From a71489b611edec79031f3911a07e706897594c31 Mon Sep 17 00:00:00 2001
From: Miek Gieben <miek@miek.nl>
Date: Mon, 21 Jul 2014 19:31:28 +0100
Subject: [PATCH] EDNS0: implement RFC 7314

Add the new option code.
---
 README.md |  3 ++-
 edns.go   | 32 +++++++++++++++++++++++++++++---
 2 files changed, 31 insertions(+), 4 deletions(-)

diff --git a/README.md b/README.md
index 27cd7387..3c04d625 100644
--- a/README.md
+++ b/README.md
@@ -114,6 +114,7 @@ Example programs can be found in the `github.com/miekg/exdns` repository.
 * 6891 - EDNS0 update
 * 6895 - DNS IANA considerations
 * 7043 - EUI48/EUI64 records
+* 7314 - DNS (EDNS) EXPIRE Option
 * xxxx - URI record (draft)
 * xxxx - EDNS0 DNS Update Lease (draft)
 * xxxx - Algorithm-Signal (draft)
@@ -129,7 +130,7 @@ Example programs can be found in the `github.com/miekg/exdns` repository.
 
 * Support for on-the-fly-signing or check how to do it;
 * Ratelimiting? server side (RRL);
-* Make a srv.Stop() that stops the server;
+* Make a srv.Shutdown() that stops the server;
 * privatekey.Precompute() when signing?
 * Last remaining RRs: APL, ATMA, A6, KEY, SIG and NXT;
 * CAA parsing is broken;
diff --git a/edns.go b/edns.go
index 127f37ee..f075719b 100644
--- a/edns.go
+++ b/edns.go
@@ -46,7 +46,7 @@ const (
 	EDNS0N3U         = 0x7    // NSEC3 Hash Understood
 	EDNS0SUBNET      = 0x8    // client-subnet (RFC6891)
 	EDNS0EXPIRE      = 0x9    // EDNS0 expire
-	EDNS0SUBNETDRAFT = 0x50fa // client-subnet draft: http://tools.ietf.org/html/draft-vandergaast-edns-client-subnet-01
+	EDNS0SUBNETDRAFT = 0x50fa // Don't use! Use EDNS0SUBNET
 	_DO              = 1 << 7 // dnssec ok
 )
 
@@ -335,6 +335,9 @@ type EDNS0_UL struct {
 	Lease uint32
 }
 
+func (e *EDNS0_UL) Option() uint16 { return EDNS0UL }
+func (e *EDNS0_UL) String() string { return strconv.FormatUint(uint64(e.Lease), 10) }
+
 // Copied: http://golang.org/src/pkg/net/dnsmsg.go
 func (e *EDNS0_UL) pack() ([]byte, error) {
 	b := make([]byte, 4)
@@ -345,7 +348,6 @@ func (e *EDNS0_UL) pack() ([]byte, error) {
 	return b, nil
 }
 
-func (e *EDNS0_UL) Option() uint16 { return EDNS0UL }
 func (e *EDNS0_UL) unpack(b []byte) error {
 	if len(b) < 4 {
 		return ErrBuf
@@ -353,7 +355,6 @@ func (e *EDNS0_UL) unpack(b []byte) error {
 	e.Lease = uint32(b[0])<<24 | uint32(b[1])<<16 | uint32(b[2])<<8 | uint32(b[3])
 	return nil
 }
-func (e *EDNS0_UL) String() string { return strconv.FormatUint(uint64(e.Lease), 10) }
 
 // Long Lived Queries: http://tools.ietf.org/html/draft-sekar-dns-llq-01
 // Implemented for completeness, as the EDNS0 type code is assigned.
@@ -471,3 +472,28 @@ func (e *EDNS0_N3U) String() string {
 	}
 	return s
 }
+
+type EDNS0_EXPIRE struct {
+	Code   uint16 // Always EDNS0EXPIRE
+	Expire uint32
+}
+
+func (e *EDNS0_EXPIRE) Option() uint16 { return EDNS0EXPIRE }
+func (e *EDNS0_EXPIRE) String() string { return strconv.FormatUint(uint64(e.Expire), 10) }
+
+func (e *EDNS0_EXPIRE) pack() ([]byte, error) {
+	b := make([]byte, 4)
+	b[0] = byte(e.Expire >> 24)
+	b[1] = byte(e.Expire >> 16)
+	b[2] = byte(e.Expire >> 8)
+	b[3] = byte(e.Expire)
+	return b, nil
+}
+
+func (e *EDNS0_EXPIRE) unpack(b []byte) error {
+	if len(b) < 4 {
+		return ErrBuf
+	}
+	e.Expire = uint32(b[0])<<24 | uint32(b[1])<<16 | uint32(b[2])<<8 | uint32(b[3])
+	return nil
+}