1 files changed, 228 insertions, 0 deletions
diff --git a/src/net/ipsock_plan9.go b/src/net/ipsock_plan9.go
new file mode 100644
index 000000000..94ceea31b
--- /dev/null
+++ b/src/net/ipsock_plan9.go
@@ -0,0 +1,228 @@
+// 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 (
+	"errors"
+	"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, errors.New("parsing IP failed")
+		}
+	}
+	p, _, ok := dtoi(s[i+1:], 0)
+	if !ok {
+		return nil, 0, errors.New("parsing port failed")
+	}
+	if p < 0 || p > 0xFFFF {
+		return nil, 0, &AddrError{"invalid port", 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, errors.New("unknown protocol " + proto)
+	}
+	return addr, nil
+}
+
+func startPlan9(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
+	}
+
+	clone, dest, err := queryCS1(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 netErr(e error) {
+	oe, ok := e.(*OpError)
+	if !ok {
+		return
+	}
+	if pe, ok := oe.Err.(*os.PathError); ok {
+		if _, ok = pe.Err.(syscall.ErrorString); ok {
+			oe.Err = pe.Err
+		}
+	}
+}
+
+func dialPlan9(net string, laddr, raddr Addr) (fd *netFD, err error) {
+	defer func() { netErr(err) }()
+	f, dest, proto, name, err := startPlan9(net, raddr)
+	if err != nil {
+		return nil, &OpError{"dial", net, raddr, err}
+	}
+	_, err = f.WriteString("connect " + dest)
+	if err != nil {
+		f.Close()
+		return nil, &OpError{"dial", f.Name(), raddr, err}
+	}
+	data, err := os.OpenFile(netdir+"/"+proto+"/"+name+"/data", os.O_RDWR, 0)
+	if err != nil {
+		f.Close()
+		return nil, &OpError{"dial", net, raddr, err}
+	}
+	laddr, err = readPlan9Addr(proto, netdir+"/"+proto+"/"+name+"/local")
+	if err != nil {
+		data.Close()
+		f.Close()
+		return nil, &OpError{"dial", proto, raddr, err}
+	}
+	return newFD(proto, name, f, data, laddr, raddr)
+}
+
+func listenPlan9(net string, laddr Addr) (fd *netFD, err error) {
+	defer func() { netErr(err) }()
+	f, dest, proto, name, err := startPlan9(net, laddr)
+	if err != nil {
+		return nil, &OpError{"listen", net, laddr, err}
+	}
+	_, err = f.WriteString("announce " + dest)
+	if err != nil {
+		f.Close()
+		return nil, &OpError{"announce", proto, laddr, err}
+	}
+	laddr, err = readPlan9Addr(proto, netdir+"/"+proto+"/"+name+"/local")
+	if err != nil {
+		f.Close()
+		return nil, &OpError{Op: "listen", Net: net, Err: err}
+	}
+	return newFD(proto, name, f, nil, laddr, nil)
+}
+
+func (l *netFD) netFD() (*netFD, error) {
+	return newFD(l.proto, l.n, l.ctl, l.data, l.laddr, l.raddr)
+}
+
+func (l *netFD) acceptPlan9() (fd *netFD, err error) {
+	defer func() { netErr(err) }()
+	if err := l.readLock(); err != nil {
+		return nil, err
+	}
+	defer l.readUnlock()
+	f, err := os.Open(l.dir + "/listen")
+	if err != nil {
+		return nil, &OpError{"accept", l.dir + "/listen", l.laddr, err}
+	}
+	var buf [16]byte
+	n, err := f.Read(buf[:])
+	if err != nil {
+		f.Close()
+		return nil, &OpError{"accept", l.dir + "/listen", l.laddr, err}
+	}
+	name := string(buf[:n])
+	data, err := os.OpenFile(netdir+"/"+l.proto+"/"+name+"/data", os.O_RDWR, 0)
+	if err != nil {
+		f.Close()
+		return nil, &OpError{"accept", l.proto, l.laddr, err}
+	}
+	raddr, err := readPlan9Addr(l.proto, netdir+"/"+l.proto+"/"+name+"/remote")
+	if err != nil {
+		data.Close()
+		f.Close()
+		return nil, &OpError{"accept", l.proto, l.laddr, err}
+	}
+	return newFD(l.proto, name, f, data, l.laddr, raddr)
+}