Alexei Frolov | dea46f7 | 2020-01-07 13:28:24 -0800 | [diff] [blame] | 1 | // Copyright 2020 The Pigweed Authors |
| 2 | // |
| 3 | // Licensed under the Apache License, Version 2.0 (the "License"); you may not |
| 4 | // use this file except in compliance with the License. You may obtain a copy of |
| 5 | // the License at |
| 6 | // |
| 7 | // https://www.apache.org/licenses/LICENSE-2.0 |
| 8 | // |
| 9 | // Unless required by applicable law or agreed to in writing, software |
| 10 | // distributed under the License is distributed on an "AS IS" BASIS, WITHOUT |
| 11 | // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the |
| 12 | // License for the specific language governing permissions and limitations under |
| 13 | // the License. |
| 14 | |
| 15 | #include "pw_protobuf/decoder.h" |
| 16 | |
Alexei Frolov | 6d9b9b4 | 2020-01-14 12:57:33 -0800 | [diff] [blame] | 17 | #include <cstring> |
| 18 | |
Alexei Frolov | dea46f7 | 2020-01-07 13:28:24 -0800 | [diff] [blame] | 19 | #include "pw_varint/varint.h" |
| 20 | |
| 21 | namespace pw::protobuf { |
| 22 | |
Alexei Frolov | fe9723c | 2020-05-11 13:20:47 -0700 | [diff] [blame] | 23 | Status Decoder::Next() { |
| 24 | if (!previous_field_consumed_) { |
| 25 | if (Status status = SkipField(); !status.ok()) { |
Alexei Frolov | dea46f7 | 2020-01-07 13:28:24 -0800 | [diff] [blame] | 26 | return status; |
| 27 | } |
Alexei Frolov | fe9723c | 2020-05-11 13:20:47 -0700 | [diff] [blame] | 28 | } |
| 29 | if (proto_.empty()) { |
Wyatt Hepler | d78f7c6 | 2020-09-28 14:27:32 -0700 | [diff] [blame] | 30 | return Status::OutOfRange(); |
Alexei Frolov | fe9723c | 2020-05-11 13:20:47 -0700 | [diff] [blame] | 31 | } |
| 32 | previous_field_consumed_ = false; |
Wyatt Hepler | 1b3da3a | 2021-01-07 13:26:57 -0800 | [diff] [blame^] | 33 | return FieldSize() == 0 ? Status::DataLoss() : OkStatus(); |
Alexei Frolov | fe9723c | 2020-05-11 13:20:47 -0700 | [diff] [blame] | 34 | } |
Alexei Frolov | dea46f7 | 2020-01-07 13:28:24 -0800 | [diff] [blame] | 35 | |
Alexei Frolov | fe9723c | 2020-05-11 13:20:47 -0700 | [diff] [blame] | 36 | Status Decoder::SkipField() { |
| 37 | if (proto_.empty()) { |
Wyatt Hepler | d78f7c6 | 2020-09-28 14:27:32 -0700 | [diff] [blame] | 38 | return Status::OutOfRange(); |
Alexei Frolov | dea46f7 | 2020-01-07 13:28:24 -0800 | [diff] [blame] | 39 | } |
| 40 | |
Alexei Frolov | fe9723c | 2020-05-11 13:20:47 -0700 | [diff] [blame] | 41 | size_t bytes_to_skip = FieldSize(); |
| 42 | if (bytes_to_skip == 0) { |
Wyatt Hepler | d78f7c6 | 2020-09-28 14:27:32 -0700 | [diff] [blame] | 43 | return Status::DataLoss(); |
Alexei Frolov | dea46f7 | 2020-01-07 13:28:24 -0800 | [diff] [blame] | 44 | } |
| 45 | |
Alexei Frolov | fe9723c | 2020-05-11 13:20:47 -0700 | [diff] [blame] | 46 | proto_ = proto_.subspan(bytes_to_skip); |
Wyatt Hepler | 1b3da3a | 2021-01-07 13:26:57 -0800 | [diff] [blame^] | 47 | return proto_.empty() ? Status::OutOfRange() : OkStatus(); |
Alexei Frolov | fe9723c | 2020-05-11 13:20:47 -0700 | [diff] [blame] | 48 | } |
| 49 | |
| 50 | uint32_t Decoder::FieldNumber() const { |
| 51 | uint64_t key; |
| 52 | varint::Decode(proto_, &key); |
| 53 | return key >> kFieldNumberShift; |
| 54 | } |
| 55 | |
| 56 | Status Decoder::ReadUint32(uint32_t* out) { |
| 57 | uint64_t value = 0; |
| 58 | Status status = ReadUint64(&value); |
| 59 | if (!status.ok()) { |
| 60 | return status; |
| 61 | } |
| 62 | if (value > std::numeric_limits<uint32_t>::max()) { |
Wyatt Hepler | d78f7c6 | 2020-09-28 14:27:32 -0700 | [diff] [blame] | 63 | return Status::OutOfRange(); |
Alexei Frolov | fe9723c | 2020-05-11 13:20:47 -0700 | [diff] [blame] | 64 | } |
| 65 | *out = value; |
Wyatt Hepler | 1b3da3a | 2021-01-07 13:26:57 -0800 | [diff] [blame^] | 66 | return OkStatus(); |
Alexei Frolov | dea46f7 | 2020-01-07 13:28:24 -0800 | [diff] [blame] | 67 | } |
| 68 | |
Alexei Frolov | fe9723c | 2020-05-11 13:20:47 -0700 | [diff] [blame] | 69 | Status Decoder::ReadSint32(int32_t* out) { |
| 70 | int64_t value = 0; |
| 71 | Status status = ReadSint64(&value); |
Alexei Frolov | 6d9b9b4 | 2020-01-14 12:57:33 -0800 | [diff] [blame] | 72 | if (!status.ok()) { |
| 73 | return status; |
| 74 | } |
Alexei Frolov | fe9723c | 2020-05-11 13:20:47 -0700 | [diff] [blame] | 75 | if (value > std::numeric_limits<int32_t>::max()) { |
Wyatt Hepler | d78f7c6 | 2020-09-28 14:27:32 -0700 | [diff] [blame] | 76 | return Status::OutOfRange(); |
Alexei Frolov | fe9723c | 2020-05-11 13:20:47 -0700 | [diff] [blame] | 77 | } |
| 78 | *out = value; |
Wyatt Hepler | 1b3da3a | 2021-01-07 13:26:57 -0800 | [diff] [blame^] | 79 | return OkStatus(); |
Alexei Frolov | fe9723c | 2020-05-11 13:20:47 -0700 | [diff] [blame] | 80 | } |
| 81 | |
| 82 | Status Decoder::ReadSint64(int64_t* out) { |
| 83 | uint64_t value = 0; |
| 84 | Status status = ReadUint64(&value); |
| 85 | if (!status.ok()) { |
| 86 | return status; |
| 87 | } |
| 88 | *out = varint::ZigZagDecode(value); |
Wyatt Hepler | 1b3da3a | 2021-01-07 13:26:57 -0800 | [diff] [blame^] | 89 | return OkStatus(); |
Alexei Frolov | fe9723c | 2020-05-11 13:20:47 -0700 | [diff] [blame] | 90 | } |
| 91 | |
| 92 | Status Decoder::ReadBool(bool* out) { |
| 93 | uint64_t value = 0; |
| 94 | Status status = ReadUint64(&value); |
| 95 | if (!status.ok()) { |
| 96 | return status; |
| 97 | } |
| 98 | *out = value; |
Wyatt Hepler | 1b3da3a | 2021-01-07 13:26:57 -0800 | [diff] [blame^] | 99 | return OkStatus(); |
Alexei Frolov | fe9723c | 2020-05-11 13:20:47 -0700 | [diff] [blame] | 100 | } |
| 101 | |
| 102 | Status Decoder::ReadString(std::string_view* out) { |
Wyatt Hepler | e2cbadf | 2020-06-22 11:21:45 -0700 | [diff] [blame] | 103 | std::span<const std::byte> bytes; |
Alexei Frolov | fe9723c | 2020-05-11 13:20:47 -0700 | [diff] [blame] | 104 | Status status = ReadDelimited(&bytes); |
| 105 | if (!status.ok()) { |
| 106 | return status; |
| 107 | } |
| 108 | *out = std::string_view(reinterpret_cast<const char*>(bytes.data()), |
| 109 | bytes.size()); |
Wyatt Hepler | 1b3da3a | 2021-01-07 13:26:57 -0800 | [diff] [blame^] | 110 | return OkStatus(); |
Alexei Frolov | fe9723c | 2020-05-11 13:20:47 -0700 | [diff] [blame] | 111 | } |
| 112 | |
| 113 | size_t Decoder::FieldSize() const { |
| 114 | uint64_t key; |
| 115 | size_t key_size = varint::Decode(proto_, &key); |
| 116 | if (key_size == 0) { |
| 117 | return 0; |
| 118 | } |
| 119 | |
Wyatt Hepler | e2cbadf | 2020-06-22 11:21:45 -0700 | [diff] [blame] | 120 | std::span<const std::byte> remainder = proto_.subspan(key_size); |
Alexei Frolov | fe9723c | 2020-05-11 13:20:47 -0700 | [diff] [blame] | 121 | WireType wire_type = static_cast<WireType>(key & kWireTypeMask); |
| 122 | uint64_t value = 0; |
| 123 | size_t expected_size = 0; |
| 124 | |
| 125 | switch (wire_type) { |
| 126 | case WireType::kVarint: |
| 127 | expected_size = varint::Decode(remainder, &value); |
| 128 | if (expected_size == 0) { |
| 129 | return 0; |
| 130 | } |
| 131 | break; |
| 132 | |
| 133 | case WireType::kDelimited: |
| 134 | // Varint at cursor indicates size of the field. |
| 135 | expected_size = varint::Decode(remainder, &value); |
| 136 | if (expected_size == 0) { |
| 137 | return 0; |
| 138 | } |
| 139 | expected_size += value; |
| 140 | break; |
| 141 | |
| 142 | case WireType::kFixed32: |
| 143 | expected_size = sizeof(uint32_t); |
| 144 | break; |
| 145 | |
| 146 | case WireType::kFixed64: |
| 147 | expected_size = sizeof(uint64_t); |
| 148 | break; |
| 149 | } |
| 150 | |
| 151 | if (remainder.size() < expected_size) { |
| 152 | return 0; |
| 153 | } |
| 154 | |
| 155 | return key_size + expected_size; |
| 156 | } |
| 157 | |
| 158 | Status Decoder::ConsumeKey(WireType expected_type) { |
| 159 | uint64_t key; |
| 160 | size_t bytes_read = varint::Decode(proto_, &key); |
| 161 | if (bytes_read == 0) { |
Wyatt Hepler | d78f7c6 | 2020-09-28 14:27:32 -0700 | [diff] [blame] | 162 | return Status::FailedPrecondition(); |
Alexei Frolov | fe9723c | 2020-05-11 13:20:47 -0700 | [diff] [blame] | 163 | } |
| 164 | |
| 165 | WireType wire_type = static_cast<WireType>(key & kWireTypeMask); |
| 166 | if (wire_type != expected_type) { |
Wyatt Hepler | d78f7c6 | 2020-09-28 14:27:32 -0700 | [diff] [blame] | 167 | return Status::FailedPrecondition(); |
Alexei Frolov | fe9723c | 2020-05-11 13:20:47 -0700 | [diff] [blame] | 168 | } |
| 169 | |
| 170 | // Advance past the key. |
| 171 | proto_ = proto_.subspan(bytes_read); |
Wyatt Hepler | 1b3da3a | 2021-01-07 13:26:57 -0800 | [diff] [blame^] | 172 | return OkStatus(); |
Alexei Frolov | fe9723c | 2020-05-11 13:20:47 -0700 | [diff] [blame] | 173 | } |
| 174 | |
| 175 | Status Decoder::ReadVarint(uint64_t* out) { |
| 176 | if (Status status = ConsumeKey(WireType::kVarint); !status.ok()) { |
| 177 | return status; |
| 178 | } |
Alexei Frolov | 6d9b9b4 | 2020-01-14 12:57:33 -0800 | [diff] [blame] | 179 | |
| 180 | size_t bytes_read = varint::Decode(proto_, out); |
| 181 | if (bytes_read == 0) { |
Wyatt Hepler | d78f7c6 | 2020-09-28 14:27:32 -0700 | [diff] [blame] | 182 | return Status::DataLoss(); |
Alexei Frolov | 6d9b9b4 | 2020-01-14 12:57:33 -0800 | [diff] [blame] | 183 | } |
| 184 | |
| 185 | // Advance to the next field. |
| 186 | proto_ = proto_.subspan(bytes_read); |
Alexei Frolov | fe9723c | 2020-05-11 13:20:47 -0700 | [diff] [blame] | 187 | previous_field_consumed_ = true; |
Wyatt Hepler | 1b3da3a | 2021-01-07 13:26:57 -0800 | [diff] [blame^] | 188 | return OkStatus(); |
Alexei Frolov | 6d9b9b4 | 2020-01-14 12:57:33 -0800 | [diff] [blame] | 189 | } |
| 190 | |
Alexei Frolov | fe9723c | 2020-05-11 13:20:47 -0700 | [diff] [blame] | 191 | Status Decoder::ReadFixed(std::byte* out, size_t size) { |
Alexei Frolov | 6d9b9b4 | 2020-01-14 12:57:33 -0800 | [diff] [blame] | 192 | WireType expected_wire_type = |
| 193 | size == sizeof(uint32_t) ? WireType::kFixed32 : WireType::kFixed64; |
Alexei Frolov | fe9723c | 2020-05-11 13:20:47 -0700 | [diff] [blame] | 194 | Status status = ConsumeKey(expected_wire_type); |
Alexei Frolov | 6d9b9b4 | 2020-01-14 12:57:33 -0800 | [diff] [blame] | 195 | if (!status.ok()) { |
| 196 | return status; |
| 197 | } |
| 198 | |
| 199 | if (proto_.size() < size) { |
Wyatt Hepler | d78f7c6 | 2020-09-28 14:27:32 -0700 | [diff] [blame] | 200 | return Status::DataLoss(); |
Alexei Frolov | 6d9b9b4 | 2020-01-14 12:57:33 -0800 | [diff] [blame] | 201 | } |
| 202 | |
| 203 | std::memcpy(out, proto_.data(), size); |
| 204 | proto_ = proto_.subspan(size); |
Alexei Frolov | fe9723c | 2020-05-11 13:20:47 -0700 | [diff] [blame] | 205 | previous_field_consumed_ = true; |
Alexei Frolov | 6d9b9b4 | 2020-01-14 12:57:33 -0800 | [diff] [blame] | 206 | |
Wyatt Hepler | 1b3da3a | 2021-01-07 13:26:57 -0800 | [diff] [blame^] | 207 | return OkStatus(); |
Alexei Frolov | 6d9b9b4 | 2020-01-14 12:57:33 -0800 | [diff] [blame] | 208 | } |
| 209 | |
Wyatt Hepler | e2cbadf | 2020-06-22 11:21:45 -0700 | [diff] [blame] | 210 | Status Decoder::ReadDelimited(std::span<const std::byte>* out) { |
Alexei Frolov | fe9723c | 2020-05-11 13:20:47 -0700 | [diff] [blame] | 211 | Status status = ConsumeKey(WireType::kDelimited); |
Alexei Frolov | 6d9b9b4 | 2020-01-14 12:57:33 -0800 | [diff] [blame] | 212 | if (!status.ok()) { |
| 213 | return status; |
| 214 | } |
| 215 | |
| 216 | uint64_t length; |
| 217 | size_t bytes_read = varint::Decode(proto_, &length); |
| 218 | if (bytes_read == 0) { |
Wyatt Hepler | d78f7c6 | 2020-09-28 14:27:32 -0700 | [diff] [blame] | 219 | return Status::DataLoss(); |
Alexei Frolov | 6d9b9b4 | 2020-01-14 12:57:33 -0800 | [diff] [blame] | 220 | } |
| 221 | |
| 222 | proto_ = proto_.subspan(bytes_read); |
| 223 | if (proto_.size() < length) { |
Wyatt Hepler | d78f7c6 | 2020-09-28 14:27:32 -0700 | [diff] [blame] | 224 | return Status::DataLoss(); |
Alexei Frolov | 6d9b9b4 | 2020-01-14 12:57:33 -0800 | [diff] [blame] | 225 | } |
| 226 | |
| 227 | *out = proto_.first(length); |
| 228 | proto_ = proto_.subspan(length); |
Alexei Frolov | fe9723c | 2020-05-11 13:20:47 -0700 | [diff] [blame] | 229 | previous_field_consumed_ = true; |
Alexei Frolov | 6d9b9b4 | 2020-01-14 12:57:33 -0800 | [diff] [blame] | 230 | |
Wyatt Hepler | 1b3da3a | 2021-01-07 13:26:57 -0800 | [diff] [blame^] | 231 | return OkStatus(); |
Alexei Frolov | 6d9b9b4 | 2020-01-14 12:57:33 -0800 | [diff] [blame] | 232 | } |
| 233 | |
Wyatt Hepler | e2cbadf | 2020-06-22 11:21:45 -0700 | [diff] [blame] | 234 | Status CallbackDecoder::Decode(std::span<const std::byte> proto) { |
Alexei Frolov | fe9723c | 2020-05-11 13:20:47 -0700 | [diff] [blame] | 235 | if (handler_ == nullptr || state_ != kReady) { |
Wyatt Hepler | d78f7c6 | 2020-09-28 14:27:32 -0700 | [diff] [blame] | 236 | return Status::FailedPrecondition(); |
Alexei Frolov | fe9723c | 2020-05-11 13:20:47 -0700 | [diff] [blame] | 237 | } |
| 238 | |
| 239 | state_ = kDecodeInProgress; |
| 240 | decoder_.Reset(proto); |
| 241 | |
| 242 | // Iterate the proto, calling the handler with each field number. |
| 243 | while (state_ == kDecodeInProgress) { |
| 244 | if (Status status = decoder_.Next(); !status.ok()) { |
Wyatt Hepler | d78f7c6 | 2020-09-28 14:27:32 -0700 | [diff] [blame] | 245 | if (status == Status::OutOfRange()) { |
Alexei Frolov | fe9723c | 2020-05-11 13:20:47 -0700 | [diff] [blame] | 246 | // Reached the end of the proto. |
| 247 | break; |
| 248 | } |
| 249 | |
| 250 | // Proto data is malformed. |
| 251 | return status; |
| 252 | } |
| 253 | |
| 254 | Status status = handler_->ProcessField(*this, decoder_.FieldNumber()); |
| 255 | if (!status.ok()) { |
Wyatt Hepler | d78f7c6 | 2020-09-28 14:27:32 -0700 | [diff] [blame] | 256 | state_ = status == Status::Cancelled() ? kDecodeCancelled : kDecodeFailed; |
Alexei Frolov | fe9723c | 2020-05-11 13:20:47 -0700 | [diff] [blame] | 257 | return status; |
| 258 | } |
| 259 | |
| 260 | // The callback function can modify the decoder's state; check that |
| 261 | // everything is still okay. |
| 262 | if (state_ == kDecodeFailed) { |
| 263 | break; |
| 264 | } |
| 265 | } |
| 266 | |
Alexei Frolov | dea46f7 | 2020-01-07 13:28:24 -0800 | [diff] [blame] | 267 | if (state_ != kDecodeInProgress) { |
Wyatt Hepler | d78f7c6 | 2020-09-28 14:27:32 -0700 | [diff] [blame] | 268 | return Status::DataLoss(); |
Alexei Frolov | dea46f7 | 2020-01-07 13:28:24 -0800 | [diff] [blame] | 269 | } |
| 270 | |
Alexei Frolov | fe9723c | 2020-05-11 13:20:47 -0700 | [diff] [blame] | 271 | state_ = kReady; |
Wyatt Hepler | 1b3da3a | 2021-01-07 13:26:57 -0800 | [diff] [blame^] | 272 | return OkStatus(); |
Alexei Frolov | dea46f7 | 2020-01-07 13:28:24 -0800 | [diff] [blame] | 273 | } |
| 274 | |
Alexei Frolov | dea46f7 | 2020-01-07 13:28:24 -0800 | [diff] [blame] | 275 | } // namespace pw::protobuf |