ConnectClientInfo(), ConnectClientInfo_r()

Store information about a client connection

Synopsis:

#include <sys/neutrino.h>

int ConnectClientInfo( int scoid,
                       struct _client_info * info
                       int ngroups );

int ConnectClientInfo_r( int scoid,
                         struct _client_info * info
                         int ngroups );

Arguments:

scoid: A server connection ID that identifies the client process that you want to get information about. This client is typically a process that's made a connection to the server to try to access a resource. You can get it from the _msg_info argument to MsgReceivev() or MsgInfo().
info: A pointer to a _client_info structure that the function can fill with information about the client. For more information, see below.
ngroups: The size of the caller's grouplist in the credential part of the _client_info structure. If you make it smaller than NGROUPS_MAX, you might get information only about a subset of the groups.

Library:

libc

Use the -l c option to qcc to link against this library. This library is usually included automatically.

Description:

These calls get information about a client connection identified by scoid, and store it in the buffer that info points to.

The ConnectClientInfo() and ConnectClientInfo_r() functions are identical except in the way they indicate errors. See the Returns section for details.

A server uses these functions to determine whether or not a client has permission to access a resource. For example, in a resource manager, it would be called on an open() connection request.

`_client_info` structure

The _client_info structure has at least the following members:

uint32_t nd: The client's node ID.
pid_t pid: The client's process ID.
pid_t sid: Used internally by Qnet.
struct _cred_info cred: The user and group ID credentials; see below.

The nd (node descriptor) is a temporary numeric description of a remote node; ND_LOCAL_NODE (or 0) is the descriptor for the local node. For more information, see the Qnet Networking chapter of the System Architecture guide.

To:	Use this function:
Compare two nd objects	ND_NODE_CMP()
Convert a nd to text	netmgr_ndtostr()
Convert text to a nd	netmgr_strtond()

`_cred_info` structure

The cred member of the _client_info is a _cred_info structure that includes at least the following members:

uid_t ruid: The real user ID of the sending process.
uid_t euid: The effective user ID of the sending process.
uid_t suid: The saved user ID of the sending process.
gid_t rgid: The real group ID of the sending process.
gid_t egid: The effective group ID of the sending process.
gid_t sgid: The saved group ID of the sending process.
uint32_t ngroups: The number of groups actually stored in grouplist.
gid_t grouplist[NGROUPS_MAX]: The supplementary group IDs of the sending process.

The ngroups argument to ConnectClientInfo() indicates the size of the grouplist array. If the group array size is zero, the ngroups member of the _cred_info is set to the number of groups available.

Returns:

The only difference between these functions is the way they indicate errors:

ConnectClientInfo(): If an error occurs, the function returns -1 and sets errno. Any other value returned indicates success.
ConnectClientInfo_r(): EOK is returned on success. This function does NOT set errno. If an error occurs, the function can return any value in the Errors section.