feat: add mrs format ipcidr ruleset

component/cidr/ipcidr_set_bin.go

@@ -0,0 +1,77 @@
+package cidr
+
+import (
+	"encoding/binary"
+	"errors"
+	"io"
+	"net/netip"
+
+	"go4.org/netipx"
+)
+
+func (ss *IpCidrSet) WriteBin(w io.Writer) (err error) {
+	// version
+	_, err = w.Write([]byte{1})
+	if err != nil {
+		return err
+	}
+
+	// rr
+	err = binary.Write(w, binary.BigEndian, int64(len(ss.rr)))
+	if err != nil {
+		return err
+	}
+	for _, r := range ss.rr {
+		err = binary.Write(w, binary.BigEndian, r.From().As16())
+		if err != nil {
+			return err
+		}
+		err = binary.Write(w, binary.BigEndian, r.To().As16())
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func ReadIpCidrSet(r io.Reader) (ss *IpCidrSet, err error) {
+	// version
+	version := make([]byte, 1)
+	_, err = io.ReadFull(r, version)
+	if err != nil {
+		return nil, err
+	}
+	if version[0] != 1 {
+		return nil, errors.New("version is invalid")
+	}
+
+	ss = NewIpCidrSet()
+	var length int64
+
+	// rr
+	err = binary.Read(r, binary.BigEndian, &length)
+	if err != nil {
+		return nil, err
+	}
+	if length < 1 {
+		return nil, errors.New("length is invalid")
+	}
+	ss.rr = make([]netipx.IPRange, length)
+	for i := int64(0); i < length; i++ {
+		var a16 [16]byte
+		err = binary.Read(r, binary.BigEndian, &a16)
+		if err != nil {
+			return nil, err
+		}
+		from := netip.AddrFrom16(a16).Unmap()
+		err = binary.Read(r, binary.BigEndian, &a16)
+		if err != nil {
+			return nil, err
+		}
+		to := netip.AddrFrom16(a16).Unmap()
+		ss.rr[i] = netipx.IPRangeFrom(from, to)
+	}
+
+	return ss, nil
+}