======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.