458 lines
18 KiB
Rust

//! Core types used to define the requests and responses for each endpoint in the various
//! [Matrix API specifications][apis].
//!
//! When implementing a new Matrix API, each endpoint has a request type which implements
//! [`IncomingRequest`] and [`OutgoingRequest`], and a response type connected via an associated
//! type.
//!
//! An implementation of [`IncomingRequest`] or [`OutgoingRequest`] contains all the information
//! about the HTTP method, the path and input parameters for requests, and the structure of a
//! successful response. Such types can then be used by client code to make requests, and by server
//! code to fulfill those requests.
//!
//! [apis]: https://spec.matrix.org/v1.2/#matrix-apis
use std::{convert::TryInto as _, error::Error as StdError, fmt};
use bytes::BufMut;
use tracing::warn;
use crate::UserId;
/// Generates [`IncomingRequest`] and [`OutgoingRequest`] from a concise definition.
///
/// The macro expects the following structure as input:
///
/// ```text
/// ruma_api! {
/// metadata: {
/// description: &'static str,
/// method: http::Method,
/// name: &'static str,
/// path: &'static str,
/// rate_limited: bool,
/// authentication: ruma_common::api::AuthScheme,
/// }
///
/// request: {
/// // Struct fields for each piece of data required
/// // to make a request to this API endpoint.
/// }
///
/// response: {
/// // Struct fields for each piece of data expected
/// // in the response from this API endpoint.
/// }
///
/// // The error returned when a response fails, defaults to `MatrixError`.
/// error: path::to::Error
/// }
/// ```
///
/// This will generate a [`Metadata`] value to be used for the associated constants of
/// [`IncomingRequest`] and [`OutgoingRequest`], single `Request` and `Response` structs, and
/// the necessary trait implementations to convert the request into a `http::Request` and to
/// create a response from a `http::Response` and vice versa.
///
/// The details of each of the three sections of the macros are documented below.
///
/// ## Metadata
///
/// * `description`: A short description of what the endpoint does.
/// * `method`: The HTTP method used for requests to the endpoint. It's not necessary to import
/// `http::Method`'s associated constants. Just write the value as if it was imported, e.g.
/// `GET`.
/// * `name`: A unique name for the endpoint. Generally this will be the same as the containing
/// module.
/// * `path`: The path component of the URL for the endpoint, e.g. "/foo/bar". Components of
/// the path that are parameterized can indicate a variable by using a Rust identifier
/// prefixed with a colon, e.g. `/foo/:some_parameter`. A corresponding query string
/// parameter will be expected in the request struct (see below for details).
/// * `rate_limited`: Whether or not the endpoint enforces rate limiting on requests.
/// * `authentication`: What authentication scheme the endpoint uses.
///
/// ## Request
///
/// The request block contains normal struct field definitions. Doc comments and attributes are
/// allowed as normal. There are also a few special attributes available to control how the
/// struct is converted into an `http::Request`:
///
/// * `#[ruma_api(header = HEADER_NAME)]`: Fields with this attribute will be treated as HTTP
/// headers on the request. The value must implement `AsRef<str>`. Generally this is a
/// `String`. The attribute value shown above as `HEADER_NAME` must be a header name constant
/// from `http::header`, e.g. `CONTENT_TYPE`.
/// * `#[ruma_api(path)]`: Fields with this attribute will be inserted into the matching path
/// component of the request URL.
/// * `#[ruma_api(query)]`: Fields with this attribute will be inserting into the URL's query
/// string.
/// * `#[ruma_api(query_map)]`: Instead of individual query fields, one query_map field, of any
/// type that implements `IntoIterator<Item = (String, String)>` (e.g. `HashMap<String,
/// String>`, can be used for cases where an endpoint supports arbitrary query parameters.
///
/// Any field that does not include one of these attributes will be part of the request's JSON
/// body.
///
/// ## Response
///
/// Like the request block, the response block consists of normal struct field definitions.
/// Doc comments and attributes are allowed as normal.
/// There is also a special attribute available to control how the struct is created from a
/// `http::Request`:
///
/// * `#[ruma_api(header = HEADER_NAME)]`: Fields with this attribute will be treated as HTTP
/// headers on the response. The value must implement `AsRef<str>`. Generally this is a
/// `String`. The attribute value shown above as `HEADER_NAME` must be a header name constant
/// from `http::header`, e.g. `CONTENT_TYPE`.
///
/// Any field that does not include the above attribute will be expected in the response's JSON
/// body.
///
/// ## Newtype bodies
///
/// Both the request and response block also support "newtype bodies" by using the
/// `#[ruma_api(body)]` attribute on a field. If present on a field, the entire request or
/// response body will be treated as the value of the field. This allows you to treat the
/// entire request or response body as a specific type, rather than a JSON object with named
/// fields. Only one field in each struct can be marked with this attribute. It is an error to
/// have a newtype body field and normal body fields within the same struct.
///
/// There is another kind of newtype body that is enabled with `#[ruma_api(raw_body)]`. It is
/// used for endpoints in which the request or response body can be arbitrary bytes instead of
/// a JSON objects. A field with `#[ruma_api(raw_body)]` needs to have the type `Vec<u8>`.
///
/// # Examples
///
/// ```
/// pub mod some_endpoint {
/// use ruma_common::api::ruma_api;
///
/// ruma_api! {
/// metadata: {
/// description: "Does something.",
/// method: POST,
/// name: "some_endpoint",
/// stable_path: "/_matrix/some/endpoint/:baz",
/// rate_limited: false,
/// authentication: None,
/// added: 1.1,
/// }
///
/// request: {
/// pub foo: String,
///
/// #[ruma_api(header = CONTENT_TYPE)]
/// pub content_type: String,
///
/// #[ruma_api(query)]
/// pub bar: String,
///
/// #[ruma_api(path)]
/// pub baz: String,
/// }
///
/// response: {
/// #[ruma_api(header = CONTENT_TYPE)]
/// pub content_type: String,
///
/// pub value: String,
/// }
/// }
/// }
///
/// pub mod newtype_body_endpoint {
/// use ruma_common::api::ruma_api;
/// use serde::{Deserialize, Serialize};
///
/// #[derive(Clone, Debug, Deserialize, Serialize)]
/// pub struct MyCustomType {
/// pub foo: String,
/// }
///
/// ruma_api! {
/// metadata: {
/// description: "Does something.",
/// method: PUT,
/// name: "newtype_body_endpoint",
/// stable_path: "/_matrix/some/newtype/body/endpoint",
/// rate_limited: false,
/// authentication: None,
/// added: 1.1,
/// }
///
/// request: {
/// #[ruma_api(raw_body)]
/// pub file: &'a [u8],
/// }
///
/// response: {
/// #[ruma_api(body)]
/// pub my_custom_type: MyCustomType,
/// }
/// }
/// }
/// ```
pub use ruma_macros::ruma_api;
pub mod error;
mod metadata;
pub use metadata::{MatrixVersion, Metadata, VersioningDecision};
use error::{FromHttpRequestError, FromHttpResponseError, IntoHttpError};
/// An enum to control whether an access token should be added to outgoing requests
#[derive(Clone, Copy, Debug)]
#[allow(clippy::exhaustive_enums)]
pub enum SendAccessToken<'a> {
/// Add the given access token to the request only if the `METADATA` on the request requires
/// it.
IfRequired(&'a str),
/// Always add the access token.
Always(&'a str),
/// Don't add an access token.
///
/// This will lead to an error if the request endpoint requires authentication
None,
}
impl<'a> SendAccessToken<'a> {
/// Get the access token for an endpoint that requires one.
///
/// Returns `Some(_)` if `self` contains an access token.
pub fn get_required_for_endpoint(self) -> Option<&'a str> {
match self {
Self::IfRequired(tok) | Self::Always(tok) => Some(tok),
Self::None => None,
}
}
/// Get the access token for an endpoint that should not require one.
///
/// Returns `Some(_)` only if `self` is `SendAccessToken::Always(_)`.
pub fn get_not_required_for_endpoint(self) -> Option<&'a str> {
match self {
Self::Always(tok) => Some(tok),
Self::IfRequired(_) | Self::None => None,
}
}
}
/// A request type for a Matrix API endpoint, used for sending requests.
pub trait OutgoingRequest: Sized {
/// A type capturing the expected error conditions the server can return.
type EndpointError: EndpointError;
/// Response type returned when the request is successful.
type IncomingResponse: IncomingResponse<EndpointError = Self::EndpointError>;
/// Metadata about the endpoint.
const METADATA: Metadata;
/// Tries to convert this request into an `http::Request`.
///
/// On endpoints with authentication, when adequate information isn't provided through
/// access_token, this could result in an error. It may also fail with a serialization error
/// in case of bugs in Ruma though.
///
/// It may also fail if, for every version in `considering_versions`;
/// - The endpoint is too old, and has been removed in all versions.
/// ([`EndpointRemoved`](error::IntoHttpError::EndpointRemoved))
/// - The endpoint is too new, and no unstable path is known for this endpoint.
/// ([`NoUnstablePath`](error::IntoHttpError::NoUnstablePath))
///
/// Finally, this will emit a warning through `tracing` if it detects if any version in
/// `considering_versions` has deprecated this endpoint.
///
/// The endpoints path will be appended to the given `base_url`, for example
/// `https://matrix.org`. Since all paths begin with a slash, it is not necessary for the
/// `base_url` to have a trailing slash. If it has one however, it will be ignored.
fn try_into_http_request<T: Default + BufMut>(
self,
base_url: &str,
access_token: SendAccessToken<'_>,
considering_versions: &'_ [MatrixVersion],
) -> Result<http::Request<T>, IntoHttpError>;
}
/// A response type for a Matrix API endpoint, used for receiving responses.
pub trait IncomingResponse: Sized {
/// A type capturing the expected error conditions the server can return.
type EndpointError: EndpointError;
/// Tries to convert the given `http::Response` into this response type.
fn try_from_http_response<T: AsRef<[u8]>>(
response: http::Response<T>,
) -> Result<Self, FromHttpResponseError<Self::EndpointError>>;
}
/// An extension to [`OutgoingRequest`] which provides Appservice specific methods.
pub trait OutgoingRequestAppserviceExt: OutgoingRequest {
/// Tries to convert this request into an `http::Request` and appends a virtual `user_id` to
/// [assert Appservice identity][id_assert].
///
/// [id_assert]: https://spec.matrix.org/v1.2/application-service-api/#identity-assertion
fn try_into_http_request_with_user_id<T: Default + BufMut>(
self,
base_url: &str,
access_token: SendAccessToken<'_>,
user_id: &UserId,
considering_versions: &'_ [MatrixVersion],
) -> Result<http::Request<T>, IntoHttpError> {
let mut http_request =
self.try_into_http_request(base_url, access_token, considering_versions)?;
let user_id_query = crate::serde::urlencoded::to_string(&[("user_id", user_id)])?;
let uri = http_request.uri().to_owned();
let mut parts = uri.into_parts();
let path_and_query_with_user_id = match &parts.path_and_query {
Some(path_and_query) => match path_and_query.query() {
Some(_) => format!("{path_and_query}&{user_id_query}"),
None => format!("{path_and_query}?{user_id_query}"),
},
None => format!("/?{user_id_query}"),
};
parts.path_and_query =
Some(path_and_query_with_user_id.try_into().map_err(http::Error::from)?);
*http_request.uri_mut() = parts.try_into().map_err(http::Error::from)?;
Ok(http_request)
}
}
impl<T: OutgoingRequest> OutgoingRequestAppserviceExt for T {}
/// A request type for a Matrix API endpoint, used for receiving requests.
pub trait IncomingRequest: Sized {
/// A type capturing the error conditions that can be returned in the response.
type EndpointError: EndpointError;
/// Response type to return when the request is successful.
type OutgoingResponse: OutgoingResponse;
/// Metadata about the endpoint.
const METADATA: Metadata;
/// Tries to turn the given `http::Request` into this request type,
/// together with the corresponding path arguments.
///
/// Note: The strings in path_args need to be percent-decoded.
fn try_from_http_request<B, S>(
req: http::Request<B>,
path_args: &[S],
) -> Result<Self, FromHttpRequestError>
where
B: AsRef<[u8]>,
S: AsRef<str>;
}
/// A request type for a Matrix API endpoint, used for sending responses.
pub trait OutgoingResponse {
/// Tries to convert this response into an `http::Response`.
///
/// This method should only fail when when invalid header values are specified. It may also
/// fail with a serialization error in case of bugs in Ruma though.
fn try_into_http_response<T: Default + BufMut>(
self,
) -> Result<http::Response<T>, IntoHttpError>;
}
/// Gives users the ability to define their own serializable / deserializable errors.
pub trait EndpointError: OutgoingResponse + StdError + Sized + Send + 'static {
/// Tries to construct `Self` from an `http::Response`.
///
/// This will always return `Err` variant when no `error` field is defined in
/// the `ruma_api` macro.
fn try_from_http_response<T: AsRef<[u8]>>(
response: http::Response<T>,
) -> Result<Self, error::DeserializationError>;
}
/// Marker trait for requests that don't require authentication, for the client side.
pub trait OutgoingNonAuthRequest: OutgoingRequest {}
/// Marker trait for requests that don't require authentication, for the server side.
pub trait IncomingNonAuthRequest: IncomingRequest {}
/// Authentication scheme used by the endpoint.
#[derive(Copy, Clone, Debug, PartialEq, Eq)]
#[allow(clippy::exhaustive_enums)]
pub enum AuthScheme {
/// No authentication is performed.
None,
/// Authentication is performed by including an access token in the `Authentication` http
/// header, or an `access_token` query parameter.
///
/// It is recommended to use the header over the query parameter.
AccessToken,
/// Authentication is performed by including X-Matrix signatures in the request headers,
/// as defined in the federation API.
ServerSignatures,
/// Authentication is performed by setting the `access_token` query parameter.
QueryOnlyAccessToken,
}
// This function helps picks the right path (or an error) from a set of matrix versions.
//
// This function needs to be public, yet hidden, as all `try_into_http_request`s would be using it.
#[doc(hidden)]
pub fn select_path<'a>(
versions: &'_ [MatrixVersion],
metadata: &'_ Metadata,
unstable: Option<fmt::Arguments<'a>>,
r0: Option<fmt::Arguments<'a>>,
stable: Option<fmt::Arguments<'a>>,
) -> Result<fmt::Arguments<'a>, IntoHttpError> {
match metadata.versioning_decision_for(versions) {
VersioningDecision::Removed => Err(IntoHttpError::EndpointRemoved(
metadata.removed.expect("VersioningDecision::Removed implies metadata.removed"),
)),
VersioningDecision::Stable { any_deprecated, all_deprecated, any_removed } => {
if any_removed {
if all_deprecated {
warn!(
"endpoint {} is removed in some (and deprecated in ALL) of the following versions: {:?}",
metadata.name,
versions
);
} else if any_deprecated {
warn!(
"endpoint {} is removed (and deprecated) in some of the following versions: {:?}",
metadata.name,
versions
);
} else {
unreachable!("any_removed implies *_deprecated");
}
} else if all_deprecated {
warn!(
"endpoint {} is deprecated in ALL of the following versions: {:?}",
metadata.name, versions
);
} else if any_deprecated {
warn!(
"endpoint {} is deprecated in some of the following versions: {:?}",
metadata.name, versions
);
}
if let Some(r0) = r0 {
if versions.iter().all(|&v| v == MatrixVersion::V1_0) {
// Endpoint was added in 1.0, we return the r0 variant.
return Ok(r0);
}
}
Ok(stable.expect("metadata.added enforces the stable path to exist"))
}
VersioningDecision::Unstable => unstable.ok_or(IntoHttpError::NoUnstablePath),
}
}