lokinet/llarp/dht/messages/findintro.cpp
2019-01-19 01:41:14 +00:00

218 lines
5.6 KiB
C++

#include <dht/context.hpp>
#include <dht/messages/findintro.hpp>
#include <dht/messages/gotintro.hpp>
#include <routing/message.hpp>
namespace llarp
{
namespace dht
{
/*
struct IntroSetLookupInformer
{
llarp::Router* router;
service::Address target;
void
SendReply(const llarp::routing::IMessage* msg)
{
}
};
*/
FindIntroMessage::~FindIntroMessage()
{
}
bool
FindIntroMessage::DecodeKey(llarp_buffer_t k, llarp_buffer_t* val)
{
bool read = false;
if(!BEncodeMaybeReadDictEntry("N", N, read, k, val))
return false;
if(!BEncodeMaybeReadDictInt("R", R, read, k, val))
return false;
if(!BEncodeMaybeReadDictEntry("S", S, read, k, val))
return false;
if(!BEncodeMaybeReadDictInt("T", T, read, k, val))
return false;
if(!BEncodeMaybeReadVersion("V", version, LLARP_PROTO_VERSION, read, k,
val))
return false;
return read;
}
bool
FindIntroMessage::BEncode(llarp_buffer_t* buf) const
{
if(!bencode_start_dict(buf))
return false;
// message id
if(!BEncodeWriteDictMsgType(buf, "A", "F"))
return false;
if(N.Empty())
{
// recursion
if(!BEncodeWriteDictInt("R", R, buf))
return false;
// service address
if(!BEncodeWriteDictEntry("S", S, buf))
return false;
}
else
{
if(!BEncodeWriteDictEntry("N", N, buf))
return false;
// recursion
if(!BEncodeWriteDictInt("R", R, buf))
return false;
}
// txid
if(!BEncodeWriteDictInt("T", T, buf))
return false;
// protocol version
if(!BEncodeWriteDictInt("V", LLARP_PROTO_VERSION, buf))
return false;
return bencode_end(buf);
}
bool
FindIntroMessage::HandleMessage(
llarp_dht_context* ctx,
std::vector< std::unique_ptr< IMessage > >& replies) const
{
if(R > 5)
{
llarp::LogError("R value too big, ", R, "> 5");
return false;
}
auto& dht = ctx->impl;
if(dht.pendingIntrosetLookups.HasPendingLookupFrom(TXOwner{From, T}))
{
llarp::LogWarn("duplicate FIM from ", From, " txid=", T);
return false;
}
Key_t peer;
std::set< Key_t > exclude = {dht.OurKey(), From};
if(N.Empty())
{
llarp::LogInfo("lookup ", S.ToString());
const auto introset = dht.GetIntroSetByServiceAddress(S);
if(introset)
{
service::IntroSet i = *introset;
replies.emplace_back(new GotIntroMessage({i}, T));
return true;
}
else
{
if(R == 0)
{
// we don't have it
Key_t target = S.ToKey();
Key_t closer;
// find closer peer
if(!dht.nodes->FindClosest(target, closer))
return false;
if(relayed)
dht.LookupIntroSetForPath(S, T, pathID, closer);
else
replies.emplace_back(new GotIntroMessage(From, closer, T));
return true;
}
else
{
Key_t us = dht.OurKey();
Key_t target = S.ToKey();
// we are recursive
if(dht.nodes->FindCloseExcluding(target, peer, exclude))
{
if(relayed)
dht.LookupIntroSetForPath(S, T, pathID, peer);
else
{
if((us ^ target) < (peer ^ target))
{
// we are not closer than our peer to the target so don't
// recurse farther
replies.emplace_back(new GotIntroMessage({}, T));
return true;
}
else if(R > 0)
dht.LookupIntroSetRecursive(S, From, T, peer, R - 1);
else
dht.LookupIntroSetIterative(S, From, T, peer);
}
return true;
}
else
{
// no more closer peers
replies.emplace_back(new GotIntroMessage({}, T));
return true;
}
}
}
}
else
{
if(relayed)
{
// tag lookup
if(dht.nodes->GetRandomNodeExcluding(peer, exclude))
{
dht.LookupTagForPath(N, T, pathID, peer);
}
else
{
// no more closer peers
replies.emplace_back(new GotIntroMessage({}, T));
return true;
}
}
else
{
if(R == 0)
{
// base case
auto introsets = dht.FindRandomIntroSetsWithTagExcluding(N, 2, {});
std::vector< service::IntroSet > reply;
for(const auto& introset : introsets)
{
reply.push_back(introset);
}
replies.emplace_back(new GotIntroMessage(reply, T));
return true;
}
else if(R < 5)
{
// tag lookup
if(dht.nodes->GetRandomNodeExcluding(peer, exclude))
{
dht.LookupTagRecursive(N, From, T, peer, R - 1);
}
else
{
replies.emplace_back(new GotIntroMessage({}, T));
}
}
else
{
// too big R value
replies.emplace_back(new GotIntroMessage({}, T));
}
}
}
return true;
}
} // namespace dht
} // namespace llarp