netfilter: helper: Remove unused function declarations

Commit b118509076b3 ("netfilter: remove nf_conntrack_helper sysctl and modparam toggles")
leave these unused declarations.

Signed-off-by: Yue Haibing <yuehaibing@huawei.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Florian Westphal <fw@strlen.de>

net: move add ct helper function to nf_conntrack_helper for ovs and tc

Move ovs_ct_add_helper from openvswitch to nf_conntrack_helper and
rename as nf_ct_add_helper, so that it can be used in TC act_ct in
the next patch.

Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

net: move the ct helper function to nf_conntrack_helper for ovs and tc

Move ovs_ct_helper from openvswitch to nf_conntrack_helper and rename
as nf_ct_helper so that it can be used in TC act_ct in the next patch.
Note that it also adds the checks for the family and proto, as in TC
act_ct, the packets with correct family and proto are not guaranteed.

Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

netfilter: conntrack: Add and use nf_ct_set_auto_assign_helper_warned()

The function sets the pernet boolean to avoid the spurious warning from
nf_ct_lookup_helper() when assigning conntrack helpers via nftables.

Fixes: 1a64edf54f55 ("netfilter: nft_ct: add helper set support")
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

treewide: Use sizeof_field() macro

Replace all the occurrences of FIELD_SIZEOF() with sizeof_field() except
at places where these are defined. Later patches will remove the unused
definition of FIELD_SIZEOF().

This patch is generated using following script:

EXCLUDE_FILES="include/linux/stddef.h|include/linux/kernel.h"

git grep -l -e "\bFIELD_SIZEOF\b" | while read file;
do

if [[ "$file" =~ $EXCLUDE_FILES ]]; then
continue
fi
sed -i -e 's/\bFIELD_SIZEOF\b/sizeof_field/g' $file;
done

Signed-off-by: Pankaj Bharadiya <pankaj.laxminarayan.bharadiya@intel.com>
Link: https://lore.kernel.org/r/20190924105839.110713-3-pankaj.laxminarayan.bharadiya@intel.com
Co-developed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: David Miller <davem@davemloft.net> # for net

netfilter: add API to manage NAT helpers.

The API allows a conntrack helper to indicate its corresponding
NAT helper which then can be loaded and reference counted.

Signed-off-by: Flavio Leitner <fbl@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: use macros to create module aliases.

Each NAT helper creates a module alias which follows a pattern.
Use macros for consistency.

Signed-off-by: Flavio Leitner <fbl@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: conntrack: remove empty pernet fini stubs

after moving sysctl handling into single place, the init functions
can't fail anymore and some of the fini functions are empty.

Remove them and change return type to void.
This also simplifies error unwinding in conntrack module init path.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: Remove useless param helper of nf_ct_helper_ext_add

The param helper of nf_ct_helper_ext_add is useless now, then remove
it now.

Signed-off-by: Gao Feng <gfree.wind@vip.163.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: nf_conntrack_broadcast: remove useless parameter

parameter protoff in nf_conntrack_broadcast_help is not used anywhere.

Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

netfilter: nfnl_cthelper: reject del request if helper obj is in use

We can still delete the ct helper even if it is in use, this will cause
a use-after-free error. In more detail, I mean:
# nfct helper add ssdp inet udp
# iptables -t raw -A OUTPUT -p udp -j CT --helper ssdp
# nfct helper delete ssdp //--> oops, succeed!
BUG: unable to handle kernel paging request at 000026ca
IP: 0x26ca
[...]
Call Trace:
? ipv4_helper+0x62/0x80 [nf_conntrack_ipv4]
nf_hook_slow+0x21/0xb0
ip_output+0xe9/0x100
? ip_fragment.constprop.54+0xc0/0xc0
ip_local_out+0x33/0x40
ip_send_skb+0x16/0x80
udp_send_skb+0x84/0x240
udp_sendmsg+0x35d/0xa50

So add reference count to fix this issue, if ct helper is used by
others, reject the delete request.

Apply this patch:
# nfct helper delete ssdp
nfct v1.4.3: netlink error: Device or resource busy

Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: introduce nf_conntrack_helper_put helper function

And convert module_put invocation to nf_conntrack_helper_put, this is
prepared for the followup patch, which will add a refcnt for cthelper,
so we can reject the deleting request when cthelper is in use.

Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: helpers: remove data_len usage for inkernel helpers

No need to track this for inkernel helpers anymore as
NF_CT_HELPER_BUILD_BUG_ON checks do this now.

All inkernel helpers know what kind of structure they
stored in helper->data.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: helper: add build-time asserts for helper data size

add a 32 byte scratch area in the helper struct instead of relying
on variable sized helpers plus compile-time asserts to let us know
if 32 bytes aren't enough anymore.

Not having variable sized helpers will later allow to add BUILD_BUG_ON
for the total size of conntrack extensions -- the helper extension is
the only one that doesn't have a fixed size.

The (useless!) NF_CT_HELPER_BUILD_BUG_ON(0); are added so that in case
someone adds a new helper and copy-pastes from one that doesn't store
private data at least some indication that this macro should be used
somehow is there...

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: conntrack: move helper struct to nf_conntrack_helper.h

its definition is not needed in nf_conntrack.h.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: Add helper array register/unregister functions

Add nf_ct_helper_init(), nf_conntrack_helpers_register() and
nf_conntrack_helpers_unregister() functions to avoid repetitive
opencoded initialization in helpers.

This patch keeps an id parameter for nf_ct_helper_init() not to break
helper matching by name that has been inconsistently exposed to
userspace through ports, eg. ftp-2121, and through an incremental id,
eg. tftp-1.

Signed-off-by: Gao Feng <fgao@ikuai8.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: Remove extern from function prototypes

There are a mix of function prototypes with and without extern
in the kernel sources. Standardize on not using extern for
function prototypes.

Function prototypes don't need to be written with extern.
extern is assumed by the compiler. Its use is as unnecessary as
using auto to declare automatic/local variables in a block.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

netfilter: nf_ct_helper: better logging for dropped packets

Connection tracking helpers have to drop packets under exceptional
situations. Currently, the user gets the following logging message
in case that happens:

nf_ct_%s: dropping packet ...

However, depending on the helper, there are different reasons why a
packet can be dropped.

This patch modifies the existing code to provide more specific
error message in the scope of each helper to help users to debug
the reason why the packet has been dropped, ie:

nf_ct_%s: dropping packet: reason ...

Thanks to Joe Perches for many formatting suggestions.

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

netfilter: nf_ct_helper: move initialization out of pernet_operations

Move the global initial codes to the module_init/exit context.

Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: add user-space connection tracking helper infrastructure

There are good reasons to supports helpers in user-space instead:

* Rapid connection tracking helper development, as developing code
in user-space is usually faster.

* Reliability: A buggy helper does not crash the kernel. Moreover,
we can monitor the helper process and restart it in case of problems.

* Security: Avoid complex string matching and mangling in kernel-space
running in privileged mode. Going further, we can even think about
running user-space helpers as a non-root process.

* Extensibility: It allows the development of very specific helpers (most
likely non-standard proprietary protocols) that are very likely not to be
accepted for mainline inclusion in the form of kernel-space connection
tracking helpers.

This patch adds the infrastructure to allow the implementation of
user-space conntrack helpers by means of the new nfnetlink subsystem
`nfnetlink_cthelper' and the existing queueing infrastructure
(nfnetlink_queue).

I had to add the new hook NF_IP6_PRI_CONNTRACK_HELPER to register
ipv[4|6]_helper which results from splitting ipv[4|6]_confirm into
two pieces. This change is required not to break NAT sequence
adjustment and conntrack confirmation for traffic that is enqueued
to our user-space conntrack helpers.

Basic operation, in a few steps:

1) Register user-space helper by means of `nfct':

nfct helper add ftp inet tcp

[ It must be a valid existing helper supported by conntrack-tools ]

2) Add rules to enable the FTP user-space helper which is
used to track traffic going to TCP port 21.

For locally generated packets:

iptables -I OUTPUT -t raw -p tcp --dport 21 -j CT --helper ftp

For non-locally generated packets:

iptables -I PREROUTING -t raw -p tcp --dport 21 -j CT --helper ftp

3) Run the test conntrackd in helper mode (see example files under
doc/helper/conntrackd.conf

conntrackd

4) Generate FTP traffic going, if everything is OK, then conntrackd
should create expectations (you can check that with `conntrack':

conntrack -E expect

[NEW] 301 proto=6 src=192.168.1.136 dst=130.89.148.12 sport=0 dport=54037 mask-src=255.255.255.255 mask-dst=255.255.255.255 sport=0 dport=65535 master-src=192.168.1.136 master-dst=130.89.148.12 sport=57127 dport=21 class=0 helper=ftp
[DESTROY] 301 proto=6 src=192.168.1.136 dst=130.89.148.12 sport=0 dport=54037 mask-src=255.255.255.255 mask-dst=255.255.255.255 sport=0 dport=65535 master-src=192.168.1.136 master-dst=130.89.148.12 sport=57127 dport=21 class=0 helper=ftp

This confirms that our test helper is receiving packets including the
conntrack information, and adding expectations in kernel-space.

The user-space helper can also store its private tracking information
in the conntrack structure in the kernel via the CTA_HELP_INFO. The
kernel will consider this a binary blob whose layout is unknown. This
information will be included in the information that is transfered
to user-space via glue code that integrates nfnetlink_queue and
ctnetlink.

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

netfilter: ctnetlink: add CTA_HELP_INFO attribute

This attribute can be used to modify and to dump the internal
protocol information.

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

netfilter: nf_ct_helper: implement variable length helper private data

This patch uses the new variable length conntrack extensions.

Instead of using union nf_conntrack_help that contain all the
helper private data information, we allocate variable length
area to store the private helper data.

This patch includes the modification of all existing helpers.
It also includes a couple of include header to avoid compilation
warnings.

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

netfilter: nf_ct_helper: allocate 16 bytes for the helper and policy names

This patch modifies the struct nf_conntrack_helper to allocate
the room for the helper name. The maximum length is 16 bytes
(this was already introduced in 2.6.24).

For the maximum length for expectation policy names, I have
also selected 16 bytes.

This patch is required by the follow-up patch to support
user-space connection tracking helpers.

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

netfilter: nf_ct_helper: allow to disable automatic helper assignment

This patch allows you to disable automatic conntrack helper
lookup based on TCP/UDP ports, eg.

echo 0 > /proc/sys/net/netfilter/nf_conntrack_helper

[ Note: flows that already got a helper will keep using it even
if automatic helper assignment has been disabled ]

Once this behaviour has been disabled, you have to explicitly
use the iptables CT target to attach helper to flows.

There are good reasons to stop supporting automatic helper
assignment, for further information, please read:

http://www.netfilter.org/news.html#2012-04-03

This patch also adds one message to inform that automatic helper
assignment is deprecated and it will be removed soon (this is
spotted only once, with the first flow that gets a helper attached
to make it as less annoying as possible).

Signed-off-by: Eric Leblond <eric@regit.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: ctnetlink: allow to set expectfn for expectations

This patch allows you to set expectfn which is specifically used
by the NAT side of most of the existing conntrack helpers.

I have added a symbol map that uses a string as key to look up for
the function that is attached to the expectation object. This is
the best solution I came out with to solve this issue.

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

netfilter: nf_conntrack: nf_conntrack snmp helper

Adding support for SNMP broadcast connection tracking. The SNMP
broadcast requests are now paired with the SNMP responses.
Thus allowing using SNMP broadcasts with firewall enabled.

Please refer to the following conversation:
http://marc.info/?l=netfilter-devel&m=125992205006600&w=2

Patrick McHardy wrote:
> > The best solution would be to add generic broadcast tracking, the
> > use of expectations for this is a bit of abuse.
> > The second best choice I guess would be to move the help() function
> > to a shared module and generalize it so it can be used for both.
This patch implements the "second best choice".

Since the netbios-ns conntrack module uses the same helper
functionality as the snmp, only one helper function is added
for both snmp and netbios-ns modules into the new object -
nf_conntrack_broadcast.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

netfilter: xtables: add CT target

Add a new target for the raw table, which can be used to specify conntrack
parameters for specific connections, f.i. the conntrack helper.

The target attaches a "template" connection tracking entry to the skb, which
is used by the conntrack core when initializing a new conntrack.

Signed-off-by: Patrick McHardy <kaber@trash.net>

netfilter: nf_conntrack: support conntrack templates

Support initializing selected parameters of new conntrack entries from a
"conntrack template", which is a specially marked conntrack entry attached
to the skb.

Currently the helper and the event delivery masks can be initialized this
way.

Signed-off-by: Patrick McHardy <kaber@trash.net>

netfilter: ctnetlink: only assign helpers for matching protocols

Make sure not to assign a helper for a different network or transport
layer protocol to a connection.

Additionally change expectation deletion by helper to compare the name
directly - there might be multiple helper registrations using the same
name, currently one of them is chosen in an unpredictable manner and
only those expectations are removed.

Signed-off-by: Patrick McHardy <kaber@trash.net>

net: cleanup include/net

This cleanup patch puts struct/union/enum opening braces,
in first line to ease grep games.

struct something
{

becomes :

struct something {

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

netfilter: conntrack: move helper destruction to nf_ct_helper_destroy()

This patch moves the helper destruction to a function that lives
in nf_conntrack_helper.c. This new function is used in the patch
to add ctnetlink reliable event delivery.

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

netfilter: limit the length of the helper name

This is necessary in order to have an upper bound for Netlink
message calculation, which is not a problem at all, as there
are no helpers with a longer name.

Signed-off-by: Holger Eitzenberger <holger@eitzenberger.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>

netfilter: ctnetlink: helper modules load-on-demand support

This patch adds module loading for helpers via ctnetlink.

* Creation path: We support explicit and implicit helper assignation. For
the explicit case, we try to load the module. If the module is correctly
loaded and the helper is present, we return EAGAIN to re-start the
creation. Otherwise, we return EOPNOTSUPP.
* Update path: release the spin lock, load the module and check. If it is
present, then return EAGAIN to re-start the update.

This patch provides a refactorized function to lookup-and-set the
connection tracking helper. The function removes the exported symbol
__nf_ct_helper_find as it has not clients anymore.

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

[NETFILTER]: nf_conntrack: introduce expectation classes and policies

Introduce expectation classes and policies. An expectation class
is used to distinguish different types of expectations by the
same helper (for example audio/video/t.120). The expectation
policy is used to hold the maximum number of expectations and
the initial timeout for each class.

The individual classes are isolated from each other, which means
that for example an audio expectation will only evict other audio
expectations.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

[NETFILTER]: nf_conntrack: use RCU for conntrack helpers

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

[NETFILTER]: nf_conntrack: clean up a few header files

- Remove declarations of non-existing variables and functions
- Move helper init/cleanup function declarations to nf_conntrack_helper.h
- Remove unneeded __nf_conntrack_attach declaration and make it static

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

[NETFILTER]: Replace sk_buff ** with sk_buff *

With all the users of the double pointers removed, this patch mops up by
finally replacing all occurances of sk_buff ** in the netfilter API by
sk_buff *.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

[NETFILTER]: nfnetlink: rename functions containing 'nfattr'

There is no struct nfattr anymore, rename functions to 'nlattr'.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

[NETFILTER]: nf_conntrack_helper: use hashtable for conntrack helpers

Eliminate the last global list searched for every new connection.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

[NETFILTER]: nf_conntrack_expect: maintain per conntrack expectation list

This patch brings back the per-conntrack expectation list that was
removed around 2.6.10 to avoid walking all expectations on expectation
eviction and conntrack destruction.

As these were the last users of the global expectation list, this patch
also kills that.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

[NETFILTER]: nf_conntrack: reduce masks to a subset of tuples

Since conntrack currently allows to use masks for every bit of both
helper and expectation tuples, we can't hash them and have to keep
them on two global lists that are searched for every new connection.

This patch removes the never used ability to use masks for the
destination part of the expectation tuple and completely removes
masks from helpers since the only reasonable choice is a full
match on l3num, protonum and src.u.all.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

[NETFILTER]: nf_conntrack: use extension infrastructure for helper

Signed-off-by: Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

[NETFILTER]: nf_conntrack/nf_nat: add PPTP helper port

Add nf_conntrack port of the PPtP conntrack/NAT helper. Since there seems
to be no IPv6-capable PPtP implementation the helper only support IPv4.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

[NETFILTER]: nf_conntrack: split out helper handling

This patch splits out handling of helpers into its own file
nf_conntrack_helper.c

Signed-off-by: Martin Josefsson <gandalf@wlug.westbo.se>
Signed-off-by: Patrick McHardy <kaber@trash.net>

[NETFILTER]: nf_conntrack: split out expectation handling

This patch splits out expectation handling into its own file
nf_conntrack_expect.c

Signed-off-by: Martin Josefsson <gandalf@wlug.westbo.se>
Signed-off-by: Patrick McHardy <kaber@trash.net>

[NETFILTER]: Add ctnetlink port for nf_conntrack

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

[NETFILTER]: Add nf_conntrack subsystem.

The existing connection tracking subsystem in netfilter can only
handle ipv4. There were basically two choices present to add
connection tracking support for ipv6. We could either duplicate all
of the ipv4 connection tracking code into an ipv6 counterpart, or (the
choice taken by these patches) we could design a generic layer that
could handle both ipv4 and ipv6 and thus requiring only one sub-protocol
(TCP, UDP, etc.) connection tracking helper module to be written.

In fact nf_conntrack is capable of working with any layer 3
protocol.

The existing ipv4 specific conntrack code could also not deal
with the pecularities of doing connection tracking on ipv6,
which is also cured here. For example, these issues include:

1) ICMPv6 handling, which is used for neighbour discovery in
ipv6 thus some messages such as these should not participate
in connection tracking since effectively they are like ARP
messages

2) fragmentation must be handled differently in ipv6, because
the simplistic "defrag, connection track and NAT, refrag"
(which the existing ipv4 connection tracking does) approach simply
isn't feasible in ipv6

3) ipv6 extension header parsing must occur at the correct spots
before and after connection tracking decisions, and there were
no provisions for this in the existing connection tracking
design

4) ipv6 has no need for stateful NAT

The ipv4 specific conntrack layer is kept around, until all of
the ipv4 specific conntrack helpers are ported over to nf_conntrack
and it is feature complete. Once that occurs, the old conntrack
stuff will get placed into the feature-removal-schedule and we will
fully kill it off 6 months later.

Signed-off-by: Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>