Packetspammer
Andy Green <andy@warmcat.com>

Packetspammer sends unencrypted broadcast packets down a mac80211 wireless
interface that should be set for Monitor mode.  It spams the packets down the
interface as fast as it can, although you can specify a delay between packets.

At the same time it is listening for packets with a MAC of 13:22:33:44:xx:xx
and will display metadata about any incoming packets (like the bitrate) and
the packet contents.  So if you run packetspammer on two nearby machines, they
will show each other's packets like this:

RX: Rate: 54.0Mbps, Freq: 2.417GHz, Ant: 0, Flags: 10
0000: 50 61 63 6B 65 74 73 70 61 6D 6D 65 72 20 2D 2D  Packetspammer --
0010: 62 72 6F 61 64 63 61 73 74 20 70 61 63 6B 65 74  broadcast packet
0020: 23 34 37 39 31 36 20 2D 2D 20 3A 2D 44 20 2D 2D  #47916 -- :-D --
0030: 75 6C 74 72 61 63 61 74 2E 68 6F 6D 65 2E 77 61  ultracat.home.wa
0040: 72 6D 63 61 74 2E 63 6F 6D                       rmcat.com


Typical usage:

  echo -n mon0 > /sys/class/ieee80211/phy0/add_iface
  iwconfig mon0 mode monitor
  ifconfig mon0 up
  packetspammer mon0

You may need to bring up your normal interface first and set its channel, eg

ifconfig wlan0 up
iwconfig wlan0 channel 2

If you normal interface is associated to an AP on a particular channel, that's
fine, the packet injection won't disturb the association.