

                  HOWTO for the linux packet generator 
                  ------------------------------------

Date: 041221

Enable CONFIG_NET_PKTGEN to compile and build pktgen.o either in kernel
or as module. Module is preferred. insmod pktgen if needed. Once running
pktgen creates a thread on each CPU where each thread has affinty it's CPU.
Monitoring and controlling is done via /proc. Easiest to select a suitable 
a sample script and configure.

On a dual CPU:

ps aux | grep pkt
root       129  0.3  0.0     0    0 ?        SW    2003 523:20 [pktgen/0]
root       130  0.3  0.0     0    0 ?        SW    2003 509:50 [pktgen/1]


For montoring and control pktgen creates:
	/proc/net/pktgen/pgctrl
	/proc/net/pktgen/kpktgend_X
        /proc/net/pktgen/ethX


Viewing threads
===============
/proc/net/pktgen/kpktgend_0 
Name: kpktgend_0  max_before_softirq: 10000
Running: 
Stopped: eth1 
Result: OK: max_before_softirq=10000

Most important the devices assigend to thread. Note! A device can only belong 
to one thread.


Viewing devices
===============

Parm section holds configured info. Current hold running stats. 
Result is printed after run or after interruption. Example:

/proc/net/pktgen/eth1       

Params: count 10000000  min_pkt_size: 60  max_pkt_size: 60
     frags: 0  delay: 0  clone_skb: 1000000  ifname: eth1
     flows: 0 flowlen: 0
     dst_min: 10.10.11.2  dst_max: 
     src_min:   src_max: 
     src_mac: 00:00:00:00:00:00  dst_mac: 00:04:23:AC:FD:82
     udp_src_min: 9  udp_src_max: 9  udp_dst_min: 9  udp_dst_max: 9
     src_mac_count: 0  dst_mac_count: 0 
     Flags: 
Current:
     pkts-sofar: 10000000  errors: 39664
     started: 1103053986245187us  stopped: 1103053999346329us idle: 880401us
     seq_num: 10000011  cur_dst_mac_offset: 0  cur_src_mac_offset: 0
     cur_saddr: 0x10a0a0a  cur_daddr: 0x20b0a0a
     cur_udp_dst: 9  cur_udp_src: 9
     flows: 0
Result: OK: 13101142(c12220741+d880401) usec, 10000000 (60byte,0frags)
  763292pps 390Mb/sec (390805504bps) errors: 39664

Confguring threads and devices
==============================
This is done via the /proc interface easiest done via pgset in the scripts

Examples:

 pgset "clone_skb 1"     sets the number of copies of the same packet
 pgset "clone_skb 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, set to zero
                         for continuous sends until explicitly stopped.

 pgset "delay 5000"      adds delay to hard_start_xmit(). nanoseconds

 pgset "dst 10.0.0.1"    sets IP destination address
                         (BEWARE! This generator is very aggressive!)

 pgset "dst_min 10.0.0.1"            Same as dst
 pgset "dst_max 10.0.0.254"          Set the maximum destination IP.
 pgset "src_min 10.0.0.1"            Set the minimum (or only) source IP.
 pgset "src_max 10.0.0.254"          Set the maximum source IP.
 pgset "dst6 fec0::1"     IPV6 destination address
 pgset "src6 fec0::2"     IPV6 source address
 pgset "dstmac 00:00:00:00:00:00"    sets MAC destination address
 pgset "srcmac 00:00:00:00:00:00"    sets MAC source address

 pgset "src_mac_count 1" Sets the number of MACs we'll range through.  
                         The 'minimum' MAC is what you set with srcmac.

 pgset "dst_mac_count 1" Sets the number of MACs we'll range through.
                         The 'minimum' MAC is what you set with dstmac.

 pgset "flag [name]"     Set a flag to determine behaviour.  Current flags
                         are: IPSRC_RND #IP Source is random (between min/max),
                              IPDST_RND, UDPSRC_RND,
                              UDPDST_RND, MACSRC_RND, MACDST_RND 

 pgset "udp_src_min 9"   set UDP source port min, If < udp_src_max, then
                         cycle through the port range.

 pgset "udp_src_max 9"   set UDP source port max.
 pgset "udp_dst_min 9"   set UDP destination port min, If < udp_dst_max, then
                         cycle through the port range.
 pgset "udp_dst_max 9"   set UDP destination port max.

 pgset "mpls 0001000a,0002000a,0000000a" set MPLS labels (in this example
                                         outer label=16,middle label=32,
					 inner label=0 (IPv4 NULL)) Note that
					 there must be no spaces between the
					 arguments. Leading zeros are required.
					 Do not set the bottom of stack bit,
					 thats done automatically. If you do
					 set the bottom of stack bit, that
					 indicates that you want to randomly
					 generate that address and the flag
					 MPLS_RND will be turned on. You
					 can have any mix of random and fixed
					 labels in the label stack.

 pgset "mpls 0"		  turn off mpls (or any invalid argument works too!)

 pgset stop    	          aborts injection. Also, ^C aborts generator.


Example scripts
===============

A collection of small tutorial scripts for pktgen is in expamples dir.

pktgen.conf-1-1                  # 1 CPU 1 dev 
pktgen.conf-1-2                  # 1 CPU 2 dev
pktgen.conf-2-1                  # 2 CPU's 1 dev 
pktgen.conf-2-2                  # 2 CPU's 2 dev
pktgen.conf-1-1-rdos             # 1 CPU 1 dev w. route DoS 
pktgen.conf-1-1-ip6              # 1 CPU 1 dev ipv6
pktgen.conf-1-1-ip6-rdos         # 1 CPU 1 dev ipv6  w. route DoS
pktgen.conf-1-1-flows            # 1 CPU 1 dev multiple flows.

Run in shell: ./pktgen.conf-X-Y It does all the setup including sending. 


Interrupt affinity
===================
Note when adding devices to a specific CPU there good idea to also assign 
/proc/irq/XX/smp_affinity so the TX-interrupts gets bound to the same CPU.
as this reduces cache bouncing when freeing skb's.


Current commands and configuration options
==========================================

** Pgcontrol commands:

start
stop

** Thread commands:

add_device
rem_device_all
max_before_softirq


** Device commands:

count
clone_skb
debug

frags
delay

src_mac_count
dst_mac_count

pkt_size 
min_pkt_size
max_pkt_size

mpls

udp_src_min
udp_src_max

udp_dst_min
udp_dst_max

flag
  IPSRC_RND
  TXSIZE_RND
  IPDST_RND
  UDPSRC_RND
  UDPDST_RND
  MACSRC_RND
  MACDST_RND

dst_min
dst_max

src_min
src_max

dst_mac
src_mac

clear_counters

dst6
src6

flows
flowlen

References:
ftp://robur.slu.se/pub/Linux/net-development/pktgen-testing/
ftp://robur.slu.se/pub/Linux/net-development/pktgen-testing/examples/

Paper from Linux-Kongress in Erlangen 2004.
ftp://robur.slu.se/pub/Linux/net-development/pktgen-testing/pktgen_paper.pdf

Thanks to:
Grant Grundler for testing on IA-64 and parisc, Harald Welte,  Lennert Buytenhek
Stephen Hemminger, Andi Kleen, Dave Miller and many others.


Good luck with the linux net-development.