1 /** @file
2 Provides variable driver extended services.
3
4 Copyright (c) 2015, Intel Corporation. All rights reserved.<BR>
5 This program and the accompanying materials
6 are licensed and made available under the terms and conditions of the BSD License
7 which accompanies this distribution. The full text of the license may be found at
8 http://opensource.org/licenses/bsd-license.php
9
10 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
11 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
12
13 **/
14
15 #include "Variable.h"
16
17 /**
18 Finds variable in storage blocks of volatile and non-volatile storage areas.
19
20 This code finds variable in storage blocks of volatile and non-volatile storage areas.
21 If VariableName is an empty string, then we just return the first
22 qualified variable without comparing VariableName and VendorGuid.
23
24 @param[in] VariableName Name of the variable to be found.
25 @param[in] VendorGuid Variable vendor GUID to be found.
26 @param[out] AuthVariableInfo Pointer to AUTH_VARIABLE_INFO structure for
27 output of the variable found.
28
29 @retval EFI_INVALID_PARAMETER If VariableName is not an empty string,
30 while VendorGuid is NULL.
31 @retval EFI_SUCCESS Variable successfully found.
32 @retval EFI_NOT_FOUND Variable not found
33
34 **/
35 EFI_STATUS
36 EFIAPI
VariableExLibFindVariable(IN CHAR16 * VariableName,IN EFI_GUID * VendorGuid,OUT AUTH_VARIABLE_INFO * AuthVariableInfo)37 VariableExLibFindVariable (
38 IN CHAR16 *VariableName,
39 IN EFI_GUID *VendorGuid,
40 OUT AUTH_VARIABLE_INFO *AuthVariableInfo
41 )
42 {
43 EFI_STATUS Status;
44 VARIABLE_POINTER_TRACK Variable;
45 AUTHENTICATED_VARIABLE_HEADER *AuthVariable;
46
47 Status = FindVariable (
48 VariableName,
49 VendorGuid,
50 &Variable,
51 &mVariableModuleGlobal->VariableGlobal,
52 FALSE
53 );
54 if (EFI_ERROR (Status)) {
55 AuthVariableInfo->Data = NULL;
56 AuthVariableInfo->DataSize = 0;
57 AuthVariableInfo->Attributes = 0;
58 AuthVariableInfo->PubKeyIndex = 0;
59 AuthVariableInfo->MonotonicCount = 0;
60 AuthVariableInfo->TimeStamp = NULL;
61 return Status;
62 }
63
64 AuthVariableInfo->DataSize = DataSizeOfVariable (Variable.CurrPtr);
65 AuthVariableInfo->Data = GetVariableDataPtr (Variable.CurrPtr);
66 AuthVariableInfo->Attributes = Variable.CurrPtr->Attributes;
67 if (mVariableModuleGlobal->VariableGlobal.AuthFormat) {
68 AuthVariable = (AUTHENTICATED_VARIABLE_HEADER *) Variable.CurrPtr;
69 AuthVariableInfo->PubKeyIndex = AuthVariable->PubKeyIndex;
70 AuthVariableInfo->MonotonicCount = ReadUnaligned64 (&(AuthVariable->MonotonicCount));
71 AuthVariableInfo->TimeStamp = &AuthVariable->TimeStamp;
72 }
73
74 return EFI_SUCCESS;
75 }
76
77 /**
78 Finds next variable in storage blocks of volatile and non-volatile storage areas.
79
80 This code finds next variable in storage blocks of volatile and non-volatile storage areas.
81 If VariableName is an empty string, then we just return the first
82 qualified variable without comparing VariableName and VendorGuid.
83
84 @param[in] VariableName Name of the variable to be found.
85 @param[in] VendorGuid Variable vendor GUID to be found.
86 @param[out] AuthVariableInfo Pointer to AUTH_VARIABLE_INFO structure for
87 output of the next variable.
88
89 @retval EFI_INVALID_PARAMETER If VariableName is not an empty string,
90 while VendorGuid is NULL.
91 @retval EFI_SUCCESS Variable successfully found.
92 @retval EFI_NOT_FOUND Variable not found
93
94 **/
95 EFI_STATUS
96 EFIAPI
VariableExLibFindNextVariable(IN CHAR16 * VariableName,IN EFI_GUID * VendorGuid,OUT AUTH_VARIABLE_INFO * AuthVariableInfo)97 VariableExLibFindNextVariable (
98 IN CHAR16 *VariableName,
99 IN EFI_GUID *VendorGuid,
100 OUT AUTH_VARIABLE_INFO *AuthVariableInfo
101 )
102 {
103 EFI_STATUS Status;
104 VARIABLE_HEADER *VariablePtr;
105 AUTHENTICATED_VARIABLE_HEADER *AuthVariablePtr;
106
107 Status = VariableServiceGetNextVariableInternal (
108 VariableName,
109 VendorGuid,
110 &VariablePtr
111 );
112 if (EFI_ERROR (Status)) {
113 AuthVariableInfo->VariableName = NULL;
114 AuthVariableInfo->VendorGuid = NULL;
115 AuthVariableInfo->Data = NULL;
116 AuthVariableInfo->DataSize = 0;
117 AuthVariableInfo->Attributes = 0;
118 AuthVariableInfo->PubKeyIndex = 0;
119 AuthVariableInfo->MonotonicCount = 0;
120 AuthVariableInfo->TimeStamp = NULL;
121 return Status;
122 }
123
124 AuthVariableInfo->VariableName = GetVariableNamePtr (VariablePtr);
125 AuthVariableInfo->VendorGuid = GetVendorGuidPtr (VariablePtr);
126 AuthVariableInfo->DataSize = DataSizeOfVariable (VariablePtr);
127 AuthVariableInfo->Data = GetVariableDataPtr (VariablePtr);
128 AuthVariableInfo->Attributes = VariablePtr->Attributes;
129 if (mVariableModuleGlobal->VariableGlobal.AuthFormat) {
130 AuthVariablePtr = (AUTHENTICATED_VARIABLE_HEADER *) VariablePtr;
131 AuthVariableInfo->PubKeyIndex = AuthVariablePtr->PubKeyIndex;
132 AuthVariableInfo->MonotonicCount = ReadUnaligned64 (&(AuthVariablePtr->MonotonicCount));
133 AuthVariableInfo->TimeStamp = &AuthVariablePtr->TimeStamp;
134 }
135
136 return EFI_SUCCESS;
137 }
138
139 /**
140 Update the variable region with Variable information.
141
142 @param[in] AuthVariableInfo Pointer AUTH_VARIABLE_INFO structure for
143 input of the variable.
144
145 @retval EFI_SUCCESS The update operation is success.
146 @retval EFI_INVALID_PARAMETER Invalid parameter.
147 @retval EFI_WRITE_PROTECTED Variable is write-protected.
148 @retval EFI_OUT_OF_RESOURCES There is not enough resource.
149
150 **/
151 EFI_STATUS
152 EFIAPI
VariableExLibUpdateVariable(IN AUTH_VARIABLE_INFO * AuthVariableInfo)153 VariableExLibUpdateVariable (
154 IN AUTH_VARIABLE_INFO *AuthVariableInfo
155 )
156 {
157 VARIABLE_POINTER_TRACK Variable;
158
159 FindVariable (AuthVariableInfo->VariableName, AuthVariableInfo->VendorGuid, &Variable, &mVariableModuleGlobal->VariableGlobal, FALSE);
160 return UpdateVariable (
161 AuthVariableInfo->VariableName,
162 AuthVariableInfo->VendorGuid,
163 AuthVariableInfo->Data,
164 AuthVariableInfo->DataSize,
165 AuthVariableInfo->Attributes,
166 AuthVariableInfo->PubKeyIndex,
167 AuthVariableInfo->MonotonicCount,
168 &Variable,
169 AuthVariableInfo->TimeStamp
170 );
171 }
172
173 /**
174 Get scratch buffer.
175
176 @param[in, out] ScratchBufferSize Scratch buffer size. If input size is greater than
177 the maximum supported buffer size, this value contains
178 the maximum supported buffer size as output.
179 @param[out] ScratchBuffer Pointer to scratch buffer address.
180
181 @retval EFI_SUCCESS Get scratch buffer successfully.
182 @retval EFI_UNSUPPORTED If input size is greater than the maximum supported buffer size.
183
184 **/
185 EFI_STATUS
186 EFIAPI
VariableExLibGetScratchBuffer(IN OUT UINTN * ScratchBufferSize,OUT VOID ** ScratchBuffer)187 VariableExLibGetScratchBuffer (
188 IN OUT UINTN *ScratchBufferSize,
189 OUT VOID **ScratchBuffer
190 )
191 {
192 UINTN MaxBufferSize;
193
194 MaxBufferSize = mVariableModuleGlobal->ScratchBufferSize;
195 if (*ScratchBufferSize > MaxBufferSize) {
196 *ScratchBufferSize = MaxBufferSize;
197 return EFI_UNSUPPORTED;
198 }
199
200 *ScratchBuffer = GetEndPointer ((VARIABLE_STORE_HEADER *) ((UINTN) mVariableModuleGlobal->VariableGlobal.VolatileVariableBase));
201 return EFI_SUCCESS;
202 }
203
204 /**
205 This function is to check if the remaining variable space is enough to set
206 all Variables from argument list successfully. The purpose of the check
207 is to keep the consistency of the Variables to be in variable storage.
208
209 Note: Variables are assumed to be in same storage.
210 The set sequence of Variables will be same with the sequence of VariableEntry from argument list,
211 so follow the argument sequence to check the Variables.
212
213 @param[in] Attributes Variable attributes for Variable entries.
214 @param ... The variable argument list with type VARIABLE_ENTRY_CONSISTENCY *.
215 A NULL terminates the list. The VariableSize of
216 VARIABLE_ENTRY_CONSISTENCY is the variable data size as input.
217 It will be changed to variable total size as output.
218
219 @retval TRUE Have enough variable space to set the Variables successfully.
220 @retval FALSE No enough variable space to set the Variables successfully.
221
222 **/
223 BOOLEAN
224 EFIAPI
VariableExLibCheckRemainingSpaceForConsistency(IN UINT32 Attributes,...)225 VariableExLibCheckRemainingSpaceForConsistency (
226 IN UINT32 Attributes,
227 ...
228 )
229 {
230 VA_LIST Marker;
231 BOOLEAN Return;
232
233 VA_START (Marker, Attributes);
234
235 Return = CheckRemainingSpaceForConsistencyInternal (Attributes, Marker);
236
237 VA_END (Marker);
238
239 return Return;
240 }
241
242 /**
243 Return TRUE if at OS runtime.
244
245 @retval TRUE If at OS runtime.
246 @retval FALSE If at boot time.
247
248 **/
249 BOOLEAN
250 EFIAPI
VariableExLibAtRuntime(VOID)251 VariableExLibAtRuntime (
252 VOID
253 )
254 {
255 return AtRuntime ();
256 }
257