommand * command ) {
unsigned int ssrc;
unsigned int msg[16];
int len;
command->size = sizeof(command->addr);
len = recvfrom( fd, &msg[0], sizeof(msg), 0,
(struct sockaddr *) &(command->addr), &(command->size) );
if( command->addr.ss_family == AF_INET ) {
struct sockaddr_in * a = (struct sockaddr_in *) &(command->addr);
MIDILog( DEBUG, "recv %i bytes from %s:%i on s(%i)\n", len, inet_ntoa( a->sin_addr ), ntohs( a->sin_port ), fd );
} else {
MIDILog( DEBUG, "recv %i bytes from <unknown addr family> on s(%i)\n", len, fd );
}
command->type = ntohl( msg[0] ) & 0xffff;
switch( command->type ) {
case APPLEMIDI_COMMAND_INVITATION:
case APPLEMIDI_COMMAND_INVITATION_ACCEPTED:
case APPLEMIDI_COMMAND_INVITATION_REJECTED:
case APPLEMIDI_COMMAND_ENDSESSION:
if( len < 16 ) return 1;
command->data.session.version = ntohl( msg[1] );
command->data.session.token = ntohl( msg[2] );
command->data.session.ssrc = ntohl( msg[3] );
len -= 16;
if( len > 0 ) {
if( len > sizeof( command->data.session.name ) - 1 ) {
len = sizeof( command->data.session.name ) - 1;
}
memcpy( &(command->data.session.name[0]), &msg[4], len );
command->data.session.name[len] = '\0';
}
ssrc = command->data.session.ssrc;
break;
case APPLEMIDI_COMMAND_SYNCHRONIZATION:
if( len != 36 ) return 1;
command->data.sync.ssrc = ntohl( msg[1] );
command->data.sync.count = ntohl( msg[2] ) >> 24;
command->data.sync.timestamp1 = (unsigned long long) ntohl( msg[3] ) << 32;
command->data.sync.timestamp1 += ntohl( msg[4] );
command->data.sync.timestamp2 = (unsigned long long) ntohl( msg[5] ) << 32;
command->data.sync.timestamp2 += ntohl( msg[6] );
command->data.sync.timestamp3 = (unsigned long long) ntohl( msg[7] ) << 32;
command->data.sync.timestamp3 += ntohl( msg[8] );
ssrc = command->data.sync.ssrc;
break;
case APPLEMIDI_COMMAND_RECEIVER_FEEDBACK:
if( len != 12 ) return 1;
command->data.feedback.ssrc = ntohl( msg[1] );
command->data.feedback.seqnum = ntohl( msg[2] );
ssrc = command->data.feedback.ssrc;
break;
default:
return 1;
}
return 0;
}
/**
* @brief Send the given AppleMIDI command.
* Compose a message buffer and send the datagram to the given peer.
* @private @memberof MIDIDriverAppleMIDI
* @param driver The driver.
* @param fd The file descriptor to use for communication.
* @param command The command.
* @retval 0 On success.
* @retval >0 If the packet could not be sent.
*/
static int _applemidi_send_command( struct MIDIDriverAppleMIDI * driver, int fd, struct AppleMIDICommand * command ) {
unsigned int ssrc;
unsigned int msg[16];
int len;
msg[0] = htonl( ( APPLEMIDI_PROTOCOL_SIGNATURE << 16 ) | command->type );
switch( command->type ) {
case APPLEMIDI_COMMAND_INVITATION:
case APPLEMIDI_COMMAND_INVITATION_ACCEPTED:
case APPLEMIDI_COMMAND_INVITATION_REJECTED:
case APPLEMIDI_COMMAND_ENDSESSION:
ssrc = command->data.session.ssrc;
msg[1] = htonl( command->data.session.version );
msg[2] = htonl( command->data.session.token );
msg[3] = htonl( command->data.session.ssrc );
if( command->data.session.name[0] != '\0' ) {
len = strlen( command->data.session.name );
memcpy( &(msg[4]), command->data.session.name, len );
len += 16;
} else {
len = 16;
}
break;
case APPLEMIDI_COMMAND_SYNCHRONIZATION:
ssrc = command->data.sync.ssrc;
msg[1] = htonl( command->data.sync.ssrc );
msg[2] = htonl( command->data.sync.count << 24 );
msg[3] = htonl( command->data.sync.timestamp1 >> 32 );
msg[4] = htonl( command->data.sync.timestamp1 & 0xffffffff );
msg[5] = htonl( command->data.sync.timestamp2 >> 32 );
msg[6] = htonl( command->data.sync.timestamp2 & 0xffffffff );
msg[7] = htonl( command->data.sync.timestamp3 >> 32 );
msg[8] = htonl( command->data.sync.timestamp3 & 0xffffffff );
len = 36;
break;
case APPLEMIDI_COMMAND_RECEIVER_FEEDBACK:
ssrc = command->data.feedback.ssrc;
msg[1] = htonl( command->data.feedback.ssrc );
msg[2] = htonl( command->data.feedback.seqnum );
len = 12;
break;
default:
return 1;
}
if( command->addr.ss_family == AF_INET ) {
struct sockaddr_in * a = (struct sockaddr_in *) &(command->addr);
MIDILog( DEBUG, "send %i bytes to %s:%i on s(%i)\n", len, inet_ntoa( a->sin_addr ), ntohs( a->sin_port ), fd );
} else {
MIDILog( DEBUG, "send %i bytes to <unknown addr family> on s(%i)\n", len, fd );
}
if( sendto( fd, &msg[0], len, 0,
(struct sockaddr *) &(command->addr), command->size ) != len ) {
return 1;
} else {
return 0;
}
}
/**
* @brief Create a MIDIDriverAppleMIDI instance.
* Allocate space and initialize an MIDIDriverAppleMIDI instance.
* @public @memberof MIDIDriverAppleMIDI
* @return a pointer to the created driver structure on success.
* @return a @c NULL pointer if the driver could not created.
*/
struct MIDIDriverAppleMIDI * MIDIDriverAppleMIDICreate( char * name, unsigned short port ) {
struct MIDIDriverAppleMIDI * driver;
MIDITimestamp timestamp;
int ret = 0;
driver = malloc( sizeof( struct MIDIDriverAppleMIDI ) );
MIDIPrecondReturn( driver != NULL, ENOMEM, NULL );
MIDIDriverInit( &(driver->base), name, APPLEMIDI_CLOCK_RATE );
driver->control_socket = 0;
driver->rtp_socket = 0;
driver->port = port;
driver->accept = 0;
driver->sync = 0;
strncpy( &(driver->name[0]), name, sizeof(driver->name) );
driver->in_queue = MIDIMessageQueueCreate();
driver->out_queue = MIDIMessageQueueCreate();
driver->base.send = &_driver_send;
driver->base.destroy = &_driver_destroy;
ret = _applemidi_connect( driver );
if (ret==-1)
MIDILog( ERROR, "Bind failed for port: %hu\n", port);
driver->peer = NULL;
driver->rtp_session = RTPSessionCreate( driver->rtp_socket );
driver->rtpmidi_session = RTPMIDISessionCreate( driver->rtp_session );
MIDIClockGetNow( driver->base.clock, ×tamp );
MIDILog( DEBUG, "initial timestamp: %lli\n", timestamp );
driver->token = timestamp;
memset( &(driver->command), 0, sizeof(driver->command) );
driver->command.peer = NULL;
_applemidi_init_runloop_source( driver );
return driver;
}
