Commit Graph

12 Commits

Author SHA1 Message Date
Phil Sutter 7d34aa3e03 netfilter: nf_tables: Extend nft_expr_ops::dump callback parameters
Add a 'reset' flag just like with nft_object_ops::dump. This will be
useful to reset "anonymous stateful objects", e.g. simple rule counters.

No functional change intended.

Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2022-11-15 10:46:34 +01:00
Pablo Neira Ayuso be8be04e5d netfilter: nft_fib: reverse path filter for policy-based routing on iif
If policy-based routing using the iif selector is used, then the fib
expression fails to look up for the reverse path from the prerouting
hook because the input interface cannot be inferred. In order to support
this scenario, extend the fib expression to allow to use after the route
lookup, from the forward hook.

This patch also adds support for the input hook for usability reasons.
Since the prerouting hook cannot be used for the scenario described
above, users need two rules: one for the forward chain and another rule
for the input chain to check for the reverse path check for locally
targeted traffic.

Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2022-04-11 12:10:09 +02:00
Florian Westphal 3c1eb413a4 netfilter: nft_fib: add reduce support
The fib expression stores to a register, so we can't add empty stub.
Check that the register that is being written is in fact redundant.

In most cases, this is expected to cancel tracking as re-use is
unlikely.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2022-03-20 00:29:47 +01:00
Pablo Neira Ayuso 345023b0db netfilter: nftables: add nft_parse_register_store() and use it
This new function combines the netlink register attribute parser
and the store validation function.

This update requires to replace:

        enum nft_registers      dreg:8;

in many of the expression private areas otherwise compiler complains
with:

        error: cannot take address of bit-field ‘dreg’

when passing the register field as reference.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-01-27 23:16:02 +01:00
Gustavo A. R. Silva 954d82979b netfilter: Use fallthrough pseudo-keyword
Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-07-22 01:18:05 +02:00
Thomas Gleixner d2912cb15b treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500
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>
2019-06-19 17:09:55 +02:00
Phil Sutter e633508a95 netfilter: nft_fib: Fix existence check support
NFTA_FIB_F_PRESENT flag was not always honored since eval functions did
not call nft_fib_store_result in all cases.

Given that in all callsites there is a struct net_device pointer
available which holds the interface data to be stored in destination
register, simplify nft_fib_store_result() to just accept that pointer
instead of the nft_pktinfo pointer and interface index. This also
allows to drop the index to interface lookup previously needed to get
the name associated with given index.

Fixes: 055c4b34b9 ("netfilter: nft_fib: Support existence check")
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-05-21 16:10:38 +02:00
Phil Sutter 055c4b34b9 netfilter: nft_fib: Support existence check
Instead of the actual interface index or name, set destination register
to just 1 or 0 depending on whether the lookup succeeded or not if
NFTA_FIB_F_PRESENT was set in userspace.

Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-03-13 13:45:36 +01:00
Liping Zhang c56e3956c1 netfilter: nf_tables: validate the expr explicitly after init successfully
When we want to validate the expr's dependency or hooks, we must do two
things to accomplish it. First, write a X_validate callback function
and point ->validate to it. Second, call X_validate in init routine.
This is very common, such as fib, nat, reject expr and so on ...

It is a little ugly, since we will call X_validate in the expr's init
routine, it's better to do it in nf_tables_newexpr. So we can avoid to
do this again and again. After doing this, the second step listed above
is not useful anymore, remove them now.

Patch was tested by nftables/tests/py/nft-test.py and
nftables/tests/shell/run-tests.sh.

Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-03-06 18:22:12 +01:00
Liping Zhang 11583438b7 netfilter: nft_fib: convert htonl to ntohl properly
Acctually ntohl and htonl are identical, so this doesn't affect
anything, but it is conceptually wrong.

Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-12-06 21:42:20 +01:00
Pablo Neira Ayuso 0e5a1c7eb3 netfilter: nf_tables: use hook state from xt_action_param structure
Don't copy relevant fields from hook state structure, instead use the
one that is already available in struct xt_action_param.

This patch also adds a set of new wrapper functions to fetch relevant
hook state structure fields.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-11-03 11:52:34 +01:00
Florian Westphal f6d0cbcf09 netfilter: nf_tables: add fib expression
Add FIB expression, supported for ipv4, ipv6 and inet family (the latter
just dispatches to ipv4 or ipv6 one based on nfproto).

Currently supports fetching output interface index/name and the
rtm_type associated with an address.

This can be used for adding path filtering. rtm_type is useful
to e.g. enforce a strong-end host model where packets
are only accepted if daddr is configured on the interface the
packet arrived on.

The fib expression is a native nftables alternative to the
xtables addrtype and rp_filter matches.

FIB result order for oif/oifname retrieval is as follows:
 - if packet is local (skb has rtable, RTF_LOCAL set, this
   will also catch looped-back multicast packets), set oif to
   the loopback interface.
 - if fib lookup returns an error, or result points to local,
   store zero result.  This means '--local' option of -m rpfilter
   is not supported. It is possible to use 'fib type local' or add
   explicit saddr/daddr matching rules to create exceptions if this
   is really needed.
 - store result in the destination register.
   In case of multiple routes, search set for desired oif in case
   strict matching is requested.

ipv4 and ipv6 behave fib expressions are supposed to behave the same.

[ I have collapsed Arnd Bergmann's ("netfilter: nf_tables: fib warnings")

	http://patchwork.ozlabs.org/patch/688615/

  to address fallout from this patch after rebasing nf-next, that was
  posted to address compilation warnings. --pablo ]

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-11-01 20:50:14 +01:00