net: LookupHost and Resolve{TCP,UDP,IP}Addr should use zone from getaddrinfo

The unix and windows getaddrinfo calls return a zone with IPv6
addresses. IPv6 link-local addresses returned are only valid on the
given zone. When the zone is dropped, connections to the address
will fail. This patch replaces IP with IPAddr in several internal
resolver functions, and plumbs through the zone.

Change-Id: Ifea891654f586f15b76988464f82e04a42ccff6d
Reviewed-on: https://go-review.googlesource.com/5851
Reviewed-by: Mikio Hara <mikioh.mikioh@gmail.com>

1 files changed, 11 insertions, 10 deletions

diff --git a/src/net/lookup_windows.go b/src/net/lookup_windows.go
index 6a925b0a7a..6a8d9181ba 100644
--- a/src/net/lookup_windows.go
+++ b/src/net/lookup_windows.go
@@ -62,7 +62,7 @@ func lookupHost(name string) (addrs []string, err error) {
 	return
 }
 
-func gethostbyname(name string) (addrs []IP, err error) {
+func gethostbyname(name string) (addrs []IPAddr, err error) {
 	// caller already acquired thread
 	h, err := syscall.GetHostByName(name)
 	if err != nil {
@@ -71,9 +71,9 @@ func gethostbyname(name string) (addrs []IP, err error) {
 	switch h.AddrType {
 	case syscall.AF_INET:
 		i := 0
-		addrs = make([]IP, 100) // plenty of room to grow
+		addrs = make([]IPAddr, 100) // plenty of room to grow
 		for p := (*[100](*[4]byte))(unsafe.Pointer(h.AddrList)); i < cap(addrs) && p[i] != nil; i++ {
-			addrs[i] = IPv4(p[i][0], p[i][1], p[i][2], p[i][3])
+			addrs[i] = IPAddr{IP: IPv4(p[i][0], p[i][1], p[i][2], p[i][3])}
 		}
 		addrs = addrs[0:i]
 	default: // TODO(vcc): Implement non IPv4 address lookups.
@@ -82,11 +82,11 @@ func gethostbyname(name string) (addrs []IP, err error) {
 	return addrs, nil
 }
 
-func oldLookupIP(name string) (addrs []IP, err error) {
+func oldLookupIP(name string) (addrs []IPAddr, err error) {
 	// GetHostByName return value is stored in thread local storage.
 	// Start new os thread before the call to prevent races.
 	type result struct {
-		addrs []IP
+		addrs []IPAddr
 		err   error
 	}
 	ch := make(chan result)
@@ -99,10 +99,10 @@ func oldLookupIP(name string) (addrs []IP, err error) {
 		ch <- result{addrs: addrs, err: err}
 	}()
 	r := <-ch
-	return r.addrs, r.err
+	return addrs, r.err
 }
 
-func newLookupIP(name string) (addrs []IP, err error) {
+func newLookupIP(name string) (addrs []IPAddr, err error) {
 	acquireThread()
 	defer releaseThread()
 	hints := syscall.AddrinfoW{
@@ -116,16 +116,17 @@ func newLookupIP(name string) (addrs []IP, err error) {
 		return nil, os.NewSyscallError("GetAddrInfoW", e)
 	}
 	defer syscall.FreeAddrInfoW(result)
-	addrs = make([]IP, 0, 5)
+	addrs = make([]IPAddr, 0, 5)
 	for ; result != nil; result = result.Next {
 		addr := unsafe.Pointer(result.Addr)
 		switch result.Family {
 		case syscall.AF_INET:
 			a := (*syscall.RawSockaddrInet4)(addr).Addr
-			addrs = append(addrs, IPv4(a[0], a[1], a[2], a[3]))
+			addrs = append(addrs, IPAddr{IP: IPv4(a[0], a[1], a[2], a[3])})
 		case syscall.AF_INET6:
 			a := (*syscall.RawSockaddrInet6)(addr).Addr
-			addrs = append(addrs, IP{a[0], a[1], a[2], a[3], a[4], a[5], a[6], a[7], a[8], a[9], a[10], a[11], a[12], a[13], a[14], a[15]})
+			zone := zoneToString(int((*syscall.RawSockaddrInet6)(addr).Scope_id))
+			addrs = append(addrs, IPAddr{IP: IP{a[0], a[1], a[2], a[3], a[4], a[5], a[6], a[7], a[8], a[9], a[10], a[11], a[12], a[13], a[14], a[15]}, Zone: zone})
 		default:
 			return nil, os.NewSyscallError("LookupIP", syscall.EWINDOWS)
 		}