#!/bin/sh
#------------------------------------------------------------------------------
# /var/install/bin/update-systemfiles - update system files
#
# Copyright (c) 2002 Frank Meyer <frank(at)eisfair(dot)org>
#
# Creation:     31.07.2004  jed
# Last Update:  $Id$
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#------------------------------------------------------------------------------

# exec 2>./updates-trace-$$.log
# set -x

pgmname=`basename $0`

# include eislib
. /var/install/include/eislib


#------------------------------------------------------------------------------
# check if numeric value
# input : $1 - value
# return:  0 - numeric
#          1 - no numeric
#------------------------------------------------------------------------------
function is_numeric ()
{
    numeric=0

    tmpstr=`echo "$1"|sed 's/[!0-9]*//g'`

    if [ "$tmpstr" != "" ]
    then
        # false
        numeric=1
    fi

    return $numeric
}

#------------------------------------------------------------------------------
# check if text value
# input : $1 - value
# return:  0 - text
#          1 - no text
#------------------------------------------------------------------------------
function is_text ()
{
    text=0

    tmpstr=`echo "$1"|sed 's/[!0-9_a-z.A-Z-]*//g'`

    if [ "$tmpstr" != "" ]
    then
        # false
        text=1
    fi

    return $text
}

#------------------------------------------------------------------------------
# check if inittab-id value
# input : $1 - value
# return:  0 - id
#          1 - no id
#------------------------------------------------------------------------------
function is_inittab_id ()
{
    # The id is a unique sequence of 1-4 characters which identifies an entry
    # in inittab.

    id=0

    len=`expr length "$1"`

    if [ $len -le 4 ]
    then
        tmpstr=`echo "$1"|sed 's/[!0-9a-zA-Z]*//g'`

        if [ "$tmpstr" != "" ]
        then
            # false
            id=1
        fi
    else
        # length > 4 => false
        id=1
    fi

    return $id
}

#------------------------------------------------------------------------------
# check if runlevel value
# input : $1 - runlevel
#         $2 - action
# return:  0 - runlevel
#          1 - no runlevel
#------------------------------------------------------------------------------
function is_inittab_runlevel ()
{
    # The runlevels field may contain multiple characters for different
    # runlevels. For example, 123 specifies that the process should be
    # started in runlevels 1, 2, and 3. The runlevels for 'ondemand'
    # entries may contain an A, B, or C. The runlevels field of 'sysinit',
    # 'boot', and 'bootwait' entries are ignored.

    runlevel=0

    case "$2" in
        boot|bootwait|sysinit )
            # runlevels will be ignored
            ;;
        ondemand )
            # allowed runlevels: 0123456ABC
            tmpstr=`echo "$1"|sed 's/[!0-6ABC]*//g'`
            ;;
        * )
            # allowed runlevels: 0123456
            tmpstr=`echo "$1"|sed 's/[!0-6]*//g'`
            ;;
    esac        

    if [ "$tmpstr" != "" ]
    then
        # false
        runlevel=1
    fi

    return $runlevel
}

#------------------------------------------------------------------------------
# check if inittab process exists
# input : $1 - value
# return:  0 - process ok
#          1 - process error
#------------------------------------------------------------------------------
function check_inittab_process ()
{
    process=0

    # remove leading + sign
    procstr=`echo "$1"|sed 's/^\+//g'`

    # check if file exists and is executable
    if [ ! -f $procstr -o ! -x $procstr ]
    then
        # false
        process=1
    fi

    return $process
}

#------------------------------------------------------------------------------
# check services line
# input : $1 - value
# return:  0 - ok
#          1 - error
#------------------------------------------------------------------------------
function check_services_line ()
{
    rtc=0

    # strip comments and replace slash
    line=`echo "$1"|sed 's/\#.*//g'|tr '/' ' '`

    if [ "$line" != "" ]
    then
        echo "$line"|grep "^#" /dev/null

        if [ $? -ne 0 ]
        then
            set $line

            idx=1
            while [ $# -ne 0 -a $rtc -eq 0 ]
            do
                case $idx in
                    1 ) # service name
                        if ! is_text $1
                        then
                            print_debug -error "parameter $idx - NAME not allowed: $1"
                            rtc=$idx
                        fi    
                        ;;
                    2 ) # service port
                        if ! is_numeric $1
                        then
                            print_debug -error "parameter $idx - PORT not allowed: $1"
                            rtc=$idx
                        fi    
                        ;;
                    3 ) # service protocol    
                        if [ "$1" != "tcp" -a "$1" != "udp" -a "$1" != "ddp" ]
                        then
                            print_debug -error "parameter $idx - PROTOCOL not allowed: $1"
                            rtc=$idx
                        fi
                        ;;
                    * ) # service alias
                        if ! is_text $1
                        then
                            print_debug -error "parameter $idx - ALIAS not allowed: $1"
                            rtc=$idx
                        fi    
                        ;;
                esac    

                # next parameter
                shift

                idx=`expr $idx + 1`
            done
        fi
    fi

    return $rtc
}

#------------------------------------------------------------------------------
# check inittab line
# input : $1 - value
# return:  0 - ok
#          1 - error
#------------------------------------------------------------------------------
function check_inittab_line ()
{
    # id:runlevels:action:process
    rtc=0

    # strip comments and replace slash
    line=`echo "$1"|sed 's/\#.*//g'|tr ':' ' '`

    if [ "$line" != "" ]
    then
        echo "$line"|grep "^#" /dev/null

        if [ $? -ne 0 ]
        then
            set $line

            idx=1
            while [ $# -ne 0 -a $rtc -eq 0 ]
            do
                case $idx in
                    1 ) # inittab id
                        if ! is_inittab_id $1
                        then
                            print_debug -error "parameter $idx - ID not allowed: $1"
                            rtc=$idx
                        fi
                        ;;
                    2 ) # inittab runlevel
                        if ! is_inittab_runlevel $1 $2
                        then
                            print_debug -error "parameter $idx - RUNLEVEL not allowed: $1:$2"
                            rtc=$idx
                        fi
                        ;;

                    3 ) # inittab action
                        case "$1" in
                            respawn|wait|once|boot|bootwait|off|ondemand|initdefault|sysinit|powerwait|powerfail|powerokwait|ctrlaltdel|kbrequest ) # ok
                                ;;
                            * ) # error
                                print_debug -error "parameter $idx - ACTION not allowed: $1"
                                rtc=$idx
                                ;;
                        esac
                        ;;
                    4 ) # inittab process
                        if ! check_inittab_process $1
                        then
                            print_debug -error "parameter $idx - FILE not found or not executable: $1"
                            rtc=$idx
                        fi
                        ;;
                    * ) # ignore rest
                        ;;
                esac

                # next parameter
                shift

                idx=`expr $idx + 1`
            done
        fi
    fi

    return $rtc
}

#------------------------------------------------------------------------------
# check services file
# input :  $1 - file name
# output:   0 - ok
#         <>0 - error (line number)
#------------------------------------------------------------------------------
function check_services_file ()
{
    rtc=0
    f_name="$1"

    idx=1
    while read LINE
    do
        if ! check_services_line "$LINE"
        then
            rtc=$idx
            break
        fi

        idx=`expr $idx + 1`
    done < $f_name

    return $rtc
}

#------------------------------------------------------------------------------
# check inittab file
# input :  $1 - file name
# output:   0 - ok
#         <>0 - error (line number)
#------------------------------------------------------------------------------
function check_inittab_file ()
{
    rtc=0
    f_name="$1"

    idx=1
    while read LINE
    do
        if ! check_inittab_line "$LINE"
        then
            rtc=$idx
            break
        fi

        idx=`expr $idx + 1`
    done < $f_name

    return $rtc
}

#------------------------------------------------------------------------------
# print file header
# $1 - file name
# $2 - program name
#------------------------------------------------------------------------------
print_file_header ()
{
    f_name="$1"
    i_str="$2"

    echo '#----------------------------------------------------------------------'
    echo "# ${f_name} file generated by '${i_str}'"
    echo '#'
    echo "# Creation date:  `date '+%d.%m.%Y'`  `whoami`"
    echo '#'
    echo "# Do not edit this file directly, create a '${f_name}.package-name'"
    echo "# file and re-run the '${pgmname}' command to update."
    echo '#----------------------------------------------------------------------'
}

#------------------------------------------------------------------------------
# print help
#------------------------------------------------------------------------------
print_help ()
{
    # show help
    mecho -info "Usage:"
    mecho -info "  $pgmname [-debug] program-name"
    mecho
    mecho -info "It can be called under one the following names:"
    mecho -info "  update-hosts.allow program-name  -> update /etc/hosts.allow file."
    mecho -info "  update-hosts.deny  program-name  -> update /etc/hosts.deny file."
    mecho -info "  update-services    program-name  -> update /etc/services file."
    mecho -info "  update-inittab     program-name  -> update /etc/inittab file."
}

#------------------------------------------------------------------------------
# print debug
# input: $1 - output string
#------------------------------------------------------------------------------
print_debug ()
{
    if [ "$debug" = "-debug" ]
    then
        mecho $@
    fi
}

#------------------------------------------------------------------------------
# update hosts.allow or hosts.deny file
# $1 - file name
# $2 - program name
#------------------------------------------------------------------------------
update_hosts_allow_deny_file ()
{
    fname="$1"
    istr="$2"

    ls ${fname} ${fname}.* >/dev/null 2>/dev/null

    if [ $? -eq 0 ]
    then
        # backup file
        /var/install/bin/backup-file -quiet $fname backup

        # create new file
        {
            # print header
            print_file_header "$fname" "$istr"

            for FN in `ls ${fname}.*|grep -v ".backup"`
            do
                cat $FN
            done    
        } > ${fname}
    fi    
}

#------------------------------------------------------------------------------
# update services file
# $1 - file name
# $2 - program name
#------------------------------------------------------------------------------
update_services_file ()
{
    fname="$1"
    istr="$2"

    src_work=$fname-work-src
    dest_work=$fname-work-dest

    # check if files exist
    ls ${fname}.*|egrep -v ".backup" >/dev/null 2>/dev/null

    if [ $? -eq 0 ]
    then
        # backup file
        /var/install/bin/backup-file -quiet $fname backup

        # create working copy
        cp $fname.std $src_work

        # process all files
        filelist=`ls ${fname}.*|egrep -v -E ".backup|.std"`

        for FN in $filelist
        do
            if check_services_file $FN
            then
                # read files line by line
                while read line
                do
                    # ignore comments
                    echo $line|grep "^#" > /dev/null

                    if [ $? -ne 0 ]
                    then
                        # get service name
                        sname=`echo $line|cut -d" " -f1|sed 's/ //g'`

                        if [ "$sname" != "" ]
                        then
                            # remove old entry if exist
                            grep -v "^$sname" $src_work > $dest_work

                            # take result as base for next compare
                            mv $dest_work $src_work
                        fi
                    fi
                done < $FN
            else
                # error in file - skip it
                filelist=`echo $filelist|sed "s#$FN##g"`
                mecho -warn "warning: skipping file $FN because of syntax errors."
            fi    
        done

        # create new file
        {
            # print header
            print_file_header "$fname" "$istr"

            # use standard file
            cat $src_work

            for FN in $filelist
            do
                cat $FN
            done
        } > ${fname}

        # remove working copy
        rm -f $src_work
    fi
}

#------------------------------------------------------------------------------
# update inittab file
# $1 - file name
# $2 - program name
#------------------------------------------------------------------------------
update_inittab_file ()
{
    fname="$1"
    istr="$2"

    src_work=$fname-work-src
    dest_work=$fname-work-dest

    # check if files exist
    ls ${fname}.*|egrep -v ".backup" >/dev/null 2>/dev/null

    if [ $? -eq 0 ]
    then
        # backup file
        /var/install/bin/backup-file -quiet $fname backup

        # create working copy
        cp $fname.std $src_work

        # process all files
        filelist=`ls ${fname}.*|egrep -v -E ".backup|.std"`

        for FN in $filelist
        do
            if check_inittab_file $FN
            then
                # read files line by line
                while read line
                do
                    # ignore comments
                    echo $line|grep "^#" > /dev/null

                    if [ $? -ne 0 ]
                    then
                        # get service name
                        sname=`echo $line|cut -d":" -f1|sed 's/ //g'`

                        if [ "$sname" != "" ]
                        then
                            # remove old entry if exist
                            grep -v "^$sname" $src_work > $dest_work

                            # take result as base for next compare
                            mv $dest_work $src_work
                        fi
                    fi
                done < $FN
            else
                # error in file - skip it
                filelist=`echo $filelist|sed "s#$FN##g"`
                mecho -warn "warning: skipping file $FN because of syntax errors."
            fi
        done

        # create new file
        {
            # print header
            print_file_header "$fname" "$istr"

            # use standard file
            cat $src_work

            for FN in $filelist
            do
                cat $FN
            done
        } > ${fname}

        # remove working copy
        rm -f $src_work
    fi
}
#==============================================================================
# main
#==============================================================================

if [ $# -eq 0 ]
then
    # show help
    print_help
else
    # update files
    while [ 1 ]
    do
        case "$1" in
            -debug)
                debug='-debug'
                shift
                ;;
            *)
                infostr="$1"
                break
                ;;
        esac
    done

    case $pgmname
    in
        update-hosts.allow|hosts.allow)
            update_hosts_allow_deny_file /etc/hosts.allow "$infostr"
            ;;
        update-hosts.deny|hosts.deny)
            update_hosts_allow_deny_file /etc/hosts.deny "$infostr"
            ;;
        update-services|services)
            update_services_file /etc/services "$infostr"
            ;;
        update-inittab|inittab)
            update_inittab_file /etc/inittab "$infostr"

            if [ "$debug" != "-debug" ]
            then
                /sbin/init q >/dev/null 2>/dev/null
            else
                mecho -warn "warning: debug mode enabled, inittab configuration will not be reloaded."
            fi    
            ;;
        *)
            mecho -info 'program name not allowed, use one of the following names:'
            print_help
    esac
fi

#==============================================================================
# end
#==============================================================================