一、编译dpdk lib

1、配置编译工具链

make config T=x86_64-native-linuxapp-gcc

2、编译

cd build

make

编译错误一：/root/dpdk-18.11/lib/librte_eal/linuxapp/eal/eal_memory.c:29:18: fatal error: numa.h: No such file or directory

原因：缺少库

解决方法：yum install numactl-devel*x86_64 -y

编译错误二：make: *** /lib/modules/3.10.0-957.1.3.el7.x86_64/build: No such file or directory. Stop.

原因：系统没有安装内核开发包

解决方法：（1）yum install kernel-devel -y （2）ln -s /usr/src/kernels/3.10.0-957.5.1.el7.x86_64 /usr/src/kernels/3.10.0-957.1.3.el7.x86_64

3、结果

编译出来的.a文件在目录/root/dpdk-18.11/build/lib下

二、dpdk用例

1、例1：hello world

（1）编译

cd /root/dpdk-18.11/examples/helloworld

export RTE_SDK=/root/dpdk-18.11

export RTE_TARGET=x86_64-native-linuxapp-gcc

export RTE_TARGET=build

make

会在当前目录生成build目录，里面有编译生成的可执行文件。

（2）运行helloworld

[root@localhost helloworld]# ./build/helloworld

EAL: Detected 4 lcore(s)

EAL: Detected 1 NUMA nodes

EAL: Multi-process socket /var/run/dpdk/rte/mp_socket

EAL: No free hugepages reported in hugepages-2048kB

EAL: No free hugepages reported in hugepages-2048kB

EAL: FATAL: Cannot get hugepage information.

EAL: Cannot get hugepage information.

PANIC in main():

Cannot init EAL

5: [./build/helloworld() [0x4804df]]

4: [/lib64/libc.so.6(__libc_start_main+0xf5) [0x7fe22c67c3d5]]

3: [./build/helloworld() [0x4774b8]]

2: [./build/helloworld(__rte_panic+0xb8) [0x4609fb]]

1: [./build/helloworld(rte_dump_stack+0x1a) [0x5526ba]]

Aborted (core dumped)

运行环境配有配置，需要配置一下运行环境。

source usertools/dpdk-setup.sh,分别设置18,20,22

然后就可以正常运行了。

[root@localhost dpdk-18.11]# ./examples/helloworld/build/helloworld -l 0-1 -n 4

EAL: Detected 4 lcore(s)

EAL: Detected 1 NUMA nodes

EAL: Multi-process socket /var/run/dpdk/rte/mp_socket

EAL: Probing VFIO support...

hello from core 0

hello from core 1

2、例子2：Basic Forwarding/Skeleton Application

（1）编译完运行./build/basicfwd -l 1 -n 4

[root@localhost skeleton]# ./build/basicfwd -l 1 -n 4

EAL: Detected 4 lcore(s)

EAL: Detected 1 NUMA nodes

EAL: Multi-process socket /var/run/dpdk/rte/mp_socket

EAL: Probing VFIO support...

EAL: Error - exiting with code: 1

Cause: Error: number of ports must be even

原因：dpdk没有绑定网卡。

看下服务器的网卡信息，只有一块网卡。

[root@localhost skeleton]# ifconfig

enp3s0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500

inet 172.19.8.93 netmask 255.255.255.0 broadcast 172.19.8.255

inet6 fe80::5246:5dff:fe5b:49be prefixlen 64 scopeid 0x20<link>

ether 50:46:5d:5b:49:be txqueuelen 1000 (Ethernet)

RX packets 765935 bytes 286280011 (273.0 MiB)

RX errors 0 dropped 3 overruns 0 frame 0

TX packets 128062 bytes 13559483 (12.9 MiB)

TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536

inet 127.0.0.1 netmask 255.0.0.0

inet6 ::1 prefixlen 128 scopeid 0x10<host>

loop txqueuelen 1000 (Local Loopback)

RX packets 22 bytes 1748 (1.7 KiB)

RX errors 0 dropped 0 overruns 0 frame 0

TX packets 22 bytes 1748 (1.7 KiB)

TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

下面我们着手创建两块虚拟网卡，查看dpdk支持的网卡列表，发现也支持tap虚拟网卡。

https://core.dpdk.org/supported/

支持虚拟网卡需要内核版本在4.2以上，可以通过以下命令查询是否支持虚拟tap：

zcat /proc/config.gz | ( grep 'CLS_FLOWER=' || echo 'not supported' ) |

tee -a /dev/stderr | grep -q '=m' &&

lsmod | ( grep cls_flower || echo 'try modprobe cls_flower' )

由于我们的系统内核不能升级，只能用virtualbox创建虚机时多加两块网卡。创建的虚机有三块网卡，下面把其中的两块绑定dpdk

（2）网卡绑定dpdk

[root@localhost dpdk-18.11]# ./usertools/dpdk-devbind.py --bind=uio_pci_generic enp0s8

Error - no supported modules(DPDK driver) are loaded

原因：uio驱动没有加载。回头看下，source usertools/dpdk-setup.sh,设置18时，报错了：## ERROR: Target does not have the DPDK UIO Kernel Module.To fix, please try to rebuild target.

解决方法：

[root@localhost dpdk-18.11]# modprobe uio

[root@localhost dpdk-18.11]# cd build/kmod/

[root@localhost kmod]# insmod igb_uio.ko

[root@localhost kmod]# lsmod | grep uio

再次运次

[root@localhost dpdk-18.11]# ./usertools/dpdk-devbind.py --bind=uio_pci_generic enp0s8

Routing table indicates that interface 0000:00:08.0 is active. Not modifying

原因：接口up无法绑定，先把期望绑定的接口down掉，再绑定。仍然报错。

[root@localhost dpdk-18.11]# ifconfig enp0s8 down

[root@localhost dpdk-18.11]# ./usertools/dpdk-devbind.py --bind=uio_pci_generic enp0s8

Error: bind failed for 0000:00:08.0 - Cannot open /sys/bus/pci/drivers/uio_pci_generic/bind

Error: unbind failed for 0000:00:08.0 - Cannot open /sys/bus/pci/drivers//unbind

[root@localhost dpdk-18.11]#

加载驱动 uio_pci_generic，继续绑定，仍然报错。

[root@localhost dpdk-18.11]# modprobe uio_pci_generic

[root@localhost dpdk-18.11]# lsmod | grep uio_pci_generic

uio_pci_generic 12588 0

uio 19338 2 uio_pci_generic,igb_uio

[root@localhost dpdk-18.11]# ./usertools/dpdk-devbind.py --bind=uio_pci_generic enp0s8

Unknown device: enp0s8. Please specify device in "bus:slot.func" format

查看一下网卡信息，发现enp0s8网卡不见了。查看一下状态，

用id好绑定：

[root@localhost dpdk-18.11]# ./usertools/dpdk-devbind.py --bind=uio_pci_generic 00:08.0

成功。

同样绑定第二块网卡。最终状态如下。

执行程序：

由于虚机和办公网络是通的，一下把办公网络搞挂了。抓包看全是ARP报文。

（3）下面对照例子代码，分析为什么用这个IP发包。

答案：其实这个例子本身没有发生三层报文，只是简单的转发了网卡上收到的ARP广播报文，这个报文并不是自身协议栈产生的。