| Julian Hall | 0a86f76 | 2021-11-08 13:31:23 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2021, Arm Limited. All rights reserved. |
| 3 | * |
| 4 | * SPDX-License-Identifier: BSD-3-Clause |
| 5 | * |
| 6 | */ |
| 7 | |
| 8 | #include "variable_checker.h" |
| 9 | |
| 10 | efi_status_t variable_checker_set_constraints( |
| 11 | struct variable_constraints *constraints, |
| 12 | bool is_update, |
| 13 | const VAR_CHECK_VARIABLE_PROPERTY *check_var_property) |
| 14 | { |
| 15 | /* Sanity check input parameters */ |
| 16 | if (check_var_property->Revision != VAR_CHECK_VARIABLE_PROPERTY_REVISION) |
| 17 | return EFI_INVALID_PARAMETER; |
| 18 | |
| 19 | if (check_var_property->MinSize > check_var_property->MaxSize) |
| 20 | return EFI_INVALID_PARAMETER; |
| 21 | |
| 22 | /* Check for an attempt to undo previously set access constraints */ |
| 23 | if (is_update) { |
| 24 | |
| 25 | if ((constraints->property & VAR_CHECK_VARIABLE_PROPERTY_READ_ONLY) && |
| 26 | !(check_var_property->Property & VAR_CHECK_VARIABLE_PROPERTY_READ_ONLY)) |
| 27 | return EFI_INVALID_PARAMETER; |
| 28 | } |
| 29 | |
| 30 | /* New check constraints accepted */ |
| 31 | constraints->revision = check_var_property->Revision; |
| 32 | constraints->attributes = check_var_property->Attributes; |
| 33 | constraints->property = check_var_property->Property; |
| 34 | constraints->min_size = check_var_property->MinSize; |
| 35 | constraints->max_size = check_var_property->MaxSize; |
| 36 | |
| 37 | return EFI_SUCCESS; |
| 38 | } |
| 39 | |
| 40 | void variable_checker_get_constraints( |
| 41 | const struct variable_constraints *constraints, |
| 42 | VAR_CHECK_VARIABLE_PROPERTY *check_var_property) |
| 43 | { |
| 44 | check_var_property->Revision = constraints->revision; |
| 45 | check_var_property->Attributes = constraints->attributes; |
| 46 | check_var_property->Property = constraints->property; |
| 47 | check_var_property->MinSize = constraints->min_size; |
| 48 | check_var_property->MaxSize = constraints->max_size; |
| 49 | } |
| 50 | |
| 51 | efi_status_t variable_checker_check_on_set( |
| 52 | const struct variable_constraints *constraints, |
| 53 | uint32_t attributes, |
| 54 | size_t data_size) |
| 55 | { |
| 56 | if (constraints->property & VAR_CHECK_VARIABLE_PROPERTY_READ_ONLY) |
| 57 | return EFI_WRITE_PROTECTED; |
| 58 | |
| 59 | if (data_size < constraints->min_size) |
| 60 | return EFI_INVALID_PARAMETER; |
| 61 | |
| 62 | if (data_size > constraints->max_size) |
| 63 | return EFI_INVALID_PARAMETER; |
| 64 | |
| 65 | return EFI_SUCCESS; |
| 66 | } |