Re: 2.4.21+ - IPv6 over IPv4 tunneling b0rked

From: Mika Liljeberg <mika.liljeberg@welho.com>
To: "Mika Penttilä" <mika.penttila@kolumbus.fi>
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: 11 Jul 2003 17:32:34 +0300	[thread overview]
Message-ID: <1057933954.695.6.camel@hades> (raw)
In-Reply-To: <3F0EC96D.6080102@kolumbus.fi>

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On Fri, 2003-07-11 at 17:27, Mika Penttilä wrote:
> 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).

Nope, since the tunnel interface will have 2002::/16. It seems to work
with the attached patch (against 2.4.21-ac4). A small fix to sit was
required as well. Look:

hades:~# ifconfig 6to4
6to4      Link encap:IPv6-in-IPv4
          inet6 addr: ::213.243.180.94/128 Scope:Compat
          inet6 addr: 2002:d5f3:b45e::1/16 Scope:Global
          UP RUNNING NOARP  MTU:1480  Metric:1
          RX packets:4 errors:0 dropped:0 overruns:0 frame:0
          TX packets:4 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:416 (416.0 b)  TX bytes:496 (496.0 b)

hades:~# ip -6 route list
::/96 via :: dev 6to4  metric 256  mtu 1480 advmss 1420
2002::/16 dev 6to4  proto kernel  metric 256  mtu 1480 advmss 1420
fe80::/64 dev eth0  proto kernel  metric 256  mtu 1500 advmss 1440
fe80::/64 dev 6to4  proto kernel  metric 256  mtu 1480 advmss 1420
ff00::/8 dev eth0  proto kernel  metric 256  mtu 1500 advmss 1440
ff00::/8 dev 6to4  proto kernel  metric 256  mtu 1480 advmss 1420
default via 2002:c058:6301:: dev 6to4  metric 1024  mtu 1480 advmss 1420
hades:~# ping6 -c4 -n www.ipv6.org
PING www.ipv6.org(2001:6b0:1:ea:a00:20ff:fe8f:708f) 56 data bytes
64 bytes from 2001:6b0:1:ea:a00:20ff:fe8f:708f: icmp_seq=1 ttl=250 time=207 ms
64 bytes from 2001:6b0:1:ea:a00:20ff:fe8f:708f: icmp_seq=2 ttl=250 time=206 ms
64 bytes from 2001:6b0:1:ea:a00:20ff:fe8f:708f: icmp_seq=3 ttl=250 time=177 ms
64 bytes from 2001:6b0:1:ea:a00:20ff:fe8f:708f: icmp_seq=4 ttl=250 time=78.5 ms

--- www.ipv6.org ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3030ms
rtt min/avg/max/mdev = 78.547/167.637/207.698/52.821 ms

Anyone see any problems with this?

	MikaL


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--- route.c.org	2003-07-11 16:41:55.000000000 +0300
+++ route.c	2003-07-11 16:42:16.000000000 +0300
@@ -743,7 +743,7 @@
 			   some exceptions. --ANK
 			 */
 			err = -EINVAL;
-			if (!(gwa_type&IPV6_ADDR_UNICAST))
+			if (!(gwa_type&(IPV6_ADDR_UNICAST|IPV6_ADDR_ANYCAST)))
 				goto out;
 
 			grt = rt6_lookup(gw_addr, NULL, rtmsg->rtmsg_ifindex, 1);
--- sit.c.org	2003-07-11 16:57:53.000000000 +0300
+++ sit.c	2003-07-11 17:17:42.000000000 +0300
@@ -495,10 +495,13 @@
 			addr_type = ipv6_addr_type(addr6);
 		}
 
-		if ((addr_type & IPV6_ADDR_COMPATv4) == 0)
-			goto tx_error_icmp;
+		if ((addr_type & IPV6_ADDR_COMPATv4))
+			dst = addr6->s6_addr32[3];
+		else
+			dst = try_6to4(addr6);
 
-		dst = addr6->s6_addr32[3];
+		if (!dst)
+			goto tx_error_icmp;
 	}
 
 	if (ip_route_output(&rt, dst, tiph->saddr, RT_TOS(tos), tunnel->parms.link)) {
