Having frag_list members which holds wmem of an sk leads to nightmares
with partially cloned frag skb's. The reason is that once you unleash
a skb with a frag_list that has individual sk ownerships into the stack
you can never undo those ownerships safely as they may have been cloned
by things like netfilter. Since we have to undo them in order to make
skb_linearize happy this approach leads to a dead-end.
So let's go the other way and make this an invariant:
For any skb on a frag_list, skb->sk must be NULL.
That is, the socket ownership always belongs to the head skb.
It turns out that the implementation is actually pretty simple.
The above invariant is actually violated in the following patch
for a short duration inside ip_fragment. This is OK because the
offending frag_list member is either destroyed at the end of the
slow path without being sent anywhere, or it is detached from
the frag_list before being sent.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
While looking at this problem I noticed that IPv6 was sometimes
looking at inet->recverr which is bogus. Here is a patch to
correct that and use np->recverr.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Herbert Xu
Linus Torvalds