| // Copyright 2009 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 ( | 
 | 	"context" | 
 | 	"io" | 
 | 	"os" | 
 | ) | 
 |  | 
 | func (c *TCPConn) readFrom(r io.Reader) (int64, error) { | 
 | 	return genericReadFrom(c, r) | 
 | } | 
 |  | 
 | func (sd *sysDialer) dialTCP(ctx context.Context, laddr, raddr *TCPAddr) (*TCPConn, error) { | 
 | 	if testHookDialTCP != nil { | 
 | 		return testHookDialTCP(ctx, sd.network, laddr, raddr) | 
 | 	} | 
 | 	return sd.doDialTCP(ctx, laddr, raddr) | 
 | } | 
 |  | 
 | func (sd *sysDialer) doDialTCP(ctx context.Context, laddr, raddr *TCPAddr) (*TCPConn, error) { | 
 | 	switch sd.network { | 
 | 	case "tcp4": | 
 | 		// Plan 9 doesn't complain about [::]:0->127.0.0.1, so it's up to us. | 
 | 		if laddr != nil && len(laddr.IP) != 0 && laddr.IP.To4() == nil { | 
 | 			return nil, &AddrError{Err: "non-IPv4 local address", Addr: laddr.String()} | 
 | 		} | 
 | 	case "tcp", "tcp6": | 
 | 	default: | 
 | 		return nil, UnknownNetworkError(sd.network) | 
 | 	} | 
 | 	if raddr == nil { | 
 | 		return nil, errMissingAddress | 
 | 	} | 
 | 	fd, err := dialPlan9(ctx, sd.network, laddr, raddr) | 
 | 	if err != nil { | 
 | 		return nil, err | 
 | 	} | 
 | 	return newTCPConn(fd), nil | 
 | } | 
 |  | 
 | func (ln *TCPListener) ok() bool { return ln != nil && ln.fd != nil && ln.fd.ctl != nil } | 
 |  | 
 | func (ln *TCPListener) accept() (*TCPConn, error) { | 
 | 	fd, err := ln.fd.acceptPlan9() | 
 | 	if err != nil { | 
 | 		return nil, err | 
 | 	} | 
 | 	tc := newTCPConn(fd) | 
 | 	if ln.lc.KeepAlive >= 0 { | 
 | 		setKeepAlive(fd, true) | 
 | 		ka := ln.lc.KeepAlive | 
 | 		if ln.lc.KeepAlive == 0 { | 
 | 			ka = defaultTCPKeepAlive | 
 | 		} | 
 | 		setKeepAlivePeriod(fd, ka) | 
 | 	} | 
 | 	return tc, nil | 
 | } | 
 |  | 
 | func (ln *TCPListener) close() error { | 
 | 	if err := ln.fd.pfd.Close(); err != nil { | 
 | 		return err | 
 | 	} | 
 | 	if _, err := ln.fd.ctl.WriteString("hangup"); err != nil { | 
 | 		ln.fd.ctl.Close() | 
 | 		return err | 
 | 	} | 
 | 	if err := ln.fd.ctl.Close(); err != nil { | 
 | 		return err | 
 | 	} | 
 | 	return nil | 
 | } | 
 |  | 
 | func (ln *TCPListener) file() (*os.File, error) { | 
 | 	f, err := ln.dup() | 
 | 	if err != nil { | 
 | 		return nil, err | 
 | 	} | 
 | 	return f, nil | 
 | } | 
 |  | 
 | func (sl *sysListener) listenTCP(ctx context.Context, laddr *TCPAddr) (*TCPListener, error) { | 
 | 	fd, err := listenPlan9(ctx, sl.network, laddr) | 
 | 	if err != nil { | 
 | 		return nil, err | 
 | 	} | 
 | 	return &TCPListener{fd: fd, lc: sl.ListenConfig}, nil | 
 | } |