netdev - Re: [RFC:] struct net_device_ops: Add function pointer to fill device specific ndisc information

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:	Mon, 21 Jan 2013 03:47:13 +0900
From:	YOSHIFUJI Hideaki <yoshfuji@...ux-ipv6.org>
To:	stephan.gatzka@...il.com
CC:	linux1394-devel@...ts.sourceforge.net,
	netdev <netdev@...r.kernel.org>,
	David Miller <davem@...emloft.net>
Subject: Re: [RFC:] struct net_device_ops: Add function pointer to fill device
 specific ndisc information

Stephan Gatzka wrote:
> I've implemented IPv6 over firewire. Right now I'm facing the problem that the corresponding RFC3146 requires very firewire specific information sent during neighborhood discovery.
> 
> There was already a discussion on the linux1394 mailing list (http://sourceforge.net/mailarchive/message.php?msg_id=30342089 and http://sourceforge.net/mailarchive/forum.php?thread_name=50E4A3E5.8080304%40gmail.com&forum_name=linux1394-devel)
> 
> During that discussion all participants agreed that it makes no sense to introduce a dependency between the ndisc code and the firewire net driver.
> 
> So the most appealing option seems to be to introduce on more callback routine either in struct net_device or struct net_device_ops:
> 
> int (*ndo_fill_llao)(void *llao);
> 
> Because I'm not so familiar with the structure of the whole network infrastructure in Linux, I need some advice if struct net_device or struct net_device_ops is the right place.
> 
> Maybe it's worth to generalize this and do the same for IPv4/ARP because right now the ARP packets are mangled in the firewire net driver.
> 
> Nevertheless, I've to admit that right now it seems that only IPv6 over firewire requires such a callback routine.

My current position is to change "mac address" to

struct fwnet_hwaddr {
	u8	guid[8];
	u8	max_rec;
	u8	sspd;
	u8	fifo[6];
};

Benefits:

[ARP and NDISC]
- both can be handled in more natural way.
-- You will not need to mangle those packets when
   sending/receiving.
-- You do not need to inspect ARP/NDISC packet.
   By using netevent notification mechanism, you can
   learn peer parameters.
-- IP layer is not required to change very much.

[Multicast]
-it can be handled in more natural way.
-- MCAP (Multicast Channel Allocation Protocol) needs to
   know full IP multicast address.
-- We have IP multicast address => "hardware address"
   mapping for each L2 type in IP layer.
-- We expect that IP layer can request net_device to
   receive multicast stream for some multicast address
   via corresponding "hardware address".
-- This means that we need to have "hardware address"
   of 128bits (16 octets) or more.
-- By increasing size of dev->dev_addr, we can embedded
   full IPv6 address in it.

--yoshfuji
--
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