l1ctl_proto.h: use flexible array member to store a traffic frame

Unlike the LAPDm messages, traffic frames may have different
length. Instead of having a buffer with fixed length, let's
use flexible array member. This would allow one to calculate
a frame length using the MSGB API (i.e. msgb_l3len()).

Change-Id: I119fa36c84e95c3003d57c19e25f8146ed45c3c6

1 files changed, 25 insertions, 9 deletions

diff --git a/src/host/layer23/src/common/l1ctl.c b/src/host/layer23/src/common/l1ctl.c
index eedfb938..4291d81b 100644
--- a/src/host/layer23/src/common/l1ctl.c
+++ b/src/host/layer23/src/common/l1ctl.c
@@ -775,13 +775,22 @@ static int rx_l1_traffic_ind(struct osmocom_ms *ms, struct msgb *msg)
 {
 	struct l1ctl_info_dl *dl;
 	struct l1ctl_traffic_ind *ti;
+	size_t frame_len;
+	uint8_t *frame;
 
 	/* Header handling */
 	dl = (struct l1ctl_info_dl *) msg->l1h;
+	ti = (struct l1ctl_traffic_ind *) dl->payload;
+	frame = (uint8_t *) ti->data;
+
 	msg->l2h = dl->payload;
-	ti = (struct l1ctl_traffic_ind *) msg->l2h;
+	msg->l3h = frame;
+
+	/* Calculate the frame length */
+	frame_len = msgb_l3len(msg);
 
-	DEBUGP(DL1C, "TRAFFIC IND (%s)\n", osmo_hexdump(ti->data, 33));
+	DEBUGP(DL1C, "TRAFFIC IND (len=%zu): %s\n", frame_len,
+		osmo_hexdump(frame, frame_len));
 
 	/* distribute or drop */
 	if (ms->l1_entity.l1_traffic_ind) {
@@ -803,28 +812,35 @@ int l1ctl_tx_traffic_req(struct osmocom_ms *ms, struct msgb *msg,
 	struct l1ctl_hdr *l1h;
 	struct l1ctl_info_ul *l1i_ul;
 	struct l1ctl_traffic_req *tr;
+	size_t frame_len;
+	uint8_t *frame;
 
 	/* Header handling */
 	tr = (struct l1ctl_traffic_req *) msg->l2h;
+	frame = (uint8_t *) tr->data;
+	msg->l3h = frame;
+
+	/* Calculate the frame length */
+	frame_len = msgb_l3len(msg);
 
-	DEBUGP(DL1C, "TRAFFIC REQ (%s)\n",
-		osmo_hexdump(msg->l2h, msgb_l2len(msg)));
+	DEBUGP(DL1C, "TRAFFIC REQ (len=%zu): %s\n", frame_len,
+		osmo_hexdump(frame, frame_len));
 
-	if (msgb_l2len(msg) != 33) {
+	if (frame_len != 33) {
 		LOGP(DL1C, LOGL_ERROR, "Traffic Request has incorrect length "
-			"(%u != 33)\n", msgb_l2len(msg));
+			"(%u != 33)\n", frame_len);
 		msgb_free(msg);
 		return -EINVAL;
 	}
 
-	if ((tr->data[0] >> 4) != 0xd) {
+	if ((frame[0] >> 4) != 0xd) {
 		LOGP(DL1C, LOGL_ERROR, "Traffic Request has incorrect magic "
-			"(%u != 0xd)\n", tr->data[0] >> 4);
+			"(%u != 0xd)\n", frame[0] >> 4);
 		msgb_free(msg);
 		return -EINVAL;
 	}
 
-//	printf("TX %s\n", osmo_hexdump(tr->data, 33));
+//	printf("TX %s\n", osmo_hexdump(frame, frame_len));
 
 	/* prepend uplink info header */
 	l1i_ul = (struct l1ctl_info_ul *) msgb_push(msg, sizeof(*l1i_ul));