Re: Adding inode field to /proc/net/netlink

[Eric Dumazet <eric.dumazet@gmail.com>]

Le dimanche 28 février 2010 à 18:50 +0900, Masatake YAMATO a écrit :

> I understood but it has been already breaking:
> 
>     [yamato@xxx /proc/net]$ uname -a; cat /proc/net/netlink 
>     Linux xxx.redhat.com 2.6.29.6-217.2.16.fc11.x86_64 #1 SMP Mon Aug 24 17:17:40 EDT 2009 x86_64 x86_64 x86_64 GNU/Linux
>     sk       Eth Pid    Groups   Rmem     Wmem     Dump     Locks
>     ffff8801bbde0400 0   2758   00000111 0        0        (null) 2
>     ...
> 
>     [yamato@yyy /proc/net]$ uname -a; cat /proc/net/netlink 
>     Linux yyy.redhat.com 2.6.30.10-105.2.23.fc11.x86_64 #1 SMP Thu Feb 11 07:06:34 UTC 2010 x86_64 x86_64 x86_64 GNU/Linux
>     sk       Eth Pid    Groups   Rmem     Wmem     Dump     Locks     Drops
>     ffff8800d83f5800 0   1783   00000001 0        0        (null) 2        0       
> 
> Drops field may be added between 2.6.29 and 2.6.30.
> Adding one more field is really problem?
> In other word, why "Drops" field was acceptable?
> 
> lsof uses following technique. It parses the header raw
> (here "    sk       Eth Pid    Groups   Rmem     Wmem     Dump     Locks     Drops")
> and picks values from columns only if the columns exits in the header raw.
> e.g. If "Inode" exists in the header, lsof tries to use Inode value.
> With the technique just adding(not deleting or swapping) a new column is not a big problem.
> 
> Masatake YAMATO
> 

Indeed :)

I am a big fan of Vic Abell lsof tool that I used before Linux was even
born :)