feat(security): add domain-scoped IP allow list support across HTTP and passthrough filtering

rust/crates/rustproxy-security/src/ip_filter.rs

@@ -2,12 +2,24 @@ use ipnet::IpNet;
 use std::net::IpAddr;
 use std::str::FromStr;
 
+use rustproxy_config::IpAllowEntry;
+
 /// IP filter supporting CIDR ranges, wildcards, and exact matches.
+/// Supports domain-scoped allow entries that restrict an IP to specific domains.
 pub struct IpFilter {
+    /// Plain allow entries — IP allowed for any domain on the route
     allow_list: Vec<IpPattern>,
+    /// Domain-scoped allow entries — IP allowed only for matching domains
+    domain_scoped: Vec<DomainScopedEntry>,
     block_list: Vec<IpPattern>,
 }
 
+/// A domain-scoped allow entry: IP + list of allowed domain patterns.
+struct DomainScopedEntry {
+    pattern: IpPattern,
+    domains: Vec<String>,
+}
+
 /// Represents an IP pattern for matching.
 #[derive(Debug)]
 enum IpPattern {
@@ -31,10 +43,6 @@ impl IpPattern {
         if let Ok(addr) = IpAddr::from_str(s) {
             return IpPattern::Exact(addr);
         }
-        // Try as CIDR by appending default prefix
-        if let Ok(addr) = IpAddr::from_str(s) {
-            return IpPattern::Exact(addr);
-        }
         // Fallback: treat as exact, will never match an invalid string
         IpPattern::Exact(IpAddr::from_str("0.0.0.0").unwrap())
     }
@@ -48,19 +56,56 @@ impl IpPattern {
     }
 }
 
+/// Simple domain pattern matching (exact, `*`, or `*.suffix`).
+fn domain_matches_pattern(pattern: &str, domain: &str) -> bool {
+    let p = pattern.trim();
+    let d = domain.trim();
+    if p == "*" {
+        return true;
+    }
+    if p.eq_ignore_ascii_case(d) {
+        return true;
+    }
+    if p.starts_with("*.") {
+        let suffix = &p[1..]; // e.g., ".abc.xyz"
+        d.len() > suffix.len()
+            && d[d.len() - suffix.len()..].eq_ignore_ascii_case(suffix)
+    } else {
+        false
+    }
+}
+
 impl IpFilter {
-    /// Create a new IP filter from allow and block lists.
-    pub fn new(allow_list: &[String], block_list: &[String]) -> Self {
+    /// Create a new IP filter from allow entries and a block list.
+    pub fn new(allow_entries: &[IpAllowEntry], block_list: &[String]) -> Self {
+        let mut allow_list = Vec::new();
+        let mut domain_scoped = Vec::new();
+
+        for entry in allow_entries {
+            match entry {
+                IpAllowEntry::Plain(ip) => {
+                    allow_list.push(IpPattern::parse(ip));
+                }
+                IpAllowEntry::DomainScoped { ip, domains } => {
+                    domain_scoped.push(DomainScopedEntry {
+                        pattern: IpPattern::parse(ip),
+                        domains: domains.clone(),
+                    });
+                }
+            }
+        }
+
         Self {
-            allow_list: allow_list.iter().map(|s| IpPattern::parse(s)).collect(),
+            allow_list,
+            domain_scoped,
             block_list: block_list.iter().map(|s| IpPattern::parse(s)).collect(),
         }
     }
 
-    /// Check if an IP is allowed.
-    /// If allow_list is non-empty, IP must match at least one entry.
-    /// If block_list is non-empty, IP must NOT match any entry.
-    pub fn is_allowed(&self, ip: &IpAddr) -> bool {
+    /// Check if an IP is allowed, considering domain-scoped entries.
+    /// If `domain` is Some, domain-scoped entries are evaluated against it.
+    /// If `domain` is None, only plain allow entries are considered.
+    pub fn is_allowed_for_domain(&self, ip: &IpAddr, domain: Option<&str>) -> bool {
         // Check block list first
         if !self.block_list.is_empty() {
             for pattern in &self.block_list {
@@ -70,14 +115,36 @@ impl IpFilter {
             }
         }
 
-        // If allow list is non-empty, must match at least one
-        if !self.allow_list.is_empty() {
-            return self.allow_list.iter().any(|p| p.matches(ip));
+        // If there are any allow entries (plain or domain-scoped), IP must match
+        let has_any_allow = !self.allow_list.is_empty() || !self.domain_scoped.is_empty();
+        if has_any_allow {
+            // Check plain allow list — grants access to entire route
+            if self.allow_list.iter().any(|p| p.matches(ip)) {
+                return true;
+            }
+
+            // Check domain-scoped entries — grants access only if domain matches
+            if let Some(req_domain) = domain {
+                for entry in &self.domain_scoped {
+                    if entry.pattern.matches(ip) {
+                        if entry.domains.iter().any(|d| domain_matches_pattern(d, req_domain)) {
+                            return true;
+                        }
+                    }
+                }
+            }
+
+            return false;
         }
 
         true
     }
 
+    /// Check if an IP is allowed (backwards-compat wrapper, no domain context).
+    pub fn is_allowed(&self, ip: &IpAddr) -> bool {
+        self.is_allowed_for_domain(ip, None)
+    }
+
     /// Normalize IPv4-mapped IPv6 addresses (::ffff:x.x.x.x -> x.x.x.x)
     pub fn normalize_ip(ip: &IpAddr) -> IpAddr {
         match ip {
@@ -97,19 +164,28 @@ impl IpFilter {
 mod tests {
     use super::*;
 
+    fn plain(s: &str) -> IpAllowEntry {
+        IpAllowEntry::Plain(s.to_string())
+    }
+
+    fn scoped(ip: &str, domains: &[&str]) -> IpAllowEntry {
+        IpAllowEntry::DomainScoped {
+            ip: ip.to_string(),
+            domains: domains.iter().map(|s| s.to_string()).collect(),
+        }
+    }
+
     #[test]
     fn test_empty_lists_allow_all() {
         let filter = IpFilter::new(&[], &[]);
         let ip: IpAddr = "192.168.1.1".parse().unwrap();
         assert!(filter.is_allowed(&ip));
+        assert!(filter.is_allowed_for_domain(&ip, Some("example.com")));
     }
 
     #[test]
-    fn test_allow_list_exact() {
-        let filter = IpFilter::new(
-            &["10.0.0.1".to_string()],
-            &[],
-        );
+    fn test_plain_allow_list_exact() {
+        let filter = IpFilter::new(&[plain("10.0.0.1")], &[]);
         let allowed: IpAddr = "10.0.0.1".parse().unwrap();
         let denied: IpAddr = "10.0.0.2".parse().unwrap();
         assert!(filter.is_allowed(&allowed));
@@ -117,11 +193,8 @@ mod tests {
     }
 
     #[test]
-    fn test_allow_list_cidr() {
-        let filter = IpFilter::new(
-            &["10.0.0.0/8".to_string()],
-            &[],
-        );
+    fn test_plain_allow_list_cidr() {
+        let filter = IpFilter::new(&[plain("10.0.0.0/8")], &[]);
         let allowed: IpAddr = "10.255.255.255".parse().unwrap();
         let denied: IpAddr = "192.168.1.1".parse().unwrap();
         assert!(filter.is_allowed(&allowed));
@@ -130,10 +203,7 @@ mod tests {
 
     #[test]
     fn test_block_list() {
-        let filter = IpFilter::new(
-            &[],
-            &["192.168.1.100".to_string()],
-        );
+        let filter = IpFilter::new(&[], &["192.168.1.100".to_string()]);
         let blocked: IpAddr = "192.168.1.100".parse().unwrap();
         let allowed: IpAddr = "192.168.1.101".parse().unwrap();
         assert!(!filter.is_allowed(&blocked));
@@ -143,7 +213,7 @@ mod tests {
     #[test]
     fn test_block_trumps_allow() {
         let filter = IpFilter::new(
-            &["10.0.0.0/8".to_string()],
+            &[plain("10.0.0.0/8")],
             &["10.0.0.5".to_string()],
         );
         let blocked: IpAddr = "10.0.0.5".parse().unwrap();
@@ -154,20 +224,14 @@ mod tests {
 
     #[test]
     fn test_wildcard_allow() {
-        let filter = IpFilter::new(
-            &["*".to_string()],
-            &[],
-        );
+        let filter = IpFilter::new(&[plain("*")], &[]);
         let ip: IpAddr = "1.2.3.4".parse().unwrap();
         assert!(filter.is_allowed(&ip));
     }
 
     #[test]
     fn test_wildcard_block() {
-        let filter = IpFilter::new(
-            &[],
-            &["*".to_string()],
-        );
+        let filter = IpFilter::new(&[], &["*".to_string()]);
         let ip: IpAddr = "1.2.3.4".parse().unwrap();
         assert!(!filter.is_allowed(&ip));
     }
@@ -186,4 +250,97 @@ mod tests {
         let normalized = IpFilter::normalize_ip(&ip);
         assert_eq!(normalized, ip);
     }
+
+    // Domain-scoped tests
+
+    #[test]
+    fn test_domain_scoped_allows_matching_domain() {
+        let filter = IpFilter::new(
+            &[scoped("10.8.0.2", &["outline.abc.xyz"])],
+            &[],
+        );
+        let ip: IpAddr = "10.8.0.2".parse().unwrap();
+        assert!(filter.is_allowed_for_domain(&ip, Some("outline.abc.xyz")));
+    }
+
+    #[test]
+    fn test_domain_scoped_denies_non_matching_domain() {
+        let filter = IpFilter::new(
+            &[scoped("10.8.0.2", &["outline.abc.xyz"])],
+            &[],
+        );
+        let ip: IpAddr = "10.8.0.2".parse().unwrap();
+        assert!(!filter.is_allowed_for_domain(&ip, Some("app.abc.xyz")));
+    }
+
+    #[test]
+    fn test_domain_scoped_denies_without_domain() {
+        let filter = IpFilter::new(
+            &[scoped("10.8.0.2", &["outline.abc.xyz"])],
+            &[],
+        );
+        let ip: IpAddr = "10.8.0.2".parse().unwrap();
+        // Without domain context, domain-scoped entries cannot match
+        assert!(!filter.is_allowed_for_domain(&ip, None));
+    }
+
+    #[test]
+    fn test_domain_scoped_wildcard_domain() {
+        let filter = IpFilter::new(
+            &[scoped("10.8.0.2", &["*.abc.xyz"])],
+            &[],
+        );
+        let ip: IpAddr = "10.8.0.2".parse().unwrap();
+        assert!(filter.is_allowed_for_domain(&ip, Some("outline.abc.xyz")));
+        assert!(filter.is_allowed_for_domain(&ip, Some("app.abc.xyz")));
+        assert!(!filter.is_allowed_for_domain(&ip, Some("other.com")));
+    }
+
+    #[test]
+    fn test_plain_and_domain_scoped_coexist() {
+        let filter = IpFilter::new(
+            &[
+                plain("1.2.3.4"),                          // full route access
+                scoped("10.8.0.2", &["outline.abc.xyz"]),  // scoped access
+            ],
+            &[],
+        );
+
+        let admin: IpAddr = "1.2.3.4".parse().unwrap();
+        let vpn: IpAddr = "10.8.0.2".parse().unwrap();
+        let other: IpAddr = "9.9.9.9".parse().unwrap();
+
+        // Admin IP has full access
+        assert!(filter.is_allowed_for_domain(&admin, Some("anything.abc.xyz")));
+        assert!(filter.is_allowed_for_domain(&admin, Some("outline.abc.xyz")));
+
+        // VPN IP only has scoped access
+        assert!(filter.is_allowed_for_domain(&vpn, Some("outline.abc.xyz")));
+        assert!(!filter.is_allowed_for_domain(&vpn, Some("app.abc.xyz")));
+
+        // Unknown IP denied
+        assert!(!filter.is_allowed_for_domain(&other, Some("outline.abc.xyz")));
+    }
+
+    #[test]
+    fn test_block_trumps_domain_scoped() {
+        let filter = IpFilter::new(
+            &[scoped("10.8.0.2", &["outline.abc.xyz"])],
+            &["10.8.0.2".to_string()],
+        );
+        let ip: IpAddr = "10.8.0.2".parse().unwrap();
+        assert!(!filter.is_allowed_for_domain(&ip, Some("outline.abc.xyz")));
+    }
+
+    #[test]
+    fn test_domain_matches_pattern_fn() {
+        assert!(domain_matches_pattern("example.com", "example.com"));
+        assert!(domain_matches_pattern("*.abc.xyz", "outline.abc.xyz"));
+        assert!(domain_matches_pattern("*.abc.xyz", "app.abc.xyz"));
+        assert!(!domain_matches_pattern("*.abc.xyz", "abc.xyz")); // suffix only, not exact parent
+        assert!(domain_matches_pattern("*", "anything.com"));
+        assert!(!domain_matches_pattern("outline.abc.xyz", "app.abc.xyz"));
+        // Case insensitive
+        assert!(domain_matches_pattern("*.ABC.XYZ", "outline.abc.xyz"));
+    }
 }