synapse/rust/src/http.rs

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/*
* This file is licensed under the Affero General Public License (AGPL) version 3.
*
* Copyright (C) 2024 New Vector, Ltd
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* See the GNU Affero General Public License for more details:
* <https://www.gnu.org/licenses/agpl-3.0.html>.
*/
use bytes::{Buf, BufMut, Bytes, BytesMut};
use headers::{Header, HeaderMapExt};
use http::{HeaderName, HeaderValue, Method, Request, Response, StatusCode, Uri};
use pyo3::{
exceptions::PyValueError,
types::{PyAnyMethods, PyBytes, PyBytesMethods, PySequence, PyTuple},
Bound, PyAny, PyResult,
};
use crate::errors::SynapseError;
/// Read a file-like Python object by chunks
///
/// # Errors
///
/// Returns an error if calling the `read` on the Python object failed
fn read_io_body(body: &Bound<'_, PyAny>, chunk_size: usize) -> PyResult<Bytes> {
let mut buf = BytesMut::new();
loop {
let bound = &body.call_method1("read", (chunk_size,))?;
let bytes: &Bound<'_, PyBytes> = bound.downcast()?;
if bytes.as_bytes().is_empty() {
return Ok(buf.into());
}
buf.put(bytes.as_bytes());
}
}
/// Transform a Twisted `IRequest` to an [`http::Request`]
///
/// It uses the following members of `IRequest`:
/// - `content`, which is expected to be a file-like object with a `read` method
/// - `uri`, which is expected to be a valid URI as `bytes`
/// - `method`, which is expected to be a valid HTTP method as `bytes`
/// - `requestHeaders`, which is expected to have a `getAllRawHeaders` method
///
/// # Errors
///
/// Returns an error if the Python object doesn't properly implement `IRequest`
pub fn http_request_from_twisted(request: &Bound<'_, PyAny>) -> PyResult<Request<Bytes>> {
let content = request.getattr("content")?;
let body = read_io_body(&content, 4096)?;
let mut req = Request::new(body);
let bound = &request.getattr("uri")?;
let uri: &Bound<'_, PyBytes> = bound.downcast()?;
*req.uri_mut() =
Uri::try_from(uri.as_bytes()).map_err(|_| PyValueError::new_err("invalid uri"))?;
let bound = &request.getattr("method")?;
let method: &Bound<'_, PyBytes> = bound.downcast()?;
*req.method_mut() = Method::from_bytes(method.as_bytes())
.map_err(|_| PyValueError::new_err("invalid method"))?;
let headers_iter = request
.getattr("requestHeaders")?
.call_method0("getAllRawHeaders")?
.iter()?;
for header in headers_iter {
let header = header?;
let header: &Bound<'_, PyTuple> = header.downcast()?;
let bound = &header.get_item(0)?;
let name: &Bound<'_, PyBytes> = bound.downcast()?;
let name = HeaderName::from_bytes(name.as_bytes())
.map_err(|_| PyValueError::new_err("invalid header name"))?;
let bound = &header.get_item(1)?;
let values: &Bound<'_, PySequence> = bound.downcast()?;
for index in 0..values.len()? {
let bound = &values.get_item(index)?;
let value: &Bound<'_, PyBytes> = bound.downcast()?;
let value = HeaderValue::from_bytes(value.as_bytes())
.map_err(|_| PyValueError::new_err("invalid header value"))?;
req.headers_mut().append(name.clone(), value);
}
}
Ok(req)
}
/// Send an [`http::Response`] through a Twisted `IRequest`
///
/// It uses the following members of `IRequest`:
///
/// - `responseHeaders`, which is expected to have a `addRawHeader(bytes, bytes)` method
/// - `setResponseCode(int)` method
/// - `write(bytes)` method
/// - `finish()` method
///
/// # Errors
///
/// Returns an error if the Python object doesn't properly implement `IRequest`
pub fn http_response_to_twisted<B>(
request: &Bound<'_, PyAny>,
response: Response<B>,
) -> PyResult<()>
where
B: Buf,
{
let (parts, mut body) = response.into_parts();
request.call_method1("setResponseCode", (parts.status.as_u16(),))?;
let response_headers = request.getattr("responseHeaders")?;
for (name, value) in parts.headers.iter() {
response_headers.call_method1("addRawHeader", (name.as_str(), value.as_bytes()))?;
}
while body.remaining() != 0 {
let chunk = body.chunk();
request.call_method1("write", (chunk,))?;
body.advance(chunk.len());
}
request.call_method0("finish")?;
Ok(())
}
/// An extension trait for [`HeaderMap`] that provides typed access to headers, and throws the
/// right python exceptions when the header is missing or fails to parse.
///
/// [`HeaderMap`]: headers::HeaderMap
pub trait HeaderMapPyExt: HeaderMapExt {
/// Get a header from the map, returning an error if it is missing or invalid.
fn typed_get_required<H>(&self) -> PyResult<H>
where
H: Header,
{
self.typed_get_optional::<H>()?.ok_or_else(|| {
SynapseError::new(
StatusCode::BAD_REQUEST,
format!("Missing required header: {}", H::name()),
"M_MISSING_PARAM",
None,
None,
)
})
}
/// Get a header from the map, returning `None` if it is missing and an error if it is invalid.
fn typed_get_optional<H>(&self) -> PyResult<Option<H>>
where
H: Header,
{
self.typed_try_get::<H>().map_err(|_| {
SynapseError::new(
StatusCode::BAD_REQUEST,
format!("Invalid header: {}", H::name()),
"M_INVALID_PARAM",
None,
None,
)
})
}
}
impl<T: HeaderMapExt> HeaderMapPyExt for T {}