trafgen: proto: Update field value at runtime

Add basic infrastructure for update proto field value at runtime by
dynamic field function.

Extended 'struct packet_dyn' with proto fields which has dynamically
changing values at runtime.

Added 'field_changed' callback for proto header which may be used for
check if csum updating is needed. This callback is called after field
was changed at runtime.

Added 'packet_update' callback to let proto header know when to apply
final proto header changes at runtime (e.g. - csum update).

Signed-off-by: Vadim Kochan <vadim4j@gmail.com>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>

1 files changed, 9 insertions, 0 deletions

diff --git a/trafgen.c b/trafgen.c
index b76b5d7..553dfa5 100644
--- a/trafgen.c
+++ b/trafgen.c
@@ -619,6 +619,15 @@ static inline void packet_apply_dyn_elements(int idx)
 		apply_randomizer(idx);
 		apply_csum16(idx);
 	}
+
+	if (packet_dyn_has_fields(&packet_dyn[idx])) {
+		uint32_t i;
+
+		for (i = 0; i < packet_dyn[idx].flen; i++)
+			proto_field_dyn_apply(packet_dyn[idx].fields[i]);
+
+		proto_packet_update(idx);
+	}
 }
 
 static void xmit_slowpath_or_die(struct ctx *ctx, unsigned int cpu, unsigned long orig_num)