| Eric Laurent | 4dacbc3 | 2020-10-07 13:48:21 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2020 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | #include <media/AudioSanitizer.h> |
| 18 | |
| 19 | namespace android { |
| 20 | |
| 21 | /** returns true if string overflow was prevented by zero termination */ |
| 22 | template <size_t size> |
| 23 | bool preventStringOverflow(char (&s)[size]) { |
| 24 | if (strnlen(s, size) < size) return false; |
| 25 | s[size - 1] = '\0'; |
| 26 | return true; |
| 27 | } |
| 28 | |
| 29 | status_t safetyNetLog(status_t status, const char *bugNumber) { |
| 30 | if (status != NO_ERROR && bugNumber != nullptr) { |
| 31 | android_errorWriteLog(0x534e4554, bugNumber); // SafetyNet logging |
| 32 | } |
| 33 | return status; |
| 34 | } |
| 35 | |
| 36 | status_t AudioSanitizer::sanitizeAudioAttributes( |
| 37 | audio_attributes_t *attr, const char *bugNumber) |
| 38 | { |
| 39 | status_t status = NO_ERROR; |
| 40 | const size_t tagsMaxSize = AUDIO_ATTRIBUTES_TAGS_MAX_SIZE; |
| 41 | if (strnlen(attr->tags, tagsMaxSize) >= tagsMaxSize) { |
| 42 | status = BAD_VALUE; |
| 43 | } |
| 44 | attr->tags[tagsMaxSize - 1] = '\0'; |
| 45 | return safetyNetLog(status, bugNumber); |
| 46 | } |
| 47 | |
| 48 | /** returns BAD_VALUE if sanitization was required. */ |
| 49 | status_t AudioSanitizer::sanitizeEffectDescriptor( |
| 50 | effect_descriptor_t *desc, const char *bugNumber) |
| 51 | { |
| 52 | status_t status = NO_ERROR; |
| 53 | if (preventStringOverflow(desc->name) |
| 54 | | /* always */ preventStringOverflow(desc->implementor)) { |
| 55 | status = BAD_VALUE; |
| 56 | } |
| 57 | return safetyNetLog(status, bugNumber); |
| 58 | } |
| 59 | |
| 60 | /** returns BAD_VALUE if sanitization was required. */ |
| 61 | status_t AudioSanitizer::sanitizeAudioPortConfig( |
| 62 | struct audio_port_config *config, const char *bugNumber) |
| 63 | { |
| 64 | status_t status = NO_ERROR; |
| 65 | if (config->type == AUDIO_PORT_TYPE_DEVICE && |
| 66 | preventStringOverflow(config->ext.device.address)) { |
| 67 | status = BAD_VALUE; |
| 68 | } |
| 69 | return safetyNetLog(status, bugNumber); |
| 70 | } |
| 71 | |
| 72 | /** returns BAD_VALUE if sanitization was required. */ |
| 73 | status_t AudioSanitizer::sanitizeAudioPort( |
| 74 | struct audio_port *port, const char *bugNumber) |
| 75 | { |
| 76 | status_t status = NO_ERROR; |
| 77 | if (preventStringOverflow(port->name)) { |
| 78 | status = BAD_VALUE; |
| 79 | } |
| 80 | if (sanitizeAudioPortConfig(&port->active_config) != NO_ERROR) { |
| 81 | status = BAD_VALUE; |
| 82 | } |
| 83 | if (port->type == AUDIO_PORT_TYPE_DEVICE && |
| 84 | preventStringOverflow(port->ext.device.address)) { |
| 85 | status = BAD_VALUE; |
| 86 | } |
| 87 | return safetyNetLog(status, bugNumber); |
| 88 | } |
| 89 | |
| 90 | /** returns BAD_VALUE if sanitization was required. */ |
| 91 | status_t AudioSanitizer::sanitizeAudioPatch( |
| 92 | struct audio_patch *patch, const char *bugNumber) |
| 93 | { |
| 94 | status_t status = NO_ERROR; |
| 95 | if (patch->num_sources > AUDIO_PATCH_PORTS_MAX) { |
| 96 | patch->num_sources = AUDIO_PATCH_PORTS_MAX; |
| 97 | status = BAD_VALUE; |
| 98 | } |
| 99 | if (patch->num_sinks > AUDIO_PATCH_PORTS_MAX) { |
| 100 | patch->num_sinks = AUDIO_PATCH_PORTS_MAX; |
| 101 | status = BAD_VALUE; |
| 102 | } |
| 103 | for (size_t i = 0; i < patch->num_sources; i++) { |
| 104 | if (sanitizeAudioPortConfig(&patch->sources[i]) != NO_ERROR) { |
| 105 | status = BAD_VALUE; |
| 106 | } |
| 107 | } |
| 108 | for (size_t i = 0; i < patch->num_sinks; i++) { |
| 109 | if (sanitizeAudioPortConfig(&patch->sinks[i]) != NO_ERROR) { |
| 110 | status = BAD_VALUE; |
| 111 | } |
| 112 | } |
| 113 | return safetyNetLog(status, bugNumber); |
| 114 | } |
| 115 | |
| 116 | }; // namespace android |