This patch disallows rbtree with single elements, which is causing
problems with the recent timeout support. Before this patch, you
could opt out individual set representations per module, which is
just adding extra complexity.
Fixes: 8d8540c4f5e0("netfilter: nft_set_rbtree: add timeout support")
Reported-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Use garbage collector to schedule removal of elements based of feedback
from expression that this element comes with. Therefore, the garbage
collector is not guided by timeout expirations in this new mode.
The new connlimit expression sets on the NFT_EXPR_GC flag to enable this
behaviour, the dynset expression needs to explicitly enable the garbage
collector via set->ops->gc_init call.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Drop nft_set_type's ability to act as a container of multiple backend
implementations it chooses from. Instead consolidate the whole selection
logic in nft_select_set_ops() and the actual backend provided estimate()
callback.
This turns nf_tables_set_types into a list containing all available
backends which is traversed when selecting one matching userspace
requested criteria.
Also, this change allows to embed nft_set_ops structure into
nft_set_type and pull flags field into the latter as it's only used
during selection phase.
A crucial part of this change is to make sure the new layout respects
hash backend constraints formerly enforced by nft_hash_select_ops()
function: This is achieved by introduction of a specific estimate()
callback for nft_hash_fast_ops which returns false for key lengths != 4.
In turn, nft_hash_estimate() is changed to return false for key lengths
== 4 so it won't be chosen by accident. Also, both callbacks must return
false for unbounded sets as their size estimate depends on a known
maximum element count.
Note that this patch partially reverts commit 4f2921ca21 ("netfilter:
nf_tables: meter: pick a set backend that supports updates") by making
nft_set_ops_candidate() not explicitly look for an update callback but
make NFT_SET_EVAL a regular backend feature flag which is checked along
with the others. This way all feature requirements are checked in one
go.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
in nftables, 'meter' can be used to instantiate a hash-table at run
time:
rule add filter forward iif "internal" meter hostacct { ip saddr counter}
nft list meter ip filter hostacct
table ip filter {
meter hostacct {
type ipv4_addr
elements = { 192.168.0.1 : counter packets 8 bytes 2672, ..
because elemets get added on the fly, the kernel must chose a set
backend type that implements the ->update() function, otherwise
rule insertion fails with EOPNOTSUPP.
Therefore, skip set types that lack ->update, and also
make sure we do not discard a (bad) candidate when we did yet
find any candidate at all. This could happen when userspace prefers
low memory footprint -- the set implementation currently checked might
not be a fit at all. Make sure we pick it anyway (!bops). In
case next candidate is a better fix, it will be chosen instead.
But in case nothing else is found we at least have a non-ideal
match rather than no match at all.
Fixes: 6c03ae210c ("netfilter: nft_set_hash: add non-resizable hashtable implementation")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Most callers of rhashtable_walk_start don't care about a resize event
which is indicated by a return value of -EAGAIN. So calls to
rhashtable_walk_start are wrapped wih code to ignore -EAGAIN. Something
like this is common:
ret = rhashtable_walk_start(rhiter);
if (ret && ret != -EAGAIN)
goto out;
Since zero and -EAGAIN are the only possible return values from the
function this check is pointless. The condition never evaluates to true.
This patch changes rhashtable_walk_start to return void. This simplifies
code for the callers that ignore -EAGAIN. For the few cases where the
caller cares about the resize event, particularly where the table can be
walked in mulitple parts for netlink or seq file dump, the function
rhashtable_walk_start_check has been added that returns -EAGAIN on a
resize event.
Signed-off-by: Tom Herbert <tom@quantonium.net>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pablo Neira Ayuso says:
====================
Netfilter/IPVS updates for net-next
The following patchset contains Netfilter/IPVS updates for your net-next
tree, they are:
1) Speed up table replacement on busy systems with large tables
(and many cores) in x_tables. Now xt_replace_table() synchronizes by
itself by waiting until all cpus had an even seqcount and we use no
use seqlock when fetching old counters, from Florian Westphal.
2) Add nf_l4proto_log_invalid() and nf_ct_l4proto_log_invalid() to speed
up packet processing in the fast path when logging is not enabled, from
Florian Westphal.
3) Precompute masked address from configuration plane in xt_connlimit,
from Florian.
4) Don't use explicit size for set selection if performance set policy
is selected.
5) Allow to get elements from an existing set in nf_tables.
6) Fix incorrect check in nft_hash_deactivate(), from Florian.
7) Cache netlink attribute size result in l4proto->nla_size, from
Florian.
8) Handle NFPROTO_INET in nf_ct_netns_get() from conntrack core.
9) Use power efficient workqueue in conntrack garbage collector, from
Vincent Guittot.
10) Remove unnecessary parameter, in conntrack l4proto functions, also
from Florian.
11) Constify struct nf_conntrack_l3proto definitions, from Florian.
12) Remove all typedefs in nf_conntrack_h323 via coccinelle semantic
patch, from Harsha Sharma.
13) Don't store address in the rbtree nodes in xt_connlimit, they are
never used, from Florian.
14) Fix out of bound access in the conntrack h323 helper, patch from
Eric Sesterhenn.
15) Print symbols for the address returned with %pS in IPVS, from
Helge Deller.
16) Proc output should only display its own netns in IPVS, from
KUWAZAWA Takuya.
17) Small clean up in size_entry_mwt(), from Colin Ian King.
18) Use test_and_clear_bit from nf_nat_proto_clean() instead of separated
non-atomic test and then clear bit, from Florian Westphal.
19) Consolidate prefix length maps in ipset, from Aaron Conole.
20) Fix sparse warnings in ipset, from Jozsef Kadlecsik.
21) Simplify list_set_memsize(), from simran singhal.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds a new get operation to look up for specific elements in
a set via netlink interface. You can also use it to check if an interval
already exists.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Jindřich Makovička says:
The logical OR looks fishy to me. Shouldn't be && there instead?
Link: https://bugzilla.netfilter.org/show_bug.cgi?id=1199
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
jhash_1word of a u16 is a different value from jhash of the same u16 with
length 2.
Since elements are always inserted in sets using jhash over the actual
klen, this would lead to incorrect lookups on fixed-size sets with a key
length of 2, as they would be inserted with hash value jhash(key, 2) and
looked up with hash value jhash_1word(key), which is different.
Example reproducer(v4.13+), using anonymous sets which always have a
fixed size:
table inet t {
chain c {
type filter hook output priority 0; policy accept;
tcp dport { 10001, 10003, 10005, 10007, 10009 } counter packets 4 bytes 240 reject
tcp dport 10001 counter packets 4 bytes 240 reject
tcp dport 10003 counter packets 4 bytes 240 reject
tcp dport 10005 counter packets 4 bytes 240 reject
tcp dport 10007 counter packets 0 bytes 0 reject
tcp dport 10009 counter packets 4 bytes 240 reject
}
}
then use nc -z localhost <port> to probe; incorrectly hashed ports will
pass through the set lookup and increment the counter of an individual
rule.
jhash being seeded with a random value, it is not deterministic which
ports will incorrectly hash, but in testing with 5 ports in the set I
always had 4 or 5 with an incorrect hash value.
Signed-off-by: Anatole Denis <anatole@rezel.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch provides a faster variant of the lookup function for 2 and 4
byte keys. Optimizing the one byte case is not worth, as the set backend
selection will always select the bitmap set type for such case.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch adds a simple non-resizable hashtable implementation. If the
user specifies the set size, then this new faster hashtable flavour is
selected.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add nft_hash_buckets() helper function to calculate the number of
hashtable buckets based on the elements. This function can be reused
from the follow up patch to add non-resizable hashtables.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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 <pablo@netfilter.org>
This patch prepares the introduction of a non-resizable hashtable
implementation that is significantly faster.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This size estimation is ignored by the existing set backend selection
logic, since this estimation structure is stack allocated, set this to
~0 to make it easier to catch bugs in future changes.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
When dumping the elements related to a specified set, we may invoke the
nf_tables_dump_set with the NFNL_SUBSYS_NFTABLES lock not acquired. So
we should use the proper rcu operation to avoid race condition, just
like other nft dump operations.
Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The following Coccinelle script was used to detect this:
@r@
expression x;
void* e;
type T;
identifier f;
@@
(
*((T *)e)
|
((T *)x)[...]
|
((T*)x)->f
|
- (T*)
e
)
Unnecessary parantheses are also remove.
Signed-off-by: simran singhal <singhalsimran0@gmail.com>
Reviewed-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The space notation allows us to classify the set backend implementation
based on the amount of required memory. This provides an order of the
set representation scalability in terms of memory. The size field is
still left in place so use this if the userspace provides no explicit
number of elements, so we cannot calculate the real memory that this set
needs. This also helps us break ties in the set backend selection
routine, eg. two backend implementations provide the same performance.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Use lookup as field name instead, to prepare the introduction of the
memory class in a follow up patch.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Although semantics are similar to deactivate() with no implicit element
lookup, this is only called from the set flush path, so better rename
this to flush().
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch adds support for set flushing, that consists of walking over
the set elements if the NFTA_SET_ELEM_LIST_ELEMENTS attribute is set.
This patch requires the following changes:
1) Add set->ops->deactivate_one() operation: This allows us to
deactivate an element from the set element walk path, given we can
skip the lookup that happens in ->deactivate().
2) Add a new nft_trans_alloc_gfp() function since we need to allocate
transactions using GFP_ATOMIC given the set walk path happens with
held rcu_read_lock.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This new function allows us to deactivate one single element, this is
required by the set flush command that comes in a follow up patch.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Packets may race when create the new element in nft_hash_update:
CPU0 CPU1
lookup_fast - fail lookup_fast - fail
new - ok new - ok
insert - ok insert - fail(EEXIST)
So when race happened, we reuse the existing element. Otherwise,
these *racing* packets will not be handled properly.
Fixes: 22fe54d5fe ("netfilter: nf_tables: add support for dynamic set updates")
Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
When nft_expr_clone failed, a series of problems will happen:
1. module refcnt will leak, we call __module_get at the beginning but
we forget to put it back if ops->clone returns fail
2. memory will be leaked, if clone fail, we just return NULL and forget
to free the alloced element
3. set->nelems will become incorrect when set->size is specified. If
clone fail, we should decrease the set->nelems
Now this patch fixes these problems. And fortunately, clone fail will
only happen on counter expression when memory is exhausted.
Fixes: 086f332167 ("netfilter: nf_tables: add clone interface to expression operations")
Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
If the NLM_F_EXCL flag is set, then new elements that clash with an
existing one return EEXIST. In case you try to add an element whose
data area differs from what we have, then this returns EBUSY. If no
flag is specified at all, then this returns success to userspace.
This patch also update the set insert operation so we can fetch the
existing element that clashes with the one you want to add, we need
this to make sure the element data doesn't differ.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Use nft_set_* prefix for backend set implementations, thus we can use
nft_hash for the new hash expression.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>