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   . "$CONFIG_FILE"
  21 else
  22   ewarn "Could not read $CONFIG_FILE"
  23 fi
  24
  25 # defaults if unconfigured
  26 [ -n "$BRCTL" ]          || BRCTL='brctl'
  27 [ -n "$BRIDGE_NAME" ]    || BRIDGE_NAME='br0'
  28 [ -n "$BRIDGE_DEVICES" ] || BRIDGE_DEVICES='eth0 eth1'
  29
  30 check_devs() {
  31   for dev in $BRIDGE_DEVICES ; do
  32     ip link show dev "$dev" >/dev/null 2>&1 || return 1
  33  done
  34 }
  35
  36 if ! check_devs ; then
  37   eerror "BRIDGE_DEVICES $BRIDGE_DEVICES do not seem to exist." >&2
  38   exit 1
  39 fi
  40
  41 check4progs $BRCTL || exit 1
  42
  43 case "$1" in
  44     start)
  45         check4root || exit 1
  46         einfo "Starting sniffing setup"
  47         eindent
  48
  49             einfo "Disabling IPv6 to avoid neighbor solicitation/multicast traffic"
  50             echo 1 > /proc/sys/net/ipv6/conf/all/disable_ipv6
  51
  52             einfo "Creating bridge device"
  53             brctl addbr "$BRIDGE_NAME"
  54             eend $?
  55
  56             einfo "Bringing network device in promiscuous mode up:"
  57             eindent
  58                for i in $BRIDGE_DEVICES ; do
  59                    einfo "$i"
  60                    ifconfig "$i" -arp promisc 0.0.0.0 up ; eend $?
  61                done
  62             eoutdent
  63
  64             einfo "Adding network devices to $BRIDGE_NAME:"
  65             eindent
  66             for i in $BRIDGE_DEVICES ; do
  67                 einfo "$i"
  68                 brctl addif "$BRIDGE_NAME" $i  ; eend $?
  69             done
  70             eoutdent
  71
  72             einfo "Bringing bridge $BRIDGE_NAME in promiscuous up"
  73             ip link set "$BRIDGE_NAME" promisc on up ; eend $?
  74         eoutdent
  75    ;;
  76
  77    stop)
  78         check4root || exit 1
  79         einfo "Stopping sniffing setup"
  80         eindent
  81             einfo "Removing network devices from $BRIDGE_NAME: "
  82
  83             eindent
  84                for i in $BRIDGE_DEVICES ; do
  85                    einfo "$i "
  86                    brctl delif "$BRIDGE_NAME" $i  ; eend $?
  87                done
  88             eoutdent
  89
  90             einfo "Disabling promiscuous mode on: "
  91             eindent
  92                for i in $BRIDGE_DEVICES ; do
  93                    einfo "$i "
  94                    ip link set "$i" promisc off ; eend $?
  95                done
  96             eoutdent
  97
  98             einfo "Bringing bridge $BRIDGE_NAME down"
  99             ip link set "$BRIDGE_NAME" down; eend $?
 100
 101             einfo "Removing bridge device $BRIDGE_NAME"
 102             ifconfig "$BRIDGE_NAME" down || /bin/true
 103             brctl delbr "$BRIDGE_NAME"
 104             eend $?
 105
 106             einfo "Re-enabling IPv6"
 107             echo 0 > /proc/sys/net/ipv6/conf/all/disable_ipv6
 108         eoutdent
 109    ;;
 110
 111    restart)
 112         check4root || exit 1
 113         $0 stop
 114         sleep 1
 115         $0 start
 116    ;;
 117
 118    info|-h|--help)
 119         usage_info
 120    ;;
 121
 122    status)
 123         check4root || exit 1
 124         einfo "$0 - status:"
 125         $BRCTL show ; eend $?
 126    ;;
 127
 128    *)
 129         echo "Usage: $0 {start|stop|restart|status|info}"
 130         exit 1
 131    ;;
 132 esac
 133
 134 ## END OF FILE #################################################################
 135 # vim: ft=sh expandtab ai