yumechi-no-kuni-proxy-worker/src/fetch/mod.rs
eternal-flame-AD dc619349d4
fix via formatting
Signed-off-by: eternal-flame-AD <yume@yumechi.jp>
2024-11-23 04:49:57 -06:00

644 lines
22 KiB
Rust

use crate::{ErrorResponse, FetchConfig, MAX_SIZE};
use axum::{
body::Bytes,
extract::FromRequestParts,
http::{request::Parts, HeaderMap},
};
use std::{borrow::Cow, collections::HashSet, convert::Infallible, pin::Pin};
/// Default maximum number of redirects to follow
pub const DEFAULT_MAX_REDIRECTS: usize = 6;
/// Some context about the request for writing response and logging
#[allow(missing_docs)]
pub struct RequestCtx<'a> {
pub time_to_body: std::time::Duration,
pub url: &'a str,
pub secure: bool,
}
const fn http_version_to_via(v: axum::http::Version) -> &'static str {
#[allow(clippy::match_same_arms)]
match v {
axum::http::Version::HTTP_09 => "0.9",
axum::http::Version::HTTP_10 => "1.0",
axum::http::Version::HTTP_11 => "1.1",
axum::http::Version::HTTP_2 => "2.0",
axum::http::Version::HTTP_3 => "3.0",
_ => "1.1",
}
}
/// Trait for HTTP responses
pub trait HTTPResponse {
/// Type of the byte buffer
type Bytes: Into<Vec<u8>> + AsRef<[u8]> + Into<Bytes> + Send + 'static;
/// Type of body stream
type BodyStream: futures::Stream<Item = Result<Self::Bytes, ErrorResponse>> + Send + 'static;
/// Get some context about the request
fn request(&self) -> RequestCtx<'_>;
/// Get the status code
fn status(&self) -> u16;
/// Get a header value
fn header_one<'a>(&'a self, name: &str) -> Result<Option<Cow<'a, str>>, ErrorResponse>;
/// Walk through all headers with a callback
fn header_walk<F: FnMut(&str, &str) -> bool>(&self, f: F);
/// Collect all headers
fn header_collect(&self, out: &mut HeaderMap) -> Result<(), ErrorResponse>;
/// Get the body stream
fn body(self) -> Self::BodyStream;
}
/// Information about the incoming request
pub struct IncomingInfo {
version: axum::http::Version,
user_agent: String,
via: String,
}
impl IncomingInfo {
/// Check if the request is potentially looping
#[must_use]
pub fn looping(&self, self_via: &str) -> bool {
if self.user_agent.is_empty() {
return true;
}
if self.via.contains(self_via) {
return true;
}
// defense against upstream
if self.user_agent.contains("Misskey/") ||
// Purposefully typoed
// https://raw.githubusercontent.com/backrunner/misskey-media-proxy-worker/refs/heads/main/wrangler.toml
self.user_agent.contains("Edg/119.0.2109.1")
{
return true;
}
let split = self.via.split(", ");
let mut seen = HashSet::new();
for part in split {
if !seen.insert(part) {
return true;
}
}
false
}
}
#[axum::async_trait]
impl<S> FromRequestParts<S> for IncomingInfo {
type Rejection = Infallible;
async fn from_request_parts(parts: &mut Parts, _state: &S) -> Result<Self, Self::Rejection> {
Ok(Self {
version: parts.version,
user_agent: parts
.headers
.get("user-agent")
.and_then(|v| v.to_str().ok())
.unwrap_or_default()
.to_string(),
via: parts
.headers
.get_all("via")
.into_iter()
.fold(String::new(), |mut acc, v| {
if !acc.is_empty() {
acc.push_str(", ");
}
acc.push_str(v.to_str().unwrap_or_default());
acc
}),
})
}
}
/// Trait for upstream clients
pub trait UpstreamClient {
/// Type of the response
type Response: HTTPResponse;
/// Create a new client
fn new(config: &FetchConfig) -> Self;
/// Request the upstream
fn request_upstream(
&self,
info: &IncomingInfo,
url: &str,
polish: bool,
secure: bool,
remaining: usize,
) -> impl std::future::Future<Output = Result<Self::Response, ErrorResponse>>;
}
/// Reqwest client
#[cfg(feature = "reqwest")]
pub mod reqwest {
use crate::config::AddrFamilyConfig;
use super::{
http_version_to_via, Cow, ErrorResponse, HTTPResponse, HeaderMap, Pin, RequestCtx,
UpstreamClient, MAX_SIZE,
};
use ::reqwest::{redirect::Policy, ClientBuilder, Url};
use axum::body::Bytes;
use futures::TryStreamExt;
use reqwest::dns::Resolve;
use std::{net::SocketAddrV4, sync::Arc, time::Duration};
use url::Host;
/// A Safe DNS resolver that only resolves to global addresses unless the requester itself is local.
pub struct SafeResolver(AddrFamilyConfig);
// pulled from https://doc.rust-lang.org/src/core/net/ip_addr.rs.html#1650
const fn is_unicast_local_v6(ip: &std::net::Ipv6Addr) -> bool {
(ip.segments()[0] & 0xfe00) == 0xfc00
}
const fn is_unicast_link_local_v6(ip: &std::net::Ipv6Addr) -> bool {
(ip.segments()[0] & 0xffc0) == 0xfe80
}
impl Resolve for SafeResolver {
fn resolve(&self, name: reqwest::dns::Name) -> reqwest::dns::Resolving {
let af = self.0;
Box::pin(async move {
log::trace!("Resolving {}", name.as_str());
match tokio::net::lookup_host(format!("{}:443", name.as_str())).await {
Ok(lookup) => Ok(Box::new(
lookup
.map(|addr| match addr {
std::net::SocketAddr::V6(a) => {
if let Some(v4) = a.ip().to_ipv4() {
std::net::SocketAddr::V4(SocketAddrV4::new(v4, a.port()))
} else {
std::net::SocketAddr::V6(a)
}
}
std::net::SocketAddr::V4(a) => std::net::SocketAddr::V4(a),
})
.filter(move |addr| match addr {
std::net::SocketAddr::V4(a) if af != AddrFamilyConfig::V6Only => {
log::trace!("Resolved v4 addr {}", a);
!a.ip().is_loopback()
&& !a.ip().is_private()
&& !a.ip().is_link_local()
&& !a.ip().is_multicast()
&& !a.ip().is_documentation()
&& !a.ip().is_unspecified()
}
std::net::SocketAddr::V6(a) if af != AddrFamilyConfig::V4Only => {
log::trace!("Resolved v6 addr {}", a);
!a.ip().is_loopback()
&& !a.ip().is_multicast()
&& !a.ip().is_unspecified()
&& !is_unicast_local_v6(a.ip())
&& !is_unicast_link_local_v6(a.ip())
}
_ => false,
}),
)
as Box<dyn Iterator<Item = std::net::SocketAddr> + Send>),
Err(e) => {
log::error!("Failed to resolve {}: {}", name.as_str(), e);
Err(e.into())
}
}
})
}
}
/// Reqwest client
pub struct ReqwestClient {
https_only: bool,
via_ident: String,
client: ::reqwest::Client,
}
/// Response from Reqwest
pub struct ReqwestResponse {
time_to_body: std::time::Duration,
resp: ::reqwest::Response,
}
impl HTTPResponse for ReqwestResponse {
type Bytes = Bytes;
type BodyStream = Pin<
Box<dyn futures::Stream<Item = Result<Self::Bytes, ErrorResponse>> + Send + 'static>,
>;
fn request(&self) -> RequestCtx<'_> {
RequestCtx {
time_to_body: self.time_to_body,
url: self.resp.url().as_str(),
secure: self.resp.url().scheme().eq_ignore_ascii_case("https"),
}
}
fn status(&self) -> u16 {
self.resp.status().as_u16()
}
fn header_one<'a>(&'a self, name: &str) -> Result<Option<Cow<'a, str>>, ErrorResponse> {
self.resp
.headers()
.get(name)
.map(|v| v.to_str().map(Cow::Borrowed))
.transpose()
.map_err(|_| ErrorResponse::upstream_protocol_error())
}
fn header_walk<F: FnMut(&str, &str) -> bool>(&self, mut f: F) {
for (name, value) in self.resp.headers() {
if !f(name.as_str(), value.to_str().unwrap_or_default()) {
break;
}
}
}
fn header_collect(&self, out: &mut HeaderMap) -> Result<(), ErrorResponse> {
for (name, value) in self.resp.headers() {
out.insert(name, value.clone());
}
Ok(())
}
fn body(self) -> Self::BodyStream {
Box::pin(self.resp.bytes_stream().map_err(Into::into))
}
}
impl UpstreamClient for ReqwestClient {
type Response = ReqwestResponse;
fn new(config: &crate::FetchConfig) -> Self {
Self {
https_only: !config.allow_http,
via_ident: config.via.clone(),
client: ClientBuilder::new()
.https_only(!config.allow_http)
.dns_resolver(Arc::new(SafeResolver(config.addr_family)))
.brotli(true)
.zstd(true)
.gzip(true)
.redirect(Policy::none())
.connect_timeout(Duration::from_secs(5))
.timeout(Duration::from_secs(15))
.user_agent(config.user_agent.clone())
.build()
.expect("Failed to create reqwest client"),
}
}
async fn request_upstream(
&self,
info: &super::IncomingInfo,
url: &str,
polish: bool,
mut secure: bool,
remaining: usize,
) -> Result<ReqwestResponse, ErrorResponse> {
if remaining == 0 {
return Err(ErrorResponse::too_many_redirects());
}
if info.looping(&self.via_ident) {
return Err(ErrorResponse::loop_detected());
}
let url_parsed = Url::parse(url).map_err(|_| ErrorResponse::bad_url())?;
if !url_parsed.host().map_or(false, |h| match h {
Host::Domain(_) => true,
_ => false,
}) {
return Err(ErrorResponse::non_dns_name());
}
secure &= url_parsed.scheme().eq_ignore_ascii_case("https");
if self.https_only && !secure {
return Err(ErrorResponse::insecure_request());
}
let begin = crate::timing::Instant::now();
let resp = self
.client
.get(url_parsed)
.header(
"via",
format!(
"{}, {} {}",
info.via,
http_version_to_via(info.version),
self.via_ident
),
)
.send()
.await?;
if resp.status().is_redirection() {
if let Some(location) = resp.headers().get("location").and_then(|l| l.to_str().ok())
{
return Box::pin(self.request_upstream(
info,
location,
polish,
secure,
remaining - 1,
))
.await;
}
return Err(ErrorResponse::missing_location());
}
if !resp.status().is_success() {
return Err(ErrorResponse::unexpected_status(
url,
resp.status().as_u16(),
));
}
let content_length = resp.headers().get("content-length");
if let Some(content_length) = content_length.and_then(|c| c.to_str().ok()) {
if content_length.parse::<usize>().unwrap_or(0) > MAX_SIZE {
return Err(ErrorResponse::payload_too_large());
}
}
let content_type = resp.headers().get("content-type");
if let Some(content_type) = content_type.and_then(|c| c.to_str().ok()) {
if !["image/", "video/", "audio/", "application/octet-stream"]
.iter()
.any(|prefix| {
content_type[..prefix.len().min(content_type.len())]
.eq_ignore_ascii_case(prefix)
})
{
return Err(ErrorResponse::not_media());
}
}
Ok(ReqwestResponse {
time_to_body: begin.elapsed(),
resp,
})
}
}
}
/// Cloudflare Workers client
#[cfg(feature = "cf-worker")]
#[cfg_attr(
not(target_arch = "wasm32"),
deprecated = "You should use reqwest instead when not on Cloudflare Workers"
)]
pub mod cf_worker {
use std::time::Duration;
use super::{
http_version_to_via, Cow, ErrorResponse, HTTPResponse, HeaderMap, Pin, RequestCtx,
UpstreamClient, MAX_SIZE,
};
use axum::http::{HeaderName, HeaderValue};
use futures::{Stream, TryFutureExt};
use worker::{
AbortController, ByteStream, CfProperties, Fetch, Headers, Method, PolishConfig, Request,
RequestInit, RequestRedirect, Url,
};
/// Cloudflare Workers client
pub struct CfWorkerClient {
https_only: bool,
user_agent: String,
via_ident: String,
}
/// Wrapper for the body stream
pub struct CfBodyStreamWrapper {
stream: Option<Result<ByteStream, ErrorResponse>>,
}
impl Stream for CfBodyStreamWrapper {
type Item = Result<Vec<u8>, ErrorResponse>;
fn poll_next(
self: Pin<&mut Self>,
cx: &mut std::task::Context<'_>,
) -> std::task::Poll<Option<Self::Item>> {
let this = self.get_mut();
match this.stream.as_mut() {
Some(Ok(stream)) => match futures::ready!(std::pin::pin!(stream).poll_next(cx)) {
Some(Ok(chunk)) => std::task::Poll::Ready(Some(Ok(chunk))),
Some(Err(e)) => std::task::Poll::Ready(Some(Err(ErrorResponse::from(e)))),
None => std::task::Poll::Ready(None),
},
Some(Err(e)) => std::task::Poll::Ready(Some(Err(e.clone()))),
None => std::task::Poll::Ready(None),
}
}
fn size_hint(&self) -> (usize, Option<usize>) {
match self.stream {
Some(Ok(ref stream)) => stream.size_hint(),
_ => (0, None),
}
}
}
#[allow(unsafe_code, reason = "this is never used concurrently")]
unsafe impl Send for CfBodyStreamWrapper {}
#[allow(unsafe_code, reason = "this is never used concurrently")]
unsafe impl Sync for CfBodyStreamWrapper {}
/// Response from Cloudflare Workers
pub struct CfWorkerResponse {
time_to_body: std::time::Duration,
resp: worker::Response,
url: Url,
}
impl HTTPResponse for CfWorkerResponse {
type Bytes = Vec<u8>;
type BodyStream = CfBodyStreamWrapper;
fn request(&self) -> RequestCtx<'_> {
RequestCtx {
time_to_body: self.time_to_body,
url: self.url.as_str(),
secure: self.url.scheme().eq_ignore_ascii_case("https"),
}
}
fn status(&self) -> u16 {
self.resp.status_code()
}
fn header_one<'a>(&'a self, name: &str) -> Result<Option<Cow<'a, str>>, ErrorResponse> {
self.resp
.headers()
.get(name)
.map(|v| v.map(|v| Cow::Owned(v.to_string())))
.map_err(|_| ErrorResponse::upstream_protocol_error())
}
fn header_walk<F: FnMut(&str, &str) -> bool>(&self, mut f: F) {
for (name, value) in self.resp.headers().entries() {
if !f(&name, &value) {
break;
}
}
}
fn header_collect(&self, out: &mut HeaderMap) -> Result<(), ErrorResponse> {
for name in self.resp.headers().keys() {
out.insert(
HeaderName::from_bytes(name.as_bytes())
.map_err(|_| ErrorResponse::upstream_protocol_error())?,
self.resp
.headers()
.get(&name)
.map_err(|_| ErrorResponse::upstream_protocol_error())?
.map(HeaderValue::try_from)
.transpose()
.map_err(|_| ErrorResponse::upstream_protocol_error())?
.ok_or(ErrorResponse::upstream_protocol_error())?,
);
}
Ok(())
}
fn body(mut self) -> Self::BodyStream {
let stream = self.resp.stream().map_err(ErrorResponse::from);
CfBodyStreamWrapper {
stream: Some(stream),
}
}
}
impl UpstreamClient for CfWorkerClient {
type Response = CfWorkerResponse;
fn new(config: &crate::FetchConfig) -> Self {
Self {
https_only: !config.allow_http,
user_agent: config.user_agent.clone(),
via_ident: config.via.clone(),
}
}
async fn request_upstream(
&self,
info: &super::IncomingInfo,
url: &str,
polish: bool,
mut secure: bool,
remaining: usize,
) -> Result<Self::Response, ErrorResponse> {
if remaining == 0 {
return Err(ErrorResponse::too_many_redirects());
}
if info.looping(&self.via_ident) {
return Err(ErrorResponse::loop_detected());
}
let mut headers = Headers::new();
headers.set("user-agent", &self.user_agent)?;
headers.set(
"via",
&format!(
"{}, {} {}",
info.via,
http_version_to_via(info.version),
self.via_ident
),
)?;
let mut prop = CfProperties::new();
if polish {
prop.polish = Some(PolishConfig::Lossless);
}
let mut init = RequestInit::new();
let init = init
.with_method(Method::Get)
.with_headers(headers)
.with_cf_properties(prop)
.with_redirect(RequestRedirect::Manual);
let url_parsed = Url::parse(url).map_err(|_| ErrorResponse::bad_url())?;
if self.https_only && !url_parsed.scheme().eq_ignore_ascii_case("https") {
return Err(ErrorResponse::insecure_request());
}
secure &= url_parsed.scheme().eq_ignore_ascii_case("http");
let begin = crate::timing::Instant::now();
let req = Request::new_with_init(url, init)?;
let abc = AbortController::default();
let abs = abc.signal();
let req = Fetch::Request(req);
worker::wasm_bindgen_futures::spawn_local(async move {
worker::Delay::from(Duration::from_secs(5)).await;
abc.abort();
});
let resp = std::pin::pin!(req
.send_with_signal(&abs)
.map_err(ErrorResponse::worker_fetch_error))
.await?;
if resp.status_code() >= 300 && resp.status_code() < 400 {
if let Ok(Some(location)) = resp.headers().get("location") {
return Box::pin(self.request_upstream(
info,
&location,
polish,
secure,
remaining - 1,
))
.await;
}
return Err(ErrorResponse::missing_location());
}
if resp.status_code() < 200 || resp.status_code() >= 300 {
return Err(ErrorResponse::unexpected_status(url, resp.status_code()));
}
let content_length = resp.headers().get("content-length").unwrap_or_default();
if let Some(content_length) = content_length {
if content_length.parse::<usize>().unwrap_or(0) > MAX_SIZE {
return Err(ErrorResponse::payload_too_large());
}
}
let content_type = resp.headers().get("content-type").unwrap_or_default();
if let Some(content_type) = content_type {
if !["image/", "video/", "audio/", "application/octet-stream"]
.iter()
.any(|prefix| {
content_type.as_str()[..prefix.len().min(content_type.len())]
.eq_ignore_ascii_case(prefix)
})
{
return Err(ErrorResponse::not_media());
}
}
Ok(CfWorkerResponse {
time_to_body: begin.elapsed(),
resp,
url: url_parsed,
})
}
}
}