netfilter: nf_tables: switch registers to 32 bit addressing

Switch the nf_tables registers from 128 bit addressing to 32 bit
addressing to support so called concatenations, where multiple values
can be concatenated over multiple registers for O(1) exact matches of
multiple dimensions using sets.

The old register values are mapped to areas of 128 bits for compatibility.
When dumping register numbers, values are expressed using the old values
if they refer to the beginning of a 128 bit area for compatibility.

To support concatenations, register loads of less than a full 32 bit
value need to be padded. This mainly affects the payload and exthdr
expressions, which both unconditionally zero the last word before
copying the data.

Userspace fully passes the testsuite using both old and new register
addressing.

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

1 files changed, 1 insertions, 1 deletions

diff --git a/net/bridge/netfilter/nft_meta_bridge.c b/net/bridge/netfilter/nft_meta_bridge.c
index 99dab70ecae0..a21269b83f16 100644
--- a/net/bridge/netfilter/nft_meta_bridge.c
+++ b/net/bridge/netfilter/nft_meta_bridge.c
@@ -24,7 +24,7 @@ static void nft_meta_bridge_get_eval(const struct nft_expr *expr,
 {
 	const struct nft_meta *priv = nft_expr_priv(expr);
 	const struct net_device *in = pkt->in, *out = pkt->out;
-	u32 *dest = &regs->data[priv->dreg].data[0];
+	u32 *dest = &regs->data[priv->dreg];
 	const struct net_bridge_port *p;
 
 	switch (priv->key) {