Allow to recycle the previous output of the OS fingerprint expression
if flags and ttl are the same.
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
v2: use nft_reg_track_cmp()
net/netfilter/nft_osf.c | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)
diff --git a/net/netfilter/nft_osf.c b/net/netfilter/nft_osf.c
index d82677e83400..5eed18f90b02 100644
--- a/net/netfilter/nft_osf.c
+++ b/net/netfilter/nft_osf.c
@@ -120,6 +120,30 @@ static int nft_osf_validate(const struct nft_ctx *ctx,
(1 << NF_INET_FORWARD));
}
+static bool nft_osf_reduce(struct nft_regs_track *track,
+ const struct nft_expr *expr)
+{
+ struct nft_osf *priv = nft_expr_priv(expr);
+ struct nft_osf *osf;
+
+ if (!nft_reg_track_cmp(track, expr, priv->dreg)) {
+ nft_reg_track_update(track, expr, priv->dreg, NFT_OSF_MAXGENRELEN);
+ return false;
+ }
+
+ osf = nft_expr_priv(track->regs[priv->dreg].selector);
+ if (priv->flags != osf->flags ||
+ priv->ttl != osf->ttl) {
+ nft_reg_track_update(track, expr, priv->dreg, NFT_OSF_MAXGENRELEN);
+ return false;
+ }
+
+ if (!track->regs[priv->dreg].bitwise)
+ return true;
+
+ return false;
+}
+
static struct nft_expr_type nft_osf_type;
static const struct nft_expr_ops nft_osf_op = {
.eval = nft_osf_eval,
@@ -128,6 +152,7 @@ static const struct nft_expr_ops nft_osf_op = {
.dump = nft_osf_dump,
.type = &nft_osf_type,
.validate = nft_osf_validate,
+ .reduce = nft_osf_reduce,
};
static struct nft_expr_type nft_osf_type __read_mostly = {
--
2.30.2
