rps: fix insufficient bounds checking in store_rps_dev_flow_table_cnt()

Setting a large rps_flow_cnt like (1 << 30) on 32-bit platform will
cause a kernel oops due to insufficient bounds checking.

	if (count > 1<<30) {
		/* Enforce a limit to prevent overflow */
		return -EINVAL;
	}
	count = roundup_pow_of_two(count);
	table = vmalloc(RPS_DEV_FLOW_TABLE_SIZE(count));

Note that the macro RPS_DEV_FLOW_TABLE_SIZE(count) is defined as:

	... + (count * sizeof(struct rps_dev_flow))

where sizeof(struct rps_dev_flow) is 8.  (1 << 30) * 8 will overflow
32 bits.

This patch replaces the magic number (1 << 30) with a symbolic bound.

Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Xi Wang <xi.wang@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
netlink: af_netlink cleanup (v2)

Don't inline functions that cover several lines, and do inline
the trivial ones. Also make some arguments const.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
netlink: wake up netlink listeners sooner (v2)

This patch changes it to yield sooner at halfway instead. Still not a cure-all
for listener overrun if listner is slow, but works much reliably.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: relax rcvbuf limits

skb->truesize might be big even for a small packet.

Its even bigger after commit 87fb4b7b533 (net: more accurate skb
truesize) and big MTU.

We should allow queueing at least one packet per receiver, even with a
low RCVBUF setting.

Reported-by: Michal Simek <monstr@monstr.eu>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
netfilter: rework user-space expectation helper support

This partially reworks bc01befdcf3e40979eb518085a075cbf0aacede0
which added userspace expectation support.

This patch removes the nf_ct_userspace_expect_list since now we
force to use the new iptables CT target feature to add the helper
extension for conntracks that have attached expectations from
userspace.

A new version of the proof-of-concept code to implement userspace
helpers from userspace is available at:

http://people.netfilter.org/pablo/userspace-conntrack-helpers/nf-ftp-helper-POC.tar.bz2

This patch also modifies the CT target to allow to set the
conntrack's userspace helper status flags. This flag is used
to tell the conntrack system to explicitly allocate the helper
extension.

This helper extension is useful to link the userspace expectations
with the master conntrack that is being tracked from one userspace
helper.

This feature fixes a problem in the current approach of the
userspace helper support. Basically, if the master conntrack that
has got a userspace expectation vanishes, the expectations point to
one invalid memory address. Thus, triggering an oops in the
expectation deletion event path.

I decided not to add a new revision of the CT target because
I only needed to add a new flag for it. I'll document in this
issue in the iptables manpage. I have also changed the return
value from EINVAL to EOPNOTSUPP if one flag not supported is
specified. Thus, in the future adding new features that only
require a new flag can be added without a new revision.

There is no official code using this in userspace (apart from
the proof-of-concept) that uses this infrastructure but there
will be some by beginning 2012.

Reported-by: Sam Roberts <vieuxtech@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
netfilter: nf_nat: use hash random for bysource hash

Use nf_conntrack_hash_rnd in NAT bysource hash to avoid hash chain attacks.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
netfilter: nf_nat: add missing nla_policy entry for CTA_NAT_PROTO attribute

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
netfilter: nat: remove module reference counting from NAT protocols

The only remaining user of NAT protocol module reference counting is NAT
ctnetlink support. Since this is a fairly short sequence of code, convert
over to use RCU and remove module reference counting.

Module unregistration is already protected by RCU using synchronize_rcu(),
so no further changes are necessary.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
netfilter: nf_nat: remove obsolete code from nf_nat_icmp_reply_translation()

The inner tuple that is extracted from the packet is unused. The code also
doesn't have any useful side-effects like verifying the packet does contain
enough data to extract the inner tuple since conntrack already does the
same, so remove it.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
netfilter: nf_nat: remove obsolete check in nf_nat_mangle_udp_packet()

The packet size check originates from a time when UDP helpers could
accidentally mangle incorrect packets (NEWNAT) and is unnecessary
nowadays since the conntrack helpers invoke the NAT helpers for the
proper packet directly.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
netfilter: ctnetlink: remove dead NAT code

The NAT range to nlattr conversation callbacks and helpers are entirely
dead code and are also useless since there are no NAT ranges in conntrack
context, they are only used for initially selecting a tuple. The final NAT
information is contained in the selected tuples of the conntrack entry.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
netfilter: xt_connbytes: handle negation correctly

"! --connbytes 23:42" should match if the packet/byte count is not in range.

As there is no explict "invert match" toggle in the match structure,
userspace swaps the from and to arguments
(i.e., as if "--connbytes 42:23" were given).

However, "what <= 23 && what >= 42" will always be false.

Change things so we use "||" in case "from" is larger than "to".

This change may look like it breaks backwards compatibility when "to" is 0.
However, older iptables binaries will refuse "connbytes 42:0",
and current releases treat it to mean "! --connbytes 0:42",
so we should be fine.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
update config
netlink: Undo const marker in netlink_is_kernel().

We can't do this without propagating the const to nlk_sk()
too, otherwise:

net/netlink/af_netlink.c: In function ‘netlink_is_kernel’:
net/netlink/af_netlink.c:103:2: warning: passing argument 1 of ‘nlk_sk’ discards ‘const’ qualifier from pointer target type [enabled by default]
net/netlink/af_netlink.c:96:36: note: expected ‘struct sock *’ but argument is of type ‘const struct sock *’

Signed-off-by: David S. Miller <davem@davemloft.net>
netfilter: ctnetlink: get and zero operations must be atomic

The get and zero operations have to be done in an atomic context,
otherwise counters added between them will be lost.

This problem was spotted by Changli Gao while discussing the
nfacct infrastructure.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
netfilter: ctnetlink: fix return value of ctnetlink_get_expect()

This fixes one bogus error that is returned to user-space:

libnetfilter_conntrack/utils# ./expect_get
TEST: get expectation (-1)(Unknown error 18446744073709551504)

This patch includes the correct handling for EAGAIN (nfnetlink
uses this error value to restart the operation after module
auto-loading).

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
netfilter: ctnetlink: fix scheduling while atomic if helper is autoloaded

This patch fixes one scheduling while atomic error:

[  385.565186] ctnetlink v0.93: registering with nfnetlink.
[  385.565349] BUG: scheduling while atomic: lt-expect_creat/16163/0x00000200

It can be triggered with utils/expect_create included in
libnetfilter_conntrack if the FTP helper is not loaded.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
rfs: better sizing of dev_flow_table

Aim of this patch is to provide full range of rps_flow_cnt on 64bit arches.

Theorical limit on number of flows is 2^32

Fix some buggy RPS/RFS macros as well.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Tom Herbert <therbert@google.com>
CC: Xi Wang <xi.wang@gmail.com>
CC: Laurent Chavey <chavey@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
netfilter: add extended accounting infrastructure over nfnetlink

We currently have two ways to account traffic in netfilter:

- iptables chain and rule counters:

 # iptables -L -n -v
Chain INPUT (policy DROP 3 packets, 867 bytes)
 pkts bytes target     prot opt in     out     source               destination
    8  1104 ACCEPT     all  --  lo     *       0.0.0.0/0            0.0.0.0/0

- use flow-based accounting provided by ctnetlink:

 # conntrack -L
tcp      6 431999 ESTABLISHED src=192.168.1.130 dst=212.106.219.168 sport=58152 dport=80 packets=47 bytes=7654 src=212.106.219.168 dst=192.168.1.130 sport=80 dport=58152 packets=49 bytes=66340 [ASSURED] mark=0 use=1

While trying to display real-time accounting statistics, we require
to pool the kernel periodically to obtain this information. This is
OK if the number of flows is relatively low. However, in case that
the number of flows is huge, we can spend a considerable amount of
cycles to iterate over the list of flows that have been obtained.

Moreover, if we want to obtain the sum of the flow accounting results
that match some criteria, we have to iterate over the whole list of
existing flows, look for matchings and update the counters.

This patch adds the extended accounting infrastructure for
nfnetlink which aims to allow displaying real-time traffic accounting
without the need of complicated and resource-consuming implementation
in user-space. Basically, this new infrastructure allows you to create
accounting objects. One accounting object is composed of packet and
byte counters.

In order to manipulate create accounting objects, you require the
new libnetfilter_acct library. It contains several examples of use:

libnetfilter_acct/examples# ./nfacct-add http-traffic
libnetfilter_acct/examples# ./nfacct-get
http-traffic = { pkts = 000000000000,   bytes = 000000000000 };

Then, you can use one of this accounting objects in several iptables
rules using the new nfacct match (which comes in a follow-up patch):

 # iptables -I INPUT -p tcp --sport 80 -m nfacct --nfacct-name http-traffic
 # iptables -I OUTPUT -p tcp --dport 80 -m nfacct --nfacct-name http-traffic

The idea is simple: if one packet matches the rule, the nfacct match
updates the counters.

Thanks to Patrick McHardy, Eric Dumazet, Changli Gao for reviewing and
providing feedback for this contribution.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
netfilter: xtables: add nfacct match to support extended accounting

This patch adds the match that allows to perform extended
accounting. It requires the new nfnetlink_acct infrastructure.

 # iptables -I INPUT -p tcp --sport 80 -m nfacct --nfacct-name http-traffic
 # iptables -I OUTPUT -p tcp --dport 80 -m nfacct --nfacct-name http-traffic

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>