KernelLand/Modules/IPStack/tcp.h

   1 /*
   2  * Acess2 IP Stack
   3  * - TCP Definitions
   4  */
   5 #ifndef _TCP_H_
   6 #define _TCP_H_
   7
   8 #include "ipstack.h"
   9 #include <adt.h>        // tRingBuffer
  10 #include <timers.h>     // tTimer
  11 #include <semaphore.h>  // tSemaphore
  12
  13 typedef struct sTCPHeader       tTCPHeader;
  14 typedef struct sTCPListener     tTCPListener;
  15 typedef struct sTCPStoredPacket tTCPStoredPacket;
  16 typedef struct sTCPConnection   tTCPConnection;
  17
  18 struct sTCPHeader
  19 {
  20         Uint16  SourcePort;
  21         Uint16  DestPort;
  22         Uint32  SequenceNumber;
  23         Uint32  AcknowlegementNumber;
  24         #if 0
  25         struct {        // Lowest to highest
  26                 unsigned Reserved:      4;
  27                 unsigned DataOffset: 4; // Size of the header in 32-bit words
  28         } __attribute__ ((packed));
  29         #else
  30         Uint8   DataOffset;
  31         #endif
  32         #if 0
  33         struct {        // Lowest to Highest
  34                 unsigned FIN:   1;      // Last packet
  35                 unsigned SYN:   1;      // Synchronise Sequence Numbers
  36                 unsigned RST:   1;      // Reset Connection
  37                 unsigned PSH:   1;      // Push Function
  38                 unsigned ACK:   1;      // Acknowlegement field is significant
  39                 unsigned URG:   1;      // Urgent pointer is significant
  40                 unsigned ECE:   1;      // ECN-Echo
  41                 unsigned CWR:   1;      // Congestion Window Reduced
  42         } __attribute__ ((packed)) Flags;
  43         #else
  44         Uint8   Flags;
  45         #endif
  46         Uint16  WindowSize;
  47
  48         Uint16  Checksum;
  49         Uint16  UrgentPointer;
  50
  51         Uint8   Options[];
  52 } __attribute__ ((packed));
  53
  54 enum eTCPFlags
  55 {
  56         TCP_FLAG_FIN    = 0x01,
  57         TCP_FLAG_SYN    = 0x02,
  58         TCP_FLAG_RST    = 0x04,
  59         TCP_FLAG_PSH    = 0x08,
  60         TCP_FLAG_ACK    = 0x10,
  61         TCP_FLAG_URG    = 0x20,
  62         TCP_FLAG_ECE    = 0x40,
  63         TCP_FLAG_CWR    = 0x80
  64 };
  65
  66 struct sTCPListener
  67 {
  68         struct sTCPListener     *Next;  //!< Next server in the list
  69         Uint16  Port;           //!< Listening port (0 disables the server)
  70         tInterface      *Interface;     //!< Listening Interface
  71         tVFS_Node       Node;   //!< Server Directory node
  72          int    NextID;         //!< Name of the next connection
  73         tSemaphore      WaitingConnections;
  74         tShortSpinlock  lConnections;   //!< Spinlock for connections
  75         tTCPConnection  *Connections;   //!< Connections (linked list)
  76         tTCPConnection  *volatile NewConnections;
  77         tTCPConnection  *ConnectionsTail;
  78 };
  79
  80 struct sTCPStoredPacket
  81 {
  82         struct sTCPStoredPacket *Next;
  83         size_t  Length;
  84         Uint32  Sequence;
  85         Uint8   Data[];
  86 };
  87
  88 enum eTCPConnectionState
  89 {
  90         TCP_ST_CLOSED,          // 0 - Connection invalid
  91
  92         TCP_ST_SYN_SENT,        // 1 - SYN sent by local, waiting for SYN-ACK
  93         TCP_ST_SYN_RCVD,        // 2 - SYN recieved, SYN-ACK sent
  94
  95         TCP_ST_OPEN,            // 3 - Connection open
  96
  97         // Local Close
  98         TCP_ST_FIN_WAIT1,       // 4 - FIN sent, waiting for reply (ACK or FIN)
  99         TCP_ST_FIN_WAIT2,       // 5 - sent FIN acked, waiting for FIN from peer
 100         TCP_ST_CLOSING,         // 6 - Waiting for ACK of FIN (FIN sent and recieved)
 101         TCP_ST_TIME_WAIT,       // 7 - Waiting for timeout after local close
 102         // Remote close
 103         TCP_ST_CLOSE_WAIT,      // 8 - FIN recieved, waiting for user to close (error set, wait for node close)
 104         TCP_ST_LAST_ACK,        // 9 - FIN sent and recieved, waiting for ACK
 105         TCP_ST_FINISHED         // 10 - Essentially closed, all packets are invalid
 106 };
 107
 108 struct sTCPConnection
 109 {
 110         struct sTCPConnection   *Next;
 111         enum eTCPConnectionState        State;  //!< Connection state (see ::eTCPConnectionState)
 112         Uint16  LocalPort;      //!< Local port
 113         Uint16  RemotePort;     //!< Remote port
 114         tInterface      *Interface;     //!< Listening Interface
 115         tVFS_Node       Node;   //!< Node
 116
 117         Uint32  NextSequenceSend;       //!< Next sequence value for outbound packets
 118         Uint32  NextSequenceRcv;        //!< Next expected sequence value for inbound
 119
 120         // Deferred ACK handling
 121         Uint32  LastACKSequence;
 122         tTimer  *DeferredACKTimer;
 123
 124         #if 0
 125         /**
 126          * \brief Non-ACKed packets
 127          * \note Ring buffer
 128          * \{
 129          */
 130         tMutex  lNonACKedPackets;
 131         tTCPStoredPacket        *SentPackets;   //!< Non-acknowleged packets
 132         /**
 133          * \}
 134          */
 135         #endif
 136
 137         /**
 138          * \brief Unread Packets
 139          * \note Ring buffer
 140          * \{
 141          */
 142         tMutex  lRecievedPackets;
 143         tRingBuffer     *RecievedBuffer;
 144         /**
 145          * \}
 146          */
 147
 148         /**
 149          * \brief Out of sequence packets
 150          * \note Sorted list to improve times
 151          * \todo Convert this to a ring buffer and a bitmap of valid bytes
 152          * \{
 153          */
 154         #if CACHE_FUTURE_PACKETS_OR_BYTES == bytes
 155         Uint32  HighestSequenceRcvd;    //!< Highest sequence number (within window) recieved
 156         Uint8   *FuturePacketData;      //!< Future packet data (indexed by sequence number)
 157         Uint8   *FuturePacketValidBytes;        //!< Valid byte bitmap (WINDOW_SIZE/8 bytes)
 158         #else
 159         tShortSpinlock  lFuturePackets; //!< Future packets spinlock
 160         tTCPStoredPacket        *FuturePackets; //!< Out of sequence packets
 161         #endif
 162         /**
 163          * \}
 164          */
 165
 166         union {
 167                 tIPv4   v4;
 168                 tIPv6   v6;
 169         } RemoteIP;     //!< Remote IP Address
 170         // Type is determined by LocalInterface->Type
 171 };
 172
 173 #endif