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 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 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 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 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 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 251 VariableExLibAtRuntime ( 252 VOID 253 ) 254 { 255 return AtRuntime (); 256 } 257
