src: allow to use typeof of raw expressions in set declaration

Use the dynamic datatype to allocate an instance of TYPE_INTEGER and set
length and byteorder. Add missing information to the set userdata area
for raw payload expressions which allows to rebuild the set typeof from
the listing path.

A few examples:

- With anonymous sets:

  nft add rule x y ip saddr . @ih,32,32 { 1.1.1.1 . 0x14, 2.2.2.2 . 0x1e }

- With named sets:

 table x {
        set y {
                typeof ip saddr . @ih,32,32
                elements = { 1.1.1.1 . 0x14 }
        }
 }

Incremental updates are also supported, eg.

 nft add element x y { 3.3.3.3 . 0x28 }

expr_evaluate_concat() is used to evaluate both set key definitions
and set key values, using two different function might help to simplify
this code in the future.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 4 insertions, 2 deletions

diff --git a/src/expression.c b/src/expression.c
index 612f2c06..9c9a7ced 100644
--- a/src/expression.c
+++ b/src/expression.c
@@ -18,6 +18,7 @@
 #include <expression.h>
 #include <statement.h>
 #include <datatype.h>
+#include <netlink.h>
 #include <rule.h>
 #include <gmputil.h>
 #include <utils.h>
@@ -950,7 +951,7 @@ 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;
-	uint32_t dt = 0;
+	uint32_t dt = 0, len = 0;
 	unsigned int i;
 	int err;
 
@@ -991,6 +992,7 @@ static struct expr *concat_expr_parse_udata(const struct nftnl_udata *attr)
 
 		dt = concat_subtype_add(dt, expr->dtype->type);
 		compound_expr_add(concat_expr, expr);
+		len += netlink_padded_len(expr->len);
 	}
 
 	dtype = concat_type_alloc(dt);
@@ -998,7 +1000,7 @@ static struct expr *concat_expr_parse_udata(const struct nftnl_udata *attr)
 		goto err_free;
 
 	concat_expr->dtype = datatype_get(dtype);
-	concat_expr->len = dtype->size;
+	concat_expr->len = len;
 
 	return concat_expr;