heinrich5991 6b65ccb945 Add HTTP masterserver registering and HTTP masterserver ... Registering ----------- The idea is that game servers push their server info to the masterservers every 15 seconds or when the server info changes, but not more than once per second. The game servers do not support the old registering protocol anymore, the backward compatibility is handled by the masterserver. The register call is a HTTP POST to a URL like `https://master1.ddnet.tw/ddnet/15/register` and looks like this: ```json POST /ddnet/15/register HTTP/1.1 Address: tw-0.6+udp://connecting-address.invalid:8303 Secret: 81fa3955-6f83-4290-818d-31c0906b1118 Challenge-Secret: 81fa3955-6f83-4290-818d-31c0906b1118:tw0.6/ipv6 Info-Serial: 0 { "max_clients": 64, "max_players": 64, "passworded": false, "game_type": "TestDDraceNetwork", "name": "My DDNet server", "map": { "name": "dm1", "sha256": "0b0c481d77519c32fbe85624ef16ec0fa9991aec7367ad538bd280f28d8c26cf", "size": 5805 }, "version": "0.6.4, 16.0.3", "clients": [] } ``` The `Address` header declares that the server wants to register itself as a `tw-0.6+udp` server, i.e. a server speaking a Teeworlds-0.6-compatible protocol. The free-form `Secret` header is used as a server identity, the server list will be deduplicated via this secret. The free-form `Challenge-Secret` is sent back via UDP for a port forward check. This might have security implications as the masterserver can be asked to send a UDP packet containing some user-controlled bytes. This is somewhat mitigated by the fact that it can only go to an attacker-controlled IP address. The `Info-Serial` header is an integer field that should increase each time the server info (in the body) changes. The masterserver uses that field to ensure that it doesn't use old server infos. The body is a free-form JSON object set by the game server. It should contain certain keys in the correct form to be accepted by clients. The body is optional if the masterserver already confirmed the reception of the info with the given `Info-Serial`. Not shown in this payload is the `Connless-Token` header that is used for Teeworlds 0.7 style communication. Also not shown is the `Challenge-Token` that should be included once the server receives the challenge token via UDP. The masterserver responds with a `200 OK` with a body like this: ``` {"status":"success"} ``` The `status` field can be `success` if the server was successfully registered on the masterserver, `need_challenge` if the masterserver wants the correct `Challenge-Token` header before the register process is successful, `need_info` if the server sent an empty body but the masterserver doesn't actually know the server info. It can also be `error` if the request was malformed, only in this case an HTTP status code except `200 OK` is sent. Synchronization --------------- The masterserver keeps state and outputs JSON files every second. ```json { "servers": [ { "addresses": [ "tw-0.6+udp://127.0.0.1:8303", "tw-0.6+udp://[::1]:8303" ], "info_serial": 0, "info": { "max_clients": 64, "max_players": 64, "passworded": false, "game_type": "TestDDraceNetwork", "name": "My DDNet server", "map": { "name": "dm1", "sha256": "0b0c481d77519c32fbe85624ef16ec0fa9991aec7367ad538bd280f28d8c26cf", "size": 5805 }, "version": "0.6.4, 16.0.3", "clients": [] } } ] } ``` `servers.json` (or configured by `--out`) is a server list that is compatible with DDNet 15.5+ clients. It is a JSON object containing a single key `servers` with a list of game servers. Each game server is represented by a JSON object with an `addresses` key containing a list of all known addresses of the server and an `info` key containing the free-form server info sent by the game server. The free-form `info` JSON object re-encoded by the master server and thus canonicalized and stripped of any whitespace characters outside strings. ```json { "kind": "mastersrv", "now": 1816002, "secrets": { "tw-0.6+udp://127.0.0.1:8303": { "ping_time": 1811999, "secret": "42d8f991-f2fa-46e5-a9ae-ebcc93846feb" }, "tw-0.6+udp://[::1]:8303": { "ping_time": 1811999, "secret": "42d8f991-f2fa-46e5-a9ae-ebcc93846feb" } }, "servers": { "42d8f991-f2fa-46e5-a9ae-ebcc93846feb": { "info_serial": 0, "info": { "max_clients": 64, "max_players": 64, "passworded": false, "game_type": "TestDDraceNetwork", "name": "My DDNet server", "map": { "name": "dm1", "sha256": "0b0c481d77519c32fbe85624ef16ec0fa9991aec7367ad538bd280f28d8c26cf", "size": 5805 }, "version": "0.6.4, 16.0.3", "clients": [] } } } } ``` `--write-dump` outputs a JSON file compatible with `--read-dump-dir`, this can be used to synchronize servers across different masterservers. `--read-dump-dir` is also used to ingest servers from the backward compatibility layer that pings each server for their server info using the old protocol. The `kind` field describe that this is `mastersrv` output and not from a `backcompat`. This is used for prioritizing `mastersrv` information over `backcompat` information. The `now` field contains an integer describing the current time in milliseconds relative an unspecified epoch that is fixed for each JSON file. This is done instead of using the current time as the epoch for better compression of non-changing data. `secrets` is a map from each server address and to a JSON object containing the last ping time (`ping_time`) in milliseconds relative to the same epoch as before, and the server secret (`secret`) that is used to unify server infos from different addresses of the same logical server. `servers` is a map from the aforementioned `secret`s to the corresponding `info_serial` and `info`. ```json [ "tw-0.6+udp://127.0.0.1:8303", "tw-0.6+udp://[::1]:8303" ] ``` `--write-addresses` outputs a JSON file containing all addresses corresponding to servers that are registered to HTTP masterservers. It does not contain the servers that are obtained via backward compatibility measures. This file can be used by an old-style masterserver to also list new-style servers without the game servers having to register there. An implementation of this can be found at https://github.com/heinrich5991/teeworlds/tree/mastersrv_6_backcompat for Teeworlds 0.5/0.6 masterservers and at https://github.com/heinrich5991/teeworlds/tree/mastersrv_7_backcompat for Teeworlds 0.7 masterservers. All these JSON files can be sent over the network in an efficient way using https://github.com/heinrich5991/twmaster-collect. It establishes a zstd-compressed TCP connection authenticated by a string token that is sent in plain-text. It watches the specified file and transmits it every time it changes. Due to the zstd-compression, the data sent over the network is similar to the size of a diff. Implementation -------------- The masterserver implementation was done in Rust. The current gameserver register implementation doesn't support more than one masterserver for registering.		2022-05-20 08:58:32 +02:00
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twping.cpp	Add HTTP masterserver registering and HTTP masterserver	2022-05-20 08:58:32 +02:00