ZeroTierOne/node/Network.cpp
2013-10-17 16:49:31 -04:00

398 lines
13 KiB
C++

/*
* 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 <algorithm>
#include "Constants.hpp"
#include "RuntimeEnvironment.hpp"
#include "NodeConfig.hpp"
#include "Network.hpp"
#include "Switch.hpp"
#include "Packet.hpp"
#include "Utils.hpp"
#include "Buffer.hpp"
#define ZT_NETWORK_CERT_WRITE_BUF_SIZE 524288
namespace ZeroTier {
const Network::MulticastRates::Rate Network::MulticastRates::GLOBAL_DEFAULT_RATE(65535,65535,64);
const char *Network::statusString(const Status s)
throw()
{
switch(s) {
case NETWORK_WAITING_FOR_FIRST_AUTOCONF: return "WAITING_FOR_FIRST_AUTOCONF";
case NETWORK_OK: return "OK";
case NETWORK_ACCESS_DENIED: return "ACCESS_DENIED";
case NETWORK_NOT_FOUND: return "NOT_FOUND";
}
return "(invalid)";
}
Network::~Network()
{
delete _tap;
if (_destroyOnDelete) {
Utils::rm(std::string(_r->homePath + ZT_PATH_SEPARATOR_S + "networks.d" + ZT_PATH_SEPARATOR_S + idString() + ".conf"));
Utils::rm(std::string(_r->homePath + ZT_PATH_SEPARATOR_S + "networks.d" + ZT_PATH_SEPARATOR_S + idString() + ".mcerts"));
} else {
// Causes flush of membership certs to disk
clean();
_dumpMulticastCerts();
}
}
SharedPtr<Network> Network::newInstance(const RuntimeEnvironment *renv,uint64_t id)
throw(std::runtime_error)
{
// Tag to identify tap device -- used on some OSes like Windows
char tag[32];
Utils::snprintf(tag,sizeof(tag),"%.16llx",(unsigned long long)id);
// 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->_ready = false; // disable handling of Ethernet frames during construct
nw->_r = renv;
nw->_tap = new EthernetTap(renv,tag,renv->identity.address().toMAC(),ZT_IF_MTU,&_CBhandleTapData,nw.ptr());
nw->_isOpen = false;
nw->_emulateArp = false;
nw->_emulateNdp = false;
nw->_arpCacheTtl = 0;
nw->_ndpCacheTtl = 0;
nw->_multicastPrefixBits = ZT_DEFAULT_MULTICAST_PREFIX_BITS;
nw->_multicastDepth = ZT_DEFAULT_MULTICAST_DEPTH;
nw->_status = NETWORK_WAITING_FOR_FIRST_AUTOCONF;
memset(nw->_etWhitelist,0,sizeof(nw->_etWhitelist));
nw->_id = id;
nw->_lastConfigUpdate = 0;
nw->_destroyOnDelete = false;
if (nw->controller() == renv->identity.address()) // netconf masters can't really join networks
throw std::runtime_error("cannot join a network for which I am the netconf master");
nw->_restoreState();
nw->_ready = true; // enable handling of Ethernet frames
nw->requestConfiguration();
return nw;
}
void Network::setConfiguration(const Network::Config &conf,bool saveToDisk)
{
Mutex::Lock _l(_lock);
try {
if (conf.networkId() == _id) { // sanity check
_configuration = conf;
// Grab some things from conf for faster lookup and memoize them
_myCertificate = conf.certificateOfMembership();
_mcRates = conf.multicastRates();
_staticAddresses = conf.staticAddresses();
_isOpen = conf.isOpen();
_emulateArp = conf.emulateArp();
_emulateNdp = conf.emulateNdp();
_arpCacheTtl = conf.arpCacheTtl();
_ndpCacheTtl = conf.ndpCacheTtl();
_multicastPrefixBits = conf.multicastPrefixBits();
_multicastDepth = conf.multicastDepth();
_lastConfigUpdate = Utils::now();
_tap->setIps(_staticAddresses);
_tap->setDisplayName((std::string("ZeroTier One [") + conf.name() + "]").c_str());
// Expand ethertype whitelist into fast-lookup bit field (more memoization)
memset(_etWhitelist,0,sizeof(_etWhitelist));
std::set<unsigned int> wl(conf.etherTypes());
for(std::set<unsigned int>::const_iterator t(wl.begin());t!=wl.end();++t)
_etWhitelist[*t / 8] |= (unsigned char)(1 << (*t % 8));
_status = NETWORK_OK;
if (saveToDisk) {
std::string confPath(_r->homePath + ZT_PATH_SEPARATOR_S + "networks.d" + ZT_PATH_SEPARATOR_S + idString() + ".conf");
if (!Utils::writeFile(confPath.c_str(),conf.toString())) {
LOG("error: unable to write network configuration file at: %s",confPath.c_str());
}
}
}
} catch ( ... ) {
// If conf is invalid, reset everything
_configuration = Config();
_myCertificate = CertificateOfMembership();
_mcRates = MulticastRates();
_staticAddresses.clear();
_isOpen = false;
_emulateArp = false;
_emulateNdp = false;
_arpCacheTtl = 0;
_ndpCacheTtl = 0;
_status = NETWORK_WAITING_FOR_FIRST_AUTOCONF;
_lastConfigUpdate = 0;
LOG("unexpected exception handling config for network %.16llx, retrying fetch...",(unsigned long long)_id);
}
}
void Network::requestConfiguration()
{
if (controller() == _r->identity.address()) {
// netconf master cannot be a member of its own nets
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 CertificateOfMembership &cert)
{
Mutex::Lock _l(_lock);
// We go ahead and accept certs provisionally even if _isOpen is true, since
// that might be changed in short order if the user is fiddling in the UI.
// These will be purged on clean() for open networks eventually.
CertificateOfMembership &old = _membershipCertificates[cert.issuedTo()];
if (cert.timestamp() >= old.timestamp())
old = 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 (_isOpen)
return true; // network is public
std::map<Address,CertificateOfMembership>::const_iterator pc(_membershipCertificates.find(peer));
if (pc == _membershipCertificates.end())
return false; // no certificate on file
return _myCertificate.agreesWith(pc->second); // is other cert valid against ours?
} 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; // default position on any failure
}
void Network::clean()
{
Mutex::Lock _l(_lock);
uint64_t timestampMaxDelta = _myCertificate.timestampMaxDelta();
if (_isOpen) {
// Open (public) networks do not track certs or cert pushes at all.
_membershipCertificates.clear();
_lastPushedMembershipCertificate.clear();
} else if (timestampMaxDelta) {
// Clean certificates that are no longer valid from the cache.
for(std::map<Address,CertificateOfMembership>::iterator c=(_membershipCertificates.begin());c!=_membershipCertificates.end();) {
if (_myCertificate.agreesWith(c->second))
++c;
else _membershipCertificates.erase(c++);
}
// Clean entries from the last pushed tracking map if they're so old as
// to be no longer relevant.
uint64_t forgetIfBefore = Utils::now() - (timestampMaxDelta * 3);
for(std::map<Address,uint64_t>::iterator lp(_lastPushedMembershipCertificate.begin());lp!=_lastPushedMembershipCertificate.end();) {
if (lp->second < forgetIfBefore)
_lastPushedMembershipCertificate.erase(lp++);
else ++lp;
}
}
}
void Network::_CBhandleTapData(void *arg,const MAC &from,const MAC &to,unsigned int etherType,const Buffer<4096> &data)
{
if (!((Network *)arg)->isUp())
return;
const RuntimeEnvironment *_r = ((Network *)arg)->_r;
if (_r->shutdownInProgress)
return;
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::_pushMembershipCertificate(const Address &peer,bool force,uint64_t now)
{
uint64_t timestampMaxDelta = _myCertificate.timestampMaxDelta();
if (!timestampMaxDelta)
return; // still waiting on my own cert
uint64_t &lastPushed = _lastPushedMembershipCertificate[peer];
if ((force)||((now - lastPushed) > (timestampMaxDelta / 2))) {
lastPushed = now;
Packet outp(peer,_r->identity.address(),Packet::VERB_NETWORK_MEMBERSHIP_CERTIFICATE);
_myCertificate.serialize(outp);
_r->sw->send(outp,true);
}
}
void Network::_restoreState()
{
if (!_id)
return; // sanity check
Buffer<ZT_NETWORK_CERT_WRITE_BUF_SIZE> buf;
std::string idstr(idString());
std::string confPath(_r->homePath + ZT_PATH_SEPARATOR_S + "networks.d" + ZT_PATH_SEPARATOR_S + idstr + ".conf");
std::string mcdbPath(_r->homePath + ZT_PATH_SEPARATOR_S + "networks.d" + ZT_PATH_SEPARATOR_S + idstr + ".mcerts");
// Read configuration file containing last config from netconf master
{
std::string confs;
if (Utils::readFile(confPath.c_str(),confs)) {
try {
if (confs.length())
setConfiguration(Config(confs),false);
} catch ( ... ) {} // ignore invalid config on disk, we will re-request from netconf master
} 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(),"wb");
if (tmp)
fclose(tmp);
}
}
// Read most recent multicast cert dump
if ((!_isOpen)&&(Utils::fileExists(mcdbPath.c_str()))) {
CertificateOfMembership com;
Mutex::Lock _l(_lock);
_membershipCertificates.clear();
FILE *mcdb = fopen(mcdbPath.c_str(),"rb");
if (mcdb) {
try {
char magic[6];
if ((fread(magic,6,1,mcdb) == 1)&&(!memcmp("ZTMCD0",magic,6))) {
for(;;) {
long rlen = (long)fread(buf.data() + buf.size(),1,ZT_NETWORK_CERT_WRITE_BUF_SIZE - buf.size(),mcdb);
if (rlen <= 0)
break;
buf.setSize(buf.size() + (unsigned int)rlen);
unsigned int ptr = 0;
while ((ptr < (ZT_NETWORK_CERT_WRITE_BUF_SIZE / 2))&&(ptr < buf.size())) {
ptr += com.deserialize(buf,ptr);
if (com.issuedTo())
_membershipCertificates[com.issuedTo()] = com;
}
if (ptr) {
memmove(buf.data(),buf.data() + ptr,buf.size() - ptr);
buf.setSize(buf.size() - ptr);
}
}
fclose(mcdb);
} else {
fclose(mcdb);
Utils::rm(mcdbPath);
}
} catch ( ... ) {
// Membership cert dump file invalid. We'll re-learn them off the net.
_membershipCertificates.clear();
fclose(mcdb);
Utils::rm(mcdbPath);
}
}
}
}
void Network::_dumpMulticastCerts()
{
Buffer<ZT_NETWORK_CERT_WRITE_BUF_SIZE> buf;
std::string mcdbPath(_r->homePath + ZT_PATH_SEPARATOR_S + "networks.d" + ZT_PATH_SEPARATOR_S + idString() + ".mcerts");
Mutex::Lock _l(_lock);
if ((!_id)||(_isOpen)) {
Utils::rm(mcdbPath);
return;
}
FILE *mcdb = fopen(mcdbPath.c_str(),"wb");
if (!mcdb)
return;
if (fwrite("ZTMCD0",6,1,mcdb) != 1) {
Utils::rm(mcdbPath);
return;
}
for(std::map<Address,CertificateOfMembership>::iterator c=(_membershipCertificates.begin());c!=_membershipCertificates.end();++c) {
try {
c->second.serialize(buf);
if (buf.size() >= (ZT_NETWORK_CERT_WRITE_BUF_SIZE / 2)) {
if (fwrite(buf.data(),buf.size(),1,mcdb) != 1) {
fclose(mcdb);
Utils::rm(mcdbPath);
return;
}
buf.clear();
}
} catch ( ... ) {
// Sanity check... no cert will ever be big enough to overflow buf
fclose(mcdb);
Utils::rm(mcdbPath);
return;
}
}
if (buf.size()) {
if (fwrite(buf.data(),buf.size(),1,mcdb) != 1) {
fclose(mcdb);
Utils::rm(mcdbPath);
return;
}
}
fclose(mcdb);
}
} // namespace ZeroTier