sad(7D)
NAME
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, int 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 using /dev/sad/admin. Unprivileged operations
may access the sad driver using /dev/sad/user.
The fildes argument is an open file descriptor that refers
to the sad driver. The command argument determines the
control function to be performed as described below. The
arg argument 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.
COMMAND FUNCTIONS
The autopush facility (see autopush(1M)) allows one to con-
figure a list of modules to be automatically pushed on a
stream when a driver is first opened. Autopush is con-
trolled by the following commands:
SAD_SAP
Allows the administrator to configure the given
device's autopush information. arg points to a
strapush structure, which contains the following
members:
unit_t ap_cmd;
major_t sap_major;
minor_t sap_minor;
minor_t sap_lastminor;
unit_t sap_npush;
unit_t sap_list [MAXAPUSH] [FMNAMESZ + 1];
The sap_cmd field indicates the type of confi-
guration 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.
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, which configures a range of minor
devices between sap_minor and sap_lastminor,
inclusive. 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 NULL-
terminated 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 configura-
tion 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 config-
ured 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 con-
figured.
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 dev-
ice. arg points to a strapush structure as described
in the previous command.
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 config-
ure 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 (that
is, to see if they are installed on the system). arg
is a pointer to a str_list structure with the follow-
ing 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 ALSO
intro(2), ioctl(2), open(2)
STREAMS Programming Guide
DIAGNOSTICS
Unless otherwise specified, the return value from ioctl()
is 0 upon success and -1 upon failure with errno set as
indicated.
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