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