+/*\r
+ LUFA Library\r
+ Copyright (C) Dean Camera, 2009.\r
+ \r
+ dean [at] fourwalledcubicle [dot] com\r
+ www.fourwalledcubicle.com\r
+*/\r
+\r
+/*\r
+ Copyright 2009 Dean Camera (dean [at] fourwalledcubicle [dot] com)\r
+\r
+ Permission to use, copy, modify, and distribute this software\r
+ and its documentation for any purpose and without fee is hereby\r
+ granted, provided that the above copyright notice appear in all\r
+ copies and that both that the copyright notice and this\r
+ permission notice and warranty disclaimer appear in supporting\r
+ documentation, and that the name of the author not be used in\r
+ advertising or publicity pertaining to distribution of the\r
+ software without specific, written prior permission.\r
+\r
+ The author disclaim all warranties with regard to this\r
+ software, including all implied warranties of merchantability\r
+ and fitness. In no event shall the author be liable for any\r
+ special, indirect or consequential damages or any damages\r
+ whatsoever resulting from loss of use, data or profits, whether\r
+ in an action of contract, negligence or other tortious action,\r
+ arising out of or in connection with the use or performance of\r
+ this software.\r
+*/\r
+\r
+/** \file\r
+ *\r
+ * Transmission Control Protocol (TCP) packet handling routines. This protocol handles the reliable in-order transmission\r
+ * and reception of packets to and from devices on a network, to "ports" on the device. It is used in situations where data\r
+ * delivery must be reliable and correct, e.g. HTTP, TELNET and most other non-streaming protocols.\r
+ */\r
+ \r
+#define INCLUDE_FROM_TCP_C\r
+#include "TCP.h"\r
+\r
+/* Global Variables: */\r
+/** Port state table array. This contains the current status of TCP ports in the device. To save on space, only open ports are\r
+ * stored - closed ports may be overwritten at any time, and the system will assume any ports not present in the array are closed. This\r
+ * allows for MAX_OPEN_TCP_PORTS to be less than the number of ports used by the application if desired.\r
+ */\r
+TCP_PortState_t PortStateTable[MAX_OPEN_TCP_PORTS];\r
+\r
+/** Connection state table array. This contains the current status of TCP connections in the device. To save on space, only active\r
+ * (non-closed) connections are stored - closed connections may be overwritten at any time, and the system will assume any connections\r
+ * not present in the array are closed.\r
+ */\r
+TCP_ConnectionState_t ConnectionStateTable[MAX_TCP_CONNECTIONS];\r
+\r
+\r
+/** Task to handle the calling of each registered application's callback function, to process and generate TCP packets at the application\r
+ * level. If an application produces a response, this task constructs the appropriate Ethernet frame and places it into the Ethernet OUT\r
+ * buffer for later transmission.\r
+ */\r
+TASK(TCP_Task)\r
+{\r
+ /* Task to hand off TCP packets to and from the listening applications. */\r
+\r
+ /* Run each application in sequence, to process incoming and generate outgoing packets */\r
+ for (uint8_t CSTableEntry = 0; CSTableEntry < MAX_TCP_CONNECTIONS; CSTableEntry++)\r
+ {\r
+ /* Find the corresponding port entry in the port table */\r
+ for (uint8_t PTableEntry = 0; PTableEntry < MAX_TCP_CONNECTIONS; PTableEntry++)\r
+ {\r
+ /* Run the application handler for the port */\r
+ if ((PortStateTable[PTableEntry].Port == ConnectionStateTable[CSTableEntry].Port) && \r
+ (PortStateTable[PTableEntry].State == TCP_Port_Open))\r
+ {\r
+ PortStateTable[PTableEntry].ApplicationHandler(&ConnectionStateTable[CSTableEntry], &ConnectionStateTable[CSTableEntry].Info.Buffer);\r
+ }\r
+ }\r
+ }\r
+ \r
+ /* Bail out early if there is already a frame waiting to be sent in the Ethernet OUT buffer */\r
+ if (FrameOUT.FrameInBuffer)\r
+ return;\r
+ \r
+ /* Send response packets from each application as the TCP packet buffers are filled by the applications */\r
+ for (uint8_t CSTableEntry = 0; CSTableEntry < MAX_TCP_CONNECTIONS; CSTableEntry++)\r
+ {\r
+ /* For each completely received packet, pass it along to the listening application */\r
+ if ((ConnectionStateTable[CSTableEntry].Info.Buffer.Direction == TCP_PACKETDIR_OUT) &&\r
+ (ConnectionStateTable[CSTableEntry].Info.Buffer.Ready))\r
+ {\r
+ Ethernet_Frame_Header_t* FrameOUTHeader = (Ethernet_Frame_Header_t*)&FrameOUT.FrameData;\r
+ IP_Header_t* IPHeaderOUT = (IP_Header_t*)&FrameOUT.FrameData[sizeof(Ethernet_Frame_Header_t)];\r
+ TCP_Header_t* TCPHeaderOUT = (TCP_Header_t*)&FrameOUT.FrameData[sizeof(Ethernet_Frame_Header_t) +\r
+ sizeof(IP_Header_t)]; \r
+ void* TCPDataOUT = &FrameOUT.FrameData[sizeof(Ethernet_Frame_Header_t) +\r
+ sizeof(IP_Header_t) +\r
+ sizeof(TCP_Header_t)];\r
+\r
+ uint16_t PacketSize = ConnectionStateTable[CSTableEntry].Info.Buffer.Length;\r
+\r
+ /* Fill out the TCP data */\r
+ TCPHeaderOUT->SourcePort = ConnectionStateTable[CSTableEntry].Port;\r
+ TCPHeaderOUT->DestinationPort = ConnectionStateTable[CSTableEntry].RemotePort;\r
+ TCPHeaderOUT->SequenceNumber = SwapEndian_32(ConnectionStateTable[CSTableEntry].Info.SequenceNumberOut);\r
+ TCPHeaderOUT->AcknowledgmentNumber = SwapEndian_32(ConnectionStateTable[CSTableEntry].Info.SequenceNumberIn);\r
+ TCPHeaderOUT->DataOffset = (sizeof(TCP_Header_t) / sizeof(uint32_t));\r
+ TCPHeaderOUT->WindowSize = SwapEndian_16(TCP_WINDOW_SIZE);\r
+\r
+ TCPHeaderOUT->Flags = TCP_FLAG_ACK;\r
+ TCPHeaderOUT->UrgentPointer = 0;\r
+ TCPHeaderOUT->Checksum = 0;\r
+ TCPHeaderOUT->Reserved = 0;\r
+\r
+ memcpy(TCPDataOUT, ConnectionStateTable[CSTableEntry].Info.Buffer.Data, PacketSize);\r
+ \r
+ ConnectionStateTable[CSTableEntry].Info.SequenceNumberOut += PacketSize;\r
+\r
+ TCPHeaderOUT->Checksum = TCP_Checksum16(TCPHeaderOUT, ServerIPAddress,\r
+ ConnectionStateTable[CSTableEntry].RemoteAddress,\r
+ (sizeof(TCP_Header_t) + PacketSize));\r
+\r
+ PacketSize += sizeof(TCP_Header_t);\r
+\r
+ /* Fill out the response IP header */\r
+ IPHeaderOUT->TotalLength = SwapEndian_16(sizeof(IP_Header_t) + PacketSize);\r
+ IPHeaderOUT->TypeOfService = 0;\r
+ IPHeaderOUT->HeaderLength = (sizeof(IP_Header_t) / sizeof(uint32_t));\r
+ IPHeaderOUT->Version = 4;\r
+ IPHeaderOUT->Flags = 0;\r
+ IPHeaderOUT->FragmentOffset = 0;\r
+ IPHeaderOUT->Identification = 0;\r
+ IPHeaderOUT->HeaderChecksum = 0;\r
+ IPHeaderOUT->Protocol = PROTOCOL_TCP;\r
+ IPHeaderOUT->TTL = DEFAULT_TTL;\r
+ IPHeaderOUT->SourceAddress = ServerIPAddress;\r
+ IPHeaderOUT->DestinationAddress = ConnectionStateTable[CSTableEntry].RemoteAddress;\r
+ \r
+ IPHeaderOUT->HeaderChecksum = Ethernet_Checksum16(IPHeaderOUT, sizeof(IP_Header_t));\r
+ \r
+ PacketSize += sizeof(IP_Header_t);\r
+ \r
+ /* Fill out the response Ethernet frame header */\r
+ FrameOUTHeader->Source = ServerMACAddress;\r
+ FrameOUTHeader->Destination = (MAC_Address_t){{0x02, 0x00, 0x02, 0x00, 0x02, 0x00}};\r
+ FrameOUTHeader->EtherType = SwapEndian_16(ETHERTYPE_IPV4);\r
+\r
+ PacketSize += sizeof(Ethernet_Frame_Header_t);\r
+\r
+ /* Set the response length in the buffer and indicate that a response is ready to be sent */\r
+ FrameOUT.FrameLength = PacketSize;\r
+ FrameOUT.FrameInBuffer = true;\r
+ \r
+ ConnectionStateTable[CSTableEntry].Info.Buffer.Ready = false;\r
+ \r
+ break;\r
+ }\r
+ }\r
+}\r
+\r
+/** Initializes the TCP protocol handler, clearing the port and connection state tables. This must be called before TCP packets are\r
+ * processed.\r
+ */\r
+void TCP_Init(void)\r
+{\r
+ /* Initialize the port state table with all CLOSED entries */\r
+ for (uint8_t PTableEntry = 0; PTableEntry < MAX_OPEN_TCP_PORTS; PTableEntry++)\r
+ PortStateTable[PTableEntry].State = TCP_Port_Closed;\r
+\r
+ /* Initialize the connection table with all CLOSED entries */\r
+ for (uint8_t CSTableEntry = 0; CSTableEntry < MAX_TCP_CONNECTIONS; CSTableEntry++)\r
+ ConnectionStateTable[CSTableEntry].State = TCP_Connection_Closed;\r
+}\r
+\r
+/** Sets the state and callback handler of the given port, specified in big endian to the given state.\r
+ *\r
+ * \param Port Port whose state and callback function to set, specified in big endian\r
+ * \param State New state of the port, a value from the TCP_PortStates_t enum\r
+ * \param Handler Application callback handler for the port\r
+ *\r
+ * \return Boolean true if the port state was set, false otherwise (no more space in the port state table)\r
+ */\r
+bool TCP_SetPortState(uint16_t Port, uint8_t State, void (*Handler)(TCP_ConnectionState_t*, TCP_ConnectionBuffer_t*))\r
+{\r
+ /* Note, Port number should be specified in BIG endian to simplify network code */\r
+\r
+ /* Check to see if the port entry is already in the port state table */\r
+ for (uint8_t PTableEntry = 0; PTableEntry < MAX_TCP_CONNECTIONS; PTableEntry++)\r
+ {\r
+ /* Find existing entry for the port in the table, update it if found */\r
+ if (PortStateTable[PTableEntry].Port == Port)\r
+ {\r
+ PortStateTable[PTableEntry].State = State;\r
+ PortStateTable[PTableEntry].ApplicationHandler = Handler;\r
+ return true;\r
+ }\r
+ }\r
+\r
+ /* Check if trying to open the port -- if so we need to find an unused (closed) entry and replace it */\r
+ if (State == TCP_Port_Open)\r
+ {\r
+ for (uint8_t PTableEntry = 0; PTableEntry < MAX_TCP_CONNECTIONS; PTableEntry++)\r
+ {\r
+ /* Find a closed port entry in the table, change it to the given port and state */\r
+ if (PortStateTable[PTableEntry].State == TCP_Port_Closed)\r
+ {\r
+ PortStateTable[PTableEntry].Port = Port;\r
+ PortStateTable[PTableEntry].State = State;\r
+ PortStateTable[PTableEntry].ApplicationHandler = Handler;\r
+ return true;\r
+ }\r
+ }\r
+ \r
+ /* Port not in table and no room to add it, return failure */\r
+ return false;\r
+ }\r
+ else\r
+ {\r
+ /* Port not in table but trying to close it, so operation successful */\r
+ return true;\r
+ }\r
+}\r
+\r
+/** Retrieves the current state of a given TCP port, specified in big endian.\r
+ *\r
+ * \param Port TCP port whose state is to be retrieved, given in big-endian\r
+ *\r
+ * \return A value from the TCP_PortStates_t enum\r
+ */\r
+uint8_t TCP_GetPortState(uint16_t Port)\r
+{\r
+ /* Note, Port number should be specified in BIG endian to simplify network code */\r
+\r
+ for (uint8_t PTableEntry = 0; PTableEntry < MAX_TCP_CONNECTIONS; PTableEntry++)\r
+ {\r
+ /* Find existing entry for the port in the table, return the port status if found */\r
+ if (PortStateTable[PTableEntry].Port == Port)\r
+ return PortStateTable[PTableEntry].State;\r
+ }\r
+ \r
+ /* Port not in table, assume closed */\r
+ return TCP_Port_Closed;\r
+}\r
+\r
+/** Sets the connection state of the given port, remote address and remote port to the given TCP connection state. If the\r
+ * connection exists in the connection state table it is updated, otherwise it is created if possible.\r
+ *\r
+ * \param Port TCP port of the connection on the device, specified in big endian\r
+ * \param RemoteAddress Remote protocol IP address of the connected device\r
+ * \param RemotePort TCP port of the remote device in the connection, specified in big endian\r
+ * \param State TCP connection state, a value from the TCP_ConnectionStates_t enum\r
+ *\r
+ * \return Boolean true if the connection was updated or created, false otherwise (no more space in the connection state table)\r
+ */\r
+bool TCP_SetConnectionState(uint16_t Port, IP_Address_t RemoteAddress, uint16_t RemotePort, uint8_t State)\r
+{\r
+ /* Note, Port number should be specified in BIG endian to simplify network code */\r
+\r
+ for (uint8_t CSTableEntry = 0; CSTableEntry < MAX_TCP_CONNECTIONS; CSTableEntry++)\r
+ {\r
+ /* Find port entry in the table */\r
+ if ((ConnectionStateTable[CSTableEntry].Port == Port) &&\r
+ IP_COMPARE(&ConnectionStateTable[CSTableEntry].RemoteAddress, &RemoteAddress) &&\r
+ ConnectionStateTable[CSTableEntry].RemotePort == RemotePort)\r
+ {\r
+ ConnectionStateTable[CSTableEntry].State = State;\r
+ return true;\r
+ }\r
+ }\r
+ \r
+ for (uint8_t CSTableEntry = 0; CSTableEntry < MAX_TCP_CONNECTIONS; CSTableEntry++)\r
+ {\r
+ /* Find empty entry in the table */\r
+ if (ConnectionStateTable[CSTableEntry].State == TCP_Connection_Closed)\r
+ {\r
+ ConnectionStateTable[CSTableEntry].Port = Port;\r
+ ConnectionStateTable[CSTableEntry].RemoteAddress = RemoteAddress; \r
+ ConnectionStateTable[CSTableEntry].RemotePort = RemotePort;\r
+ ConnectionStateTable[CSTableEntry].State = State;\r
+ return true;\r
+ }\r
+ }\r
+ \r
+ return false;\r
+}\r
+\r
+/** Retrieves the current state of a given TCP connection to a host.\r
+ *\r
+ * \param Port TCP port on the device in the connection, specified in big endian\r
+ * \param RemoteAddress Remote protocol IP address of the connected host\r
+ * \param RemotePort Remote TCP port of the connected host, specified in big endian\r
+ *\r
+ * \return A value from the TCP_ConnectionStates_t enum\r
+ */\r
+uint8_t TCP_GetConnectionState(uint16_t Port, IP_Address_t RemoteAddress, uint16_t RemotePort)\r
+{\r
+ /* Note, Port number should be specified in BIG endian to simplify network code */\r
+\r
+ for (uint8_t CSTableEntry = 0; CSTableEntry < MAX_TCP_CONNECTIONS; CSTableEntry++)\r
+ {\r
+ /* Find port entry in the table */\r
+ if ((ConnectionStateTable[CSTableEntry].Port == Port) &&\r
+ IP_COMPARE(&ConnectionStateTable[CSTableEntry].RemoteAddress, &RemoteAddress) &&\r
+ ConnectionStateTable[CSTableEntry].RemotePort == RemotePort)\r
+ \r
+ {\r
+ return ConnectionStateTable[CSTableEntry].State;\r
+ }\r
+ }\r
+ \r
+ return TCP_Connection_Closed;\r
+}\r
+\r
+/** Retrieves the connection info structure of a given connection to a host.\r
+ *\r
+ * \param Port TCP port on the device in the connection, specified in big endian\r
+ * \param RemoteAddress Remote protocol IP address of the connected host\r
+ * \param RemotePort Remote TCP port of the connected host, specified in big endian\r
+ *\r
+ * \return ConnectionInfo structure of the connection if found, NULL otherwise\r
+ */\r
+TCP_ConnectionInfo_t* TCP_GetConnectionInfo(uint16_t Port, IP_Address_t RemoteAddress, uint16_t RemotePort)\r
+{\r
+ /* Note, Port number should be specified in BIG endian to simplify network code */\r
+\r
+ for (uint8_t CSTableEntry = 0; CSTableEntry < MAX_TCP_CONNECTIONS; CSTableEntry++)\r
+ {\r
+ /* Find port entry in the table */\r
+ if ((ConnectionStateTable[CSTableEntry].Port == Port) &&\r
+ IP_COMPARE(&ConnectionStateTable[CSTableEntry].RemoteAddress, &RemoteAddress) &&\r
+ ConnectionStateTable[CSTableEntry].RemotePort == RemotePort)\r
+ {\r
+ return &ConnectionStateTable[CSTableEntry].Info;\r
+ }\r
+ }\r
+ \r
+ return NULL;\r
+}\r
+\r
+/** Processes a TCP packet inside an Ethernet frame, and writes the appropriate response\r
+ * to the output Ethernet frame if one is created by a application handler.\r
+ *\r
+ * \param IPHeaderInStart Pointer to the start of the incoming packet's IP header\r
+ * \param TCPHeaderInStart Pointer to the start of the incoming packet's TCP header\r
+ * \param TCPHeaderOutStart Pointer to the start of the outgoing packet's TCP header\r
+ *\r
+ * \return The number of bytes written to the out Ethernet frame if any, NO_RESPONSE if no\r
+ * response was generated, NO_PROCESS if the packet processing was deferred until the\r
+ * next Ethernet packet handler iteration\r
+ */\r
+int16_t TCP_ProcessTCPPacket(void* IPHeaderInStart, void* TCPHeaderInStart, void* TCPHeaderOutStart)\r
+{\r
+ IP_Header_t* IPHeaderIN = (IP_Header_t*)IPHeaderInStart;\r
+ TCP_Header_t* TCPHeaderIN = (TCP_Header_t*)TCPHeaderInStart;\r
+ TCP_Header_t* TCPHeaderOUT = (TCP_Header_t*)TCPHeaderOutStart;\r
+\r
+ TCP_ConnectionInfo_t* ConnectionInfo;\r
+ \r
+ DecodeTCPHeader(TCPHeaderInStart);\r
+\r
+ bool PacketResponse = false;\r
+ \r
+ /* Check if the destination port is open and allows incoming connections */\r
+ if (TCP_GetPortState(TCPHeaderIN->DestinationPort) == TCP_Port_Open)\r
+ {\r
+ /* Detect SYN from host to start a connection */\r
+ if (TCPHeaderIN->Flags & TCP_FLAG_SYN)\r
+ TCP_SetConnectionState(TCPHeaderIN->DestinationPort, IPHeaderIN->SourceAddress, TCPHeaderIN->SourcePort, TCP_Connection_Listen);\r
+\r
+ /* Detect RST from host to abort existing connection */\r
+ if (TCPHeaderIN->Flags & TCP_FLAG_RST)\r
+ {\r
+ TCPHeaderOUT->Flags = (TCP_FLAG_RST | TCP_FLAG_ACK); \r
+ PacketResponse = true;\r
+ \r
+ TCP_SetConnectionState(TCPHeaderIN->DestinationPort, IPHeaderIN->SourceAddress,\r
+ TCPHeaderIN->SourcePort, TCP_Connection_Closed); \r
+ }\r
+ else\r
+ {\r
+ /* Process the incoming TCP packet based on the current connection state for the sender and port */\r
+ switch (TCP_GetConnectionState(TCPHeaderIN->DestinationPort, IPHeaderIN->SourceAddress, TCPHeaderIN->SourcePort))\r
+ {\r
+ case TCP_Connection_Listen:\r
+ if (TCPHeaderIN->Flags == TCP_FLAG_SYN)\r
+ {\r
+ /* SYN connection when closed starts a connection with a peer */\r
+\r
+ TCPHeaderOUT->Flags = (TCP_FLAG_SYN | TCP_FLAG_ACK); \r
+ PacketResponse = true;\r
+ \r
+ TCP_SetConnectionState(TCPHeaderIN->DestinationPort, IPHeaderIN->SourceAddress, TCPHeaderIN->SourcePort,\r
+ TCP_Connection_SYNReceived);\r
+ \r
+ ConnectionInfo = TCP_GetConnectionInfo(TCPHeaderIN->DestinationPort, IPHeaderIN->SourceAddress, TCPHeaderIN->SourcePort);\r
+\r
+ ConnectionInfo->SequenceNumberIn = (SwapEndian_32(TCPHeaderIN->SequenceNumber) + 1);\r
+ ConnectionInfo->SequenceNumberOut = 0;\r
+ ConnectionInfo->Buffer.InUse = false;\r
+ }\r
+ \r
+ break;\r
+ case TCP_Connection_SYNReceived:\r
+ if (TCPHeaderIN->Flags == TCP_FLAG_ACK)\r
+ {\r
+ /* ACK during the connection process completes the connection to a peer */\r
+\r
+ TCP_SetConnectionState(TCPHeaderIN->DestinationPort, IPHeaderIN->SourceAddress,\r
+ TCPHeaderIN->SourcePort, TCP_Connection_Established);\r
+\r
+ ConnectionInfo = TCP_GetConnectionInfo(TCPHeaderIN->DestinationPort, IPHeaderIN->SourceAddress,\r
+ TCPHeaderIN->SourcePort);\r
+ \r
+ ConnectionInfo->SequenceNumberOut++;\r
+ }\r
+ \r
+ break;\r
+ case TCP_Connection_Established:\r
+ if (TCPHeaderIN->Flags == (TCP_FLAG_FIN | TCP_FLAG_ACK))\r
+ {\r
+ /* FIN ACK when connected to a peer starts the finalization process */\r
+ \r
+ TCPHeaderOUT->Flags = (TCP_FLAG_FIN | TCP_FLAG_ACK); \r
+ PacketResponse = true;\r
+ \r
+ TCP_SetConnectionState(TCPHeaderIN->DestinationPort, IPHeaderIN->SourceAddress,\r
+ TCPHeaderIN->SourcePort, TCP_Connection_CloseWait);\r
+\r
+ ConnectionInfo = TCP_GetConnectionInfo(TCPHeaderIN->DestinationPort, IPHeaderIN->SourceAddress,\r
+ TCPHeaderIN->SourcePort);\r
+\r
+ ConnectionInfo->SequenceNumberIn++;\r
+ ConnectionInfo->SequenceNumberOut++;\r
+ }\r
+ else if ((TCPHeaderIN->Flags == TCP_FLAG_ACK) || (TCPHeaderIN->Flags == (TCP_FLAG_ACK | TCP_FLAG_PSH)))\r
+ {\r
+ ConnectionInfo = TCP_GetConnectionInfo(TCPHeaderIN->DestinationPort, IPHeaderIN->SourceAddress,\r
+ TCPHeaderIN->SourcePort);\r
+\r
+ /* Check if the buffer is currently in use either by a buffered data to send, or receive */ \r
+ if ((ConnectionInfo->Buffer.InUse == false) && (ConnectionInfo->Buffer.Ready == false))\r
+ { \r
+ ConnectionInfo->Buffer.Direction = TCP_PACKETDIR_IN;\r
+ ConnectionInfo->Buffer.InUse = true;\r
+ ConnectionInfo->Buffer.Length = 0;\r
+ }\r
+ \r
+ /* Check if the buffer has been claimed by us to read in data from the peer */\r
+ if ((ConnectionInfo->Buffer.Direction == TCP_PACKETDIR_IN) &&\r
+ (ConnectionInfo->Buffer.Length != TCP_WINDOW_SIZE))\r
+ {\r
+ uint16_t IPOffset = (IPHeaderIN->HeaderLength * sizeof(uint32_t));\r
+ uint16_t TCPOffset = (TCPHeaderIN->DataOffset * sizeof(uint32_t));\r
+ uint16_t DataLength = (SwapEndian_16(IPHeaderIN->TotalLength) - IPOffset - TCPOffset);\r
+\r
+ /* Copy the packet data into the buffer */\r
+ memcpy(&ConnectionInfo->Buffer.Data[ConnectionInfo->Buffer.Length],\r
+ &((uint8_t*)TCPHeaderInStart)[TCPOffset],\r
+ DataLength);\r
+\r
+ ConnectionInfo->SequenceNumberIn += DataLength;\r
+ ConnectionInfo->Buffer.Length += DataLength;\r
+ \r
+ /* Check if the buffer is full or if the PSH flag is set, if so indicate buffer ready */\r
+ if ((!(TCP_WINDOW_SIZE - ConnectionInfo->Buffer.Length)) || (TCPHeaderIN->Flags & TCP_FLAG_PSH))\r
+ {\r
+ ConnectionInfo->Buffer.InUse = false;\r
+ ConnectionInfo->Buffer.Ready = true;\r
+\r
+ TCPHeaderOUT->Flags = TCP_FLAG_ACK;\r
+ PacketResponse = true;\r
+ }\r
+ }\r
+ else\r
+ {\r
+ /* Buffer is currently in use by the application, defer processing of the incoming packet */\r
+ return NO_PROCESS;\r
+ }\r
+ }\r
+ \r
+ break;\r
+ case TCP_Connection_Closing:\r
+ ConnectionInfo = TCP_GetConnectionInfo(TCPHeaderIN->DestinationPort, IPHeaderIN->SourceAddress,\r
+ TCPHeaderIN->SourcePort);\r
+\r
+ TCPHeaderOUT->Flags = (TCP_FLAG_ACK | TCP_FLAG_FIN);\r
+ PacketResponse = true;\r
+ \r
+ ConnectionInfo->Buffer.InUse = false;\r
+ \r
+ TCP_SetConnectionState(TCPHeaderIN->DestinationPort, IPHeaderIN->SourceAddress,\r
+ TCPHeaderIN->SourcePort, TCP_Connection_FINWait1);\r
+\r
+ break;\r
+ case TCP_Connection_FINWait1:\r
+ if (TCPHeaderIN->Flags == (TCP_FLAG_FIN | TCP_FLAG_ACK))\r
+ {\r
+ ConnectionInfo = TCP_GetConnectionInfo(TCPHeaderIN->DestinationPort, IPHeaderIN->SourceAddress,\r
+ TCPHeaderIN->SourcePort);\r
+\r
+ TCPHeaderOUT->Flags = TCP_FLAG_ACK;\r
+ PacketResponse = true;\r
+\r
+ ConnectionInfo->SequenceNumberIn++;\r
+ ConnectionInfo->SequenceNumberOut++;\r
+ \r
+ TCP_SetConnectionState(TCPHeaderIN->DestinationPort, IPHeaderIN->SourceAddress,\r
+ TCPHeaderIN->SourcePort, TCP_Connection_Closed);\r
+ }\r
+ else if (TCPHeaderIN->Flags == TCP_FLAG_ACK)\r
+ {\r
+ TCP_SetConnectionState(TCPHeaderIN->DestinationPort, IPHeaderIN->SourceAddress,\r
+ TCPHeaderIN->SourcePort, TCP_Connection_FINWait2);\r
+ }\r
+ \r
+ break;\r
+ case TCP_Connection_FINWait2:\r
+ if (TCPHeaderIN->Flags == (TCP_FLAG_FIN | TCP_FLAG_ACK))\r
+ {\r
+ ConnectionInfo = TCP_GetConnectionInfo(TCPHeaderIN->DestinationPort, IPHeaderIN->SourceAddress,\r
+ TCPHeaderIN->SourcePort);\r
+\r
+ TCPHeaderOUT->Flags = TCP_FLAG_ACK;\r
+ PacketResponse = true;\r
+\r
+ ConnectionInfo->SequenceNumberIn++;\r
+ ConnectionInfo->SequenceNumberOut++;\r
+ \r
+ TCP_SetConnectionState(TCPHeaderIN->DestinationPort, IPHeaderIN->SourceAddress,\r
+ TCPHeaderIN->SourcePort, TCP_Connection_Closed);\r
+ }\r
+ \r
+ break;\r
+ case TCP_Connection_CloseWait:\r
+ if (TCPHeaderIN->Flags == TCP_FLAG_ACK)\r
+ {\r
+ TCP_SetConnectionState(TCPHeaderIN->DestinationPort, IPHeaderIN->SourceAddress,\r
+ TCPHeaderIN->SourcePort, TCP_Connection_Closed);\r
+ }\r
+ \r
+ break;\r
+ }\r
+ }\r
+ }\r
+ else\r
+ {\r
+ /* Port is not open, indicate via a RST/ACK response to the sender */\r
+ TCPHeaderOUT->Flags = (TCP_FLAG_RST | TCP_FLAG_ACK); \r
+ PacketResponse = true;\r
+ }\r
+ \r
+ /* Check if we need to respond to the sent packet */\r
+ if (PacketResponse)\r
+ {\r
+ ConnectionInfo = TCP_GetConnectionInfo(TCPHeaderIN->DestinationPort, IPHeaderIN->SourceAddress,\r
+ TCPHeaderIN->SourcePort);\r
+\r
+ TCPHeaderOUT->SourcePort = TCPHeaderIN->DestinationPort;\r
+ TCPHeaderOUT->DestinationPort = TCPHeaderIN->SourcePort;\r
+ TCPHeaderOUT->SequenceNumber = SwapEndian_32(ConnectionInfo->SequenceNumberOut);\r
+ TCPHeaderOUT->AcknowledgmentNumber = SwapEndian_32(ConnectionInfo->SequenceNumberIn);\r
+ TCPHeaderOUT->DataOffset = (sizeof(TCP_Header_t) / sizeof(uint32_t));\r
+ \r
+ if (!(ConnectionInfo->Buffer.InUse))\r
+ TCPHeaderOUT->WindowSize = SwapEndian_16(TCP_WINDOW_SIZE);\r
+ else\r
+ TCPHeaderOUT->WindowSize = SwapEndian_16(TCP_WINDOW_SIZE - ConnectionInfo->Buffer.Length);\r
+\r
+ TCPHeaderOUT->UrgentPointer = 0;\r
+ TCPHeaderOUT->Checksum = 0;\r
+ TCPHeaderOUT->Reserved = 0;\r
+ \r
+ TCPHeaderOUT->Checksum = TCP_Checksum16(TCPHeaderOUT, IPHeaderIN->DestinationAddress,\r
+ IPHeaderIN->SourceAddress, sizeof(TCP_Header_t)); \r
+\r
+ return sizeof(TCP_Header_t); \r
+ }\r
+\r
+ return NO_RESPONSE;\r
+}\r
+\r
+/** Calculates the appropriate TCP checksum, consisting of the addition of the one's compliment of each word,\r
+ * complimented.\r
+ *\r
+ * \param TCPHeaderOutStart Pointer to the start of the packet's outgoing TCP header\r
+ * \param SourceAddress Source protocol IP address of the outgoing IP header\r
+ * \param SourceAddress DestinationAddress protocol IP address of the outgoing IP header\r
+ * \param TCPOutSize Size in bytes of the TCP data header and payload\r
+ *\r
+ * \return A 16-bit TCP checksum value\r
+ */\r
+static uint16_t TCP_Checksum16(void* TCPHeaderOutStart, IP_Address_t SourceAddress,\r
+ IP_Address_t DestinationAddress, uint16_t TCPOutSize)\r
+{\r
+ uint32_t Checksum = 0;\r
+ \r
+ /* TCP/IP checksums are the addition of the one's compliment of each word including the IP pseudo-header,\r
+ complimented */\r
+ \r
+ Checksum += ((uint16_t*)&SourceAddress)[0];\r
+ Checksum += ((uint16_t*)&SourceAddress)[1];\r
+ Checksum += ((uint16_t*)&DestinationAddress)[0];\r
+ Checksum += ((uint16_t*)&DestinationAddress)[1];\r
+ Checksum += SwapEndian_16(PROTOCOL_TCP);\r
+ Checksum += SwapEndian_16(TCPOutSize);\r
+\r
+ for (uint8_t CurrWord = 0; CurrWord < (TCPOutSize >> 1); CurrWord++)\r
+ Checksum += ((uint16_t*)TCPHeaderOutStart)[CurrWord];\r
+ \r
+ if (TCPOutSize & 0x01)\r
+ Checksum += (((uint16_t*)TCPHeaderOutStart)[TCPOutSize >> 1] & 0x00FF);\r
+ \r
+ while (Checksum & 0xFFFF0000)\r
+ Checksum = ((Checksum & 0xFFFF) + (Checksum >> 16));\r
+ \r
+ return ~Checksum;\r
+}\r
projects / pub / USBasp.git / commitdiff