Do not allow VERB_RENDEZVOUS from non-upstream peers to block potential DOS vector.

This commit is contained in:
Adam Ierymenko 2015-10-19 12:56:29 -07:00
parent aa6e3c79a0
commit 95953b48f9
3 changed files with 43 additions and 20 deletions

View file

@ -461,21 +461,26 @@ bool IncomingPacket::_doWHOIS(const RuntimeEnvironment *RR,const SharedPtr<Peer>
bool IncomingPacket::_doRENDEZVOUS(const RuntimeEnvironment *RR,const SharedPtr<Peer> &peer)
{
try {
const Address with(field(ZT_PROTO_VERB_RENDEZVOUS_IDX_ZTADDRESS,ZT_ADDRESS_LENGTH),ZT_ADDRESS_LENGTH);
const SharedPtr<Peer> withPeer(RR->topology->getPeer(with));
if (withPeer) {
const unsigned int port = at<uint16_t>(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<Peer> withPeer(RR->topology->getPeer(with));
if (withPeer) {
const unsigned int port = at<uint16_t>(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());