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Update documentation on STKHost

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Benau 2018-11-24 00:26:29 +08:00
parent 1e178cdcf9
commit 17075082e6
1 changed files with 33 additions and 47 deletions
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src/network/stk_host.cpp
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@ -109,7 +109,7 @@ std::shared_ptr<LobbyProtocol> STKHost::create(SeparateProcess* p)
* server, which is regularly polled by the client. On detecting a new * server, which is regularly polled by the client. On detecting a new
* connection request the server will try to send a message to the client. * connection request the server will try to send a message to the client.
* This allows connections between server and client even if they are * This allows connections between server and client even if they are
* sitting behind a NAT translating firewall. The following tables on * sitting behind a NAT firewall. The following tables on
* the stk server are used: * the stk server are used:
* client_sessions: It stores the list of all online users (so loging in * client_sessions: It stores the list of all online users (so loging in
* means to insert a row in this table), including their token * means to insert a row in this table), including their token
@ -119,64 +119,52 @@ std::shared_ptr<LobbyProtocol> STKHost::create(SeparateProcess* p)
* servers: Registers all servers and gives them a unique id, together * servers: Registers all servers and gives them a unique id, together
* with the user id (which is stored as host_id in this table). * with the user id (which is stored as host_id in this table).
* server_conn: This table stores connection requests from clients to * server_conn: This table stores connection requests from clients to
* servers. A 'request' bit is set to 1 if the request has not * servers. It has the aes_key and aes_iv which are used to validate
* been handled, and is reset to 0 the moment the server receives * clients if it's the same online user id joining a server,
* the information about the client request. * ip and port for NAT penetration and a connected_since which
* stores the timestamp the user joined this server to know the time
* playing spent playing on it.
* *
* The following outlines the protocol happening in order to connect a * The following outlines the protocol happening in order to connect a
* client to a server in more details: * client to a server in more details:
* *
* First it calls setPublicAddress() here to discover the public ip address
* and port number of this host,
* Server: * Server:
* *
* 1. ServerLobby: * 1. ServerLobby:
* Spawns the following sub-protocols: * 1. Register this server with stk server (i.e. publish its public
* 1. GetPublicAddress: Use STUN to discover the public ip address * ip address, port number and game info) - 'create' request. This
* and port number of this host. * enters the server into the 'servers' table. This server can now
* 2. Register this server with stk server (i.e. publish its public
* ip address and port number) - 'start' request. This enters the
* public information into the 'client_sessions' table, and then
* the server into the 'servers' table. This server can now
* be detected by other clients, so they can request a connection. * be detected by other clients, so they can request a connection.
* 3. The server lobby now polls the stk server for client connection * 2. The server lobby now polls the stk server for client connection
* requests using the 'poll-connection-requests', which queries the * requests using the 'poll-connection-requests' each 5 seconds, which
* servers table to get the server id (based on address and user id), * queries the servers table to get the server id (based on address
* and then the server_conn table. The rows in this table are updated * and user id), and then the server_conn table. The server will map
* by setting the 'request' bit to 0 (i.e. connection request was * each joined AES key within 45 seconds to each connected client to
* send to server). * handle validation.
*
* Client: * Client:
* *
* The GUI queries the stk server to get a list of available servers * The GUI queries the stk server to get a list of available servers
* ('get-all' request, submitted from ServersManager to query the 'servers' * ('get-all' request, submitted from ServersManager to query the 'servers'
* table). The user picks one (or in case of quick play one is picked * table). The user picks one (or in case of quick play one is picked
* randomly), and then instantiates STKHost with the id of this server. * randomly), and then instantiates STKHost with the id of this server.
* STKHost then triggers ConnectToServer, which starts the following * STKHost then triggers ConnectToServer, which do the following:
* protocols: * 1. Register the client with the STK host ('join-server-key' command,
* 1. GetPublicAddress: Use STUN to discover the public ip address * into the table 'server_conn'). Its public ip address and port will
* and port number of this host. * be registerd with a AES key and iv set by client.
* 2. Register the client with the STK host ('set' command, into the * 2. Run ConnectToServer::tryConnect for 30 seconds to connect to server,
* table 'client_sessions'). Its public ip address and port will * It will auto change to a correct server port in case the server is
* be registerd. * behind a strong firewall, see intercept below.
* 3. GetPeerAddress. Submits a 'get' request to the STK server to get
* the ip address and port for the selected server from
* 'client_sessions'.
* If the ip address of the server is the same as this client, they
* will connect using the LAN connection.
* 4. RequestConnection will do a 'request-connection' to the stk server.
* The user id and server id are stored in server_conn. This is the
* request that the server will detect using polling.
* *
* Server: * Server:
* *
* The ServerLobbyProtocol (SLP) will then detect the above client * The ServerLobbyProtocol (SLP) will then detect the above client
* requests, and start a ConnectToPeer protocol for each incoming client. * requests, and start a ConnectToPeer protocol for each incoming client.
* The ConnectToPeer protocol uses: * The ConnectToPeer protocol send client a raw packet with
* 1. GetPeerAddress to get the ip address and port of the client. * "0xffff" and "aloha-stk", so the client can use the intercept in enet for
* Once this is received, it will start the: * advanced NAT penetration, see ConnectToServer::interceptCallback for
* 2. PingProtocol * details.
* This sends a raw packet (i.e. no enet header) to the
* destination (unless if it is a LAN connection, then UDP
* broadcasts will be used).
* *
* Each client will run a ClientLobbyProtocol (CLP) to handle the further * Each client will run a ClientLobbyProtocol (CLP) to handle the further
* interaction with the server. The client will first request a connection * interaction with the server. The client will first request a connection
@ -195,9 +183,7 @@ std::shared_ptr<LobbyProtocol> STKHost::create(SeparateProcess* p)
* *
* The server will reply with either a reject message (e.g. too many clients * The server will reply with either a reject message (e.g. too many clients
* already connected), or an accept message. The accept message will contain * already connected), or an accept message. The accept message will contain
* the global player id of the client, and a unique (random) token used to * the global player id of the client. The message
* authenticate all further messages from the server: each message from the
* client to the server and vice versa will contain this token. The message
* also contains the global ids and names of all currently connected * also contains the global ids and names of all currently connected
* clients for the new client. The server then informs all existing clients * clients for the new client. The server then informs all existing clients
* about the newly connected client, and its global player id. * about the newly connected client, and its global player id.