#! /bin/sh
#	$Id: wedged.sh.in,v 1.2 2006/06/02 18:57:58 faxguy Exp $
#
# HylaFAX Facsimile Software
#
# Copyright (c) 1994-1996 Sam Leffler
# Copyright (c) 1994-1996 Silicon Graphics, Inc.
# HylaFAX is a trademark of Silicon Graphics
# 
# Permission to use, copy, modify, distribute, and sell this software and 
# its documentation for any purpose is hereby granted without fee, provided
# that (i) the above copyright notices and this permission notice appear in
# all copies of the software and related documentation, and (ii) the names of
# Sam Leffler and Silicon Graphics may not be used in any advertising or
# publicity relating to the software without the specific, prior written
# permission of Sam Leffler and Silicon Graphics.
# 
# THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND, 
# EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY 
# WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.  
# 
# IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR
# ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
# OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
# WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF 
# LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE 
# OF THIS SOFTWARE.
#

#
# wedged deviceID device 
#
# Do something when a modem looks irretrievably wedged.
#
if [ $# != 2 ]; then
    echo "Usage: $0 deviceID device"
    exit 1
fi

test -f etc/setup.cache || {
    SPOOL=`pwd`
    cat<<EOF

FATAL ERROR: $SPOOL/etc/setup.cache is missing!

The file $SPOOL/etc/setup.cache is not present.  This
probably means the machine has not been setup using the faxsetup(8C)
command.  Read the documentation on setting up HylaFAX before you
startup a server system.

EOF
    exit 1
}
. etc/setup.cache

#
# Redirect errors to a tty, if possible, rather than
# dev-nulling them or allowing them to creep into
# the mail.
#
if $TTYCMD >/dev/null 2>&1; then
    ERRORSTO=`$TTYCMD`
else
    ERRORSTO=/dev/null
fi   
#
# Command line params
#
devID=$1
device=$2

#
# Variables customizable through etc/FaxDispatch
#
TOADDR=FaxMaster
FROMADDR=fax
WEDGED_EMAIL_INTERVAL=5		# minutes: at most 1 wedged email every X mins
WEDGED_DISABLE_FAXGETTY=	# if set, faxgetty disabled from inittab

if [ -f etc/FaxDispatch ]; then
    . etc/FaxDispatch	
fi

#
# Internal variables
#

# unix secs since epoch for systems without GNU date +%s extension
unixtime() {
    TZ=GMT date "+%Y %j %H %M %S" | $SED 's/ 0*/ /g' | {
    read year yday hour min sec
    expr  $sec + $min \* 60 + $hour \* 3600 \
	+ \(  \( $year - 1969 \) / 4 \
	    - \( $year / 100 - 19 \) \
	    + \( $year / 400 - 4  \) \
	    + $yday - 1 \
	   \) \* 86400 \
	+ \( $year - 1970 \) \* 31536000
    }
}

tty=`basename $device`
wedged_last_time=0		# seconds: unix timestamp
wedged_interval=0		# minutes
wedged_log_file="tmp/${devID}_last_wedged_email"
wedged_current_time=`date +%s`	# seconds: unix timestamp
# If it's not a number (no GNU date), fallback to internal function
wedged_current_time=`expr "$wedged_current_time" + 0 2>/dev/null || unixtime`


#
# Read last time 'wedged modem' email was sent
#
if [ -r $wedged_log_file ]; then
    # read stored timestamp
    read wedged_last_time < $wedged_log_file 2>/dev/null
    # Set it to 0 if it's not a number
    wedged_last_time=`expr "$wedged_last_time" + 0 2>/dev/null || echo 0`
    # shouldn't happen, just in case...
    if [ $wedged_last_time -gt $wedged_current_time ]; then
	wedged_last_time=0
    fi
fi

#
# Minutes since last 'wedged modem' email was sent
#
wedged_interval=`expr \( $wedged_current_time - $wedged_last_time \) / 60`

#
# Send 'wedged modem' email if either is true:
# 1. there's no log file (email was never sent before or someone deleted it)
# 2. email was sent longer than WEDGED_EMAIL_INTERVAL minutes ago
# Cases like 'modem was wedged 1 year ago, and is now again wedged for the
# first time', fall into #1 if someone deleted the log file, into #2 if
# log file was left in place.
#
if [ ! -r $wedged_log_file \
	-o $wedged_interval -gt $WEDGED_EMAIL_INTERVAL ]; then

    #
    # Write current timestamp into logfile under tmp/
    #
    if [ $wedged_current_time -gt 0 ]; then
	$RM -f $wedged_log_file # symlink? :-)
	$CAT<<EOF > $wedged_log_file
$wedged_current_time

This is a temp file written and read by bin/wedged to rate-limit
the emails it sends about the wedged status of device $device.

The first line contains a timestamp for when the last email was sent.

This file is never deleted automatically, there's no need to do it
and it may be useful to know when/if a device had last a problem.
However, you can safely delete it at any time if you wish, it will
be recreated when needed.

last modified: `date`

EOF
    fi

    #
    # Send 'modem is wedged' email
    #
    ($CAT<<EOF
To: $TOADDR
From: The HylaFAX Receive Agent <$FROMADDR>
Subject: modem on $device appears wedged

The HylaFAX software thinks that there is a problem with the modem
on device $device that needs attention; repeated attempts to
initialize the modem have failed.

Consult the server trace logs for more information on what is happening.

You will be notified again after $WEDGED_EMAIL_INTERVAL minutes if the problem persists.

EOF
    if [ -x etc/resetmodem ]; then
	echo "An attempt to reset the modem has been made."
	etc/resetmodem $device
    fi

    #
    # Disable faxgetty
    # NB: this is for an System V-style system.
    #
    if [ -f /etc/inittab ] && [ -n "$WEDGED_DISABLE_FAXGETTY" ]; then
	ed - /etc/inittab<<EOF
/^[^#].*:respawn:.*faxgetty .*$tty/s/respawn/off/
w
q
EOF
	#
	# ed doesn't appear to have consistent exit
	# status under SysV-style systems (does under BSD);
	# this means checking if the above succeeded is
	# problematic.
	#
	if [ $? -ne 0 ] && /bin/kill -1 1; then
	    cat<<EOF

The $tty entry in /etc/inittab that spawns faxgetty on $device has
been disabled.  After you have figured out what is wrong you may
want to restart this process.
EOF
	fi
    fi

    ) 2>$ERRORSTO | $SENDMAIL -f$FROMADDR -oi $TOADDR
fi

exit 0