#!/usr/bin/sh
#----------------------------------------------------------------------------
# /var/install/bin/update-systemfiles - update system files
#
# Creation:     2004-07-31 jed
# Last Update:  $Id$
#
# Copyright (c) 2001-@@YEAR@@ the eisfair team, team(at)eisfair(dot)org
#
# 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.
#----------------------------------------------------------------------------

pgmname=$(basename $0)

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

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


#----------------------------------------------------------------------------
# check if numeric value
# input : $1 - value
# return:  0 - numeric
#          1 - no numeric
#----------------------------------------------------------------------------
is_numeric()
{
    echo "$1" | grep -q '^[0-9]*$'
}

#----------------------------------------------------------------------------
# check if text value
# input : $1 - value
# return:  0 - text
#          1 - no text
#----------------------------------------------------------------------------
is_text()
{
    # used for service and service aliases
    # space and tab are not allowed
    # a-z, 0-9, and hyphen (-) would seem a sensible choice.
    echo "$1" | grep -q '^[[:alnum:]_.-]*$'
}

#----------------------------------------------------------------------------
# check service port and protocol
# input : $1 - value port/protocol
# return:  0 - values ok
#          1 - values error
#----------------------------------------------------------------------------
check_port_and_protocol()
{
    values=0

    oldifs="$IFS"
    IFS='/'
    set $1
    IFS="$oldifs"

    # service port
    if ! is_numeric $1
    then
        print_debug --error "parameter $idx - PORT not allowed: $1"
        values=1
    fi

    # service protocol
    if [ "$2" != "tcp" -a "$2" != "udp" -a "$2" != "ddp" -a "$2" != "sctp" ]
    then
        print_debug --error "parameter $idx - PROTOCOL not allowed: $2"
        values=1
    fi

    return $values
}

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

    # strip comments
    line=$(echo "$1"|sed 's/\#.*//g')

    if [ "$line" != "" ]
    then
        echo "$line"|grep -q "^#"

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

            idx=1
            while [ $# -ne 0 -a $check_services_line_rtc -eq 0 ]
            do
                case $idx in
                    1 ) # service name
                        if ! is_text $1
                        then
                            print_debug --error "parameter $idx - NAME not allowed: $1"
                            check_services_line_rtc=$idx
                        fi
                        ;;
                    2 ) # service port and protocol
                        if ! check_port_and_protocol $1
                        then
                            check_services_line_rtc=$idx
                        fi
                        ;;
                    * ) # service alias
                        if ! is_text $1
                        then
                            print_debug --error "parameter $idx - ALIAS not allowed: $1"
                            check_services_line_rtc=$idx
                        fi
                        ;;
                esac

                # next parameter
                shift

                idx=$(($idx + 1))
            done
        fi
    fi

    return $check_services_line_rtc
}

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

    idx=1
    while read LINE
    do
        if ! check_services_line "$LINE"
        then
            check_services_file_rtc=$idx
            # no break, check whole file
            #break
        fi

        idx=$(($idx + 1))
    done < $f_name

    return $check_services_file_rtc
}

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

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

#----------------------------------------------------------------------------
# print help
#----------------------------------------------------------------------------
print_help()
{
    # show help
    mecho "Usage:"
    mecho "  $pgmname cannot be called directly. Please use one of the following names:"
    mecho
    mecho "  update-at.allow    [-debug] package-name  -> update /etc/at.allow file."
    mecho "  update-at.deny     [-debug] package-name  -> update /etc/at.deny file."
    mecho "  update-hosts.allow [-debug] package-name  -> update /etc/hosts.allow file."
    mecho "  update-hosts.deny  [-debug] package-name  -> update /etc/hosts.deny file."
    mecho "  update-services    [-debug] package-name  -> update /etc/services file."
    mecho "  update-nsswitch    [-debug] package-name  -> update /etc/nsswitch.conf file."
}

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

#----------------------------------------------------------------------------
# update at.allow or at.deny file
# $1 - file name
# $2 - package name
#----------------------------------------------------------------------------
update_at_allow_deny_file()
{
    fname="${1}"
    fname_dir=$(dirname ${fname})
    fname_base=$(basename ${fname})
    fname_tmp=$fname.$$
    istr="${2}"

    find ${fname_dir} -maxdepth 1 -type f -name "${fname_base}.*" |
    grep -qvE ".backup|.std|~"

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

        # create fname_tmp with same file access permission like fname
        if [ -f ${fname} ]
        then
            cp -p ${fname} ${fname_tmp}
        else
            # create new file and set initial file permissions
            > ${fname_tmp}
            chmod 0640     ${fname_tmp}
            chown root:at  ${fname_tmp}
        fi

        # create new file (temporary one)
        {
            # print header
            print_file_header "${fname}" "${istr}"

            for FN in $(ls ${fname}.*|grep -vE ".backup|~|.$$")
            do
                cat ${FN}
            done
        } > ${fname_tmp}

        # copy file, preserve access permissions
        cp -p ${fname_tmp} ${fname}
        rm -f ${fname_tmp}
    else
        # create stadard entry
        if [ -f ${fname}.std ]
        then
            # backup file
            /var/install/bin/backup-file --quiet ${fname} backup

            {
                # print header
                print_file_header "${fname}" "${istr}"

                cat ${fname}.std
            } > ${fname}

            chmod 0640    ${fname}
            chown root:at ${fname}
        fi
    fi
}

#----------------------------------------------------------------------------
# update hosts.allow or hosts.deny file
# $1 - file name
# $2 - package name
#----------------------------------------------------------------------------
update_hosts_allow_deny_file()
{
    fname="$1"
    fname_dir=$(dirname ${fname})
    fname_base=$(basename ${fname})
    fname_tmp=$fname.$$
    istr="$2"

    find ${fname_dir} -maxdepth 1 -type f -name "${fname_base}.*" |
    grep -qvE ".backup|.std|~"

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

        # create fname_tmp with same file access permission like fname
        if [ -f $fname ]
        then
            cp -p $fname $fname_tmp
        else
            # create new file and set initial file permissions
            > $fname_tmp
            chmod 644 $fname_tmp
        fi

        # create new file (temporary one)
        {
            # print header
            print_file_header "$fname" "$istr"

            for FN in $(ls ${fname}.*|grep -vE ".backup|~|.$$")
            do
                cat $FN
            done
        } > ${fname_tmp}

        # copy file, preserve access permissions
        cp -p ${fname_tmp} ${fname}
        rm -f ${fname_tmp}
    else
        # remove file
        if [ -f ${fname} ]
        then
            # backup file
            /var/install/bin/backup-file --quiet $fname backup

            rm -f ${fname}
        fi
    fi
}

#----------------------------------------------------------------------------
# update services file
# $1 - file name
# $2 - package name
#----------------------------------------------------------------------------
#
# format of services file:
#
#      service-name   port/protocol   [aliases ...]
#
#   separator spaces or tabs
#   ignore blank line
#   comments start by #
#
#   old style format (port,protocol) is not supported
#
update_services_file()
{
    fname="$1"
    fname_dir=$(dirname ${fname})
    fname_base=$(basename ${fname})
    fname_tmp=$fname.$$
    istr="$2"

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

    # backup file
    /var/install/bin/backup-file --quiet $fname backup

    # create working copy
    cp $fname.std $src_work

    # process all files
    filelist=$(find ${fname_dir} -maxdepth 1 -type f -name "${fname_base}.*" |
               grep -vE ".backup|.std|~")

    for FN in $filelist
    do
        if check_services_file $FN
        then
            # read files line by line
            while read line
            do
                # ignore blank or empty lines
                echo "$line" | grep -q '^[[:space:]]*$' && continue
                # ignore comment only lines
                echo "$line" | grep "^#" > /dev/null

                if [ $? -ne 0 ]
                then
                    # get service name and service protocol
                    sname=$(echo $line|cut -d" " -f1|sed 's/ //g')
                    sprotocol=$(echo $line|cut -d" " -f2|sed 's/ //g'|sed 's|[0-9]*/||')

                    if [ -n "$sname" ]
                    then
                        # remove old entry if exist
                        grep -v "^$sname[[:space:]]*[0-9]*/$sprotocol" $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 fname_tmp with same file access permission like fname
    cp -p $fname $fname_tmp

    # create new file (temporary one)
    {
        # print header
        print_file_header "$fname" "$istr"

        # use standard file
        cat $src_work

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

    # copy file, preserve access permissions
    cp -p ${fname_tmp} ${fname}
    rm -f ${fname_tmp}
    # remove working copy
    rm -f $src_work
}

#----------------------------------------------------------------------------
# update nsswitch.conf
# $1 - file name
# $2 - package name
#----------------------------------------------------------------------------
#
# format of nsswitch.conf:
#
#      hosts:          files wins dns
#
#   separator :
#
update_nsswitch_file()
{
    fname="$1"
    fname_dir=$(dirname ${fname})
    fname_base=$(basename ${fname})
    fname_tmp=$fname.$$
    istr="$2"
    src_work=$fname-work-src.$$

    # backup file
    /var/install/bin/backup-file --quiet $fname backup

    # create working copy without comments
    grep -v "^#" ${fname}.std > ${src_work}

    # process all files
    filelist=$(find ${fname_dir} -maxdepth 1 -type f -name "${fname_base}.*" |
               grep -vE ".backup|.std|~")
    # create fname_tmp with same file access permission like fname
    cp -p $fname $fname_tmp

    # create new file (temporary one)
    {
        # print header
        print_file_header "$fname" "$istr"

        while read a
        do
            id_a=''
            id_b=''
            id_a=$(echo $a | cut -d":" -f1 | sed 's/ //g')

            if [ -n "$filelist" ]
            then
                id_b=$(grep -h "^${id_a}:" ${filelist})
                wcl=$(grep -h "^${id_a}:" ${filelist} | wc -l)
            fi

            if [ -n "$id_a" -a -n "$id_b" ]
            then
                if [ "$wcl" -gt "1" ]
                then
                    mecho --error "More than one entry for $id_a:!" >&2
                    #echo "id_a is $id_a, id_b is $id_b, wcl is $wcl"
                    echo "$a"
                else
                    echo "$id_b"
                fi
            else
                echo "$a"
            fi
        done < $src_work
    } 1> ${fname_tmp}

    # copy file, preserve access permissions
    cp -p ${fname_tmp} ${fname}
    rm -f ${fname_tmp}

    # remove working copy
    rm -f $src_work
}

#============================================================================
# main
#============================================================================

if [ ${#} -eq 0 ]
then
    # show help
    print_help
else
    # update files
    while [ 1 ]
    do
        case "${1}" in
            -debug|--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-nsswitch|nsswitch)
            update_nsswitch_file /etc/nsswitch.conf "${infostr}"
            ;;
        update-at.allow|at.allow)
            update_at_allow_deny_file /etc/at.allow "${infostr}"
            ;;
        update-at.deny|at.deny)
            update_at_allow_deny_file /etc/at.deny "${infostr}"
            ;;
        *)
            mecho --info 'program name not allowed, use one of the following names:'
            print_help
            ;;
    esac
fi


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