269 lines
8.1 KiB
Go
269 lines
8.1 KiB
Go
// Copyright 2009 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// +build darwin dragonfly freebsd linux nacl netbsd openbsd solaris windows
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package net
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import (
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"syscall"
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"time"
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)
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func sockaddrToUDP(sa syscall.Sockaddr) Addr {
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switch sa := sa.(type) {
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case *syscall.SockaddrInet4:
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return &UDPAddr{IP: sa.Addr[0:], Port: sa.Port}
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case *syscall.SockaddrInet6:
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return &UDPAddr{IP: sa.Addr[0:], Port: sa.Port, Zone: zoneToString(int(sa.ZoneId))}
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}
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return nil
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}
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func (a *UDPAddr) family() int {
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if a == nil || len(a.IP) <= IPv4len {
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return syscall.AF_INET
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}
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if a.IP.To4() != nil {
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return syscall.AF_INET
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}
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return syscall.AF_INET6
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}
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func (a *UDPAddr) isWildcard() bool {
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if a == nil || a.IP == nil {
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return true
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}
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return a.IP.IsUnspecified()
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}
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func (a *UDPAddr) sockaddr(family int) (syscall.Sockaddr, error) {
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if a == nil {
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return nil, nil
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}
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return ipToSockaddr(family, a.IP, a.Port, a.Zone)
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}
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// UDPConn is the implementation of the Conn and PacketConn interfaces
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// for UDP network connections.
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type UDPConn struct {
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conn
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}
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func newUDPConn(fd *netFD) *UDPConn { return &UDPConn{conn{fd}} }
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// ReadFromUDP reads a UDP packet from c, copying the payload into b.
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// It returns the number of bytes copied into b and the return address
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// that was on the packet.
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//
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// ReadFromUDP can be made to time out and return an error with
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// Timeout() == true after a fixed time limit; see SetDeadline and
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// SetReadDeadline.
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func (c *UDPConn) ReadFromUDP(b []byte) (n int, addr *UDPAddr, err error) {
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if !c.ok() {
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return 0, nil, syscall.EINVAL
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}
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n, sa, err := c.fd.readFrom(b)
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switch sa := sa.(type) {
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case *syscall.SockaddrInet4:
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addr = &UDPAddr{IP: sa.Addr[0:], Port: sa.Port}
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case *syscall.SockaddrInet6:
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addr = &UDPAddr{IP: sa.Addr[0:], Port: sa.Port, Zone: zoneToString(int(sa.ZoneId))}
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}
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return
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}
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// ReadFrom implements the PacketConn ReadFrom method.
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func (c *UDPConn) ReadFrom(b []byte) (int, Addr, error) {
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if !c.ok() {
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return 0, nil, syscall.EINVAL
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}
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n, addr, err := c.ReadFromUDP(b)
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return n, addr.toAddr(), err
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}
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// ReadMsgUDP reads a packet from c, copying the payload into b and
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// the associated out-of-band data into oob. It returns the number
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// of bytes copied into b, the number of bytes copied into oob, the
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// flags that were set on the packet and the source address of the
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// packet.
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func (c *UDPConn) ReadMsgUDP(b, oob []byte) (n, oobn, flags int, addr *UDPAddr, err error) {
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if !c.ok() {
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return 0, 0, 0, nil, syscall.EINVAL
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}
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var sa syscall.Sockaddr
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n, oobn, flags, sa, err = c.fd.readMsg(b, oob)
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switch sa := sa.(type) {
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case *syscall.SockaddrInet4:
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addr = &UDPAddr{IP: sa.Addr[0:], Port: sa.Port}
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case *syscall.SockaddrInet6:
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addr = &UDPAddr{IP: sa.Addr[0:], Port: sa.Port, Zone: zoneToString(int(sa.ZoneId))}
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}
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return
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}
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// WriteToUDP writes a UDP packet to addr via c, copying the payload
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// from b.
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//
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// WriteToUDP can be made to time out and return an error with
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// Timeout() == true after a fixed time limit; see SetDeadline and
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// SetWriteDeadline. On packet-oriented connections, write timeouts
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// are rare.
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func (c *UDPConn) WriteToUDP(b []byte, addr *UDPAddr) (int, error) {
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if !c.ok() {
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return 0, syscall.EINVAL
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}
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if c.fd.isConnected {
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return 0, &OpError{"write", c.fd.net, addr, ErrWriteToConnected}
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}
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if addr == nil {
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return 0, &OpError{Op: "write", Net: c.fd.net, Addr: nil, Err: errMissingAddress}
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}
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sa, err := addr.sockaddr(c.fd.family)
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if err != nil {
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return 0, &OpError{"write", c.fd.net, addr, err}
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}
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return c.fd.writeTo(b, sa)
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}
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// WriteTo implements the PacketConn WriteTo method.
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func (c *UDPConn) WriteTo(b []byte, addr Addr) (int, error) {
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if !c.ok() {
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return 0, syscall.EINVAL
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}
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a, ok := addr.(*UDPAddr)
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if !ok {
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return 0, &OpError{"write", c.fd.net, addr, syscall.EINVAL}
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}
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return c.WriteToUDP(b, a)
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}
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// WriteMsgUDP writes a packet to addr via c, copying the payload from
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// b and the associated out-of-band data from oob. It returns the
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// number of payload and out-of-band bytes written.
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func (c *UDPConn) WriteMsgUDP(b, oob []byte, addr *UDPAddr) (n, oobn int, err error) {
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if !c.ok() {
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return 0, 0, syscall.EINVAL
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}
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if c.fd.isConnected {
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return 0, 0, &OpError{"write", c.fd.net, addr, ErrWriteToConnected}
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}
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if addr == nil {
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return 0, 0, &OpError{Op: "write", Net: c.fd.net, Addr: nil, Err: errMissingAddress}
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}
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sa, err := addr.sockaddr(c.fd.family)
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if err != nil {
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return 0, 0, &OpError{"write", c.fd.net, addr, err}
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}
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return c.fd.writeMsg(b, oob, sa)
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}
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// DialUDP connects to the remote address raddr on the network net,
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// which must be "udp", "udp4", or "udp6". If laddr is not nil, it is
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// used as the local address for the connection.
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func DialUDP(net string, laddr, raddr *UDPAddr) (*UDPConn, error) {
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switch net {
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case "udp", "udp4", "udp6":
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default:
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return nil, &OpError{Op: "dial", Net: net, Addr: raddr, Err: UnknownNetworkError(net)}
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}
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if raddr == nil {
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return nil, &OpError{Op: "dial", Net: net, Addr: nil, Err: errMissingAddress}
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}
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return dialUDP(net, laddr, raddr, noDeadline)
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}
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func dialUDP(net string, laddr, raddr *UDPAddr, deadline time.Time) (*UDPConn, error) {
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fd, err := internetSocket(net, laddr, raddr, deadline, syscall.SOCK_DGRAM, 0, "dial", sockaddrToUDP)
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if err != nil {
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return nil, &OpError{Op: "dial", Net: net, Addr: raddr, Err: err}
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}
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return newUDPConn(fd), nil
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}
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// ListenUDP listens for incoming UDP packets addressed to the local
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// address laddr. Net must be "udp", "udp4", or "udp6". If laddr has
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// a port of 0, ListenUDP will choose an available port.
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// The LocalAddr method of the returned UDPConn can be used to
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// discover the port. The returned connection's ReadFrom and WriteTo
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// methods can be used to receive and send UDP packets with per-packet
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// addressing.
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func ListenUDP(net string, laddr *UDPAddr) (*UDPConn, error) {
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switch net {
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case "udp", "udp4", "udp6":
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default:
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return nil, &OpError{Op: "listen", Net: net, Addr: laddr, Err: UnknownNetworkError(net)}
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}
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if laddr == nil {
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laddr = &UDPAddr{}
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}
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fd, err := internetSocket(net, laddr, nil, noDeadline, syscall.SOCK_DGRAM, 0, "listen", sockaddrToUDP)
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if err != nil {
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return nil, &OpError{Op: "listen", Net: net, Addr: laddr, Err: err}
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}
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return newUDPConn(fd), nil
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}
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// ListenMulticastUDP listens for incoming multicast UDP packets
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// addressed to the group address gaddr on ifi, which specifies the
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// interface to join. ListenMulticastUDP uses default multicast
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// interface if ifi is nil.
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func ListenMulticastUDP(net string, ifi *Interface, gaddr *UDPAddr) (*UDPConn, error) {
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switch net {
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case "udp", "udp4", "udp6":
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default:
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return nil, &OpError{Op: "listen", Net: net, Addr: gaddr, Err: UnknownNetworkError(net)}
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}
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if gaddr == nil || gaddr.IP == nil {
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return nil, &OpError{Op: "listen", Net: net, Addr: nil, Err: errMissingAddress}
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}
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fd, err := internetSocket(net, gaddr, nil, noDeadline, syscall.SOCK_DGRAM, 0, "listen", sockaddrToUDP)
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if err != nil {
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return nil, &OpError{Op: "listen", Net: net, Addr: gaddr, Err: err}
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}
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c := newUDPConn(fd)
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if ip4 := gaddr.IP.To4(); ip4 != nil {
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if err := listenIPv4MulticastUDP(c, ifi, ip4); err != nil {
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c.Close()
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return nil, &OpError{Op: "listen", Net: net, Addr: &IPAddr{IP: ip4}, Err: err}
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}
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} else {
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if err := listenIPv6MulticastUDP(c, ifi, gaddr.IP); err != nil {
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c.Close()
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return nil, &OpError{Op: "listen", Net: net, Addr: &IPAddr{IP: gaddr.IP}, Err: err}
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}
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}
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return c, nil
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}
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func listenIPv4MulticastUDP(c *UDPConn, ifi *Interface, ip IP) error {
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if ifi != nil {
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if err := setIPv4MulticastInterface(c.fd, ifi); err != nil {
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return err
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}
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}
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if err := setIPv4MulticastLoopback(c.fd, false); err != nil {
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return err
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}
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if err := joinIPv4Group(c.fd, ifi, ip); err != nil {
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return err
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}
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return nil
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}
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func listenIPv6MulticastUDP(c *UDPConn, ifi *Interface, ip IP) error {
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if ifi != nil {
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if err := setIPv6MulticastInterface(c.fd, ifi); err != nil {
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return err
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}
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}
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if err := setIPv6MulticastLoopback(c.fd, false); err != nil {
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return err
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}
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if err := joinIPv6Group(c.fd, ifi, ip); err != nil {
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return err
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}
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return nil
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}
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