[PATCH nft] concat: provide proper dtype when parsing typeof udata

[Florian Westphal <fw@xxxxxxxxx>]

Pablo reports following list bug:
table ip foo {
        map whitelist {
                typeof ip saddr . ip daddr : meta mark
                elements = { 0x0 [invalid type] . 0x0 [invalid type] : 0x00000001,
                             0x0 [invalid type] . 0x0 [invalid type] : 0x00000002 }
        }
}

Problem is that concat provided 'invalid' dtype.

Reported-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
Signed-off-by: Florian Westphal <fw@xxxxxxxxx>
---
 src/expression.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/src/expression.c b/src/expression.c
index 863cf86ec1d0..6605beb30407 100644
--- a/src/expression.c
+++ b/src/expression.c
@@ -906,8 +906,9 @@ static int concat_parse_udata_nested(const struct nftnl_udata *attr, void *data)
 static struct expr *concat_expr_parse_udata(const struct nftnl_udata *attr)
 {
 	const struct nftnl_udata *ud[NFTNL_UDATA_SET_KEY_CONCAT_NEST_MAX] = {};
+	const struct datatype *dtype;
 	struct expr *concat_expr;
-	struct datatype *dtype;
+	uint32_t dt = 0;
 	unsigned int i;
 	int err;
 
@@ -920,8 +921,6 @@ static struct expr *concat_expr_parse_udata(const struct nftnl_udata *attr)
 	if (!concat_expr)
 		return NULL;
 
-	dtype = xzalloc(sizeof(*dtype));
-
 	for (i = 0; i < array_size(ud); i++) {
 		const struct nftnl_udata *nest_ud[NFTNL_UDATA_SET_KEY_CONCAT_SUB_MAX];
 		const struct nftnl_udata *nested, *subdata;
@@ -948,11 +947,14 @@ static struct expr *concat_expr_parse_udata(const struct nftnl_udata *attr)
 		if (!expr)
 			goto err_free;
 
-		dtype->subtypes++;
+		dt = concat_subtype_add(dt, expr->dtype->type);
 		compound_expr_add(concat_expr, expr);
-		dtype->size += round_up(expr->len, BITS_PER_BYTE * sizeof(uint32_t));
 	}
 
+	dtype = concat_type_alloc(dt);
+	if (!dtype)
+		goto err_free;
+
 	concat_expr->dtype = dtype;
 	concat_expr->len = dtype->size;
 
-- 
2.24.1