GETPEERUCRED(3C) Standard C Library Functions GETPEERUCRED(3C)

NAME

getpeerucred - get connected socket or stream peer's credentials

SYNOPSIS

#include <ucred.h>

int getpeerucred(int fd, ucred_t **ucred);

DESCRIPTION

The getpeerucred() function returns the credentials of the peer endpoint
of a connection-oriented socket (SOCK_STREAM) or stream fd at the time
the endpoint was created or the connection was established. A process
that initiates a connection retrieves the credentials of its peer at the
time the peer's endpoint was created. A process that listens for
connections retrieves the credentials of the peer at the time the peer
initiated the connection.


When successful, getpeerucred() stores the pointer to a freshly allocated
ucred_t in the memory location pointed to by the ucred argument if that
memory location contains the null pointer. If the memory location is non-
null, it will reuse the existing ucred_t.


When ucred is no longer needed, a credential allocated by getpeerucred()
should be freed with ucred_free(3C).


It is possible that all fields of the ucred_t are not available to all
peer endpoints and all callers.

RETURN VALUES

Upon successful completion, getpeerucred() returns 0. Otherwise, it
returns -1 and errno is set to indicate the error.

ERRORS

The getpeerucred() function will fail if:

EAGAIN
There is not enough memory available to allocate sufficient
memory to hold the user credential. The application can try
again later.


EBADF
The fd argument is not a valid file descriptor.


EFAULT
The pointer location pointed to by the ucred_t ** argument
points to an invalid, non-null address.


EINVAL
The socket is connected but the peer credentials are unknown.


ENOMEM
The physical limits of the system are exceeded by the memory
allocation needed to hold the user credential.


ENOTCONN
The socket or stream is not connected or the stream's peer is
unknown.


ENOTSUP
This operation is not supported on this file descriptor.

ATTRIBUTES

See attributes(7) for descriptions of the following attributes:


+--------------------+-----------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-----------------+
|Interface Stability | Evolving |
+--------------------+-----------------+
|MT-Level | MT-Safe |
+--------------------+-----------------+

SEE ALSO

door_ucred(3C), ucred_get(3C), connld(4M), attributes(7)

NOTES

The system currently supports both sides of connection endpoints for
local AF_UNIX, AF_INET, and AF_INET6 sockets, /dev/tcp, /dev/ticots, and
/dev/ticotsord XTI/TLI connections, and pipe file descriptors sent using
I_SENDFD as a result of the open of a named pipe with the "connld" module
pushed.

May 26, 2004 GETPEERUCRED(3C)