evaluate: maps: check element data mapping matches set data definition

This change is similar to
7f4d7fef31bd ("evaluate: check element key vs. set definition")

but this time for data mappings.

The included bogon asserts with:
BUG: invalid data expression type catch-all set element
nft: src/netlink.c:596: __netlink_gen_data: Assertion `0' failed.

after:
internal:0:0-0: Error: Element mapping mismatches map definition, expected packet mark, not 'invalid'

Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/src/evaluate.c b/src/evaluate.c
index f7e97ef7ea10f52facd1f48aa7f734446edce4c7..c20a1d526c1ebacd2420c89843edd84cbaf3c16c 100644 (file)
--- a/src/evaluate.c
+++ b/src/evaluate.c
@@ -2361,6 +2361,20 @@ static bool data_mapping_has_interval(struct expr *data)
        return false;
 }
 
+static bool elem_data_compatible(const struct expr *set_data,
+                               const struct expr *elem_data)
+{
+       if (elem_data->etype == EXPR_RANGE) {
+               /* EXPR_RANGE has invalid_type, use the lhs type.
+                * It should be impossible to have a EXPR_RANGE where
+                * lhs and rhs don't have the same dtype.
+                */
+               return elem_data_compatible(set_data, elem_data->left);
+       }
+
+       return datatype_compatible(set_data->dtype, elem_data->dtype);
+}
+
 static int expr_evaluate_mapping(struct eval_ctx *ctx, struct expr **expr)
 {
        struct expr *mapping = *expr;
@@ -2417,6 +2431,12 @@ static int expr_evaluate_mapping(struct eval_ctx *ctx, struct expr **expr)
                                  "Object mapping data should be a value, not %s",
                                  expr_name(mapping->right));
 
+       if (set_is_datamap(set->flags) &&
+           !elem_data_compatible(set->data, mapping->right))
+               return expr_error(ctx->msgs, mapping->right,
+                                 "Element mapping mismatches map definition, expected %s, not '%s'",
+                                 set->data->dtype->desc, mapping->right->dtype->desc);
+
        mapping->flags |= EXPR_F_CONSTANT;
        return 0;
 }

diff --git a/tests/shell/testcases/bogons/nft-j-f/catchall_as_data_element_assert b/tests/shell/testcases/bogons/nft-j-f/catchall_as_data_element_assert
new file mode 100644 (file)
index 0000000..5b224f9
--- /dev/null
+++ b/tests/shell/testcases/bogons/nft-j-f/catchall_as_data_element_assert
@@ -0,0 +1,34 @@
+{
+  "nftables": [
+    {
+      "metainfo": {
+        "version": "1.1.1",
+        "release_name": "Commodore Bullmoose #2",
+        "json_schema_version": 1
+      }
+    },
+    {
+      "table": {
+        "family": "ip",
+        "name": "t",
+        "handle": 1
+      }
+    },
+    {
+      "map": {
+        "family": "ip",
+        "name": "m",
+        "table": "t",
+        "type": "ipv4_addr",
+        "handle": 1,
+        "map": "mark",
+        "elem": [
+          [
+            "1.2.3.4",
+            "*"
+          ]
+        ]
+      }
+    }
+  ]
+}