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sad(7)


sad -- STREAMS Administrative Driver

Synopsis

#include <sys/types.h>
#include <sys/conf.h>
#include <sys/sad.h>
#include <sys/stropts.h>

int ioctl (int fildes, int command, . . . /* arg */);

Description

The STREAMS Administrative Driver provides an interface for applications to perform administrative operations on STREAMS modules and drivers. The interface is provided through ioctl(2) commands. Privileged operations may access the sad driver via /dev/sad/admin. Unprivileged operations may access the sad driver via /dev/sad/user.

fildes is an open file descriptor that refers to the sad driver. command determines the control function to be performed as described below. arg represents additional information that is needed by this command. The type of arg depends upon the command, but it is generally an integer or a pointer to a command-specific data structure.

Commands

The ``autopush'' facility (see autopush(1M)) allows a list of modules to be automatically pushed on a stream when a driver is first opened. Autopush is controlled by the following commands:

SAD_SAP
Allows the administrator to configure the autopush information for the given device. arg points to a strapush structure containing the following members:
uint   sap_cmd;
long   sap_major;
long   sap_minor;
long   sap_lastminor;
long   sap_npush;
uint   sap_list[MAXAPUSH] [FMNAMESZ + 1];
char   sap_modname[FMNAMESZ + 1];
The sap_cmd member indicates the type of configuration to be performed. It may take one of the following values:

SAP_ONE
Configure one minor device (``channel'' if DDI 8) of a driver.

SAP_RANGE
Configure a range of minor devices (or channels) of a driver.

SAP_ALL
Configure all minor devices (or channels) of a driver.

SAP_CLONE
Configure any minor device (or channel) that is returned by cloning the minor device (or by performing ``open redirection'' on the ``clone channel'' if DDI 8).

SAP_CLEAR
Undo configuration information for a driver.

The sap_major member is the major device number of the device to be configured. If sap_major is set to -1, the sap_modname (module name) member is used to specify the device that is to be configured. This specification method is mandatory for DDI 8 modules but it will also work with previous versions of the DDI.

When used with the SAP_RANGE command, the sap_lastminor member determines the upper limit of the range of minor devices (or channels), from sap_minor to sap_lastminor inclusively, which are to be configured.

When the SAP_CLONE command is used with modules that conform to versions of the DDI prior to DDI 8, sap_minor represents the minor number that is used to open a clone device. When the SAP_CLONE command is used with modules that conform to DDI 8, sap_minor represents the clone channel that is used to open a device.

sap_minor and sap_lastminor have no meaning for the SAP_ALL command. The sap_npush member indicates the number of modules to be automatically pushed when the device is opened. It must be less than or equal to MAXAPUSH, defined in sad.h. It must also be less than or equal to NSTRPUSH, the maximum number of modules that can be pushed on a stream, defined in the kernel master file.

The member sap_list is an array of module names to be pushed in the order in which they appear in the list.

When using the SAP_CLEAR command, set only sap_major, sap_minor, and possibly sap_modname (if sap_major is set to -1). This will undo the configuration information for any of the other commands. If a previous entry was configured as SAP_ALL, sap_minor should be set to 0. If a previous entry was configured as SAP_RANGE, sap_minor should be set to the lowest minor device (or channel) number in the range configured.

On failure, errno is set to the following value:


EFAULT
arg points outside the allocated address space.

EINVAL
The major device number (or module name) is invalid, the number of modules is invalid, or the list of module names is invalid.

ENOSTR
The major device number (or module name) does not represent a STREAMS driver.

EEXIST
The major-minor (or module name and channel) device pair is already configured.

ERANGE
The command is SAP_RANGE and sap_lastminor is not greater than sap_minor, or the command is SAP_CLEAR and sap_minor is not equal to the first minor in the range.

ENODEV
The command is SAP_CLEAR and the device is not configured for autopush.

ENOSR
An internal autopush data structure cannot be allocated.

SAD_GAP
Allows any user to query the sad driver to get the autopush configuration information for a given device. arg points to a strapush structure as described in the previous command.

For pre-DDI 8 modules, set the sap_major and sap_minor members of the strapush structure to the major and minor device numbers, respectively, of the device. For DDI 8 modules, set sap_major to -1, sap_modname to the module name, and sap_minor to the channel number of the device. On return, the strapush structure will be filled in with the entire information used to configure the device. Unused entries in the module list will be zero-filled.

On failure, errno is set to one of the following values:


EFAULT
arg points outside the allocated address space.

EINVAL
The major device number (or module name) is invalid.

ENOSTR
The major device (or channel) number does not represent a STREAMS driver.

ENODEV
The device is not configured for autopush.

SAD_VML
Allows any user to validate a list of modules (for example, to see if they are installed on the system). arg is a pointer to a str_list structure with the following members:
int                sl_nmods;
struct str_mlist   *sl_modlist;
The str_mlist structure has the following member:
char    l_name[FMNAMESZ+1];
sl_nmods indicates the number of entries that the user has allocated in the array and sl_modlist points to the array of module names. The return value is 0 if the list is valid, 1 if the list contains an invalid module name, or -1 on failure. On failure, errno is set to one of the following values:

EFAULT
arg points outside the allocated address space.

EINVAL
The sl_nmods member of the str_list structure is less than or equal to 0.

Return values

Unless specified otherwise above, the return value from ioctl is 0 upon success and -1 upon failure with errno set as indicated.

References

autopush(1M), intro(2), ioctl(2), open(2), streamio(7)
© 2004 The SCO Group, Inc. All rights reserved.
UnixWare 7 Release 7.1.4 - 25 April 2004