Module server

Links redirector server utilities, including:

• Listeners, which listen for incoming network traffic
• Acceptors, which accept incoming connections and direct it to the handlers
• Handlers, which handle requests, doing HTTP redirects or RPC calls
• miscellaneous functions used by the server binary

Listeners

A listener controls a network socket and calls its associated acceptor when a new connection is received. One listener exists for every socket that the links redirector server listens on. Listeners can be added and removed while the server is active.

Acceptors

Acceptors are the bridge between listeners and handlers. They hold (references to) all necessary state used by themselves and the handlers. One acceptor exists for every combination of listener + encryption + handler type, e.g. an unencrypted TCP acceptor for HTTP, an encrypted TCP/TLS acceptor for RPC, etc. Acceptors are predefined for the lifetime of the redirector server, and initialized at server startup. Acceptors initially process incoming connections (doing handshakes and de/en-cryption if necessary), and then call their associated handler.

Handlers

Handlers are responsible for all application logic. A handler is an async function called from an acceptor. There is one predefined handler for each kind of request: currently one external HTTP redirector, one HTTP to HTTPS redirector, and one RPC handler.

Structs

Listener

A links redirector listener.

PlainHttpAcceptor

An acceptor for plaintext (unencrypted) HTTP requests. Supports HTTP/1.0, HTTP/1.1, and HTTP/2 (in its rare unencrypted variety usually not found in any browsers).

PlainRpcAcceptor

An acceptor for plaintext (unencrypted) RPC calls. Supports gRPC over unencrypted HTTP/2.

TlsHttpAcceptor

An acceptor for TLS-encrypted HTTPS requests. Supports HTTP/1.0, HTTP/1.1, and HTTP/2.

TlsRpcAcceptor

An acceptor for TLS-encrypted RPC calls. Supports gRPC over HTTP/2 with HTTPS.

Enums

Protocol

The protocols that links redirector servers can listen on

Constants

LISTENER_TCP_BACKLOG_SIZE 🔒

Number of incoming connections that can be kept in the TCP socket backlog of a listener (see listen’s linux man page or winsock docs for details)

Traits

Acceptor

A trait for defining links server acceptors.

Functions

http_handler

A handler that does external HTTP redirects using information from the provided store. Extra information for statistics can be passed via stat_info.

http_to_https_handler

A handler that redirects incoming requests to their original URL, but with the HTTPS scheme instead.

rpc_handler

Handler processing RPC API calls.

store_setup

Set up the links store, optionally setting an example redirect (example -> 9dDbKpJP -> https://example.com/).