Cppcheck report - Godot - branch: 3.x, commit: cd92ad0f69a842d94dc2d56f83cbd8f724ed2959 (2024-12-15): modules/webrtc/webrtc_multiplayer.cpp

/**************************************************************************/
/*  webrtc_multiplayer.cpp                                                */
/**************************************************************************/
/*                         This file is part of:                          */
/*                             GODOT ENGINE                               */
/*                        https://godotengine.org                         */
/**************************************************************************/
/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
/*                                                                        */
/* Permission is hereby granted, free of charge, to any person obtaining  */
/* a copy of this software and associated documentation files (the        */
/* "Software"), to deal in the Software without restriction, including    */
/* without limitation the rights to use, copy, modify, merge, publish,    */
/* distribute, sublicense, and/or sell copies of the Software, and to     */
/* permit persons to whom the Software is furnished to do so, subject to  */
/* the following conditions:                                              */
/*                                                                        */
/* The above copyright notice and this permission notice shall be         */
/* included in all copies or substantial portions of the Software.        */
/*                                                                        */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,        */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF     */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. */
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY   */
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,   */
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE      */
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                 */
/**************************************************************************/

#include "webrtc_multiplayer.h"

#include "core/io/marshalls.h"
#include "core/os/os.h"

void WebRTCMultiplayer::_bind_methods() {
	ClassDB::bind_method(D_METHOD("initialize", "peer_id", "server_compatibility"), &WebRTCMultiplayer::initialize, DEFVAL(false));
	ClassDB::bind_method(D_METHOD("add_peer", "peer", "peer_id", "unreliable_lifetime"), &WebRTCMultiplayer::add_peer, DEFVAL(1));
	ClassDB::bind_method(D_METHOD("remove_peer", "peer_id"), &WebRTCMultiplayer::remove_peer);
	ClassDB::bind_method(D_METHOD("has_peer", "peer_id"), &WebRTCMultiplayer::has_peer);
	ClassDB::bind_method(D_METHOD("get_peer", "peer_id"), &WebRTCMultiplayer::get_peer);
	ClassDB::bind_method(D_METHOD("get_peers"), &WebRTCMultiplayer::get_peers);
	ClassDB::bind_method(D_METHOD("close"), &WebRTCMultiplayer::close);
}

void WebRTCMultiplayer::set_transfer_mode(TransferMode p_mode) {
	transfer_mode = p_mode;
}

NetworkedMultiplayerPeer::TransferMode WebRTCMultiplayer::get_transfer_mode() const {
	return transfer_mode;
}

void WebRTCMultiplayer::set_target_peer(int p_peer_id) {
	target_peer = p_peer_id;
}

/* Returns the ID of the NetworkedMultiplayerPeer who sent the most recent packet: */
int WebRTCMultiplayer::get_packet_peer() const {
	return next_packet_peer;
}

bool WebRTCMultiplayer::is_server() const {
	return unique_id == TARGET_PEER_SERVER;
}

void WebRTCMultiplayer::poll() {
	if (peer_map.size() == 0) {
		return;
	}

	List<int> remove;
	List<int> add;
	for (Map<int, Ref<ConnectedPeer>>::Element *E = peer_map.front(); E; E = E->next()) {
		Ref<ConnectedPeer> peer = E->get();
		peer->connection->poll();
		// Check peer state
		switch (peer->connection->get_connection_state()) {
			case WebRTCPeerConnection::STATE_NEW:
			case WebRTCPeerConnection::STATE_CONNECTING:
				// Go to next peer, not ready yet.
				continue;
			case WebRTCPeerConnection::STATE_CONNECTED:
				// Good to go, go ahead and check channel state.
				break;
			default:
				// Peer is closed or in error state. Got to next peer.
				remove.push_back(E->key());
				continue;
		}
		// Check channels state
		int ready = 0;
		for (List<Ref<WebRTCDataChannel>>::Element *C = peer->channels.front(); C && C->get().is_valid(); C = C->next()) {
			Ref<WebRTCDataChannel> ch = C->get();
			switch (ch->get_ready_state()) {
				case WebRTCDataChannel::STATE_CONNECTING:
					continue;
				case WebRTCDataChannel::STATE_OPEN:
					ready++;
					continue;
				default:
					// Channel was closed or in error state, remove peer id.
					remove.push_back(E->key());
			}
			// We got a closed channel break out, the peer will be removed.
			break;
		}
		// This peer has newly connected, and all channels are now open.
		if (ready == peer->channels.size() && !peer->connected) {
			peer->connected = true;
			add.push_back(E->key());
		}
	}
	// Remove disconnected peers
	for (List<int>::Element *E = remove.front(); E; E = E->next()) {
		remove_peer(E->get());
		if (next_packet_peer == E->get()) {
			next_packet_peer = 0;
		}
	}
	// Signal newly connected peers
	for (List<int>::Element *E = add.front(); E; E = E->next()) {
		// Already connected to server: simply notify new peer.
		// NOTE: Mesh is always connected.
		if (connection_status == CONNECTION_CONNECTED) {
			emit_signal("peer_connected", E->get());
		}

		// Server emulation mode suppresses peer_conencted until server connects.
		if (server_compat && E->get() == TARGET_PEER_SERVER) {
			// Server connected.
			connection_status = CONNECTION_CONNECTED;
			emit_signal("peer_connected", TARGET_PEER_SERVER);
			emit_signal("connection_succeeded");
			// Notify of all previously connected peers
			for (Map<int, Ref<ConnectedPeer>>::Element *F = peer_map.front(); F; F = F->next()) {
				if (F->key() != 1 && F->get()->connected) {
					emit_signal("peer_connected", F->key());
				}
			}
			break; // Because we already notified of all newly added peers.
		}
	}
	// Fetch next packet
	if (next_packet_peer == 0) {
		_find_next_peer();
	}
}

void WebRTCMultiplayer::_find_next_peer() {
	Map<int, Ref<ConnectedPeer>>::Element *E = peer_map.find(next_packet_peer);
	if (E) {
		E = E->next();
	}
	// After last.
	while (E) {
		if (!E->get()->connected) {
			E = E->next();
			continue;
		}
		for (List<Ref<WebRTCDataChannel>>::Element *F = E->get()->channels.front(); F; F = F->next()) {
			if (F->get()->get_available_packet_count()) {
				next_packet_peer = E->key();
				return;
			}
		}
		E = E->next();
	}
	E = peer_map.front();
	// Before last
	while (E) {
		if (!E->get()->connected) {
			E = E->next();
			continue;
		}
		for (List<Ref<WebRTCDataChannel>>::Element *F = E->get()->channels.front(); F; F = F->next()) {
			if (F->get()->get_available_packet_count()) {
				next_packet_peer = E->key();
				return;
			}
		}
		if (E->key() == (int)next_packet_peer) {
			break;
		}
		E = E->next();
	}
	// No packet found
	next_packet_peer = 0;
}

void WebRTCMultiplayer::set_refuse_new_connections(bool p_enable) {
	refuse_connections = p_enable;
}

bool WebRTCMultiplayer::is_refusing_new_connections() const {
	return refuse_connections;
}

NetworkedMultiplayerPeer::ConnectionStatus WebRTCMultiplayer::get_connection_status() const {
	return connection_status;
}

Error WebRTCMultiplayer::initialize(int p_self_id, bool p_server_compat) {
	ERR_FAIL_COND_V(p_self_id < 0 || p_self_id > ~(1 << 31), ERR_INVALID_PARAMETER);<--- Integer overflow
	unique_id = p_self_id;
	server_compat = p_server_compat;

	// Mesh and server are always connected
	if (!server_compat || p_self_id == 1) {
		connection_status = CONNECTION_CONNECTED;
	} else {
		connection_status = CONNECTION_CONNECTING;
	}
	return OK;
}

int WebRTCMultiplayer::get_unique_id() const {
	ERR_FAIL_COND_V(connection_status == CONNECTION_DISCONNECTED, 1);
	return unique_id;
}

void WebRTCMultiplayer::_peer_to_dict(Ref<ConnectedPeer> p_connected_peer, Dictionary &r_dict) {
	Array channels;
	for (List<Ref<WebRTCDataChannel>>::Element *F = p_connected_peer->channels.front(); F; F = F->next()) {
		channels.push_back(F->get());
	}
	r_dict["connection"] = p_connected_peer->connection;
	r_dict["connected"] = p_connected_peer->connected;
	r_dict["channels"] = channels;
}

bool WebRTCMultiplayer::has_peer(int p_peer_id) {
	return peer_map.has(p_peer_id);
}

Dictionary WebRTCMultiplayer::get_peer(int p_peer_id) {
	ERR_FAIL_COND_V(!peer_map.has(p_peer_id), Dictionary());
	Dictionary out;
	_peer_to_dict(peer_map[p_peer_id], out);
	return out;
}

Dictionary WebRTCMultiplayer::get_peers() {
	Dictionary out;
	for (Map<int, Ref<ConnectedPeer>>::Element *E = peer_map.front(); E; E = E->next()) {
		Dictionary d;
		_peer_to_dict(E->get(), d);
		out[E->key()] = d;
	}
	return out;
}

Error WebRTCMultiplayer::add_peer(Ref<WebRTCPeerConnection> p_peer, int p_peer_id, int p_unreliable_lifetime) {
	ERR_FAIL_COND_V(p_peer_id < 0 || p_peer_id > ~(1 << 31), ERR_INVALID_PARAMETER);<--- Integer overflow
	ERR_FAIL_COND_V(p_unreliable_lifetime < 0, ERR_INVALID_PARAMETER);
	ERR_FAIL_COND_V(refuse_connections, ERR_UNAUTHORIZED);
	// Peer must be valid, and in new state (to create data channels)
	ERR_FAIL_COND_V(!p_peer.is_valid(), ERR_INVALID_PARAMETER);
	ERR_FAIL_COND_V(p_peer->get_connection_state() != WebRTCPeerConnection::STATE_NEW, ERR_INVALID_PARAMETER);

	Ref<ConnectedPeer> peer = memnew(ConnectedPeer);
	peer->connection = p_peer;

	// Initialize data channels
	Dictionary cfg;
	cfg["negotiated"] = true;
	cfg["ordered"] = true;

	cfg["id"] = 1;
	peer->channels[CH_RELIABLE] = p_peer->create_data_channel("reliable", cfg);
	ERR_FAIL_COND_V(!peer->channels[CH_RELIABLE].is_valid(), FAILED);

	cfg["id"] = 2;
	cfg["maxPacketLifetime"] = p_unreliable_lifetime;
	peer->channels[CH_ORDERED] = p_peer->create_data_channel("ordered", cfg);
	ERR_FAIL_COND_V(!peer->channels[CH_ORDERED].is_valid(), FAILED);

	cfg["id"] = 3;
	cfg["ordered"] = false;
	peer->channels[CH_UNRELIABLE] = p_peer->create_data_channel("unreliable", cfg);
	ERR_FAIL_COND_V(!peer->channels[CH_UNRELIABLE].is_valid(), FAILED);

	peer_map[p_peer_id] = peer; // add the new peer connection to the peer_map

	return OK;
}

void WebRTCMultiplayer::remove_peer(int p_peer_id) {
	ERR_FAIL_COND(!peer_map.has(p_peer_id));
	Ref<ConnectedPeer> peer = peer_map[p_peer_id];
	peer_map.erase(p_peer_id);
	if (peer->connected) {
		peer->connected = false;
		emit_signal("peer_disconnected", p_peer_id);
		if (server_compat && p_peer_id == TARGET_PEER_SERVER) {
			emit_signal("server_disconnected");
			connection_status = CONNECTION_DISCONNECTED;
		}
	}
}

Error WebRTCMultiplayer::get_packet(const uint8_t **r_buffer, int &r_buffer_size) {
	// Peer not available
	if (next_packet_peer == 0 || !peer_map.has(next_packet_peer)) {
		_find_next_peer();
		ERR_FAIL_V(ERR_UNAVAILABLE);
	}
	for (List<Ref<WebRTCDataChannel>>::Element *E = peer_map[next_packet_peer]->channels.front(); E; E = E->next()) {
		if (E->get()->get_available_packet_count()) {
			Error err = E->get()->get_packet(r_buffer, r_buffer_size);
			_find_next_peer();
			return err;
		}
	}
	// Channels for that peer were empty. Bug?
	_find_next_peer();
	ERR_FAIL_V(ERR_BUG);
}

Error WebRTCMultiplayer::put_packet(const uint8_t *p_buffer, int p_buffer_size) {
	ERR_FAIL_COND_V(connection_status == CONNECTION_DISCONNECTED, ERR_UNCONFIGURED);

	int ch = CH_RELIABLE;
	switch (transfer_mode) {
		case TRANSFER_MODE_RELIABLE:
			ch = CH_RELIABLE;
			break;
		case TRANSFER_MODE_UNRELIABLE_ORDERED:
			ch = CH_ORDERED;
			break;
		case TRANSFER_MODE_UNRELIABLE:
			ch = CH_UNRELIABLE;
			break;
	}

	Map<int, Ref<ConnectedPeer>>::Element *E = nullptr;

	if (target_peer > 0) {
		E = peer_map.find(target_peer);
		ERR_FAIL_COND_V_MSG(!E, ERR_INVALID_PARAMETER, "Invalid target peer: " + itos(target_peer) + ".");

		ERR_FAIL_COND_V(E->value()->channels.size() <= ch, ERR_BUG);
		ERR_FAIL_COND_V(!E->value()->channels[ch].is_valid(), ERR_BUG);
		return E->value()->channels[ch]->put_packet(p_buffer, p_buffer_size);

	} else {
		int exclude = -target_peer;

		for (Map<int, Ref<ConnectedPeer>>::Element *F = peer_map.front(); F; F = F->next()) {
			// Exclude packet. If target_peer == 0 then don't exclude any packets
			if (target_peer != 0 && F->key() == exclude) {
				continue;
			}

			ERR_CONTINUE(F->value()->channels.size() <= ch || !F->value()->channels[ch].is_valid());
			F->value()->channels[ch]->put_packet(p_buffer, p_buffer_size);
		}
	}
	return OK;
}

int WebRTCMultiplayer::get_available_packet_count() const {
	if (next_packet_peer == 0) {
		return 0; // To be sure next call to get_packet works if size > 0 .
	}
	int size = 0;
	for (Map<int, Ref<ConnectedPeer>>::Element *E = peer_map.front(); E; E = E->next()) {
		if (!E->get()->connected) {
			continue;
		}
		for (List<Ref<WebRTCDataChannel>>::Element *F = E->get()->channels.front(); F; F = F->next()) {
			size += F->get()->get_available_packet_count();
		}
	}
	return size;
}

int WebRTCMultiplayer::get_max_packet_size() const {
	return 1200;
}

void WebRTCMultiplayer::close() {
	peer_map.clear();
	unique_id = 0;
	next_packet_peer = 0;
	target_peer = 0;
	connection_status = CONNECTION_DISCONNECTED;
}

WebRTCMultiplayer::WebRTCMultiplayer() {<--- Member variable 'WebRTCMultiplayer::client_count' is not initialized in the constructor.
	unique_id = 0;
	next_packet_peer = 0;
	target_peer = 0;
	transfer_mode = TRANSFER_MODE_RELIABLE;
<--- Variable 'transfer_mode' is assigned in constructor body. Consider performing initialization in initialization list. [+]
When an object of a class is created, the constructors of all member variables are called consecutively in the order the variables are declared, even if you don't explicitly write them to the initialization list. You could avoid assigning 'transfer_mode' a value by passing the value to the constructor in the initialization list.
	refuse_connections = false;
	connection_status = CONNECTION_DISCONNECTED;
<--- Variable 'connection_status' is assigned in constructor body. Consider performing initialization in initialization list. [+]
When an object of a class is created, the constructors of all member variables are called consecutively in the order the variables are declared, even if you don't explicitly write them to the initialization list. You could avoid assigning 'connection_status' a value by passing the value to the constructor in the initialization list.
	server_compat = false;
}

WebRTCMultiplayer::~WebRTCMultiplayer() {
	close();
}