lib/dns: implements RFC 9460 for SVCB RR and HTTPS RR

1 files changed, 48 insertions, 0 deletions

diff --git a/lib/dns/rdata_https.go b/lib/dns/rdata_https.go
new file mode 100644
index 00000000..dae748e4
--- /dev/null
+++ b/lib/dns/rdata_https.go
@@ -0,0 +1,48 @@
+// Copyright 2024, Shulhan <ms@kilabit.info>. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package dns
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+)
+
+// RDataHTTPS the resource record for type 65 [HTTPS RR].
+//
+// [HTTPS RR]: https://datatracker.ietf.org/doc/html/rfc9460
+type RDataHTTPS struct {
+	RDataSVCB
+}
+
+// WriteTo write the SVCB record as zone format to out.
+func (https *RDataHTTPS) WriteTo(out io.Writer) (_ int64, err error) {
+	var buf bytes.Buffer
+
+	fmt.Fprintf(&buf, `HTTPS %d %s`, https.Priority, https.TargetName)
+
+	var (
+		keys = https.keys()
+
+		keyid int
+	)
+	for _, keyid = range keys {
+		buf.WriteByte(' ')
+
+		if keyid == svcbKeyIDNoDefaultALPN {
+			buf.WriteString(svcbKeyNameNoDefaultALPN)
+			continue
+		}
+
+		https.writeParam(&buf, keyid)
+	}
+	buf.WriteByte('\n')
+
+	var n int
+
+	n, err = out.Write(buf.Bytes())
+
+	return int64(n), err
+}