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|
use anyhow::bail;
use http::{
header::{AUTHORIZATION, CONNECTION, HOST, TRANSFER_ENCODING, UPGRADE},
HeaderValue, Method as HttpMethod, Request, Response, Uri,
};
use hyper::{client::HttpConnector, Body, Client};
use hyper_rustls::HttpsConnector;
use std::{
collections::hash_map::DefaultHasher,
convert::TryFrom,
hash::{Hash, Hasher},
str::FromStr,
sync::Arc,
};
use tracing::{debug_span, error, info_span, instrument, Instrument};
use twilight_http_ratelimiting::{Method, Path};
use crate::ratelimit_client::RemoteRatelimiter;
/// Normalizes the path
fn normalize_path(request_path: &str) -> (&str, &str) {
if let Some(trimmed_path) = request_path.strip_prefix("/api") {
if let Some(maybe_api_version) = trimmed_path.split('/').nth(1) {
if let Some(version_number) = maybe_api_version.strip_prefix('v') {
if version_number.parse::<u8>().is_ok() {
let len = "/api/v".len() + version_number.len();
return (&request_path[..len], &request_path[len..]);
};
};
}
("/api", trimmed_path)
} else {
("/api", request_path)
}
}
#[instrument]
pub async fn handle_request(
client: Client<HttpsConnector<HttpConnector>, Body>,
ratelimiter: Arc<RemoteRatelimiter>,
token: String,
mut request: Request<Body>,
) -> Result<Response<Body>, anyhow::Error> {
let (hash, uri_string) = {
let method = match *request.method() {
HttpMethod::DELETE => Method::Delete,
HttpMethod::GET => Method::Get,
HttpMethod::PATCH => Method::Patch,
HttpMethod::POST => Method::Post,
HttpMethod::PUT => Method::Put,
_ => {
error!("Unsupported HTTP method in request, {}", request.method());
bail!("unsupported method");
}
};
let request_path = request.uri().path();
let (api_path, trimmed_path) = normalize_path(request_path);
let mut uri_string = format!("https://discord.com{api_path}{trimmed_path}");
if let Some(query) = request.uri().query() {
uri_string.push('?');
uri_string.push_str(query);
}
let mut hash = DefaultHasher::new();
match Path::try_from((method, trimmed_path)) {
Ok(path) => path,
Err(e) => {
error!(
"Failed to parse path for {:?} {}: {:?}",
method, trimmed_path, e
);
bail!("failed to parse");
}
}
.hash(&mut hash);
(hash.finish().to_string(), uri_string)
};
// waits for the request to be authorized
ratelimiter
.ticket(hash.clone())
.instrument(debug_span!("ticket validation request"))
.await?;
request
.headers_mut()
.insert(HOST, HeaderValue::from_static("discord.com"));
// Remove forbidden HTTP/2 headers
// https://datatracker.ietf.org/doc/html/rfc7540#section-8.1.2.2
request.headers_mut().remove(CONNECTION);
request.headers_mut().remove("keep-alive");
request.headers_mut().remove("proxy-connection");
request.headers_mut().remove(TRANSFER_ENCODING);
request.headers_mut().remove(UPGRADE);
if let Some(auth) = request.headers_mut().get_mut(AUTHORIZATION) {
if auth
.to_str()
.expect("Failed to check header")
.starts_with("Bot")
{
*auth = HeaderValue::from_str(&format!("Bot {token}"))?;
}
} else {
request.headers_mut().insert(
AUTHORIZATION,
HeaderValue::from_str(&format!("Bot {token}"))?,
);
}
let uri = match Uri::from_str(&uri_string) {
Ok(uri) => uri,
Err(e) => {
error!("Failed to create URI for requesting Discord API: {:?}", e);
bail!("failed to create uri");
}
};
*request.uri_mut() = uri;
let span = debug_span!("upstream request to discord");
let resp = match client.request(request).instrument(span).await {
Ok(response) => response,
Err(e) => {
error!("Error when requesting the Discord API: {:?}", e);
bail!("failed to request the discord api");
}
};
let headers = resp
.headers()
.into_iter()
.map(|(k, v)| (k.to_string(), v.to_str().map(std::string::ToString::to_string)))
.filter(|f| f.1.is_ok())
.map(|f| (f.0, f.1.expect("errors should be filtered")))
.collect();
let _submit_headers = ratelimiter
.submit_headers(hash, headers)
.instrument(info_span!("submitting headers"))
.await;
Ok(resp)
}
|
