switch len(a) {
	case 0:
		return syscall.Syscall(p.Addr(), uintptr(len(a)), 0, 0, 0)
	case 1:
		return syscall.Syscall(p.Addr(), uintptr(len(a)), a[0], 0, 0)
	case 2:
		return syscall.Syscall(p.Addr(), uintptr(len(a)), a[0], a[1], 0)
	case 3:
		return syscall.Syscall(p.Addr(), uintptr(len(a)), a[0], a[1], a[2])
	case 4:
		return syscall.Syscall6(p.Addr(), uintptr(len(a)), a[0], a[1], a[2], a[3], 0, 0)
	case 5:

	// network address.
	Source Addr

	// Addr is the network address for which this error occurred.
	// For local operations, like Listen or SetDeadline, Addr is
	// the address of the local endpoint being manipulated.
	// For operations involving a remote network connection, like
	// Dial, Read, or Write, Addr is the remote address of that
	// connection.
	Addr Addr

func ipIterator(first netip.Addr, last netip.Addr, offset uint64) func() netip.Addr {
	// There are no modulo operations for IP addresses
	modulo := func(addr netip.Addr) netip.Addr {
		if addr.Compare(last) == 1 {
			return first
		}
		return addr
	}
	next := func(addr netip.Addr) netip.Addr {
		return modulo(addr.Next())
	}
	start, err := addOffsetAddress(first, offset)

	}
	for _, addr := range []Addr{e.Source, e.Addr} {
		switch addr := addr.(type) {
		case nil:
		case *TCPAddr:
			if addr == nil {
				return fmt.Errorf("OpError.Source or Addr is non-nil interface: %#v, %v", addr, e)
			}
		case *UDPAddr:
			if addr == nil {
				return fmt.Errorf("OpError.Source or Addr is non-nil interface: %#v, %v", addr, e)
			}
		case *IPAddr:
			if addr == nil {

	testCases := []struct {
		tcase    string
		addr     []net.Addr
		family   AddressFamily
		expected net.IP
	}{
		{"no ipv4", []net.Addr{addrStruct{val: "2001::5/64"}}, familyIPv4, nil},
		{"no ipv6", []net.Addr{addrStruct{val: "10.128.0.4/32"}}, familyIPv6, nil},
		{"invalidV4CIDR", []net.Addr{addrStruct{val: "10.20.30.40.50/24"}}, familyIPv4, nil},

				{
					itf:   net.Interface{Index: 0, MTU: 0, Name: "eth0", HardwareAddr: nil, Flags: 0},
					addrs: []net.Addr{&net.IPNet{IP: netutils.ParseIPSloppy("10.20.30.51"), Mask: net.CIDRMask(24, 32)}},
				},
				{
					itf:   net.Interface{Index: 2, MTU: 0, Name: "eth1", HardwareAddr: nil, Flags: 0},
					addrs: []net.Addr{&net.IPNet{IP: netutils.ParseIPSloppy("100.200.201.1"), Mask: net.CIDRMask(24, 32)}},
				},
			},

	if len(b) < l {
		return 0, nil, errInvalidAddr
	}
	data := b[4:]
	var name string
	var addr []byte
	if nlen > 0 {
		name = string(data[:nlen])
		data = data[nlen:]
	}
	if alen > 0 {
		addr = data[:alen]
		data = data[alen:]
	}
	return l, &LinkAddr{Name: name, Addr: addr}, nil
}

// An Inet4Addr represents an internet address for IPv4.
type Inet4Addr struct {

	for _, tt := range resolveUDPAddrTests {
		addr, err := ResolveUDPAddr(tt.network, tt.litAddrOrName)
		if !reflect.DeepEqual(addr, tt.addr) || !reflect.DeepEqual(err, tt.err) {
			t.Errorf("ResolveUDPAddr(%q, %q) = %#v, %v, want %#v, %v", tt.network, tt.litAddrOrName, addr, err, tt.addr, tt.err)
			continue
		}
		if err == nil {
			addr2, err := ResolveUDPAddr(addr.Network(), addr.String())

	switch {
	case ctx.IsSet("config-dir"):
		ctxt.ConfigDir = ctx.String("config-dir")
		ctxt.configDirSet = true
	case ctx.GlobalIsSet("config-dir"):
		ctxt.ConfigDir = ctx.GlobalString("config-dir")
		ctxt.configDirSet = true
	}

	switch {
	case ctx.IsSet("certs-dir"):
		ctxt.CertsDir = ctx.String("certs-dir")
		ctxt.certsDirSet = true
	case ctx.GlobalIsSet("certs-dir"):

		}
	}

	for i, tt := range tests {
		d := &Dialer{LocalAddr: tt.laddr}
		var addr string
		ip := ParseIP(tt.raddr)
		if ip.To4() != nil {
			addr = lss[0].Listener.Addr().String()
		}
		if ip.To16() != nil && ip.To4() == nil {
			addr = lss[1].Listener.Addr().String()
		}
		c, err := d.Dial(tt.network, addr)
		if err == nil && tt.error != nil || err != nil && tt.error == nil {