reactos/drivers/lib/ip/network/receive.c

   1 /*
   2  * COPYRIGHT:   See COPYING in the top level directory
   3  * PROJECT:     ReactOS TCP/IP protocol driver
   4  * FILE:        network/receive.c
   5  * PURPOSE:     Internet Protocol receive routines
   6  * PROGRAMMERS: Casper S. Hornstrup (chorns@users.sourceforge.net)
   7  * NOTES:       The IP datagram reassembly algorithm is taken from
   8  *              from RFC 815
   9  * REVISIONS:
  10  *   CSH 01/08-2000 Created
  11  */
  12
  13 #include "precomp.h"
  14
  15 LIST_ENTRY ReassemblyListHead;
  16 KSPIN_LOCK ReassemblyListLock;
  17 NPAGED_LOOKASIDE_LIST IPDRList;
  18 NPAGED_LOOKASIDE_LIST IPFragmentList;
  19 NPAGED_LOOKASIDE_LIST IPHoleList;
  20
  21 VOID ReflectPacketComplete(
  22     PVOID Context,
  23     PNDIS_PACKET Packet,
  24     NDIS_STATUS Status ) {
  25 }
  26
  27 PIPDATAGRAM_HOLE CreateHoleDescriptor(
  28   ULONG First,
  29   ULONG Last)
  30 /*
  31  * FUNCTION: Returns a pointer to a IP datagram hole descriptor
  32  * ARGUMENTS:
  33  *     First = Offset of first octet of the hole
  34  *     Last  = Offset of last octet of the hole
  35  * RETURNS:
  36  *     Pointer to descriptor, NULL if there was not enough free
  37  *     resources
  38  */
  39 {
  40         PIPDATAGRAM_HOLE Hole;
  41
  42         TI_DbgPrint(DEBUG_IP, ("Called. First (%d)  Last (%d).\n", First, Last));
  43
  44         Hole = TcpipAllocateFromNPagedLookasideList(&IPHoleList);
  45         if (!Hole) {
  46             TI_DbgPrint(MIN_TRACE, ("Insufficient resources.\n"));
  47             return NULL;
  48         }
  49
  50         Hole->First = First;
  51         Hole->Last  = Last;
  52
  53         TI_DbgPrint(DEBUG_IP, ("Returning hole descriptor at (0x%X).\n", Hole));
  54
  55         return Hole;
  56 }
  57
  58
  59 VOID FreeIPDR(
  60   PIPDATAGRAM_REASSEMBLY IPDR)
  61 /*
  62  * FUNCTION: Frees an IP datagram reassembly structure
  63  * ARGUMENTS:
  64  *     IPDR = Pointer to IP datagram reassembly structure
  65  */
  66 {
  67   PLIST_ENTRY CurrentEntry;
  68   PLIST_ENTRY NextEntry;
  69   PIPDATAGRAM_HOLE CurrentH;
  70   PIP_FRAGMENT CurrentF;
  71
  72   TI_DbgPrint(DEBUG_IP, ("Freeing IP datagram reassembly descriptor (0x%X).\n", IPDR));
  73
  74   /* Free all descriptors */
  75   CurrentEntry = IPDR->HoleListHead.Flink;
  76   while (CurrentEntry != &IPDR->HoleListHead) {
  77     NextEntry = CurrentEntry->Flink;
  78           CurrentH = CONTAINING_RECORD(CurrentEntry, IPDATAGRAM_HOLE, ListEntry);
  79     /* Unlink it from the list */
  80     RemoveEntryList(CurrentEntry);
  81
  82     TI_DbgPrint(DEBUG_IP, ("Freeing hole descriptor at (0x%X).\n", CurrentH));
  83
  84     /* And free the hole descriptor */
  85     TcpipFreeToNPagedLookasideList(&IPHoleList, CurrentH);
  86
  87     CurrentEntry = NextEntry;
  88   }
  89
  90   /* Free all fragments */
  91   CurrentEntry = IPDR->FragmentListHead.Flink;
  92   while (CurrentEntry != &IPDR->FragmentListHead) {
  93     NextEntry = CurrentEntry->Flink;
  94           CurrentF = CONTAINING_RECORD(CurrentEntry, IP_FRAGMENT, ListEntry);
  95     /* Unlink it from the list */
  96     RemoveEntryList(CurrentEntry);
  97
  98     TI_DbgPrint(DEBUG_IP, ("Freeing fragment data at (0x%X).\n", CurrentF->Data));
  99
 100     /* Free the fragment data buffer */
 101     exFreePool(CurrentF->Data);
 102
 103     TI_DbgPrint(DEBUG_IP, ("Freeing fragment at (0x%X).\n", CurrentF));
 104
 105     /* And free the fragment descriptor */
 106     TcpipFreeToNPagedLookasideList(&IPFragmentList, CurrentF);
 107     CurrentEntry = NextEntry;
 108   }
 109
 110   TI_DbgPrint(DEBUG_IP, ("Freeing IPDR data at (0x%X).\n", IPDR));
 111
 112   TcpipFreeToNPagedLookasideList(&IPDRList, IPDR);
 113 }
 114
 115
 116 VOID RemoveIPDR(
 117   PIPDATAGRAM_REASSEMBLY IPDR)
 118 /*
 119  * FUNCTION: Removes an IP datagram reassembly structure from the global list
 120  * ARGUMENTS:
 121  *     IPDR = Pointer to IP datagram reassembly structure
 122  */
 123 {
 124   KIRQL OldIrql;
 125
 126   TI_DbgPrint(DEBUG_IP, ("Removing IPDR at (0x%X).\n", IPDR));
 127
 128   TcpipAcquireSpinLock(&ReassemblyListLock, &OldIrql);
 129   RemoveEntryList(&IPDR->ListEntry);
 130   TcpipReleaseSpinLock(&ReassemblyListLock, OldIrql);
 131 }
 132
 133
 134 PIPDATAGRAM_REASSEMBLY GetReassemblyInfo(
 135   PIP_PACKET IPPacket)
 136 /*
 137  * FUNCTION: Returns a pointer to an IP datagram reassembly structure
 138  * ARGUMENTS:
 139  *     IPPacket = Pointer to IP packet
 140  * NOTES:
 141  *     A datagram is identified by four paramters, which are
 142  *     Source and destination address, protocol number and
 143  *     identification number
 144  */
 145 {
 146   KIRQL OldIrql;
 147   PLIST_ENTRY CurrentEntry;
 148   PIPDATAGRAM_REASSEMBLY Current;
 149   PIPv4_HEADER Header = (PIPv4_HEADER)IPPacket->Header;
 150
 151   TI_DbgPrint(DEBUG_IP, ("Searching for IPDR for IP packet at (0x%X).\n", IPPacket));
 152
 153   TcpipAcquireSpinLock(&ReassemblyListLock, &OldIrql);
 154
 155   /* FIXME: Assume IPv4 */
 156
 157   CurrentEntry = ReassemblyListHead.Flink;
 158   while (CurrentEntry != &ReassemblyListHead) {
 159           Current = CONTAINING_RECORD(CurrentEntry, IPDATAGRAM_REASSEMBLY, ListEntry);
 160     if (AddrIsEqual(&IPPacket->SrcAddr, &Current->SrcAddr) &&
 161       (Header->Id == Current->Id) &&
 162       (Header->Protocol == Current->Protocol) &&
 163       (AddrIsEqual(&IPPacket->DstAddr, &Current->DstAddr))) {
 164       TcpipReleaseSpinLock(&ReassemblyListLock, OldIrql);
 165
 166       return Current;
 167     }
 168     CurrentEntry = CurrentEntry->Flink;
 169   }
 170
 171   TcpipReleaseSpinLock(&ReassemblyListLock, OldIrql);
 172
 173   return NULL;
 174 }
 175
 176
 177 PIP_PACKET ReassembleDatagram(
 178   PIPDATAGRAM_REASSEMBLY IPDR)
 179 /*
 180  * FUNCTION: Reassembles an IP datagram
 181  * ARGUMENTS:
 182  *     IPDR = Pointer to IP datagram reassembly structure
 183  * NOTES:
 184  *     This routine concatenates fragments into a complete IP datagram.
 185  *     The lock is held when this routine is called
 186  * RETURNS:
 187  *     Pointer to IP packet, NULL if there was not enough free resources
 188  * NOTES:
 189  *     At this point, header is expected to point to the IP header
 190  */
 191 {
 192   PIP_PACKET IPPacket;
 193   PLIST_ENTRY CurrentEntry;
 194   PIP_FRAGMENT Current;
 195   PVOID Data;
 196
 197   TI_DbgPrint(DEBUG_IP, ("Reassembling datagram from IPDR at (0x%X).\n", IPDR));
 198   TI_DbgPrint(DEBUG_IP, ("IPDR->HeaderSize = %d\n", IPDR->HeaderSize));
 199   TI_DbgPrint(DEBUG_IP, ("IPDR->DataSize = %d\n", IPDR->DataSize));
 200
 201   TI_DbgPrint(DEBUG_IP, ("Fragment header:\n"));
 202   //OskitDumpBuffer((PCHAR)IPDR->IPv4Header, IPDR->HeaderSize);
 203
 204   /* FIXME: Assume IPv4 */
 205   IPPacket = IPCreatePacket(IP_ADDRESS_V4);
 206   if (!IPPacket)
 207     return NULL;
 208
 209   IPPacket->TotalSize  = IPDR->HeaderSize + IPDR->DataSize;
 210   IPPacket->ContigSize = IPPacket->TotalSize;
 211   IPPacket->HeaderSize = IPDR->HeaderSize;
 212   /*IPPacket->Position   = IPDR->HeaderSize;*/
 213
 214   RtlCopyMemory(&IPPacket->SrcAddr, &IPDR->SrcAddr, sizeof(IP_ADDRESS));
 215   RtlCopyMemory(&IPPacket->DstAddr, &IPDR->DstAddr, sizeof(IP_ADDRESS));
 216
 217   /* Allocate space for full IP datagram */
 218   IPPacket->Header = exAllocatePool(NonPagedPool, IPPacket->TotalSize);
 219   if (!IPPacket->Header) {
 220     TI_DbgPrint(MIN_TRACE, ("Insufficient resources.\n"));
 221     (*IPPacket->Free)(IPPacket);
 222     return NULL;
 223   }
 224
 225   /* Copy the header into the buffer */
 226   RtlCopyMemory(IPPacket->Header, &IPDR->IPv4Header, IPDR->HeaderSize);
 227
 228   Data = (PVOID)((ULONG_PTR)IPPacket->Header + IPDR->HeaderSize);
 229   IPPacket->Data = Data;
 230
 231   /* Copy data from all fragments into buffer */
 232   CurrentEntry = IPDR->FragmentListHead.Flink;
 233   while (CurrentEntry != &IPDR->FragmentListHead) {
 234     Current = CONTAINING_RECORD(CurrentEntry, IP_FRAGMENT, ListEntry);
 235
 236     TI_DbgPrint(DEBUG_IP, ("Copying (%d) bytes of fragment data from (0x%X) to offset (%d).\n",
 237       Current->Size, Data, Current->Offset));
 238     /* Copy fragment data to the destination buffer at the correct offset */
 239     RtlCopyMemory((PVOID)((ULONG_PTR)Data + Current->Offset),
 240                   Current->Data,
 241                   Current->Size);
 242     //OskitDumpBuffer( Data, Current->Offset + Current->Size );
 243     CurrentEntry = CurrentEntry->Flink;
 244   }
 245
 246   return IPPacket;
 247 }
 248
 249
 250 __inline VOID Cleanup(
 251   PKSPIN_LOCK Lock,
 252   KIRQL OldIrql,
 253   PIPDATAGRAM_REASSEMBLY IPDR,
 254   PVOID Buffer OPTIONAL)
 255 /*
 256  * FUNCTION: Performs cleaning operations on errors
 257  * ARGUMENTS:
 258  *     Lock     = Pointer to spin lock to be released
 259  *     OldIrql  = Value of IRQL when spin lock was acquired
 260  *     IPDR     = Pointer to IP datagram reassembly structure to free
 261  *     Buffer   = Optional pointer to a buffer to free
 262  */
 263 {
 264   TI_DbgPrint(MIN_TRACE, ("Insufficient resources.\n"));
 265
 266   TcpipReleaseSpinLock(Lock, OldIrql);
 267   RemoveIPDR(IPDR);
 268   FreeIPDR(IPDR);
 269   if (Buffer)
 270     exFreePool(Buffer);
 271 }
 272
 273
 274 VOID ProcessFragment(
 275   PIP_INTERFACE IF,
 276   PIP_PACKET IPPacket)
 277 /*
 278  * FUNCTION: Processes an IP datagram or fragment
 279  * ARGUMENTS:
 280  *     IF       = Pointer to IP interface packet was receive on
 281  *     IPPacket = Pointer to IP packet
 282  * NOTES:
 283  *     This routine reassembles fragments and, if a whole datagram can
 284  *     be assembled, passes the datagram on to the IP protocol dispatcher
 285  */
 286 {
 287   KIRQL OldIrql;
 288   PIPDATAGRAM_REASSEMBLY IPDR;
 289   PLIST_ENTRY CurrentEntry;
 290   PIPDATAGRAM_HOLE Hole, NewHole;
 291   USHORT FragFirst;
 292   USHORT FragLast;
 293   BOOLEAN MoreFragments;
 294   PIPv4_HEADER IPv4Header;
 295   PIP_PACKET Datagram;
 296   PIP_FRAGMENT Fragment;
 297
 298   /* FIXME: Assume IPv4 */
 299
 300   IPv4Header = (PIPv4_HEADER)IPPacket->Header;
 301
 302   /* Check if we already have an reassembly structure for this datagram */
 303   IPDR = GetReassemblyInfo(IPPacket);
 304   if (IPDR) {
 305     TI_DbgPrint(DEBUG_IP, ("Continueing assembly.\n"));
 306     /* We have a reassembly structure */
 307     TcpipAcquireSpinLock(&IPDR->Lock, &OldIrql);
 308     CurrentEntry = IPDR->HoleListHead.Flink;
 309     Hole = CONTAINING_RECORD(CurrentEntry, IPDATAGRAM_HOLE, ListEntry);
 310   } else {
 311     TI_DbgPrint(DEBUG_IP, ("Starting new assembly.\n"));
 312
 313     /* We don't have a reassembly structure, create one */
 314     IPDR = TcpipAllocateFromNPagedLookasideList(&IPDRList);
 315     if (!IPDR)
 316       /* We don't have the resources to process this packet, discard it */
 317       return;
 318
 319     /* Create a descriptor spanning from zero to infinity.
 320        Actually, we use a value slightly greater than the
 321        maximum number of octets an IP datagram can contain */
 322     Hole = CreateHoleDescriptor(0, 65536);
 323     if (!Hole) {
 324       /* We don't have the resources to process this packet, discard it */
 325       TcpipFreeToNPagedLookasideList(&IPDRList, IPDR);
 326       return;
 327     }
 328     AddrInitIPv4(&IPDR->SrcAddr, IPv4Header->SrcAddr);
 329     AddrInitIPv4(&IPDR->DstAddr, IPv4Header->DstAddr);
 330     IPDR->Id         = IPv4Header->Id;
 331     IPDR->Protocol   = IPv4Header->Protocol;
 332     InitializeListHead(&IPDR->FragmentListHead);
 333     InitializeListHead(&IPDR->HoleListHead);
 334     InsertTailList(&IPDR->HoleListHead, &Hole->ListEntry);
 335     CurrentEntry = IPDR->HoleListHead.Flink;
 336
 337     TcpipInitializeSpinLock(&IPDR->Lock);
 338
 339     TcpipAcquireSpinLock(&IPDR->Lock, &OldIrql);
 340
 341     /* Update the reassembly list */
 342     TcpipInterlockedInsertTailList(
 343         &ReassemblyListHead,
 344         &IPDR->ListEntry,
 345         &ReassemblyListLock);
 346   }
 347
 348   FragFirst     = (WN2H(IPv4Header->FlagsFragOfs) & IPv4_FRAGOFS_MASK) << 3;
 349   FragLast      = FragFirst + WN2H(IPv4Header->TotalLength);
 350   MoreFragments = (WN2H(IPv4Header->FlagsFragOfs) & IPv4_MF_MASK) > 0;
 351
 352   for (;;) {
 353     if (CurrentEntry == &IPDR->HoleListHead)
 354       /* No more entries */
 355       break;
 356
 357     TI_DbgPrint(DEBUG_IP, ("Comparing Fragment (%d,%d) to Hole (%d,%d).\n",
 358       FragFirst, FragLast, Hole->First, Hole->Last));
 359
 360     if ((FragFirst > Hole->Last) || (FragLast < Hole->First)) {
 361       TI_DbgPrint(MID_TRACE, ("No overlap.\n"));
 362       /* The fragment does not overlap with the hole, try next
 363          descriptor in the list */
 364
 365       CurrentEntry = CurrentEntry->Flink;
 366       if (CurrentEntry != &IPDR->HoleListHead)
 367           Hole = CONTAINING_RECORD(CurrentEntry, IPDATAGRAM_HOLE, ListEntry);
 368       continue;
 369     }
 370
 371     /* The fragment overlap with the hole, unlink the descriptor */
 372     RemoveEntryList(CurrentEntry);
 373
 374     if (FragFirst > Hole->First) {
 375       NewHole = CreateHoleDescriptor(Hole->First, FragLast - 1);
 376       if (!NewHole) {
 377         /* We don't have the resources to process this packet, discard it */
 378         Cleanup(&IPDR->Lock, OldIrql, IPDR, Hole);
 379         return;
 380       }
 381
 382       /* Put the new descriptor in the list */
 383       InsertTailList(&IPDR->HoleListHead, &NewHole->ListEntry);
 384     }
 385
 386     if ((FragLast < Hole->Last) && (MoreFragments)) {
 387       /* We can reuse the descriptor for the new hole */
 388                   Hole->First = FragLast + 1;
 389
 390                   /* Put the new hole descriptor in the list */
 391       InsertTailList(&IPDR->HoleListHead, &Hole->ListEntry);
 392     } else
 393       TcpipFreeToNPagedLookasideList(&IPHoleList, Hole);
 394
 395     /* If this is the first fragment, save the IP header */
 396     if (FragFirst == 0) {
 397       TI_DbgPrint(DEBUG_IP, ("First fragment found. Header buffer is at (0x%X). "
 398         "Header size is (%d).\n", &IPDR->IPv4Header, IPPacket->HeaderSize));
 399
 400       RtlCopyMemory(&IPDR->IPv4Header, IPPacket->Header, IPPacket->HeaderSize);
 401       IPDR->HeaderSize = IPPacket->HeaderSize;
 402     }
 403
 404     /* Create a buffer, copy the data into it and put it
 405        in the fragment list */
 406
 407     Fragment = TcpipAllocateFromNPagedLookasideList(&IPFragmentList);
 408     if (!Fragment) {
 409       /* We don't have the resources to process this packet, discard it */
 410       Cleanup(&IPDR->Lock, OldIrql, IPDR, NULL);
 411       return;
 412     }
 413
 414     TI_DbgPrint(DEBUG_IP, ("Fragment descriptor allocated at (0x%X).\n", Fragment));
 415
 416     Fragment->Size = IPPacket->TotalSize - IPPacket->HeaderSize;
 417     Fragment->Data = exAllocatePool(NonPagedPool, Fragment->Size);
 418     if (!Fragment->Data) {
 419       /* We don't have the resources to process this packet, discard it */
 420       Cleanup(&IPDR->Lock, OldIrql, IPDR, Fragment);
 421       return;
 422     }
 423
 424     /* Position here is an offset from the NdisPacket start, not the header */
 425     TI_DbgPrint(DEBUG_IP, ("Fragment data buffer allocated at (0x%X)  Size (%d) Pos (%d).\n",
 426                            Fragment->Data, Fragment->Size, IPPacket->Position));
 427
 428     /* Copy datagram data into fragment buffer */
 429     CopyPacketToBuffer(Fragment->Data,
 430                        IPPacket->NdisPacket,
 431                        IPPacket->Position,
 432                        Fragment->Size);
 433     Fragment->Offset = FragFirst;
 434
 435     /* If this is the last fragment, compute and save the datagram data size */
 436     if (!MoreFragments)
 437       IPDR->DataSize = FragFirst + Fragment->Size;
 438
 439     /* Put the fragment in the list */
 440     InsertTailList(&IPDR->FragmentListHead, &Fragment->ListEntry);
 441           break;
 442   }
 443
 444   TI_DbgPrint(DEBUG_IP, ("Done searching for hole descriptor.\n"));
 445
 446   if (IsListEmpty(&IPDR->HoleListHead)) {
 447     /* Hole list is empty which means a complete datagram can be assembled.
 448        Assemble the datagram and pass it to an upper layer protocol */
 449
 450     TI_DbgPrint(DEBUG_IP, ("Complete datagram received.\n"));
 451
 452     Datagram = ReassembleDatagram(IPDR);
 453
 454     RemoveIPDR(IPDR);
 455     TcpipReleaseSpinLock(&IPDR->Lock, OldIrql);
 456
 457     FreeIPDR(IPDR);
 458
 459     if (!Datagram)
 460       /* Not enough free resources, discard the packet */
 461       return;
 462
 463     DISPLAY_IP_PACKET(Datagram);
 464
 465     /* Give the packet to the protocol dispatcher */
 466     IPDispatchProtocol(IF, Datagram);
 467
 468     /* We're done with this datagram */
 469     exFreePool(Datagram->Header);
 470     TI_DbgPrint(MAX_TRACE, ("Freeing datagram at (0x%X).\n", Datagram));
 471     (*Datagram->Free)(Datagram);
 472   } else
 473     TcpipReleaseSpinLock(&IPDR->Lock, OldIrql);
 474 }
 475
 476
 477 VOID IPFreeReassemblyList(
 478   VOID)
 479 /*
 480  * FUNCTION: Frees all IP datagram reassembly structures in the list
 481  */
 482 {
 483   KIRQL OldIrql;
 484   PLIST_ENTRY CurrentEntry;
 485   PIPDATAGRAM_REASSEMBLY Current;
 486
 487   TcpipAcquireSpinLock(&ReassemblyListLock, &OldIrql);
 488
 489   CurrentEntry = ReassemblyListHead.Flink;
 490   while (CurrentEntry != &ReassemblyListHead) {
 491           Current = CONTAINING_RECORD(CurrentEntry, IPDATAGRAM_REASSEMBLY, ListEntry);
 492     /* Unlink it from the list */
 493     RemoveEntryList(CurrentEntry);
 494
 495     /* And free the descriptor */
 496     FreeIPDR(Current);
 497
 498     CurrentEntry = CurrentEntry->Flink;
 499   }
 500
 501   TcpipReleaseSpinLock(&ReassemblyListLock, OldIrql);
 502 }
 503
 504
 505 VOID IPDatagramReassemblyTimeout(
 506   VOID)
 507 /*
 508  * FUNCTION: IP datagram reassembly timeout handler
 509  * NOTES:
 510  *     This routine is called by IPTimeout to free any resources used
 511  *     to hold IP fragments that have taken too long to reassemble
 512  */
 513 {
 514 }
 515
 516 VOID IPv4Receive(PIP_INTERFACE IF, PIP_PACKET IPPacket)
 517 /*
 518  * FUNCTION: Receives an IPv4 datagram (or fragment)
 519  * ARGUMENTS:
 520  *     Context  = Pointer to context information (IP_INTERFACE)
 521  *     IPPacket = Pointer to IP packet
 522  */
 523 {
 524     TI_DbgPrint(DEBUG_IP, ("Received IPv4 datagram.\n"));
 525
 526     IPPacket->HeaderSize = (((PIPv4_HEADER)IPPacket->Header)->VerIHL & 0x0F) << 2;
 527     TI_DbgPrint(DEBUG_IP, ("IPPacket->HeaderSize = %d\n", IPPacket->HeaderSize));
 528
 529     if (IPPacket->HeaderSize > IPv4_MAX_HEADER_SIZE) {
 530         TI_DbgPrint
 531             (MIN_TRACE,
 532              ("Datagram received with incorrect header size (%d).\n",
 533               IPPacket->HeaderSize));
 534         /* Discard packet */
 535         return;
 536     }
 537
 538     /* Checksum IPv4 header */
 539     if (!IPv4CorrectChecksum(IPPacket->Header, IPPacket->HeaderSize)) {
 540         TI_DbgPrint
 541             (MIN_TRACE,
 542              ("Datagram received with bad checksum. Checksum field (0x%X)\n",
 543               WN2H(((PIPv4_HEADER)IPPacket->Header)->Checksum)));
 544         /* Discard packet */
 545         return;
 546     }
 547
 548     IPPacket->TotalSize = WN2H(((PIPv4_HEADER)IPPacket->Header)->TotalLength);
 549
 550     AddrInitIPv4(&IPPacket->SrcAddr, ((PIPv4_HEADER)IPPacket->Header)->SrcAddr);
 551     AddrInitIPv4(&IPPacket->DstAddr, ((PIPv4_HEADER)IPPacket->Header)->DstAddr);
 552
 553     IPPacket->Position += IPPacket->HeaderSize;
 554     IPPacket->Data     = (PVOID)((ULONG_PTR)IPPacket->Header + IPPacket->HeaderSize);
 555
 556     TI_DbgPrint(MID_TRACE,("IPPacket->Position = %d\n",
 557                            IPPacket->Position));
 558
 559     //OskitDumpBuffer(IPPacket->Header, IPPacket->TotalSize);
 560
 561     /* FIXME: Possibly forward packets with multicast addresses */
 562
 563     /* FIXME: Should we allow packets to be received on the wrong interface? */
 564     /* XXX Find out if this packet is destined for us */
 565     ProcessFragment(IF, IPPacket);
 566 #if 0
 567     } else {
 568         /* This packet is not destined for us. If we are a router,
 569            try to find a route and forward the packet */
 570
 571         /* FIXME: Check if acting as a router */
 572         NCE = NULL;
 573         if (NCE) {
 574             PROUTE_CACHE_NODE RCN;
 575
 576             /* FIXME: Possibly fragment datagram */
 577             /* Forward the packet */
 578             if(!RouteGetRouteToDestination( &IPPacket->DstAddr, NULL, &RCN ))
 579                 IPSendDatagram(IPPacket, RCN, ReflectPacketComplete, IPPacket);
 580         } else {
 581             TI_DbgPrint(MIN_TRACE, ("No route to destination (0x%X).\n",
 582                                     IPPacket->DstAddr.Address.IPv4Address));
 583
 584             /* FIXME: Send ICMP error code */
 585         }
 586     }
 587 #endif
 588 }
 589
 590
 591 VOID IPReceive( PIP_INTERFACE IF, PIP_PACKET IPPacket )
 592 /*
 593  * FUNCTION: Receives an IP datagram (or fragment)
 594  * ARGUMENTS:
 595  *     IF       = Interface
 596  *     IPPacket = Pointer to IP packet
 597  */
 598 {
 599   UINT Version;
 600
 601   /* Check that IP header has a supported version */
 602   Version = (((PIPv4_HEADER)IPPacket->Header)->VerIHL >> 4);
 603
 604   switch (Version) {
 605   case 4:
 606     IPPacket->Type = IP_ADDRESS_V4;
 607     IPv4Receive(IF, IPPacket);
 608     break;
 609   case 6:
 610     IPPacket->Type = IP_ADDRESS_V6;
 611     TI_DbgPrint(MAX_TRACE, ("Datagram of type IPv6 discarded.\n"));
 612     return;
 613   default:
 614           TI_DbgPrint(MIN_TRACE, ("Datagram has an unsupported IP version %d.\n", Version));
 615     return;
 616   }
 617 }
 618
 619 /* EOF */