Commit Graph

582 Commits

Author SHA1 Message Date
Gao Feng 4440a2ab3b netfilter: synproxy: Check oom when adding synproxy and seqadj ct extensions
When memory is exhausted, nfct_seqadj_ext_add may fail to add the
synproxy and seqadj extensions. The function nf_ct_seqadj_init doesn't
check if get valid seqadj pointer by the nfct_seqadj.

Now drop the packet directly when fail to add seqadj extension to
avoid dereference NULL pointer in nf_ct_seqadj_init from
init_conntrack().

Signed-off-by: Gao Feng <fgao@ikuai8.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-09-13 10:50:56 +02:00
Liping Zhang 960fa72f67 netfilter: nft_meta: improve the validity check of pkttype set expr
"meta pkttype set" is only supported on prerouting chain with bridge
family and ingress chain with netdev family.

But the validate check is incomplete, and the user can add the nft
rules on input chain with bridge family, for example:
  # nft add table bridge filter
  # nft add chain bridge filter input {type filter hook input \
    priority 0 \;}
  # nft add chain bridge filter test
  # nft add rule bridge filter test meta pkttype set unicast
  # nft add rule bridge filter input jump test

This patch fixes the problem.

Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-08-25 13:12:03 +02:00
Liping Zhang 89e1f6d2b9 netfilter: nft_reject: restrict to INPUT/FORWARD/OUTPUT
After I add the nft rule "nft add rule filter prerouting reject
with tcp reset", kernel panic happened on my system:
  NULL pointer dereference at ...
  IP: [<ffffffff81b9db2f>] nf_send_reset+0xaf/0x400
  Call Trace:
  [<ffffffff81b9da80>] ? nf_reject_ip_tcphdr_get+0x160/0x160
  [<ffffffffa0928061>] nft_reject_ipv4_eval+0x61/0xb0 [nft_reject_ipv4]
  [<ffffffffa08e836a>] nft_do_chain+0x1fa/0x890 [nf_tables]
  [<ffffffffa08e8170>] ? __nft_trace_packet+0x170/0x170 [nf_tables]
  [<ffffffffa06e0900>] ? nf_ct_invert_tuple+0xb0/0xc0 [nf_conntrack]
  [<ffffffffa07224d4>] ? nf_nat_setup_info+0x5d4/0x650 [nf_nat]
  [...]

Because in the PREROUTING chain, routing information is not exist,
then we will dereference the NULL pointer and oops happen.

So we restrict reject expression to INPUT, FORWARD and OUTPUT chain.
This is consistent with iptables REJECT target.

Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-08-25 12:55:34 +02:00
David S. Miller c42d7121fb 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 updates for net-next,
they are:

1) Count pre-established connections as active in "least connection"
   schedulers such that pre-established connections to avoid overloading
   backend servers on peak demands, from Michal Kubecek via Simon Horman.

2) Address a race condition when resizing the conntrack table by caching
   the bucket size when fulling iterating over the hashtable in these
   three possible scenarios: 1) dump via /proc/net/nf_conntrack,
   2) unlinking userspace helper and 3) unlinking custom conntrack timeout.
   From Liping Zhang.

3) Revisit early_drop() path to perform lockless traversal on conntrack
   eviction under stress, use del_timer() as synchronization point to
   avoid two CPUs evicting the same entry, from Florian Westphal.

4) Move NAT hlist_head to nf_conn object, this simplifies the existing
   NAT extension and it doesn't increase size since recent patches to
   align nf_conn, from Florian.

5) Use rhashtable for the by-source NAT hashtable, also from Florian.

6) Don't allow --physdev-is-out from OUTPUT chain, just like
   --physdev-out is not either, from Hangbin Liu.

7) Automagically set on nf_conntrack counters if the user tries to
   match ct bytes/packets from nftables, from Liping Zhang.

8) Remove possible_net_t fields in nf_tables set objects since we just
   simply pass the net pointer to the backend set type implementations.

9) Fix possible off-by-one in h323, from Toby DiPasquale.

10) early_drop() may be called from ctnetlink patch, so we must hold
    rcu read size lock from them too, this amends Florian's patch #3
    coming in this batch, from Liping Zhang.

11) Use binary search to validate jump offset in x_tables, this
    addresses the O(n!) validation that was introduced recently
    resolve security issues with unpriviledge namespaces, from Florian.

12) Fix reference leak to connlabel in error path of nft_ct, from Zhang.

13) Three updates for nft_log: Fix log prefix leak in error path. Bail
    out on loglevel larger than debug in nft_log and set on the new
    NF_LOG_F_COPY_LEN flag when snaplen is specified. Again from Zhang.

14) Allow to filter rule dumps in nf_tables based on table and chain
    names.

15) Simplify connlabel to always use 128 bits to store labels and
    get rid of unused function in xt_connlabel, from Florian.

16) Replace set_expect_timeout() by mod_timer() from the h323 conntrack
    helper, by Gao Feng.

17) Put back x_tables module reference in nft_compat on error, from
    Liping Zhang.

18) Add a reference count to the x_tables extensions cache in
    nft_compat, so we can remove them when unused and avoid a crash
    if the extensions are rmmod, again from Zhang.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-24 22:02:36 -07:00
David S. Miller de0ba9a0d8 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Just several instances of overlapping changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-24 00:53:32 -04:00
Florian Westphal 857ed310c0 netfilter: connlabels: move set helper to xt_connlabel
xt_connlabel is the only user so move it.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-07-22 17:05:10 +02:00
Florian Westphal 23014011ba netfilter: conntrack: support a fixed size of 128 distinct labels
The conntrack label extension is currently variable-sized, e.g. if
only 2 labels are used by iptables rules then the labels->bits[] array
will only contain one element.

We track size of each label storage area in the 'words' member.

But in nftables and openvswitch we always have to ask for worst-case
since we don't know what bit will be used at configuration time.

As most arches are 64bit we need to allocate 24 bytes in this case:

struct nf_conn_labels {
    u8            words;   /*     0     1 */
    /* XXX 7 bytes hole, try to pack */
    long unsigned bits[2]; /*     8     24 */

Make bits a fixed size and drop the words member, it simplifies
the code and only increases memory requirements on x86 when
less than 64bit labels are required.

We still only allocate the extension if its needed.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-07-22 17:04:55 +02:00
Gao Feng 82de0be686 netfilter: Add helper array register/unregister functions
Add nf_ct_helper_init(), nf_conntrack_helpers_register() and
nf_conntrack_helpers_unregister() functions to avoid repetitive
opencoded initialization in helpers.

This patch keeps an id parameter for nf_ct_helper_init() not to break
helper matching by name that has been inconsistently exposed to
userspace through ports, eg. ftp-2121, and through an incremental id,
eg. tftp-1.

Signed-off-by: Gao Feng <fgao@ikuai8.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-07-21 02:31:53 +02:00
Pablo Neira Ayuso 42a5576913 netfilter: nf_tables: get rid of possible_net_t from set and basechain
We can pass the netns pointer as parameter to the functions that need to
gain access to it. From basechains, I didn't find any client for this
field anymore so let's remove this too.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-07-11 12:16:04 +02:00
Florian Westphal d51ed8367b netfilter: constify arg to is_dying/confirmed
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-07-11 12:16:03 +02:00
Florian Westphal 870190a9ec netfilter: nat: convert nat bysrc hash to rhashtable
It did use a fixed-size bucket list plus single lock to protect add/del.

Unlike the main conntrack table we only need to add and remove keys.
Convert it to rhashtable to get table autosizing and per-bucket locking.

The maximum number of entries is -- as before -- tied to the number of
conntracks so we do not need another upperlimit.

The change does not handle rhashtable_remove_fast error, only possible
"error" is -ENOENT, and that is something that can happen legitimetely,
e.g. because nat module was inserted at a later time and no src manip
took place yet.

Tested with http-client-benchmark + httpterm with DNAT and SNAT rules
in place.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-07-11 12:07:57 +02:00
Florian Westphal 7c96643519 netfilter: move nat hlist_head to nf_conn
The nat extension structure is 32bytes in size on x86_64:

struct nf_conn_nat {
        struct hlist_node          bysource;             /*     0    16 */
        struct nf_conn *           ct;                   /*    16     8 */
        union nf_conntrack_nat_help help;                /*    24     4 */
        int                        masq_index;           /*    28     4 */
        /* size: 32, cachelines: 1, members: 4 */
        /* last cacheline: 32 bytes */
};

The hlist is needed to quickly check for possible tuple collisions
when installing a new nat binding. Storing this in the extension
area has two drawbacks:

1. We need ct backpointer to get the conntrack struct from the extension.
2. When reallocation of extension area occurs we need to fixup the bysource
   hash head via hlist_replace_rcu.

We can avoid both by placing the hlist_head in nf_conn and place nf_conn in
the bysource hash rather than the extenstion.

We can also remove the ->move support; no other extension needs it.

Moving the entire nat extension into nf_conn would be possible as well but
then we have to add yet another callback for deletion from the bysource
hash table rather than just using nat extension ->destroy hook for this.

nf_conn size doesn't increase due to aligment, followup patch replaces
hlist_node with single pointer.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-07-11 11:47:50 +02:00
Florian Westphal 242922a027 netfilter: conntrack: simplify early_drop
We don't need to acquire the bucket lock during early drop, we can
use lockless traveral just like ____nf_conntrack_find.

The timer deletion serves as synchronization point, if another cpu
attempts to evict same entry, only one will succeed with timer deletion.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-07-11 11:46:22 +02:00
Liping Zhang 64b87639c9 netfilter: conntrack: fix race between nf_conntrack proc read and hash resize
When we do "cat /proc/net/nf_conntrack", and meanwhile resize the conntrack
hash table via /sys/module/nf_conntrack/parameters/hashsize, race will
happen, because reader can observe a newly allocated hash but the old size
(or vice versa). So oops will happen like follows:

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000017
  IP: [<ffffffffa0418e21>] seq_print_acct+0x11/0x50 [nf_conntrack]
  Call Trace:
  [<ffffffffa0412f4e>] ? ct_seq_show+0x14e/0x340 [nf_conntrack]
  [<ffffffff81261a1c>] seq_read+0x2cc/0x390
  [<ffffffff812a8d62>] proc_reg_read+0x42/0x70
  [<ffffffff8123bee7>] __vfs_read+0x37/0x130
  [<ffffffff81347980>] ? security_file_permission+0xa0/0xc0
  [<ffffffff8123cf75>] vfs_read+0x95/0x140
  [<ffffffff8123e475>] SyS_read+0x55/0xc0
  [<ffffffff817c2572>] entry_SYSCALL_64_fastpath+0x1a/0xa4

It is very easy to reproduce this kernel crash.
1. open one shell and input the following cmds:
  while : ; do
    echo $RANDOM > /sys/module/nf_conntrack/parameters/hashsize
  done
2. open more shells and input the following cmds:
  while : ; do
    cat /proc/net/nf_conntrack
  done
3. just wait a monent, oops will happen soon.

The solution in this patch is based on Florian's Commit 5e3c61f981
("netfilter: conntrack: fix lookup race during hash resize"). And
add a wrapper function nf_conntrack_get_ht to get hash and hsize
suggested by Florian Westphal.

Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-07-11 11:38:57 +02:00
Florian Westphal c8607e0200 netfilter: nft_ct: fix expiration getter
We need to compute timeout.expires - jiffies, not the other way around.
Add a helper, another patch can then later change more places in
conntrack code where we currently open-code this.

Will allow us to only change one place later when we remove per-ct timer.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-07-08 14:55:14 +02:00
David S. Miller ae3e4562e2 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 net-next,
they are:

1) Don't use userspace datatypes in bridge netfilter code, from
   Tobin Harding.

2) Iterate only once over the expectation table when removing the
   helper module, instead of once per-netns, from Florian Westphal.

3) Extra sanitization in xt_hook_ops_alloc() to return error in case
   we ever pass zero hooks, xt_hook_ops_alloc():

4) Handle NFPROTO_INET from the logging core infrastructure, from
   Liping Zhang.

5) Autoload loggers when TRACE target is used from rules, this doesn't
   change the behaviour in case the user already selected nfnetlink_log
   as preferred way to print tracing logs, also from Liping Zhang.

6) Conntrack slabs with SLAB_HWCACHE_ALIGN to allow rearranging fields
   by cache lines, increases the size of entries in 11% per entry.
   From Florian Westphal.

7) Skip zone comparison if CONFIG_NF_CONNTRACK_ZONES=n, from Florian.

8) Remove useless defensive check in nf_logger_find_get() from Shivani
   Bhardwaj.

9) Remove zone extension as place it in the conntrack object, this is
   always include in the hashing and we expect more intensive use of
   zones since containers are in place. Also from Florian Westphal.

10) Owner match now works from any namespace, from Eric Bierdeman.

11) Make sure we only reply with TCP reset to TCP traffic from
    nf_reject_ipv4, patch from Liping Zhang.

12) Introduce --nflog-size to indicate amount of network packet bytes
    that are copied to userspace via log message, from Vishwanath Pai.
    This obsoletes --nflog-range that has never worked, it was designed
    to achieve this but it has never worked.

13) Introduce generic macros for nf_tables object generation masks.

14) Use generation mask in table, chain and set objects in nf_tables.
    This allows fixes interferences with ongoing preparation phase of
    the commit protocol and object listings going on at the same time.
    This update is introduced in three patches, one per object.

15) Check if the object is active in the next generation for element
    deactivation in the rbtree implementation, given that deactivation
    happens from the commit phase path we have to observe the future
    status of the object.

16) Support for deletion of just added elements in the hash set type.

17) Allow to resize hashtable from /proc entry, not only from the
    obscure /sys entry that maps to the module parameter, from Florian
    Westphal.

18) Get rid of NFT_BASECHAIN_DISABLED, this code is not exercised
    anymore since we tear down the ruleset whenever the netdevice
    goes away.

19) Support for matching inverted set lookups, from Arturo Borrero.

20) Simplify the iptables_mangle_hook() by removing a superfluous
    extra branch.

21) Introduce ether_addr_equal_masked() and use it from the netfilter
    codebase, from Joe Perches.

22) Remove references to "Use netfilter MARK value as routing key"
    from the Netfilter Kconfig description given that this toggle
    doesn't exists already for 10 years, from Moritz Sichert.

23) Introduce generic NF_INVF() and use it from the xtables codebase,
    from Joe Perches.

24) Setting logger to NONE via /proc was not working unless explicit
    nul-termination was included in the string. This fixes seems to
    leave the former behaviour there, so we don't break backward.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-06 09:15:15 -07:00
Pablo Neira Ayuso 82bec71d46 netfilter: nf_tables: get rid of NFT_BASECHAIN_DISABLED
This flag was introduced to restore rulesets from the new netdev
family, but since 5ebe0b0eec ("netfilter: nf_tables: destroy
basechain and rules on netdevice removal") the ruleset is released
once the netdev is gone.

This also removes nft_register_basechain() and
nft_unregister_basechain() since they have no clients anymore after
this rework.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-06-24 11:03:28 +02:00
Florian Westphal 3183ab8997 netfilter: conntrack: allow increasing bucket size via sysctl too
No need to restrict this to module parameter.

We export a copy of the real hash size -- when user alters the value we
allocate the new table, copy entries etc before we update the real size
to the requested one.

This is also needed because the real size is used by concurrent readers
and cannot be changed without synchronizing the conntrack generation
seqcnt.

We only allow changing this value from the initial net namespace.

Tested using http-client-benchmark vs. httpterm with concurrent

while true;do
 echo $RANDOM > /proc/sys/net/netfilter/nf_conntrack_buckets
done

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-06-24 11:03:28 +02:00
Pablo Neira Ayuso 37a9cc5255 netfilter: nf_tables: add generation mask to sets
Similar to ("netfilter: nf_tables: add generation mask to tables").

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-06-24 11:03:26 +02:00
Pablo Neira Ayuso 664b0f8cd8 netfilter: nf_tables: add generation mask to chains
Similar to ("netfilter: nf_tables: add generation mask to tables").

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-06-24 11:03:25 +02:00
Pablo Neira Ayuso f2a6d76676 netfilter: nf_tables: add generation mask to tables
This patch addresses two problems:

1) The netlink dump is inconsistent when interfering with an ongoing
   transaction update for several reasons:

1.a) We don't honor the internal NFT_TABLE_INACTIVE flag, and we should
     be skipping these inactive objects in the dump.

1.b) We perform speculative deletion during the preparation phase, that
     may result in skipping active objects.

1.c) The listing order changes, which generates noise when tracking
     incremental ruleset update via tools like git or our own
     testsuite.

2) We don't allow to add and to update the object in the same batch,
   eg. add table x; add table x { flags dormant\; }.

In order to resolve these problems:

1) If the user requests a deletion, the object becomes inactive in the
   next generation. Then, ignore objects that scheduled to be deleted
   from the lookup path, as they will be effectively removed in the
   next generation.

2) From the get/dump path, if the object is not currently active, we
   skip it.

3) Support 'add X -> update X' sequence from a transaction.

After this update, we obtain a consistent list as long as we stay
in the same generation. The userspace side can detect interferences
through the generation counter so it can restart the dumping.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-06-24 11:03:24 +02:00
Pablo Neira Ayuso 889f7ee7c6 netfilter: nf_tables: add generic macros to check for generation mask
Thus, we can reuse these to check the genmask of any object type, not
only rules. This is required now that tables, chain and sets will get a
generation mask field too in follow up patches.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-06-24 11:03:24 +02:00
Vishwanath Pai 7643507fe8 netfilter: xt_NFLOG: nflog-range does not truncate packets
li->u.ulog.copy_len is currently ignored by the kernel, we should truncate
the packet to either li->u.ulog.copy_len (if set) or copy_range before
sending it to userspace. 0 is a valid input for copy_len, so add a new
flag to indicate whether this was option was specified by the user or not.

Add two flags to indicate whether nflog-size/copy_len was set or not.
XT_NFLOG_F_COPY_LEN is for XT_NFLOG and NFLOG_F_COPY_LEN for nfnetlink_log

On the userspace side, this was initially represented by the option
nflog-range, this will be replaced by --nflog-size now. --nflog-range would
still exist but does not do anything.

Reported-by: Joe Dollard <jdollard@akamai.com>
Reviewed-by: Josh Hunt <johunt@akamai.com>
Signed-off-by: Vishwanath Pai <vpai@akamai.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-06-24 11:03:23 +02:00
Florian Westphal 6c8dee9842 netfilter: move zone info into struct nf_conn
Curently we store zone information as a conntrack extension.
This has one drawback: for every lookup we need to fetch the zone data
from the extension area.

This change place the zone data directly into the main conntrack object
structure and then removes the zone conntrack extension.

The zone data is just 4 bytes, it fits into a padding hole before
the tuplehash info, so we do not even increase the nf_conn structure size.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-06-23 13:33:12 +02:00
Florian Westphal 506e65df52 netfilter: make comparision helpers stub functions in ZONES=n case
Those comparisions are useless in case of ZONES=n; all conntracks
will reside in the same zone by definition.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-06-23 13:32:02 +02:00
Pablo Neira Ayuso 8588ac097b netfilter: nf_tables: reject loops from set element jump to chain
Liping Zhang says:

"Users may add such a wrong nft rules successfully, which will cause an
endless jump loop:

  # nft add rule filter test tcp dport vmap {1: jump test}

This is because before we commit, the element in the current anonymous
set is inactive, so osp->walk will skip this element and miss the
validate check."

To resolve this problem, this patch passes the generation mask to the
walk function through the iter container structure depending on the code
path:

1) If we're dumping the elements, then we have to check if the element
   is active in the current generation. Thus, we check for the current
   bit in the genmask.

2) If we're checking for loops, then we have to check if the element is
   active in the next generation, as we're in the middle of a
   transaction. Thus, we check for the next bit in the genmask.

Based on original patch from Liping Zhang.

Reported-by: Liping Zhang <liping.zhang@spreadtrum.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Tested-by: Liping Zhang <liping.zhang@spreadtrum.com>
2016-06-15 12:17:23 +02:00
David S. Miller fc14963f24 Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf
Pablo Neira Ayuso says:

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

The following patchset contains Netfilter fixes for your net tree,
they are:

1) Fix incorrect timestamp in nfnetlink_queue introduced when addressing
   y2038 safe timestamp, from Florian Westphal.

2) Get rid of leftover conntrack definition from the previous merge
   window, oneliner from Florian.

3) Make nf_queue handler pernet to resolve race on dereferencing the
   hook state structure with netns removal, from Eric Biederman.

4) Ensure clean exit on unregistered helper ports, from Taehee Yoo.

5) Restore FLOWI_FLAG_KNOWN_NH in nf_dup_ipv6. This got lost while
   generalizing xt_TEE to add packet duplication support in nf_tables,
   from Paolo Abeni.

6) Insufficient netlink NFTA_SET_TABLE attribute check in
   nf_tables_getset(), from Phil Turnbull.

7) Reject helper registration on duplicated ports via modparams.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-01 17:54:19 -07:00
Eric W. Biederman dc3ee32e96 netfilter: nf_queue: Make the queue_handler pernet
Florian Weber reported:
> Under full load (unshare() in loop -> OOM conditions) we can
> get kernel panic:
>
> BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
> IP: [<ffffffff81476c85>] nfqnl_nf_hook_drop+0x35/0x70
> [..]
> task: ffff88012dfa3840 ti: ffff88012dffc000 task.ti: ffff88012dffc000
> RIP: 0010:[<ffffffff81476c85>]  [<ffffffff81476c85>] nfqnl_nf_hook_drop+0x35/0x70
> RSP: 0000:ffff88012dfffd80  EFLAGS: 00010206
> RAX: 0000000000000008 RBX: ffffffff81add0c0 RCX: ffff88013fd80000
> [..]
> Call Trace:
>  [<ffffffff81474d98>] nf_queue_nf_hook_drop+0x18/0x20
>  [<ffffffff814738eb>] nf_unregister_net_hook+0xdb/0x150
>  [<ffffffff8147398f>] netfilter_net_exit+0x2f/0x60
>  [<ffffffff8141b088>] ops_exit_list.isra.4+0x38/0x60
>  [<ffffffff8141b652>] setup_net+0xc2/0x120
>  [<ffffffff8141bd09>] copy_net_ns+0x79/0x120
>  [<ffffffff8106965b>] create_new_namespaces+0x11b/0x1e0
>  [<ffffffff810698a7>] unshare_nsproxy_namespaces+0x57/0xa0
>  [<ffffffff8104baa2>] SyS_unshare+0x1b2/0x340
>  [<ffffffff81608276>] entry_SYSCALL_64_fastpath+0x1e/0xa8
> Code: 65 00 48 89 e5 41 56 41 55 41 54 53 83 e8 01 48 8b 97 70 12 00 00 48 98 49 89 f4 4c 8b 74 c2 18 4d 8d 6e 08 49 81 c6 88 00 00 00 <49> 8b 5d 00 48 85 db 74 1a 48 89 df 4c 89 e2 48 c7 c6 90 68 47
>

The simple fix for this requires a new pernet variable for struct
nf_queue that indicates when it is safe to use the dynamically
allocated nf_queue state.

As we need a variable anyway make nf_register_queue_handler and
nf_unregister_queue_handler pernet.  This allows the existing logic of
when it is safe to use the state from the nfnetlink_queue module to be
reused with no changes except for making it per net.

The syncrhonize_rcu from nf_unregister_queue_handler is moved to a new
function nfnl_queue_net_exit_batch so that the worst case of having a
syncrhonize_rcu in the pernet exit path is not experienced in batch
mode.

Reported-by: Florian Westphal <fw@strlen.de>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-05-25 11:54:22 +02:00
Florian Westphal 0a93aaedc4 netfilter: conntrack: use a single expectation table for all namespaces
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>
2016-05-06 11:50:01 +02:00
Pablo Neira Ayuso cb39ad8b8e netfilter: nf_tables: allow set names up to 32 bytes
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>
2016-05-05 16:39:51 +02:00
Pablo Neira Ayuso 71d8c47fc6 netfilter: conntrack: introduce clash resolution on insertion race
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>
2016-05-05 16:39:50 +02:00
Florian Westphal 56d52d4892 netfilter: conntrack: use a single hashtable for all namespaces
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>
2016-05-05 16:39:47 +02:00
Florian Westphal 141658fb02 netfilter: conntrack: use get_random_once for conntrack hash seed
As earlier commit removed accessed to the hash from other files we can
also make it static.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-25 14:52:12 +02:00
Florian Westphal adff6c6560 netfilter: connlabels: change nf_connlabels_get bit arg to 'highest used'
nf_connlabel_set() takes the bit number that we would like to set.
nf_connlabels_get() however took the number of bits that we want to
support.

So e.g. nf_connlabels_get(32) support bits 0 to 31, but not 32.
This changes nf_connlabels_get() to take the highest bit that we want
to set.

Callers then don't have to cope with a potential integer wrap
when using nf_connlabels_get(bit + 1) anymore.

Current callers are fine, this change is only to make folloup
nft ct label set support simpler.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-18 20:39:48 +02:00
Florian Westphal b4ef159927 netfilter: connlabels: move helpers to xt_connlabel
Currently labels can only be set either by iptables connlabel
match or via ctnetlink.

Before adding nftables set support, clean up the clabel core and move
helpers that nft will not need after all to the xtables module.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-18 20:39:41 +02:00
Florian Westphal ecdfb48cdd netfilter: conntrack: move expectation event helper to ecache.c
Not performance critical, it is only invoked when an expectation is
added/destroyed.

While at it, kill unused nf_ct_expect_event() wrapper.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-12 23:01:57 +02:00
Florian Westphal 3c435e2e41 netfilter: conntrack: de-inline nf_conntrack_eventmask_report
Way too large; move it to nf_conntrack_ecache.c.
Reduces total object size by 1216 byte on my machine.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-12 23:01:52 +02:00
Pablo Neira Ayuso 8a6bf5da1a netfilter: nft_masq: support port range
Complete masquerading support by allowing port range selection.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-03-02 20:05:27 +01:00
Sasha Levin b16c29191d netfilter: nf_conntrack: use safer way to lock all buckets
When we need to lock all buckets in the connection hashtable we'd attempt to
lock 1024 spinlocks, which is way more preemption levels than supported by
the kernel. Furthermore, this behavior was hidden by checking if lockdep is
enabled, and if it was - use only 8 buckets(!).

Fix this by using a global lock and synchronize all buckets on it when we
need to lock them all. This is pretty heavyweight, but is only done when we
need to resize the hashtable, and that doesn't happen often enough (or at all).

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-01-20 14:15:31 +01:00
Carlos Falgueras García e6d8ecac9e netfilter: nf_tables: Add new attributes into nft_set to store user data.
User data is stored at after 'nft_set_ops' private data into 'data[]'
flexible array. The field 'udata' points to user data and 'udlen' stores
its length.

Add new flag NFTA_SET_USERDATA.

Signed-off-by: Carlos Falgueras García <carlosfg@riseup.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-01-08 13:25:08 +01:00
Pablo Neira Ayuso 502061f81d netfilter: nf_tables: add packet duplication to the netdev family
You can use this to duplicate packets and inject them at the egress path
of the specified interface. This duplication allows you to inspect
traffic from the dummy or any other interface dedicated to this purpose.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-01-03 21:04:23 +01:00
Pablo Neira Ayuso 5ebe0b0eec netfilter: nf_tables: destroy basechain and rules on netdevice removal
If the netdevice is destroyed, the resources that are attached should
be released too as they belong to the device that is now gone.

Suggested-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-12-28 18:34:35 +01:00
Pablo Neira Ayuso df05ef874b netfilter: nf_tables: release objects on netns destruction
We have to release the existing objects on netns removal otherwise we
leak them. Chains are unregistered in first place to make sure no
packets are walking on our rules and sets anymore.

The object release happens by when we unregister the family via
nft_release_afinfo() which is called from nft_unregister_afinfo() from
the corresponding __net_exit path in every family.

Reported-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-12-28 18:34:35 +01:00
Pablo Neira 19576c9478 netfilter: cttimeout: add netns support
Add a per-netns list of timeout objects and adjust code to use it.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-12-14 12:48:58 +01:00
Florian Westphal e639f7ab07 netfilter: nf_tables: wrap tracing with a static key
Only needed when meta nftrace rule(s) were added.
The assumption is that no such rules are active, so the call to
nft_trace_init is "never" needed.

When nftrace rules are active, we always call the nft_trace_* functions,
but will only send netlink messages when all of the following are true:

 - traceinfo structure was initialised
 - skb->nf_trace == 1
 - at least one subscriber to trace group.

Adding an extra conditional
(static_branch ... && skb->nf_trace)
	nft_trace_init( ..)

Is possible but results in a larger nft_do_chain footprint.

Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-12-09 13:23:13 +01:00
Florian Westphal 33d5a7b14b netfilter: nf_tables: extend tracing infrastructure
nft monitor mode can then decode and display this trace data.

Parts of LL/Network/Transport headers are provided as separate
attributes.

Otherwise, printing IP address data becomes virtually impossible
for userspace since in the case of the netdev family we really don't
want userspace to have to know all the possible link layer types
and/or sizes just to display/print an ip address.

We also don't want userspace to have to follow ipv6 header chains
to get the s/dport info, the kernel already did this work for us.

To avoid bloating nft_do_chain all data required for tracing is
encapsulated in nft_traceinfo.

The structure is initialized unconditionally(!) for each nft_do_chain
invocation.

This unconditionall call will be moved under a static key in a
followup patch.

With lots of help from Patrick McHardy and Pablo Neira.

Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-12-09 13:18:37 +01:00
Patrick McHardy 7ec3f7b47b netfilter: nft_payload: add packet mangling support
Add support for mangling packet payload. Checksum for the specified base
header is updated automatically if requested, however no updates for any
kind of pseudo headers are supported, meaning no stateless NAT is supported.

For checksum updates different checksumming methods can be specified. The
currently supported methods are NONE for no checksum updates, and INET for
internet type checksums.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-11-25 13:54:51 +01:00
Florian Westphal a9ecfbe7fc netfilter: nf_tables: remove unused struct members
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-11-25 13:54:50 +01:00
Florian Westphal daaa7d647f netfilter: ipv6: avoid nf_iterate recursion
The previous patch changed nf_ct_frag6_gather() to morph reassembled skb
with the previous one.

This means that the return value is always NULL or the skb argument.
So change it to an err value.

Instead of invoking NF_HOOK recursively with threshold to skip already-called hooks
we can now just return NF_ACCEPT to move on to the next hook except for
-EINPROGRESS (which means skb has been queued for reassembly), in which case we
return NF_STOLEN.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-11-23 17:54:45 +01:00
Florian Westphal 029f7f3b87 netfilter: ipv6: nf_defrag: avoid/free clone operations
commit 6aafeef03b
("netfilter: push reasm skb through instead of original frag skbs")
changed ipv6 defrag to not use the original skbs anymore.

So rather than keeping the original skbs around just to discard them
afterwards just use the original skbs directly for the fraglist of
the newly assembled skb and remove the extra clone/free operations.

The skb that completes the fragment queue is morphed into a the
reassembled one instead, just like ipv4 defrag.

openvswitch doesn't need any additional skb_morph magic anymore to deal
with this situation so just remove that.

A followup patch can then also remove the NF_HOOK (re)invocation in
the ipv6 netfilter defrag hook.

Cc: Joe Stringer <joestringer@nicira.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-11-23 17:54:44 +01:00