Re: ICMPv6 Redirects

[Alexander Aring <alex.aring@gmail.com>]

On Mon, Sep 29, 2014 at 05:29:42PM +0530, Varka Bhadram wrote:
> On 09/29/2014 05:27 PM, Alexander Aring wrote:
> >On Mon, Sep 29, 2014 at 01:53:51PM +0200, Alexander Aring wrote:
> >>On Mon, Sep 29, 2014 at 05:15:51PM +0530, Varka Bhadram wrote:
> >>>On 09/29/2014 05:05 PM, Varka Bhadram wrote:
> >>>>On 09/29/2014 04:39 PM, Simon Vincent wrote:
> >>>>>On 29/09/14 11:58, Varka Bhadram wrote:
> >>>>>>Simon,
> >>>>>>
> >>>>>>On 09/29/2014 03:50 PM, Simon Vincent wrote:
> >>>>>>>Currently there does not seem to be any filtering in the mac layer
> >>>>>>>anyway. In wpan.c mac802154_subif_frame we check the pan id and dest
> >>>>>>>address but we don't discard any packets. Should we be discarding
> >>>>>>>packets at this point? For example packets of type PACKET_OTHERHOST.
> >>>>>>>
> >>>>>>>If I discard all PACKET_OTHERHOST in mac802154_subif_frame it solves
> >>>>>>>my problem. I just don't know if this will effect anything else.
> >>>>>>>
> >>>>>>I think we are not supposed to discard the packets like this. This will
> >>>>>>create the problems if routing enabled on the node.
> >>>>>>
> >>>>>>This not problem with the IEEE-802.15.4 driver or MAC implementation.
> >>>>>>
> >>>>>>These issues related to IPv6/ICMPv6 (ECHO request and ECHO reply).
> >>>>>>Here RFC2461/RFC4861 will
> >>>>>>come into picture. see:http://www.tahi.org/logo/phase2-core/result/Self_Test_4-0-3/freebsd71.router/nd.p2/
> >>>>>>
> >>>>>>Can you explain the setup..? What h/w you are using. How the network
> >>>>>>connected..?
> >>>>>>
> >>>>>I am running three nodes all directly connected to each other via
> >>>>>powerline networking running 802.15.4.
> >>>>>Therefore all nodes can see all the traffic. The nodes are setup with
> >>>>>ipv6 forwarding enabled.
> >>>>>If I ping node A from node B node C sends ICMP redirects.
> >>>>Please add:
> >>>>
> >>>>net.ipv6.conf.all.accept_redirects = 1
> >>>>net.ipv6.conf.all.send_redirects = 1
> >>>>
> >>>>to your//etc/sysctl.conf/  file.. It will disable redirect..
> >>>>
> >>>>Try this . I hope it will work.
> >>>Sorry for the wrong info...
> >>>
> >>>Set up accept_redirects/send_redirects to boolean value '0'
> >>>
> >>>echo 0 > /proc/sys/net/ipv6/conf/all/accept_redirects
> >>>
> >>don't know but I think this is only if we send or accept the route
> >>ICMPv6 messages. You only configure some filtering if you get these
> >>ICMPv6 messages or not, or if you send these ICMPv6 messages.
> >>
> >ah yes and this also make handling of these ICMPv6 messages or not.
> >
> >But Simon, did some dropping of skb's when these are PACKET_OTHERHOST,
> >and then it works for him. So this should some other issues, because
> >IPv6 should drop all sk_buff's which are PACKET_OTHERHOST.
> >
> >Which should be the same like dropping PACKET_OTHERHOST in mac802154.
> >
> >- Alex
> 
> Please see:*http://lxr.free-electrons.com/source/net/ieee802154/af_ieee802154.c?v=2.6.34#L319*
> 
> If packet type is PACKET_OTHERHOST its dropping, isn't it..?

Yep that's why dropping PACKET_OTHERHOST is handled by next layer. Not
mac802154. We have as next layer 6LoWPAN and af_ieee802154.

- Alex