// 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. // Internet protocol family sockets for Plan 9 package net import ( "context" "os" "syscall" ) func probe(filename, query string) bool { var file *file var err error if file, err = open(filename); err != nil { return false } 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 } } } file.close() return r } func probeIPv4Stack() bool { return probe(netdir+"/iproute", "4i") } // probeIPv6Stack returns two boolean values. If the first boolean // value is true, kernel supports basic IPv6 functionality. If the // second boolean value is true, kernel supports IPv6 IPv4-mapping. func probeIPv6Stack() (supportsIPv6, supportsIPv4map bool) { // Plan 9 uses IPv6 natively, see ip(3). r := probe(netdir+"/iproute", "6i") v := false if r { v = probe(netdir+"/iproute", "4i") } return r, v } // 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 := byteIndex(s, '!') if i >= 0 { addr = ParseIP(s[:i]) if addr == nil { return nil, 0, &ParseError{Type: "IP address", Text: s} } } p, _, 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: string(p)} } return addr, p, nil } func readPlan9Addr(proto, 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 proto { case "tcp": addr = &TCPAddr{IP: ip, Port: port} case "udp": addr = &UDPAddr{IP: ip, Port: port} default: return nil, UnknownNetworkError(proto) } 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.(*os.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 } _, err = f.WriteString("connect " + dest) 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(proto, 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, err } laddr, err = readPlan9Addr(proto, 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.readLock(); err != nil { return nil, err } defer fd.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 }