resmgr(3)

NAME

resmgr - resource manager library functions

SYNOPSIS

#include <resmgr.h>
char **rsm_list_devices(const char *family);
int rsm_open_device(const char *pathname, int flags);
int  rsm_open_device_as(const  char  *family,  const  char
*pathname,
                        int flags);
int rsm_login(const char *user, const char *id);
int rsm_logout(const char *user);
int rsm_grant(const char *user, const char *classname);
int   rsm_add_device(const   char   *device,   const  char
*classname);
int  rsm_remove_device(const  char  *device,  const   char
*classname);
int rsm_lock_device(const char *device);
int rsm_unlock_device(const char *device);

DESCRIPTION

This manual page lists the resource manager functions
available to client applications. All functions connect to
the resource manager daemon resmgrd(8), transmit one or more commands, and close the connection.

User functions

The following functions are intended to be used by user
applications wishing to open or lock a device.

char **rsm_list_devices(const char *family)

This function will return the list of devices the
client is permitted to open.

The optional family argument can be used to specify a resource family. If specified, the listing will
include only names from that specific family. In
addition, device names will be mapped to that par
ticular name space.

For instance, if the resource class includes the
device /dev/cdrom, listing the scsi family would return a corresponding SCSI device specifier such
as scsi:0,0,1. (Of course, this assumes that /dev/cdrom uses the SCSI CD driver, and that the user has permission to open the corresponding raw
SCSI device).

int rsm_open_device(const char *pathname, int flags)

This function will open the device specified by
pathname.

The flags argument contains the usual flags recog
nized by open(2), including O_RDWR, O_RDONLY, and O_NONBLOCK. O_WRONLY is not supported; the resource manager will silently use O_RDWR instead.

int rsm_open_device_as(const char *family,

const char *pathname, int flags)

This function will open a device from the specified
family, related to the the device specified by
pathname. For instance, if you specify a family of scsi, and a device of /dev/cdrom, this will as the resource manager to open the raw SCSI device asso
ciated with the CDROM (if there is any, and if
/dev/cdrom has the scsi flag set (see resmgr.conf(5)).

If there is no corresponding device in the indi
cated family, access is denied.

The flags argument has the same meaning as with
rsm_open_device.

Instead of the path name of a device, you can also
identify the SCSI device using its SCSI ID, using
the notation [bus,]target,lun.

int rsm_lock_device(const char *device)

This function will create a lock file for device. If a conflicting lock exists, an error is returned.

int rsm_unlock_device(const char *device)

This will remove a previously created lock file.
The lock file must have been created by the calling
user, or the lock file must be stale (i.e. the PID
listed in the file does not correspond to a cur
rently running process).

Administrative Functions

The following functions are administrative and are
restricted to the administrator:

int rsm_login(const char *user, const char *id)

This function will establish a resource manager
session for user . The id argument is a identifier uniquely describing where the user is logged in.
For instance, if the user is logged in at the con
sole or via remote login, id would usually specify
the tty on which the user is logged in. Graphic
logins such as kdm or gdm would probably use the X11 display string.

int rsm_logout(const char *id)

This function destroys the resource manager session
for the given identifier. If this was the last ses
sion for the user, the user's access rights to
devices managed by resmgrd are revoked.

int rsm_grant(const char *user, const char *classname)

This function grants user access to resource class
classname.

int rsm_revoke(const char *user, const char *classname)

This function revokes user's access rights to class
classname. If classname is NULL, all access rights of the user are revoked.

int rsm_add_device(const char *device, const char *class_ name)

Add device device to class classname. The device will immediately become accessible to all users who
have been granted access to this class.

int rsm_remove_device(const char *device,

const char *classname)

Remove the specified device from class classname.

RETURN VALUE

rsm_open_device and rsm_open_scsi_device return a file descriptor for the opened device on success, and -1 on
error.

All other functions return 0 in case of success, and -1
otherwise.

AUTHOR

Olaf Kirch <okir@lst.de>

SEE ALSO

resmgrd(8), resmgr(1).

resmgr(3)