Daniele Di Proietto | 7451ea6 | 2023-01-09 11:31:16 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2023 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 "perfetto/public/abi/pb_decoder_abi.h" |
| 18 | |
| 19 | #include <limits> |
| 20 | #include <type_traits> |
| 21 | |
| 22 | #include "perfetto/public/pb_utils.h" |
| 23 | |
| 24 | namespace { |
| 25 | template <typename T> |
| 26 | bool Uint64RepresentableIn(uint64_t val) { |
| 27 | return val <= std::numeric_limits<T>::max(); |
| 28 | } |
| 29 | } // namespace |
| 30 | |
| 31 | struct PerfettoPbDecoderField PerfettoPbDecoderParseField( |
| 32 | struct PerfettoPbDecoder* decoder) { |
| 33 | struct PerfettoPbDecoderField field; |
| 34 | const uint8_t* read_ptr = decoder->read_ptr; |
| 35 | if (read_ptr >= decoder->end_ptr) { |
| 36 | field.status = PERFETTO_PB_DECODER_DONE; |
| 37 | return field; |
| 38 | } |
| 39 | field.status = PERFETTO_PB_DECODER_ERROR; |
| 40 | uint64_t tag; |
| 41 | const uint8_t* end_of_tag = |
| 42 | PerfettoPbParseVarInt(read_ptr, decoder->end_ptr, &tag); |
| 43 | if (end_of_tag == read_ptr) { |
| 44 | field.status = PERFETTO_PB_DECODER_ERROR; |
| 45 | return field; |
| 46 | } |
| 47 | read_ptr = end_of_tag; |
| 48 | constexpr uint8_t kFieldTypeNumBits = 3; |
| 49 | |
| 50 | field.wire_type = tag & ((1 << kFieldTypeNumBits) - 1); |
| 51 | uint64_t id = tag >> kFieldTypeNumBits; |
| 52 | static_assert(std::is_same<uint32_t, decltype(field.id)>::value); |
| 53 | if (id > std::numeric_limits<uint32_t>::max()) { |
| 54 | field.status = PERFETTO_PB_DECODER_ERROR; |
| 55 | return field; |
| 56 | } |
| 57 | field.id = static_cast<uint32_t>(id); |
| 58 | |
| 59 | switch (field.wire_type) { |
| 60 | case PERFETTO_PB_WIRE_TYPE_DELIMITED: { |
| 61 | uint64_t len; |
| 62 | const uint8_t* end_of_len = |
| 63 | PerfettoPbParseVarInt(read_ptr, decoder->end_ptr, &len); |
| 64 | if (end_of_len == read_ptr || !Uint64RepresentableIn<size_t>(len)) { |
| 65 | field.status = PERFETTO_PB_DECODER_ERROR; |
| 66 | return field; |
| 67 | } |
| 68 | read_ptr = end_of_len; |
| 69 | field.value.delimited.len = static_cast<size_t>(len); |
| 70 | field.value.delimited.start = read_ptr; |
| 71 | read_ptr += len; |
| 72 | if (read_ptr > decoder->end_ptr) { |
| 73 | field.status = PERFETTO_PB_DECODER_ERROR; |
| 74 | return field; |
| 75 | } |
| 76 | field.status = PERFETTO_PB_DECODER_OK; |
| 77 | decoder->read_ptr = read_ptr; |
| 78 | break; |
| 79 | } |
| 80 | case PERFETTO_PB_WIRE_TYPE_VARINT: { |
| 81 | uint64_t val; |
| 82 | const uint8_t* end_of_val = |
| 83 | PerfettoPbParseVarInt(read_ptr, decoder->end_ptr, &val); |
| 84 | if (end_of_val == read_ptr) { |
| 85 | field.status = PERFETTO_PB_DECODER_ERROR; |
| 86 | return field; |
| 87 | } |
| 88 | read_ptr = end_of_val; |
| 89 | field.value.integer64 = val; |
| 90 | field.status = PERFETTO_PB_DECODER_OK; |
| 91 | decoder->read_ptr = read_ptr; |
| 92 | break; |
| 93 | } |
| 94 | case PERFETTO_PB_WIRE_TYPE_FIXED32: { |
| 95 | const uint8_t* end_of_val = read_ptr + sizeof(uint32_t); |
| 96 | if (end_of_val > decoder->end_ptr) { |
| 97 | field.status = PERFETTO_PB_DECODER_ERROR; |
| 98 | return field; |
| 99 | } |
| 100 | // Little endian on the wire. |
| 101 | field.value.integer32 = read_ptr[0] | |
| 102 | (static_cast<uint32_t>(read_ptr[1]) << 8) | |
| 103 | (static_cast<uint32_t>(read_ptr[2]) << 16) | |
| 104 | (static_cast<uint32_t>(read_ptr[3]) << 24); |
| 105 | read_ptr = end_of_val; |
| 106 | decoder->read_ptr = read_ptr; |
| 107 | field.status = PERFETTO_PB_DECODER_OK; |
| 108 | break; |
| 109 | } |
| 110 | case PERFETTO_PB_WIRE_TYPE_FIXED64: { |
| 111 | const uint8_t* end_of_val = read_ptr + sizeof(uint64_t); |
| 112 | if (end_of_val > decoder->end_ptr) { |
| 113 | field.status = PERFETTO_PB_DECODER_ERROR; |
| 114 | return field; |
| 115 | } |
| 116 | // Little endian on the wire. |
| 117 | field.value.integer64 = read_ptr[0] | |
| 118 | (static_cast<uint64_t>(read_ptr[1]) << 8) | |
| 119 | (static_cast<uint64_t>(read_ptr[2]) << 16) | |
| 120 | (static_cast<uint64_t>(read_ptr[3]) << 24) | |
| 121 | (static_cast<uint64_t>(read_ptr[4]) << 32) | |
| 122 | (static_cast<uint64_t>(read_ptr[5]) << 40) | |
| 123 | (static_cast<uint64_t>(read_ptr[6]) << 48) | |
| 124 | (static_cast<uint64_t>(read_ptr[7]) << 56); |
| 125 | read_ptr = end_of_val; |
| 126 | decoder->read_ptr = read_ptr; |
| 127 | field.status = PERFETTO_PB_DECODER_OK; |
| 128 | break; |
| 129 | } |
| 130 | default: |
| 131 | field.status = PERFETTO_PB_DECODER_ERROR; |
| 132 | return field; |
| 133 | } |
| 134 | return field; |
| 135 | } |
| 136 | |
| 137 | uint32_t PerfettoPbDecoderSkipField(struct PerfettoPbDecoder* decoder) { |
| 138 | const uint8_t* read_ptr = decoder->read_ptr; |
| 139 | if (read_ptr >= decoder->end_ptr) { |
| 140 | return PERFETTO_PB_DECODER_DONE; |
| 141 | } |
| 142 | uint64_t tag; |
| 143 | const uint8_t* end_of_tag = |
| 144 | PerfettoPbParseVarInt(decoder->read_ptr, decoder->end_ptr, &tag); |
| 145 | if (end_of_tag == read_ptr) { |
| 146 | return PERFETTO_PB_DECODER_ERROR; |
| 147 | } |
| 148 | read_ptr = end_of_tag; |
| 149 | constexpr uint8_t kFieldTypeNumBits = 3; |
| 150 | |
| 151 | uint32_t wire_type = tag & ((1 << kFieldTypeNumBits) - 1); |
| 152 | switch (wire_type) { |
| 153 | case PERFETTO_PB_WIRE_TYPE_DELIMITED: { |
| 154 | uint64_t len; |
| 155 | const uint8_t* end_of_len = |
| 156 | PerfettoPbParseVarInt(read_ptr, decoder->end_ptr, &len); |
| 157 | if (end_of_len == read_ptr) { |
| 158 | return PERFETTO_PB_DECODER_ERROR; |
| 159 | } |
| 160 | read_ptr = end_of_len; |
| 161 | read_ptr += len; |
| 162 | if (read_ptr > decoder->end_ptr) { |
| 163 | return PERFETTO_PB_DECODER_ERROR; |
| 164 | } |
| 165 | decoder->read_ptr = read_ptr; |
| 166 | return PERFETTO_PB_DECODER_OK; |
| 167 | } |
| 168 | case PERFETTO_PB_WIRE_TYPE_VARINT: { |
| 169 | uint64_t val; |
| 170 | const uint8_t* end_of_val = |
| 171 | PerfettoPbParseVarInt(read_ptr, decoder->end_ptr, &val); |
| 172 | if (end_of_val == read_ptr) { |
| 173 | return PERFETTO_PB_DECODER_ERROR; |
| 174 | } |
| 175 | read_ptr = end_of_val; |
| 176 | decoder->read_ptr = read_ptr; |
| 177 | return PERFETTO_PB_DECODER_OK; |
| 178 | } |
| 179 | case PERFETTO_PB_WIRE_TYPE_FIXED32: { |
| 180 | const uint8_t* end_of_val = read_ptr + sizeof(uint32_t); |
| 181 | if (end_of_val > decoder->end_ptr) { |
| 182 | return PERFETTO_PB_DECODER_ERROR; |
| 183 | } |
| 184 | read_ptr = end_of_val; |
| 185 | decoder->read_ptr = read_ptr; |
| 186 | return PERFETTO_PB_DECODER_OK; |
| 187 | } |
| 188 | case PERFETTO_PB_WIRE_TYPE_FIXED64: { |
| 189 | const uint8_t* end_of_val = read_ptr + sizeof(uint64_t); |
| 190 | if (read_ptr > decoder->end_ptr) { |
| 191 | return PERFETTO_PB_DECODER_ERROR; |
| 192 | } |
| 193 | read_ptr = end_of_val; |
| 194 | decoder->read_ptr = read_ptr; |
| 195 | return PERFETTO_PB_DECODER_OK; |
| 196 | } |
| 197 | default: |
| 198 | break; |
| 199 | } |
| 200 | return PERFETTO_PB_DECODER_ERROR; |
| 201 | } |