1 // Copyright 2021 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 #pragma once 15 16 #include <cstdint> 17 #include <optional> 18 19 #include "pw_bytes/span.h" 20 #include "pw_span/span.h" 21 22 namespace pw::router { 23 24 // A PacketParser is an abstract interface for extracting data from different 25 // kinds of transport layer packets or frames. It is used by routers to examine 26 // fields within packets to know how to route them. 27 class PacketParser { 28 public: 29 virtual ~PacketParser() = default; 30 31 // Parses a packet, storing its data for subsequent calls to Get* functions. 32 // Any currently stored packet is cleared. Returns true if successful, or 33 // false if the packet is incomplete or corrupt. 34 // 35 // The raw binary data passed to this function is guaranteed to remain valid 36 // through all subsequent Get* calls made for the packet's information, so 37 // implementations may store and use it directly. 38 virtual bool Parse(ConstByteSpan packet) = 0; 39 40 // Extracts the destination address the last parsed packet, if it exists. 41 // 42 // Guaranteed to only be called if Parse() succeeded and while the data passed 43 // to Parse() is valid. 44 virtual std::optional<uint32_t> GetDestinationAddress() const = 0; 45 }; 46 47 } // namespace pw::router 48