#! /bin/bash
#
# tcng:       Starts the tcng Server
#
# Version:      @(#) /etc/rc.d/init.d/tcng 0.1
#
# chkconfig: 2345 90 10
# description: Starts and stops the tcng at boot time and shutdown.
#
# processname: tcng
#
# created : from Raptor
#
# 2003-03-15: by Martin A. Brown <mabrown@securepipe.com>
#  - minor/cosmetic changes: removed an eval, changed looping
#  - added favorite shell functions, gripe/abort, replacing gprintf
#  - altered the way configuration file was used
#  - used a bit of awk instead of three binaries to get device names;
#    there has to be an even more elegant solution!
#  - added a syntax check on tcng config file before "start"
# 2003-03-31: by Martin A. Brown <mabrown@securepipe.com>
#  - better handling of tcstats and tcdebug
#  - more debugging information
#  - handle root/dsmark and ingress qdiscs correctly
#  - add "$0 flush" and "$0 panic"
#

# -- my favorite shell functions
#
gripe  () { echo "$@" >&2;       }
abort  () { gripe "$@"; exit 1;  }
inform () { test "$tcdebug" -ge "$INFORM" && gripe "$@" ; }
debug  () { test "$tcdebug" -ge "$DEBUG"  && gripe "$@" ; }

# -- debugging globals
#
DEBUG=2
INFORM=1

# -- path to the tc and tcc commands; assuming this script is only run
#    by root with a sensible $PATH; otherwise, hardcode the paths
#    to tc and tcc in /etc/sysconfig/tcng
#
tc=$( which tc )
# -- path to the tcc command
#
tcc=$( which tcc )

# -- source the system-wide tcng configuration file; it must set AT LEAST
#    the variable TCCONF
#
sysconfig=/etc/sysconfig/tcng
. $sysconfig

# -- add a few sanity variables, just in case:
#
tcstats=${tcstats:-no}

# -- this can (and should) be set for preference in $sysconfig
#
tcdebug=${tcdebug:-0}

test "$tcstats" = "yes"  && stats="-s"

debug "About to test configuration file specifications"
test ! -z "$TCCONF" || abort "\$TCCONF must contain path to config; got $TCCONF."
test -r "$TCCONF"   || abort "\$TCCONF must be readable: $TCCONF is not."

offMsg=OFF
onMsg=ON

# Source function library.
. /etc/rc.d/init.d/functions

# - - - - - - - - - -
  isup () {
# - - - - - - - - - -
#
# -- this function returns 1 if the qdisc is located on the specified
#    device
#
  local d=$1
  local qtype=$2
  if test "$qtype" = "ingress" ; then
    $tc qdisc show dev $d 2>/dev/null | grep -q $qtype && return 1
    # -- no ingress qdisc, return safely
    return 0
  fi
  #
  # -- sadly, we break our nice symmetry, because the "root" qdisc
  #    can sometimes be a dsmark qdisc....so; let's account for it
  #
  $tc qdisc show dev $d 2>/dev/null | grep -q root   && return 1
  $tc qdisc show dev $d 2>/dev/null | grep -q dsmark && return 1
  #
  # -- Yowza!  Found no qdiscs.
  #
  return 0 ;
  #
}

# - - - - - - - - - -
  exists_qdisc () {       # -- ingress or root qdisc exist?  return 1
# - - - - - - - - - -
#
  local d=$1
  isup $d ingress
  test "$?" -gt "0" && return 1
  isup $d root
  test "$?" -gt "0" && return 1
  return 0 ;
}

# - - - - - - - - - -
  clearqdisc () {
# - - - - - - - - - -
#
# -- this function tests to see if a qdisc exists, and
#    removes it if found.
#
  local d=$1
  local qtype=$2
  isup $d $qtype
  if test "$?" -eq "1" ; then
    inform "Removing $qtype qdisc: $d"
    $tc qdisc del dev $d $qtype 2>/dev/null
  else
    inform "No $qtype qdisc running on device: $d"
  fi
}

# - - - - - - - - - -
  clearingress () {       # -- remove an ingress qdisc
# - - - - - - - - - -
#
  local d=$1
  clearqdisc $d ingress
}

# - - - - - - - - - -
  clearroot () {          # -- remove a root qdisc
# - - - - - - - - - -
#
  local d=$1
  clearqdisc $d root
}

# - - - - - - - - - -
  syntax () {
# - - - - - - - - - -
#
# -- this function tests the configuration file specified in
#    /etc/sysconfig/tcng to see if tcc understands it.  If so,
#    it returns 0, and processing continues.
#
  tcc -c $TCCONF >/dev/null 2>&1
  test "$?" != "0" && return 1;
  return 0 ;
}

# - - - - - - - - - -
  start () {
# - - - - - - - - - -
#
# -- main loop to bring up traffic control on interfaces
#
    test "$#" -ne "0" && local devs=$@
    echo -n $"Starting tcng services: "
    #
    # -- first, make sure that the configuration makes sense to tcc
    #
    debug "About to check syntax on tcng config file ${TCCONF##*/}"
    syntax $TCCONF
    if test "$?" != "0" ; then
      failure ; echo  # -- for the pretty red output
      gripe "tcc failed to parse $TCCONF, try:"
      abort "  \"tcc -c $TCCONF\""
    fi
    #
    # -- then, make sure no traffic control is currently in use on
    #    any devices specified in the tcng configuration
    #
    debug "About to test for active qdiscs on devices in ${TCCONF##*/}"
    for d in $( $tcc $TCCONF | awk '/^tc/{ print $5 }' | sort | uniq ) ; do
      exists_qdisc $d
      if test "$?" -ne "0" ; then
        gripe "Found active traffic control on device $d."
        gripe "Device $d is used in $TCCONF."
        gripe "Remove traffic control with \"$0 stop $d\"."
        abort "Consider also \"$0 restart\" or \"$0 flush\"."
      fi
    done
    #
    # -- now, actually parse the tcng config file and spit it through
    #    a little loop, which executes the tc commands one at a time
    #
    $tcc $TCCONF | grep -Ev "^#|^$" | sed -e "s/^tc//" | {
      while read cmd ; do
        #
        # -- inform the user we are adding qdiscs to devices when new
	#    devices are found
        #
        thisdev=$( echo $cmd | awk '/root/{print $4}' )
        test "$thisdev" = "" || inform "Adding root qdisc to $thisdev"
        thisdev=$( echo $cmd | awk '/ingress/{print $4}' )
        test "$thisdev" = "" || inform "Adding ingress qdisc to $thisdev"
        #
        # -- debug, if necessary...this will print the command just prior
        #    to execution.
        #
        debug "Executing: $cmd"
        $tc $cmd
      done
    }
    success  # -- this is sort of silly, but some people like the pretty
             #    green "OK" to make them feel warm and fuzzy at night
    echo ;
}


# - - - - - - - - - -
  stop () {
# - - - - - - - - - -
#
  test "$#" -ne "0" && local devs=$@
  echo -n $"Stopping tcng services: "
  for d in $devs; do
    inform "Stopping traffic control on: $d"
    clearingress  $d
    clearroot     $d
  done	
  success  # -- this is sort of silly, but some people like the pretty
           #    green "OK" to make them feel warm and fuzzy at night
  echo ;
}


# - - - - - - - - - -
  status () {
# - - - - - - - - - -
#
  if [ "$1" ]; then devs=$*; fi	
  for d in $devs; do
    exists_qdisc $d
    if test "$?" -gt "0" ; then
      gripe "traffic control on $d: [$onMsg]" ;
    else
      gripe "traffic control on $d: [$offMsg]" ;
    fi
  done		
}

# - - - - - - - - - -
  show () {
# - - - - - - - - - -
#
  what=all
  if test "$#" -gt "0" ; then
    case "$1" in
      qdisc|class|filter) what=$1 ; shift  ;;
    esac
    test "$#" -gt "0" && local devs=$@
  fi
  for d in $devs; do
    isup $d root
    if test "$?" -gt "0" ; then
      for OBJ in qdisc class filter ; do
        test "$what" = "all" || test "$what" = "$OBJ" \
          && $tc $stats $OBJ show dev $d
      done
    fi
  done ;
}

# -- this little pile of shell gets a list of the "REAL" devices on
#    the system.  Just a touch easier than "ip -o link", which we
#    should probably be using.
#
devs=$( ifconfig -a | awk '/^\w+:/ || /^lo/ {next}; /^[a-z]/{print $1}' )
command=$1
shift;

case "$command" in
  start)         start         ;;
  flush|panic)	 stop   $devs  ;;   # -- stop ALL traffic control
  stop)	         stop   $@     ;;
  status)        status $@     ;;
  show)          show   $@     ;;	
  restart)       stop   $@
	         start  $@     ;;
  *)
	gripe "Usage: ${0##*/}"
	gripe "  ${0##*/} {start|stop|status|restart} [ device [ ... ] ]"
	abort "  ${0##*/} show [ qdisc|class|filter ] [ device [ ...] ]"
	abort "  ${0##*/} show [ device [ ...] ]"
esac

exit 0