Shaochun Chen points out we leak dumper filter state allocations
stored in dump_control->data in case there is an error before netlink sets
cb_running (after which ->done will be called at some point).
In order to fix this, add .start functions and do the allocations
there.
->done is going to clean up, and in case error occurs before
->start invocation no cleanups need to be done anymore.
Reported-by: shaochun chen <cscnull@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Pablo Neira Ayuso says:
====================
Netfilter/IPVS updates for net-next
The following patchset contains Netfilter/IPVS updates for your net-next
tree:
1) No need to set ttl from reject action for the bridge family, from
Taehee Yoo.
2) Use a fixed timeout for flow that are passed up from the flowtable
to conntrack, from Florian Westphal.
3) More preparation patches for tproxy support for nf_tables, from Mate
Eckl.
4) Remove unnecessary indirection in core IPv6 checksum function, from
Florian Westphal.
5) Use nf_ct_get_tuplepr() from openvswitch, instead of opencoding it.
From Florian Westphal.
6) socket match now selects socket infrastructure, instead of depending
on it. From Mate Eckl.
7) Patch series to simplify conntrack tuple building/parsing from packet
path and ctnetlink, from Florian Westphal.
8) Fetch timeout policy from protocol helpers, instead of doing it from
core, from Florian Westphal.
9) Merge IPv4 and IPv6 protocol trackers into conntrack core, from
Florian Westphal.
10) Depend on CONFIG_NF_TABLES_IPV6 and CONFIG_IP6_NF_IPTABLES
respectively, instead of IPV6. Patch from Mate Eckl.
11) Add specific function for garbage collection in conncount,
from Yi-Hung Wei.
12) Catch number of elements in the connlimit list, from Yi-Hung Wei.
13) Move locking to nf_conncount, from Yi-Hung Wei.
14) Series of patches to add lockless tree traversal in nf_conncount,
from Yi-Hung Wei.
15) Resolve clash in matching conntracks when race happens, from
Martynas Pumputis.
16) If connection entry times out, remove template entry from the
ip_vs_conn_tab table to improve behaviour under flood, from
Julian Anastasov.
17) Remove useless parameter from nf_ct_helper_ext_add(), from Gao feng.
18) Call abort from 2-phase commit protocol before requesting modules,
make sure this is done under the mutex, from Florian Westphal.
19) Grab module reference when starting transaction, also from Florian.
20) Dynamically allocate expression info array for pre-parsing, from
Florian.
21) Add per netns mutex for nf_tables, from Florian Westphal.
22) A couple of patches to simplify and refactor nf_osf code to prepare
for nft_osf support.
23) Break evaluation on missing socket, from Mate Eckl.
24) Allow to match socket mark from nft_socket, from Mate Eckl.
25) Remove dependency on nf_defrag_ipv6, now that IPv6 tracker is
built-in into nf_conntrack. From Florian Westphal.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
When first DCCP packet is SYNC or SYNCACK, we insert a new conntrack
that has an un-initialized timeout value, i.e. such entry could be
reaped at any time.
Mark them as INVALID and only ignore SYNC/SYNCACK when connection had
an old state.
Reported-by: syzbot+6f18401420df260e37ed@syzkaller.appspotmail.com
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Its possible to rename two chains to the same name in one
transaction:
nft add chain t c1
nft add chain t c2
nft 'rename chain t c1 c3;rename chain t c2 c3'
This creates two chains named 'c3'.
Appears to be harmless, both chains can still be deleted both
by name or handle, but, nevertheless, its a bug.
Walk transaction log and also compare vs. the pending renames.
Both chains can still be deleted, but nevertheless it is a bug as
we don't allow to create chains with identical names, so we should
prevent this from happening-by-rename too.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The new name is stored in the transaction metadata, on commit,
the pointers to the old and new names are swapped.
Therefore in abort and commit case we have to free the
pointer in the chain_trans container.
In commit case, the pointer can be used by another cpu that
is currently dumping the renamed chain, thus kfree needs to
happen after waiting for rcu readers to complete.
Fixes: b7263e071a ("netfilter: nf_tables: Allow chain name of up to 255 chars")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
no need to store the name in separate area.
Furthermore, it uses kmalloc but not kfree and most accesses seem to treat
it as char[IFNAMSIZ] not char *.
Remove this and use dev->name instead.
In case event zeroed dev, just omit the name in the dump.
Fixes: d92191aa84 ("netfilter: nf_tables: cache device name in flowtable object")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Actual implementation stores 0 in the destination register if no socket
is found by the lookup, but that is not intentional as it is not really
a value of any socket metadata.
This patch fixes this and breaks rule evaluation in this case.
Fixes: 554ced0a6e ("netfilter: nf_tables: add support for native socket matching")
Signed-off-by: Máté Eckl <ecklm94@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This new function allows us to check if there is TCP syn packet matching
with a given fingerprint that can be reused from the upcoming new
nf_osf_find() function.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Continue to use nftnl subsys mutex to protect (un)registration of hook types,
expressions and so on, but force batch operations to do their own
locking.
This allows distinct net namespaces to perform transactions in parallel.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This works because all accesses are currently serialized by nfnl
nf_tables subsys mutex.
If we want to have per-netns locking, we need to make this scratch
area pernetns or allocate it on demand.
This does the latter, its ~28kbyte but we can fallback to vmalloc
so it should be fine.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
always call this function, followup patch can use this to
aquire a per-netns transaction log to guard the entire batch
instead of using the nfnl susbsys mutex (which is shared among all
namespaces).
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
module autoload is problematic, it requires dropping the mutex that
protects the transaction. Once the mutex has been dropped, another
client can start a new transaction before we had a chance to abort
current transaction log.
This helper makes sure we first zap the transaction log, then
drop mutex for module autoload.
In case autload is successful, the caller has to reply entire
message anyway.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The param helper of nf_ct_helper_ext_add is useless now, then remove
it now.
Signed-off-by: Gao Feng <gfree.wind@vip.163.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Before now, connection templates were ignored by the random
dropentry procedure. But Michal Koutný suggests that we
should add exception for connections under SYN attack.
He provided patch that implements it for TCP:
<quote>
IPVS includes protection against filling the ip_vs_conn_tab by
dropping 1/32 of feasible entries every second. The template
entries (for persistent services) are never directly deleted by
this mechanism but when a picked TCP connection entry is being
dropped (1), the respective template entry is dropped too (realized
by expiring 60 seconds after the connection entry being dropped).
There is another mechanism that removes connection entries when they
time out (2), in this case the associated template entry is not deleted.
Under SYN flood template entries would accumulate (due to their entry
longer timeout).
The accumulation takes place also with drop_entry being enabled. Roughly
15% ((31/32)^60) of SYN_RECV connections survive the dropping mechanism
(1) and are removed by the timeout mechanism (2)(defaults to 60 seconds
for SYN_RECV), thus template entries would still accumulate.
The patch ensures that when a connection entry times out, we also remove
the template entry from the table. To prevent breaking persistent
services (since the connection may time out in already established state)
we add a new entry flag to protect templates what spawned at least one
established TCP connection.
</quote>
We already added ASSURED flag for the templates in previous patch, so
that we can use it now to decide which connection templates should be
dropped under attack. But we also have some cases that need special
handling.
We modify the dropentry procedure as follows:
- Linux timers currently use LIFO ordering but we can not rely on
this to drop controlling connections. So, set cp->timeout to 0
to indicate that connection was dropped and that on expiration we
should try to drop our controlling connections. As result, we can
now avoid the ip_vs_conn_expire_now call.
- move the cp->n_control check above, so that it avoids restarting
the timer for controlling connections when not needed.
- drop unassured connection templates here if they are not referred
by any connections.
On connection expiration: if connection was dropped (cp->timeout=0)
try to drop our controlling connection except if it is a template
in assured state.
In ip_vs_conn_flush change order of ip_vs_conn_expire_now calls
according to the LIFO timer expiration order. It should work
faster for controlling connections with single controlled one.
Suggested-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
cp->state was not used for templates. Add support for state bits
and for the first "assured" bit which indicates that some
connection controlled by this template was established or assured
by the real server. In a followup patch we will use it to drop
templates under SYN attack.
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
In preparation for followup patches, provide just the cp
ptr to ip_vs_state_name.
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch enables the clash resolution for NAT (disabled in
"590b52e10d41") if clashing conntracks match (i.e. both tuples are equal)
and a protocol allows it.
The clash might happen for a connections-less protocol (e.g. UDP) when
two threads in parallel writes to the same socket and consequent calls
to "get_unique_tuple" return the same tuples (incl. reply tuples).
In this case it is safe to perform the resolution, as the losing CT
describes the same mangling as the winning CT, so no modifications to
the packet are needed, and the result of rules traversal for the loser's
packet stays valid.
Signed-off-by: Martynas Pumputis <martynas@weave.works>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch is originally from Florian Westphal.
This patch does the following 3 main tasks.
1) Add list lock to 'struct nf_conncount_list' so that we can
alter the lists containing the individual connections without holding the
main tree lock. It would be useful when we only need to add/remove to/from
a list without allocate/remove a node in the tree. With this change, we
update nft_connlimit accordingly since we longer need to maintain
a list lock in nft_connlimit now.
2) Use RCU for the initial tree search to improve tree look up performance.
3) Add a garbage collection worker. This worker is schedule when there
are excessive tree node that needed to be recycled.
Moreover,the rbnode reclaim logic is moved from search tree to insert tree
to avoid race condition.
Signed-off-by: Yi-Hung Wei <yihung.wei@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch is originally from Florian Westphal.
When we have a very coarse grouping, e.g. by large subnets, zone id,
etc, it's likely that we do not need to do tree rotation because
we'll find a node where we can attach new entry. Based on this
observation, we split tree traversal and insertion.
Later on, we can make traversal lockless (tree protected
by RCU), and add extra lock in the individual nodes to protect list
insertion/deletion, thereby allowing parallel insert/delete in different
tree nodes.
Signed-off-by: Yi-Hung Wei <yihung.wei@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch is originally from Florian Westphal.
This is a preparation patch to allow lockless traversal
of the tree via RCU.
Signed-off-by: Yi-Hung Wei <yihung.wei@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch is originally from Florian Westphal.
This patch does the following three tasks.
It applies the same early exit technique for nf_conncount_lookup().
Since now we keep the number of connections in 'struct nf_conncount_list',
we no longer need to return the count in nf_conncount_lookup().
Moreover, we expose the garbage collection function nf_conncount_gc_list()
for nft_connlimit.
Signed-off-by: Yi-Hung Wei <yihung.wei@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Original patch is from Florian Westphal.
This patch switches from hlist to plain list to store the list of
connections with the same filtering key in nf_conncount. With the
plain list, we can insert new connections at the tail, so over time
the beginning of list holds long-running connections and those are
expired, while the newly creates ones are at the end.
Later on, we could probably move checked ones to the end of the list,
so the next run has higher chance to reclaim stale entries in the front.
Signed-off-by: Yi-Hung Wei <yihung.wei@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch is originally from Florian Westphal.
We use an extra function with early exit for garbage collection.
It is not necessary to traverse the full list for every node since
it is enough to zap a couple of entries for garbage collection.
Signed-off-by: Yi-Hung Wei <yihung.wei@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
... from IPV6 to NF_TABLES_IPV6 and IP6_NF_IPTABLES.
In some cases module selects depend on IPV6, but this means that they
select another module even if eg. NF_TABLES_IPV6 is not set in which
case the selected module is useless due to the lack of IPv6 nf_tables
functionality.
The same applies for IP6_NF_IPTABLES and iptables.
Joint work with: Arnd Bermann <arnd@arndb.de>
Signed-off-by: Máté Eckl <ecklm94@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This unifies ipv4 and ipv6 protocol trackers and removes the l3proto
abstraction.
This gets rid of all l3proto indirect calls and the need to do
a lookup on the function to call for l3 demux.
It increases module size by only a small amount (12kbyte), so this reduces
size because nf_conntrack.ko is useless without either nf_conntrack_ipv4
or nf_conntrack_ipv6 module.
before:
text data bss dec hex filename
7357 1088 0 8445 20fd nf_conntrack_ipv4.ko
7405 1084 4 8493 212d nf_conntrack_ipv6.ko
72614 13689 236 86539 1520b nf_conntrack.ko
19K nf_conntrack_ipv4.ko
19K nf_conntrack_ipv6.ko
179K nf_conntrack.ko
after:
text data bss dec hex filename
79277 13937 236 93450 16d0a nf_conntrack.ko
191K nf_conntrack.ko
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Not needed, we can have the l4trackers fetch it themselvs.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Handle common protocols (udp, tcp, ..), in the core and only
do the call if needed by the l4proto tracker.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Handle the common cases (tcp, udp, etc). in the core and only
do the indirect call for the protocols that need it (GRE for instance).
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Handle it in the core instead.
ipv6_skip_exthdr() is built-in even if ipv6 is a module, i.e. this
doesn't create an ipv6 dependency.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Its simpler to just handle it directly in nf_ct_invert_tuple().
Also gets rid of need to pass l3proto pointer to resolve_conntrack().
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
handle everything from ctnetlink directly.
After all these years we still only support ipv4 and ipv6, so it
seems reasonable to remove l3 protocol tracker support and instead
handle ipv4/ipv6 from a common, always builtin inet tracker.
Step 1: Get rid of all the l3proto->func() calls.
Start with ctnetlink, then move on to packet-path ones.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
These versions deal with the l3proto/l4proto details internally.
It removes only caller of nf_ct_get_tuple, so make it static.
After this, l3proto->get_l4proto() can be removed in a followup patch.
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Pravin B Shelar <pshelar@ovn.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
similar to previous change, this also allows to remove it
from nf_ipv6_ops and avoid the indirection.
It also removes the bogus dependency of nf_conntrack_ipv6 on ipv6 module:
ipv6 checksum functions are built into kernel even if CONFIG_IPV6=m,
but ipv6/netfilter.o isn't.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
allows to make nf_ip_checksum_partial static, it no longer
has an external caller.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This function is also necessary to implement nft tproxy support
Fixes: 45ca4e0cf2 ("netfilter: Libify xt_TPROXY")
Signed-off-by: Máté Eckl <ecklm94@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This is one of the very few external callers of ->get_timeouts(),
We can use a fixed timeout instead, conntrack core will refresh this in
case a new packet comes within this period.
Use of ESTABLISHED timeout seems way too huge anyway.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This adds a global netfilter function to extract a conntrack tuple from an
skb. The function uses a new function added to nf_ct_hook, which will try
to get the tuple from skb->_nfct, and do a full lookup if that fails. This
makes it possible to use the lookup function before the skb has passed
through the conntrack init hooks (e.g., in an ingress qdisc). The tuple is
copied to the caller to avoid issues with reference counting.
The function returns false if conntrack is not loaded, allowing it to be
used without incurring a module dependency on conntrack. This is used by
the NAT mode in sch_cake.
Cc: netfilter-devel@vger.kernel.org
Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Loading the nf_conntrack module with doubled hashsize parameter, i.e.
modprobe nf_conntrack hashsize=12345 hashsize=12345
causes NULL-ptr deref.
If 'hashsize' specified twice, the nf_conntrack_set_hashsize() function
will be called also twice.
The first nf_conntrack_set_hashsize() call will set the
'nf_conntrack_htable_size' variable:
nf_conntrack_set_hashsize()
...
/* On boot, we can set this without any fancy locking. */
if (!nf_conntrack_htable_size)
return param_set_uint(val, kp);
But on the second invocation, the nf_conntrack_htable_size is already set,
so the nf_conntrack_set_hashsize() will take a different path and call
the nf_conntrack_hash_resize() function. Which will crash on the attempt
to dereference 'nf_conntrack_hash' pointer:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
RIP: 0010:nf_conntrack_hash_resize+0x255/0x490 [nf_conntrack]
Call Trace:
nf_conntrack_set_hashsize+0xcd/0x100 [nf_conntrack]
parse_args+0x1f9/0x5a0
load_module+0x1281/0x1a50
__se_sys_finit_module+0xbe/0xf0
do_syscall_64+0x7c/0x390
entry_SYSCALL_64_after_hwframe+0x49/0xbe
Fix this, by checking !nf_conntrack_hash instead of
!nf_conntrack_htable_size. nf_conntrack_hash will be initialized only
after the module loaded, so the second invocation of the
nf_conntrack_set_hashsize() won't crash, it will just reinitialize
nf_conntrack_htable_size again.
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
iptables-nft never requests these, but make this explicitly illegal.
If it were quested, kernel could oops as ->eval is NULL, furthermore,
the builtin targets have no owning module so its possible to rmmod
eb/ip/ip6_tables module even if they would be loaded.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
