Make XPLAINBridge serial bridge much more reliable for the reception of characters...
[pub/USBasp.git] / Demos / Host / Incomplete / BluetoothHost / Lib / RFCOMM.c
index 5a7edc2..7c39cb0 100644 (file)
@@ -61,93 +61,89 @@ const uint8_t CRC8_Table[256] PROGMEM =
                0xB4, 0x25, 0x57, 0xC6, 0xB3, 0x22, 0x50, 0xC1, 0xBA, 0x2B, 0x59, 0xC8, 0xBD, 0x2C, 0x5E, 0xCF
        };
 
+/** RFCOMM channel state structure, to retain information about each open channel in the RFCOMM multiplexer. */
+RFCOMM_Channel_t RFCOMM_Channels[RFCOMM_MAX_OPEN_CHANNELS];
+
+
 /** Initializes the RFCOMM service, ready for new connections from a SDP client. */
 void RFCOMM_Initialize(void)
 {
-       /* Not currently used */
+       /* Reset the RFCOMM channel structures, to invalidate any confiured RFCOMM channels */
+       for (uint8_t i = 0; i < RFCOMM_MAX_OPEN_CHANNELS; i++)
+         RFCOMM_Channels[i].State = RFCOMM_Channel_Closed;
 }
 
 void RFCOMM_ProcessPacket(void* Data, Bluetooth_Channel_t* const Channel)
 {
-       const RFCOMM_Header_t* FrameHeader = (const RFCOMM_Header_t*)Data;
+       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, Channel);
+                       RFCOMM_ProcessDM(&FrameHeader->Address, Channel);
                        break;
                case RFCOMM_Frame_DISC:
-                       RFCOMM_ProcessDISC(FrameHeader, Channel);
+                       RFCOMM_ProcessDISC(&FrameHeader->Address, Channel);
                        break;
                case RFCOMM_Frame_SABM:
-                       RFCOMM_ProcessSABM(FrameHeader, Channel);
+                       RFCOMM_ProcessSABM(&FrameHeader->Address, Channel);
                        break;
                case RFCOMM_Frame_UA:
-                       RFCOMM_ProcessUA(FrameHeader, Channel);
+                       RFCOMM_ProcessUA(&FrameHeader->Address, Channel);
                        break;
                case RFCOMM_Frame_UIH:
-                       RFCOMM_ProcessUIH(FrameHeader, Channel);
+                       RFCOMM_ProcessUIH(&FrameHeader->Address, FrameDataLen, FrameData, Channel);
                        break;
                default:
-                       BT_RFCOMM_DEBUG(1, "<< Unknown Frame Type");
+                       BT_RFCOMM_DEBUG(1, "<< Unknown Frame Received");
                        break;
        }
 }
 
-static void RFCOMM_ProcessDM(const RFCOMM_Header_t* const FrameHeader, Bluetooth_Channel_t* const Channel)
-{
-       BT_RFCOMM_DEBUG(1, "<< DM Received");
-       BT_RFCOMM_DEBUG(2, "-- DLCI 0x%02X", FrameHeader->Address.DLCI);
-}
-
-static void RFCOMM_ProcessDISC(const RFCOMM_Header_t* const FrameHeader, Bluetooth_Channel_t* const Channel)
-{
-       BT_RFCOMM_DEBUG(1, "<< DISC Received");
-       BT_RFCOMM_DEBUG(2, "-- DLCI 0x%02X", FrameHeader->Address.DLCI);
-
-       // TODO: Close down connection
-
-       BT_RFCOMM_DEBUG(1, ">> UA Sent");
-       RFCOMM_SendFrame(FrameHeader->Address.DLCI, true, (RFCOMM_Frame_UA | FRAME_POLL_FINAL), 0, NULL, Channel);
-}
-
-static void RFCOMM_ProcessSABM(const RFCOMM_Header_t* const FrameHeader, Bluetooth_Channel_t* const Channel)
+RFCOMM_Channel_t* RFCOMM_GetChannelData(const uint8_t DLCI)
 {
-       BT_RFCOMM_DEBUG(1, "<< SABM Received");
-       BT_RFCOMM_DEBUG(2, "-- DLCI 0x%02X", FrameHeader->Address.DLCI);
-       
-       // TODO: Reset channel send/receive state
+       /* 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];
        
-       BT_RFCOMM_DEBUG(1, ">> UA Sent");
-       RFCOMM_SendFrame(FrameHeader->Address.DLCI, true, (RFCOMM_Frame_UA | FRAME_POLL_FINAL), 0, NULL, Channel);
-}
+               /* If the current non-closed channel's DLCI matches the search DLCI, return it to the caller */
+               if ((CurrRFCOMMChannel->DLCI == DLCI) && (CurrRFCOMMChannel->State != RFCOMM_Channel_Closed))
+                 return CurrRFCOMMChannel;
+       }
 
-static void RFCOMM_ProcessUA(const RFCOMM_Header_t* const FrameHeader, Bluetooth_Channel_t* const Channel)
-{
-       BT_RFCOMM_DEBUG(1, "<< UA Received");
-       BT_RFCOMM_DEBUG(2, "-- DLCI 0x%02X", FrameHeader->Address.DLCI);
+       /* Channel not found in the channel state table, return failure */
+       return NULL;
 }
 
-static void RFCOMM_ProcessUIH(const RFCOMM_Header_t* const FrameHeader, Bluetooth_Channel_t* const Channel)
+uint16_t RFCOMM_GetVariableFieldValue(const uint8_t** BufferPos)
 {
-       BT_RFCOMM_DEBUG(1, "<< UIH Received");
-       BT_RFCOMM_DEBUG(2, "-- DLCI 0x%02X", FrameHeader->Address.DLCI);
-       
-       uint8_t* FrameData    = (uint8_t*)FrameHeader + sizeof(RFCOMM_Header_t);
-       uint16_t FrameDataLen = RFCOMM_GetFrameDataLength(FrameData);
-       FrameData += (FrameDataLen < 128) ? 1 : 2;
+       uint8_t FirstOctet;
+       uint8_t SecondOctet = 0;
        
-       BT_RFCOMM_DEBUG(2, "-- Length 0x%02X", FrameDataLen);
+       FirstOctet = **BufferPos;
+       (*BufferPos)++;
        
-       if (FrameHeader->Address.DLCI == RFCOMM_CONTROL_DLCI)
+       /* If the field size is more than a single byte, fetch the next byte in the variable length field */
+       if (!(FirstOctet & 0x01))
        {
-               // TODO: Process control command
+               SecondOctet = **BufferPos;
+               (*BufferPos)++;
+
+               /* Discard any remaining bytes in the variable length field that won't fit in the return value */
+               while (!(**BufferPos & 0x01))
+                 (*BufferPos)++;
        }
+
+       /* Bitshift the bytes that comprise the variable length field so that they form a single integer */
+       return (((uint16_t)SecondOctet << 7) | FirstOctet >> 1);
 }
 
-static void RFCOMM_SendFrame(const uint8_t DLCI, const bool CommandResponse, const uint8_t Control, const uint16_t DataLen, const uint8_t* Data,
-                             Bluetooth_Channel_t* const Channel)
+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 Channel)
 {
        struct
        {
@@ -181,6 +177,7 @@ static void RFCOMM_SendFrame(const uint8_t DLCI, const bool CommandResponse, con
        /* 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);
        
@@ -193,23 +190,92 @@ static void RFCOMM_SendFrame(const uint8_t DLCI, const bool CommandResponse, con
 
 static uint8_t RFCOMM_GetFCSValue(const void* FrameStart, uint8_t Length)
 {
-       const uint8_t* CurrPos = FrameStart;
-       uint8_t        FCS     = 0xFF;
+       uint8_t FCS = 0xFF;
        
        for (uint8_t i = 0; i < Length; i++)
-         FCS = pgm_read_byte(&CRC8_Table[FCS ^ *(CurrPos++)]);
+         FCS = pgm_read_byte(&CRC8_Table[FCS ^ ((uint8_t*)FrameStart)[i]]);
 
        return ~FCS;
 }
 
-static uint16_t RFCOMM_GetFrameDataLength(const uint8_t* const BufferPos)
+static void RFCOMM_ProcessDM(const RFCOMM_Address_t* const FrameAddress, Bluetooth_Channel_t* const Channel)
 {
-       uint8_t FirstOctet  = BufferPos[0];
-       uint8_t SecondOctet = 0;
+       BT_RFCOMM_DEBUG(1, "<< DM Received");
+       BT_RFCOMM_DEBUG(2, "-- DLCI 0x%02X", FrameAddress->DLCI);
+}
+
+static void RFCOMM_ProcessDISC(const RFCOMM_Address_t* const FrameAddress, Bluetooth_Channel_t* const Channel)
+{
+       BT_RFCOMM_DEBUG(1, "<< DISC Received");
+       BT_RFCOMM_DEBUG(2, "-- DLCI 0x%02X", FrameAddress->DLCI);
+
+       RFCOMM_Channel_t* RFCOMMChannel = RFCOMM_GetChannelData(FrameAddress->DLCI);
        
-       if (!(FirstOctet & 0x01))
-         SecondOctet = BufferPos[1];
+       /* If the requested channel is currently open, destroy it */
+       if (RFCOMMChannel != NULL)
+         RFCOMMChannel->DLCI = 0x00;
+
+       BT_RFCOMM_DEBUG(1, ">> UA Sent");
+       RFCOMM_SendFrame(FrameAddress->DLCI, true, (RFCOMM_Frame_UA | FRAME_POLL_FINAL), 0, NULL, Channel);
+}
+
+static void RFCOMM_ProcessSABM(const RFCOMM_Address_t* const FrameAddress, Bluetooth_Channel_t* const Channel)
+{
+       BT_RFCOMM_DEBUG(1, "<< SABM Received");
+       BT_RFCOMM_DEBUG(2, "-- DLCI 0x%02X", FrameAddress->DLCI);
        
-       return (((uint16_t)SecondOctet << 7) | FirstOctet >> 1);
+       /* 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* CurrRFCOMMChannel = &RFCOMM_Channels[i];
+       
+               /* If the channel's DLCI is zero, the channel state entry is free */
+               if (!(CurrRFCOMMChannel->DLCI))
+               {
+                       CurrRFCOMMChannel->DLCI     = FrameAddress->DLCI;
+                       CurrRFCOMMChannel->State    = RFCOMM_Channel_Open;
+                       CurrRFCOMMChannel->Priority = 7 + (CurrRFCOMMChannel->DLCI >> 3) + ((CurrRFCOMMChannel->DLCI >> 3) * 7);
+                       CurrRFCOMMChannel->MTU      = 0xFFFF;
+                       CurrRFCOMMChannel->Remote.Signals     = 0 | (1 << 0);
+                       CurrRFCOMMChannel->Remote.BreakSignal = 0 | (1 << 0);
+                       CurrRFCOMMChannel->Local.Signals      = RFCOMM_SIGNAL_RTC | RFCOMM_SIGNAL_RTR | RFCOMM_SIGNAL_DV | (1 << 0);
+                       CurrRFCOMMChannel->Local.BreakSignal  = 0 | (1 << 0);
+               
+                       BT_RFCOMM_DEBUG(1, ">> UA Sent");
+                       RFCOMM_SendFrame(FrameAddress->DLCI, true, (RFCOMM_Frame_UA | FRAME_POLL_FINAL), 0, NULL, Channel);
+                       return;
+               }
+       }
+
+       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, Channel);
+}
+
+static void RFCOMM_ProcessUA(const RFCOMM_Address_t* const FrameAddress, Bluetooth_Channel_t* const Channel)
+{
+       BT_RFCOMM_DEBUG(1, "<< UA Received");
+       BT_RFCOMM_DEBUG(2, "-- DLCI 0x%02X", FrameAddress->DLCI);
 }
 
+static void RFCOMM_ProcessUIH(const RFCOMM_Address_t* const FrameAddress, const uint16_t FrameLength, 
+                              const uint8_t* FrameData, Bluetooth_Channel_t* const Channel)
+{
+       if (FrameAddress->DLCI == RFCOMM_CONTROL_DLCI)
+       {
+               RFCOMM_ProcessControlCommand(FrameData, Channel);
+               return;
+       }
+
+       BT_RFCOMM_DEBUG(1, "<< UIH Received");
+       BT_RFCOMM_DEBUG(2, "-- DLCI 0x%02X", FrameAddress->DLCI);
+       BT_RFCOMM_DEBUG(2, "-- Length 0x%02X", FrameLength);
+               
+       puts("RFCOMM Data: ");
+       
+       for (uint8_t i = 0; i < FrameLength; i++)
+         printf("0x%02X (%c) ", FrameData[i], FrameData[i]);
+       
+       printf("\r\n");
+}