Slattach ported from 1.1.5 plus Bruce Evans suggested fix (close

FDs and fork before redialing) to prevent dialer from hanging with
newer sio.c.

Also moved history from the source to the cvs log (here) per
David G's suggestion.

This compiles but needs testing now...  Rich

/*
 * Hacks to support "-a|c|n" flags on the command line which enable VJ
 * header compresion and disable ICMP.
 * If this is good all rights go to B & L Jolitz, otherwise send your
 * comments to Reagan (/dev/null).
 *
 * nerd@percival.rain.com (Michael Galassi) 92.09.03
 *
 * Hacked to change from sgtty to POSIX termio style serial line control
 * and added flag to enable cts/rts style flow control.
 *
 * blymn@awadi.com.au (Brett Lymn) 93.04.04
 *
 * Put slattach in it's own process group so it can't be killed
 * accidentally. Close the connection on SIGHUP and SIGINT. Write a
 * syslog entry upon opening and closing the connection.  Rich Murphey
 * and Brad Huntting.
 *
 * Add '-r command' option: runs 'command' upon recieving SIGHUP
 * resulting from loss of carrier.  Log any errors after forking.
 * Rich 8/13/93
 *
 * This version of slattach includes many changes by David Greenman, Brian
 * Smith, Chris Bradley, and me (Michael Galassi).  None of them are
 * represented as functional anywhere outside of RAINet though they do work
 * for us.  Documentation is limited to the usage message for now.  If you
 * make improovments please pass them back.
 *
 * Added '-u UCMD' which runs 'UCMD <old> <new>' whenever the slip
 * unit number changes where <old> and <new> are the old and new unit
 * numbers, respectively.  Also added the '-z' option which forces
 * invocation of the redial command (-r CMD) upon startup regardless
 * of whether the com driver claims (sometimes mistakenly) that
 * carrier is present. Also added '-e ECMD' which runs ECMD before
 * exiting.
 *
 * marc@escargot.rain.com (Marc Frajola) 93/09/10
 *
 * Minor fixes to allow passive SLIP links to work (connections with
 * modem control that do not have an associated dial command). Added
 * code to re-check for carrier after dial command has been executed.
 * Added SIGTERM handler to properly handle normal kill signals. Fixed
 * bug in logic that caused message about no -u command to be logged
 * even when -u was specified and the sl number changes. Tried to get
 * rid of redundant syslog()'s to minimize console log output. Improved
 * logging of improper command line options or number of command
 * arguments. Removed spurious newline characters from syslog() calls.
 *
 * gjung@gjbsd.franken.de
 *
 * sighup_handler changed to set CLOCAL before running redial_cmd.
 * added flag exiting, so exit_handler is not run twice.  Fork
 * before reopening tty.
 */

1 files changed, 106 insertions, 17 deletions

diff --git a/sbin/slattach/slattach.8 b/sbin/slattach/slattach.8
index 217c4817b8f1..e45ba3c2cbd9 100644
--- a/sbin/slattach/slattach.8
+++ b/sbin/slattach/slattach.8
@@ -1,5 +1,5 @@
-.\" Copyright (c) 1986, 1991, 1993
-.\"	The Regents of the University of California.  All rights reserved.
+.\" Copyright (c) 1986, 1991 The Regents of the University of California.
+.\" All rights reserved.
 .\"
 .\" Redistribution and use in source and binary forms, with or without
 .\" modification, are permitted provided that the following conditions
@@ -29,17 +29,30 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.\"     @(#)slattach.8	8.2 (Berkeley) 4/1/94
+.\"     from: @(#)slattach.8	6.4 (Berkeley) 3/16/91
 .\"
-.Dd April 1, 1994
+.\"	$Id: slattach.8,v 1.7 1993/10/13 07:16:39 rgrimes Exp $
+.\"
+.Dd April 4, 1993
 .Dt SLATTACH 8
 .Os BSD 4.3
 .Sh NAME
 .Nm slattach
 .Nd attach serial lines as network interfaces
-.Sh SYNOPSIS
+.Sh SYOPNSIS
 .Nm Slattach
-.Ar ttyname Op Ar baudrate
+.Op \-a
+.Op \-c
+.Op \-e exit-command
+.Op \-f
+.Op \-h
+.Op \-l
+.Op \-n
+.Op \-r redial-command
+.Op \-s baudrate
+.Op \-u unit-command
+.Op \-z
+.Ar ttyname 
 .Sh DESCRIPTION
 .Nm Slattach
 is used to assign a tty line to a network interface,
@@ -47,16 +60,53 @@ and to define the network source and destination addresses.
 The following operands are supported by
 .Nm slattach :
 .Bl -tag -width Ar
+.It Ar \-a
+Autoenable the VJ header compression option, if the other end of the link
+is capable of VJ header compression then it will be used otherwise normal
+headers will be used.
+.It Ar \-c
+Enables the VJ header compression option.  Note that both ends of the link
+must be able to use VJ header compression for this to work.
+.It Ar \-e exit-command
+Specifies a command to be invoked within a shell (sh -c exit-command)
+before slattach exits.
+.It Ar \-f
+Disables the invocation of daemon() to run slattach in the background.
+.It Ar \-h
+Turn on cts/rts style flow control on the slip port, by default no flow
+control is done.
+.It Ar \-l
+disable modem control (CLOCAL) and ignore carrier detect on the slip
+port.  By default the redial-command is invoked upon carrier drop and
+slattach aborts if no redial-command is specified.
+.It Ar \-n
+Throw away ICMP packets.  The slip interface will ignore ICMP packets
+to prevent slow lines being saturated by ICMP responses.
+.It Ar \-r redial-command
+Specifies a command to be invoked within a shell (sh -c
+redial-command) whenever carrier is lost on the line.
+.It Ar \-s baudrate
+Specifies the speed of the connection. If not specified, the
+default of 9600 is used.
+.It Ar \-u unit-command
+When the line is switched to slip discipline, run
+.Ql sh \-c unit-command <last> <current> 
+where <last> and <current> are the slip unit numbers when the line was
+last opened and the unit number of the current slip connection
+respecitvely.  The unit number can change after redialing if you are
+using more than one slip line.  Slattach will abort if the unit number
+changes and
+.Ql \-u unit-command
+was not specified.
+.It Ar \-z
+forces redial
+redial-cmd upon startup irrespective of carrier.
 .It Ar ttyname
 Specifies the name of the tty device.
 .Ar Ttyname
-should be a string of the form
-.Ql ttyXX ,
-or
-.Ql /dev/ttyXX .
-.It Ar baudrate
-Specifies the speed of the connection. If not specified, the
-default of 9600 is used.
+should be a string of the form 
+.Ql ttyXX or
+.Ql /dev/ttyXX.
 .El
 .Pp
 Only the super-user may attach a network interface.
@@ -65,19 +115,58 @@ To detach the interface, use
 .Dq Li ifconfig interface-name down
 after killing off the
 .Nm slattach
-process.
+process using
+.Ql kill -INT .
 .Ar Interface-name
 is the name that is shown by
 .Xr netstat 1
+.Pp
+To setup slattach to redial the phone when carrier is lost, use the
+.Ql \-r redial-cmd
+option to specify a script or executable that will reconnect the
+serial line to the slip server.  For example, the script could redial
+the server and log in, etc.
+.Pp
+To reconfigure the network interface in case the slip unit number
+changes, use the
+.Ql \-u unit-cmd
+option to specify a script or executable that will be invoked as 
+.Ql sh \-c unit-cmd old new,
+where old and new are the slip unit numbers before and after
+reconnecting the line.  The unit number can change if you have more
+than one line disconnect at the same time.  The first to succeed in
+reconnecting will get the lowest unit number.
+.Pp
+To kill slattach use
+.Ql kill -INT
+(SIGINT) which causes it to close the tty and exit.
+.Pp
+To force a redial, use
+.Ql kill -HUP
+(SIGHUP) which causes slattach to think carrier was lost and thus invoke 
+.Ql sh -c redial-command
+to reconnect to the server.
+.Pp
+If you use a hard-wired connection rather than a modem, invoke
+slattach with the
+.Ql \-l
+option in order to ignore carrier on the slip line.
 .Sh EXAMPLES
 .Bd -literal -offset indent -compact
 slattach ttyh8
-slattach /dev/tty01 4800
+slattach \-s 4800 /dev/tty01
+slattach \-c \-s 38400 /dev/sio01
+slattach \-r 'kermit -y dial.script >kermit.log 2>&1'
 .Ed
 .Sh DIAGNOSTICS
+Look for error messages in /var/log/messages (slattach is a daemon).
 Messages indicating the specified interface does not exit, the
-requested address is unknown, the user is not privileged and
-tried to alter an interface's configuration.
+requested address is unknown, the user is not privileged and tried to
+alter an interface's configuration are logged there.  Slattach also
+logs failure to set the controlling terminal or failure to install
+signal handlers.  Upon connection and redial the ttyname and baud rate
+are logged and on shutdown the ttyname is logged.
+.Pp
 .Sh SEE ALSO
 .Xr netstat 1 ,
 .Xr netintro 4 ,