SLIP(7)

NAME
SLIP - Serial Link Internet Protocol

SYNOPSIS
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/stream.h>
#include <net/if.h>
#include <sys/slip.h>
s = open ("/dev/slip", O_RDWR);

DESCRIPTION

SLIP is a multiplexing STREAMS driver that implements the packet framing protocol specified in RFC1055.

The SLIP driver is usually linked below the ip driver and above the asy (serial) driver. The slattach command constructs the required ip to SLIP to asy STREAMS stack so that serial lines can be used as a network interfaces.

Multiple serial devices can be linked below the SLIP driver. The maximum number of serial devices the SLIP driver can have is controlled by the configuration parameter SLIP_NUM in the file /etc/conf/pack.d/slip/space.c. Note that the slip hangup daemon (slhangupd), if used, takes one entry of SLIP's driver data structure, and should be considered before setting SLIP_NUM.

I_STR ioctl commands:

The I_STR ioctl commands are provided to add the capability of passing M_HANGUP signal received by the SLIP driver to the process that builds the SLIP protocol stack. This is necessary because the TCP/IP protocol stack may disregard M_HANGUP messages.

The I_STR ioctl commands codes below are defined in <sys/slip.h>.

REG_SLHUP
    A process that sends this ioctl will be notified of M_HANGUP messages sent by any of the lower ttys associated with the SLIP driver. The notification is done by sending an M_DATA messages containing the process ID of the program that linked the effected tty to the SLIP driver. This ioctl is generally sent by SLIP hangup daemon slhangupd. Only one process can be registered to receive M_HANGUP notifications at any one time.

UNREG_SLHUP
    This ioctl unregisters a process from receiving M_HANGUP notifications. Since only one process can be registered to receive M_HANGUP notifications, it is important that a process unregister before it exits.

SEE ALSO
slattach(1M), sldetach(1M), slhangupd(1M), asy(7), ip(7)

FILES
/dev/slip

AUTHOR
Sudji Husodo