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/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/**
* Copyright (c) 2014, Regents of the University of California,
* Arizona Board of Regents,
* Colorado State University,
* University Pierre & Marie Curie, Sorbonne University,
* Washington University in St. Louis,
* Beijing Institute of Technology,
* The University of Memphis
*
* This file is part of NFD (Named Data Networking Forwarding Daemon).
* See AUTHORS.md for complete list of NFD authors and contributors.
*
* NFD is free software: you can redistribute it and/or modify it under the terms
* of the GNU General Public License as published by the Free Software Foundation,
* either version 3 of the License, or (at your option) any later version.
*
* NFD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
* without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
* PURPOSE. See the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along with
* NFD, e.g., in COPYING.md file. If not, see <http://www.gnu.org/licenses/>.
*/
#include "version.hpp"
#include "core/face-uri.hpp"
#include <ndn-cxx/face.hpp>
#include <ndn-cxx/management/nfd-controller.hpp>
#include <ndn-cxx/management/nfd-face-status.hpp>
#include <ndn-cxx/security/key-chain.hpp>
#include <ndn-cxx/encoding/buffer-stream.hpp>
#include <boost/lexical_cast.hpp>
#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/nameser.h>
#include <resolv.h>
#ifdef __APPLE__
#include <arpa/nameser_compat.h>
#endif
namespace ndn {
namespace tools {
void
usage(const char* programName)
{
std::cout << "Usage:\n" << programName << " [-h] [-V]\n"
<< " -h - print usage and exit\n"
<< " -V - print version number and exit\n"
<< std::endl;
}
class NdnAutoconfig
{
public:
union QueryAnswer
{
HEADER header;
uint8_t buf[NS_PACKETSZ];
};
class Error : public std::runtime_error
{
public:
explicit
Error(const std::string& what)
: std::runtime_error(what)
{
}
};
explicit
NdnAutoconfig()
: m_controller(m_face)
{
}
void
run()
{
m_face.processEvents();
}
void
fetchSegments(const Data& data, const shared_ptr<OBufferStream>& buffer,
void (NdnAutoconfig::*onDone)(const shared_ptr<OBufferStream>&))
{
buffer->write(reinterpret_cast<const char*>(data.getContent().value()),
data.getContent().value_size());
uint64_t currentSegment = data.getName().get(-1).toSegment();
const name::Component& finalBlockId = data.getMetaInfo().getFinalBlockId();
if (finalBlockId.empty() ||
finalBlockId.toSegment() > currentSegment)
{
m_face.expressInterest(data.getName().getPrefix(-1).appendSegment(currentSegment+1),
bind(&NdnAutoconfig::fetchSegments, this, _2, buffer, onDone),
bind(&NdnAutoconfig::discoverHubStage2, this, "Timeout"));
}
else
{
return (this->*onDone)(buffer);
}
}
void
discoverHubStage1()
{
shared_ptr<OBufferStream> buffer = make_shared<OBufferStream>();
Interest interest("/localhost/nfd/faces/list");
interest.setChildSelector(1);
interest.setMustBeFresh(true);
m_face.expressInterest(interest,
bind(&NdnAutoconfig::fetchSegments, this, _2, buffer,
&NdnAutoconfig::discoverHubStage1_registerLocalhubNdnAutoconfHub),
bind(&NdnAutoconfig::discoverHubStage2, this, "Timeout"));
}
void
discoverHubStage1_registerLocalhubNdnAutoconfHub(const shared_ptr<OBufferStream>& buffer)
{
ConstBufferPtr buf = buffer->buf();
std::vector<uint64_t> multicastFaces;
size_t offset = 0;
while (offset < buf->size())
{
Block block;
bool ok = Block::fromBuffer(buf, offset, block);
if (!ok)
{
std::cerr << "ERROR: cannot decode FaceStatus TLV" << std::endl;
break;
}
offset += block.size();
nfd::FaceStatus faceStatus(block);
::nfd::FaceUri uri(faceStatus.getRemoteUri());
if (uri.getScheme() == "udp4") {
namespace ip = boost::asio::ip;
boost::system::error_code ec;
ip::address address = ip::address::from_string(uri.getHost(), ec);
if (!ec && address.is_multicast()) {
multicastFaces.push_back(faceStatus.getFaceId());
}
else
continue;
}
}
if (multicastFaces.empty()) {
discoverHubStage2("No multicast faces available, skipping stage 1");
}
else {
shared_ptr<nfd::Controller> controller = make_shared<nfd::Controller>(ref(m_face));
shared_ptr<std::pair<size_t, size_t> > nRegistrations =
make_shared<std::pair<size_t, size_t> >(0, 0);
nfd::ControlParameters parameters;
parameters
.setName("/localhop/ndn-autoconf/hub")
.setCost(1);
nRegistrations->first = multicastFaces.size();
for (std::vector<uint64_t>::iterator i = multicastFaces.begin();
i != multicastFaces.end(); ++i) {
parameters.setFaceId(*i);
controller->start<nfd::RibRegisterCommand>(parameters,
bind(&NdnAutoconfig::discoverHubStage1_onRegisterSuccess,
this, controller, nRegistrations),
bind(&NdnAutoconfig::discoverHubStage1_onRegisterFailure,
this, _1, _2, controller, nRegistrations));
}
}
}
void
discoverHubStage1_onRegisterSuccess(const shared_ptr<nfd::Controller>& controller,
const shared_ptr<std::pair<size_t, size_t> >& nRegistrations)
{
nRegistrations->second++;
if (nRegistrations->first == nRegistrations->second) {
discoverHubStage1_requestHubData();
}
}
void
discoverHubStage1_onRegisterFailure(uint32_t code, const std::string& error,
const shared_ptr<nfd::Controller> controller,
const shared_ptr<std::pair<size_t, size_t> >& nRegistrations)
{
std::cerr << "ERROR: " << error << " (code: " << code << ")" << std::endl;
nRegistrations->first--;
if (nRegistrations->first == nRegistrations->second) {
if (nRegistrations->first > 0) {
discoverHubStage1_requestHubData();
} else {
discoverHubStage2("Failed to register /localhop/ndn-autoconf/hub for all multicast faces");
}
}
}
// Start to look for a hub (NDN hub discovery first stage)
void
discoverHubStage1_requestHubData()
{
Interest interest(Name("/localhop/ndn-autoconf/hub"));
interest.setInterestLifetime(time::milliseconds(4000)); // 4 seconds
interest.setMustBeFresh(true);
std::cerr << "Stage 1: Trying multicast discovery..." << std::endl;
m_face.expressInterest(interest,
bind(&NdnAutoconfig::onDiscoverHubStage1Success, this, _1, _2),
bind(&NdnAutoconfig::discoverHubStage2, this, "Timeout"));
}
// First stage OnData Callback
void
onDiscoverHubStage1Success(const Interest& interest, Data& data)
{
const Block& content = data.getContent();
content.parse();
// Get Uri
Block::element_const_iterator blockValue = content.find(tlv::nfd::Uri);
if (blockValue == content.elements_end())
{
discoverHubStage2("Incorrect reply to stage1");
return;
}
std::string faceMgmtUri(reinterpret_cast<const char*>(blockValue->value()),
blockValue->value_size());
connectToHub(faceMgmtUri);
}
// First stage OnTimeout callback - start 2nd stage
void
discoverHubStage2(const std::string& message)
{
std::cerr << message << std::endl;
std::cerr << "Stage 2: Trying DNS query with default suffix..." << std::endl;
_res.retry = 2;
_res.ndots = 10;
QueryAnswer queryAnswer;
int answerSize = res_search("_ndn._udp",
ns_c_in,
ns_t_srv,
queryAnswer.buf,
sizeof(queryAnswer));
// 2nd stage failed - move on to the third stage
if (answerSize < 0)
{
discoverHubStage3("Failed to find NDN router using default suffix DNS query");
}
else
{
bool isParsed = parseHostAndConnectToHub(queryAnswer, answerSize);
if (isParsed == false)
{
// Failed to parse DNS response, try stage 3
discoverHubStage3("Failed to parse DNS response");
}
}
}
// Second stage OnTimeout callback
void
discoverHubStage3(const std::string& message)
{
std::cerr << message << std::endl;
std::cerr << "Stage 3: Trying to find home router..." << std::endl;
KeyChain keyChain;
Name identity = keyChain.getDefaultIdentity();
std::string serverName = "_ndn._udp.";
for (Name::const_reverse_iterator i = identity.rbegin(); i != identity.rend(); i++)
{
serverName.append(i->toUri());
serverName.append(".");
}
serverName += "_homehub._autoconf.named-data.net";
std::cerr << "Stage3: About to query for a home router: " << serverName << std::endl;
QueryAnswer queryAnswer;
int answerSize = res_query(serverName.c_str(),
ns_c_in,
ns_t_srv,
queryAnswer.buf,
sizeof(queryAnswer));
// 3rd stage failed - abort
if (answerSize < 0)
{
std::cerr << "Failed to find a home router" << std::endl;
std::cerr << "exit" << std::endl;
}
else
{
bool isParsed = parseHostAndConnectToHub(queryAnswer, answerSize);
if (isParsed == false)
{
// Failed to parse DNS response
throw Error("Failed to parse DNS response");
}
}
}
void
connectToHub(const std::string& uri)
{
std::cerr << "about to connect to: " << uri << std::endl;
m_controller.start<nfd::FaceCreateCommand>(
nfd::ControlParameters()
.setUri(uri),
bind(&NdnAutoconfig::onHubConnectSuccess, this, _1),
bind(&NdnAutoconfig::onHubConnectError, this, _1, _2)
);
}
void
onHubConnectSuccess(const nfd::ControlParameters& resp)
{
std::cerr << "Successfully created face: " << resp << std::endl;
// Register a prefix in RIB
nfd::ControlParameters ribParameters;
ribParameters
.setName("/ndn")
.setFaceId(resp.getFaceId());
m_controller.start<nfd::RibRegisterCommand>(
ribParameters,
bind(&NdnAutoconfig::onPrefixRegistrationSuccess, this, _1),
bind(&NdnAutoconfig::onPrefixRegistrationError, this, _1, _2));
}
void
onHubConnectError(uint32_t code, const std::string& error)
{
std::ostringstream os;
os << "Failed to create face: " << error << " (code: " << code << ")";
throw Error(os.str());
}
bool parseHostAndConnectToHub(QueryAnswer& queryAnswer, int answerSize)
{
// The references of the next classes are:
// http://www.diablotin.com/librairie/networking/dnsbind/ch14_02.htm
// https://gist.github.com/mologie/6027597
struct rechdr
{
uint16_t type;
uint16_t iclass;
uint32_t ttl;
uint16_t length;
};
struct srv_t
{
uint16_t priority;
uint16_t weight;
uint16_t port;
uint8_t* target;
};
if (ntohs(queryAnswer.header.ancount) == 0)
{
std::cerr << "No records found\n" << std::endl;
return false;
}
uint8_t* blob = queryAnswer.buf + NS_HFIXEDSZ;
blob += dn_skipname(blob, queryAnswer.buf + answerSize) + NS_QFIXEDSZ;
for (int i = 0; i < ntohs(queryAnswer.header.ancount); i++)
{
char srvName[NS_MAXDNAME];
int serverNameSize = dn_expand(queryAnswer.buf, // message pointer
queryAnswer.buf + answerSize, // end of message
blob, // compressed server name
srvName, // expanded server name
NS_MAXDNAME);
if (serverNameSize < 0)
{
return false;
}
srv_t* server = reinterpret_cast<srv_t*>(&blob[sizeof(rechdr)]);
uint16_t convertedPort = be16toh(server->port);
blob += serverNameSize + NS_HFIXEDSZ + NS_QFIXEDSZ;
char hostName[NS_MAXDNAME];
int hostNameSize = dn_expand(queryAnswer.buf, // message pointer
queryAnswer.buf + answerSize, // end of message
blob, // compressed host name
hostName, // expanded host name
NS_MAXDNAME);
if (hostNameSize < 0)
{
return false;
}
std::string uri = "udp://";
uri.append(hostName);
uri.append(":");
uri.append(boost::lexical_cast<std::string>(convertedPort));
connectToHub(uri);
return true;
}
return false;
}
void
onPrefixRegistrationSuccess(const nfd::ControlParameters& commandSuccessResult)
{
std::cerr << "Successful in name registration: " << commandSuccessResult << std::endl;
}
void
onPrefixRegistrationError(uint32_t code, const std::string& error)
{
std::ostringstream os;
os << "Failed in name registration, " << error << " (code: " << code << ")";
throw Error(os.str());
}
private:
Face m_face;
nfd::Controller m_controller;
};
} // namespace tools
} // namespace ndn
int
main(int argc, char** argv)
{
int opt;
const char* programName = argv[0];
while ((opt = getopt(argc, argv, "hV")) != -1) {
switch (opt) {
case 'h':
ndn::tools::usage(programName);
return 0;
case 'V':
std::cout << NFD_VERSION_BUILD_STRING << std::endl;
return 0;
}
}
try {
ndn::tools::NdnAutoconfig autoConfigInstance;
autoConfigInstance.discoverHubStage1();
autoConfigInstance.run();
}
catch (const std::exception& error) {
std::cerr << "ERROR: " << error.what() << std::endl;
return 1;
}
return 0;
}