payload: print base and raw values for unknown payloads

We currently print 'unknown' rather than the raw offset values
for unrecognized header values.

If its unknown, prefer to print

payload @nh,0,16 set payload @nh,0,16

rather than 'unknown'.

Also add a helper to check if payload expression has a description
assigned to it.

Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>

2 files changed, 14 insertions, 1 deletions

diff --git a/include/payload.h b/include/payload.h
index 37375c10..bda31886 100644
--- a/include/payload.h
+++ b/include/payload.h
@@ -31,6 +31,7 @@ struct payload_dep_ctx {
 	struct stmt		*prev;
 };
 
+extern bool payload_is_known(const struct expr *expr);
 extern bool payload_is_stacked(const struct proto_desc *desc,
 			       const struct expr *expr);
 extern void payload_dependency_store(struct payload_dep_ctx *ctx,
diff --git a/src/payload.c b/src/payload.c
index 9ba980a5..af533b2a 100644
--- a/src/payload.c
+++ b/src/payload.c
@@ -26,6 +26,18 @@
 #include <gmputil.h>
 #include <utils.h>
 
+bool payload_is_known(const struct expr *expr)
+{
+	const struct proto_hdr_template *tmpl;
+	const struct proto_desc *desc;
+
+	desc = expr->payload.desc;
+	tmpl = expr->payload.tmpl;
+
+	return desc && tmpl && desc != &proto_unknown &&
+	       tmpl != &proto_unknown_template;
+}
+
 static void payload_expr_print(const struct expr *expr)
 {
 	const struct proto_desc *desc;
@@ -33,7 +45,7 @@ static void payload_expr_print(const struct expr *expr)
 
 	desc = expr->payload.desc;
 	tmpl = expr->payload.tmpl;
-	if (desc != NULL && tmpl != NULL)
+	if (payload_is_known(expr))
 		printf("%s %s", desc->name, tmpl->token);
 	else
 		printf("payload @%s,%u,%u",