summaryrefslogtreecommitdiff
path: root/MdeModulePkg/Library/DxeUdpIoLib/DxeUdpIoLib.c
blob: 21af998d25449a456c42c39c67e8aa4ef237fc20 (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
/** @file
  Help functions to access UDP service, it is used by both the DHCP and MTFTP.
  
Copyright (c) 2005 - 2007, Intel Corporation.<BR>
All rights reserved. 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<BR>
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 <Uefi.h>

#include <Protocol/Udp4.h>

#include <Library/UdpIoLib.h>
#include <Library/BaseLib.h>
#include <Library/DebugLib.h>
#include <Library/UefiBootServicesTableLib.h>
#include <Library/MemoryAllocationLib.h>
#include <Library/BaseMemoryLib.h>


/**
  Free a UDP_TX_TOKEN. The TX event is closed.

  @param  Token                 The UDP_TX_TOKEN to release.

**/
VOID
UdpIoFreeTxToken (
  IN UDP_TX_TOKEN           *Token
  )
{
  gBS->CloseEvent (Token->UdpToken.Event);
  gBS->FreePool (Token);
}

/**
  Free a UDP_RX_TOKEN. The RX event is closed.

  @param  Token                 The UDP_RX_TOKEN to release.

**/
VOID
UdpIoFreeRxToken (
  IN UDP_RX_TOKEN           *Token
  )
{
  gBS->CloseEvent (Token->UdpToken.Event);
  gBS->FreePool (Token);
}

/**
  The callback function when the packet is sent by UDP.
  
  It will remove the packet from the local list then call
  the packet owner's callback function set by UdpIoSendDatagram.

  @param  Context               The UDP TX Token.

**/
VOID
EFIAPI
UdpIoOnDgramSentDpc (
  IN VOID                   *Context
  )
{
  UDP_TX_TOKEN              *Token;

  Token   = (UDP_TX_TOKEN *) Context;
  ASSERT (Token->Signature == UDP_IO_TX_SIGNATURE);

  RemoveEntryList (&Token->Link);
  Token->CallBack (Token->Packet, NULL, Token->UdpToken.Status, Token->Context);

  UdpIoFreeTxToken (Token);
}

/**
  Request UdpIoOnDgramSentDpc as a DPC at TPL_CALLBACK.
  
  @param  Event                 The event signaled.
  @param  Context               The UDP TX Token.

**/
VOID
EFIAPI
UdpIoOnDgramSent (
  IN EFI_EVENT              Event,
  IN VOID                   *Context
  )
{
  //
  // Request UdpIoOnDgramSentDpc as a DPC at TPL_CALLBACK
  //
  NetLibQueueDpc (TPL_CALLBACK, UdpIoOnDgramSentDpc, Context);
}

/**
  Recycle the received UDP data.

  @param  Context               The UDP_RX_TOKEN

**/
VOID
UdpIoRecycleDgram (
  IN VOID                   *Context
  )
{
  UDP_RX_TOKEN              *Token;

  Token = (UDP_RX_TOKEN *) Context;
  gBS->SignalEvent (Token->UdpToken.Packet.RxData->RecycleSignal);
  UdpIoFreeRxToken (Token);
}

/**
  The event handle for UDP receive request.
  
  It will build a NET_BUF from the recieved UDP data, then deliver it
  to the receiver.

  @param  Context               The UDP RX token.

**/
VOID
EFIAPI
UdpIoOnDgramRcvdDpc (
  IN VOID                   *Context
  )
{
  EFI_UDP4_COMPLETION_TOKEN *UdpToken;
  EFI_UDP4_RECEIVE_DATA     *UdpRxData;
  EFI_UDP4_SESSION_DATA     *UdpSession;
  UDP_RX_TOKEN              *Token;
  UDP_POINTS                Points;
  NET_BUF                   *Netbuf;

  Token   = (UDP_RX_TOKEN *) Context;

  ASSERT ((Token->Signature == UDP_IO_RX_SIGNATURE) &&
          (Token == Token->UdpIo->RecvRequest));

  //
  // Clear the receive request first in case that the caller
  // wants to restart the receive in the callback.
  //
  Token->UdpIo->RecvRequest = NULL;

  UdpToken  = &Token->UdpToken;
  UdpRxData = UdpToken->Packet.RxData;

  if (EFI_ERROR (UdpToken->Status) || (UdpRxData == NULL)) {
    if (UdpToken->Status != EFI_ABORTED) {
      //
      // Invoke the CallBack only if the reception is not actively aborted.
      //
      Token->CallBack (NULL, NULL, UdpToken->Status, Token->Context);
    }

    UdpIoFreeRxToken (Token);
    return;
  }

  //
  // Build a NET_BUF from the UDP receive data, then deliver it up.
  //
  Netbuf = NetbufFromExt (
             (NET_FRAGMENT *) UdpRxData->FragmentTable,
             UdpRxData->FragmentCount,
             0,
             (UINT32) Token->HeadLen,
             UdpIoRecycleDgram,
             Token
             );

  if (Netbuf == NULL) {
    gBS->SignalEvent (UdpRxData->RecycleSignal);
    Token->CallBack (NULL, NULL, EFI_OUT_OF_RESOURCES, Token->Context);

    UdpIoFreeRxToken (Token);
    return;
  }

  UdpSession        = &UdpRxData->UdpSession;
  Points.LocalPort  = UdpSession->DestinationPort;
  Points.RemotePort = UdpSession->SourcePort;

  CopyMem (&Points.LocalAddr, &UdpSession->DestinationAddress, sizeof (IP4_ADDR));
  CopyMem (&Points.RemoteAddr, &UdpSession->SourceAddress, sizeof (IP4_ADDR));
  Points.LocalAddr  = NTOHL (Points.LocalAddr);
  Points.RemoteAddr = NTOHL (Points.RemoteAddr);

  Token->CallBack (Netbuf, &Points, EFI_SUCCESS, Token->Context);
}

/**
  Request UdpIoOnDgramRcvdDpc as a DPC at TPL_CALLBACK.

  @param  Event                 The UDP receive request event.
  @param  Context               The UDP RX token.

**/
VOID
EFIAPI
UdpIoOnDgramRcvd (
  IN EFI_EVENT              Event,
  IN VOID                   *Context
  )
{
  //
  // Request UdpIoOnDgramRcvdDpc as a DPC at TPL_CALLBACK
  //
  NetLibQueueDpc (TPL_CALLBACK, UdpIoOnDgramRcvdDpc, Context);
}

/**
  Create a UDP_RX_TOKEN to wrap the request.

  @param  UdpIo                 The UdpIo to receive packets from
  @param  CallBack              The function to call when receive finished.
  @param  Context               The opaque parameter to the CallBack
  @param  HeadLen               The head length to reserver for the packet.

  @return The Wrapped request or NULL if failed to allocate resources or some errors happened.

**/
UDP_RX_TOKEN *
UdpIoCreateRxToken (
  IN UDP_IO_PORT            *UdpIo,
  IN UDP_IO_CALLBACK        CallBack,
  IN VOID                   *Context,
  IN UINT32                 HeadLen
  )
{
  UDP_RX_TOKEN              *Token;
  EFI_STATUS                Status;

  Token = AllocatePool (sizeof (UDP_RX_TOKEN));

  if (Token == NULL) {
    return NULL;
  }

  Token->Signature              = UDP_IO_RX_SIGNATURE;
  Token->UdpIo                  = UdpIo;
  Token->CallBack               = CallBack;
  Token->Context                = Context;
  Token->HeadLen                = HeadLen;

  Token->UdpToken.Status        = EFI_NOT_READY;
  Token->UdpToken.Packet.RxData = NULL;

  Status = gBS->CreateEvent (
                  EVT_NOTIFY_SIGNAL,
                  TPL_NOTIFY,
                  UdpIoOnDgramRcvd,
                  Token,
                  &Token->UdpToken.Event
                  );

  if (EFI_ERROR (Status)) {
    gBS->FreePool (Token);
    return NULL;
  }

  return Token;
}

/**
  Wrap a transmit request into a UDP_TX_TOKEN.

  @param  UdpIo                 The UdpIo port to send packet to
  @param  Packet                The user's packet
  @param  EndPoint              The local and remote access point
  @param  Gateway               The overrided next hop
  @param  CallBack              The function to call when transmission completed.
  @param  Context               The opaque parameter to the call back

  @return The wrapped transmission request or NULL if failed to allocate resources 
          or for some errors.

**/
UDP_TX_TOKEN *
UdpIoWrapTx (
  IN UDP_IO_PORT            *UdpIo,
  IN NET_BUF                *Packet,
  IN UDP_POINTS             *EndPoint  OPTIONAL,
  IN IP4_ADDR               Gateway,
  IN UDP_IO_CALLBACK        CallBack,
  IN VOID                   *Context
  )
{
  UDP_TX_TOKEN              *Token;
  EFI_UDP4_COMPLETION_TOKEN *UdpToken;
  EFI_UDP4_TRANSMIT_DATA    *UdpTxData;
  EFI_STATUS                Status;
  UINT32                    Count;
  IP4_ADDR                  Ip;

  Token = AllocatePool (sizeof (UDP_TX_TOKEN) +
                           sizeof (EFI_UDP4_FRAGMENT_DATA) * (Packet->BlockOpNum - 1));

  if (Token == NULL) {
    return NULL;
  }

  Token->Signature  = UDP_IO_TX_SIGNATURE;
  InitializeListHead (&Token->Link);

  Token->UdpIo      = UdpIo;
  Token->CallBack   = CallBack;
  Token->Packet     = Packet;
  Token->Context    = Context;

  UdpToken          = &(Token->UdpToken);
  UdpToken->Status  = EFI_NOT_READY;

  Status = gBS->CreateEvent (
                  EVT_NOTIFY_SIGNAL,
                  TPL_NOTIFY,
                  UdpIoOnDgramSent,
                  Token,
                  &UdpToken->Event
                  );

  if (EFI_ERROR (Status)) {
    gBS->FreePool (Token);
    return NULL;
  }

  UdpTxData                 = &Token->UdpTxData;
  UdpToken->Packet.TxData   = UdpTxData;

  UdpTxData->UdpSessionData = NULL;
  UdpTxData->GatewayAddress = NULL;

  if (EndPoint != NULL) {
    Ip = HTONL (EndPoint->LocalAddr);
    CopyMem (&Token->UdpSession.SourceAddress, &Ip, sizeof (EFI_IPv4_ADDRESS));

    Ip = HTONL (EndPoint->RemoteAddr);
    CopyMem (&Token->UdpSession.DestinationAddress, &Ip, sizeof (EFI_IPv4_ADDRESS));

    Token->UdpSession.SourcePort      = EndPoint->LocalPort;
    Token->UdpSession.DestinationPort = EndPoint->RemotePort;
    UdpTxData->UdpSessionData         = &Token->UdpSession;
  }

  if (Gateway != 0) {
    Ip = HTONL (Gateway);
    CopyMem (&Token->Gateway, &Ip, sizeof (EFI_IPv4_ADDRESS));

    UdpTxData->GatewayAddress = &Token->Gateway;
  }

  UdpTxData->DataLength = Packet->TotalSize;
  Count                 = Packet->BlockOpNum;
  NetbufBuildExt (Packet, (NET_FRAGMENT *) UdpTxData->FragmentTable, &Count);
  UdpTxData->FragmentCount = Count;

  return Token;
}

/**
  Create a UDP_IO_PORT to access the UDP service. It will create and configure
  a UDP child.
  
  The function will locate the UDP service binding prototype on the Controller
  parameter and use it to create a UDP child (aka Udp instance). Then the UDP
  child will be configured by calling Configure function prototype. Any failures
  in creating or configure the UDP child will lead to the failure of UDP_IO_PORT
  creation.

  @param  Controller            The controller that has the UDP service binding
                                protocol installed.
  @param  Image                 The image handle for the driver.
  @param  Configure             The function to configure the created UDP child
  @param  Context               The opaque parameter for the Configure funtion.

  @return Newly-created UDP_IO_PORT or NULL if failed.

**/
UDP_IO_PORT *
EFIAPI
UdpIoCreatePort (
  IN  EFI_HANDLE            Controller,
  IN  EFI_HANDLE            Image,
  IN  UDP_IO_CONFIG         Configure,
  IN  VOID                  *Context
  )
{
  UDP_IO_PORT               *UdpIo;
  EFI_STATUS                Status;

  ASSERT (Configure != NULL);

  UdpIo = AllocatePool (sizeof (UDP_IO_PORT));

  if (UdpIo == NULL) {
    return NULL;
  }

  UdpIo->Signature    = UDP_IO_SIGNATURE;
  InitializeListHead (&UdpIo->Link);
  UdpIo->RefCnt       = 1;

  UdpIo->Controller   = Controller;
  UdpIo->Image        = Image;

  InitializeListHead (&UdpIo->SentDatagram);
  UdpIo->RecvRequest  = NULL;
  UdpIo->UdpHandle    = NULL;

  //
  // Create a UDP child then open and configure it
  //
  Status = NetLibCreateServiceChild (
             Controller,
             Image,
             &gEfiUdp4ServiceBindingProtocolGuid,
             &UdpIo->UdpHandle
             );

  if (EFI_ERROR (Status)) {
    goto FREE_MEM;
  }

  Status = gBS->OpenProtocol (
                  UdpIo->UdpHandle,
                  &gEfiUdp4ProtocolGuid,
                  (VOID **) &UdpIo->Udp,
                  Image,
                  Controller,
                  EFI_OPEN_PROTOCOL_BY_DRIVER
                  );

  if (EFI_ERROR (Status)) {
    goto FREE_CHILD;
  }

  if (EFI_ERROR (Configure (UdpIo, Context))) {
    goto CLOSE_PROTOCOL;
  }

  Status = UdpIo->Udp->GetModeData (UdpIo->Udp, NULL, NULL, NULL, &UdpIo->SnpMode);

  if (EFI_ERROR (Status)) {
    goto CLOSE_PROTOCOL;
  }

  return UdpIo;

CLOSE_PROTOCOL:
  gBS->CloseProtocol (UdpIo->UdpHandle, &gEfiUdp4ProtocolGuid, Image, Controller);

FREE_CHILD:
  NetLibDestroyServiceChild (
    Controller,
    Image,
    &gEfiUdp4ServiceBindingProtocolGuid,
    UdpIo->UdpHandle
    );

FREE_MEM:
  gBS->FreePool (UdpIo);
  return NULL;
}

/**
  Cancel all the sent datagram that pass the selection criteria of ToCancel.
  If ToCancel is NULL, all the datagrams are cancelled.

  @param  UdpIo                 The UDP_IO_PORT to cancel packet
  @param  IoStatus              The IoStatus to return to the packet owners.
  @param  ToCancel              The select funtion to test whether to cancel this
                                packet or not.
  @param  Context               The opaque parameter to the ToCancel.

**/
VOID
UdpIoCancelDgrams (
  IN UDP_IO_PORT            *UdpIo,
  IN EFI_STATUS             IoStatus,
  IN UDP_IO_TO_CANCEL       ToCancel,        OPTIONAL
  IN VOID                   *Context
  )
{
  LIST_ENTRY                *Entry;
  LIST_ENTRY                *Next;
  UDP_TX_TOKEN              *Token;

  NET_LIST_FOR_EACH_SAFE (Entry, Next, &UdpIo->SentDatagram) {
    Token = NET_LIST_USER_STRUCT (Entry, UDP_TX_TOKEN, Link);

    if ((ToCancel == NULL) || (ToCancel (Token, Context))) {
      UdpIo->Udp->Cancel (UdpIo->Udp, &Token->UdpToken);
    }
  }
}

/**
  Free the UDP_IO_PORT and all its related resources.
  
  The function will cancel all sent datagram and receive request.

  @param  UdpIo                 The UDP_IO_PORT to free.

  @retval EFI_SUCCESS           The UDP_IO_PORT is freed.

**/
EFI_STATUS
EFIAPI
UdpIoFreePort (
  IN  UDP_IO_PORT           *UdpIo
  )
{
  UDP_RX_TOKEN  *RxToken;

  //
  // Cancel all the sent datagram and receive requests. The
  // callbacks of transmit requests are executed to allow the
  // caller to release the resource. The callback of receive
  // request are NOT executed. This is because it is most
  // likely that the current user of the UDP IO port is closing
  // itself.
  //
  UdpIoCancelDgrams (UdpIo, EFI_ABORTED, NULL, NULL);

  if ((RxToken = UdpIo->RecvRequest) != NULL) {
    UdpIo->Udp->Cancel (UdpIo->Udp, &RxToken->UdpToken);
  }

  //
  // Close then destory the UDP child
  //
  gBS->CloseProtocol (
         UdpIo->UdpHandle,
         &gEfiUdp4ProtocolGuid,
         UdpIo->Image,
         UdpIo->Controller
         );

  NetLibDestroyServiceChild (
    UdpIo->Controller,
    UdpIo->Image,
    &gEfiUdp4ServiceBindingProtocolGuid,
    UdpIo->UdpHandle
    );

  if (!IsListEmpty(&UdpIo->Link)) {
    RemoveEntryList (&UdpIo->Link);
  }

  gBS->FreePool (UdpIo);
  return EFI_SUCCESS;
}


/**
  Clean up the UDP_IO_PORT without freeing it. The function is called when
  user wants to re-use the UDP_IO_PORT later.
  
  It will release all the transmitted datagrams and receive request. It will
  also configure NULL for the UDP instance.

  @param  UdpIo                 The UDP_IO_PORT to clean up.

**/
VOID
EFIAPI
UdpIoCleanPort (
  IN  UDP_IO_PORT           *UdpIo
  )
{
  UDP_RX_TOKEN              *RxToken;

  //
  // Cancel all the sent datagram and receive requests.
  //
  UdpIoCancelDgrams (UdpIo, EFI_ABORTED, NULL, NULL);

  if ((RxToken = UdpIo->RecvRequest) != NULL) {
    UdpIo->Udp->Cancel (UdpIo->Udp, &RxToken->UdpToken);
  }

  UdpIo->Udp->Configure (UdpIo->Udp, NULL);
}

/**
  Send a packet through the UDP_IO_PORT.
  
  The packet will be wrapped in UDP_TX_TOKEN. Function Callback will be called
  when the packet is sent. The optional parameter EndPoint overrides the default
  address pair if specified.

  @param  UdpIo                 The UDP_IO_PORT to send the packet through
  @param  Packet                The packet to send
  @param  EndPoint              The local and remote access point. Override the
                                default address pair set during configuration.
  @param  Gateway               The gateway to use
  @param  CallBack              The function being called when packet is
                                transmitted or failed.
  @param  Context               The opaque parameter passed to CallBack

  @retval EFI_OUT_OF_RESOURCES  Failed to allocate resource for the packet
  @retval EFI_SUCCESS           The packet is successfully delivered to UDP  for
                                transmission.

**/
EFI_STATUS
EFIAPI
UdpIoSendDatagram (
  IN  UDP_IO_PORT           *UdpIo,
  IN  NET_BUF               *Packet,
  IN  UDP_POINTS            *EndPoint, OPTIONAL
  IN  IP4_ADDR              Gateway,
  IN  UDP_IO_CALLBACK       CallBack,
  IN  VOID                  *Context
  )
{
  UDP_TX_TOKEN              *Token;
  EFI_STATUS                Status;

  Token = UdpIoWrapTx (UdpIo, Packet, EndPoint, Gateway, CallBack, Context);

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

  //
  // Insert the tx token into SendDatagram list before transmitting it. Remove
  // it from the list if the returned status is not EFI_SUCCESS.
  //
  InsertHeadList (&UdpIo->SentDatagram, &Token->Link);
  Status = UdpIo->Udp->Transmit (UdpIo->Udp, &Token->UdpToken);
  if (EFI_ERROR (Status)) {
    RemoveEntryList (&Token->Link);
    UdpIoFreeTxToken (Token);
    return Status;
  }

  return EFI_SUCCESS;
}


/**
  The select function to cancel a single sent datagram.

  @param  Token                 The UDP_TX_TOKEN to test against
  @param  Context               The NET_BUF of the sent datagram

  @retval TRUE              The packet is to be cancelled.
  @retval FALSE             The packet is not to be cancelled.
**/
BOOLEAN
UdpIoCancelSingleDgram (
  IN UDP_TX_TOKEN           *Token,
  IN VOID                   *Context
  )
{
  NET_BUF                   *Packet;

  Packet = (NET_BUF *) Context;

  if (Token->Packet == Packet) {
    return TRUE;
  }

  return FALSE;
}

/**
  Cancel a single sent datagram.

  @param  UdpIo                 The UDP_IO_PORT to cancel the packet from
  @param  Packet                The packet to cancel

**/
VOID
EFIAPI
UdpIoCancelSentDatagram (
  IN  UDP_IO_PORT           *UdpIo,
  IN  NET_BUF               *Packet
  )
{
  UdpIoCancelDgrams (UdpIo, EFI_ABORTED, UdpIoCancelSingleDgram, Packet);
}

/**
  Issue a receive request to the UDP_IO_PORT.
  
  This function is called when upper-layer needs packet from UDP for processing.
  Only one receive request is acceptable at a time so a common usage model is
  to invoke this function inside its Callback function when the former packet
  is processed.

  @param  UdpIo                 The UDP_IO_PORT to receive the packet from.
  @param  CallBack              The call back function to execute when the packet
                                is received.
  @param  Context               The opaque context passed to Callback
  @param  HeadLen               The length of the upper-layer's protocol header

  @retval EFI_ALREADY_STARTED   There is already a pending receive request. Only
                                one receive request is supported at a time.
  @retval EFI_OUT_OF_RESOURCES  Failed to allocate needed resources.
  @retval EFI_SUCCESS           The receive request is issued successfully.

**/
EFI_STATUS
EFIAPI
UdpIoRecvDatagram (
  IN  UDP_IO_PORT           *UdpIo,
  IN  UDP_IO_CALLBACK       CallBack,
  IN  VOID                  *Context,
  IN  UINT32                HeadLen
  )
{
  UDP_RX_TOKEN              *Token;
  EFI_STATUS                Status;

  if (UdpIo->RecvRequest != NULL) {
    return EFI_ALREADY_STARTED;
  }

  Token = UdpIoCreateRxToken (UdpIo, CallBack, Context, HeadLen);

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

  UdpIo->RecvRequest = Token;
  Status = UdpIo->Udp->Receive (UdpIo->Udp, &Token->UdpToken);

  if (EFI_ERROR (Status)) {
    UdpIo->RecvRequest = NULL;
    UdpIoFreeRxToken (Token);
  }

  return Status;
}