Jan Engelhardt wrote: > On Wednesday 2010-03-17 14:35, Patrick McHardy wrote: >>> + /* >>> + * Normally, we would just use ip_local_out. Because iph->check is >>> + * already correct, we could take a shortcut and call dst_output >>> + * [forwards to ip_output] directly. ip_output however will invoke >>> + * Netfilter hooks >>> > [ok we can skip these with IPSKB_REROUTED] > > >>> and cause reentrancy. So we skip that too and go >>> + * directly to ip_finish_output. >>> > > And since we don't want fragmentation, we would need to call > ip_finish_output2. That function is not exported, so it is copied. I > am not even sure what the IPv4 layer does when it has to fragment a > fragment (because fragments don't seem to carry IP_DF). > I guess whether someone wants fragmentation is a question of the specific use case. In many possible cases conntrack might have defragmented the packet previously to reaching TEE, so it might actually be necessary to refragment the packet. > Setting IP_DF on the cloned skb could possibly lead to a Packet Too > Big being sent back to the original sender - which should probably be > avoided too. > Indeed. This might also happen if the packet is passed through another router of course. > > So removing the copied code does not look that easy. > Well, worst case export the original function in case of duplicating it. -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
