/* * 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 . * * -- * * 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 #include #include #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" #include "SoftwareUpdater.hpp" namespace ZeroTier { bool PacketDecoder::tryDecode(const RuntimeEnvironment *_r) { 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) (normal unencrypted HELLO)",source().toString().c_str(),_remoteAddress.toString().c_str()); return _doHELLO(_r); } SharedPtr 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; } TRACE("<< %s from %s(%s)",Packet::verbString(verb()),source().toString().c_str(),_remoteAddress.toString().c_str()); switch(verb()) { case Packet::VERB_NOP: peer->onReceive(_r,_localPort,_remoteAddress,hops(),packetId(),Packet::VERB_NOP,0,Packet::VERB_NOP,Utils::now()); 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: // ignore unknown verbs 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) { try { Packet::Verb inReVerb = (Packet::Verb)(*this)[ZT_PROTO_VERB_ERROR_IDX_IN_RE_VERB]; uint64_t inRePacketId = at(ZT_PROTO_VERB_ERROR_IDX_IN_RE_PACKET_ID); 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(_r->nc->network(at(ZT_PROTO_VERB_ERROR_IDX_PAYLOAD))); if ((network)&&(network->controller() == source())) network->setNotFound(); } 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(_r->nc->network(at(ZT_PROTO_VERB_ERROR_IDX_PAYLOAD))); if (network) network->pushMembershipCertificate(source(),true,Utils::now()); } break; case Packet::ERROR_NETWORK_ACCESS_DENIED_: { SharedPtr network(_r->nc->network(at(ZT_PROTO_VERB_ERROR_IDX_PAYLOAD))); if ((network)&&(network->controller() == source())) network->setAccessDenied(); } break; default: break; } peer->onReceive(_r,_localPort,_remoteAddress,hops(),packetId(),Packet::VERB_ERROR,inRePacketId,inReVerb,Utils::now()); } 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(ZT_PROTO_VERB_HELLO_IDX_REVISION); uint64_t timestamp = at(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; } // Do we already have this peer? SharedPtr peer(_r->topology->getPeer(id.address())); if (peer) { // Check to make sure this isn't a colliding identity (different key, // but same address). The odds are spectacularly low but it could happen. // Could also be a sign of someone doing something nasty. if (peer->identity() != id) { unsigned char key[ZT_PEER_SECRET_KEY_LENGTH]; if (_r->identity.agree(id,key,ZT_PEER_SECRET_KEY_LENGTH)) { if (dearmor(key)) { // ensure packet is authentic, otherwise drop 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); } else { LOG("rejected HELLO from %s(%s): packet failed authentication",source().toString().c_str(),_remoteAddress.toString().c_str()); } } else { TRACE("rejected HELLO from %s(%s): key agreement failed",source().toString().c_str(),_remoteAddress.toString().c_str()); } return true; } else if (!dearmor(peer->key())) { TRACE("rejected HELLO from %s(%s): packet failed authentication",source().toString().c_str(),_remoteAddress.toString().c_str()); return true; } // else continue and respond } else { // If we don't have a peer record on file, check the identity cache (if // we have one) to see if we have a cached identity. Then check that for // collision before adding a new peer. Identity alreadyHaveCachedId(_r->topology->getIdentity(id.address())); if ((alreadyHaveCachedId)&&(id != alreadyHaveCachedId)) { unsigned char key[ZT_PEER_SECRET_KEY_LENGTH]; if (_r->identity.agree(id,key,ZT_PEER_SECRET_KEY_LENGTH)) { if (dearmor(key)) { // ensure packet is authentic, otherwise drop 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); } else { LOG("rejected HELLO from %s(%s): packet failed authentication",source().toString().c_str(),_remoteAddress.toString().c_str()); } } else { TRACE("rejected HELLO from %s(%s): key agreement failed",source().toString().c_str(),_remoteAddress.toString().c_str()); } return true; } // else continue since identity is already known and matches // If this is a new peer, learn it SharedPtr newPeer(new Peer(_r->identity,id)); if (!dearmor(newPeer->key())) { LOG("rejected HELLO from %s(%s): packet failed authentication",source().toString().c_str(),_remoteAddress.toString().c_str()); return true; } peer = _r->topology->addPeer(newPeer); } peer->onReceive(_r,_localPort,_remoteAddress,hops(),packetId(),Packet::VERB_HELLO,0,Packet::VERB_NOP,Utils::now()); peer->setRemoteVersion(vMajor,vMinor,vRevision); // If a supernode has a version higher than ours, this causes a software // update check to run now. if ((_r->updater)&&(_r->topology->isSupernode(peer->address()))) _r->updater->sawRemoteVersion(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) { try { Packet::Verb inReVerb = (Packet::Verb)(*this)[ZT_PROTO_VERB_OK_IDX_IN_RE_VERB]; uint64_t inRePacketId = at(ZT_PROTO_VERB_OK_IDX_IN_RE_PACKET_ID); //TRACE("%s(%s): OK(%s)",source().toString().c_str(),_remoteAddress.toString().c_str(),Packet::verbString(inReVerb)); switch(inReVerb) { case Packet::VERB_HELLO: { unsigned int latency = std::min((unsigned int)(Utils::now() - at(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(ZT_PROTO_VERB_HELLO__OK__IDX_REVISION); TRACE("%s(%s): OK(HELLO), version %u.%u.%u, latency %u",source().toString().c_str(),_remoteAddress.toString().c_str(),vMajor,vMinor,vRevision,latency); peer->addDirectLatencyMeasurment(latency); peer->setRemoteVersion(vMajor,vMinor,vRevision); // If a supernode has a version higher than ours, this causes a software // update check to run now. This might bum-rush download.zerotier.com, but // it's hosted on S3 so hopefully it can take it. This should cause updates // to propagate out very quickly. if ((_r->updater)&&(_r->topology->isSupernode(peer->address()))) _r->updater->sawRemoteVersion(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(new Peer(_r->identity,id)))); } } break; case Packet::VERB_NETWORK_CONFIG_REQUEST: { SharedPtr nw(_r->nc->network(at(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(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()) { nw->setConfiguration(Dictionary(dict)); TRACE("got network configuration for network %.16llx from %s",(unsigned long long)nw->id(),source().toString().c_str()); } } } break; default: break; } peer->onReceive(_r,_localPort,_remoteAddress,hops(),packetId(),Packet::VERB_OK,inRePacketId,inReVerb,Utils::now()); } 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) { if (payloadLength() == ZT_ADDRESS_LENGTH) { Identity id(_r->topology->getIdentity(Address(payload(),ZT_ADDRESS_LENGTH))); if (id) { Packet outp(source(),_r->identity.address(),Packet::VERB_OK); outp.append((unsigned char)Packet::VERB_WHOIS); outp.append(packetId()); id.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()); } peer->onReceive(_r,_localPort,_remoteAddress,hops(),packetId(),Packet::VERB_WHOIS,0,Packet::VERB_NOP,Utils::now()); return true; } bool PacketDecoder::_doRENDEZVOUS(const RuntimeEnvironment *_r,const SharedPtr &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 withPeer(_r->topology->getPeer(with)); if (withPeer) { unsigned int port = at(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()); peer->onReceive(_r,_localPort,_remoteAddress,hops(),packetId(),Packet::VERB_RENDEZVOUS,0,Packet::VERB_NOP,Utils::now()); _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) { try { SharedPtr network(_r->nc->network(at(ZT_PROTO_VERB_FRAME_IDX_NETWORK_ID))); if (network) { if (network->isAllowed(source())) { unsigned int etherType = at(ZT_PROTO_VERB_FRAME_IDX_ETHERTYPE); if (size() > ZT_PROTO_VERB_FRAME_IDX_PAYLOAD) { if (network->config()->permitsEtherType(etherType)) { network->tapPut(source().toMAC(),etherType,data() + ZT_PROTO_VERB_FRAME_IDX_PAYLOAD,size() - ZT_PROTO_VERB_FRAME_IDX_PAYLOAD); } else { TRACE("dropped FRAME from %s: ethernet type %u not allowed on network %.16llx",source().toString().c_str(),etherType,(unsigned long long)network->id()); return true; } } else return true; // ignore empty frames // 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()); peer->onReceive(_r,_localPort,_remoteAddress,hops(),packetId(),Packet::VERB_FRAME,0,Packet::VERB_NOP,Utils::now()); } else { TRACE("dropped FRAME from %s(%s): sender not a member of closed network %.16llx",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); return true; } } else { TRACE("dropped FRAME from %s(%s): we are not connected to network %.16llx",source().toString().c_str(),_remoteAddress.toString().c_str(),at(ZT_PROTO_VERB_FRAME_IDX_NETWORK_ID)); return true; } } 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) { // TODO: bridging is not implemented yet return true; } bool PacketDecoder::_doMULTICAST_FRAME(const RuntimeEnvironment *_r,const SharedPtr &peer) { try { Address origin(Address(field(ZT_PROTO_VERB_MULTICAST_FRAME_IDX_ORIGIN,ZT_PROTO_VERB_MULTICAST_FRAME_LEN_ORIGIN),ZT_ADDRESS_LENGTH)); SharedPtr 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(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(ZT_PROTO_VERB_MULTICAST_FRAME_IDX_NETWORK_ID); const uint16_t bloomNonce = at(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(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(ZT_PROTO_VERB_MULTICAST_FRAME_IDX_DEST_ADI)); const unsigned int etherType = at(ZT_PROTO_VERB_MULTICAST_FRAME_IDX_ETHERTYPE); const unsigned int frameLen = at(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(ZT_PROTO_VERB_MULTICAST_FRAME_IDX_FRAME + frameLen); const unsigned char *const signature = field(ZT_PROTO_VERB_MULTICAST_FRAME_IDX_FRAME + frameLen + 2,signatureLen); SharedPtr network(_r->nc->network(nwid)); /* Grab, verify, and learn certificate of network membership if any -- provided we are * a member of this network. Note: we can do this before verification of the actual * packet, since the certificate has its own separate signature. In other words a valid * COM does not imply a valid multicast; they are two separate things. The ability to * include the COM with the multicast is a performance optimization to allow peers to * distribute their COM along with their packets instead of as a separate transaction. * This causes network memberships to start working faster. */ if (((flags & ZT_PROTO_VERB_MULTICAST_FRAME_FLAGS_HAS_MEMBERSHIP_CERTIFICATE))&&(network)) { CertificateOfMembership originCom(*this,ZT_PROTO_VERB_MULTICAST_FRAME_IDX_FRAME + frameLen + 2 + signatureLen); Address comSignedBy(originCom.signedBy()); if ((originCom.networkId() == nwid)&&(comSignedBy == network->controller())) { SharedPtr comSigningPeer(_r->topology->getPeer(comSignedBy)); if (!comSigningPeer) { // Technically this should never happen because the COM should be signed by // the master for this network (in current usage) and we ought to already have // that cached. But handle it anyway. _r->sw->requestWhois(comSignedBy); _step = DECODE_WAITING_FOR_MULTICAST_FRAME_ORIGINAL_SENDER_LOOKUP; // causes processing to come back here return false; } else if (originCom.verify(comSigningPeer->identity())) { // The certificate is valid so learn it. As explained above this does not // imply validation of the multicast. That happens later. Look for a call // to network->isAllowed(). network->addMembershipCertificate(originCom); } else { // Go ahead and drop the multicast though if the COM was invalid, since this // obviously signifies a problem. LOG("dropped MULTICAST_FRAME from %s(%s): included COM failed authentication check",source().toString().c_str(),_remoteAddress.toString().c_str()); return true; } } else { // Go ahead and drop the multicast here too, since this also ought never to // happen and certainly indicates a problem. LOG("dropped MULTICAST_FRAME from %s(%s): included COM is not for this network",source().toString().c_str(),_remoteAddress.toString().c_str()); return true; } } // Check the multicast frame's signature to verify that its original sender is // who it claims to be. 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)) { LOG("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... // otherwise people could do weird things like multicast out a TCP SYN. if (!dest.mac().isMulticast()) { LOG("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 // This code, if enabled, sends a UDP pingback to a logger for each multicast. char mct[1024],mctdepth[1024]; unsigned int startingFifoItems = 0; for(unsigned int i=0;itopology->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 // At this point the frame is basically valid, so we can call it a receive peer->onReceive(_r,_localPort,_remoteAddress,hops(),packetId(),Packet::VERB_MULTICAST_FRAME,0,Packet::VERB_NOP,Utils::now()); // This gets updated later in most cases but start with the global limit. unsigned int maxDepth = ZT_MULTICAST_GLOBAL_MAX_DEPTH; if ((origin == _r->identity.address())||(_r->mc->deduplicate(nwid,guid))) { // This is a boomerang or a duplicate of a multicast we've already seen. Ordinary // nodes drop these, while supernodes will keep propagating them since they can // act as bridges between sparse multicast networks more than once. 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) { SharedPtr nconf(network->config2()); if (nconf) { maxDepth = std::min((unsigned int)ZT_MULTICAST_GLOBAL_MAX_DEPTH,nconf->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 ((!nconf->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(),_remoteAddress.toString().c_str(),nwid,sourceMac.toString().c_str(),origin.toString().c_str()); return true; } else if (!nconf->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->tapPut(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; } // Update depth in packet with new incremented value 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. We pad the remainder with // zeroes because this improves data compression ratios. while (newFifoPtr != newFifoEnd) *(newFifoPtr++) = (unsigned char)0; // First element in newFifo[] is next hop Address nextHop(newFifo,ZT_ADDRESS_LENGTH); if ((!nextHop)&&(!_r->topology->amSupernode())) { SharedPtr 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) { 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(ptr); SharedPtr 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(ptr + 14)),now); if (network) network->pushMembershipCertificate(peer->address(),false,now); } } peer->onReceive(_r,_localPort,_remoteAddress,hops(),packetId(),Packet::VERB_MULTICAST_LIKE,0,Packet::VERB_NOP,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) { try { CertificateOfMembership com; unsigned int ptr = ZT_PACKET_IDX_PAYLOAD; while (ptr < size()) { ptr += com.deserialize(*this,ptr); if ((com.hasRequiredFields())&&(com.signedBy())) { SharedPtr signer(_r->topology->getPeer(com.signedBy())); if (signer) { if (com.verify(signer->identity())) { uint64_t nwid = com.networkId(); SharedPtr network(_r->nc->network(nwid)); if (network) { if (network->controller() == signer) network->addMembershipCertificate(com); } } } else { _r->sw->requestWhois(com.signedBy()); _step = DECODE_WAITING_FOR_NETWORK_MEMBERSHIP_CERTIFICATE_SIGNER_LOOKUP; return false; } } } peer->onReceive(_r,_localPort,_remoteAddress,hops(),packetId(),Packet::VERB_NETWORK_MEMBERSHIP_CERTIFICATE,0,Packet::VERB_NOP,Utils::now()); } 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) { try { uint64_t nwid = at(ZT_PROTO_VERB_NETWORK_CONFIG_REQUEST_IDX_NETWORK_ID); #ifndef __WINDOWS__ if (_r->netconfService) { char tmp[128]; unsigned int dictLen = at(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__ peer->onReceive(_r,_localPort,_remoteAddress,hops(),packetId(),Packet::VERB_NETWORK_CONFIG_REQUEST,0,Packet::VERB_NOP,Utils::now()); } 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) { try { unsigned int ptr = ZT_PACKET_IDX_PAYLOAD; while ((ptr + sizeof(uint64_t)) <= size()) { uint64_t nwid = at(ptr); ptr += sizeof(uint64_t); SharedPtr nw(_r->nc->network(nwid)); if ((nw)&&(source() == nw->controller())) { // only respond to requests from controller TRACE("NETWORK_CONFIG_REFRESH from %s, refreshing network %.16llx",source().toString().c_str(),nwid); nw->requestConfiguration(); } } peer->onReceive(_r,_localPort,_remoteAddress,hops(),packetId(),Packet::VERB_NETWORK_CONFIG_REFRESH,0,Packet::VERB_NOP,Utils::now()); } 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