Struct MessageHandler 

pub struct MessageHandler;

Message handler for request/response manipulation.

Implementations

impl MessageHandler

pub fn upgrade_protocol( request: &Request<BoxBody<Bytes, Error>>, ) -> Option<String>

The protocol a request is asking to upgrade to, if it is a valid upgrade request.

Requires both Upgrade: <proto> and an upgrade token in Connection, per RFC 9110 section 7.8 – Upgrade alone is not a request to switch. HTTP/2 is excluded deliberately: it carries no Upgrade header and negotiates extended CONNECT instead (RFC 8441), which is not implemented.

pub fn h2_connect_protocol( request: &Request<BoxBody<Bytes, Error>>, ) -> Option<String>

The protocol an HTTP/2 extended CONNECT is asking for (RFC 8441).

HTTP/2 has no Upgrade; a WebSocket is opened with :method = CONNECT plus a :protocol pseudo-header, which hyper surfaces as a hyper::ext::Protocol extension. This is only ever offered when the listener advertised SETTINGS_ENABLE_CONNECT_PROTOCOL.

pub fn restore_upgrade_headers( request: &mut Request<BoxBody<Bytes, Error>>, protocol: &str, )

Re-apply the upgrade headers that Self::strip_hop_by_hop_headers took.

An upgrade is the one case where these headers legitimately travel to the next hop. Only a normalised Connection: upgrade and the requested protocol go back – not whatever token list the client sent – so the carve-out cannot be used to smuggle other headers through.

pub fn has_ambiguous_framing(request: &Request<BoxBody<Bytes, Error>>) -> bool

Whether the request’s body framing is ambiguous.

RFC 9112 section 6.1: a message carrying both Content-Length and Transfer-Encoding is either a smuggling attempt or a broken client. Transfer-Encoding wins per the spec, but a proxy that quietly normalises the disagreement is how a smuggling chain starts, so reject it – which is also how hyper’s own parser already treats a duplicate Content-Length.

Must be called before Self::strip_hop_by_hop_headers, which removes the Transfer-Encoding this inspects.

pub fn strip_hop_by_hop_headers(request: &mut Request<BoxBody<Bytes, Error>>)

Remove hop-by-hop headers before forwarding, per RFC 9110 section 7.6.1.

Two sets go: the standard hop-by-hop headers, and every header named as a token in the incoming Connection field. Call this before Self::add_forwarding_headers – a client that names x-forwarded-for in Connection then strips only its own inbound value, and we set a fresh one afterwards, rather than being able to suppress ours.

pub fn add_forwarding_headers( request: &mut Request<BoxBody<Bytes, Error>>, client_addr: SocketAddr, proto: &str, )

Add X-Forwarded-* headers to a request.

pub fn rewrite_host_header( request: &mut Request<BoxBody<Bytes, Error>>, upstream_host: &str, )

Rewrite the Host header for upstream.

pub fn strip_path_prefix( request: &mut Request<BoxBody<Bytes, Error>>, prefix: &str, )

Strip path prefix from request URI.

pub fn apply_route_headers( request: &mut Request<BoxBody<Bytes, Error>>, route: &Route, )

Apply route-specific header modifications.

pub fn error_response( status: StatusCode, message: &str, ) -> Response<BoxBody<Bytes, Error>>

Create a synthetic error response.

pub fn bad_request(message: &str) -> Response<BoxBody<Bytes, Error>>

Create a 502 Bad Gateway response.

pub fn bad_gateway(message: &str) -> Response<BoxBody<Bytes, Error>>

Create a 502 Bad Gateway response.

pub fn service_unavailable(message: &str) -> Response<BoxBody<Bytes, Error>>

Create a 503 Service Unavailable response.

pub fn request_host(request: &Request<impl Body>) -> String

The host a request is for, without its port.

Not just the Host header. HTTP/2 has no Host: RFC 9113 section 8.3.1 replaces it with the :authority pseudo-header, which reaches us on the URI. Reading only the header therefore yields an empty host for every h2 and h2c request, and a route with a match.host matches nothing – confirmed against a running proxy, where the same host-matched route answered 200 over HTTP/1.1 and 404 over HTTP/2.

add_forwarding_headers already had this fallback for x-forwarded-host; route selection did not.

pub fn gateway_timeout(message: &str) -> Response<BoxBody<Bytes, Error>>

Create a 504 Gateway Timeout response.

Takes a message so the body can say how long the request waited. A bare “Gateway Timeout” leaves the caller unable to tell a route configured with one second from an upstream that is genuinely wedged.

pub fn too_many_requests() -> Response<BoxBody<Bytes, Error>>

Create a 429 Too Many Requests response.

pub fn not_found() -> Response<BoxBody<Bytes, Error>>

Create a 404 Not Found response.