warp/filters/
host.rs

1//! Host ("authority") filter
2//!
3use crate::filter::{filter_fn_one, Filter, One};
4use crate::reject::{self, Rejection};
5use futures_util::future;
6pub use http::uri::Authority;
7use std::str::FromStr;
8
9/// Creates a `Filter` that requires a specific authority (target server's
10/// host and port) in the request.
11///
12/// Authority is specified either in the `Host` header or in the target URI.
13///
14/// # Example
15///
16/// ```
17/// use warp::Filter;
18///
19/// let multihost =
20///     warp::host::exact("foo.com").map(|| "you've reached foo.com")
21///     .or(warp::host::exact("bar.com").map(|| "you've reached bar.com"));
22/// ```
23pub fn exact(expected: &str) -> impl Filter<Extract = (), Error = Rejection> + Clone {
24    let expected = Authority::from_str(expected).expect("invalid host/authority");
25    optional()
26        .and_then(move |option: Option<Authority>| match option {
27            Some(authority) if authority == expected => future::ok(()),
28            _ => future::err(reject::not_found()),
29        })
30        .untuple_one()
31}
32
33/// Creates a `Filter` that looks for an authority (target server's host
34/// and port) in the request.
35///
36/// Authority is specified either in the `Host` header or in the target URI.
37///
38/// If found, extracts the `Authority`, otherwise continues the request,
39/// extracting `None`.
40///
41/// Rejects with `400 Bad Request` if the `Host` header is malformed or if there
42/// is a mismatch between the `Host` header and the target URI.
43///
44/// # Example
45///
46/// ```
47/// use warp::{Filter, host::Authority};
48///
49/// let host = warp::host::optional()
50///     .map(|authority: Option<Authority>| {
51///         if let Some(a) = authority {
52///             format!("{} is currently not at home", a.host())
53///         } else {
54///             "please state who you're trying to reach".to_owned()
55///         }
56///     });
57/// ```
58pub fn optional() -> impl Filter<Extract = One<Option<Authority>>, Error = Rejection> + Copy {
59    filter_fn_one(move |route| {
60        // The authority can be sent by clients in various ways:
61        //
62        //  1) in the "target URI"
63        //    a) serialized in the start line (HTTP/1.1 proxy requests)
64        //    b) serialized in `:authority` pseudo-header (HTTP/2 generated - "SHOULD")
65        //  2) in the `Host` header (HTTP/1.1 origin requests, HTTP/2 converted)
66        //
67        // Hyper transparently handles 1a/1b, but not 2, so we must look at both.
68
69        let from_uri = route.uri().authority();
70
71        let name = "host";
72        let from_header = route.headers()
73            .get(name)
74            .map(|value|
75                // Header present, parse it
76                value.to_str().map_err(|_| reject::invalid_header(name))
77                    .and_then(|value| Authority::from_str(value).map_err(|_| reject::invalid_header(name)))
78            );
79
80        future::ready(match (from_uri, from_header) {
81            // no authority in the request (HTTP/1.0 or non-conforming)
82            (None, None) => Ok(None),
83
84            // authority specified in either or both matching
85            (Some(a), None) => Ok(Some(a.clone())),
86            (None, Some(Ok(a))) => Ok(Some(a)),
87            (Some(a), Some(Ok(b))) if *a == b => Ok(Some(b)),
88
89            // mismatch
90            (Some(_), Some(Ok(_))) => Err(reject::invalid_header(name)),
91
92            // parse error
93            (_, Some(Err(r))) => Err(r),
94        })
95    })
96}
warp/filters/host.rs

warp/filters/
host.rs
