Support for X-Envoy-External-Address (#41)

Author: dimitrmo

Cargo.toml

@@ -21,7 +21,7 @@ serde = ["dep:serde"]
 
 [dependencies]
 axum = { version = "0.8", default-features = false }
-client-ip = "0.1"
+client-ip = "0.2"
 serde = { version = "1", features = ["derive"], optional = true }
 
 [dev-dependencies]

README.md

@@ -24,13 +24,14 @@ application independent from a proxy it can run behind (if any) and also
 separate extractors for each proxy / source header.
 
 | Extractor / `ClientIpSource` Variant | Header Used                 | Typical Proxy / Service                                 |
-| ------------------------------------ | --------------------------- | ------------------------------------------------------- |
+|--------------------------------------| --------------------------- |---------------------------------------------------------|
 | [`CfConnectingIp`]                   | `CF-Connecting-IP`          | Cloudflare                                              |
 | [`CloudFrontViewerAddress`]          | `CloudFront-Viewer-Address` | AWS CloudFront                                          |
 | [`FlyClientIp`]                      | `Fly-Client-IP`             | Fly.io                                                  |
 | [`RightmostForwarded`]               | `Forwarded`                 | Proxies supporting RFC 7239 (extracts rightmost `for=`) |
 | [`RightmostXForwardedFor`]           | `X-Forwarded-For`           | Nginx, Apache, HAProxy, CDNs, LBs                       |
 | [`TrueClientIp`]                     | `True-Client-IP`            | Cloudflare, Akamai                                      |
+| [`XEnvoyExternalAddress`]            | `X-Envoy-External-Address`  | Envoy, Istio                                            |
 | [`XRealIp`]                          | `X-Real-Ip`                 | Nginx                                                   |
 | [`ConnectInfo`]                      | N/A (uses socket address)   | No proxy, e.g. listening directly to 80 port            |
 

src/lib.rs

@@ -87,6 +87,12 @@ define_extractor!(
     client_ip::true_client_ip
 );
 
+define_extractor!(
+    /// Extracts an IP from `X-Envoy-External-Address` (Envoy, Istio) header
+    XEnvoyExternalAddress,
+    client_ip::x_envoy_external_address
+);
+
 define_extractor!(
     /// Extracts an IP from `X-Real-Ip` (Nginx) header
     XRealIp,
@@ -126,6 +132,8 @@ pub enum ClientIpSource {
     RightmostXForwardedFor,
     /// IP from the `True-Client-IP` header
     TrueClientIp,
+    /// IP from the `X-Envoy-External-Address` address
+    XEnvoyExternalAddress,
     /// IP from the `X-Real-Ip` header
     XRealIp,
 }
@@ -164,6 +172,7 @@ impl FromStr for ClientIpSource {
             "RightmostForwarded" => Self::RightmostForwarded,
             "RightmostXForwardedFor" => Self::RightmostXForwardedFor,
             "TrueClientIp" => Self::TrueClientIp,
+            "XEnvoyExternalAddress" => Self::XEnvoyExternalAddress,
             "XRealIp" => Self::XRealIp,
             _ => return Err(ParseClientIpSourceError(s.to_string())),
         })
@@ -183,6 +192,7 @@ impl fmt::Display for ClientIpSource {
             ClientIpSource::RightmostForwarded => "RightmostForwarded",
             ClientIpSource::RightmostXForwardedFor => "RightmostXForwardedFor",
             ClientIpSource::TrueClientIp => "TrueClientIp",
+            ClientIpSource::XEnvoyExternalAddress => "XEnvoyExternalAddress",
             ClientIpSource::XRealIp => "XRealIp",
         })
     }
@@ -219,6 +229,9 @@ where
                 RightmostXForwardedFor::ip_from_headers(&parts.headers)
             }
             ClientIpSource::TrueClientIp => TrueClientIp::ip_from_headers(&parts.headers),
+            ClientIpSource::XEnvoyExternalAddress => {
+                XEnvoyExternalAddress::ip_from_headers(&parts.headers)
+            }
             ClientIpSource::XRealIp => XRealIp::ip_from_headers(&parts.headers),
         }
         .map(Self)
@@ -289,9 +302,7 @@ mod tests {
 
     #[cfg(feature = "forwarded-header")]
     use super::RightmostForwarded;
-    use super::{
-        CfConnectingIp, ClientIpSource, FlyClientIp, RightmostXForwardedFor, TrueClientIp, XRealIp,
-    };
+    use super::{CfConnectingIp, ClientIpSource, FlyClientIp, RightmostXForwardedFor, TrueClientIp, XEnvoyExternalAddress, XRealIp};
     use crate::CloudFrontViewerAddress;
 
     const VALID_IPV4: &str = "1.2.3.4";
@@ -489,6 +500,35 @@ mod tests {
         assert_eq!(body_to_string(resp.into_body()).await, VALID_IPV6);
     }
 
+    #[tokio::test]
+    async fn x_envoy_external_address() {
+        let header = "x-envoy-external-address";
+
+        fn app() -> Router {
+            Router::new().route("/", get(|ip: XEnvoyExternalAddress| async move { ip.0.to_string() }))
+        }
+
+        let req = Request::builder().uri("/").body(Body::empty()).unwrap();
+        let resp = app().oneshot(req).await.unwrap();
+        assert_eq!(resp.status(), StatusCode::INTERNAL_SERVER_ERROR);
+
+        let req = Request::builder()
+            .uri("/")
+            .header(header, VALID_IPV4)
+            .body(Body::empty())
+            .unwrap();
+        let resp = app().oneshot(req).await.unwrap();
+        assert_eq!(body_to_string(resp.into_body()).await, VALID_IPV4);
+
+        let req = Request::builder()
+            .uri("/")
+            .header(header, VALID_IPV6)
+            .body(Body::empty())
+            .unwrap();
+        let resp = app().oneshot(req).await.unwrap();
+        assert_eq!(body_to_string(resp.into_body()).await, VALID_IPV6);
+    }
+
     #[tokio::test]
     async fn x_real_ip() {
         let header = "x-real-ip";
@@ -539,6 +579,7 @@ mod tests {
         assert_match(ClientIpSource::RightmostForwarded);
         assert_match(ClientIpSource::RightmostXForwardedFor);
         assert_match(ClientIpSource::TrueClientIp);
+        assert_match(ClientIpSource::XEnvoyExternalAddress);
         assert_match(ClientIpSource::XRealIp);
     }
 }