netdev - Re: [PATCH 5/5] [NETLINK]: Ignore control messages directly in netlink_run

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]

Message-ID: <46012357.2030701@trash.net>
Date:	Wed, 21 Mar 2007 13:21:43 +0100
From:	Patrick McHardy <kaber@...sh.net>
To:	Thomas Graf <tgraf@...g.ch>
CC:	davem@...emloft.net, netdev@...r.kernel.org,
	Netfilter Development Mailinglist 
	<netfilter-devel@...ts.netfilter.org>
Subject: Re: [PATCH 5/5] [NETLINK]: Ignore control messages directly in netlink_run_queue()

Patrick McHardy wrote:
> Thomas Graf wrote:
> 
>>* Patrick McHardy <kaber@...sh.net> 2007-03-21 05:44
>>
>>
>>>This looks like it would break nfnetlink, which appears to be
>>>using 0 as smallest message type.
>>
>>
>>It shouldn't do that, the first 16 message types are reserved
>>for control messages.
> 
> 
> 
> I'm afraid it does:
> 
> enum cntl_msg_types {
>         IPCTNL_MSG_CT_NEW,
>         IPCTNL_MSG_CT_GET,
>         IPCTNL_MSG_CT_DELETE,
>         IPCTNL_MSG_CT_GET_CTRZERO,
>         IPCTNL_MSG_MAX
> };
> 
> This is totally broken of course since it also uses netlink_ack(),
> netlink_dump() etc. :( Any smart ideas how to fix this without
> breaking compatibility?


Seems like we're lucky, nfnetlink encodes the "subsystem ID"
in the upper 8 bits of the message type and uses 1 as the
smallest ID:

/* netfilter netlink message types are split in two pieces:
 * 8 bit subsystem, 8bit operation.
 */

#define NFNL_SUBSYS_ID(x)       ((x & 0xff00) >> 8)
#define NFNL_MSG_TYPE(x)        (x & 0x00ff)

#define NFNL_SUBSYS_NONE                0
#define NFNL_SUBSYS_CTNETLINK           1
#define NFNL_SUBSYS_CTNETLINK_EXP       2
#define NFNL_SUBSYS_QUEUE               3
#define NFNL_SUBSYS_ULOG                4
#define NFNL_SUBSYS_COUNT               5



So this should work fine.

-
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html