This is possible now that the xt_table structure is passed in via *priv.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
For historical reasons x_tables still register tables by default in the
initial namespace.
Only newly created net namespaces add the hook on demand.
This means that the init_net always pays hook cost, even if no filtering
rules are added (e.g. only used inside a single netns).
Note that the hooks are added even when 'iptables -L' is called.
This is because there is no way to tell 'iptables -A' and 'iptables -L'
apart at kernel level.
The only solution would be to register the table, but delay hook
registration until the first rule gets added (or policy gets changed).
That however means that counters are not hooked either, so 'iptables -L'
would always show 0-counters even when traffic is flowing which might be
unexpected.
This keeps table and hook registration consistent with what is already done
in non-init netns: first iptables(-save) invocation registers both table
and hooks.
This applies the same solution adopted for ebtables.
All tables register a template that contains the l3 family, the name
and a constructor function that is called when the initial table has to
be added.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
iptable_x modules rely on 'struct net' to contain a pointer to the
table that should be evaluated.
In order to remove these pointers from struct net, pass them via
the 'priv' pointer in a similar fashion as nf_tables passes the
rule data.
To do that, duplicate the nf_hook_info array passed in from the
iptable_x modules, update the ops->priv pointers of the copy to
refer to the table and then change the hookfn implementations to
just pass the 'priv' argument to the traverser.
After this patch, the xt_table pointers can already be removed
from struct net.
However, changes to struct net result in re-compile of the entire
network stack, so do the removal after arptables and ip6tables
have been converted as well.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
No need for these.
There is only one caller, the xtables core, when the table is registered
for the first time with a particular network namespace.
After ->table_init() call, the table is linked into the tables[af] list,
so next call to that function will skip the ->table_init().
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
xtables stores the xt_table structs in the struct net. This isn't
needed anymore, the structures could be passed via the netfilter hook
'private' pointer to the hook functions, which would allow us to remove
those pointers from struct net.
As a first step, reduce the number of accesses to the
net->ipv4.ip6table_{raw,filter,...} pointers.
This allows the tables to get unregistered by name instead of having to
pass the raw address.
The xt_table structure cane looked up by name+address family instead.
This patch is useless as-is (the backends still have the raw pointer
address), but it lowers the bar to remove those.
It also allows to put the 'was table registered in the first place' check
into ip_tables.c rather than have it in each table sub module.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Using new helpers ipt_unregister_table_pre_exit() and
ipt_unregister_table_exit().
Fixes: b9e69e1273 ("netfilter: xtables: don't hook tables by default")
Signed-off-by: David Wilder <dwilder@us.ibm.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Based on 2 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 4122 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Users cannot forge malformed IPv4/IPv6 headers via raw sockets that they
can inject into the stack. Specifically, not for IPv4 since 55888dfb6b
("AF_RAW: Augment raw_send_hdrinc to expand skb to fit iphdr->ihl
(v2)"). IPv6 raw sockets also ensure that packets have a well-formed
IPv6 header available in the skbuff.
At quick glance, br_netfilter also validates layer 3 headers and it
drops malformed both IPv4 and IPv6 packets.
Therefore, let's remove this defensive check all over the place.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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>
This change prepares for upcoming on-demand xtables hook registration.
We change the protoypes of the register/unregister functions.
A followup patch will then add nf_hook_register/unregister calls
to the iptables one.
Once a hook is registered packets will be picked up, so all assignments
of the form
net->ipv4.iptable_$table = new_table
have to be moved to ip(6)t_register_table, else we can see NULL
net->ipv4.iptable_$table later.
This patch doesn't change functionality; without this the actual change
simply gets too big.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Use tabs instead of spaces to indent code.
No changes detected by objdiff.
Signed-off-by: Ian Morris <ipm@chirality.org.uk>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Only pass the void *priv parameter out of the nf_hook_ops. That is
all any of the functions are interested now, and by limiting what is
passed it becomes simpler to change implementation details.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The values of ops->hooknum and state->hook are guaraneted to be equal
making the hook argument to ip6t_do_table, arp_do_table, and
ipt_do_table is unnecessary. Remove the unnecessary hook argument.
In the callers use state->hook instead of ops->hooknum for clarity and
to reduce the number of cachelines the callers touch.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Instead of saying "net = dev_net(state->in?state->in:state->out)"
just say "state->net". As that information is now availabe,
much less confusing and much less error prone.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pass the hook ops to the hookfn to allow for generic hook
functions. This change is required by nf_tables.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This quiets the coccinelle warnings:
net/bridge/netfilter/ebtable_filter.c:107:1-3: WARNING: PTR_RET can be used
net/bridge/netfilter/ebtable_nat.c:107:1-3: WARNING: PTR_RET can be used
net/ipv6/netfilter/ip6table_filter.c:65:1-3: WARNING: PTR_RET can be used
net/ipv6/netfilter/ip6table_mangle.c💯1-3: WARNING: PTR_RET can be used
net/ipv6/netfilter/ip6table_raw.c:44:1-3: WARNING: PTR_RET can be used
net/ipv6/netfilter/ip6table_security.c:62:1-3: WARNING: PTR_RET can be used
net/ipv4/netfilter/iptable_filter.c:72:1-3: WARNING: PTR_RET can be used
net/ipv4/netfilter/iptable_mangle.c:107:1-3: WARNING: PTR_RET can be used
net/ipv4/netfilter/iptable_raw.c:51:1-3: WARNING: PTR_RET can be used
net/ipv4/netfilter/iptable_security.c:70:1-3: WARNING: PTR_RET can be used
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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>
The static initial tables are pretty large, and after the net
namespace has been instantiated, they just hang around for nothing.
This commit removes them and creates tables on-demand at runtime when
needed.
Size shrinks by 7735 bytes (x86_64).
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
The respective xt_table structures already have most of the metadata
needed for hook setup. Add a 'priority' field to struct xt_table so
that xt_hook_link() can be called with a reduced number of arguments.
So should we be having more tables in the future, it comes at no
static cost (only runtime, as before) - space saved:
6807373->6806555.
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
The calls to ip6t_do_table only show minimal differences, so it seems
like a good cleanup to merge them to a single one too.
Space saving obtained by both patches: 6807725->6807373
("Total" column from `size -A`.)
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
This patch combines all the per-hook functions in a given table into
a single function. Together with the 2nd patch, further
simplifications are possible up to the point of output code reduction.
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Add ->net to match destructor list like ->net in constructor list.
Make sure it's set in ebtables/iptables/ip6tables, this requires to
propagate netns up to *_unregister_table().
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
The inputted table is never modified, so should be considered const.
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Later patches change the locking on xt_table and the initialization of
the lock element is not needed since the lock is always initialized in
xt_table_register anyway.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Don't spam logs for locally generated short packets. these can only
be generated by root.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Now that dev_net() exists, the usefullness of them is even less. Also they're
a big problem in resolving circular header dependencies necessary for
NOTRACK-in-netns patch. See below.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Currently not visible, because NET_NS is mutually exclusive with SYSFS
which is required by SECURITY.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
The following patch implements a new "security" table for iptables, so
that MAC (SELinux etc.) networking rules can be managed separately to
standard DAC rules.
This is to help with distro integration of the new secmark-based
network controls, per various previous discussions.
The need for a separate table arises from the fact that existing tools
and usage of iptables will likely clash with centralized MAC policy
management.
The SECMARK and CONNSECMARK targets will still be valid in the mangle
table to prevent breakage of existing users.
Signed-off-by: James Morris <jmorris@namei.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
