linux-stable.git/net/ipv4/netfilter, branch v4.2.4

netfilter: SYNPROXY: fix sending window update to client

2015-08-10T11:55:07+00:00

Upon receipt of SYNACK from the server, ipt_SYNPROXY first sends back an ACK to
finish the server handshake, then calls nf_ct_seqadj_init() to initiate
sequence number adjustment of forwarded packets to the client and finally sends
a window update to the client to unblock it's TX queue.

Since synproxy_send_client_ack() does not set synproxy_send_tcp()'s nfct
parameter, no sequence number adjustment happens and the client receives the
window update with incorrect sequence number. Depending on client TCP
implementation, this leads to a significant delay (until a window probe is
being sent).

Signed-off-by: Phil Sutter 
Signed-off-by: Pablo Neira Ayuso

netfilter: arptables: use percpu jumpstack

2015-07-02T15:58:59+00:00

commit 482cfc318559 ("netfilter: xtables: avoid percpu ruleset duplication")

Unlike ip and ip6tables, arp tables were never converted to use the percpu
jump stack.

It still uses the rule blob to store return address, which isn't safe
anymore since we now share this blob among all processors.

Because there is no TEE support for arptables, we don't need to cope
with reentrancy, so we can use loocal variable to hold stack offset.

Fixes: 482cfc318559 ("netfilter: xtables: avoid percpu ruleset duplication")
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso

net: ipv4 sysctl option to ignore routes when nexthop link is down

2015-06-24T09:15:54+00:00

This feature is only enabled with the new per-interface or ipv4 global
sysctls called 'ignore_routes_with_linkdown'.

net.ipv4.conf.all.ignore_routes_with_linkdown = 0
net.ipv4.conf.default.ignore_routes_with_linkdown = 0
net.ipv4.conf.lo.ignore_routes_with_linkdown = 0
...

When the above sysctls are set, will report to userspace that a route is
dead and will no longer resolve to this nexthop when performing a fib
lookup.  This will signal to userspace that the route will not be
selected.  The signalling of a RTNH_F_DEAD is only passed to userspace
if the sysctl is enabled and link is down.  This was done as without it
the netlink listeners would have no idea whether or not a nexthop would
be selected.   The kernel only sets RTNH_F_DEAD internally if the
interface has IFF_UP cleared.

With the new sysctl set, the following behavior can be observed
(interface p8p1 is link-down):

default via 10.0.5.2 dev p9p1
10.0.5.0/24 dev p9p1  proto kernel  scope link  src 10.0.5.15
70.0.0.0/24 dev p7p1  proto kernel  scope link  src 70.0.0.1
80.0.0.0/24 dev p8p1  proto kernel  scope link  src 80.0.0.1 dead linkdown
90.0.0.0/24 via 80.0.0.2 dev p8p1  metric 1 dead linkdown
90.0.0.0/24 via 70.0.0.2 dev p7p1  metric 2
90.0.0.1 via 70.0.0.2 dev p7p1  src 70.0.0.1
    cache
local 80.0.0.1 dev lo  src 80.0.0.1
    cache 
80.0.0.2 via 10.0.5.2 dev p9p1  src 10.0.5.15
    cache

While the route does remain in the table (so it can be modified if
needed rather than being wiped away as it would be if IFF_UP was
cleared), the proper next-hop is chosen automatically when the link is
down.  Now interface p8p1 is linked-up:

default via 10.0.5.2 dev p9p1
10.0.5.0/24 dev p9p1  proto kernel  scope link  src 10.0.5.15
70.0.0.0/24 dev p7p1  proto kernel  scope link  src 70.0.0.1
80.0.0.0/24 dev p8p1  proto kernel  scope link  src 80.0.0.1
90.0.0.0/24 via 80.0.0.2 dev p8p1  metric 1
90.0.0.0/24 via 70.0.0.2 dev p7p1  metric 2
192.168.56.0/24 dev p2p1  proto kernel  scope link  src 192.168.56.2
90.0.0.1 via 80.0.0.2 dev p8p1  src 80.0.0.1
    cache
local 80.0.0.1 dev lo  src 80.0.0.1
    cache 
80.0.0.2 dev p8p1  src 80.0.0.1
    cache

and the output changes to what one would expect.

If the sysctl is not set, the following output would be expected when
p8p1 is down:

default via 10.0.5.2 dev p9p1
10.0.5.0/24 dev p9p1  proto kernel  scope link  src 10.0.5.15
70.0.0.0/24 dev p7p1  proto kernel  scope link  src 70.0.0.1
80.0.0.0/24 dev p8p1  proto kernel  scope link  src 80.0.0.1 linkdown
90.0.0.0/24 via 80.0.0.2 dev p8p1  metric 1 linkdown
90.0.0.0/24 via 70.0.0.2 dev p7p1  metric 2

Since the dead flag does not appear, there should be no expectation that
the kernel would skip using this route due to link being down.

v2: Split kernel changes into 2 patches, this actually makes a
behavioral change if the sysctl is set.  Also took suggestion from Alex
to simplify code by only checking sysctl during fib lookup and
suggestion from Scott to add a per-interface sysctl.

v3: Code clean-ups to make it more readable and efficient as well as a
reverse path check fix.

v4: Drop binary sysctl

v5: Whitespace fixups from Dave

v6: Style changes from Dave and checkpatch suggestions

v7: One more checkpatch fixup

Signed-off-by: Andy Gospodarek 
Signed-off-by: Dinesh Dutt 
Acked-by: Scott Feldman 
Signed-off-by: David S. Miller

netfilter: x_tables: remove XT_TABLE_INFO_SZ and a dereference.

2015-06-15T18:19:20+00:00

After Florian patches, there is no need for XT_TABLE_INFO_SZ anymore :
Only one copy of table is kept, instead of one copy per cpu.

We also can avoid a dereference if we put table data right after
xt_table_info. It reduces register pressure and helps compiler.

Then, we attempt a kmalloc() if total size is under order-3 allocation,
to reduce TLB pressure, as in many cases, rules fit in 32 KB.

Signed-off-by: Eric Dumazet 
Cc: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso

netfilter: Kconfig: get rid of parens around depends on

2015-06-15T15:26:37+00:00

According to the reporter, they are not needed.

Reported-by: Sergei Shtylyov 
Signed-off-by: Pablo Neira Ayuso

netfilter: xtables: avoid percpu ruleset duplication

2015-06-12T12:27:10+00:00

We store the rule blob per (possible) cpu.  Unfortunately this means we can
waste lot of memory on big smp machines. ipt_entry structure ('rule head')
is 112 byte, so e.g. with maxcpu=64 one single rule eats
close to 8k RAM.

Since previous patch made counters percpu it appears there is nothing
left in the rule blob that needs to be percpu.

On my test system (144 possible cpus, 400k dummy rules) this
change saves close to 9 Gigabyte of RAM.

Reported-by: Marcelo Ricardo Leitner 
Acked-by: Jesper Dangaard Brouer 
Signed-off-by: Florian Westphal 
Acked-by: Eric Dumazet 
Signed-off-by: Pablo Neira Ayuso

netfilter: xtables: use percpu rule counters

2015-06-12T12:27:09+00:00

The binary arp/ip/ip6tables ruleset is stored per cpu.

The only reason left as to why we need percpu duplication are the rule
counters embedded into ipt_entry et al -- since each cpu has its own copy
of the rules, all counters can be lockless.

The downside is that the more cpus are supported, the more memory is
required.  Rules are not just duplicated per online cpu but for each
possible cpu, i.e. if maxcpu is 144, then rule is duplicated 144 times,
not for the e.g. 64 cores present.

To save some memory and also improve utilization of shared caches it
would be preferable to only store the rule blob once.

So we first need to separate counters and the rule blob.

Instead of using entry->counters, allocate this percpu and store the
percpu address in entry->counters.pcnt on CONFIG_SMP.

This change makes no sense as-is; it is merely an intermediate step to
remove the percpu duplication of the rule set in a followup patch.

Suggested-by: Eric Dumazet 
Acked-by: Jesper Dangaard Brouer 
Reported-by: Marcelo Ricardo Leitner 
Signed-off-by: Florian Westphal 
Acked-by: Eric Dumazet 
Signed-off-by: Pablo Neira Ayuso

Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next

2015-05-31T07:02:30+00:00

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

netfilter: remove unused comefrom hookmask argument

2015-05-26T16:40:30+00:00

Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2015-05-23T05:22:35+00:00

Conflicts:
	drivers/net/ethernet/cadence/macb.c
	drivers/net/phy/phy.c
	include/linux/skbuff.h
	net/ipv4/tcp.c
	net/switchdev/switchdev.c

Switchdev was a case of RTNH_H_{EXTERNAL --> OFFLOAD}
renaming overlapping with net-next changes of various
sorts.

phy.c was a case of two changes, one adding a local
variable to a function whilst the second was removing
one.

tcp.c overlapped a deadlock fix with the addition of new tcp_info
statistic values.

macb.c involved the addition of two zyncq device entries.

skbuff.h involved adding back ipv4_daddr to nf_bridge_info
whilst net-next changes put two other existing members of
that struct into a union.

Signed-off-by: David S. Miller