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// 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 (
"errors"
"io"
"os"
"syscall"
)
func (fd *netFD) status(ln int) (string, error) {
if !fd.ok() {
return "", syscall.EINVAL
}
status, err := os.Open(fd.dir + "/status")
if err != nil {
return "", err
}
defer status.Close()
buf := make([]byte, ln)
n, err := io.ReadFull(status, buf[:])
if err != nil {
return "", err
}
return string(buf[:n]), nil
}
func newFileFD(f *os.File) (net *netFD, err error) {
var ctl *os.File
close := func(fd int) {
if err != nil {
syscall.Close(fd)
}
}
path, err := syscall.Fd2path(int(f.Fd()))
if err != nil {
return nil, os.NewSyscallError("fd2path", err)
}
comp := splitAtBytes(path, "/")
n := len(comp)
if n < 3 || comp[0] != "net" {
return nil, syscall.EPLAN9
}
name := comp[2]
switch file := comp[n-1]; file {
case "ctl", "clone":
syscall.ForkLock.RLock()
fd, err := syscall.Dup(int(f.Fd()), -1)
syscall.ForkLock.RUnlock()
if err != nil {
return nil, os.NewSyscallError("dup", err)
}
defer close(fd)
dir := "/net/" + comp[n-2]
ctl = os.NewFile(uintptr(fd), dir+"/"+file)
ctl.Seek(0, 0)
var buf [16]byte
n, err := ctl.Read(buf[:])
if err != nil {
return nil, err
}
name = string(buf[:n])
default:
if len(comp) < 4 {
return nil, errors.New("could not find control file for connection")
}
dir := "/net/" + comp[1] + "/" + name
ctl, err = os.OpenFile(dir+"/ctl", os.O_RDWR, 0)
if err != nil {
return nil, err
}
defer close(int(ctl.Fd()))
}
dir := "/net/" + comp[1] + "/" + name
laddr, err := readPlan9Addr(comp[1], dir+"/local")
if err != nil {
return nil, err
}
return newFD(comp[1], name, ctl, nil, laddr, nil), nil
}
func newFileConn(f *os.File) (c Conn, err error) {
fd, err := newFileFD(f)
if err != nil {
return nil, err
}
if !fd.ok() {
return nil, syscall.EINVAL
}
fd.data, err = os.OpenFile(fd.dir+"/data", os.O_RDWR, 0)
if err != nil {
return nil, err
}
switch fd.laddr.(type) {
case *TCPAddr:
return newTCPConn(fd), nil
case *UDPAddr:
return newUDPConn(fd), nil
}
return nil, syscall.EPLAN9
}
func newFileListener(f *os.File) (l Listener, err error) {
fd, err := newFileFD(f)
if err != nil {
return nil, err
}
switch fd.laddr.(type) {
case *TCPAddr:
default:
return nil, syscall.EPLAN9
}
// check that file corresponds to a listener
s, err := fd.status(len("Listen"))
if err != nil {
return nil, err
}
if s != "Listen" {
return nil, errors.New("file does not represent a listener")
}
return &TCPListener{fd}, nil
}
// 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 error) {
return newFileConn(f)
}
// 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 l does not affect f, and closing f does not
// affect l.
func FileListener(f *os.File) (l Listener, err error) {
return newFileListener(f)
}
// 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 error) {
return nil, syscall.EPLAN9
}
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