trafgen: proto: Introduce proto_upper_header() function

Added proto_upper_header() function to fetch upper proto header.

It will be used by IPv4/IPv6 proto header to notify UDP/TCP proto
headers to invalidate L4 csum when L3 pseudo header field was changed.

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

1 files changed, 12 insertions, 0 deletions

diff --git a/trafgen_proto.c b/trafgen_proto.c
index b0a198f..f4b2828 100644
--- a/trafgen_proto.c
+++ b/trafgen_proto.c
@@ -40,6 +40,18 @@ struct proto_hdr *proto_lower_header(struct proto_hdr *hdr)
 	return headers[hdr->index - 1];
 }
 
+struct proto_hdr *proto_upper_header(struct proto_hdr *hdr)
+{
+	struct packet *pkt = packet_get(hdr->pkt_id);
+	struct proto_hdr **headers = &pkt->headers[0];
+	size_t headers_count = pkt->headers_count;
+
+	if (hdr->index == headers_count - 1)
+		return NULL;
+
+	return headers[hdr->index + 1];
+}
+
 uint8_t *proto_header_ptr(struct proto_hdr *hdr)
 {
 	return &packet_get(hdr->pkt_id)->payload[hdr->pkt_offset];