summaryrefslogtreecommitdiff
path: root/Core/NetworkPkg/Ip6Dxe/Ip6Output.c
blob: 8330e37935d01958dbe890e7dc8c1da0054fc9b8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
/** @file
  The internal functions and routines to transmit the IP6 packet.

  Copyright (c) 2009 - 2015, Intel Corporation. All rights reserved.<BR>

  This program and the accompanying materials
  are licensed and made available under the terms and conditions of the BSD License
  which accompanies this distribution.  The full text of the license may be found at
  http://opensource.org/licenses/bsd-license.php.

  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

**/

#include "Ip6Impl.h"

UINT32 mIp6Id;

/**
  Output all the available source addresses to a list entry head SourceList. The
  number of source addresses are also returned.

  @param[in]       IpSb             Points to an IP6 service binding instance.
  @param[out]      SourceList       The list entry head of all source addresses.
                                    It is the caller's responsibility to free the
                                    resources.
  @param[out]      SourceCount      The number of source addresses.

  @retval EFI_SUCCESS           The source addresses were copied to a list entry head
                                SourceList.
  @retval EFI_OUT_OF_RESOURCES  Failed to allocate resources to complete the operation.

**/
EFI_STATUS
Ip6CandidateSource (
  IN IP6_SERVICE            *IpSb,
  OUT LIST_ENTRY            *SourceList,
  OUT UINT32                *SourceCount
  )
{
  IP6_INTERFACE             *IpIf;
  LIST_ENTRY                *Entry;
  LIST_ENTRY                *Entry2;
  IP6_ADDRESS_INFO          *AddrInfo;
  IP6_ADDRESS_INFO          *Copy;

  *SourceCount = 0;

  if (IpSb->LinkLocalOk) {
    Copy = AllocatePool (sizeof (IP6_ADDRESS_INFO));
    if (Copy == NULL) {
      return EFI_OUT_OF_RESOURCES;
    }

    Copy->Signature         = IP6_ADDR_INFO_SIGNATURE;
    IP6_COPY_ADDRESS (&Copy->Address, &IpSb->LinkLocalAddr);
    Copy->IsAnycast         = FALSE;
    Copy->PrefixLength      = IP6_LINK_LOCAL_PREFIX_LENGTH;
    Copy->ValidLifetime     = (UINT32) IP6_INFINIT_LIFETIME;
    Copy->PreferredLifetime = (UINT32) IP6_INFINIT_LIFETIME;

    InsertTailList (SourceList, &Copy->Link);
    (*SourceCount)++;
  }

  NET_LIST_FOR_EACH (Entry, &IpSb->Interfaces) {
    IpIf = NET_LIST_USER_STRUCT (Entry, IP6_INTERFACE, Link);

    NET_LIST_FOR_EACH (Entry2, &IpIf->AddressList) {
      AddrInfo = NET_LIST_USER_STRUCT_S (Entry2, IP6_ADDRESS_INFO, Link, IP6_ADDR_INFO_SIGNATURE);

      if (AddrInfo->IsAnycast) {
        //
        // Never use an anycast address.
        //
        continue;
      }

      Copy = AllocateCopyPool (sizeof (IP6_ADDRESS_INFO), AddrInfo);
      if (Copy == NULL) {
        return EFI_OUT_OF_RESOURCES;
      }

      InsertTailList (SourceList, &Copy->Link);
      (*SourceCount)++;
    }
  }

  return EFI_SUCCESS;
}

/**
  Calculate how many bits are the same between two IPv6 addresses.

  @param[in]       AddressA         Points to an IPv6 address.
  @param[in]       AddressB         Points to another IPv6 address.

  @return The common bits of the AddressA and AddressB.

**/
UINT8
Ip6CommonPrefixLen (
  IN EFI_IPv6_ADDRESS       *AddressA,
  IN EFI_IPv6_ADDRESS       *AddressB
  )
{
  UINT8                     Count;
  UINT8                     Index;
  UINT8                     ByteA;
  UINT8                     ByteB;
  UINT8                     NumBits;

  Count = 0;
  Index = 0;

  while (Index < 16) {
    ByteA = AddressA->Addr[Index];
    ByteB = AddressB->Addr[Index];

    if (ByteA == ByteB) {
      Count += 8;
      Index++;
      continue;
    }

    //
    // Check how many bits are common between the two bytes.
    //
    NumBits = 8;
    ByteA   = (UINT8) (ByteA ^ ByteB);

    while (ByteA != 0) {
      NumBits--;
      ByteA = (UINT8) (ByteA >> 1);
    }

    return (UINT8) (Count + NumBits);
  }

  return Count;
}

/**
  Output all the available source addresses to a list entry head SourceList. The
  number of source addresses are also returned.

  @param[in]       IpSb             Points to a IP6 service binding instance.
  @param[in]       Destination      The IPv6 destination address.
  @param[out]      Source           The selected IPv6 source address according to
                                    the Destination.

  @retval EFI_SUCCESS           The source addresses were copied to a list entry
                                head SourceList.
  @retval EFI_NO_MAPPING        The IPv6 stack is not auto configured.

**/
EFI_STATUS
Ip6SelectSourceAddress (
  IN IP6_SERVICE            *IpSb,
  IN EFI_IPv6_ADDRESS       *Destination,
  OUT EFI_IPv6_ADDRESS      *Source
  )
{
  EFI_STATUS                Status;
  LIST_ENTRY                SourceList;
  UINT32                    SourceCount;
  UINT8                     ScopeD;
  LIST_ENTRY                *Entry;
  IP6_ADDRESS_INFO          *AddrInfo;
  IP6_PREFIX_LIST_ENTRY     *Prefix;
  UINT8                     LastCommonLength;
  UINT8                     CurrentCommonLength;
  EFI_IPv6_ADDRESS          *TmpAddress;

  NET_CHECK_SIGNATURE (IpSb, IP6_SERVICE_SIGNATURE);

  Status = EFI_SUCCESS;
  InitializeListHead (&SourceList);

  if (!IpSb->LinkLocalOk) {
    return EFI_NO_MAPPING;
  }

  //
  // Rule 1: Prefer same address.
  //
  if (Ip6IsOneOfSetAddress (IpSb, Destination, NULL, NULL)) {
    IP6_COPY_ADDRESS (Source, Destination);
    goto Exit;
  }

  //
  // Rule 2: Prefer appropriate scope.
  //
  if (IP6_IS_MULTICAST (Destination)) {
    ScopeD = (UINT8) (Destination->Addr[1] >> 4);
  } else if (NetIp6IsLinkLocalAddr (Destination)) {
    ScopeD = 0x2;
  } else {
    ScopeD = 0xE;
  }

  if (ScopeD <= 0x2) {
    //
    // Return the link-local address if it exists
    // One IP6_SERVICE only has one link-local address.
    //
    IP6_COPY_ADDRESS (Source, &IpSb->LinkLocalAddr);
    goto Exit;
  }

  //
  // All candidate source addresses are global unicast address.
  //
  Ip6CandidateSource (IpSb, &SourceList, &SourceCount);

  if (SourceCount == 0) {
    Status = EFI_NO_MAPPING;
    goto Exit;
  }

  IP6_COPY_ADDRESS (Source, &IpSb->LinkLocalAddr);

  if (SourceCount == 1) {
    goto Exit;
  }

  //
  // Rule 3: Avoid deprecated addresses.
  // TODO: check the "deprecated" state of the stateful configured address
  //
  NET_LIST_FOR_EACH (Entry, &IpSb->AutonomousPrefix) {
    Prefix = NET_LIST_USER_STRUCT (Entry, IP6_PREFIX_LIST_ENTRY, Link);
    if (Prefix->PreferredLifetime == 0) {
      Ip6RemoveAddr (NULL, &SourceList, &SourceCount, &Prefix->Prefix, Prefix->PrefixLength);

      if (SourceCount == 1) {
        goto Exit;
      }
    }
  }

  //
  // TODO: Rule 4: Prefer home addresses.
  // TODO: Rule 5: Prefer outgoing interface.
  // TODO: Rule 6: Prefer matching label.
  // TODO: Rule 7: Prefer public addresses.
  //

  //
  // Rule 8: Use longest matching prefix.
  //
  LastCommonLength = Ip6CommonPrefixLen (Source, Destination);
  TmpAddress       = NULL;

  for (Entry = SourceList.ForwardLink; Entry != &SourceList; Entry = Entry->ForwardLink) {
    AddrInfo = NET_LIST_USER_STRUCT_S (Entry, IP6_ADDRESS_INFO, Link, IP6_ADDR_INFO_SIGNATURE);

    CurrentCommonLength = Ip6CommonPrefixLen (&AddrInfo->Address, Destination);
    if (CurrentCommonLength > LastCommonLength) {
      LastCommonLength = CurrentCommonLength;
      TmpAddress       = &AddrInfo->Address;
    }
  }

  if (TmpAddress != NULL) {
    IP6_COPY_ADDRESS (Source, TmpAddress);
  }

Exit:

  Ip6RemoveAddr (NULL, &SourceList, &SourceCount, NULL, 0);

  return Status;
}

/**
  Select an interface to send the packet generated in the IP6 driver
  itself: that is, not by the requests of the IP6 child's consumer. Such
  packets include the ICMPv6 echo replies and other ICMPv6 error packets.

  @param[in]  IpSb                 The IP4 service that wants to send the packets.
  @param[in]  Destination          The destination of the packet.
  @param[in, out]  Source          The source of the packet.

  @return NULL if no proper interface is found, otherwise, the interface that
          can be used to send the system packet from.

**/
IP6_INTERFACE *
Ip6SelectInterface (
  IN IP6_SERVICE            *IpSb,
  IN EFI_IPv6_ADDRESS       *Destination,
  IN OUT EFI_IPv6_ADDRESS   *Source
  )
{
  EFI_STATUS                Status;
  EFI_IPv6_ADDRESS          SelectedSource;
  IP6_INTERFACE             *IpIf;
  BOOLEAN                   Exist;

  NET_CHECK_SIGNATURE (IpSb, IP6_SERVICE_SIGNATURE);
  ASSERT (Destination != NULL && Source != NULL);

  if (NetIp6IsUnspecifiedAddr (Destination)) {
    return NULL;
  }

  if (!NetIp6IsUnspecifiedAddr (Source)) {
    Exist = Ip6IsOneOfSetAddress (IpSb, Source, &IpIf, NULL);
    ASSERT (Exist);

    return IpIf;
  }

  //
  // If source is unspecified, select a source according to the destination.
  //
  Status = Ip6SelectSourceAddress (IpSb, Destination, &SelectedSource);
  if (EFI_ERROR (Status)) {
    return IpSb->DefaultInterface;
  }

  Ip6IsOneOfSetAddress (IpSb, &SelectedSource, &IpIf, NULL);
  IP6_COPY_ADDRESS (Source, &SelectedSource);

  return IpIf;
}

/**
  The default callback function for the system generated packet.
  It will free the packet.

  @param[in]  Packet        The packet that transmitted.
  @param[in]  IoStatus      The result of the transmission, succeeded or failed.
  @param[in]  LinkFlag      Not used when transmitted. Check IP6_FRAME_CALLBACK
                            for reference.
  @param[in]  Context       The context provided by us.

**/
VOID
Ip6SysPacketSent (
  NET_BUF                   *Packet,
  EFI_STATUS                IoStatus,
  UINT32                    LinkFlag,
  VOID                      *Context
  )
{
  NetbufFree (Packet);
  Packet = NULL;
}

/**
  Prefix an IP6 basic head and unfragmentable extension headers and a fragment header
  to the Packet. Used for IP6 fragmentation.

  @param[in]  IpSb             The IP6 service instance to transmit the packet.
  @param[in]  Packet           The packet to prefix the IP6 header to.
  @param[in]  Head             The caller supplied header.
  @param[in]  FragmentOffset   The fragment offset of the data following the header.
  @param[in]  ExtHdrs          The length of the original extension header.
  @param[in]  ExtHdrsLen       The length of the extension headers.
  @param[in]  LastHeader       The pointer of next header of last extension header.
  @param[in]  HeadLen          The length of the unfragmented part of the IP6 header.

  @retval EFI_BAD_BUFFER_SIZE  There is no enough room in the head space of
                               Packet.
  @retval EFI_SUCCESS          The operation performed successfully.

**/
EFI_STATUS
Ip6PrependHead (
  IN IP6_SERVICE            *IpSb,
  IN NET_BUF                *Packet,
  IN EFI_IP6_HEADER         *Head,
  IN UINT16                 FragmentOffset,
  IN UINT8                  *ExtHdrs,
  IN UINT32                 ExtHdrsLen,
  IN UINT8                  LastHeader,
  IN UINT32                 HeadLen
  )
{
  UINT32                    Len;
  UINT32                    UnFragExtHdrsLen;
  EFI_IP6_HEADER            *PacketHead;
  UINT8                     *UpdatedExtHdrs;
  EFI_STATUS                Status;
  UINT8                     NextHeader;

  UpdatedExtHdrs = NULL;

  //
  // HeadLen is the length of the fixed part of the sequences of fragments, i.e.
  // the unfragment part.
  //
  PacketHead = (EFI_IP6_HEADER *) NetbufAllocSpace (Packet, HeadLen, NET_BUF_HEAD);
  if (PacketHead == NULL) {
    return EFI_BAD_BUFFER_SIZE;
  }

  //
  // Set the head up, convert the host byte order to network byte order
  //
  CopyMem (PacketHead, Head, sizeof (EFI_IP6_HEADER));
  PacketHead->PayloadLength = HTONS ((UINT16) (Packet->TotalSize - sizeof (EFI_IP6_HEADER)));
  Packet->Ip.Ip6            = PacketHead;

  Len              = HeadLen - sizeof (EFI_IP6_HEADER);
  UnFragExtHdrsLen = Len - sizeof (IP6_FRAGMENT_HEADER);

  if (UnFragExtHdrsLen == 0) {
    PacketHead->NextHeader = IP6_FRAGMENT;
  }

  //
  // Append the extension headers: firstly copy the unfragmentable headers, then append
  // fragmentation header.
  //
  if ((FragmentOffset & IP6_FRAGMENT_OFFSET_MASK) == 0) {
    NextHeader = Head->NextHeader;
  } else {
    NextHeader = PacketHead->NextHeader;
  }

  Status = Ip6FillFragmentHeader (
             IpSb,
             NextHeader,
             LastHeader,
             ExtHdrs,
             ExtHdrsLen,
             FragmentOffset,
             &UpdatedExtHdrs
             );
  if (EFI_ERROR (Status)) {
    return Status;
  }

  CopyMem (
    (UINT8 *) (PacketHead + 1),
    UpdatedExtHdrs,
    UnFragExtHdrsLen + sizeof (IP6_FRAGMENT_HEADER)
    );

  FreePool (UpdatedExtHdrs);
  return EFI_SUCCESS;
}

/**
  Transmit an IP6 packet. The packet comes either from the IP6
  child's consumer (IpInstance != NULL) or the IP6 driver itself
  (IpInstance == NULL). It will route the packet, fragment it,
  then transmit all the fragments through an interface.

  @param[in]  IpSb             The IP6 service instance to transmit the packet.
  @param[in]  Interface        The IP6 interface to transmit the packet. Ignored
                               if NULL.
  @param[in]  IpInstance       The IP6 child that issues the transmission.  It is
                               NULL if the packet is from the system.
  @param[in]  Packet           The user data to send, excluding the IP header.
  @param[in]  Head             The caller supplied header. The caller should set
                               the  following header fields: NextHeader, HopLimit,
                               Src, Dest, FlowLabel, PayloadLength. This function
                               will fill in the Ver, TrafficClass.
  @param[in]  ExtHdrs          The extension headers to append to the IPv6 basic
                               header.
  @param[in]  ExtHdrsLen       The length of the extension headers.
  @param[in]  Callback         The callback function to issue when transmission
                               completed.
  @param[in]  Context          The opaque context for the callback.

  @retval EFI_INVALID_PARAMETER Any input parameter or the packet is invalid.
  @retval EFI_NO_MAPPING        There is no interface to the destination.
  @retval EFI_NOT_FOUND         There is no route to the destination.
  @retval EFI_SUCCESS           The packet successfully transmitted.
  @retval EFI_OUT_OF_RESOURCES  Failed to finish the operation due to lack of
                                resources.
  @retval Others                Failed to transmit the packet.

**/
EFI_STATUS
Ip6Output (
  IN IP6_SERVICE            *IpSb,
  IN IP6_INTERFACE          *Interface   OPTIONAL,
  IN IP6_PROTOCOL           *IpInstance  OPTIONAL,
  IN NET_BUF                *Packet,
  IN EFI_IP6_HEADER         *Head,
  IN UINT8                  *ExtHdrs,
  IN UINT32                 ExtHdrsLen,
  IN IP6_FRAME_CALLBACK     Callback,
  IN VOID                   *Context
  )
{
  IP6_INTERFACE             *IpIf;
  EFI_IPv6_ADDRESS          NextHop;
  IP6_NEIGHBOR_ENTRY        *NeighborCache;
  IP6_ROUTE_CACHE_ENTRY     *RouteCache;
  EFI_STATUS                Status;
  UINT32                    Mtu;
  UINT32                    HeadLen;
  UINT16                    FragmentOffset;
  UINT8                     *LastHeader;
  UINT32                    UnFragmentLen;
  UINT32                    UnFragmentHdrsLen;
  UINT32                    FragmentHdrsLen;
  UINT16                    *Checksum;
  UINT16                    PacketChecksum;
  UINT16                    PseudoChecksum;
  UINT32                    Index;
  UINT32                    PacketLen;
  UINT32                    RealExtLen;
  UINT32                    Offset;
  NET_BUF                   *TmpPacket;
  NET_BUF                   *Fragment;
  UINT32                    Num;
  UINT8                     *Buf;
  EFI_IP6_HEADER            *PacketHead;
  IP6_ICMP_HEAD             *IcmpHead;
  IP6_TXTOKEN_WRAP          *Wrap;
  IP6_ROUTE_ENTRY           *RouteEntry;
  UINT8                     *UpdatedExtHdrs;
  UINT8                     NextHeader;
  UINT8                     LastHeaderBackup;
  BOOLEAN                   FragmentHeadInserted;
  UINT8                     *ExtHdrsBackup;
  UINT8                     NextHeaderBackup;
  EFI_IPv6_ADDRESS          Source;
  EFI_IPv6_ADDRESS          Destination;

  NET_CHECK_SIGNATURE (IpSb, IP6_SERVICE_SIGNATURE);

  //
  // RFC2460: Each extension header is an integer multiple of 8 octets long,
  // in order to retain 8-octet alignment for subsequent headers.
  //
  if ((ExtHdrsLen & 0x7) != 0) {
    return EFI_INVALID_PARAMETER;
  }

  LastHeader = NULL;

  Ip6IsExtsValid (
    NULL,
    NULL,
    &Head->NextHeader,
    ExtHdrs,
    ExtHdrsLen,
    FALSE,
    NULL,
    &LastHeader,
    NULL,
    NULL,
    NULL
    );

  //
  // Select an interface/source for system packet, application
  // should select them itself.
  //
  IpIf = Interface;
  if (IpIf == NULL) {
    //
    // IpInstance->Interface is NULL when IpInstance is configured with both stationaddress
    // and destinationaddress is unspecified.
    //
    if (IpInstance == NULL || IpInstance->Interface == NULL) {
      IpIf = Ip6SelectInterface (IpSb, &Head->DestinationAddress, &Head->SourceAddress);
      if (IpInstance != NULL) {
        IpInstance->Interface = IpIf;
      }
    } else {
      IpIf = IpInstance->Interface;
    }
  }

  if (IpIf == NULL) {
    return EFI_NO_MAPPING;
  }

  //
  // Update the common field in Head here.
  //
  Head->Version       = 6;
  Head->TrafficClassL = 0;
  Head->TrafficClassH = 0;

  Checksum            = NULL;
  NextHeader          = *LastHeader;

  switch (NextHeader) {
  case EFI_IP_PROTO_UDP:
    Packet->Udp = (EFI_UDP_HEADER *) NetbufGetByte (Packet, 0, NULL);
    ASSERT (Packet->Udp != NULL);
    if (Packet->Udp->Checksum == 0) {
      Checksum = &Packet->Udp->Checksum;
    }
    break;

  case EFI_IP_PROTO_TCP:
    Packet->Tcp = (TCP_HEAD *) NetbufGetByte (Packet, 0, NULL);
    ASSERT (Packet->Tcp != NULL);
    if (Packet->Tcp->Checksum == 0) {
      Checksum = &Packet->Tcp->Checksum;
    }
    break;

  case IP6_ICMP:
    //
    // Don't send ICMP packet to an IPv6 anycast address.
    //
    if (Ip6IsAnycast (IpSb, &Head->DestinationAddress)) {
      return EFI_INVALID_PARAMETER;
    }

    IcmpHead = (IP6_ICMP_HEAD *) NetbufGetByte (Packet, 0, NULL);
    ASSERT (IcmpHead != NULL);
    if (IcmpHead->Checksum == 0) {
      Checksum = &IcmpHead->Checksum;
    }
    break;

  default:
    break;
  }

  if (Checksum != NULL) {
    //
    // Calculate the checksum for upper layer protocol if it is not calculated due to lack of
    // IPv6 source address.
    //
    PacketChecksum = NetbufChecksum (Packet);
    PseudoChecksum = NetIp6PseudoHeadChecksum (
                      &Head->SourceAddress,
                      &Head->DestinationAddress,
                      NextHeader,
                      Packet->TotalSize
                      );
    *Checksum = (UINT16) ~NetAddChecksum (PacketChecksum, PseudoChecksum);
  }

  Status = Ip6IpSecProcessPacket (
             IpSb,
             &Head,
             LastHeader, // no need get the lasthead value for output
             &Packet,
             &ExtHdrs,
             &ExtHdrsLen,
             EfiIPsecOutBound,
             Context
             );

  if (EFI_ERROR(Status)) {
    return Status;
  }

  LastHeader = NULL;
  //
  // Check incoming parameters.
  //
  if (!Ip6IsExtsValid (
         IpSb,
         Packet,
         &Head->NextHeader,
         ExtHdrs,
         ExtHdrsLen,
         FALSE,
         NULL,
         &LastHeader,
         &RealExtLen,
         &UnFragmentHdrsLen,
         NULL
         )) {
    return EFI_INVALID_PARAMETER;
  }

  if ((RealExtLen & 0x7) != 0) {
    return EFI_INVALID_PARAMETER;
  }

  LastHeaderBackup = *LastHeader;

  //
  // Perform next hop determination:
  // For multicast packets, the next-hop is always the destination address and
  // is considered to be on-link.
  //
  if (IP6_IS_MULTICAST (&Head->DestinationAddress)) {
    IP6_COPY_ADDRESS (&NextHop, &Head->DestinationAddress);
  } else {
    //
    // For unicast packets, use a combination of the Destination Cache, the Prefix List
    // and the Default Router List to determine the IP address of the appropriate next hop.
    //

    NeighborCache = Ip6FindNeighborEntry (IpSb, &Head->DestinationAddress);
    if (NeighborCache != NULL) {
      //
      // Hit Neighbor Cache.
      //
      IP6_COPY_ADDRESS (&NextHop, &Head->DestinationAddress);
    } else {
      //
      // Not in Neighbor Cache, check Router cache
      //
      RouteCache = Ip6Route (IpSb, &Head->DestinationAddress, &Head->SourceAddress);
      if (RouteCache == NULL) {
        return EFI_NOT_FOUND;
      }

      IP6_COPY_ADDRESS (&NextHop, &RouteCache->NextHop);
      Ip6FreeRouteCacheEntry (RouteCache);
    }
  }

  //
  // Examines the Neighbor Cache for link-layer information about that neighbor.
  // DO NOT create neighbor cache if neighbor is itself - when reporting ICMP error.
  //
  if (!IP6_IS_MULTICAST (&NextHop) && !EFI_IP6_EQUAL (&Head->DestinationAddress, &Head->SourceAddress)) {
    NeighborCache = Ip6FindNeighborEntry (IpSb, &NextHop);
    if (NeighborCache == NULL) {
      NeighborCache = Ip6CreateNeighborEntry (IpSb, Ip6OnArpResolved, &NextHop, NULL);

      if (NeighborCache == NULL) {
        return EFI_OUT_OF_RESOURCES;
      }

      //
      // Send out multicast neighbor solicitation for address resolution immediately.
      //
      Ip6CreateSNMulticastAddr (&NeighborCache->Neighbor, &Destination);
      Status = Ip6SelectSourceAddress (IpSb, &NeighborCache->Neighbor, &Source);
      if (EFI_ERROR (Status)) {
        return Status;
      }

      Status = Ip6SendNeighborSolicit (
                 IpSb,
                 &Source,
                 &Destination,
                 &NeighborCache->Neighbor,
                 &IpSb->SnpMode.CurrentAddress
                 );
      if (EFI_ERROR (Status)) {
        return Status;
      }

      --NeighborCache->Transmit;
      NeighborCache->Ticks = IP6_GET_TICKS (IpSb->RetransTimer) + 1;
    }

    NeighborCache->Interface = IpIf;
  }

  UpdatedExtHdrs       = NULL;
  ExtHdrsBackup        = NULL;
  NextHeaderBackup     = 0;
  FragmentHeadInserted = FALSE;

  //
  // Check whether we received Packet Too Big message for the packet sent to the
  // Destination. If yes include a Fragment Header in the subsequent packets.
  //
  RouteEntry = Ip6FindRouteEntry (
                 IpSb->RouteTable,
                 &Head->DestinationAddress,
                 NULL
                 );
  if (RouteEntry != NULL) {
    if ((RouteEntry->Flag & IP6_PACKET_TOO_BIG) == IP6_PACKET_TOO_BIG) {

      //
      // FragmentHead is inserted after Hop-by-Hop Options header, Destination
      // Options header (first occur), Routing header, and before Fragment header,
      // Authentication header, Encapsulating Security Payload header, and
      // Destination Options header (last occur), and upper-layer header.
      //
      Status = Ip6FillFragmentHeader (
                 IpSb,
                 Head->NextHeader,
                 LastHeaderBackup,
                 ExtHdrs,
                 ExtHdrsLen,
                 0,
                 &UpdatedExtHdrs
                 );
      if (EFI_ERROR (Status)) {
        return Status;
      }

      if ((ExtHdrs == NULL) && (ExtHdrsLen == 0)) {
        NextHeaderBackup = Head->NextHeader;
        Head->NextHeader = IP6_FRAGMENT;
      }

      ExtHdrsBackup    = ExtHdrs;
      ExtHdrs          = UpdatedExtHdrs;
      ExtHdrsLen       = ExtHdrsLen + sizeof (IP6_FRAGMENT_HEADER);
      RealExtLen       = RealExtLen + sizeof (IP6_FRAGMENT_HEADER);

      mIp6Id++;

      FragmentHeadInserted = TRUE;
    }

    Ip6FreeRouteEntry (RouteEntry);
  }

  //
  // OK, selected the source and route, fragment the packet then send
  // them. Tag each fragment other than the first one as spawn from it.
  // Each extension header is an integer multiple of 8 octets long, in
  // order to retain 8-octet alignment for subsequent headers.
  //
  Mtu     = IpSb->MaxPacketSize + sizeof (EFI_IP6_HEADER);
  HeadLen = sizeof (EFI_IP6_HEADER) + RealExtLen;

  if (Packet->TotalSize + HeadLen > Mtu) {
    //
    // Remove the inserted Fragment Header since we need fragment the packet.
    //
    if (FragmentHeadInserted) {
      ExtHdrs    = ExtHdrsBackup;
      ExtHdrsLen = ExtHdrsLen - sizeof (IP6_FRAGMENT_HEADER);

      if ((ExtHdrs == NULL) && (ExtHdrsLen == 0)) {
        Head->NextHeader = NextHeaderBackup;
      }
    }

    FragmentHdrsLen = ExtHdrsLen - UnFragmentHdrsLen;

    //
    // The packet is beyond the maximum which can be described through the
    // fragment offset field in Fragment header.
    //
    if ((((Packet->TotalSize + FragmentHdrsLen) >> 3) & (~0x1fff)) != 0) {
      Status = EFI_BAD_BUFFER_SIZE;
      goto Error;
    }

    if (FragmentHdrsLen != 0) {
      //
      // Append the fragmentable extension hdrs before the upper layer payload
      // to form a new NET_BUF. This NET_BUF contains all the buffer which will
      // be fragmented below.
      //
      TmpPacket = NetbufGetFragment (Packet, 0, Packet->TotalSize, FragmentHdrsLen);
      ASSERT (TmpPacket != NULL);

      //
      // Allocate the space to contain the fragmentable hdrs and copy the data.
      //
      Buf = NetbufAllocSpace (TmpPacket, FragmentHdrsLen, TRUE);
      ASSERT (Buf != NULL);
      CopyMem (Buf, ExtHdrs + UnFragmentHdrsLen, FragmentHdrsLen);

      //
      // Free the old Packet.
      //
      NetbufFree (Packet);
      Packet = TmpPacket;
    }

    //
    // The unfragment part which appears in every fragmented IPv6 packet includes
    // the IPv6 header, the unfragmentable extension hdrs and the fragment header.
    //
    UnFragmentLen = sizeof (EFI_IP6_HEADER) + UnFragmentHdrsLen + sizeof (IP6_FRAGMENT_HEADER);

    //
    // Mtu now is the length of the fragment part in a full-length fragment.
    //
    Mtu = (Mtu - UnFragmentLen) & (~0x07);
    Num = (Packet->TotalSize + Mtu - 1) / Mtu;

    for (Index = 0, Offset = 0, PacketLen = Mtu; Index < Num; Index++) {
      //
      // Get fragment from the Packet, append UnFragnmentLen spare buffer
      // before the fragmented data, the corresponding data is filled in later.
      //
      Fragment = NetbufGetFragment (Packet, Offset, PacketLen, UnFragmentLen);
      if (Fragment == NULL) {
        Status = EFI_OUT_OF_RESOURCES;
        goto Error;
      }

      FragmentOffset = (UINT16) ((UINT16) Offset | 0x1);
      if (Index == Num - 1){
        //
        // The last fragment, clear the M flag.
        //
        FragmentOffset &= (~0x1);
      }

      Status = Ip6PrependHead (
                 IpSb,
                 Fragment,
                 Head,
                 FragmentOffset,
                 ExtHdrs,
                 ExtHdrsLen,
                 LastHeaderBackup,
                 UnFragmentLen
                 );
      ASSERT (Status == EFI_SUCCESS);

      Status = Ip6SendFrame (
                 IpIf,
                 IpInstance,
                 Fragment,
                 &NextHop,
                 Ip6SysPacketSent,
                 Packet
                 );
      if (EFI_ERROR (Status)) {
        goto Error;
      }

      //
      // The last fragment of upper layer packet, update the IP6 token status.
      //
      if ((Index == Num -1) && (Context != NULL)) {
        Wrap                = (IP6_TXTOKEN_WRAP *) Context;
        Wrap->Token->Status = Status;
      }

      Offset    += PacketLen;
      PacketLen = Packet->TotalSize - Offset;
      if (PacketLen > Mtu) {
        PacketLen = Mtu;
      }
    }

    NetbufFree (Packet);
    mIp6Id++;

    if (UpdatedExtHdrs != NULL) {
      FreePool (UpdatedExtHdrs);
    }

    return EFI_SUCCESS;
  }

  //
  // Need not fragment the packet, send it in one frame.
  //
  PacketHead = (EFI_IP6_HEADER *) NetbufAllocSpace (Packet, HeadLen, NET_BUF_HEAD);
  if (PacketHead == NULL) {
    Status = EFI_BAD_BUFFER_SIZE;
    goto Error;
  }

  CopyMem (PacketHead, Head, sizeof (EFI_IP6_HEADER));
  Packet->Ip.Ip6 = PacketHead;

  if (ExtHdrs != NULL) {
    Buf = (UINT8 *) (PacketHead + 1);
    CopyMem (Buf, ExtHdrs, ExtHdrsLen);
  }

  if (UpdatedExtHdrs != NULL) {
    //
    // A Fragment Header is inserted to the packet, update the payload length.
    //
    PacketHead->PayloadLength = (UINT16) (NTOHS (PacketHead->PayloadLength) +
                                sizeof (IP6_FRAGMENT_HEADER));
    PacketHead->PayloadLength = HTONS (PacketHead->PayloadLength);
    FreePool (UpdatedExtHdrs);
  }

  return Ip6SendFrame (
           IpIf,
           IpInstance,
           Packet,
           &NextHop,
           Callback,
           Context
           );

Error:
  if (UpdatedExtHdrs != NULL) {
    FreePool (UpdatedExtHdrs);
  }
  Ip6CancelPacket (IpIf, Packet, Status);
  return Status;
}

/**
  The filter function to find a packet and all its fragments.
  The packet's fragments have their Context set to the packet.

  @param[in]  Frame            The frames hold by the low level interface.
  @param[in]  Context          Context to the function, which is the packet.

  @retval TRUE                 This is the packet to cancel or its fragments.
  @retval FALSE                This is an unrelated packet.

**/
BOOLEAN
Ip6CancelPacketFragments (
  IN IP6_LINK_TX_TOKEN   *Frame,
  IN VOID                *Context
  )
{
  if ((Frame->Packet == (NET_BUF *) Context) || (Frame->Context == Context)) {
    return TRUE;
  }

  return FALSE;
}

/**
  Remove all the frames on the interface that pass the FrameToCancel,
  either queued on ARP queues or that have already been delivered to
  MNP and not yet recycled.

  @param[in]  Interface     Interface to remove the frames from.
  @param[in]  IoStatus      The transmit status returned to the frames' callback.
  @param[in]  FrameToCancel Function to select the frame to cancel; NULL to select all.
  @param[in]  Context       Opaque parameters passed to FrameToCancel. Ignored if
                            FrameToCancel is NULL.

**/
VOID
Ip6CancelFrames (
  IN IP6_INTERFACE          *Interface,
  IN EFI_STATUS             IoStatus,
  IN IP6_FRAME_TO_CANCEL    FrameToCancel   OPTIONAL,
  IN VOID                   *Context        OPTIONAL
  )
{
  LIST_ENTRY                *Entry;
  LIST_ENTRY                *Next;
  IP6_LINK_TX_TOKEN         *Token;
  IP6_SERVICE               *IpSb;
  IP6_NEIGHBOR_ENTRY        *ArpQue;
  EFI_STATUS                Status;

  IpSb = Interface->Service;
  NET_CHECK_SIGNATURE (IpSb, IP6_SERVICE_SIGNATURE);

  //
  // Cancel all the pending frames on ARP requests
  //
  NET_LIST_FOR_EACH_SAFE (Entry, Next, &Interface->ArpQues) {
    ArpQue = NET_LIST_USER_STRUCT (Entry, IP6_NEIGHBOR_ENTRY, ArpList);

    Status = Ip6FreeNeighborEntry (
               IpSb,
               ArpQue,
               FALSE,
               FALSE,
               IoStatus,
               FrameToCancel,
               Context
               );
    ASSERT_EFI_ERROR (Status);
  }

  //
  // Cancel all the frames that have been delivered to MNP
  // but not yet recycled.
  //
  NET_LIST_FOR_EACH_SAFE (Entry, Next, &Interface->SentFrames) {
    Token = NET_LIST_USER_STRUCT (Entry, IP6_LINK_TX_TOKEN, Link);

    if ((FrameToCancel == NULL) || FrameToCancel (Token, Context)) {
      IpSb->Mnp->Cancel (IpSb->Mnp, &Token->MnpToken);
    }
  }
}

/**
  Cancel the Packet and all its fragments.

  @param[in]  IpIf                 The interface from which the Packet is sent.
  @param[in]  Packet               The Packet to cancel.
  @param[in]  IoStatus             The status returns to the sender.

**/
VOID
Ip6CancelPacket (
  IN IP6_INTERFACE    *IpIf,
  IN NET_BUF          *Packet,
  IN EFI_STATUS       IoStatus
  )
{
  Ip6CancelFrames (IpIf, IoStatus, Ip6CancelPacketFragments, Packet);
}