sad(7)sad(7)NAMEsad - 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 one to configure a list
of modules to be automatically pushed on a stream when a driver is first
opened. Autopush is controlled by the next commands.
SAD_SAP Allows the administrator to configure the autopush
information for the given device. arg points to a strapush
structure which contains the following members:
uint sap_cmd;
long sap_major;
long sap_minor;
long sap_lastminor;
long sap_npush;
uint sap_list[MAXAPUSH] [FMNAMESZ + 1];
The sap_cmd field indicates the type of configuration being
done. It may take on one of the following values:
SAP_ONE Configure one minor device of a driver.
SAP_RANGE Configure a range of minor devices of a driver.
SAP_ALL Configure all minor devices of a driver.
SAP_CLEAR Undo configuration information for a driver.
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The sap_major field is the major device number of the device
to be configured. The sap_minor field is the minor device
number of the device to be configured. The sap_lastminor
field is used only with the SAP_RANGE command, with which a
range of minor devices between sap_minor and sap_lastminor,
inclusive, are to be configured. The minor fields have no
meaning for the SAP_ALL command. The sap_npush field
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
field 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, the user sets only
sap_major and sap_minor. 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
zero. If a previous entry was configured as SAP_RANGE,
sap_minor should be set to the lowest minor device 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 is invalid, the number
of modules is invalid, or the list of module
names is invalid.
ENOSTR The major device number does not represent a
STREAMS driver.
EEXIST The major-minor 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.
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The user should set the sap_major and sap_minor fields of
the strapush structure to the major and minor device
numbers, respectively, of the device in question. 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 is invalid.
ENOSTR The major device 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 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 field of the str_list structure is
less than or equal to zero.
SEE ALSOintro(2), ioctl(2), open(2)DIAGNOSTICS
Unless specified otherwise above, the return value from ioctl is 0 upon
success and -1 upon failure with errno set as indicated.
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