ethernet-protocol.cpp
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1 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
2 /*
3  * Copyright (c) 2014-2018, Regents of the University of California,
4  * Arizona Board of Regents,
5  * Colorado State University,
6  * University Pierre & Marie Curie, Sorbonne University,
7  * Washington University in St. Louis,
8  * Beijing Institute of Technology,
9  * The University of Memphis.
10  *
11  * This file is part of NFD (Named Data Networking Forwarding Daemon).
12  * See AUTHORS.md for complete list of NFD authors and contributors.
13  *
14  * NFD is free software: you can redistribute it and/or modify it under the terms
15  * of the GNU General Public License as published by the Free Software Foundation,
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20  * PURPOSE. See the GNU General Public License for more details.
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23  * NFD, e.g., in COPYING.md file. If not, see <http://www.gnu.org/licenses/>.
24  */
25 
26 #include "ethernet-protocol.hpp"
27 
28 #include <boost/endian/conversion.hpp>
29 
30 namespace nfd {
31 namespace ethernet {
32 
33 std::pair<const ether_header*, std::string>
34 checkFrameHeader(const uint8_t* packet, size_t length,
35  const Address& localAddr, const Address& destAddr)
36 {
37  if (length < HDR_LEN + MIN_DATA_LEN)
38  return {nullptr, "Received frame too short: " + to_string(length) + " bytes"};
39 
40  const ether_header* eh = reinterpret_cast<const ether_header*>(packet);
41 
42  // in some cases VLAN-tagged frames may survive the BPF filter,
43  // make sure we do not process those frames (see #3348)
44  uint16_t ethertype = boost::endian::big_to_native(eh->ether_type);
45  if (ethertype != ETHERTYPE_NDN)
46  return {nullptr, "Received frame with wrong ethertype: " + to_string(ethertype)};
47 
48 #ifdef _DEBUG
49  Address shost(eh->ether_shost);
50  if (shost == localAddr)
51  return {nullptr, "Received frame sent by this host"};
52 
53  Address dhost(eh->ether_dhost);
54  if (dhost != destAddr)
55  return {nullptr, "Received frame addressed to another host or multicast group: " + dhost.toString()};
56 #endif
57 
58  return {eh, ""};
59 }
60 
61 } // namespace ethernet
62 } // namespace nfd
Copyright (c) 2014-2015, Regents of the University of California, Arizona Board of Regents...
Definition: algorithm.hpp:32
std::pair< const ether_header *, std::string > checkFrameHeader(const uint8_t *packet, size_t length, const Address &localAddr, const Address &destAddr)