func (c *IPConn) WriteToIP(b []byte, addr *IPAddr) (int, error) {
	if !c.ok() {
		return 0, syscall.EINVAL
	}
	n, err := c.writeTo(b, addr)
	if err != nil {
		err = &OpError{Op: "write", Net: c.fd.net, Source: c.fd.laddr, Addr: addr.opAddr(), Err: err}
	}
	return n, err
}

// WriteTo implements the [PacketConn] WriteTo method.
func (c *IPConn) WriteTo(b []byte, addr Addr) (int, error) {
	if !c.ok() {

)

const Enabled = true

func Acquire(addr unsafe.Pointer) {
	runtime.RaceAcquire(addr)
}

func Release(addr unsafe.Pointer) {
	runtime.RaceRelease(addr)
}

func ReleaseMerge(addr unsafe.Pointer) {
	runtime.RaceReleaseMerge(addr)
}

func Disable() {
	runtime.RaceDisable()
}

func Enable() {
	runtime.RaceEnable()
}

func Read(addr unsafe.Pointer) {
	runtime.RaceRead(addr)
}

		}
		// See struct sockaddr_in
		daddr = net.IPv4(
			addr.Addr.Addr[0], addr.Addr.Addr[1], addr.Addr.Addr[2], addr.Addr.Addr[3])
	} else {
		addr, err = unix.GetsockoptIPv6MTUInfo(
			int(fd), unix.IPPROTO_IPV6,
			constants.SoOriginalDst)
		if err != nil {
			log.Errorf("Error to ipv6 getsockopt: %v", err)
			return
		}
		// See struct sockaddr_in6
		daddr = addr.Addr.Addr[:]
	}
	// See sockaddr_in6 and sockaddr_in

	MOVV	addr+0(FP), RARG0
	MOVV	sz+8(FP), RARG1
	MOVV	sp+16(FP), RARG2
	MOVV	pc+24(FP), RARG3
	// void __asan_write_go(void *addr, uintptr_t sz, void *sp, void *pc);
	MOVV	$__asan_write_go(SB), FARG
	JMP	asancall<>(SB)

// func runtime·asanunpoison(addr unsafe.Pointer, sz uintptr)
TEXT	runtime·asanunpoison(SB), NOSPLIT, $0-16
	MOVV	addr+0(FP), RARG0
	MOVV	sz+8(FP), RARG1
	// void __asan_unpoison_go(void *addr, uintptr_t sz);

	if loc.Address != 0 {
		panic("can only synthesize addresses for locations without an address")
	}
	if addr, ok := s.addr[loc]; ok {
		return addr
	}
	if s.addr == nil {
		s.addr = map[*profile.Location]uint64{}
	}
	addr := s.next
	s.next++
	s.addr[loc] = addr
	return addr

type addrList []Addr

// isIPv4 reports whether addr contains an IPv4 address.
func isIPv4(addr Addr) bool {
	switch addr := addr.(type) {
	case *TCPAddr:
		return addr.IP.To4() != nil
	case *UDPAddr:
		return addr.IP.To4() != nil
	case *IPAddr:
		return addr.IP.To4() != nil
	}
	return false
}

// isNotIPv4 reports whether addr does not contain an IPv4 address.

	addr := ap.Addr()
	if !addr.IsValid() {
		return syscall.SockaddrInet6{}, &AddrError{Err: "non-IPv6 address", Addr: addr.String()}
	}
	sa := syscall.SockaddrInet6{
		Addr:   addr.As16(),
		Port:   int(ap.Port()),
		ZoneId: uint32(zoneCache.index(addr.Zone())),
	}
	return sa, nil

	// type to avoid the header trim/copy
	var addr *IPAddr
	n, sa, err := c.fd.readFrom(b)
	switch sa := sa.(type) {
	case *syscall.SockaddrInet4:
		addr = &IPAddr{IP: sa.Addr[0:]}
		n = stripIPv4Header(n, b)
	case *syscall.SockaddrInet6:
		addr = &IPAddr{IP: sa.Addr[0:], Zone: zoneCache.name(int(sa.ZoneId))}
	}
	return n, addr, err
}

func stripIPv4Header(n int, b []byte) int {
	if len(b) < 20 {

	fake.SetLocalAddresses("eth0", "1.2.3.4")
	var expected, addr sets.Set[string]
	expected = sets.New("1.2.3.4")
	addr, _ = fake.GetLocalAddresses("eth0")
	if !addr.Equal(expected) {
		t.Errorf("Unexpected mismatch, expected: %v, got: %v", expected, addr)
	}
	addr, _ = fake.GetAllLocalAddresses()
	if !addr.Equal(expected) {
		t.Errorf("Unexpected mismatch, expected: %v, got: %v", expected, addr)
	}
	fake.SetLocalAddresses("lo", "127.0.0.1")

	MOVD	addr+0(FP), RARG0
	MOVD	sz+8(FP), RARG1
	MOVD	sp+16(FP), RARG2
	MOVD	pc+24(FP), RARG3
	// void __asan_write_go(void *addr, uintptr_t sz, void *sp, void *pc);
	MOVD	$__asan_write_go(SB), FARG
	BR	asancall<>(SB)

// func runtime·asanunpoison(addr unsafe.Pointer, sz uintptr)
TEXT	runtime·asanunpoison(SB),NOSPLIT|NOFRAME,$0-16
	MOVD	addr+0(FP), RARG0
	MOVD	sz+8(FP), RARG1
	// void __asan_unpoison_go(void *addr, uintptr_t sz);