Modules/IPStack/ipv6.c

   1 /*
   2  * Acess2 IP Stack
   3  * - IPv6 Protcol Handling
   4  */
   5 #include "ipstack.h"
   6 #include "link.h"
   7 #include "ipv6.h"
   8 #include "firewall.h"
   9
  10 // === IMPORTS ===
  11 extern tInterface       *gIP_Interfaces;
  12 extern Uint32   IPv4_Netmask(int FixedBits);
  13
  14 // === PROTOTYPES ===
  15  int    IPv6_Initialise();
  16  int    IPv6_RegisterCallback(int ID, tIPCallback Callback);
  17 void    IPv6_int_GetPacket(tAdapter *Interface, tMacAddr From, int Length, void *Buffer);
  18 tInterface      *IPv6_GetInterface(tAdapter *Adapter, tIPv6 Address, int Broadcast);
  19
  20 // === GLOBALS ===
  21 tIPCallback     gaIPv6_Callbacks[256];
  22
  23 // === CODE ===
  24 /**
  25  * \brief Initialise the IPv6 handling code
  26  */
  27 int IPv6_Initialise()
  28 {
  29         Link_RegisterType(IPV6_ETHERNET_ID, IPv6_int_GetPacket);
  30         return 1;
  31 }
  32
  33 /**
  34  * \brief Registers a callback
  35  * \param ID    8-bit packet type ID
  36  * \param Callback      Callback function
  37  */
  38 int IPv6_RegisterCallback(int ID, tIPCallback Callback)
  39 {
  40         if( ID < 0 || ID > 255 )        return 0;
  41         if( gaIPv6_Callbacks[ID] )      return 0;
  42         gaIPv6_Callbacks[ID] = Callback;
  43         return 1;
  44 }
  45
  46 /**
  47  * \brief Creates and sends an IPv6 Packet
  48  * \param Iface Interface
  49  * \param Destination   Destination IP
  50  * \param Protocol      Protocol ID
  51  * \param Length        Data Length
  52  * \param Data  Packet Data
  53  * \return Boolean Success
  54  */
  55 int IPv6_SendPacket(tInterface *Iface, tIPv6 Destination, int Protocol, size_t Length, const void *Data)
  56 {
  57         return 0;
  58 }
  59
  60 /**
  61  * \fn void IPv6_int_GetPacket(tInterface *Interface, tMacAddr From, int Length, void *Buffer)
  62  * \brief Process an IPv6 Packet
  63  * \param Interface     Input interface
  64  * \param From  Source MAC address
  65  * \param Length        Packet length
  66  * \param Buffer        Packet data
  67  */
  68 void IPv6_int_GetPacket(tAdapter *Adapter, tMacAddr From, int Length, void *Buffer)
  69 {
  70         tInterface      *iface;
  71         tIPv6Header     *hdr = Buffer;
  72          int    ret, dataLength;
  73         char    *dataPtr;
  74         Uint8   nextHeader;
  75
  76         if(Length < sizeof(tIPv6Header))        return;
  77
  78         hdr->Head = ntohl(hdr->Head);
  79
  80         //if( ((hdr->Head >> (20+8)) & 0xF) != 6 )
  81         if( hdr->Version != 6 )
  82                 return;
  83
  84         #if 1
  85         Log_Debug("IPv6", "hdr = {");
  86         Log_Debug("IPv6", " .Version       = %i", hdr->Version );
  87         Log_Debug("IPv6", " .TrafficClass  = %i", hdr->TrafficClass );
  88         Log_Debug("IPv6", " .FlowLabel     = %i", hdr->FlowLabel );
  89         Log_Debug("IPv6", " .PayloadLength = 0x%04x", ntohs(hdr->PayloadLength) );
  90         Log_Debug("IPv6", " .NextHeader    = 0x%02x", hdr->NextHeader );
  91         Log_Debug("IPv6", " .HopLimit      = 0x%02x", hdr->HopLimit );
  92         Log_Debug("IPv6", " .Source        = %04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x", hdr->Source );
  93         Log_Debug("IPv6", " .Destination   = %04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x", hdr->Destination );
  94         Log_Debug("IPv6", "}");
  95         #endif
  96
  97         // No checksum in IPv6
  98
  99         // Check Packet length
 100         if( ntohs(hdr->PayloadLength)+sizeof(tIPv6Header) > Length) {
 101                 Log_Log("IPv6", "hdr->PayloadLength(%i) > Length(%i)", ntohs(hdr->PayloadLength), Length);
 102                 return;
 103         }
 104
 105         // Process Options
 106         nextHeader = hdr->NextHeader;
 107         dataPtr = hdr->Data;
 108         dataLength = hdr->PayloadLength;
 109         for( ;; )
 110         {
 111                 struct {
 112                         Uint8   NextHeader;
 113                         Uint8   Length; // In 8-byte chunks, with 0 being 8 bytes long
 114                         Uint8   Data[];
 115                 }       *optionHdr;
 116                 optionHdr = (void*)dataPtr;
 117                 // Hop-by-hop options
 118                 if(nextHeader == 0)
 119                 {
 120                         // TODO: Parse the options (actually, RFC2460 doesn't specify any)
 121                 }
 122                 // Routing Options
 123                 else if(nextHeader == 43)
 124                 {
 125                         // TODO: Routing Header options
 126                 }
 127                 else
 128                 {
 129                         break;  // Unknown, pass on
 130                 }
 131                 nextHeader = optionHdr->NextHeader;
 132                 dataPtr += (optionHdr->Length + 1) * 8; // 8-octet length (0 = 8 bytes long)
 133         }
 134
 135         // Get Interface (allowing broadcasts)
 136         iface = IPv6_GetInterface(Adapter, hdr->Destination, 1);
 137
 138         // Firewall rules
 139         if( iface ) {
 140                 // Incoming Packets
 141                 ret = IPTables_TestChain("INPUT",
 142                         6, &hdr->Source, &hdr->Destination,
 143                         hdr->NextHeader, 0,
 144                         hdr->PayloadLength, hdr->Data
 145                         );
 146         }
 147         else {
 148                 // Routed packets
 149                 ret = IPTables_TestChain("FORWARD",
 150                         6, &hdr->Source, &hdr->Destination,
 151                         hdr->NextHeader, 0,
 152                         hdr->PayloadLength, hdr->Data
 153                         );
 154         }
 155
 156         switch(ret)
 157         {
 158         // 0 - Allow
 159         case 0: break;
 160         // 1 - Silent Drop
 161         case 1:
 162                 Log_Debug("IPv6", "Silently dropping packet");
 163                 return ;
 164         // Unknown, silent drop
 165         default:
 166                 return ;
 167         }
 168
 169         // Routing
 170         if(!iface)
 171         {
 172                 #if 0
 173                 tMacAddr        to;
 174                 tRoute  *rt;
 175
 176                 Log_Debug("IPv6", "Route the packet");
 177                 // Drop the packet if the TTL is zero
 178                 if( hdr->HopLimit == 0 ) {
 179                         Log_Warning("IPv6", "TODO: Sent ICMP-Timeout when TTL exceeded");
 180                         return ;
 181                 }
 182
 183                 hdr->HopLimit --;
 184
 185                 rt = IPStack_FindRoute(6, NULL, &hdr->Destination);     // Get the route (gets the interface)
 186                 to = ICMP6_ResolveHWAddr(rt->Interface, hdr->Destination);      // Resolve address
 187
 188                 // Send packet
 189                 Log_Log("IPv6", "Forwarding packet");
 190                 Link_SendPacket(rt->Interface->Adapter, IPV6_ETHERNET_ID, to, Length, Buffer);
 191                 #endif
 192
 193                 return ;
 194         }
 195
 196         // Send it on
 197         if( !gaIPv6_Callbacks[hdr->NextHeader] ) {
 198                 Log_Log("IPv6", "Unknown Protocol %i", hdr->NextHeader);
 199                 return ;
 200         }
 201
 202         gaIPv6_Callbacks[hdr->NextHeader]( iface, &hdr->Source, hdr->PayloadLength, hdr->Data );
 203 }
 204
 205 /**
 206  * \fn tInterface *IPv6_GetInterface(tAdapter *Adapter, tIPv6 Address)
 207  * \brief Searches an adapter for a matching address
 208  * \param Adapter       Source adapter
 209  * \param Address       Destination Address
 210  * \param Broadcast     Allow broadcast?
 211  */
 212 tInterface *IPv6_GetInterface(tAdapter *Adapter, tIPv6 Address, int Broadcast)
 213 {
 214          int    i, j;
 215         tInterface      *iface = NULL;
 216         Uint32  netmask;
 217
 218         for( iface = gIP_Interfaces; iface; iface = iface->Next)
 219         {
 220                 tIPv6   *thisAddr;
 221
 222                 // Check for this adapter
 223                 if( iface->Adapter != Adapter ) continue;
 224
 225                 // Skip non-IPv6 Interfaces
 226                 if( iface->Type != 6 )  continue;
 227
 228                 thisAddr = (tIPv6*)iface->Address;
 229                 // If the address is a perfect match, return this interface
 230                 if( IP6_EQU(Address, *thisAddr) )       return iface;
 231
 232                 // Check if we want to match broadcast addresses
 233                 if( !Broadcast )        continue;
 234
 235                 // Check for broadcast
 236                 // - Check first DWORDs
 237                 if( iface->SubnetBits > 32 && Address.L[0] != thisAddr->L[0] )
 238                         continue;
 239                 if( iface->SubnetBits > 64 && Address.L[1] != thisAddr->L[1] )
 240                         continue;
 241                 if( iface->SubnetBits > 96 && Address.L[2] != thisAddr->L[2] )
 242                         continue;
 243
 244                 // Check final DWORD
 245                 j = iface->SubnetBits / 32;
 246                 i = iface->SubnetBits % 32;
 247                 netmask = IPv4_Netmask( iface->SubnetBits % 32 );
 248
 249                 // Check the last bit of the netmask
 250                 if( (Address.L[j] >> i) != (thisAddr->L[j] >> i) )      continue;
 251
 252                 // Check that the host portion is one
 253                 if( (Address.L[j] & ~netmask) != (0xFFFFFFFF & ~netmask) )      continue;
 254                 if( j >= 2 && Address.L[3] != 0xFFFFFFFF)       continue;
 255                 if( j >= 1 && Address.L[2] != 0xFFFFFFFF)       continue;
 256                 if( j >= 0 && Address.L[1] != 0xFFFFFFFF)       continue;
 257
 258                 return iface;
 259         }
 260         return NULL;
 261 }