Re: 2.4.21+ - IPv6 over IPv4 tunneling b0rked

From: "Mika Penttilä" <mika.penttila@kolumbus.fi>
To: Mika Liljeberg <mika.liljeberg@welho.com>
Cc: Pekka Savola <pekkas@netcore.fi>, Andre Tomt <andre@tomt.net>,
	linux-kernel@vger.kernel.org, netdev@oss.sgi.com
Subject: Re: 2.4.21+ - IPv6 over IPv4 tunneling b0rked
Date: Fri, 11 Jul 2003 17:27:57 +0300	[thread overview]
Message-ID: <3F0EC96D.6080102@kolumbus.fi> (raw)
In-Reply-To: 1057930712.895.32.camel@hades

afaics, ipv6_addr_type() checks just for some rfc-specified reserved 
anycast addresses, not the ones in device list. Anyway, it will surely 
also bail out from the loopback test (anycast subnet router address is 
ours).

--Mika

Mika Liljeberg wrote:

>On Fri, 2003-07-11 at 15:48, Mika Penttilä wrote:
>  
>
>>It turns out to be the (otherwise valid) check for  IFF_LOOPBACK for 
>>gateway's address in ip6_route_add() that gives EINVAL for prefix::, and 
>>has nothing to do with iid being 0, just a coinsidence....
>>    
>>
>
>Not sure. Seems to me that ipv6_addr_type() flags the gateway address as
>anycast. In ip6_route_addr() [2.5.74] we have:
>
>        if (rtmsg->rtmsg_flags & RTF_GATEWAY) {
>                struct in6_addr *gw_addr;
>                int gwa_type;
>
>                gw_addr = &rtmsg->rtmsg_gateway;
>                ipv6_addr_copy(&rt->rt6i_gateway, &rtmsg->rtmsg_gateway);
>                gwa_type = ipv6_addr_type(gw_addr);
>
>                if (gwa_type != (IPV6_ADDR_LINKLOCAL|IPV6_ADDR_UNICAST)) {
>                        struct rt6_info *grt;
>
>                        /* IPv6 strictly inhibits using not link-local
>                           addresses as nexthop address.
>                           Otherwise, router will not able to send redirects.
>                           It is very good, but in some (rare!) curcumstances
>                           (SIT, PtP, NBMA NOARP links) it is handy to allow
>                           some exceptions. --ANK
>                         */
>                        err = -EINVAL;
>                        if (!(gwa_type&IPV6_ADDR_UNICAST))
>                                goto out;
>
>Looks like it would bail out here, unless I read the code wrong. How about:
>
>                        if (!(gwa_type&(IPV6_ADDR_UNICAST|IPV6_ADDR_ANYCAST)))
>                                goto out;
>
>	MikaL
>
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