1 files changed, 203 insertions, 0 deletions
diff --git a/src/net/udpsock_plan9.go b/src/net/udpsock_plan9.go
new file mode 100644
index 000000000..510ac5e4a
--- /dev/null
+++ b/src/net/udpsock_plan9.go
@@ -0,0 +1,203 @@
+// 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 (
+	"errors"
+	"os"
+	"syscall"
+	"time"
+)
+
+// UDPConn is the implementation of the Conn and PacketConn interfaces
+// for UDP network connections.
+type UDPConn struct {
+	conn
+}
+
+func newUDPConn(fd *netFD) *UDPConn { return &UDPConn{conn{fd}} }
+
+// ReadFromUDP reads a UDP packet from c, copying the payload into b.
+// It returns the number of bytes copied into b and the return address
+// that was on the packet.
+//
+// ReadFromUDP can be made to time out and return an error with
+// Timeout() == true after a fixed time limit; see SetDeadline and
+// SetReadDeadline.
+func (c *UDPConn) ReadFromUDP(b []byte) (n int, addr *UDPAddr, err error) {
+	if !c.ok() || c.fd.data == nil {
+		return 0, nil, syscall.EINVAL
+	}
+	buf := make([]byte, udpHeaderSize+len(b))
+	m, err := c.fd.data.Read(buf)
+	if err != nil {
+		return
+	}
+	if m < udpHeaderSize {
+		return 0, nil, errors.New("short read reading UDP header")
+	}
+	buf = buf[:m]
+
+	h, buf := unmarshalUDPHeader(buf)
+	n = copy(b, buf)
+	return n, &UDPAddr{IP: h.raddr, Port: int(h.rport)}, nil
+}
+
+// ReadFrom implements the PacketConn ReadFrom method.
+func (c *UDPConn) ReadFrom(b []byte) (int, Addr, error) {
+	if !c.ok() {
+		return 0, nil, syscall.EINVAL
+	}
+	return c.ReadFromUDP(b)
+}
+
+// ReadMsgUDP reads a packet from c, copying the payload into b and
+// the associated out-of-band data into oob.  It returns the number
+// of bytes copied into b, the number of bytes copied into oob, the
+// flags that were set on the packet and the source address of the
+// packet.
+func (c *UDPConn) ReadMsgUDP(b, oob []byte) (n, oobn, flags int, addr *UDPAddr, err error) {
+	return 0, 0, 0, nil, syscall.EPLAN9
+}
+
+// WriteToUDP writes a UDP packet to addr via c, copying the payload
+// from b.
+//
+// WriteToUDP can be made to time out and return an error with
+// Timeout() == true after a fixed time limit; see SetDeadline and
+// SetWriteDeadline.  On packet-oriented connections, write timeouts
+// are rare.
+func (c *UDPConn) WriteToUDP(b []byte, addr *UDPAddr) (int, error) {
+	if !c.ok() || c.fd.data == nil {
+		return 0, syscall.EINVAL
+	}
+	if addr == nil {
+		return 0, &OpError{Op: "write", Net: c.fd.dir, Addr: nil, Err: errMissingAddress}
+	}
+	h := new(udpHeader)
+	h.raddr = addr.IP.To16()
+	h.laddr = c.fd.laddr.(*UDPAddr).IP.To16()
+	h.ifcaddr = IPv6zero // ignored (receive only)
+	h.rport = uint16(addr.Port)
+	h.lport = uint16(c.fd.laddr.(*UDPAddr).Port)
+
+	buf := make([]byte, udpHeaderSize+len(b))
+	i := copy(buf, h.Bytes())
+	copy(buf[i:], b)
+	return c.fd.data.Write(buf)
+}
+
+// WriteTo implements the PacketConn WriteTo method.
+func (c *UDPConn) WriteTo(b []byte, addr Addr) (int, error) {
+	if !c.ok() {
+		return 0, syscall.EINVAL
+	}
+	a, ok := addr.(*UDPAddr)
+	if !ok {
+		return 0, &OpError{"write", c.fd.dir, addr, syscall.EINVAL}
+	}
+	return c.WriteToUDP(b, a)
+}
+
+// WriteMsgUDP writes a packet to addr via c, copying the payload from
+// b and the associated out-of-band data from oob.  It returns the
+// number of payload and out-of-band bytes written.
+func (c *UDPConn) WriteMsgUDP(b, oob []byte, addr *UDPAddr) (n, oobn int, err error) {
+	return 0, 0, syscall.EPLAN9
+}
+
+// DialUDP connects to the remote address raddr on the network net,
+// which must be "udp", "udp4", or "udp6".  If laddr is not nil, it is
+// used as the local address for the connection.
+func DialUDP(net string, laddr, raddr *UDPAddr) (*UDPConn, error) {
+	return dialUDP(net, laddr, raddr, noDeadline)
+}
+
+func dialUDP(net string, laddr, raddr *UDPAddr, deadline time.Time) (*UDPConn, error) {
+	if !deadline.IsZero() {
+		panic("net.dialUDP: deadline not implemented on Plan 9")
+	}
+	switch net {
+	case "udp", "udp4", "udp6":
+	default:
+		return nil, UnknownNetworkError(net)
+	}
+	if raddr == nil {
+		return nil, &OpError{"dial", net, nil, errMissingAddress}
+	}
+	fd, err := dialPlan9(net, laddr, raddr)
+	if err != nil {
+		return nil, err
+	}
+	return newUDPConn(fd), nil
+}
+
+const udpHeaderSize = 16*3 + 2*2
+
+type udpHeader struct {
+	raddr, laddr, ifcaddr IP
+	rport, lport          uint16
+}
+
+func (h *udpHeader) Bytes() []byte {
+	b := make([]byte, udpHeaderSize)
+	i := 0
+	i += copy(b[i:i+16], h.raddr)
+	i += copy(b[i:i+16], h.laddr)
+	i += copy(b[i:i+16], h.ifcaddr)
+	b[i], b[i+1], i = byte(h.rport>>8), byte(h.rport), i+2
+	b[i], b[i+1], i = byte(h.lport>>8), byte(h.lport), i+2
+	return b
+}
+
+func unmarshalUDPHeader(b []byte) (*udpHeader, []byte) {
+	h := new(udpHeader)
+	h.raddr, b = IP(b[:16]), b[16:]
+	h.laddr, b = IP(b[:16]), b[16:]
+	h.ifcaddr, b = IP(b[:16]), b[16:]
+	h.rport, b = uint16(b[0])<<8|uint16(b[1]), b[2:]
+	h.lport, b = uint16(b[0])<<8|uint16(b[1]), b[2:]
+	return h, b
+}
+
+// ListenUDP listens for incoming UDP packets addressed to the local
+// address laddr.  Net must be "udp", "udp4", or "udp6".  If laddr has
+// a port of 0, ListenUDP will choose an available port.
+// The LocalAddr method of the returned UDPConn can be used to
+// discover the port.  The returned connection's ReadFrom and WriteTo
+// methods can be used to receive and send UDP packets with per-packet
+// addressing.
+func ListenUDP(net string, laddr *UDPAddr) (*UDPConn, error) {
+	switch net {
+	case "udp", "udp4", "udp6":
+	default:
+		return nil, UnknownNetworkError(net)
+	}
+	if laddr == nil {
+		laddr = &UDPAddr{}
+	}
+	l, err := listenPlan9(net, laddr)
+	if err != nil {
+		return nil, err
+	}
+	_, err = l.ctl.WriteString("headers")
+	if err != nil {
+		return nil, err
+	}
+	l.data, err = os.OpenFile(l.dir+"/data", os.O_RDWR, 0)
+	if err != nil {
+		return nil, err
+	}
+	fd, err := l.netFD()
+	return newUDPConn(fd), err
+}
+
+// ListenMulticastUDP listens for incoming multicast UDP packets
+// addressed to the group address gaddr on ifi, which specifies the
+// interface to join.  ListenMulticastUDP uses default multicast
+// interface if ifi is nil.
+func ListenMulticastUDP(net string, ifi *Interface, gaddr *UDPAddr) (*UDPConn, error) {
+	return nil, syscall.EPLAN9
+}