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, 1 insertions, 3 deletions

diff --git a/src/mnl.c b/src/mnl.c
index 6be991a4..e83e0a16 100644
--- a/src/mnl.c
+++ b/src/mnl.c
@@ -1093,9 +1093,7 @@ static void set_key_expression(struct netlink_ctx *ctx,
 {
 	struct nftnl_udata *nest1, *nest2;
 
-	if (expr->flags & EXPR_F_CONSTANT ||
-	    set_is_anonymous(set_flags) ||
-	    !expr_ops(expr)->build_udata)
+	if (!expr_ops(expr)->build_udata)
 		return;
 
 	nest1 = nftnl_udata_nest_start(udbuf, type);