sad(7) sad(7)
NAME
sad - STREAMS Administrative Driver
SYNOPSIS
#include <sys/types.h>
#include <sys/conf.h>
#include <sys/sad.h>
int ioctl (fildes, command, arg);
int fildes, command;
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.
COMMAND FUNCTIONS
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 two commands.
SADSAP Allows the super-user to configure the autopush
information for the given device. arg points to a
strapush structure which contains the following members:
uint sapcmd;
long sapmajor;
long sapminor;
long saplastminor;
long sapnpush;
uint saplist[MAXAPUSH] [FMNAMESZ + 1];
The sapcmd field indicates the type of configuration
being done. It may take on one of the following values:
SAPONE Configure one minor device of a driver.
SAPRANGE Configure a range of minor devices of a
driver.
SAPALL Configure all minor devices of a driver.
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sad(7) sad(7)
SAPCLEAR Undo configuration information for a
driver.
The sapmajor field is the major device number of the
device to be configured. The sapminor field is the
minor device number of the device to be configured. The
saplastminor field is used only with the SAPRANGE
command, with which a range of minor devices between
sapminor and saplastminor, inclusive, are to be
configured. These fields have no meaning for the
SAPALL command. The sapnpush 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. The field saplist is an
array of module names to be pushed in the order in which
they appear in the list.
When using the SAPCLEAR command, the user sets only
sapmajor and sapminor. This will undo the
configuration information for any of the other commands.
If a previous entry was configured as SAPALL, sapminor
should be set to zero. If a previous entry was
configured as SAPRANGE, sapminor 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.
EPERM The user does not have permission to set
autopush configuration information (e.g.,
the user is not the super-user).
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.
ENODEV The command was SAPCLEAR and the entry
could not be found. The autopush
configuration information for the given
major/minor device can not be found in the
cache maintained by the sad driver,
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sad(7) sad(7)
probably because the given major/minor
device has not yet been configured for
autopush.
SADGAP 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.
The user should set the sapmajor and sapminor 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 An entry could not be found for the given
major/minor device. The autopush
configuration information for the given
major/minor device can not be found in the
cache maintained by the sad driver,
probably because the given major/minor
device has not yet been configured for
autopush.
SEE ALSO
intro(2), ioctl(2), open(2).
Programmer's Guide: STREAMS.
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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