IPv6 : ICMPV6_DEST_UNREACH type with ICMPV6_NOROUTE code

IPv6 : ICMPV6_DEST_UNREACH type with ICMPV6_NOROUTE code

[Seong Moon]

Hi, there.
I'm recently analyzing the kernel source for IPv6 router.

I found that when the kernel has no forwarding entry of a packet,
the kernel sends an ICMPV6_DEST_UNREACH icmp message with
ICMPV6_ADDR_UNREACH code
to the source of the packet.

But According to RFC 2463, If the kerenl has no forwarding entry of a
packet,
the kernel must send an ICMPV6_DEST_UNREACH icmp message with ICMPV6_NOROUTE
code.

In my opinion, ip6_pkt_discard() should be modified as follows :

int ip6_pkt_discard(struct sk_buff *skb)
{
    IP6_INC_STATS(Ip6OutNoRoutes);
    /* icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0,
skb->dev); */
    icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_NOROUTE, 0, skb->dev);
    kfree_skb(skb);
    return 0;
}

How about you ? Am I right ?

And I found another doubtable thing,
ipv6_routing_header() sends an ICMPv6 Parameter Problem message if the
extention header's length is odd value.
Then ICMPv6 Parameter Problem Message includes the pointer that indicates
the byte offset of errorneous field in a packet.
ipv6_routing_header() calculates the byte offset from the beginning of the
extention header.

In my opinion, ipv6_routing_header() must calculates the byte offset from
the beginning of the
IPv6 packet.

Is this right ?

bye.

IPv6 : ICMPV6_DEST_UNREACH type with ICMPV6_NOROUTE code

[Robert Olsson]

Seong Moon writes:

 > I found that when the kernel has no forwarding entry of a packet,
 > the kernel sends an ICMPV6_DEST_UNREACH icmp message with
 > ICMPV6_ADDR_UNREACH code  to the source of the packet.
 > 
 > But According to RFC 2463, If the kerenl has no forwarding entry of a
 > packet,
 > the kernel must send an ICMPV6_DEST_UNREACH icmp message with ICMPV6_NOROUTE
 > code.
 > How about you ? Am I right ?

 I think you are...

--- linux/net/ipv6/route.c.030508       2003-03-24 23:01:14.000000000 +0100
+++ linux/net/ipv6/route.c      2003-05-09 13:29:31.000000000 +0200
@@ -1166,7 +1166,7 @@
 int ip6_pkt_discard(struct sk_buff *skb)
 {
        IP6_INC_STATS(Ip6OutNoRoutes);
-       icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0, skb->dev);
+       icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_NOROUTE, 0, skb->dev);
        kfree_skb(skb);
        return 0;
 }


 Cheers.
						--ro

Re: IPv6 : ICMPV6_DEST_UNREACH type with ICMPV6_NOROUTE code

[YOSHIFUJI Hideaki / 吉藤英明]

In article <16059.37474.453731.39031@robur.slu.se> (at Fri, 9 May 2003 13:34:58 +0200), Robert Olsson <Robert.Olsson@data.slu.se> says:

>  > the kernel must send an ICMPV6_DEST_UNREACH icmp message with ICMPV6_NOROUTE
>  > code.
>  > How about you ? Am I right ?
> 
>  I think you are...
> 
> --- linux/net/ipv6/route.c.030508       2003-03-24 23:01:14.000000000 +0100
> +++ linux/net/ipv6/route.c      2003-05-09 13:29:31.000000000 +0200
> @@ -1166,7 +1166,7 @@
>  int ip6_pkt_discard(struct sk_buff *skb)
>  {
>         IP6_INC_STATS(Ip6OutNoRoutes);
> -       icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0, skb->dev);
> +       icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_NOROUTE, 0, skb->dev);
>         kfree_skb(skb);
>         return 0;
>  }

Yes, code is already in the tree.  Thanks.

--yoshfuji

Re: IPv6 : ICMPV6_DEST_UNREACH type with ICMPV6_NOROUTE code

[David S. Miller]

   From: Robert Olsson <Robert.Olsson@data.slu.se>
   Date: Fri, 9 May 2003 13:34:58 +0200
   
   Seong Moon writes:
   
    > How about you ? Am I right ?
   
    I think you are...

Yoshfuji already composed a patch which is already in
the tree.