net: fix broken setDefaultSockopts

R=rsc, bradfitz
CC=golang-dev
https://golang.org/cl/5536068

8 files changed, 44 insertions, 35 deletions

diff --git a/src/pkg/net/fd.go b/src/pkg/net/fd.go
index 1b39cd7c4b..7ecd135d20 100644
--- a/src/pkg/net/fd.go
+++ b/src/pkg/net/fd.go
@@ -24,7 +24,7 @@ type netFD struct {
 	// immutable until Close
 	sysfd   int
 	family  int
-	proto   int
+	sotype  int
 	sysfile *os.File
 	cr      chan bool
 	cw      chan bool
@@ -274,7 +274,7 @@ func startServer() {
 	pollserver = p
 }
 
-func newFD(fd, family, proto int, net string) (f *netFD, err error) {
+func newFD(fd, family, sotype int, net string) (f *netFD, err error) {
 	onceStartServer.Do(startServer)
 	if e := syscall.SetNonblock(fd, true); e != nil {
 		return nil, e
@@ -282,7 +282,7 @@ func newFD(fd, family, proto int, net string) (f *netFD, err error) {
 	f = &netFD{
 		sysfd:  fd,
 		family: family,
-		proto:  proto,
+		sotype: sotype,
 		net:    net,
 	}
 	f.cr = make(chan bool, 1)
@@ -397,7 +397,7 @@ func (fd *netFD) Read(p []byte) (n int, err error) {
 		}
 		if err != nil {
 			n = 0
-		} else if n == 0 && err == nil && fd.proto != syscall.SOCK_DGRAM {
+		} else if n == 0 && err == nil && fd.sotype != syscall.SOCK_DGRAM {
 			err = io.EOF
 		}
 		break
@@ -599,7 +599,7 @@ func (fd *netFD) accept(toAddr func(syscall.Sockaddr) Addr) (nfd *netFD, err err
 	syscall.CloseOnExec(s)
 	syscall.ForkLock.RUnlock()
 
-	if nfd, err = newFD(s, fd.family, fd.proto, fd.net); err != nil {
+	if nfd, err = newFD(s, fd.family, fd.sotype, fd.net); err != nil {
 		syscall.Close(s)
 		return nil, err
 	}
diff --git a/src/pkg/net/ipsock_posix.go b/src/pkg/net/ipsock_posix.go
index 45fe0d9640..3a059f516b 100644
--- a/src/pkg/net/ipsock_posix.go
+++ b/src/pkg/net/ipsock_posix.go
@@ -101,7 +101,7 @@ type sockaddr interface {
 	family() int
 }
 
-func internetSocket(net string, laddr, raddr sockaddr, socktype, proto int, mode string, toAddr func(syscall.Sockaddr) Addr) (fd *netFD, err error) {
+func internetSocket(net string, laddr, raddr sockaddr, sotype, proto int, mode string, toAddr func(syscall.Sockaddr) Addr) (fd *netFD, err error) {
 	var oserr error
 	var la, ra syscall.Sockaddr
 	family := favoriteAddrFamily(net, raddr, laddr, mode)
@@ -115,7 +115,7 @@ func internetSocket(net string, laddr, raddr sockaddr, socktype, proto int, mode
 			goto Error
 		}
 	}
-	fd, oserr = socket(net, family, socktype, proto, la, ra, toAddr)
+	fd, oserr = socket(net, family, sotype, proto, la, ra, toAddr)
 	if oserr != nil {
 		goto Error
 	}
diff --git a/src/pkg/net/sock.go b/src/pkg/net/sock.go
index 5e775e87d9..2f3210b428 100644
--- a/src/pkg/net/sock.go
+++ b/src/pkg/net/sock.go
@@ -17,10 +17,10 @@ import (
 var listenerBacklog = maxListenerBacklog()
 
 // Generic socket creation.
-func socket(net string, f, p, t int, la, ra syscall.Sockaddr, toAddr func(syscall.Sockaddr) Addr) (fd *netFD, err error) {
+func socket(net string, f, t, p int, la, ra syscall.Sockaddr, toAddr func(syscall.Sockaddr) Addr) (fd *netFD, err error) {
 	// See ../syscall/exec.go for description of ForkLock.
 	syscall.ForkLock.RLock()
-	s, err := syscall.Socket(f, p, t)
+	s, err := syscall.Socket(f, t, p)
 	if err != nil {
 		syscall.ForkLock.RUnlock()
 		return nil, err
@@ -28,7 +28,7 @@ func socket(net string, f, p, t int, la, ra syscall.Sockaddr, toAddr func(syscal
 	syscall.CloseOnExec(s)
 	syscall.ForkLock.RUnlock()
 
-	setDefaultSockopts(s, f, p)
+	setDefaultSockopts(s, f, t)
 
 	if la != nil {
 		err = syscall.Bind(s, la)
@@ -38,7 +38,7 @@ func socket(net string, f, p, t int, la, ra syscall.Sockaddr, toAddr func(syscal
 		}
 	}
 
-	if fd, err = newFD(s, f, p, net); err != nil {
+	if fd, err = newFD(s, f, t, net); err != nil {
 		closesocket(s)
 		return nil, err
 	}
diff --git a/src/pkg/net/sockopt_bsd.go b/src/pkg/net/sockopt_bsd.go
index e99fb418cd..2093e08127 100644
--- a/src/pkg/net/sockopt_bsd.go
+++ b/src/pkg/net/sockopt_bsd.go
@@ -12,14 +12,15 @@ import (
 	"syscall"
 )
 
-func setDefaultSockopts(s, f, p int) {
+func setDefaultSockopts(s, f, t int) {
 	switch f {
 	case syscall.AF_INET6:
 		// Allow both IP versions even if the OS default is otherwise.
 		syscall.SetsockoptInt(s, syscall.IPPROTO_IPV6, syscall.IPV6_V6ONLY, 0)
 	}
 
-	if f == syscall.AF_UNIX || p == syscall.IPPROTO_TCP {
+	if f == syscall.AF_UNIX ||
+		(f == syscall.AF_INET || f == syscall.AF_INET6) && t == syscall.SOCK_STREAM {
 		// Allow reuse of recently-used addresses.
 		syscall.SetsockoptInt(s, syscall.SOL_SOCKET, syscall.SO_REUSEADDR, 1)
 
diff --git a/src/pkg/net/sockopt_linux.go b/src/pkg/net/sockopt_linux.go
index 51583844f1..9dbb4e5dde 100644
--- a/src/pkg/net/sockopt_linux.go
+++ b/src/pkg/net/sockopt_linux.go
@@ -10,14 +10,15 @@ import (
 	"syscall"
 )
 
-func setDefaultSockopts(s, f, p int) {
+func setDefaultSockopts(s, f, t int) {
 	switch f {
 	case syscall.AF_INET6:
 		// Allow both IP versions even if the OS default is otherwise.
 		syscall.SetsockoptInt(s, syscall.IPPROTO_IPV6, syscall.IPV6_V6ONLY, 0)
 	}
 
-	if f == syscall.AF_UNIX || p == syscall.IPPROTO_TCP {
+	if f == syscall.AF_UNIX ||
+		(f == syscall.AF_INET || f == syscall.AF_INET6) && t == syscall.SOCK_STREAM {
 		// Allow reuse of recently-used addresses.
 		syscall.SetsockoptInt(s, syscall.SOL_SOCKET, syscall.SO_REUSEADDR, 1)
 	}
diff --git a/src/pkg/net/sockopt_windows.go b/src/pkg/net/sockopt_windows.go
index 485c14a2d3..a7b5606d86 100644
--- a/src/pkg/net/sockopt_windows.go
+++ b/src/pkg/net/sockopt_windows.go
@@ -10,7 +10,7 @@ import (
 	"syscall"
 )
 
-func setDefaultSockopts(s syscall.Handle, f, p int) {
+func setDefaultSockopts(s syscall.Handle, f, t int) {
 	switch f {
 	case syscall.AF_INET6:
 		// Allow both IP versions even if the OS default is otherwise.
diff --git a/src/pkg/net/unicast_test.go b/src/pkg/net/unicast_test.go
index 6ed6f59cdd..a89b9baa5e 100644
--- a/src/pkg/net/unicast_test.go
+++ b/src/pkg/net/unicast_test.go
@@ -15,10 +15,12 @@ var unicastTests = []struct {
 	ipv6   bool
 	packet bool
 }{
-	{"tcp4", "127.0.0.1:0", false, false},
-	{"tcp6", "[::1]:0", true, false},
-	{"udp4", "127.0.0.1:0", false, true},
-	{"udp6", "[::1]:0", true, true},
+	{net: "tcp4", laddr: "127.0.0.1:0"},
+	{net: "tcp4", laddr: "previous"},
+	{net: "tcp6", laddr: "[::1]:0", ipv6: true},
+	{net: "tcp6", laddr: "previous", ipv6: true},
+	{net: "udp4", laddr: "127.0.0.1:0", packet: true},
+	{net: "udp6", laddr: "[::1]:0", ipv6: true, packet: true},
 }
 
 func TestUnicastTCPAndUDP(t *testing.T) {
@@ -26,16 +28,21 @@ func TestUnicastTCPAndUDP(t *testing.T) {
 		return
 	}
 
+	prevladdr := ""
 	for _, tt := range unicastTests {
 		if tt.ipv6 && !supportsIPv6 {
 			continue
 		}
 		var fd *netFD
 		if !tt.packet {
+			if tt.laddr == "previous" {
+				tt.laddr = prevladdr
+			}
 			c, err := Listen(tt.net, tt.laddr)
 			if err != nil {
 				t.Fatalf("Listen failed: %v", err)
 			}
+			prevladdr = c.Addr().String()
 			defer c.Close()
 			fd = c.(*TCPListener).fd
 		} else {
diff --git a/src/pkg/net/unixsock_posix.go b/src/pkg/net/unixsock_posix.go
index c1bb90b60a..5b8b2e4c7c 100644
--- a/src/pkg/net/unixsock_posix.go
+++ b/src/pkg/net/unixsock_posix.go
@@ -15,16 +15,16 @@ import (
 )
 
 func unixSocket(net string, laddr, raddr *UnixAddr, mode string) (fd *netFD, err error) {
-	var proto int
+	var sotype int
 	switch net {
 	default:
 		return nil, UnknownNetworkError(net)
 	case "unix":
-		proto = syscall.SOCK_STREAM
+		sotype = syscall.SOCK_STREAM
 	case "unixgram":
-		proto = syscall.SOCK_DGRAM
+		sotype = syscall.SOCK_DGRAM
 	case "unixpacket":
-		proto = syscall.SOCK_SEQPACKET
+		sotype = syscall.SOCK_SEQPACKET
 	}
 
 	var la, ra syscall.Sockaddr
@@ -38,7 +38,7 @@ func unixSocket(net string, laddr, raddr *UnixAddr, mode string) (fd *netFD, err
 		}
 		if raddr != nil {
 			ra = &syscall.SockaddrUnix{Name: raddr.Name}
-		} else if proto != syscall.SOCK_DGRAM || laddr == nil {
+		} else if sotype != syscall.SOCK_DGRAM || laddr == nil {
 			return nil, &OpError{Op: mode, Net: net, Err: errMissingAddress}
 		}
 
@@ -53,13 +53,13 @@ func unixSocket(net string, laddr, raddr *UnixAddr, mode string) (fd *netFD, err
 	}
 
 	f := sockaddrToUnix
-	if proto == syscall.SOCK_DGRAM {
+	if sotype == syscall.SOCK_DGRAM {
 		f = sockaddrToUnixgram
-	} else if proto == syscall.SOCK_SEQPACKET {
+	} else if sotype == syscall.SOCK_SEQPACKET {
 		f = sockaddrToUnixpacket
 	}
 
-	fd, oserr := socket(net, syscall.AF_UNIX, proto, 0, la, ra, f)
+	fd, oserr := socket(net, syscall.AF_UNIX, sotype, 0, la, ra, f)
 	if oserr != nil {
 		goto Error
 	}
@@ -94,8 +94,8 @@ func sockaddrToUnixpacket(sa syscall.Sockaddr) Addr {
 	return nil
 }
 
-func protoToNet(proto int) string {
-	switch proto {
+func sotypeToNet(sotype int) string {
+	switch sotype {
 	case syscall.SOCK_STREAM:
 		return "unix"
 	case syscall.SOCK_SEQPACKET:
@@ -103,7 +103,7 @@ func protoToNet(proto int) string {
 	case syscall.SOCK_DGRAM:
 		return "unixgram"
 	default:
-		panic("protoToNet unknown protocol")
+		panic("sotypeToNet unknown socket type")
 	}
 	return ""
 }
@@ -221,7 +221,7 @@ func (c *UnixConn) ReadFromUnix(b []byte) (n int, addr *UnixAddr, err error) {
 	n, sa, err := c.fd.ReadFrom(b)
 	switch sa := sa.(type) {
 	case *syscall.SockaddrUnix:
-		addr = &UnixAddr{sa.Name, protoToNet(c.fd.proto)}
+		addr = &UnixAddr{sa.Name, sotypeToNet(c.fd.sotype)}
 	}
 	return
 }
@@ -245,7 +245,7 @@ func (c *UnixConn) WriteToUnix(b []byte, addr *UnixAddr) (n int, err error) {
 	if !c.ok() {
 		return 0, os.EINVAL
 	}
-	if addr.Net != protoToNet(c.fd.proto) {
+	if addr.Net != sotypeToNet(c.fd.sotype) {
 		return 0, os.EAFNOSUPPORT
 	}
 	sa := &syscall.SockaddrUnix{Name: addr.Name}
@@ -271,7 +271,7 @@ func (c *UnixConn) ReadMsgUnix(b, oob []byte) (n, oobn, flags int, addr *UnixAdd
 	n, oobn, flags, sa, err := c.fd.ReadMsg(b, oob)
 	switch sa := sa.(type) {
 	case *syscall.SockaddrUnix:
-		addr = &UnixAddr{sa.Name, protoToNet(c.fd.proto)}
+		addr = &UnixAddr{sa.Name, sotypeToNet(c.fd.sotype)}
 	}
 	return
 }
@@ -281,7 +281,7 @@ func (c *UnixConn) WriteMsgUnix(b, oob []byte, addr *UnixAddr) (n, oobn int, err
 		return 0, 0, os.EINVAL
 	}
 	if addr != nil {
-		if addr.Net != protoToNet(c.fd.proto) {
+		if addr.Net != sotypeToNet(c.fd.sotype) {
 			return 0, 0, os.EAFNOSUPPORT
 		}
 		sa := &syscall.SockaddrUnix{Name: addr.Name}