FindClosestNodes, select DHT port from wider range

libi2pd_client/TorrentsDHT.cpp

@@ -17,18 +17,6 @@ namespace i2p
 {
 namespace torrents
 {
-	NodeDistance operator^(const NodeID& node1, const NodeID& node2)
-	{
-		NodeDistance d;
-
-		d.l[0] = node1.l[0] ^ node2.l[0];
-		d.l[1] = node1.l[1] ^ node2.l[1];
-		d.l[2] = node1.l[2] ^ node2.l[2];
-		d.l[3] = node1.l[3] ^ node2.l[3];
-		d.l[4] = node1.l[4] ^ node2.l[4];
-
-		return d;
-	}
 
 	RoutingTable::RoutingTable (const NodeID& ourNode):
 		m_OurNode (ourNode)
@@ -36,7 +24,7 @@ namespace torrents
 		m_Buckets.push_back (std::make_shared<Bucket> ());
 	}
 
-	std::shared_ptr<Bucket> RoutingTable::FindBucket (const NodeID& id)
+	std::shared_ptr<Bucket> RoutingTable::FindBucket (const Torrent::InfoHash& id) const
 	{
 		if (m_Buckets.empty ()) return nullptr;
 		auto it = m_Buckets.begin ();
@@ -59,23 +47,47 @@ namespace torrents
 		return node;
 	}
 
+	std::list<std::pair<std::shared_ptr<Node>, Distance> > RoutingTable::FindClosestNodes (const Torrent::InfoHash& infoHash, size_t num) const
+	{
+		std::list<std::pair<std::shared_ptr<Node>, Distance> > ret;
+		if (num > 0)
+		{
+			auto bucket = FindBucket (infoHash);
+			if (bucket)
+			{
+				for (auto it: bucket->nodes)
+				{
+					auto nodeDistance = it->id ^ infoHash;
+					auto it1 = std::find_if (ret.begin (), ret.end (),
+						[&nodeDistance](const std::pair<std::shared_ptr<Node>, Distance>& alreadyFound)
+						{
+							return nodeDistance < alreadyFound.second;
+						});
+					ret.insert (it1, { it, nodeDistance } );
+				}
+				if (ret.size () > num) ret.resize (num);
+			}
+		}
+		return ret;
+	}
+
 	TorrentsDHT::TorrentsDHT (TorrentsTunnel& tunnel, uint16_t port):
 		m_Tunnel (tunnel), m_Port (port)
 	{
 		auto dest = tunnel.GetLocalDestination ();
 		if (dest)
 		{
-			memcpy (m_NodeID.buf, dest->GetIdentHash (), m_NodeID.len);
-			m_NodeID.buf[4] ^= (port >> 8);
-			m_NodeID.buf[5] ^= (port & 0xFF);
-			memcpy (m_NodeInfo.data (), m_NodeID.buf, m_NodeID.len);
-			memcpy (m_NodeInfo.data () + m_NodeID.len, dest->GetIdentHash (), i2p::data::IdentHash::len);
+			memcpy (m_NodeID.data (), dest->GetIdentHash (), m_NodeID.size ());
+			m_NodeID[4] ^= (port >> 8);
+			m_NodeID[5] ^= (port & 0xFF);
+			memcpy (m_NodeInfo.data (), m_NodeID.data (), m_NodeID.size ());
+			memcpy (m_NodeInfo.data () + m_NodeID.size (), dest->GetIdentHash (), i2p::data::IdentHash::len);
 			htobe16buf (m_NodeInfo.data () + m_NodeInfo.size () - 2, port);
 			m_RoutingTable = std::make_unique<RoutingTable> (m_NodeID);
 		}
 		else
 		{
-			memset (m_NodeID.buf, 0, m_NodeID.len);
+			m_NodeID.fill (0);
 			m_NodeInfo.fill (0);
 		}
 	}

libi2pd_client/TorrentsDHT.h

@@ -17,34 +17,29 @@
 #include <array>
 #include <list>
 #include <algorithm>
+#include <utility>
 #include "Identity.h"
 #include "I2PService.h"
 #include "util.h"
+#include "Torrents.h"
 
 namespace i2p
 {
 namespace torrents
 {
-	struct NodeID
+	using Distance = Torrent::InfoHash;
+	struct NodeID: public Torrent::InfoHash
 	{
-		static constexpr size_t len = SHA_DIGEST_LENGTH;
-
-		union // 4 bytes aligned
+		static constexpr size_t len = std::tuple_size<Torrent::InfoHash>::value;
+		constexpr Distance operator^(const Torrent::InfoHash& hash)
 		{
-			uint8_t buf[len];
-			uint32_t l[len/4];
-		};
-
-		auto operator<=>(const NodeID& other) const { return memcmp (buf, other.buf, len) <=> 0; }
-		bool operator==(const NodeID& other) const { return !memcmp (buf, other.buf, len); }
-		static constexpr NodeID Zero () { NodeID n; std::fill_n (n.buf, len, 0); return n; }
+			Distance d;
+			for (size_t i = 0; i < size (); i++)
+				d[i] = (*this)[i] ^ hash[i];
+			return d;
+		}
 	};
 
-	struct NodeDistance: public NodeID
-	{
-	};
-	NodeDistance operator^(const NodeID& node1, const NodeID& node2);
-
 	struct Node
 	{
 		NodeID id;
@@ -61,7 +56,7 @@ namespace torrents
 		std::list<std::shared_ptr<Node> > nodes;
 		NodeID start;
 
-		Bucket (): start (NodeID::Zero ()) {}
+		Bucket (): start{} {}
 	};
 
 	class RoutingTable
@@ -71,10 +66,11 @@ namespace torrents
 			RoutingTable (const NodeID& ourNode);
 
 			std::shared_ptr<Node> AddNode (const NodeID& id, i2p::data::IdentHash& peer, uint16_t port);
+			std::list<std::pair<std::shared_ptr<Node>, Distance> > FindClosestNodes (const Torrent::InfoHash& infoHash, size_t num) const;
 
 		private:
 
-			std::shared_ptr<Bucket> FindBucket (const NodeID& id);
+			std::shared_ptr<Bucket> FindBucket (const Torrent::InfoHash& id) const;
 
 		private:
 

libi2pd_client/TorrentsTunnel.cpp

@@ -29,7 +29,8 @@ namespace torrents
 		i2p::client::I2PService (localDestination), m_Name (name), m_PeerID ("-I2PD-"),
 		m_TorrentsDir (torrentsDir), m_TrackerRequestsCheckTimer (GetService ()),
 		m_KeepAliveCheckTimer (GetService ()), m_ReconnectCheckTimer (GetService ()),
-		m_TorrentsStatusUpdateTimer (GetService ()), m_DHT (*this, localDestination->GetRng()() % 1000 + 6000)
+		m_TorrentsStatusUpdateTimer (GetService ()),
+		m_DHT (*this, TORRENT_PORT + (localDestination ? localDestination->GetRng()() % (65535 - TORRENT_PORT - 1) : 1))
 	{
 		if (localDestination)
 			m_PeerID += localDestination->GetIdentHash ().ToBase64 ();