initial commit, 4.5 stable

drivers/windows/net_socket_winsock.cpp

@@ -0,0 +1,613 @@
+/**************************************************************************/
+/*  net_socket_winsock.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.                 */
+/**************************************************************************/
+
+#ifdef WINDOWS_ENABLED
+
+#include "net_socket_winsock.h"
+
+#include <winsock2.h>
+#include <ws2tcpip.h>
+
+#include <mswsock.h>
+// Workaround missing flag in MinGW
+#if defined(__MINGW32__) && !defined(SIO_UDP_NETRESET)
+#define SIO_UDP_NETRESET _WSAIOW(IOC_VENDOR, 15)
+#endif
+
+size_t NetSocketWinSock::_set_addr_storage(struct sockaddr_storage *p_addr, const IPAddress &p_ip, uint16_t p_port, IP::Type p_ip_type) {
+	memset(p_addr, 0, sizeof(struct sockaddr_storage));
+	if (p_ip_type == IP::TYPE_IPV6 || p_ip_type == IP::TYPE_ANY) { // IPv6 socket.
+
+		// IPv6 only socket with IPv4 address.
+		ERR_FAIL_COND_V(!p_ip.is_wildcard() && p_ip_type == IP::TYPE_IPV6 && p_ip.is_ipv4(), 0);
+
+		struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)p_addr;
+		addr6->sin6_family = AF_INET6;
+		addr6->sin6_port = htons(p_port);
+		if (p_ip.is_valid()) {
+			memcpy(&addr6->sin6_addr.s6_addr, p_ip.get_ipv6(), 16);
+		} else {
+			addr6->sin6_addr = in6addr_any;
+		}
+		return sizeof(sockaddr_in6);
+	} else { // IPv4 socket.
+
+		// IPv4 socket with IPv6 address.
+		ERR_FAIL_COND_V(!p_ip.is_wildcard() && !p_ip.is_ipv4(), 0);
+
+		struct sockaddr_in *addr4 = (struct sockaddr_in *)p_addr;
+		addr4->sin_family = AF_INET;
+		addr4->sin_port = htons(p_port); // Short, network byte order.
+
+		if (p_ip.is_valid()) {
+			memcpy(&addr4->sin_addr.s_addr, p_ip.get_ipv4(), 4);
+		} else {
+			addr4->sin_addr.s_addr = INADDR_ANY;
+		}
+
+		return sizeof(sockaddr_in);
+	}
+}
+
+void NetSocketWinSock::_set_ip_port(struct sockaddr_storage *p_addr, IPAddress *r_ip, uint16_t *r_port) {
+	if (p_addr->ss_family == AF_INET) {
+		struct sockaddr_in *addr4 = (struct sockaddr_in *)p_addr;
+		if (r_ip) {
+			r_ip->set_ipv4((uint8_t *)&(addr4->sin_addr.s_addr));
+		}
+		if (r_port) {
+			*r_port = ntohs(addr4->sin_port);
+		}
+	} else if (p_addr->ss_family == AF_INET6) {
+		struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)p_addr;
+		if (r_ip) {
+			r_ip->set_ipv6(addr6->sin6_addr.s6_addr);
+		}
+		if (r_port) {
+			*r_port = ntohs(addr6->sin6_port);
+		}
+	}
+}
+
+NetSocket *NetSocketWinSock::_create_func() {
+	return memnew(NetSocketWinSock);
+}
+
+void NetSocketWinSock::make_default() {
+	ERR_FAIL_COND(_create != nullptr);
+
+	WSADATA data;
+	WSAStartup(MAKEWORD(2, 2), &data);
+	_create = _create_func;
+}
+
+void NetSocketWinSock::cleanup() {
+	ERR_FAIL_COND(_create == nullptr);
+
+	WSACleanup();
+	_create = nullptr;
+}
+
+NetSocketWinSock::NetSocketWinSock() {
+}
+
+NetSocketWinSock::~NetSocketWinSock() {
+	close();
+}
+
+NetSocketWinSock::NetError NetSocketWinSock::_get_socket_error() const {
+	int err = WSAGetLastError();
+	if (err == WSAEISCONN) {
+		return ERR_NET_IS_CONNECTED;
+	}
+	if (err == WSAEINPROGRESS || err == WSAEALREADY) {
+		return ERR_NET_IN_PROGRESS;
+	}
+	if (err == WSAEWOULDBLOCK) {
+		return ERR_NET_WOULD_BLOCK;
+	}
+	if (err == WSAEADDRINUSE || err == WSAEADDRNOTAVAIL) {
+		return ERR_NET_ADDRESS_INVALID_OR_UNAVAILABLE;
+	}
+	if (err == WSAEACCES) {
+		return ERR_NET_UNAUTHORIZED;
+	}
+	if (err == WSAEMSGSIZE || err == WSAENOBUFS) {
+		return ERR_NET_BUFFER_TOO_SMALL;
+	}
+	print_verbose("Socket error: " + itos(err) + ".");
+	return ERR_NET_OTHER;
+}
+
+bool NetSocketWinSock::_can_use_ip(const IPAddress &p_ip, const bool p_for_bind) const {
+	if (p_for_bind && !(p_ip.is_valid() || p_ip.is_wildcard())) {
+		return false;
+	} else if (!p_for_bind && !p_ip.is_valid()) {
+		return false;
+	}
+	// Check if socket support this IP type.
+	IP::Type type = p_ip.is_ipv4() ? IP::TYPE_IPV4 : IP::TYPE_IPV6;
+	return !(_ip_type != IP::TYPE_ANY && !p_ip.is_wildcard() && _ip_type != type);
+}
+
+_FORCE_INLINE_ Error NetSocketWinSock::_change_multicast_group(IPAddress p_ip, String p_if_name, bool p_add) {
+	ERR_FAIL_COND_V(!is_open(), ERR_UNCONFIGURED);
+	ERR_FAIL_COND_V(!_can_use_ip(p_ip, false), ERR_INVALID_PARAMETER);
+
+	// Need to force level and af_family to IP(v4) when using dual stacking and provided multicast group is IPv4.
+	IP::Type type = _ip_type == IP::TYPE_ANY && p_ip.is_ipv4() ? IP::TYPE_IPV4 : _ip_type;
+	// This needs to be the proper level for the multicast group, no matter if the socket is dual stacking.
+	int level = type == IP::TYPE_IPV4 ? IPPROTO_IP : IPPROTO_IPV6;
+	int ret = -1;
+
+	IPAddress if_ip;
+	uint32_t if_v6id = 0;
+	HashMap<String, IP::Interface_Info> if_info;
+	IP::get_singleton()->get_local_interfaces(&if_info);
+	for (KeyValue<String, IP::Interface_Info> &E : if_info) {
+		IP::Interface_Info &c = E.value;
+		if (c.name != p_if_name) {
+			continue;
+		}
+
+		if_v6id = (uint32_t)c.index.to_int();
+		if (type == IP::TYPE_IPV6) {
+			break; // IPv6 uses index.
+		}
+
+		for (const IPAddress &F : c.ip_addresses) {
+			if (!F.is_ipv4()) {
+				continue; // Wrong IP type.
+			}
+			if_ip = F;
+			break;
+		}
+		break;
+	}
+
+	if (level == IPPROTO_IP) {
+		ERR_FAIL_COND_V(!if_ip.is_valid(), ERR_INVALID_PARAMETER);
+		struct ip_mreq greq;
+		int sock_opt = p_add ? IP_ADD_MEMBERSHIP : IP_DROP_MEMBERSHIP;
+		memcpy(&greq.imr_multiaddr, p_ip.get_ipv4(), 4);
+		memcpy(&greq.imr_interface, if_ip.get_ipv4(), 4);
+		ret = setsockopt(_sock, level, sock_opt, (const char *)&greq, sizeof(greq));
+	} else {
+		struct ipv6_mreq greq;
+		int sock_opt = p_add ? IPV6_ADD_MEMBERSHIP : IPV6_DROP_MEMBERSHIP;
+		memcpy(&greq.ipv6mr_multiaddr, p_ip.get_ipv6(), 16);
+		greq.ipv6mr_interface = if_v6id;
+		ret = setsockopt(_sock, level, sock_opt, (const char *)&greq, sizeof(greq));
+	}
+	ERR_FAIL_COND_V(ret != 0, FAILED);
+
+	return OK;
+}
+
+void NetSocketWinSock::_set_socket(SOCKET p_sock, IP::Type p_ip_type, bool p_is_stream) {
+	_sock = p_sock;
+	_ip_type = p_ip_type;
+	_is_stream = p_is_stream;
+}
+
+Error NetSocketWinSock::open(Type p_sock_type, IP::Type &ip_type) {
+	ERR_FAIL_COND_V(is_open(), ERR_ALREADY_IN_USE);
+	ERR_FAIL_COND_V(ip_type > IP::TYPE_ANY || ip_type < IP::TYPE_NONE, ERR_INVALID_PARAMETER);
+
+	int family = ip_type == IP::TYPE_IPV4 ? AF_INET : AF_INET6;
+	int protocol = p_sock_type == TYPE_TCP ? IPPROTO_TCP : IPPROTO_UDP;
+	int type = p_sock_type == TYPE_TCP ? SOCK_STREAM : SOCK_DGRAM;
+	_sock = socket(family, type, protocol);
+
+	if (_sock == INVALID_SOCKET && ip_type == IP::TYPE_ANY) {
+		// Careful here, changing the referenced parameter so the caller knows that we are using an IPv4 socket
+		// in place of a dual stack one, and further calls to _set_sock_addr will work as expected.
+		ip_type = IP::TYPE_IPV4;
+		family = AF_INET;
+		_sock = socket(family, type, protocol);
+	}
+
+	ERR_FAIL_COND_V(_sock == INVALID_SOCKET, FAILED);
+	_ip_type = ip_type;
+
+	if (family == AF_INET6) {
+		// Select IPv4 over IPv6 mapping.
+		set_ipv6_only_enabled(ip_type != IP::TYPE_ANY);
+	}
+
+	if (protocol == IPPROTO_UDP) {
+		// Make sure to disable broadcasting for UDP sockets.
+		// Depending on the OS, this option might or might not be enabled by default. Let's normalize it.
+		set_broadcasting_enabled(false);
+	}
+
+	_is_stream = p_sock_type == TYPE_TCP;
+
+	if (!_is_stream) {
+		// Disable windows feature/bug reporting WSAECONNRESET/WSAENETRESET when
+		// recv/recvfrom and an ICMP reply was received from a previous send/sendto.
+		unsigned long disable = 0;
+		if (ioctlsocket(_sock, SIO_UDP_CONNRESET, &disable) == SOCKET_ERROR) {
+			print_verbose("Unable to turn off UDP WSAECONNRESET behavior on Windows.");
+		}
+		if (ioctlsocket(_sock, SIO_UDP_NETRESET, &disable) == SOCKET_ERROR) {
+			// This feature seems not to be supported on wine.
+			print_verbose("Unable to turn off UDP WSAENETRESET behavior on Windows.");
+		}
+	}
+	return OK;
+}
+
+void NetSocketWinSock::close() {
+	if (_sock != INVALID_SOCKET) {
+		closesocket(_sock);
+	}
+
+	_sock = INVALID_SOCKET;
+	_ip_type = IP::TYPE_NONE;
+	_is_stream = false;
+}
+
+Error NetSocketWinSock::bind(IPAddress p_addr, uint16_t p_port) {
+	ERR_FAIL_COND_V(!is_open(), ERR_UNCONFIGURED);
+	ERR_FAIL_COND_V(!_can_use_ip(p_addr, true), ERR_INVALID_PARAMETER);
+
+	sockaddr_storage addr;
+	size_t addr_size = _set_addr_storage(&addr, p_addr, p_port, _ip_type);
+
+	if (::bind(_sock, (struct sockaddr *)&addr, addr_size) != 0) {
+		NetError err = _get_socket_error();
+		print_verbose("Failed to bind socket. Error: " + itos(err) + ".");
+		close();
+		return ERR_UNAVAILABLE;
+	}
+
+	return OK;
+}
+
+Error NetSocketWinSock::listen(int p_max_pending) {
+	ERR_FAIL_COND_V(!is_open(), ERR_UNCONFIGURED);
+
+	if (::listen(_sock, p_max_pending) != 0) {
+		_get_socket_error();
+		print_verbose("Failed to listen from socket.");
+		close();
+		return FAILED;
+	}
+
+	return OK;
+}
+
+Error NetSocketWinSock::connect_to_host(IPAddress p_host, uint16_t p_port) {
+	ERR_FAIL_COND_V(!is_open(), ERR_UNCONFIGURED);
+	ERR_FAIL_COND_V(!_can_use_ip(p_host, false), ERR_INVALID_PARAMETER);
+
+	struct sockaddr_storage addr;
+	size_t addr_size = _set_addr_storage(&addr, p_host, p_port, _ip_type);
+
+	if (::WSAConnect(_sock, (struct sockaddr *)&addr, addr_size, nullptr, nullptr, nullptr, nullptr) != 0) {
+		NetError err = _get_socket_error();
+
+		switch (err) {
+			// We are already connected.
+			case ERR_NET_IS_CONNECTED:
+				return OK;
+			// Still waiting to connect, try again in a while.
+			case ERR_NET_WOULD_BLOCK:
+			case ERR_NET_IN_PROGRESS:
+				return ERR_BUSY;
+			default:
+				print_verbose("Connection to remote host failed.");
+				close();
+				return FAILED;
+		}
+	}
+
+	return OK;
+}
+
+Error NetSocketWinSock::poll(PollType p_type, int p_timeout) const {
+	ERR_FAIL_COND_V(!is_open(), ERR_UNCONFIGURED);
+
+	bool ready = false;
+	fd_set rd, wr, ex;
+	fd_set *rdp = nullptr;
+	fd_set *wrp = nullptr;
+	FD_ZERO(&rd);
+	FD_ZERO(&wr);
+	FD_ZERO(&ex);
+	FD_SET(_sock, &ex);
+	struct timeval timeout = { p_timeout / 1000, (p_timeout % 1000) * 1000 };
+	// For blocking operation, pass nullptr timeout pointer to select.
+	struct timeval *tp = nullptr;
+	if (p_timeout >= 0) {
+		// If timeout is non-negative, we want to specify the timeout instead.
+		tp = &timeout;
+	}
+
+	switch (p_type) {
+		case POLL_TYPE_IN:
+			FD_SET(_sock, &rd);
+			rdp = &rd;
+			break;
+		case POLL_TYPE_OUT:
+			FD_SET(_sock, &wr);
+			wrp = &wr;
+			break;
+		case POLL_TYPE_IN_OUT:
+			FD_SET(_sock, &rd);
+			FD_SET(_sock, &wr);
+			rdp = &rd;
+			wrp = &wr;
+	}
+	// WSAPoll is broken: https://daniel.haxx.se/blog/2012/10/10/wsapoll-is-broken/.
+	int ret = select(1, rdp, wrp, &ex, tp);
+
+	if (ret == SOCKET_ERROR) {
+		return FAILED;
+	}
+
+	if (ret == 0) {
+		return ERR_BUSY;
+	}
+
+	if (FD_ISSET(_sock, &ex)) {
+		_get_socket_error();
+		print_verbose("Exception when polling socket.");
+		return FAILED;
+	}
+
+	if (rdp && FD_ISSET(_sock, rdp)) {
+		ready = true;
+	}
+	if (wrp && FD_ISSET(_sock, wrp)) {
+		ready = true;
+	}
+
+	return ready ? OK : ERR_BUSY;
+}
+
+Error NetSocketWinSock::recv(uint8_t *p_buffer, int p_len, int &r_read) {
+	ERR_FAIL_COND_V(!is_open(), ERR_UNCONFIGURED);
+
+	r_read = ::recv(_sock, (char *)p_buffer, p_len, 0);
+
+	if (r_read < 0) {
+		NetError err = _get_socket_error();
+		if (err == ERR_NET_WOULD_BLOCK) {
+			return ERR_BUSY;
+		}
+
+		if (err == ERR_NET_BUFFER_TOO_SMALL) {
+			return ERR_OUT_OF_MEMORY;
+		}
+
+		return FAILED;
+	}
+
+	return OK;
+}
+
+Error NetSocketWinSock::recvfrom(uint8_t *p_buffer, int p_len, int &r_read, IPAddress &r_ip, uint16_t &r_port, bool p_peek) {
+	ERR_FAIL_COND_V(!is_open(), ERR_UNCONFIGURED);
+
+	struct sockaddr_storage from;
+	socklen_t len = sizeof(struct sockaddr_storage);
+	memset(&from, 0, len);
+
+	r_read = ::recvfrom(_sock, (char *)p_buffer, p_len, p_peek ? MSG_PEEK : 0, (struct sockaddr *)&from, &len);
+
+	if (r_read < 0) {
+		NetError err = _get_socket_error();
+		if (err == ERR_NET_WOULD_BLOCK) {
+			return ERR_BUSY;
+		}
+
+		if (err == ERR_NET_BUFFER_TOO_SMALL) {
+			return ERR_OUT_OF_MEMORY;
+		}
+
+		return FAILED;
+	}
+
+	if (from.ss_family == AF_INET) {
+		struct sockaddr_in *sin_from = (struct sockaddr_in *)&from;
+		r_ip.set_ipv4((uint8_t *)&sin_from->sin_addr);
+		r_port = ntohs(sin_from->sin_port);
+	} else if (from.ss_family == AF_INET6) {
+		struct sockaddr_in6 *s6_from = (struct sockaddr_in6 *)&from;
+		r_ip.set_ipv6((uint8_t *)&s6_from->sin6_addr);
+		r_port = ntohs(s6_from->sin6_port);
+	} else {
+		// Unsupported socket family, should never happen.
+		ERR_FAIL_V(FAILED);
+	}
+
+	return OK;
+}
+
+Error NetSocketWinSock::send(const uint8_t *p_buffer, int p_len, int &r_sent) {
+	ERR_FAIL_COND_V(!is_open(), ERR_UNCONFIGURED);
+
+	int flags = 0;
+	r_sent = ::send(_sock, (const char *)p_buffer, p_len, flags);
+
+	if (r_sent < 0) {
+		NetError err = _get_socket_error();
+		if (err == ERR_NET_WOULD_BLOCK) {
+			return ERR_BUSY;
+		}
+		if (err == ERR_NET_BUFFER_TOO_SMALL) {
+			return ERR_OUT_OF_MEMORY;
+		}
+
+		return FAILED;
+	}
+
+	return OK;
+}
+
+Error NetSocketWinSock::sendto(const uint8_t *p_buffer, int p_len, int &r_sent, IPAddress p_ip, uint16_t p_port) {
+	ERR_FAIL_COND_V(!is_open(), ERR_UNCONFIGURED);
+
+	struct sockaddr_storage addr;
+	size_t addr_size = _set_addr_storage(&addr, p_ip, p_port, _ip_type);
+	r_sent = ::sendto(_sock, (const char *)p_buffer, p_len, 0, (struct sockaddr *)&addr, addr_size);
+
+	if (r_sent < 0) {
+		NetError err = _get_socket_error();
+		if (err == ERR_NET_WOULD_BLOCK) {
+			return ERR_BUSY;
+		}
+		if (err == ERR_NET_BUFFER_TOO_SMALL) {
+			return ERR_OUT_OF_MEMORY;
+		}
+
+		return FAILED;
+	}
+
+	return OK;
+}
+
+Error NetSocketWinSock::set_broadcasting_enabled(bool p_enabled) {
+	ERR_FAIL_COND_V(!is_open(), ERR_UNCONFIGURED);
+	// IPv6 has no broadcast support.
+	if (_ip_type == IP::TYPE_IPV6) {
+		return ERR_UNAVAILABLE;
+	}
+
+	int par = p_enabled ? 1 : 0;
+	if (setsockopt(_sock, SOL_SOCKET, SO_BROADCAST, (const char *)&par, sizeof(int)) != 0) {
+		WARN_PRINT("Unable to change broadcast setting.");
+		return FAILED;
+	}
+	return OK;
+}
+
+void NetSocketWinSock::set_blocking_enabled(bool p_enabled) {
+	ERR_FAIL_COND(!is_open());
+
+	int ret = 0;
+	unsigned long par = p_enabled ? 0 : 1;
+	ret = ioctlsocket(_sock, FIONBIO, &par);
+	if (ret != 0) {
+		WARN_PRINT("Unable to change non-block mode.");
+	}
+}
+
+void NetSocketWinSock::set_ipv6_only_enabled(bool p_enabled) {
+	ERR_FAIL_COND(!is_open());
+	// This option is only available in IPv6 sockets.
+	ERR_FAIL_COND(_ip_type == IP::TYPE_IPV4);
+
+	int par = p_enabled ? 1 : 0;
+	if (setsockopt(_sock, IPPROTO_IPV6, IPV6_V6ONLY, (const char *)&par, sizeof(int)) != 0) {
+		WARN_PRINT("Unable to change IPv4 address mapping over IPv6 option.");
+	}
+}
+
+void NetSocketWinSock::set_tcp_no_delay_enabled(bool p_enabled) {
+	ERR_FAIL_COND(!is_open());
+	ERR_FAIL_COND(!_is_stream); // Not TCP.
+
+	int par = p_enabled ? 1 : 0;
+	if (setsockopt(_sock, IPPROTO_TCP, TCP_NODELAY, (const char *)&par, sizeof(int)) < 0) {
+		WARN_PRINT("Unable to set TCP no delay option.");
+	}
+}
+
+void NetSocketWinSock::set_reuse_address_enabled(bool p_enabled) {
+	ERR_FAIL_COND(!is_open());
+
+	// On Windows, enabling SO_REUSEADDR actually would also enable reuse port, very bad on TCP. Denying...
+	// Windows does not have this option, SO_REUSEADDR in this magical world means SO_REUSEPORT
+}
+
+bool NetSocketWinSock::is_open() const {
+	return _sock != INVALID_SOCKET;
+}
+
+int NetSocketWinSock::get_available_bytes() const {
+	ERR_FAIL_COND_V(!is_open(), -1);
+
+	unsigned long len;
+	int ret = ioctlsocket(_sock, FIONREAD, &len);
+	if (ret == -1) {
+		_get_socket_error();
+		print_verbose("Error when checking available bytes on socket.");
+		return -1;
+	}
+	return len;
+}
+
+Error NetSocketWinSock::get_socket_address(IPAddress *r_ip, uint16_t *r_port) const {
+	ERR_FAIL_COND_V(!is_open(), FAILED);
+
+	struct sockaddr_storage saddr;
+	socklen_t len = sizeof(saddr);
+	if (getsockname(_sock, (struct sockaddr *)&saddr, &len) != 0) {
+		_get_socket_error();
+		print_verbose("Error when reading local socket address.");
+		return FAILED;
+	}
+	_set_ip_port(&saddr, r_ip, r_port);
+	return OK;
+}
+
+Ref<NetSocket> NetSocketWinSock::accept(IPAddress &r_ip, uint16_t &r_port) {
+	Ref<NetSocket> out;
+	ERR_FAIL_COND_V(!is_open(), out);
+
+	struct sockaddr_storage their_addr;
+	socklen_t size = sizeof(their_addr);
+	SOCKET fd = ::accept(_sock, (struct sockaddr *)&their_addr, &size);
+	if (fd == INVALID_SOCKET) {
+		_get_socket_error();
+		print_verbose("Error when accepting socket connection.");
+		return out;
+	}
+
+	_set_ip_port(&their_addr, &r_ip, &r_port);
+
+	NetSocketWinSock *ns = memnew(NetSocketWinSock);
+	ns->_set_socket(fd, _ip_type, _is_stream);
+	ns->set_blocking_enabled(false);
+	return Ref<NetSocket>(ns);
+}
+
+Error NetSocketWinSock::join_multicast_group(const IPAddress &p_multi_address, const String &p_if_name) {
+	return _change_multicast_group(p_multi_address, p_if_name, true);
+}
+
+Error NetSocketWinSock::leave_multicast_group(const IPAddress &p_multi_address, const String &p_if_name) {
+	return _change_multicast_group(p_multi_address, p_if_name, false);
+}
+
+#endif // WINDOWS_ENABLED