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use hyper::Body;
use std::net::IpAddr;
use std::str::FromStr;
use hyper::header::{HeaderMap, HeaderValue};
use hyper::{Request, Response, Client, Uri, StatusCode};
use futures::future::{self, Future};
use lazy_static::lazy_static;
type BoxFut = Box<Future<Item=Response<Body>, Error=hyper::Error> + Send>;
fn is_hop_header(name: &str) -> bool {
use unicase::Ascii;
lazy_static! {
static ref HOP_HEADERS: Vec<Ascii<&'static str>> = vec![
Ascii::new("Connection"),
Ascii::new("Keep-Alive"),
Ascii::new("Proxy-Authenticate"),
Ascii::new("Proxy-Authorization"),
Ascii::new("Te"),
Ascii::new("Trailers"),
Ascii::new("Transfer-Encoding"),
Ascii::new("Upgrade"),
];
}
HOP_HEADERS.iter().any(|h| h == &name)
}
fn remove_hop_headers(headers: &HeaderMap<HeaderValue>) -> HeaderMap<HeaderValue> {
let mut result = HeaderMap::new();
for (k, v) in headers.iter() {
if !is_hop_header(k.as_str()) {
result.insert(k.clone(), v.clone());
}
}
result
}
fn create_proxied_response<B>(mut response: Response<B>) -> Response<B> {
*response.headers_mut() = remove_hop_headers(response.headers());
response
}
fn forward_uri<B>(forward_url: &str, req: &Request<B>) -> Uri {
let forward_uri = match req.uri().query() {
Some(query) => format!("{}{}?{}", forward_url, req.uri().path(), query),
None => format!("{}{}", forward_url, req.uri().path()),
};
Uri::from_str(forward_uri.as_str()).unwrap()
}
fn create_proxied_request<B>(client_ip: IpAddr, forward_url: &str, mut request: Request<B>) -> Request<B> {
*request.headers_mut() = remove_hop_headers(request.headers());
*request.uri_mut() = forward_uri(forward_url, &request);
let x_forwarded_for_header_name = "x-forwarded-for";
match request.headers_mut().entry(x_forwarded_for_header_name) {
Ok(header_entry) => {
match header_entry {
hyper::header::Entry::Vacant(entry) => {
let addr = format!("{}", client_ip);
entry.insert(addr.parse().unwrap());
},
hyper::header::Entry::Occupied(mut entry) => {
let addr = format!("{}, {}", entry.get().to_str().unwrap(), client_ip);
entry.insert(addr.parse().unwrap());
}
}
}
Err(_) => panic!("Invalid header name: {}", x_forwarded_for_header_name),
}
request
}
pub fn call(client_ip: IpAddr, forward_uri: &str, request: Request<Body>) -> BoxFut {
let proxied_request = create_proxied_request(client_ip, forward_uri, request);
let client = Client::new();
let response = client.request(proxied_request).then(|response| {
let proxied_response = match response {
Ok(response) => create_proxied_response(response),
Err(error) => {
println!("Error: {}", error);
Response::builder()
.status(StatusCode::INTERNAL_SERVER_ERROR)
.body(Body::empty())
.unwrap()
},
};
future::ok(proxied_response)
});
Box::new(response)
}