[PATCH nftables] Allow concatenation of rt nexthop etc.

[PATCH nftables] Allow concatenation of rt nexthop etc.

[Anders K. Pedersen | Cohaesio]

From: Anders K. Pedersen <akp@cohaesio.com>

Concatenations of rt nexthop or ct {orignal | reply} {saddr | daddr} fail
due to

 # nft add rule ip filter postrouting flow table acct \{ ip saddr . rt nexthop counter \}
 <cmdline>:1:61-70: Error: can not use variable sized data types (invalid) in concat expressions
 add rule ip filter postrouting flow table acct { ip saddr . rt nexthop counter }
                                                  ~~~~~~~~~~~^^^^^^^^^^

Fix this by reordering the check for variable size data types in
expr_evaluate_concat() to happen after expr_evaluate() has been called (via
list_member_evaluate()) for the sub expression. This allows
expr_evaluate_[cr]t() to call [cr]t_expr_update_type() and set the data type
before the check.

Signed-off-by: Anders K. Pedersen <akp@cohaesio.com>
---
 src/evaluate.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/src/evaluate.c b/src/evaluate.c
index 79add5e..878efac 100644
--- a/src/evaluate.c
+++ b/src/evaluate.c
@@ -987,13 +987,6 @@ static int expr_evaluate_concat(struct eval_ctx *ctx, struct expr **expr)
 						 "expecting %s",
 						 dtype->desc);
 
-		if (dtype == NULL && i->dtype->size == 0)
-			return expr_binary_error(ctx->msgs, i, *expr,
-						 "can not use variable sized "
-						 "data types (%s) in concat "
-						 "expressions",
-						 i->dtype->name);
-
 		if (dtype == NULL)
 			tmp = datatype_lookup(TYPE_INVALID);
 		else
@@ -1004,6 +997,13 @@ static int expr_evaluate_concat(struct eval_ctx *ctx, struct expr **expr)
 			return -1;
 		flags &= i->flags;
 
+		if (dtype == NULL && i->dtype->size == 0)
+			return expr_binary_error(ctx->msgs, i, *expr,
+						 "can not use variable sized "
+						 "data types (%s) in concat "
+						 "expressions",
+						 i->dtype->name);
+
 		ntype = concat_subtype_add(ntype, i->dtype->type);
 	}
 

Re: [PATCH nftables] Allow concatenation of rt nexthop etc.

[Pablo Neira Ayuso]

On Sat, Oct 29, 2016 at 09:49:09AM +0000, Anders K. Pedersen | Cohaesio wrote:
> From: Anders K. Pedersen <akp@cohaesio.com>
> 
> Concatenations of rt nexthop or ct {orignal | reply} {saddr | daddr} fail
> due to
> 
>  # nft add rule ip filter postrouting flow table acct \{ ip saddr . rt nexthop counter \}
>  <cmdline>:1:61-70: Error: can not use variable sized data types (invalid) in concat expressions
>  add rule ip filter postrouting flow table acct { ip saddr . rt nexthop counter }
>                                                   ~~~~~~~~~~~^^^^^^^^^^
> 
> Fix this by reordering the check for variable size data types in
> expr_evaluate_concat() to happen after expr_evaluate() has been called (via
> list_member_evaluate()) for the sub expression. This allows
> expr_evaluate_[cr]t() to call [cr]t_expr_update_type() and set the data type
> before the check.

Applied, thanks Anders.

P.S: I can see git am sometimes complain about trailing CRLF, also
patchwork seems to skip some of your patches for some reason, which
makes it easier for us to lose stuff from you. I guess it's probably
MUA related problem, it would be great if you find the root cause.