Commit Graph

1233 Commits

Author SHA1 Message Date
Florian Westphal
36ce9982ef xtables: move icmp/icmpv6 logic to xt_tcpudp
icmp/icmp6 matches are baked into ip(6)_tables.ko.

This means that even if iptables-nft is used, a rule like
"-p icmp --icmp-type 1" will load the ip(6)tables modules.

Move them to xt_tcpdudp.ko instead to avoid this.

This will also allow to eventually add kconfig knobs to build kernels
that support iptables-nft but not iptables-legacy (old set/getsockopt
interface).

Signed-off-by: Florian Westphal <fw@strlen.de>
2023-03-22 21:48:59 +01:00
Florian Westphal
4a02426787 netfilter: tproxy: fix deadlock due to missing BH disable
The xtables packet traverser performs an unconditional local_bh_disable(),
but the nf_tables evaluation loop does not.

Functions that are called from either xtables or nftables must assume
that they can be called in process context.

inet_twsk_deschedule_put() assumes that no softirq interrupt can occur.
If tproxy is used from nf_tables its possible that we'll deadlock
trying to aquire a lock already held in process context.

Add a small helper that takes care of this and use it.

Link: https://lore.kernel.org/netfilter-devel/401bd6ed-314a-a196-1cdc-e13c720cc8f2@balasys.hu/
Fixes: 4ed8eb6570 ("netfilter: nf_tables: Add native tproxy support")
Reported-and-tested-by: Major Dávid <major.david@balasys.hu>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2023-03-06 12:09:48 +01:00
Jakub Kicinski
fd2a55e74a Merge git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf
Pablo Neira Ayuso says:

====================
Netfilter fixes for net

1) Fix broken listing of set elements when table has an owner.

2) Fix conntrack refcount leak in ctnetlink with related conntrack
   entries, from Hangyu Hua.

3) Fix use-after-free/double-free in ctnetlink conntrack insert path,
   from Florian Westphal.

4) Fix ip6t_rpfilter with VRF, from Phil Sutter.

5) Fix use-after-free in ebtables reported by syzbot, also from Florian.

6) Use skb->len in xt_length to deal with IPv6 jumbo packets,
   from Xin Long.

7) Fix NETLINK_LISTEN_ALL_NSID with ctnetlink, from Florian Westphal.

8) Fix memleak in {ip_,ip6_,arp_}tables in ENOMEM error case,
   from Pavel Tikhomirov.

* git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  netfilter: x_tables: fix percpu counter block leak on error path when creating new netns
  netfilter: ctnetlink: make event listener tracking global
  netfilter: xt_length: use skb len to match in length_mt6
  netfilter: ebtables: fix table blob use-after-free
  netfilter: ip6t_rpfilter: Fix regression with VRF interfaces
  netfilter: conntrack: fix rmmod double-free race
  netfilter: ctnetlink: fix possible refcount leak in ctnetlink_create_conntrack()
  netfilter: nf_tables: allow to fetch set elements when table has an owner
====================

Link: https://lore.kernel.org/r/20230222092137.88637-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-02-22 21:25:23 -08:00
Pavel Tikhomirov
0af8c09c89 netfilter: x_tables: fix percpu counter block leak on error path when creating new netns
Here is the stack where we allocate percpu counter block:

  +-< __alloc_percpu
    +-< xt_percpu_counter_alloc
      +-< find_check_entry # {arp,ip,ip6}_tables.c
        +-< translate_table

And it can be leaked on this code path:

  +-> ip6t_register_table
    +-> translate_table # allocates percpu counter block
    +-> xt_register_table # fails

there is no freeing of the counter block on xt_register_table fail.
Note: xt_percpu_counter_free should be called to free it like we do in
do_replace through cleanup_entry helper (or in __ip6t_unregister_table).

Probability of hitting this error path is low AFAICS (xt_register_table
can only return ENOMEM here, as it is not replacing anything, as we are
creating new netns, and it is hard to imagine that all previous
allocations succeeded and after that one in xt_register_table failed).
But it's worth fixing even the rare leak.

Fixes: 71ae0dff02 ("netfilter: xtables: use percpu rule counters")
Signed-off-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2023-02-22 10:11:27 +01:00
Florian Westphal
e58a171d35 netfilter: ebtables: fix table blob use-after-free
We are not allowed to return an error at this point.
Looking at the code it looks like ret is always 0 at this
point, but its not.

t = find_table_lock(net, repl->name, &ret, &ebt_mutex);

... this can return a valid table, with ret != 0.

This bug causes update of table->private with the new
blob, but then frees the blob right away in the caller.

Syzbot report:

BUG: KASAN: vmalloc-out-of-bounds in __ebt_unregister_table+0xc00/0xcd0 net/bridge/netfilter/ebtables.c:1168
Read of size 4 at addr ffffc90005425000 by task kworker/u4:4/74
Workqueue: netns cleanup_net
Call Trace:
 kasan_report+0xbf/0x1f0 mm/kasan/report.c:517
 __ebt_unregister_table+0xc00/0xcd0 net/bridge/netfilter/ebtables.c:1168
 ebt_unregister_table+0x35/0x40 net/bridge/netfilter/ebtables.c:1372
 ops_exit_list+0xb0/0x170 net/core/net_namespace.c:169
 cleanup_net+0x4ee/0xb10 net/core/net_namespace.c:613
...

ip(6)tables appears to be ok (ret should be 0 at this point) but make
this more obvious.

Fixes: c58dd2dd44 ("netfilter: Can't fail and free after table replacement")
Reported-by: syzbot+f61594de72d6705aea03@syzkaller.appspotmail.com
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2023-02-22 00:22:31 +01:00
Phil Sutter
efb056e5f1 netfilter: ip6t_rpfilter: Fix regression with VRF interfaces
When calling ip6_route_lookup() for the packet arriving on the VRF
interface, the result is always the real (slave) interface. Expect this
when validating the result.

Fixes: acc641ab95 ("netfilter: rpfilter/fib: Populate flowic_l3mdev field")
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2023-02-22 00:22:20 +01:00
Florian Westphal
2954fe60e3 netfilter: let reset rules clean out conntrack entries
iptables/nftables support responding to tcp packets with tcp resets.

The generated tcp reset packet passes through both output and postrouting
netfilter hooks, but conntrack will never see them because the generated
skb has its ->nfct pointer copied over from the packet that triggered the
reset rule.

If the reset rule is used for established connections, this
may result in the conntrack entry to be around for a very long
time (default timeout is 5 days).

One way to avoid this would be to not copy the nf_conn pointer
so that the rest packet passes through conntrack too.

Problem is that output rules might not have the same conntrack
zone setup as the prerouting ones, so its possible that the
reset skb won't find the correct entry.  Generating a template
entry for the skb seems error prone as well.

Add an explicit "closing" function that switches a confirmed
conntrack entry to closed state and wire this up for tcp.

If the entry isn't confirmed, no action is needed because
the conntrack entry will never be committed to the table.

Reported-by: Russel King <linux@armlinux.org.uk>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2023-02-17 13:04:56 +01:00
Phil Sutter
7d34aa3e03 netfilter: nf_tables: Extend nft_expr_ops::dump callback parameters
Add a 'reset' flag just like with nft_object_ops::dump. This will be
useful to reset "anonymous stateful objects", e.g. simple rule counters.

No functional change intended.

Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2022-11-15 10:46:34 +01:00
Eric Dumazet
4ecbb1c27c net: dropreason: add SKB_DROP_REASON_DUP_FRAG
This is used to track when a duplicate segment received by various
reassembly units is dropped.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-10-31 20:14:26 -07:00
Guillaume Nault
1fcc064b30 netfilter: rpfilter/fib: Set ->flowic_uid correctly for user namespaces.
Currently netfilter's rpfilter and fib modules implicitely initialise
->flowic_uid with 0. This is normally the root UID. However, this isn't
the case in user namespaces, where user ID 0 is mapped to a different
kernel UID. By initialising ->flowic_uid with sock_net_uid(), we get
the root UID of the user namespace, thus keeping the same behaviour
whether or not we're running in a user namepspace.

Note, this is similar to commit 8bcfd0925e ("ipv4: add missing
initialization for flowi4_uid"), which fixed the rp_filter sysctl.

Fixes: 622ec2c9d5 ("net: core: add UID to flows, rules, and routes")
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2022-10-19 08:46:48 +02:00
Phil Sutter
acc641ab95 netfilter: rpfilter/fib: Populate flowic_l3mdev field
Use the introduced field for correct operation with VRF devices instead
of conditionally overwriting flowic_oif. This is a partial revert of
commit b575b24b8e ("netfilter: Fix rpfilter dropping vrf packets by
mistake"), implementing a simpler solution.

Signed-off-by: Phil Sutter <phil@nwl.cc>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
2022-10-12 14:08:15 +02:00
Phil Sutter
2a8a7c0eaa netfilter: nft_fib: Fix for rpath check with VRF devices
Analogous to commit b575b24b8e ("netfilter: Fix rpfilter
dropping vrf packets by mistake") but for nftables fib expression:
Add special treatment of VRF devices so that typical reverse path
filtering via 'fib saddr . iif oif' expression works as expected.

Fixes: f6d0cbcf09 ("netfilter: nf_tables: add fib expression")
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Florian Westphal <fw@strlen.de>
2022-09-28 13:33:26 +02:00
Kuniyuki Iwashima
4461568aa4 tcp: Access &tcp_hashinfo via net.
We will soon introduce an optional per-netns ehash.

This means we cannot use tcp_hashinfo directly in most places.

Instead, access it via net->ipv4.tcp_death_row.hashinfo.

The access will be valid only while initialising tcp_hashinfo
itself and creating/destroying each netns.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-09-20 10:21:49 -07:00
Eric Dumazet
00cd7bf9f9 netfilter: nf_defrag_ipv6: allow nf_conntrack_frag6_high_thresh increases
Currently, net.netfilter.nf_conntrack_frag6_high_thresh can only be lowered.

I found this issue while investigating a probable kernel issue
causing flakes in tools/testing/selftests/net/ip_defrag.sh

In particular, these sysctl changes were ignored:
	ip netns exec "${NETNS}" sysctl -w net.netfilter.nf_conntrack_frag6_high_thresh=9000000 >/dev/null 2>&1
	ip netns exec "${NETNS}" sysctl -w net.netfilter.nf_conntrack_frag6_low_thresh=7000000  >/dev/null 2>&1

This change is inline with commit 8361962392 ("net/ipfrag: let ip[6]frag_high_thresh
in ns be higher than in init_net")

Fixes: 8db3d41569bb ("netfilter: nf_defrag_ipv6: use net_generic infra")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2022-08-24 08:06:44 +02:00
Kevin Mitchell
4f9bd53084 netfilter: conntrack: skip verification of zero UDP checksum
The checksum is optional for UDP packets. However nf_reject would
previously require a valid checksum to elicit a response such as
ICMP_DEST_UNREACH.

Add some logic to nf_reject_verify_csum to determine if a UDP packet has
a zero checksum and should therefore not be verified.

Signed-off-by: Kevin Mitchell <kevmitch@arista.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2022-05-13 18:56:28 +02:00
Pablo Neira Ayuso
be8be04e5d netfilter: nft_fib: reverse path filter for policy-based routing on iif
If policy-based routing using the iif selector is used, then the fib
expression fails to look up for the reverse path from the prerouting
hook because the input interface cannot be inferred. In order to support
this scenario, extend the fib expression to allow to use after the route
lookup, from the forward hook.

This patch also adds support for the input hook for usability reasons.
Since the prerouting hook cannot be used for the scenario described
above, users need two rules: one for the forward chain and another rule
for the input chain to check for the reverse path check for locally
targeted traffic.

Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2022-04-11 12:10:09 +02:00
Florian Westphal
3c1eb413a4 netfilter: nft_fib: add reduce support
The fib expression stores to a register, so we can't add empty stub.
Check that the register that is being written is in fact redundant.

In most cases, this is expected to cancel tracking as re-use is
unlikely.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2022-03-20 00:29:47 +01:00
Pablo Neira Ayuso
b2d306542f netfilter: nf_tables: do not reduce read-only expressions
Skip register tracking for expressions that perform read-only operations
on the registers. Define and use a cookie pointer NFT_REDUCE_READONLY to
avoid defining stubs for these expressions.

This patch re-enables register tracking which was disabled in ed5f85d422
("netfilter: nf_tables: disable register tracking"). Follow up patches
add remaining register tracking for existing expressions.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2022-03-20 00:29:46 +01:00
Martin KaFai Lau
335c8cf3b5 net: ipv6: Handle delivery_time in ipv6 defrag
A latter patch will postpone the delivery_time clearing until the stack
knows the skb is being delivered locally (i.e. calling
skb_clear_delivery_time() at ip_local_deliver_finish() for IPv4
and at ip6_input_finish() for IPv6).  That will allow other kernel
forwarding path (e.g. ip[6]_forward) to keep the delivery_time also.

A very similar IPv6 defrag codes have been duplicated in
multiple places: regular IPv6, nf_conntrack, and 6lowpan.

Unlike the IPv4 defrag which is done before ip_local_deliver_finish(),
the regular IPv6 defrag is done after ip6_input_finish().
Thus, no change should be needed in the regular IPv6 defrag
logic because skb_clear_delivery_time() should have been called.

6lowpan also does not need special handling on delivery_time
because it is a non-inet packet_type.

However, cf_conntrack has a case in NF_INET_PRE_ROUTING that needs
to do the IPv6 defrag earlier.  Thus, it needs to save the
mono_delivery_time bit in the inet_frag_queue which is similar
to how it is handled in the previous patch for the IPv4 defrag.

This patch chooses to do it consistently and stores the mono_delivery_time
in the inet_frag_queue for all cases such that it will be easier
for the future refactoring effort on the IPv6 reasm code.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-03-03 14:38:48 +00:00
Geert Uytterhoeven
7355bfe0e0 netfilter: Remove flowtable relics
NF_FLOW_TABLE_IPV4 and NF_FLOW_TABLE_IPV6 are invisble, selected by
nothing (so they can no longer be enabled), and their last real users
have been removed (nf_flow_table_ipv6.c is empty).

Clean up the leftovers.

Fixes: c42ba4290b ("netfilter: flowtable: remove ipv4/ipv6 modules")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2022-01-27 00:00:20 +01:00
Florian Westphal
c42ba4290b netfilter: flowtable: remove ipv4/ipv6 modules
Just place the structs and registration in the inet module.
nf_flow_table_ipv6, nf_flow_table_ipv4 and nf_flow_table_inet share
same module dependencies: nf_flow_table, nf_tables.

before:
   text	   data	    bss	    dec	    hex	filename
   2278	   1480	      0	   3758	    eae	nf_flow_table_inet.ko
   1159	   1352	      0	   2511	    9cf	nf_flow_table_ipv6.ko
   1154	   1352	      0	   2506	    9ca	nf_flow_table_ipv4.ko

after:
   2369	   1672	      0	   4041	    fc9	nf_flow_table_inet.ko

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-12-23 01:07:44 +01:00
David S. Miller
bdfa75ad70 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Lots of simnple overlapping additions.

With a build fix from Stephen Rothwell.

Signed-off-by: David S. Miller <davem@davemloft.net>
2021-10-22 11:41:16 +01:00
David S. Miller
7adaf56edd Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next
Pablo Neira Ayuso says:

====================
Netfilter/IPVS updates for net-next

The following patchset contains Netfilter/IPVS for net-next:

1) Add new run_estimation toggle to IPVS to stop the estimation_timer
   logic, from Dust Li.

2) Relax superfluous dynset check on NFT_SET_TIMEOUT.

3) Add egress hook, from Lukas Wunner.

4) Nowadays, almost all hook functions in x_table land just call the hook
   evaluation loop. Remove remaining hook wrappers from iptables and IPVS.
   From Florian Westphal.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2021-10-18 14:05:25 +01:00
Xin Long
a482c5e00a netfilter: ip6t_rt: fix rt0_hdr parsing in rt_mt6
In rt_mt6(), when it's a nonlinear skb, the 1st skb_header_pointer()
only copies sizeof(struct ipv6_rt_hdr) to _route that rh points to.
The access by ((const struct rt0_hdr *)rh)->reserved will overflow
the buffer. So this access should be moved below the 2nd call to
skb_header_pointer().

Besides, after the 2nd skb_header_pointer(), its return value should
also be checked, othersize, *rp may cause null-pointer-ref.

v1->v2:
  - clean up some old debugging log.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-10-14 23:08:35 +02:00
Florian Westphal
44b5990e7b netfilter: ip6tables: allow use of ip6t_do_table as hookfn
This is possible now that the xt_table structure is passed via *priv.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-10-14 23:06:53 +02:00
Florian Westphal
339031bafe netfilter: conntrack: fix boot failure with nf_conntrack.enable_hooks=1
This is a revert of
7b1957b049 ("netfilter: nf_defrag_ipv4: use net_generic infra")
and a partial revert of
8b0adbe3e3 ("netfilter: nf_defrag_ipv6: use net_generic infra").

If conntrack is builtin and kernel is booted with:
nf_conntrack.enable_hooks=1

.... kernel will fail to boot due to a NULL deref in
nf_defrag_ipv4_enable(): Its called before the ipv4 defrag initcall is
made, so net_generic() returns NULL.

To resolve this, move the user refcount back to struct net so calls
to those functions are possible even before their initcalls have run.

Fixes: 7b1957b049 ("netfilter: nf_defrag_ipv4: use net_generic infra")
Fixes: 8b0adbe3e3 ("netfilter: nf_defrag_ipv6: use net_generic infra").
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-09-28 13:04:55 +02:00
Jeremy Sowden
310e2d43c3 netfilter: ip6_tables: zero-initialize fragment offset
ip6tables only sets the `IP6T_F_PROTO` flag on a rule if a protocol is
specified (`-p tcp`, for example).  However, if the flag is not set,
`ip6_packet_match` doesn't call `ipv6_find_hdr` for the skb, in which
case the fragment offset is left uninitialized and a garbage value is
passed to each matcher.

Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-09-15 17:00:28 +02:00
Jakub Kicinski
10905b4a68 Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf
Pablo Neira Ayuso says:

====================
Netfilter fixes for net

1) Protect nft_ct template with global mutex, from Pavel Skripkin.

2) Two recent commits switched inet rt and nexthop exception hashes
   from jhash to siphash. If those two spots are problematic then
   conntrack is affected as well, so switch voer to siphash too.
   While at it, add a hard upper limit on chain lengths and reject
   insertion if this is hit. Patches from Florian Westphal.

3) Fix use-after-scope in nf_socket_ipv6 reported by KASAN,
   from Benjamin Hesmans.

* git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf:
  netfilter: socket: icmp6: fix use-after-scope
  netfilter: refuse insertion if chain has grown too large
  netfilter: conntrack: switch to siphash
  netfilter: conntrack: sanitize table size default settings
  netfilter: nft_ct: protect nft_ct_pcpu_template_refcnt with mutex
====================

Link: https://lore.kernel.org/r/20210903163020.13741-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-09-03 16:20:37 -07:00
Benjamin Hesmans
730affed24 netfilter: socket: icmp6: fix use-after-scope
Bug reported by KASAN:

BUG: KASAN: use-after-scope in inet6_ehashfn (net/ipv6/inet6_hashtables.c:40)
Call Trace:
(...)
inet6_ehashfn (net/ipv6/inet6_hashtables.c:40)
(...)
nf_sk_lookup_slow_v6 (net/ipv6/netfilter/nf_socket_ipv6.c:91
net/ipv6/netfilter/nf_socket_ipv6.c:146)

It seems that this bug has already been fixed by Eric Dumazet in the
past in:
commit 78296c97ca ("netfilter: xt_socket: fix a stack corruption bug")

But a variant of the same issue has been introduced in
commit d64d80a2cd ("netfilter: x_tables: don't extract flow keys on early demuxed sks in socket match")

`daddr` and `saddr` potentially hold a reference to ipv6_var that is no
longer in scope when the call to `nf_socket_get_sock_v6` is made.

Fixes: d64d80a2cd ("netfilter: x_tables: don't extract flow keys on early demuxed sks in socket match")
Acked-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Benjamin Hesmans <benjamin.hesmans@tessares.net>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-09-03 18:25:31 +02:00
Florian Westphal
fdacd57c79 netfilter: x_tables: never register tables by default
For historical reasons x_tables still register tables by default in the
initial namespace.
Only newly created net namespaces add the hook on demand.

This means that the init_net always pays hook cost, even if no filtering
rules are added (e.g. only used inside a single netns).

Note that the hooks are added even when 'iptables -L' is called.
This is because there is no way to tell 'iptables -A' and 'iptables -L'
apart at kernel level.

The only solution would be to register the table, but delay hook
registration until the first rule gets added (or policy gets changed).

That however means that counters are not hooked either, so 'iptables -L'
would always show 0-counters even when traffic is flowing which might be
unexpected.

This keeps table and hook registration consistent with what is already done
in non-init netns: first iptables(-save) invocation registers both table
and hooks.

This applies the same solution adopted for ebtables.
All tables register a template that contains the l3 family, the name
and a constructor function that is called when the initial table has to
be added.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-08-09 10:22:01 +02:00
Jakub Kicinski
adc2e56ebe Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Trivial conflicts in net/can/isotp.c and
tools/testing/selftests/net/mptcp/mptcp_connect.sh

scaled_ppm_to_ppb() was moved from drivers/ptp/ptp_clock.c
to include/linux/ptp_clock_kernel.h in -next so re-apply
the fix there.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-06-18 19:47:02 -07:00
Florian Westphal
12f36e9bf6 netfilter: nft_fib_ipv6: skip ipv6 packets from any to link-local
The ip6tables rpfilter match has an extra check to skip packets with
"::" source address.

Extend this to ipv6 fib expression.  Else ipv6 duplicate address detection
packets will fail rpf route check -- lookup returns -ENETUNREACH.

While at it, extend the prerouting check to also cover the ingress hook.

Closes: https://bugzilla.netfilter.org/show_bug.cgi?id=1543
Fixes: f6d0cbcf09 ("netfilter: nf_tables: add fib expression")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-06-09 21:11:03 +02:00
Florian Westphal
85554eb981 netfilter: nf_tables: add and use nft_sk helper
This allows to change storage placement later on without changing readers.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-05-29 01:04:53 +02:00
Florian Westphal
586d5a8bce netfilter: x_tables: reduce xt_action_param by 8 byte
The fragment offset in ipv4/ipv6 is a 16bit field, so use
u16 instead of unsigned int.

On 64bit: 40 bytes to 32 bytes. By extension this also reduces
nft_pktinfo (56 to 48 byte).

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-05-29 01:04:53 +02:00
Florian Westphal
47a6959fa3 netfilter: allow to turn off xtables compat layer
The compat layer needs to parse untrusted input (the ruleset)
to translate it to a 64bit compatible format.

We had a number of bugs in this department in the past, so allow users
to turn this feature off.

Add CONFIG_NETFILTER_XTABLES_COMPAT kconfig knob and make it default to y
to keep existing behaviour.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-04-26 18:16:56 +02:00
Florian Westphal
ee177a5441 netfilter: ip6_tables: pass table pointer via nf_hook_ops
Same patch as the ip_tables one: removal of all accesses to ip6_tables
xt_table pointers.  After this patch the struct net xt_table anchors
can be removed.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-04-26 03:20:47 +02:00
Florian Westphal
a4aeafa28c netfilter: xt_nat: pass table to hookfn
This changes how ip(6)table nat passes the ruleset/table to the
evaluation loop.

At the moment, it will fetch the table from struct net.

This change stores the table in the hook_ops 'priv' argument
instead.

This requires to duplicate the hook_ops for each netns, so
they can store the (per-net) xt_table structure.

The dupliated nat hook_ops get stored in net_generic data area.
They are free'd in the namespace exit path.

This is a pre-requisite to remove the xt_table/ruleset pointers
from struct net.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-04-26 03:20:46 +02:00
Florian Westphal
f68772ed67 netfilter: x_tables: remove paranoia tests
No need for these.
There is only one caller, the xtables core, when the table is registered
for the first time with a particular network namespace.

After ->table_init() call, the table is linked into the tables[af] list,
so next call to that function will skip the ->table_init().

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-04-26 03:20:46 +02:00
Florian Westphal
6c0717545f netfilter: ip6tables: unregister the tables by name
Same as the previous patch, but for ip6tables.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-04-26 03:20:46 +02:00
Florian Westphal
7716bf090e netfilter: x_tables: remove ipt_unregister_table
Its the same function as ipt_unregister_table_exit.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-04-26 03:20:08 +02:00
Florian Westphal
de8c12110a netfilter: disable defrag once its no longer needed
When I changed defrag hooks to no longer get registered by default I
intentionally made it so that registration can only be un-done by unloading
the nf_defrag_ipv4/6 module.

In hindsight this was too conservative; there is no reason to keep defrag
on while there is no feature dependency anymore.

Moreover, this won't work if user isn't allowed to remove nf_defrag module.

This adds the disable() functions for both ipv4 and ipv6 and calls them
from conntrack, TPROXY and the xtables socket module.

ipvs isn't converted here, it will behave as before this patch and
will need module removal.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-04-26 03:20:07 +02:00
Jakub Kicinski
8203c7ce4e Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
 - keep the ZC code, drop the code related to reinit
net/bridge/netfilter/ebtables.c
 - fix build after move to net_generic

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-04-17 11:08:07 -07:00
Florian Westphal
b29c457a65 netfilter: x_tables: fix compat match/target pad out-of-bound write
xt_compat_match/target_from_user doesn't check that zeroing the area
to start of next rule won't write past end of allocated ruleset blob.

Remove this code and zero the entire blob beforehand.

Reported-by: syzbot+cfc0247ac173f597aaaa@syzkaller.appspotmail.com
Reported-by: Andy Nguyen <theflow@google.com>
Fixes: 9fa492cdc1 ("[NETFILTER]: x_tables: simplify compat API")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-04-13 00:18:57 +02:00
Florian Westphal
8b0adbe3e3 netfilter: nf_defrag_ipv6: use net_generic infra
This allows followup patch to remove these members from struct net.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-04-06 00:34:51 +02:00
Florian Westphal
f5466caab9 netfilter: nf_log_ipv6: merge with nf_log_syslog
This removes the nf_log_ipv6 module, the functionality is now
provided by nf_log_syslog.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-03-31 00:37:27 +02:00
Mark Tomlinson
d3d40f2374 Revert "netfilter: x_tables: Switch synchronization to RCU"
This reverts commit cc00bcaa58.

This (and the preceding) patch basically re-implemented the RCU
mechanisms of patch 784544739a. That patch was replaced because of the
performance problems that it created when replacing tables. Now, we have
the same issue: the call to synchronize_rcu() makes replacing tables
slower by as much as an order of magnitude.

Prior to using RCU a script calling "iptables" approx. 200 times was
taking 1.16s. With RCU this increased to 11.59s.

Revert these patches and fix the issue in a different way.

Signed-off-by: Mark Tomlinson <mark.tomlinson@alliedtelesis.co.nz>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-03-15 18:42:01 +01:00
Mark Tomlinson
abe7034b9a Revert "netfilter: x_tables: Update remaining dereference to RCU"
This reverts commit 443d6e86f8.

This (and the following) patch basically re-implemented the RCU
mechanisms of patch 784544739a. That patch was replaced because of the
performance problems that it created when replacing tables. Now, we have
the same issue: the call to synchronize_rcu() makes replacing tables
slower by as much as an order of magnitude.

Revert these patches and fix the issue in a different way.

Signed-off-by: Mark Tomlinson <mark.tomlinson@alliedtelesis.co.nz>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-03-15 18:42:00 +01:00
Pablo Neira Ayuso
4f16d25c68 netfilter: nftables: add nft_parse_register_load() and use it
This new function combines the netlink register attribute parser
and the load validation function.

This update requires to replace:

	enum nft_registers      sreg:8;

in many of the expression private areas otherwise compiler complains
with:

	error: cannot take address of bit-field ‘sreg’

when passing the register field as reference.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-01-27 22:53:29 +01:00
Jakub Kicinski
1e72faedcd Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf
Pablo Neira Ayuso says:

====================
Netfilter fixes for net

1) Incorrect loop in error path of nft_set_elem_expr_clone(),
   from Colin Ian King.

2) Missing xt_table_get_private_protected() to access table
   private data in x_tables, from Subash Abhinov Kasiviswanathan.

3) Possible oops in ipset hash type resize, from Vasily Averin.

4) Fix shift-out-of-bounds in ipset hash type, also from Vasily.

* git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf:
  netfilter: ipset: fix shift-out-of-bounds in htable_bits()
  netfilter: ipset: fixes possible oops in mtype_resize
  netfilter: x_tables: Update remaining dereference to RCU
  netfilter: nftables: fix incorrect increment of loop counter
====================

Link: https://lore.kernel.org/r/20201218120409.3659-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-18 18:07:14 -08:00
Subash Abhinov Kasiviswanathan
443d6e86f8 netfilter: x_tables: Update remaining dereference to RCU
This fixes the dereference to fetch the RCU pointer when holding
the appropriate xtables lock.

Reported-by: kernel test robot <lkp@intel.com>
Fixes: cc00bcaa58 ("netfilter: x_tables: Switch synchronization to RCU")
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-12-17 19:44:52 +01:00