SizeofIPv6MTUInfo      = 0x20
	SizeofMsghdr           = 0x30
	SizeofCmsghdr          = 0xc
	SizeofICMPv6Filter     = 0x20
)

const (
	SizeofIfMsghdr = 0x10
)

type IfMsgHdr struct {
	Msglen  uint16
	Version uint8
	Type    uint8
	Addrs   int32
	Flags   int32
	Index   uint16
	Addrlen uint8
	_       [1]byte
}

type FdSet struct {
	Bits [1024]int64
}

	g4 = make(chan cblock, big)
}

func overflowchan() {
	const ptrSize = unsafe.Sizeof(uintptr(0))
	g4 = make(chan cblock, 1<<(30*(ptrSize/4)))
}

func main() {
	shouldfail(badlen, "badlen")
	shouldfail(biglen, "biglen")
	shouldfail(badcap, "badcap")
	shouldfail(badcap1, "badcap1")
	shouldfail(bigcap, "bigcap")
	shouldfail(badchancap, "badchancap")
	shouldfail(bigchancap, "bigchancap")
	shouldfail(overflowchan, "overflowchan")

// Socket control messages

package unix

import (
	"unsafe"
)

// CmsgLen returns the value to store in the Len field of the Cmsghdr
// structure, taking into account any necessary alignment.
func CmsgLen(datalen int) int {
	return cmsgAlignOf(SizeofCmsghdr) + datalen
}

// CmsgSpace returns the number of bytes an ancillary element with

//go:build unix

// Socket control messages

package syscall

import (
	"unsafe"
)

// CmsgLen returns the value to store in the Len field of the [Cmsghdr]
// structure, taking into account any necessary alignment.
func CmsgLen(datalen int) int {
	return cmsgAlignOf(SizeofCmsghdr) + datalen
}

// CmsgSpace returns the number of bytes an ancillary element with

// authentication.
func UnixCredentials(ucred *Ucred) []byte {
	b := make([]byte, CmsgSpace(SizeofUcred))
	h := (*Cmsghdr)(unsafe.Pointer(&b[0]))
	h.Level = SOL_SOCKET
	h.Type = SCM_CREDENTIALS
	h.SetLen(CmsgLen(SizeofUcred))
	*(*Ucred)(h.data(0)) = *ucred
	return b
}

// ParseUnixCredentials decodes a socket control message that contains
// credentials in a Ucred structure. To receive such a message, the

// authentication.
func UnixCredentials(ucred *Ucred) []byte {
	b := make([]byte, CmsgSpace(SizeofUcred))
	h := (*Cmsghdr)(unsafe.Pointer(&b[0]))
	h.Level = SOL_SOCKET
	h.Type = SCM_CREDENTIALS
	h.SetLen(CmsgLen(SizeofUcred))
	*(*Ucred)(h.data(0)) = *ucred
	return b
}

// ParseUnixCredentials decodes a socket control message that contains
// credentials in a Ucred structure. To receive such a message, the

// remove duplicate expressions.
func zcse(f *Func) {
	vals := make(map[vkey]*Value)

	for _, b := range f.Blocks {
		for i := 0; i < len(b.Values); i++ {
			v := b.Values[i]
			if opcodeTable[v.Op].argLen == 0 {
				key := vkey{v.Op, keyFor(v), v.Aux, v.Type}
				if vals[key] == nil {
					vals[key] = v
					if b != f.Entry {
						// Move v to the entry block so it will dominate every block

package net

/*
#include <sys/types.h>
#include <sys/socket.h>

#include <netdb.h>
*/
import "C"

import "unsafe"

func cgoNameinfoPTR(b []byte, sa *C.struct_sockaddr, salen C.socklen_t) (int, error) {
	gerrno, err := C.getnameinfo(sa, salen, (*C.char)(unsafe.Pointer(&b[0])), C.size_t(len(b)), nil, 0, C.NI_NAMEREQD)
	return int(gerrno), err

package unix

// Round the length of a raw sockaddr up to align it properly.
func cmsgAlignOf(salen int) int {
	salign := SizeofPtr
	if SizeofPtr == 8 && !supportsABI(_dragonflyABIChangeVersion) {
		// 64-bit Dragonfly before the September 2019 ABI changes still requires
		// 32-bit aligned access to network subsystem.
		salign = 4
	}
	return (salen + salign - 1) & ^(salign - 1)

	size := C._goboringcrypto_ECDSA_size(priv.key)
	sig := make([]byte, size)
	var sigLen C.uint
	if C._goboringcrypto_ECDSA_sign(0, base(hash), C.size_t(len(hash)), base(sig), &sigLen, priv.key) == 0 {
		return nil, fail("ECDSA_sign")
	}
	runtime.KeepAlive(priv)
	return sig[:sigLen], nil
}

func VerifyECDSA(pub *PublicKeyECDSA, hash []byte, sig []byte) bool {