feat(rustproxy): introduce a Rust-powered proxy engine and workspace with core crates for proxy functionality, ACME/TLS support, passthrough and HTTP proxies, metrics, nftables integration, routing/security, management IPC, tests, and README updates

rust/crates/rustproxy-routing/src/matchers/header.rs

@@ -0,0 +1,98 @@
+use std::collections::HashMap;
+use regex::Regex;
+
+/// Match HTTP headers against a set of patterns.
+///
+/// Pattern values can be:
+/// - Exact string: `"application/json"`
+/// - Regex (surrounded by /): `"/^text\/.*/"`
+pub fn headers_match(
+    patterns: &HashMap<String, String>,
+    headers: &HashMap<String, String>,
+) -> bool {
+    for (key, pattern) in patterns {
+        let key_lower = key.to_lowercase();
+
+        // Find the header (case-insensitive)
+        let header_value = headers
+            .iter()
+            .find(|(k, _)| k.to_lowercase() == key_lower)
+            .map(|(_, v)| v.as_str());
+
+        let header_value = match header_value {
+            Some(v) => v,
+            None => return false, // Required header not present
+        };
+
+        // Check if pattern is a regex (surrounded by /)
+        if pattern.starts_with('/') && pattern.ends_with('/') && pattern.len() > 2 {
+            let regex_str = &pattern[1..pattern.len() - 1];
+            match Regex::new(regex_str) {
+                Ok(re) => {
+                    if !re.is_match(header_value) {
+                        return false;
+                    }
+                }
+                Err(_) => {
+                    // Invalid regex, fall back to exact match
+                    if header_value != pattern {
+                        return false;
+                    }
+                }
+            }
+        } else {
+            // Exact match
+            if header_value != pattern {
+                return false;
+            }
+        }
+    }
+
+    true
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_exact_header_match() {
+        let patterns: HashMap<String, String> = {
+            let mut m = HashMap::new();
+            m.insert("Content-Type".to_string(), "application/json".to_string());
+            m
+        };
+        let headers: HashMap<String, String> = {
+            let mut m = HashMap::new();
+            m.insert("content-type".to_string(), "application/json".to_string());
+            m
+        };
+        assert!(headers_match(&patterns, &headers));
+    }
+
+    #[test]
+    fn test_regex_header_match() {
+        let patterns: HashMap<String, String> = {
+            let mut m = HashMap::new();
+            m.insert("Content-Type".to_string(), "/^text\\/.*/".to_string());
+            m
+        };
+        let headers: HashMap<String, String> = {
+            let mut m = HashMap::new();
+            m.insert("content-type".to_string(), "text/html".to_string());
+            m
+        };
+        assert!(headers_match(&patterns, &headers));
+    }
+
+    #[test]
+    fn test_missing_header() {
+        let patterns: HashMap<String, String> = {
+            let mut m = HashMap::new();
+            m.insert("X-Custom".to_string(), "value".to_string());
+            m
+        };
+        let headers: HashMap<String, String> = HashMap::new();
+        assert!(!headers_match(&patterns, &headers));
+    }
+}