Add missing set->ndeact update on each deactivated element from the set
flush path. Otherwise, sets with fixed size break after flush since
accounting breaks.
# nft add set x y { type ipv4_addr\; size 2\; }
# nft add element x y { 1.1.1.1 }
# nft add element x y { 1.1.1.2 }
# nft flush set x y
# nft add element x y { 1.1.1.1 }
<cmdline>:1:1-28: Error: Could not process rule: Too many open files in system
Fixes: 8411b6442e ("netfilter: nf_tables: support for set flushing")
Reported-by: Elise Lennion <elise.lennion@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
If the element exists and no NLM_F_EXCL is specified, do not bump
set->nelems, otherwise we leak one set element slot. This problem
amplifies if the set is full since the abort path always decrements the
counter for the -ENFILE case too, giving one spare extra slot.
Fix this by moving set->nelems update to nft_add_set_elem() after
successful element insertion. Moreover, remove the element if the set is
full so there is no need to rely on the abort path to undo things
anymore.
Fixes: c016c7e45d ("netfilter: nf_tables: honor NLM_F_EXCL flag in set element insertion")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
First, log prefix will be truncated to NF_LOG_PREFIXLEN-1, i.e. 127,
at nf_log_packet(), so the extra part is useless.
Second, after adding a log rule with a very very long prefix, we will
fail to dump the nft rules after this _special_ one, but acctually,
they do exist. For example:
# name_65000=$(printf "%0.sQ" {1..65000})
# nft add rule filter output log prefix "$name_65000"
# nft add rule filter output counter
# nft add rule filter output counter
# nft list chain filter output
table ip filter {
chain output {
type filter hook output priority 0; policy accept;
}
}
So now, restrict the log prefix length to NF_LOG_PREFIXLEN-1.
Fixes: 96518518cc ("netfilter: add nftables")
Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Currently, if the user add a stateful object with the name size exceed
NFT_OBJ_MAXNAMELEN - 1 (i.e. 31), we truncate it down to 31 silently.
This is not friendly, furthermore, this will cause duplicated stateful
objects when the first 31 characters of the name is same. So limit the
stateful object's name size to NFT_OBJ_MAXNAMELEN - 1.
After apply this patch, error message will be printed out like this:
# name_32=$(printf "%0.sQ" {1..32})
# nft add counter filter $name_32
<cmdline>:1:1-52: Error: Could not process rule: Numerical result out
of range
add counter filter QQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQ
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Also this patch cleans up the codes which missing the name size limit
validation in nftables.
Fixes: e50092404c ("netfilter: nf_tables: add stateful objects")
Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This further refines the changes made to conntrack gc_worker in
commit e0df8cae6c ("netfilter: conntrack: refine gc worker heuristics").
The main idea of that change was to reduce the scan interval when evictions
take place.
However, on the reporters' setup, there are 1-2 million conntrack entries
in total and roughly 8k new (and closing) connections per second.
In this case we'll always evict at least one entry per gc cycle and scan
interval is always at 1 jiffy because of this test:
} else if (expired_count) {
gc_work->next_gc_run /= 2U;
next_run = msecs_to_jiffies(1);
being true almost all the time.
Given we scan ~10k entries per run its clearly wrong to reduce interval
based on nonzero eviction count, it will only waste cpu cycles since a vast
majorities of conntracks are not timed out.
Thus only look at the ratio (scanned entries vs. evicted entries) to make
a decision on whether to reduce or not.
Because evictor is supposed to only kick in when system turns idle after
a busy period, pick a high ratio -- this makes it 50%. We thus keep
the idea of increasing scan rate when its likely that table contains many
expired entries.
In order to not let timed-out entries hang around for too long
(important when using event logging, in which case we want to timely
destroy events), we now scan the full table within at most
GC_MAX_SCAN_JIFFIES (16 seconds) even in worst-case scenario where all
timed-out entries sit in same slot.
I tested this with a vm under synflood (with
sysctl net.netfilter.nf_conntrack_tcp_timeout_syn_recv=3).
While flood is ongoing, interval now stays at its max rate
(GC_MAX_SCAN_JIFFIES / GC_MAX_BUCKETS_DIV -> 125ms).
With feedback from Nicolas Dichtel.
Reported-by: Denys Fedoryshchenko <nuclearcat@nuclearcat.com>
Cc: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Fixes: b87a2f9199 ("netfilter: conntrack: add gc worker to remove timed-out entries")
Signed-off-by: Florian Westphal <fw@strlen.de>
Tested-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Tested-by: Denys Fedoryshchenko <nuclearcat@nuclearcat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Instead of breaking loop and instant resched, don't bother checking
this in first place (the loop calls cond_resched for every bucket anyway).
Suggested-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The NF_CONNTRACK Kconfig option description makes an incorrect reference
to the "meta" expression where the "ct" expression would be correct.This
patch fixes the respective typographical error.
Fixes: d497c63527 ("netfilter: add help information to new nf_tables Kconfig options")
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
When dumping nft stateful objects, if NFTA_OBJ_TABLE and NFTA_OBJ_TYPE
attributes are not specified either, filter will become NULL, so oops
will happen(actually nft utility will always set NFTA_OBJ_TABLE attr,
so I write a test program to make this happen):
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: nf_tables_dump_obj+0x17c/0x330 [nf_tables]
[...]
Call Trace:
? nf_tables_dump_obj+0x5/0x330 [nf_tables]
? __kmalloc_reserve.isra.35+0x31/0x90
? __alloc_skb+0x5b/0x1e0
netlink_dump+0x124/0x2a0
__netlink_dump_start+0x161/0x190
nf_tables_getobj+0xe8/0x280 [nf_tables]
Fixes: a9fea2a3c3 ("netfilter: nf_tables: allow to filter stateful object dumps by type")
Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Pablo Neira Ayuso says:
====================
Netfilter fixes for net
The following patchset contains accumulated Netfilter fixes for your
net tree:
1) Ensure quota dump and reset happens iff we can deliver numbers to
userspace.
2) Silence splat on incorrect use of smp_processor_id() from nft_queue.
3) Fix an out-of-bound access reported by KASAN in
nf_tables_rule_destroy(), patch from Florian Westphal.
4) Fix layer 4 checksum mangling in the nf_tables payload expression
with IPv6.
5) Fix a race in the CLUSTERIP target from control plane path when two
threads run to add a new configuration object. Serialize invocations
of clusterip_config_init() using spin_lock. From Xin Long.
6) Call br_nf_pre_routing_finish_bridge_finish() once we are done with
the br_nf_pre_routing_finish() hook. From Artur Molchanov.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
ktime is a union because the initial implementation stored the time in
scalar nanoseconds on 64 bit machine and in a endianess optimized timespec
variant for 32bit machines. The Y2038 cleanup removed the timespec variant
and switched everything to scalar nanoseconds. The union remained, but
become completely pointless.
Get rid of the union and just keep ktime_t as simple typedef of type s64.
The conversion was done with coccinelle and some manual mopping up.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
This was entirely automated, using the script by Al:
PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>'
sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \
$(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)
to do the replacement at the end of the merge window.
Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If the NFT_PAYLOAD_L4CSUM_PSEUDOHDR flag is set, then mangle layer 4
checksum. This should not depend on csum_type NFT_PAYLOAD_CSUM_INET
since IPv6 header has no checksum field, but still an update of any of
the pseudoheader fields may trigger a layer 4 checksum update.
Fixes: 1814096980 ("netfilter: nft_payload: layer 4 checksum adjustment for pseudoheader fields")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
BUG: KASAN: slab-out-of-bounds in nf_tables_rule_destroy+0xf1/0x130 at addr ffff88006a4c35c8
Read of size 8 by task nft/1607
When we've destroyed last valid expr, nft_expr_next() returns an invalid expr.
We must not dereference it unless it passes != nft_expr_last() check.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Using smp_processor_id() causes splats with PREEMPT_RCU:
[19379.552780] BUG: using smp_processor_id() in preemptible [00000000] code: ping/32389
[19379.552793] caller is debug_smp_processor_id+0x17/0x19
[...]
[19379.552823] Call Trace:
[19379.552832] [<ffffffff81274e9e>] dump_stack+0x67/0x90
[19379.552837] [<ffffffff8129a4d4>] check_preemption_disabled+0xe5/0xf5
[19379.552842] [<ffffffff8129a4fb>] debug_smp_processor_id+0x17/0x19
[19379.552849] [<ffffffffa07c42dd>] nft_queue_eval+0x35/0x20c [nft_queue]
No need to disable preemption since we only fetch the numeric value, so
let's use raw_smp_processor_id() instead.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Dumping of netlink attributes may fail due to insufficient room in the
skbuff, so let's reset consumed quota if we succeed to put netlink
attributes into the skbuff.
Fixes: 43da04a593 ("netfilter: nf_tables: atomic dump and reset for stateful objects")
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Dump and reset doesn't work unless cmpxchg64() is used both from packet
and control plane paths. This approach is going to be slow though.
Instead, use a percpu seqcount to fetch counters consistently, then
subtract bytes and packets in case a reset was requested.
The cpu that running over the reset code is guaranteed to own this stats
exclusively, we have to turn counters into signed 64bit though so stats
update on reset don't get wrong on underflow.
This patch is based on original sketch from Eric Dumazet.
Fixes: 43da04a593 ("netfilter: nf_tables: atomic dump and reset for stateful objects")
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pablo Neira Ayuso says:
====================
Netfilter/IPVS updates for net-next
The following patchset contains a large Netfilter update for net-next,
to summarise:
1) Add support for stateful objects. This series provides a nf_tables
native alternative to the extended accounting infrastructure for
nf_tables. Two initial stateful objects are supported: counters and
quotas. Objects are identified by a user-defined name, you can fetch
and reset them anytime. You can also use a maps to allow fast lookups
using any arbitrary key combination. More info at:
http://marc.info/?l=netfilter-devel&m=148029128323837&w=2
2) On-demand registration of nf_conntrack and defrag hooks per netns.
Register nf_conntrack hooks if we have a stateful ruleset, ie.
state-based filtering or NAT. The new nf_conntrack_default_on sysctl
enables this from newly created netnamespaces. Default behaviour is not
modified. Patches from Florian Westphal.
3) Allocate 4k chunks and then use these for x_tables counter allocation
requests, this improves ruleset load time and also datapath ruleset
evaluation, patches from Florian Westphal.
4) Add support for ebpf to the existing x_tables bpf extension.
From Willem de Bruijn.
5) Update layer 4 checksum if any of the pseudoheader fields is updated.
This provides a limited form of 1:1 stateless NAT that make sense in
specific scenario, eg. load balancing.
6) Add support to flush sets in nf_tables. This series comes with a new
set->ops->deactivate_one() indirection given that we have to walk
over the list of set elements, then deactivate them one by one.
The existing set->ops->deactivate() performs an element lookup that
we don't need.
7) Two patches to avoid cloning packets, thus speed up packet forwarding
via nft_fwd from ingress. From Florian Westphal.
8) Two IPVS patches via Simon Horman: Decrement ttl in all modes to
prevent infinite loops, patch from Dwip Banerjee. And one minor
refactoring from Gao feng.
9) Revisit recent log support for nf_tables netdev families: One patch
to ensure that we correctly handle non-ethernet packets. Another
patch to add missing logger definition for netdev. Patches from
Liping Zhang.
10) Three patches for nft_fib, one to address insufficient register
initialization and another to solve incorrect (although harmless)
byteswap operation. Moreover update xt_rpfilter and nft_fib to match
lbcast packets with zeronet as source, eg. DHCP Discover packets
(0.0.0.0 -> 255.255.255.255). Also from Liping Zhang.
11) Built-in DCCP, SCTP and UDPlite conntrack and NAT support, from
Davide Caratti. While DCCP is rather hopeless lately, and UDPlite has
been broken in many-cast mode for some little time, let's give them a
chance by placing them at the same level as other existing protocols.
Thus, users don't explicitly have to modprobe support for this and
NAT rules work for them. Some people point to the lack of support in
SOHO Linux-based routers that make deployment of new protocols harder.
I guess other middleboxes outthere on the Internet are also to blame.
Anyway, let's see if this has any impact in the midrun.
12) Skip software SCTP software checksum calculation if the NIC comes
with SCTP checksum offload support. From Davide Caratti.
13) Initial core factoring to prepare conversion to hook array. Three
patches from Aaron Conole.
14) Gao Feng made a wrong conversion to switch in the xt_multiport
extension in a patch coming in the previous batch. Fix it in this
batch.
15) Get vmalloc call in sync with kmalloc flags to avoid a warning
and likely OOM killer intervention from x_tables. From Marcelo
Ricardo Leitner.
16) Update Arturo Borrero's email address in all source code headers.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Add support for attaching an eBPF object by file descriptor.
The iptables binary can be called with a path to an elf object or a
pinned bpf object. Also pass the mode and path to the kernel to be
able to return it later for iptables dump and save.
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Andrey Konovalov reported that this vmalloc call is based on an
userspace request and that it's spewing traces, which may flood the logs
and cause DoS if abused.
Florian Westphal also mentioned that this call should not trigger OOM
killer.
This patch brings the vmalloc call in sync to kmalloc and disables the
warn trace on allocation failure and also disable OOM killer invocation.
Note, however, that under such stress situation, other places may
trigger OOM killer invocation.
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Florian Westphal <fw@strlen.de>
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
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>
SCTP GSO and hardware can do CRC32c computation after netfilter processing,
so we can avoid calling sctp_compute_checksum() on skb if skb->ip_summed
is equal to CHECKSUM_PARTIAL. Moreover, set skb->ip_summed to CHECKSUM_NONE
when the NAT code computes the CRC, to prevent offloaders from computing
it again (on ixgbe this resulted in a transmission with wrong L4 checksum).
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch adds the netlink code to filter out dump of stateful objects,
through the NFTA_OBJ_TYPE netlink attribute.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch allows us to refer to stateful object dictionaries, the
source register indicates the key data to be used to look up for the
corresponding state object. We can refer to these maps through names or,
alternatively, the map transaction id. This allows us to refer to both
anonymous and named maps.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch allows you to refer to stateful objects from set elements.
This provides the infrastructure to create maps where the right hand
side of the mapping is a stateful object.
This allows us to build dictionaries of stateful objects, that you can
use to perform fast lookups using any arbitrary key combination.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Notify on depleted quota objects. The NFT_QUOTA_F_DEPLETED flag
indicates we have reached overquota.
Add pointer to table from nft_object, so we can use it when sending the
depletion notification to userspace.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Introduce nf_tables_obj_notify() to notify internal state changes in
stateful objects. This is used by the quota object to report depletion
in a follow up patch.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch adds a new NFT_MSG_GETOBJ_RESET command perform an atomic
dump-and-reset of the stateful object. This also comes with add support
for atomic dump and reset for counter and quota objects.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add a new attribute NFTA_QUOTA_CONSUMED that displays the amount of
quota that has been already consumed. This allows us to restore the
internal state of the quota object between reboots as well as to monitor
how wasted it is.
This patch changes the logic to account for the consumed bytes, instead
of the bytes that remain to be consumed.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch augments nf_tables to support stateful objects. This new
infrastructure allows you to create, dump and delete stateful objects,
that are identified by a user-defined name.
This patch adds the generic infrastructure, follow up patches add
support for two stateful objects: counters and quotas.
This patch provides a native infrastructure for nf_tables to replace
nfacct, the extended accounting infrastructure for iptables.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
... so we can use current skb instead of working with a clone.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
I lost one test case in the last commit for xt_multiport.
For example, the rule is "-m multiport --dports 22,80,443".
When first port is unmatched and the second is matched, the curent codes
could not return the right result.
It would return false directly when the first port is unmatched.
Fixes: dd2602d00f ("netfilter: xt_multiport: Use switch case instead
of multiple condition checks")
Signed-off-by: Gao Feng <fgao@ikuai8.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch adds a new flag that signals the kernel to update layer 4
checksum if the packet field belongs to the layer 4 pseudoheader. This
implicitly provides stateless NAT 1:1 that is useful under very specific
usecases.
Since rules mangling layer 3 fields that are part of the pseudoheader
may potentially convey any layer 4 packet, we have to deal with the
layer 4 checksum adjustment using protocol specific code.
This patch adds support for TCP, UDP and ICMPv6, since they include the
pseudoheader in the layer 4 checksum calculation. ICMP doesn't, so we
can skip it.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Acctually ntohl and htonl are identical, so this doesn't affect
anything, but it is conceptually wrong.
Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
instead of allocating each xt_counter individually, allocate 4k chunks
and then use these for counter allocation requests.
This should speed up rule evaluation by increasing data locality,
also speeds up ruleset loading because we reduce calls to the percpu
allocator.
As Eric points out we can't use PAGE_SIZE, page_allocator would fail on
arches with 64k page size.
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Keeps some noise away from a followup patch.
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
On SMP we overload the packet counter (unsigned long) to contain
percpu offset. Hide this from callers and pass xt_counters address
instead.
Preparation patch to allocate the percpu counters in page-sized batch
chunks.
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This is to facilitate converting from a singly-linked list to an array
of elements.
Signed-off-by: Aaron Conole <aconole@bytheb.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
nf_defrag modules for ipv4 and ipv6 export an empty stub function.
Any module that needs the defragmentation hooks registered simply 'calls'
this empty function to create a phony module dependency -- modprobe will
then load the defrag module too.
This extends netfilter ipv4/ipv6 defragmentation modules to delay the hook
registration until the functionality is requested within a network namespace
instead of module load time for all namespaces.
Hooks are only un-registered on module unload or when a namespace that used
such defrag functionality exits.
We have to use struct net for this as the register hooks can be called
before netns initialization here from the ipv4/ipv6 conntrack module
init path.
There is no unregister functionality support, defrag will always be
active once it was requested inside a net namespace.
The reason is that defrag has impact on nft and iptables rulesets
(without defrag we might see framents).
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
1) Old code was hard to maintain, due to complex lock chains.
(We probably will be able to remove some kfree_rcu() in callers)
2) Using a single timer to update all estimators does not scale.
3) Code was buggy on 32bit kernel (WRITE_ONCE() on 64bit quantity
is not supposed to work well)
In this rewrite :
- I removed the RB tree that had to be scanned in
gen_estimator_active(). qdisc dumps should be much faster.
- Each estimator has its own timer.
- Estimations are maintained in net_rate_estimator structure,
instead of dirtying the qdisc. Minor, but part of the simplification.
- Reading the estimator uses RCU and a seqcount to provide proper
support for 32bit kernels.
- We reduce memory need when estimators are not used, since
we store a pointer, instead of the bytes/packets counters.
- xt_rateest_mt() no longer has to grab a spinlock.
(In the future, xt_rateest_tg() could be switched to per cpu counters)
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This switch (default on) can be used to disable automatic registration
of connection tracking functionality in newly created network
namespaces.
This means that when net namespace goes down (or the tracker protocol
module is unloaded) we *might* have to unregister the hooks.
We can either add another per-netns variable that tells if
the hooks got registered by default, or, alternatively, just call
the protocol _put() function and have the callee deal with a possible
'extra' put() operation that doesn't pair with a get() one.
This uses the latter approach, i.e. a put() without a get has no effect.
Conntrack is still enabled automatically regardless of the new sysctl
setting if the new net namespace requires connection tracking, e.g. when
NAT rules are created.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This makes use of nf_ct_netns_get/put added in previous patch.
We add get/put functions to nf_conntrack_l3proto structure, ipv4 and ipv6
then implement use-count to track how many users (nft or xtables modules)
have a dependency on ipv4 and/or ipv6 connection tracking functionality.
When count reaches zero, the hooks are unregistered.
This delays activation of connection tracking inside a namespace until
stateful firewall rule or nat rule gets added.
This patch breaks backwards compatibility in the sense that connection
tracking won't be active anymore when the protocol tracker module is
loaded. This breaks e.g. setups that ctnetlink for flow accounting and
the like, without any '-m conntrack' packet filter rules.
Followup patch restores old behavour and makes new delayed scheme
optional via sysctl.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
so that conntrack core will add the needed hooks in this namespace.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
