We already include netns address in the hash and compare the netns pointers
during lookup, so even if namespaces have overlapping addresses entries
will be spread across the expectation table.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Currently, we support set names of up to 16 bytes, get this aligned
with the maximum length we can use in ipset to make it easier when
considering migration to nf_tables.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The dprintf() and duprintf() functions are enabled at compile time,
these days we have better runtime debugging through pr_debug() and
static keys.
On top of this, this debugging is so old that I don't expect anyone
using this anymore, so let's get rid of this.
IP_NF_ASSERT() is still left in place, although this needs that
NETFILTER_DEBUG is enabled, I think these assertions provide useful
context information when reading the code.
Note that ARP_NF_ASSERT() has been removed as there is no user of
this.
Kill also DEBUG_ALLOW_ALL and a couple of pr_error() and pr_debug()
spots that are inconsistently placed in the code.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
If the protocol is not natively supported, this assigns generic protocol
tracker so we can always assume a valid pointer after these calls.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Acked-by: Jarno Rajahalme <jrajahalme@nicira.com>
Acked-by: Joe Stringer <joe@ovn.org>
This patch introduces nf_ct_resolve_clash() to resolve race condition on
conntrack insertions.
This is particularly a problem for connection-less protocols such as
UDP, with no initial handshake. Two or more packets may race to insert
the entry resulting in packet drops.
Another problematic scenario are packets enqueued to userspace via
NFQUEUE after the raw table, that make it easier to trigger this
race.
To resolve this, the idea is to reset the conntrack entry to the one
that won race. Packet and bytes counters are also merged.
The 'insert_failed' stats still accounts for this situation, after
this patch, the drop counter is bumped whenever we drop packets, so we
can watch for unresolved clashes.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Introduce a helper function to update conntrack counters.
__nf_ct_kill_acct() was unnecessarily subtracting skb_network_offset()
that is expected to be zero from the ipv4/ipv6 hooks.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Remove unnecessary check for non-nul pointer in destroy_conntrack()
given that __nf_ct_l4proto_find() returns the generic protocol tracker
if the protocol is not supported.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
When iterating, skip conntrack entries living in a different netns.
We could ignore netns and kill some other non-assured one, but it
has two problems:
- a netns can kill non-assured conntracks in other namespace
- we would start to 'over-subscribe' the affected/overlimit netns.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
We already include netns address in the hash and compare the netns pointers
during lookup, so even if namespaces have overlapping addresses entries
will be spread across the table.
Assuming 64k bucket size, this change saves 0.5 mbyte per namespace on a
64bit system.
NAT bysrc and expectation hash is still per namespace, those will
changed too soon.
Future patch will also make conntrack object slab cache global again.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Once we place all conntracks into a global hash table we want them to be
spread across entire hash table, even if namespaces have overlapping ip
addresses.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Once we place all conntracks in the same hash table we must also compare
the netns pointer to skip conntracks that belong to a different namespace.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The iteration process is lockless, so we test if the conntrack object is
eligible for printing (e.g. is AF_INET) after obtaining the reference
count.
Once we put all conntracks into same hash table we might see more
entries that need to be skipped.
So add a helper and first perform the test in a lockless fashion
for fast skip.
Once we obtain the reference count, just repeat the check.
Note that this refactoring also includes a missing check for unconfirmed
conntrack entries due to slab rcu object re-usage, so they need to be
skipped since they are not part of the listing.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This prepares for upcoming change that places all conntracks into a
single, global table. For this to work we will need to also compare
net pointer during lookup. To avoid open-coding such check use the
nf_ct_key_equal helper and then later extend it to also consider net_eq.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Once we place all conntracks into same table iteration becomes more
costly because the table contains conntracks that we are not interested
in (belonging to other netns).
So don't bother scanning if the current namespace has no entries.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
When resizing the conntrack hash table at runtime via
echo 42 > /sys/module/nf_conntrack/parameters/hashsize, we are racing with
the conntrack lookup path -- reads can happen in parallel and nothing
prevents readers from observing a the newly allocated hash but the old
size (or vice versa).
So access to hash[bucket] can trigger OOB read access in case the table got
expanded and we saw the new size but the old hash pointer (or it got shrunk
and we got new hash ptr but the size of the old and larger table):
kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] SMP KASAN
CPU: 0 PID: 3 Comm: ksoftirqd/0 Not tainted 4.6.0-rc2+ #107
[..]
Call Trace:
[<ffffffff822c3d6a>] ? nf_conntrack_tuple_taken+0x12a/0xe90
[<ffffffff822c3ac1>] ? nf_ct_invert_tuplepr+0x221/0x3a0
[<ffffffff8230e703>] get_unique_tuple+0xfb3/0x2760
Use generation counter to obtain the address/length of the same table.
Also add a synchronize_net before freeing the old hash.
AFAICS, without it we might access ct_hash[bucket] after ct_hash has been
freed, provided that lockless reader got delayed by another event:
CPU1 CPU2
seq_begin
seq_retry
<delay> resize occurs
free oldhash
for_each(oldhash[size])
Note that resize is only supported in init_netns, it took over 2 minutes
of constant resizing+flooding to produce the warning, so this isn't a
big problem in practice.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
No need to disable BH here anymore:
stats are switched to _ATOMIC variant (== this_cpu_inc()), which
nowadays generates same code as the non _ATOMIC NF_STAT, at least on x86.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Conntrack labels are currently sized depending on the iptables
ruleset, i.e. if we're asked to test or set bits 1, 2, and 65 then we
would allocate enough room to store at least bit 65.
However, with nft, the input is just a register with arbitrary runtime
content.
We therefore ask for the upper ceiling we currently have, which is
enough room to store 128 bits.
Alternatively, we could alter nf_connlabel_replace to increase
net->ct.label_words at run time, but since 128 bits is not that
big we'd only save sizeof(long) so it doesn't seem worth it for now.
This follows a similar approach that xtables 'connlabel'
match uses, so when user inputs
ct label set bar
then we will set the bit used by the 'bar' label and leave the rest alone.
This is done by passing the sreg content to nf_connlabels_replace
as both value and mask argument.
Labels (bits) already set thus cannot be re-set to zero, but
this is not supported by xtables connlabel match either.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This is a forward-port of the original patch from Andrzej Hajda,
he said:
"IS_ERR_VALUE should be used only with unsigned long type.
Otherwise it can work incorrectly. To achieve this function
xt_percpu_counter_alloc is modified to return unsigned long,
and its result is assigned to temporary variable to perform
error checking, before assigning to .pcnt field.
The patch follows conclusion from discussion on LKML [1][2].
[1]: http://permalink.gmane.org/gmane.linux.kernel/2120927
[2]: http://permalink.gmane.org/gmane.linux.kernel/2150581"
Original patch from Andrzej is here:
http://patchwork.ozlabs.org/patch/582970/
This patch has clashed with input validation fixes for x_tables.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Simon Horman says:
====================
IPVS Updates for v4.7
please consider these enhancements to the IPVS. They allow SIP connections
originating from real-servers to be load balanced by the SIP psersitence
engine as is already implemented in the other direction. And for better one
packet scheduling (OPS) performance.
====================
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
ip6_route_output() will never return a NULL pointer, so there's no need
to check it.
Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Four years ago we introduced a new sysctl knob to disable automatic
helper assignment in 72110dfaa907 ("netfilter: nf_ct_helper: disable
automatic helper assignment"). This knob kept this behaviour enabled by
default to remain conservative.
This measure was introduced to provide a secure way to configure
iptables and connection tracking helpers through explicit rules.
Give the time we have waited for this, let's turn off this by default
now, worse case users still have a chance to recover the former
behaviour by explicitly enabling this back through sysctl.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch fixes dynamic element updates for adjacent intervals in the
rb-tree representation.
Since elements are sorted in the rb-tree, in case of adjacent nodes with
the same key, the assumption is that an interval end node must be placed
before an interval opening.
In tree lookup operations, the idea is to search for the closer element
that is smaller than the one we're searching for. Given that we'll have
two possible matchings, we have to take the opening interval in case of
adjacent nodes.
Range merges are not trivial with the current representation,
specifically we have to check if node extensions are equal and make sure
we keep the existing internal states around.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Florian Westphal
Pablo Neira Ayuso
Liping Zhang