libgo/go/net/ipsock_plan9.go

   1 // Copyright 2009 The Go Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style
   3 // license that can be found in the LICENSE file.
   4
   5 package net
   6
   7 import (
   8         "context"
   9         "internal/bytealg"
  10         "os"
  11         "syscall"
  12 )
  13
  14 // Probe probes IPv4, IPv6 and IPv4-mapped IPv6 communication
  15 // capabilities.
  16 //
  17 // Plan 9 uses IPv6 natively, see ip(3).
  18 func (p *ipStackCapabilities) probe() {
  19         p.ipv4Enabled = probe(netdir+"/iproute", "4i")
  20         p.ipv6Enabled = probe(netdir+"/iproute", "6i")
  21         if p.ipv4Enabled && p.ipv6Enabled {
  22                 p.ipv4MappedIPv6Enabled = true
  23         }
  24 }
  25
  26 func probe(filename, query string) bool {
  27         var file *file
  28         var err error
  29         if file, err = open(filename); err != nil {
  30                 return false
  31         }
  32         defer file.close()
  33
  34         r := false
  35         for line, ok := file.readLine(); ok && !r; line, ok = file.readLine() {
  36                 f := getFields(line)
  37                 if len(f) < 3 {
  38                         continue
  39                 }
  40                 for i := 0; i < len(f); i++ {
  41                         if query == f[i] {
  42                                 r = true
  43                                 break
  44                         }
  45                 }
  46         }
  47         return r
  48 }
  49
  50 // parsePlan9Addr parses address of the form [ip!]port (e.g. 127.0.0.1!80).
  51 func parsePlan9Addr(s string) (ip IP, iport int, err error) {
  52         addr := IPv4zero // address contains port only
  53         i := bytealg.IndexByteString(s, '!')
  54         if i >= 0 {
  55                 addr = ParseIP(s[:i])
  56                 if addr == nil {
  57                         return nil, 0, &ParseError{Type: "IP address", Text: s}
  58                 }
  59         }
  60         p, _, ok := dtoi(s[i+1:])
  61         if !ok {
  62                 return nil, 0, &ParseError{Type: "port", Text: s}
  63         }
  64         if p < 0 || p > 0xFFFF {
  65                 return nil, 0, &AddrError{Err: "invalid port", Addr: string(p)}
  66         }
  67         return addr, p, nil
  68 }
  69
  70 func readPlan9Addr(proto, filename string) (addr Addr, err error) {
  71         var buf [128]byte
  72
  73         f, err := os.Open(filename)
  74         if err != nil {
  75                 return
  76         }
  77         defer f.Close()
  78         n, err := f.Read(buf[:])
  79         if err != nil {
  80                 return
  81         }
  82         ip, port, err := parsePlan9Addr(string(buf[:n]))
  83         if err != nil {
  84                 return
  85         }
  86         switch proto {
  87         case "tcp":
  88                 addr = &TCPAddr{IP: ip, Port: port}
  89         case "udp":
  90                 addr = &UDPAddr{IP: ip, Port: port}
  91         default:
  92                 return nil, UnknownNetworkError(proto)
  93         }
  94         return addr, nil
  95 }
  96
  97 func startPlan9(ctx context.Context, net string, addr Addr) (ctl *os.File, dest, proto, name string, err error) {
  98         var (
  99                 ip   IP
 100                 port int
 101         )
 102         switch a := addr.(type) {
 103         case *TCPAddr:
 104                 proto = "tcp"
 105                 ip = a.IP
 106                 port = a.Port
 107         case *UDPAddr:
 108                 proto = "udp"
 109                 ip = a.IP
 110                 port = a.Port
 111         default:
 112                 err = UnknownNetworkError(net)
 113                 return
 114         }
 115
 116         if port > 65535 {
 117                 err = InvalidAddrError("port should be < 65536")
 118                 return
 119         }
 120
 121         clone, dest, err := queryCS1(ctx, proto, ip, port)
 122         if err != nil {
 123                 return
 124         }
 125         f, err := os.OpenFile(clone, os.O_RDWR, 0)
 126         if err != nil {
 127                 return
 128         }
 129         var buf [16]byte
 130         n, err := f.Read(buf[:])
 131         if err != nil {
 132                 f.Close()
 133                 return
 134         }
 135         return f, dest, proto, string(buf[:n]), nil
 136 }
 137
 138 func fixErr(err error) {
 139         oe, ok := err.(*OpError)
 140         if !ok {
 141                 return
 142         }
 143         nonNilInterface := func(a Addr) bool {
 144                 switch a := a.(type) {
 145                 case *TCPAddr:
 146                         return a == nil
 147                 case *UDPAddr:
 148                         return a == nil
 149                 case *IPAddr:
 150                         return a == nil
 151                 default:
 152                         return false
 153                 }
 154         }
 155         if nonNilInterface(oe.Source) {
 156                 oe.Source = nil
 157         }
 158         if nonNilInterface(oe.Addr) {
 159                 oe.Addr = nil
 160         }
 161         if pe, ok := oe.Err.(*os.PathError); ok {
 162                 if _, ok = pe.Err.(syscall.ErrorString); ok {
 163                         oe.Err = pe.Err
 164                 }
 165         }
 166 }
 167
 168 func dialPlan9(ctx context.Context, net string, laddr, raddr Addr) (fd *netFD, err error) {
 169         defer func() { fixErr(err) }()
 170         type res struct {
 171                 fd  *netFD
 172                 err error
 173         }
 174         resc := make(chan res)
 175         go func() {
 176                 testHookDialChannel()
 177                 fd, err := dialPlan9Blocking(ctx, net, laddr, raddr)
 178                 select {
 179                 case resc <- res{fd, err}:
 180                 case <-ctx.Done():
 181                         if fd != nil {
 182                                 fd.Close()
 183                         }
 184                 }
 185         }()
 186         select {
 187         case res := <-resc:
 188                 return res.fd, res.err
 189         case <-ctx.Done():
 190                 return nil, mapErr(ctx.Err())
 191         }
 192 }
 193
 194 func dialPlan9Blocking(ctx context.Context, net string, laddr, raddr Addr) (fd *netFD, err error) {
 195         if isWildcard(raddr) {
 196                 raddr = toLocal(raddr, net)
 197         }
 198         f, dest, proto, name, err := startPlan9(ctx, net, raddr)
 199         if err != nil {
 200                 return nil, err
 201         }
 202         _, err = f.WriteString("connect " + dest)
 203         if err != nil {
 204                 f.Close()
 205                 return nil, err
 206         }
 207         data, err := os.OpenFile(netdir+"/"+proto+"/"+name+"/data", os.O_RDWR, 0)
 208         if err != nil {
 209                 f.Close()
 210                 return nil, err
 211         }
 212         laddr, err = readPlan9Addr(proto, netdir+"/"+proto+"/"+name+"/local")
 213         if err != nil {
 214                 data.Close()
 215                 f.Close()
 216                 return nil, err
 217         }
 218         return newFD(proto, name, nil, f, data, laddr, raddr)
 219 }
 220
 221 func listenPlan9(ctx context.Context, net string, laddr Addr) (fd *netFD, err error) {
 222         defer func() { fixErr(err) }()
 223         f, dest, proto, name, err := startPlan9(ctx, net, laddr)
 224         if err != nil {
 225                 return nil, err
 226         }
 227         _, err = f.WriteString("announce " + dest)
 228         if err != nil {
 229                 f.Close()
 230                 return nil, err
 231         }
 232         laddr, err = readPlan9Addr(proto, netdir+"/"+proto+"/"+name+"/local")
 233         if err != nil {
 234                 f.Close()
 235                 return nil, err
 236         }
 237         return newFD(proto, name, nil, f, nil, laddr, nil)
 238 }
 239
 240 func (fd *netFD) netFD() (*netFD, error) {
 241         return newFD(fd.net, fd.n, fd.listen, fd.ctl, fd.data, fd.laddr, fd.raddr)
 242 }
 243
 244 func (fd *netFD) acceptPlan9() (nfd *netFD, err error) {
 245         defer func() { fixErr(err) }()
 246         if err := fd.pfd.ReadLock(); err != nil {
 247                 return nil, err
 248         }
 249         defer fd.pfd.ReadUnlock()
 250         listen, err := os.Open(fd.dir + "/listen")
 251         if err != nil {
 252                 return nil, err
 253         }
 254         var buf [16]byte
 255         n, err := listen.Read(buf[:])
 256         if err != nil {
 257                 listen.Close()
 258                 return nil, err
 259         }
 260         name := string(buf[:n])
 261         ctl, err := os.OpenFile(netdir+"/"+fd.net+"/"+name+"/ctl", os.O_RDWR, 0)
 262         if err != nil {
 263                 listen.Close()
 264                 return nil, err
 265         }
 266         data, err := os.OpenFile(netdir+"/"+fd.net+"/"+name+"/data", os.O_RDWR, 0)
 267         if err != nil {
 268                 listen.Close()
 269                 ctl.Close()
 270                 return nil, err
 271         }
 272         raddr, err := readPlan9Addr(fd.net, netdir+"/"+fd.net+"/"+name+"/remote")
 273         if err != nil {
 274                 listen.Close()
 275                 ctl.Close()
 276                 data.Close()
 277                 return nil, err
 278         }
 279         return newFD(fd.net, name, listen, ctl, data, fd.laddr, raddr)
 280 }
 281
 282 func isWildcard(a Addr) bool {
 283         var wildcard bool
 284         switch a := a.(type) {
 285         case *TCPAddr:
 286                 wildcard = a.isWildcard()
 287         case *UDPAddr:
 288                 wildcard = a.isWildcard()
 289         case *IPAddr:
 290                 wildcard = a.isWildcard()
 291         }
 292         return wildcard
 293 }
 294
 295 func toLocal(a Addr, net string) Addr {
 296         switch a := a.(type) {
 297         case *TCPAddr:
 298                 a.IP = loopbackIP(net)
 299         case *UDPAddr:
 300                 a.IP = loopbackIP(net)
 301         case *IPAddr:
 302                 a.IP = loopbackIP(net)
 303         }
 304         return a
 305 }