Revert "net, internal/syscall/unix: add SocketConn, SocketPacketConn"

This reverts commit 6f7961da28232c609f7c51b3bed7f15db7dd33e1.

Russ suggests changing the frozon syscall package and obviously it's a
better solution. Perhaps he will also let me know the way how to get the
project owners to agree later.

Fixes #11492.

Change-Id: I98f9f366b72b85db54b4acfc3a604b62fb6d783c
Reviewed-on: https://go-review.googlesource.com/11854
Run-TryBot: Mikio Hara <mikioh.mikioh@gmail.com>
Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

14 files changed, 30 insertions, 609 deletions

diff --git a/src/go/build/deps_test.go b/src/go/build/deps_test.go
index de29b56f6d..fb64418866 100644
--- a/src/go/build/deps_test.go
+++ b/src/go/build/deps_test.go
@@ -244,7 +244,7 @@ var pkgDeps = map[string][]string{
 	// Basic networking.
 	// Because net must be used by any package that wants to
 	// do networking portably, it must have a small dependency set: just L1+basic os.
-	"net": {"L1", "CGO", "os", "syscall", "time", "internal/syscall/unix", "internal/syscall/windows", "internal/singleflight"},
+	"net": {"L1", "CGO", "os", "syscall", "time", "internal/syscall/windows", "internal/singleflight"},
 
 	// NET enables use of basic network-related packages.
 	"NET": {
diff --git a/src/internal/syscall/unix/socket.go b/src/internal/syscall/unix/socket.go
deleted file mode 100644
index d7a9b9cb1d..0000000000
--- a/src/internal/syscall/unix/socket.go
+++ /dev/null
@@ -1,39 +0,0 @@
-// Copyright 2015 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// +build darwin dragonfly freebsd linux nacl netbsd openbsd solaris
-
-package unix
-
-// Getsockname copies the binary encoding of the current address for s
-// into addr.
-func Getsockname(s int, addr []byte) error {
-	return getsockname(s, addr)
-}
-
-// Getpeername copies the binary encoding of the peer address for s
-// into addr.
-func Getpeername(s int, addr []byte) error {
-	return getpeername(s, addr)
-}
-
-var emptyPayload uintptr
-
-// Recvfrom receives a message from s, copying the message into b.
-// The socket address addr must be large enough for storing the source
-// address of the message.
-// Flags must be operation control flags or 0.
-// It retunrs the number of bytes copied into b.
-func Recvfrom(s int, b []byte, flags int, addr []byte) (int, error) {
-	return recvfrom(s, b, flags, addr)
-}
-
-// Sendto sends a message to the socket address addr, copying the
-// message from b.
-// The socket address addr must be suitable for s.
-// Flags must be operation control flags or 0.
-// It retunrs the number of bytes copied from b.
-func Sendto(s int, b []byte, flags int, addr []byte) (int, error) {
-	return sendto(s, b, flags, addr)
-}
diff --git a/src/internal/syscall/unix/socket_linux_386.go b/src/internal/syscall/unix/socket_linux_386.go
deleted file mode 100644
index 47105e0b1d..0000000000
--- a/src/internal/syscall/unix/socket_linux_386.go
+++ /dev/null
@@ -1,67 +0,0 @@
-// Copyright 2015 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package unix
-
-import (
-	"syscall"
-	"unsafe"
-)
-
-const (
-	sysGETSOCKNAME = 0x6
-	sysGETPEERNAME = 0x7
-	sysSENDTO      = 0xb
-	sysRECVFROM    = 0xc
-)
-
-func socketcall(call int, a0, a1, a2, a3, a4, a5 uintptr) (int, syscall.Errno)
-func rawsocketcall(call int, a0, a1, a2, a3, a4, a5 uintptr) (int, syscall.Errno)
-
-func getsockname(s int, addr []byte) error {
-	l := uint32(len(addr))
-	_, errno := rawsocketcall(sysGETSOCKNAME, uintptr(s), uintptr(unsafe.Pointer(&addr[0])), uintptr(unsafe.Pointer(&l)), 0, 0, 0)
-	if errno != 0 {
-		return error(errno)
-	}
-	return nil
-}
-
-func getpeername(s int, addr []byte) error {
-	l := uint32(len(addr))
-	_, errno := rawsocketcall(sysGETPEERNAME, uintptr(s), uintptr(unsafe.Pointer(&addr[0])), uintptr(unsafe.Pointer(&l)), 0, 0, 0)
-	if errno != 0 {
-		return error(errno)
-	}
-	return nil
-}
-
-func recvfrom(s int, b []byte, flags int, from []byte) (int, error) {
-	var p unsafe.Pointer
-	if len(b) > 0 {
-		p = unsafe.Pointer(&b[0])
-	} else {
-		p = unsafe.Pointer(&emptyPayload)
-	}
-	l := uint32(len(from))
-	n, errno := socketcall(sysRECVFROM, uintptr(s), uintptr(p), uintptr(len(b)), uintptr(flags), uintptr(unsafe.Pointer(&from[0])), uintptr(unsafe.Pointer(&l)))
-	if errno != 0 {
-		return int(n), error(errno)
-	}
-	return int(n), nil
-}
-
-func sendto(s int, b []byte, flags int, to []byte) (int, error) {
-	var p unsafe.Pointer
-	if len(b) > 0 {
-		p = unsafe.Pointer(&b[0])
-	} else {
-		p = unsafe.Pointer(&emptyPayload)
-	}
-	n, errno := socketcall(sysSENDTO, uintptr(s), uintptr(p), uintptr(len(b)), uintptr(flags), uintptr(unsafe.Pointer(&to[0])), uintptr(len(to)))
-	if errno != 0 {
-		return int(n), error(errno)
-	}
-	return int(n), nil
-}
diff --git a/src/internal/syscall/unix/socket_linux_386.s b/src/internal/syscall/unix/socket_linux_386.s
deleted file mode 100644
index 48e2094db5..0000000000
--- a/src/internal/syscall/unix/socket_linux_386.s
+++ /dev/null
@@ -1,11 +0,0 @@
-// Copyright 2015 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-#include "textflag.h"
-
-TEXT	·socketcall(SB),NOSPLIT,$0-36
-	JMP	syscall·socketcall(SB)
-
-TEXT	·rawsocketcall(SB),NOSPLIT,$0-36
-	JMP	syscall·socketcall(SB)
diff --git a/src/internal/syscall/unix/socket_stub.go b/src/internal/syscall/unix/socket_stub.go
deleted file mode 100644
index 1c89ed1820..0000000000
--- a/src/internal/syscall/unix/socket_stub.go
+++ /dev/null
@@ -1,25 +0,0 @@
-// Copyright 2015 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// +build nacl solaris
-
-package unix
-
-import "syscall"
-
-func getsockname(s int, addr []byte) error {
-	return syscall.EOPNOTSUPP
-}
-
-func getpeername(s int, addr []byte) error {
-	return syscall.EOPNOTSUPP
-}
-
-func recvfrom(s int, b []byte, flags int, from []byte) (int, error) {
-	return 0, syscall.EOPNOTSUPP
-}
-
-func sendto(s int, b []byte, flags int, to []byte) (int, error) {
-	return 0, syscall.EOPNOTSUPP
-}
diff --git a/src/internal/syscall/unix/socket_unix.go b/src/internal/syscall/unix/socket_unix.go
deleted file mode 100644
index a769bb38b6..0000000000
--- a/src/internal/syscall/unix/socket_unix.go
+++ /dev/null
@@ -1,59 +0,0 @@
-// Copyright 2015 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// +build darwin dragonfly freebsd linux,!386 netbsd openbsd
-
-package unix
-
-import (
-	"syscall"
-	"unsafe"
-)
-
-func getsockname(s int, addr []byte) error {
-	l := uint32(len(addr))
-	_, _, errno := syscall.RawSyscall(syscall.SYS_GETSOCKNAME, uintptr(s), uintptr(unsafe.Pointer(&addr[0])), uintptr(unsafe.Pointer(&l)))
-	if errno != 0 {
-		return error(errno)
-	}
-	return nil
-}
-
-func getpeername(s int, addr []byte) error {
-	l := uint32(len(addr))
-	_, _, errno := syscall.RawSyscall(syscall.SYS_GETPEERNAME, uintptr(s), uintptr(unsafe.Pointer(&addr[0])), uintptr(unsafe.Pointer(&l)))
-	if errno != 0 {
-		return error(errno)
-	}
-	return nil
-}
-
-func recvfrom(s int, b []byte, flags int, from []byte) (int, error) {
-	var p unsafe.Pointer
-	if len(b) > 0 {
-		p = unsafe.Pointer(&b[0])
-	} else {
-		p = unsafe.Pointer(&emptyPayload)
-	}
-	l := uint32(len(from))
-	n, _, errno := syscall.Syscall6(syscall.SYS_RECVFROM, uintptr(s), uintptr(p), uintptr(len(b)), uintptr(flags), uintptr(unsafe.Pointer(&from[0])), uintptr(unsafe.Pointer(&l)))
-	if errno != 0 {
-		return int(n), error(errno)
-	}
-	return int(n), nil
-}
-
-func sendto(s int, b []byte, flags int, to []byte) (int, error) {
-	var p unsafe.Pointer
-	if len(b) > 0 {
-		p = unsafe.Pointer(&b[0])
-	} else {
-		p = unsafe.Pointer(&emptyPayload)
-	}
-	n, _, errno := syscall.Syscall6(syscall.SYS_SENDTO, uintptr(s), uintptr(p), uintptr(len(b)), uintptr(flags), uintptr(unsafe.Pointer(&to[0])), uintptr(len(to)))
-	if errno != 0 {
-		return int(n), error(errno)
-	}
-	return int(n), nil
-}
diff --git a/src/net/fd_unix.go b/src/net/fd_unix.go
index 827045b13d..f2d7b348bf 100644
--- a/src/net/fd_unix.go
+++ b/src/net/fd_unix.go
@@ -7,7 +7,6 @@
 package net
 
 import (
-	"internal/syscall/unix"
 	"io"
 	"os"
 	"runtime"
@@ -271,33 +270,6 @@ func (fd *netFD) readFrom(p []byte) (n int, sa syscall.Sockaddr, err error) {
 	return
 }
 
-func (fd *netFD) recvFrom(b []byte, flags int, from []byte) (n int, err error) {
-	if err := fd.readLock(); err != nil {
-		return 0, err
-	}
-	defer fd.readUnlock()
-	if err := fd.pd.PrepareRead(); err != nil {
-		return 0, err
-	}
-	for {
-		n, err = unix.Recvfrom(fd.sysfd, b, flags, from)
-		if err != nil {
-			n = 0
-			if err == syscall.EAGAIN {
-				if err = fd.pd.WaitRead(); err == nil {
-					continue
-				}
-			}
-		}
-		err = fd.eofError(n, err)
-		break
-	}
-	if _, ok := err.(syscall.Errno); ok {
-		err = os.NewSyscallError("recvfrom", err)
-	}
-	return
-}
-
 func (fd *netFD) readMsg(p []byte, oob []byte) (n, oobn, flags int, sa syscall.Sockaddr, err error) {
 	if err := fd.readLock(); err != nil {
 		return 0, 0, 0, nil, err
@@ -387,29 +359,6 @@ func (fd *netFD) writeTo(p []byte, sa syscall.Sockaddr) (n int, err error) {
 	return
 }
 
-func (fd *netFD) sendTo(b []byte, flags int, to []byte) (n int, err error) {
-	if err := fd.writeLock(); err != nil {
-		return 0, err
-	}
-	defer fd.writeUnlock()
-	if err := fd.pd.PrepareWrite(); err != nil {
-		return 0, err
-	}
-	for {
-		n, err = unix.Sendto(fd.sysfd, b, flags, to)
-		if err == syscall.EAGAIN {
-			if err = fd.pd.WaitWrite(); err == nil {
-				continue
-			}
-		}
-		break
-	}
-	if _, ok := err.(syscall.Errno); ok {
-		err = os.NewSyscallError("sendto", err)
-	}
-	return
-}
-
 func (fd *netFD) writeMsg(p []byte, oob []byte, sa syscall.Sockaddr) (n int, oobn int, err error) {
 	if err := fd.writeLock(); err != nil {
 		return 0, 0, err
diff --git a/src/net/file.go b/src/net/file.go
index 1d0686c9fc..1aad477400 100644
--- a/src/net/file.go
+++ b/src/net/file.go
@@ -46,47 +46,3 @@ func FilePacketConn(f *os.File) (c PacketConn, err error) {
 	}
 	return
 }
-
-// A SocketAddr is used with SocketConn or SocketPacketConn to
-// implement a user-configured socket address.
-// The net package does not provide any implementations of SocketAddr;
-// the caller of SocketConn or SocketPacketConn is expected to provide
-// one.
-type SocketAddr interface {
-	// Addr takes a platform-specific socket address and returns
-	// a net.Addr. The result may be nil when the syscall package,
-	// system call or underlying protocol does not support the
-	// socket address.
-	Addr([]byte) Addr
-
-	// Raw takes a net.Addr and returns a platform-specific socket
-	// address. The result may be nil when the syscall package,
-	// system call or underlying protocol does not support the
-	// socket address.
-	Raw(Addr) []byte
-}
-
-// SocketConn returns a copy of the network connection corresponding
-// to the open file f and user-defined socket address sa.
-// It is the caller's responsibility to close f when finished.
-// Closing c does not affect f, and closing f does not affect c.
-func SocketConn(f *os.File, sa SocketAddr) (c Conn, err error) {
-	c, err = socketConn(f, sa)
-	if err != nil {
-		err = &OpError{Op: "file", Net: "file+net", Source: nil, Addr: fileAddr(f.Name()), Err: err}
-	}
-	return
-}
-
-// SocketPacketConn returns a copy of the packet network connection
-// corresponding to the open file f and user-defined socket address
-// sa.
-// It is the caller's responsibility to close f when finished.
-// Closing c does not affect f, and closing f does not affect c.
-func SocketPacketConn(f *os.File, sa SocketAddr) (c PacketConn, err error) {
-	c, err = socketPacketConn(f, sa)
-	if err != nil {
-		err = &OpError{Op: "file", Net: "file+net", Source: nil, Addr: fileAddr(f.Name()), Err: err}
-	}
-	return
-}
diff --git a/src/net/file_bsd_test.go b/src/net/file_bsd_test.go
deleted file mode 100644
index ffe3c612b4..0000000000
--- a/src/net/file_bsd_test.go
+++ /dev/null
@@ -1,95 +0,0 @@
-// Copyright 2015 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// +build darwin dragonfly freebsd netbsd openbsd
-
-package net
-
-import (
-	"os"
-	"runtime"
-	"strings"
-	"sync"
-	"syscall"
-	"testing"
-	"unsafe"
-)
-
-type routeAddr struct{}
-
-func (a *routeAddr) Network() string { return "route" }
-func (a *routeAddr) String() string  { return "<nil>" }
-
-func (a *routeAddr) Addr(rsa []byte) Addr { return &routeAddr{} }
-func (a *routeAddr) Raw(addr Addr) []byte { return nil }
-
-func TestSocketConn(t *testing.T) {
-	var freebsd32o64 bool
-	if runtime.GOOS == "freebsd" && runtime.GOARCH == "386" {
-		archs, _ := syscall.Sysctl("kern.supported_archs")
-		for _, s := range strings.Split(archs, " ") {
-			if strings.TrimSpace(s) == "amd64" {
-				freebsd32o64 = true
-				break
-			}
-		}
-	}
-
-	s, err := syscall.Socket(syscall.AF_ROUTE, syscall.SOCK_RAW, syscall.AF_UNSPEC)
-	if err != nil {
-		t.Fatal(err)
-	}
-	f := os.NewFile(uintptr(s), "route")
-	c, err := SocketConn(f, &routeAddr{})
-	f.Close()
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer c.Close()
-
-	const N = 3
-	var wg sync.WaitGroup
-	wg.Add(2 * N)
-	for i := 0; i < N; i++ {
-		go func(i int) {
-			defer wg.Done()
-			l := syscall.SizeofRtMsghdr + syscall.SizeofSockaddrInet4
-			if freebsd32o64 {
-				l += syscall.SizeofRtMetrics // see syscall/route_freebsd_32bit.go
-			}
-			b := make([]byte, l)
-			h := (*syscall.RtMsghdr)(unsafe.Pointer(&b[0]))
-			h.Msglen = uint16(len(b))
-			h.Version = syscall.RTM_VERSION
-			h.Type = syscall.RTM_GET
-			h.Addrs = syscall.RTA_DST
-			h.Pid = int32(os.Getpid())
-			h.Seq = int32(i)
-			p := (*syscall.RawSockaddrInet4)(unsafe.Pointer(&b[syscall.SizeofRtMsghdr]))
-			p.Len = syscall.SizeofSockaddrInet4
-			p.Family = syscall.AF_INET
-			p.Addr = [4]byte{127, 0, 0, 1}
-			if _, err := c.Write(b); err != nil {
-				t.Error(err)
-				return
-			}
-		}(i + 1)
-	}
-	for i := 0; i < N; i++ {
-		go func() {
-			defer wg.Done()
-			b := make([]byte, os.Getpagesize())
-			n, err := c.Read(b)
-			if err != nil {
-				t.Error(err)
-				return
-			}
-			if _, err := syscall.ParseRoutingMessage(b[:n]); err != nil {
-				t.Error(err)
-				return
-			}
-		}()
-	}
-	wg.Wait()
-}
diff --git a/src/net/file_linux_test.go b/src/net/file_linux_test.go
deleted file mode 100644
index e04fea38f6..0000000000
--- a/src/net/file_linux_test.go
+++ /dev/null
@@ -1,98 +0,0 @@
-// Copyright 2015 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package net
-
-import (
-	"fmt"
-	"os"
-	"sync"
-	"syscall"
-	"testing"
-	"unsafe"
-)
-
-type netlinkAddr struct {
-	PID    uint32
-	Groups uint32
-}
-
-func (a *netlinkAddr) Network() string { return "netlink" }
-func (a *netlinkAddr) String() string  { return fmt.Sprintf("%x:%x", a.PID, a.Groups) }
-
-func (a *netlinkAddr) Addr(rsa []byte) Addr {
-	if len(rsa) < syscall.SizeofSockaddrNetlink {
-		return nil
-	}
-	var addr netlinkAddr
-	b := (*[unsafe.Sizeof(addr)]byte)(unsafe.Pointer(&addr))
-	copy(b[0:4], rsa[4:8])
-	copy(b[4:8], rsa[8:12])
-	return &addr
-}
-
-func (a *netlinkAddr) Raw(addr Addr) []byte {
-	if addr, ok := addr.(*netlinkAddr); ok {
-		rsa := &syscall.RawSockaddrNetlink{Family: syscall.AF_NETLINK, Pid: addr.PID, Groups: addr.Groups}
-		return (*[unsafe.Sizeof(*rsa)]byte)(unsafe.Pointer(rsa))[:]
-	}
-	return nil
-}
-
-func TestSocketPacketConn(t *testing.T) {
-	s, err := syscall.Socket(syscall.AF_NETLINK, syscall.SOCK_RAW, syscall.NETLINK_ROUTE)
-	if err != nil {
-		t.Fatal(err)
-	}
-	lsa := syscall.SockaddrNetlink{Family: syscall.AF_NETLINK}
-	if err := syscall.Bind(s, &lsa); err != nil {
-		syscall.Close(s)
-		t.Fatal(err)
-	}
-	f := os.NewFile(uintptr(s), "netlink")
-	c, err := SocketPacketConn(f, &netlinkAddr{})
-	f.Close()
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer c.Close()
-
-	const N = 3
-	var wg sync.WaitGroup
-	wg.Add(2 * N)
-	dst := &netlinkAddr{PID: 0}
-	for i := 0; i < N; i++ {
-		go func() {
-			defer wg.Done()
-			l := syscall.NLMSG_HDRLEN + syscall.SizeofRtGenmsg
-			b := make([]byte, l)
-			*(*uint32)(unsafe.Pointer(&b[0:4][0])) = uint32(l)
-			*(*uint16)(unsafe.Pointer(&b[4:6][0])) = uint16(syscall.RTM_GETLINK)
-			*(*uint16)(unsafe.Pointer(&b[6:8][0])) = uint16(syscall.NLM_F_DUMP | syscall.NLM_F_REQUEST)
-			*(*uint32)(unsafe.Pointer(&b[8:12][0])) = uint32(1)
-			*(*uint32)(unsafe.Pointer(&b[12:16][0])) = uint32(0)
-			b[16] = byte(syscall.AF_UNSPEC)
-			if _, err := c.WriteTo(b, dst); err != nil {
-				t.Error(err)
-				return
-			}
-		}()
-	}
-	for i := 0; i < N; i++ {
-		go func() {
-			defer wg.Done()
-			b := make([]byte, os.Getpagesize())
-			n, _, err := c.ReadFrom(b)
-			if err != nil {
-				t.Error(err)
-				return
-			}
-			if _, err := syscall.ParseNetlinkMessage(b[:n]); err != nil {
-				t.Error(err)
-				return
-			}
-		}()
-	}
-	wg.Wait()
-}
diff --git a/src/net/file_plan9.go b/src/net/file_plan9.go
index efe416f690..892775a024 100644
--- a/src/net/file_plan9.go
+++ b/src/net/file_plan9.go
@@ -135,11 +135,3 @@ func fileListener(f *os.File) (Listener, error) {
 func filePacketConn(f *os.File) (PacketConn, error) {
 	return nil, syscall.EPLAN9
 }
-
-func socketConn(f *os.File, sa SocketAddr) (Conn, error) {
-	return nil, syscall.EPLAN9
-}
-
-func socketPacketConn(f *os.File, sa SocketAddr) (PacketConn, error) {
-	return nil, syscall.EPLAN9
-}
diff --git a/src/net/file_stub.go b/src/net/file_stub.go
index 41ca78b437..0f7460c757 100644
--- a/src/net/file_stub.go
+++ b/src/net/file_stub.go
@@ -11,8 +11,6 @@ import (
 	"syscall"
 )
 
-func fileConn(f *os.File) (Conn, error)                              { return nil, syscall.ENOPROTOOPT }
-func fileListener(f *os.File) (Listener, error)                      { return nil, syscall.ENOPROTOOPT }
-func filePacketConn(f *os.File) (PacketConn, error)                  { return nil, syscall.ENOPROTOOPT }
-func socketConn(f *os.File, sa SocketAddr) (Conn, error)             { return nil, syscall.ENOPROTOOPT }
-func socketPacketConn(f *os.File, sa SocketAddr) (PacketConn, error) { return nil, syscall.ENOPROTOOPT }
+func fileConn(f *os.File) (Conn, error)             { return nil, syscall.ENOPROTOOPT }
+func fileListener(f *os.File) (Listener, error)     { return nil, syscall.ENOPROTOOPT }
+func filePacketConn(f *os.File) (PacketConn, error) { return nil, syscall.ENOPROTOOPT }
diff --git a/src/net/file_unix.go b/src/net/file_unix.go
index 83a2936c82..5b24c7d09d 100644
--- a/src/net/file_unix.go
+++ b/src/net/file_unix.go
@@ -7,7 +7,6 @@
 package net
 
 import (
-	"internal/syscall/unix"
 	"os"
 	"syscall"
 )
@@ -24,55 +23,38 @@ func dupSocket(f *os.File) (int, error) {
 	return s, nil
 }
 
-func newFileFD(f *os.File, sa SocketAddr) (*netFD, error) {
+func newFileFD(f *os.File) (*netFD, error) {
 	s, err := dupSocket(f)
 	if err != nil {
 		return nil, err
 	}
-	var laddr, raddr Addr
-	var fd *netFD
-	if sa != nil {
-		lsa := make([]byte, syscall.SizeofSockaddrAny)
-		if err := unix.Getsockname(s, lsa); err != nil {
-			lsa = nil
-		}
-		rsa := make([]byte, syscall.SizeofSockaddrAny)
-		if err := unix.Getpeername(s, rsa); err != nil {
-			rsa = nil
-		}
-		laddr = sa.Addr(lsa)
-		raddr = sa.Addr(rsa)
-		fd, err = newFD(s, -1, -1, laddr.Network())
-	} else {
-		family := syscall.AF_UNSPEC
-		var sotype int
-		sotype, err = syscall.GetsockoptInt(s, syscall.SOL_SOCKET, syscall.SO_TYPE)
-		if err != nil {
-			closeFunc(s)
-			return nil, os.NewSyscallError("getsockopt", err)
-		}
-		lsa, _ := syscall.Getsockname(s)
-		rsa, _ := syscall.Getpeername(s)
-		switch lsa.(type) {
-		case *syscall.SockaddrInet4:
-			family = syscall.AF_INET
-		case *syscall.SockaddrInet6:
-			family = syscall.AF_INET6
-		case *syscall.SockaddrUnix:
-			family = syscall.AF_UNIX
-		default:
-			closeFunc(s)
-			return nil, syscall.EPROTONOSUPPORT
-		}
-		fd, err = newFD(s, family, sotype, "")
-		laddr = fd.addrFunc()(lsa)
-		raddr = fd.addrFunc()(rsa)
-		fd.net = laddr.Network()
+	family := syscall.AF_UNSPEC
+	sotype, err := syscall.GetsockoptInt(s, syscall.SOL_SOCKET, syscall.SO_TYPE)
+	if err != nil {
+		closeFunc(s)
+		return nil, os.NewSyscallError("getsockopt", err)
+	}
+	lsa, _ := syscall.Getsockname(s)
+	rsa, _ := syscall.Getpeername(s)
+	switch lsa.(type) {
+	case *syscall.SockaddrInet4:
+		family = syscall.AF_INET
+	case *syscall.SockaddrInet6:
+		family = syscall.AF_INET6
+	case *syscall.SockaddrUnix:
+		family = syscall.AF_UNIX
+	default:
+		closeFunc(s)
+		return nil, syscall.EPROTONOSUPPORT
 	}
+	fd, err := newFD(s, family, sotype, "")
 	if err != nil {
 		closeFunc(s)
 		return nil, err
 	}
+	laddr := fd.addrFunc()(lsa)
+	raddr := fd.addrFunc()(rsa)
+	fd.net = laddr.Network()
 	if err := fd.init(); err != nil {
 		fd.Close()
 		return nil, err
@@ -82,7 +64,7 @@ func newFileFD(f *os.File, sa SocketAddr) (*netFD, error) {
 }
 
 func fileConn(f *os.File) (Conn, error) {
-	fd, err := newFileFD(f, nil)
+	fd, err := newFileFD(f)
 	if err != nil {
 		return nil, err
 	}
@@ -101,7 +83,7 @@ func fileConn(f *os.File) (Conn, error) {
 }
 
 func fileListener(f *os.File) (Listener, error) {
-	fd, err := newFileFD(f, nil)
+	fd, err := newFileFD(f)
 	if err != nil {
 		return nil, err
 	}
@@ -116,7 +98,7 @@ func fileListener(f *os.File) (Listener, error) {
 }
 
 func filePacketConn(f *os.File) (PacketConn, error) {
-	fd, err := newFileFD(f, nil)
+	fd, err := newFileFD(f)
 	if err != nil {
 		return nil, err
 	}
@@ -131,55 +113,3 @@ func filePacketConn(f *os.File) (PacketConn, error) {
 	fd.Close()
 	return nil, syscall.EINVAL
 }
-
-func socketConn(f *os.File, sa SocketAddr) (Conn, error) {
-	fd, err := newFileFD(f, sa)
-	if err != nil {
-		return nil, err
-	}
-	return &socketFile{conn: conn{fd}, SocketAddr: sa}, nil
-}
-
-func socketPacketConn(f *os.File, sa SocketAddr) (PacketConn, error) {
-	fd, err := newFileFD(f, sa)
-	if err != nil {
-		return nil, err
-	}
-	return &socketFile{conn: conn{fd}, SocketAddr: sa}, nil
-}
-
-var (
-	_ Conn       = &socketFile{}
-	_ PacketConn = &socketFile{}
-)
-
-// A socketFile is a placeholder that holds a user-specified socket
-// descriptor and a profile of socket address encoding.
-// It implements both Conn and PacketConn interfaces.
-type socketFile struct {
-	conn
-	SocketAddr
-}
-
-func (c *socketFile) ReadFrom(b []byte) (int, Addr, error) {
-	if !c.ok() {
-		return 0, nil, syscall.EINVAL
-	}
-	from := make([]byte, syscall.SizeofSockaddrAny)
-	n, err := c.fd.recvFrom(b, 0, from)
-	if err != nil {
-		return n, nil, &OpError{Op: "read", Net: c.fd.net, Source: c.fd.laddr, Addr: c.fd.raddr, Err: err}
-	}
-	return n, c.SocketAddr.Addr(from), nil
-}
-
-func (c *socketFile) WriteTo(b []byte, addr Addr) (int, error) {
-	if !c.ok() {
-		return 0, syscall.EINVAL
-	}
-	n, err := c.fd.sendTo(b, 0, c.SocketAddr.Raw(addr))
-	if err != nil {
-		return n, &OpError{Op: "write", Net: c.fd.net, Source: c.fd.laddr, Addr: c.fd.raddr, Err: err}
-	}
-	return n, nil
-}
diff --git a/src/net/file_windows.go b/src/net/file_windows.go
index 1ed72d5bd4..241fa17617 100644
--- a/src/net/file_windows.go
+++ b/src/net/file_windows.go
@@ -23,13 +23,3 @@ func filePacketConn(f *os.File) (PacketConn, error) {
 	// TODO: Implement this
 	return nil, syscall.EWINDOWS
 }
-
-func socketConn(f *os.File, sa SocketAddr) (Conn, error) {
-	// TODO: Implement this
-	return nil, syscall.EWINDOWS
-}
-
-func socketPacketConn(f *os.File, sa SocketAddr) (PacketConn, error) {
-	// TODO: Implement this
-	return nil, syscall.EWINDOWS
-}