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netfilter: nft_tunnel: track register operations

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Check if the destination register already contains the data that this
tunnel expression performs. This allows to skip this redundant operation.
If the destination contains a different selector, update the register
tracking information. This patch does not perform bitwise tracking.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Pablo Neira Ayuso 2022-03-14 18:23:11 +01:00
parent 48f1910326
commit 611580d2df
1 changed files with 28 additions and 0 deletions
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28
net/netfilter/nft_tunnel.c
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@ -17,6 +17,7 @@ struct nft_tunnel {
enum nft_tunnel_keys key:8;
u8 dreg;
enum nft_tunnel_mode mode:8;
u8 len;
};
static void nft_tunnel_get_eval(const struct nft_expr *expr,
@ -101,6 +102,7 @@ static int nft_tunnel_get_init(const struct nft_ctx *ctx,
priv->mode = NFT_TUNNEL_MODE_NONE;
}
priv->len = len;
return nft_parse_register_store(ctx, tb[NFTA_TUNNEL_DREG], &priv->dreg,
NULL, NFT_DATA_VALUE, len);
}
@ -122,6 +124,31 @@ static int nft_tunnel_get_dump(struct sk_buff *skb,
return -1;
}
static bool nft_tunnel_get_reduce(struct nft_regs_track *track,
const struct nft_expr *expr)
{
const struct nft_tunnel *priv = nft_expr_priv(expr);
const struct nft_tunnel *tunnel;
if (!nft_reg_track_cmp(track, expr, priv->dreg)) {
nft_reg_track_update(track, expr, priv->dreg, priv->len);
return false;
}
tunnel = nft_expr_priv(track->regs[priv->dreg].selector);
if (priv->key != tunnel->key ||
priv->dreg != tunnel->dreg ||
priv->mode != tunnel->mode) {
nft_reg_track_update(track, expr, priv->dreg, priv->len);
return false;
}
if (!track->regs[priv->dreg].bitwise)
return true;
return false;
}
static struct nft_expr_type nft_tunnel_type;
static const struct nft_expr_ops nft_tunnel_get_ops = {
.type = &nft_tunnel_type,
@ -129,6 +156,7 @@ static const struct nft_expr_ops nft_tunnel_get_ops = {
.eval = nft_tunnel_get_eval,
.init = nft_tunnel_get_init,
.dump = nft_tunnel_get_dump,
.reduce = nft_tunnel_get_reduce,
};
static struct nft_expr_type nft_tunnel_type __read_mostly = {