From ddeeadc22ac5c45844e013f30d4f6227263afb86 Mon Sep 17 00:00:00 2001
From: Miek Gieben <miek@miek.nl>
Date: Wed, 4 Aug 2010 23:41:05 +0200
Subject: [PATCH] add packers for ipv4/6 to

---
 dnsmsg.go | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/dnsmsg.go b/dnsmsg.go
index 0eda4ba1..f9bf69e8 100644
--- a/dnsmsg.go
+++ b/dnsmsg.go
@@ -177,6 +177,29 @@ func packStructValue(val *reflect.StructValue, msg []byte, off int) (off1 int, o
 		BadType:
 			fmt.Fprintf(os.Stderr, "net: dns: unknown packing type %v", f.Type)
 			return len(msg), false
+		case *reflect.SliceValue:
+			switch f.Tag {
+			default:
+				fmt.Fprintf(os.Stderr, "net: dns: unknown IP tag %v", f.Tag)
+				return len(msg), false
+			case "ipv4":
+				if fv.Len() > net.IPv4len || off+fv.Len() > len(msg) {
+					return len(msg), false
+				}
+				msg[off]   = byte(fv.Elem(0).(*reflect.UintValue).Get())
+				msg[off+1] = byte(fv.Elem(1).(*reflect.UintValue).Get())
+				msg[off+2] = byte(fv.Elem(2).(*reflect.UintValue).Get())
+				msg[off+3] = byte(fv.Elem(3).(*reflect.UintValue).Get())
+				off += net.IPv4len
+			case "ipv6":
+				if fv.Len() > net.IPv6len || off+fv.Len() > len(msg) {
+					return len(msg), false
+				}
+				for j:=0; j<net.IPv6len; j++ {
+					msg[off] = byte(fv.Elem(j).(*reflect.UintValue).Get())
+					off++
+				}
+			}
 		case *reflect.StructValue:
 			off, ok = packStructValue(fv, msg, off)
 		case *reflect.UintValue: