fix(filter): normalize matching

Author: miguelangel-nubla

docs/filtering.md

@@ -61,7 +61,8 @@ filter:
 *   **`prefix`** (Single String): CIDR subnet. The address must be contained within this subnet.
     *   Example: `2001:db8::/32`
 *   **`suffix`** (Single String): The host part (suffix) of the address.
-    *   Example: `::1` (Matches `2001:db8::1`, `fe80::1`, etc.)
+    *   Case-insensitive. The filter matches against the lowercase, RFC 5952 canonical representation of the address.
+    *   Example: `::1` (Matches `2001:db8::1`, `fe80::1`, etc.) or `dead:beef` (Matches `...:DEAD:BEEF`)
 *   **`type`** (List of Strings): Match semantic IP types. All types must match.
     *   Values:
         *   `global`: Global Unicast Address (Publicly routable).

pkg/filter/filter.go

@@ -170,18 +170,18 @@ func isEUI64(addr *ipv6disc.Addr) bool {
 	return bytes.Equal(iid, eui64)
 }
 
-func CheckPrefix(ip netip.Addr, subnet netip.Prefix) bool {
-	if !subnet.IsValid() {
+func CheckPrefix(ip netip.Addr, prefix netip.Prefix) bool {
+	if !prefix.IsValid() {
 		return true
 	}
-	return subnet.Contains(ip)
+	return prefix.Contains(ip.WithZone(""))
 }
 
 func CheckSuffix(ip netip.Addr, suffix string) bool {
 	if suffix == "" {
 		return true
 	}
-	return strings.HasSuffix(ip.String(), suffix)
+	return strings.HasSuffix(ip.WithZone("").String(), strings.ToLower(suffix))
 }
 
 func CheckMask(ip netip.Addr, filters []string) bool {