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2021-10-14netfilter: iptables: allow use of ipt_do_table as hookfnFlorian Westphal1-8/+1
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>
2021-08-09netfilter: x_tables: never register tables by defaultFlorian Westphal1-12/+11
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>
2021-04-26netfilter: ip_tables: pass table pointer via nf_hook_opsFlorian Westphal1-5/+3
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>
2021-04-26netfilter: x_tables: remove paranoia testsFlorian Westphal1-3/+0
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>
2021-04-26netfilter: iptables: unregister the tables by nameFlorian Westphal1-6/+2
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>
2020-06-25netfilter: iptables: Add a .pre_exit hook in all iptable_foo.c.David Wilder1-2/+9
Using new helpers ipt_unregister_table_pre_exit() and ipt_unregister_table_exit(). Fixes: b9e69e127397 ("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>
2019-06-19treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500Thomas Gleixner1-4/+1
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>
2018-01-08netfilter: remove defensive check on malformed packets from raw socketsPablo Neira Ayuso1-6/+0
Users cannot forge malformed IPv4/IPv6 headers via raw sockets that they can inject into the stack. Specifically, not for IPv4 since 55888dfb6ba7 ("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>
2016-03-02netfilter: xtables: don't hook tables by defaultFlorian Westphal1-12/+23
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>
2016-03-02netfilter: xtables: prepare for on-demand hook registerFlorian Westphal1-4/+5
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>
2015-10-16netfilter: ipv4: code indentationIan Morris1-1/+1
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>
2015-09-18netfilter: Pass priv instead of nf_hook_ops to netfilter hooksEric W. Biederman1-1/+1
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>
2015-09-18inet netfilter: Remove hook from ip6t_do_table, arp_do_table, ipt_do_tableEric W. Biederman1-3/+2
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>
2015-09-17netfilter: Use nf_hook_state.netEric W. Biederman1-4/+1
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>
2015-04-04netfilter: Pass nf_hook_state through ipt_do_table().David S. Miller1-1/+1
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-04netfilter: Make nf_hookfn use nf_hook_state.David S. Miller1-5/+3
Pass the nf_hook_state all the way down into the hook functions themselves. Signed-off-by: David S. Miller <davem@davemloft.net>
2013-10-14netfilter: pass hook ops to hookfnPatrick McHardy1-3/+4
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>
2013-07-15PTR_RET is now PTR_ERR_OR_ZERO(): Replace most.Rusty Russell1-1/+1
Sweep of the simple cases. Cc: netdev@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-arm-kernel@lists.infradead.org Cc: Julia Lawall <julia.lawall@lip6.fr> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-08-14netfilter: PTR_RET can be usedWu Fengguang1-4/+1
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:100:1-3: 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>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo1-0/+1
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>
2010-02-10netfilter: xtables: generate initial table on-demandJan Engelhardt1-32/+7
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>
2010-02-10netfilter: xtables: use xt_table for hook instantiationJan Engelhardt1-26/+7
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>
2010-02-10netfilter: xtables: compact table hook functions (2/2)Jan Engelhardt1-13/+10
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>
2010-02-10netfilter: xtables: compact table hook functions (1/2)Jan Engelhardt1-33/+17
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>
2010-01-18netfilter: xtables: add struct xt_mtdtor_param::netAlexey Dobriyan1-1/+1
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>
2009-11-23netfilter: net/ipv[46]/netfilter: Move && and || to end of previous lineJoe Perches1-2/+2
Compile tested only. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Patrick McHardy <kaber@trash.net>
2009-08-24netfilter: xtables: mark initial tables constantJan Engelhardt1-2/+2
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>
2009-08-10netfilter: xtables: switch table AFs to nfprotoJan Engelhardt1-1/+1
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
2009-08-10netfilter: xtables: switch hook PFs to nfprotoJan Engelhardt1-3/+3
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
2009-02-18netfilter: x_tables: remove unneeded initializationsStephen Hemminger1-1/+0
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>
2009-01-12netfilter 01/09: remove "happy cracking" messagePatrick McHardy1-5/+1
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>
2008-10-08netfilter: netns: remove nf_*_net() wrappersAlexey Dobriyan1-3/+3
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>
2008-07-26netfilter: ip{,6}tables_security: fix future section mismatchAlexey Dobriyan1-1/+1
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>
2008-06-09netfilter: ip_tables: add iptables security table for mandatory access ↵James Morris1-0/+180
control rules 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>