[PATCH nft] json: fix parse of flagcmp expression

[PATCH nft] json: fix parse of flagcmp expression

[Florian Westphal]

The json test case for the flagcmp notation ('tcp flags syn,fin / syn,fin') fails with:
command: {"nftables": [{"add": {"rule": {"family": "ip", "table": "test-ip4", "chain": "input", "expr": [{"match": {"left": {"&": [{"payload": {"field": "flags", "protocol": "tcp"}}, ["fin", "syn"]]}, "op": "==", "right": ["fin", "syn"]}}]}}}]}
internal:0:0-0: Error: List expression only allowed on RHS or in statement expression.
internal:0:0-0: Error: Failed to parse RHS of binop expression.
internal:0:0-0: Error: Invalid LHS of relational.
internal:0:0-0: Error: Parsing expr array at index 0 failed.
internal:0:0-0: Error: Parsing command array at index 0 failed.

Signed-off-by: Florian Westphal <fw@strlen.de>
---
 src/parser_json.c        |  2 +-
 tests/py/inet/tcp.t.json | 27 +++++++++++++++++++++++++++
 2 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/src/parser_json.c b/src/parser_json.c
index fd0d4fd85a2d..2e791807cce6 100644
--- a/src/parser_json.c
+++ b/src/parser_json.c
@@ -1135,7 +1135,7 @@ static struct expr *json_parse_binop_expr(struct json_ctx *ctx,
 		json_error(ctx, "Failed to parse LHS of binop expression.");
 		return NULL;
 	}
-	right = json_parse_primary_expr(ctx, jright);
+	right = json_parse_rhs_expr(ctx, jright);
 	if (!right) {
 		json_error(ctx, "Failed to parse RHS of binop expression.");
 		expr_free(left);
diff --git a/tests/py/inet/tcp.t.json b/tests/py/inet/tcp.t.json
index 922ab91c9f0e..b04556769c81 100644
--- a/tests/py/inet/tcp.t.json
+++ b/tests/py/inet/tcp.t.json
@@ -1749,3 +1749,30 @@
         }
     }
 ]
+
+# tcp flags fin,syn / fin,syn
+[
+    {
+        "match": {
+            "left": {
+                "&": [
+                    {
+                        "payload": {
+                            "field": "flags",
+                            "protocol": "tcp"
+                        }
+                    },
+                    [
+                        "fin",
+                        "syn"
+                    ]
+                ]
+            },
+            "op": "==",
+            "right": [
+                "fin",
+                "syn"
+            ]
+        }
+    }
+]
-- 
2.26.3