netfilter: nf_tables: use NLA_POLICY_MASK to test for valid flag options

nf_tables relies on manual test of netlink attributes coming from userspace
even in cases where this could be handled via netlink policy.

Convert a bunch of 'flag' attributes to use NLA_POLICY_MASK checks.

Signed-off-by: Florian Westphal <fw@strlen.de>

netfilter: nft_redir: use `struct nf_nat_range2` throughout and deduplicate eval call-backs

`nf_nat_redirect_ipv4` takes a `struct nf_nat_ipv4_multi_range_compat`,
but converts it internally to a `struct nf_nat_range2`. Change the
function to take the latter, factor out the code now shared with
`nf_nat_redirect_ipv6`, move the conversion to the xt_REDIRECT module,
and update the ipv4 range initialization in the nft_redir module.

Replace a bare hex constant for 127.0.0.1 with a macro.

Remove `WARN_ON`. `nf_nat_setup_info` calls `nf_ct_is_confirmed`:

/* Can't setup nat info for confirmed ct. */
if (nf_ct_is_confirmed(ct))
return NF_ACCEPT;

This means that `ct` cannot be null or the kernel will crash, and
implies that `ctinfo` is `IP_CT_NEW` or `IP_CT_RELATED`.

nft_redir has separate ipv4 and ipv6 call-backs which share much of
their code, and an inet one switch containing a switch that calls one of
the others based on the family of the packet. Merge the ipv4 and ipv6
ones into the inet one in order to get rid of the duplicate code.

Const-qualify the `priv` pointer since we don't need to write through
it.

Assign `priv->flags` to the range instead of OR-ing it in.

Set the `NF_NAT_RANGE_PROTO_SPECIFIED` flag once during init, rather
than on every eval.

Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
Signed-off-by: Florian Westphal <fw@strlen.de>

netfilter: nft_redir: correct value of inet type `.maxattrs`

`nft_redir_inet_type.maxattrs` was being set, presumably because of a
cut-and-paste error, to `NFTA_MASQ_MAX`, instead of `NFTA_REDIR_MAX`.

Fixes: 63ce3940f3ab ("netfilter: nft_redir: add inet support")
Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: nft_redir: correct length for loading protocol registers

The values in the protocol registers are two bytes wide. However, when
parsing the register loads, the code currently uses the larger 16-byte
size of a `union nf_inet_addr`. Change it to use the (correct) size of
a `union nf_conntrack_man_proto` instead.

Fixes: d07db9884a5f ("netfilter: nf_tables: introduce nft_validate_register_load()")
Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

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>

netfilter: nf_tables: do not reduce read-only expressions

Skip register tracking for expressions that perform read-only operations
on the registers. Define and use a cookie pointer NFT_REDUCE_READONLY to
avoid defining stubs for these expressions.

This patch re-enables register tracking which was disabled in ed5f85d42290
("netfilter: nf_tables: disable register tracking"). Follow up patches
add remaining register tracking for existing expressions.

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

netfilter: nftables: add nft_parse_register_load() and use it

This new function combines the netlink register attribute parser
and the load validation function.

This update requires to replace:

enum nft_registers sreg:8;

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

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

when passing the register field as reference.

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

netfilter: Add MODULE_DESCRIPTION entries to kernel modules

The user tool modinfo is used to get information on kernel modules, including a
description where it is available.

This patch adds a brief MODULE_DESCRIPTION to netfilter kernel modules
(descriptions taken from Kconfig file or code comments)

Signed-off-by: Rob Gill <rrobgill@protonmail.com>
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: nf_tables: fix module autoload for redir

Fix expression for autoloading.

Fixes: 5142967ab524 ("netfilter: nf_tables: fix module autoload with inet family")
Signed-off-by: Christian Hesse <mail@eworm.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

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>

netfilter: nf_tables: fix module autoload with inet family

Use MODULE_ALIAS_NFT_EXPR() to make happy the inet family with nat.

Fixes: 63ce3940f3ab ("netfilter: nft_redir: add inet support")
Fixes: 071657d2c38c ("netfilter: nft_masq: add inet support")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: nft_redir: add inet support

allows to redirect both ipv4 and ipv6 with a single rule in an
inet nat table.

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

netfilter: nft_redir: Make nft_redir_dump static

Fix sparse warning:

net/netfilter/nft_redir.c:85:5:
warning: symbol 'nft_redir_dump' was not declared. Should it be static?

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: nft_redir: fix module autoload with ip4

AF_INET4 does not exist.

Fixes: c78efc99c750 ("netfilter: nf_tables: nat: merge nft_redir protocol specific modules)"
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: nf_tables: nat: merge nft_redir protocol specific modules

before:
text data bss dec hex filename
990 832 0 1822 71e nft_redir.ko
697 896 0 1593 639 nft_redir_ipv4.ko
713 896 0 1609 649 nft_redir_ipv6.ko

after:
text data bss dec hex filename
1910 960 0 2870 b36 nft_redir.ko

size is reduced, all helpers from nft_redir.ko can be made static.

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

netfilter: nf_tables: add single table list for all families

Place all existing user defined tables in struct net *, instead of
having one list per family. This saves us from one level of indentation
in netlink dump functions.

Place pointer to struct nft_af_info in struct nft_table temporarily, as
we still need this to put back reference module reference counter on
table removal.

This patch comes in preparation for the removal of struct nft_af_info.

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

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>

netfilter: nf_tables: add conntrack dependencies for nat/masq/redir expressions

so that conntrack core will add the needed hooks in this namespace.

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

netfilter: update Arturo Borrero Gonzalez email address

The email address has changed, let's update the copyright statements.

Signed-off-by: Arturo Borrero Gonzalez <arturo@debian.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: nf_tables: add register parsing/dumping helpers

Add helper functions to parse and dump register values in netlink attributes.
These helpers will later be changed to take care of translation between the
old 128 bit and the new 32 bit register numbers.

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

netfilter: nf_tables: introduce nft_validate_register_load()

Change nft_validate_input_register() to not only validate the input
register number, but also the length of the load, and rename it to
nft_validate_register_load() to reflect that change.

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

netfilter: nf_tables: validate hooks in NAT expressions

The user can crash the kernel if it uses any of the existing NAT
expressions from the wrong hook, so add some code to validate this
when loading the rule.

This patch introduces nft_chain_validate_hooks() which is based on
an existing function in the bridge version of the reject expression.

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

netfilter: nft_redir: fix sparse warnings

>> net/netfilter/nft_redir.c:39:26: sparse: incorrect type in assignment (different base types)
net/netfilter/nft_redir.c:39:26: expected unsigned int [unsigned] [usertype] nla_be32
net/netfilter/nft_redir.c:39:26: got restricted __be32
>> net/netfilter/nft_redir.c:40:40: sparse: cast to restricted __be32
>> net/netfilter/nft_redir.c:40:40: sparse: cast to restricted __be32
>> net/netfilter/nft_redir.c:40:40: sparse: cast to restricted __be32
>> net/netfilter/nft_redir.c:40:40: sparse: cast to restricted __be32
>> net/netfilter/nft_redir.c:40:40: sparse: cast to restricted __be32
>> net/netfilter/nft_redir.c:40:40: sparse: cast to restricted __be32
>> net/netfilter/nft_redir.c:46:34: sparse: incorrect type in assignment (different base types)
net/netfilter/nft_redir.c:46:34: expected unsigned int [unsigned] [usertype] nla_be32
net/netfilter/nft_redir.c:46:34: got restricted __be32
>> net/netfilter/nft_redir.c:47:48: sparse: cast to restricted __be32
>> net/netfilter/nft_redir.c:47:48: sparse: cast to restricted __be32
>> net/netfilter/nft_redir.c:47:48: sparse: cast to restricted __be32
>> net/netfilter/nft_redir.c:47:48: sparse: cast to restricted __be32
>> net/netfilter/nft_redir.c:47:48: sparse: cast to restricted __be32
>> net/netfilter/nft_redir.c:47:48: sparse: cast to restricted __be32

Fixes: e9105f1 ("netfilter: nf_tables: add new expression nft_redir")
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: nf_tables: add new expression nft_redir

This new expression provides NAT in the redirect flavour, which is to
redirect packets to local machine.

Signed-off-by: Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>