reactos/lib/drivers/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 PIPDATAGRAM_HOLE CreateHoleDescriptor(
  22   ULONG First,
  23   ULONG Last)
  24 /*
  25  * FUNCTION: Returns a pointer to a IP datagram hole descriptor
  26  * ARGUMENTS:
  27  *     First = Offset of first octet of the hole
  28  *     Last  = Offset of last octet of the hole
  29  * RETURNS:
  30  *     Pointer to descriptor, NULL if there was not enough free
  31  *     resources
  32  */
  33 {
  34         PIPDATAGRAM_HOLE Hole;
  35
  36         TI_DbgPrint(DEBUG_IP, ("Called. First (%d)  Last (%d).\n", First, Last));
  37
  38         Hole = ExAllocateFromNPagedLookasideList(&IPHoleList);
  39         if (!Hole) {
  40             TI_DbgPrint(MIN_TRACE, ("Insufficient resources.\n"));
  41             return NULL;
  42         }
  43
  44         Hole->First = First;
  45         Hole->Last  = Last;
  46
  47         TI_DbgPrint(DEBUG_IP, ("Returning hole descriptor at (0x%X).\n", Hole));
  48
  49         return Hole;
  50 }
  51
  52
  53 VOID FreeIPDR(
  54   PIPDATAGRAM_REASSEMBLY IPDR)
  55 /*
  56  * FUNCTION: Frees an IP datagram reassembly structure
  57  * ARGUMENTS:
  58  *     IPDR = Pointer to IP datagram reassembly structure
  59  */
  60 {
  61   PLIST_ENTRY CurrentEntry;
  62   PLIST_ENTRY NextEntry;
  63   PIPDATAGRAM_HOLE CurrentH;
  64   PIP_FRAGMENT CurrentF;
  65
  66   TI_DbgPrint(DEBUG_IP, ("Freeing IP datagram reassembly descriptor (0x%X).\n", IPDR));
  67
  68   /* Free all descriptors */
  69   CurrentEntry = IPDR->HoleListHead.Flink;
  70   while (CurrentEntry != &IPDR->HoleListHead) {
  71     NextEntry = CurrentEntry->Flink;
  72           CurrentH = CONTAINING_RECORD(CurrentEntry, IPDATAGRAM_HOLE, ListEntry);
  73     /* Unlink it from the list */
  74     RemoveEntryList(CurrentEntry);
  75
  76     TI_DbgPrint(DEBUG_IP, ("Freeing hole descriptor at (0x%X).\n", CurrentH));
  77
  78     /* And free the hole descriptor */
  79     ExFreeToNPagedLookasideList(&IPHoleList, CurrentH);
  80
  81     CurrentEntry = NextEntry;
  82   }
  83
  84   /* Free all fragments */
  85   CurrentEntry = IPDR->FragmentListHead.Flink;
  86   while (CurrentEntry != &IPDR->FragmentListHead) {
  87     NextEntry = CurrentEntry->Flink;
  88           CurrentF = CONTAINING_RECORD(CurrentEntry, IP_FRAGMENT, ListEntry);
  89     /* Unlink it from the list */
  90     RemoveEntryList(CurrentEntry);
  91
  92     TI_DbgPrint(DEBUG_IP, ("Freeing fragment packet at (0x%X).\n", CurrentF->Packet));
  93
  94     /* Free the fragment data buffer */
  95     FreeNdisPacket(CurrentF->Packet);
  96
  97     TI_DbgPrint(DEBUG_IP, ("Freeing fragment at (0x%X).\n", CurrentF));
  98
  99     /* And free the fragment descriptor */
 100     ExFreeToNPagedLookasideList(&IPFragmentList, CurrentF);
 101     CurrentEntry = NextEntry;
 102   }
 103
 104   TI_DbgPrint(DEBUG_IP, ("Freeing IPDR data at (0x%X).\n", IPDR));
 105
 106   ExFreeToNPagedLookasideList(&IPDRList, IPDR);
 107 }
 108
 109
 110 VOID RemoveIPDR(
 111   PIPDATAGRAM_REASSEMBLY IPDR)
 112 /*
 113  * FUNCTION: Removes an IP datagram reassembly structure from the global list
 114  * ARGUMENTS:
 115  *     IPDR = Pointer to IP datagram reassembly structure
 116  */
 117 {
 118   KIRQL OldIrql;
 119
 120   TI_DbgPrint(DEBUG_IP, ("Removing IPDR at (0x%X).\n", IPDR));
 121
 122   TcpipAcquireSpinLock(&ReassemblyListLock, &OldIrql);
 123   RemoveEntryList(&IPDR->ListEntry);
 124   TcpipReleaseSpinLock(&ReassemblyListLock, OldIrql);
 125 }
 126
 127
 128 PIPDATAGRAM_REASSEMBLY GetReassemblyInfo(
 129   PIP_PACKET IPPacket)
 130 /*
 131  * FUNCTION: Returns a pointer to an IP datagram reassembly structure
 132  * ARGUMENTS:
 133  *     IPPacket = Pointer to IP packet
 134  * NOTES:
 135  *     A datagram is identified by four paramters, which are
 136  *     Source and destination address, protocol number and
 137  *     identification number
 138  */
 139 {
 140   KIRQL OldIrql;
 141   PLIST_ENTRY CurrentEntry;
 142   PIPDATAGRAM_REASSEMBLY Current;
 143   PIPv4_HEADER Header = (PIPv4_HEADER)IPPacket->Header;
 144
 145   TI_DbgPrint(DEBUG_IP, ("Searching for IPDR for IP packet at (0x%X).\n", IPPacket));
 146
 147   TcpipAcquireSpinLock(&ReassemblyListLock, &OldIrql);
 148
 149   /* FIXME: Assume IPv4 */
 150
 151   CurrentEntry = ReassemblyListHead.Flink;
 152   while (CurrentEntry != &ReassemblyListHead) {
 153           Current = CONTAINING_RECORD(CurrentEntry, IPDATAGRAM_REASSEMBLY, ListEntry);
 154     if (AddrIsEqual(&IPPacket->SrcAddr, &Current->SrcAddr) &&
 155       (Header->Id == Current->Id) &&
 156       (Header->Protocol == Current->Protocol) &&
 157       (AddrIsEqual(&IPPacket->DstAddr, &Current->DstAddr))) {
 158       TcpipReleaseSpinLock(&ReassemblyListLock, OldIrql);
 159
 160       return Current;
 161     }
 162     CurrentEntry = CurrentEntry->Flink;
 163   }
 164
 165   TcpipReleaseSpinLock(&ReassemblyListLock, OldIrql);
 166
 167   return NULL;
 168 }
 169
 170
 171 BOOLEAN
 172 ReassembleDatagram(
 173   PIP_PACKET             IPPacket,
 174   PIPDATAGRAM_REASSEMBLY IPDR)
 175 /*
 176  * FUNCTION: Reassembles an IP datagram
 177  * ARGUMENTS:
 178  *     IPDR = Pointer to IP datagram reassembly structure
 179  * NOTES:
 180  *     This routine concatenates fragments into a complete IP datagram.
 181  *     The lock is held when this routine is called
 182  * RETURNS:
 183  *     Pointer to IP packet, NULL if there was not enough free resources
 184  * NOTES:
 185  *     At this point, header is expected to point to the IP header
 186  */
 187 {
 188   PLIST_ENTRY CurrentEntry;
 189   PIP_FRAGMENT Fragment;
 190   PCHAR Data;
 191
 192   TI_DbgPrint(DEBUG_IP, ("Reassembling datagram from IPDR at (0x%X).\n", IPDR));
 193   TI_DbgPrint(DEBUG_IP, ("IPDR->HeaderSize = %d\n", IPDR->HeaderSize));
 194   TI_DbgPrint(DEBUG_IP, ("IPDR->DataSize = %d\n", IPDR->DataSize));
 195
 196   IPPacket->TotalSize  = IPDR->HeaderSize + IPDR->DataSize;
 197   IPPacket->ContigSize = IPPacket->TotalSize;
 198   IPPacket->HeaderSize = IPDR->HeaderSize;
 199
 200   RtlCopyMemory(&IPPacket->SrcAddr, &IPDR->SrcAddr, sizeof(IP_ADDRESS));
 201   RtlCopyMemory(&IPPacket->DstAddr, &IPDR->DstAddr, sizeof(IP_ADDRESS));
 202
 203   /* Allocate space for full IP datagram */
 204   IPPacket->Header = ExAllocatePoolWithTag(NonPagedPool, IPPacket->TotalSize, PACKET_BUFFER_TAG);
 205   if (!IPPacket->Header) {
 206     TI_DbgPrint(MIN_TRACE, ("Insufficient resources.\n"));
 207     (*IPPacket->Free)(IPPacket);
 208     return FALSE;
 209   }
 210
 211   /* Copy the header into the buffer */
 212   RtlCopyMemory(IPPacket->Header, &IPDR->IPv4Header, IPDR->HeaderSize);
 213
 214   Data = (PVOID)((ULONG_PTR)IPPacket->Header + IPDR->HeaderSize);
 215   IPPacket->Data = Data;
 216
 217   /* Copy data from all fragments into buffer */
 218   CurrentEntry = IPDR->FragmentListHead.Flink;
 219   while (CurrentEntry != &IPDR->FragmentListHead) {
 220     Fragment = CONTAINING_RECORD(CurrentEntry, IP_FRAGMENT, ListEntry);
 221
 222     /* Copy fragment data into datagram buffer */
 223     CopyPacketToBuffer(Data + Fragment->Offset,
 224                        Fragment->Packet,
 225                        Fragment->PacketOffset,
 226                        Fragment->Size);
 227
 228     CurrentEntry = CurrentEntry->Flink;
 229   }
 230
 231   return TRUE;
 232 }
 233
 234
 235 __inline VOID Cleanup(
 236   PKSPIN_LOCK Lock,
 237   KIRQL OldIrql,
 238   PIPDATAGRAM_REASSEMBLY IPDR)
 239 /*
 240  * FUNCTION: Performs cleaning operations on errors
 241  * ARGUMENTS:
 242  *     Lock     = Pointer to spin lock to be released
 243  *     OldIrql  = Value of IRQL when spin lock was acquired
 244  *     IPDR     = Pointer to IP datagram reassembly structure to free
 245  *     Buffer   = Optional pointer to a buffer to free
 246  */
 247 {
 248   TI_DbgPrint(MIN_TRACE, ("Insufficient resources.\n"));
 249
 250   TcpipReleaseSpinLock(Lock, OldIrql);
 251   RemoveIPDR(IPDR);
 252   FreeIPDR(IPDR);
 253 }
 254
 255
 256 VOID ProcessFragment(
 257   PIP_INTERFACE IF,
 258   PIP_PACKET IPPacket)
 259 /*
 260  * FUNCTION: Processes an IP datagram or fragment
 261  * ARGUMENTS:
 262  *     IF       = Pointer to IP interface packet was receive on
 263  *     IPPacket = Pointer to IP packet
 264  * NOTES:
 265  *     This routine reassembles fragments and, if a whole datagram can
 266  *     be assembled, passes the datagram on to the IP protocol dispatcher
 267  */
 268 {
 269   KIRQL OldIrql;
 270   PIPDATAGRAM_REASSEMBLY IPDR;
 271   PLIST_ENTRY CurrentEntry;
 272   PIPDATAGRAM_HOLE Hole, NewHole;
 273   USHORT FragFirst;
 274   USHORT FragLast;
 275   BOOLEAN MoreFragments;
 276   PIPv4_HEADER IPv4Header;
 277   IP_PACKET Datagram;
 278   PIP_FRAGMENT Fragment;
 279   BOOLEAN Success;
 280
 281   /* FIXME: Assume IPv4 */
 282
 283   IPv4Header = (PIPv4_HEADER)IPPacket->Header;
 284
 285   /* Check if we already have an reassembly structure for this datagram */
 286   IPDR = GetReassemblyInfo(IPPacket);
 287   if (IPDR) {
 288     TI_DbgPrint(DEBUG_IP, ("Continueing assembly.\n"));
 289     /* We have a reassembly structure */
 290     TcpipAcquireSpinLock(&IPDR->Lock, &OldIrql);
 291
 292     /* Reset the timeout since we received a fragment */
 293     IPDR->TimeoutCount = 0;
 294   } else {
 295     TI_DbgPrint(DEBUG_IP, ("Starting new assembly.\n"));
 296
 297     /* We don't have a reassembly structure, create one */
 298     IPDR = ExAllocateFromNPagedLookasideList(&IPDRList);
 299     if (!IPDR)
 300       /* We don't have the resources to process this packet, discard it */
 301       return;
 302
 303     /* Create a descriptor spanning from zero to infinity.
 304        Actually, we use a value slightly greater than the
 305        maximum number of octets an IP datagram can contain */
 306     Hole = CreateHoleDescriptor(0, 65536);
 307     if (!Hole) {
 308       /* We don't have the resources to process this packet, discard it */
 309       ExFreeToNPagedLookasideList(&IPDRList, IPDR);
 310       return;
 311     }
 312     AddrInitIPv4(&IPDR->SrcAddr, IPv4Header->SrcAddr);
 313     AddrInitIPv4(&IPDR->DstAddr, IPv4Header->DstAddr);
 314     IPDR->Id         = IPv4Header->Id;
 315     IPDR->Protocol   = IPv4Header->Protocol;
 316     IPDR->TimeoutCount = 0;
 317     InitializeListHead(&IPDR->FragmentListHead);
 318     InitializeListHead(&IPDR->HoleListHead);
 319     InsertTailList(&IPDR->HoleListHead, &Hole->ListEntry);
 320
 321     TcpipInitializeSpinLock(&IPDR->Lock);
 322
 323     TcpipAcquireSpinLock(&IPDR->Lock, &OldIrql);
 324
 325     /* Update the reassembly list */
 326     TcpipInterlockedInsertTailList(
 327         &ReassemblyListHead,
 328         &IPDR->ListEntry,
 329         &ReassemblyListLock);
 330   }
 331
 332   FragFirst     = (WN2H(IPv4Header->FlagsFragOfs) & IPv4_FRAGOFS_MASK) << 3;
 333   FragLast      = FragFirst + WN2H(IPv4Header->TotalLength);
 334   MoreFragments = (WN2H(IPv4Header->FlagsFragOfs) & IPv4_MF_MASK) > 0;
 335
 336   CurrentEntry = IPDR->HoleListHead.Flink;
 337   for (;;) {
 338     if (CurrentEntry == &IPDR->HoleListHead)
 339         break;
 340
 341     Hole = CONTAINING_RECORD(CurrentEntry, IPDATAGRAM_HOLE, ListEntry);
 342
 343     TI_DbgPrint(DEBUG_IP, ("Comparing Fragment (%d,%d) to Hole (%d,%d).\n",
 344       FragFirst, FragLast, Hole->First, Hole->Last));
 345
 346     if ((FragFirst > Hole->Last) || (FragLast < Hole->First)) {
 347       TI_DbgPrint(MID_TRACE, ("No overlap.\n"));
 348       /* The fragment does not overlap with the hole, try next
 349          descriptor in the list */
 350
 351       CurrentEntry = CurrentEntry->Flink;
 352       continue;
 353     }
 354
 355     /* The fragment overlap with the hole, unlink the descriptor */
 356     RemoveEntryList(CurrentEntry);
 357
 358     if (FragFirst > Hole->First) {
 359       NewHole = CreateHoleDescriptor(Hole->First, FragFirst - 1);
 360       if (!NewHole) {
 361         /* We don't have the resources to process this packet, discard it */
 362         ExFreeToNPagedLookasideList(&IPHoleList, Hole);
 363         Cleanup(&IPDR->Lock, OldIrql, IPDR);
 364         return;
 365       }
 366
 367       /* Put the new descriptor in the list */
 368       InsertTailList(&IPDR->HoleListHead, &NewHole->ListEntry);
 369     }
 370
 371     if ((FragLast < Hole->Last) && MoreFragments) {
 372       NewHole = CreateHoleDescriptor(FragLast + 1, Hole->Last);
 373       if (!NewHole) {
 374         /* We don't have the resources to process this packet, discard it */
 375         ExFreeToNPagedLookasideList(&IPHoleList, Hole);
 376         Cleanup(&IPDR->Lock, OldIrql, IPDR);
 377         return;
 378       }
 379
 380       /* Put the new hole descriptor in the list */
 381       InsertTailList(&IPDR->HoleListHead, &NewHole->ListEntry);
 382     }
 383
 384     ExFreeToNPagedLookasideList(&IPHoleList, Hole);
 385
 386     /* If this is the first fragment, save the IP header */
 387     if (FragFirst == 0) {
 388       TI_DbgPrint(DEBUG_IP, ("First fragment found. Header buffer is at (0x%X). "
 389         "Header size is (%d).\n", &IPDR->IPv4Header, IPPacket->HeaderSize));
 390
 391       RtlCopyMemory(&IPDR->IPv4Header, IPPacket->Header, IPPacket->HeaderSize);
 392       IPDR->HeaderSize = IPPacket->HeaderSize;
 393     }
 394
 395     /* Create a buffer, copy the data into it and put it
 396        in the fragment list */
 397
 398     Fragment = ExAllocateFromNPagedLookasideList(&IPFragmentList);
 399     if (!Fragment) {
 400       /* We don't have the resources to process this packet, discard it */
 401       Cleanup(&IPDR->Lock, OldIrql, IPDR);
 402       return;
 403     }
 404
 405     TI_DbgPrint(DEBUG_IP, ("Fragment descriptor allocated at (0x%X).\n", Fragment));
 406
 407     Fragment->Size = IPPacket->TotalSize - IPPacket->HeaderSize;
 408     Fragment->Packet = IPPacket->NdisPacket;
 409     Fragment->PacketOffset = IPPacket->Position + IPPacket->HeaderSize;
 410     Fragment->Offset = FragFirst;
 411
 412     /* Disassociate the NDIS packet so it isn't freed upon return from IPReceive() */
 413     IPPacket->NdisPacket = NULL;
 414
 415     /* If this is the last fragment, compute and save the datagram data size */
 416     if (!MoreFragments)
 417       IPDR->DataSize = FragFirst + Fragment->Size;
 418
 419     /* Put the fragment in the list */
 420     InsertTailList(&IPDR->FragmentListHead, &Fragment->ListEntry);
 421     break;
 422   }
 423
 424   TI_DbgPrint(DEBUG_IP, ("Done searching for hole descriptor.\n"));
 425
 426   if (IsListEmpty(&IPDR->HoleListHead)) {
 427     /* Hole list is empty which means a complete datagram can be assembled.
 428        Assemble the datagram and pass it to an upper layer protocol */
 429
 430     TI_DbgPrint(DEBUG_IP, ("Complete datagram received.\n"));
 431
 432     /* FIXME: Assumes IPv4 */
 433     IPInitializePacket(&Datagram, IP_ADDRESS_V4);
 434
 435     Success = ReassembleDatagram(&Datagram, IPDR);
 436
 437     RemoveIPDR(IPDR);
 438     TcpipReleaseSpinLock(&IPDR->Lock, OldIrql);
 439
 440     FreeIPDR(IPDR);
 441
 442     if (!Success)
 443       /* Not enough free resources, discard the packet */
 444       return;
 445
 446     DISPLAY_IP_PACKET(&Datagram);
 447
 448     /* Give the packet to the protocol dispatcher */
 449     IPDispatchProtocol(IF, &Datagram);
 450
 451     IF->Stats.InBytes += Datagram.TotalSize;
 452
 453     /* We're done with this datagram */
 454     ExFreePoolWithTag(Datagram.Header, PACKET_BUFFER_TAG);
 455     TI_DbgPrint(MAX_TRACE, ("Freeing datagram at (0x%X).\n", Datagram));
 456     (*Datagram.Free)(&Datagram);
 457   } else
 458     TcpipReleaseSpinLock(&IPDR->Lock, OldIrql);
 459 }
 460
 461
 462 VOID IPFreeReassemblyList(
 463   VOID)
 464 /*
 465  * FUNCTION: Frees all IP datagram reassembly structures in the list
 466  */
 467 {
 468   KIRQL OldIrql;
 469   PLIST_ENTRY CurrentEntry;
 470   PIPDATAGRAM_REASSEMBLY Current;
 471
 472   TcpipAcquireSpinLock(&ReassemblyListLock, &OldIrql);
 473
 474   CurrentEntry = ReassemblyListHead.Flink;
 475   while (CurrentEntry != &ReassemblyListHead) {
 476           Current = CONTAINING_RECORD(CurrentEntry, IPDATAGRAM_REASSEMBLY, ListEntry);
 477     /* Unlink it from the list */
 478     RemoveEntryList(CurrentEntry);
 479
 480     /* And free the descriptor */
 481     FreeIPDR(Current);
 482
 483     CurrentEntry = CurrentEntry->Flink;
 484   }
 485
 486   TcpipReleaseSpinLock(&ReassemblyListLock, OldIrql);
 487 }
 488
 489
 490 VOID IPDatagramReassemblyTimeout(
 491   VOID)
 492 /*
 493  * FUNCTION: IP datagram reassembly timeout handler
 494  * NOTES:
 495  *     This routine is called by IPTimeout to free any resources used
 496  *     to hold IP fragments that have taken too long to reassemble
 497  */
 498 {
 499     PLIST_ENTRY CurrentEntry, NextEntry;
 500     PIPDATAGRAM_REASSEMBLY CurrentIPDR;
 501
 502     TcpipAcquireSpinLockAtDpcLevel(&ReassemblyListLock);
 503
 504     CurrentEntry = ReassemblyListHead.Flink;
 505     while (CurrentEntry != &ReassemblyListHead)
 506     {
 507        NextEntry = CurrentEntry->Flink;
 508        CurrentIPDR = CONTAINING_RECORD(CurrentEntry, IPDATAGRAM_REASSEMBLY, ListEntry);
 509
 510        TcpipAcquireSpinLockAtDpcLevel(&CurrentIPDR->Lock);
 511
 512        if (++CurrentIPDR->TimeoutCount == MAX_TIMEOUT_COUNT)
 513        {
 514            TcpipReleaseSpinLockFromDpcLevel(&CurrentIPDR->Lock);
 515            RemoveEntryList(CurrentEntry);
 516            FreeIPDR(CurrentIPDR);
 517        }
 518        else
 519        {
 520            ASSERT(CurrentIPDR->TimeoutCount < MAX_TIMEOUT_COUNT);
 521            TcpipReleaseSpinLockFromDpcLevel(&CurrentIPDR->Lock);
 522        }
 523
 524        CurrentEntry = NextEntry;
 525     }
 526
 527     TcpipReleaseSpinLockFromDpcLevel(&ReassemblyListLock);
 528 }
 529
 530 VOID IPv4Receive(PIP_INTERFACE IF, PIP_PACKET IPPacket)
 531 /*
 532  * FUNCTION: Receives an IPv4 datagram (or fragment)
 533  * ARGUMENTS:
 534  *     Context  = Pointer to context information (IP_INTERFACE)
 535  *     IPPacket = Pointer to IP packet
 536  */
 537 {
 538     TI_DbgPrint(DEBUG_IP, ("Received IPv4 datagram.\n"));
 539
 540     IPPacket->HeaderSize = (((PIPv4_HEADER)IPPacket->Header)->VerIHL & 0x0F) << 2;
 541     TI_DbgPrint(DEBUG_IP, ("IPPacket->HeaderSize = %d\n", IPPacket->HeaderSize));
 542
 543     if (IPPacket->HeaderSize > IPv4_MAX_HEADER_SIZE) {
 544         TI_DbgPrint
 545             (MIN_TRACE,
 546              ("Datagram received with incorrect header size (%d).\n",
 547               IPPacket->HeaderSize));
 548         /* Discard packet */
 549         return;
 550     }
 551
 552     /* Checksum IPv4 header */
 553     if (!IPv4CorrectChecksum(IPPacket->Header, IPPacket->HeaderSize)) {
 554         TI_DbgPrint
 555             (MIN_TRACE,
 556              ("Datagram received with bad checksum. Checksum field (0x%X)\n",
 557               WN2H(((PIPv4_HEADER)IPPacket->Header)->Checksum)));
 558         /* Discard packet */
 559         return;
 560     }
 561
 562     IPPacket->TotalSize = WN2H(((PIPv4_HEADER)IPPacket->Header)->TotalLength);
 563
 564     AddrInitIPv4(&IPPacket->SrcAddr, ((PIPv4_HEADER)IPPacket->Header)->SrcAddr);
 565     AddrInitIPv4(&IPPacket->DstAddr, ((PIPv4_HEADER)IPPacket->Header)->DstAddr);
 566
 567     IPPacket->Data     = (PVOID)((ULONG_PTR)IPPacket->Header + IPPacket->HeaderSize);
 568
 569     TI_DbgPrint(MID_TRACE,("IPPacket->Position = %d\n",
 570                            IPPacket->Position));
 571
 572     //OskitDumpBuffer(IPPacket->Header, IPPacket->TotalSize);
 573
 574     /* FIXME: Possibly forward packets with multicast addresses */
 575
 576     /* FIXME: Should we allow packets to be received on the wrong interface? */
 577     /* XXX Find out if this packet is destined for us */
 578     ProcessFragment(IF, IPPacket);
 579 #if 0
 580     } else {
 581         /* This packet is not destined for us. If we are a router,
 582            try to find a route and forward the packet */
 583
 584         /* FIXME: Check if acting as a router */
 585         NCE = NULL;
 586         if (NCE) {
 587             PROUTE_CACHE_NODE RCN;
 588
 589             /* FIXME: Possibly fragment datagram */
 590             /* Forward the packet */
 591             if(!RouteGetRouteToDestination( &IPPacket->DstAddr, NULL, &RCN ))
 592                 IPSendDatagram(IPPacket, RCN, ReflectPacketComplete, IPPacket);
 593         } else {
 594             TI_DbgPrint(MIN_TRACE, ("No route to destination (0x%X).\n",
 595                                     IPPacket->DstAddr.Address.IPv4Address));
 596
 597             /* FIXME: Send ICMP error code */
 598         }
 599     }
 600 #endif
 601 }
 602
 603
 604 VOID IPReceive( PIP_INTERFACE IF, PIP_PACKET IPPacket )
 605 /*
 606  * FUNCTION: Receives an IP datagram (or fragment)
 607  * ARGUMENTS:
 608  *     IF       = Interface
 609  *     IPPacket = Pointer to IP packet
 610  */
 611 {
 612   UINT Version;
 613
 614   /* Check that IP header has a supported version */
 615   Version = (((PIPv4_HEADER)IPPacket->Header)->VerIHL >> 4);
 616
 617   switch (Version) {
 618   case 4:
 619     IPPacket->Type = IP_ADDRESS_V4;
 620     IPv4Receive(IF, IPPacket);
 621     break;
 622   case 6:
 623     IPPacket->Type = IP_ADDRESS_V6;
 624     TI_DbgPrint(MAX_TRACE, ("Datagram of type IPv6 discarded.\n"));
 625     break;
 626   default:
 627           TI_DbgPrint(MIN_TRACE, ("Datagram has an unsupported IP version %d.\n", Version));
 628     break;
 629   }
 630
 631   IPPacket->Free(IPPacket);
 632 }
 633
 634 /* EOF */