Feature: play easier together with friends from behind home routers

src/console_cmds.cpp

@@ -702,6 +702,7 @@ DEF_CONSOLE_CMD(ConServerInfo)
 		return true;
 	}
 
+	IConsolePrint(CC_DEFAULT, "Invite code: {}", _network_game_info.join_key);
 	IConsolePrint(CC_DEFAULT, "Current/maximum clients:    {:3d}/{:3d}", _network_game_info.clients_on, _settings_client.network.max_clients);
 	IConsolePrint(CC_DEFAULT, "Current/maximum companies:  {:3d}/{:3d}", Company::GetNumItems(), _settings_client.network.max_companies);
 	IConsolePrint(CC_DEFAULT, "Current/maximum spectators: {:3d}/{:3d}", NetworkSpectatorCount(), _settings_client.network.max_spectators);
@@ -2419,7 +2420,6 @@ void IConsoleStdLibRegister()
 	IConsole::AliasRegister("name",                  "setting client_name %+");
 	IConsole::AliasRegister("server_name",           "setting server_name %+");
 	IConsole::AliasRegister("server_port",           "setting server_port %+");
-	IConsole::AliasRegister("server_advertise",      "setting server_advertise %+");
 	IConsole::AliasRegister("max_clients",           "setting max_clients %+");
 	IConsole::AliasRegister("max_companies",         "setting max_companies %+");
 	IConsole::AliasRegister("max_spectators",        "setting max_spectators %+");

src/lang/english.txt

@@ -1995,8 +1995,11 @@ STR_FACE_TIE                                                    :Tie:
 STR_FACE_EARRING                                                :Earring:
 STR_FACE_TIE_EARRING_TOOLTIP                                    :{BLACK}Change tie or earring
 
-STR_NETWORK_SERVER_VISIBILITY_PRIVATE                           :Private
+############ Next lines match ServerGameType
+STR_NETWORK_SERVER_VISIBILITY_LOCAL                             :Local
 STR_NETWORK_SERVER_VISIBILITY_PUBLIC                            :Public
+STR_NETWORK_SERVER_VISIBILITY_INVITE_ONLY                       :Invite only
+############ End of leave-in-this-order
 
 # Network server list
 STR_NETWORK_SERVER_LIST_CAPTION                                 :{WHITE}Multiplayer
@@ -2030,6 +2033,7 @@ STR_NETWORK_SERVER_LIST_SERVER_VERSION                          :{SILVER}Server
 STR_NETWORK_SERVER_LIST_SERVER_ADDRESS                          :{SILVER}Server address: {WHITE}{RAW_STRING}
 STR_NETWORK_SERVER_LIST_START_DATE                              :{SILVER}Start date: {WHITE}{DATE_SHORT}
 STR_NETWORK_SERVER_LIST_CURRENT_DATE                            :{SILVER}Current date: {WHITE}{DATE_SHORT}
+STR_NETWORK_SERVER_LIST_GAMESCRIPT                              :{SILVER}Gamescript: {WHITE}{RAW_STRING} (v{NUM})
 STR_NETWORK_SERVER_LIST_PASSWORD                                :{SILVER}Password protected!
 STR_NETWORK_SERVER_LIST_SERVER_OFFLINE                          :{SILVER}SERVER OFFLINE
 STR_NETWORK_SERVER_LIST_SERVER_FULL                             :{SILVER}SERVER FULL
@@ -2045,12 +2049,12 @@ STR_NETWORK_SERVER_LIST_SEARCH_SERVER_INTERNET_TOOLTIP          :{BLACK}Search i
 STR_NETWORK_SERVER_LIST_SEARCH_SERVER_LAN                       :{BLACK}Search LAN
 STR_NETWORK_SERVER_LIST_SEARCH_SERVER_LAN_TOOLTIP               :{BLACK}Search local area network for servers
 STR_NETWORK_SERVER_LIST_ADD_SERVER                              :{BLACK}Add server
-STR_NETWORK_SERVER_LIST_ADD_SERVER_TOOLTIP                      :{BLACK}Adds a server to the list which will always be checked for running games
+STR_NETWORK_SERVER_LIST_ADD_SERVER_TOOLTIP                      :{BLACK}Adds a server to the list. This can either be a server address or an invite-code
 STR_NETWORK_SERVER_LIST_START_SERVER                            :{BLACK}Start server
 STR_NETWORK_SERVER_LIST_START_SERVER_TOOLTIP                    :{BLACK}Start your own server
 
 STR_NETWORK_SERVER_LIST_PLAYER_NAME_OSKTITLE                    :{BLACK}Enter your name
-STR_NETWORK_SERVER_LIST_ENTER_IP                                :{BLACK}Enter the address of the host
+STR_NETWORK_SERVER_LIST_ENTER_SERVER_ADDRESS                    :{BLACK}Enter server address or invite-code
 
 # Start new multiplayer server
 STR_NETWORK_START_SERVER_CAPTION                                :{WHITE}Start new multiplayer game
@@ -2136,6 +2140,10 @@ STR_NETWORK_CLIENT_LIST_SERVER_NAME_EDIT_TOOLTIP                :{BLACK}Edit the
 STR_NETWORK_CLIENT_LIST_SERVER_NAME_QUERY_CAPTION               :Name of the server
 STR_NETWORK_CLIENT_LIST_SERVER_VISIBILITY                       :{BLACK}Visibility
 STR_NETWORK_CLIENT_LIST_SERVER_VISIBILITY_TOOLTIP               :{BLACK}Whether other people can see your server in the public listing
+STR_NETWORK_CLIENT_LIST_SERVER_JOIN_KEY                         :{BLACK}Invite code
+STR_NETWORK_CLIENT_LIST_SERVER_JOIN_KEY_TOOLTIP                 :{BLACK}Invite code other players can use to join this server
+STR_NETWORK_CLIENT_LIST_SERVER_CONNECTION_TYPE                  :{BLACK}Connection type
+STR_NETWORK_CLIENT_LIST_SERVER_CONNECTION_TYPE_TOOLTIP          :{BLACK}Whether and how your server can be reached by others
 STR_NETWORK_CLIENT_LIST_PLAYER                                  :{BLACK}Player
 STR_NETWORK_CLIENT_LIST_PLAYER_NAME                             :{BLACK}Name
 STR_NETWORK_CLIENT_LIST_PLAYER_NAME_TOOLTIP                     :{BLACK}Your player name
@@ -2154,6 +2162,14 @@ STR_NETWORK_CLIENT_LIST_PLAYER_ICON_SELF_TOOLTIP                :{BLACK}This is
 STR_NETWORK_CLIENT_LIST_PLAYER_ICON_HOST_TOOLTIP                :{BLACK}This is the host of the game
 STR_NETWORK_CLIENT_LIST_CLIENT_COMPANY_COUNT                    :{BLACK}{NUM} client{P "" s} / {NUM} compan{P y ies}
 
+############ Begin of ConnectionType
+STR_NETWORK_CLIENT_LIST_SERVER_CONNECTION_TYPE_UNKNOWN          :{BLACK}Local
+STR_NETWORK_CLIENT_LIST_SERVER_CONNECTION_TYPE_ISOLATED         :{RED}Remote players can't connect
+STR_NETWORK_CLIENT_LIST_SERVER_CONNECTION_TYPE_DIRECT           :{BLACK}Public
+STR_NETWORK_CLIENT_LIST_SERVER_CONNECTION_TYPE_STUN             :{BLACK}Behind NAT
+STR_NETWORK_CLIENT_LIST_SERVER_CONNECTION_TYPE_TURN             :{BLACK}Via relay
+############ End of ConnectionType
+
 STR_NETWORK_CLIENT_LIST_ADMIN_CLIENT_KICK                       :Kick
 STR_NETWORK_CLIENT_LIST_ADMIN_CLIENT_BAN                        :Ban
 STR_NETWORK_CLIENT_LIST_ADMIN_COMPANY_RESET                     :Delete
@@ -2281,6 +2297,10 @@ STR_NETWORK_MESSAGE_SERVER_SHUTDOWN                             :{WHITE}The serv
 STR_NETWORK_MESSAGE_SERVER_REBOOT                               :{WHITE}The server is restarting...{}Please wait...
 STR_NETWORK_MESSAGE_KICKED                                      :*** {RAW_STRING} was kicked. Reason: ({RAW_STRING})
 
+STR_NETWORK_ERROR_COORDINATOR_REGISTRATION_FAILED               :{WHITE}Server registration failed
+STR_NETWORK_ERROR_COORDINATOR_ISOLATED                          :{WHITE}Your server doesn't allow remote connections
+STR_NETWORK_ERROR_COORDINATOR_ISOLATED_DETAIL                   :{WHITE}Other players won't be able to connect to your server
+
 # Content downloading window
 STR_CONTENT_TITLE                                               :{WHITE}Content downloading
 STR_CONTENT_TYPE_CAPTION                                        :{BLACK}Type

src/network/CMakeLists.txt

@@ -14,6 +14,8 @@ add_files(
     network_content.h
     network_content_gui.cpp
     network_content_gui.h
+    network_coordinator.cpp
+    network_coordinator.h
     network_func.h
     network_gamelist.cpp
     network_gamelist.h
@@ -22,6 +24,10 @@ add_files(
     network_internal.h
     network_server.cpp
     network_server.h
+    network_stun.cpp
+    network_stun.h
+    network_turn.cpp
+    network_turn.h
     network_type.h
     network_udp.cpp
     network_udp.h

src/network/core/CMakeLists.txt

@@ -20,11 +20,17 @@ add_files(
     tcp_content.cpp
     tcp_content.h
     tcp_content_type.h
+    tcp_coordinator.cpp
+    tcp_coordinator.h
     tcp_game.cpp
     tcp_game.h
     tcp_http.cpp
     tcp_http.h
     tcp_listen.h
+    tcp_stun.cpp
+    tcp_stun.h
+    tcp_turn.cpp
+    tcp_turn.h
     udp.cpp
     udp.h
 )

src/network/core/address.cpp

@@ -10,6 +10,7 @@
 #include "../../stdafx.h"
 
 #include "address.h"
+#include "../network_internal.h"
 #include "../../debug.h"
 
 #include "../../safeguards.h"
@@ -312,13 +313,12 @@ static SOCKET ListenLoopProc(addrinfo *runp)
 		Debug(net, 1, "Setting no-delay mode failed: {}", NetworkError::GetLast().AsString());
 	}
 
-	int on = 1;
-	/* The (const char*) cast is needed for windows!! */
-	if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (const char*)&on, sizeof(on)) == -1) {
+	if (!SetReusePort(sock)) {
 		Debug(net, 0, "Setting reuse-address mode failed: {}", NetworkError::GetLast().AsString());
 	}
 
 #ifndef __OS2__
+	int on = 1;
 	if (runp->ai_family == AF_INET6 &&
 			setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, (const char*)&on, sizeof(on)) == -1) {
 		Debug(net, 3, "Could not disable IPv4 over IPv6: {}", NetworkError::GetLast().AsString());
@@ -399,15 +399,66 @@ void NetworkAddress::Listen(int socktype, SocketList *sockets)
 	}
 }
 
+/**
+ * Get the peer address of a socket as NetworkAddress.
+ * @param sock The socket to get the peer address of.
+ * @return The NetworkAddress of the peer address.
+ */
+/* static */ NetworkAddress NetworkAddress::GetPeerAddress(SOCKET sock)
+{
+	sockaddr_storage addr = {};
+	socklen_t addr_len = sizeof(addr);
+	if (getpeername(sock, (sockaddr *)&addr, &addr_len) != 0) {
+		Debug(net, 0, "Failed to get address of the peer: {}", NetworkError::GetLast().AsString());
+		return NetworkAddress();
+	}
+	return NetworkAddress(addr, addr_len);
+}
+
+/**
+ * Get the local address of a socket as NetworkAddress.
+ * @param sock The socket to get the local address of.
+ * @return The NetworkAddress of the local address.
+ */
+/* static */ NetworkAddress NetworkAddress::GetSockAddress(SOCKET sock)
+{
+	sockaddr_storage addr = {};
+	socklen_t addr_len = sizeof(addr);
+	if (getsockname(sock, (sockaddr *)&addr, &addr_len) != 0) {
+		Debug(net, 0, "Failed to get address of the socket: {}", NetworkError::GetLast().AsString());
+		return NetworkAddress();
+	}
+	return NetworkAddress(addr, addr_len);
+}
+
 /**
  * Get the peer name of a socket in string format.
  * @param sock The socket to get the peer name of.
  * @return The string representation of the peer name.
  */
 /* static */ const std::string NetworkAddress::GetPeerName(SOCKET sock)
 {
-	sockaddr_storage addr;
-	socklen_t addr_len = sizeof(addr);
-	getpeername(sock, (sockaddr *)&addr, &addr_len);
-	return NetworkAddress(addr, addr_len).GetAddressAsString();
+	return NetworkAddress::GetPeerAddress(sock).GetAddressAsString();
+}
+
+/**
+ * Convert a string containing either "hostname" or "hostname:ip" to a
+ * ServerAddress, where the string can be postfixed with "#company" to
+ * indicate the requested company.
+ *
+ * @param connection_string The string to parse.
+ * @param default_port The default port to set port to if not in connection_string.
+ * @param company Pointer to the company variable to set iff indicted.
+ * @return A valid ServerAddress of the parsed information.
+ */
+/* static */ ServerAddress ServerAddress::Parse(const std::string &connection_string, uint16 default_port, CompanyID *company_id)
+{
+	if (!connection_string.empty() && connection_string[0] == '+') {
+		std::string_view ip = ParseCompanyFromConnectionString(connection_string, company_id);
+		return ServerAddress(SERVER_ADDRESS_JOIN_KEY, std::string(ip));
+	}
+
+	uint16 port = default_port;
+	std::string_view ip = ParseFullConnectionString(connection_string, port, company_id);
+	return ServerAddress(SERVER_ADDRESS_DIRECT, std::string(ip) + ":" + std::to_string(port));
 }

src/network/core/address.h

@@ -12,6 +12,7 @@
 
 #include "os_abstraction.h"
 #include "config.h"
+#include "../../company_type.h"
 #include "../../string_func.h"
 #include "../../core/smallmap_type.hpp"
 
@@ -174,7 +175,43 @@ class NetworkAddress {
 
 	static const char *SocketTypeAsString(int socktype);
 	static const char *AddressFamilyAsString(int family);
+	static NetworkAddress GetPeerAddress(SOCKET sock);
+	static NetworkAddress GetSockAddress(SOCKET sock);
 	static const std::string GetPeerName(SOCKET sock);
 };
 
+/**
+ * Types of server addresses we know.
+ *
+ * Sorting will prefer entries at the top of this list above ones at the bottom.
+ */
+enum ServerAddressType {
+	SERVER_ADDRESS_DIRECT,   ///< Server-address is based on an IP:port.
+	SERVER_ADDRESS_JOIN_KEY, ///< Server-address is based on a join-key given by the Game Coordinator.
+};
+
+/**
+ * Address to a game server.
+ *
+ * This generalises addresses which are based on different identifiers.
+ */
+class ServerAddress {
+private:
+	/**
+	 * Create a new ServerAddress object.
+	 *
+	 * Please use ServerAddress::Parse() instead of calling this directly.
+	 *
+	 * @param type The type of the ServerAdress.
+	 * @param connection_string The connection_string that belongs to this ServerAddress type.
+	 */
+	ServerAddress(ServerAddressType type, const std::string &connection_string) : type(type), connection_string(connection_string) {}
+
+public:
+	ServerAddressType type;        ///< The type of this ServerAddress.
+	std::string connection_string; ///< The connection string for this ServerAddress.
+
+	static ServerAddress Parse(const std::string &connection_string, uint16 default_port, CompanyID *company_id = nullptr);
+};
+
 #endif /* NETWORK_CORE_ADDRESS_H */

src/network/core/config.h

@@ -14,6 +14,10 @@
 
 /** DNS hostname of the masterserver */
 static const char * const NETWORK_MASTER_SERVER_HOST            = "master.openttd.org";
+/** DNS hostname of the Game Coordinator server */
+static const char * const NETWORK_COORDINATOR_SERVER_HOST       = "coordinator.openttd.org";
+/** DNS hostname of the STUN server */
+static const char * const NETWORK_STUN_SERVER_HOST              = "stun.openttd.org";
 /** DNS hostname of the content server */
 static const char * const NETWORK_CONTENT_SERVER_HOST           = "content.openttd.org";
 /** DNS hostname of the HTTP-content mirror server */
@@ -23,14 +27,16 @@ static const char * const NETWORK_CONTENT_MIRROR_URL            = "/bananas";
 /** Message sent to the masterserver to 'identify' this client as OpenTTD */
 static const char * const NETWORK_MASTER_SERVER_WELCOME_MESSAGE = "OpenTTDRegister";
 
-static const uint16 NETWORK_MASTER_SERVER_PORT    = 3978;         ///< The default port of the master server (UDP)
-static const uint16 NETWORK_CONTENT_SERVER_PORT   = 3978;         ///< The default port of the content server (TCP)
-static const uint16 NETWORK_CONTENT_MIRROR_PORT   =   80;         ///< The default port of the content mirror (TCP)
-static const uint16 NETWORK_DEFAULT_PORT          = 3979;         ///< The default port of the game server (TCP & UDP)
-static const uint16 NETWORK_ADMIN_PORT            = 3977;         ///< The default port for admin network
-static const uint16 NETWORK_DEFAULT_DEBUGLOG_PORT = 3982;         ///< The default port debug-log is sent to (TCP)
+static const uint16 NETWORK_MASTER_SERVER_PORT      = 3978;       ///< The default port of the master server (UDP)
+static const uint16 NETWORK_COORDINATOR_SERVER_PORT = 3976;       ///< The default port of the Game Coordinator server (TCP)
+static const uint16 NETWORK_STUN_SERVER_PORT        = 3975;       ///< The default port of the STUN server (TCP)
+static const uint16 NETWORK_CONTENT_SERVER_PORT     = 3978;       ///< The default port of the content server (TCP)
+static const uint16 NETWORK_CONTENT_MIRROR_PORT     =   80;       ///< The default port of the content mirror (TCP)
+static const uint16 NETWORK_DEFAULT_PORT            = 3979;       ///< The default port of the game server (TCP & UDP)
+static const uint16 NETWORK_ADMIN_PORT              = 3977;       ///< The default port for admin network
+static const uint16 NETWORK_DEFAULT_DEBUGLOG_PORT   = 3982;       ///< The default port debug-log is sent to (TCP)
 
-static const uint16 UDP_MTU                       = 1460;         ///< Number of bytes we can pack in a single UDP packet
+static const uint16 UDP_MTU                         = 1460;       ///< Number of bytes we can pack in a single UDP packet
 /*
  * Technically a TCP packet could become 64kiB, however the high bit is kept so it becomes possible in the future
  * to go to (significantly) larger packets if needed. This would entail a strategy such as employed for UTF-8.
@@ -49,9 +55,10 @@ static const uint16 TCP_MTU                       = 32767;        ///< Number of
 static const uint16 COMPAT_MTU                    = 1460;         ///< Number of bytes we can pack in a single packet for backward compatibility
 
 static const byte NETWORK_GAME_ADMIN_VERSION      =    1;         ///< What version of the admin network do we use?
-static const byte NETWORK_GAME_INFO_VERSION       =    4;         ///< What version of game-info do we use?
+static const byte NETWORK_GAME_INFO_VERSION       =    6;         ///< What version of game-info do we use?
 static const byte NETWORK_COMPANY_INFO_VERSION    =    6;         ///< What version of company info is this?
 static const byte NETWORK_MASTER_SERVER_VERSION   =    2;         ///< What version of master-server-protocol do we use?
+static const byte NETWORK_COORDINATOR_VERSION     =    1;         ///< What version of game-coordinator-protocol do we use?
 
 static const uint NETWORK_NAME_LENGTH             =   80;         ///< The maximum length of the server name and map name, in bytes including '\0'
 static const uint NETWORK_COMPANY_NAME_LENGTH     =  128;         ///< The maximum length of the company name, in bytes including '\0'
@@ -71,14 +78,29 @@ static const uint NETWORK_CONTENT_VERSION_LENGTH  =   16;         ///< The maxim
 static const uint NETWORK_CONTENT_URL_LENGTH      =   96;         ///< The maximum length of a content's url, in bytes including '\0'.
 static const uint NETWORK_CONTENT_DESC_LENGTH     =  512;         ///< The maximum length of a content's description, in bytes including '\0'.
 static const uint NETWORK_CONTENT_TAG_LENGTH      =   32;         ///< The maximum length of a content's tag, in bytes including '\0'.
+static const uint NETWORK_JOIN_KEY_LENGTH         =   64;         ///< The maximum length of the join key, in bytes including '\0'
+static const uint NETWORK_JOIN_KEY_SECRET_LENGTH  =   80;         ///< The maximum length of the join key secret, in bytes including '\0'
+static const uint NETWORK_ERROR_DETAIL_LENGTH     =  100;         ///< The maximum length of the error detail, in bytes including '\0'
+static const uint NETWORK_TOKEN_LENGTH            =   64;         ///< The maximum length of a token, in bytes including '\0'
 
 static const uint NETWORK_GRF_NAME_LENGTH         =   80;         ///< Maximum length of the name of a GRF
 
 /**
  * Maximum number of GRFs that can be sent.
- * This limit is reached when PACKET_UDP_SERVER_RESPONSE reaches the maximum size of UDP_MTU bytes.
+ *
+ * This limit exists to avoid that the SERVER_INFO packet exceeding the
+ * maximum MTU. At the time of writing this limit is 32767 (TCP_MTU).
+ *
+ * In the SERVER_INFO packet is the NetworkGameInfo struct, which is
+ * 142 bytes + 100 per NewGRF (under the assumption strings are used to
+ * their max). This brings us to roughly 326 possible NewGRFs. Round it
+ * down so people don't freak out because they see a weird value, and you
+ * get the limit: 255.
+ *
+ * PS: in case you ever want to raise this number, please be mindful that
+ * "amount of NewGRFs" in NetworkGameInfo is currently an uint8.
  */
-static const uint NETWORK_MAX_GRF_COUNT           =   62;
+static const uint NETWORK_MAX_GRF_COUNT           =   255;
 
 /**
  * The number of landscapes in OpenTTD.