Merge pull request #17227 from Faless/multiplayer_api

[RFC] MultiplayerAPI refactor

2 files changed, 809 insertions, 0 deletions

diff --git a/core/io/multiplayer_api.cpp b/core/io/multiplayer_api.cpp
new file mode 100644
index 0000000000..cbe7f87d92
--- /dev/null
+++ b/core/io/multiplayer_api.cpp
@@ -0,0 +1,722 @@
+#include "core/io/multiplayer_api.h"
+#include "core/io/marshalls.h"
+#include "scene/main/node.h"
+
+void MultiplayerAPI::poll() {
+
+	if (!network_peer.is_valid() || network_peer->get_connection_status() == NetworkedMultiplayerPeer::CONNECTION_DISCONNECTED)
+		return;
+
+	network_peer->poll();
+
+	if (!network_peer.is_valid()) //it's possible that polling might have resulted in a disconnection, so check here
+		return;
+
+	while (network_peer->get_available_packet_count()) {
+
+		int sender = network_peer->get_packet_peer();
+		const uint8_t *packet;
+		int len;
+
+		Error err = network_peer->get_packet(&packet, len);
+		if (err != OK) {
+			ERR_PRINT("Error getting packet!");
+		}
+
+		rpc_sender_id = sender;
+		_process_packet(sender, packet, len);
+		rpc_sender_id = 0;
+
+		if (!network_peer.is_valid()) {
+			break; //it's also possible that a packet or RPC caused a disconnection, so also check here
+		}
+	}
+}
+
+void MultiplayerAPI::clear() {
+	connected_peers.clear();
+	path_get_cache.clear();
+	path_send_cache.clear();
+	last_send_cache_id = 1;
+}
+
+void MultiplayerAPI::set_root_node(Node *p_node) {
+	root_node = p_node;
+}
+
+void MultiplayerAPI::set_network_peer(const Ref<NetworkedMultiplayerPeer> &p_peer) {
+
+	if (network_peer.is_valid()) {
+		network_peer->disconnect("peer_connected", this, "add_peer");
+		network_peer->disconnect("peer_disconnected", this, "del_peer");
+		network_peer->disconnect("connection_succeeded", this, "connected_to_server");
+		network_peer->disconnect("connection_failed", this, "connection_failed");
+		network_peer->disconnect("server_disconnected", this, "server_disconnected");
+		clear();
+	}
+
+	network_peer = p_peer;
+
+	ERR_EXPLAIN("Supplied NetworkedNetworkPeer must be connecting or connected.");
+	ERR_FAIL_COND(p_peer.is_valid() && p_peer->get_connection_status() == NetworkedMultiplayerPeer::CONNECTION_DISCONNECTED);
+
+	if (network_peer.is_valid()) {
+		network_peer->connect("peer_connected", this, "add_peer");
+		network_peer->connect("peer_disconnected", this, "del_peer");
+		network_peer->connect("connection_succeeded", this, "connected_to_server");
+		network_peer->connect("connection_failed", this, "connection_failed");
+		network_peer->connect("server_disconnected", this, "server_disconnected");
+	}
+}
+
+Ref<NetworkedMultiplayerPeer> MultiplayerAPI::get_network_peer() const {
+	return network_peer;
+}
+
+void MultiplayerAPI::_process_packet(int p_from, const uint8_t *p_packet, int p_packet_len) {
+
+	ERR_FAIL_COND(root_node == NULL);
+	ERR_FAIL_COND(p_packet_len < 5);
+
+	uint8_t packet_type = p_packet[0];
+
+	switch (packet_type) {
+
+		case NETWORK_COMMAND_SIMPLIFY_PATH: {
+
+			_process_simplify_path(p_from, p_packet, p_packet_len);
+		} break;
+
+		case NETWORK_COMMAND_CONFIRM_PATH: {
+
+			_process_confirm_path(p_from, p_packet, p_packet_len);
+		} break;
+
+		case NETWORK_COMMAND_REMOTE_CALL:
+		case NETWORK_COMMAND_REMOTE_SET: {
+
+			ERR_FAIL_COND(p_packet_len < 6);
+
+			Node *node = _process_get_node(p_from, p_packet, p_packet_len);
+
+			ERR_FAIL_COND(node == NULL);
+
+			//detect cstring end
+			int len_end = 5;
+			for (; len_end < p_packet_len; len_end++) {
+				if (p_packet[len_end] == 0) {
+					break;
+				}
+			}
+
+			ERR_FAIL_COND(len_end >= p_packet_len);
+
+			StringName name = String::utf8((const char *)&p_packet[5]);
+
+			if (packet_type == NETWORK_COMMAND_REMOTE_CALL) {
+
+				_process_rpc(node, name, p_from, p_packet, p_packet_len, len_end + 1);
+
+			} else {
+
+				_process_rset(node, name, p_from, p_packet, p_packet_len, len_end + 1);
+			}
+
+		} break;
+	}
+}
+
+Node *MultiplayerAPI::_process_get_node(int p_from, const uint8_t *p_packet, int p_packet_len) {
+
+	uint32_t target = decode_uint32(&p_packet[1]);
+	Node *node = NULL;
+
+	if (target & 0x80000000) {
+		//use full path (not cached yet)
+
+		int ofs = target & 0x7FFFFFFF;
+		ERR_FAIL_COND_V(ofs >= p_packet_len, NULL);
+
+		String paths;
+		paths.parse_utf8((const char *)&p_packet[ofs], p_packet_len - ofs);
+
+		NodePath np = paths;
+
+		node = root_node->get_node(np);
+
+		if (!node)
+			ERR_PRINTS("Failed to get path from RPC: " + String(np));
+	} else {
+		//use cached path
+		int id = target;
+
+		Map<int, PathGetCache>::Element *E = path_get_cache.find(p_from);
+		ERR_FAIL_COND_V(!E, NULL);
+
+		Map<int, PathGetCache::NodeInfo>::Element *F = E->get().nodes.find(id);
+		ERR_FAIL_COND_V(!F, NULL);
+
+		PathGetCache::NodeInfo *ni = &F->get();
+		//do proper caching later
+
+		node = root_node->get_node(ni->path);
+		if (!node)
+			ERR_PRINTS("Failed to get cached path from RPC: " + String(ni->path));
+	}
+	return node;
+}
+
+void MultiplayerAPI::_process_rpc(Node *p_node, const StringName &p_name, int p_from, const uint8_t *p_packet, int p_packet_len, int p_offset) {
+	if (!p_node->can_call_rpc(p_name, p_from))
+		return;
+
+	ERR_FAIL_COND(p_offset >= p_packet_len);
+
+	int argc = p_packet[p_offset];
+	Vector<Variant> args;
+	Vector<const Variant *> argp;
+	args.resize(argc);
+	argp.resize(argc);
+
+	p_offset++;
+
+	for (int i = 0; i < argc; i++) {
+
+		ERR_FAIL_COND(p_offset >= p_packet_len);
+		int vlen;
+		Error err = decode_variant(args[i], &p_packet[p_offset], p_packet_len - p_offset, &vlen);
+		ERR_FAIL_COND(err != OK);
+		//args[i]=p_packet[3+i];
+		argp[i] = &args[i];
+		p_offset += vlen;
+	}
+
+	Variant::CallError ce;
+
+	p_node->call(p_name, (const Variant **)argp.ptr(), argc, ce);
+	if (ce.error != Variant::CallError::CALL_OK) {
+		String error = Variant::get_call_error_text(p_node, p_name, (const Variant **)argp.ptr(), argc, ce);
+		error = "RPC - " + error;
+		ERR_PRINTS(error);
+	}
+}
+
+void MultiplayerAPI::_process_rset(Node *p_node, const StringName &p_name, int p_from, const uint8_t *p_packet, int p_packet_len, int p_offset) {
+
+	if (!p_node->can_call_rset(p_name, p_from))
+		return;
+
+	ERR_FAIL_COND(p_offset >= p_packet_len);
+
+	Variant value;
+	decode_variant(value, &p_packet[p_offset], p_packet_len - p_offset);
+
+	bool valid;
+
+	p_node->set(p_name, value, &valid);
+	if (!valid) {
+		String error = "Error setting remote property '" + String(p_name) + "', not found in object of type " + p_node->get_class();
+		ERR_PRINTS(error);
+	}
+}
+
+void MultiplayerAPI::_process_simplify_path(int p_from, const uint8_t *p_packet, int p_packet_len) {
+
+	ERR_FAIL_COND(p_packet_len < 5);
+	int id = decode_uint32(&p_packet[1]);
+
+	String paths;
+	paths.parse_utf8((const char *)&p_packet[5], p_packet_len - 5);
+
+	NodePath path = paths;
+
+	if (!path_get_cache.has(p_from)) {
+		path_get_cache[p_from] = PathGetCache();
+	}
+
+	PathGetCache::NodeInfo ni;
+	ni.path = path;
+	ni.instance = 0;
+
+	path_get_cache[p_from].nodes[id] = ni;
+
+	//send ack
+
+	//encode path
+	CharString pname = String(path).utf8();
+	int len = encode_cstring(pname.get_data(), NULL);
+
+	Vector<uint8_t> packet;
+
+	packet.resize(1 + len);
+	packet[0] = NETWORK_COMMAND_CONFIRM_PATH;
+	encode_cstring(pname.get_data(), &packet[1]);
+
+	network_peer->set_transfer_mode(NetworkedMultiplayerPeer::TRANSFER_MODE_RELIABLE);
+	network_peer->set_target_peer(p_from);
+	network_peer->put_packet(packet.ptr(), packet.size());
+}
+
+void MultiplayerAPI::_process_confirm_path(int p_from, const uint8_t *p_packet, int p_packet_len) {
+
+	String paths;
+	paths.parse_utf8((const char *)&p_packet[1], p_packet_len - 1);
+
+	NodePath path = paths;
+
+	PathSentCache *psc = path_send_cache.getptr(path);
+	ERR_FAIL_COND(!psc);
+
+	Map<int, bool>::Element *E = psc->confirmed_peers.find(p_from);
+	ERR_FAIL_COND(!E);
+	E->get() = true;
+}
+
+bool MultiplayerAPI::_send_confirm_path(NodePath p_path, PathSentCache *psc, int p_target) {
+	bool has_all_peers = true;
+	List<int> peers_to_add; //if one is missing, take note to add it
+
+	for (Set<int>::Element *E = connected_peers.front(); E; E = E->next()) {
+
+		if (p_target < 0 && E->get() == -p_target)
+			continue; //continue, excluded
+
+		if (p_target > 0 && E->get() != p_target)
+			continue; //continue, not for this peer
+
+		Map<int, bool>::Element *F = psc->confirmed_peers.find(E->get());
+
+		if (!F || F->get() == false) {
+			//path was not cached, or was cached but is unconfirmed
+			if (!F) {
+				//not cached at all, take note
+				peers_to_add.push_back(E->get());
+			}
+
+			has_all_peers = false;
+		}
+	}
+
+	//those that need to be added, send a message for this
+
+	for (List<int>::Element *E = peers_to_add.front(); E; E = E->next()) {
+
+		//encode function name
+		CharString pname = String(p_path).utf8();
+		int len = encode_cstring(pname.get_data(), NULL);
+
+		Vector<uint8_t> packet;
+
+		packet.resize(1 + 4 + len);
+		packet[0] = NETWORK_COMMAND_SIMPLIFY_PATH;
+		encode_uint32(psc->id, &packet[1]);
+		encode_cstring(pname.get_data(), &packet[5]);
+
+		network_peer->set_target_peer(E->get()); //to all of you
+		network_peer->set_transfer_mode(NetworkedMultiplayerPeer::TRANSFER_MODE_RELIABLE);
+		network_peer->put_packet(packet.ptr(), packet.size());
+
+		psc->confirmed_peers.insert(E->get(), false); //insert into confirmed, but as false since it was not confirmed
+	}
+
+	return has_all_peers;
+}
+
+void MultiplayerAPI::_send_rpc(Node *p_from, int p_to, bool p_unreliable, bool p_set, const StringName &p_name, const Variant **p_arg, int p_argcount) {
+
+	if (network_peer.is_null()) {
+		ERR_EXPLAIN("Attempt to remote call/set when networking is not active in SceneTree.");
+		ERR_FAIL();
+	}
+
+	if (network_peer->get_connection_status() == NetworkedMultiplayerPeer::CONNECTION_CONNECTING) {
+		ERR_EXPLAIN("Attempt to remote call/set when networking is not connected yet in SceneTree.");
+		ERR_FAIL();
+	}
+
+	if (network_peer->get_connection_status() == NetworkedMultiplayerPeer::CONNECTION_DISCONNECTED) {
+		ERR_EXPLAIN("Attempt to remote call/set when networking is disconnected.");
+		ERR_FAIL();
+	}
+
+	if (p_argcount > 255) {
+		ERR_EXPLAIN("Too many arguments >255.");
+		ERR_FAIL();
+	}
+
+	if (p_to != 0 && !connected_peers.has(ABS(p_to))) {
+		if (p_to == network_peer->get_unique_id()) {
+			ERR_EXPLAIN("Attempt to remote call/set yourself! unique ID: " + itos(network_peer->get_unique_id()));
+		} else {
+			ERR_EXPLAIN("Attempt to remote call unexisting ID: " + itos(p_to));
+		}
+
+		ERR_FAIL();
+	}
+
+	NodePath from_path = (root_node->get_path()).rel_path_to(p_from->get_path());
+	ERR_FAIL_COND(from_path.is_empty());
+
+	//see if the path is cached
+	PathSentCache *psc = path_send_cache.getptr(from_path);
+	if (!psc) {
+		//path is not cached, create
+		path_send_cache[from_path] = PathSentCache();
+		psc = path_send_cache.getptr(from_path);
+		psc->id = last_send_cache_id++;
+	}
+
+	//create base packet, lots of hardcode because it must be tight
+
+	int ofs = 0;
+
+#define MAKE_ROOM(m_amount) \
+	if (packet_cache.size() < m_amount) packet_cache.resize(m_amount);
+
+	//encode type
+	MAKE_ROOM(1);
+	packet_cache[0] = p_set ? NETWORK_COMMAND_REMOTE_SET : NETWORK_COMMAND_REMOTE_CALL;
+	ofs += 1;
+
+	//encode ID
+	MAKE_ROOM(ofs + 4);
+	encode_uint32(psc->id, &(packet_cache[ofs]));
+	ofs += 4;
+
+	//encode function name
+	CharString name = String(p_name).utf8();
+	int len = encode_cstring(name.get_data(), NULL);
+	MAKE_ROOM(ofs + len);
+	encode_cstring(name.get_data(), &(packet_cache[ofs]));
+	ofs += len;
+
+	if (p_set) {
+		//set argument
+		Error err = encode_variant(*p_arg[0], NULL, len);
+		ERR_FAIL_COND(err != OK);
+		MAKE_ROOM(ofs + len);
+		encode_variant(*p_arg[0], &(packet_cache[ofs]), len);
+		ofs += len;
+
+	} else {
+		//call arguments
+		MAKE_ROOM(ofs + 1);
+		packet_cache[ofs] = p_argcount;
+		ofs += 1;
+		for (int i = 0; i < p_argcount; i++) {
+			Error err = encode_variant(*p_arg[i], NULL, len);
+			ERR_FAIL_COND(err != OK);
+			MAKE_ROOM(ofs + len);
+			encode_variant(*p_arg[i], &(packet_cache[ofs]), len);
+			ofs += len;
+		}
+	}
+
+	//see if all peers have cached path (is so, call can be fast)
+	bool has_all_peers = _send_confirm_path(from_path, psc, p_to);
+
+	//take chance and set transfer mode, since all send methods will use it
+	network_peer->set_transfer_mode(p_unreliable ? NetworkedMultiplayerPeer::TRANSFER_MODE_UNRELIABLE : NetworkedMultiplayerPeer::TRANSFER_MODE_RELIABLE);
+
+	if (has_all_peers) {
+
+		//they all have verified paths, so send fast
+		network_peer->set_target_peer(p_to); //to all of you
+		network_peer->put_packet(packet_cache.ptr(), ofs); //a message with love
+	} else {
+		//not all verified path, so send one by one
+
+		//apend path at the end, since we will need it for some packets
+		CharString pname = String(from_path).utf8();
+		int path_len = encode_cstring(pname.get_data(), NULL);
+		MAKE_ROOM(ofs + path_len);
+		encode_cstring(pname.get_data(), &(packet_cache[ofs]));
+
+		for (Set<int>::Element *E = connected_peers.front(); E; E = E->next()) {
+
+			if (p_to < 0 && E->get() == -p_to)
+				continue; //continue, excluded
+
+			if (p_to > 0 && E->get() != p_to)
+				continue; //continue, not for this peer
+
+			Map<int, bool>::Element *F = psc->confirmed_peers.find(E->get());
+			ERR_CONTINUE(!F); //should never happen
+
+			network_peer->set_target_peer(E->get()); //to this one specifically
+
+			if (F->get() == true) {
+				//this one confirmed path, so use id
+				encode_uint32(psc->id, &(packet_cache[1]));
+				network_peer->put_packet(packet_cache.ptr(), ofs);
+			} else {
+				//this one did not confirm path yet, so use entire path (sorry!)
+				encode_uint32(0x80000000 | ofs, &(packet_cache[1])); //offset to path and flag
+				network_peer->put_packet(packet_cache.ptr(), ofs + path_len);
+			}
+		}
+	}
+}
+
+void MultiplayerAPI::add_peer(int p_id) {
+	connected_peers.insert(p_id);
+	path_get_cache.insert(p_id, PathGetCache());
+	emit_signal("network_peer_connected", p_id);
+}
+
+void MultiplayerAPI::del_peer(int p_id) {
+	connected_peers.erase(p_id);
+	path_get_cache.erase(p_id); //I no longer need your cache, sorry
+	emit_signal("network_peer_disconnected", p_id);
+}
+
+void MultiplayerAPI::connected_to_server() {
+
+	emit_signal("connected_to_server");
+}
+
+void MultiplayerAPI::connection_failed() {
+
+	emit_signal("connection_failed");
+}
+
+void MultiplayerAPI::server_disconnected() {
+
+	emit_signal("server_disconnected");
+}
+
+bool _should_call_native(Node::RPCMode mode, bool is_master, bool &r_skip_rpc) {
+
+	switch (mode) {
+
+		case Node::RPC_MODE_DISABLED: {
+			//do nothing
+		} break;
+		case Node::RPC_MODE_REMOTE: {
+			//do nothing also, no need to call local
+		} break;
+		case Node::RPC_MODE_SYNC: {
+			//call it, sync always results in call
+			return true;
+		} break;
+		case Node::RPC_MODE_MASTER: {
+			if (is_master)
+				r_skip_rpc = true; //no other master so..
+			return is_master;
+		} break;
+		case Node::RPC_MODE_SLAVE: {
+			return !is_master;
+		} break;
+	}
+	return false;
+}
+
+bool _should_call_script(ScriptInstance::RPCMode mode, bool is_master, bool &r_skip_rpc) {
+	switch (mode) {
+
+		case ScriptInstance::RPC_MODE_DISABLED: {
+			//do nothing
+		} break;
+		case ScriptInstance::RPC_MODE_REMOTE: {
+			//do nothing also, no need to call local
+		} break;
+		case ScriptInstance::RPC_MODE_SYNC: {
+			//call it, sync always results in call
+			return true;
+		} break;
+		case ScriptInstance::RPC_MODE_MASTER: {
+			if (is_master)
+				r_skip_rpc = true; //no other master so..
+			return is_master;
+		} break;
+		case ScriptInstance::RPC_MODE_SLAVE: {
+			return !is_master;
+		} break;
+	}
+	return false;
+}
+
+void MultiplayerAPI::rpcp(Node *p_node, int p_peer_id, bool p_unreliable, const StringName &p_method, const Variant **p_arg, int p_argcount) {
+
+	ERR_FAIL_COND(!p_node->is_inside_tree());
+	ERR_FAIL_COND(!network_peer.is_valid());
+
+	int node_id = network_peer->get_unique_id();
+	bool skip_rpc = false;
+	bool call_local_native = false;
+	bool call_local_script = false;
+	bool is_master = p_node->is_network_master();
+
+	if (p_peer_id == 0 || p_peer_id == node_id || (p_peer_id < 0 && p_peer_id != -node_id)) {
+		//check that send mode can use local call
+
+		const Map<StringName, Node::RPCMode>::Element *E = p_node->get_node_rpc_mode(p_method);
+		if (E) {
+			call_local_native = _should_call_native(E->get(), is_master, skip_rpc);
+		}
+
+		if (call_local_native) {
+			// done below
+		} else if (p_node->get_script_instance()) {
+			//attempt with script
+			ScriptInstance::RPCMode rpc_mode = p_node->get_script_instance()->get_rpc_mode(p_method);
+			call_local_script = _should_call_script(rpc_mode, is_master, skip_rpc);
+		}
+	}
+
+	if (!skip_rpc) {
+		_send_rpc(p_node, p_peer_id, p_unreliable, false, p_method, p_arg, p_argcount);
+	}
+
+	if (call_local_native) {
+		Variant::CallError ce;
+		p_node->call(p_method, p_arg, p_argcount, ce);
+		if (ce.error != Variant::CallError::CALL_OK) {
+			String error = Variant::get_call_error_text(p_node, p_method, p_arg, p_argcount, ce);
+			error = "rpc() aborted in local call:  - " + error;
+			ERR_PRINTS(error);
+			return;
+		}
+	}
+
+	if (call_local_script) {
+		Variant::CallError ce;
+		ce.error = Variant::CallError::CALL_OK;
+		p_node->get_script_instance()->call(p_method, p_arg, p_argcount, ce);
+		if (ce.error != Variant::CallError::CALL_OK) {
+			String error = Variant::get_call_error_text(p_node, p_method, p_arg, p_argcount, ce);
+			error = "rpc() aborted in script local call:  - " + error;
+			ERR_PRINTS(error);
+			return;
+		}
+	}
+}
+
+void MultiplayerAPI::rsetp(Node *p_node, int p_peer_id, bool p_unreliable, const StringName &p_property, const Variant &p_value) {
+
+	ERR_FAIL_COND(!p_node->is_inside_tree());
+	ERR_FAIL_COND(!network_peer.is_valid());
+
+	int node_id = network_peer->get_unique_id();
+	bool is_master = p_node->is_network_master();
+	bool skip_rset = false;
+
+	if (p_peer_id == 0 || p_peer_id == node_id || (p_peer_id < 0 && p_peer_id != -node_id)) {
+		//check that send mode can use local call
+
+		bool set_local = false;
+
+		const Map<StringName, Node::RPCMode>::Element *E = p_node->get_node_rset_mode(p_property);
+		if (E) {
+
+			set_local = _should_call_native(E->get(), is_master, skip_rset);
+		}
+
+		if (set_local) {
+			bool valid;
+			p_node->set(p_property, p_value, &valid);
+
+			if (!valid) {
+				String error = "rset() aborted in local set, property not found:  - " + String(p_property);
+				ERR_PRINTS(error);
+				return;
+			}
+		} else if (p_node->get_script_instance()) {
+			//attempt with script
+			ScriptInstance::RPCMode rpc_mode = p_node->get_script_instance()->get_rset_mode(p_property);
+
+			set_local = _should_call_script(rpc_mode, is_master, skip_rset);
+
+			if (set_local) {
+
+				bool valid = p_node->get_script_instance()->set(p_property, p_value);
+
+				if (!valid) {
+					String error = "rset() aborted in local script set, property not found:  - " + String(p_property);
+					ERR_PRINTS(error);
+					return;
+				}
+			}
+		}
+	}
+
+	if (skip_rset)
+		return;
+
+	const Variant *vptr = &p_value;
+
+	_send_rpc(p_node, p_peer_id, p_unreliable, true, p_property, &vptr, 1);
+}
+
+int MultiplayerAPI::get_network_unique_id() const {
+
+	ERR_FAIL_COND_V(!network_peer.is_valid(), 0);
+	return network_peer->get_unique_id();
+}
+
+bool MultiplayerAPI::is_network_server() const {
+
+	ERR_FAIL_COND_V(!network_peer.is_valid(), false);
+	return network_peer->is_server();
+}
+
+void MultiplayerAPI::set_refuse_new_network_connections(bool p_refuse) {
+
+	ERR_FAIL_COND(!network_peer.is_valid());
+	network_peer->set_refuse_new_connections(p_refuse);
+}
+
+bool MultiplayerAPI::is_refusing_new_network_connections() const {
+
+	ERR_FAIL_COND_V(!network_peer.is_valid(), false);
+	return network_peer->is_refusing_new_connections();
+}
+
+Vector<int> MultiplayerAPI::get_network_connected_peers() const {
+
+	ERR_FAIL_COND_V(!network_peer.is_valid(), Vector<int>());
+
+	Vector<int> ret;
+	for (Set<int>::Element *E = connected_peers.front(); E; E = E->next()) {
+		ret.push_back(E->get());
+	}
+
+	return ret;
+}
+
+void MultiplayerAPI::_bind_methods() {
+	ClassDB::bind_method(D_METHOD("set_root_node", "node"), &MultiplayerAPI::set_root_node);
+	ClassDB::bind_method(D_METHOD("has_network_peer"), &MultiplayerAPI::has_network_peer);
+	ClassDB::bind_method(D_METHOD("get_network_peer"), &MultiplayerAPI::get_network_peer);
+	ClassDB::bind_method(D_METHOD("get_network_unique_id"), &MultiplayerAPI::get_network_unique_id);
+	ClassDB::bind_method(D_METHOD("is_network_server"), &MultiplayerAPI::is_network_server);
+	ClassDB::bind_method(D_METHOD("get_rpc_sender_id"), &MultiplayerAPI::get_rpc_sender_id);
+	ClassDB::bind_method(D_METHOD("add_peer", "id"), &MultiplayerAPI::add_peer);
+	ClassDB::bind_method(D_METHOD("del_peer", "id"), &MultiplayerAPI::del_peer);
+	ClassDB::bind_method(D_METHOD("set_network_peer", "peer"), &MultiplayerAPI::set_network_peer);
+	ClassDB::bind_method(D_METHOD("poll"), &MultiplayerAPI::poll);
+	ClassDB::bind_method(D_METHOD("clear"), &MultiplayerAPI::clear);
+
+	ClassDB::bind_method(D_METHOD("connected_to_server"), &MultiplayerAPI::connected_to_server);
+	ClassDB::bind_method(D_METHOD("connection_failed"), &MultiplayerAPI::connection_failed);
+	ClassDB::bind_method(D_METHOD("server_disconnected"), &MultiplayerAPI::server_disconnected);
+	ClassDB::bind_method(D_METHOD("get_network_connected_peers"), &MultiplayerAPI::get_network_connected_peers);
+	ClassDB::bind_method(D_METHOD("set_refuse_new_network_connections", "refuse"), &MultiplayerAPI::set_refuse_new_network_connections);
+	ClassDB::bind_method(D_METHOD("is_refusing_new_network_connections"), &MultiplayerAPI::is_refusing_new_network_connections);
+	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "refuse_new_network_connections"), "set_refuse_new_network_connections", "is_refusing_new_network_connections");
+	ADD_PROPERTY(PropertyInfo(Variant::OBJECT, "network_peer", PROPERTY_HINT_RESOURCE_TYPE, "NetworkedMultiplayerPeer", 0), "set_network_peer", "get_network_peer");
+
+	ADD_SIGNAL(MethodInfo("network_peer_connected", PropertyInfo(Variant::INT, "id")));
+	ADD_SIGNAL(MethodInfo("network_peer_disconnected", PropertyInfo(Variant::INT, "id")));
+	ADD_SIGNAL(MethodInfo("connected_to_server"));
+	ADD_SIGNAL(MethodInfo("connection_failed"));
+	ADD_SIGNAL(MethodInfo("server_disconnected"));
+}
+
+MultiplayerAPI::MultiplayerAPI() {
+	clear();
+}
+
+MultiplayerAPI::~MultiplayerAPI() {
+	clear();
+}
diff --git a/core/io/multiplayer_api.h b/core/io/multiplayer_api.h
new file mode 100644
index 0000000000..e7c6ffbea6
--- /dev/null
+++ b/core/io/multiplayer_api.h
@@ -0,0 +1,87 @@
+#ifndef MULTIPLAYER_PROTOCOL_H
+#define MULTIPLAYER_PROTOCOL_H
+
+#include "core/io/networked_multiplayer_peer.h"
+#include "core/reference.h"
+
+class MultiplayerAPI : public Reference {
+
+	GDCLASS(MultiplayerAPI, Reference);
+
+private:
+	//path sent caches
+	struct PathSentCache {
+		Map<int, bool> confirmed_peers;
+		int id;
+	};
+
+	//path get caches
+	struct PathGetCache {
+		struct NodeInfo {
+			NodePath path;
+			ObjectID instance;
+		};
+
+		Map<int, NodeInfo> nodes;
+	};
+
+	Ref<NetworkedMultiplayerPeer> network_peer;
+	int rpc_sender_id;
+	Set<int> connected_peers;
+	HashMap<NodePath, PathSentCache> path_send_cache;
+	Map<int, PathGetCache> path_get_cache;
+	int last_send_cache_id;
+	Vector<uint8_t> packet_cache;
+	Node *root_node;
+
+protected:
+	static void _bind_methods();
+
+	void _process_packet(int p_from, const uint8_t *p_packet, int p_packet_len);
+	void _process_simplify_path(int p_from, const uint8_t *p_packet, int p_packet_len);
+	void _process_confirm_path(int p_from, const uint8_t *p_packet, int p_packet_len);
+	Node *_process_get_node(int p_from, const uint8_t *p_packet, int p_packet_len);
+	void _process_rpc(Node *p_node, const StringName &p_name, int p_from, const uint8_t *p_packet, int p_packet_len, int p_offset);
+	void _process_rset(Node *p_node, const StringName &p_name, int p_from, const uint8_t *p_packet, int p_packet_len, int p_offset);
+
+	void _send_rpc(Node *p_from, int p_to, bool p_unreliable, bool p_set, const StringName &p_name, const Variant **p_arg, int p_argcount);
+	bool _send_confirm_path(NodePath p_path, PathSentCache *psc, int p_from);
+
+public:
+	enum NetworkCommands {
+		NETWORK_COMMAND_REMOTE_CALL,
+		NETWORK_COMMAND_REMOTE_SET,
+		NETWORK_COMMAND_SIMPLIFY_PATH,
+		NETWORK_COMMAND_CONFIRM_PATH,
+	};
+
+	void poll();
+	void clear();
+	void set_root_node(Node *p_node);
+	void set_network_peer(const Ref<NetworkedMultiplayerPeer> &p_peer);
+	Ref<NetworkedMultiplayerPeer> get_network_peer() const;
+
+	// Called by Node.rpc
+	void rpcp(Node *p_node, int p_peer_id, bool p_unreliable, const StringName &p_method, const Variant **p_arg, int p_argcount);
+	// Called by Node.rset
+	void rsetp(Node *p_node, int p_peer_id, bool p_unreliable, const StringName &p_property, const Variant &p_value);
+
+	void add_peer(int p_id);
+	void del_peer(int p_id);
+	void connected_to_server();
+	void connection_failed();
+	void server_disconnected();
+
+	bool has_network_peer() const { return network_peer.is_valid(); }
+	Vector<int> get_network_connected_peers() const;
+	int get_rpc_sender_id() const { return rpc_sender_id; }
+	int get_network_unique_id() const;
+	bool is_network_server() const;
+	void set_refuse_new_network_connections(bool p_refuse);
+	bool is_refusing_new_network_connections() const;
+
+	MultiplayerAPI();
+	~MultiplayerAPI();
+};
+
+#endif // MULTIPLAYER_PROTOCOL_H