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ZeroTierOne/node/PacketDecoder.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 "../version.h"
#include "Constants.hpp"
#include "Defaults.hpp"
#include "RuntimeEnvironment.hpp"
#include "Topology.hpp"
#include "PacketDecoder.hpp"
#include "Switch.hpp"
#include "Peer.hpp"
#include "NodeConfig.hpp"
#include "Service.hpp"
#include "Demarc.hpp"
namespace ZeroTier {
bool PacketDecoder::tryDecode(const RuntimeEnvironment *_r)
throw(std::out_of_range,std::runtime_error)
{
if ((!encrypted())&&(verb() == Packet::VERB_HELLO)) {
// Unencrypted HELLOs are handled here since they are used to
// populate our identity cache in the first place. _doHELLO() is special
// in that it contains its own authentication logic.
TRACE("HELLO from %s(%s)",source().toString().c_str(),_remoteAddress.toString().c_str());
return _doHELLO(_r);
}
SharedPtr<Peer> peer = _r->topology->getPeer(source());
if (peer) {
// Resume saved intermediate decode state?
if (_step == DECODE_WAITING_FOR_MULTICAST_FRAME_ORIGINAL_SENDER_LOOKUP) {
// In this state we have already authenticated and decrypted the
// packet and are waiting for the lookup of the original sender
// for a multicast frame. So check to see if we've got it.
return _doMULTICAST_FRAME(_r,peer);
} else if (_step == DECODE_WAITING_FOR_NETWORK_MEMBERSHIP_CERTIFICATE_SIGNER_LOOKUP) {
// In this state we have already authenticated and decoded the
// packet and we're waiting for the identity of the cert's signer.
return _doNETWORK_MEMBERSHIP_CERTIFICATE(_r,peer);
}
if (!dearmor(peer->key())) {
TRACE("dropped packet from %s(%s), MAC authentication failed (size: %u)",source().toString().c_str(),_remoteAddress.toString().c_str(),size());
return true;
}
if (!uncompress()) {
TRACE("dropped packet from %s(%s), compressed data invalid",source().toString().c_str(),_remoteAddress.toString().c_str());
return true;
}
Packet::Verb v = verb();
// Once a packet is determined to be basically valid, it can be used
// to passively learn a new network path to the sending peer. It
// also results in statistics updates.
peer->onReceive(_r,_localPort,_remoteAddress,hops(),v,Utils::now());
switch(v) {
case Packet::VERB_NOP:
TRACE("NOP from %s(%s)",source().toString().c_str(),_remoteAddress.toString().c_str());
return true;
case Packet::VERB_HELLO:
return _doHELLO(_r); // legal, but why? :)
case Packet::VERB_ERROR:
return _doERROR(_r,peer);
case Packet::VERB_OK:
return _doOK(_r,peer);
case Packet::VERB_WHOIS:
return _doWHOIS(_r,peer);
case Packet::VERB_RENDEZVOUS:
return _doRENDEZVOUS(_r,peer);
case Packet::VERB_FRAME:
return _doFRAME(_r,peer);
case Packet::VERB_BRIDGED_FRAME:
return _doBRIDGED_FRAME(_r,peer);
case Packet::VERB_MULTICAST_FRAME:
return _doMULTICAST_FRAME(_r,peer);
case Packet::VERB_MULTICAST_LIKE:
return _doMULTICAST_LIKE(_r,peer);
case Packet::VERB_NETWORK_MEMBERSHIP_CERTIFICATE:
return _doNETWORK_MEMBERSHIP_CERTIFICATE(_r,peer);
case Packet::VERB_NETWORK_CONFIG_REQUEST:
return _doNETWORK_CONFIG_REQUEST(_r,peer);
case Packet::VERB_NETWORK_CONFIG_REFRESH:
return _doNETWORK_CONFIG_REFRESH(_r,peer);
default:
// This might be something from a new or old version of the protocol.
// Technically it passed MAC so the packet is still valid, but we
// ignore it.
TRACE("ignored unrecognized verb %.2x from %s(%s)",(unsigned int)v,source().toString().c_str(),_remoteAddress.toString().c_str());
return true;
}
} else {
_step = DECODE_WAITING_FOR_SENDER_LOOKUP; // should already be this...
_r->sw->requestWhois(source());
return false;
}
}
bool PacketDecoder::_doERROR(const RuntimeEnvironment *_r,const SharedPtr<Peer> &peer)
{
try {
Packet::Verb inReVerb = (Packet::Verb)(*this)[ZT_PROTO_VERB_ERROR_IDX_IN_RE_VERB];
Packet::ErrorCode errorCode = (Packet::ErrorCode)(*this)[ZT_PROTO_VERB_ERROR_IDX_ERROR_CODE];
TRACE("ERROR %s from %s(%s) in-re %s",Packet::errorString(errorCode),source().toString().c_str(),_remoteAddress.toString().c_str(),Packet::verbString(inReVerb));
switch(errorCode) {
case Packet::ERROR_OBJ_NOT_FOUND:
if (inReVerb == Packet::VERB_WHOIS) {
if (_r->topology->isSupernode(source()))
_r->sw->cancelWhoisRequest(Address(field(ZT_PROTO_VERB_ERROR_IDX_PAYLOAD,ZT_ADDRESS_LENGTH),ZT_ADDRESS_LENGTH));
} else if (inReVerb == Packet::VERB_NETWORK_CONFIG_REQUEST) {
SharedPtr<Network> network(_r->nc->network(at<uint64_t>(ZT_PROTO_VERB_ERROR_IDX_PAYLOAD)));
if ((network)&&(network->controller() == source()))
network->forceStatusTo(Network::NETWORK_NOT_FOUND);
}
break;
case Packet::ERROR_IDENTITY_COLLISION:
// TODO: if it comes from a supernode, regenerate a new identity
// if (_r->topology->isSupernode(source())) {}
break;
case Packet::ERROR_NEED_MEMBERSHIP_CERTIFICATE: {
SharedPtr<Network> network(_r->nc->network(at<uint64_t>(ZT_PROTO_VERB_ERROR_IDX_PAYLOAD)));
if (network)
network->pushMembershipCertificate(source(),true,Utils::now());
} break;
case Packet::ERROR_NETWORK_ACCESS_DENIED: {
SharedPtr<Network> network(_r->nc->network(at<uint64_t>(ZT_PROTO_VERB_ERROR_IDX_PAYLOAD)));
if ((network)&&(network->controller() == source()))
network->forceStatusTo(Network::NETWORK_ACCESS_DENIED);
} break;
default:
break;
}
} catch (std::exception &ex) {
TRACE("dropped ERROR from %s(%s): unexpected exception: %s",source().toString().c_str(),_remoteAddress.toString().c_str(),ex.what());
} catch ( ... ) {
TRACE("dropped ERROR from %s(%s): unexpected exception: (unknown)",source().toString().c_str(),_remoteAddress.toString().c_str());
}
return true;
}
bool PacketDecoder::_doHELLO(const RuntimeEnvironment *_r)
{
try {
unsigned int protoVersion = (*this)[ZT_PROTO_VERB_HELLO_IDX_PROTOCOL_VERSION];
unsigned int vMajor = (*this)[ZT_PROTO_VERB_HELLO_IDX_MAJOR_VERSION];
unsigned int vMinor = (*this)[ZT_PROTO_VERB_HELLO_IDX_MINOR_VERSION];
unsigned int vRevision = at<uint16_t>(ZT_PROTO_VERB_HELLO_IDX_REVISION);
uint64_t timestamp = at<uint64_t>(ZT_PROTO_VERB_HELLO_IDX_TIMESTAMP);
Identity id(*this,ZT_PROTO_VERB_HELLO_IDX_IDENTITY);
if (protoVersion != ZT_PROTO_VERSION) {
TRACE("dropped HELLO from %s(%s): protocol version mismatch (%u, expected %u)",source().toString().c_str(),_remoteAddress.toString().c_str(),protoVersion,(unsigned int)ZT_PROTO_VERSION);
return true;
}
if (!id.locallyValidate()) {
TRACE("dropped HELLO from %s(%s): identity invalid",source().toString().c_str(),_remoteAddress.toString().c_str());
return true;
}
SharedPtr<Peer> peer(_r->topology->getPeer(id.address()));
if (peer) {
if (peer->identity() != id) {
// Sorry, someone beat you to that address. What are the odds?
// Well actually they're around two in 2^40. You should play
// the lottery.
unsigned char key[ZT_PEER_SECRET_KEY_LENGTH];
if (_r->identity.agree(id,key,ZT_PEER_SECRET_KEY_LENGTH)) {
TRACE("rejected HELLO from %s(%s): address already claimed",source().toString().c_str(),_remoteAddress.toString().c_str());
Packet outp(source(),_r->identity.address(),Packet::VERB_ERROR);
outp.append((unsigned char)Packet::VERB_HELLO);
outp.append(packetId());
outp.append((unsigned char)Packet::ERROR_IDENTITY_COLLISION);
outp.armor(key,true);
_r->demarc->send(_localPort,_remoteAddress,outp.data(),outp.size(),-1);
}
return true;
} // else continue and send OK since we already know thee...
} else {
// Learn a new peer
peer = _r->topology->addPeer(SharedPtr<Peer>(new Peer(_r->identity,id)));
}
peer->onReceive(_r,_localPort,_remoteAddress,hops(),Packet::VERB_HELLO,Utils::now());
peer->setRemoteVersion(vMajor,vMinor,vRevision);
Packet outp(source(),_r->identity.address(),Packet::VERB_OK);
outp.append((unsigned char)Packet::VERB_HELLO);
outp.append(packetId());
outp.append(timestamp);
outp.append((unsigned char)ZT_PROTO_VERSION);
outp.append((unsigned char)ZEROTIER_ONE_VERSION_MAJOR);
outp.append((unsigned char)ZEROTIER_ONE_VERSION_MINOR);
outp.append((uint16_t)ZEROTIER_ONE_VERSION_REVISION);
outp.armor(peer->key(),true);
_r->demarc->send(_localPort,_remoteAddress,outp.data(),outp.size(),-1);
} catch (std::exception &ex) {
TRACE("dropped HELLO from %s(%s): %s",source().toString().c_str(),_remoteAddress.toString().c_str(),ex.what());
} catch ( ... ) {
TRACE("dropped HELLO from %s(%s): unexpected exception",source().toString().c_str(),_remoteAddress.toString().c_str());
}
return true;
}
bool PacketDecoder::_doOK(const RuntimeEnvironment *_r,const SharedPtr<Peer> &peer)
{
try {
Packet::Verb inReVerb = (Packet::Verb)(*this)[ZT_PROTO_VERB_OK_IDX_IN_RE_VERB];
//TRACE("%s(%s): OK(%s)",source().toString().c_str(),_remoteAddress.toString().c_str(),Packet::verbString(inReVerb));
switch(inReVerb) {
case Packet::VERB_HELLO: {
// OK from HELLO permits computation of latency.
unsigned int latency = std::min((unsigned int)(Utils::now() - at<uint64_t>(ZT_PROTO_VERB_HELLO__OK__IDX_TIMESTAMP)),(unsigned int)0xffff);
unsigned int vMajor = (*this)[ZT_PROTO_VERB_HELLO__OK__IDX_MAJOR_VERSION];
unsigned int vMinor = (*this)[ZT_PROTO_VERB_HELLO__OK__IDX_MINOR_VERSION];
unsigned int vRevision = at<uint16_t>(ZT_PROTO_VERB_HELLO__OK__IDX_REVISION);
TRACE("%s(%s): OK(HELLO), latency: %u, version %u.%u.%u",source().toString().c_str(),_remoteAddress.toString().c_str(),latency,vMajor,vMinor,vRevision);
peer->setLatency(_remoteAddress,latency);
peer->setRemoteVersion(vMajor,vMinor,vRevision);
} break;
case Packet::VERB_WHOIS: {
// Right now only supernodes are allowed to send OK(WHOIS) to prevent
// poisoning attacks. Further decentralization will require some other
// kind of trust mechanism.
if (_r->topology->isSupernode(source())) {
Identity id(*this,ZT_PROTO_VERB_WHOIS__OK__IDX_IDENTITY);
if (id.locallyValidate())
_r->sw->doAnythingWaitingForPeer(_r->topology->addPeer(SharedPtr<Peer>(new Peer(_r->identity,id))));
}
} break;
case Packet::VERB_NETWORK_CONFIG_REQUEST: {
SharedPtr<Network> nw(_r->nc->network(at<uint64_t>(ZT_PROTO_VERB_NETWORK_CONFIG_REQUEST__OK__IDX_NETWORK_ID)));
if ((nw)&&(nw->controller() == source())) {
// OK(NETWORK_CONFIG_REQUEST) is only accepted from a network's
// controller.
unsigned int dictlen = at<uint16_t>(ZT_PROTO_VERB_NETWORK_CONFIG_REQUEST__OK__IDX_DICT_LEN);
std::string dict((const char *)field(ZT_PROTO_VERB_NETWORK_CONFIG_REQUEST__OK__IDX_DICT,dictlen),dictlen);
if (dict.length()) {
Network::Config netconf(dict);
TRACE("got network configuration for network %.16llx from %s",(unsigned long long)nw->id(),source().toString().c_str());
nw->setConfiguration(netconf);
}
}
} break;
default: break;
}
} catch (std::exception &ex) {
TRACE("dropped OK from %s(%s): unexpected exception: %s",source().toString().c_str(),_remoteAddress.toString().c_str(),ex.what());
} catch ( ... ) {
TRACE("dropped OK from %s(%s): unexpected exception: (unknown)",source().toString().c_str(),_remoteAddress.toString().c_str());
}
return true;
}
bool PacketDecoder::_doWHOIS(const RuntimeEnvironment *_r,const SharedPtr<Peer> &peer)
{
if (payloadLength() == ZT_ADDRESS_LENGTH) {
SharedPtr<Peer> p(_r->topology->getPeer(Address(payload(),ZT_ADDRESS_LENGTH)));
if (p) {
Packet outp(source(),_r->identity.address(),Packet::VERB_OK);
outp.append((unsigned char)Packet::VERB_WHOIS);
outp.append(packetId());
p->identity().serialize(outp,false);
outp.armor(peer->key(),true);
_r->demarc->send(_localPort,_remoteAddress,outp.data(),outp.size(),-1);
//TRACE("sent WHOIS response to %s for %s",source().toString().c_str(),Address(payload(),ZT_ADDRESS_LENGTH).toString().c_str());
} else {
Packet outp(source(),_r->identity.address(),Packet::VERB_ERROR);
outp.append((unsigned char)Packet::VERB_WHOIS);
outp.append(packetId());
outp.append((unsigned char)Packet::ERROR_OBJ_NOT_FOUND);
outp.append(payload(),ZT_ADDRESS_LENGTH);
outp.armor(peer->key(),true);
_r->demarc->send(_localPort,_remoteAddress,outp.data(),outp.size(),-1);
//TRACE("sent WHOIS ERROR to %s for %s (not found)",source().toString().c_str(),Address(payload(),ZT_ADDRESS_LENGTH).toString().c_str());
}
} else {
TRACE("dropped WHOIS from %s(%s): missing or invalid address",source().toString().c_str(),_remoteAddress.toString().c_str());
}
return true;
}
bool PacketDecoder::_doRENDEZVOUS(const RuntimeEnvironment *_r,const SharedPtr<Peer> &peer)
{
try {
/*
* At the moment, we only obey RENDEZVOUS if it comes from a designated
* supernode. If relay offloading is implemented to scale the net, this
* will need reconsideration.
*
* The reason is that RENDEZVOUS could technically be used to cause a
* peer to send a weird encrypted UDP packet to an arbitrary IP:port.
* The sender of RENDEZVOUS has no control over the content of this
* packet, but it's still maybe something we want to not allow just
* anyone to order due to possible DDOS or network forensic implications.
* So if we diversify relays, we'll need some way of deciding whether the
* sender is someone we should trust with a RENDEZVOUS hint.
*/
if (_r->topology->isSupernode(source())) {
Address with(field(ZT_PROTO_VERB_RENDEZVOUS_IDX_ZTADDRESS,ZT_ADDRESS_LENGTH),ZT_ADDRESS_LENGTH);
SharedPtr<Peer> withPeer(_r->topology->getPeer(with));
if (withPeer) {
unsigned int port = at<uint16_t>(ZT_PROTO_VERB_RENDEZVOUS_IDX_PORT);
unsigned int addrlen = (*this)[ZT_PROTO_VERB_RENDEZVOUS_IDX_ADDRLEN];
if ((port > 0)&&((addrlen == 4)||(addrlen == 16))) {
InetAddress atAddr(field(ZT_PROTO_VERB_RENDEZVOUS_IDX_ADDRESS,addrlen),addrlen,port);
TRACE("RENDEZVOUS from %s says %s might be at %s, starting NAT-t",source().toString().c_str(),with.toString().c_str(),atAddr.toString().c_str());
_r->sw->contact(withPeer,atAddr);
} else {
TRACE("dropped corrupt RENDEZVOUS from %s(%s) (bad address or port)",source().toString().c_str(),_remoteAddress.toString().c_str());
}
} else {
TRACE("ignored RENDEZVOUS from %s(%s) to meet unknown peer %s",source().toString().c_str(),_remoteAddress.toString().c_str(),with.toString().c_str());
}
} else {
TRACE("ignored RENDEZVOUS from %s(%s): source not supernode",source().toString().c_str(),_remoteAddress.toString().c_str());
}
} catch (std::exception &ex) {
TRACE("dropped RENDEZVOUS from %s(%s): %s",source().toString().c_str(),_remoteAddress.toString().c_str(),ex.what());
} catch ( ... ) {
TRACE("dropped RENDEZVOUS from %s(%s): unexpected exception",source().toString().c_str(),_remoteAddress.toString().c_str());
}
return true;
}
bool PacketDecoder::_doFRAME(const RuntimeEnvironment *_r,const SharedPtr<Peer> &peer)
{
try {
SharedPtr<Network> network(_r->nc->network(at<uint64_t>(ZT_PROTO_VERB_FRAME_IDX_NETWORK_ID)));
if (network) {
if (network->isAllowed(source())) {
unsigned int etherType = at<uint16_t>(ZT_PROTO_VERB_FRAME_IDX_ETHERTYPE);
if (network->permitsEtherType(etherType)) {
network->tap().put(source().toMAC(),network->tap().mac(),etherType,data() + ZT_PROTO_VERB_FRAME_IDX_PAYLOAD,size() - ZT_PROTO_VERB_FRAME_IDX_PAYLOAD);
} else if (size() > ZT_PROTO_VERB_FRAME_IDX_PAYLOAD) {
TRACE("dropped FRAME from %s: ethernet type %u not allowed on network %.16llx",source().toString().c_str(),etherType,(unsigned long long)network->id());
}
// Source moves "closer" to us in multicast propagation priority when
// we receive unicast frames from it. This is called "implicit social
// ordering" in other docs.
_r->mc->bringCloser(network->id(),source());
} else {
TRACE("dropped FRAME from %s(%s): not a member of closed network %llu",source().toString().c_str(),_remoteAddress.toString().c_str(),network->id());
Packet outp(source(),_r->identity.address(),Packet::VERB_ERROR);
outp.append((unsigned char)Packet::VERB_FRAME);
outp.append(packetId());
outp.append((unsigned char)Packet::ERROR_NEED_MEMBERSHIP_CERTIFICATE);
outp.append(network->id());
outp.armor(peer->key(),true);
_r->demarc->send(_localPort,_remoteAddress,outp.data(),outp.size(),-1);
}
} else {
TRACE("dropped FRAME from %s(%s): network %llu unknown",source().toString().c_str(),_remoteAddress.toString().c_str(),at<uint64_t>(ZT_PROTO_VERB_FRAME_IDX_NETWORK_ID));
}
} catch (std::exception &ex) {
TRACE("dropped FRAME from %s(%s): unexpected exception: %s",source().toString().c_str(),_remoteAddress.toString().c_str(),ex.what());
} catch ( ... ) {
TRACE("dropped FRAME from %s(%s): unexpected exception: (unknown)",source().toString().c_str(),_remoteAddress.toString().c_str());
}
return true;
}
bool PacketDecoder::_doBRIDGED_FRAME(const RuntimeEnvironment *_r,const SharedPtr<Peer> &peer)
{
// TODO: bridging is not implemented yet
return true;
}
bool PacketDecoder::_doMULTICAST_FRAME(const RuntimeEnvironment *_r,const SharedPtr<Peer> &peer)
{
try {
Address origin(Address(field(ZT_PROTO_VERB_MULTICAST_FRAME_IDX_ORIGIN,ZT_PROTO_VERB_MULTICAST_FRAME_LEN_ORIGIN),ZT_ADDRESS_LENGTH));
SharedPtr<Peer> originPeer(_r->topology->getPeer(origin));
if (!originPeer) {
// We must have the origin's identity in order to authenticate a multicast
_r->sw->requestWhois(origin);
_step = DECODE_WAITING_FOR_MULTICAST_FRAME_ORIGINAL_SENDER_LOOKUP; // causes processing to come back here
return false;
}
// These fields change
unsigned int depth = at<uint16_t>(ZT_PROTO_VERB_MULTICAST_FRAME_IDX_PROPAGATION_DEPTH);
unsigned char *const fifo = field(ZT_PROTO_VERB_MULTICAST_FRAME_IDX_PROPAGATION_FIFO,ZT_PROTO_VERB_MULTICAST_FRAME_LEN_PROPAGATION_FIFO);
unsigned char *const bloom = field(ZT_PROTO_VERB_MULTICAST_FRAME_IDX_PROPAGATION_BLOOM,ZT_PROTO_VERB_MULTICAST_FRAME_LEN_PROPAGATION_BLOOM);
// These fields don't -- they're signed by the original sender
// const unsigned int flags = (*this)[ZT_PROTO_VERB_MULTICAST_FRAME_IDX_FLAGS];
const uint64_t nwid = at<uint64_t>(ZT_PROTO_VERB_MULTICAST_FRAME_IDX_NETWORK_ID);
const uint16_t bloomNonce = at<uint16_t>(ZT_PROTO_VERB_MULTICAST_FRAME_IDX_PROPAGATION_BLOOM_NONCE);
const unsigned int prefixBits = (*this)[ZT_PROTO_VERB_MULTICAST_FRAME_IDX_PROPAGATION_PREFIX_BITS];
const unsigned int prefix = (*this)[ZT_PROTO_VERB_MULTICAST_FRAME_IDX_PROPAGATION_PREFIX];
const uint64_t guid = at<uint64_t>(ZT_PROTO_VERB_MULTICAST_FRAME_IDX_GUID);
const MAC sourceMac(field(ZT_PROTO_VERB_MULTICAST_FRAME_IDX_SOURCE_MAC,ZT_PROTO_VERB_MULTICAST_FRAME_LEN_SOURCE_MAC));
const MulticastGroup dest(MAC(field(ZT_PROTO_VERB_MULTICAST_FRAME_IDX_DEST_MAC,ZT_PROTO_VERB_MULTICAST_FRAME_LEN_DEST_MAC)),at<uint32_t>(ZT_PROTO_VERB_MULTICAST_FRAME_IDX_DEST_ADI));
const unsigned int etherType = at<uint16_t>(ZT_PROTO_VERB_MULTICAST_FRAME_IDX_ETHERTYPE);
const unsigned int frameLen = at<uint16_t>(ZT_PROTO_VERB_MULTICAST_FRAME_IDX_FRAME_LEN);
const unsigned char *const frame = field(ZT_PROTO_VERB_MULTICAST_FRAME_IDX_FRAME,frameLen);
const unsigned int signatureLen = at<uint16_t>(ZT_PROTO_VERB_MULTICAST_FRAME_IDX_FRAME + frameLen);
const unsigned char *const signature = field(ZT_PROTO_VERB_MULTICAST_FRAME_IDX_FRAME + frameLen + 2,signatureLen);
// Check multicast signature to verify original sender
const unsigned int signedPartLen = (ZT_PROTO_VERB_MULTICAST_FRAME_IDX_FRAME - ZT_PROTO_VERB_MULTICAST_FRAME_IDX__START_OF_SIGNED_PORTION) + frameLen;
if (!originPeer->identity().verify(field(ZT_PROTO_VERB_MULTICAST_FRAME_IDX__START_OF_SIGNED_PORTION,signedPartLen),signedPartLen,signature,signatureLen)) {
TRACE("dropped MULTICAST_FRAME from %s(%s): failed signature verification, claims to be from %s",source().toString().c_str(),_remoteAddress.toString().c_str(),origin.toString().c_str());
return true;
}
// Security check to prohibit multicasts that are really Ethernet unicasts
if (!dest.mac().isMulticast()) {
TRACE("dropped MULTICAST_FRAME from %s(%s): %s is not a multicast/broadcast address",source().toString().c_str(),_remoteAddress.toString().c_str(),dest.mac().toString().c_str());
return true;
}
#ifdef ZT_TRACE_MULTICAST
char mct[1024],mctdepth[1024];
unsigned int startingFifoItems = 0;
for(unsigned int i=0;i<ZT_PROTO_VERB_MULTICAST_FRAME_LEN_PROPAGATION_FIFO;i+=ZT_ADDRESS_LENGTH) {
if (Utils::isZero(fifo + i,ZT_ADDRESS_LENGTH))
break;
else ++startingFifoItems;
}
for(unsigned int i=0;i<depth;++i)
mctdepth[i] = ' ';
mctdepth[depth] = 0;
Utils::snprintf(mct,sizeof(mct),
"%.16llx %.2u %.3u%s %c %s <- %s via %s len:%u fifosize:%u",
guid,
prefix,
depth,
mctdepth,
(_r->topology->amSupernode() ? 'S' : '-'),
_r->identity.address().toString().c_str(),
origin.toString().c_str(),
source().toString().c_str(),
frameLen,
startingFifoItems);
_r->demarc->send(Demarc::ANY_PORT,ZT_DEFAULTS.multicastTraceWatcher,mct,strlen(mct),-1);
#endif
unsigned int maxDepth = ZT_MULTICAST_GLOBAL_MAX_DEPTH;
SharedPtr<Network> network(_r->nc->network(nwid));
if ((origin == _r->identity.address())||(_r->mc->deduplicate(nwid,guid))) {
// Ordinary nodes will drop duplicates. Supernodes keep propagating
// them since they're used as hubs to link disparate clusters of
// members of the same multicast group.
if (!_r->topology->amSupernode()) {
#ifdef ZT_TRACE_MULTICAST
Utils::snprintf(mct,sizeof(mct),
"%.16llx %.2u %.3u%s %c %s dropped: duplicate",
guid,
prefix,
depth,
mctdepth,
(_r->topology->amSupernode() ? 'S' : '-'),
_r->identity.address().toString().c_str());
_r->demarc->send(Demarc::ANY_PORT,ZT_DEFAULTS.multicastTraceWatcher,mct,strlen(mct),-1);
#endif
TRACE("dropped MULTICAST_FRAME from %s(%s): duplicate",source().toString().c_str(),_remoteAddress.toString().c_str());
return true;
}
} else {
// If we are actually a member of this network (will just about always
// be the case unless we're a supernode), check to see if we should
// inject the packet. This also gives us an opportunity to check things
// like multicast bandwidth constraints.
if (network) {
maxDepth = std::min((unsigned int)ZT_MULTICAST_GLOBAL_MAX_DEPTH,network->multicastDepth());
if (!maxDepth)
maxDepth = ZT_MULTICAST_GLOBAL_MAX_DEPTH;
if (!network->isAllowed(origin)) {
TRACE("didn't inject MULTICAST_FRAME from %s(%s) into %.16llx: sender %s not allowed or we don't have a certificate",source().toString().c_str(),nwid,_remoteAddress.toString().c_str(),origin.toString().c_str());
// Tell them we need a certificate
Packet outp(source(),_r->identity.address(),Packet::VERB_ERROR);
outp.append((unsigned char)Packet::VERB_FRAME);
outp.append(packetId());
outp.append((unsigned char)Packet::ERROR_NEED_MEMBERSHIP_CERTIFICATE);
outp.append(nwid);
outp.armor(peer->key(),true);
_r->demarc->send(_localPort,_remoteAddress,outp.data(),outp.size(),-1);
// We do not terminate here, since if the member just has an out of
// date cert or hasn't sent us a cert yet we still want to propagate
// the message so multicast keeps working downstream.
} else if ((!network->permitsBridging(origin))&&(!origin.wouldHaveMac(sourceMac))) {
// This *does* terminate propagation, since it's technically a
// security violation of the network's bridging policy. But if we
// were to keep propagating it wouldn't hurt anything, just waste
// bandwidth as everyone else would reject it too.
#ifdef ZT_TRACE_MULTICAST
Utils::snprintf(mct,sizeof(mct),
"%.16llx %.2u %.3u%s %c %s dropped: bridging not allowed",
guid,
prefix,
depth,
mctdepth,
(_r->topology->amSupernode() ? 'S' : '-'),
_r->identity.address().toString().c_str());
_r->demarc->send(Demarc::ANY_PORT,ZT_DEFAULTS.multicastTraceWatcher,mct,strlen(mct),-1);
#endif
TRACE("dropped MULTICAST_FRAME from %s(%s) into %.16llx: source mac %s doesn't belong to %s, and bridging is not supported on network",source().toString().c_str(),nwid,_remoteAddress.toString().c_str(),sourceMac.toString().c_str(),origin.toString().c_str());
return true;
} else if (!network->permitsEtherType(etherType)) {
// Ditto for this-- halt propagation if this is for an ethertype
// this network doesn't allow. Same principle as bridging test.
#ifdef ZT_TRACE_MULTICAST
Utils::snprintf(mct,sizeof(mct),
"%.16llx %.2u %.3u%s %c %s dropped: ethertype not allowed",
guid,
prefix,
depth,
mctdepth,
(_r->topology->amSupernode() ? 'S' : '-'),
_r->identity.address().toString().c_str());
_r->demarc->send(Demarc::ANY_PORT,ZT_DEFAULTS.multicastTraceWatcher,mct,strlen(mct),-1);
#endif
TRACE("dropped MULTICAST_FRAME from %s(%s) into %.16llx: ethertype %u is not allowed",source().toString().c_str(),nwid,_remoteAddress.toString().c_str(),etherType);
return true;
} else if (!network->updateAndCheckMulticastBalance(origin,dest,frameLen)) {
// Rate limits can only be checked by members of this network, but
// there should be enough of them that over-limit multicasts get
// their propagation aborted.
#ifdef ZT_TRACE_MULTICAST
Utils::snprintf(mct,sizeof(mct),
"%.16llx %.2u %.3u%s %c %s dropped: rate limits exceeded",
guid,
prefix,
depth,
mctdepth,
(_r->topology->amSupernode() ? 'S' : '-'),
_r->identity.address().toString().c_str());
_r->demarc->send(Demarc::ANY_PORT,ZT_DEFAULTS.multicastTraceWatcher,mct,strlen(mct),-1);
#endif
TRACE("dropped MULTICAST_FRAME from %s(%s): rate limits exceeded for sender %s",source().toString().c_str(),_remoteAddress.toString().c_str(),origin.toString().c_str());
return true;
} else {
network->tap().put(sourceMac,dest.mac(),etherType,frame,frameLen);
}
}
}
if (depth == 0xffff) {
#ifdef ZT_TRACE_MULTICAST
Utils::snprintf(mct,sizeof(mct),
"%.16llx %.2u %.3u%s %c %s not forwarding: depth == 0xffff (do not forward)",
guid,
prefix,
depth,
mctdepth,
(_r->topology->amSupernode() ? 'S' : '-'),
_r->identity.address().toString().c_str());
_r->demarc->send(Demarc::ANY_PORT,ZT_DEFAULTS.multicastTraceWatcher,mct,strlen(mct),-1);
#endif
TRACE("not forwarding MULTICAST_FRAME from %s(%s): depth == 0xffff (do not forward)",source().toString().c_str(),_remoteAddress.toString().c_str());
return true;
}
if (++depth > maxDepth) {
#ifdef ZT_TRACE_MULTICAST
Utils::snprintf(mct,sizeof(mct),
"%.16llx %.2u %.3u%s %c %s not forwarding: max propagation depth reached",
guid,
prefix,
depth,
mctdepth,
(_r->topology->amSupernode() ? 'S' : '-'),
_r->identity.address().toString().c_str());
_r->demarc->send(Demarc::ANY_PORT,ZT_DEFAULTS.multicastTraceWatcher,mct,strlen(mct),-1);
#endif
TRACE("not forwarding MULTICAST_FRAME from %s(%s): max propagation depth reached",source().toString().c_str(),_remoteAddress.toString().c_str());
return true;
}
setAt(ZT_PROTO_VERB_MULTICAST_FRAME_IDX_PROPAGATION_DEPTH,(uint16_t)depth);
// New FIFO with room for one extra, since head will be next hop
unsigned char newFifo[ZT_PROTO_VERB_MULTICAST_FRAME_LEN_PROPAGATION_FIFO + ZT_ADDRESS_LENGTH];
unsigned char *newFifoPtr = newFifo;
unsigned char *const newFifoEnd = newFifo + sizeof(newFifo);
// Copy old FIFO into new buffer, terminating at first NULL address
for(unsigned char *f=fifo,*const fifoEnd=(fifo + ZT_PROTO_VERB_MULTICAST_FRAME_LEN_PROPAGATION_FIFO);f!=fifoEnd;) {
unsigned char *nf = newFifoPtr;
unsigned char *e = nf + ZT_ADDRESS_LENGTH;
unsigned char *ftmp = f;
unsigned char zeroCheckMask = 0;
while (nf != e)
zeroCheckMask |= (*(nf++) = *(ftmp++));
if (zeroCheckMask) {
f = ftmp;
newFifoPtr = nf;
} else break;
}
// Add any next hops we know about to FIFO
#ifdef ZT_TRACE_MULTICAST
unsigned char *beforeAdd = newFifoPtr;
#endif
_r->mc->getNextHops(nwid,dest,Multicaster::AddToPropagationQueue(&newFifoPtr,newFifoEnd,bloom,bloomNonce,origin,prefixBits,prefix));
#ifdef ZT_TRACE_MULTICAST
unsigned int numAdded = (unsigned int)(newFifoPtr - beforeAdd) / ZT_ADDRESS_LENGTH;
#endif
// Zero-terminate new FIFO if not completely full
while (newFifoPtr != newFifoEnd)
*(newFifoPtr++) = (unsigned char)0;
// If we're forwarding a packet within a private network that we are
// a member of, also propagate our cert if needed. This propagates
// it to everyone including people who will receive this multicast.
if (network)
network->pushMembershipCertificate(newFifo,sizeof(newFifo),false,Utils::now());
// First element in newFifo[] is next hop
Address nextHop(newFifo,ZT_ADDRESS_LENGTH);
if ((!nextHop)&&(!_r->topology->amSupernode())) {
SharedPtr<Peer> supernode(_r->topology->getBestSupernode(&origin,1,true));
if (supernode)
nextHop = supernode->address();
}
if ((!nextHop)||(nextHop == _r->identity.address())) { // check against our addr is a sanity check
#ifdef ZT_TRACE_MULTICAST
Utils::snprintf(mct,sizeof(mct),
"%.16llx %.2u %.3u%s %c %s not forwarding: no next hop",
guid,
prefix,
depth,
mctdepth,
(_r->topology->amSupernode() ? 'S' : '-'),
_r->identity.address().toString().c_str());
_r->demarc->send(Demarc::ANY_PORT,ZT_DEFAULTS.multicastTraceWatcher,mct,strlen(mct),-1);
#endif
//TRACE("not forwarding MULTICAST_FRAME from %s(%s): no next hop",source().toString().c_str(),_remoteAddress.toString().c_str());
return true;
}
// The rest of newFifo[] goes back into the packet
memcpy(fifo,newFifo + ZT_ADDRESS_LENGTH,ZT_PROTO_VERB_MULTICAST_FRAME_LEN_PROPAGATION_FIFO);
#ifdef ZT_TRACE_MULTICAST
Utils::snprintf(mct,sizeof(mct),
"%.16llx %.2u %.3u%s %c %s -> origin %s, sending to next hop %s, +fifosize:%u",
guid,
prefix,
depth,
mctdepth,
(_r->topology->amSupernode() ? 'S' : '-'),
_r->identity.address().toString().c_str(),
origin.toString().c_str(),
nextHop.toString().c_str(),
numAdded);
_r->demarc->send(Demarc::ANY_PORT,ZT_DEFAULTS.multicastTraceWatcher,mct,strlen(mct),-1);
#endif
// Send to next hop, reusing this packet as scratch space
newInitializationVector();
setDestination(nextHop);
setSource(_r->identity.address());
compress(); // note: bloom filters and empty FIFOs are highly compressable!
_r->sw->send(*this,true);
return true;
} catch (std::exception &ex) {
TRACE("dropped MULTICAST_FRAME from %s(%s): unexpected exception: %s",source().toString().c_str(),_remoteAddress.toString().c_str(),ex.what());
} catch ( ... ) {
TRACE("dropped MULTICAST_FRAME from %s(%s): unexpected exception: (unknown)",source().toString().c_str(),_remoteAddress.toString().c_str());
}
return true;
}
bool PacketDecoder::_doMULTICAST_LIKE(const RuntimeEnvironment *_r,const SharedPtr<Peer> &peer)
{
try {
Address src(source());
uint64_t now = Utils::now();
// Iterate through 18-byte network,MAC,ADI tuples
for(unsigned int ptr=ZT_PACKET_IDX_PAYLOAD;ptr<size();ptr+=18) {
uint64_t nwid = at<uint64_t>(ptr);
SharedPtr<Network> network(_r->nc->network(nwid));
if ((_r->topology->amSupernode())||((network)&&(network->isAllowed(peer->address())))) {
_r->mc->likesGroup(nwid,src,MulticastGroup(MAC(field(ptr + 8,6)),at<uint32_t>(ptr + 14)),now);
if (network)
network->pushMembershipCertificate(peer->address(),false,now);
}
}
} catch (std::exception &ex) {
TRACE("dropped MULTICAST_LIKE from %s(%s): unexpected exception: %s",source().toString().c_str(),_remoteAddress.toString().c_str(),ex.what());
} catch ( ... ) {
TRACE("dropped MULTICAST_LIKE from %s(%s): unexpected exception: (unknown)",source().toString().c_str(),_remoteAddress.toString().c_str());
}
return true;
}
bool PacketDecoder::_doNETWORK_MEMBERSHIP_CERTIFICATE(const RuntimeEnvironment *_r,const SharedPtr<Peer> &peer)
{
try {
CertificateOfMembership com;
unsigned int ptr = ZT_PACKET_IDX_PAYLOAD;
while (ptr < size()) {
ptr += com.deserialize(*this,ptr);
if (!com.hasRequiredFields()) {
TRACE("dropped NETWORK_MEMBERSHIP_CERTIFICATE from %s(%s): invalid cert: at least one required field is missing",source().toString().c_str(),_remoteAddress.toString().c_str());
return true;
} else if (com.signedBy()) {
SharedPtr<Peer> signer(_r->topology->getPeer(com.signedBy()));
if (signer) {
if (com.verify(signer->identity())) {
uint64_t nwid = com.networkId();
SharedPtr<Network> network(_r->nc->network(nwid));
if (network) {
if (network->controller() == signer) {
network->addMembershipCertificate(com);
return true;
} else {
TRACE("dropped NETWORK_MEMBERSHIP_CERTIFICATE from %s(%s): signer %s is not the controller for network %.16llx",source().toString().c_str(),_remoteAddress.toString().c_str(),signer->address().toString().c_str(),(unsigned long long)nwid);
return true;
}
} else {
TRACE("dropped NETWORK_MEMBERSHIP_CERTIFICATE from %s(%s): not a member of network %.16llx",source().toString().c_str(),_remoteAddress.toString().c_str(),(unsigned long long)nwid);
return true;
}
} else {
TRACE("dropped NETWORK_MEMBERSHIP_CERTIFICATE from %s(%s): failed signature verification for signer %s",source().toString().c_str(),_remoteAddress.toString().c_str(),signer->address().toString().c_str());
return true;
}
} else {
_r->sw->requestWhois(com.signedBy());
_step = DECODE_WAITING_FOR_NETWORK_MEMBERSHIP_CERTIFICATE_SIGNER_LOOKUP;
return false;
}
} else {
TRACE("dropped NETWORK_MEMBERSHIP_CERTIFICATE from %s(%s): invalid cert: no signature",source().toString().c_str(),_remoteAddress.toString().c_str());
return true;
}
}
} catch (std::exception &ex) {
TRACE("dropped NETWORK_MEMBERSHIP_CERTIFICATE from %s(%s): unexpected exception: %s",source().toString().c_str(),_remoteAddress.toString().c_str(),ex.what());
} catch ( ... ) {
TRACE("dropped NETWORK_MEMBERSHIP_CERTIFICATE from %s(%s): unexpected exception: (unknown)",source().toString().c_str(),_remoteAddress.toString().c_str());
}
return true;
}
bool PacketDecoder::_doNETWORK_CONFIG_REQUEST(const RuntimeEnvironment *_r,const SharedPtr<Peer> &peer)
{
try {
uint64_t nwid = at<uint64_t>(ZT_PROTO_VERB_NETWORK_CONFIG_REQUEST_IDX_NETWORK_ID);
#ifndef __WINDOWS__
if (_r->netconfService) {
char tmp[128];
unsigned int dictLen = at<uint16_t>(ZT_PROTO_VERB_NETWORK_CONFIG_REQUEST_IDX_DICT_LEN);
Dictionary request;
if (dictLen)
request["meta"] = std::string((const char *)field(ZT_PROTO_VERB_NETWORK_CONFIG_REQUEST_IDX_DICT,dictLen),dictLen);
request["type"] = "netconf-request";
request["peerId"] = peer->identity().toString(false);
Utils::snprintf(tmp,sizeof(tmp),"%llx",(unsigned long long)nwid);
request["nwid"] = tmp;
Utils::snprintf(tmp,sizeof(tmp),"%llx",(unsigned long long)packetId());
request["requestId"] = tmp;
if (!hops())
request["from"] = _remoteAddress.toString();
//TRACE("to netconf:\n%s",request.toString().c_str());
_r->netconfService->send(request);
} else {
#endif // !__WINDOWS__
Packet outp(source(),_r->identity.address(),Packet::VERB_ERROR);
outp.append((unsigned char)Packet::VERB_NETWORK_CONFIG_REQUEST);
outp.append(packetId());
outp.append((unsigned char)Packet::ERROR_UNSUPPORTED_OPERATION);
outp.append(nwid);
outp.armor(peer->key(),true);
_r->demarc->send(_localPort,_remoteAddress,outp.data(),outp.size(),-1);
#ifndef __WINDOWS__
}
#endif // !__WINDOWS__
} catch (std::exception &exc) {
TRACE("dropped NETWORK_CONFIG_REQUEST from %s(%s): unexpected exception: %s",source().toString().c_str(),_remoteAddress.toString().c_str(),exc.what());
} catch ( ... ) {
TRACE("dropped NETWORK_CONFIG_REQUEST from %s(%s): unexpected exception: (unknown)",source().toString().c_str(),_remoteAddress.toString().c_str());
}
return true;
}
bool PacketDecoder::_doNETWORK_CONFIG_REFRESH(const RuntimeEnvironment *_r,const SharedPtr<Peer> &peer)
{
try {
unsigned int ptr = ZT_PACKET_IDX_PAYLOAD;
while ((ptr + sizeof(uint64_t)) <= size()) {
uint64_t nwid = at<uint64_t>(ptr); ptr += sizeof(uint64_t);
SharedPtr<Network> nw(_r->nc->network(nwid));
if ((nw)&&(source() == nw->controller())) // only respond to requests from controller
nw->requestConfiguration();
}
} catch (std::exception &exc) {
TRACE("dropped NETWORK_CONFIG_REFRESH from %s(%s): unexpected exception: %s",source().toString().c_str(),_remoteAddress.toString().c_str(),exc.what());
} catch ( ... ) {
TRACE("dropped NETWORK_CONFIG_REFRESH from %s(%s): unexpected exception: (unknown)",source().toString().c_str(),_remoteAddress.toString().c_str());
}
return true;
}
} // namespace ZeroTier
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