基于 Open vSwitch 的 OpenFlow 亲测实践

内容简介：基于 Open vSwitch 的 OpenFlow 亲测实践

今天看到朋友推荐的一篇IBM的文章 http://www.linuxidc.com/Linux/2017-06/144770.htm

文章内容很好，如果我只是收藏起来，那就实在是太浪费，还是动手练习一次，好好补一下我的网络。还是用UnitedStack的UOS，创建一个虚拟机来完成全部的试验。

文章就一个小笔误，把ns2写成ns3。外面很多转载的文章，都没注明出处，搞的以为是原创。如果错误都一样，就有点不好意思。

和IBM的文档不一样的地方是：我使用的是Ubuntu 14.04，减少很多没必要的麻烦。

创建一个Ubuntu 14.04的最小配置虚拟机，ssh到虚拟机上。

查看Ubuntu版本

# lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 14.04.1 LTS
Release:        14.04
Codename:       trusty

OVS

Ubuntu 14.04的OVS版本，已经是2.02，所以默认安装就可以。不过不同的发行版，ovs的名字会有点不同。

apt-cache search openvswitch

开始安装

apt-get install openvswitch-switch

查看OVS运行情况

# ps -ea | grep ovs
 3007 ?        00:00:00 ovsdb-server
 3017 ?        00:00:00 ovs-vswitchd

查看OVS版本

# ovs-appctl --version
ovs-appctl (Open vSwitch) 2.0.2
Compiled Aug 15 2014 14:31:01

查看 OVS 支持的 OpenFlow 协议的版本

# ovs-ofctl --version
ovs-ofctl (Open vSwitch) 2.0.2
Compiled Aug 15 2014 14:31:02
OpenFlow versions 0x1:0x4

OpenFlow 命令

创建一个OVS交换机

ovs-vsctl add-br ovs-switch

创建一个端口 p0，设置端口 p0 的 OpenFlow 端口编号为 100

ovs-vsctl add-port ovs-switch p0 -- set Interface p0 ofport_request=100

设置网络接口设备类型为”internal”,

ovs-vsctl set Interface p0 type=internal

查看设置结果

# ethtool -i p0
driver: openvswitch
version: 
firmware-version: 
bus-info: 
supports-statistics: no
supports-test: no
supports-eeprom-access: no
supports-register-dump: no
supports-priv-flags: no

创建一个name space：ns0，把p0端口接入到ns0里，并且配置ip地址 192.168.1.100/24

ip netns add ns0
ip link set p0 netns ns0
ip netns exec ns0 ip addr add 192.168.1.100/24 dev p0
ip netns exec ns0 ifconfig p0 promisc up

查看创建结果

# ovs-vsctl show
6507c214-0c7a-4159-9813-977074f73aa1
    Bridge ovs-switch
        Port "p0"
            Interface "p0"
                type: internal
        Port ovs-switch
            Interface ovs-switch
                type: internal
    ovs_version: "2.0.2"

重复步骤，创建p1和p2端口

ovs-vsctl add-port ovs-switch p1 -- set Interface p1 ofport_request=101
ovs-vsctl set Interface p1 type=internal
ip netns add ns1
ip link set p1 netns ns1
ip netns exec ns1 ip addr add 192.168.1.101/24 dev p1
ip netns exec ns1 ifconfig p1 promisc up

查看创建结果

# ovs-vsctl show
6507c214-0c7a-4159-9813-977074f73aa1
    Bridge ovs-switch
        Port "p1"
            Interface "p1"
                type: internal
        Port "p0"
            Interface "p0"
                type: internal
        Port ovs-switch
            Interface ovs-switch
                type: internal
    ovs_version: "2.0.2"

创建p2

ovs-vsctl add-port ovs-switch p2 -- set Interface p2 ofport_request=102
ovs-vsctl set Interface p2 type=internal
ip netns add ns2
ip link set p2 netns ns2
ip netns exec ns2 ip addr add 192.168.1.102/24 dev p2
ip netns exec ns2 ifconfig p2 promisc up

查看

# ovs-vsctl show
6507c214-0c7a-4159-9813-977074f73aa1
    Bridge ovs-switch
        Port "p1"
            Interface "p1"
                type: internal
        Port "p2"
            Interface "p2"
                type: internal
        Port "p0"
            Interface "p0"
                type: internal
        Port ovs-switch
            Interface ovs-switch
                type: internal
    ovs_version: "2.0.2"

查看创建的交换机信息，获得dpid，端口openflow端口编号

# ovs-ofctl show ovs-switch
OFPT_FEATURES_REPLY (xid=0x2): dpid:0000d23b94ce4146
n_tables:254, n_buffers:256
capabilities: FLOW_STATS TABLE_STATS PORT_STATS QUEUE_STATS ARP_MATCH_IP
actions: OUTPUT SET_VLAN_VID SET_VLAN_PCP STRIP_VLAN 
SET_DL_SRC SET_DL_DST SET_NW_SRC SET_NW_
DST SET_NW_TOS SET_TP_SRC SET_TP_DST ENQUEUE
 100(p0): addr:00:00:00:00:00:00
     config:     PORT_DOWN
     state:      LINK_DOWN
     speed: 0 Mbps now, 0 Mbps max
 101(p1): addr:00:00:00:00:00:00
     config:     PORT_DOWN
     state:      LINK_DOWN
     speed: 0 Mbps now, 0 Mbps max
 102(p2): addr:00:00:00:00:00:00
     config:     PORT_DOWN
     state:      LINK_DOWN
     speed: 0 Mbps now, 0 Mbps max
 LOCAL(ovs-switch): addr:2a:be:0c:72:40:45
     config:     PORT_DOWN
     state:      LINK_DOWN
     speed: 0 Mbps now, 0 Mbps max
OFPT_GET_CONFIG_REPLY (xid=0x4): frags=normal miss_send_len=0

获取openflow端口编号

# ovs-vsctl get Interface p0 ofport
100
# ovs-vsctl get Interface p1 ofport
101
# ovs-vsctl get Interface p2 ofport
102

查看 datapath 的信息

# ovs-dpctl show
system@ovs-system:
        lookups: hit:34 missed:21 lost:0
        flows: 0
        port 0: ovs-system (internal)
        port 1: ovs-switch (internal)
        port 2: p0 (internal)
        port 3: p1 (internal)
        port 4: p2 (internal)

查看mac地址

ip netns exec ns0 ping 192.168.1.100
ip netns exec ns0 ping 192.168.1.101
ip netns exec ns0 ping 192.168.1.102

然后运行

# ovs-appctl fdb/show ovs-switch      
 port  VLAN  MAC                Age
  102     0  22:8e:52:36:92:25   17
  100     0  d6:0f:7e:ed:11:e4    4
  101     0  f2:0d:06:ff:79:d7    4

查看交换机所有table

ovs-ofctl dump-tables ovs-switch

查看交换机中的所有流表项

ovs−ofctl dump−flows ovs-switch

删除编号为 100 的端口上的所有流表项

ovs-ofctl del-flows ovs-switch "in_port=100"

查看交换机端口信息

ovs-ofctl show ovs-switch

修改数据包

屏蔽所有进入 OVS 的以太网广播数据包

$ ovs-ofctl add-flow ovs-switch "table=0, dl_src=01:00:00:00:00:00/01:00:00:00:00:00, actions=drop"

屏蔽 STP 协议的广播数据包

$ ovs-ofctl add-flow ovs-switch "table=0, dl_dst=01:80:c2:00:00:00/ff:ff:ff:ff:ff:f0, actions=drop"

修改数据包，添加新的 OpenFlow 条目，修改从端口 p0 收到的数据包的源地址为 9.181.137.1

ovs-ofctl add-flow ovs-switch "priority=1 idle_timeout=0,\
    in_port=100,actions=mod_nw_src:9.181.137.1,normal"

从端口 p0（192.168.1.100）发送测试数据到端口 p1（192.168.1.101），就是没啥响应

# ip netns exec ns0 ping 192.168.1.101
PING 192.168.1.101 (192.168.1.101) 56(84) bytes of data.

再打开一个ssh终端，登录进去，运行tcpdump，需要等待几分钟，才能看到响应

~# ip netns exec ns1 tcpdump -i p1 icmp
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on p1, link-type EN10MB (Ethernet), capture size 65535 bytes
06:21:23.802308 IP 9.181.137.1 > 192.168.1.101: ICMP echo request, id 4533, seq 19, length 64
06:21:24.802358 IP 9.181.137.1 > 192.168.1.101: ICMP echo request, id 4533, seq 20, length 64

重定向数据包

添加新的 OpenFlow 条目，重定向所有的 ICMP 数据包到端口 p2

ovs-ofctl add-flow ovs-switch idle_timeout=0,dl_type=0x0800,nw_proto=1,actions=output:102

从端口 p0 （192.168.1.100）发送数据到端口 p1（192.168.1.101）

ip netns exec ns0 ping 192.168.1.101

这个时候你从p2里，可以看到

# ip netns exec ns2 tcpdump -i p2 icmp 
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on p2, link-type EN10MB (Ethernet), capture size 65535 bytes
06:25:38.252471 IP 192.168.1.100 > 192.168.1.101: ICMP echo request, id 4668, seq 35, length 64
06:25:39.260438 IP 192.168.1.100 > 192.168.1.101: ICMP echo request, id 4668, seq 36, length 64
06:25:40.268419 IP 192.168.1.100 > 192.168.1.101: ICMP echo request, id 4668, seq 37, length 64

修改vlan tag

修改端口 p1 的 VLAN tag 为 101，使端口 p1 成为一个隶属于 VLAN 101 的端口

ovs-vsctl set Port p1 tag=101

现在由于端口 p0 和 p1 属于不同的 VLAN，它们之间无法进行数据交换。我们使用 ovs-appctl ofproto/trace 生成一个从端口 p0 发送到端口 p1 的数据包，这个数据包不包含任何 VLAN tag，并观察 OVS 的处理过程

ovs-appctl ofproto/trace ovs-switch in_port=100,dl_src=d6:0f:7e:ed:11:e4,\
dl_dst=f2:0d:06:ff:79:d7 -generate

注意：上面��一个mac地址，是p0的，第二个mac地址是p1的，你需要替换，上面有获取mac地址的方法。

# ovs-appctl ofproto/trace ovs-switch in_port=100,dl_src=d6:0f:7e:ed:11:e4,\
> dl_dst=f2:0d:06:ff:79:d7 -generate
Flow: metadata=0,in_port=100,vlan_tci=0x0000,dl_src=d6:0f:7e:ed:11:e4,dl_dst=f2:0d:06:ff:79:d7,dl_type=0x0000
Rule: table=0 cookie=0 priority=1,in_port=100
OpenFlow actions=mod_nw_src:9.181.137.1,NORMAL
no learned MAC for destination, flooding

Final flow: unchanged
Relevant fields: skb_priority=0,in_port=100,vlan_tci=0x0000/0x1fff,dl_src=d6:0f:7e:ed:11:e4,
dl_dst=f2:0d:06:ff:79:d7,dl_type=0x0000,nw_src=0.0.0.0,nw_proto=0,nw_frag=no
Datapath actions: 1,4

在第一行输出中，“Flow:”之后的字段描述了输入的流的信息。由于我们没有指定太多信息，所以多数字段 （例如 dl_type 和 vlan_tci）被 OVS 设置为空值。

在第二行的输出中，“Rule:” 之后的字段描述了匹配成功的流表项。

在第三行的输出中，“OpenFlow actions”之后的字段描述了实际执行的操作。

最后一段以”Final flow”开始的字段是整个处理过程的总结，“Datapath actions: 4,1”代表数据包被发送到 datapath 的 4 和 1 号端口。

创建一条新的 Flow

对于从端口 p0 进入交换机的数据包，如果它不包含任何 VLAN tag，则自动为它添加 VLAN tag 101

ovs-ofctl add-flow ovs-switch "priority=3,in_port=100,dl_vlan=0xffff,\
actions=mod_vlan_vid:101,normal"

再次尝试从端口 p0 发送一个不包含任何 VLAN tag 的数据包，发现数据包进入端口 p0 之后, 会被加上 VLAN tag101, 同时转发到端口 p1 上

# ovs-appctl ofproto/trace ovs-switch in_port=100,dl_src=d6:0f:7e:ed:11:e4,\
> dl_dst=f2:0d:06:ff:79:d7 -generate
Flow: metadata=0,in_port=100,vlan_tci=0x0000,dl_src=d6:0f:7e:ed:11:e4,dl_dst=f2:0d:06:ff:79:d7,dl_type=0x0000
Rule: table=0 cookie=0 priority=1,in_port=100
OpenFlow actions=mod_nw_src:9.181.137.1,NORMAL
no learned MAC for destination, flooding

Final flow: unchanged
Relevant fields: skb_priority=0,in_port=100,vlan_tci=0x0000/0x1fff,dl_src=d6:0f:7e:ed:11:e4,dl_dst=f2:0d:06:ff:79:d7,dl_type=0x0000,nw_src=0.0.0.0,nw_proto=0,nw_frag=no
Datapath actions: 1,4
root@ovs:~# ovs-ofctl add-flow ovs-switch "priority=3,in_port=100,dl_vlan=0xffff,\
> actions=mod_vlan_vid:101,normal"
root@ovs:~# ovs-appctl ofproto/trace ovs-switch in_port=100,dl_src=d6:0f:7e:ed:11:e4,\
> dl_dst=f2:0d:06:ff:79:d7 -generate
Flow: metadata=0,in_port=100,vlan_tci=0x0000,dl_src=d6:0f:7e:ed:11:e4,dl_dst=f2:0d:06:ff:79:d7,dl_type=0x0000
Rule: table=0 cookie=0 priority=3,in_port=100,vlan_tci=0x0000
OpenFlow actions=mod_vlan_vid:101,NORMAL
no learned MAC for destination, flooding

Final flow: metadata=0,in_port=100,dl_vlan=101,dl_vlan_pcp=0,dl_src=d6:0f:7e:ed:11:e4,dl_dst=f2:0d:06:ff:79:d7,dl_type=0x0000
Relevant fields: skb_priority=0,in_port=100,vlan_tci=0x0000,dl_src=d6:0f:7e:ed:11:e4,dl_dst=f2:0d:06:ff:79:d7,dl_type=0x0000,nw_proto=0,nw_frag=no
Datapath actions: push_vlan(vid=101,pcp=0),1,pop_vlan,3,push_vlan(vid=101,pcp=0),4

反过来从端口 p1 发送数据包，由于 p1 现在是带有 VLAN tag 101 的 Access 类型的端口，所以数据包进入端口 p1 之后，会被 OVS 添加 VLAN tag 101 并发送到端口 p0

# ovs-appctl ofproto/trace ovs-switch in_port=101,dl_src=f2:0d:06:ff:79:d7,\
> dl_dst=d6:0f:7e:ed:11:e4 -generate
Flow: metadata=0,in_port=101,vlan_tci=0x0000,dl_src=f2:0d:06:ff:79:d7,dl_dst=d6:0f:7e:ed:11:e4,dl_type=0x0000
Rule: table=0 cookie=0 priority=0
OpenFlow actions=NORMAL
no learned MAC for destination, flooding

Final flow: unchanged
Relevant fields: skb_priority=0,in_port=101,vlan_tci=0x0000,dl_src=f2:0d:06:ff:79:d7,dl_dst=d6:0f:7e:ed:11:e4,dl_type=0x0000,nw_proto=0,nw_frag=no
Datapath actions: push_vlan(vid=101,pcp=0),1,2,4

Floodlight

新创建一个ubuntu 14.04的虚拟机。

apt-get update
apt-get install git
apt-get install ant
apt-get install openjdk-7-jdk

源码安装

git clone git://github.com/floodlight/floodlight.git
cd floodlight/
ant
java -jar target/floodlight.jar

这个时候floodlight就启动起来，最后一条命令，就是启动floodlight。

登录OVS节点

设置ovs的控制器为floodlight，10.250.3.10，就是floodlight虚拟机的IP。

ovs-vsctl set-controller ovs-switch tcp:10.250.3.10:6633

设置 OVS 的连接模式为 secure 模式

ovs-vsctl set Bridge ovs-switch fail-mode=secure

查看

# ovs-vsctl show
6507c214-0c7a-4159-9813-977074f73aa1
    Bridge ovs-switch
        Controller "tcp:10.250.3.10:6633"
            is_connected: true
        fail_mode: secure
        Port "p1"
            tag: 101
            Interface "p1"
                type: internal
        Port "p2"
            Interface "p2"
                type: internal
        Port "p0"
            Interface "p0"
                type: internal
        Port ovs-switch
            Interface ovs-switch
                type: internal
    ovs_version: "2.0.2"

通过访问 Floodlight 提供的 Web 管理界面 http://<Host Address>:8080/ui/index.html，我们可以查看 Floodlight 控制器的状态以及所有连接到 Floodlight 的交换机列表

通过 Floodlight 的 RESTAPI，添加两条新的规则让端口 p0 和 p1 可以相互通讯。注意：替换命令行中的 switch 的 ID 为交换机的 datapath ID

注意curl命令，尽量别用 / 换行

curl -d '{"switch": "00:00:d2:3b:94:ce:41:46", "name":"my-flow1", "cookie":"0","priority":"32768","ingress-port":"100","active":"true", "actions":"output=flood"}' http://10.250.3.10:8080/wm/staticflowentrypusher/json

curl -d '{"switch": "00:00:d2:3b:94:ce:41:46", "name":"my-flow2", "cookie":"0","priority":"32768","ingress-port":"101","active":"true", "actions":"output=flood"}' http://10.250.3.10:8080/wm/staticflowentrypusher/json

验证是否能从端口 p0 发送数据包到 p1

# ip netns exec ns0 ping -c4 192.168.1.101
PING 192.168.1.101 (192.168.1.101) 56(84) bytes of data.
64 bytes from 192.168.1.101: icmp_seq=1 ttl=64 time=0.625 ms
64 bytes from 192.168.1.101: icmp_seq=2 ttl=64 time=0.088 ms
64 bytes from 192.168.1.101: icmp_seq=3 ttl=64 time=0.082 ms
64 bytes from 192.168.1.101: icmp_seq=4 ttl=64 time=0.048 ms

在 OVS 端也可以看到，流表规则已经被 OVS 同步到本地。

# ovs-ofctl dump-flows ovs-switch
NXST_FLOW reply (xid=0x4):
 cookie=0xa00000626d6af5, duration=111.468s, table=0, n_packets=7, n_bytes=630, idle_age=2, in_port=100 actions=FLOOD
 cookie=0xa00000626d6af6, duration=83.717s, table=0, n_packets=7, n_bytes=630, idle_age=1, in_port=101 actions=FLOOD

通过 Floodlight 的 RestAPI，查看交换机上的流表规则

curl http://10.250.3.10:8080/wm/staticflowentrypusher/list/00:00:d2:3b:94:ce:41:46/json | python -mjson.tool

采用 python 的输出，好看很多的

# curl http://10.250.3.10:8080/wm/staticflowentrypusher/list/00:00:d2:3b:94:ce:41:46/json | python -mjson.tool
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100  1435    0  1435    0     0   109k      0 --:--:-- --:--:-- --:--:--  116k
{
    "00:00:d2:3b:94:ce:41:46": {
        "my-flow1": {
            "actions": [
                {
                    "length": 8,
                    "lengthU": 8,
                    "maxLength": 32767,
                    "port": -5,
                    "type": "OUTPUT"
                }
            ],
            "bufferId": -1,
            "command": 0,
            "cookie": 45035997925042933,
            "flags": 0,
            "hardTimeout": 0,
            "idleTimeout": 0,
            "length": 80,
            "lengthU": 80,
            "match": {
                "dataLayerDestination": "00:00:00:00:00:00",
                "dataLayerSource": "00:00:00:00:00:00",
                "dataLayerType": "0x0000",
                "dataLayerVirtualLan": -1,
                "dataLayerVirtualLanPriorityCodePoint": 0,
                "inputPort": 100,
                "networkDestination": "0.0.0.0",
                "networkDestinationMaskLen": 0,
                "networkProtocol": 0,
                "networkSource": "0.0.0.0",
                "networkSourceMaskLen": 0,
                "networkTypeOfService": 0,
                "transportDestination": 0,
                "transportSource": 0,
                "wildcards": 4194302
            },
            "outPort": -1,
            "priority": -32768,
            "type": "FLOW_MOD",
            "version": 1,
            "xid": 0
        },
        "my-flow2": {
            "actions": [
                {
                    "length": 8,
                    "lengthU": 8,
                    "maxLength": 32767,
                    "port": -5,
                    "type": "OUTPUT"
                }
            ],
            "bufferId": -1,
            "command": 0,
            "cookie": 45035997925042934,
            "flags": 0,
            "hardTimeout": 0,
            "idleTimeout": 0,
            "length": 80,
            "lengthU": 80,
            "match": {
                "dataLayerDestination": "00:00:00:00:00:00",
                "dataLayerSource": "00:00:00:00:00:00",
                "dataLayerType": "0x0000",
                "dataLayerVirtualLan": -1,
                "dataLayerVirtualLanPriorityCodePoint": 0,
                "inputPort": 101,
                "networkDestination": "0.0.0.0",
                "networkDestinationMaskLen": 0,
                "networkProtocol": 0,
                "networkSource": "0.0.0.0",
                "networkSourceMaskLen": 0,
                "networkTypeOfService": 0,
                "transportDestination": 0,
                "transportSource": 0,
                "wildcards": 4194302
            },
            "outPort": -1,
            "priority": -32768,
            "type": "FLOW_MOD",
            "version": 1,
            "xid": 0
        }
    }
}

通过 Floodlight 的 RestAPI，删除交换机上的流表规则

curl http://10.250.3.10:8080/wm/staticflowentrypusher/clear/00:00:d2:3b:94:ce:41:46/json

本文永久更新链接地址 ： http://www.linuxidc.com/Linux/2017-06/144772.htm

以上就是本文的全部内容，希望本文的内容对大家的学习或者工作能带来一定的帮助，也希望大家多多支持 码农网

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