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authorPablo Neira Ayuso <pablo@netfilter.org>2022-01-09 17:11:24 +0100
committerPablo Neira Ayuso <pablo@netfilter.org>2022-01-09 23:35:17 +0100
commitbe5650f8f47e8cffbbbcad08b71103685e971f20 (patch)
treeb54dc263320322cd31e6c8ba7c733225120b595e /net/netfilter
parentnetfilter: nft_meta: track register operations (diff)
downloadlinux-dev-be5650f8f47e8cffbbbcad08b71103685e971f20.tar.xz
linux-dev-be5650f8f47e8cffbbbcad08b71103685e971f20.zip
netfilter: nft_bitwise: track register operations
Check if the destination register already contains the data that this bitwise expression performs. This allows to skip this redundant operation. If the destination contains a different bitwise operation, cancel the register tracking information. If the destination contains no bitwise operation, update the register tracking information. Update the payload and meta expression to check if this bitwise operation has been already performed on the register. Hence, both the payload/meta and the bitwise expressions are reduced. There is also a special case: If source register != destination register and source register is not updated by a previous bitwise operation, then transfer selector from the source register to the destination register. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net/netfilter')
-rw-r--r--net/netfilter/nft_bitwise.c95
-rw-r--r--net/netfilter/nft_meta.c2
-rw-r--r--net/netfilter/nft_payload.c2
3 files changed, 97 insertions, 2 deletions
diff --git a/net/netfilter/nft_bitwise.c b/net/netfilter/nft_bitwise.c
index 47b0dba95054..7b727d3ebf9d 100644
--- a/net/netfilter/nft_bitwise.c
+++ b/net/netfilter/nft_bitwise.c
@@ -278,12 +278,52 @@ static int nft_bitwise_offload(struct nft_offload_ctx *ctx,
return 0;
}
+static bool nft_bitwise_reduce(struct nft_regs_track *track,
+ const struct nft_expr *expr)
+{
+ const struct nft_bitwise *priv = nft_expr_priv(expr);
+ const struct nft_bitwise *bitwise;
+
+ if (!track->regs[priv->sreg].selector)
+ return false;
+
+ bitwise = nft_expr_priv(expr);
+ if (track->regs[priv->sreg].selector == track->regs[priv->dreg].selector &&
+ track->regs[priv->dreg].bitwise &&
+ track->regs[priv->dreg].bitwise->ops == expr->ops &&
+ priv->sreg == bitwise->sreg &&
+ priv->dreg == bitwise->dreg &&
+ priv->op == bitwise->op &&
+ priv->len == bitwise->len &&
+ !memcmp(&priv->mask, &bitwise->mask, sizeof(priv->mask)) &&
+ !memcmp(&priv->xor, &bitwise->xor, sizeof(priv->xor)) &&
+ !memcmp(&priv->data, &bitwise->data, sizeof(priv->data))) {
+ track->cur = expr;
+ return true;
+ }
+
+ if (track->regs[priv->sreg].bitwise) {
+ track->regs[priv->dreg].selector = NULL;
+ track->regs[priv->dreg].bitwise = NULL;
+ return false;
+ }
+
+ if (priv->sreg != priv->dreg) {
+ track->regs[priv->dreg].selector =
+ track->regs[priv->sreg].selector;
+ }
+ track->regs[priv->dreg].bitwise = expr;
+
+ return false;
+}
+
static const struct nft_expr_ops nft_bitwise_ops = {
.type = &nft_bitwise_type,
.size = NFT_EXPR_SIZE(sizeof(struct nft_bitwise)),
.eval = nft_bitwise_eval,
.init = nft_bitwise_init,
.dump = nft_bitwise_dump,
+ .reduce = nft_bitwise_reduce,
.offload = nft_bitwise_offload,
};
@@ -385,12 +425,49 @@ static int nft_bitwise_fast_offload(struct nft_offload_ctx *ctx,
return 0;
}
+static bool nft_bitwise_fast_reduce(struct nft_regs_track *track,
+ const struct nft_expr *expr)
+{
+ const struct nft_bitwise_fast_expr *priv = nft_expr_priv(expr);
+ const struct nft_bitwise_fast_expr *bitwise;
+
+ if (!track->regs[priv->sreg].selector)
+ return false;
+
+ bitwise = nft_expr_priv(expr);
+ if (track->regs[priv->sreg].selector == track->regs[priv->dreg].selector &&
+ track->regs[priv->dreg].bitwise &&
+ track->regs[priv->dreg].bitwise->ops == expr->ops &&
+ priv->sreg == bitwise->sreg &&
+ priv->dreg == bitwise->dreg &&
+ priv->mask == bitwise->mask &&
+ priv->xor == bitwise->xor) {
+ track->cur = expr;
+ return true;
+ }
+
+ if (track->regs[priv->sreg].bitwise) {
+ track->regs[priv->dreg].selector = NULL;
+ track->regs[priv->dreg].bitwise = NULL;
+ return false;
+ }
+
+ if (priv->sreg != priv->dreg) {
+ track->regs[priv->dreg].selector =
+ track->regs[priv->sreg].selector;
+ }
+ track->regs[priv->dreg].bitwise = expr;
+
+ return false;
+}
+
const struct nft_expr_ops nft_bitwise_fast_ops = {
.type = &nft_bitwise_type,
.size = NFT_EXPR_SIZE(sizeof(struct nft_bitwise_fast_expr)),
.eval = NULL, /* inlined */
.init = nft_bitwise_fast_init,
.dump = nft_bitwise_fast_dump,
+ .reduce = nft_bitwise_fast_reduce,
.offload = nft_bitwise_fast_offload,
};
@@ -427,3 +504,21 @@ struct nft_expr_type nft_bitwise_type __read_mostly = {
.maxattr = NFTA_BITWISE_MAX,
.owner = THIS_MODULE,
};
+
+bool nft_expr_reduce_bitwise(struct nft_regs_track *track,
+ const struct nft_expr *expr)
+{
+ const struct nft_expr *last = track->last;
+ const struct nft_expr *next;
+
+ if (expr == last)
+ return false;
+
+ next = nft_expr_next(expr);
+ if (next->ops == &nft_bitwise_ops)
+ return nft_bitwise_reduce(track, next);
+ else if (next->ops == &nft_bitwise_fast_ops)
+ return nft_bitwise_fast_reduce(track, next);
+
+ return false;
+}
diff --git a/net/netfilter/nft_meta.c b/net/netfilter/nft_meta.c
index 430f40bc3cb4..40fe48fcf9d0 100644
--- a/net/netfilter/nft_meta.c
+++ b/net/netfilter/nft_meta.c
@@ -774,7 +774,7 @@ static bool nft_meta_get_reduce(struct nft_regs_track *track,
if (!track->regs[priv->dreg].bitwise)
return true;
- return false;
+ return nft_expr_reduce_bitwise(track, expr);
}
static const struct nft_expr_ops nft_meta_get_ops = {
diff --git a/net/netfilter/nft_payload.c b/net/netfilter/nft_payload.c
index 7a7c66e9a50e..f518bf634997 100644
--- a/net/netfilter/nft_payload.c
+++ b/net/netfilter/nft_payload.c
@@ -235,7 +235,7 @@ static bool nft_payload_reduce(struct nft_regs_track *track,
if (!track->regs[priv->dreg].bitwise)
return true;
- return false;
+ return nft_expr_reduce_bitwise(track, expr);
}
static bool nft_payload_offload_mask(struct nft_offload_reg *reg,