litmus-rt.git/net/netfilter, branch master

netfilter: nfnetlink_{log,queue}: Register pernet in first place

2015-05-20T11:46:48+00:00

nfnetlink_{log,queue}_init() register the netlink callback nf*_rcv_nl_event
before registering the pernet_subsys, but the callback relies on data
structures allocated by pernet init functions.

When nfnetlink_{log,queue} is loaded, if a netlink message is received after
the netlink callback is registered but before the pernet_subsys is registered,
the kernel will panic in the sequence

nfulnl_rcv_nl_event
  nfnl_log_pernet
    net_generic
      BUG_ON(id == 0)  where id is nfnl_log_net_id.

The panic can be easily reproduced in 4.0.3 by:

while true ;do modprobe nfnetlink_log ; rmmod nfnetlink_log ; done &
while true ;do ip netns add dummy ; ip netns del dummy ; done &

This patch moves register_pernet_subsys to earlier in nfnetlink_log_init.

Notice that the BUG_ON hit in 4.0.3 was recently removed in 2591ffd308
["netns: remove BUG_ONs from net_generic()"].

Signed-off-by: Francesco Ruggeri 
Signed-off-by: Pablo Neira Ayuso

netfilter: nf_tables: fix bogus warning in nft_data_uninit()

2015-05-15T20:07:30+00:00

The values 0x00000000-0xfffffeff are reserved for userspace datatype. When,
deleting set elements with maps, a bogus warning is triggered.

WARNING: CPU: 0 PID: 11133 at net/netfilter/nf_tables_api.c:4481 nft_data_uninit+0x35/0x40 [nf_tables]()

This fixes the check accordingly to enum definition in
include/linux/netfilter/nf_tables.h

Fixes: https://bugzilla.netfilter.org/show_bug.cgi?id=1013
Signed-off-by: Mirek Kratochvil 
Signed-off-by: Pablo Neira Ayuso

conntrack: RFC5961 challenge ACK confuse conntrack LAST-ACK transition

2015-05-15T18:50:56+00:00

In compliance with RFC5961, the network stack send challenge ACK in
response to spurious SYN packets, since commit 0c228e833c88 ("tcp:
Restore RFC5961-compliant behavior for SYN packets").

This pose a problem for netfilter conntrack in state LAST_ACK, because
this challenge ACK is (falsely) seen as ACKing last FIN, causing a
false state transition (into TIME_WAIT).

The challenge ACK is hard to distinguish from real last ACK.  Thus,
solution introduce a flag that tracks the potential for seeing a
challenge ACK, in case a SYN packet is let through and current state
is LAST_ACK.

When conntrack transition LAST_ACK to TIME_WAIT happens, this flag is
used for determining if we are expecting a challenge ACK.

Scapy based reproducer script avail here:
 https://github.com/netoptimizer/network-testing/blob/master/scapy/tcp_hacks_3WHS_LAST_ACK.py

Fixes: 0c228e833c88 ("tcp: Restore RFC5961-compliant behavior for SYN packets")
Signed-off-by: Jesper Dangaard Brouer 
Acked-by: Jozsef Kadlecsik 
Signed-off-by: Pablo Neira Ayuso

netfilter: avoid build error if TPROXY/SOCKET=y && NF_DEFRAG_IPV6=m

2015-05-15T18:18:27+00:00

With TPROXY=y but DEFRAG_IPV6=m we get build failure:

net/built-in.o: In function `tproxy_tg_init':
net/netfilter/xt_TPROXY.c:588: undefined reference to `nf_defrag_ipv6_enable'

If DEFRAG_IPV6 is modular, TPROXY must be too.
(or both must be builtin).

This enforces =m for both.

Reported-and-tested-by: Liu Hua 
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso

ipvs: fix memory leak in ip_vs_ctl.c

2015-05-08T08:58:54+00:00

Fix memory leak introduced in commit a0840e2e165a ("IPVS: netns,
ip_vs_ctl local vars moved to ipvs struct."):

unreferenced object 0xffff88005785b800 (size 2048):
  comm "(-localed)", pid 1434, jiffies 4294755650 (age 1421.089s)
  hex dump (first 32 bytes):
    bb 89 0b 83 ff ff ff ff b0 78 f0 4e 00 88 ff ff  .........x.N....
    04 00 00 00 a4 01 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [] kmemleak_alloc+0x4e/0xb0
    [] __kmalloc_track_caller+0x244/0x430
    [] kmemdup+0x20/0x50
    [] ip_vs_control_net_init+0x1f7/0x510
    [] __ip_vs_init+0x100/0x250
    [] ops_init+0x41/0x190
    [] setup_net+0x93/0x150
    [] copy_net_ns+0x82/0x140
    [] create_new_namespaces+0xfd/0x190
    [] unshare_nsproxy_namespaces+0x5a/0xc0
    [] SyS_unshare+0x173/0x310
    [] system_call_fastpath+0x12/0x6f
    [] 0xffffffffffffffff

Fixes: a0840e2e165a ("IPVS: netns, ip_vs_ctl local vars moved to ipvs struct.")
Signed-off-by: Tommi Rantala 
Acked-by: Julian Anastasov 
Signed-off-by: Simon Horman

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

2015-04-28T03:12:34+00:00

Pablo Neira Ayuso says:

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

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

1) Fix a crash in nf_tables when dictionaries are used from the ruleset,
   due to memory corruption, from Florian Westphal.

2) Fix another crash in nf_queue when used with br_netfilter. Also from
   Florian.

Both fixes are related to new stuff that got in 4.0-rc.
====================

Signed-off-by: David S. Miller

netfilter; Add some missing default cases to switch statements in nft_reject.

2015-04-27T17:20:34+00:00

This fixes:

====================
net/netfilter/nft_reject.c: In function ‘nft_reject_dump’:
net/netfilter/nft_reject.c:61:2: warning: enumeration value ‘NFT_REJECT_TCP_RST’ not handled in switch [-Wswitch]
  switch (priv->type) {
  ^
net/netfilter/nft_reject.c:61:2: warning: enumeration value ‘NFT_REJECT_ICMPX_UNREACH’ not handled in switch [-Wswi\
tch]
net/netfilter/nft_reject_inet.c: In function ‘nft_reject_inet_dump’:
net/netfilter/nft_reject_inet.c:105:2: warning: enumeration value ‘NFT_REJECT_TCP_RST’ not handled in switch [-Wswi\
tch]
  switch (priv->type) {
  ^
====================

Signed-off-by: David S. Miller

netfilter: nf_tables: fix wrong length for jump/goto verdicts

2015-04-24T18:51:23+00:00

NFT_JUMP/GOTO erronously sets length to sizeof(void *).

We then allocate insufficient memory when such element is added to a vmap.

Suggested-by: Patrick McHardy 
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso

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

2015-04-14T22:51:19+00:00

Pablo Neira Ayuso says:

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

A final pull request, I know it's very late but this time I think it's worth a
bit of rush.

The following patchset contains Netfilter/nf_tables updates for net-next, more
specifically concatenation support and dynamic stateful expression
instantiation.

This also comes with a couple of small patches. One to fix the ebtables.h
userspace header and another to get rid of an obsolete example file in tree
that describes a nf_tables expression.

This time, I decided to paste the original descriptions. This will result in a
rather large commit description, but I think these bytes to keep.

Patrick McHardy says:

====================
netfilter: nf_tables: concatenation support

The following patches add support for concatenations, which allow multi
dimensional exact matches in O(1).

The basic idea is to split the data registers, currently consisting of
4 registers of 16 bytes each, into smaller units, 16 registers of 4
bytes each, and making sure each register store always leaves the
full 32 bit in a well defined state, meaning smaller stores will
zero the remaining bits.

Based on that, we can load multiple adjacent registers with different
values, thereby building a concatenated bigger value, and use that
value for set lookups.

Sets are changed to use variable sized extensions for their key and
data values, removing the fixed limit of 16 bytes while saving memory
if less space is needed.

As a side effect, these patches will allow some nice optimizations in
the future, like using jhash2 in nft_hash, removing the masking in
nft_cmp_fast, optimized data comparison using 32 bit word size etc.
These are not done so far however.

The patches are split up as follows:

 * the first five patches add length validation to register loads and
   stores to make sure we stay within bounds and prepare the validation
   functions for the new addressing mode

 * the next patches prepare for changing to 32 bit addressing by
   introducing a struct nft_regs, which holds the verdict register as
   well as the data registers. The verdict members are moved to a new
   struct nft_verdict to allow to pull struct nft_data out of the stack.

 * the next patches contain preparatory conversions of expressions and
   sets to use 32 bit addressing

 * the next patch introduces so far unused register conversion helpers
   for parsing and dumping register numbers over netlink

 * following is the real conversion to 32 bit addressing, consisting of
   replacing struct nft_data in struct nft_regs by an array of u32s and
   actually translating and validating the new register numbers.

 * the final two patches add support for variable sized data items and
   variable sized keys / data in set elements

The patches have been verified to work correctly with nft binaries using
both old and new addressing.
====================

Patrick McHardy says:

====================
netfilter: nf_tables: dynamic stateful expression instantiation

The following patches are the grand finale of my nf_tables set work,
using all the building blocks put in place by the previous patches
to support something like iptables hashlimit, but a lot more powerful.

Sets are extended to allow attaching expressions to set elements.
The dynset expression dynamically instantiates these expressions
based on a template when creating new set elements and evaluates
them for all new or updated set members.

In combination with concatenations this effectively creates state
tables for arbitrary combinations of keys, using the existing
expression types to maintain that state. Regular set GC takes care
of purging expired states.

We currently support two different stateful expressions, counter
and limit. Using limit as a template we can express the functionality
of hashlimit, but completely unrestricted in the combination of keys.
Using counter we can perform accounting for arbitrary flows.

The following examples from patch 5/5 show some possibilities.
Userspace syntax is still WIP, especially the listing of state
tables will most likely be seperated from normal set listings
and use a more structured format:

1. Limit the rate of new SSH connections per host, similar to iptables
   hashlimit:

        flow ip saddr timeout 60s \
        limit 10/second \
        accept

2. Account network traffic between each set of /24 networks:

        flow ip saddr & 255.255.255.0 . ip daddr & 255.255.255.0 \
        counter

3. Account traffic to each host per user:

        flow skuid . ip daddr \
        counter

4. Account traffic for each combination of source address and TCP flags:

        flow ip saddr . tcp flags \
        counter

The resulting set content after a Xmas-scan look like this:

{
        192.168.122.1 . fin | psh | urg : counter packets 1001 bytes 40040,
        192.168.122.1 . ack : counter packets 74 bytes 3848,
        192.168.122.1 . psh | ack : counter packets 35 bytes 3144
}

In the future the "expressions attached to elements" will be extended
to also support user created non-stateful expressions to allow to
efficiently select beween a set of parameter sets, f.i. a set of log
statements with different prefixes based on the interface, which currently
require one rule each. This will most likely have to wait until the next
kernel version though.
====================

Signed-off-by: David S. Miller

tcp/dccp: get rid of central timewait timer

2015-04-13T20:40:05+00:00

Using a timer wheel for timewait sockets was nice ~15 years ago when
memory was expensive and machines had a single processor.

This does not scale, code is ugly and source of huge latencies
(Typically 30 ms have been seen, cpus spinning on death_lock spinlock.)

We can afford to use an extra 64 bytes per timewait sock and spread
timewait load to all cpus to have better behavior.

Tested:

On following test, /proc/sys/net/ipv4/tcp_tw_recycle is set to 1
on the target (lpaa24)

Before patch :

lpaa23:~# ./super_netperf 200 -H lpaa24 -t TCP_CC -l 60 -- -p0,0
419594

lpaa23:~# ./super_netperf 200 -H lpaa24 -t TCP_CC -l 60 -- -p0,0
437171

While test is running, we can observe 25 or even 33 ms latencies.

lpaa24:~# ping -c 1000 -i 0.02 -qn lpaa23
...
1000 packets transmitted, 1000 received, 0% packet loss, time 20601ms
rtt min/avg/max/mdev = 0.020/0.217/25.771/1.535 ms, pipe 2

lpaa24:~# ping -c 1000 -i 0.02 -qn lpaa23
...
1000 packets transmitted, 1000 received, 0% packet loss, time 20702ms
rtt min/avg/max/mdev = 0.019/0.183/33.761/1.441 ms, pipe 2

After patch :

About 90% increase of throughput :

lpaa23:~# ./super_netperf 200 -H lpaa24 -t TCP_CC -l 60 -- -p0,0
810442

lpaa23:~# ./super_netperf 200 -H lpaa24 -t TCP_CC -l 60 -- -p0,0
800992

And latencies are kept to minimal values during this load, even
if network utilization is 90% higher :

lpaa24:~# ping -c 1000 -i 0.02 -qn lpaa23
...
1000 packets transmitted, 1000 received, 0% packet loss, time 19991ms
rtt min/avg/max/mdev = 0.023/0.064/0.360/0.042 ms

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller