Make XPLAINBridge serial bridge much more reliable for the reception of characters...
[pub/USBasp.git] / Demos / Host / Incomplete / BluetoothHost / Lib / RFCOMM.c
index a57f3a4..7c39cb0 100644 (file)
@@ -61,123 +61,221 @@ const uint8_t CRC8_Table[256] PROGMEM =
                0xB4, 0x25, 0x57, 0xC6, 0xB3, 0x22, 0x50, 0xC1, 0xBA, 0x2B, 0x59, 0xC8, 0xBD, 0x2C, 0x5E, 0xCF
        };
 
                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)
 {
 /** 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)
 {
 }
 
 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)
        {
        
        /* Decode the RFCOMM frame type from the header */
        switch (FrameHeader->Control & ~FRAME_POLL_FINAL)
        {
-               case RFCOMM_Frame_SABM:
-                       RFCOMM_ProcessSABM(FrameHeader, Channel);
-                       break;
-               case RFCOMM_Frame_UA:
-                       RFCOMM_ProcessUA(FrameHeader, Channel);
-                       break;
                case RFCOMM_Frame_DM:
                case RFCOMM_Frame_DM:
-                       RFCOMM_ProcessDM(FrameHeader, Channel);
+                       RFCOMM_ProcessDM(&FrameHeader->Address, Channel);
                        break;
                case RFCOMM_Frame_DISC:
                        break;
                case RFCOMM_Frame_DISC:
-                       RFCOMM_ProcessDISC(FrameHeader, Channel);
+                       RFCOMM_ProcessDISC(&FrameHeader->Address, Channel);
+                       break;
+               case RFCOMM_Frame_SABM:
+                       RFCOMM_ProcessSABM(&FrameHeader->Address, Channel);
+                       break;
+               case RFCOMM_Frame_UA:
+                       RFCOMM_ProcessUA(&FrameHeader->Address, Channel);
                        break;
                case RFCOMM_Frame_UIH:
                        break;
                case RFCOMM_Frame_UIH:
-                       RFCOMM_ProcessUIH(FrameHeader, Channel);
+                       RFCOMM_ProcessUIH(&FrameHeader->Address, FrameDataLen, FrameData, Channel);
                        break;
                default:
                        break;
                default:
-                       BT_RFCOMM_DEBUG(1, "<< Unknown Frame Type");
+                       BT_RFCOMM_DEBUG(1, "<< Unknown Frame Received");
                        break;
        }
 }
 
                        break;
        }
 }
 
-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, "-- Address 0x%02X", FrameHeader->Address);
+       /* 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];
        
        
-       // TODO: Reset channel send/receive state here
+               /* 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;
+       }
+
+       /* 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)++;
+       }
+
+       /* Bitshift 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 Channel)
+{
        struct
        {
                RFCOMM_Header_t FrameHeader;
        struct
        {
                RFCOMM_Header_t FrameHeader;
-               uint8_t         FrameLength;
+               uint8_t         Size[(DataLen < 128) ? 1 : 2];
+               uint8_t         Data[DataLen];
                uint8_t         FCS;
        } ResponsePacket;
        
                uint8_t         FCS;
        } ResponsePacket;
        
-       /* Copy over the same frame header as the sent packet to copy the logical RFCOMM channel address */
-       ResponsePacket.FrameHeader.Address              = FrameHeader->Address;
+       /* Set the frame header values to the specified address and frame type */
+       ResponsePacket.FrameHeader.Control = Control;
+       ResponsePacket.FrameHeader.Address = (RFCOMM_Address_t)
+               {
+                       .EA   = true,
+                       .CR   = CommandResponse,
+                       .DLCI = DLCI,
+               };
        
        
-       /* Set the frame type to an Unnumbered Acknowledgement to acknowledge the SABM request */
-       ResponsePacket.FrameHeader.Control = RFCOMM_Frame_UA;
+       /* Set the lower 7 bits of the packet length */
+       ResponsePacket.Size[0] = (DataLen << 1);
        
        
-       /* Set the length to 0 (LSB indicates end of 8-bit length field) */
-       ResponsePacket.FrameLength = 0x01;
+       /* 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);
        
        
-       /* Calculate the frame checksum from all fields except the FCS field itself */
-       ResponsePacket.FCS = RFCOMM_GetFCSValue(&ResponsePacket, sizeof(ResponsePacket) - sizeof(ResponsePacket.FCS));
+       /* Copy over the packet data from the source buffer to the response packet buffer */
+       memcpy(ResponsePacket.Data, Data, DataLen);
        
        
-       BT_RFCOMM_DEBUG(1, ">> UA Sent");
+       /* 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), Channel);
 }
 
 
        /* Send the completed response packet to the sender */
        Bluetooth_SendPacket(&ResponsePacket, sizeof(ResponsePacket), Channel);
 }
 
-static void RFCOMM_ProcessUA(const RFCOMM_Header_t* const FrameHeader, Bluetooth_Channel_t* const Channel)
+static uint8_t RFCOMM_GetFCSValue(const void* FrameStart, uint8_t Length)
 {
 {
-       const uint8_t* CurrBufferPos = ((const uint8_t*)FrameHeader + sizeof(RFCOMM_Header_t));
+       uint8_t FCS = 0xFF;
+       
+       for (uint8_t i = 0; i < Length; i++)
+         FCS = pgm_read_byte(&CRC8_Table[FCS ^ ((uint8_t*)FrameStart)[i]]);
 
 
-       BT_RFCOMM_DEBUG(1, "<< UA Received");
-       BT_RFCOMM_DEBUG(2, "-- Address 0x%02X", FrameHeader->Address);
+       return ~FCS;
 }
 
 }
 
-static void RFCOMM_ProcessDM(const RFCOMM_Header_t* const FrameHeader, Bluetooth_Channel_t* const Channel)
+static void RFCOMM_ProcessDM(const RFCOMM_Address_t* const FrameAddress, Bluetooth_Channel_t* const Channel)
 {
 {
-       const uint8_t* CurrBufferPos = ((const uint8_t*)FrameHeader + sizeof(RFCOMM_Header_t));
-
        BT_RFCOMM_DEBUG(1, "<< DM Received");
        BT_RFCOMM_DEBUG(1, "<< DM Received");
-       BT_RFCOMM_DEBUG(2, "-- Address 0x%02X", FrameHeader->Address);
+       BT_RFCOMM_DEBUG(2, "-- DLCI 0x%02X", FrameAddress->DLCI);
 }
 
 }
 
-static void RFCOMM_ProcessDISC(const RFCOMM_Header_t* const FrameHeader, Bluetooth_Channel_t* const Channel)
+static void RFCOMM_ProcessDISC(const RFCOMM_Address_t* const FrameAddress, Bluetooth_Channel_t* const Channel)
 {
 {
-       const uint8_t* CurrBufferPos = ((const uint8_t*)FrameHeader + sizeof(RFCOMM_Header_t));
-
        BT_RFCOMM_DEBUG(1, "<< DISC Received");
        BT_RFCOMM_DEBUG(1, "<< DISC Received");
-       BT_RFCOMM_DEBUG(2, "-- Address 0x%02X", FrameHeader->Address);
-}
+       BT_RFCOMM_DEBUG(2, "-- DLCI 0x%02X", FrameAddress->DLCI);
 
 
-static void RFCOMM_ProcessUIH(const RFCOMM_Header_t* const FrameHeader, Bluetooth_Channel_t* const Channel)
-{
-       const uint8_t* CurrBufferPos = ((const uint8_t*)FrameHeader + sizeof(RFCOMM_Header_t));
+       RFCOMM_Channel_t* RFCOMMChannel = RFCOMM_GetChannelData(FrameAddress->DLCI);
+       
+       /* If the requested channel is currently open, destroy it */
+       if (RFCOMMChannel != NULL)
+         RFCOMMChannel->DLCI = 0x00;
 
 
-       BT_RFCOMM_DEBUG(1, "<< UIH Received");
-       BT_RFCOMM_DEBUG(2, "-- Address 0x%02X", FrameHeader->Address);
+       BT_RFCOMM_DEBUG(1, ">> UA Sent");
+       RFCOMM_SendFrame(FrameAddress->DLCI, true, (RFCOMM_Frame_UA | FRAME_POLL_FINAL), 0, NULL, Channel);
 }
 
 }
 
-static uint8_t RFCOMM_GetFCSValue(const void* FrameStart, uint16_t Length)
+static void RFCOMM_ProcessSABM(const RFCOMM_Address_t* const FrameAddress, Bluetooth_Channel_t* const Channel)
 {
 {
-       const uint8_t* CurrPos = FrameStart;
-       uint8_t        FCS     = 0xFF;
+       BT_RFCOMM_DEBUG(1, "<< SABM Received");
+       BT_RFCOMM_DEBUG(2, "-- DLCI 0x%02X", FrameAddress->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* CurrRFCOMMChannel = &RFCOMM_Channels[i];
        
        
-       while (Length--)
-         FCS = pgm_read_byte(CRC8_Table[FCS ^ *(CurrPos++)]);
+               /* 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;
+               }
+       }
 
 
-       return ~FCS;
+       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 uint16_t RFCOMM_GetFrameDataLength(const uint8_t** BufferPos)
+static void RFCOMM_ProcessUA(const RFCOMM_Address_t* const FrameAddress, Bluetooth_Channel_t* const Channel)
 {
 {
-       uint8_t FirstOctet  = *((*BufferPos)++);
-       uint8_t SecondOctet = 0;
+       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: ");
        
        
-       if (!(FirstOctet & 0x01))
-         SecondOctet = *((*BufferPos)++);
+       for (uint8_t i = 0; i < FrameLength; i++)
+         printf("0x%02X (%c) ", FrameData[i], FrameData[i]);
        
        
-       return (((uint16_t)SecondOctet << 7) | (FirstOctet >> 1));
+       printf("\r\n");
 }
 }
-