sbin/grml-sniff

   1 #!/bin/sh
   2 # Filename:      grml-sniff
   3 # Purpose:       script for configuring a network sniffing setup
   4 # Authors:       grml-team (grml.org), (c) Michael Prokop <mika@grml.org>
   5 # Bug-Reports:   see http://grml.org/bugs/
   6 # License:       This file is licensed under the GPL v2.
   7 ################################################################################
   8
   9 CONFIG_FILE=/etc/grml/routersetup
  10 . /etc/grml/lsb-functions
  11 . /etc/grml/script-functions
  12
  13 usage_info()
  14 {
  15    einfo "$0 - script for configuring a network sniffing setup"
  16    einfo "Configure via $CONFIG_FILE - see man 8 grml-sniff" ; eend 0
  17 }
  18
  19 if ! [ -r "$CONFIG_FILE" ] ; then
  20   eerror "$CONFIG_FILE could not be read."
  21   exit 1
  22 fi
  23
  24 . "$CONFIG_FILE"
  25
  26 if [ -z "$BRIDGE_DEVICES" ] ; then
  27    eerror "Bridge devices (\$BRIDGE_DEVICES) not set in $CONFIG_FILE"
  28    exit 1
  29 fi
  30
  31 [ -n "$BRCTL" ]          || BRCTL='brctl'
  32 [ -n "$BRIDGE_NAME" ]    || BRIDGE_NAME='br0'
  33 [ -n "$BRIDGE_DEVICES" ] || BRIDGE_DEVICES='eth0 eth1'
  34
  35 check_devs() {
  36   for dev in $BRIDGE_DEVICES ; do
  37     ip link show dev "$dev" >/dev/null 2>&1 || return 1
  38  done
  39 }
  40
  41 if ! check_devs ; then
  42   eerror "BRIDGE_DEVICES $BRIDGE_DEVICES do not seem to exist." >&2
  43   exit 1
  44 fi
  45
  46 check4progs $BRCTL || exit 1
  47
  48 case "$1" in
  49     start)
  50         check4root || exit 1
  51         einfo "Starting sniffing setup"
  52         eindent
  53             einfo "Creating bridge device"
  54             brctl addbr "$BRIDGE_NAME"
  55             eend $?
  56
  57             einfo "Bringing network device in promiscuous mode up:"
  58             eindent
  59                for i in $BRIDGE_DEVICES ; do
  60                    einfo "$i"
  61                    ifconfig "$i" -arp promisc 0.0.0.0 up ; eend $?
  62                done
  63             eoutdent
  64
  65             einfo "Adding network devices to $BRIDGE_NAME:"
  66             eindent
  67             for i in $BRIDGE_DEVICES ; do
  68                 einfo "$i"
  69                 brctl addif "$BRIDGE_NAME" $i  ; eend $?
  70             done
  71             eoutdent
  72
  73             einfo "Bringing bridge $BRIDGE_NAME in promiscuous up"
  74             ip link set "$BRIDGE_NAME" promisc on up ; eend $?
  75         eoutdent
  76    ;;
  77
  78    stop)
  79         check4root || exit 1
  80         einfo "Stopping sniffing setup"
  81         eindent
  82             einfo "Removing network devices from $BRIDGE_NAME: "
  83
  84             eindent
  85                for i in $BRIDGE_DEVICES ; do
  86                    einfo "$i "
  87                    brctl delif "$BRIDGE_NAME" $i  ; eend $?
  88                done
  89             eoutdent
  90
  91             einfo "Disabling promiscuous mode on: "
  92             eindent
  93                for i in $BRIDGE_DEVICES ; do
  94                    einfo "$i "
  95                    ip link set "$i" promisc off ; eend $?
  96                done
  97             eoutdent
  98
  99             einfo "Bringing bridge $BRIDGE_NAME down"
 100             ip link set "$BRIDGE_NAME" down; eend $?
 101
 102             einfo "Removing bridge device $BRIDGE_NAME"
 103             ifconfig "$BRIDGE_NAME" down || /bin/true
 104             brctl delbr "$BRIDGE_NAME"
 105             eend $?
 106         eoutdent
 107    ;;
 108
 109    restart)
 110         check4root || exit 1
 111         $0 stop
 112         sleep 1
 113         $0 start
 114    ;;
 115
 116    info|-h|--help)
 117         usage_info
 118    ;;
 119
 120    status)
 121         check4root || exit 1
 122         einfo "$0 - status:"
 123         $BRCTL show ; eend $?
 124    ;;
 125
 126    *)
 127         echo "Usage: $0 {start|stop|restart|status|info}"
 128         exit 1
 129    ;;
 130 esac
 131
 132 ## END OF FILE #################################################################
 133 # vim: ft=sh expandtab ai