Clone the expression that defines the variable value if there are
multiple reference to it in the ruleset. This saves us heap consumption
specifically in case the variable defines a set with a huge number of
elements.
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
src/evaluate.c | 11 ++++++++++-
.../testcases/nft-f/0030variable_reuse_0 | 19 +++++++++++++++++++
.../nft-f/dumps/0030variable_reuse_0.nft | 11 +++++++++++
3 files changed, 40 insertions(+), 1 deletion(-)
create mode 100755 tests/shell/testcases/nft-f/0030variable_reuse_0
create mode 100644 tests/shell/testcases/nft-f/dumps/0030variable_reuse_0.nft
diff --git a/src/evaluate.c b/src/evaluate.c
index a268b3cb9ee2..fd7818da1116 100644
--- a/src/evaluate.c
+++ b/src/evaluate.c
@@ -2187,7 +2187,16 @@ static int expr_evaluate_osf(struct eval_ctx *ctx, struct expr **expr)
static int expr_evaluate_variable(struct eval_ctx *ctx, struct expr **exprp)
{
- struct expr *new = expr_clone((*exprp)->sym->expr);
+ struct symbol *sym = (*exprp)->sym;
+ struct expr *new;
+
+ /* If variable is reused from different locations in the ruleset, then
+ * clone expression.
+ */
+ if (sym->refcnt > 2)
+ new = expr_clone(sym->expr);
+ else
+ new = expr_get(sym->expr);
if (expr_evaluate(ctx, &new) < 0) {
expr_free(new);
diff --git a/tests/shell/testcases/nft-f/0030variable_reuse_0 b/tests/shell/testcases/nft-f/0030variable_reuse_0
new file mode 100755
index 000000000000..8afc54aa0c10
--- /dev/null
+++ b/tests/shell/testcases/nft-f/0030variable_reuse_0
@@ -0,0 +1,19 @@
+#!/bin/bash
+
+set -e
+
+RULESET="define test = { 1.1.1.1 }
+
+table ip x {
+ set y {
+ type ipv4_addr
+ elements = { 2.2.2.2, \$test }
+ }
+
+ set z {
+ type ipv4_addr
+ elements = { 3.3.3.3, \$test }
+ }
+}"
+
+$NFT -f - <<< "$RULESET"
diff --git a/tests/shell/testcases/nft-f/dumps/0030variable_reuse_0.nft b/tests/shell/testcases/nft-f/dumps/0030variable_reuse_0.nft
new file mode 100644
index 000000000000..d895539bbfa5
--- /dev/null
+++ b/tests/shell/testcases/nft-f/dumps/0030variable_reuse_0.nft
@@ -0,0 +1,11 @@
+table ip x {
+ set y {
+ type ipv4_addr
+ elements = { 1.1.1.1, 2.2.2.2 }
+ }
+
+ set z {
+ type ipv4_addr
+ elements = { 1.1.1.1, 3.3.3.3 }
+ }
+}
--
2.30.2
