improve forwarded header parsing. (#896)

* improve forwarded header parsing.

* trim key name before compare.

http-rate/src/lib.rs

@@ -34,9 +34,9 @@ impl RateLimit {
     }
 
     /// Rate limit [Request] based on it's [HeaderMap] state and given client [SocketAddr]
-    /// "x-real-ip", "x-forwarded-for" and "forwarded" are checked in order start from left to
-    /// determine client's socket address. Received [SocketAddr] will be used as fallback when
-    /// all headers are absent or can't provide valid client address.
+    /// "x-real-ip", "x-forwarded-for" and "forwarded" headers are checked in order start
+    /// from left to determine client's socket address. Received [SocketAddr] will be used
+    /// as fallback when all headers are absent or can't provide valid client address.
     ///
     /// [Request]: http::Request
     pub fn rate_limit(&self, headers: &HeaderMap, addr: &SocketAddr) -> Result<RateSnapshot, TooManyRequests> {
@@ -66,28 +66,22 @@ fn maybe_x_real_ip(headers: &HeaderMap) -> Option<IpAddr> {
 }
 
 fn maybe_forwarded(headers: &HeaderMap) -> Option<IpAddr> {
-    let mut res = None;
-
-    for mut val in headers
+    headers
         .get_all(FORWARDED)
         .iter()
         .filter_map(|h| h.to_str().ok())
         .flat_map(|val| val.split(';'))
         .flat_map(|p| p.split(','))
         .map(|val| val.trim().splitn(2, '='))
-    {
-        if let (Some(name), Some(val)) = (val.next(), val.next()) {
-            if name.eq_ignore_ascii_case("for") {
+        .find_map(|mut val| match (val.next(), val.next()) {
+            (Some(name), Some(val)) if name.trim().eq_ignore_ascii_case("for") => {
                 let val = val.trim();
-                match val.parse::<SocketAddr>() {
-                    Ok(addr) => res = Some(addr.ip()),
-                    Err(_) => res = val.parse::<IpAddr>().ok(),
-                }
+                val.parse::<IpAddr>()
+                    .or_else(|_| val.parse::<SocketAddr>().map(|addr| addr.ip()))
+                    .ok()
             }
-        }
-    }
-
-    res
+            _ => None,
+        })
 }
 
 #[cfg(test)]
@@ -117,7 +111,7 @@ mod test {
         let mut headers = HeaderMap::new();
         headers.insert(
             FORWARDED,
-            HeaderValue::from_static("for=192.0.2.60;proto=http;by=203.0.113.43"),
+            HeaderValue::from_static("for =192.0.2.60;proto=http;by=203.0.113.43"),
         );
         assert_eq!(maybe_forwarded(&headers).unwrap().to_string(), "192.0.2.60");
     }
@@ -143,7 +137,7 @@ mod test {
         assert!(lb.check().is_ok());
 
         clock.advance(ms);
-        assert!(lb.check().is_err(), "{:?}", lb);
+        assert!(lb.check().is_err(), "{lb:?}");
     }
 
     #[test]
@@ -168,7 +162,7 @@ mod test {
         assert!(lb.check_n(one).unwrap().is_ok());
 
         clock.advance(ms);
-        assert!(lb.check_n(one).unwrap().is_err(), "{:?}", lb);
+        assert!(lb.check_n(one).unwrap().is_err(), "{lb:?}");
     }
 
     #[test]