[PATCH nft 1/4] evaluate: tunnel: don't assume src is set

[Florian Westphal <fw@strlen.de>]

Included bogon crashes, after fix:

empty_geneve_definition_crash:2:9-16: Error: Could not process rule: Invalid argument

Since this feature is undocumented (hint, hint) I don't know
if there are cases where ip daddr can be elided.

If not, a followup patch should reject empty dst upfront
so users get a more verbose error message.

Signed-off-by: Florian Westphal <fw@strlen.de>
---
 src/evaluate.c                                           | 9 +++++----
 .../testcases/bogons/nft-f/empty_geneve_definition_crash | 4 ++++
 2 files changed, 9 insertions(+), 4 deletions(-)
 create mode 100644 tests/shell/testcases/bogons/nft-f/empty_geneve_definition_crash

diff --git a/src/evaluate.c b/src/evaluate.c
index 0c7d90f8f43b..ac482c83cce2 100644
--- a/src/evaluate.c
+++ b/src/evaluate.c
@@ -5865,11 +5865,12 @@ static int tunnel_evaluate(struct eval_ctx *ctx, struct obj *obj)
 				 obj->tunnel.dst->dtype->size);
 		if (expr_evaluate(ctx, &obj->tunnel.dst) < 0)
 			return -1;
-	}
 
-	if (obj->tunnel.src->dtype != obj->tunnel.dst->dtype)
-		return __stmt_binary_error(ctx, &obj->location, NULL,
-					  "specify either ip or ip6 for address");
+		if (obj->tunnel.src &&
+		    obj->tunnel.src->dtype != obj->tunnel.dst->dtype)
+			return __stmt_binary_error(ctx, &obj->location, NULL,
+						  "specify either ip or ip6 for address");
+	}
 
 	return 0;
 }
diff --git a/tests/shell/testcases/bogons/nft-f/empty_geneve_definition_crash b/tests/shell/testcases/bogons/nft-f/empty_geneve_definition_crash
new file mode 100644
index 000000000000..d1bc76c56bd5
--- /dev/null
+++ b/tests/shell/testcases/bogons/nft-f/empty_geneve_definition_crash
@@ -0,0 +1,4 @@
+table netdev x {
+	tunnel geneve-t {
+	}
+}
-- 
2.51.0