Commit Graph

320 Commits

Author SHA1 Message Date
Eric W. Biederman
dc3ee32e96 netfilter: nf_queue: Make the queue_handler pernet
Florian Weber reported:
> Under full load (unshare() in loop -> OOM conditions) we can
> get kernel panic:
>
> BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
> IP: [<ffffffff81476c85>] nfqnl_nf_hook_drop+0x35/0x70
> [..]
> task: ffff88012dfa3840 ti: ffff88012dffc000 task.ti: ffff88012dffc000
> RIP: 0010:[<ffffffff81476c85>]  [<ffffffff81476c85>] nfqnl_nf_hook_drop+0x35/0x70
> RSP: 0000:ffff88012dfffd80  EFLAGS: 00010206
> RAX: 0000000000000008 RBX: ffffffff81add0c0 RCX: ffff88013fd80000
> [..]
> Call Trace:
>  [<ffffffff81474d98>] nf_queue_nf_hook_drop+0x18/0x20
>  [<ffffffff814738eb>] nf_unregister_net_hook+0xdb/0x150
>  [<ffffffff8147398f>] netfilter_net_exit+0x2f/0x60
>  [<ffffffff8141b088>] ops_exit_list.isra.4+0x38/0x60
>  [<ffffffff8141b652>] setup_net+0xc2/0x120
>  [<ffffffff8141bd09>] copy_net_ns+0x79/0x120
>  [<ffffffff8106965b>] create_new_namespaces+0x11b/0x1e0
>  [<ffffffff810698a7>] unshare_nsproxy_namespaces+0x57/0xa0
>  [<ffffffff8104baa2>] SyS_unshare+0x1b2/0x340
>  [<ffffffff81608276>] entry_SYSCALL_64_fastpath+0x1e/0xa8
> Code: 65 00 48 89 e5 41 56 41 55 41 54 53 83 e8 01 48 8b 97 70 12 00 00 48 98 49 89 f4 4c 8b 74 c2 18 4d 8d 6e 08 49 81 c6 88 00 00 00 <49> 8b 5d 00 48 85 db 74 1a 48 89 df 4c 89 e2 48 c7 c6 90 68 47
>

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

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

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

Reported-by: Florian Westphal <fw@strlen.de>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-05-25 11:54:22 +02:00
David S. Miller
32b583a0cb Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec
Steffen Klassert says:

====================
pull request (net): ipsec 2016-05-04

1) The flowcache can hit an OOM condition if too
   many entries are in the gc_list. Fix this by
   counting the entries in the gc_list and refuse
   new allocations if the value is too high.

2) The inner headers are invalid after a xfrm transformation,
   so reset the skb encapsulation field to ensure nobody tries
   access the inner headers. Otherwise tunnel devices stacked
   on top of xfrm may build the outer headers based on wrong
   informations.

3) Add pmtu handling to vti, we need it to report
   pmtu informations for local generated packets.

Please pull or let me know if there are problems.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-04 16:35:31 -04:00
Steffen Klassert
6ad3122a08 flowcache: Avoid OOM condition under preasure
We can hit an OOM condition if we are under presure because
we can not free the entries in gc_list fast enough. So add
a counter for the not yet freed entries in the gc_list and
refuse new allocations if the value is too high.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2016-03-17 10:28:42 +01:00
Michal Kubeček
3dc94f93be ipv6: per netns FIB garbage collection
One of our customers observed issues with FIB6 garbage collectors
running in different network namespaces blocking each other, resulting
in soft lockups (fib6_run_gc() initiated from timer runs always in
forced mode).

Now that FIB6 walkers are separated per namespace, there is no more need
for instances of fib6_run_gc() in different namespaces blocking each
other. There is still a call to icmp6_dst_gc() which operates on shared
data but this function is protected by its own shared lock.

Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Reviewed-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-08 15:16:51 -05:00
Michal Kubeček
9a03cd8f38 ipv6: per netns fib6 walkers
The IPv6 FIB data structures are separated per network namespace but
there is still only one global walkers list and one global walker list
lock. This means changes in one namespace unnecessarily interfere with
walkers in other namespaces.

Replace the global list with per-netns lists (and give each its own
lock).

Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Reviewed-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-08 15:16:51 -05:00
Nikolay Borisov
e21145a987 ipv4: namespacify ip_early_demux sysctl knob
Signed-off-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-16 20:42:54 -05:00
Nikolay Borisov
287b7f38fd ipv4: Namespacify ip_dynaddr sysctl knob
Signed-off-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-16 20:42:54 -05:00
Nikolay Borisov
fa50d974d1 ipv4: Namespaceify ip_default_ttl sysctl knob
Signed-off-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-16 20:42:54 -05:00
Nikolay Borisov
165094afce igmp: Namespacify igmp_qrv sysctl knob
Signed-off-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-11 09:59:22 -05:00
Nikolay Borisov
87a8a2ae65 igmp: Namespaceify igmp_llm_reports sysctl knob
This was initially introduced in df2cf4a78e ("IGMP: Inhibit
reports for local multicast groups") by defining the sysctl in the
ipv4_net_table array, however it was never implemented to be
namespace aware. Fix this by changing the code accordingly.

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-11 09:59:22 -05:00
Nikolay Borisov
166b6b2d6f igmp: Namespaceify igmp_max_msf sysctl knob
Signed-off-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-11 09:59:22 -05:00
Nikolay Borisov
815c527007 igmp: Namespaceify igmp_max_memberships sysctl knob
Signed-off-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-11 09:59:22 -05:00
Nikolay Borisov
4979f2d9f7 ipv4: Namespaceify tcp_notsent_lowat sysctl knob
Signed-off-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-07 14:36:11 -05:00
Nikolay Borisov
1e579caa18 ipv4: Namespaceify tcp_fin_timeout sysctl knob
Signed-off-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-07 14:36:11 -05:00
Nikolay Borisov
c402d9beff ipv4: Namespaceify tcp_orphan_retries sysctl knob
Signed-off-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-07 14:35:11 -05:00
Nikolay Borisov
c6214a97c8 ipv4: Namespaceify tcp_retries2 sysctl knob
Signed-off-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-07 14:35:11 -05:00
Nikolay Borisov
ae5c3f406c ipv4: Namespaceify tcp_retries1 sysctl knob
Signed-off-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-07 14:35:10 -05:00
Nikolay Borisov
1043e25ff9 ipv4: Namespaceify tcp reordering sysctl knob
Signed-off-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-07 14:35:10 -05:00
Nikolay Borisov
12ed8244ed ipv4: Namespaceify tcp syncookies sysctl knob
Signed-off-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-07 14:35:10 -05:00
Nikolay Borisov
7c083ecb3b ipv4: Namespaceify tcp synack retries sysctl knob
Signed-off-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-07 14:35:10 -05:00
Nikolay Borisov
6fa2516630 ipv4: Namespaceify tcp syn retries sysctl knob
Signed-off-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-07 14:35:10 -05:00
Nikolay Borisov
b840d15d39 ipv4: Namespecify the tcp_keepalive_intvl sysctl knob
This is the final part required to namespaceify the tcp
keep alive mechanism.

Signed-off-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-01-10 17:32:09 -05:00
Nikolay Borisov
9bd6861bd4 ipv4: Namespecify tcp_keepalive_probes sysctl knob
This is required to have full tcp keepalive mechanism namespace
support.

Signed-off-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-01-10 17:32:09 -05:00
Nikolay Borisov
13b287e8d1 ipv4: Namespaceify tcp_keepalive_time sysctl knob
Different net namespaces might have different requirements as to
the keepalive time of tcp sockets. This might be required in cases
where different firewall rules are in place which require tcp
timeout sockets to be increased/decreased independently of the host.

Signed-off-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-01-10 17:32:09 -05:00
David Ahern
6dd9a14e92 net: Allow accepted sockets to be bound to l3mdev domain
Allow accepted sockets to derive their sk_bound_dev_if setting from the
l3mdev domain in which the packets originated. A sysctl setting is added
to control the behavior which is similar to sk_mark and
sysctl_tcp_fwmark_accept.

This effectively allow a process to have a "VRF-global" listen socket,
with child sockets bound to the VRF device in which the packet originated.
A similar behavior can be achieved using sk_mark, but a solution using marks
is incomplete as it does not handle duplicate addresses in different L3
domains/VRFs. Allowing sockets to inherit the sk_bound_dev_if from l3mdev
domain provides a complete solution.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-18 14:43:38 -05:00
Zhu Yanjun
566178f853 net: sctp: dynamically enable or disable pf state
As we all know, the value of pf_retrans >= max_retrans_path can
disable pf state. The variables of pf_retrans and max_retrans_path
can be changed by the userspace application.

Sometimes the user expects to disable pf state while the 2
variables are changed to enable pf state. So it is necessary to
introduce a new variable to disable pf state.

According to the suggestions from Vlad Yasevich, extra1 and extra2
are removed. The initialization of pf_enable is added.

Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: Zhu Yanjun <zyjzyj2000@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-16 10:56:50 -05:00
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