linux-kernel - Re: [net-next PATCH v4 0/3] net: reserve ports for applications using fixed port

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Tue, 16 Feb 2010 10:49:37 -0800
From:	ebiederm@...ssion.com (Eric W. Biederman)
To:	Octavian Purdila <opurdila@...acom.com>
Cc:	David Miller <davem@...emloft.net>,
	Linux Kernel Network Developers <netdev@...r.kernel.org>,
	Linux Kernel Developers <linux-kernel@...r.kernel.org>,
	Amerigo Wang <amwang@...hat.com>
Subject: Re: [net-next PATCH v4 0/3] net: reserve ports for applications using fixed port

Octavian Purdila <opurdila@...acom.com> writes:

> Hi Eric, thanks for going over this.
>
> The use case (large bitmaps/lists) is different enough from what we have today 
> (small bitmaps) and that is why I think that we need this new interface. 
>
> If I get bitmap_parse_user correctly, for a 64k bitmap it expects a 2K comma 
> separated values. That is not the most intuitively way for the user to set a 
> list of ports he wants to reserve. 

In this case I expect an interface of comma separated ranges would be
ideal.  Typically compact, and modifiable by writing the new value to
the file.

I think the default value would be something like 32768-61000.

> Using 64K files has the same practical issues (the user would have to cat all 
> 64K files to determine which ports are reserved) plus it has issues caused by 
> the large number of files: significant memory overhead and also significant time 
> for registering those files.

"grep -l 1 *" isn't particularly difficult, and it would be one sysctl registration
call.  It is true that the sysctl memory footprint would be a pain in that case.

Eric




--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/