path: root/vendor/golang.org/x/sys/unix/sockcmsg_linux.go

// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

// Socket control messages

package unix

import "unsafe"

// UnixCredentials encodes credentials into a socket control message
// for sending to another process. This can be used for
// 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)(cmsgData(h))) = *ucred
    return b
}

// ParseUnixCredentials decodes a socket control message that contains
// credentials in a Ucred structure. To receive such a message, the
// SO_PASSCRED option must be enabled on the socket.
func ParseUnixCredentials(m *SocketControlMessage) (*Ucred, error) {
    if m.Header.Level != SOL_SOCKET {
        return nil, EINVAL
    }
    if m.Header.Type != SCM_CREDENTIALS {
        return nil, EINVAL
    }
    ucred := *(*Ucred)(unsafe.Pointer(&m.Data[0]))
    return &ucred, nil
}