static void RFCOMM_ProcessTestCommand(const RFCOMM_Command_t* const CommandHeader,
const uint8_t CommandDataLen,
const uint8_t* CommandData,
Bluetooth_Channel_t* const ACLChannel)
{
const uint8_t* Params = (const uint8_t*)CommandData;
BT_RFCOMM_DEBUG(1, "<< TEST Command");
struct
{
RFCOMM_Command_t CommandHeader;
uint8_t Length;
uint8_t TestData[CommandDataLen];
} TestResponse;
/* Fill out the Test response data */
TestResponse.CommandHeader = (RFCOMM_Command_t){.Command = RFCOMM_Control_Test, .EA = true, .CR = false};
TestResponse.Length = (CommandDataLen << 1) | 0x01;
memcpy(TestResponse.TestData, Params, CommandDataLen);
BT_RFCOMM_DEBUG(1, ">> TEST Response");
/* Send the PDN response to acknowledge the command */
RFCOMM_SendFrame(RFCOMM_CONTROL_DLCI, false, RFCOMM_Frame_UIH, sizeof(TestResponse), &TestResponse, ACLChannel);
}
static void RFCOMM_ProcessFCECommand(const RFCOMM_Command_t* const CommandHeader,
const uint8_t* CommandData,
Bluetooth_Channel_t* const ACLChannel)
{
BT_RFCOMM_DEBUG(1, "<< FCE Command");
}
static void RFCOMM_ProcessMSCCommand(const RFCOMM_Command_t* const CommandHeader,
const uint8_t CommandDataLen,
const uint8_t* CommandData,
Bluetooth_Channel_t* const ACLChannel)
{
const RFCOMM_MSC_Parameters_t* Params = (const RFCOMM_MSC_Parameters_t*)CommandData;
BT_RFCOMM_DEBUG(1, "<< MSC %s", (CommandHeader->CR) ? "Command" : "Response");
BT_RFCOMM_DEBUG(2, "-- DLCI: 0x%02X", Params->Channel.DLCI);
/* Ignore status flags sent to the control channel */
if (Params->Channel.DLCI == RFCOMM_CONTROL_DLCI)
return;
/* Retrieve existing channel configuration data, if already opened */
RFCOMM_Channel_t* RFCOMMChannel = RFCOMM_GetChannelData(Params->Channel.DLCI);
/* If the channel does not exist, abort */
if (RFCOMMChannel == NULL)
return;
/* Check if the MSC packet is a command or a response */
if (CommandHeader->CR)
{
/* Save the new channel signals to the channel state structure */
RFCOMMChannel->Remote.Signals = Params->Signals;
RFCOMMChannel->ConfigFlags |= RFCOMM_CONFIG_REMOTESIGNALS;
/* If the command contains the optional break signals field, store the value */
if (CommandDataLen == sizeof(RFCOMM_MSC_Parameters_t))
RFCOMMChannel->Remote.BreakSignal = Params->BreakSignal;
/* Notify the user application that the signals have been received */
RFCOMM_ChannelSignalsReceived(RFCOMMChannel);
struct
{
RFCOMM_Command_t CommandHeader;
uint8_t Length;
RFCOMM_MSC_Parameters_t Params;
} MSResponse;
/* Fill out the MS response data */
MSResponse.CommandHeader = (RFCOMM_Command_t){.Command = RFCOMM_Control_ModemStatus, .EA = true, .CR = false};
MSResponse.Length = (CommandDataLen << 1) | 0x01;
memcpy(&MSResponse.Params, Params, sizeof(RFCOMM_MSC_Parameters_t));
BT_RFCOMM_DEBUG(1, ">> MSC Response");
/* Send the MSC response to acknowledge the command */
RFCOMM_SendFrame(RFCOMM_CONTROL_DLCI, false, RFCOMM_Frame_UIH,
(sizeof(MSResponse) - sizeof(MSResponse.Params) + CommandDataLen), &MSResponse, ACLChannel);
}
else
{
static void RFCOMM_ProcessDISC(const RFCOMM_Address_t* const FrameAddress,
Bluetooth_Channel_t* const ACLChannel)
{
BT_RFCOMM_DEBUG(1, "<< DISC Received");
BT_RFCOMM_DEBUG(2, "-- DLCI 0x%02X", FrameAddress->DLCI);
RFCOMM_Channel_t* RFCOMMChannel = RFCOMM_GetChannelData(FrameAddress->DLCI);
/* If the requested channel is currently open, destroy it */
if (RFCOMMChannel != NULL)
RFCOMMChannel->State = RFCOMM_Channel_Closed;
BT_RFCOMM_DEBUG(1, ">> UA Sent");
RFCOMM_SendFrame(FrameAddress->DLCI, true, (RFCOMM_Frame_UA | FRAME_POLL_FINAL), 0, NULL, ACLChannel);
}
void RFCOMM_ProcessControlCommand(const uint8_t* Command,
Bluetooth_Channel_t* const ACLChannel)
{
const RFCOMM_Command_t* CommandHeader = (const RFCOMM_Command_t*)Command;
const uint8_t* CommandData = (const uint8_t*)Command + sizeof(RFCOMM_Command_t);
uint8_t CommandDataLen = RFCOMM_GetVariableFieldValue(&CommandData);
switch (CommandHeader->Command)
{
case RFCOMM_Control_Test:
RFCOMM_ProcessTestCommand(CommandHeader, CommandDataLen, CommandData, ACLChannel);
break;
case RFCOMM_Control_FlowControlEnable:
RFCOMM_ProcessFCECommand(CommandHeader, CommandData, ACLChannel);
break;
case RFCOMM_Control_FlowControlDisable:
RFCOMM_ProcessFCDCommand(CommandHeader, CommandData, ACLChannel);
break;
case RFCOMM_Control_ModemStatus:
RFCOMM_ProcessMSCCommand(CommandHeader, CommandDataLen, CommandData, ACLChannel);
break;
case RFCOMM_Control_RemotePortNegotiation:
RFCOMM_ProcessRPNCommand(CommandHeader, CommandData, ACLChannel);
break;
case RFCOMM_Control_RemoteLineStatus:
RFCOMM_ProcessRLSCommand(CommandHeader, CommandData, ACLChannel);
break;
case RFCOMM_Control_DLCParameterNegotiation:
RFCOMM_ProcessDPNCommand(CommandHeader, CommandData, ACLChannel);
break;
default:
BT_RFCOMM_DEBUG(1, "<< Unknown Command");
break;
}
}
/** Processes an incoming RFCOMM packet on an ACL channel which has been previously opened between the local and
* a remote device to handle RFCOMM traffic.
*
* \param[in] Data Incoming packet data containing the RFCOMM packet
* \param[in] ACLChannel ACL channel the request was issued to by the remote device
*/
void RFCOMM_ProcessPacket(void* Data,
Bluetooth_Channel_t* const ACLChannel)
{
const RFCOMM_Header_t* FrameHeader = (const RFCOMM_Header_t*)Data;
const uint8_t* FrameData = (const uint8_t*)Data + sizeof(RFCOMM_Header_t);
uint16_t FrameDataLen = RFCOMM_GetVariableFieldValue(&FrameData);
/* Decode the RFCOMM frame type from the header */
switch (FrameHeader->Control & ~FRAME_POLL_FINAL)
{
case RFCOMM_Frame_DM:
RFCOMM_ProcessDM(&FrameHeader->Address, ACLChannel);
break;
case RFCOMM_Frame_DISC:
RFCOMM_ProcessDISC(&FrameHeader->Address, ACLChannel);
break;
case RFCOMM_Frame_SABM:
RFCOMM_ProcessSABM(&FrameHeader->Address, ACLChannel);
break;
case RFCOMM_Frame_UA:
RFCOMM_ProcessUA(&FrameHeader->Address, ACLChannel);
break;
case RFCOMM_Frame_UIH:
RFCOMM_ProcessUIH(&FrameHeader->Address, FrameDataLen, FrameData, ACLChannel);
break;
default:
BT_RFCOMM_DEBUG(1, "<< Unknown Frame Received");
break;
}
}
static void RFCOMM_ProcessUIH(const RFCOMM_Address_t* const FrameAddress,
const uint16_t FrameLength,
const uint8_t* FrameData,
Bluetooth_Channel_t* const ACLChannel)
{
if (FrameAddress->DLCI == RFCOMM_CONTROL_DLCI)
{
RFCOMM_ProcessControlCommand(FrameData, ACLChannel);
return;
}
BT_RFCOMM_DEBUG(1, "<< UIH Received");
BT_RFCOMM_DEBUG(2, "-- DLCI 0x%02X", FrameAddress->DLCI);
BT_RFCOMM_DEBUG(2, "-- Length 0x%02X", FrameLength);
RFCOMM_Channel_t* RFCOMMChannel = RFCOMM_GetChannelData(FrameAddress->DLCI);
if (RFCOMMChannel != NULL)
RFCOMM_DataReceived(RFCOMMChannel, FrameLength, FrameData);
}
static void RFCOMM_ProcessSABM(const RFCOMM_Address_t* const FrameAddress,
Bluetooth_Channel_t* const ACLChannel)
{
BT_RFCOMM_DEBUG(1, "<< SABM Received");
BT_RFCOMM_DEBUG(2, "-- DLCI 0x%02X", FrameAddress->DLCI);
if (FrameAddress->DLCI == RFCOMM_CONTROL_DLCI)
{
BT_RFCOMM_DEBUG(1, ">> UA Sent");
/* Free channel found, or request was to the control channel - accept SABM by sending a UA frame */
RFCOMM_SendFrame(FrameAddress->DLCI, true, (RFCOMM_Frame_UA | FRAME_POLL_FINAL), 0, NULL, ACLChannel);
return;
}
/* Find the existing channel's entry in the channel table */
RFCOMM_Channel_t* RFCOMMChannel = RFCOMM_GetChannelData(FrameAddress->DLCI);
/* Existing entry not found, create a new entry for the channel */
if (RFCOMMChannel == NULL)
RFCOMMChannel = RFCOMM_GetFreeChannelEntry(FrameAddress->DLCI);
/* If space was found in the channel table for the new channel, ACK the request */
if (RFCOMMChannel != NULL)
{
BT_RFCOMM_DEBUG(1, ">> UA Sent");
/* Free channel found, or request was to the control channel - accept SABM by sending a UA frame */
RFCOMM_SendFrame(FrameAddress->DLCI, true, (RFCOMM_Frame_UA | FRAME_POLL_FINAL), 0, NULL, ACLChannel);
}
else
{
BT_RFCOMM_DEBUG(1, ">> DM Sent");
/* No free channel in the multiplexer - decline the SABM by sending a DM frame */
RFCOMM_SendFrame(FrameAddress->DLCI, true, (RFCOMM_Frame_DM | FRAME_POLL_FINAL), 0, NULL, ACLChannel);
}
}
static void RFCOMM_ProcessFCDCommand(const RFCOMM_Command_t* const CommandHeader,
const uint8_t* CommandData,
Bluetooth_Channel_t* const ACLChannel)
{
BT_RFCOMM_DEBUG(1, "<< FCD Command");
}
static void RFCOMM_ProcessUA(const RFCOMM_Address_t* const FrameAddress,
Bluetooth_Channel_t* const ACLChannel)
{
BT_RFCOMM_DEBUG(1, "<< UA Received");
BT_RFCOMM_DEBUG(2, "-- DLCI 0x%02X", FrameAddress->DLCI);
}
/** Sends an RFCOMM notification to the remote device that the local terminal control signals (located in the
* "Local" structure of the RFCOMM channel) have changed, pushing the new signals to the remote device.
*
* \param[in] RFCOMMChannel RFCOMM logical channel whose local terminal signals have changed
* \param[in] ACLChannel ACL channel which has been opened to carry RFCOMM traffic between devices
*/
void RFCOMM_SendChannelSignals(const RFCOMM_Channel_t* const RFCOMMChannel,
Bluetooth_Channel_t* const ACLChannel)
{
BT_RFCOMM_DEBUG(1, ">> MSC Command");
BT_RFCOMM_DEBUG(2, "-- DLCI 0x%02X", RFCOMMChannel->DLCI);
struct
{
RFCOMM_Command_t CommandHeader;
uint8_t Length;
RFCOMM_MSC_Parameters_t Params;
} MSCommand;
MSCommand.CommandHeader = (RFCOMM_Command_t){.Command = RFCOMM_Control_ModemStatus, .EA = true, .CR = true};
MSCommand.Length = (sizeof(MSCommand.Params) << 1) | 0x01;
MSCommand.Params.Channel = (RFCOMM_Address_t){.DLCI = RFCOMMChannel->DLCI, .EA = true, .CR = true};
MSCommand.Params.Signals = RFCOMMChannel->Local.Signals;
MSCommand.Params.BreakSignal = RFCOMMChannel->Local.BreakSignal;
/* Send the MSC command to the remote device */
RFCOMM_SendFrame(RFCOMM_CONTROL_DLCI, true, RFCOMM_Frame_UIH, sizeof(MSCommand), &MSCommand, ACLChannel);
}
/** Sends new data through an open logical RFCOMM channel. This should be used to transmit data through a
* RFCOMM channel once it has been opened.
*
* \param[in] DataLen Length of the RFCOMM data to send, in bytes
* \param[in] Data Pointer to a buffer where the data to send is located
* \param[in] RFCOMMChannel RFCOMM logical channel which is to be transmitted to
* \param[in] ACLChannel ACL channel which has been opened to carry RFCOMM traffic between devices
*/
void RFCOMM_SendData(const uint16_t DataLen,
const uint8_t* Data,
const RFCOMM_Channel_t* const RFCOMMChannel,
Bluetooth_Channel_t* const ACLChannel)
{
if (RFCOMMChannel->State != RFCOMM_Channel_Open)
return;
BT_RFCOMM_DEBUG(1, ">> UIH Frame");
BT_RFCOMM_DEBUG(2, "-- DLCI 0x%02X", RFCOMMChannel->DLCI);
/* Send the MSC command to the remote device */
RFCOMM_SendFrame(RFCOMMChannel->DLCI, false, RFCOMM_Frame_UIH, DataLen, Data, ACLChannel);
}
RFCOMM_Channel_t* RFCOMM_GetFreeChannelEntry(const uint8_t DLCI)
{
/* Find a free entry in the RFCOMM channel multiplexer state array */
for (uint8_t i = 0; i < RFCOMM_MAX_OPEN_CHANNELS; i++)
{
RFCOMM_Channel_t* RFCOMMChannel = &RFCOMM_Channels[i];
/* If the channel's state is closed, the channel state entry is free */
if (RFCOMMChannel->State == RFCOMM_Channel_Closed)
{
RFCOMMChannel->DLCI = DLCI;
RFCOMMChannel->State = RFCOMM_Channel_Configure;
RFCOMMChannel->Priority = 7 + (RFCOMMChannel->DLCI & 0xF8);
RFCOMMChannel->MTU = 0xFFFF;
RFCOMMChannel->Remote.Signals = 0 | (1 << 0);
RFCOMMChannel->Remote.BreakSignal = 0 | (1 << 0);
RFCOMMChannel->Local.Signals = RFCOMM_SIGNAL_RTC | RFCOMM_SIGNAL_RTR | RFCOMM_SIGNAL_DV | (1 << 0);
RFCOMMChannel->Local.BreakSignal = 0 | (1 << 0);
RFCOMMChannel->ConfigFlags = 0;
return RFCOMMChannel;
}
}
return NULL;
}
RFCOMM_Channel_t* RFCOMM_GetChannelData(const uint8_t DLCI)
{
/* Search through the RFCOMM channel list, looking for the specified channel */
for (uint8_t i = 0; i < RFCOMM_MAX_OPEN_CHANNELS; i++)
{
RFCOMM_Channel_t* CurrRFCOMMChannel = &RFCOMM_Channels[i];
/* If the current non-closed channel's DLCI matches the search DLCI, return it to the caller */
if ((CurrRFCOMMChannel->State != RFCOMM_Channel_Closed) && (CurrRFCOMMChannel->DLCI == DLCI))
return CurrRFCOMMChannel;
}
/* Channel not found in the channel state table, return failure */
return NULL;
}
uint16_t RFCOMM_GetVariableFieldValue(const uint8_t** BufferPos)
{
uint8_t FirstOctet;
uint8_t SecondOctet = 0;
FirstOctet = **BufferPos;
(*BufferPos)++;
/* If the field size is more than a single byte, fetch the next byte in the variable length field */
if (!(FirstOctet & 0x01))
{
SecondOctet = **BufferPos;
(*BufferPos)++;
/* Discard any remaining bytes in the variable length field that won't fit in the return value */
while (!(**BufferPos & 0x01))
(*BufferPos)++;
}
/* Bit-shift the bytes that comprise the variable length field so that they form a single integer */
return (((uint16_t)SecondOctet << 7) | FirstOctet >> 1);
}
void RFCOMM_SendFrame(const uint8_t DLCI,
const bool CommandResponse,
const uint8_t Control,
const uint16_t DataLen,
const void* Data,
Bluetooth_Channel_t* const ACLChannel)
{
struct
{
RFCOMM_Header_t FrameHeader;
uint8_t Size[(DataLen < 128) ? 1 : 2];
uint8_t Data[DataLen];
uint8_t FCS;
} ResponsePacket;
/* Set the frame header values to the specified address and frame type */
ResponsePacket.FrameHeader.Control = Control;
ResponsePacket.FrameHeader.Address = (RFCOMM_Address_t){.DLCI = DLCI, .EA = true, .CR = CommandResponse};
/* Set the lower 7 bits of the packet length */
ResponsePacket.Size[0] = (DataLen << 1);
/* Terminate the size field if size is 7 bits or lower, otherwise set the upper 8 bits of the length */
if (DataLen < 128)
ResponsePacket.Size[0] |= 0x01;
else
ResponsePacket.Size[1] = (DataLen >> 7);
/* Copy over the packet data from the source buffer to the response packet buffer */
memcpy(ResponsePacket.Data, Data, DataLen);
/* Determine the length of the frame which is to be used to calculate the CRC value */
uint8_t CRCLength = sizeof(ResponsePacket.FrameHeader);
/* UIH frames do not have the CRC calculated on the Size field in the response, all other frames do */
if ((Control & ~FRAME_POLL_FINAL) != RFCOMM_Frame_UIH)
CRCLength += sizeof(ResponsePacket.Size);
/* Calculate the frame checksum from the appropriate fields */
ResponsePacket.FCS = RFCOMM_GetFCSValue(&ResponsePacket, CRCLength);
/* Send the completed response packet to the sender */
Bluetooth_SendPacket(&ResponsePacket, sizeof(ResponsePacket), ACLChannel);
}
static uint8_t RFCOMM_GetFCSValue(const void* FrameStart,
uint8_t Length)
{
uint8_t FCS = 0xFF;
/* Calculate new Frame CRC value via the given data bytes and the CRC table */
for (uint8_t i = 0; i < Length; i++)
FCS = pgm_read_byte(&CRC8_Table[FCS ^ ((const uint8_t*)FrameStart)[i]]);
return ~FCS;
}
static void RFCOMM_ProcessDM(const RFCOMM_Address_t* const FrameAddress,
Bluetooth_Channel_t* const ACLChannel)
{
BT_RFCOMM_DEBUG(1, "<< DM Received");
BT_RFCOMM_DEBUG(2, "-- DLCI 0x%02X", FrameAddress->DLCI);
}