src: netlink_delinarize: don't stop when encountering unsupported expression

The error message is still shown, but try to make sense of further
expressions (if any).

I tried to replace the expression by a textual representation.

Two variants I tested are:
1. append as comment:
   ip saddr 127.0.0.2 drop comment "unknown expression 'foo'"
   This allows nft -f, but it adds/alters a comment.

2. substitute in-place (i.e., add a constant expression
   with the error message instead of 'unkown' message:

   unknown expression "foo" ip saddr 127.0.0.2 drop

This won't allow 'nft -f' however.
I'm not sure this is a problem, in any case we lose information
if we can't find an expression (e.g. added by newer version).

Signed-off-by: Florian Westphal <fw@strlen.de>

diff --git a/src/netlink_delinearize.c b/src/netlink_delinearize.c
index 8da7c17c8c00d63dfe709629136fdebde74876ec..31d62420d41c8eea307a99d5e948bc545cface82 100644 (file)
--- a/src/netlink_delinearize.c
+++ b/src/netlink_delinearize.c
@@ -1399,7 +1399,7 @@ static int netlink_parse_expr(const struct nftnl_expr *nle,
        }
 
        netlink_error(ctx, &loc, "unknown expression type '%s'", type);
-       return -1;
+       return 0;
 }
 
 static int netlink_parse_rule_expr(struct nftnl_expr *nle, void *arg)