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// 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.
//go:build aix || darwin || dragonfly || freebsd || (js && wasm) || linux || netbsd || openbsd || solaris || windows
package net
import (
"context"
"syscall"
)
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: zoneCache.name(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) sockaddr(family int) (syscall.Sockaddr, error) {
if a == nil {
return nil, nil
}
return ipToSockaddr(family, a.IP, a.Port, a.Zone)
}
func (a *UDPAddr) toLocal(net string) sockaddr {
return &UDPAddr{loopbackIP(net), a.Port, a.Zone}
}
func (c *UDPConn) readFrom(b []byte, addr *UDPAddr) (int, *UDPAddr, error) {
var n int
var err error
switch c.fd.family {
case syscall.AF_INET:
var from syscall.SockaddrInet4
n, err = c.fd.readFromInet4(b, &from)
if err == nil {
ip := from.Addr // copy from.Addr; ip escapes, so this line allocates 4 bytes
*addr = UDPAddr{IP: ip[:], Port: from.Port}
}
case syscall.AF_INET6:
var from syscall.SockaddrInet6
n, err = c.fd.readFromInet6(b, &from)
if err == nil {
ip := from.Addr // copy from.Addr; ip escapes, so this line allocates 16 bytes
*addr = UDPAddr{IP: ip[:], Port: from.Port, Zone: zoneCache.name(int(from.ZoneId))}
}
}
if err != nil {
// No sockaddr, so don't return UDPAddr.
addr = nil
}
return n, addr, err
}
func (c *UDPConn) readMsg(b, oob []byte) (n, oobn, flags int, addr *UDPAddr, err error) {
var sa syscall.Sockaddr
n, oobn, flags, sa, err = c.fd.readMsg(b, oob, 0)
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: zoneCache.name(int(sa.ZoneId))}
}
return
}
func (c *UDPConn) writeTo(b []byte, addr *UDPAddr) (int, error) {
if c.fd.isConnected {
return 0, ErrWriteToConnected
}
if addr == nil {
return 0, errMissingAddress
}
switch c.fd.family {
case syscall.AF_INET:
sa, err := ipToSockaddrInet4(addr.IP, addr.Port)
if err != nil {
return 0, err
}
return c.fd.writeToInet4(b, sa)
case syscall.AF_INET6:
sa, err := ipToSockaddrInet6(addr.IP, addr.Port, addr.Zone)
if err != nil {
return 0, err
}
return c.fd.writeToInet6(b, sa)
default:
return 0, &AddrError{Err: "invalid address family", Addr: addr.IP.String()}
}
}
func (c *UDPConn) writeMsg(b, oob []byte, addr *UDPAddr) (n, oobn int, err error) {
if c.fd.isConnected && addr != nil {
return 0, 0, ErrWriteToConnected
}
if !c.fd.isConnected && addr == nil {
return 0, 0, errMissingAddress
}
sa, err := addr.sockaddr(c.fd.family)
if err != nil {
return 0, 0, err
}
return c.fd.writeMsg(b, oob, sa)
}
func (sd *sysDialer) dialUDP(ctx context.Context, laddr, raddr *UDPAddr) (*UDPConn, error) {
fd, err := internetSocket(ctx, sd.network, laddr, raddr, syscall.SOCK_DGRAM, 0, "dial", sd.Dialer.Control)
if err != nil {
return nil, err
}
return newUDPConn(fd), nil
}
func (sl *sysListener) listenUDP(ctx context.Context, laddr *UDPAddr) (*UDPConn, error) {
fd, err := internetSocket(ctx, sl.network, laddr, nil, syscall.SOCK_DGRAM, 0, "listen", sl.ListenConfig.Control)
if err != nil {
return nil, err
}
return newUDPConn(fd), nil
}
func (sl *sysListener) listenMulticastUDP(ctx context.Context, ifi *Interface, gaddr *UDPAddr) (*UDPConn, error) {
fd, err := internetSocket(ctx, sl.network, gaddr, nil, syscall.SOCK_DGRAM, 0, "listen", sl.ListenConfig.Control)
if err != nil {
return nil, err
}
c := newUDPConn(fd)
if ip4 := gaddr.IP.To4(); ip4 != nil {
if err := listenIPv4MulticastUDP(c, ifi, ip4); err != nil {
c.Close()
return nil, err
}
} else {
if err := listenIPv6MulticastUDP(c, ifi, gaddr.IP); err != nil {
c.Close()
return nil, 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
}
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