return 0, syscall.ENOSYS
}

func RecvfromInet6(fd int, p []byte, flags int, from *syscall.SockaddrInet6) (n int, err error) {
	return 0, syscall.ENOSYS
}

func SendtoInet4(fd int, p []byte, flags int, to *syscall.SockaddrInet4) (err error) {
	return syscall.ENOSYS
}

func SendtoInet6(fd int, p []byte, flags int, to *syscall.SockaddrInet6) (err error) {
	return syscall.ENOSYS
}

//go:noescape
func RecvfromInet6(fd int, p []byte, flags int, from *syscall.SockaddrInet6) (n int, err error)

//go:linkname SendtoInet4 syscall.sendtoInet4
//go:noescape
func SendtoInet4(fd int, p []byte, flags int, to *syscall.SockaddrInet4) (err error)

//go:linkname SendtoInet6 syscall.sendtoInet6
//go:noescape
func SendtoInet6(fd int, p []byte, flags int, to *syscall.SockaddrInet6) (err error)

//go:linkname SendmsgNInet4 syscall.sendmsgNInet4

	return 0, syscall.ENOSYS
}

func RecvfromInet6(fd int, p []byte, flags int, from *syscall.SockaddrInet6) (n int, err error) {
	return 0, syscall.ENOSYS
}

func SendtoInet4(fd int, p []byte, flags int, to *syscall.SockaddrInet4) (err error) {
	return syscall.ENOSYS
}

func SendtoInet6(fd int, p []byte, flags int, to *syscall.SockaddrInet6) (err error) {
	return syscall.ENOSYS
}

		ip = IPv6zero
	}
	// We accept any IPv6 address including IPv4-mapped
	// IPv6 address.
	ip6 := ip.To16()
	if ip6 == nil {
		return syscall.SockaddrInet6{}, &AddrError{Err: "non-IPv6 address", Addr: ip.String()}
	}
	sa := syscall.SockaddrInet6{Port: port, ZoneId: uint32(zoneCache.index(zone))}
	copy(sa.Addr[:], ip6)
	return sa, nil
}

// ipToSockaddr should be an internal detail,

	n, err = fd.pfd.ReadFromInet4(p, from)
	runtime.KeepAlive(fd)
	return n, wrapSyscallError(readFromSyscallName, err)
}

func (fd *netFD) readFromInet6(p []byte, from *syscall.SockaddrInet6) (n int, err error) {
	n, err = fd.pfd.ReadFromInet6(p, from)
	runtime.KeepAlive(fd)
	return n, wrapSyscallError(readFromSyscallName, err)
}

package net

import (
	"context"
	"syscall"
)

func sockaddrToIP(sa syscall.Sockaddr) Addr {
	switch sa := sa.(type) {
	case *syscall.SockaddrInet4:
		return &IPAddr{IP: sa.Addr[0:]}
	case *syscall.SockaddrInet6:
		return &IPAddr{IP: sa.Addr[0:], Zone: zoneCache.name(int(sa.ZoneId))}
	}
	return nil
}

func (a *IPAddr) family() int {
	if a == nil || len(a.IP) <= IPv4len {
		return syscall.AF_INET
	}

	// ConnectEx windows API requires an unconnected, previously bound socket.
	if la == nil {
		switch ra.(type) {
		case *syscall.SockaddrInet4:
			la = &syscall.SockaddrInet4{}
		case *syscall.SockaddrInet6:
			la = &syscall.SockaddrInet6{}
		default:
			panic("unexpected type in connect")
		}
		if err := syscall.Bind(fd.pfd.Sysfd, la); err != nil {
			return nil, os.NewSyscallError("bind", err)
		}
	}

				switch sa := sa.(type) {
				case *syscall.SockaddrInet4:
					ifat = append(ifat, &IPNet{IP: IPv4(sa.Addr[0], sa.Addr[1], sa.Addr[2], sa.Addr[3]), Mask: CIDRMask(int(puni.OnLinkPrefixLength), 8*IPv4len)})
				case *syscall.SockaddrInet6:
					ifa := &IPNet{IP: make(IP, IPv6len), Mask: CIDRMask(int(puni.OnLinkPrefixLength), 8*IPv6len)}
					copy(ifa.IP, sa.Addr[:])
					ifat = append(ifat, ifa)
				}
			}

const (
	_ = iota
	F_DUPFD_CLOEXEC
	SYS_FCNTL = 500 // unsupported
)

type Sockaddr any

type SockaddrInet4 struct {
	Port int
	Addr [4]byte
}

type SockaddrInet6 struct {
	Port   int
	ZoneId uint32
	Addr   [16]byte
}

type SockaddrUnix struct {
	Name string

	"context"
	"net/netip"
	"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
	}