add LookupHTTPS method to client

client_resolver.go

@@ -52,3 +52,52 @@ func (c *Client) LookupNetIP(ctx context.Context, network, host string) (ips []n
 
 	return
 }
+
+func (c *Client) LookupHTTPS(ctx context.Context, network, host string) (https []NetHTTPS, err error) {
+	req, resp := AcquireMessage(), AcquireMessage()
+	defer ReleaseMessage(resp)
+	defer ReleaseMessage(req)
+
+	req.SetRequestQuestion(host, TypeHTTPS, ClassINET)
+
+	err = c.Exchange(req, resp)
+	if err != nil {
+		return
+	}
+
+	_ = resp.Walk(func(name []byte, typ Type, class Class, ttl uint32, data []byte) bool {
+		switch typ {
+		case TypeHTTPS:
+			var h NetHTTPS
+			data = data[3:]
+			for len(data) != 0 {
+				key := int(data[0])<<8 | int(data[1])
+				length := int(data[2])<<8 | int(data[3])
+				value := data[4 : 4+length]
+				data = data[4+length:]
+				switch key {
+				case 1: // alpn
+					for len(value) != 0 {
+						length := int(value[0])
+						h.ALPN = append(h.ALPN, string(value[1:1+length]))
+						value = value[1+length:]
+					}
+				case 4: // ipv4hint
+					for i := 0; i < length; i += 4 {
+						h.IPv4Hint = append(h.IPv4Hint, netip.AddrFrom4(*(*[4]byte)(value[i : i+4])))
+					}
+				case 5: // ech
+					h.ECH = value[2:]
+				case 6: // ipv6hint
+					for i := 0; i < length; i += 16 {
+						h.IPv6Hint = append(h.IPv6Hint, netip.AddrFrom16(*(*[16]byte)(value[i : i+16])))
+					}
+				}
+			}
+			https = append(https, h)
+		}
+		return true
+	})
+
+	return
+}

client_test.go

@@ -61,3 +61,17 @@ func TestLookupNetIP(t *testing.T) {
 
 	t.Logf("client.LookupNetIP(%+v) return ips=%s err=%+v\n", host, ips, err)
 }
+
+func TestLookupHTTPS(t *testing.T) {
+	host := "cloud.phus.lu"
+
+	client := &Client{
+		AddrPort:    netip.AddrPortFrom(netip.AddrFrom4([4]byte{8, 8, 8, 8}), 53),
+		ReadTimeout: 1 * time.Second,
+		MaxConns:    1000,
+	}
+
+	https, err := client.LookupHTTPS(context.Background(), "ip", host)
+
+	t.Logf("client.LookupHTTPS(%+v) return https=%+v err=%+v\n", host, https, err)
+}

types.go

@@ -1,5 +1,9 @@
 package fastdns
 
+import (
+	"net/netip"
+)
+
 // Rcode denotes a 4bit field that specifies the response
 // code for a query.
 type Rcode byte
@@ -102,7 +106,8 @@ func (c Opcode) String() string {
 
 // Flags is an arbitrary 16bit represents QR, Opcode, AA, TC, RD, RA, Z and RCODE.
 //
-//   0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F
+//	0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F
+//
 // +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
 // |QR|   Opcode  |AA|TC|RD|RA|   Z    |   RCODE   |
 // +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
@@ -616,3 +621,10 @@ func ParseType(s string) (t Type) {
 	}
 	return
 }
+
+type NetHTTPS struct {
+	ALPN     []string
+	IPv4Hint []netip.Addr
+	IPv6Hint []netip.Addr
+	ECH      []byte
+}