NAME
getpeereid — get the effective credentials of a UNIX-domain peerLIBRARY
library “libbsd”SYNOPSIS
#include <sys/types.h>#include <unistd.h> (See libbsd(7) for include usage.)
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 UNIX-domain socket (unix(4)) of typeSOCK_STREAM
on which either
connect(2) or
listen(2) have been called. The effective used 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 mechanism is
reliable; there is no way for either side to influence the credentials
returned to its peer except by calling the appropriate system call (i.e.,
either connect(2) or
listen(2)) under different effective credentials.
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 theLOCAL_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 connect(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.July 15, 2001 | Debian |