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use futures::future::{Future, FutureExt};
use crate::data::IoHandler;
use crate::form::Form;
use crate::http::{Header, Method, Status};
use crate::outcome::Outcome;
use crate::trace::Trace;
use crate::util::Formatter;
use crate::{catcher, route, Data, Orbit, Request, Response, Rocket};
// A token returned to force the execution of one method before another.
pub(crate) struct RequestToken;
async fn catch_handle<Fut, T, F>(name: Option<&str>, run: F) -> Option<T>
where
F: FnOnce() -> Fut,
Fut: Future<Output = T>,
{
macro_rules! panic_info {
($name:expr, $e:expr) => {{
error!(
handler = name.as_ref().map(display),
"handler panicked\n\
This is an application bug.\n\
A panic in Rust must be treated as an exceptional event.\n\
Panicking is not a suitable error handling mechanism.\n\
Unwinding, the result of a panic, is an expensive operation.\n\
Panics will degrade application performance.\n\
Instead of panicking, return `Option` and/or `Result`.\n\
Values of either type can be returned directly from handlers.\n\
A panic is treated as an internal server error."
);
$e
}};
}
let run = std::panic::AssertUnwindSafe(run);
#[allow(clippy::manual_inspect)]
let fut = std::panic::catch_unwind(run)
.map_err(|e| panic_info!(name, e))
.ok()?;
#[allow(clippy::manual_inspect)]
std::panic::AssertUnwindSafe(fut)
.catch_unwind()
.await
.map_err(|e| panic_info!(name, e))
.ok()
}
impl Rocket<Orbit> {
/// Preprocess the request for Rocket things. Currently, this means:
///
/// * Rewriting the method in the request if _method form field exists.
/// * Run the request fairings.
///
/// This is the only place during lifecycle processing that `Request` is
/// mutable. Keep this in-sync with the `FromForm` derive.
pub(crate) async fn preprocess(
&self,
req: &mut Request<'_>,
data: &mut Data<'_>,
) -> RequestToken {
// Check if this is a form and if the form contains the special _method
// field which we use to reinterpret the request's method.
if req.method() == Method::Post && req.content_type().is_some_and(|v| v.is_form()) {
let peek_buffer = data.peek(32).await;
let method = std::str::from_utf8(peek_buffer)
.ok()
.and_then(|raw_form| Form::values(raw_form).next())
.filter(|field| field.name == "_method")
.and_then(|field| field.value.parse().ok());
if let Some(method) = method {
req.set_method(method);
}
}
// Run request fairings.
self.fairings.handle_request(req, data).await;
RequestToken
}
/// Dispatches the request to the router and processes the outcome to
/// produce a response. If the initial outcome is a *forward* and the
/// request was a HEAD request, the request is rewritten and rerouted as a
/// GET. This is automatic HEAD handling.
///
/// After performing the above, if the outcome is a forward or error, the
/// appropriate error catcher is invoked to produce the response. Otherwise,
/// the successful response is used directly.
///
/// Finally, new cookies in the cookie jar are added to the response,
/// Rocket-specific headers are written, and response fairings are run. Note
/// that error responses have special cookie handling. See `handle_error`.
pub(crate) async fn dispatch<'r, 's: 'r>(
&'s self,
_token: RequestToken,
request: &'r Request<'s>,
data: Data<'r>,
// io_stream: impl Future<Output = io::Result<IoStream>> + Send,
) -> Response<'r> {
// Remember if the request is `HEAD` for later body stripping.
let was_head_request = request.method() == Method::Head;
// Route the request and run the user's handlers.
let mut response = match self.route(request, data).await {
Outcome::Success(response) => response,
Outcome::Forward((data, _)) if request.method() == Method::Head => {
tracing::Span::current().record("autohandled", true);
// Dispatch the request again with Method `GET`.
request._set_method(Method::Get);
match self.route(request, data).await {
Outcome::Success(response) => response,
Outcome::Error(status) => self.dispatch_error(status, request).await,
Outcome::Forward((_, status)) => self.dispatch_error(status, request).await,
}
}
Outcome::Forward((_, status)) => self.dispatch_error(status, request).await,
Outcome::Error(status) => self.dispatch_error(status, request).await,
};
// Set the cookies. Note that error responses will only include cookies
// set by the error handler. See `handle_error` for more.
let delta_jar = request.cookies().take_delta_jar();
for cookie in delta_jar.delta() {
response.adjoin_header(cookie);
}
// Add a default 'Server' header if it isn't already there.
// TODO: If removing Hyper, write out `Date` header too.
if let Some(ident) = request.rocket().config.ident.as_str() {
if !response.headers().contains("Server") {
response.set_header(Header::new("Server", ident));
}
}
// Run the response fairings.
self.fairings.handle_response(request, &mut response).await;
// Strip the body if this is a `HEAD` request or a 304 response.
if was_head_request || response.status() == Status::NotModified {
response.strip_body();
}
// If the response status is 204, strip the body and its size (no
// content-length header). Otherwise, check if the body is sized and use
// that size to set the content-length headr appropriately.
if response.status() == Status::NoContent {
*response.body_mut() = crate::response::Body::unsized_none();
} else if let Some(size) = response.body_mut().size().await {
response.set_raw_header("Content-Length", size.to_string());
}
if let Some(alt_svc) = request.rocket().alt_svc() {
response.set_raw_header("Alt-Svc", alt_svc);
}
// TODO: Should upgrades be handled here? We miss them on local clients.
response
}
pub(crate) fn extract_io_handler<'r>(
request: &'r Request<'_>,
response: &mut Response<'r>,
// io_stream: impl Future<Output = io::Result<IoStream>> + Send,
) -> Option<(String, Box<dyn IoHandler + 'r>)> {
let upgrades = request.headers().get("upgrade");
let Ok(upgrade) = response.search_upgrades(upgrades) else {
info!(
upgrades = %Formatter(|f| f.debug_list()
.entries(request.headers().get("upgrade"))
.finish()),
"request wants upgrade but no i/o handler matched\n\
refusing to upgrade request"
);
return None;
};
if let Some((proto, io_handler)) = upgrade {
let proto = proto.to_string();
response.set_status(Status::SwitchingProtocols);
response.set_raw_header("Connection", "Upgrade");
response.set_raw_header("Upgrade", proto.clone());
return Some((proto, io_handler));
}
None
}
/// Calls the handler for each matching route until one of the handlers
/// returns success or error, or there are no additional routes to try, in
/// which case a `Forward` with the last forwarding state is returned.
#[inline]
#[tracing::instrument("routing", skip_all, fields(
method = %request.method(),
uri = %request.uri(),
format = request.format().map(display),
))]
async fn route<'s, 'r: 's>(
&'s self,
request: &'r Request<'s>,
mut data: Data<'r>,
) -> route::Outcome<'r> {
// Go through all matching routes until we fail or succeed or run out of
// routes to try, in which case we forward with the last status.
let mut status = Status::NotFound;
for route in self.router.route(request) {
// Retrieve and set the requests parameters.
route.trace_info();
request.set_route(route);
let name = route.name.as_deref();
let outcome = catch_handle(name, || route.handler.handle(request, data))
.await
.unwrap_or(Outcome::Error(Status::InternalServerError));
// Check if the request processing completed (Some) or if the
// request needs to be forwarded. If it does, continue the loop
outcome.trace_info();
match outcome {
o @ Outcome::Success(_) | o @ Outcome::Error(_) => return o,
Outcome::Forward(forwarded) => (data, status) = forwarded,
}
}
Outcome::Forward((data, status))
}
// Invokes the catcher for `status`. Returns the response on success.
//
// Resets the cookie jar delta state to prevent any modifications from
// earlier unsuccessful paths from being reflected in the error response.
//
// On catcher error, the 500 error catcher is attempted. If _that_ errors,
// the (infallible) default 500 error cather is used.
#[tracing::instrument("catching", skip_all, fields(status = status.code, uri = %req.uri()))]
pub(crate) async fn dispatch_error<'r, 's: 'r>(
&'s self,
mut status: Status,
req: &'r Request<'s>,
) -> Response<'r> {
// We may wish to relax this in the future.
req.cookies().reset_delta();
loop {
// Dispatch to the `status` catcher.
match self.invoke_catcher(status, req).await {
Ok(r) => return r,
// If the catcher failed, try `500` catcher, unless this is it.
Err(e) if status.code != 500 => {
warn!(
status = e.map(|r| r.code),
"catcher failed: trying 500 catcher"
);
status = Status::InternalServerError;
}
// The 500 catcher failed. There's no recourse. Use default.
Err(e) => {
error!(status = e.map(|r| r.code), "500 catcher failed");
return catcher::default_handler(Status::InternalServerError, req);
}
}
}
}
/// Invokes the handler with `req` for catcher with status `status`.
///
/// In order of preference, invoked handler is:
/// * the user's registered handler for `status`
/// * the user's registered `default` handler
/// * Rocket's default handler for `status`
///
/// Return `Ok(result)` if the handler succeeded. Returns `Ok(Some(Status))`
/// if the handler ran to completion but failed. Returns `Ok(None)` if the
/// handler panicked while executing.
async fn invoke_catcher<'s, 'r: 's>(
&'s self,
status: Status,
req: &'r Request<'s>,
) -> Result<Response<'r>, Option<Status>> {
if let Some(catcher) = self.router.catch(status, req) {
catcher.trace_info();
catch_handle(catcher.name.as_deref(), || {
catcher.handler.handle(status, req)
})
.await
.map(|result| result.map_err(Some))
.unwrap_or_else(|| Err(None))
} else {
info!(name: "catcher", name = "rkt::default", "uri.base" = "/", code = status.code,
"no registered catcher: using Rocket default");
Ok(catcher::default_handler(status, req))
}
}
}