#!/bin/sh
# (c) Eduard Bloch <blade@debian.org>
# LICENSE: GPL
# Purpose: initial PPPoE configuration on Debian
# Depends: bash, pppd, pppoe, whiptail, my usepeerdns script

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

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

# 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 ] ; 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
  else
    gettext "Please become root before running pppoeconf!"
    echo
    gettext "Press return to continue..."
    echo
    read
    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
  DISCOVERY_PROGRAM=pppoe
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
usepeerdns
EOM
fi
chmod 0640 $OPTSFILE
chown root:dip $OPTSFILE

if ! grep -q "dsl-provider" $INTFILE ; then
   printf '\niface dsl-provider inet ppp\nprovider dsl-provider\n' >> $INTFILE
fi

# old crap, unreliable, does not work after reboot
# if ! grep -q "line maintained by pppoeconf" $INTFILE ; then
#    sed -i -e 's,provider dsl-provider$,     provider dsl-provider\n# please do not modify the following line\n     pre-up /sbin/ifconfig eth0 up # line maintained by pppoeconf\n,' $INTFILE
# fi
   
umask 177
# make a secure directory
TMP="`mktemp -d -p /etc/ppp`"
export TMP
sectempfile="`mktemp -p $TMP`"
export sectempfile
trap "rm -rf '$TMP'" 0 HUP INT TRAP TERM

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

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 $list | wc -w| tr -d " "`
  text=$(eval_ngettext \
  'I found $number ethernet device:
$list

Are all your ethernet interfaces listed above?
(If No, modconf will be started so you can load the card drivers manually).

$escmsg' \
  'I found $number ethernet devices:
$list

Are all your ethernet interfaces listed above?
(If No, modconf will be started so you can load the card drivers manually).

$escmsg' \
  "$number" )
  title=$(gettext 'ALL DEVICES FOUND?')
  $DIALOG --title "$title" --clear --yesno "$text" 15 60
  case $? in
    1)
    # configure and restart
      modconf
      $0
      exit $?
      ;;
    255)
      rm -rf "$TMP"
      exit 1
      ;;
   esac
   # 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=$1
   else
      iface=`grep -l AC *.pppoe| cut -f1 -d"." | head -n1`
   fi
   ifacenocomma=$(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 "$text" 22 70
     if test "$?" != "0" ; then
        rm -rf "$TMP"
        exit 0
     fi
  fi

  # Adding iface config
  if ! grep -q "^auto[[:space:]]\+$iface" $INTFILE ; then
      echo >> $INTFILE
      echo "# added by pppoeconf" >> $INTFILE
      echo "auto $iface" >> $INTFILE

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

#   if test "$?" = "0"; then
      if [ "$kernel_pppoe" ]; then
         # interface activation code - this sucks here, pppd plugin should do it as needed
         # 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
             echo >> $INTFILE
             echo "    $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 "^plugin.*rp-pppoe.so" $OPTSFILE || echo "plugin rp-pppoe.so $iface" >> $OPTSFILE
       else
           grep -q "^plugin.*rp-pppoe.so" $OPTSFILE || echo "plugin rp-pppoe.so" >> $OPTSFILE
           grep -q "^nic-$iface" $OPTSFILE || echo "nic-$iface" >> $OPTSFILE
       fi

       # disable the pppoe tunnel command
       if grep -q '^pty' $OPTSFILE ; then
          sed -i -e 's/^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

       # install the default line
       grep -q '^.*pty.*pppoe.*-I' $OPTSFILE || echo 'pty "pppoe -I eth0 -T 80"' >> $OPTSFILE
       # install alternative lines
       grep -q '^.*pty.*pppoe.*-m.*1452' $OPTSFILE || echo '#pty "pppoe -I eth0 -T 80 -m 1452"' >> $OPTSFILE
       grep -q '^.*pty.*pppoe.*-m.*1412' $OPTSFILE || echo '#pty "pppoe -I eth0 -T 80 -m 1412"' >> $OPTSFILE
       # at least one must work
       grep -q '^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 "$text" 22 70
  if test "$?" = "0" ; then
    grep -q '^noauth' $OPTSFILE || echo 'noauth' >> $OPTSFILE
    grep -q '^defaultroute' $OPTSFILE  || echo 'defaultroute' >> $OPTSFILE
    sed -i -e "/^nodetach.*/d" $OPTSFILE
#    sed -i -e "s/^lcp-echo-interval 20$/lcp-echo-interval 60/" $OPTSFILE
  fi
  
  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\"" >> $OPTSFILE
      goahead="yes"
      export goahead
    fi
      ;;
    *)
      exit 1
      rm -rf "$TMP"
      ;;
    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 "^usepeerdns" $OPTSFILE || echo "usepeerdns" >> $OPTSFILE
     ;;
  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 -o "$PPP_IFACE" --insert FORWARD 1 -p tcp --tcp-flags SYN,RST SYN -m tcpmss --mss 1400:1536 -j TCPMSS --clamp-mss-to-pmtu\n' > /etc/ppp/ip-up.d/0clampmss
        printf '#!/bin/sh\n# Disable MSS clamping (autogenerated by pppoeconf)\n\niptables -L -n -v --line-numbers | grep "TCPMSS.*$PPP_IFACE.*clamp" | cut -f1 -d " " | xargs -n1 -r iptables -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 the old 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
     ;;
  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 "^auto.*dsl-provider" $INTFILE || sed -i -e 's/^iface.*dsl-provider/auto dsl-provider\n&/' $INTFILE
     else
        sed -i -e '/^auto.*dsl-provider/d' $INTFILE
     fi
  fi

  cd /
  
  # end of story
  rm -rf "$TMP"
  
  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
    ;;
  *)
    exit 0
    ;;
  esac

else
  title=$(gettext 'NO INTERFACE FOUND')
  text=$(gettext 'Sorry, no working ethernet card could be found. If you do have an interface card which was not autodetected so far, you probably wish to load the driver manually using the modconf utility. Run modconf now?')
  $DIALOG --title "$title" --clear --yesno "$text" 20 70
  case $? in
  0)
    rm -rf "$TMP"
    modconf
    exec $0
    exit $?
    ;;
  *)
    rm -rf "$TMP"
    exit 1
    ;;
  esac
fi
