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
|
/** @file -- VariablePolicyLib.h
Business logic for Variable Policy enforcement.
Copyright (c) Microsoft Corporation.
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#ifndef _VARIABLE_POLICY_LIB_H_
#define _VARIABLE_POLICY_LIB_H_
#include <Protocol/VariablePolicy.h>
/**
This API function validates and registers a new policy with
the policy enforcement engine.
@param[in] NewPolicy Pointer to the incoming policy structure.
@retval EFI_SUCCESS
@retval EFI_INVALID_PARAMETER NewPolicy is NULL or is internally inconsistent.
@retval EFI_ALREADY_STARTED An identical matching policy already exists.
@retval EFI_WRITE_PROTECTED The interface has been locked until the next reboot.
@retval EFI_UNSUPPORTED Policy enforcement has been disabled. No reason to add more policies.
@retval EFI_ABORTED A calculation error has prevented this function from completing.
@retval EFI_OUT_OF_RESOURCES Cannot grow the table to hold any more policies.
@retval EFI_NOT_READY Library has not yet been initialized.
**/
EFI_STATUS
EFIAPI
RegisterVariablePolicy (
IN CONST VARIABLE_POLICY_ENTRY *NewPolicy
);
/**
This API function checks to see whether the parameters to SetVariable would
be allowed according to the current variable policies.
@param[in] VariableName Same as EFI_SET_VARIABLE.
@param[in] VendorGuid Same as EFI_SET_VARIABLE.
@param[in] Attributes Same as EFI_SET_VARIABLE.
@param[in] DataSize Same as EFI_SET_VARIABLE.
@param[in] Data Same as EFI_SET_VARIABLE.
@retval EFI_SUCCESS A matching policy allows this update.
@retval EFI_SUCCESS There are currently no policies that restrict this update.
@retval EFI_SUCCESS The protections have been disable until the next reboot.
@retval EFI_WRITE_PROTECTED Variable is currently locked.
@retval EFI_INVALID_PARAMETER Attributes or size are invalid.
@retval EFI_ABORTED A lock policy exists, but an error prevented evaluation.
@retval EFI_NOT_READY Library has not been initialized.
**/
EFI_STATUS
EFIAPI
ValidateSetVariable (
IN CHAR16 *VariableName,
IN EFI_GUID *VendorGuid,
IN UINT32 Attributes,
IN UINTN DataSize,
IN VOID *Data
);
/**
This API function disables the variable policy enforcement. If it's
already been called once, will return EFI_ALREADY_STARTED.
@retval EFI_SUCCESS
@retval EFI_ALREADY_STARTED Has already been called once this boot.
@retval EFI_WRITE_PROTECTED Interface has been locked until reboot.
@retval EFI_WRITE_PROTECTED Interface option is disabled by platform PCD.
@retval EFI_NOT_READY Library has not yet been initialized.
**/
EFI_STATUS
EFIAPI
DisableVariablePolicy (
VOID
);
/**
This API function will dump the entire contents of the variable policy table.
Similar to GetVariable, the first call can be made with a 0 size and it will return
the size of the buffer required to hold the entire table.
@param[out] Policy Pointer to the policy buffer. Can be NULL if Size is 0.
@param[in,out] Size On input, the size of the output buffer. On output, the size
of the data returned.
@retval EFI_SUCCESS Policy data is in the output buffer and Size has been updated.
@retval EFI_INVALID_PARAMETER Size is NULL, or Size is non-zero and Policy is NULL.
@retval EFI_BUFFER_TOO_SMALL Size is insufficient to hold policy. Size updated with required size.
@retval EFI_NOT_READY Library has not yet been initialized.
**/
EFI_STATUS
EFIAPI
DumpVariablePolicy (
OUT UINT8 *Policy,
IN OUT UINT32 *Size
);
/**
This function will return variable policy information for a UEFI variable with a
registered variable policy.
@param[in] VariableName The name of the variable to use for the policy search.
@param[in] VendorGuid The vendor GUID of the variable to use for the policy search.
@param[in,out] VariablePolicyVariableNameBufferSize On input, the size, in bytes, of the VariablePolicyVariableName
buffer.
On output, the size, in bytes, needed to store the variable
policy variable name.
If testing for the VariablePolicyVariableName buffer size
needed, set this value to zero so EFI_BUFFER_TOO_SMALL is
guaranteed to be returned if the variable policy variable name
is found.
@param[out] VariablePolicy Pointer to a buffer where the policy entry will be written
if found.
@param[out] VariablePolicyVariableName Pointer to a buffer where the variable name used for the
variable policy will be written if a variable name is
registered.
If the variable policy is not associated with a variable name
(e.g. applied to variable vendor namespace) and this parameter
is given, this parameter will not be modified and
VariablePolicyVariableNameBufferSize will be set to zero to
indicate a name was not present.
If the pointer given is not NULL,
VariablePolicyVariableNameBufferSize must be non-NULL.
@retval EFI_SUCCESS A variable policy entry was found and returned successfully.
@retval EFI_BAD_BUFFER_SIZE An internal buffer size caused a calculation error.
@retval EFI_BUFFER_TOO_SMALL The VariablePolicyVariableName buffer value is too small for the size needed.
The buffer should now point to the size needed.
@retval EFI_NOT_READY Variable policy has not yet been initialized.
@retval EFI_INVALID_PARAMETER A required pointer argument passed is NULL. This will be returned if
VariablePolicyVariableName is non-NULL and VariablePolicyVariableNameBufferSize
is NULL.
@retval EFI_NOT_FOUND A variable policy was not found for the given UEFI variable name and vendor GUID.
**/
EFI_STATUS
EFIAPI
GetVariablePolicyInfo (
IN CONST CHAR16 *VariableName,
IN CONST EFI_GUID *VendorGuid,
IN OUT UINTN *VariablePolicyVariableNameBufferSize OPTIONAL,
OUT VARIABLE_POLICY_ENTRY *VariablePolicy,
OUT CHAR16 *VariablePolicyVariableName OPTIONAL
);
/**
This function will return the Lock on Variable State policy information for the policy
associated with the given UEFI variable.
@param[in] VariableName The name of the variable to use for the policy search.
@param[in] VendorGuid The vendor GUID of the variable to use for the policy
search.
@param[in,out] VariableLockPolicyVariableNameBufferSize On input, the size, in bytes, of the
VariableLockPolicyVariableName buffer.
On output, the size, in bytes, needed to store the variable
policy variable name.
If testing for the VariableLockPolicyVariableName buffer
size needed, set this value to zero so EFI_BUFFER_TOO_SMALL
is guaranteed to be returned if the variable policy variable
name is found.
@param[out] VariablePolicy Pointer to a buffer where the policy entry will be written
if found.
@param[out] VariableLockPolicyVariableName Pointer to a buffer where the variable name used for the
variable lock on variable state policy will be written if
a variable name is registered.
If the lock on variable policy is not associated with a
variable name (e.g. applied to variable vendor namespace)
and this parameter is given, this parameter will not be
modified and VariableLockPolicyVariableNameBufferSize will
be set to zero to indicate a name was not present.
If the pointer given is not NULL,
VariableLockPolicyVariableNameBufferSize must be non-NULL.
@retval EFI_SUCCESS A Lock on Variable State variable policy entry was found and returned
successfully.
@retval EFI_BAD_BUFFER_SIZE An internal buffer size caused a calculation error.
@retval EFI_BUFFER_TOO_SMALL The VariableLockPolicyVariableName buffer is too small for the size needed.
The buffer should now point to the size needed.
@retval EFI_NOT_READY Variable policy has not yet been initialized.
@retval EFI_INVALID_PARAMETER A required pointer argument passed is NULL. This will be returned if
VariableLockPolicyVariableName is non-NULL and
VariableLockPolicyVariableNameBufferSize is NULL.
@retval EFI_NOT_FOUND A Lock on Variable State variable policy was not found for the given UEFI
variable name and vendor GUID.
**/
EFI_STATUS
EFIAPI
GetLockOnVariableStateVariablePolicyInfo (
IN CONST CHAR16 *VariableName,
IN CONST EFI_GUID *VendorGuid,
IN OUT UINTN *VariableLockPolicyVariableNameBufferSize OPTIONAL,
OUT VARIABLE_LOCK_ON_VAR_STATE_POLICY *VariablePolicy,
OUT CHAR16 *VariableLockPolicyVariableName OPTIONAL
);
/**
This API function returns whether or not the policy engine is
currently being enforced.
@retval TRUE
@retval FALSE
@retval FALSE Library has not yet been initialized.
**/
BOOLEAN
EFIAPI
IsVariablePolicyEnabled (
VOID
);
/**
This API function locks the interface so that no more policy updates
can be performed or changes made to the enforcement until the next boot.
@retval EFI_SUCCESS
@retval EFI_NOT_READY Library has not yet been initialized.
**/
EFI_STATUS
EFIAPI
LockVariablePolicy (
VOID
);
/**
This API function returns whether or not the policy interface is locked
for the remainder of the boot.
@retval TRUE
@retval FALSE
@retval FALSE Library has not yet been initialized.
**/
BOOLEAN
EFIAPI
IsVariablePolicyInterfaceLocked (
VOID
);
/**
This helper function initializes the library and sets
up any required internal structures or handlers.
Also registers the internal pointer for the GetVariable helper.
@param[in] GetVariableHelper A function pointer matching the EFI_GET_VARIABLE prototype that will be used to
check policy criteria that involve the existence of other variables.
@retval EFI_SUCCESS
@retval EFI_ALREADY_STARTED The initialize function has been called more than once without a call to
deinitialize.
**/
EFI_STATUS
EFIAPI
InitVariablePolicyLib (
IN EFI_GET_VARIABLE GetVariableHelper
);
/**
This helper function returns whether or not the library is currently initialized.
@retval TRUE
@retval FALSE
**/
BOOLEAN
EFIAPI
IsVariablePolicyLibInitialized (
VOID
);
/**
This helper function tears down the library.
Should generally only be used for test harnesses.
@retval EFI_SUCCESS
@retval EFI_NOT_READY Deinitialize was called without first calling initialize.
**/
EFI_STATUS
EFIAPI
DeinitVariablePolicyLib (
VOID
);
#endif // _VARIABLE_POLICY_LIB_H_
|
