Re: pmtu discovery on SA

["Mika Penttilä" <mika.penttila@kolumbus.fi>]

Patrick McHardy wrote:
> Mika Penttilä wrote:
>   
>> Patrick McHardy wrote:
>>
>>     
>>> Its a debugging message nowadays (NETDEBUG). I was mostly interested
>>> in this since I changed the IPsec MTU calculation in 2.6.22 and it
>>> might have been a bug.
>>>
>>>   
>>>       
>> And we don't have pmtu discovery for esp yet, right?
>>     
>
>
> We do. The best I have seen to date in any IPsec implementation :)
> -
> To unsubscribe from this list: send the line "unsubscribe netdev" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>
>   
Hmm. esp4_err() looks like this :

    struct iphdr *iph = (struct iphdr*)skb->data;
    struct ip_esp_hdr *esph = (struct ip_esp_hdr*)(skb->data+(iph->ihl<<2));
    struct xfrm_state *x;

    if (icmp_hdr(skb)->type != ICMP_DEST_UNREACH ||
        icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
        return;

    x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr, esph->spi, 
IPPROTO_ESP, AF_INET);
    if (!x)
        return;
    NETDEBUG(KERN_DEBUG "pmtu discovery on SA ESP/%08x/%08x\n",
         ntohl(esph->spi), ntohl(iph->daddr));
    xfrm_state_put(x);



where could pmtu discovery be happening?

--Mika