Revert commits unrelated to PackDomainName

This reverts commit 2eeda8aabc,
                    8e6e188a87
                and 7bef528091.

edns.go

@@ -273,16 +273,22 @@ func (e *EDNS0_SUBNET) unpack(b []byte) error {
 		if e.SourceNetmask > net.IPv4len*8 || e.SourceScope > net.IPv4len*8 {
 			return errors.New("dns: bad netmask")
 		}
-		addr := make(net.IP, net.IPv4len)
-		copy(addr, b[4:])
-		e.Address = addr.To16()
+		addr := make([]byte, net.IPv4len)
+		for i := 0; i < net.IPv4len && 4+i < len(b); i++ {
+			addr[i] = b[4+i]
+		}
+		e.Address = net.IPv4(addr[0], addr[1], addr[2], addr[3])
 	case 2:
 		if e.SourceNetmask > net.IPv6len*8 || e.SourceScope > net.IPv6len*8 {
 			return errors.New("dns: bad netmask")
 		}
-		addr := make(net.IP, net.IPv6len)
-		copy(addr, b[4:])
-		e.Address = addr
+		addr := make([]byte, net.IPv6len)
+		for i := 0; i < net.IPv6len && 4+i < len(b); i++ {
+			addr[i] = b[4+i]
+		}
+		e.Address = net.IP{addr[0], addr[1], addr[2], addr[3], addr[4],
+			addr[5], addr[6], addr[7], addr[8], addr[9], addr[10],
+			addr[11], addr[12], addr[13], addr[14], addr[15]}
 	default:
 		return errors.New("dns: bad address family")
 	}

edns_test.go

@@ -1,9 +1,6 @@
 package dns
 
-import (
-	"net"
-	"testing"
-)
+import "testing"
 
 func TestOPTTtl(t *testing.T) {
 	e := &OPT{}
@@ -66,8 +63,8 @@ func TestOPTTtl(t *testing.T) {
 
 	e.SetExtendedRcode(42)
 	// ExtendedRcode has the last 4 bits set to 0.
-	if e.ExtendedRcode() != 42&0xFFFFFFF0 {
-		t.Errorf("set 42, expected %d, got %d", 42&0xFFFFFFF0, e.ExtendedRcode())
+	if e.ExtendedRcode() != 42 & 0xFFFFFFF0 {
+		t.Errorf("set 42, expected %d, got %d", 42 & 0xFFFFFFF0, e.ExtendedRcode())
 	}
 
 	// This will reset the 8 upper bits of the extended rcode
@@ -76,36 +73,3 @@ func TestOPTTtl(t *testing.T) {
 		t.Errorf("Setting a non-extended rcode is expected to set extended rcode to 0, got: %d", e.ExtendedRcode())
 	}
 }
-
-func TestEDNS0_SUBNETUnpack(t *testing.T) {
-	for _, ip := range []net.IP{
-		net.IPv4(0xde, 0xad, 0xbe, 0xef),
-		net.ParseIP("192.0.2.1"),
-		net.ParseIP("2001:db8::68"),
-	} {
-		var s1 EDNS0_SUBNET
-		s1.Address = ip
-
-		if ip.To4() == nil {
-			s1.Family = 2
-			s1.SourceNetmask = net.IPv6len * 8
-		} else {
-			s1.Family = 1
-			s1.SourceNetmask = net.IPv4len * 8
-		}
-
-		b, err := s1.pack()
-		if err != nil {
-			t.Fatalf("failed to pack: %v", err)
-		}
-
-		var s2 EDNS0_SUBNET
-		if err := s2.unpack(b); err != nil {
-			t.Fatalf("failed to unpack: %v", err)
-		}
-
-		if !ip.Equal(s2.Address) {
-			t.Errorf("address different after unpacking; expected %s, got %s", ip, s2.Address)
-		}
-	}
-}

msg.go

@@ -1019,9 +1019,11 @@ func compressionLenHelper(c map[string]int, s string, currentLen int) int {
 		return 0
 	}
 	initLen := currentLen
+	pref := ""
 	prev := s
-	for off, end := 0, false; !end; off, end = NextLabel(s, off) {
-		pref := s[off:]
+	lbs := Split(s)
+	for j := 0; j < len(lbs); j++ {
+		pref = s[lbs[j]:]
 		currentLen += len(prev) - len(pref)
 		prev = pref
 		if _, ok := c[pref]; !ok {
@@ -1031,7 +1033,7 @@ func compressionLenHelper(c map[string]int, s string, currentLen int) int {
 			}
 		} else {
 			added := currentLen - initLen
-			if off > 0 {
+			if j > 0 {
 				// We added a new PTR
 				added += 2
 			}

msg_helpers.go

@@ -223,8 +223,8 @@ func unpackUint48(msg []byte, off int) (i uint64, off1 int, err error) {
 		return 0, len(msg), &Error{err: "overflow unpacking uint64 as uint48"}
 	}
 	// Used in TSIG where the last 48 bits are occupied, so for now, assume a uint48 (6 bytes)
-	i = uint64(msg[off])<<40 | uint64(msg[off+1])<<32 | uint64(msg[off+2])<<24 | uint64(msg[off+3])<<16 |
-		uint64(msg[off+4])<<8 | uint64(msg[off+5])
+	i = uint64(uint64(msg[off])<<40 | uint64(msg[off+1])<<32 | uint64(msg[off+2])<<24 | uint64(msg[off+3])<<16 |
+		uint64(msg[off+4])<<8 | uint64(msg[off+5]))
 	off += 6
 	return i, off, nil
 }