OpenFlow规则元数据

问题描述

我想了解如何在开放流规则中计算元数据.

I would like to understand how the Metadata are calculated in an Open Flow rule.

cookie = 0x6900000，持续时间= 228925.519s，table = 17，n_packets = 384，n_bytes = 35436，优先级= 10，元数据= 0xf30000000000/0xffffff0000000000 actions = write_metadata:0xc000f30000000000/0xffffffffffffffffe，goto_table:211

cookie=0x6900000, duration=228925.519s, table=17, n_packets=384, n_bytes=35436, priority=10,metadata=0xf30000000000/0xffffff0000000000 actions=write_metadata:0xc000f30000000000/0xfffffffffffffffe,goto_table:211

示例:我的流程与此非常相似.如何精确计算元数据.

Example: I have a flow very similar to this. How are exactly the Metadata are Calculated.

以及如何解释元数据值和掩码

And how to Intrepret the Metadata Values and Mask

有人说new_metadata = old_metadata& 〜遮罩|价值和面具

Some saysnew_metadata = old_metadata & ~mask | value & Mask

老实说我听不懂，有人可以解释一下

Honestly i do not understand it, could some one explain it

推荐答案

Open vSwitch文档:

write_metadata:value[/mask]
    Updates the metadata field for the flow. If mask is omit‐
    ted, the metadata field is set exactly to value; if  mask
    is  specified,  then  a  1-bit in mask indicates that the
    corresponding bit in the metadata field will be  replaced
    with  the  corresponding  bit  from value. Both value and
    mask are 64-bit values that are decimal by default; use a
    0x prefix to specify them in hexadecimal.

前面的解释确实等同于:

The preceding explanation is indeed equivalent to:

new_metadata = (old_metadata & ~mask) | (value & mask)

换句话说，我们首先擦除掩码(old_metadata & ~mask)中设置为1的旧元数据值的位，然后将掩码中也设置为1的值的位设置为1(| (value & mask) ).

In other words, we first erase bits of the old metadata value set to 1 in the mask (old_metadata & ~mask) and then set to 1 the bits of the value that are also set to 1 in the mask (| (value & mask)).

这篇关于OpenFlow规则元数据的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！