iknt(ADMP)
iknt --
In-Kernel Network Terminal driver
Syntax
Programmer's interface:
#include <sys/types.h>
#include <sys/stream.h>
#include <sys/net/iknt.h>
#include <sys/spt.h>
s = ioctl(p, TIOCAIKNT, &ikarg);
Description
The In-Kernel Network Terminal (IKNT) driver
provides reliable, flow-controlled, two-way transmission of
data between the master side of the pseudo-tty
(SPT) driver and the underlying transport
driver/protocol, bypassing the server process. Thus it
eliminates two context-switches per character exchanged
between the client and the user processes. The
SPT driver opens the IKNT driver
automatically when the master side is opened. The server
process (usually
telnetd(ADMN)
or
rlogind(ADMN))
issues an ioctl to set up a connection between
the master side of the pseudo-tty and the transport driver.
Thus all the characters which arrive at that transport
provider (destined for the user process) are automatically
accessible to the SPT driver, bypassing the
server process, thereby eliminating two context switches.
Similarly, all the characters generated by the user process
and destined for the client also bypass the server
process.
For more information about how pseudo-tty's are implemented and
examples of code that use them, see the ``Terminal Modes'' chapter
in W. Richard Stevens, UNIX Network Programming.
IKNT
supports several options which are set with the following
ioctl:
TIOCAIKNT-
To set up the connection between the master side of the
SPT driver and TCP driver. The
following structure is passed as an argument to the
TIOCAIKNT ioctl to extract the desired
information:
struct ikarg {
int file_p;
u_long flags;
};
The argument flags can be set to any of the
following values.
#define IK_RLOGIN 0x020 /* invoke in rlogin mode */
#define IK_TELNET 0x040 /* invoke in telnet mode */
#define IK_HS_WONT_BIN 0x100 /* client not using telnet binary option */
#define IK_MY_WONT_BIN 0x200 /* server not using telnet binary option */
Diagnostics
An ioctl operation may fail with the
errno
set to one of the following:
[EBADF]-
when the associated file pointer does not point to an inode or
the associated stream is not found
[EFAULT]-
when bad argument/NULL argument is passed to the driver
[EINVAL]-
when the file descriptor in the
ikarg
structure is not valid
Files
/dev/inet/tcp
/dev/ttyp
See also
rlogind(ADMN),
telnetd(ADMN),
tcp(ADMP)
© 2003 Caldera International, Inc. All rights reserved.
SCO OpenServer Release 5.0.7 -- 11 February 2003