ZeroTierOne/node/Network.cpp

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/*
* ZeroTier One - Global Peer to Peer Ethernet
* Copyright (C) 2012-2013 ZeroTier Networks LLC
*
* This program 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.
*
* This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
*
* --
*
* ZeroTier may be used and distributed under the terms of the GPLv3, which
* are available at: http://www.gnu.org/licenses/gpl-3.0.html
*
* If you would like to embed ZeroTier into a commercial application or
* redistribute it in a modified binary form, please contact ZeroTier Networks
* LLC. Start here: http://www.zerotier.com/
*/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <math.h>
#include <openssl/sha.h>
#include "RuntimeEnvironment.hpp"
#include "NodeConfig.hpp"
#include "Network.hpp"
#include "Switch.hpp"
#include "Packet.hpp"
#include "Utils.hpp"
namespace ZeroTier {
void Network::Certificate::_shaForSignature(unsigned char *dig) const
{
SHA256_CTX sha;
SHA256_Init(&sha);
unsigned char zero = 0;
for(const_iterator i(begin());i!=end();++i) {
SHA256_Update(&sha,&zero,1);
SHA256_Update(&sha,(const unsigned char *)i->first.data(),i->first.length());
SHA256_Update(&sha,&zero,1);
SHA256_Update(&sha,(const unsigned char *)i->second.data(),i->second.length());
SHA256_Update(&sha,&zero,1);
}
SHA256_Final(dig,&sha);
}
static const std::string _DELTA_PREFIX("~");
bool Network::Certificate::qualifyMembership(const Network::Certificate &mc) const
{
// Note: optimization probably needed here, probably via some kind of
// memoization / dynamic programming. But make it work first, then make
// it fast.
for(const_iterator myField(begin());myField!=end();++myField) {
if (!((myField->first.length() > 1)&&(myField->first[0] == '~'))) { // ~fields are max delta range specs
// If they lack the same field, comparison fails.
const_iterator theirField(mc.find(myField->first));
if (theirField == mc.end())
return false;
const_iterator deltaField(find(_DELTA_PREFIX + myField->first));
if (deltaField == end()) {
// If there is no delta, compare on simple equality
if (myField->second != theirField->second)
return false;
} else {
// Otherwise compare range with max delta. Presence of a dot in delta
// indicates a floating point comparison. Otherwise an integer
// comparison occurs.
if (deltaField->second.find('.') != std::string::npos) {
double my = strtod(myField->second.c_str(),(char **)0);
double their = strtod(theirField->second.c_str(),(char **)0);
double delta = strtod(deltaField->second.c_str(),(char **)0);
if (fabs(my - their) > delta)
return false;
} else {
int64_t my = strtoll(myField->second.c_str(),(char **)0,10);
int64_t their = strtoll(theirField->second.c_str(),(char **)0,10);
int64_t delta = strtoll(deltaField->second.c_str(),(char **)0,10);
if (my > their) {
if ((my - their) > delta)
return false;
} else {
if ((their - my) > delta)
return false;
}
}
}
}
}
return true;
}
Network::~Network()
{
delete _tap;
if (_destroyOnDelete) {
std::string confPath(_r->homePath + ZT_PATH_SEPARATOR_S + "networks.d" + ZT_PATH_SEPARATOR_S + toString() + ".conf");
std::string mcdbPath(_r->homePath + ZT_PATH_SEPARATOR_S + "networks.d" + ZT_PATH_SEPARATOR_S + toString() + ".mcerts");
unlink(confPath.c_str());
unlink(mcdbPath.c_str());
} else {
// Causes flush of membership certs to disk
clean();
}
}
SharedPtr<Network> Network::newInstance(const RuntimeEnvironment *renv,uint64_t id)
throw(std::runtime_error)
{
// We construct Network via a static method to ensure that it is immediately
// wrapped in a SharedPtr<>. Otherwise if there is traffic on the Ethernet
// tap device, a SharedPtr<> wrap can occur in the Ethernet frame handler
// that then causes the Network instance to be deleted before it is finished
// being constructed. C++ edge cases, how I love thee.
SharedPtr<Network> nw(new Network());
nw->_r = renv;
nw->_tap = new EthernetTap(renv,renv->identity.address().toMAC(),ZT_IF_MTU,&_CBhandleTapData,nw.ptr());
nw->_id = id;
nw->_lastConfigUpdate = 0;
nw->_destroyOnDelete = false;
if (nw->controller() == renv->identity.address()) // sanity check, this isn't supported for now
throw std::runtime_error("cannot add a network for which I am the netconf master");
nw->_restoreState();
nw->requestConfiguration();
return nw;
}
void Network::setConfiguration(const Network::Config &conf)
{
Mutex::Lock _l(_lock);
if ((conf.networkId() == _id)&&(conf.peerAddress() == _r->identity.address())) { // sanity check
//TRACE("network %.16llx got netconf:\n%s",(unsigned long long)_id,conf.toString().c_str());
_configuration = conf;
_myCertificate = conf.certificateOfMembership();
_lastConfigUpdate = Utils::now();
_tap->setIps(conf.staticAddresses());
std::string confPath(_r->homePath + ZT_PATH_SEPARATOR_S + "networks.d" + ZT_PATH_SEPARATOR_S + toString() + ".conf");
if (!Utils::writeFile(confPath.c_str(),conf.toString())) {
LOG("error: unable to write network configuration file at: %s",confPath.c_str());
}
}
}
void Network::requestConfiguration()
{
if (controller() == _r->identity.address()) {
LOG("unable to request network configuration for network %.16llx: I am the network master, cannot query self",(unsigned long long)_id);
return;
}
TRACE("requesting netconf for network %.16llx from netconf master %s",(unsigned long long)_id,controller().toString().c_str());
Packet outp(controller(),_r->identity.address(),Packet::VERB_NETWORK_CONFIG_REQUEST);
outp.append((uint64_t)_id);
outp.append((uint16_t)0); // no meta-data
_r->sw->send(outp,true);
}
void Network::addMembershipCertificate(const Address &peer,const Certificate &cert)
{
Mutex::Lock _l(_lock);
if (!_configuration.isOpen())
_membershipCertificates[peer] = cert;
}
bool Network::isAllowed(const Address &peer) const
{
// Exceptions can occur if we do not yet have *our* configuration.
try {
Mutex::Lock _l(_lock);
if (_configuration.isOpen())
return true;
std::map<Address,Certificate>::const_iterator pc(_membershipCertificates.find(peer));
if (pc == _membershipCertificates.end())
return false;
return _myCertificate.qualifyMembership(pc->second);
} catch (std::exception &exc) {
TRACE("isAllowed() check failed for peer %s: unexpected exception: %s",peer.toString().c_str(),exc.what());
} catch ( ... ) {
TRACE("isAllowed() check failed for peer %s: unexpected exception: unknown exception",peer.toString().c_str());
}
return false;
}
void Network::clean()
{
std::string mcdbPath(_r->homePath + ZT_PATH_SEPARATOR_S + "networks.d" + ZT_PATH_SEPARATOR_S + toString() + ".mcerts");
Mutex::Lock _l(_lock);
if (_configuration.isOpen()) {
_membershipCertificates.clear();
unlink(mcdbPath.c_str());
} else {
FILE *mcdb = fopen(mcdbPath.c_str(),"wb");
bool writeError = false;
if (!mcdb) {
LOG("error: unable to open membership cert database at: %s",mcdbPath.c_str());
} else {
if ((writeError)||(fwrite("MCDB0",5,1,mcdb) != 1)) // version
writeError = true;
}
for(std::map<Address,Certificate>::iterator i=(_membershipCertificates.begin());i!=_membershipCertificates.end();) {
if (_myCertificate.qualifyMembership(i->second)) {
if ((!writeError)&&(mcdb)) {
char tmp[ZT_ADDRESS_LENGTH];
i->first.copyTo(tmp,ZT_ADDRESS_LENGTH);
if ((writeError)||(fwrite(tmp,ZT_ADDRESS_LENGTH,1,mcdb) != 1))
writeError = true;
std::string c(i->second.toString());
uint32_t cl = Utils::hton((uint32_t)c.length());
if ((writeError)||(fwrite(&cl,sizeof(cl),1,mcdb) != 1))
writeError = true;
if ((writeError)||(fwrite(c.data(),c.length(),1,mcdb) != 1))
writeError = true;
}
++i;
} else _membershipCertificates.erase(i++);
}
if (mcdb)
fclose(mcdb);
if (writeError) {
unlink(mcdbPath.c_str());
LOG("error: unable to write to membership cert database at: %s",mcdbPath.c_str());
}
}
}
void Network::_CBhandleTapData(void *arg,const MAC &from,const MAC &to,unsigned int etherType,const Buffer<4096> &data)
{
const RuntimeEnvironment *_r = ((Network *)arg)->_r;
try {
_r->sw->onLocalEthernet(SharedPtr<Network>((Network *)arg),from,to,etherType,data);
} catch (std::exception &exc) {
TRACE("unexpected exception handling local packet: %s",exc.what());
} catch ( ... ) {
TRACE("unexpected exception handling local packet");
}
}
void Network::_restoreState()
{
std::string confPath(_r->homePath + ZT_PATH_SEPARATOR_S + "networks.d" + ZT_PATH_SEPARATOR_S + toString() + ".conf");
std::string confs;
if (Utils::readFile(confPath.c_str(),confs)) {
try {
if (confs.length()) {
Config conf(confs);
if (conf.containsAllFields())
setConfiguration(conf);
}
} catch ( ... ) {} // ignore invalid config on disk, we will re-request
} else {
// If the conf file isn't present, "touch" it so we'll remember
// the existence of this network.
FILE *tmp = fopen(confPath.c_str(),"w");
if (tmp)
fclose(tmp);
}
// TODO: restore membership certs
}
} // namespace ZeroTier