DPDK（五）：发包工具------pktgen
测试DPDK不可或缺的一个发包工具，一般需要一台实体测试仪，家中环境简单，只能使用软发包工具了，找到一款叫做pktgen，其实也可以自己用pcap或者raw socket实现，看介绍使用pktgen性能很不错，也进行了绑核，不再造轮子了。
pktgen的原理以及使用可以参考http://www.lenky.info/archives/2012/02/1165。
看一下我的测试环境，虚拟机环境上三个网卡绑到了同一个网桥上，相当于将三个网卡连上了光纤，分别是eth2、eth3、eth4，如下图所示：
eth2 eth3 eth4
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---------------------------------------------------- veth8
网卡配置信息如下：
root@ubuntu:/home# ifconfig
eth0 Link encap:Ethernet HWaddr 00:0c:29:41:a2:1f
inet addr:192.168.91.128 Bcast:192.168.91.255 Mask:255.255.255.0
inet6 addr: fe80::20c:29ff:fe41:a21f/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:113 errors:0 dropped:0 overruns:0 frame:0
TX packets:303 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:16138 (16.1 KB) TX bytes:48250 (48.2 KB)
eth1 Link encap:Ethernet HWaddr 00:50:56:38:e6:f6
inet addr:192.168.174.128 Bcast:192.168.174.255 Mask:255.255.255.0
inet6 addr: fe80::250:56ff:fe38:e6f6/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:5352 errors:0 dropped:0 overruns:0 frame:0
TX packets:7505 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:347980 (347.9 KB) TX bytes:12763065 (12.7 MB)
eth2 Link encap:Ethernet HWaddr 00:50:56:36:8d:e6
inet addr:192.168.19.129 Bcast:192.168.19.255 Mask:255.255.255.0
inet6 addr: fe80::250:56ff:fe36:8de6/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:299 errors:0 dropped:0 overruns:0 frame:0
TX packets:5313663 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:39253 (39.2 KB) TX bytes:318866365 (318.8 MB)
eth3 Link encap:Ethernet HWaddr 00:0c:29:41:a2:3d
inet addr:192.168.19.128 Bcast:192.168.19.255 Mask:255.255.255.0
inet6 addr: fe80::20c:29ff:fe41:a23d/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:5305660 errors:0 dropped:0 overruns:0 frame:0
TX packets:125 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:318399640 (318.3 MB) TX bytes:14485 (14.4 KB)
eth4 Link encap:Ethernet HWaddr 00:50:56:3c:96:c7
inet addr:192.168.19.130 Bcast:192.168.19.255 Mask:255.255.255.0
inet6 addr: fe80::250:56ff:fe3c:96c7/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:561 errors:0 dropped:0 overruns:0 frame:0
TX packets:67 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:94079 (94.0 KB) TX bytes:10020 (10.0 KB)
Interrupt:19 Base address:0x2000
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:68 errors:0 dropped:0 overruns:0 frame:0
TX packets:68 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:5750 (5.7 KB) TX bytes:5750 (5.7 KB)
现在我想从eth2发送报文到eth3，最终目标是使用DPDK绑定eth3，然后进行二层转发测试将报文转发到eth4。
配置文件如下（ pkggen.conf ）：
#!/bin/sh
# FileName: pktgen-eth5-eth6.conf
# modprobe pktgen
function pgset(){
local result
echo $1 > $PGDEV
result=`cat $PGDEV | fgrep "Result: OK:"`
if [ "$result" = "" ]; then
cat $PGDEV | fgrep Result:
fi
}
function pg(){
echo inject > $PGDEV
cat $PGDEV
}
# Config Start Here -----------------------------------------------------------
# thread config
# Each CPU has own thread. Two CPU exammple. We add eth1, eth2 respectivly.
PGDEV=/proc/net/pktgen/kpktgend_2
echo "Removing all devices"
pgset "rem_device_all"
echo "Adding eth2"
pgset "add_device eth2"
# device config
# delay 0 means maximum speed.
CLONE_SKB="clone_skb 1000000"
# NIC adds 4 bytes CRC
PKT_SIZE="pkt_size 60"
# COUNT 0 means forever
#COUNT="count 0"
COUNT="count 0"
DELAY="delay 0"
PGDEV=/proc/net/pktgen/eth2
echo "Configuring $PGDEV"
pgset "$COUNT"
pgset "$CLONE_SKB"
pgset "$PKT_SIZE"
pgset "$DELAY"
pgset "dst 192.168.19.128"
pgset "dst_mac 00:0c:29:41:a2:3d"
# Time to run
PGDEV=/proc/net/pktgen/pgctrl
echo "Running... ctrl^C to stop"
pgset "start"
echo "Done"
# Result can be vieved in /proc/net/pktgen/eth[2]
步骤：
（1）、modprobe pktgen
（2）、sh pkggen.conf
（3）、tcpdump查看eth3上的报文情况，可以收到报文
root@ubuntu:/opt/code/dpdk-1.8.0/examples# tcpdump -vv -i eth3 -c 10
tcpdump: listening on eth3, link-type EN10MB (Ethernet), capture size 262144 bytes
00:37:41.068632 IP (tos 0x0, ttl 32, id 4, offset 0, flags [none], proto UDP (17), length 46)
192.168.19.129.discard > 192.168.19.128.discard: [no cksum] UDP, length 18
00:37:41.068638 IP (tos 0x0, ttl 32, id 4, offset 0, flags [none], proto UDP (17), length 46)
192.168.19.129.discard > 192.168.19.128.discard: [no cksum] UDP, length 18
00:37:41.068640 IP (tos 0x0, ttl 32, id 4, offset 0, flags [none], proto UDP (17), length 46)
192.168.19.129.discard > 192.168.19.128.discard: [no cksum] UDP, length 18
00:37:41.068642 IP (tos 0x0, ttl 32, id 4, offset 0, flags [none], proto UDP (17), length 46)
192.168.19.129.discard > 192.168.19.128.discard: [no cksum] UDP, length 18
00:37:41.068757 IP (tos 0x0, ttl 32, id 4, offset 0, flags [none], proto UDP (17), length 46)
192.168.19.129.discard > 192.168.19.128.discard: [no cksum] UDP, length 18
00:37:41.068762 IP (tos 0x0, ttl 32, id 4, offset 0, flags [none], proto UDP (17), length 46)
192.168.19.129.discard > 192.168.19.128.discard: [no cksum] UDP, length 18
00:37:41.068968 IP (tos 0x0, ttl 32, id 4, offset 0, flags [none], proto UDP (17), length 46)
192.168.19.129.discard > 192.168.19.128.discard: [no cksum] UDP, length 18
00:37:41.184195 IP (tos 0x0, ttl 32, id 4, offset 0, flags [none], proto UDP (17), length 46)
192.168.19.129.discard > 192.168.19.128.discard: [no cksum] UDP, length 18
00:37:41.194487 IP (tos 0x0, ttl 32, id 4, offset 0, flags [none], proto UDP (17), length 46)
192.168.19.129.discard > 192.168.19.128.discard: [no cksum] UDP, length 18
00:37:41.194493 IP (tos 0x0, ttl 32, id 4, offset 0, flags [none], proto UDP (17), length 46)
192.168.19.129.discard > 192.168.19.128.discard: [no cksum] UDP, length 18
10 packets captured
3525 packets received by filter
3188 packets dropped by kernel