net: add FileConn, FilePacketConn, FileListener

R=iant, rsc, brainman
CC=golang-dev
https://golang.org/cl/4306042

4 files changed, 267 insertions, 0 deletions

diff --git a/src/pkg/net/Makefile b/src/pkg/net/Makefile
index 6b6d7c0e3c..3f48907446 100644
--- a/src/pkg/net/Makefile
+++ b/src/pkg/net/Makefile
@@ -24,6 +24,7 @@ GOFILES=\
 GOFILES_freebsd=\
 	newpollserver.go\
 	fd.go\
+	file.go\
 	dnsconfig.go\
 	dnsclient.go\
 	port.go\
@@ -31,6 +32,7 @@ GOFILES_freebsd=\
 GOFILES_darwin=\
 	newpollserver.go\
 	fd.go\
+	file.go\
 	dnsconfig.go\
 	dnsclient.go\
 	port.go\
@@ -38,12 +40,14 @@ GOFILES_darwin=\
 GOFILES_linux=\
 	newpollserver.go\
 	fd.go\
+	file.go\
 	dnsconfig.go\
 	dnsclient.go\
 	port.go\
 
 GOFILES_windows=\
 	resolv_windows.go\
+	file_windows.go\
 
 GOFILES+=$(GOFILES_$(GOOS))
 
diff --git a/src/pkg/net/file.go b/src/pkg/net/file.go
new file mode 100644
index 0000000000..5439ed994f
--- /dev/null
+++ b/src/pkg/net/file.go
@@ -0,0 +1,115 @@
+// Copyright 2011 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 (
+	"os"
+	"syscall"
+)
+
+func newFileFD(f *os.File) (*netFD, os.Error) {
+	fd, errno := syscall.Dup(f.Fd())
+	if errno != 0 {
+		return nil, os.NewSyscallError("dup", errno)
+	}
+
+	proto, errno := syscall.GetsockoptInt(fd, syscall.SOL_SOCKET, syscall.SO_TYPE)
+	if errno != 0 {
+		return nil, os.NewSyscallError("getsockopt", errno)
+	}
+
+	toAddr := sockaddrToTCP
+	sa, _ := syscall.Getsockname(fd)
+	switch sa.(type) {
+	default:
+		closesocket(fd)
+		return nil, os.EINVAL
+	case *syscall.SockaddrInet4:
+		if proto == syscall.SOCK_DGRAM {
+			toAddr = sockaddrToUDP
+		} else if proto == syscall.SOCK_RAW {
+			toAddr = sockaddrToIP
+		}
+	case *syscall.SockaddrInet6:
+		if proto == syscall.SOCK_DGRAM {
+			toAddr = sockaddrToUDP
+		} else if proto == syscall.SOCK_RAW {
+			toAddr = sockaddrToIP
+		}
+	case *syscall.SockaddrUnix:
+		toAddr = sockaddrToUnix
+		if proto == syscall.SOCK_DGRAM {
+			toAddr = sockaddrToUnixgram
+		} else if proto == syscall.SOCK_SEQPACKET {
+			toAddr = sockaddrToUnixpacket
+		}
+	}
+	laddr := toAddr(sa)
+	sa, _ = syscall.Getpeername(fd)
+	raddr := toAddr(sa)
+
+	return newFD(fd, 0, proto, laddr.Network(), laddr, raddr)
+}
+
+// FileConn returns a copy of the network connection corresponding to
+// the open file f.  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 FileConn(f *os.File) (c Conn, err os.Error) {
+	fd, err := newFileFD(f)
+	if err != nil {
+		return nil, err
+	}
+	switch fd.laddr.(type) {
+	case *TCPAddr:
+		return newTCPConn(fd), nil
+	case *UDPAddr:
+		return newUDPConn(fd), nil
+	case *UnixAddr:
+		return newUnixConn(fd), nil
+	case *IPAddr:
+		return newIPConn(fd), nil
+	}
+	fd.Close()
+	return nil, os.EINVAL
+}
+
+// FileListener returns a copy of the network listener corresponding
+// to the open file f.  It is the caller's responsibility to close l
+// when finished.  Closing c does not affect l, and closing l does not
+// affect c.
+func FileListener(f *os.File) (l Listener, err os.Error) {
+	fd, err := newFileFD(f)
+	if err != nil {
+		return nil, err
+	}
+	switch laddr := fd.laddr.(type) {
+	case *TCPAddr:
+		return &TCPListener{fd}, nil
+	case *UnixAddr:
+		return &UnixListener{fd, laddr.Name}, nil
+	}
+	fd.Close()
+	return nil, os.EINVAL
+}
+
+// FilePacketConn returns a copy of the packet network connection
+// corresponding to the open file f.  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 FilePacketConn(f *os.File) (c PacketConn, err os.Error) {
+	fd, err := newFileFD(f)
+	if err != nil {
+		return nil, err
+	}
+	switch fd.laddr.(type) {
+	case *UDPAddr:
+		return newUDPConn(fd), nil
+	case *UnixAddr:
+		return newUnixConn(fd), nil
+	}
+	fd.Close()
+	return nil, os.EINVAL
+}
diff --git a/src/pkg/net/file_test.go b/src/pkg/net/file_test.go
new file mode 100644
index 0000000000..1824d04eeb
--- /dev/null
+++ b/src/pkg/net/file_test.go
@@ -0,0 +1,131 @@
+// Copyright 2011 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 (
+	"os"
+	"reflect"
+	"runtime"
+	"syscall"
+	"testing"
+)
+
+type listenerFile interface {
+	Listener
+	File() (f *os.File, err os.Error)
+}
+
+type packetConnFile interface {
+	PacketConn
+	File() (f *os.File, err os.Error)
+}
+
+type connFile interface {
+	Conn
+	File() (f *os.File, err os.Error)
+}
+
+func testFileListener(t *testing.T, net, laddr string) {
+	if net == "tcp" {
+		laddr += ":0" // any available port
+	}
+	l, err := Listen(net, laddr)
+	if err != nil {
+		t.Fatalf("Listen failed: %v", err)
+	}
+	defer l.Close()
+	lf := l.(listenerFile)
+	f, err := lf.File()
+	if err != nil {
+		t.Fatalf("File failed: %v", err)
+	}
+	c, err := FileListener(f)
+	if err != nil {
+		t.Fatalf("FileListener failed: %v", err)
+	}
+	if !reflect.DeepEqual(l.Addr(), c.Addr()) {
+		t.Fatalf("Addrs not equal: %#v != %#v", l.Addr(), c.Addr())
+	}
+	if err := c.Close(); err != nil {
+		t.Fatalf("Close failed: %v", err)
+	}
+	if err := f.Close(); err != nil {
+		t.Fatalf("Close failed: %v", err)
+	}
+}
+
+func TestFileListener(t *testing.T) {
+	if runtime.GOOS == "windows" {
+		return
+	}
+	testFileListener(t, "tcp", "127.0.0.1")
+	testFileListener(t, "tcp", "127.0.0.1")
+	if kernelSupportsIPv6() {
+		testFileListener(t, "tcp", "[::ffff:127.0.0.1]")
+		testFileListener(t, "tcp", "127.0.0.1")
+		testFileListener(t, "tcp", "[::ffff:127.0.0.1]")
+	}
+	if syscall.OS == "linux" {
+		testFileListener(t, "unix", "@gotest/net")
+		testFileListener(t, "unixpacket", "@gotest/net")
+	}
+}
+
+func testFilePacketConn(t *testing.T, pcf packetConnFile) {
+	f, err := pcf.File()
+	if err != nil {
+		t.Fatalf("File failed: %v", err)
+	}
+	c, err := FilePacketConn(f)
+	if err != nil {
+		t.Fatalf("FilePacketConn failed: %v", err)
+	}
+	if !reflect.DeepEqual(pcf.LocalAddr(), c.LocalAddr()) {
+		t.Fatalf("LocalAddrs not equal: %#v != %#v", pcf.LocalAddr(), c.LocalAddr())
+	}
+	if err := c.Close(); err != nil {
+		t.Fatalf("Close failed: %v", err)
+	}
+	if err := f.Close(); err != nil {
+		t.Fatalf("Close failed: %v", err)
+	}
+}
+
+func testFilePacketConnListen(t *testing.T, net, laddr string) {
+	l, err := ListenPacket(net, laddr)
+	if err != nil {
+		t.Fatalf("Listen failed: %v", err)
+	}
+	testFilePacketConn(t, l.(packetConnFile))
+	if err := l.Close(); err != nil {
+		t.Fatalf("Close failed: %v", err)
+	}
+}
+
+func testFilePacketConnDial(t *testing.T, net, raddr string) {
+	c, err := Dial(net, "", raddr)
+	if err != nil {
+		t.Fatalf("Dial failed: %v", err)
+	}
+	testFilePacketConn(t, c.(packetConnFile))
+	if err := c.Close(); err != nil {
+		t.Fatalf("Close failed: %v", err)
+	}
+}
+
+func TestFilePacketConn(t *testing.T) {
+	if runtime.GOOS == "windows" {
+		return
+	}
+	testFilePacketConnListen(t, "udp", "127.0.0.1:0")
+	testFilePacketConnDial(t, "udp", "127.0.0.1:12345")
+	if kernelSupportsIPv6() {
+		testFilePacketConnListen(t, "udp", "[::1]:0")
+		testFilePacketConnDial(t, "udp", "[::ffff:127.0.0.1]:12345")
+	}
+	if syscall.OS == "linux" {
+		testFilePacketConnListen(t, "unixgram", "@gotest1/net")
+	}
+}
diff --git a/src/pkg/net/file_windows.go b/src/pkg/net/file_windows.go
new file mode 100644
index 0000000000..7aef9c1064
--- /dev/null
+++ b/src/pkg/net/file_windows.go
@@ -0,0 +1,17 @@
+// Copyright 2011 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
+
+func FileConn(f *os.File) (c Conn, err os.Error) {
+	return nil, os.EWINDOWS
+}
+
+func FileListener(f *os.File) (l Listener, err os.Error) {
+	return nil, os.EWINDOWS
+}
+
+func FilePacketConn(f *os.File) (c PacketConn, err os.Error) {
+	return nil, os.EWINDOWS
+}