From 95953b48f963213a803b230e2d83416257716e65 Mon Sep 17 00:00:00 2001 From: Adam Ierymenko Date: Mon, 19 Oct 2015 12:56:29 -0700 Subject: Do not allow VERB_RENDEZVOUS from non-upstream peers to block potential DOS vector. --- node/IncomingPacket.cpp | 29 +++++++++++++++++------------ 1 file changed, 17 insertions(+), 12 deletions(-) (limited to 'node/IncomingPacket.cpp') diff --git a/node/IncomingPacket.cpp b/node/IncomingPacket.cpp index 4386e370..6b39963a 100644 --- a/node/IncomingPacket.cpp +++ b/node/IncomingPacket.cpp @@ -461,21 +461,26 @@ bool IncomingPacket::_doWHOIS(const RuntimeEnvironment *RR,const SharedPtr bool IncomingPacket::_doRENDEZVOUS(const RuntimeEnvironment *RR,const SharedPtr &peer) { try { - const Address with(field(ZT_PROTO_VERB_RENDEZVOUS_IDX_ZTADDRESS,ZT_ADDRESS_LENGTH),ZT_ADDRESS_LENGTH); - const SharedPtr withPeer(RR->topology->getPeer(with)); - if (withPeer) { - const unsigned int port = at(ZT_PROTO_VERB_RENDEZVOUS_IDX_PORT); - const 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",peer->address().toString().c_str(),with.toString().c_str(),atAddr.toString().c_str()); - peer->received(RR,_localAddress,_remoteAddress,hops(),packetId(),Packet::VERB_RENDEZVOUS,0,Packet::VERB_NOP); - RR->sw->rendezvous(withPeer,_localAddress,atAddr); + if (RR->topology->isUpstream(peer->identity())) { + const Address with(field(ZT_PROTO_VERB_RENDEZVOUS_IDX_ZTADDRESS,ZT_ADDRESS_LENGTH),ZT_ADDRESS_LENGTH); + const SharedPtr withPeer(RR->topology->getPeer(with)); + if (withPeer) { + const unsigned int port = at(ZT_PROTO_VERB_RENDEZVOUS_IDX_PORT); + const 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",peer->address().toString().c_str(),with.toString().c_str(),atAddr.toString().c_str()); + peer->received(RR,_localAddress,_remoteAddress,hops(),packetId(),Packet::VERB_RENDEZVOUS,0,Packet::VERB_NOP); + RR->sw->rendezvous(withPeer,_localAddress,atAddr); + } else { + TRACE("dropped corrupt RENDEZVOUS from %s(%s) (bad address or port)",peer->address().toString().c_str(),_remoteAddress.toString().c_str()); + } } else { - TRACE("dropped corrupt RENDEZVOUS from %s(%s) (bad address or port)",peer->address().toString().c_str(),_remoteAddress.toString().c_str()); + RR->sw->requestWhois(with); + TRACE("ignored RENDEZVOUS from %s(%s) to meet unknown peer %s",peer->address().toString().c_str(),_remoteAddress.toString().c_str(),with.toString().c_str()); } } else { - TRACE("ignored RENDEZVOUS from %s(%s) to meet unknown peer %s",peer->address().toString().c_str(),_remoteAddress.toString().c_str(),with.toString().c_str()); + TRACE("ignored RENDEZVOUS from %s(%s): not a root server or a network relay",peer->address().toString().c_str(),_remoteAddress.toString().c_str()); } } catch ( ... ) { TRACE("dropped RENDEZVOUS from %s(%s): unexpected exception",peer->address().toString().c_str(),_remoteAddress.toString().c_str()); -- cgit v1.2.3