#!/bin/sh
# (c) Eduard Bloch <blade@debian.org>, Gregory Colpart <reg@evolix.fr>
# LICENSE: GPL
# Purpose: initial PPPoE configuration on Debian
# Depends: ppp, whiptail, gettext, sed

export TEXTDOMAINDIR="/usr/share/locale"
export TEXTDOMAIN=pppoeconf
export OPTSFILE="/etc/ppp/peers/dsl-provider"
export REALINTFILE="/etc/network/interfaces"

# IMPORTANT: Do not use gdialog unless it has been fixed!
DIALOG=whiptail

# Get -nox option to force ncurses use
if [ "$1" = "-nox" ]; then
    export NOX=true
    shift  
fi

# Set up (X)dialog - added by Fabian Franz <knx-ppp@fabian-franz.de>
XDIALOG_HIGH_DIALOG_COMPAT=1
export XDIALOG_HIGH_DIALOG_COMPAT
if [ -n "$DISPLAY" ] && [ -x /usr/bin/Xdialog ] && [ ! -n "$NOX" ]; then
  DIALOG="Xdialog"
  X11="-X"
fi

# SUID wrapper for KNOPPIX added by Klaus Knopper <knoppix@knopper.net>
# mod. by EB
PATH="/bin:/sbin:/usr/bin:/usr/sbin"
export PATH

. /usr/bin/gettext.sh

# for non-root, try to reexec with sudo, warn otherwise
if [ "`id -u`" != "0" ]; then
   # sudo only 
  if which sudo >/dev/null && ( sudo -l -S </dev/null >/dev/null 2>&1 ) ; then
    exec sudo "$0" "$@"  || exit 1
  elif which su-to-root >/dev/null; then
    exec su-to-root $X11 -c "$0" "$@"  || exit 1
  elif [ -n "$X11" ] && which gksu >/dev/null; then
    exec gksu "$0" "$@" || exit 1
  else
    gettext "Please become root before running pppoeconf!"
    echo
    gettext "Press return to continue..."
    echo
    read enter
    exit 1
  fi
fi

# EOF SUID wrapper

modprobe -q pppoe
# recent ppp packages have a PPPoE discovery helper program
if test -x /usr/sbin/pppoe-discovery && test -e /proc/net/pppoe ; then
  kernel_pppoe=1
  DISCOVERY_PROGRAM=pppoe-discovery
else
  if test -x /usr/sbin/pppoe ; then  
    DISCOVERY_PROGRAM=pppoe
  else
    gettext "Please install ppp package and enable pppoe support in the kernel, or install pppoe package!"
    echo
    gettext "Press return to continue..."
    echo
    read enter
    exit 1
  fi
fi
export DISCOVERY_PROGRAM

# create a default peers file if there is none
if ! test -r $OPTSFILE ; then
   fresh_optsfile=1
   cat <<EOM > $OPTSFILE
# Minimalistic default options file for DSL/PPPoE connections

noipdefault
defaultroute
replacedefaultroute
hide-password
#lcp-echo-interval 30
#lcp-echo-failure 4
noauth
persist
#mtu 1492
#persist
#maxfail 0
#holdoff 20
EOM
fi
chmod 0640 $OPTSFILE
chown root:dip $OPTSFILE

# get all Ethernet interfaces
if test "$*" ; then 
   list="$*"
   force_manual=1
else
   list=$( LANG=C /sbin/ifconfig -a | grep "Ethernet" | grep -v irlan | cut -f1 -d" " )
fi

if test "$list" ; then
   test "$DIALOG" = "whiptail" && escmsg=$(gettext 'Or press ESC to abort here.')
  number=`echo $list | wc -w| tr -d " "`

   INTFILE="`mktemp -t interfaces.pppoeconf.XXXXXX`" || exit 1
   export INTFILE
   cp $REALINTFILE $INTFILE

   # set up interfaces file if not present
   if ! grep -q "^[[:space:]]*iface[[:space:]]\+dsl-provider" $INTFILE ; then
      printf '\niface dsl-provider inet ppp\nprovider dsl-provider\n' >> $INTFILE
   fi

   umask 177
   # make a secure directory
   #TMP="`mktemp -d -p /etc/ppp`"
   TMP="`mktemp -d`"
   chmod 700 $TMP
   export TMP

   gettext '
Most providers send the needed login information per mail. Some providers describe it in odd ways, assuming the user to input the data in their "user-friendly" setup programs. But in fact, these applications generate usuall PPP user names and passwords from the entered data. You can find the real names too and input the correct data in the dialog box.

For example, this are methods used some german providers:

Sample username (alias "login" or "login name"): 11111111111

T-Online T-DSL:
  additional data:
    sample T-Onlinenummer: 222222222222
    sample Mitbenutzer: 0001

  complete username: 111111111111222222222222#0001@t-online.de

Telekom Business Online (DSL):

  complete username: t-online-com/111111111111@t-online-com.de

1und1 uses another scheme (using above example):

  complete username: 1und1/11111111111

Cyberfun:

  complete username: sdt/11111111111

Komtel:
  additional data:
    downstream speed class: 768

  complete username: 11111111111@FoniNet-768

Net Cologne:

  complete username: 11111111111@netcologne.de

Q-DSL:

  complete username: 11111111111@q-dsl.de

Versatel:

  complete username: 11111111111@VersaNet-1024k

Webnetix:

  complete username: sdt/11111111111
' > $TMP/namehelp.txt

   sectempfile="`mktemp -p $TMP`"
   export sectempfile
   trap "rm -rf '$TMP'" 0 HUP INT TRAP TERM

   # now, execute an AC lookup on each interface
   for mmm in '' ' -U ' ; do
      for iface in $list; do
         # use the first candidate only, this is done anyways, below
         if test -z "`grep -l AC $TMP/*.pppoe 2>/dev/null| cut -f1 -d"." | head -n1`" ; then
            title=$(gettext 'SCANNING DEVICE')
            text=$(eval_gettext 'Looking for PPPoE Access Concentrator on $iface...')
            if test -n "$mmm" ; then
               mmode=$(gettext '(multi-modem mode)')
            fi

            touch $TMP/pppoe.scan
            ifconfig $iface up
            ($DISCOVERY_PROGRAM $mmm -A -I $iface > $TMP/$iface.pppoe ; rm $TMP/pppoe.scan) &

            ( time=0 ; while test -f $TMP/pppoe.scan ; do time=`expr $time + 6`; echo $time; sleep 1; done ) | $DIALOG --title "$title" --gauge "$text $mmode" 10 60 0

true
         fi
      done
   done
   cd "$TMP"
   if test "$force_manual" ; then
      iface=$1
   else
      iface=`grep -l AC *.pppoe| sed "s/\.pppoe$//" | head -n1`
   fi
   ifacenocomma=$(echo $iface | sed -e 's/,/\\,/g')

   if test -z "$iface" ; then
      title=$(gettext 'NOT CONNECTED')
      text=$(eval_ngettext \
      'Sorry, I scanned $number interface, but the Access Concentrator of your provider did not respond. Please check your network and modem cables. Another reason for the scan failure may also be another running pppoe process which controls the modem.' \
      'Sorry, I scanned $number interfaces, but the Access Concentrator of your provider did not respond. Please check your network and modem cables. Another reason for the scan failure may also be another running pppoe process which controls the modem.' \
      $number)

      $DIALOG --title "$title" --clear --msgbox "$text" 15 60
      rm -rf "$TMP"
      exit 1
   fi
#   title=$(gettext 'DSL CONNECTION FOUND')
#   text=$(eval_gettext 'I found an Access Concentrator on $iface. Should I setup PPPOE for this connection?')
#   $DIALOG --title "$title" --clear --yesno "$text" 15 60
#  # STATUS: interface is $iface, we can continue
  
  if ! test "$fresh_optsfile" ; then 
     title=$(gettext 'OKAY TO MODIFY')
     text=$(eval_gettext 'If you continue with this program, the configuration file $OPTSFILE will be modified. Please make sure that you have a backup copy before saying Yes.

Continue with configuration?')
     $DIALOG --title "$title" --clear --yesno "$text" 22 70
     case $? in
       1)
         rm -rf "$TMP"
         exit 0
         ;;
       255)
         rm -rf "$TMP"
         exit 1
     esac
  fi

  if ! grep -q "^[[:space:]]*\(allow-\)\?\(auto\|hotplug\)[[:space:]]\+$iface" $INTFILE ; then
      echo >> $INTFILE
      echo "auto $iface" >> $INTFILE
  fi

  if ! grep -q "^[[:space:]]*iface[[:space:]]\+$iface" $INTFILE ; then
      echo "iface $iface inet manual" >> $INTFILE
  fi

#   if test "$?" = "0"; then
      if [ "$kernel_pppoe" ]; then
         # interface activation code - this sucks here, pppd plugin should do it as needed
         #sed -i -e "s,pre-up /sbin/ifconfig[[:space:]]\+[^[:space:]]\+[[:space:]]\+up.#.line.maintained.by.pppoeconf,pre-up /sbin/ifconfig $ifacenocomma up # line maintained by pppoeconf," $INTFILE
    # FIXME: Make sure that it gets added to correct iface stanza! (Because it's not always added above)
    PATTERN_PREUP_IFACE="pre-up /sbin/ifconfig[[:space:]]\+[^[:space:]]\+[[:space:]]\+up.#.line.maintained.by.pppoeconf"
    REPLACE_PREUP_IFACE="pre-up /sbin/ifconfig $ifacenocomma up # line maintained by pppoeconf"
    if grep -q "$PATTERN_PREUP_IFACE" $INTFILE; then 
        sed -i -e "s,$PATTERN_PREUP_IFACE,$REPLACE_PREUP_IFACE," $INTFILE
    else
        sed -i -e "s,[^#]*\(iface dsl-provider.*\),\1\n$REPLACE_PREUP_IFACE," $INTFILE
    fi

         # change peers config file, sanity check first
#       grep -q "^plugin.*rp-pppoe.so" $OPTSFILE || echo "plugin rp-pppoe.so $iface" >> $OPTSFILE
       if [ "${iface##eth*}" = "" ]; then
           # Name is eth*
           grep -q "^[[:space:]]*plugin.*rp-pppoe.so" $OPTSFILE || echo "plugin rp-pppoe.so $iface" >> $OPTSFILE
       else
           grep -q "^[[:space:]]*plugin.*rp-pppoe.so" $OPTSFILE || echo "plugin rp-pppoe.so" >> $OPTSFILE
           grep -q "^[[:space:]]*nic-$iface" $OPTSFILE || echo "nic-$iface" >> $OPTSFILE
       fi

       # disable the pppoe tunnel command
       if grep -q '^[[:space:]]*pty' $OPTSFILE ; then
          sed -i -e 's/^[[:space:]]*pty/#pty/' $OPTSFILE
       fi

       # set the interface
       sed -i -e "s,^plugin.\+rp-pppoe.so[[:space:]]\+[^[:space:]]*,plugin rp-pppoe.so $ifacenocomma," $OPTSFILE
       sed -i -e "s,^nic-[[:alnum:]]*,nic-$ifacenocomma," $OPTSFILE
    else
       # sanity check first, fix the config file

       # disable all lines
       sed -i -e 's/^pty/#&/' $OPTSFILE
       # install alternative lines
       grep -q '^[[:space:]]*#[[:space:]]*pty.*pppoe.*-m.*1452' $OPTSFILE || echo '#pty "pppoe -I eth0 -T 80 -m 1452"' >> $OPTSFILE
       grep -q '^[[:space:]]*#[[:space:]]*pty.*pppoe.*-m.*1412' $OPTSFILE || echo '#pty "pppoe -I eth0 -T 80 -m 1412"' >> $OPTSFILE
       # activate or install default line before the question
       sed -i -e '/^[[:space:]]*#[[:space:]]*pty "pppoe -I.*-T 80"/d' $OPTSFILE
       grep -q '^[[:space:]]*pty' $OPTSFILE || echo 'pty "pppoe -I eth0 -T 80"' >> $OPTSFILE

       # set the interface
       sed -i -e "s,-I[[:space:]]*[[:alnum:]]*,-I $ifacenocomma," $OPTSFILE
    fi
    # fix final newline
    test -e /etc/ppp/pap-secrets && ( [ $(tail -1 /etc/ppp/pap-secrets | wc -l) -eq 0 ] || echo >> /etc/ppp/pap-secrets )
    test -e /etc/ppp/chap-secrets && ( [ $(tail -1 /etc/ppp/chap-secrets | wc -l) -eq 0 ] || echo >> /etc/ppp/chap-secrets )
#  else
#    rm -rf "$TMP"
#    exit 1
#  fi

  # ask about sane options
  #$DIALOG --title $"POPULAR OPTIONS" --clear --yesno $"Most people using popular dialup providers prefer the options 'noauth' and 'defaultroute' in their configuration and remove the 'nodetach' option. Further, for busy providers the lcp-echo-interval could be increased. Should I check your configuration file and change these settings where neccessary?" 22 70
  title=$(gettext 'POPULAR OPTIONS')
  text=$(gettext "Most people using popular dialup providers prefer the options 'noauth' and 'defaultroute' in their configuration and remove the 'nodetach' option. Should I check your configuration file and change these settings where neccessary?")
  $DIALOG --title "$title" --clear --yesno "$text" 22 70
  case $? in
    0)
      grep -q '^[[:space:]]*noauth' $OPTSFILE || echo 'noauth' >> $OPTSFILE
      grep -q '^[[:space:]]*defaultroute' $OPTSFILE  || echo 'defaultroute' >> $OPTSFILE
      sed -i -e "/^[[:space:]]*nodetach.*/d" $OPTSFILE
      #sed -i -e "s/^lcp-echo-interval 20$/lcp-echo-interval 60/" $OPTSFILE
      ;;
    255)
      rm -rf "$TMP"
      exit 1
      ;;
  esac
  
  user=`grep ^user $OPTSFILE|cut -f2 -d" " | tr -d '"'`
  test -z "$user" && user="username"
  while test "$goahead" != "yes" ; do
    title=$(gettext 'ENTER USERNAME')
    text=$(gettext 'Please enter the username which you usually need for the PPP login to your provider in the input box below. If you wish to see the help screen, delete the username and press OK.')
    $DIALOG --nocancel --title "$title" --clear --inputbox "$text" 15 60 $user 2> "$sectempfile"
    user=`cat "$sectempfile"`
    case $? in
      0)
        if test -z "$user" ; then
          $DIALOG --scrolltext --textbox "$TMP/namehelp.txt" 17 75
        else
          sed -i -e '/^user .*/d' $OPTSFILE
          echo  "user \"$user\"" >> $OPTSFILE
          goahead="yes"
          export goahead
        fi
        ;;
      *)
        rm -rf "$TMP"
        exit 1
        ;;
    esac
  done

  title=$(gettext 'ENTER PASSWORD')
  text=$(gettext 'Please enter the password which you usually need for the PPP login to your provider in the input box below.

NOTE: you can see the password in plain text while typing.')
  $DIALOG --nocancel --title "$title" --clear --inputbox "$text" 15 60 2> "$sectempfile"
  pass=`cat "$sectempfile"`
  usernoslash=$(echo $user | sed -e 's,/,\\/,')
  case $? in
    0)
      sed -i -e "/^\"*$usernoslash\"* .*/ d" /etc/ppp/pap-secrets
      echo "\"$user\" * \"$pass\"" >> /etc/ppp/pap-secrets
      sed -i -e "/^\"*$usernoslash\"* .*/ d" /etc/ppp/chap-secrets
      echo "\"$user\" * \"$pass\"" >> /etc/ppp/chap-secrets
      ;;
    *)
      rm -rf "$TMP"
      exit 1
      ;;
  esac

  # ask about DNS
  title=$(gettext 'USE PEER DNS')
  text=$(gettext 'You need at least one DNS IP address to resolve the normal host names. Normally your provider sends you addresses of useable servers when the connection is established. Would you like to add these addresses automatically to the list of nameservers in your local /etc/resolv.conf file? (recommended)')
  $DIALOG --title "$title" --clear --yesno "$text" 15 60
  case $? in
    0)
      grep -q "^[[:space:]]*usepeerdns" $OPTSFILE || echo "usepeerdns" >> $OPTSFILE
      ;;
    1)
      sed -i -e "/^[[:space:]]*usepeerdns/d" $OPTSFILE
      ;;
    255)
      rm -rf "$TMP"
      exit 1
      ;;
  esac
  
  # ask about MSS limitation
  title=$(gettext 'LIMITED MSS PROBLEM')
  text=$(gettext "Many providers have routers that do not support TCP packets with a MSS higher than 1460. Usually, outgoing packets have this MSS when they go through one real Ethernet link with the default MTU size (1500). Unfortunately, if you are forwarding packets from other hosts (i.e. doing masquerading) the MSS may be increased depending on the packet size and the route to the client hosts, so your client machines won't be able to connect to some sites. There is a solution: the maximum MSS can be limited by pppoe. You can find more details about this issue in the pppoe documentation.

Should pppoe clamp MSS at 1452 bytes?

If unsure, say yes.

(If you still get problems described above, try setting to 1412 in the dsl-provider file.)")
  $DIALOG --title "$title" --clear --yesno "$text" 22 70
  case $? in
    0)
      if [ "$kernel_pppoe" ]; then
        printf '#!/bin/sh\n# Enable MSS clamping (autogenerated by pppoeconf)\n\niptables -t mangle -o "$PPP_IFACE" --insert FORWARD 1 -p tcp --tcp-flags SYN,RST SYN -m tcpmss --mss 1400:65495 -j TCPMSS --clamp-mss-to-pmtu\n' > /etc/ppp/ip-up.d/0clampmss
        printf '#!/bin/sh\n# Disable MSS clamping (autogenerated by pppoeconf)\n\niptables -t mangle -L -n -v --line-numbers | grep "TCPMSS.*$PPP_IFACE.*clamp" | cut -f1 -d " " | sort -r | xargs -n1 -r iptables -t mangle -D FORWARD\n' > /etc/ppp/ip-down.d/0clampmss
        chmod 755 /etc/ppp/ip-up.d/0clampmss /etc/ppp/ip-down.d/0clampmss
      else
        # disable default line
        sed -i -e 's/^pty/#&/' $OPTSFILE
        # enable the one with our mss size
        sed -i -e 's/^#\(pty.*-m 1452.*\)/\1/' $OPTSFILE
        #rm -f "$sectempfile"
      fi
      ;;
    255)
      rm -rf "$TMP"
      exit 1
      ;;
  esac

  if test -z "`mount | grep KNOPPIX`" ; then
     title=$(gettext 'DONE')
     text=$(gettext 'Your PPPD is configured now. Would you like to start the connection at boot time?')
     $DIALOG --title "$title" --clear --yesno "$text" 15 60
     if test "$?" = "0"; then
        grep -q "^[[:space:]]*auto.*dsl-provider" $INTFILE || sed -i -e 's/^[[:space:]]*iface.*dsl-provider/auto dsl-provider\n&/' $INTFILE
     else
        sed -i -e '/^[[:space:]]*auto.*dsl-provider/d' $INTFILE
     fi
  fi

  cd /
  
  # end of story
  rm -rf "$TMP"
  chmod --reference=$REALINTFILE $INTFILE
  # check that final file is valid or original one was already invalid. otherwise ask what to do
  ifup -nai $INTFILE 2>/dev/null
  if test "$?" = "1" &&  (ifup -na 2>/dev/null; test "$?" = "0"); then
    title=$(gettext 'ERROR')
    text=$(eval_gettext 'The interfaces file generated by pppoeconf appears to be invalid. This is probably because pppoeconf is unable to handle your original interfaces file. Should pppoeconf nevertheless change your interfaces file with the one that appears to be invalid?
If you agree, you will probably break your network connectivity after rebooting, and cause some local problems if lo is down. Your original interfaces file will be moved to $REALINTFILE~ so you can restore it.
If not, you will have to make sure that $iface is configured before starting your DSL connection and start the connection manually.

Note that this situation is not expected and you should consider submitting a bug report against pppoeconf including your original interfaces file and the one generated by pppoeconf.')
    $DIALOG --title "$title" --clear --defaultno --yesno "$text" 20 75
    case $? in
      0)
        mv -b $INTFILE $REALINTFILE || exit 1
        ;;
      1)
        exit 0
        ;;
      255)
        exit 1
        ;;
    esac
  else
    mv $INTFILE $REALINTFILE || exit 1
  fi

  title=$(gettext 'ESTABLISH A CONNECTION')
  text=$(gettext 'Now, you can make a DSL connection with "pon dsl-provider" and terminate it with "poff". Would you like to start the connection now?')
  $DIALOG --title "$title" --clear --yesno "$text" 15 60
  case $? in
    0)
      cd /
      pon dsl-provider
      title=$(gettext 'CONNECTION INITIATED')
      text=$(gettext 'The DSL connection has been triggered. You can use the "plog" command to see the status or "ifconfig ppp0" for general interface info.')
      $DIALOG --title "$title" --clear --msgbox "$text" 10 60
      ;;
    1)
      exit 0
      ;;
    255)
      exit 1
      ;;
  esac

else
  title=$(gettext 'NO INTERFACE FOUND')
  text=$(gettext 'Sorry, no working ethernet card could be found.')
  $DIALOG --title "$title" --clear --msgbox "$text" 20 70
  exit 0
fi