evaluate: check that set type is identical before merging

Reject maps and sets of the same name:
 BUG: invalid range expression type catch-all set element
 nft: src/expression.c:1704: range_expr_value_low: Assertion `0' failed.

After:
Error: Cannot merge set with existing datamap of same name
  set z {
      ^

v2:
Pablo points out that we shouldn't merge datamaps (plain value) and objref
maps either, catch this too and add another test:

nft --check -f invalid_transcation_merge_map_and_objref_map
invalid_transcation_merge_map_and_objref_map:9:13-13: Error: Cannot merge map with incompatible existing map of same name

We should also make sure that both data (for map case) and
set keys are identical, this is added in a followup patch.

Signed-off-by: Florian Westphal <fw@strlen.de>

1 files changed, 21 insertions, 2 deletions

diff --git a/src/evaluate.c b/src/evaluate.c
index 5f46aaf9..fc9d82f7 100644
--- a/src/evaluate.c
+++ b/src/evaluate.c
@@ -5165,6 +5165,18 @@ static int elems_evaluate(struct eval_ctx *ctx, struct set *set)
 	return 0;
 }
 
+static bool set_type_compatible(const struct set *set, const struct set *existing_set)
+{
+	if (set_is_datamap(set->flags))
+		return set_is_datamap(existing_set->flags);
+
+	if (set_is_objmap(set->flags))
+		return set_is_objmap(existing_set->flags);
+
+	assert(!set_is_map(set->flags));
+	return !set_is_map(existing_set->flags);
+}
+
 static int set_evaluate(struct eval_ctx *ctx, struct set *set)
 {
 	struct set *existing_set = NULL;
@@ -5288,8 +5300,15 @@ static int set_evaluate(struct eval_ctx *ctx, struct set *set)
 		return 0;
 	}
 
-	if (existing_set && set_is_interval(set->flags) && !set_is_interval(existing_set->flags))
-		return set_error(ctx, set, "existing %s lacks interval flag", type);
+	if (existing_set) {
+		if (set_is_interval(set->flags) && !set_is_interval(existing_set->flags))
+			return set_error(ctx, set,
+					 "existing %s lacks interval flag", type);
+		if (!set_type_compatible(set, existing_set))
+			return set_error(ctx, set, "Cannot merge %s with incompatible existing %s of same name",
+					type,
+					set_is_map(existing_set->flags) ? "map" : "set");
+	}
 
 	set->existing_set = existing_set;