multicast-ethernet-transport.cpp
Go to the documentation of this file.
1 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
2 /*
3  * Copyright (c) 2014-2023, 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,
16  * either version 3 of the License, or (at your option) any later version.
17  *
18  * NFD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
19  * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
20  * PURPOSE. See the GNU General Public License for more details.
21  *
22  * You should have received a copy of the GNU General Public License along with
23  * NFD, e.g., in COPYING.md file. If not, see <http://www.gnu.org/licenses/>.
24  */
25 
27 #include "common/global.hpp"
28 
29 #include <cerrno> // for errno
30 #include <cstdio> // for snprintf()
31 #include <cstring> // for memcpy(), strerror(), strncpy()
32 #include <net/if.h> // for struct ifreq
33 #include <sys/ioctl.h> // for ioctl()
34 
35 #if defined(__linux__)
36 #include <netpacket/packet.h> // for struct packet_mreq
37 #include <sys/socket.h> // for setsockopt()
38 #endif
39 
40 #ifdef SIOCADDMULTI
41 #if defined(__APPLE__) || defined(__FreeBSD__)
42 #include <net/if_dl.h> // for struct sockaddr_dl
43 #endif
44 #endif
45 
46 namespace nfd::face {
47 
48 NFD_LOG_INIT(MulticastEthernetTransport);
49 
50 MulticastEthernetTransport::MulticastEthernetTransport(const ndn::net::NetworkInterface& localEndpoint,
51  const ethernet::Address& mcastAddress,
52  ndn::nfd::LinkType linkType)
53  : EthernetTransport(localEndpoint, mcastAddress)
54 #if defined(__linux__)
55  , m_interfaceIndex(localEndpoint.getIndex())
56 #endif
57 {
58  this->setLocalUri(FaceUri::fromDev(m_interfaceName));
59  this->setRemoteUri(FaceUri(m_destAddress));
60  this->setScope(ndn::nfd::FACE_SCOPE_NON_LOCAL);
61  this->setPersistency(ndn::nfd::FACE_PERSISTENCY_PERMANENT);
62  this->setLinkType(linkType);
63  this->setMtu(localEndpoint.getMtu());
64 
65  NFD_LOG_FACE_DEBUG("Creating transport");
66 
67  char filter[110];
68  // Note: "not vlan" must appear last in the filter expression, or the
69  // rest of the filter won't work as intended (see pcap-filter(7))
70  std::snprintf(filter, sizeof(filter),
71  "(ether proto 0x%x) && (ether dst %s) && (not ether src %s) && (not vlan)",
72  ethernet::ETHERTYPE_NDN,
73  m_destAddress.toString().data(),
74  m_srcAddress.toString().data());
75  m_pcap.setPacketFilter(filter);
76 
77  BOOST_ASSERT(m_destAddress.isMulticast());
78  if (!m_destAddress.isBroadcast()) {
79  joinMulticastGroup();
80  }
81 }
82 
83 void
84 MulticastEthernetTransport::joinMulticastGroup()
85 {
86 #if defined(__linux__)
87  packet_mreq mr{};
88  mr.mr_ifindex = m_interfaceIndex;
89  mr.mr_type = PACKET_MR_MULTICAST;
90  mr.mr_alen = m_destAddress.size();
91  std::memcpy(mr.mr_address, m_destAddress.data(), m_destAddress.size());
92 
93  if (::setsockopt(m_socket.native_handle(), SOL_PACKET,
94  PACKET_ADD_MEMBERSHIP, &mr, sizeof(mr)) == 0)
95  return; // success
96 
97  NFD_LOG_FACE_WARN("setsockopt(PACKET_ADD_MEMBERSHIP) failed: " << std::strerror(errno));
98 #endif
99 
100 #if defined(SIOCADDMULTI)
101  ifreq ifr{};
102  std::strncpy(ifr.ifr_name, m_interfaceName.data(), sizeof(ifr.ifr_name) - 1);
103 
104 #if defined(__APPLE__) || defined(__FreeBSD__)
105  // see bug #2327
106  boost::asio::ip::udp::socket sock(getGlobalIoService(), boost::asio::ip::udp::v4());
107  int fd = sock.native_handle();
108 
109  // Differences between Linux and the BSDs (including macOS):
110  // o BSD does not have ifr_hwaddr; use ifr_addr instead.
111  // o While macOS seems to accept both AF_LINK and AF_UNSPEC as the address
112  // family, FreeBSD explicitly requires AF_LINK, so we have to use AF_LINK
113  // and sockaddr_dl instead of the generic sockaddr structure.
114  // o BSD's sockaddr (and sockaddr_dl in particular) contains an additional
115  // field, sa_len (sdl_len), which must be set to the total length of the
116  // structure, including the length field itself.
117  // o We do not specify the interface name, thus sdl_nlen is left at 0 and
118  // LLADDR is effectively the same as sdl_data.
119 
120  sockaddr_dl* sdl = reinterpret_cast<sockaddr_dl*>(&ifr.ifr_addr);
121  sdl->sdl_len = sizeof(ifr.ifr_addr);
122  sdl->sdl_family = AF_LINK;
123  sdl->sdl_alen = m_destAddress.size();
124  std::memcpy(LLADDR(sdl), m_destAddress.data(), m_destAddress.size());
125 
126  static_assert(sizeof(ifr.ifr_addr) >= offsetof(sockaddr_dl, sdl_data) + ethernet::ADDR_LEN,
127  "ifr_addr in struct ifreq is too small on this platform");
128 #else
129  int fd = m_socket.native_handle();
130 
131  ifr.ifr_hwaddr.sa_family = AF_UNSPEC;
132  std::memcpy(ifr.ifr_hwaddr.sa_data, m_destAddress.data(), m_destAddress.size());
133 
134  static_assert(sizeof(ifr.ifr_hwaddr.sa_data) >= ethernet::ADDR_LEN,
135  "ifr_hwaddr in struct ifreq is too small on this platform");
136 #endif
137 
138  if (::ioctl(fd, SIOCADDMULTI, &ifr) == 0)
139  return; // success
140 
141  NFD_LOG_FACE_WARN("ioctl(SIOCADDMULTI) failed: " << std::strerror(errno));
142 #endif
143 
144  NDN_THROW(Error("Failed to join multicast group"));
145 }
146 
147 } // namespace nfd::face
Base class for Ethernet-based Transports.
boost::asio::posix::stream_descriptor m_socket
MulticastEthernetTransport(const ndn::net::NetworkInterface &localEndpoint, const ethernet::Address &mcastAddress, ndn::nfd::LinkType linkType)
Creates an Ethernet-based transport for multicast communication.
void setPacketFilter(const char *filter) const
Install a BPF filter on the receiving socket.
void setScope(ndn::nfd::FaceScope scope) noexcept
Definition: transport.hpp:355
void setPersistency(ndn::nfd::FacePersistency newPersistency)
Changes the persistency setting of the transport.
Definition: transport.cpp:152
void setMtu(ssize_t mtu) noexcept
Definition: transport.cpp:114
void setLocalUri(const FaceUri &uri) noexcept
Definition: transport.hpp:343
void setLinkType(ndn::nfd::LinkType linkType) noexcept
Definition: transport.hpp:361
void setRemoteUri(const FaceUri &uri) noexcept
Definition: transport.hpp:349
#define NFD_LOG_FACE_DEBUG(msg)
Log a message at DEBUG level.
#define NFD_LOG_FACE_WARN(msg)
Log a message at WARN level.
#define NFD_LOG_INIT(name)
Definition: logger.hpp:31
boost::asio::io_context & getGlobalIoService()
Returns the global io_context instance for the calling thread.
Definition: global.cpp:36