linux-stable.git/include/net/netfilter, branch linux-4.13.y

netfilter: nat: Revert "netfilter: nat: convert nat bysrc hash to rhashtable"

2017-11-15T09:09:15+00:00

commit e1bf1687740ce1a3598a1c5e452b852ff2190682 upstream.

This reverts commit 870190a9ec9075205c0fa795a09fa931694a3ff1.

It was not a good idea. The custom hash table was a much better
fit for this purpose.

A fast lookup is not essential, in fact for most cases there is no lookup
at all because original tuple is not taken and can be used as-is.
What needs to be fast is insertion and deletion.

rhlist removal however requires a rhlist walk.
We can have thousands of entries in such a list if source port/addresses
are reused for multiple flows, if this happens removal requests are so
expensive that deletions of a few thousand flows can take several
seconds(!).

The advantages that we got from rhashtable are:
1) table auto-sizing
2) multiple locks

1) would be nice to have, but it is not essential as we have at
most one lookup per new flow, so even a million flows in the bysource
table are not a problem compared to current deletion cost.
2) is easy to add to custom hash table.

I tried to add hlist_node to rhlist to speed up rhltable_remove but this
isn't doable without changing semantics.  rhltable_remove_fast will
check that the to-be-deleted object is part of the table and that
requires a list walk that we want to avoid.

Furthermore, using hlist_node increases size of struct rhlist_head, which
in turn increases nf_conn size.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=196821
Reported-by: Ivan Babrou 
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

net: convert nf_bridge_info.use from atomic_t to refcount_t

2017-07-01T14:39:07+00:00

refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova 
Signed-off-by: Hans Liljestrand 
Signed-off-by: Kees Cook 
Signed-off-by: David Windsor 
Signed-off-by: David S. Miller

netfilter: conntrack: use NFPROTO_MAX to size array

2017-06-19T17:20:49+00:00

We don't support anything larger than NFPROTO_MAX, so we can shrink this a bit:

     text data  dec  hex filename
old: 8259 1096 9355 248b net/netfilter/nf_conntrack_proto.o
new: 8259  624 8883 22b3 net/netfilter/nf_conntrack_proto.o

Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso

netfilter: nf_tables: pass set description to ->privsize

2017-05-29T10:46:18+00:00

The new non-resizable hashtable variant needs this to calculate the
size of the bucket array.

Signed-off-by: Pablo Neira Ayuso

netfilter: nf_tables: select set backend flavour depending on description

2017-05-29T10:46:17+00:00

This patch adds the infrastructure to support several implementations of
the same set type. This selection will be based on the set description
and the features available for this set. This allow us to select set
backend implementation that will result in better performance numbers.

Signed-off-by: Pablo Neira Ayuso

netfilter: conntrack: add nf_ct_iterate_destroy

2017-05-29T10:46:10+00:00

sledgehammer to be used on module unload (to remove affected conntracks
from all namespaces).

It will also flag all unconfirmed conntracks as dying, i.e. they will
not be committed to main table.

Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso

netfilter: conntrack: rename nf_ct_iterate_cleanup

2017-05-29T10:46:08+00:00

There are several places where we needlesly call nf_ct_iterate_cleanup,
we should instead iterate the full table at module unload time.

This is a leftover from back when the conntrack table got duplicated
per net namespace.

So rename nf_ct_iterate_cleanup to nf_ct_iterate_cleanup_net.
A later patch will then add a non-net variant.

Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso

netfilter: nf_tables: revisit chain/object refcounting from elements

2017-05-15T10:51:41+00:00

Andreas reports that the following incremental update using our commit
protocol doesn't work.

 # nft -f incremental-update.nft
 delete element ip filter client_to_any { 10.180.86.22 : goto CIn_1 }
 delete chain ip filter CIn_1
 ... Error: Could not process rule: Device or resource busy

The existing code is not well-integrated into the commit phase protocol,
since element deletions do not result in refcount decrement from the
preparation phase. This results in bogus EBUSY errors like the one
above.

Two new functions come with this patch:

* nft_set_elem_activate() function is used from the abort path, to
  restore the set element refcounting on objects that occurred from
  the preparation phase.

* nft_set_elem_deactivate() that is called from nft_del_setelem() to
  decrement set element refcounting on objects from the preparation
  phase in the commit protocol.

The nft_data_uninit() has been renamed to nft_data_release() since this
function does not uninitialize any data store in the data register,
instead just releases the references to objects. Moreover, a new
function nft_data_hold() has been introduced to be used from
nft_set_elem_activate().

Reported-by: Andreas Schultz 
Signed-off-by: Pablo Neira Ayuso

netfilter: nfnl_cthelper: reject del request if helper obj is in use

2017-05-15T10:42:29+00:00

We can still delete the ct helper even if it is in use, this will cause
a use-after-free error. In more detail, I mean:
  # nfct helper add ssdp inet udp
  # iptables -t raw -A OUTPUT -p udp -j CT --helper ssdp
  # nfct helper delete ssdp //--> oops, succeed!
  BUG: unable to handle kernel paging request at 000026ca
  IP: 0x26ca
  [...]
  Call Trace:
   ? ipv4_helper+0x62/0x80 [nf_conntrack_ipv4]
   nf_hook_slow+0x21/0xb0
   ip_output+0xe9/0x100
   ? ip_fragment.constprop.54+0xc0/0xc0
   ip_local_out+0x33/0x40
   ip_send_skb+0x16/0x80
   udp_send_skb+0x84/0x240
   udp_sendmsg+0x35d/0xa50

So add reference count to fix this issue, if ct helper is used by
others, reject the delete request.

Apply this patch:
  # nfct helper delete ssdp
  nfct v1.4.3: netlink error: Device or resource busy

Signed-off-by: Liping Zhang 
Signed-off-by: Pablo Neira Ayuso

netfilter: introduce nf_conntrack_helper_put helper function

2017-05-15T10:42:29+00:00

And convert module_put invocation to nf_conntrack_helper_put, this is
prepared for the followup patch, which will add a refcnt for cthelper,
so we can reject the deleting request when cthelper is in use.

Signed-off-by: Liping Zhang 
Signed-off-by: Pablo Neira Ayuso