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Diffstat (limited to 'third_party/rust/warp/src/reject.rs')
| -rw-r--r-- | third_party/rust/warp/src/reject.rs | 844 |
1 files changed, 844 insertions, 0 deletions
diff --git a/third_party/rust/warp/src/reject.rs b/third_party/rust/warp/src/reject.rs new file mode 100644 index 0000000000..fd09188412 --- /dev/null +++ b/third_party/rust/warp/src/reject.rs @@ -0,0 +1,844 @@ +//! Rejections +//! +//! Part of the power of the [`Filter`](../trait.Filter.html) system is being able to +//! reject a request from a filter chain. This allows for filters to be +//! combined with `or`, so that if one side of the chain finds that a request +//! doesn't fulfill its requirements, the other side can try to process +//! the request. +//! +//! Many of the built-in [`filters`](../filters) will automatically reject +//! the request with an appropriate rejection. However, you can also build +//! new custom [`Filter`](../trait.Filter.html)s and still want other routes to be +//! matchable in the case a predicate doesn't hold. +//! +//! As a request is processed by a Filter chain, the rejections are accumulated into +//! a list contained by the [`Rejection`](struct.Rejection.html) type. Rejections from +//! filters can be handled using [`Filter::recover`](../trait.Filter.html#method.recover). +//! This is a convenient way to map rejections into a [`Reply`](../reply/trait.Reply.html). +//! +//! For a more complete example see the +//! [Rejection Example](https://github.com/seanmonstar/warp/blob/master/examples/rejections.rs) +//! from the repository. +//! +//! # Example +//! +//! ``` +//! use warp::{reply, Reply, Filter, reject, Rejection, http::StatusCode}; +//! +//! #[derive(Debug)] +//! struct InvalidParameter; +//! +//! impl reject::Reject for InvalidParameter {} +//! +//! // Custom rejection handler that maps rejections into responses. +//! async fn handle_rejection(err: Rejection) -> Result<impl Reply, std::convert::Infallible> { +//! if err.is_not_found() { +//! Ok(reply::with_status("NOT_FOUND", StatusCode::NOT_FOUND)) +//! } else if let Some(e) = err.find::<InvalidParameter>() { +//! Ok(reply::with_status("BAD_REQUEST", StatusCode::BAD_REQUEST)) +//! } else { +//! eprintln!("unhandled rejection: {:?}", err); +//! Ok(reply::with_status("INTERNAL_SERVER_ERROR", StatusCode::INTERNAL_SERVER_ERROR)) +//! } +//! } +//! +//! +//! // Filter on `/:id`, but reject with InvalidParameter if the `id` is `0`. +//! // Recover from this rejection using a custom rejection handler. +//! let route = warp::path::param() +//! .and_then(|id: u32| async move { +//! if id == 0 { +//! Err(warp::reject::custom(InvalidParameter)) +//! } else { +//! Ok("id is valid") +//! } +//! }) +//! .recover(handle_rejection); +//! ``` + +use std::any::Any; +use std::convert::Infallible; +use std::error::Error as StdError; +use std::fmt; + +use http::{ + self, + header::{HeaderValue, CONTENT_TYPE}, + StatusCode, +}; +use hyper::Body; + +pub(crate) use self::sealed::{CombineRejection, IsReject}; + +/// Rejects a request with `404 Not Found`. +#[inline] +pub fn reject() -> Rejection { + not_found() +} + +/// Rejects a request with `404 Not Found`. +#[inline] +pub fn not_found() -> Rejection { + Rejection { + reason: Reason::NotFound, + } +} + +// 400 Bad Request +#[inline] +pub(crate) fn invalid_query() -> Rejection { + known(InvalidQuery { _p: () }) +} + +// 400 Bad Request +#[inline] +pub(crate) fn missing_header(name: &'static str) -> Rejection { + known(MissingHeader { name }) +} + +// 400 Bad Request +#[inline] +pub(crate) fn invalid_header(name: &'static str) -> Rejection { + known(InvalidHeader { name }) +} + +// 400 Bad Request +#[inline] +pub(crate) fn missing_cookie(name: &'static str) -> Rejection { + known(MissingCookie { name }) +} + +// 405 Method Not Allowed +#[inline] +pub(crate) fn method_not_allowed() -> Rejection { + known(MethodNotAllowed { _p: () }) +} + +// 411 Length Required +#[inline] +pub(crate) fn length_required() -> Rejection { + known(LengthRequired { _p: () }) +} + +// 413 Payload Too Large +#[inline] +pub(crate) fn payload_too_large() -> Rejection { + known(PayloadTooLarge { _p: () }) +} + +// 415 Unsupported Media Type +// +// Used by the body filters if the request payload content-type doesn't match +// what can be deserialized. +#[inline] +pub(crate) fn unsupported_media_type() -> Rejection { + known(UnsupportedMediaType { _p: () }) +} + +/// Rejects a request with a custom cause. +/// +/// A [`recover`][] filter should convert this `Rejection` into a `Reply`, +/// or else this will be returned as a `500 Internal Server Error`. +/// +/// [`recover`]: ../trait.Filter.html#method.recover +pub fn custom<T: Reject>(err: T) -> Rejection { + Rejection::custom(Box::new(err)) +} + +/// Protect against re-rejecting a rejection. +/// +/// ```compile_fail +/// fn with(r: warp::Rejection) { +/// let _wat = warp::reject::custom(r); +/// } +/// ``` +fn __reject_custom_compilefail() {} + +/// A marker trait to ensure proper types are used for custom rejections. +/// +/// Can be converted into Rejection. +/// +/// # Example +/// +/// ``` +/// use warp::{Filter, reject::Reject}; +/// +/// #[derive(Debug)] +/// struct RateLimited; +/// +/// impl Reject for RateLimited {} +/// +/// let route = warp::any().and_then(|| async { +/// Err::<(), _>(warp::reject::custom(RateLimited)) +/// }); +/// ``` +// Require `Sized` for now to prevent passing a `Box<dyn Reject>`, since we +// would be double-boxing it, and the downcasting wouldn't work as expected. +pub trait Reject: fmt::Debug + Sized + Send + Sync + 'static {} + +trait Cause: fmt::Debug + Send + Sync + 'static { + fn as_any(&self) -> &dyn Any; +} + +impl<T> Cause for T +where + T: fmt::Debug + Send + Sync + 'static, +{ + fn as_any(&self) -> &dyn Any { + self + } +} + +impl dyn Cause { + fn downcast_ref<T: Any>(&self) -> Option<&T> { + self.as_any().downcast_ref::<T>() + } +} + +pub(crate) fn known<T: Into<Known>>(err: T) -> Rejection { + Rejection::known(err.into()) +} + +/// Rejection of a request by a [`Filter`](crate::Filter). +/// +/// See the [`reject`](module@crate::reject) documentation for more. +pub struct Rejection { + reason: Reason, +} + +enum Reason { + NotFound, + Other(Box<Rejections>), +} + +enum Rejections { + Known(Known), + Custom(Box<dyn Cause>), + Combined(Box<Rejections>, Box<Rejections>), +} + +macro_rules! enum_known { + ($($(#[$attr:meta])* $var:ident($ty:path),)+) => ( + pub(crate) enum Known { + $( + $(#[$attr])* + $var($ty), + )+ + } + + impl Known { + fn inner_as_any(&self) -> &dyn Any { + match *self { + $( + $(#[$attr])* + Known::$var(ref t) => t, + )+ + } + } + } + + impl fmt::Debug for Known { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + match *self { + $( + $(#[$attr])* + Known::$var(ref t) => t.fmt(f), + )+ + } + } + } + + impl fmt::Display for Known { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + match *self { + $( + $(#[$attr])* + Known::$var(ref t) => t.fmt(f), + )+ + } + } + } + + $( + #[doc(hidden)] + $(#[$attr])* + impl From<$ty> for Known { + fn from(ty: $ty) -> Known { + Known::$var(ty) + } + } + )+ + ); +} + +enum_known! { + MethodNotAllowed(MethodNotAllowed), + InvalidHeader(InvalidHeader), + MissingHeader(MissingHeader), + MissingCookie(MissingCookie), + InvalidQuery(InvalidQuery), + LengthRequired(LengthRequired), + PayloadTooLarge(PayloadTooLarge), + UnsupportedMediaType(UnsupportedMediaType), + FileOpenError(crate::fs::FileOpenError), + FilePermissionError(crate::fs::FilePermissionError), + BodyReadError(crate::body::BodyReadError), + BodyDeserializeError(crate::body::BodyDeserializeError), + CorsForbidden(crate::cors::CorsForbidden), + #[cfg(feature = "websocket")] + MissingConnectionUpgrade(crate::ws::MissingConnectionUpgrade), + MissingExtension(crate::ext::MissingExtension), + BodyConsumedMultipleTimes(crate::body::BodyConsumedMultipleTimes), +} + +impl Rejection { + fn known(known: Known) -> Self { + Rejection { + reason: Reason::Other(Box::new(Rejections::Known(known))), + } + } + + fn custom(other: Box<dyn Cause>) -> Self { + Rejection { + reason: Reason::Other(Box::new(Rejections::Custom(other))), + } + } + + /// Searches this `Rejection` for a specific cause. + /// + /// A `Rejection` will accumulate causes over a `Filter` chain. This method + /// can search through them and return the first cause of this type. + /// + /// # Example + /// + /// ``` + /// #[derive(Debug)] + /// struct Nope; + /// + /// impl warp::reject::Reject for Nope {} + /// + /// let reject = warp::reject::custom(Nope); + /// + /// if let Some(nope) = reject.find::<Nope>() { + /// println!("found it: {:?}", nope); + /// } + /// ``` + pub fn find<T: 'static>(&self) -> Option<&T> { + if let Reason::Other(ref rejections) = self.reason { + return rejections.find(); + } + None + } + + /// Returns true if this Rejection was made via `warp::reject::not_found`. + /// + /// # Example + /// + /// ``` + /// let rejection = warp::reject(); + /// + /// assert!(rejection.is_not_found()); + /// ``` + pub fn is_not_found(&self) -> bool { + matches!(self.reason, Reason::NotFound) + } +} + +impl<T: Reject> From<T> for Rejection { + #[inline] + fn from(err: T) -> Rejection { + custom(err) + } +} + +impl From<Infallible> for Rejection { + #[inline] + fn from(infallible: Infallible) -> Rejection { + match infallible {} + } +} + +impl IsReject for Infallible { + fn status(&self) -> StatusCode { + match *self {} + } + + fn into_response(&self) -> crate::reply::Response { + match *self {} + } +} + +impl IsReject for Rejection { + fn status(&self) -> StatusCode { + match self.reason { + Reason::NotFound => StatusCode::NOT_FOUND, + Reason::Other(ref other) => other.status(), + } + } + + fn into_response(&self) -> crate::reply::Response { + match self.reason { + Reason::NotFound => { + let mut res = http::Response::default(); + *res.status_mut() = StatusCode::NOT_FOUND; + res + } + Reason::Other(ref other) => other.into_response(), + } + } +} + +impl fmt::Debug for Rejection { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_tuple("Rejection").field(&self.reason).finish() + } +} + +impl fmt::Debug for Reason { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + match *self { + Reason::NotFound => f.write_str("NotFound"), + Reason::Other(ref other) => match **other { + Rejections::Known(ref e) => fmt::Debug::fmt(e, f), + Rejections::Custom(ref e) => fmt::Debug::fmt(e, f), + Rejections::Combined(ref a, ref b) => { + let mut list = f.debug_list(); + a.debug_list(&mut list); + b.debug_list(&mut list); + list.finish() + } + }, + } + } +} + +// ===== Rejections ===== + +impl Rejections { + fn status(&self) -> StatusCode { + match *self { + Rejections::Known(ref k) => match *k { + Known::MethodNotAllowed(_) => StatusCode::METHOD_NOT_ALLOWED, + Known::InvalidHeader(_) + | Known::MissingHeader(_) + | Known::MissingCookie(_) + | Known::InvalidQuery(_) + | Known::BodyReadError(_) + | Known::BodyDeserializeError(_) => StatusCode::BAD_REQUEST, + #[cfg(feature = "websocket")] + Known::MissingConnectionUpgrade(_) => StatusCode::BAD_REQUEST, + Known::LengthRequired(_) => StatusCode::LENGTH_REQUIRED, + Known::PayloadTooLarge(_) => StatusCode::PAYLOAD_TOO_LARGE, + Known::UnsupportedMediaType(_) => StatusCode::UNSUPPORTED_MEDIA_TYPE, + Known::FilePermissionError(_) | Known::CorsForbidden(_) => StatusCode::FORBIDDEN, + Known::FileOpenError(_) + | Known::MissingExtension(_) + | Known::BodyConsumedMultipleTimes(_) => StatusCode::INTERNAL_SERVER_ERROR, + }, + Rejections::Custom(..) => StatusCode::INTERNAL_SERVER_ERROR, + Rejections::Combined(ref a, ref b) => preferred(a, b).status(), + } + } + + fn into_response(&self) -> crate::reply::Response { + match *self { + Rejections::Known(ref e) => { + let mut res = http::Response::new(Body::from(e.to_string())); + *res.status_mut() = self.status(); + res.headers_mut().insert( + CONTENT_TYPE, + HeaderValue::from_static("text/plain; charset=utf-8"), + ); + res + } + Rejections::Custom(ref e) => { + tracing::error!( + "unhandled custom rejection, returning 500 response: {:?}", + e + ); + let body = format!("Unhandled rejection: {:?}", e); + let mut res = http::Response::new(Body::from(body)); + *res.status_mut() = self.status(); + res.headers_mut().insert( + CONTENT_TYPE, + HeaderValue::from_static("text/plain; charset=utf-8"), + ); + res + } + Rejections::Combined(ref a, ref b) => preferred(a, b).into_response(), + } + } + + fn find<T: 'static>(&self) -> Option<&T> { + match *self { + Rejections::Known(ref e) => e.inner_as_any().downcast_ref(), + Rejections::Custom(ref e) => e.downcast_ref(), + Rejections::Combined(ref a, ref b) => a.find().or_else(|| b.find()), + } + } + + fn debug_list(&self, f: &mut fmt::DebugList<'_, '_>) { + match *self { + Rejections::Known(ref e) => { + f.entry(e); + } + Rejections::Custom(ref e) => { + f.entry(e); + } + Rejections::Combined(ref a, ref b) => { + a.debug_list(f); + b.debug_list(f); + } + } + } +} + +fn preferred<'a>(a: &'a Rejections, b: &'a Rejections) -> &'a Rejections { + // Compare status codes, with this priority: + // - NOT_FOUND is lowest + // - METHOD_NOT_ALLOWED is second + // - if one status code is greater than the other + // - otherwise, prefer A... + match (a.status(), b.status()) { + (_, StatusCode::NOT_FOUND) => a, + (StatusCode::NOT_FOUND, _) => b, + (_, StatusCode::METHOD_NOT_ALLOWED) => a, + (StatusCode::METHOD_NOT_ALLOWED, _) => b, + (sa, sb) if sa < sb => b, + _ => a, + } +} + +unit_error! { + /// Invalid query + pub InvalidQuery: "Invalid query string" +} + +unit_error! { + /// HTTP method not allowed + pub MethodNotAllowed: "HTTP method not allowed" +} + +unit_error! { + /// A content-length header is required + pub LengthRequired: "A content-length header is required" +} + +unit_error! { + /// The request payload is too large + pub PayloadTooLarge: "The request payload is too large" +} + +unit_error! { + /// The request's content-type is not supported + pub UnsupportedMediaType: "The request's content-type is not supported" +} + +/// Missing request header +#[derive(Debug)] +pub struct MissingHeader { + name: &'static str, +} + +impl MissingHeader { + /// Retrieve the name of the header that was missing + pub fn name(&self) -> &str { + self.name + } +} + +impl fmt::Display for MissingHeader { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + write!(f, "Missing request header {:?}", self.name) + } +} + +impl StdError for MissingHeader {} + +/// Invalid request header +#[derive(Debug)] +pub struct InvalidHeader { + name: &'static str, +} + +impl InvalidHeader { + /// Retrieve the name of the header that was invalid + pub fn name(&self) -> &str { + self.name + } +} + +impl fmt::Display for InvalidHeader { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + write!(f, "Invalid request header {:?}", self.name) + } +} + +impl StdError for InvalidHeader {} + +/// Missing cookie +#[derive(Debug)] +pub struct MissingCookie { + name: &'static str, +} + +impl MissingCookie { + /// Retrieve the name of the cookie that was missing + pub fn name(&self) -> &str { + self.name + } +} + +impl fmt::Display for MissingCookie { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + write!(f, "Missing request cookie {:?}", self.name) + } +} + +impl StdError for MissingCookie {} + +mod sealed { + use super::{Reason, Rejection, Rejections}; + use http::StatusCode; + use std::convert::Infallible; + use std::fmt; + + // This sealed trait exists to allow Filters to return either `Rejection` + // or `!`. There are no other types that make sense, and so it is sealed. + pub trait IsReject: fmt::Debug + Send + Sync { + fn status(&self) -> StatusCode; + fn into_response(&self) -> crate::reply::Response; + } + + fn _assert_object_safe() { + fn _assert(_: &dyn IsReject) {} + } + + // This weird trait is to allow optimizations of propagating when a + // rejection can *never* happen (currently with the `Never` type, + // eventually to be replaced with `!`). + // + // Using this trait means the `Never` gets propagated to chained filters, + // allowing LLVM to eliminate more code paths. Without it, such as just + // requiring that `Rejection::from(Never)` were used in those filters, + // would mean that links later in the chain may assume a rejection *could* + // happen, and no longer eliminate those branches. + pub trait CombineRejection<E>: Send + Sized { + /// The type that should be returned when only 1 of the two + /// "rejections" occurs. + /// + /// # For example: + /// + /// `warp::any().and(warp::path("foo"))` has the following steps: + /// + /// 1. Since this is `and`, only **one** of the rejections will occur, + /// and as soon as it does, it will be returned. + /// 2. `warp::any()` rejects with `Never`. So, it will never return `Never`. + /// 3. `warp::path()` rejects with `Rejection`. It may return `Rejection`. + /// + /// Thus, if the above filter rejects, it will definitely be `Rejection`. + type One: IsReject + From<Self> + From<E> + Into<Rejection>; + + /// The type that should be returned when both rejections occur, + /// and need to be combined. + type Combined: IsReject; + + fn combine(self, other: E) -> Self::Combined; + } + + impl CombineRejection<Rejection> for Rejection { + type One = Rejection; + type Combined = Rejection; + + fn combine(self, other: Rejection) -> Self::Combined { + let reason = match (self.reason, other.reason) { + (Reason::Other(left), Reason::Other(right)) => { + Reason::Other(Box::new(Rejections::Combined(left, right))) + } + (Reason::Other(other), Reason::NotFound) + | (Reason::NotFound, Reason::Other(other)) => { + // ignore the NotFound + Reason::Other(other) + } + (Reason::NotFound, Reason::NotFound) => Reason::NotFound, + }; + + Rejection { reason } + } + } + + impl CombineRejection<Infallible> for Rejection { + type One = Rejection; + type Combined = Infallible; + + fn combine(self, other: Infallible) -> Self::Combined { + match other {} + } + } + + impl CombineRejection<Rejection> for Infallible { + type One = Rejection; + type Combined = Infallible; + + fn combine(self, _: Rejection) -> Self::Combined { + match self {} + } + } + + impl CombineRejection<Infallible> for Infallible { + type One = Infallible; + type Combined = Infallible; + + fn combine(self, _: Infallible) -> Self::Combined { + match self {} + } + } +} + +#[cfg(test)] +mod tests { + use super::*; + use http::StatusCode; + + #[derive(Debug, PartialEq)] + struct Left; + + #[derive(Debug, PartialEq)] + struct Right; + + impl Reject for Left {} + impl Reject for Right {} + + #[test] + fn rejection_status() { + assert_eq!(not_found().status(), StatusCode::NOT_FOUND); + assert_eq!( + method_not_allowed().status(), + StatusCode::METHOD_NOT_ALLOWED + ); + assert_eq!(length_required().status(), StatusCode::LENGTH_REQUIRED); + assert_eq!(payload_too_large().status(), StatusCode::PAYLOAD_TOO_LARGE); + assert_eq!( + unsupported_media_type().status(), + StatusCode::UNSUPPORTED_MEDIA_TYPE + ); + assert_eq!(custom(Left).status(), StatusCode::INTERNAL_SERVER_ERROR); + } + + #[tokio::test] + async fn combine_rejection_causes_with_some_left_and_none_right() { + let left = custom(Left); + let right = not_found(); + let reject = left.combine(right); + let resp = reject.into_response(); + + assert_eq!(resp.status(), StatusCode::INTERNAL_SERVER_ERROR); + assert_eq!( + response_body_string(resp).await, + "Unhandled rejection: Left" + ) + } + + #[tokio::test] + async fn combine_rejection_causes_with_none_left_and_some_right() { + let left = not_found(); + let right = custom(Right); + let reject = left.combine(right); + let resp = reject.into_response(); + + assert_eq!(resp.status(), StatusCode::INTERNAL_SERVER_ERROR); + assert_eq!( + response_body_string(resp).await, + "Unhandled rejection: Right" + ) + } + + #[tokio::test] + async fn unhandled_customs() { + let reject = not_found().combine(custom(Right)); + + let resp = reject.into_response(); + assert_eq!(resp.status(), StatusCode::INTERNAL_SERVER_ERROR); + assert_eq!( + response_body_string(resp).await, + "Unhandled rejection: Right" + ); + + // There's no real way to determine which is worse, since both are a 500, + // so pick the first one. + let reject = custom(Left).combine(custom(Right)); + + let resp = reject.into_response(); + assert_eq!(resp.status(), StatusCode::INTERNAL_SERVER_ERROR); + assert_eq!( + response_body_string(resp).await, + "Unhandled rejection: Left" + ); + + // With many rejections, custom still is top priority. + let reject = not_found() + .combine(not_found()) + .combine(not_found()) + .combine(custom(Right)) + .combine(not_found()); + + let resp = reject.into_response(); + assert_eq!(resp.status(), StatusCode::INTERNAL_SERVER_ERROR); + assert_eq!( + response_body_string(resp).await, + "Unhandled rejection: Right" + ); + } + + async fn response_body_string(resp: crate::reply::Response) -> String { + let (_, body) = resp.into_parts(); + let body_bytes = hyper::body::to_bytes(body).await.expect("failed concat"); + String::from_utf8_lossy(&body_bytes).to_string() + } + + #[test] + fn find_cause() { + let rej = custom(Left); + + assert_eq!(rej.find::<Left>(), Some(&Left)); + + let rej = rej.combine(method_not_allowed()); + + assert_eq!(rej.find::<Left>(), Some(&Left)); + assert!(rej.find::<MethodNotAllowed>().is_some(), "MethodNotAllowed"); + } + + #[test] + fn size_of_rejection() { + assert_eq!( + ::std::mem::size_of::<Rejection>(), + ::std::mem::size_of::<usize>(), + ); + } + + #[derive(Debug)] + struct X(u32); + impl Reject for X {} + + fn combine_n<F, R>(n: u32, new_reject: F) -> Rejection + where + F: Fn(u32) -> R, + R: Reject, + { + let mut rej = not_found(); + + for i in 0..n { + rej = rej.combine(custom(new_reject(i))); + } + + rej + } + + #[test] + fn test_debug() { + let rej = combine_n(3, X); + + let s = format!("{:?}", rej); + assert_eq!(s, "Rejection([X(0), X(1), X(2)])"); + } +} |