======pktgen======
Linux packet generator is a tool to generate packets at very high speed
in the kernel.
=====Contents=====
* [[https://www.linuxfoundation.org/#Setup|1 Setup]]
* [[https://www.linuxfoundation.org/#Confguring|1.1 Confguring]]
* [[https://www.linuxfoundation.org/#Examples|2 Examples]]
* [[https://www.linuxfoundation.org/#Interrupt_affinity|2.1 Interrupt affinity]]
* [[https://www.linuxfoundation.org/#Commands|3 Commands]]
* [[https://www.linuxfoundation.org/#References|4 References]]
* [[https://www.linuxfoundation.org/#Thanks|5 Thanks]]
===== Setup=====
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
# cat /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 assigned to thread. Note! A device can only belong
to one thread.
* /proc/net/pktgen/ethX
Param section holds configured info. Current hold running stats.
Result is printed after run or after interruption. Example:
# cat /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====
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 continious sends untill explicitl stopped.
pgset "delay 5000" adds delay to hard_start_xmit(). nanoseconds
pgset "dst 10.0.0.1" sets IP destination addres
(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 stop aborts injection. Also, ^C aborts generator.
===== Examples=====
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.
===== Commands=====
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
* 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/|pktgen testing]]
* [[ftp://robur.slu.se/pub/Linux/net-development/pktgen-testing/examples/|pktgen examples]]
* [[ftp://robur.slu.se/pub/Linux/net-development/pktgen-testing/pktgen_paper.pdf|Paper from Linux-Kongress in Erlangen 2004]].
* [[http://www.linuxsymposium.org/2005/linuxsymposium_procv2.pdf|Paper at linuxsymposium 2005 (page 11-24)]].
===== Thanks=====
Grant Grundler for testing on IA-64 and parisc, Harald Welte, Lennert Buytenhek
Stephen Hemminger, Andi Kleen, Dave Miller and many others.