RSL/LAPDm: Not all RLL message are "transparent"
3GPP TS 48.058 has a very clear definition of which messages are
"transparent" and hence have the T-bit == 1. This is *not* just
all RLL messages, but basically only RLL_DATA.{ind,req} and
RLL_UNITDATA.{ind,req}. All other messages are non-transparent.
Change-Id: I9f83654af189d818563d799bf623325b7fee8e70
Closes: OS#3188
diff --git a/src/gsm/lapdm.c b/src/gsm/lapdm.c
index 80c0d17..6a16012 100644
--- a/src/gsm/lapdm.c
+++ b/src/gsm/lapdm.c
@@ -349,12 +349,29 @@
return le->l1_prim_cb(&pp.oph, le->l1_ctx);
}
+/* Is a given msg_type "transparent" as per TS 48.058 Section 8.1 */
+static int rsl_is_transparent(uint8_t msg_type)
+{
+ switch (msg_type) {
+ case RSL_MT_DATA_IND:
+ case RSL_MT_UNIT_DATA_IND:
+ return 1;
+ case RSL_MT_DATA_REQ:
+ case RSL_MT_UNIT_DATA_REQ:
+ return 1;
+ default:
+ return 0;
+ }
+}
+
/* Create RSLms various RSLms messages */
static int send_rslms_rll_l3(uint8_t msg_type, struct lapdm_msg_ctx *mctx,
struct msgb *msg)
{
+ int transparent = rsl_is_transparent(msg_type);
+
/* Add the RSL + RLL header */
- rsl_rll_push_l3(msg, msg_type, mctx->chan_nr, mctx->link_id, 1);
+ rsl_rll_push_l3(msg, msg_type, mctx->chan_nr, mctx->link_id, transparent);
/* send off the RSLms message to L3 */
return rslms_sendmsg(msg, mctx->dl->entity);
@@ -385,8 +402,9 @@
static int send_rll_simple(uint8_t msg_type, struct lapdm_msg_ctx *mctx)
{
struct msgb *msg;
+ int transparent = rsl_is_transparent(msg_type);
- msg = rsl_rll_simple(msg_type, mctx->chan_nr, mctx->link_id, 1);
+ msg = rsl_rll_simple(msg_type, mctx->chan_nr, mctx->link_id, transparent);
/* send off the RSLms message to L3 */
return rslms_sendmsg(msg, mctx->dl->entity);
@@ -397,7 +415,7 @@
struct msgb *msg;
LOGP(DLLAPD, LOGL_NOTICE, "sending MDL-ERROR-IND %d\n", cause);
- msg = rsl_rll_simple(RSL_MT_ERROR_IND, mctx->chan_nr, mctx->link_id, 1);
+ msg = rsl_rll_simple(RSL_MT_ERROR_IND, mctx->chan_nr, mctx->link_id, 0);
msgb_tlv_put(msg, RSL_IE_RLM_CAUSE, 1, &cause);
return rslms_sendmsg(msg, mctx->dl->entity);
}
diff --git a/tests/lapd/lapd_test.c b/tests/lapd/lapd_test.c
index 3f15afe..8a4e931 100644
--- a/tests/lapd/lapd_test.c
+++ b/tests/lapd/lapd_test.c
@@ -356,7 +356,6 @@
/* verify the header */
memset(&hdr, 0, sizeof(hdr));
rsl_init_rll_hdr(&hdr, RSL_MT_EST_CONF);
- hdr.c.msg_discr |= ABIS_RSL_MDISC_TRANSP;
OSMO_ASSERT(memcmp(msg->data, &hdr, sizeof(hdr)) == 0);
} else if (state->ms_read == 1) {
printf("MS: Verifying incoming MM message: %d\n", msgb_l3len(msg));