Re: [PATCH 2.6.18 try 2] net/ipv4: sysctl to allow non-superuser to bypass CAP_NET_BIND_SERVICE requirement

["YOSHIFUJI Hideaki / 吉藤英明" <yoshfuji@linux-ipv6.org>]

In article <736CE60D-FB88-4246-8728-B7AC7880B28E@atheme.org> (at Fri, 22 Sep 2006 02:31:59 -0500), William Pitcock <nenolod@atheme.org> says:

> This patch allows for a user to disable the requirement to meet the  
> CAP_NET_BIND_SERVICE capability for a non-superuser. It is toggled by  
> the net.ipv4.allow_lowport_bind_nonsuperuser sysctl value.

Why?  I don't think this is a good idea.

> diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
> index e4b1a4d..c3f7c3c 100644
> --- a/include/linux/sysctl.h
> +++ b/include/linux/sysctl.h
> @@ -411,6 +411,7 @@ enum
> 	NET_IPV4_TCP_WORKAROUND_SIGNED_WINDOWS=115,
> 	NET_TCP_DMA_COPYBREAK=116,
> 	NET_TCP_SLOW_START_AFTER_IDLE=117,
> +	NET_IPV4_ALLOW_LOWPORT_BIND_NONSUPERUSER=118,
>    };
> 
>    enum {

This implies all IPv4 protocols including other protocols
such as UDP, SCTP, ...

> @@ -1412,3 +1418,4 @@ EXPORT_SYMBOL(inet_stream_ops);
>    EXPORT_SYMBOL(inet_unregister_protosw);
>    EXPORT_SYMBOL(net_statistics);
>    EXPORT_SYMBOL(sysctl_ip_nonlocal_bind);
> +EXPORT_SYMBOL(sysctl_ip_allow_lowport_bind_nonsuperuser);

Please be aware about indent.

--yoshfuji