// 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

//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

// 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

// 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

		{{}},
		{{1, 2}, {3, 4, 5}, {}, {7}},
	}
	for _, testCase := range testCases {
		b := []byte{}
		var n int
		for _, fds := range testCase {
			// Last assignment to n wins
			n = len(b) + syscall.CmsgLen(4*len(fds))
			b = append(b, syscall.UnixRights(fds...)...)
		}
		// Truncate b
		b = b[:n]

		scms, err := syscall.ParseSocketControlMessage(b)
		if err != nil {

pkg syscall (freebsd-386-cgo), func Chroot(string) error
pkg syscall (freebsd-386-cgo), func Close(int) error
pkg syscall (freebsd-386-cgo), func CloseOnExec(int)
pkg syscall (freebsd-386-cgo), func CmsgLen(int) int
pkg syscall (freebsd-386-cgo), func CmsgSpace(int) int
pkg syscall (freebsd-386-cgo), func Connect(int, Sockaddr) error
pkg syscall (freebsd-386-cgo), func Dup(int) (int, error)

			}
			var msglen int
			for shift := uint(0); ; shift += 7 {
				if shift >= 64 {
					return ErrIntOverflowGenerated
				}
				if iNdEx >= l {
					return io.ErrUnexpectedEOF
				}
				b := dAtA[iNdEx]
				iNdEx++
				msglen |= int(b&0x7F) << shift
				if b < 0x80 {
					break
				}
			}
			if msglen < 0 {
				return ErrInvalidLengthGenerated

			for shift := uint(0); ; shift += 7 {
				if shift >= 64 {
					return ErrIntOverflowGenerated
				}
				if iNdEx >= l {
					return io.ErrUnexpectedEOF
				}
				b := dAtA[iNdEx]
				iNdEx++
				msglen |= int(b&0x7F) << shift
				if b < 0x80 {
					break
				}
			}
			if msglen < 0 {
				return ErrInvalidLengthGenerated
			}
			postIndex := iNdEx + msglen

			}
			var msglen int
			for shift := uint(0); ; shift += 7 {
				if shift >= 64 {
					return ErrIntOverflowGenerated
				}
				if iNdEx >= l {
					return io.ErrUnexpectedEOF
				}
				b := dAtA[iNdEx]
				iNdEx++
				msglen |= int(b&0x7F) << shift
				if b < 0x80 {
					break
				}
			}
			if msglen < 0 {
				return ErrInvalidLengthGenerated
			}