Send a random small payload for NAT keepalives, since zero byte packets seem to fail to keep associations alive behind some NATs.

This commit is contained in:
Adam Ierymenko 2015-09-22 15:58:00 -07:00
parent ddf3d1f949
commit d656e87395

View File

@ -39,6 +39,9 @@
namespace ZeroTier {
// Used to send varying values for NAT keepalive
static uint32_t _natKeepaliveBuf = 0;
Peer::Peer(const Identity &myIdentity,const Identity &peerIdentity)
throw(std::runtime_error) :
_lastUsed(0),
@ -217,8 +220,9 @@ void Peer::doPingAndKeepalive(const RuntimeEnvironment *RR,uint64_t now)
attemptToContactAt(RR,bestPath->address(),now);
bestPath->sent(now);
} else if (((now - bestPath->lastSend()) >= ZT_NAT_KEEPALIVE_DELAY)&&(!bestPath->reliable())) {
_natKeepaliveBuf += (uint32_t)now * 2654435761; // tumble this around to send constantly varying (meaningless) payloads
TRACE("NAT keepalive %s(%s)",_id.address().toString().c_str(),bestPath->address().toString().c_str());
RR->node->putPacket(bestPath->address(),"",0);
RR->node->putPacket(bestPath->address(),&_natKeepaliveBuf,sizeof(_natKeepaliveBuf));
bestPath->sent(now);
}
}