implement middleware compose

internal/types/cidr.go

@@ -0,0 +1,34 @@
+package types
+
+import (
+	"net"
+	"strings"
+
+	E "github.com/yusing/go-proxy/internal/error"
+)
+
+type CIDR net.IPNet
+
+func (*CIDR) ConvertFrom(val any) (any, E.NestedError) {
+	cidr, ok := val.(string)
+	if !ok {
+		return nil, E.TypeMismatch[string](val)
+	}
+
+	if !strings.Contains(cidr, "/") {
+		cidr += "/32" // single IP
+	}
+	_, ipnet, err := net.ParseCIDR(cidr)
+	if err != nil {
+		return nil, E.Invalid("CIDR", cidr)
+	}
+	return (*CIDR)(ipnet), nil
+}
+
+func (cidr *CIDR) Contains(ip net.IP) bool {
+	return (*net.IPNet)(cidr).Contains(ip)
+}
+
+func (cidr *CIDR) String() string {
+	return (*net.IPNet)(cidr).String()
+}