ethernet-protocol.cpp
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1 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
26 #include "ethernet-protocol.hpp"
27 
28 #include <arpa/inet.h> // for ntohs()
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  if (ntohs(eh->ether_type) != ETHERTYPE_NDN)
45  return {nullptr, "Received frame with wrong ethertype: " + to_string(ntohs(eh->ether_type))};
46 
47 #ifdef _DEBUG
48  Address shost(eh->ether_shost);
49  if (shost == localAddr)
50  return {nullptr, "Received frame sent by this host"};
51 
52  Address dhost(eh->ether_dhost);
53  if (dhost != destAddr)
54  return {nullptr, "Received frame addressed to another host or multicast group: " + dhost.toString()};
55 #endif
56 
57  return {eh, ""};
58 }
59 
60 } // namespace ethernet
61 } // 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)