2
0
mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-23 04:34:11 +08:00
Commit Graph

294 Commits

Author SHA1 Message Date
David S. Miller
9dc20a6496 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) A couple of cleanups for the netfilter core hook from Eric Biederman.

2) Net namespace hook registration, also from Eric. This adds a dependency with
   the rtnl_lock. This should be fine by now but we have to keep an eye on this
   because if we ever get the per-subsys nfnl_lock before rtnl we have may
   problems in the future. But we have room to remove this in the future by
   propagating the complexity to the clients, by registering hooks for the init
   netns functions.

3) Update nf_tables to use the new net namespace hook infrastructure, also from
   Eric.

4) Three patches to refine and to address problems from the new net namespace
   hook infrastructure.

5) Switch to alternate jumpstack in xtables iff the packet is reentering. This
   only applies to a very special case, the TEE target, but Eric Dumazet
   reports that this is slowing down things for everyone else. So let's only
   switch to the alternate jumpstack if the tee target is in used through a
   static key. This batch also comes with offline precalculation of the
   jumpstack based on the callchain depth. From Florian Westphal.

6) Minimal SCTP multihoming support for our conntrack helper, from Michal
   Kubecek.

7) Reduce nf_bridge_info per skbuff scratchpad area to 32 bytes, from Florian
   Westphal.

8) Fix several checkpatch errors in bridge netfilter, from Bernhard Thaler.

9) Get rid of useless debug message in ip6t_REJECT, from Subash Abhinov.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-04 23:57:45 -07:00
David S. Miller
5510b3c2a1 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	arch/s390/net/bpf_jit_comp.c
	drivers/net/ethernet/ti/netcp_ethss.c
	net/bridge/br_multicast.c
	net/ipv4/ip_fragment.c

All four conflicts were cases of simple overlapping
changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 23:52:20 -07:00
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
085db2c045 netfilter: Per network namespace netfilter hooks.
- Add a new set of functions for registering and unregistering per
  network namespace hooks.

- Modify the old global namespace hook functions to use the per
  network namespace hooks in their implementation, so their remains a
  single list that needs to be walked for any hook (this is important
  for keeping the hook priority working and for keeping the code
  walking the hooks simple).

- Only allow registering the per netdevice hooks in the network
  namespace where the network device lives.

- Dynamically allocate the structures in the per network namespace
  hook list in nf_register_net_hook, and unregister them in
  nf_unregister_net_hook.

  Dynamic allocate is required somewhere as the number of network
  namespaces are not fixed so we might as well allocate them in the
  registration function.

  The chain of registered hooks on any list is expected to be small so
  the cost of walking that list to find the entry we are unregistering
  should also be small.

  Performing the management of the dynamically allocated list entries
  in the registration and unregistration functions keeps the complexity
  from spreading.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2015-07-15 18:17:26 +02:00
Tom Herbert
35a256fee5 ipv6: Nonlocal bind
Add support to allow non-local binds similar to how this was done for IPv4.
Non-local binds are very useful in emulating the Internet in a box, etc.

This add the ip_nonlocal_bind sysctl under ipv6.

Testing:

Set up nonlocal binding and receive routing on a host, e.g.:

ip -6 rule add from ::/0 iif eth0 lookup 200
ip -6 route add local 2001:0:0:1::/64 dev lo proto kernel scope host table 200
sysctl -w net.ipv6.ip_nonlocal_bind=1

Set up routing to 2001:0:0:1::/64 on peer to go to first host

ping6 -I 2001:0:0:1::1 peer-address -- to verify

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-09 21:09:10 -07:00
David S. Miller
3a07bd6fea Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/ethernet/mellanox/mlx4/main.c
	net/packet/af_packet.c

Both conflicts were cases of simple overlapping changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-06-24 02:58:51 -07:00
Pablo Neira Ayuso
a263653ed7 netfilter: don't pull include/linux/netfilter.h from netns headers
This pulls the full hook netfilter definitions from all those that include
net_namespace.h.

Instead let's just include the bare minimum required in the new
linux/netfilter_defs.h file, and use it from the netfilter netns header files.

I also needed to include in.h and in6.h from linux/netfilter.h otherwise we hit
this compilation error:

In file included from include/linux/netfilter_defs.h:4:0,
                 from include/net/netns/netfilter.h:4,
                 from include/net/net_namespace.h:22,
                 from include/linux/netdevice.h:43,
                 from net/netfilter/nfnetlink_queue_core.c:23:
include/uapi/linux/netfilter.h:76:17: error: field ‘in’ has incomplete type struct in_addr in;

And also explicit include linux/netfilter.h in several spots.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2015-06-18 21:14:31 +02:00
Pablo Neira Ayuso
10c04a8e71 netfilter: use forward declaration instead of including linux/proc_fs.h
We don't need to pull the full definitions in that file, a simple forward
declaration is enough.

Moreover, include linux/procfs.h from nf_synproxy_core, otherwise this hits a
compilation error due to missing declarations, ie.

net/netfilter/nf_synproxy_core.c: In function ‘synproxy_proc_init’:
net/netfilter/nf_synproxy_core.c:326:2: error: implicit declaration of function ‘proc_create’ [-Werror=implicit-function-declaration]
  if (!proc_create("synproxy", S_IRUGO, net->proc_net_stat,
  ^

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2015-06-18 21:14:30 +02:00
Marcelo Ricardo Leitner
2d45a02d01 sctp: fix ASCONF list handling
->auto_asconf_splist is per namespace and mangled by functions like
sctp_setsockopt_auto_asconf() which doesn't guarantee any serialization.

Also, the call to inet_sk_copy_descendant() was backuping
->auto_asconf_list through the copy but was not honoring
->do_auto_asconf, which could lead to list corruption if it was
different between both sockets.

This commit thus fixes the list handling by using ->addr_wq_lock
spinlock to protect the list. A special handling is done upon socket
creation and destruction for that. Error handlig on sctp_init_sock()
will never return an error after having initialized asconf, so
sctp_destroy_sock() can be called without addrq_wq_lock. The lock now
will be take on sctp_close_sock(), before locking the socket, so we
don't do it in inverse order compared to sctp_addr_wq_timeout_handler().

Instead of taking the lock on sctp_sock_migrate() for copying and
restoring the list values, it's preferred to avoid rewritting it by
implementing sctp_copy_descendant().

Issue was found with a test application that kept flipping sysctl
default_auto_asconf on and off, but one could trigger it by issuing
simultaneous setsockopt() calls on multiple sockets or by
creating/destroying sockets fast enough. This is only triggerable
locally.

Fixes: 9f7d653b67 ("sctp: Add Auto-ASCONF support (core).")
Reported-by: Ji Jianwen <jiji@redhat.com>
Suggested-by: Neil Horman <nhorman@tuxdriver.com>
Suggested-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-06-14 12:55:49 -07:00
David S. Miller
583d3f5af2 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) default CONFIG_NETFILTER_INGRESS to y for easier compile-testing of all
   options.

2) Allow to bind a table to net_device. This introduces the internal
   NFT_AF_NEEDS_DEV flag to perform a mandatory check for this binding.
   This is required by the next patch.

3) Add the 'netdev' table family, this new table allows you to create ingress
   filter basechains. This provides access to the existing nf_tables features
   from ingress.

4) Kill unused argument from compat_find_calc_{match,target} in ip_tables
   and ip6_tables, from Florian Westphal.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-31 00:02:30 -07:00
Eric Dumazet
ed2dfd9009 tcp/dccp: warn user for preferred ip_local_port_range
After commit 07f4c90062 ("tcp/dccp: try to not exhaust
ip_local_port_range in connect()") it is advised to have an even number
of ports described in /proc/sys/net/ipv4/ip_local_port_range

This means start/end values should have a different parity.

Let's warn sysadmins of this, so that they can update their settings
if they want to.

Suggested-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-27 14:35:36 -04:00
Pablo Neira Ayuso
ed6c4136f1 netfilter: nf_tables: add netdev table to filter from ingress
This allows us to create netdev tables that contain ingress chains. Use
skb_header_pointer() as we may see shared sk_buffs at this stage.

This change provides access to the existing nf_tables features from the ingress
hook.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-05-26 18:41:23 +02:00
Daniel Borkmann
492135557d tcp: add rfc3168, section 6.1.1.1. fallback
This work as a follow-up of commit f7b3bec6f5 ("net: allow setting ecn
via routing table") and adds RFC3168 section 6.1.1.1. fallback for outgoing
ECN connections. In other words, this work adds a retry with a non-ECN
setup SYN packet, as suggested from the RFC on the first timeout:

  [...] A host that receives no reply to an ECN-setup SYN within the
  normal SYN retransmission timeout interval MAY resend the SYN and
  any subsequent SYN retransmissions with CWR and ECE cleared. [...]

Schematic client-side view when assuming the server is in tcp_ecn=2 mode,
that is, Linux default since 2009 via commit 255cac91c3 ("tcp: extend
ECN sysctl to allow server-side only ECN"):

 1) Normal ECN-capable path:

    SYN ECE CWR ----->
                <----- SYN ACK ECE
            ACK ----->

 2) Path with broken middlebox, when client has fallback:

    SYN ECE CWR ----X crappy middlebox drops packet
                      (timeout, rtx)
            SYN ----->
                <----- SYN ACK
            ACK ----->

In case we would not have the fallback implemented, the middlebox drop
point would basically end up as:

    SYN ECE CWR ----X crappy middlebox drops packet
                      (timeout, rtx)
    SYN ECE CWR ----X crappy middlebox drops packet
                      (timeout, rtx)
    SYN ECE CWR ----X crappy middlebox drops packet
                      (timeout, rtx)

In any case, it's rather a smaller percentage of sites where there would
occur such additional setup latency: it was found in end of 2014 that ~56%
of IPv4 and 65% of IPv6 servers of Alexa 1 million list would negotiate
ECN (aka tcp_ecn=2 default), 0.42% of these webservers will fail to connect
when trying to negotiate with ECN (tcp_ecn=1) due to timeouts, which the
fallback would mitigate with a slight latency trade-off. Recent related
paper on this topic:

  Brian Trammell, Mirja Kühlewind, Damiano Boppart, Iain Learmonth,
  Gorry Fairhurst, and Richard Scheffenegger:
    "Enabling Internet-Wide Deployment of Explicit Congestion Notification."
    Proc. PAM 2015, New York.
  http://ecn.ethz.ch/ecn-pam15.pdf

Thus, when net.ipv4.tcp_ecn=1 is being set, the patch will perform RFC3168,
section 6.1.1.1. fallback on timeout. For users explicitly not wanting this
which can be in DC use case, we add a net.ipv4.tcp_ecn_fallback knob that
allows for disabling the fallback.

tp->ecn_flags are not being cleared in tcp_ecn_clear_syn() on output, but
rather we let tcp_ecn_rcv_synack() take that over on input path in case a
SYN ACK ECE was delayed. Thus a spurious SYN retransmission will not prevent
ECN being negotiated eventually in that case.

Reference: https://www.ietf.org/proceedings/92/slides/slides-92-iccrg-1.pdf
Reference: https://www.ietf.org/proceedings/89/slides/slides-89-tsvarea-1.pdf
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mirja Kühlewind <mirja.kuehlewind@tik.ee.ethz.ch>
Signed-off-by: Brian Trammell <trammell@tik.ee.ethz.ch>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Dave That <dave.taht@gmail.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-19 16:53:37 -04:00
Tom Herbert
82a584b7cd ipv6: Flow label state ranges
This patch divides the IPv6 flow label space into two ranges:
0-7ffff is reserved for flow label manager, 80000-fffff will be
used for creating auto flow labels (per RFC6438). This only affects how
labels are set on transmit, it does not affect receive. This range split
can be disbaled by systcl.

Background:

IPv6 flow labels have been an unmitigated disappointment thus far
in the lifetime of IPv6. Support in HW devices to use them for ECMP
is lacking, and OSes don't turn them on by default. If we had these
we could get much better hashing in IPv6 networks without resorting
to DPI, possibly eliminating some of the motivations to to define new
encaps in UDP just for getting ECMP.

Unfortunately, the initial specfications of IPv6 did not clarify
how they are to be used. There has always been a vague concept that
these can be used for ECMP, flow hashing, etc. and we do now have a
good standard how to this in RFC6438. The problem is that flow labels
can be either stateful or stateless (as in RFC6438), and we are
presented with the possibility that a stateless label may collide
with a stateful one.  Attempts to split the flow label space were
rejected in IETF. When we added support in Linux for RFC6438, we
could not turn on flow labels by default due to this conflict.

This patch splits the flow label space and should give us
a path to enabling auto flow labels by default for all IPv6 packets.
This is an API change so we need to consider compatibility with
existing deployment. The stateful range is chosen to be the lower
values in hopes that most uses would have chosen small numbers.

Once we resolve the stateless/stateful issue, we can proceed to
look at enabling RFC6438 flow labels by default (starting with
scaled testing).

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-03 21:58:01 -04:00
Denys Vlasenko
2591ffd308 netns: remove BUG_ONs from net_generic()
This inline has ~500 callsites.

On 04/14/2015 08:37 PM, David Miller wrote:
> That BUG_ON() was added 7 years ago, and I don't remember it ever
> triggering or helping us diagnose something, so just remove it and
> keep the function inlined.

On x86 allyesconfig build:

    text     data      bss       dec     hex filename
82447071 22255384 20627456 125329911 77861f7 vmlinux4
82441375 22255384 20627456 125324215 7784bb7 vmlinux5prime

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
CC: Eric W. Biederman <ebiederm@xmission.com>
CC: David S. Miller <davem@davemloft.net>
CC: Jan Engelhardt <jengelh@medozas.de>
CC: Jiri Pirko <jpirko@redhat.com>
CC: linux-kernel@vger.kernel.org
CC: netdev@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-17 15:21:48 -04:00
Hannes Frederic Sowa
1855b7c3e8 ipv6: introduce idgen_delay and idgen_retries knobs
This is specified by RFC 7217.

Cc: Erik Kline <ek@google.com>
Cc: Fernando Gont <fgont@si6networks.com>
Cc: Lorenzo Colitti <lorenzo@google.com>
Cc: YOSHIFUJI Hideaki/吉藤英明 <hideaki.yoshifuji@miraclelinux.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-23 22:12:09 -04:00
Eric Dumazet
6eada0110c netns: constify net_hash_mix() and various callers
const qualifiers ease code review by making clear
which objects are not written in a function.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-18 22:00:34 -04:00
Eric W. Biederman
098a697b49 tcp_metrics: Use a single hash table for all network namespaces.
Now that all of the operations are safe on a single hash table
accross network namespaces, allocate a single global hash table
and update the code to use it.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-13 01:57:07 -04:00
David S. Miller
5428aef811 Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next
Pablo Neira Ayuso says:

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

The following patchset contains Netfilter updates for your net-next
tree. Basically, improvements for the packet rejection infrastructure,
deprecation of CLUSTERIP, cleanups for nf_tables and some untangling for
br_netfilter. More specifically they are:

1) Send packet to reset flow if checksum is valid, from Florian Westphal.

2) Fix nf_tables reject bridge from the input chain, also from Florian.

3) Deprecate the CLUSTERIP target, the cluster match supersedes it in
   functionality and it's known to have problems.

4) A couple of cleanups for nf_tables rule tracing infrastructure, from
   Patrick McHardy.

5) Another cleanup to place transaction declarations at the bottom of
   nf_tables.h, also from Patrick.

6) Consolidate Kconfig dependencies wrt. NF_TABLES.

7) Limit table names to 32 bytes in nf_tables.

8) mac header copying in bridge netfilter is already required when
   calling ip_fragment(), from Florian Westphal.

9) move nf_bridge_update_protocol() to br_netfilter.c, also from
   Florian.

10) Small refactor in br_netfilter in the transmission path, again from
    Florian.

11) Move br_nf_pre_routing_finish_bridge_slow() to br_netfilter.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-09 15:58:21 -04:00
Fan Du
05cbc0db03 ipv4: Create probe timer for tcp PMTU as per RFC4821
As per RFC4821 7.3.  Selecting Probe Size, a probe timer should
be armed once probing has converged. Once this timer expired,
probing again to take advantage of any path PMTU change. The
recommended probing interval is 10 minutes per RFC1981. Probing
interval could be sysctled by sysctl_tcp_probe_interval.

Eric Dumazet suggested to implement pseudo timer based on 32bits
jiffies tcp_time_stamp instead of using classic timer for such
rare event.

Signed-off-by: Fan Du <fan.du@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-06 14:57:42 -05:00
Fan Du
6b58e0a5f3 ipv4: Use binary search to choose tcp PMTU probe_size
Current probe_size is chosen by doubling mss_cache,
the probing process will end shortly with a sub-optimal
mss size, and the link mtu will not be taken full
advantage of, in return, this will make user to tweak
tcp_base_mss with care.

Use binary search to choose probe_size in a fine
granularity manner, an optimal mss will be found
to boost performance as its maxmium.

In addition, introduce a sysctl_tcp_probe_threshold
to control when probing will stop in respect to
the width of search range.

Test env:
Docker instance with vxlan encapuslation(82599EB)
iperf -c 10.0.0.24  -t 60

before this patch:
1.26 Gbits/sec

After this patch: increase 26%
1.59 Gbits/sec

Signed-off-by: Fan Du <fan.du@intel.com>
Acked-by: John Heffner <johnwheffner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-06 14:57:41 -05:00
Scott Feldman
448b128a14 ipv4: add net bool fib_offload_disabled
If something goes wrong with IPv4 FIB offload, mark entire net offload
disabled.  This is brute force policy to basically shut down IPv4 FIB offload
permanently if there is a problem offloading any route to an external device.
We can refine the policy in the future, to handle failures on a per-device or
per-route basis, but for now, this policy is per-net.

What we're trying to avoid is an inconsistent split between the kernel's FIB
and the offload device's FIB.  We don't want the device to fwd a pkt
inconsitent with what the kernel would do.  An example of a split is if device
has 10.0.0.0/16 and kernel has 10.0.0.0/16 and 10.0.0.0/24, the device wouldn't
see the longest prefix 10.0.0.0/24 and potentially forward pkts incorrectly.

Limited capacity or limited capability are two ways a route may fail to install
to the offload device.  We'll not differentiate between failures at this time,
and treat any failure as fatal and mark the net as fib_offload_disabled.

Signed-off-by: Scott Feldman <sfeldma@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-06 00:24:58 -05:00
Pablo Neira Ayuso
43270b1bc5 netfilter: ipt_CLUSTERIP: deprecate it in favour of xt_cluster
xt_cluster supersedes ipt_CLUSTERIP since it can be also used in
gateway configurations (not only from the backend side).

ipt_CLUSTER is also known to leak the netdev that it uses on
device removal, which requires a rather large fix to workaround
the problem: http://patchwork.ozlabs.org/patch/358629/

So let's deprecate this so we can probably kill code this in the
future.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-03-06 01:21:05 +01:00
Alexander Duyck
a7e5353123 fib_trie: Make fib_table rcu safe
The fib_table was wrapped in several places with an
rcu_read_lock/rcu_read_unlock however after looking over the code I found
several spots where the tables were being accessed as just standard
pointers without any protections.  This change fixes that so that all of
the proper protections are in place when accessing the table to take RCU
replacement or removal of the table into account.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-04 23:35:18 -05:00
Eric W. Biederman
7720c01f3f mpls: Add a sysctl to control the size of the mpls label table
This sysctl gives two benefits.  By defaulting the table size to 0
mpls even when compiled in and enabled defaults to not forwarding
any packets.  This prevents unpleasant surprises for users.

The other benefit is that as mpls labels are allocated locally a dense
table a small dense label table may be used which saves memory and
is extremely simple and efficient to implement.

This sysctl allows userspace to choose the restrictions on the label
table size userspace applications need to cope with.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-04 00:26:06 -05:00
Eric W. Biederman
0189197f44 mpls: Basic routing support
This change adds a new Kconfig option MPLS_ROUTING.

The core of this change is the code to look at an mpls packet received
from another machine.  Look that packet up in a routing table and
forward the packet on.

Support of MPLS over ATM is not considered or attempted here.  This
implemntation follows RFC3032 and implements the MPLS shim header that
can pass over essentially any network.

What RFC3021 refers to as the as the Incoming Label Map (ILM) I call
net->mpls.platform_label[].  What RFC3031 refers to as the Next Label
Hop Forwarding Entry (NHLFE) I call mpls_route.  Though calling it the
label fordwarding information base (lfib) might also be valid.

Further the implemntation forwards packets as described in RFC3032.
There is no need and given the original motivation for MPLS a strong
discincentive to have a flexible label forwarding path.  In essence
the logic is the topmost label is read, looked up, removed, and
replaced by 0 or more new lables and the sent out the specified
interface to it's next hop.

Quite a few optional features are not implemented here.  Among them
are generation of ICMP errors when the TTL is exceeded or the packet
is larger than the next hop MTU (those conditions are detected and the
packets are dropped instead of generating an icmp error).  The traffic
class field is always set to 0.  The implementation focuses on IP over
MPLS and does not handle egress of other kinds of protocols.

Instead of implementing coordination with the neighbour table and
sorting out how to input next hops in a different address family (for
which there is value).  I was lazy and implemented a next hop mac
address instead.  The code is simpler and there are flavor of MPLS
such as MPLS-TP where neither an IPv4 nor an IPv6 next hop is
appropriate so a next hop by mac address would need to be implemented
at some point.

Two new definitions AF_MPLS and PF_MPLS are exposed to userspace.

Decoding the mpls header must be done by first byeswapping a 32bit bit
endian word into the local cpu endian and then bit shifting to extract
the pieces.  There is no C bit-field that can represent a wire format
mpls header on a little endian machine as the low bits of the 20bit
label wind up in the wrong half of third byte.  Therefore internally
everything is deal with in cpu native byte order except when writing
to and reading from a packet.

For management simplicity if a label is configured to forward out
an interface that is down the packet is dropped early.  Similarly
if an network interface is removed rt_dev is updated to NULL
(so no reference is preserved) and any packets for that label
are dropped.  Keeping the label entries in the kernel allows
the kernel label table to function as the definitive source
of which labels are allocated and which are not.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-04 00:26:06 -05:00
Madhu Challa
93a714d6b5 multicast: Extend ip address command to enable multicast group join/leave on
Joining multicast group on ethernet level via "ip maddr" command would
not work if we have an Ethernet switch that does igmp snooping since
the switch would not replicate multicast packets on ports that did not
have IGMP reports for the multicast addresses.

Linux vxlan interfaces created via "ip link add vxlan" have the group option
that enables then to do the required join.

By extending ip address command with option "autojoin" we can get similar
functionality for openvswitch vxlan interfaces as well as other tunneling
mechanisms that need to receive multicast traffic. The kernel code is
structured similar to how the vxlan driver does a group join / leave.

example:
ip address add 224.1.1.10/24 dev eth5 autojoin
ip address del 224.1.1.10/24 dev eth5

Signed-off-by: Madhu Challa <challa@noironetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-27 16:25:25 -05:00
Fan Du
b0f9ca53cb ipv4: Namespecify TCP PMTU mechanism
Packetization Layer Path MTU Discovery works separately beside
Path MTU Discovery at IP level, different net namespace has
various requirements on which one to chose, e.g., a virutalized
container instance would require TCP PMTU to probe an usable
effective mtu for underlying tunnel, while the host would
employ classical ICMP based PMTU to function.

Hence making TCP PMTU mechanism per net namespace to decouple
two functionality. Furthermore the probe base MSS should also
be configured separately for each namespace.

Signed-off-by: Fan Du <fan.du@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-09 18:45:00 -08:00
David S. Miller
6e03f896b5 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/vxlan.c
	drivers/vhost/net.c
	include/linux/if_vlan.h
	net/core/dev.c

The net/core/dev.c conflict was the overlap of one commit marking an
existing function static whilst another was adding a new function.

In the include/linux/if_vlan.h case, the type used for a local
variable was changed in 'net', whereas the function got rewritten
to fix a stacked vlan bug in 'net-next'.

In drivers/vhost/net.c, Al Viro's iov_iter conversions in 'net-next'
overlapped with an endainness fix for VHOST 1.0 in 'net'.

In drivers/net/vxlan.c, vxlan_find_vni() added a 'flags' parameter
in 'net-next' whereas in 'net' there was a bug fix to pass in the
correct network namespace pointer in calls to this function.

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-05 14:33:28 -08:00
Eric Dumazet
bdbbb8527b ipv4: tcp: get rid of ugly unicast_sock
In commit be9f4a44e7 ("ipv4: tcp: remove per net tcp_sock")
I tried to address contention on a socket lock, but the solution
I chose was horrible :

commit 3a7c384ffd ("ipv4: tcp: unicast_sock should not land outside
of TCP stack") addressed a selinux regression.

commit 0980e56e50 ("ipv4: tcp: set unicast_sock uc_ttl to -1")
took care of another regression.

commit b5ec8eeac4 ("ipv4: fix ip_send_skb()") fixed another regression.

commit 811230cd85 ("tcp: ipv4: initialize unicast_sock sk_pacing_rate")
was another shot in the dark.

Really, just use a proper socket per cpu, and remove the skb_orphan()
call, to re-enable flow control.

This solves a serious problem with FQ packet scheduler when used in
hostile environments, as we do not want to allocate a flow structure
for every RST packet sent in response to a spoofed packet.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-01 23:06:19 -08:00
Eric Dumazet
349c9e3c73 ipv4: icmp: use percpu allocation
Get rid of nr_cpu_ids and use modern percpu allocation.

Note that the sockets themselves are not yet allocated
using NUMA affinity.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-31 17:48:18 -08:00
Herbert Xu
53c2e285f9 xfrm: Do not hash socket policies
Back in 2003 when I added policy expiration, I half-heartedly
did a clean-up and renamed xfrm_sk_policy_link/xfrm_sk_policy_unlink
to __xfrm_policy_link/__xfrm_policy_unlink, because the latter
could be reused for all policies.  I never actually got around
to using __xfrm_policy_link for non-socket policies.

Later on hashing was added to all xfrm policies, including socket
policies.  In fact, we don't need hashing on socket policies at
all since they're always looked up via a linked list.

This patch restores xfrm_sk_policy_link/xfrm_sk_policy_unlink
as wrappers around __xfrm_policy_link/__xfrm_policy_unlink so
that it's obvious we're dealing with socket policies.

This patch also removes hashing from __xfrm_policy_link as for
now it's only used by socket policies which do not need to be
hashed.  Ironically this will in fact allow us to use this helper
for non-socket policies which I shall do later.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2014-11-13 11:25:03 +01:00
Hannes Frederic Sowa
812918c464 ipv6: make fib6 serial number per namespace
Try to reduce number of possible fn_sernum mutation by constraining them
to their namespace.

Also remove rt_genid which I forgot to remove in 705f1c869d ("ipv6:
remove rt6i_genid").

Cc: YOSHIFUJI Hideaki <hideaki@yoshifuji.org>
Cc: Martin Lau <kafai@fb.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-07 00:02:30 -04:00
David S. Miller
f5c7e1a47a Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next
Steffen Klassert says:

====================
pull request (net-next): ipsec-next 2014-09-25

1) Remove useless hash_resize_mutex in xfrm_hash_resize().
   This mutex is used only there, but xfrm_hash_resize()
   can't be called concurrently at all. From Ying Xue.

2) Extend policy hashing to prefixed policies based on
   prefix lenght thresholds. From Christophe Gouault.

3) Make the policy hash table thresholds configurable
   via netlink. From Christophe Gouault.

4) Remove the maximum authentication length for AH.
   This was needed to limit stack usage. We switched
   already to allocate space, so no need to keep the
   limit. From Herbert Xu.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-28 17:19:15 -04:00
Vincent Bernat
49a601589c net/ipv4: bind ip_nonlocal_bind to current netns
net.ipv4.ip_nonlocal_bind sysctl was global to all network
namespaces. This patch allows to set a different value for each
network namespace.

Signed-off-by: Vincent Bernat <vincent@bernat.im>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-09 11:27:09 -07:00
Christophe Gouault
880a6fab8f xfrm: configure policy hash table thresholds by netlink
Enable to specify local and remote prefix length thresholds for the
policy hash table via a netlink XFRM_MSG_NEWSPDINFO message.

prefix length thresholds are specified by XFRMA_SPD_IPV4_HTHRESH and
XFRMA_SPD_IPV6_HTHRESH optional attributes (struct xfrmu_spdhthresh).

example:

    struct xfrmu_spdhthresh thresh4 = {
        .lbits = 0;
        .rbits = 24;
    };
    struct xfrmu_spdhthresh thresh6 = {
        .lbits = 0;
        .rbits = 56;
    };
    struct nlmsghdr *hdr;
    struct nl_msg *msg;

    msg = nlmsg_alloc();
    hdr = nlmsg_put(msg, NL_AUTO_PORT, NL_AUTO_SEQ, XFRMA_SPD_IPV4_HTHRESH, sizeof(__u32), NLM_F_REQUEST);
    nla_put(msg, XFRMA_SPD_IPV4_HTHRESH, sizeof(thresh4), &thresh4);
    nla_put(msg, XFRMA_SPD_IPV6_HTHRESH, sizeof(thresh6), &thresh6);
    nla_send_auto(sk, msg);

The numbers are the policy selector minimum prefix lengths to put a
policy in the hash table.

- lbits is the local threshold (source address for out policies,
  destination address for in and fwd policies).

- rbits is the remote threshold (destination address for out
  policies, source address for in and fwd policies).

The default values are:

XFRMA_SPD_IPV4_HTHRESH: 32 32
XFRMA_SPD_IPV6_HTHRESH: 128 128

Dynamic re-building of the SPD is performed when the thresholds values
are changed.

The current thresholds can be read via a XFRM_MSG_GETSPDINFO request:
the kernel replies to XFRM_MSG_GETSPDINFO requests by an
XFRM_MSG_NEWSPDINFO message, with both attributes
XFRMA_SPD_IPV4_HTHRESH and XFRMA_SPD_IPV6_HTHRESH.

Signed-off-by: Christophe Gouault <christophe.gouault@6wind.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2014-09-02 13:37:56 +02:00
Christophe Gouault
b58555f176 xfrm: hash prefixed policies based on preflen thresholds
The idea is an extension of the current policy hashing.

Today only non-prefixed policies are stored in a hash table. This
patch relaxes the constraints, and hashes policies whose prefix
lengths are greater or equal to a configurable threshold.

Each hash table (one per direction) maintains its own set of IPv4 and
IPv6 thresholds (dbits4, sbits4, dbits6, sbits6), by default (32, 32,
128, 128).

Example, if the output hash table is configured with values (16, 24,
56, 64):

ip xfrm policy add dir out src 10.22.0.0/20 dst 10.24.1.0/24 ... => hashed
ip xfrm policy add dir out src 10.22.0.0/16 dst 10.24.1.1/32 ... => hashed
ip xfrm policy add dir out src 10.22.0.0/16 dst 10.24.0.0/16 ... => unhashed

ip xfrm policy add dir out \
    src 3ffe:304:124:2200::/60 dst 3ffe:304:124:2401::/64 ...    => hashed
ip xfrm policy add dir out \
    src 3ffe:304:124:2200::/56 dst 3ffe:304:124:2401::2/128 ...  => hashed
ip xfrm policy add dir out \
    src 3ffe:304:124:2200::/56 dst 3ffe:304:124:2400::/56 ...    => unhashed

The high order bits of the addresses (up to the threshold) are used to
compute the hash key.

Signed-off-by: Christophe Gouault <christophe.gouault@6wind.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2014-09-02 13:29:44 +02:00
Martin Townsend
6697dabe27 ieee802154: 6lowpan: ensure MTU of 1280 for 6lowpan
This patch drops the userspace accessable sysfs entry for the maximum
datagram size of a 6LoWPAN fragment packet.

A fragment should not have a datagram size value greater than 1280 byte.
Instead of make this value configurable, we accept 1280 datagram size
fragment packets only.

Signed-off-by: Martin Townsend <martin.townsend@xsilon.com>
Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
2014-08-19 19:17:42 +02:00
Paul Bolle
d4da843e6f netfilter: kill remnants of ulog targets
The ulog targets were recently killed. A few references to the Kconfig
macros CONFIG_IP_NF_TARGET_ULOG and CONFIG_BRIDGE_EBT_ULOG were left
untouched. Kill these too.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-07-25 14:55:44 +02:00
David S. Miller
8fd90bb889 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/infiniband/hw/cxgb4/device.c

The cxgb4 conflict was simply overlapping changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2014-07-22 00:44:59 -07:00
David S. Miller
a8138f42d4 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 updates for your net-next tree,
they are:

1) Use kvfree() helper function from x_tables, from Eric Dumazet.

2) Remove extra timer from the conntrack ecache extension, use a
   workqueue instead to redeliver lost events to userspace instead,
   from Florian Westphal.

3) Removal of the ulog targets for ebtables and iptables. The nflog
   infrastructure superseded this almost 9 years ago, time to get rid
   of this code.

4) Replace the list of loggers by an array now that we can only have
   two possible non-overlapping logger flavours, ie. kernel ring buffer
   and netlink logging.

5) Move Eric Dumazet's log buffer code to nf_log to reuse it from
   all of the supported per-family loggers.

6) Consolidate nf_log_packet() as an unified interface for packet logging.
   After this patch, if the struct nf_loginfo is available, it explicitly
   selects the logger that is used.

7) Move ip and ip6 logging code from xt_LOG to the corresponding
   per-family loggers. Thus, x_tables and nf_tables share the same code
   for packet logging.

8) Add generic ARP packet logger, which is used by nf_tables. The
   format aims to be consistent with the output of xt_LOG.

9) Add generic bridge packet logger. Again, this is used by nf_tables
   and it routes the packets to the real family loggers. As a result,
   we get consistent logging format for the bridge family. The ebt_log
   logging code has been intentionally left in place not to break
   backward compatibility since the logging output differs from xt_LOG.

10) Update nft_log to explicitly request the required family logger when
    needed.

11) Finish nft_log so it supports arp, ip, ip6, bridge and inet families.
    Allowing selection between netlink and kernel buffer ring logging.

12) Several fixes coming after the netfilter core logging changes spotted
    by robots.

13) Use IS_ENABLED() macros whenever possible in the netfilter tree,
    from Duan Jiong.

14) Removal of a couple of unnecessary branch before kfree, from Fabian
    Frederick.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2014-07-20 21:01:43 -07:00
David S. Miller
38a4dfcf80 Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf
Pablo Neira Ayuso says:

====================
Netfilter/nf_tables fixes

The following patchset contains nf_tables fixes, they are:

1) Fix wrong transaction handling when the table flags are not
   modified.

2) Fix missing rcu read_lock section in the netlink dump path, which
   is not protected by the nfnl_lock.

3) Set NLM_F_DUMP_INTR in the netlink dump path to indicate
   interferences with updates.

4) Fix 64 bits chain counters when they are retrieved from a 32 bits
   arch, from Eric Dumazet.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2014-07-16 15:27:16 -07:00
David S. Miller
1a98c69af1 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-07-16 14:09:34 -07:00
Pablo Neira Ayuso
38e029f14a netfilter: nf_tables: set NLM_F_DUMP_INTR if netlink dumping is stale
An updater may interfer with the dumping of any of the object lists.
Fix this by using a per-net generation counter and use the
nl_dump_check_consistent() interface so the NLM_F_DUMP_INTR flag is set
to notify userspace that it has to restart the dump since an updater
has interfered.

This patch also replaces the existing consistency checking code in the
rule dumping path since it is broken. Basically, the value that the
dump callback returns is not propagated to userspace via
netlink_dump_start().

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-07-14 12:00:16 +02:00
Tom Herbert
cb1ce2ef38 ipv6: Implement automatic flow label generation on transmit
Automatically generate flow labels for IPv6 packets on transmit.
The flow label is computed based on skb_get_hash. The flow label will
only automatically be set when it is zero otherwise (i.e. flow label
manager hasn't set one). This supports the transmit side functionality
of RFC 6438.

Added an IPv6 sysctl auto_flowlabels to enable/disable this behavior
system wide, and added IPV6_AUTOFLOWLABEL socket option to enable this
functionality per socket.

By default, auto flowlabels are disabled to avoid possible conflicts
with flow label manager, however if this feature proves useful we
may want to enable it by default.

It should also be noted that FreeBSD has already implemented automatic
flow labels (including the sysctl and socket option). In FreeBSD,
automatic flow labels default to enabled.

Performance impact:

Running super_netperf with 200 flows for TCP_RR and UDP_RR for
IPv6. Note that in UDP case, __skb_get_hash will be called for
every packet with explains slight regression. In the TCP case
the hash is saved in the socket so there is no regression.

Automatic flow labels disabled:

  TCP_RR:
    86.53% CPU utilization
    127/195/322 90/95/99% latencies
    1.40498e+06 tps

  UDP_RR:
    90.70% CPU utilization
    118/168/243 90/95/99% latencies
    1.50309e+06 tps

Automatic flow labels enabled:

  TCP_RR:
    85.90% CPU utilization
    128/199/337 90/95/99% latencies
    1.40051e+06

  UDP_RR
    92.61% CPU utilization
    115/164/236 90/95/99% latencies
    1.4687e+06

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-07-07 21:14:21 -07:00
Alexander Aring
48bc03433c ieee802154: reassembly: fix possible buffer overflow
The max_dsize attribute in ctl_table for lowpan_frags_ns_ctl_table is
configured with integer accessing methods. This patch change the
max_dsize attribute to int to avoid a possible buffer overflow.

Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-07-02 18:34:25 -07:00
Florian Westphal
9500507c61 netfilter: conntrack: remove timer from ecache extension
This brings the (per-conntrack) ecache extension back to 24 bytes in size
(was 152 byte on x86_64 with lockdep on).

When event delivery fails, re-delivery is attempted via work queue.

Redelivery is attempted at least every 0.1 seconds, but can happen
more frequently if userspace is not congested.

The nf_ct_release_dying_list() function is removed.
With this patch, ownership of the to-be-redelivered conntracks
(on-dying-list-with-DYING-bit not yet set) is with the work queue,
which will release the references once event is out.

Joint work with Pablo Neira Ayuso.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-06-25 19:15:38 +02:00
WANG Cong
122ff243f5 ipv4: make ip_local_reserved_ports per netns
ip_local_port_range is already per netns, so should ip_local_reserved_ports
be. And since it is none by default we don't actually need it when we don't
enable CONFIG_SYSCTL.

By the way, rename inet_is_reserved_local_port() to inet_is_local_reserved_port()

Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-14 15:31:45 -04:00
Lorenzo Colitti
84f39b08d7 net: support marking accepting TCP sockets
When using mark-based routing, sockets returned from accept()
may need to be marked differently depending on the incoming
connection request.

This is the case, for example, if different socket marks identify
different networks: a listening socket may want to accept
connections from all networks, but each connection should be
marked with the network that the request came in on, so that
subsequent packets are sent on the correct network.

This patch adds a sysctl to mark TCP sockets based on the fwmark
of the incoming SYN packet. If enabled, and an unmarked socket
receives a SYN, then the SYN packet's fwmark is written to the
connection's inet_request_sock, and later written back to the
accepted socket when the connection is established.  If the
socket already has a nonzero mark, then the behaviour is the same
as it is today, i.e., the listening socket's fwmark is used.

Black-box tested using user-mode linux:

- IPv4/IPv6 SYN+ACK, FIN, etc. packets are routed based on the
  mark of the incoming SYN packet.
- The socket returned by accept() is marked with the mark of the
  incoming SYN packet.
- Tested with syncookies=1 and syncookies=2.

Signed-off-by: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 18:35:09 -04:00
Lorenzo Colitti
e110861f86 net: add a sysctl to reflect the fwmark on replies
Kernel-originated IP packets that have no user socket associated
with them (e.g., ICMP errors and echo replies, TCP RSTs, etc.)
are emitted with a mark of zero. Add a sysctl to make them have
the same mark as the packet they are replying to.

This allows an administrator that wishes to do so to use
mark-based routing, firewalling, etc. for these replies by
marking the original packets inbound.

Tested using user-mode linux:
 - ICMP/ICMPv6 echo replies and errors.
 - TCP RST packets (IPv4 and IPv6).

Signed-off-by: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-13 18:35:08 -04:00