#!/bin/sh
##########################################################
# Copyright (C) 2001-2016 VMware, Inc. All rights reserved.
#
# This program is free software; you can redistribute it and/or modify it
# under the terms of the GNU Lesser General Public License as published
# by the Free Software Foundation version 2.1 and no later version.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
# or FITNESS FOR A PARTICULAR PURPOSE.  See the Lesser GNU General Public
# License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA.
#
##########################################################


#
# network (Linux)
#
# Using a combination of a system networking script, ifconfig, ifup, ifdown
# and the ip command, attempt to release and renew DHCP leases upon receipt
# of suspend and resume events, respectively.
#


echo `date` ": Executing '$0'"
echo

. `dirname "$0"`/../../statechange.subr


#
# find_networking_script --
#
#    Searches common Linux distro init/rc paths to find a singular network
#    services script.
#
# Result:
#    Returns a valid networking script path on success or "error" on failure.
#
# Side effects:
#    None.
#

find_networking_script() {
   local script="error"
   for dir in "/etc/init.d" "/sbin/init.d" "/etc" "/etc/rc.d" ; do
      if [ -d "$dir/rc0.d" ] &&
         [ -d "$dir/rc1.d" ] &&
         [ -d "$dir/rc2.d" ] &&
         [ -d "$dir/rc3.d" ] &&
         [ -d "$dir/rc4.d" ] &&
         [ -d "$dir/rc5.d" ] &&
         [ -d "$dir/rc6.d" ]; then

         # Now find the appropriate networking script.
         if [ -d "$dir/init.d" ]; then
            if [ -x "$dir/init.d/network" ]; then
               script="$dir/init.d/network"
            elif [ -x "$dir/init.d/networking" ]; then
               script="$dir/init.d/networking"
            fi
         else
            if [ -x "$dir/network" ]; then
               script="$dir/network"
            elif [ -x "$dir/networking" ]; then
               script="$dir/networking"
            fi
         fi
      fi
   done

   echo "$script"
}


#
# exec_networking_script --
#
#    Execute the networking script to bring network interfaces up or down
#    based on the given input action argument.
#

exec_networking_script()
{
   local script=$1
   local action=$2

   # Using SysV "service" if it exists, otherwise fall back to run the
   # script directly
   service=`which service 2>/dev/null`
   if [ $? = 0 -a -n "$service" ]; then
      serviceName=`basename "$script"`
      "$service" "$serviceName" "$action"
   else
      "$script" "$action"
   fi

   return $?
}


#
# exec_systemctl_service --
#
#    Handle linux distributions that use systemd to replace the legacy
#    system V startup scripts. The previous network script searching
#    approach is no longer viable in these systems. Invoke the systemctl
#    command to control the network service instead.
#

exec_systemctl_service()
{
   local rc=1
   local action=$1
   local ctlcmd=$(which systemctl 2>/dev/null)
   local service

   [ -z "$ctlcmd" ] && return $rc

   for svc in systemd-networkd network; do
      if ! $ctlcmd status $svc | grep -iq 'not-found'; then
         service=$svc && break
      fi
   done

   [ -z "$service" ] && return $rc

   $ctlcmd $action $service; rc=$?

   # When use the systemd-networkd service to shut down interfaces, interface
   # address and state remain unchanged. Need to use ip command to change its
   # address and state.
   if [ $rc = 0 -a $service = 'systemd-networkd' -a $action = 'stop' ]; then
      config_network_intfs $action; rc=$?
   fi

   return $rc
}


#
# del_intf_ip --
#
#    Use the ip command to remove all the addresses of an interface.
#

del_intf_ip()
{
   local nic=$1

   $ip_cmd addr flush dev $nic
   return $?
}


#
# ip_intf_ops --
#
#    Use the ip command to change the state of an interface to up or down.
#

ip_intf_ops()
{
   local rc=1
   local nic=$1
   local ops=$2

   [ -z "$ip_cmd" ] && return $rc

   $ip_cmd link set $nic $ops; rc=$?

   # Remove interface addresses when taking an interface down.
   if [ $rc = 0 -a $ops = down ]; then
      del_intf_ip $nic; rc=$?
   fi

   return $rc
}


#
# intf_ops --
#
#    Execute the specified command (ifup or ifdown) if available, otherwise use
#    the ip command as fallback. If ifup or ifdown fails, run the ip command to
#    retry the intended operation.
#

intf_ops()
{
   local rc=0
   local cmd=$1
   local ops=$2
   local nic=$3
   local tmp

   if [ ! -z "$cmd" ]; then
      tmp=$($cmd $nic 2>&1); rc=$?

      # Some systems still return a successful status even the command fails
      # because the interface is not configured in the configuration file. So
      # have to examine the command output to determine the actual status.
      if [ $rc = 0 ]; then
         echo $tmp | egrep -iq 'not configured|ignoring unknown' && rc=1
      fi
   fi

   # If ifup/ifdown fails, try the ip fallback.
   if [ -z "$cmd" -o $rc != 0 ]; then
      ip_intf_ops $nic $ops; rc=$?
   fi

   return $rc
}


#
# exec_intf_ops --
#
#    Perform an operation to bring an individual interface up or down.
#

exec_intf_ops()
{
   local rc=0
   local action=$1
   local nic=$2

   case $action in
      start)
         intf_ops "$ifup_cmd" up $nic; rc=$?
         ;;
      stop)
         intf_ops "$ifdown_cmd" down $nic; rc=$?
         ;;
      *)
         Panic "Illegal interface action: $action"
         ;;
   esac

   return $rc
}


#
# config_network_intfs --
#
#    For Linux systems not supporting networking scripts to bring interfaces
#    up or down, provide a way to change the interface state individually.
#

config_network_intfs()
{
   local rc=0
   local action=$1

   if [ -f "$activeList" ]; then

      while read nic; do
         exec_intf_ops $action $nic
         rc=$(expr $rc \| $?)
      done < $activeList
   fi

   return $rc
}


#
# run_network_script --
#
#    Finds out how to run the system's script used to control networking, and
#    runs it with the given argument (which should be one of the usual SysV
#    init script arguments). If it does not work, tries the other alternatives.
#    So far, our alternatives are (a) systemctl (b) network script (c) perform
#    an individual interface state change.
#

run_network_script()
{
   local action=$1
   local rc=0
   local script

   while true; do

      exec_systemctl_service $action
      [ $? != 0 ] || break

      script=`find_networking_script`

      if [ $script != "error" ]; then
         exec_networking_script $script $action
         [ $? != 0 ] || break
      fi

      # Since all the other alternatives fail, need to manually change
      # individual interface state.
      config_network_intfs $action; rc=$?
      break
   done

   return $rc
}


#
# save_active_NIC_list --
#
#    Records a list of every active NIC to /var/run/vmware-active-nics.
#
#    XXX What's the story on aliases?  Should they still be included, or will
#    they be recreated automatically upon resume?
#
# Results:
#    $activeList has, one per line, a list of all active NICs.
#
# Side effects:
#    None.
#

save_active_NIC_list()
{
   local intf_out

   >$activeList

   # Find out all the non-loopback up interfaces. Use ip if available
   # otherwise fall back to the ifconfig command.
   # ifconfig is buggy on some platforms and truncates long
   # network names
   if [ -n "$ip_cmd" ]; then
      for nic in $($ip_cmd link show up | egrep '\bUP\b' | awk -F: '{print $2}'); do
         $ip_cmd link show ${nic%@*} | grep -iq 'link/ether' && echo ${nic%@*} >> $activeList
      done
   else
      for nic in $($ifconfig_cmd | sed -n 's/^\([^: \t]*\).*$/\1/p'); do
         intf_out=$($ifconfig_cmd $nic)
         echo $intf_out | grep -iq loopback && continue
         echo $intf_out | egrep -q '\bUP\b' && echo $nic >> $activeList
      done
   fi
}


#
# rescue_NIC --
#
#    For each NIC recorded in $activeList that is not currently "up", run
#    "ifup $nic" or "ip link set $nic up" to bring the interface up.
#
# Results:
#    All downed NICs should be active.
#

rescue_NIC()
{
   local rc=0
   local intf_out

   if [ -f "$activeList" ]; then
      while read nic; do
         if [ -n "$ip_cmd" ]; then
            intf_out=$($ip_cmd link show $nic up)
         else
            intf_out=$($ifconfig_cmd $nic)
         fi

         if echo $intf_out | grep -q 'UP'; then
            echo `date` "[rescue_nic] $nic is already active."
         else
            echo `date` "[rescue_nic] activating $nic ..."

            # Our best effort to activate interfaces, use ifup if available
            # otherwise use the ip command as fallback.
            intf_ops "$ifup_cmd" up $nic
            rc=$(expr $rc \| $?)
         fi
      done < $activeList

      rm -f $activeList
   fi

   return $rc
}


#
# TranquilizeNetworkManager --
#
#    Put the NetworkManager daemon to sleep (maybe).
#
#    See http://projects.gnome.org/NetworkManager/developers/spec.html .
#
# Results:
#    Sleep(true) request is sent to the NetworkManager D-Bus interface.
#
# Side effects:
#    None.
#

TranquilizeNetworkManager()
{
   # `which' may be a bit noisy, so we'll shush it.
   dbusSend=`which dbus-send 2>/dev/null`
   rc=$?
   if [ $rc -ne 0 ]; then
      return $rc
   fi

   # Check NetworkManager state before disabling it.
   nm_state=`$dbusSend --system --print-reply		\
             --dest=org.freedesktop.NetworkManager	\
             /org/freedesktop/NetworkManager		\
             org.freedesktop.DBus.Properties.Get	\
             string:'org.freedesktop.NetworkManager'	\
             string:'State'				\
             | awk '/variant/ {print $3;}'`
   if [ -z "$nm_state" ]; then
      return 1
   fi
   # NetworkManager API     0.7/0.8   0.9
   # NM_STATE_ASLEEP           1      10
   # NM_STATE_DISCONNECTED     4      20
   case $nm_state in
      1|4|10|20)
         # Nothing needs to be done.
         return 0
         ;;
   esac

   # NetworkManager 0.8.0 and above
   $dbusSend --system --print-reply          \
      --dest=org.freedesktop.NetworkManager  \
      /org/freedesktop/NetworkManager        \
      org.freedesktop.NetworkManager.Enable boolean:false
   rc=$?
   if [ $rc -eq 0 ]; then
      return $rc
   fi
   # NetworkManager 0.7.0
   $dbusSend --system --print-reply          \
      --dest=org.freedesktop.NetworkManager  \
      /org/freedesktop/NetworkManager        \
      org.freedesktop.NetworkManager.Sleep boolean:true
   rc=$?
   if [ $rc -eq 0 ]; then
      return $rc
   fi
   # NetworkManager 0.6
   $dbusSend --system --print-reply          \
      --dest=org.freedesktop.NetworkManager  \
      /org/freedesktop/NetworkManager        \
      org.freedesktop.NetworkManager.sleep
   rc=$?

   return $rc
}


#
# WakeNetworkManager --
#
#    Wake the NetworkManager daemon (maybe).
#
#    See http://projects.gnome.org/NetworkManager/developers/spec.html .
#
# Results:
#    Sleep(false)request is sent to the NetworkManager D-Bus interface.
#
# Side effects:
#    None.
#

WakeNetworkManager()
{
   # `which' may be a bit noisy, so we'll shush it.
   dbusSend=`which dbus-send 2>/dev/null`
   rc=$?
   if [ $rc = 0 ]; then
      # NetworkManager 0.8.0
      $dbusSend --system --print-reply          \
         --dest=org.freedesktop.NetworkManager  \
         /org/freedesktop/NetworkManager        \
         org.freedesktop.NetworkManager.Enable boolean:true
      rc=$?
      if [ $rc = 0 ]; then
         return $rc
      fi
      # NetworkManager 0.7.0
      $dbusSend --system --print-reply          \
         --dest=org.freedesktop.NetworkManager  \
         /org/freedesktop/NetworkManager        \
         org.freedesktop.NetworkManager.Sleep boolean:false
      rc=$?
      if [ $rc = 0 ]; then
         return $rc
      fi
      # NetworkManager 0.6
      $dbusSend --system --print-reply          \
         --dest=org.freedesktop.NetworkManager  \
         /org/freedesktop/NetworkManager        \
         org.freedesktop.NetworkManager.wake
      rc=$?
   fi
   return $rc
}


#
# sanity_check --
#
#    Check if the script has all the commands it needs to carry out the
#    request. So far, it requires either ip or ifconfig command to read
#    interface configuration. Ifup is not checked here. It is checked at
#    the place where we need to do individual interface state change.
#

sanity_check()
{
   ip_cmd=$(which ip 2>/dev/null)
   ifconfig_cmd=$(which ifconfig 2>/dev/null)
   ifup_cmd=$(which ifup 2>/dev/null)
   ifdown_cmd=$(which ifdown 2>/dev/null)

   [ -z "$ifconfig_cmd" -a -z "$ip_cmd" ] && \
       Panic "ip and ifconfig not in search path."
}


#
# main --
#
#    Main entry point.  Perform some sanity checking, then map state change
#    events to relevant networking operations.
#
# Results:
#    See comment at top of file.
#

main() {
   exitCode=0
   activeList=/var/run/vmware-active-nics

   case "$1" in
      poweron-vm)
         rm -f $activeList
         ;;
      suspend-vm)
         TranquilizeNetworkManager
         exitCode=$?
         if [ $exitCode != 0 ]; then
            sanity_check suspend-vm
            save_active_NIC_list
            run_network_script stop
            exitCode=$?
         fi
         ;;
      resume-vm)
         WakeNetworkManager
         exitCode=$?
         if [ $exitCode != 0 ]; then
            sanity_check resume-vm
            # According to hfu, "/etc/init.d/networking restart" on Debian 5.0
            # may bring down ethernet interfaces tagged as "allow-hotplug" without
            # bringing them back up.
            #
            # This is especially a problem when reverting to a live, running
            # VM snapshot where an active NIC list hadn't yet been generated,
            # resulting in sudden loss of an otherwise operational NIC.
            #
            # So, if the active list doesn't exist, assume we're coming back to
            # a live snapshot and capture the current active list now for
            # rescue later.
            if [ ! -s $activeList ]; then
               save_active_NIC_list
            fi

            # We shall use start not restart here. Otherwise we may not be able
            # to bring back active list on distros like sles11sp2
            # -- PR 816791
            run_network_script start
            rescue_NIC
            exitCode=$?
         fi
         ;;
      *) ;;
   esac

   return $exitCode
}

main "$@"
