Commit Graph

539 Commits

Author SHA1 Message Date
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
Pablo Neira Ayuso
086f332167 netfilter: nf_tables: add clone interface to expression operations
With the conversion of the counter expressions to make it percpu, we
need to clone the percpu memory area, otherwise we crash when using
counters from flow tables.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-11-10 23:47:32 +01:00
Pablo Neira Ayuso
f0a0a978b6 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
This merge resolves conflicts with 75aec9df3a ("bridge: Remove
br_nf_push_frag_xmit_sk") as part of Eric Biederman's effort to improve
netns support in the network stack that reached upstream via David's
net-next tree.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Conflicts:
	net/bridge/br_netfilter_hooks.c
2015-10-17 14:28:03 +02:00
Florian Westphal
ed78d09d59 netfilter: make nf_queue_entry_get_refs return void
We don't care if module is being unloaded anymore since hook unregister
handling will destroy queue entries using that hook.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-10-16 18:22:23 +02:00
Eric W. Biederman
b72775977c ipv6: Pass struct net into nf_ct_frag6_gather
The function nf_ct_frag6_gather is called on both the input and the
output paths of the networking stack.  In particular ipv6_defrag which
calls nf_ct_frag6_gather is called from both the the PRE_ROUTING chain
on input and the LOCAL_OUT chain on output.

The addition of a net parameter makes it explicit which network
namespace the packets are being reassembled in, and removes the need
for nf_ct_frag6_gather to guess.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-12 19:44:17 -07:00
Pablo Neira Ayuso
ae2d708ed8 netfilter: conntrack: fix crash on timeout object removal
The object and module refcounts are updated for each conntrack template,
however, if we delete the iptables rules and we flush the timeout
database, we may end up with invalid references to timeout object that
are just gone.

Resolve this problem by setting the timeout reference to NULL when the
custom timeout entry is removed from our base. This patch requires some
RCU trickery to ensure safe pointer handling.

This handling is similar to what we already do with conntrack helpers,
the idea is to avoid bumping the timeout object reference counter from
the packet path to avoid the cost of atomic ops.

Reported-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-10-12 17:04:34 +02:00
Flavio Leitner
0647e70834 netfilter: remove dead code
Remove __nf_conntrack_find() from headers.

Fixes: dcd93ed4cd ("netfilter: nf_conntrack: remove dead code")
Signed-off-by: Flavio Leitner <fbl@sysclose.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-10-05 17:32:01 +02:00
Pablo Neira Ayuso
b7bd1809e0 netfilter: nfnetlink_queue: get rid of nfnetlink_queue_ct.c
The original intention was to avoid dependencies between nfnetlink_queue and
conntrack without ifdef pollution. However, we can achieve this by moving the
conntrack dependent code into ctnetlink and keep some glue code to access the
nfq_ct indirection from nfqueue.

After this patch, the nfq_ct indirection is always compiled in the netfilter
core to avoid polluting nfqueue with ifdefs. Thus, if nf_conntrack is not
compiled this results in only 8-bytes of memory waste in x86_64.

This patch also adds ctnetlink_nfqueue_seqadj() to avoid that the nf_conn
structure layout if exposed to nf_queue, which creates another dependency with
nf_conntrack at compilation time.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-10-04 21:45:44 +02:00
Eric W. Biederman
c1444c6357 bridge: Pass net into br_validate_ipv4 and br_validate_ipv6
The network namespace is easiliy available in state->net so use it.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-09-29 20:21:32 +02:00
Eric W. Biederman
372892ec11 ipv4: Push struct net down into nf_send_reset
This is needed so struct net can be pushed down into
ip_route_me_harder.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-09-29 20:21:31 +02:00
Eric W. Biederman
c7af6483b9 netfilter: Pass net into nf_xfrm_me_harder
Instead of calling dev_net on a likley looking network device
pass state->net into nf_xfrm_me_harder.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-09-18 22:00:22 +02:00
Eric W. Biederman
06198b34a3 netfilter: Pass priv instead of nf_hook_ops to netfilter hooks
Only pass the void *priv parameter out of the nf_hook_ops.  That is
all any of the functions are interested now, and by limiting what is
passed it becomes simpler to change implementation details.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-09-18 22:00:16 +02:00
Eric W. Biederman
a31f1adc09 netfilter: nf_conntrack: Add a struct net parameter to l4_pkt_to_tuple
As gre does not have the srckey in the packet gre_pkt_to_tuple
needs to perform a lookup in it's per network namespace tables.

Pass in the proper network namespace to all pkt_to_tuple
implementations to ensure gre (and any similar protocols) can get this
right.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-09-18 22:00:04 +02:00
Eric W. Biederman
206e8c0075 netfilter: Pass net to nf_dup_ipv4 and nf_dup_ipv6
This allows them to stop guessing the network namespace with pick_net.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-09-18 21:59:11 +02:00
Eric W. Biederman
46448d0093 netfilter: nf_tables: Pass struct net in nft_pktinfo
nft_pktinfo is passed on the stack so this does not bloat any in core
data structures.

By centrally computing this information this makes maintence of the code
simpler, and understading of the code easier.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-09-18 21:58:38 +02:00
Eric W. Biederman
156c196f60 netfilter: x_tables: Pass struct net in xt_action_param
As xt_action_param lives on the stack this does not bloat any
persistent data structures.

This is a first step in making netfilter code that needs to know
which network namespace it is executing in simpler.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-09-18 21:58:14 +02:00
Eric W. Biederman
6aa187f21c netfilter: nf_tables: kill nft_pktinfo.ops
- Add nft_pktinfo.pf to replace ops->pf
- Add nft_pktinfo.hook to replace ops->hooknum

This simplifies the code, makes it more readable, and likely reduces
cache line misses.  Maintainability is enhanced as the details of
nft_hook_ops are of no concern to the recpients of nft_pktinfo.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-09-18 21:58:01 +02:00
Eric W. Biederman
0c4b51f005 netfilter: Pass net into okfn
This is immediately motivated by the bridge code that chains functions that
call into netfilter.  Without passing net into the okfns the bridge code would
need to guess about the best expression for the network namespace to process
packets in.

As net is frequently one of the first things computed in continuation functions
after netfilter has done it's job passing in the desired network namespace is in
many cases a code simplification.

To support this change the function dst_output_okfn is introduced to
simplify passing dst_output as an okfn.  For the moment dst_output_okfn
just silently drops the struct net.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-17 17:18:37 -07:00
David S. Miller
53cfd053e4 Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf
Conflicts:
	include/net/netfilter/nf_conntrack.h

The conflict was an overlap between changing the type of the zone
argument to nf_ct_tmpl_alloc() whilst exporting nf_ct_tmpl_free.

Pablo Neira Ayuso says:

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

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

1) Oneliner to restore maps in nf_tables since we support addressing registers
   at 32 bits level.

2) Restore previous default behaviour in bridge netfilter when CONFIG_IPV6=n,
   oneliner from Bernhard Thaler.

3) Out of bound access in ipset hash:net* set types, reported by Dave Jones'
   KASan utility, patch from Jozsef Kadlecsik.

4) Fix ipset compilation with gcc 4.4.7 related to C99 initialization of
   unnamed unions, patch from Elad Raz.

5) Add a workaround to address inconsistent endianess in the res_id field of
   nfnetlink batch messages, reported by Florian Westphal.

6) Fix error paths of CT/synproxy since the conntrack template was moved to use
   kmalloc, patch from Daniel Borkmann.

All of them look good to me to reach 4.2, I can route this to -stable myself
too, just let me know what you prefer.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-05 21:57:42 -07:00
Daniel Borkmann
62da98656b netfilter: nf_conntrack: make nf_ct_zone_dflt built-in
Fengguang reported, that some randconfig generated the following linker
issue with nf_ct_zone_dflt object involved:

  [...]
  CC      init/version.o
  LD      init/built-in.o
  net/built-in.o: In function `ipv4_conntrack_defrag':
  nf_defrag_ipv4.c:(.text+0x93e95): undefined reference to `nf_ct_zone_dflt'
  net/built-in.o: In function `ipv6_defrag':
  nf_defrag_ipv6_hooks.c:(.text+0xe3ffe): undefined reference to `nf_ct_zone_dflt'
  make: *** [vmlinux] Error 1

Given that configurations exist where we have a built-in part, which is
accessing nf_ct_zone_dflt such as the two handlers nf_ct_defrag_user()
and nf_ct6_defrag_user(), and a part that configures nf_conntrack as a
module, we must move nf_ct_zone_dflt into a fixed, guaranteed built-in
area when netfilter is configured in general.

Therefore, split the more generic parts into a common header under
include/linux/netfilter/ and move nf_ct_zone_dflt into the built-in
section that already holds parts related to CONFIG_NF_CONNTRACK in the
netfilter core. This fixes the issue on my side.

Fixes: 308ac9143e ("netfilter: nf_conntrack: push zone object into functions")
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-02 16:32:56 -07:00
Daniel Borkmann
9cf94eab8b netfilter: conntrack: use nf_ct_tmpl_free in CT/synproxy error paths
Commit 0838aa7fcf ("netfilter: fix netns dependencies with conntrack
templates") migrated templates to the new allocator api, but forgot to
update error paths for them in CT and synproxy to use nf_ct_tmpl_free()
instead of nf_conntrack_free().

Due to that, memory is being freed into the wrong kmemcache, but also
we drop the per net reference count of ct objects causing an imbalance.

In Brad's case, this leads to a wrap-around of net->ct.count and thus
lets __nf_conntrack_alloc() refuse to create a new ct object:

  [   10.340913] xt_addrtype: ipv6 does not support BROADCAST matching
  [   10.810168] nf_conntrack: table full, dropping packet
  [   11.917416] r8169 0000:07:00.0 eth0: link up
  [   11.917438] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
  [   12.815902] nf_conntrack: table full, dropping packet
  [   15.688561] nf_conntrack: table full, dropping packet
  [   15.689365] nf_conntrack: table full, dropping packet
  [   15.690169] nf_conntrack: table full, dropping packet
  [   15.690967] nf_conntrack: table full, dropping packet
  [...]

With slab debugging, it also reports the wrong kmemcache (kmalloc-512 vs.
nf_conntrack_ffffffff81ce75c0) and reports poison overwrites, etc. Thus,
to fix the problem, export and use nf_ct_tmpl_free() instead.

Fixes: 0838aa7fcf ("netfilter: fix netns dependencies with conntrack templates")
Reported-by: Brad Jackson <bjackson0971@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-09-01 12:15:08 +02:00
Joe Stringer
86ca02e774 netfilter: connlabels: Export setting connlabel length
Add functions to change connlabel length into nf_conntrack_labels.c so
they may be reused by other modules like OVS and nftables without
needing to jump through xt_match_check() hoops.

Suggested-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Joe Stringer <joestringer@nicira.com>
Acked-by: Florian Westphal <fw@strlen.de>
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-27 11:40:43 -07:00
Bernhard Thaler
18e1db67e9 netfilter: bridge: fix IPv6 packets not being bridged with CONFIG_IPV6=n
230ac490f7 introduced a dependency to CONFIG_IPV6 which breaks bridging
of IPv6 packets on a bridge with CONFIG_IPV6=n.

Sysctl entry /proc/sys/net/bridge/bridge-nf-call-ip6tables defaults to 1,
for this reason packets are handled by br_nf_pre_routing_ipv6(). When compiled
with CONFIG_IPV6=n this function returns NF_DROP but should return NF_ACCEPT
to let packets through.

Change CONFIG_IPV6=n br_nf_pre_routing_ipv6() return value to NF_ACCEPT.

Tested with a simple bridge with two interfaces and IPv6 packets trying
to pass from host on left side to host on right side of the bridge.

Fixes: 230ac490f7 ("netfilter: bridge: split ipv6 code into separated file")
Signed-off-by: Bernhard Thaler <bernhard.thaler@wvnet.at>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-08-19 21:21:41 +02:00
Pablo Neira Ayuso
bf798657eb netfilter: nf_tables: Use 32 bit addressing register from nft_type_to_reg()
nft_type_to_reg() needs to return the register in the new 32 bit addressing,
otherwise we hit EINVAL when using mappings.

Fixes: 49499c3 ("netfilter: nf_tables: switch registers to 32 bit addressing")
Reported-by: Andreas Schultz <aschultz@tpip.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-08-19 21:21:41 +02:00
Daniel Borkmann
5e8018fc61 netfilter: nf_conntrack: add efficient mark to zone mapping
This work adds the possibility of deriving the zone id from the skb->mark
field in a scalable manner. This allows for having only a single template
serving hundreds/thousands of different zones, for example, instead of the
need to have one match for each zone as an extra CT jump target.

Note that we'd need to have this information attached to the template as at
the time when we're trying to lookup a possible ct object, we already need
to know zone information for a possible match when going into
__nf_conntrack_find_get(). This work provides a minimal implementation for
a possible mapping.

In order to not add/expose an extra ct->status bit, the zone structure has
been extended to carry a flag for deriving the mark.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-08-18 01:24:05 +02:00
Daniel Borkmann
deedb59039 netfilter: nf_conntrack: add direction support for zones
This work adds a direction parameter to netfilter zones, so identity
separation can be performed only in original/reply or both directions
(default). This basically opens up the possibility of doing NAT with
conflicting IP address/port tuples from multiple, isolated tenants
on a host (e.g. from a netns) without requiring each tenant to NAT
twice resp. to use its own dedicated IP address to SNAT to, meaning
overlapping tuples can be made unique with the zone identifier in
original direction, where the NAT engine will then allocate a unique
tuple in the commonly shared default zone for the reply direction.
In some restricted, local DNAT cases, also port redirection could be
used for making the reply traffic unique w/o requiring SNAT.

The consensus we've reached and discussed at NFWS and since the initial
implementation [1] was to directly integrate the direction meta data
into the existing zones infrastructure, as opposed to the ct->mark
approach we proposed initially.

As we pass the nf_conntrack_zone object directly around, we don't have
to touch all call-sites, but only those, that contain equality checks
of zones. Thus, based on the current direction (original or reply),
we either return the actual id, or the default NF_CT_DEFAULT_ZONE_ID.
CT expectations are direction-agnostic entities when expectations are
being compared among themselves, so we can only use the identifier
in this case.

Note that zone identifiers can not be included into the hash mix
anymore as they don't contain a "stable" value that would be equal
for both directions at all times, f.e. if only zone->id would
unconditionally be xor'ed into the table slot hash, then replies won't
find the corresponding conntracking entry anymore.

If no particular direction is specified when configuring zones, the
behaviour is exactly as we expect currently (both directions).

Support has been added for the CT netlink interface as well as the
x_tables raw CT target, which both already offer existing interfaces
to user space for the configuration of zones.

Below a minimal, simplified collision example (script in [2]) with
netperf sessions:

  +--- tenant-1 ---+   mark := 1
  |    netperf     |--+
  +----------------+  |                CT zone := mark [ORIGINAL]
   [ip,sport] := X   +--------------+  +--- gateway ---+
                     | mark routing |--|     SNAT      |-- ... +
                     +--------------+  +---------------+       |
  +--- tenant-2 ---+  |                                     ~~~|~~~
  |    netperf     |--+                +-----------+           |
  +----------------+   mark := 2       | netserver |------ ... +
   [ip,sport] := X                     +-----------+
                                        [ip,port] := Y
On the gateway netns, example:

  iptables -t raw -A PREROUTING -j CT --zone mark --zone-dir ORIGINAL
  iptables -t nat -A POSTROUTING -o <dev> -j SNAT --to-source <ip> --random-fully

  iptables -t mangle -A PREROUTING -m conntrack --ctdir ORIGINAL -j CONNMARK --save-mark
  iptables -t mangle -A POSTROUTING -m conntrack --ctdir REPLY -j CONNMARK --restore-mark

conntrack dump from gateway netns:

  netperf -H 10.1.1.2 -t TCP_STREAM -l60 -p12865,5555 from each tenant netns

  tcp 6 431995 ESTABLISHED src=40.1.1.1 dst=10.1.1.2 sport=5555 dport=12865 zone-orig=1
                           src=10.1.1.2 dst=10.1.1.1 sport=12865 dport=1024
               [ASSURED] mark=1 secctx=system_u:object_r:unlabeled_t:s0 use=1

  tcp 6 431994 ESTABLISHED src=40.1.1.1 dst=10.1.1.2 sport=5555 dport=12865 zone-orig=2
                           src=10.1.1.2 dst=10.1.1.1 sport=12865 dport=5555
               [ASSURED] mark=2 secctx=system_u:object_r:unlabeled_t:s0 use=1

  tcp 6 299 ESTABLISHED src=40.1.1.1 dst=10.1.1.2 sport=39438 dport=33768 zone-orig=1
                        src=10.1.1.2 dst=10.1.1.1 sport=33768 dport=39438
               [ASSURED] mark=1 secctx=system_u:object_r:unlabeled_t:s0 use=1

  tcp 6 300 ESTABLISHED src=40.1.1.1 dst=10.1.1.2 sport=32889 dport=40206 zone-orig=2
                        src=10.1.1.2 dst=10.1.1.1 sport=40206 dport=32889
               [ASSURED] mark=2 secctx=system_u:object_r:unlabeled_t:s0 use=2

Taking this further, test script in [2] creates 200 tenants and runs
original-tuple colliding netperf sessions each. A conntrack -L dump in
the gateway netns also confirms 200 overlapping entries, all in ESTABLISHED
state as expected.

I also did run various other tests with some permutations of the script,
to mention some: SNAT in random/random-fully/persistent mode, no zones (no
overlaps), static zones (original, reply, both directions), etc.

  [1] http://thread.gmane.org/gmane.comp.security.firewalls.netfilter.devel/57412/
  [2] https://paste.fedoraproject.org/242835/65657871/

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-08-18 01:22:50 +02:00
Daniel Borkmann
308ac9143e netfilter: nf_conntrack: push zone object into functions
This patch replaces the zone id which is pushed down into functions
with the actual zone object. It's a bigger one-time change, but
needed for later on extending zones with a direction parameter, and
thus decoupling this additional information from all call-sites.

No functional changes in this patch.

The default zone becomes a global const object, namely nf_ct_zone_dflt
and will be returned directly in various cases, one being, when there's
f.e. no zoning support.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-08-11 12:29:01 +02:00
Pablo Neira Ayuso
d877f07112 netfilter: nf_tables: add nft_dup expression
This new expression uses the nf_dup engine to clone packets to a given gateway.
Unlike xt_TEE, we use an index to indicate output interface which should be
fine at this stage.

Moreover, change to the preemtion-safe this_cpu_read(nf_skb_duplicated) from
nf_dup_ipv{4,6} to silence a lockdep splat.

Based on the original tee expression from Arturo Borrero Gonzalez, although
this patch has diverted quite a bit from this initial effort due to the
change to support maps.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-08-07 11:49:49 +02:00
Pablo Neira Ayuso
bbde9fc182 netfilter: factor out packet duplication for IPv4/IPv6
Extracted from the xtables TEE target. This creates two new modules for IPv4
and IPv6 that are shared between the TEE target and the new nf_tables dup
expressions.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-08-07 11:49:49 +02:00
Pablo Neira Ayuso
0838aa7fcf netfilter: fix netns dependencies with conntrack templates
Quoting Daniel Borkmann:

"When adding connection tracking template rules to a netns, f.e. to
configure netfilter zones, the kernel will endlessly busy-loop as soon
as we try to delete the given netns in case there's at least one
template present, which is problematic i.e. if there is such bravery that
the priviledged user inside the netns is assumed untrusted.

Minimal example:

  ip netns add foo
  ip netns exec foo iptables -t raw -A PREROUTING -d 1.2.3.4 -j CT --zone 1
  ip netns del foo

What happens is that when nf_ct_iterate_cleanup() is being called from
nf_conntrack_cleanup_net_list() for a provided netns, we always end up
with a net->ct.count > 0 and thus jump back to i_see_dead_people. We
don't get a soft-lockup as we still have a schedule() point, but the
serving CPU spins on 100% from that point onwards.

Since templates are normally allocated with nf_conntrack_alloc(), we
also bump net->ct.count. The issue why they are not yet nf_ct_put() is
because the per netns .exit() handler from x_tables (which would eventually
invoke xt_CT's xt_ct_tg_destroy() that drops reference on info->ct) is
called in the dependency chain at a *later* point in time than the per
netns .exit() handler for the connection tracker.

This is clearly a chicken'n'egg problem: after the connection tracker
.exit() handler, we've teared down all the connection tracking
infrastructure already, so rightfully, xt_ct_tg_destroy() cannot be
invoked at a later point in time during the netns cleanup, as that would
lead to a use-after-free. At the same time, we cannot make x_tables depend
on the connection tracker module, so that the xt_ct_tg_destroy() would
be invoked earlier in the cleanup chain."

Daniel confirms this has to do with the order in which modules are loaded or
having compiled nf_conntrack as modules while x_tables built-in. So we have no
guarantees regarding the order in which netns callbacks are executed.

Fix this by allocating the templates through kmalloc() from the respective
SYNPROXY and CT targets, so they don't depend on the conntrack kmem cache.
Then, release then via nf_ct_tmpl_free() from destroy_conntrack(). This branch
is marked as unlikely since conntrack templates are rarely allocated and only
from the configuration plane path.

Note that templates are not kept in any list to avoid further dependencies with
nf_conntrack anymore, thus, the tmpl larval list is removed.

Reported-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Tested-by: Daniel Borkmann <daniel@iogearbox.net>
2015-07-20 14:58:19 +02:00
Eric W. Biederman
8405a8fff3 netfilter: nf_qeueue: Drop queue entries on nf_unregister_hook
Add code to nf_unregister_hook to flush the nf_queue when a hook is
unregistered.  This guarantees that the pointer that the nf_queue code
retains into the nf_hook list will remain valid while a packet is
queued.

I tested what would happen if we do not flush queued packets and was
trivially able to obtain the oops below.  All that was required was
to stop the nf_queue listening process, to delete all of the nf_tables,
and to awaken the nf_queue listening process.

> BUG: unable to handle kernel paging request at 0000000100000001
> IP: [<0000000100000001>] 0x100000001
> PGD b9c35067 PUD 0
> Oops: 0010 [#1] SMP
> Modules linked in:
> CPU: 0 PID: 519 Comm: lt-nfqnl_test Not tainted
> task: ffff8800b9c8c050 ti: ffff8800ba9d8000 task.ti: ffff8800ba9d8000
> RIP: 0010:[<0000000100000001>]  [<0000000100000001>] 0x100000001
> RSP: 0018:ffff8800ba9dba40  EFLAGS: 00010a16
> RAX: ffff8800bab48a00 RBX: ffff8800ba9dba90 RCX: ffff8800ba9dba90
> RDX: ffff8800b9c10128 RSI: ffff8800ba940900 RDI: ffff8800bab48a00
> RBP: ffff8800b9c10128 R08: ffffffff82976660 R09: ffff8800ba9dbb28
> R10: dead000000100100 R11: dead000000200200 R12: ffff8800ba940900
> R13: ffffffff8313fd50 R14: ffff8800b9c95200 R15: 0000000000000000
> FS:  00007fb91fc34700(0000) GS:ffff8800bfa00000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000000100000001 CR3: 00000000babfb000 CR4: 00000000000007f0
> Stack:
>  ffffffff8206ab0f ffffffff82982240 ffff8800bab48a00 ffff8800b9c100a8
>  ffff8800b9c10100 0000000000000001 ffff8800ba940900 ffff8800b9c10128
>  ffffffff8206bd65 ffff8800bfb0d5e0 ffff8800bab48a00 0000000000014dc0
> Call Trace:
>  [<ffffffff8206ab0f>] ? nf_iterate+0x4f/0xa0
>  [<ffffffff8206bd65>] ? nf_reinject+0x125/0x190
>  [<ffffffff8206dee5>] ? nfqnl_recv_verdict+0x255/0x360
>  [<ffffffff81386290>] ? nla_parse+0x80/0xf0
>  [<ffffffff8206c42c>] ? nfnetlink_rcv_msg+0x13c/0x240
>  [<ffffffff811b2fec>] ? __memcg_kmem_get_cache+0x4c/0x150
>  [<ffffffff8206c2f0>] ? nfnl_lock+0x20/0x20
>  [<ffffffff82068159>] ? netlink_rcv_skb+0xa9/0xc0
>  [<ffffffff820677bf>] ? netlink_unicast+0x12f/0x1c0
>  [<ffffffff82067ade>] ? netlink_sendmsg+0x28e/0x650
>  [<ffffffff81fdd814>] ? sock_sendmsg+0x44/0x50
>  [<ffffffff81fde07b>] ? ___sys_sendmsg+0x2ab/0x2c0
>  [<ffffffff810e8f73>] ? __wake_up+0x43/0x70
>  [<ffffffff8141a134>] ? tty_write+0x1c4/0x2a0
>  [<ffffffff81fde9f4>] ? __sys_sendmsg+0x44/0x80
>  [<ffffffff823ff8d7>] ? system_call_fastpath+0x12/0x6a
> Code:  Bad RIP value.
> RIP  [<0000000100000001>] 0x100000001
>  RSP <ffff8800ba9dba40>
> CR2: 0000000100000001
> ---[ end trace 08eb65d42362793f ]---

Cc: stable@vger.kernel.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-06-23 06:23:23 -07:00
Pablo Neira Ayuso
230ac490f7 netfilter: bridge: split ipv6 code into separated file
Resolve compilation breakage when CONFIG_IPV6 is not set by moving the IPv6
code into a separated br_netfilter_ipv6.c file.

Fixes: efb6de9b4b ("netfilter: bridge: forward IPv6 fragmented packets")
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-06-18 21:14:21 +02:00
Pablo Neira Ayuso
835b803377 netfilter: nf_tables_netdev: unregister hooks on net_device removal
In case the net_device is gone, we have to unregister the hooks and put back
the reference on the net_device object. Once it comes back, register them
again. This also covers the device rename case.

This patch also adds a new flag to indicate that the basechain is disabled, so
their hooks are not registered. This flag is used by the netdev family to
handle the case where the net_device object is gone. Currently this flag is not
exposed to userspace.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-06-15 23:02:35 +02:00
Pablo Neira Ayuso
2cbce139fc netfilter: nf_tables: attach net_device to basechain
The device is part of the hook configuration, so instead of a global
configuration per table, set it to each of the basechain that we create.

This patch reworks ebddf1a8d7 ("netfilter: nf_tables: allow to bind table to
net_device").

Note that this adds a dev_name field in the nft_base_chain structure which is
required the netdev notification subscription that follows up in a patch to
handle gone net_devices.

Suggested-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-06-15 23:02:31 +02:00
Pablo Neira Ayuso
ebddf1a8d7 netfilter: nf_tables: allow to bind table to net_device
This patch adds the internal NFT_AF_NEEDS_DEV flag to indicate that you must
attach this table to a net_device.

This change is required by the follow up patch that introduces the new netdev
table.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-05-26 18:41:17 +02:00
Patrick McHardy
151d799a61 netfilter: nf_tables: mark stateful expressions
Add a flag to mark stateful expressions.

This is used for dynamic expression instanstiation to limit the usable
expressions. Strictly speaking only the dynset expression can not be
used in order to avoid recursion, but since dynamically instantiating
non-stateful expressions will simply create an identical copy, which
behaves no differently than the original, this limits to expressions
where it actually makes sense to dynamically instantiate them.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-04-13 20:12:31 +02:00
Patrick McHardy
f25ad2e907 netfilter: nf_tables: prepare for expressions associated to set elements
Preparation to attach expressions to set elements: add a set extension
type to hold an expression and dump the expression information with the
set element.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-04-13 20:12:31 +02:00
Patrick McHardy
0b2d8a7b63 netfilter: nf_tables: add helper functions for expression handling
Add helper functions for initializing, cloning, dumping and destroying
a single expression that is not part of a rule.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-04-13 20:12:31 +02:00
Patrick McHardy
7d7402642e netfilter: nf_tables: variable sized set element keys / data
This patch changes sets to support variable sized set element keys / data
up to 64 bytes each by using variable sized set extensions. This allows
to use concatenations with bigger data items suchs as IPv6 addresses.

As a side effect, small keys/data now don't require the full 16 bytes
of struct nft_data anymore but just the space they need.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-04-13 17:17:31 +02:00
Patrick McHardy
d0a11fc3dc netfilter: nf_tables: support variable sized data in nft_data_init()
Add a size argument to nft_data_init() and pass in the available space.
This will be used by the following patches to support variable sized
set element data.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-04-13 17:17:30 +02:00
Patrick McHardy
49499c3e6e netfilter: nf_tables: switch registers to 32 bit addressing
Switch the nf_tables registers from 128 bit addressing to 32 bit
addressing to support so called concatenations, where multiple values
can be concatenated over multiple registers for O(1) exact matches of
multiple dimensions using sets.

The old register values are mapped to areas of 128 bits for compatibility.
When dumping register numbers, values are expressed using the old values
if they refer to the beginning of a 128 bit area for compatibility.

To support concatenations, register loads of less than a full 32 bit
value need to be padded. This mainly affects the payload and exthdr
expressions, which both unconditionally zero the last word before
copying the data.

Userspace fully passes the testsuite using both old and new register
addressing.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-04-13 17:17:29 +02:00
Patrick McHardy
b1c96ed37c netfilter: nf_tables: add register parsing/dumping helpers
Add helper functions to parse and dump register values in netlink attributes.
These helpers will later be changed to take care of translation between the
old 128 bit and the new 32 bit register numbers.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-04-13 17:17:28 +02:00
Patrick McHardy
8cd8937ac0 netfilter: nf_tables: convert sets to u32 data pointers
Simple conversion to use u32 pointers to the beginning of the data
area to keep follow up patches smaller.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-04-13 17:17:27 +02:00
Patrick McHardy
e562d860d7 netfilter: nf_tables: kill nft_data_cmp()
Only needlessly complicates things due to requiring specific argument
types. Use memcmp directly.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-04-13 17:17:26 +02:00