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
CreateHoleDescriptor(ULONG First,ULONG Last)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
FreeIPDR(PIPDATAGRAM_REASSEMBLY IPDR)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 if (CurrentF->ReturnPacket)
96 {
97 NdisReturnPackets(&CurrentF->Packet, 1);
98 }
99 else
100 {
101 FreeNdisPacket(CurrentF->Packet);
102 }
103
104 TI_DbgPrint(DEBUG_IP, ("Freeing fragment at (0x%X).\n", CurrentF));
105
106 /* And free the fragment descriptor */
107 ExFreeToNPagedLookasideList(&IPFragmentList, CurrentF);
108 CurrentEntry = NextEntry;
109 }
110
111 if (IPDR->IPv4Header)
112 {
113 TI_DbgPrint(DEBUG_IP, ("Freeing IPDR header at (0x%X).\n", IPDR->IPv4Header));
114 ExFreePoolWithTag(IPDR->IPv4Header, PACKET_BUFFER_TAG);
115 }
116
117 TI_DbgPrint(DEBUG_IP, ("Freeing IPDR data at (0x%X).\n", IPDR));
118
119 ExFreeToNPagedLookasideList(&IPDRList, IPDR);
120 }
121
122
RemoveIPDR(PIPDATAGRAM_REASSEMBLY IPDR)123 VOID RemoveIPDR(
124 PIPDATAGRAM_REASSEMBLY IPDR)
125 /*
126 * FUNCTION: Removes an IP datagram reassembly structure from the global list
127 * ARGUMENTS:
128 * IPDR = Pointer to IP datagram reassembly structure
129 */
130 {
131 KIRQL OldIrql;
132
133 TI_DbgPrint(DEBUG_IP, ("Removing IPDR at (0x%X).\n", IPDR));
134
135 TcpipAcquireSpinLock(&ReassemblyListLock, &OldIrql);
136 RemoveEntryList(&IPDR->ListEntry);
137 TcpipReleaseSpinLock(&ReassemblyListLock, OldIrql);
138 }
139
140
GetReassemblyInfo(PIP_PACKET IPPacket)141 PIPDATAGRAM_REASSEMBLY GetReassemblyInfo(
142 PIP_PACKET IPPacket)
143 /*
144 * FUNCTION: Returns a pointer to an IP datagram reassembly structure
145 * ARGUMENTS:
146 * IPPacket = Pointer to IP packet
147 * NOTES:
148 * A datagram is identified by four paramters, which are
149 * Source and destination address, protocol number and
150 * identification number
151 */
152 {
153 KIRQL OldIrql;
154 PLIST_ENTRY CurrentEntry;
155 PIPDATAGRAM_REASSEMBLY Current;
156 PIPv4_HEADER Header = (PIPv4_HEADER)IPPacket->Header;
157
158 TI_DbgPrint(DEBUG_IP, ("Searching for IPDR for IP packet at (0x%X).\n", IPPacket));
159
160 TcpipAcquireSpinLock(&ReassemblyListLock, &OldIrql);
161
162 /* FIXME: Assume IPv4 */
163
164 CurrentEntry = ReassemblyListHead.Flink;
165 while (CurrentEntry != &ReassemblyListHead) {
166 Current = CONTAINING_RECORD(CurrentEntry, IPDATAGRAM_REASSEMBLY, ListEntry);
167 if (AddrIsEqual(&IPPacket->SrcAddr, &Current->SrcAddr) &&
168 (Header->Id == Current->Id) &&
169 (Header->Protocol == Current->Protocol) &&
170 (AddrIsEqual(&IPPacket->DstAddr, &Current->DstAddr))) {
171 TcpipReleaseSpinLock(&ReassemblyListLock, OldIrql);
172
173 return Current;
174 }
175 CurrentEntry = CurrentEntry->Flink;
176 }
177
178 TcpipReleaseSpinLock(&ReassemblyListLock, OldIrql);
179
180 return NULL;
181 }
182
183
184 BOOLEAN
ReassembleDatagram(PIP_PACKET IPPacket,PIPDATAGRAM_REASSEMBLY IPDR)185 ReassembleDatagram(
186 PIP_PACKET IPPacket,
187 PIPDATAGRAM_REASSEMBLY IPDR)
188 /*
189 * FUNCTION: Reassembles an IP datagram
190 * ARGUMENTS:
191 * IPDR = Pointer to IP datagram reassembly structure
192 * NOTES:
193 * This routine concatenates fragments into a complete IP datagram.
194 * The lock is held when this routine is called
195 * RETURNS:
196 * Pointer to IP packet, NULL if there was not enough free resources
197 * NOTES:
198 * At this point, header is expected to point to the IP header
199 */
200 {
201 PLIST_ENTRY CurrentEntry;
202 PIP_FRAGMENT Fragment;
203 PCHAR Data;
204
205 PAGED_CODE();
206
207 TI_DbgPrint(DEBUG_IP, ("Reassembling datagram from IPDR at (0x%X).\n", IPDR));
208 TI_DbgPrint(DEBUG_IP, ("IPDR->HeaderSize = %d\n", IPDR->HeaderSize));
209 TI_DbgPrint(DEBUG_IP, ("IPDR->DataSize = %d\n", IPDR->DataSize));
210
211 IPPacket->TotalSize = IPDR->HeaderSize + IPDR->DataSize;
212 IPPacket->HeaderSize = 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 = ExAllocatePoolWithTag(NonPagedPool, IPPacket->TotalSize, PACKET_BUFFER_TAG);
219 if (!IPPacket->Header) {
220 TI_DbgPrint(MIN_TRACE, ("Insufficient resources.\n"));
221 (*IPPacket->Free)(IPPacket);
222 return FALSE;
223 }
224 IPPacket->MappedHeader = FALSE;
225
226 /* Copy the header into the buffer */
227 RtlCopyMemory(IPPacket->Header, IPDR->IPv4Header, IPDR->HeaderSize);
228
229 Data = (PVOID)((ULONG_PTR)IPPacket->Header + IPDR->HeaderSize);
230 IPPacket->Data = Data;
231
232 /* Copy data from all fragments into buffer */
233 CurrentEntry = IPDR->FragmentListHead.Flink;
234 while (CurrentEntry != &IPDR->FragmentListHead) {
235 Fragment = CONTAINING_RECORD(CurrentEntry, IP_FRAGMENT, ListEntry);
236
237 /* Copy fragment data into datagram buffer */
238 CopyPacketToBuffer(Data + Fragment->Offset,
239 Fragment->Packet,
240 Fragment->PacketOffset,
241 Fragment->Size);
242
243 CurrentEntry = CurrentEntry->Flink;
244 }
245
246 return TRUE;
247 }
248
249
Cleanup(PKSPIN_LOCK Lock,KIRQL OldIrql,PIPDATAGRAM_REASSEMBLY IPDR)250 static inline VOID Cleanup(
251 PKSPIN_LOCK Lock,
252 KIRQL OldIrql,
253 PIPDATAGRAM_REASSEMBLY IPDR)
254 /*
255 * FUNCTION: Performs cleaning operations on errors
256 * ARGUMENTS:
257 * Lock = Pointer to spin lock to be released
258 * OldIrql = Value of IRQL when spin lock was acquired
259 * IPDR = Pointer to IP datagram reassembly structure to free
260 * Buffer = Optional pointer to a buffer to free
261 */
262 {
263 TI_DbgPrint(MIN_TRACE, ("Insufficient resources.\n"));
264
265 TcpipReleaseSpinLock(Lock, OldIrql);
266 RemoveIPDR(IPDR);
267 FreeIPDR(IPDR);
268 }
269
270
ProcessFragment(PIP_INTERFACE IF,PIP_PACKET IPPacket)271 VOID ProcessFragment(
272 PIP_INTERFACE IF,
273 PIP_PACKET IPPacket)
274 /*
275 * FUNCTION: Processes an IP datagram or fragment
276 * ARGUMENTS:
277 * IF = Pointer to IP interface packet was receive on
278 * IPPacket = Pointer to IP packet
279 * NOTES:
280 * This routine reassembles fragments and, if a whole datagram can
281 * be assembled, passes the datagram on to the IP protocol dispatcher
282 */
283 {
284 KIRQL OldIrql;
285 PIPDATAGRAM_REASSEMBLY IPDR;
286 PLIST_ENTRY CurrentEntry;
287 PIPDATAGRAM_HOLE Hole, NewHole;
288 USHORT FragFirst;
289 USHORT FragLast;
290 BOOLEAN MoreFragments;
291 PIPv4_HEADER IPv4Header;
292 IP_PACKET Datagram;
293 PIP_FRAGMENT Fragment;
294 BOOLEAN Success;
295
296 /* FIXME: Assume IPv4 */
297
298 IPv4Header = (PIPv4_HEADER)IPPacket->Header;
299
300 /* Check if we already have an reassembly structure for this datagram */
301 IPDR = GetReassemblyInfo(IPPacket);
302 if (IPDR) {
303 TI_DbgPrint(DEBUG_IP, ("Continueing assembly.\n"));
304 /* We have a reassembly structure */
305 TcpipAcquireSpinLock(&IPDR->Lock, &OldIrql);
306
307 /* Reset the timeout since we received a fragment */
308 IPDR->TimeoutCount = 0;
309 } else {
310 TI_DbgPrint(DEBUG_IP, ("Starting new assembly.\n"));
311
312 /* We don't have a reassembly structure, create one */
313 IPDR = ExAllocateFromNPagedLookasideList(&IPDRList);
314 if (!IPDR)
315 /* We don't have the resources to process this packet, discard it */
316 return;
317
318 /* Create a descriptor spanning from zero to infinity.
319 Actually, we use a value slightly greater than the
320 maximum number of octets an IP datagram can contain */
321 Hole = CreateHoleDescriptor(0, 65536);
322 if (!Hole) {
323 /* We don't have the resources to process this packet, discard it */
324 ExFreeToNPagedLookasideList(&IPDRList, IPDR);
325 return;
326 }
327 AddrInitIPv4(&IPDR->SrcAddr, IPv4Header->SrcAddr);
328 AddrInitIPv4(&IPDR->DstAddr, IPv4Header->DstAddr);
329 IPDR->Id = IPv4Header->Id;
330 IPDR->Protocol = IPv4Header->Protocol;
331 IPDR->TimeoutCount = 0;
332 InitializeListHead(&IPDR->FragmentListHead);
333 InitializeListHead(&IPDR->HoleListHead);
334 InsertTailList(&IPDR->HoleListHead, &Hole->ListEntry);
335
336 TcpipInitializeSpinLock(&IPDR->Lock);
337
338 TcpipAcquireSpinLock(&IPDR->Lock, &OldIrql);
339
340 /* Update the reassembly list */
341 TcpipInterlockedInsertTailList(
342 &ReassemblyListHead,
343 &IPDR->ListEntry,
344 &ReassemblyListLock);
345 }
346
347 FragFirst = (WN2H(IPv4Header->FlagsFragOfs) & IPv4_FRAGOFS_MASK) << 3;
348 FragLast = FragFirst + WN2H(IPv4Header->TotalLength);
349 MoreFragments = (WN2H(IPv4Header->FlagsFragOfs) & IPv4_MF_MASK) > 0;
350
351 CurrentEntry = IPDR->HoleListHead.Flink;
352 for (;;) {
353 if (CurrentEntry == &IPDR->HoleListHead)
354 break;
355
356 Hole = CONTAINING_RECORD(CurrentEntry, IPDATAGRAM_HOLE, ListEntry);
357
358 TI_DbgPrint(DEBUG_IP, ("Comparing Fragment (%d,%d) to Hole (%d,%d).\n",
359 FragFirst, FragLast, Hole->First, Hole->Last));
360
361 if ((FragFirst > Hole->Last) || (FragLast < Hole->First)) {
362 TI_DbgPrint(MID_TRACE, ("No overlap.\n"));
363 /* The fragment does not overlap with the hole, try next
364 descriptor in the list */
365
366 CurrentEntry = CurrentEntry->Flink;
367 continue;
368 }
369
370 /* The fragment overlap with the hole, unlink the descriptor */
371 RemoveEntryList(CurrentEntry);
372
373 if (FragFirst > Hole->First) {
374 NewHole = CreateHoleDescriptor(Hole->First, FragFirst - 1);
375 if (!NewHole) {
376 /* We don't have the resources to process this packet, discard it */
377 ExFreeToNPagedLookasideList(&IPHoleList, Hole);
378 Cleanup(&IPDR->Lock, OldIrql, IPDR);
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 NewHole = CreateHoleDescriptor(FragLast + 1, Hole->Last);
388 if (!NewHole) {
389 /* We don't have the resources to process this packet, discard it */
390 ExFreeToNPagedLookasideList(&IPHoleList, Hole);
391 Cleanup(&IPDR->Lock, OldIrql, IPDR);
392 return;
393 }
394
395 /* Put the new hole descriptor in the list */
396 InsertTailList(&IPDR->HoleListHead, &NewHole->ListEntry);
397 }
398
399 ExFreeToNPagedLookasideList(&IPHoleList, Hole);
400
401 /* If this is the first fragment, save the IP header */
402 if (FragFirst == 0) {
403 IPDR->IPv4Header = ExAllocatePoolWithTag(NonPagedPool,
404 IPPacket->HeaderSize,
405 PACKET_BUFFER_TAG);
406 if (!IPDR->IPv4Header)
407 {
408 Cleanup(&IPDR->Lock, OldIrql, IPDR);
409 return;
410 }
411
412 RtlCopyMemory(IPDR->IPv4Header, IPPacket->Header, IPPacket->HeaderSize);
413 IPDR->HeaderSize = IPPacket->HeaderSize;
414
415 TI_DbgPrint(DEBUG_IP, ("First fragment found. Header buffer is at (0x%X). "
416 "Header size is (%d).\n", &IPDR->IPv4Header, IPPacket->HeaderSize));
417
418 }
419
420 /* Create a buffer, copy the data into it and put it
421 in the fragment list */
422
423 Fragment = ExAllocateFromNPagedLookasideList(&IPFragmentList);
424 if (!Fragment) {
425 /* We don't have the resources to process this packet, discard it */
426 Cleanup(&IPDR->Lock, OldIrql, IPDR);
427 return;
428 }
429
430 TI_DbgPrint(DEBUG_IP, ("Fragment descriptor allocated at (0x%X).\n", Fragment));
431
432 Fragment->Size = IPPacket->TotalSize - IPPacket->HeaderSize;
433 Fragment->Packet = IPPacket->NdisPacket;
434 Fragment->ReturnPacket = IPPacket->ReturnPacket;
435 Fragment->PacketOffset = IPPacket->Position + IPPacket->HeaderSize;
436 Fragment->Offset = FragFirst;
437
438 /* Disassociate the NDIS packet so it isn't freed upon return from IPReceive() */
439 IPPacket->NdisPacket = NULL;
440
441 /* If this is the last fragment, compute and save the datagram data size */
442 if (!MoreFragments)
443 IPDR->DataSize = FragFirst + Fragment->Size;
444
445 /* Put the fragment in the list */
446 InsertTailList(&IPDR->FragmentListHead, &Fragment->ListEntry);
447 break;
448 }
449
450 TI_DbgPrint(DEBUG_IP, ("Done searching for hole descriptor.\n"));
451
452 if (IsListEmpty(&IPDR->HoleListHead)) {
453 /* Hole list is empty which means a complete datagram can be assembled.
454 Assemble the datagram and pass it to an upper layer protocol */
455
456 TI_DbgPrint(DEBUG_IP, ("Complete datagram received.\n"));
457
458 RemoveIPDR(IPDR);
459 TcpipReleaseSpinLock(&IPDR->Lock, OldIrql);
460
461 /* FIXME: Assumes IPv4 */
462 IPInitializePacket(&Datagram, IP_ADDRESS_V4);
463
464 Success = ReassembleDatagram(&Datagram, IPDR);
465
466 FreeIPDR(IPDR);
467
468 if (!Success)
469 /* Not enough free resources, discard the packet */
470 return;
471
472 DISPLAY_IP_PACKET(&Datagram);
473
474 /* Give the packet to the protocol dispatcher */
475 IPDispatchProtocol(IF, &Datagram);
476
477 /* We're done with this datagram */
478 TI_DbgPrint(MAX_TRACE, ("Freeing datagram at (0x%X).\n", Datagram));
479 Datagram.Free(&Datagram);
480 } else
481 TcpipReleaseSpinLock(&IPDR->Lock, OldIrql);
482 }
483
484
IPFreeReassemblyList(VOID)485 VOID IPFreeReassemblyList(
486 VOID)
487 /*
488 * FUNCTION: Frees all IP datagram reassembly structures in the list
489 */
490 {
491 KIRQL OldIrql;
492 PLIST_ENTRY CurrentEntry, NextEntry;
493 PIPDATAGRAM_REASSEMBLY Current;
494
495 TcpipAcquireSpinLock(&ReassemblyListLock, &OldIrql);
496
497 CurrentEntry = ReassemblyListHead.Flink;
498 while (CurrentEntry != &ReassemblyListHead) {
499 NextEntry = CurrentEntry->Flink;
500 Current = CONTAINING_RECORD(CurrentEntry, IPDATAGRAM_REASSEMBLY, ListEntry);
501
502 /* Unlink it from the list */
503 RemoveEntryList(CurrentEntry);
504
505 /* And free the descriptor */
506 FreeIPDR(Current);
507
508 CurrentEntry = NextEntry;
509 }
510
511 TcpipReleaseSpinLock(&ReassemblyListLock, OldIrql);
512 }
513
514
IPDatagramReassemblyTimeout(VOID)515 VOID IPDatagramReassemblyTimeout(
516 VOID)
517 /*
518 * FUNCTION: IP datagram reassembly timeout handler
519 * NOTES:
520 * This routine is called by IPTimeout to free any resources used
521 * to hold IP fragments that have taken too long to reassemble
522 */
523 {
524 PLIST_ENTRY CurrentEntry, NextEntry;
525 PIPDATAGRAM_REASSEMBLY CurrentIPDR;
526
527 TcpipAcquireSpinLockAtDpcLevel(&ReassemblyListLock);
528
529 CurrentEntry = ReassemblyListHead.Flink;
530 while (CurrentEntry != &ReassemblyListHead)
531 {
532 NextEntry = CurrentEntry->Flink;
533 CurrentIPDR = CONTAINING_RECORD(CurrentEntry, IPDATAGRAM_REASSEMBLY, ListEntry);
534
535 TcpipAcquireSpinLockAtDpcLevel(&CurrentIPDR->Lock);
536
537 if (++CurrentIPDR->TimeoutCount == MAX_TIMEOUT_COUNT)
538 {
539 TcpipReleaseSpinLockFromDpcLevel(&CurrentIPDR->Lock);
540 RemoveEntryList(CurrentEntry);
541 FreeIPDR(CurrentIPDR);
542 }
543 else
544 {
545 ASSERT(CurrentIPDR->TimeoutCount < MAX_TIMEOUT_COUNT);
546 TcpipReleaseSpinLockFromDpcLevel(&CurrentIPDR->Lock);
547 }
548
549 CurrentEntry = NextEntry;
550 }
551
552 TcpipReleaseSpinLockFromDpcLevel(&ReassemblyListLock);
553 }
554
IPv4Receive(PIP_INTERFACE IF,PIP_PACKET IPPacket)555 VOID IPv4Receive(PIP_INTERFACE IF, PIP_PACKET IPPacket)
556 /*
557 * FUNCTION: Receives an IPv4 datagram (or fragment)
558 * ARGUMENTS:
559 * Context = Pointer to context information (IP_INTERFACE)
560 * IPPacket = Pointer to IP packet
561 */
562 {
563 UCHAR FirstByte;
564 ULONG BytesCopied;
565
566 TI_DbgPrint(DEBUG_IP, ("Received IPv4 datagram.\n"));
567
568 /* Read in the first IP header byte for size information */
569 BytesCopied = CopyPacketToBuffer((PCHAR)&FirstByte,
570 IPPacket->NdisPacket,
571 IPPacket->Position,
572 sizeof(UCHAR));
573 if (BytesCopied != sizeof(UCHAR))
574 {
575 TI_DbgPrint(MIN_TRACE, ("Failed to copy in first byte\n"));
576 /* Discard packet */
577 return;
578 }
579
580 IPPacket->HeaderSize = (FirstByte & 0x0F) << 2;
581 TI_DbgPrint(DEBUG_IP, ("IPPacket->HeaderSize = %d\n", IPPacket->HeaderSize));
582
583 if (IPPacket->HeaderSize > IPv4_MAX_HEADER_SIZE) {
584 TI_DbgPrint(MIN_TRACE, ("Datagram received with incorrect header size (%d).\n",
585 IPPacket->HeaderSize));
586 /* Discard packet */
587 return;
588 }
589
590 /* This is freed by IPPacket->Free() */
591 IPPacket->Header = ExAllocatePoolWithTag(NonPagedPool,
592 IPPacket->HeaderSize,
593 PACKET_BUFFER_TAG);
594 if (!IPPacket->Header)
595 {
596 TI_DbgPrint(MIN_TRACE, ("No resources to allocate header\n"));
597 /* Discard packet */
598 return;
599 }
600
601 IPPacket->MappedHeader = FALSE;
602
603 BytesCopied = CopyPacketToBuffer((PCHAR)IPPacket->Header,
604 IPPacket->NdisPacket,
605 IPPacket->Position,
606 IPPacket->HeaderSize);
607 if (BytesCopied != IPPacket->HeaderSize)
608 {
609 TI_DbgPrint(MIN_TRACE, ("Failed to copy in header\n"));
610 /* Discard packet */
611 return;
612 }
613
614 /* Checksum IPv4 header */
615 if (!IPv4CorrectChecksum(IPPacket->Header, IPPacket->HeaderSize)) {
616 TI_DbgPrint(MIN_TRACE, ("Datagram received with bad checksum. Checksum field (0x%X)\n",
617 WN2H(((PIPv4_HEADER)IPPacket->Header)->Checksum)));
618 /* Discard packet */
619 return;
620 }
621
622 IPPacket->TotalSize = WN2H(((PIPv4_HEADER)IPPacket->Header)->TotalLength);
623
624 AddrInitIPv4(&IPPacket->SrcAddr, ((PIPv4_HEADER)IPPacket->Header)->SrcAddr);
625 AddrInitIPv4(&IPPacket->DstAddr, ((PIPv4_HEADER)IPPacket->Header)->DstAddr);
626
627 TI_DbgPrint(MID_TRACE,("IPPacket->Position = %d\n",
628 IPPacket->Position));
629
630 /* FIXME: Possibly forward packets with multicast addresses */
631
632 /* FIXME: Should we allow packets to be received on the wrong interface? */
633 /* XXX Find out if this packet is destined for us */
634 ProcessFragment(IF, IPPacket);
635 }
636
637
IPReceive(PIP_INTERFACE IF,PIP_PACKET IPPacket)638 VOID IPReceive( PIP_INTERFACE IF, PIP_PACKET IPPacket )
639 /*
640 * FUNCTION: Receives an IP datagram (or fragment)
641 * ARGUMENTS:
642 * IF = Interface
643 * IPPacket = Pointer to IP packet
644 */
645 {
646 UCHAR FirstByte;
647 UINT Version, BytesCopied;
648
649 /* Read in the first IP header byte for version information */
650 BytesCopied = CopyPacketToBuffer((PCHAR)&FirstByte,
651 IPPacket->NdisPacket,
652 IPPacket->Position,
653 sizeof(UCHAR));
654 if (BytesCopied != sizeof(UCHAR))
655 {
656 TI_DbgPrint(MIN_TRACE, ("Failed to copy in first byte\n"));
657 IPPacket->Free(IPPacket);
658 return;
659 }
660
661 /* Check that IP header has a supported version */
662 Version = (FirstByte >> 4);
663
664 switch (Version) {
665 case 4:
666 IPPacket->Type = IP_ADDRESS_V4;
667 IPv4Receive(IF, IPPacket);
668 break;
669 case 6:
670 IPPacket->Type = IP_ADDRESS_V6;
671 TI_DbgPrint(MAX_TRACE, ("Datagram of type IPv6 discarded.\n"));
672 break;
673 default:
674 TI_DbgPrint(MIN_TRACE, ("Datagram has an unsupported IP version %d.\n", Version));
675 break;
676 }
677
678 IPPacket->Free(IPPacket);
679 }
680
681 /* EOF */
682