Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages

  
 
  

home | help 
GETPEEREID(3)		     Library Functions Manual		   GETPEEREID(3)

NAME
     getpeereid -- get the effective credentials of a UNIX-domain peer

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <unistd.h>

     int
     getpeereid(int s, uid_t *euid, gid_t *egid);

DESCRIPTION
     The  getpeereid()	function returns the effective user and group IDs of the
     peer connected to a Unix-domain socket.  The argument s must be a connected
     Unix-domain socket (unix(4)) of type SOCK_STREAM on which either connect(2)
     or listen(2) has been called.  The effective user ID is placed in euid, and
     the effective group ID in egid.

     The credentials returned to the listen(2) caller are those of its	peer  at
     the  time	it called connect(2); the credentials returned to the connect(2)
     caller are those of its peer at the time it called listen(2).  This  mecha-
     nism  is reliable; there is no way for either side to influence the creden-
     tials returned to its peer except by calling the  appropriate  system  call
     (i.e.,  either  connect(2)  or listen(2)) under different effective creden-
     tials.

     One common use of this routine is for a Unix-domain server  to  verify  the
     credentials of its client.  Likewise, the client can verify the credentials
     of the server.

IMPLEMENTATION NOTES
     On  FreeBSD,  getpeereid()  is  implemented  in terms of the LOCAL_PEERCRED
     unix(4) socket option.

RETURN VALUES
     The getpeereid() function returns the value 0 if successful; otherwise  the
     value  -1	is returned and the global variable errno is set to indicate the
     error.

ERRORS
     The getpeereid() function fails if:

     [EBADF]		The argument s is not a valid descriptor.

     [ENOTSOCK] 	The argument s is a file, not a socket.

     [ENOTCONN] 	The argument s does not refer to a socket on which  con-
			nect(2) or listen(2) have been called.

     [EINVAL]		The  argument  s  does	not  refer  to	a socket of type
			SOCK_STREAM, or the kernel returned invalid data.

SEE ALSO
     connect(2),  getpeername(2),  getsockname(2),   getsockopt(2),   listen(2),
     unix(4)

HISTORY
     The getpeereid() function appeared in FreeBSD 4.6.

FreeBSD 14.3			November 16, 2023		   GETPEEREID(3)

Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=getpeereid&sektion=3&manpath=FreeBSD+14.3-RELEASE+and+Ports>

home | help