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