summaryrefslogtreecommitdiff
path: root/NetworkPkg/Mtftp6Dxe/Mtftp6Driver.c
blob: 28aacf198a271609bca383df8466755970ed1bbc (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
/** @file
  Driver Binding functions and Service Binding functions
  implementation for Mtftp6 Driver.

  Copyright (c) 2009 - 2011, 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 "Mtftp6Impl.h"


EFI_DRIVER_BINDING_PROTOCOL   gMtftp6DriverBinding = {
  Mtftp6DriverBindingSupported,
  Mtftp6DriverBindingStart,
  Mtftp6DriverBindingStop,
  0xa,
  NULL,
  NULL
};

EFI_SERVICE_BINDING_PROTOCOL  gMtftp6ServiceBindingTemplate = {
  Mtftp6ServiceBindingCreateChild,
  Mtftp6ServiceBindingDestroyChild
};


/**
  Destory the MTFTP6 service. The MTFTP6 service may be partly initialized,
  or partly destroyed. If a resource is destroyed, it is marked as such in
  case the destroy failed and is called again later.

  @param[in]  Service            The MTFTP6 service to be destroyed.

**/
VOID
Mtftp6DestroyService (
  IN MTFTP6_SERVICE     *Service
  )
{
  //
  // Make sure all children instances have been already destoryed.
  //
  ASSERT (Service->ChildrenNum == 0);

  if (Service->DummyUdpIo != NULL) {
    UdpIoFreeIo (Service->DummyUdpIo);
  }

  if (Service->Timer != NULL) {
    gBS->CloseEvent (Service->Timer);
  }

  FreePool (Service);
}


/**
  Create then initialize a MTFTP6 service binding instance.

  @param[in]  Controller             The controller to install the MTFTP6 service
                                     binding on.
  @param[in]  Image                  The driver binding image of the MTFTP6 driver.
  @param[out] Service                The variable to receive the created service
                                     binding instance.

  @retval EFI_OUT_OF_RESOURCES   Failed to allocate resources to create the instance
  @retval EFI_DEVICE_ERROR       Failed to create a NULL UDP port to keep connection with UDP.
  @retval EFI_SUCCESS            The service instance is created for the controller.

**/
EFI_STATUS
Mtftp6CreateService (
  IN  EFI_HANDLE            Controller,
  IN  EFI_HANDLE            Image,
  OUT MTFTP6_SERVICE        **Service
  )
{
  MTFTP6_SERVICE            *Mtftp6Srv;
  EFI_STATUS                Status;

  ASSERT (Service != NULL);

  *Service  = NULL;
  Mtftp6Srv = AllocateZeroPool (sizeof (MTFTP6_SERVICE));

  if (Mtftp6Srv == NULL) {
    return EFI_OUT_OF_RESOURCES;
  }

  Mtftp6Srv->Signature      = MTFTP6_SERVICE_SIGNATURE;
  Mtftp6Srv->Controller     = Controller;
  Mtftp6Srv->Image          = Image;
  Mtftp6Srv->InDestory      = FALSE;
  Mtftp6Srv->ChildrenNum    = 0;

  CopyMem (
    &Mtftp6Srv->ServiceBinding,
    &gMtftp6ServiceBindingTemplate,
    sizeof (EFI_SERVICE_BINDING_PROTOCOL)
    );

  InitializeListHead (&Mtftp6Srv->Children);

  //
  // Create a internal timer for all instances.
  //
  Status = gBS->CreateEvent (
                  EVT_NOTIFY_SIGNAL | EVT_TIMER,
                  TPL_CALLBACK,
                  Mtftp6OnTimerTick,
                  Mtftp6Srv,
                  &Mtftp6Srv->Timer
                  );

  if (EFI_ERROR (Status)) {
    FreePool (Mtftp6Srv);
    return Status;
  }

  //
  // Create a dummy Udp6Io to build parent-child relationship between Udp6 driver
  // and Mtftp6 driver.
  //
  Mtftp6Srv->DummyUdpIo = UdpIoCreateIo (
                            Controller,
                            Image,
                            Mtftp6ConfigDummyUdpIo,
                            UDP_IO_UDP6_VERSION,
                            NULL
                            );

  if (Mtftp6Srv->DummyUdpIo == NULL) {
    gBS->CloseEvent (Mtftp6Srv->Timer);
    FreePool (Mtftp6Srv);
    return EFI_DEVICE_ERROR;
  }

  *Service = Mtftp6Srv;
  return EFI_SUCCESS;
}


/**
  Destroy the MTFTP6 instance and recycle the resources.

  @param[in]  Instance        The pointer to the MTFTP6 instance.

**/
VOID
Mtftp6DestroyInstance (
  IN MTFTP6_INSTANCE         *Instance
  )
{
  LIST_ENTRY                 *Entry;
  LIST_ENTRY                 *Next;
  MTFTP6_BLOCK_RANGE         *Block;

  if (Instance->Config != NULL) {
    FreePool (Instance->Config);
  }

  if (Instance->Token != NULL && Instance->Token->Event != NULL) {
    gBS->SignalEvent (Instance->Token->Event);
  }

  if (Instance->LastPacket != NULL) {
    NetbufFree (Instance->LastPacket);
  }

  if (Instance->UdpIo!= NULL) {
    UdpIoFreeIo (Instance->UdpIo);
  }

  if (Instance->McastUdpIo != NULL) {
    UdpIoFreeIo (Instance->McastUdpIo);
  }

  NET_LIST_FOR_EACH_SAFE (Entry, Next, &Instance->BlkList) {
    Block = NET_LIST_USER_STRUCT (Entry, MTFTP6_BLOCK_RANGE, Link);
    RemoveEntryList (Entry);
    FreePool (Block);
  }

  FreePool (Instance);
}


/**
  Create the MTFTP6 instance and initialize it.

  @param[in]  Service              The pointer to the MTFTP6 service.
  @param[out] Instance             The pointer to the MTFTP6 instance.

  @retval EFI_OUT_OF_RESOURCES   Failed to allocate resources.
  @retval EFI_SUCCESS            The MTFTP6 instance is created.

**/
EFI_STATUS
Mtftp6CreateInstance (
  IN  MTFTP6_SERVICE         *Service,
  OUT MTFTP6_INSTANCE        **Instance
  )
{
  MTFTP6_INSTANCE            *Mtftp6Ins;

  *Instance = NULL;
  Mtftp6Ins = AllocateZeroPool (sizeof (MTFTP6_INSTANCE));

  if (Mtftp6Ins == NULL) {
    return EFI_OUT_OF_RESOURCES;
  }

  Mtftp6Ins->Signature = MTFTP6_INSTANCE_SIGNATURE;
  Mtftp6Ins->InDestory = FALSE;
  Mtftp6Ins->Service   = Service;

  CopyMem (
    &Mtftp6Ins->Mtftp6,
    &gMtftp6ProtocolTemplate,
    sizeof (EFI_MTFTP6_PROTOCOL)
    );

  InitializeListHead (&Mtftp6Ins->Link);
  InitializeListHead (&Mtftp6Ins->BlkList);

  *Instance = Mtftp6Ins;

  return EFI_SUCCESS;
}


/**
  This is the declaration of an EFI image entry point. This entry point is
  the same for UEFI Applications, UEFI OS Loaders, and UEFI Drivers, including
  both device drivers and bus drivers.

  Entry point of the MTFTP6 driver to install various protocols.

  @param[in]  ImageHandle           The firmware allocated handle for the UEFI image.
  @param[in]  SystemTable           The pointer to the EFI System Table.

  @retval EFI_SUCCESS           The operation completed successfully.
  @retval EFI_OUT_OF_RESOURCES  The request could not be completed due to a lack of resources.

**/
EFI_STATUS
EFIAPI
Mtftp6DriverEntryPoint (
  IN EFI_HANDLE             ImageHandle,
  IN EFI_SYSTEM_TABLE       *SystemTable
  )
{
  return EfiLibInstallDriverBindingComponentName2 (
           ImageHandle,
           SystemTable,
           &gMtftp6DriverBinding,
           ImageHandle,
           &gMtftp6ComponentName,
           &gMtftp6ComponentName2
           );
}


/**
  Test to see if this driver supports Controller. This service
  is called by the EFI boot service ConnectController(). In
  order to make drivers as small as possible, there are calling
  restrictions for this service. ConnectController() must
  follow these calling restrictions. If any other agent wishes to call
  Supported(), it must also follow these calling restrictions.

  @param[in]  This                Protocol instance pointer.
  @param[in]  Controller          Handle of device to test
  @param[in]  RemainingDevicePath Optional parameter use to pick a specific child.
                                  device to start.

  @retval EFI_SUCCESS         This driver supports this device.
  @retval Others              This driver does not support this device.

**/
EFI_STATUS
EFIAPI
Mtftp6DriverBindingSupported (
  IN EFI_DRIVER_BINDING_PROTOCOL    *This,
  IN EFI_HANDLE                     Controller,
  IN EFI_DEVICE_PATH_PROTOCOL       *RemainingDevicePath
  )
{
  return gBS->OpenProtocol (
                Controller,
                &gEfiUdp6ServiceBindingProtocolGuid,
                NULL,
                This->DriverBindingHandle,
                Controller,
                EFI_OPEN_PROTOCOL_TEST_PROTOCOL
                );
}


/**
  Start this driver on Controller. This service is called by the
  EFI boot service ConnectController(). In order to make
  drivers as small as possible, there are calling restrictions for
  this service. ConnectController() must follow these
  calling restrictions. If any other agent wishes to call Start() it
  must also follow these calling restrictions.

  @param[in]  This                 Protocol instance pointer.
  @param[in]  Controller           Handle of device to bind driver to.
  @param[in]  RemainingDevicePath  Optional parameter use to pick a specific child
                                   device to start.

  @retval EFI_SUCCESS          This driver is added to Controller.
  @retval EFI_ALREADY_STARTED  This driver is already running on Controller.
  @retval Others               This driver does not support this device.

**/
EFI_STATUS
EFIAPI
Mtftp6DriverBindingStart (
  IN EFI_DRIVER_BINDING_PROTOCOL  *This,
  IN EFI_HANDLE                   Controller,
  IN EFI_DEVICE_PATH_PROTOCOL     *RemainingDevicePath
  )
{
  MTFTP6_SERVICE            *Service;
  EFI_STATUS                Status;

  //
  // Directly return if driver is already running on this Nic handle.
  //
  Status = gBS->OpenProtocol (
                  Controller,
                  &gEfiMtftp6ServiceBindingProtocolGuid,
                  NULL,
                  This->DriverBindingHandle,
                  Controller,
                  EFI_OPEN_PROTOCOL_TEST_PROTOCOL
                  );

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

  //
  // Create Mtftp6 service for this Nic handle
  //
  Status = Mtftp6CreateService (
             Controller,
             This->DriverBindingHandle,
             &Service
             );

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

  ASSERT (Service != NULL);

  //
  // Start the internal timer to track the packet retransmission.
  //
  Status = gBS->SetTimer (
                  Service->Timer,
                  TimerPeriodic,
                  TICKS_PER_SECOND
                  );

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

  //
  // Install the Mtftp6 service on the Nic handle.
  //
  Status = gBS->InstallMultipleProtocolInterfaces (
                  &Controller,
                  &gEfiMtftp6ServiceBindingProtocolGuid,
                  &Service->ServiceBinding,
                  NULL
                  );

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

  return EFI_SUCCESS;

ON_ERROR:

  Mtftp6DestroyService (Service);
  return Status;
}


/**
  Stop this driver on Controller. This service is called by the
  EFI boot service DisconnectController(). In order to
  make drivers as small as possible, there are calling
  restrictions for this service. DisconnectController()
  must follow these calling restrictions. If any other agent wishes
  to call Stop(), it must also follow these calling restrictions.

  @param[in]  This              Protocol instance pointer.
  @param[in]  Controller        Handle of device to stop driver on
  @param[in]  NumberOfChildren  Number of Handles in ChildHandleBuffer. If number of
                                children is zero, stop the entire bus driver.
  @param[in]  ChildHandleBuffer List of Child Handles to Stop.

  @retval EFI_SUCCESS       This driver is removed Controller.
  @retval EFI_DEVICE_ERROR  An unexpected error.
  @retval Others            This driver was not removed from this device.

**/
EFI_STATUS
EFIAPI
Mtftp6DriverBindingStop (
  IN  EFI_DRIVER_BINDING_PROTOCOL *This,
  IN  EFI_HANDLE                  Controller,
  IN  UINTN                       NumberOfChildren,
  IN  EFI_HANDLE                  *ChildHandleBuffer
  )
{
  EFI_SERVICE_BINDING_PROTOCOL  *ServiceBinding;
  MTFTP6_SERVICE                *Service;
  MTFTP6_INSTANCE               *Instance;
  EFI_HANDLE                    NicHandle;
  EFI_STATUS                    Status;
  EFI_TPL                       OldTpl;

  //
  // Locate the Nic handle to retrieve the Mtftp6 private data.
  //
  NicHandle = NetLibGetNicHandle (Controller, &gEfiUdp6ProtocolGuid);

  if (NicHandle == NULL) {
    return EFI_DEVICE_ERROR;
  }

  Status = gBS->OpenProtocol (
                  NicHandle,
                  &gEfiMtftp6ServiceBindingProtocolGuid,
                  (VOID **) &ServiceBinding,
                  This->DriverBindingHandle,
                  NicHandle,
                  EFI_OPEN_PROTOCOL_GET_PROTOCOL
                  );

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

  Service = MTFTP6_SERVICE_FROM_THIS (ServiceBinding);

  if (Service->InDestory) {
    return EFI_SUCCESS;
  }

  OldTpl = gBS->RaiseTPL (TPL_CALLBACK);

  if (NumberOfChildren == 0) {
    //
    // Destory the Mtftp6 service if there is no Mtftp6 child instance left.
    //
    Service->InDestory = TRUE;

    gBS->UninstallProtocolInterface (
           NicHandle,
           &gEfiMtftp6ServiceBindingProtocolGuid,
           ServiceBinding
           );

    Mtftp6DestroyService (Service);

  } else {
    //
    // Destory the Mtftp6 child instance one by one.
    //
    while (!IsListEmpty (&Service->Children)) {
      Instance = NET_LIST_HEAD (&Service->Children, MTFTP6_INSTANCE, Link);
      Mtftp6ServiceBindingDestroyChild (ServiceBinding, Instance->Handle);
    }

    if (Service->ChildrenNum != 0) {
      Status = EFI_DEVICE_ERROR;
    }
  }

  gBS->RestoreTPL (OldTpl);
  return Status;
}


/**
  Creates a child handle and installs a protocol.

  The CreateChild() function installs a protocol on ChildHandle.
  If ChildHandle is a pointer to NULL, then a new handle is created and returned in ChildHandle.
  If ChildHandle is not a pointer to NULL, then the protocol installs on the existing ChildHandle.

  @param[in]      This        Pointer to the EFI_SERVICE_BINDING_PROTOCOL instance.
  @param[in, out] ChildHandle Pointer to the handle of the child to create. If it is NULL,
                              then a new handle is created. If it is a pointer to an existing
                              UEFI handle, then the protocol is added to the existing UEFI handle.

  @retval EFI_SUCCES            The protocol was added to ChildHandle.
  @retval EFI_INVALID_PARAMETER ChildHandle is NULL.
  @retval Others                The child handle was not created.

**/
EFI_STATUS
EFIAPI
Mtftp6ServiceBindingCreateChild (
  IN     EFI_SERVICE_BINDING_PROTOCOL  *This,
  IN OUT EFI_HANDLE                    *ChildHandle
  )
{
  MTFTP6_SERVICE            *Service;
  MTFTP6_INSTANCE           *Instance;
  EFI_STATUS                Status;
  EFI_TPL                   OldTpl;
  VOID                      *Udp6;

  if (This == NULL || ChildHandle == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  Service = MTFTP6_SERVICE_FROM_THIS (This);

  Status = Mtftp6CreateInstance (Service, &Instance);

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

  ASSERT (Instance != NULL);

  //
  // Install the Mtftp6 protocol on the new child handle.
  //
  Status = gBS->InstallMultipleProtocolInterfaces (
                  ChildHandle,
                  &gEfiMtftp6ProtocolGuid,
                  &Instance->Mtftp6,
                  NULL
                  );

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

  Instance->Handle = *ChildHandle;

  //
  // Open the Udp6 protocol by child.
  //
  Status = gBS->OpenProtocol (
                  Service->DummyUdpIo->UdpHandle,
                  &gEfiUdp6ProtocolGuid,
                  (VOID **) &Udp6,
                  gMtftp6DriverBinding.DriverBindingHandle,
                  Instance->Handle,
                  EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER
                  );

  if (EFI_ERROR (Status)) {
    gBS->UninstallMultipleProtocolInterfaces (
           Instance->Handle,
           &gEfiMtftp6ProtocolGuid,
           &Instance->Mtftp6,
           NULL
           );

    goto ON_ERROR;
  }

  //
  // Add the new Mtftp6 instance into the children list of Mtftp6 service.
  //
  OldTpl = gBS->RaiseTPL (TPL_CALLBACK);

  InsertTailList (&Service->Children, &Instance->Link);
  Service->ChildrenNum++;

  gBS->RestoreTPL (OldTpl);
  return EFI_SUCCESS;

ON_ERROR:

  Mtftp6DestroyInstance (Instance);
  return Status;
}


/**
  Destroys a child handle with a protocol installed on it.

  The DestroyChild() function does the opposite of CreateChild(). It removes a protocol
  that was installed by CreateChild() from ChildHandle. If the removed protocol is the
  last protocol on ChildHandle, then ChildHandle is destroyed.

  @param[in]  This        Pointer to the EFI_SERVICE_BINDING_PROTOCOL instance.
  @param[in]  ChildHandle Handle of the child to destroy.

  @retval EFI_SUCCES            The protocol was removed from ChildHandle.
  @retval EFI_UNSUPPORTED       ChildHandle does not support the protocol that is being removed.
  @retval EFI_INVALID_PARAMETER Child handle is NULL.
  @retval Others                The child handle was not destroyed

**/
EFI_STATUS
EFIAPI
Mtftp6ServiceBindingDestroyChild (
  IN EFI_SERVICE_BINDING_PROTOCOL *This,
  IN EFI_HANDLE                   ChildHandle
  )
{
  MTFTP6_SERVICE            *Service;
  MTFTP6_INSTANCE           *Instance;
  EFI_MTFTP6_PROTOCOL       *Mtftp6;
  EFI_STATUS                Status;
  EFI_TPL                   OldTpl;

  if (This == NULL || ChildHandle == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  //
  // Locate the Nic handle to retrieve the Mtftp6 private data.
  //
  Status = gBS->OpenProtocol (
                  ChildHandle,
                  &gEfiMtftp6ProtocolGuid,
                  (VOID **) &Mtftp6,
                  gMtftp6DriverBinding.DriverBindingHandle,
                  ChildHandle,
                  EFI_OPEN_PROTOCOL_GET_PROTOCOL
                  );

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

  Instance = MTFTP6_INSTANCE_FROM_THIS (Mtftp6);
  Service  = MTFTP6_SERVICE_FROM_THIS (This);

  if (Instance->Service != Service) {
    return EFI_INVALID_PARAMETER;
  }

  //
  // Check whether the instance already in destory state.
  //
  if (Instance->InDestory) {
    return EFI_SUCCESS;
  }

  OldTpl = gBS->RaiseTPL (TPL_CALLBACK);

  Instance->InDestory = TRUE;

  gBS->CloseProtocol (
         Service->DummyUdpIo->UdpHandle,
         &gEfiUdp6ProtocolGuid,
         gMtftp6DriverBinding.DriverBindingHandle,
         ChildHandle
         );

  //
  // Uninstall the MTFTP6 protocol first to enable a top down destruction.
  //
  Status = gBS->UninstallProtocolInterface (
                  ChildHandle,
                  &gEfiMtftp6ProtocolGuid,
                  Mtftp6
                  );

  if (EFI_ERROR (Status)) {
    Instance->InDestory = FALSE;
    gBS->RestoreTPL (OldTpl);
    return Status;
  }

  //
  // Remove the Mtftp6 instance from the children list of Mtftp6 service.
  //
  RemoveEntryList (&Instance->Link);
  Service->ChildrenNum --;

  Mtftp6DestroyInstance (Instance);

  gBS->RestoreTPL (OldTpl);

  return EFI_SUCCESS;
}