feat: Add LAN allowed and disallowed IP configurations (#861)

adapter/inbound/ipfilter.go

@@ -0,0 +1,57 @@
+package inbound
+
+import (
+	"net"
+	"net/netip"
+
+	C "github.com/metacubex/mihomo/constant"
+)
+
+var lanAllowedIPs []netip.Prefix
+var lanDisAllowedIPs []netip.Prefix
+
+func SetAllowedIPs(prefixes []netip.Prefix) {
+	lanAllowedIPs = prefixes
+}
+
+func SetDisAllowedIPs(prefixes []netip.Prefix) {
+	lanDisAllowedIPs = prefixes
+}
+
+func AllowedIPs() []netip.Prefix {
+	return lanAllowedIPs
+}
+
+func DisAllowedIPs() []netip.Prefix {
+	return lanDisAllowedIPs
+}
+
+func IsRemoteAddrDisAllowed(addr net.Addr) bool {
+	m := C.Metadata{}
+	if err := m.SetRemoteAddr(addr); err != nil {
+		return false
+	}
+	return isAllowed(m.AddrPort().Addr().Unmap()) && !isDisAllowed(m.AddrPort().Addr().Unmap())
+}
+
+func isAllowed(addr netip.Addr) bool {
+	if addr.IsValid() {
+		for _, prefix := range lanAllowedIPs {
+			if prefix.Contains(addr) {
+				return true
+			}
+		}
+	}
+	return false
+}
+
+func isDisAllowed(addr netip.Addr) bool {
+	if addr.IsValid() {
+		for _, prefix := range lanDisAllowedIPs {
+			if prefix.Contains(addr) {
+				return true
+			}
+		}
+	}
+	return false
+}