#!/bin/bash
# (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"

# 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

# 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
    echo $"Please become root before running pppoeconf!"
    echo $"Press return to continue..."
    read
    exit 1
  fi
fi

# EOF SUID wrapper

# recent ppp packages have a PPPoE discovery helper program
if [ -x /usr/sbin/pppoe-discovery ] && modprobe -q pppoe; then
  kernel_pppoe=1
  DISCOVERY_PROGRAM=pppoe-discovery
else
  DISCOVERY_PROGRAM=pppoe
fi

# 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
hide-password
#lcp-echo-interval 30
#lcp-echo-failure 4
noauth
persist
#mtu 1492
usepeerdns
EOM
fi
chmod 0640 $OPTSFILE
chown root:dip $OPTSFILE

umask 177
# make a secure directory
export TMP="`mktemp -d -p /etc/ppp`"
export sectempfile="`mktemp -p $TMP`"
trap "rm -rf '$TMP'" 0 HUP INT TRAP TERM

echo -e $"
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.\n\nFor 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 "$*" ; then 
   list="$*"
else
   list=$( LANG=C /sbin/ifconfig -a | grep "Ethernet" | grep -v irlan | cut -f1 -d" " )
fi

if test "$list" ; then
   test "$DIALOG" = "whiptail" && escmsg=$"Or press ESC to abort here."
  number=`echo $list | wc -w| tr -d " "`
  $DIALOG --title $"ALL DEVICES FOUND?" --clear --yesno $"I found $number ethernet device(s):\n$list\n\nAre all your ethernet interfaces listed above?\n(If No, modconf will be started so you can load the card drivers manually).\n\n$escmsg" 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 iface in $list; do
    touch $TMP/pppoe.scan
    ifconfig $iface up
    ($DISCOVERY_PROGRAM -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 $"SCANNING DEVICE" --gauge $"Looking for PPPoE Access Concentrator on $iface..." 10 60 0
  done
  cd "$TMP"
  iface=`grep -l AC *.pppoe| cut -f1 -d"." | head -n1`
  if test -z "$iface" ; then
    $DIALOG --title $"NOT CONNECTED" --clear --msgbox $"Sorry, I scanned $number interface(s), but the Access Concentrator of your provider did not respond. Please check your network and modem cables. Another reason for the scan failure may also be another running pppoe process which controls the modem." 15 60
    rm -rf "$TMP"
    exit 1;
  fi
  $DIALOG --title $"DSL CONNECTION FOUND" --clear --yesno $"I found an Access Concentrator on $iface. Should I setup PPPOE for this connection?" 15 60
  if test "$?" = "0"; then
    # sanity check
    if [ "$kernel_pppoe" ]; then
       grep -q '^plugin.*rp-pppoe.so' $OPTSFILE || echo "plugin rp-pppoe.so $iface" >> $OPTSFILE
       # disable the pppoe tunnel command
       if grep -q '^pty' $OPTSFILE ; then
          sed -e 's/^pty/#pty/' $OPTSFILE > $OPTSFILE.new && mv -f $OPTSFILE.new $OPTSFILE
       fi
    else
       # 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
    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 )
    
    sed -e "s/eth[:0-9:]* /$iface /" $OPTSFILE > "$sectempfile"
    mv "$sectempfile" $OPTSFILE
  else
    rm -rf "$TMP"
    exit 1
  fi
  # STATUS: interface is $iface, we can continue
  
  if ! test "$fresh_optsfile" ; then 
     $DIALOG --title $"OKAY TO MODIFY" --clear --yesno $"If you continue with this program, the configuration file $OPTSFILE will be modified. Please make sure that you have a backup copy before saying Yes.\n\nContinue with configuration?" 22 70
     if test "$?" != "0" ; then
        rm -rf "$TMP"
        exit 0
     fi
  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
  $DIALOG --title $"POPULAR OPTIONS" --clear --yesno $"Most people using popular dialup providers prefer the options 'noauth' and 'defaultroute' in their configuration and remove the 'nodetach' option. Should I check your configuration file and change these settings where neccessary?" 22 70
  if test "$?" = "0" ; then
    grep -q '^noauth' $OPTSFILE || echo 'noauth' >> $OPTSFILE
    grep -q '^defaultroute' $OPTSFILE  || echo 'defaultroute' >> $OPTSFILE
    sed -e "s/^nodetach.*//" $OPTSFILE > "$sectempfile"
    mv "$sectempfile" $OPTSFILE
#    sed -e "s/^lcp-echo-interval 20$/lcp-echo-interval 60/" $OPTSFILE > "$sectempfile"
#    mv "$sectempfile" $OPTSFILE
  fi
  
  user=`grep ^user $OPTSFILE|cut -f2 -d" " | tr -d '"'`
  test -z "$user" && user="username"
  while test "$goahead" != "yes" ; do
    $DIALOG --nocancel --title $"ENTER USERNAME" --clear --inputbox $"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." 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 -e 's/^user .*//' $OPTSFILE > "$sectempfile"
      mv "$sectempfile" $OPTSFILE
      echo  "user \"$user\"" >> $OPTSFILE
      export goahead="yes"
    fi
      ;;
    *)
      exit 1
      rm -rf "$TMP"
      ;;
    esac
  done

  $DIALOG --nocancel --title $"ENTER PASSWORD" --clear --inputbox $"Please enter the password which you usually need for the PPP login to your provider in the input box below.\n\nNOTE: you can see the password in plain text while typing." 15 60 2> "$sectempfile"
  pass=`cat "$sectempfile"`
  case $? in
  0)
    sed -e "s/^\"*$user\"* .*//" /etc/ppp/pap-secrets > "$sectempfile"
    mv "$sectempfile" /etc/ppp/pap-secrets
    echo "\"$user\" * \"$pass\"" >> /etc/ppp/pap-secrets
    sed -e "s/^\"*$user\"* .*//" /etc/ppp/chap-secrets > "$sectempfile"
    mv "$sectempfile" /etc/ppp/chap-secrets
    echo "\"$user\" * \"$pass\"" >> /etc/ppp/chap-secrets
    ;;
  *)
    rm -rf "$TMP"
    exit 1
    ;;
  esac

  # ask about DNS
  $DIALOG --title $"USE PEER DNS" --clear --yesno $"You need at least one DNS IP addresses 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 automaticaly to the list on nameservers in your local /etc/resolv.conf file? (recommended)" 15 60
  case $? in
     0)
     grep -q "^usepeerdns" $OPTSFILE || echo "usepeerdns" >> $OPTSFILE
     ;;
  esac
  
  # ask about MSS limitation
  $DIALOG --title $"LIMITED MSS PROBLEM" --clear --yesno $"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 trough one real Ethernet link with the default MTU size (1500). Unfortunately, if you are forwarding packets from another hosts (ie. 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.\n\nShould pppoe clamp MSS at 1452 bytes?\n\nIf unsure, say yes.\n\n(If you still get problems described above, try setting to 1412 in the dsl-provider file.)" 22 70
  case $? in
     0)
     if [ "$kernel_pppoe" ]; then
        printf "#!/bin/sh\n# Enable MSS clamping (autogenerated by pppoeconf)\n\niptables -A FORWARD -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
        chmod +x /etc/ppp/ip-up.d/0clampmss
     else
        # disable the old line
        sed -e 's/^pty/#&/' $OPTSFILE > "$sectempfile"
        mv "$sectempfile" $OPTSFILE
        # enable the one with our mss size
        sed -e 's/^#\(pty.*-m 1452.*\)/\1/' $OPTSFILE > "$sectempfile"
        mv "$sectempfile" $OPTSFILE
        rm -f "$sectempfile"
     fi
     ;;
  esac

  if test -z "`mount | grep KNOPPIX`" ; then
     $DIALOG --title $"DONE" --clear --yesno $"Your PPPD is configured now. Would you like to start the connection at boot time?" 15 60
     if test "$?" = "0"; then
        if [ ! -f /etc/ppp/ppp_on_boot ] ; then
           ln -s pppoe_on_boot /etc/ppp/ppp_on_boot || true
        fi
     fi
  fi

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

else
  $DIALOG --title $"NO INTERFACE FOUND" --clear --yesno $"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?" 20 70
  case $? in
  0)
    rm -rf "$TMP"
    modconf
    exec $0
    exit $?
    ;;
  *)
    rm -rf "$TMP"
    exit 1
    ;;
  esac
fi
