#!/bin/sh
set -e

MYNAME="${0##*/}"

report() { echo "${MYNAME}: $*" ; }
report_warn() { report "Warning: $*" >&2 ; }
report_err() { report "Error: $*" >&2 ; }

# Create /etc/network/run 
if [ "$1" = configure -a ! -d /etc/network/run ]; then
  if [ -e /etc/network/run -o -L /etc/network/run ]; then
    echo "Renaming non-directory /etc/network/run to run.dpkg-old..."
    mv /etc/network/run /etc/network/run.dpkg-old
  fi

  # The best choice is to use /run/network
  # That must be supported everywhere

  [ -d /run/network ] || mkdir /run/network
  ln -s /run/network /etc/network/run
fi 

# Move /etc/network/ifstate to /etc/network/run/ifstate
if [ "$1" = configure -a "$2" != "" -a -e /etc/network/ifstate ] &&
     dpkg --compare-versions "$2" lt "0.6.5"
then
  if [ ! -e /etc/network/run/ifstate ] || ! diff /etc/network/ifstate /etc/network/run/ifstate >/dev/null
  then
    echo "Moving /etc/network/ifstate to /etc/network/run/ifstate"
    if [ ! -L /etc/network/ifstate ]; then
      mv /etc/network/ifstate /etc/network/run/ifstate
    else
      cat /etc/network/ifstate >/etc/network/run/ifstate
      mv /etc/network/ifstate /etc/network/ifstate.dpkg-old
    fi
  fi
fi

l=$(readlink /etc/network/run || echo /etc/network/run)

# Migrate /etc/network/run to /run/network
if [ "$1" = configure -a "$2" != "" -a -e /etc/network/run -a "$l" != "/run/network" ]
then
  echo "Migrating network state directory from $l to /run/network..."
  [ -d /run/network ] || mkdir /run/network
  if [ -e /etc/network/run/ifstate ]
  then
    echo "Moving /etc/network/run/ifstate to /run/network/ifstate"
    if [ ! -L /etc/network/run/ifstate ]; then
      mv -f /etc/network/run/ifstate /run/network/ifstate
    else
      # we do this thing with .dpkg-new just so we don't truncate the
      # state file in the case of crazy symlinked or mount-bound setup
      cat /etc/network/run/ifstate >/run/network/ifstate.dpkg-new
      mv -f /etc/network/run/ifstate /run/network/ifstate.dpkg-old
      mv -f /run/network/ifstate.dpkg-new /run/network/ifstate
    fi
  fi
  mv -f /etc/network/run /etc/network/run.dpkg-old
  ln -s /run/network /etc/network/run
  rmdir /etc/network/run.dpkg-old 2>/dev/null || report_warn "Not removing the old contents of /etc/network/run: directory not empty; renamed into /etc/network/run.dpkg-old."
fi


if [ "$1" = "configure" -a "$2" != "" ] &&
     dpkg --compare-versions "$2" le "0.6.4-4.1" &&
     [ -f /etc/network/run/ifstate -a -x /sbin/dhclient ]
then
  # for every active ifupdown-controlled dhclient interface, copy
  # /var/run/dhclient.pid, so that the new ifdown is able to kill
  # dhclient.
  #
  # the old version had a bug with more than one DHCP iface anyway,
  # so we don't know which one the PID file actually belongs to.

  sed -e 's/^.*=//' /etc/network/run/ifstate |
    while read iface; do
      # handle \<newline>-continued lines
      if sed -e '/^[[:space:]]*#/b;:g /\\$/{N;s/\\\n//;bg;}' /etc/network/interfaces | grep -qe "^[[:space:]]*iface[[:space:]]*\\b${iface}\\b[[:space:]]*.*\\bdhcp\\b.*" &&
          [ -f "/var/run/dhclient.pid" ] &&
          [ ! -f "/var/run/dhclient.${iface}.pid" ]
      then
        # copy original file.  If dhclient was started
        # manually, one can still use dhclient.pid, if started
        # by ifupdown, the new ifupdown can take it down with 
        # dhclient.${iface}.pid.  Obsolete files are removed during
        # next boot (bootmisc.sh).
        cp /var/run/dhclient.pid "/var/run/dhclient.${iface}.pid"
      fi
    done
fi

# Remove the ifupdown and ifupdown-clean init script symlinks
if [ "$1" = "configure" -a "$2" != "" ] &&
     dpkg --compare-versions "$2" lt "0.6.7ubuntu4"
then
    rm -f /etc/init.d/ifupdown /etc/init.d/ifupdown-clean
    rm -f /etc/default/ifupdown

    update-rc.d -f ifupdown remove
    update-rc.d -f ifupdown-clean remove
fi

# Generic stuff done on all configurations
if [ "$1" = "configure" ] ; then
  if [ -f /etc/network/interfaces ] ; then
    # TODO: This should be handled with debconf and the script
    # could introduce the line there directly
    if ! grep -q "^[[:space:]]*iface[[:space:]]\+lo[[:space:]]\+inet[[:space:]]\+loopback\>" /etc/network/interfaces ; then
      report_warn "No 'iface lo' definition found in /etc/network/interfaces"
      report_warn " adding it for you"
      if ! grep -q "^[[:space:]]*auto[[:space:]].*\<lo\>" /etc/network/interfaces ; then
        # both are missing? add the whole block
        report_warn "No 'auto lo' statement found in /etc/network/interfaces"
        report_warn " adding it for you"
cat >> /etc/network/interfaces <<EOF

# The loopback network interface
auto lo
iface lo inet loopback
EOF
      else
        sed -i -e'/^[[:space:]]*auto[[:space:]].*\<lo\>/a\
iface lo inet loopback' /etc/network/interfaces
      fi
    fi
    if ! grep -q "^[[:space:]]*auto[[:space:]].*\<lo\>" /etc/network/interfaces ; then
      report_warn "No 'auto lo' statement found in /etc/network/interfaces"
      report_warn " adding it for you"
      sed -i -e'/^[[:space:]]*iface[[:space:]]\+lo[[:space:]]\+inet[[:space:]]\+loopback\>/i\
auto lo' /etc/network/interfaces
    fi
  else  # ! -f /etc/network/interfaces
    echo "Creating /etc/network/interfaces."
    echo "# interfaces(5) file used by ifup(8) and ifdown(8)" > /etc/network/interfaces
    echo "auto lo" >> /etc/network/interfaces
    echo "iface lo inet loopback" >> /etc/network/interfaces
  fi
fi