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>
diff --git a/net/netfilter/nft_payload.c b/net/netfilter/nft_payload.c
index 5fa9973..94fb3b2 100644
--- a/net/netfilter/nft_payload.c
+++ b/net/netfilter/nft_payload.c
@@ -23,7 +23,7 @@
{
const struct nft_payload *priv = nft_expr_priv(expr);
const struct sk_buff *skb = pkt->skb;
- u32 *dest = ®s->data[priv->dreg].data[0];
+ u32 *dest = ®s->data[priv->dreg];
int offset;
switch (priv->base) {
@@ -43,6 +43,7 @@
}
offset += priv->offset;
+ dest[priv->len / NFT_REG32_SIZE] = 0;
if (skb_copy_bits(skb, offset, dest, priv->len) < 0)
goto err;
return;
