Commit Graph

692 Commits

Author SHA1 Message Date
Liping Zhang
8eeef23504 netfilter: nf_ct_ext: invoke destroy even when ext is not attached
For NF_NAT_MANIP_SRC, we will insert the ct to the nat_bysource_table,
then remove it from the nat_bysource_table via nat_extend->destroy.

But now, the nat extension is attached on demand, so if the nat extension
is not attached, we will not be notified when the ct is destroyed, i.e.
we may fail to remove ct from the nat_bysource_table.

So just keep it simple, even if the extension is not attached, we will
still invoke the related ext->destroy. And this will also preserve the
flexibility for the future extension.

Fixes: 9a08ecfe74 ("netfilter: don't attach a nat extension by default")
Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-05-01 11:48:49 +02:00
Florian Westphal
039b40ee58 netfilter: nf_queue: only call synchronize_net twice if nf_queue is active
nf_unregister_net_hook(s) can avoid a second call to synchronize_net,
provided there is no nfqueue active in that net namespace (which is
the common case).

This also gets rid of the extra arg to nf_queue_nf_hook_drop(), normally
this gets called during netns cleanup so no packets should be queued.

For the rare case of base chain being unregistered or module removal
while nfqueue is in use the extra hiccup due to the packet drops isn't
a big deal.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-05-01 11:19:12 +02:00
Florian Westphal
9a08ecfe74 netfilter: don't attach a nat extension by default
nowadays the NAT extension only stores the interface index
(used to purge connections that got masqueraded when interface goes down)
and pptp nat information.

Previous patches moved nf_ct_nat_ext_add to those places that need it.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-04-26 09:30:22 +02:00
Florian Westphal
23f671a1b5 netfilter: conntrack: mark extension structs as const
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-04-26 09:30:22 +02:00
Florian Westphal
54044b1f02 netfilter: conntrack: remove prealloc support
It was used by the nat extension, but since commit
7c96643519 ("netfilter: move nat hlist_head to nf_conn") its only needed
for connections that use MASQUERADE target or a nat helper.

Also it seems a lot easier to preallocate a fixed size instead.

With default settings, conntrack first adds ecache extension (sysctl
defaults to 1), so we get 40(ct extension header) + 24 (ecache) == 64 byte
on x86_64 for initial allocation.

Followup patches can constify the extension structs and avoid
the initial zeroing of the entire extension area.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-04-26 09:30:22 +02:00
Florian Westphal
1fefe14725 netfilter: synproxy: only register hooks when needed
Defer registration of the synproxy hooks until the first SYNPROXY rule is
added.  Also means we only register hooks in namespaces that need it.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-04-26 09:30:21 +02:00
Florian Westphal
01026edef9 nefilter: eache: reduce struct size from 32 to 24 byte
Only "cache" needs to use ulong (its used with set_bit()), missed can use
u16.  Also add build-time assertion to ensure event bits fit.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-04-19 17:55:17 +02:00
Florian Westphal
c6dd940b1f netfilter: allow early drop of assured conntracks
If insertion of a new conntrack fails because the table is full, the kernel
searches the next buckets of the hash slot where the new connection
was supposed to be inserted at for an entry that hasn't seen traffic
in reply direction (non-assured), if it finds one, that entry is
is dropped and the new connection entry is allocated.

Allow the conntrack gc worker to also remove *assured* conntracks if
resources are low.

Do this by querying the l4 tracker, e.g. tcp connections are now dropped
if they are no longer established (e.g. in finwait).

This could be refined further, e.g. by adding 'soft' established timeout
(i.e., a timeout that is only used once we get close to resource
exhaustion).

Cc: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-04-19 17:55:17 +02:00
Florian Westphal
b3a5db109e netfilter: conntrack: use u8 for extension sizes again
commit 223b02d923
("netfilter: nf_conntrack: reserve two bytes for nf_ct_ext->len")
had to increase size of the extension offsets because total size of the
extensions had increased to a point where u8 did overflow.

3 years later we've managed to diet extensions a bit and we no longer
need u16.  Furthermore we can now add a compile-time assertion for this
problem.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-04-19 17:55:17 +02:00
Florian Westphal
faec865db9 netfilter: remove last traces of variable-sized extensions
get rid of the (now unused) nf_ct_ext_add_length define and also
rename the function to plain nf_ct_ext_add().

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-04-19 17:55:17 +02:00
Florian Westphal
9f0f3ebeda netfilter: helpers: remove data_len usage for inkernel helpers
No need to track this for inkernel helpers anymore as
NF_CT_HELPER_BUILD_BUG_ON checks do this now.

All inkernel helpers know what kind of structure they
stored in helper->data.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-04-19 17:55:17 +02:00
Florian Westphal
dcf67740f2 netfilter: helper: add build-time asserts for helper data size
add a 32 byte scratch area in the helper struct instead of relying
on variable sized helpers plus compile-time asserts to let us know
if 32 bytes aren't enough anymore.

Not having variable sized helpers will later allow to add BUILD_BUG_ON
for the total size of conntrack extensions -- the helper extension is
the only one that doesn't have a fixed size.

The (useless!) NF_CT_HELPER_BUILD_BUG_ON(0); are added so that in case
someone adds a new helper and copy-pastes from one that doesn't store
private data at least some indication that this macro should be used
somehow is there...

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-04-19 17:55:16 +02:00
Florian Westphal
906535b046 netfilter: conntrack: move helper struct to nf_conntrack_helper.h
its definition is not needed in nf_conntrack.h.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-04-19 17:55:16 +02:00
Florian Westphal
ab8bc7ed86 netfilter: remove nf_ct_is_untracked
This function is now obsolete and always returns false.
This change has no effect on generated code.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-04-15 11:51:33 +02:00
Florian Westphal
cc41c84b7e netfilter: kill the fake untracked conntrack objects
resurrect an old patch from Pablo Neira to remove the untracked objects.

Currently, there are four possible states of an skb wrt. conntrack.

1. No conntrack attached, ct is NULL.
2. Normal (kmem cache allocated) ct attached.
3. a template (kmalloc'd), not in any hash tables at any point in time
4. the 'untracked' conntrack, a percpu nf_conn object, tagged via
   IPS_UNTRACKED_BIT in ct->status.

Untracked is supposed to be identical to case 1.  It exists only
so users can check

-m conntrack --ctstate UNTRACKED vs.
-m conntrack --ctstate INVALID

e.g. attempts to set connmark on INVALID or UNTRACKED conntracks is
supposed to be a no-op.

Thus currently we need to check
 ct == NULL || nf_ct_is_untracked(ct)

in a lot of places in order to avoid altering untracked objects.

The other consequence of the percpu untracked object is that all
-j NOTRACK (and, later, kfree_skb of such skbs) result in an atomic op
(inc/dec the untracked conntracks refcount).

This adds a new kernel-private ctinfo state, IP_CT_UNTRACKED, to
make the distinction instead.

The (few) places that care about packet invalid (ct is NULL) vs.
packet untracked now need to test ct == NULL vs. ctinfo == IP_CT_UNTRACKED,
but all other places can omit the nf_ct_is_untracked() check.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-04-15 11:47:57 +02:00
Gao Feng
4f139972b4 netfilter: udplite: Remove duplicated udplite4/6 declaration
There are two nf_conntrack_l4proto_udp4 declarations in the head file
nf_conntrack_ipv4/6.h. Now remove one which is not enbraced by the macro
CONFIG_NF_CT_PROTO_UDPLITE.

Signed-off-by: Gao Feng <fgao@ikuai8.com>
2017-04-09 00:08:22 +02:00
Gao Feng
cba81cc4c9 netfilter: nat: nf_nat_mangle_{udp,tcp}_packet returns boolean
nf_nat_mangle_{udp,tcp}_packet() returns int. However, it is used as
bool type in many spots. Fix this by consistently handle this return
value as a boolean.

Signed-off-by: Gao Feng <fgao@ikuai8.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-04-06 22:01:38 +02:00
Gao Feng
ec0e3f0111 netfilter: nf_ct_expect: Add nf_ct_remove_expect()
When remove one expect, it needs three statements. And there are
multiple duplicated codes in current code. So add one common function
nf_ct_remove_expect to consolidate this.

Signed-off-by: Gao Feng <fgao@ikuai8.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-04-06 18:39:40 +02:00
Gao Feng
92f73221f9 netfilter: expect: Make sure the max_expected limit is effective
Because the type of expecting, the member of nf_conn_help, is u8, it
would overflow after reach U8_MAX(255). So it doesn't work when we
configure the max_expected exceeds 255 with expect policy.

Now add the check for max_expected. Return the -EINVAL when it exceeds
the limit.

Signed-off-by: Gao Feng <fgao@ikuai8.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-04-06 18:32:16 +02:00
Pablo Neira Ayuso
f323d95469 netfilter: nf_tables: add nft_is_base_chain() helper
This new helper function allows us to check if this is a basechain.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-04-06 18:32:04 +02:00
David S. Miller
16ae1f2236 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/ethernet/broadcom/genet/bcmmii.c
	drivers/net/hyperv/netvsc.c
	kernel/bpf/hashtab.c

Almost entirely overlapping changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-23 16:41:27 -07:00
Reshetova, Elena
b54ab92b84 netfilter: refcounter conversions
refcount_t type and corresponding API (see include/linux/refcount.h)
should be used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-03-17 12:49:43 +01:00
Pablo Neira Ayuso
04166f48d9 Revert "netfilter: nf_tables: add flush field to struct nft_set_iter"
This reverts commit 1f48ff6c53.

This patch is not required anymore now that we keep a dummy list of
set elements in the bitmap set implementation, so revert this before
we forget this code has no clients.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-03-13 17:30:16 +01:00
Phil Sutter
055c4b34b9 netfilter: nft_fib: Support existence check
Instead of the actual interface index or name, set destination register
to just 1 or 0 depending on whether the lookup succeeded or not if
NFTA_FIB_F_PRESENT was set in userspace.

Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-03-13 13:45:36 +01:00
Florian Westphal
84fba05511 netfilter: provide nft_ctx in object init function
this is needed by the upcoming ct helper object type --
we'd like to be able use the table family (ip, ip6, inet) to figure
out which helper has to be requested.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-03-13 13:42:00 +01:00
Steven Rostedt (VMware)
170a1fb9c0 netfilter: Force fake conntrack entry to be at least 8 bytes aligned
Since the nfct and nfctinfo have been combined, the nf_conn structure
must be at least 8 bytes aligned, as the 3 LSB bits are used for the
nfctinfo. But there's a fake nf_conn structure to denote untracked
connections, which is created by a PER_CPU construct. This does not
guarantee that it will be 8 bytes aligned and can break the logic in
determining the correct nfctinfo.

I triggered this on a 32bit machine with the following error:

BUG: unable to handle kernel NULL pointer dereference at 00000af4
IP: nf_ct_deliver_cached_events+0x1b/0xfb
*pdpt = 0000000031962001 *pde = 0000000000000000

Oops: 0000 [#1] SMP
[Modules linked in: ip6t_REJECT nf_reject_ipv6 nf_conntrack_ipv6 nf_defrag_ipv6 ip6table_filter ip6_tables ipv6 crc_ccitt ppdev r8169 parport_pc parport
  OK  ]
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.10.0-test+ #75
Hardware name: MSI MS-7823/CSM-H87M-G43 (MS-7823), BIOS V1.6 02/22/2014
task: c126ec00 task.stack: c1258000
EIP: nf_ct_deliver_cached_events+0x1b/0xfb
EFLAGS: 00010202 CPU: 0
EAX: 0021cd01 EBX: 00000000 ECX: 27b0c767 EDX: 32bcb17a
ESI: f34135c0 EDI: f34135c0 EBP: f2debd60 ESP: f2debd3c
 DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068
CR0: 80050033 CR2: 00000af4 CR3: 309a0440 CR4: 001406f0
Call Trace:
 <SOFTIRQ>
 ? ipv6_skip_exthdr+0xac/0xcb
 ipv6_confirm+0x10c/0x119 [nf_conntrack_ipv6]
 nf_hook_slow+0x22/0xc7
 nf_hook+0x9a/0xad [ipv6]
 ? ip6t_do_table+0x356/0x379 [ip6_tables]
 ? ip6_fragment+0x9e9/0x9e9 [ipv6]
 ip6_output+0xee/0x107 [ipv6]
 ? ip6_fragment+0x9e9/0x9e9 [ipv6]
 dst_output+0x36/0x4d [ipv6]
 NF_HOOK.constprop.37+0xb2/0xba [ipv6]
 ? icmp6_dst_alloc+0x2c/0xfd [ipv6]
 ? local_bh_enable+0x14/0x14 [ipv6]
 mld_sendpack+0x1c5/0x281 [ipv6]
 ? mark_held_locks+0x40/0x5c
 mld_ifc_timer_expire+0x1f6/0x21e [ipv6]
 call_timer_fn+0x135/0x283
 ? detach_if_pending+0x55/0x55
 ? mld_dad_timer_expire+0x3e/0x3e [ipv6]
 __run_timers+0x111/0x14b
 ? mld_dad_timer_expire+0x3e/0x3e [ipv6]
 run_timer_softirq+0x1c/0x36
 __do_softirq+0x185/0x37c
 ? test_ti_thread_flag.constprop.19+0xd/0xd
 do_softirq_own_stack+0x22/0x28
 </SOFTIRQ>
 irq_exit+0x5a/0xa4
 smp_apic_timer_interrupt+0x2a/0x34
 apic_timer_interrupt+0x37/0x3c

By using DEFINE/DECLARE_PER_CPU_ALIGNED we can enforce at least 8 byte
alignment as all cache line sizes are at least 8 bytes or more.

Fixes: a9e419dc7b ("netfilter: merge ctinfo into nfct pointer storage area")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-03-13 13:33:58 +01:00
Liping Zhang
10596608c4 netfilter: nf_tables: fix mismatch in big-endian system
Currently, there are two different methods to store an u16 integer to
the u32 data register. For example:
  u32 *dest = &regs->data[priv->dreg];
  1. *dest = 0; *(u16 *) dest = val_u16;
  2. *dest = val_u16;

For method 1, the u16 value will be stored like this, either in
big-endian or little-endian system:
  0          15           31
  +-+-+-+-+-+-+-+-+-+-+-+-+
  |   Value   |     0     |
  +-+-+-+-+-+-+-+-+-+-+-+-+

For method 2, in little-endian system, the u16 value will be the same
as listed above. But in big-endian system, the u16 value will be stored
like this:
  0          15           31
  +-+-+-+-+-+-+-+-+-+-+-+-+
  |     0     |   Value   |
  +-+-+-+-+-+-+-+-+-+-+-+-+

So later we use "memcmp(&regs->data[priv->sreg], data, 2);" to do
compare in nft_cmp, nft_lookup expr ..., method 2 will get the wrong
result in big-endian system, as 0~15 bits will always be zero.

For the similar reason, when loading an u16 value from the u32 data
register, we should use "*(u16 *) sreg;" instead of "(u16)*sreg;",
the 2nd method will get the wrong value in the big-endian system.

So introduce some wrapper functions to store/load an u8 or u16
integer to/from the u32 data register, and use them in the right
place.

Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-03-13 13:30:28 +01:00
Pablo Neira Ayuso
568af6de05 netfilter: nf_tables: set pktinfo->thoff at AH header if found
Phil Sutter reports that IPv6 AH header matching is broken. From
userspace, nft generates bytecode that expects to find the AH header at
NFT_PAYLOAD_TRANSPORT_HEADER both for IPv4 and IPv6. However,
pktinfo->thoff is set to the inner header after the AH header in IPv6,
while in IPv4 pktinfo->thoff points to the AH header indeed. This
behaviour is inconsistent. This patch fixes this problem by updating
ipv6_find_hdr() to get the IP6_FH_F_AUTH flag so this function stops at
the AH header, so both IPv4 and IPv6 pktinfo->thoff point to the AH
header.

This is also inconsistent when trying to match encapsulated headers:

1) A packet that looks like IPv4 + AH + TCP dport 22 will *not* match.
2) A packet that looks like IPv6 + AH + TCP dport 22 will match.

Reported-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-03-08 18:35:27 +01:00
Pablo Neira Ayuso
c7a72e3fdb netfilter: nf_tables: add nft_set_lookup()
This new function consolidates set lookup via either name or ID by
introducing a new nft_set_lookup() function. Replace existing spots
where we can use this too.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-03-06 18:23:23 +01:00
Pablo Neira Ayuso
25e94a997b netfilter: nf_tables: don't call nfnetlink_set_err() if nfnetlink_send() fails
The underlying nlmsg_multicast() already sets sk->sk_err for us to
notify socket overruns, so we should not do anything with this return
value. So we just call nfnetlink_set_err() if:

1) We fail to allocate the netlink message.

or

2) We don't have enough space in the netlink message to place attributes,
   which means that we likely need to allocate a larger message.

Before this patch, the internal ESRCH netlink error code was propagated
to userspace, which is quite misleading. Netlink semantics mandate that
listeners just hit ENOBUFS if the socket buffer overruns.

Reported-by: Alexander Alemayhu <alexander@alemayhu.com>
Tested-by: Alexander Alemayhu <alexander@alemayhu.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-03-03 13:48:34 +01:00
Pablo Neira Ayuso
1a94e38d25 netfilter: nf_tables: add NFTA_RULE_ID attribute
This new attribute allows us to uniquely identify a rule in transaction.
Robots may trigger an insertion followed by deletion in a batch, in that
scenario we still don't have a public rule handle that we can use to
delete the rule. This is similar to the NFTA_SET_ID attribute that
allows us to refer to an anonymous set from a batch.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-02-12 14:45:13 +01:00
Pablo Neira Ayuso
0b5a787492 netfilter: nf_tables: add space notation to sets
The space notation allows us to classify the set backend implementation
based on the amount of required memory. This provides an order of the
set representation scalability in terms of memory. The size field is
still left in place so use this if the userspace provides no explicit
number of elements, so we cannot calculate the real memory that this set
needs. This also helps us break ties in the set backend selection
routine, eg. two backend implementations provide the same performance.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-02-08 14:16:21 +01:00
Pablo Neira Ayuso
55af753cd9 netfilter: nf_tables: rename struct nft_set_estimate class field
Use lookup as field name instead, to prepare the introduction of the
memory class in a follow up patch.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-02-08 14:16:20 +01:00
Pablo Neira Ayuso
1f48ff6c53 netfilter: nf_tables: add flush field to struct nft_set_iter
This provides context to walk callback iterator, thus, we know if the
walk happens from the set flush path. This is required by the new bitmap
set type coming in a follow up patch which has no real struct
nft_set_ext, so it has to allocate it based on the two bit compact
element representation.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-02-08 14:16:20 +01:00
Pablo Neira Ayuso
1ba1c41408 netfilter: nf_tables: rename deactivate_one() to flush()
Although semantics are similar to deactivate() with no implicit element
lookup, this is only called from the set flush path, so better rename
this to flush().

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-02-08 14:16:19 +01:00
Pablo Neira Ayuso
5cb82a38c6 netfilter: nf_tables: pass netns to set->ops->remove()
This new parameter is required by the new bitmap set type that comes in a
follow up patch.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-02-08 14:16:18 +01:00
David S. Miller
52e01b84a2 Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next
Pablo Neira Ayuso says:

====================
Netfilter updates for net-next

The following patchset contains Netfilter updates for your net-next
tree, they are:

1) Stash ctinfo 3-bit field into pointer to nf_conntrack object from
   sk_buff so we only access one single cacheline in the conntrack
   hotpath. Patchset from Florian Westphal.

2) Don't leak pointer to internal structures when exporting x_tables
   ruleset back to userspace, from Willem DeBruijn. This includes new
   helper functions to copy data to userspace such as xt_data_to_user()
   as well as conversions of our ip_tables, ip6_tables and arp_tables
   clients to use it. Not surprinsingly, ebtables requires an ad-hoc
   update. There is also a new field in x_tables extensions to indicate
   the amount of bytes that we copy to userspace.

3) Add nf_log_all_netns sysctl: This new knob allows you to enable
   logging via nf_log infrastructure for all existing netnamespaces.
   Given the effort to provide pernet syslog has been discontinued,
   let's provide a way to restore logging using netfilter kernel logging
   facilities in trusted environments. Patch from Michal Kubecek.

4) Validate SCTP checksum from conntrack helper, from Davide Caratti.

5) Merge UDPlite conntrack and NAT helpers into UDP, this was mostly
   a copy&paste from the original helper, from Florian Westphal.

6) Reset netfilter state when duplicating packets, also from Florian.

7) Remove unnecessary check for broadcast in IPv6 in pkttype match and
   nft_meta, from Liping Zhang.

8) Add missing code to deal with loopback packets from nft_meta when
   used by the netdev family, also from Liping.

9) Several cleanups on nf_tables, one to remove unnecessary check from
   the netlink control plane path to add table, set and stateful objects
   and code consolidation when unregister chain hooks, from Gao Feng.

10) Fix harmless reference counter underflow in IPVS that, however,
    results in problems with the introduction of the new refcount_t
    type, from David Windsor.

11) Enable LIBCRC32C from nf_ct_sctp instead of nf_nat_sctp,
    from Davide Caratti.

12) Missing documentation on nf_tables uapi header, from Liping Zhang.

13) Use rb_entry() helper in xt_connlimit, from Geliang Tang.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-03 16:58:20 -05:00
Michal Kubeček
2851940ffe netfilter: allow logging from non-init namespaces
Commit 69b34fb996 ("netfilter: xt_LOG: add net namespace support for
xt_LOG") disabled logging packets using the LOG target from non-init
namespaces. The motivation was to prevent containers from flooding
kernel log of the host. The plan was to keep it that way until syslog
namespace implementation allows containers to log in a safe way.

However, the work on syslog namespace seems to have hit a dead end
somewhere in 2013 and there are users who want to use xt_LOG in all
network namespaces. This patch allows to do so by setting

  /proc/sys/net/netfilter/nf_log_all_netns

to a nonzero value. This sysctl is only accessible from init_net so that
one cannot switch the behaviour from inside a container.

Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-02-02 14:31:58 +01:00
Florian Westphal
a9e419dc7b netfilter: merge ctinfo into nfct pointer storage area
After this change conntrack operations (lookup, creation, matching from
ruleset) only access one instead of two sk_buff cache lines.

This works for normal conntracks because those are allocated from a slab
that guarantees hw cacheline or 8byte alignment (whatever is larger)
so the 3 bits needed for ctinfo won't overlap with nf_conn addresses.

Template allocation now does manual address alignment (see previous change)
on arches that don't have sufficent kmalloc min alignment.

Some spots intentionally use skb->_nfct instead of skb_nfct() helpers,
this is to avoid undoing the skb_nfct() use when we remove untracked
conntrack object in the future.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-02-02 14:31:56 +01:00
Florian Westphal
3032230920 netfilter: guarantee 8 byte minalign for template addresses
The next change will merge skb->nfct pointer and skb->nfctinfo
status bits into single skb->_nfct (unsigned long) area.

For this to work nf_conn addresses must always be aligned at least on
an 8 byte boundary since we will need the lower 3bits to store nfctinfo.

Conntrack templates are allocated via kmalloc.
kbuild test robot reported
BUILD_BUG_ON failed: NFCT_INFOMASK >= ARCH_KMALLOC_MINALIGN
on v1 of this patchset, so not all platforms meet this requirement.

Do manual alignment if needed,  the alignment offset is stored in the
nf_conn entry protocol area. This works because templates are not
handed off to L4 protocol trackers.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-02-02 14:31:55 +01:00
Florian Westphal
c74454fadd netfilter: add and use nf_ct_set helper
Add a helper to assign a nf_conn entry and the ctinfo bits to an sk_buff.
This avoids changing code in followup patch that merges skb->nfct and
skb->nfctinfo into skb->_nfct.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-02-02 14:31:54 +01:00
Florian Westphal
cb9c68363e skbuff: add and use skb_nfct helper
Followup patch renames skb->nfct and changes its type so add a helper to
avoid intrusive rename change later.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-02-02 14:31:53 +01:00
Florian Westphal
11df4b760f netfilter: conntrack: no need to pass ctinfo to error handler
It is never accessed for reading and the only places that write to it
are the icmp(6) handlers, which also set skb->nfct (and skb->nfctinfo).

The conntrack core specifically checks for attached skb->nfct after
->error() invocation and returns early in this case.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-02-02 14:31:51 +01:00
Pablo Neira Ayuso
de70185de0 netfilter: nf_tables: deconstify walk callback function
The flush operation needs to modify set and element objects, so let's
deconstify this.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-01-24 21:46:58 +01:00
Liping Zhang
6443ebc3fd netfilter: rpfilter: fix incorrect loopback packet judgment
Currently, we check the existing rtable in PREROUTING hook, if RTCF_LOCAL
is set, we assume that the packet is loopback.

But this assumption is incorrect, for example, a packet encapsulated
in ipsec transport mode was received and routed to local, after
decapsulation, it would be delivered to local again, and the rtable
was not dropped, so RTCF_LOCAL check would trigger. But actually, the
packet was not loopback.

So for these normal loopback packets, we can check whether the in device
is IFF_LOOPBACK or not. For these locally generated broadcast/multicast,
we can check whether the skb->pkt_type is PACKET_LOOPBACK or not.

Finally, there's a subtle difference between nft fib expr and xtables
rpfilter extension, user can add the following nft rule to do strict
rpfilter check:
  # nft add rule x y meta iif eth0 fib saddr . iif oif != eth0 drop

So when the packet is loopback, it's better to store the in device
instead of the LOOPBACK_IFINDEX, otherwise, after adding the above
nft rule, locally generated broad/multicast packets will be dropped
incorrectly.

Fixes: f83a7ea207 ("netfilter: xt_rpfilter: skip locally generated broadcast/multicast, too")
Fixes: f6d0cbcf09 ("netfilter: nf_tables: add fib expression")
Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-01-16 14:23:01 +01:00
Florian Westphal
e4781421e8 netfilter: merge udp and udplite conntrack helpers
udplite was copied from udp, they are virtually 100% identical.

This adds udplite tracker to udp instead, removes udplite module,
and then makes the udplite tracker builtin.

udplite will then simply re-use udp timeout settings.
It makes little sense to add separate sysctls, nowadays we have
fine-grained timeout policy support via the CT target.

old:
 text    data     bss     dec     hex filename
 1633     672       0    2305     901 nf_conntrack_proto_udp.o
 1756     672       0    2428     97c nf_conntrack_proto_udplite.o
69526   17937     268   87731   156b3 nf_conntrack.ko

new:
 text    data     bss     dec     hex filename
 2442    1184       0    3626     e2a nf_conntrack_proto_udp.o
68565   17721     268   86554   1521a nf_conntrack.ko

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-01-03 14:33:25 +01:00
David S. Miller
5fccd64aa4 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 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>
2016-12-07 19:16:46 -05:00
Pablo Neira Ayuso
8411b6442e netfilter: nf_tables: support for set flushing
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>
2016-12-07 13:31:40 +01:00
Pablo Neira Ayuso
8aeff920dc netfilter: nf_tables: add stateful object reference to set elements
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>
2016-12-07 13:22:47 +01:00
Pablo Neira Ayuso
1896531710 netfilter: nft_quota: add depleted flag for objects
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>
2016-12-07 13:22:12 +01:00