How to use the Linux packet generator module.

1. Enable CONFIG_NET_PKTGEN to compile and build pktgen.o, install it
   in the place where insmod may find it.
2. Cut script "ipg" (see below).
3. Edit script to set preferred device and destination IP address.
4. Run in shell: ". ipg"
5. After this two commands are defined:
   A. "pg" to start generator and to get results.
   B. "pgset" to change generator parameters. F.e.
      pgset "multiskb 1"      use multiple SKBs for packet generation
      pgset "multiskb 0"      use single SKB for all transmits
      pgset "pkt_size 9014"   sets packet size to 9014
      pgset "frags 5"         packet will consist of 5 fragments
      pgset "count 200000"    sets number of packets to send
      pgset "ipg 5000"        sets artificial gap inserted between packets
                              to 5000 nanoseconds
      pgset "dst 10.0.0.1"    sets IP destination address
                              (BEWARE! This generator is very aggressive!)
      pgset "dstmac 00:00:00:00:00:00"    sets MAC destination address
      pgset stop    	      aborts injection
      
  Also, ^C aborts generator.

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#! /bin/sh

modprobe pktgen.o

function pgset() {
    local result

    echo $1 > /proc/net/pg

    result=`cat /proc/net/pg | fgrep "Result: OK:"`
    if [ "$result" = "" ]; then
         cat /proc/net/pg | fgrep Result:
    fi
}

function pg() {
    echo inject > /proc/net/pg
    cat /proc/net/pg
}

pgset "odev eth0"
pgset "dst 0.0.0.0"

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