src/net/ipsock_plan9.go - go - Git at Google

 // 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"
 	"internal/bytealg"
 	"internal/itoa"
 	"io/fs"
 	"os"
 	"syscall"
 )

 // probe probes IPv4, IPv6 and IPv4-mapped IPv6 communication
 // capabilities.
 //
 // Plan 9 uses IPv6 natively, see ip(3).
 func (p *ipStackCapabilities) probe() {
 	p.ipv4Enabled = probe(netdir+"/iproute", "4i")
 	p.ipv6Enabled = probe(netdir+"/iproute", "6i")
 	if p.ipv4Enabled && p.ipv6Enabled {
 		p.ipv4MappedIPv6Enabled = true
 	}
 }

 func probe(filename, query string) bool {
 	var file *file
 	var err error
 	if file, err = open(filename); err != nil {
 		return false
 	}
 	defer file.close()

 	r := false
 	for line, ok := file.readLine(); ok && !r; line, ok = file.readLine() {
 		f := getFields(line)
 		if len(f) < 3 {
 			continue
 		}
 		for i := 0; i < len(f); i++ {
 			if query == f[i] {
 				r = true
 				break
 			}
 		}
 	}
 	return r
 }

 // parsePlan9Addr parses address of the form [ip!]port (e.g. 127.0.0.1!80).
 func parsePlan9Addr(s string) (ip IP, iport int, err error) {
 	addr := IPv4zero // address contains port only
 	i := bytealg.IndexByteString(s, '!')
 	if i >= 0 {
 		addr = ParseIP(s[:i])
 		if addr == nil {
 			return nil, 0, &ParseError{Type: "IP address", Text: s}
 		}
 	}
 	p, plen, ok := dtoi(s[i+1:])
 	if !ok {
 		return nil, 0, &ParseError{Type: "port", Text: s}
 	}
 	if p < 0 || p > 0xFFFF {
 		return nil, 0, &AddrError{Err: "invalid port", Addr: s[i+1 : i+1+plen]}
 	}
 	return addr, p, nil
 }

 func readPlan9Addr(net, filename string) (addr Addr, err error) {
 	var buf [128]byte

 	f, err := os.Open(filename)
 	if err != nil {
 		return
 	}
 	defer f.Close()
 	n, err := f.Read(buf[:])
 	if err != nil {
 		return
 	}
 	ip, port, err := parsePlan9Addr(string(buf[:n]))
 	if err != nil {
 		return
 	}
 	switch net {
 	case "tcp4", "udp4":
 		if ip.Equal(IPv6zero) {
 			ip = ip[:IPv4len]
 		}
 	}
 	switch net {
 	case "tcp", "tcp4", "tcp6":
 		addr = &TCPAddr{IP: ip, Port: port}
 	case "udp", "udp4", "udp6":
 		addr = &UDPAddr{IP: ip, Port: port}
 	default:
 		return nil, UnknownNetworkError(net)
 	}
 	return addr, nil
 }

 func startPlan9(ctx context.Context, net string, addr Addr) (ctl *os.File, dest, proto, name string, err error) {
 	var (
 		ip   IP
 		port int
 	)
 	switch a := addr.(type) {
 	case *TCPAddr:
 		proto = "tcp"
 		ip = a.IP
 		port = a.Port
 	case *UDPAddr:
 		proto = "udp"
 		ip = a.IP
 		port = a.Port
 	default:
 		err = UnknownNetworkError(net)
 		return
 	}

 	if port > 65535 {
 		err = InvalidAddrError("port should be < 65536")
 		return
 	}

 	clone, dest, err := queryCS1(ctx, proto, ip, port)
 	if err != nil {
 		return
 	}
 	f, err := os.OpenFile(clone, os.O_RDWR, 0)
 	if err != nil {
 		return
 	}
 	var buf [16]byte
 	n, err := f.Read(buf[:])
 	if err != nil {
 		f.Close()
 		return
 	}
 	return f, dest, proto, string(buf[:n]), nil
 }

 func fixErr(err error) {
 	oe, ok := err.(*OpError)
 	if !ok {
 		return
 	}
 	nonNilInterface := func(a Addr) bool {
 		switch a := a.(type) {
 		case *TCPAddr:
 			return a == nil
 		case *UDPAddr:
 			return a == nil
 		case *IPAddr:
 			return a == nil
 		default:
 			return false
 		}
 	}
 	if nonNilInterface(oe.Source) {
 		oe.Source = nil
 	}
 	if nonNilInterface(oe.Addr) {
 		oe.Addr = nil
 	}
 	if pe, ok := oe.Err.(*fs.PathError); ok {
 		if _, ok = pe.Err.(syscall.ErrorString); ok {
 			oe.Err = pe.Err
 		}
 	}
 }

 func dialPlan9(ctx context.Context, net string, laddr, raddr Addr) (fd *netFD, err error) {
 	defer func() { fixErr(err) }()
 	type res struct {
 		fd  *netFD
 		err error
 	}
 	resc := make(chan res)
 	go func() {
 		testHookDialChannel()
 		fd, err := dialPlan9Blocking(ctx, net, laddr, raddr)
 		select {
 		case resc <- res{fd, err}:
 		case <-ctx.Done():
 			if fd != nil {
 				fd.Close()
 			}
 		}
 	}()
 	select {
 	case res := <-resc:
 		return res.fd, res.err
 	case <-ctx.Done():
 		return nil, mapErr(ctx.Err())
 	}
 }

 func dialPlan9Blocking(ctx context.Context, net string, laddr, raddr Addr) (fd *netFD, err error) {
 	if isWildcard(raddr) {
 		raddr = toLocal(raddr, net)
 	}
 	f, dest, proto, name, err := startPlan9(ctx, net, raddr)
 	if err != nil {
 		return nil, err
 	}
 	if la := plan9LocalAddr(laddr); la == "" {
 		err = hangupCtlWrite(ctx, proto, f, "connect "+dest)
 	} else {
 		err = hangupCtlWrite(ctx, proto, f, "connect "+dest+" "+la)
 	}
 	if err != nil {
 		f.Close()
 		return nil, err
 	}
 	data, err := os.OpenFile(netdir+"/"+proto+"/"+name+"/data", os.O_RDWR, 0)
 	if err != nil {
 		f.Close()
 		return nil, err
 	}
 	laddr, err = readPlan9Addr(net, netdir+"/"+proto+"/"+name+"/local")
 	if err != nil {
 		data.Close()
 		f.Close()
 		return nil, err
 	}
 	return newFD(proto, name, nil, f, data, laddr, raddr)
 }

 func listenPlan9(ctx context.Context, net string, laddr Addr) (fd *netFD, err error) {
 	defer func() { fixErr(err) }()
 	f, dest, proto, name, err := startPlan9(ctx, net, laddr)
 	if err != nil {
 		return nil, err
 	}
 	_, err = f.WriteString("announce " + dest)
 	if err != nil {
 		f.Close()
 		return nil, &OpError{Op: "announce", Net: net, Source: laddr, Addr: nil, Err: err}
 	}
 	laddr, err = readPlan9Addr(net, netdir+"/"+proto+"/"+name+"/local")
 	if err != nil {
 		f.Close()
 		return nil, err
 	}
 	return newFD(proto, name, nil, f, nil, laddr, nil)
 }

 func (fd *netFD) netFD() (*netFD, error) {
 	return newFD(fd.net, fd.n, fd.listen, fd.ctl, fd.data, fd.laddr, fd.raddr)
 }

 func (fd *netFD) acceptPlan9() (nfd *netFD, err error) {
 	defer func() { fixErr(err) }()
 	if err := fd.pfd.ReadLock(); err != nil {
 		return nil, err
 	}
 	defer fd.pfd.ReadUnlock()
 	listen, err := os.Open(fd.dir + "/listen")
 	if err != nil {
 		return nil, err
 	}
 	var buf [16]byte
 	n, err := listen.Read(buf[:])
 	if err != nil {
 		listen.Close()
 		return nil, err
 	}
 	name := string(buf[:n])
 	ctl, err := os.OpenFile(netdir+"/"+fd.net+"/"+name+"/ctl", os.O_RDWR, 0)
 	if err != nil {
 		listen.Close()
 		return nil, err
 	}
 	data, err := os.OpenFile(netdir+"/"+fd.net+"/"+name+"/data", os.O_RDWR, 0)
 	if err != nil {
 		listen.Close()
 		ctl.Close()
 		return nil, err
 	}
 	raddr, err := readPlan9Addr(fd.net, netdir+"/"+fd.net+"/"+name+"/remote")
 	if err != nil {
 		listen.Close()
 		ctl.Close()
 		data.Close()
 		return nil, err
 	}
 	return newFD(fd.net, name, listen, ctl, data, fd.laddr, raddr)
 }

 func isWildcard(a Addr) bool {
 	var wildcard bool
 	switch a := a.(type) {
 	case *TCPAddr:
 		wildcard = a.isWildcard()
 	case *UDPAddr:
 		wildcard = a.isWildcard()
 	case *IPAddr:
 		wildcard = a.isWildcard()
 	}
 	return wildcard
 }

 func toLocal(a Addr, net string) Addr {
 	switch a := a.(type) {
 	case *TCPAddr:
 		a.IP = loopbackIP(net)
 	case *UDPAddr:
 		a.IP = loopbackIP(net)
 	case *IPAddr:
 		a.IP = loopbackIP(net)
 	}
 	return a
 }

 // plan9LocalAddr returns a Plan 9 local address string.
 // See setladdrport at https://9p.io/sources/plan9/sys/src/9/ip/devip.c.
 func plan9LocalAddr(addr Addr) string {
 	var ip IP
 	port := 0
 	switch a := addr.(type) {
 	case *TCPAddr:
 		if a != nil {
 			ip = a.IP
 			port = a.Port
 		}
 	case *UDPAddr:
 		if a != nil {
 			ip = a.IP
 			port = a.Port
 		}
 	}
 	if len(ip) == 0 || ip.IsUnspecified() {
 		if port == 0 {
 			return ""
 		}
 		return itoa.Itoa(port)
 	}
 	return ip.String() + "!" + itoa.Itoa(port)
 }

 func hangupCtlWrite(ctx context.Context, proto string, ctl *os.File, msg string) error {
 	if proto != "tcp" {
 		_, err := ctl.WriteString(msg)
 		return err
 	}
 	written := make(chan struct{})
 	errc := make(chan error)
 	go func() {
 		select {
 		case <-ctx.Done():
 			ctl.WriteString("hangup")
 			errc <- mapErr(ctx.Err())
 		case <-written:
 			errc <- nil
 		}
 	}()
 	_, err := ctl.WriteString(msg)
 	close(written)
 	if e := <-errc; err == nil && e != nil { // we hung up
 		return e
 	}
 	return err
 }
	// 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"
	"internal/bytealg"
	"internal/itoa"
	"io/fs"
	"os"
	"syscall"
	)

	// probe probes IPv4, IPv6 and IPv4-mapped IPv6 communication
	// capabilities.
	//
	// Plan 9 uses IPv6 natively, see ip(3).
	func (p *ipStackCapabilities) probe() {
	p.ipv4Enabled = probe(netdir+"/iproute", "4i")
	p.ipv6Enabled = probe(netdir+"/iproute", "6i")
	if p.ipv4Enabled && p.ipv6Enabled {
	p.ipv4MappedIPv6Enabled = true
	}
	}

	func probe(filename, query string) bool {
	var file *file
	var err error
	if file, err = open(filename); err != nil {
	return false
	}
	defer file.close()

	r := false
	for line, ok := file.readLine(); ok && !r; line, ok = file.readLine() {
	f := getFields(line)
	if len(f) < 3 {
	continue
	}
	for i := 0; i < len(f); i++ {
	if query == f[i] {
	r = true
	break
	}
	}
	}
	return r
	}

	// parsePlan9Addr parses address of the form [ip!]port (e.g. 127.0.0.1!80).
	func parsePlan9Addr(s string) (ip IP, iport int, err error) {
	addr := IPv4zero // address contains port only
	i := bytealg.IndexByteString(s, '!')
	if i >= 0 {
	addr = ParseIP(s[:i])
	if addr == nil {
	return nil, 0, &ParseError{Type: "IP address", Text: s}
	}
	}
	p, plen, ok := dtoi(s[i+1:])
	if !ok {
	return nil, 0, &ParseError{Type: "port", Text: s}
	}
	if p < 0 \|\| p > 0xFFFF {
	return nil, 0, &AddrError{Err: "invalid port", Addr: s[i+1 : i+1+plen]}
	}
	return addr, p, nil
	}

	func readPlan9Addr(net, filename string) (addr Addr, err error) {
	var buf [128]byte

	f, err := os.Open(filename)
	if err != nil {
	return
	}
	defer f.Close()
	n, err := f.Read(buf[:])
	if err != nil {
	return
	}
	ip, port, err := parsePlan9Addr(string(buf[:n]))
	if err != nil {
	return
	}
	switch net {
	case "tcp4", "udp4":
	if ip.Equal(IPv6zero) {
	ip = ip[:IPv4len]
	}
	}
	switch net {
	case "tcp", "tcp4", "tcp6":
	addr = &TCPAddr{IP: ip, Port: port}
	case "udp", "udp4", "udp6":
	addr = &UDPAddr{IP: ip, Port: port}
	default:
	return nil, UnknownNetworkError(net)
	}
	return addr, nil
	}

	func startPlan9(ctx context.Context, net string, addr Addr) (ctl *os.File, dest, proto, name string, err error) {
	var (
	ip IP
	port int
	)
	switch a := addr.(type) {
	case *TCPAddr:
	proto = "tcp"
	ip = a.IP
	port = a.Port
	case *UDPAddr:
	proto = "udp"
	ip = a.IP
	port = a.Port
	default:
	err = UnknownNetworkError(net)
	return
	}

	if port > 65535 {
	err = InvalidAddrError("port should be < 65536")
	return
	}

	clone, dest, err := queryCS1(ctx, proto, ip, port)
	if err != nil {
	return
	}
	f, err := os.OpenFile(clone, os.O_RDWR, 0)
	if err != nil {
	return
	}
	var buf [16]byte
	n, err := f.Read(buf[:])
	if err != nil {
	f.Close()
	return
	}
	return f, dest, proto, string(buf[:n]), nil
	}

	func fixErr(err error) {
	oe, ok := err.(*OpError)
	if !ok {
	return
	}
	nonNilInterface := func(a Addr) bool {
	switch a := a.(type) {
	case *TCPAddr:
	return a == nil
	case *UDPAddr:
	return a == nil
	case *IPAddr:
	return a == nil
	default:
	return false
	}
	}
	if nonNilInterface(oe.Source) {
	oe.Source = nil
	}
	if nonNilInterface(oe.Addr) {
	oe.Addr = nil
	}
	if pe, ok := oe.Err.(*fs.PathError); ok {
	if _, ok = pe.Err.(syscall.ErrorString); ok {
	oe.Err = pe.Err
	}
	}
	}

	func dialPlan9(ctx context.Context, net string, laddr, raddr Addr) (fd *netFD, err error) {
	defer func() { fixErr(err) }()
	type res struct {
	fd *netFD
	err error
	}
	resc := make(chan res)
	go func() {
	testHookDialChannel()
	fd, err := dialPlan9Blocking(ctx, net, laddr, raddr)
	select {
	case resc <- res{fd, err}:
	case <-ctx.Done():
	if fd != nil {
	fd.Close()
	}
	}
	}()
	select {
	case res := <-resc:
	return res.fd, res.err
	case <-ctx.Done():
	return nil, mapErr(ctx.Err())
	}
	}

	func dialPlan9Blocking(ctx context.Context, net string, laddr, raddr Addr) (fd *netFD, err error) {
	if isWildcard(raddr) {
	raddr = toLocal(raddr, net)
	}
	f, dest, proto, name, err := startPlan9(ctx, net, raddr)
	if err != nil {
	return nil, err
	}
	if la := plan9LocalAddr(laddr); la == "" {
	err = hangupCtlWrite(ctx, proto, f, "connect "+dest)
	} else {
	err = hangupCtlWrite(ctx, proto, f, "connect "+dest+" "+la)
	}
	if err != nil {
	f.Close()
	return nil, err
	}
	data, err := os.OpenFile(netdir+"/"+proto+"/"+name+"/data", os.O_RDWR, 0)
	if err != nil {
	f.Close()
	return nil, err
	}
	laddr, err = readPlan9Addr(net, netdir+"/"+proto+"/"+name+"/local")
	if err != nil {
	data.Close()
	f.Close()
	return nil, err
	}
	return newFD(proto, name, nil, f, data, laddr, raddr)
	}

	func listenPlan9(ctx context.Context, net string, laddr Addr) (fd *netFD, err error) {
	defer func() { fixErr(err) }()
	f, dest, proto, name, err := startPlan9(ctx, net, laddr)
	if err != nil {
	return nil, err
	}
	_, err = f.WriteString("announce " + dest)
	if err != nil {
	f.Close()
	return nil, &OpError{Op: "announce", Net: net, Source: laddr, Addr: nil, Err: err}
	}
	laddr, err = readPlan9Addr(net, netdir+"/"+proto+"/"+name+"/local")
	if err != nil {
	f.Close()
	return nil, err
	}
	return newFD(proto, name, nil, f, nil, laddr, nil)
	}

	func (fd netFD) netFD() (netFD, error) {
	return newFD(fd.net, fd.n, fd.listen, fd.ctl, fd.data, fd.laddr, fd.raddr)
	}

	func (fd netFD) acceptPlan9() (nfd netFD, err error) {
	defer func() { fixErr(err) }()
	if err := fd.pfd.ReadLock(); err != nil {
	return nil, err
	}
	defer fd.pfd.ReadUnlock()
	listen, err := os.Open(fd.dir + "/listen")
	if err != nil {
	return nil, err
	}
	var buf [16]byte
	n, err := listen.Read(buf[:])
	if err != nil {
	listen.Close()
	return nil, err
	}
	name := string(buf[:n])
	ctl, err := os.OpenFile(netdir+"/"+fd.net+"/"+name+"/ctl", os.O_RDWR, 0)
	if err != nil {
	listen.Close()
	return nil, err
	}
	data, err := os.OpenFile(netdir+"/"+fd.net+"/"+name+"/data", os.O_RDWR, 0)
	if err != nil {
	listen.Close()
	ctl.Close()
	return nil, err
	}
	raddr, err := readPlan9Addr(fd.net, netdir+"/"+fd.net+"/"+name+"/remote")
	if err != nil {
	listen.Close()
	ctl.Close()
	data.Close()
	return nil, err
	}
	return newFD(fd.net, name, listen, ctl, data, fd.laddr, raddr)
	}

	func isWildcard(a Addr) bool {
	var wildcard bool
	switch a := a.(type) {
	case *TCPAddr:
	wildcard = a.isWildcard()
	case *UDPAddr:
	wildcard = a.isWildcard()
	case *IPAddr:
	wildcard = a.isWildcard()
	}
	return wildcard
	}

	func toLocal(a Addr, net string) Addr {
	switch a := a.(type) {
	case *TCPAddr:
	a.IP = loopbackIP(net)
	case *UDPAddr:
	a.IP = loopbackIP(net)
	case *IPAddr:
	a.IP = loopbackIP(net)
	}
	return a
	}

	// plan9LocalAddr returns a Plan 9 local address string.
	// See setladdrport at https://9p.io/sources/plan9/sys/src/9/ip/devip.c.
	func plan9LocalAddr(addr Addr) string {
	var ip IP
	port := 0
	switch a := addr.(type) {
	case *TCPAddr:
	if a != nil {
	ip = a.IP
	port = a.Port
	}
	case *UDPAddr:
	if a != nil {
	ip = a.IP
	port = a.Port
	}
	}
	if len(ip) == 0 \|\| ip.IsUnspecified() {
	if port == 0 {
	return ""
	}
	return itoa.Itoa(port)
	}
	return ip.String() + "!" + itoa.Itoa(port)
	}

	func hangupCtlWrite(ctx context.Context, proto string, ctl *os.File, msg string) error {
	if proto != "tcp" {
	_, err := ctl.WriteString(msg)
	return err
	}
	written := make(chan struct{})
	errc := make(chan error)
	go func() {
	select {
	case <-ctx.Done():
	ctl.WriteString("hangup")
	errc <- mapErr(ctx.Err())
	case <-written:
	errc <- nil
	}
	}()
	_, err := ctl.WriteString(msg)
	close(written)
	if e := <-errc; err == nil && e != nil { // we hung up
	return e
	}
	return err
	}