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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
