raddr, _, _ := net.SplitHostPort(addr)
	if raddr == "" {
		return addr
	}
	return raddr
}

// GetSourceIP retrieves the IP from the request headers
// and falls back to r.RemoteAddr when necessary.
func GetSourceIP(r *http.Request) string {
	addr := GetSourceIPRaw(r)
	if strings.ContainsRune(addr, ':') {
		return "[" + addr + "]"
	}
	return addr

	Name string
	Age  uint
	Addr *Address
}

// GoString makes Person satisfy the GoStringer interface.
// The return value is valid Go code that can be used to reproduce the Person struct.
func (p Person) GoString() string {
	if p.Addr != nil {
		return fmt.Sprintf("Person{Name: %q, Age: %d, Addr: &Address{City: %q, State: %q, Country: %q}}", p.Name, int(p.Age), p.Addr.City, p.Addr.State, p.Addr.Country)
	}

const msanenabled = false

// Because msanenabled is false, none of these functions should be called.

func msanread(addr unsafe.Pointer, sz uintptr)     { throw("msan") }
func msanwrite(addr unsafe.Pointer, sz uintptr)    { throw("msan") }
func msanmalloc(addr unsafe.Pointer, sz uintptr)   { throw("msan") }
func msanfree(addr unsafe.Pointer, sz uintptr)     { throw("msan") }

		}
		if err := setKeepAliveCount(c.fd, config.Count); err != nil {
			return &OpError{Op: "set", Net: c.fd.net, Source: c.fd.laddr, Addr: c.fd.raddr, Err: err}
		}
	} else if err := setKeepAliveIdleAndIntervalAndCount(c.fd, config.Idle, config.Interval, config.Count); err != nil {
		return &OpError{Op: "set", Net: c.fd.net, Source: c.fd.laddr, Addr: c.fd.raddr, Err: err}
	}

	return nil

		systemstack(func() {
			ret = callCgoMmap(addr, n, prot, flags, fd, off)
		})
		if ret < 4096 {
			return nil, int(ret)
		}
		return unsafe.Pointer(ret), 0
	}
	return sysMmap(addr, n, prot, flags, fd, off)
}

func munmap(addr unsafe.Pointer, n uintptr) {
	if _cgo_munmap != nil {
		systemstack(func() { callCgoMunmap(addr, n) })
		return
	}
	sysMunmap(addr, n)
}

	KeepAlive(addr) // Just for consistency. Hopefully addr is not a Go address.
	return args.ret1, args.ret2
}
func mmap_trampoline()

//go:nosplit
//go:cgo_unsafe_args
func munmap(addr unsafe.Pointer, n uintptr) {
	libcCall(unsafe.Pointer(abi.FuncPCABI0(munmap_trampoline)), unsafe.Pointer(&addr))
	KeepAlive(addr) // Just for consistency. Hopefully addr is not a Go address.
}
func munmap_trampoline()

//go:nosplit

	n := copy(b, buf)
	ip, _ := netip.AddrFromSlice(h.raddr)
	addr := netip.AddrPortFrom(ip, h.rport)
	return n, addr, nil
}

func (c *UDPConn) readMsg(b, oob []byte) (n, oobn, flags int, addr netip.AddrPort, err error) {
	return 0, 0, 0, netip.AddrPort{}, syscall.EPLAN9
}

func (c *UDPConn) writeTo(b []byte, addr *UDPAddr) (int, error) {
	if addr == nil {
		return 0, errMissingAddress
	}
	h := new(udpHeader)

	instinit(&ctxt)

	regAddr := func(reg int16) *obj.Addr {
		return &obj.Addr{Type: obj.TYPE_REG, Reg: reg}
	}
	immAddr := func(v int64) *obj.Addr {
		return &obj.Addr{Type: obj.TYPE_CONST, Offset: v}
	}
	regListAddr := func(regFrom, regTo int16) *obj.Addr {
		return &obj.Addr{Type: obj.TYPE_REGLIST, Offset: EncodeRegisterRange(regFrom, regTo)}
	}
	memAddr := func(base, index int16) *obj.Addr {

	pthread_attr_getstack(&attr, &addr, &size); // low address
#elif defined(__illumos__)
	pthread_attr_get_np(pthread_self(), &attr);
	pthread_attr_getstack(&attr, &addr, &size); // low address
#else
	// We don't know how to get the current stacks, so assume they are the
	// same as the default stack bounds.
	pthread_attr_getstacksize(&attr, &size);
	addr = __builtin_frame_address(0) + 4096 - size;
#endif

	if err != nil {
		return false, fmt.Errorf("error get interface: %s, err: %v", devName, err)
	}
	addr := netutils.ParseIPSloppy(address)
	if addr == nil {
		return false, fmt.Errorf("error parse ip address: %s", address)
	}
	if err := h.AddrAdd(dev, &netlink.Addr{IPNet: netlink.NewIPNet(addr)}); err != nil {
		// "EEXIST" will be returned if the address is already bound to device
		if err == unix.EEXIST {