aboutsummaryrefslogtreecommitdiff
path: root/src/reverse_proxy.rs
blob: 82e7c7a82a09f09482e17bd3c7acaab225ec8435 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
//! Copied from https://github.com/felipenoris/hyper-reverse-proxy
//! See there for original Copyright notice

use std::sync::Arc;
use std::convert::TryInto;
use std::time::SystemTime;
use std::net::IpAddr;
use std::str::FromStr;

use anyhow::Result;
use log::*;

use http::header::HeaderName;
use hyper::header::{HeaderMap, HeaderValue};
use hyper::{Body, Client, Request, Response, Uri};
use rustls::{Certificate, ServerName};
use rustls::client::{ServerCertVerifier, ServerCertVerified};
use lazy_static::lazy_static;

use crate::tls_util::HttpsConnectorFixedDnsname;

fn is_hop_header(name: &str) -> bool {
	use unicase::Ascii;

	// A list of the headers, using `unicase` to help us compare without
	// worrying about the case, and `lazy_static!` to prevent reallocation
	// of the vector.
	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)
}

/// Returns a clone of the headers without the [hop-by-hop headers].
///
/// [hop-by-hop headers]: http://www.w3.org/Protocols/rfc2616/rfc2616-sec13.html
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>) -> Result<Uri> {
	let forward_uri = match req.uri().query() {
		Some(query) => format!("{}{}?{}", forward_url, req.uri().path(), query),
		None => format!("{}{}", forward_url, req.uri().path()),
	};

	Ok(Uri::from_str(forward_uri.as_str())?)
}

fn create_proxied_request<B>(
	client_ip: IpAddr,
	forward_url: &str,
	request: Request<B>,
) -> Result<Request<B>> {
	let mut builder = Request::builder()
		.method(request.method())
		.uri(forward_uri(forward_url, &request)?);

	*builder.headers_mut().unwrap() = remove_hop_headers(request.headers());

	// If request does not have host header, add it from original URI authority
	let host_header_name = "host";
	if let Some(authority) = request.uri().authority() {
		if let hyper::header::Entry::Vacant(entry) =
			builder.headers_mut().unwrap().entry(host_header_name)
		{
			entry.insert(authority.as_str().parse()?);
		}
	}

	// Add forwarding information in the headers
	let x_forwarded_for_header_name = "x-forwarded-for";
	match builder
		.headers_mut()
		.unwrap()
		.entry(x_forwarded_for_header_name)
	{
		hyper::header::Entry::Vacant(entry) => {
			entry.insert(client_ip.to_string().parse()?);
		}

		hyper::header::Entry::Occupied(mut entry) => {
			let addr = format!("{}, {}", entry.get().to_str()?, client_ip);
			entry.insert(addr.parse()?);
		}
	}

	builder.headers_mut().unwrap().insert(
		HeaderName::from_bytes(b"x-forwarded-proto")?,
		"https".try_into()?,
	);

	if let Some(conn) = request.headers().get("connection") {
		if conn.to_str()?.to_lowercase() == "upgrade" {
			if let Some(upgrade) = request.headers().get("upgrade") {
				builder.headers_mut().unwrap().insert(
					HeaderName::from_bytes(b"connection")?,
					"Upgrade".try_into()?,
				);
				builder
					.headers_mut()
					.unwrap()
					.insert(HeaderName::from_bytes(b"upgrade")?, upgrade.clone());
			}
		}
	}

	Ok(builder.body(request.into_body())?)
}

pub async fn call(
	client_ip: IpAddr,
	forward_uri: &str,
	request: Request<Body>,
) -> Result<Response<Body>> {
	let proxied_request = create_proxied_request(client_ip, &forward_uri, request)?;

	trace!("Proxied request: {:?}", proxied_request);

	let client = Client::new();
	let response = client.request(proxied_request).await?;

	trace!("Inner response: {:?}", response);

	let proxied_response = create_proxied_response(response);
	Ok(proxied_response)
}

pub async fn call_https(
	client_ip: IpAddr,
	forward_uri: &str,
	request: Request<Body>,
) -> Result<Response<Body>> {
	let proxied_request = create_proxied_request(client_ip, &forward_uri, request)?;

	trace!("Proxied request (HTTPS): {:?}", proxied_request);

	let tls_config = rustls::client::ClientConfig::builder()
		.with_safe_defaults()
		.with_custom_certificate_verifier(Arc::new(DontVerifyServerCert))
		.with_no_client_auth();
	let connector = HttpsConnectorFixedDnsname::new(tls_config, "dummy");
	let client: Client<_, hyper::Body> = Client::builder().build(connector);
	let response = client.request(proxied_request).await?;

	trace!("Inner response (HTTPS): {:?}", response);

	let proxied_response = create_proxied_response(response);
	Ok(proxied_response)
}

struct DontVerifyServerCert;

impl ServerCertVerifier for DontVerifyServerCert {
	fn verify_server_cert(
        &self,
        _end_entity: &Certificate,
        _intermediates: &[Certificate],
        _server_name: &ServerName,
        _scts: &mut dyn Iterator<Item = &[u8]>,
        _ocsp_response: &[u8],
        _now: SystemTime
    ) -> Result<ServerCertVerified, rustls::Error> {
		Ok(ServerCertVerified::assertion())
	}
}