1 files changed, 268 insertions, 0 deletions
diff --git a/src/net/udpsock_posix.go b/src/net/udpsock_posix.go
new file mode 100644
index 000000000..a0533366a
--- /dev/null
+++ b/src/net/udpsock_posix.go
@@ -0,0 +1,268 @@
+// 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.
+
+// +build darwin dragonfly freebsd linux nacl netbsd openbsd solaris windows
+
+package net
+
+import (
+	"syscall"
+	"time"
+)
+
+func sockaddrToUDP(sa syscall.Sockaddr) Addr {
+	switch sa := sa.(type) {
+	case *syscall.SockaddrInet4:
+		return &UDPAddr{IP: sa.Addr[0:], Port: sa.Port}
+	case *syscall.SockaddrInet6:
+		return &UDPAddr{IP: sa.Addr[0:], Port: sa.Port, Zone: zoneToString(int(sa.ZoneId))}
+	}
+	return nil
+}
+
+func (a *UDPAddr) family() int {
+	if a == nil || len(a.IP) <= IPv4len {
+		return syscall.AF_INET
+	}
+	if a.IP.To4() != nil {
+		return syscall.AF_INET
+	}
+	return syscall.AF_INET6
+}
+
+func (a *UDPAddr) isWildcard() bool {
+	if a == nil || a.IP == nil {
+		return true
+	}
+	return a.IP.IsUnspecified()
+}
+
+func (a *UDPAddr) sockaddr(family int) (syscall.Sockaddr, error) {
+	if a == nil {
+		return nil, nil
+	}
+	return ipToSockaddr(family, a.IP, a.Port, a.Zone)
+}
+
+// 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() {
+		return 0, nil, syscall.EINVAL
+	}
+	n, sa, err := c.fd.readFrom(b)
+	switch sa := sa.(type) {
+	case *syscall.SockaddrInet4:
+		addr = &UDPAddr{IP: sa.Addr[0:], Port: sa.Port}
+	case *syscall.SockaddrInet6:
+		addr = &UDPAddr{IP: sa.Addr[0:], Port: sa.Port, Zone: zoneToString(int(sa.ZoneId))}
+	}
+	return
+}
+
+// ReadFrom implements the PacketConn ReadFrom method.
+func (c *UDPConn) ReadFrom(b []byte) (int, Addr, error) {
+	if !c.ok() {
+		return 0, nil, syscall.EINVAL
+	}
+	n, addr, err := c.ReadFromUDP(b)
+	return n, addr.toAddr(), err
+}
+
+// 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) {
+	if !c.ok() {
+		return 0, 0, 0, nil, syscall.EINVAL
+	}
+	var sa syscall.Sockaddr
+	n, oobn, flags, sa, err = c.fd.readMsg(b, oob)
+	switch sa := sa.(type) {
+	case *syscall.SockaddrInet4:
+		addr = &UDPAddr{IP: sa.Addr[0:], Port: sa.Port}
+	case *syscall.SockaddrInet6:
+		addr = &UDPAddr{IP: sa.Addr[0:], Port: sa.Port, Zone: zoneToString(int(sa.ZoneId))}
+	}
+	return
+}
+
+// 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() {
+		return 0, syscall.EINVAL
+	}
+	if c.fd.isConnected {
+		return 0, &OpError{"write", c.fd.net, addr, ErrWriteToConnected}
+	}
+	if addr == nil {
+		return 0, &OpError{Op: "write", Net: c.fd.net, Addr: nil, Err: errMissingAddress}
+	}
+	sa, err := addr.sockaddr(c.fd.family)
+	if err != nil {
+		return 0, &OpError{"write", c.fd.net, addr, err}
+	}
+	return c.fd.writeTo(b, sa)
+}
+
+// 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.net, 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) {
+	if !c.ok() {
+		return 0, 0, syscall.EINVAL
+	}
+	if c.fd.isConnected {
+		return 0, 0, &OpError{"write", c.fd.net, addr, ErrWriteToConnected}
+	}
+	if addr == nil {
+		return 0, 0, &OpError{Op: "write", Net: c.fd.net, Addr: nil, Err: errMissingAddress}
+	}
+	sa, err := addr.sockaddr(c.fd.family)
+	if err != nil {
+		return 0, 0, &OpError{"write", c.fd.net, addr, err}
+	}
+	return c.fd.writeMsg(b, oob, sa)
+}
+
+// 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) {
+	switch net {
+	case "udp", "udp4", "udp6":
+	default:
+		return nil, &OpError{Op: "dial", Net: net, Addr: raddr, Err: UnknownNetworkError(net)}
+	}
+	if raddr == nil {
+		return nil, &OpError{Op: "dial", Net: net, Addr: nil, Err: errMissingAddress}
+	}
+	return dialUDP(net, laddr, raddr, noDeadline)
+}
+
+func dialUDP(net string, laddr, raddr *UDPAddr, deadline time.Time) (*UDPConn, error) {
+	fd, err := internetSocket(net, laddr, raddr, deadline, syscall.SOCK_DGRAM, 0, "dial")
+	if err != nil {
+		return nil, &OpError{Op: "dial", Net: net, Addr: raddr, Err: err}
+	}
+	return newUDPConn(fd), nil
+}
+
+// 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, &OpError{Op: "listen", Net: net, Addr: laddr, Err: UnknownNetworkError(net)}
+	}
+	if laddr == nil {
+		laddr = &UDPAddr{}
+	}
+	fd, err := internetSocket(net, laddr, nil, noDeadline, syscall.SOCK_DGRAM, 0, "listen")
+	if err != nil {
+		return nil, &OpError{Op: "listen", Net: net, Addr: laddr, Err: err}
+	}
+	return newUDPConn(fd), nil
+}
+
+// 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) {
+	switch net {
+	case "udp", "udp4", "udp6":
+	default:
+		return nil, &OpError{Op: "listen", Net: net, Addr: gaddr, Err: UnknownNetworkError(net)}
+	}
+	if gaddr == nil || gaddr.IP == nil {
+		return nil, &OpError{Op: "listen", Net: net, Addr: nil, Err: errMissingAddress}
+	}
+	fd, err := internetSocket(net, gaddr, nil, noDeadline, syscall.SOCK_DGRAM, 0, "listen")
+	if err != nil {
+		return nil, &OpError{Op: "listen", Net: net, Addr: gaddr, Err: err}
+	}
+	c := newUDPConn(fd)
+	if ip4 := gaddr.IP.To4(); ip4 != nil {
+		if err := listenIPv4MulticastUDP(c, ifi, ip4); err != nil {
+			c.Close()
+			return nil, &OpError{Op: "listen", Net: net, Addr: &IPAddr{IP: ip4}, Err: err}
+		}
+	} else {
+		if err := listenIPv6MulticastUDP(c, ifi, gaddr.IP); err != nil {
+			c.Close()
+			return nil, &OpError{Op: "listen", Net: net, Addr: &IPAddr{IP: gaddr.IP}, Err: err}
+		}
+	}
+	return c, nil
+}
+
+func listenIPv4MulticastUDP(c *UDPConn, ifi *Interface, ip IP) error {
+	if ifi != nil {
+		if err := setIPv4MulticastInterface(c.fd, ifi); err != nil {
+			return err
+		}
+	}
+	if err := setIPv4MulticastLoopback(c.fd, false); err != nil {
+		return err
+	}
+	if err := joinIPv4Group(c.fd, ifi, ip); err != nil {
+		return err
+	}
+	return nil
+}
+
+func listenIPv6MulticastUDP(c *UDPConn, ifi *Interface, ip IP) error {
+	if ifi != nil {
+		if err := setIPv6MulticastInterface(c.fd, ifi); err != nil {
+			return err
+		}
+	}
+	if err := setIPv6MulticastLoopback(c.fd, false); err != nil {
+		return err
+	}
+	if err := joinIPv6Group(c.fd, ifi, ip); err != nil {
+		return err
+	}
+	return nil
+}