tower_http/cors/
allow_headers.rs

1use std::fmt;
2
3use http::{
4    header::{self, HeaderName, HeaderValue},
5    request::Parts as RequestParts,
6};
7
8use super::{separated_by_commas, Any, WILDCARD};
9
10/// Holds configuration for how to set the [`Access-Control-Allow-Headers`][mdn] header.
11///
12/// See [`CorsLayer::allow_headers`] for more details.
13///
14/// [mdn]: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Access-Control-Allow-Headers
15/// [`CorsLayer::allow_headers`]: super::CorsLayer::allow_headers
16#[derive(Clone, Default)]
17#[must_use]
18pub struct AllowHeaders(AllowHeadersInner);
19
20impl AllowHeaders {
21    /// Allow any headers by sending a wildcard (`*`)
22    ///
23    /// See [`CorsLayer::allow_headers`] for more details.
24    ///
25    /// [`CorsLayer::allow_headers`]: super::CorsLayer::allow_headers
26    pub fn any() -> Self {
27        Self(AllowHeadersInner::Const(Some(WILDCARD)))
28    }
29
30    /// Set multiple allowed headers
31    ///
32    /// See [`CorsLayer::allow_headers`] for more details.
33    ///
34    /// [`CorsLayer::allow_headers`]: super::CorsLayer::allow_headers
35    pub fn list<I>(headers: I) -> Self
36    where
37        I: IntoIterator<Item = HeaderName>,
38    {
39        Self(AllowHeadersInner::Const(separated_by_commas(
40            headers.into_iter().map(Into::into),
41        )))
42    }
43
44    /// Allow any headers, by mirroring the preflight [`Access-Control-Request-Headers`][mdn]
45    /// header.
46    ///
47    /// See [`CorsLayer::allow_headers`] for more details.
48    ///
49    /// [`CorsLayer::allow_headers`]: super::CorsLayer::allow_headers
50    ///
51    /// [mdn]: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Access-Control-Request-Headers
52    pub fn mirror_request() -> Self {
53        Self(AllowHeadersInner::MirrorRequest)
54    }
55
56    #[allow(clippy::borrow_interior_mutable_const)]
57    pub(super) fn is_wildcard(&self) -> bool {
58        matches!(&self.0, AllowHeadersInner::Const(Some(v)) if v == WILDCARD)
59    }
60
61    pub(super) fn varies_with_request_headers(&self) -> bool {
62        !matches!(&self.0, AllowHeadersInner::Const(_))
63    }
64
65    pub(super) fn to_header(&self, parts: &RequestParts) -> Option<(HeaderName, HeaderValue)> {
66        let allow_headers = match &self.0 {
67            AllowHeadersInner::Const(v) => v.clone()?,
68            AllowHeadersInner::MirrorRequest => parts
69                .headers
70                .get(header::ACCESS_CONTROL_REQUEST_HEADERS)?
71                .clone(),
72        };
73
74        Some((header::ACCESS_CONTROL_ALLOW_HEADERS, allow_headers))
75    }
76}
77
78impl fmt::Debug for AllowHeaders {
79    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
80        match &self.0 {
81            AllowHeadersInner::Const(inner) => f.debug_tuple("Const").field(inner).finish(),
82            AllowHeadersInner::MirrorRequest => f.debug_tuple("MirrorRequest").finish(),
83        }
84    }
85}
86
87impl From<Any> for AllowHeaders {
88    fn from(_: Any) -> Self {
89        Self::any()
90    }
91}
92
93impl<const N: usize> From<[HeaderName; N]> for AllowHeaders {
94    fn from(arr: [HeaderName; N]) -> Self {
95        Self::list(arr)
96    }
97}
98
99impl From<Vec<HeaderName>> for AllowHeaders {
100    fn from(vec: Vec<HeaderName>) -> Self {
101        Self::list(vec)
102    }
103}
104
105#[derive(Clone)]
106enum AllowHeadersInner {
107    Const(Option<HeaderValue>),
108    MirrorRequest,
109}
110
111impl Default for AllowHeadersInner {
112    fn default() -> Self {
113        Self::Const(None)
114    }
115}
tower_http/cors/allow_headers.rs

tower_http/cors/
allow_headers.rs
