(raddr == nil || raddr.family() == syscall.AF_INET) {
		return syscall.AF_INET, false
	}
	return syscall.AF_INET6, false
}

func internetSocket(ctx context.Context, net string, laddr, raddr sockaddr, sotype, proto int, mode string, ctrlCtxFn func(context.Context, string, string, syscall.RawConn) error) (fd *netFD, err error) {
	switch runtime.GOOS {
	case "aix", "windows", "openbsd", "js", "wasip1":

	}
	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
	}

// license that can be found in the LICENSE file.

//go:build !netgo && darwin

package net

import (
	"internal/syscall/unix"
	"runtime"
	"syscall"
	"unsafe"
)

const (
	_C_AF_INET      = syscall.AF_INET
	_C_AF_INET6     = syscall.AF_INET6
	_C_AF_UNSPEC    = syscall.AF_UNSPEC
	_C_EAI_AGAIN    = unix.EAI_AGAIN
	_C_EAI_NONAME   = unix.EAI_NONAME
	_C_EAI_SERVICE  = unix.EAI_SERVICE
	_C_EAI_NODATA   = unix.EAI_NODATA

		sa.Data[i] = int8(b[i])
	}
	return sa, rsaAlignOf(l), nil
}

// parseSockaddrInet parses b as an internet socket address.
func parseSockaddrInet(b []byte, family byte) (Sockaddr, error) {
	switch family {
	case AF_INET:
		if len(b) < SizeofSockaddrInet4 {
			return nil, EINVAL
		}
		rsa := (*RawSockaddrAny)(unsafe.Pointer(&b[0]))
		return anyToSockaddr(rsa)
	case AF_INET6:
		if len(b) < SizeofSockaddrInet6 {

		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
	}
	if a.IP.To4() != nil {
		return syscall.AF_INET
	}
	return syscall.AF_INET6
}

func (a *IPAddr) sockaddr(family int) (syscall.Sockaddr, error) {
	if a == nil {
		return nil, nil
	}

	}

	// TODO(bradfitz,brainman): use ctx more. See TODO below.

	var family int32 = syscall.AF_UNSPEC
	switch ipVersion(network) {
	case '4':
		family = syscall.AF_INET
	case '6':
		family = syscall.AF_INET6
	}

	getaddr := func() ([]IPAddr, error) {
		if err := acquireThread(ctx); err != nil {
			return nil, &DNSError{
				Name:      name,

	"syscall"
	"testing"
)

func TestSupportSockNonblockCloexec(t *testing.T) {
	// Test that SupportSockNonblockCloexec returns true if socket succeeds with SOCK_NONBLOCK and SOCK_CLOEXEC.
	s, err := syscall.Socket(syscall.AF_INET, syscall.SOCK_STREAM|syscall.SOCK_NONBLOCK|syscall.SOCK_CLOEXEC, 0)
	if err == nil {
		syscall.Close(s)
	}
	wantSock := err != syscall.EPROTONOSUPPORT && err != syscall.EINVAL
	gotSock := unix.SupportSockNonblockCloexec()

#endif

// If nothing else defined EAI_OVERFLOW, make sure it has a value.
#ifndef EAI_OVERFLOW
#define EAI_OVERFLOW -12
#endif
*/
import "C"
import "unsafe"

const (
	_C_AF_INET      = C.AF_INET
	_C_AF_INET6     = C.AF_INET6
	_C_AF_UNSPEC    = C.AF_UNSPEC
	_C_EAI_AGAIN    = C.EAI_AGAIN
	_C_EAI_NODATA   = C.EAI_NODATA
	_C_EAI_NONAME   = C.EAI_NONAME
	_C_EAI_SERVICE  = C.EAI_SERVICE

		poll.CloseFunc(s)
		return nil, os.NewSyscallError("getsockopt", err)
	}
	lsa, _ := syscall.Getsockname(s)
	rsa, _ := syscall.Getpeername(s)
	switch lsa.(type) {
	case *syscall.SockaddrInet4:
		family = syscall.AF_INET
	case *syscall.SockaddrInet6:
		family = syscall.AF_INET6
	case *syscall.SockaddrUnix:
		family = syscall.AF_UNIX
	default:
		poll.CloseFunc(s)
		return nil, syscall.EPROTONOSUPPORT
	}

}

var (
	supportTCPKeepAliveIdle     bool
	supportTCPKeepAliveInterval bool
	supportTCPKeepAliveCount    bool
)

var initTCPKeepAlive = sync.OnceFunc(func() {
	s, err := WSASocket(syscall.AF_INET, syscall.SOCK_STREAM, syscall.IPPROTO_TCP, nil, 0, WSA_FLAG_NO_HANDLE_INHERIT)
	if err != nil {
		// Fallback to checking the Windows version.
		major, _, build := version()