Modules/IPStack/tcp.c

   1 /*
   2  * Acess2 IP Stack
   3  * - TCP Handling
   4  */
   5 #include "ipstack.h"
   6 #include "tcp.h"
   7
   8 #define TCP_MIN_DYNPORT 0x1000
   9
  10 // === PROTOTYPES ===
  11 void    TCP_Initialise();
  12 void    *TCP_Open(tInterface *Interface, Uint16 LocalPort, void *Address, Uint16 Port);
  13 void    TCP_GetPacket(tInterface *Interface, int Length, void *Buffer);
  14 Uint16  TCP_GetUnusedPort();
  15  int    TCP_AllocatePort(Uint16 Port);
  16  int    TCP_DeallocatePort(Uint16 Port);
  17
  18 // === GLOBALS ===
  19  int    giTCP_NumHalfopen = 0;
  20 tTCPListener    *gTCP_Listeners;
  21 tTCPConnection  *gTCP_OutbountCons;
  22 Uint32  gaTCP_PortBitmap[0x800];
  23  int    giTCP_NextOutPort = TCP_MIN_DYNPORT;
  24
  25 // === CODE ===
  26 /**
  27  * \fn void TCP_Initialise()
  28  * \brief Initialise the TCP Layer
  29  */
  30 void TCP_Initialise()
  31 {
  32
  33 }
  34
  35 /**
  36  * \fn void *TCP_Open(tInterface *Interface, Uint16 LocalPort, void *Address, Uint16 Port)
  37  * \brief Open a connection to another host using TCP
  38  */
  39 void *TCP_Open(tInterface *Interface, Uint16 LocalPort, void *Address, Uint16 Port)
  40 {
  41         tTCPConnection  *ret = malloc( sizeof(tTCPConnection) );
  42
  43         ret->State = TCP_ST_CLOSED;
  44         if(LocalPort == 0)
  45                 ret->LocalPort = TCP_GetUnusedPort();
  46         else
  47                 ret->LocalPort = LocalPort;
  48         ret->RemotePort = Port;
  49
  50         ret->LocalInterface = Interface;
  51
  52         if(Interface->Type == 6)
  53                 ret->RemoteIP.v6 = *(tIPv6*)Address;
  54         else
  55                 ret->RemoteIP.v4 = *(tIPv4*)Address;
  56
  57         // SEND PACKET
  58
  59         return ret;
  60 }
  61
  62 /**
  63  * \fn void TCP_GetPacket(tInterface *Interface, void *Address, int Length, void *Buffer)
  64  * \brief Handles a packet from the IP Layer
  65  */
  66 void TCP_GetPacket(tInterface *Interface, void *Address, int Length, void *Buffer)
  67 {
  68         tTCPHeader      *hdr = Buffer;
  69         tTCPListener    *srv;
  70         tTCPConnection  *conn;
  71
  72         // Check Servers
  73         {
  74                 for( srv = gTCP_Listeners; srv; srv = srv->Next )
  75                 {
  76                         // Check the interface
  77                         if(srv->Interface && srv->Interface != Interface)       continue;
  78                         // Check the destination port
  79                         if(srv->Port != hdr->DestPort)  continue;
  80
  81                         // Is this in an established connection?
  82                         for( conn = srv->Connections; conn; conn = conn->Next )
  83                         {
  84                                 // Check that it is coming in on the same interface
  85                                 if(conn->Interface != Interface)        continue;
  86
  87                                 // Check Source Port
  88                                 if(conn->RemotePort != hdr->SourcePort) continue;
  89
  90                                 // Check Source IP
  91                                 if(conn->Interface->Type == 6 && !IP6_EQU(conn->RemoteIP.v6, *(tIPv6*)Address))
  92                                         continue;
  93                                 if(conn->Interface->Type == 4 && !IP4_EQU(conn->RemoteIP.v4, *(tIPv4*)Address))
  94                                         continue;
  95
  96                                 // We have a response!
  97                                 //TODO
  98
  99                                 return;
 100                         }
 101
 102                         // Open a new connection
 103                         //TODO
 104
 105                         break;
 106                 }
 107         }
 108
 109
 110         // Check Open Connections
 111         {
 112                 for( conn = gTCP_OutbountCons; conn; conn = conn->Next )
 113                 {
 114                         // TODO
 115                 }
 116         }
 117 }
 118
 119 /**
 120  * \fn Uint16 TCP_GetUnusedPort()
 121  * \brief Gets an unused port and allocates it
 122  */
 123 Uint16 TCP_GetUnusedPort()
 124 {
 125         Uint16  ret;
 126
 127         // Get Next outbound port
 128         ret = giTCP_NextOutPort++;
 129         while( gaTCP_PortBitmap[ret/32] & (1 << (ret%32)) )
 130         {
 131                 ret ++;
 132                 giTCP_NextOutPort++;
 133                 if(giTCP_NextOutPort == 0x10000) {
 134                         ret = giTCP_NextOutPort = TCP_MIN_DYNPORT;
 135                 }
 136         }
 137
 138         // Mark the new port as used
 139         gaTCP_PortBitmap[ret/32] |= 1 << (ret%32);
 140
 141         return ret;
 142 }
 143
 144 /**
 145  * \fn int TCP_AllocatePort(Uint16 Port)
 146  * \brief Marks a port as used
 147  */
 148 int TCP_AllocatePort(Uint16 Port)
 149 {
 150         // Check if the port has already been allocated
 151         if( gaTCP_PortBitmap[Port/32] & (1 << (Port%32)) )
 152                 return 0;
 153
 154         // Allocate
 155         gaTCP_PortBitmap[Port/32] |= 1 << (Port%32);
 156
 157         return 1;
 158 }
 159
 160 /**
 161  * \fn int TCP_DeallocatePort(Uint16 Port)
 162  * \brief Marks a port as unused
 163  */
 164 int TCP_DeallocatePort(Uint16 Port)
 165 {
 166         // Check if the port has already been allocated
 167         if( !(gaTCP_PortBitmap[Port/32] & (1 << (Port%32))) )
 168                 return 0;
 169
 170         // Allocate
 171         gaTCP_PortBitmap[Port/32] &= ~(1 << (Port%32));
 172
 173         return 1;
 174 }
 175