netfilter: nf_tables: validate NFPROTO_* family

Several expressions explicitly refer to NF_INET_* hook definitions
from expr->ops->validate, however, family is not validated.

Bail out with EOPNOTSUPP in case they are used from unsupported
families.

Fixes: 0ca743a55991 ("netfilter: nf_tables: add compatibility layer for x_tables")
Fixes: a3c90f7a2323 ("netfilter: nf_tables: flow offload expression")
Fixes: 2fa841938c64 ("netfilter: nf_tables: introduce routing expression")
Fixes: 554ced0a6e29 ("netfilter: nf_tables: add support for native socket matching")
Fixes: ad49d86e07a4 ("netfilter: nf_tables: Add synproxy support")
Fixes: 4ed8eb6570a4 ("netfilter: nf_tables: Add native tproxy support")
Fixes: 6c47260250fc ("netfilter: nf_tables: add xfrm expression")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net: annotate data-races around sk->sk_mark

sk->sk_mark is often read while another thread could change the value.

Fixes: 4a19ec5800fc ("[NET]: Introducing socket mark socket option.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

netfilter: nf_tables: limit allowed range via nla_policy

These NLA_U32 types get stored in u8 fields, reject invalid values
instead of silently casting to u8.

Signed-off-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>

cgroup: Replace cgroup->ancestor_ids[] with ->ancestors[]

Every cgroup knows all its ancestors through its ->ancestor_ids[]. There's
no advantage to remembering the IDs instead of the pointers directly and
this makes the array useless for finding an actual ancestor cgroup forcing
cgroup_ancestor() to iteratively walk up the hierarchy instead. Let's
replace cgroup->ancestor_ids[] with ->ancestors[] and remove the walking-up
from cgroup_ancestor().

While at it, improve comments around cgroup_root->cgrp_ancestor_storage.

This patch shouldn't cause user-visible behavior differences.

v2: Update cgroup_ancestor() to use ->ancestors[].

v3: cgroup_root->cgrp_ancestor_storage's type is updated to match
cgroup->ancestors[]. Better comments.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>

netfilter: nf_tables: use the correct get/put helpers

Switch to be16/32 and u16/32 respectively. No code changes here,
the functions do the same thing, this is just for sparse checkers' sake.

objdiff shows no changes.

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

netfilter: nft_socket: only do sk lookups when indev is available

Check if the incoming interface is available and NFT_BREAK
in case neither skb->sk nor input device are set.

Because nf_sk_lookup_slow*() assume packet headers are in the
'in' direction, use in postrouting is not going to yield a meaningful
result. Same is true for the forward chain, so restrict the use
to prerouting, input and output.

Use in output work if a socket is already attached to the skb.

Fixes: 554ced0a6e29 ("netfilter: nf_tables: add support for native socket matching")
Reported-and-tested-by: Topi Miettinen <toiwoton@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: nft_socket: make cgroup match work in input too

cgroupv2 helper function ignores the already-looked up sk
and uses skb->sk instead.

Just pass sk from the calling function instead; this will
make cgroup matching work for udp and tcp in input even when
edemux did not set skb->sk already.

Fixes: e0bb96db96f8 ("netfilter: nft_socket: add support for cgroupsv2")
Signed-off-by: Florian Westphal <fw@strlen.de>
Tested-by: Topi Miettinen <toiwoton@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: nft_socket: track register operations

Check if the destination register already contains the data that this
socket expression performs. This allows to skip this redundant
operation. If the destination contains a different selector, update the
register tracking information.

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

netfilter: nft_socket: fix build with CONFIG_SOCK_CGROUP_DATA=n

In some configurations, the sock_cgroup_ptr() function is not available:

net/netfilter/nft_socket.c: In function 'nft_sock_get_eval_cgroupv2':
net/netfilter/nft_socket.c:47:16: error: implicit declaration of function 'sock_cgroup_ptr'; did you mean 'obj_cgroup_put'? [-Werror=implicit-function-declaration]
47 | cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
| ^~~~~~~~~~~~~~~
| obj_cgroup_put
net/netfilter/nft_socket.c:47:14: error: assignment to 'struct cgroup *' from 'int' makes pointer from integer without a cast [-Werror=int-conversion]
47 | cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
| ^

Change the caller to match the same #ifdef check, only calling it
when the function is defined.

Fixes: e0bb96db96f8 ("netfilter: nft_socket: add support for cgroupsv2")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: nft_socket: fix an unused variable warning

The variable is only used in an #ifdef, causing a harmless warning:

net/netfilter/nft_socket.c: In function 'nft_socket_init':
net/netfilter/nft_socket.c:137:27: error: unused variable 'level' [-Werror=unused-variable]
137 | unsigned int len, level;
| ^~~~~

Move it into the same #ifdef block.

Fixes: e0bb96db96f8 ("netfilter: nft_socket: add support for cgroupsv2")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: nft_socket: add support for cgroupsv2

Allow to match on the cgroupsv2 id from ancestor level.

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

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>

netfilter: nft_socket: add wildcard support

Add NFT_SOCKET_WILDCARD to match to wildcard socket listener.

Signed-off-by: Balazs Scheidler <bazsi77@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: nft_socket: fix erroneous socket assignment

The socket assignment is wrong, see skb_orphan():
When skb->destructor callback is not set, but skb->sk is set, this hits BUG().

Link: https://bugzilla.redhat.com/show_bug.cgi?id=1651813
Fixes: 554ced0a6e29 ("netfilter: nf_tables: add support for native socket matching")
Signed-off-by: Fernando Fernandez Mancera <ffmancera@riseup.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: nft_socket: Expose socket mark

Signed-off-by: Máté Eckl <ecklm94@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: nft_socket: Break evaluation if no socket found

Actual implementation stores 0 in the destination register if no socket
is found by the lookup, but that is not intentional as it is not really
a value of any socket metadata.

This patch fixes this and breaks rule evaluation in this case.

Fixes: 554ced0a6e29 ("netfilter: nf_tables: add support for native socket matching")
Signed-off-by: Máté Eckl <ecklm94@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: Kconfig: Change select IPv6 dependencies

... from IPV6 to NF_TABLES_IPV6 and IP6_NF_IPTABLES.

In some cases module selects depend on IPV6, but this means that they
select another module even if eg. NF_TABLES_IPV6 is not set in which
case the selected module is useless due to the lack of IPv6 nf_tables
functionality.

The same applies for IP6_NF_IPTABLES and iptables.

Joint work with: Arnd Bermann <arnd@arndb.de>

Signed-off-by: Máté Eckl <ecklm94@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: check if the socket netns is correct.

Netfilter assumes that if the socket is present in the skb, then
it can be used because that reference is cleaned up while the skb
is crossing netns.

We want to change that to preserve the socket reference in a future
patch, so this is a preparation updating netfilter to check if the
socket netns matches before use it.

Signed-off-by: Flavio Leitner <fbl@redhat.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

netfilter: nft_socket: fix module autoload

Add alias definition for module autoload when adding socket rules.

Fixes: 554ced0a6e29 ("netfilter: nf_tables: add support for native socket matching")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: Decrease code duplication regarding transparent socket option

There is a function in include/net/netfilter/nf_socket.h to decide if a
socket has IP(V6)_TRANSPARENT socket option set or not. However this
does the same as inet_sk_transparent() in include/net/tcp.h

include/net/tcp.h:1733
/* This helper checks if socket has IP_TRANSPARENT set */
static inline bool inet_sk_transparent(const struct sock *sk)
{
switch (sk->sk_state) {
case TCP_TIME_WAIT:
return inet_twsk(sk)->tw_transparent;
case TCP_NEW_SYN_RECV:
return inet_rsk(inet_reqsk(sk))->no_srccheck;
}
return inet_sk(sk)->transparent;
}

tproxy_sk_is_transparent has also been refactored to use this function
instead of reimplementing it.

Signed-off-by: Máté Eckl <ecklm94@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: nf_tables: add support for native socket matching

Now it can only match the transparent flag of an ip/ipv6 socket.

Signed-off-by: Máté Eckl <ecklm94@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>