Subject: Re: [PATCH 2/4] fib_trie: improve output format for /proc/net/fib_trie

From: Stephen Hemminger <[email-masked]>
Date: Tue, 12 Feb 2008 19:23:59 -0800

Andrew Morton wrote:
> On Tue, 12 Feb 2008 16:50:44 -0800 Stephen Hemminger <[email-masked]> wrote:
>
>   
>> Make output format prettier (more tree like).
>>
>>    <local>:
>>    --- 0.0.0.0/0
>>      |--- 10.111.111.0/24
>>      |  +-- 10.111.111.0/32 link broadcast
>>      |  |--- 10.111.111.254/31
>>      |  |  +-- 10.111.111.254/32 host local
>>      |  |  +-- 10.111.111.255/32 link broadcast
>>      |--- 127.0.0.0/8
>>      |  |--- 127.0.0.0/31
>>      |  |  +-- 127.0.0.0/32 link broadcast
>>      |  |  +-- 127.0.0.0/8 host local
>>      |  |  +-- 127.0.0.1/32 host local
>>      |  +-- 127.255.255.255/32 link broadcast
>>      |--- 192.168.1.0/24
>>      |  |--- 192.168.1.0/28
>>      |  |  +-- 192.168.1.0/32 link broadcast
>>      |  |  +-- 192.168.1.9/32 host local
>>      |  +-- 192.168.1.255/32 link broadcast
>>    <main>:
>>    --- 0.0.0.0/0
>>      |--- 0.0.0.0/4
>>      |  +-- 0.0.0.0/0 universe unicast
>>      |  +-- 10.111.111.0/24 link unicast
>>      +-- 169.254.0.0/16 link unicast
>>      +-- 192.168.1.0/24 link unicast
>>     
>
> isn't that a non-back-compatible kernel ABI change?  It might
> break pre-existing parsers?
>
>   
Fib trie was always experimental and the output format was intended to 
be tree like
but was broken. There are no known parsers of fib trie, and I think 
Vyatta will probably
be the first distro to ship with it enabled.
> aside: how lame are we to put pretty-printers in the kernel?
> English-only ones, at that?  Root cause: kernel developers still
> don't have a sufficiently easy way of shipping userspace tools.
Agreed, the structure of the trie doesn't come out via netlink (only the 
addresses).