2005-04-16 22:20:36 +00:00
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/*
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* This is the 1999 rewrite of IP Firewalling, aiming for kernel 2.3.x.
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*
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* Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
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* Copyright (C) 2000-2004 Netfilter Core Team <coreteam@netfilter.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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*/
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/netfilter_ipv4/ip_tables.h>
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include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 08:04:11 +00:00
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#include <linux/slab.h>
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2007-03-12 23:09:15 +00:00
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#include <net/ip.h>
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2005-04-16 22:20:36 +00:00
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
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MODULE_DESCRIPTION("iptables filter table");
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2007-11-20 02:53:30 +00:00
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#define FILTER_VALID_HOOKS ((1 << NF_INET_LOCAL_IN) | \
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(1 << NF_INET_FORWARD) | \
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(1 << NF_INET_LOCAL_OUT))
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netfilter: xtables: don't hook tables by default
delay hook registration until the table is being requested inside a
namespace.
Historically, a particular table (iptables mangle, ip6tables filter, etc)
was registered on module load.
When netns support was added to iptables only the ip/ip6tables ruleset was
made namespace aware, not the actual hook points.
This means f.e. that when ipt_filter table/module is loaded on a system,
then each namespace on that system has an (empty) iptables filter ruleset.
In other words, if a namespace sends a packet, such skb is 'caught' by
netfilter machinery and fed to hooking points for that table (i.e. INPUT,
FORWARD, etc).
Thanks to Eric Biederman, hooks are no longer global, but per namespace.
This means that we can avoid allocation of empty ruleset in a namespace and
defer hook registration until we need the functionality.
We register a tables hook entry points ONLY in the initial namespace.
When an iptables get/setockopt is issued inside a given namespace, we check
if the table is found in the per-namespace list.
If not, we attempt to find it in the initial namespace, and, if found,
create an empty default table in the requesting namespace and register the
needed hooks.
Hook points are destroyed only once namespace is deleted, there is no
'usage count' (it makes no sense since there is no 'remove table' operation
in xtables api).
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-02-25 09:08:36 +00:00
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static int __net_init iptable_filter_table_init(struct net *net);
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2005-04-16 22:20:36 +00:00
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2009-08-24 12:56:30 +00:00
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static const struct xt_table packet_filter = {
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2005-04-16 22:20:36 +00:00
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.name = "filter",
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.valid_hooks = FILTER_VALID_HOOKS,
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[NETFILTER] x_tables: Abstraction layer for {ip,ip6,arp}_tables
This monster-patch tries to do the best job for unifying the data
structures and backend interfaces for the three evil clones ip_tables,
ip6_tables and arp_tables. In an ideal world we would never have
allowed this kind of copy+paste programming... but well, our world
isn't (yet?) ideal.
o introduce a new x_tables module
o {ip,arp,ip6}_tables depend on this x_tables module
o registration functions for tables, matches and targets are only
wrappers around x_tables provided functions
o all matches/targets that are used from ip_tables and ip6_tables
are now implemented as xt_FOOBAR.c files and provide module aliases
to ipt_FOOBAR and ip6t_FOOBAR
o header files for xt_matches are in include/linux/netfilter/,
include/linux/netfilter_{ipv4,ipv6} contains compatibility wrappers
around the xt_FOOBAR.h headers
Based on this patchset we're going to further unify the code,
gradually getting rid of all the layer 3 specific assumptions.
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-01-12 21:30:04 +00:00
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.me = THIS_MODULE,
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2009-06-13 04:25:44 +00:00
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.af = NFPROTO_IPV4,
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2009-06-17 11:57:48 +00:00
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.priority = NF_IP_PRI_FILTER,
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netfilter: xtables: don't hook tables by default
delay hook registration until the table is being requested inside a
namespace.
Historically, a particular table (iptables mangle, ip6tables filter, etc)
was registered on module load.
When netns support was added to iptables only the ip/ip6tables ruleset was
made namespace aware, not the actual hook points.
This means f.e. that when ipt_filter table/module is loaded on a system,
then each namespace on that system has an (empty) iptables filter ruleset.
In other words, if a namespace sends a packet, such skb is 'caught' by
netfilter machinery and fed to hooking points for that table (i.e. INPUT,
FORWARD, etc).
Thanks to Eric Biederman, hooks are no longer global, but per namespace.
This means that we can avoid allocation of empty ruleset in a namespace and
defer hook registration until we need the functionality.
We register a tables hook entry points ONLY in the initial namespace.
When an iptables get/setockopt is issued inside a given namespace, we check
if the table is found in the per-namespace list.
If not, we attempt to find it in the initial namespace, and, if found,
create an empty default table in the requesting namespace and register the
needed hooks.
Hook points are destroyed only once namespace is deleted, there is no
'usage count' (it makes no sense since there is no 'remove table' operation
in xtables api).
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-02-25 09:08:36 +00:00
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.table_init = iptable_filter_table_init,
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2005-04-16 22:20:36 +00:00
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};
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[NETFILTER]: ip_tables: per-netns FILTER/MANGLE/RAW tables for real
Commit 9335f047fe61587ec82ff12fbb1220bcfdd32006 aka
"[NETFILTER]: ip_tables: per-netns FILTER, MANGLE, RAW"
added per-netns _view_ of iptables rules. They were shown to user, but
ignored by filtering code. Now that it's possible to at least ping loopback,
per-netns tables can affect filtering decisions.
netns is taken in case of
PRE_ROUTING, LOCAL_IN -- from in device,
POST_ROUTING, LOCAL_OUT -- from out device,
FORWARD -- from in device which should be equal to out device's netns.
This code is relatively new, so BUG_ON was plugged.
Wrappers were added to a) keep code the same from CONFIG_NET_NS=n users
(overwhelming majority), b) consolidate code in one place -- similar
changes will be done in ipv6 and arp netfilter code.
Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2008-04-14 07:56:02 +00:00
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static unsigned int
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2015-09-18 19:33:06 +00:00
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iptable_filter_hook(void *priv, struct sk_buff *skb,
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2015-04-04 00:32:56 +00:00
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const struct nf_hook_state *state)
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[NETFILTER]: ip_tables: per-netns FILTER/MANGLE/RAW tables for real
Commit 9335f047fe61587ec82ff12fbb1220bcfdd32006 aka
"[NETFILTER]: ip_tables: per-netns FILTER, MANGLE, RAW"
added per-netns _view_ of iptables rules. They were shown to user, but
ignored by filtering code. Now that it's possible to at least ping loopback,
per-netns tables can affect filtering decisions.
netns is taken in case of
PRE_ROUTING, LOCAL_IN -- from in device,
POST_ROUTING, LOCAL_OUT -- from out device,
FORWARD -- from in device which should be equal to out device's netns.
This code is relatively new, so BUG_ON was plugged.
Wrappers were added to a) keep code the same from CONFIG_NET_NS=n users
(overwhelming majority), b) consolidate code in one place -- similar
changes will be done in ipv6 and arp netfilter code.
Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2008-04-14 07:56:02 +00:00
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{
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2015-09-18 19:32:55 +00:00
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if (state->hook == NF_INET_LOCAL_OUT &&
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2009-06-13 04:57:10 +00:00
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(skb->len < sizeof(struct iphdr) ||
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ip_hdrlen(skb) < sizeof(struct iphdr)))
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/* root is playing with raw sockets. */
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return NF_ACCEPT;
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2005-04-16 22:20:36 +00:00
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2015-09-18 19:32:55 +00:00
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return ipt_do_table(skb, state, state->net->ipv4.iptable_filter);
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2005-04-16 22:20:36 +00:00
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}
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2009-06-17 11:57:48 +00:00
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static struct nf_hook_ops *filter_ops __read_mostly;
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2005-04-16 22:20:36 +00:00
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/* Default to forward because I got too much mail already. */
|
netfilter: xtables: don't hook tables by default
delay hook registration until the table is being requested inside a
namespace.
Historically, a particular table (iptables mangle, ip6tables filter, etc)
was registered on module load.
When netns support was added to iptables only the ip/ip6tables ruleset was
made namespace aware, not the actual hook points.
This means f.e. that when ipt_filter table/module is loaded on a system,
then each namespace on that system has an (empty) iptables filter ruleset.
In other words, if a namespace sends a packet, such skb is 'caught' by
netfilter machinery and fed to hooking points for that table (i.e. INPUT,
FORWARD, etc).
Thanks to Eric Biederman, hooks are no longer global, but per namespace.
This means that we can avoid allocation of empty ruleset in a namespace and
defer hook registration until we need the functionality.
We register a tables hook entry points ONLY in the initial namespace.
When an iptables get/setockopt is issued inside a given namespace, we check
if the table is found in the per-namespace list.
If not, we attempt to find it in the initial namespace, and, if found,
create an empty default table in the requesting namespace and register the
needed hooks.
Hook points are destroyed only once namespace is deleted, there is no
'usage count' (it makes no sense since there is no 'remove table' operation
in xtables api).
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-02-25 09:08:36 +00:00
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static bool forward __read_mostly = true;
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2005-04-16 22:20:36 +00:00
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module_param(forward, bool, 0000);
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netfilter: xtables: don't hook tables by default
delay hook registration until the table is being requested inside a
namespace.
Historically, a particular table (iptables mangle, ip6tables filter, etc)
was registered on module load.
When netns support was added to iptables only the ip/ip6tables ruleset was
made namespace aware, not the actual hook points.
This means f.e. that when ipt_filter table/module is loaded on a system,
then each namespace on that system has an (empty) iptables filter ruleset.
In other words, if a namespace sends a packet, such skb is 'caught' by
netfilter machinery and fed to hooking points for that table (i.e. INPUT,
FORWARD, etc).
Thanks to Eric Biederman, hooks are no longer global, but per namespace.
This means that we can avoid allocation of empty ruleset in a namespace and
defer hook registration until we need the functionality.
We register a tables hook entry points ONLY in the initial namespace.
When an iptables get/setockopt is issued inside a given namespace, we check
if the table is found in the per-namespace list.
If not, we attempt to find it in the initial namespace, and, if found,
create an empty default table in the requesting namespace and register the
needed hooks.
Hook points are destroyed only once namespace is deleted, there is no
'usage count' (it makes no sense since there is no 'remove table' operation
in xtables api).
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-02-25 09:08:36 +00:00
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static int __net_init iptable_filter_table_init(struct net *net)
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2008-01-31 12:03:23 +00:00
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{
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2009-06-17 20:14:54 +00:00
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struct ipt_replace *repl;
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2016-02-25 09:08:35 +00:00
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int err;
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2009-06-17 20:14:54 +00:00
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|
netfilter: xtables: don't hook tables by default
delay hook registration until the table is being requested inside a
namespace.
Historically, a particular table (iptables mangle, ip6tables filter, etc)
was registered on module load.
When netns support was added to iptables only the ip/ip6tables ruleset was
made namespace aware, not the actual hook points.
This means f.e. that when ipt_filter table/module is loaded on a system,
then each namespace on that system has an (empty) iptables filter ruleset.
In other words, if a namespace sends a packet, such skb is 'caught' by
netfilter machinery and fed to hooking points for that table (i.e. INPUT,
FORWARD, etc).
Thanks to Eric Biederman, hooks are no longer global, but per namespace.
This means that we can avoid allocation of empty ruleset in a namespace and
defer hook registration until we need the functionality.
We register a tables hook entry points ONLY in the initial namespace.
When an iptables get/setockopt is issued inside a given namespace, we check
if the table is found in the per-namespace list.
If not, we attempt to find it in the initial namespace, and, if found,
create an empty default table in the requesting namespace and register the
needed hooks.
Hook points are destroyed only once namespace is deleted, there is no
'usage count' (it makes no sense since there is no 'remove table' operation
in xtables api).
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-02-25 09:08:36 +00:00
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if (net->ipv4.iptable_filter)
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return 0;
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2009-06-17 20:14:54 +00:00
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repl = ipt_alloc_initial_table(&packet_filter);
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if (repl == NULL)
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return -ENOMEM;
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/* Entry 1 is the FORWARD hook */
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((struct ipt_standard *)repl->entries)[1].target.verdict =
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2012-03-22 12:27:06 +00:00
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forward ? -NF_ACCEPT - 1 : -NF_DROP - 1;
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2009-06-17 20:14:54 +00:00
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2016-02-25 09:08:35 +00:00
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err = ipt_register_table(net, &packet_filter, repl, filter_ops,
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&net->ipv4.iptable_filter);
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2009-06-17 20:14:54 +00:00
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kfree(repl);
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2016-02-25 09:08:35 +00:00
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return err;
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2008-01-31 12:03:23 +00:00
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}
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|
netfilter: xtables: don't hook tables by default
delay hook registration until the table is being requested inside a
namespace.
Historically, a particular table (iptables mangle, ip6tables filter, etc)
was registered on module load.
When netns support was added to iptables only the ip/ip6tables ruleset was
made namespace aware, not the actual hook points.
This means f.e. that when ipt_filter table/module is loaded on a system,
then each namespace on that system has an (empty) iptables filter ruleset.
In other words, if a namespace sends a packet, such skb is 'caught' by
netfilter machinery and fed to hooking points for that table (i.e. INPUT,
FORWARD, etc).
Thanks to Eric Biederman, hooks are no longer global, but per namespace.
This means that we can avoid allocation of empty ruleset in a namespace and
defer hook registration until we need the functionality.
We register a tables hook entry points ONLY in the initial namespace.
When an iptables get/setockopt is issued inside a given namespace, we check
if the table is found in the per-namespace list.
If not, we attempt to find it in the initial namespace, and, if found,
create an empty default table in the requesting namespace and register the
needed hooks.
Hook points are destroyed only once namespace is deleted, there is no
'usage count' (it makes no sense since there is no 'remove table' operation
in xtables api).
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-02-25 09:08:36 +00:00
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static int __net_init iptable_filter_net_init(struct net *net)
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{
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if (net == &init_net || !forward)
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return iptable_filter_table_init(net);
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return 0;
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}
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2008-01-31 12:03:23 +00:00
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static void __net_exit iptable_filter_net_exit(struct net *net)
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{
|
netfilter: xtables: don't hook tables by default
delay hook registration until the table is being requested inside a
namespace.
Historically, a particular table (iptables mangle, ip6tables filter, etc)
was registered on module load.
When netns support was added to iptables only the ip/ip6tables ruleset was
made namespace aware, not the actual hook points.
This means f.e. that when ipt_filter table/module is loaded on a system,
then each namespace on that system has an (empty) iptables filter ruleset.
In other words, if a namespace sends a packet, such skb is 'caught' by
netfilter machinery and fed to hooking points for that table (i.e. INPUT,
FORWARD, etc).
Thanks to Eric Biederman, hooks are no longer global, but per namespace.
This means that we can avoid allocation of empty ruleset in a namespace and
defer hook registration until we need the functionality.
We register a tables hook entry points ONLY in the initial namespace.
When an iptables get/setockopt is issued inside a given namespace, we check
if the table is found in the per-namespace list.
If not, we attempt to find it in the initial namespace, and, if found,
create an empty default table in the requesting namespace and register the
needed hooks.
Hook points are destroyed only once namespace is deleted, there is no
'usage count' (it makes no sense since there is no 'remove table' operation
in xtables api).
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-02-25 09:08:36 +00:00
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if (!net->ipv4.iptable_filter)
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return;
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2016-02-25 09:08:35 +00:00
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ipt_unregister_table(net, net->ipv4.iptable_filter, filter_ops);
|
netfilter: xtables: don't hook tables by default
delay hook registration until the table is being requested inside a
namespace.
Historically, a particular table (iptables mangle, ip6tables filter, etc)
was registered on module load.
When netns support was added to iptables only the ip/ip6tables ruleset was
made namespace aware, not the actual hook points.
This means f.e. that when ipt_filter table/module is loaded on a system,
then each namespace on that system has an (empty) iptables filter ruleset.
In other words, if a namespace sends a packet, such skb is 'caught' by
netfilter machinery and fed to hooking points for that table (i.e. INPUT,
FORWARD, etc).
Thanks to Eric Biederman, hooks are no longer global, but per namespace.
This means that we can avoid allocation of empty ruleset in a namespace and
defer hook registration until we need the functionality.
We register a tables hook entry points ONLY in the initial namespace.
When an iptables get/setockopt is issued inside a given namespace, we check
if the table is found in the per-namespace list.
If not, we attempt to find it in the initial namespace, and, if found,
create an empty default table in the requesting namespace and register the
needed hooks.
Hook points are destroyed only once namespace is deleted, there is no
'usage count' (it makes no sense since there is no 'remove table' operation
in xtables api).
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-02-25 09:08:36 +00:00
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net->ipv4.iptable_filter = NULL;
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2008-01-31 12:03:23 +00:00
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}
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static struct pernet_operations iptable_filter_net_ops = {
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|
|
.init = iptable_filter_net_init,
|
|
|
|
.exit = iptable_filter_net_exit,
|
|
|
|
};
|
|
|
|
|
2006-03-29 00:37:06 +00:00
|
|
|
static int __init iptable_filter_init(void)
|
2005-04-16 22:20:36 +00:00
|
|
|
{
|
|
|
|
int ret;
|
|
|
|
|
netfilter: xtables: don't hook tables by default
delay hook registration until the table is being requested inside a
namespace.
Historically, a particular table (iptables mangle, ip6tables filter, etc)
was registered on module load.
When netns support was added to iptables only the ip/ip6tables ruleset was
made namespace aware, not the actual hook points.
This means f.e. that when ipt_filter table/module is loaded on a system,
then each namespace on that system has an (empty) iptables filter ruleset.
In other words, if a namespace sends a packet, such skb is 'caught' by
netfilter machinery and fed to hooking points for that table (i.e. INPUT,
FORWARD, etc).
Thanks to Eric Biederman, hooks are no longer global, but per namespace.
This means that we can avoid allocation of empty ruleset in a namespace and
defer hook registration until we need the functionality.
We register a tables hook entry points ONLY in the initial namespace.
When an iptables get/setockopt is issued inside a given namespace, we check
if the table is found in the per-namespace list.
If not, we attempt to find it in the initial namespace, and, if found,
create an empty default table in the requesting namespace and register the
needed hooks.
Hook points are destroyed only once namespace is deleted, there is no
'usage count' (it makes no sense since there is no 'remove table' operation
in xtables api).
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-02-25 09:08:36 +00:00
|
|
|
filter_ops = xt_hook_ops_alloc(&packet_filter, iptable_filter_hook);
|
|
|
|
if (IS_ERR(filter_ops))
|
|
|
|
return PTR_ERR(filter_ops);
|
|
|
|
|
2008-01-31 12:03:23 +00:00
|
|
|
ret = register_pernet_subsys(&iptable_filter_net_ops);
|
|
|
|
if (ret < 0)
|
netfilter: xtables: don't hook tables by default
delay hook registration until the table is being requested inside a
namespace.
Historically, a particular table (iptables mangle, ip6tables filter, etc)
was registered on module load.
When netns support was added to iptables only the ip/ip6tables ruleset was
made namespace aware, not the actual hook points.
This means f.e. that when ipt_filter table/module is loaded on a system,
then each namespace on that system has an (empty) iptables filter ruleset.
In other words, if a namespace sends a packet, such skb is 'caught' by
netfilter machinery and fed to hooking points for that table (i.e. INPUT,
FORWARD, etc).
Thanks to Eric Biederman, hooks are no longer global, but per namespace.
This means that we can avoid allocation of empty ruleset in a namespace and
defer hook registration until we need the functionality.
We register a tables hook entry points ONLY in the initial namespace.
When an iptables get/setockopt is issued inside a given namespace, we check
if the table is found in the per-namespace list.
If not, we attempt to find it in the initial namespace, and, if found,
create an empty default table in the requesting namespace and register the
needed hooks.
Hook points are destroyed only once namespace is deleted, there is no
'usage count' (it makes no sense since there is no 'remove table' operation
in xtables api).
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-02-25 09:08:36 +00:00
|
|
|
kfree(filter_ops);
|
2005-04-16 22:20:36 +00:00
|
|
|
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
2006-03-29 00:37:06 +00:00
|
|
|
static void __exit iptable_filter_fini(void)
|
2005-04-16 22:20:36 +00:00
|
|
|
{
|
2008-01-31 12:03:23 +00:00
|
|
|
unregister_pernet_subsys(&iptable_filter_net_ops);
|
netfilter: xtables: don't hook tables by default
delay hook registration until the table is being requested inside a
namespace.
Historically, a particular table (iptables mangle, ip6tables filter, etc)
was registered on module load.
When netns support was added to iptables only the ip/ip6tables ruleset was
made namespace aware, not the actual hook points.
This means f.e. that when ipt_filter table/module is loaded on a system,
then each namespace on that system has an (empty) iptables filter ruleset.
In other words, if a namespace sends a packet, such skb is 'caught' by
netfilter machinery and fed to hooking points for that table (i.e. INPUT,
FORWARD, etc).
Thanks to Eric Biederman, hooks are no longer global, but per namespace.
This means that we can avoid allocation of empty ruleset in a namespace and
defer hook registration until we need the functionality.
We register a tables hook entry points ONLY in the initial namespace.
When an iptables get/setockopt is issued inside a given namespace, we check
if the table is found in the per-namespace list.
If not, we attempt to find it in the initial namespace, and, if found,
create an empty default table in the requesting namespace and register the
needed hooks.
Hook points are destroyed only once namespace is deleted, there is no
'usage count' (it makes no sense since there is no 'remove table' operation
in xtables api).
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-02-25 09:08:36 +00:00
|
|
|
kfree(filter_ops);
|
2005-04-16 22:20:36 +00:00
|
|
|
}
|
|
|
|
|
2006-03-29 00:37:06 +00:00
|
|
|
module_init(iptable_filter_init);
|
|
|
|
module_exit(iptable_filter_fini);
|