lapdm: Track fn of primitives in struct lapdm_msg_ctx
This field will be used in follow-up commits to provide FN information
in RSLms primitives towars upper layers. This is needed for instance on
the MS side when a CCCH_DATA.ind is received containing a TBF ImmAss
with a relative FN indicating the Starting Time. Without tracking FN
advance, the uppers layers are not capable of figuring out the absolute
FN of the TBF Starting time.
The struct lapdm_msg_ctx is not really used outside of libosmocore, so
we are safe extending it.
Related: OS#3626
Change-Id: Icf986f4202703eb452bedc1b749bb8ce0c73706f
diff --git a/include/osmocom/gsm/lapdm.h b/include/osmocom/gsm/lapdm.h
index 0e99743..1a39fca 100644
--- a/include/osmocom/gsm/lapdm.h
+++ b/include/osmocom/gsm/lapdm.h
@@ -24,6 +24,7 @@
uint8_t link_id;
uint8_t ta_ind; /* TA indicated by network */
uint8_t tx_power_ind; /* MS power indicated by network */
+ uint32_t fn;
};
/*! LAPDm datalink like TS 04.06 / Section 3.5.2 */
diff --git a/src/gsm/lapdm.c b/src/gsm/lapdm.c
index 4a82c4d..e96e218 100644
--- a/src/gsm/lapdm.c
+++ b/src/gsm/lapdm.c
@@ -700,7 +700,7 @@
/* input into layer2 (from layer 1) */
static int l2_ph_data_ind(struct msgb *msg, struct lapdm_entity *le,
- uint8_t chan_nr, uint8_t link_id)
+ uint8_t chan_nr, uint8_t link_id, uint32_t fn)
{
uint8_t cbits = chan_nr >> 3;
uint8_t sapi; /* we cannot take SAPI from link_id, as L1 has no clue */
@@ -715,6 +715,7 @@
memset(&mctx, 0, sizeof(mctx));
mctx.chan_nr = chan_nr;
mctx.link_id = link_id;
+ mctx.fn = fn;
/* check for L1 chan_nr/link_id and determine LAPDm hdr format */
if (cbits == 0x10 || cbits == 0x12) {
@@ -916,7 +917,7 @@
switch (OSMO_PRIM_HDR(oph)) {
case OSMO_PRIM(PRIM_PH_DATA, PRIM_OP_INDICATION):
rc = l2_ph_data_ind(oph->msg, le, pp->u.data.chan_nr,
- pp->u.data.link_id);
+ pp->u.data.link_id, pp->u.data.fn);
break;
case OSMO_PRIM(PRIM_PH_RTS, PRIM_OP_INDICATION):
rc = l2_ph_data_conf(oph->msg, le);
diff --git a/tests/lapd/lapd_test.c b/tests/lapd/lapd_test.c
index 739f9b7..2f2a7f4 100644
--- a/tests/lapd/lapd_test.c
+++ b/tests/lapd/lapd_test.c
@@ -184,6 +184,7 @@
/* LAPDm requires those... */
pp.u.data.chan_nr = 0;
pp.u.data.link_id = 0;
+ pp.u.data.fn = 0;
/* feed into the LAPDm code of libosmogsm */
rc = lapdm_phsap_up(&pp.oph, &chan->lapdm_dcch);
OSMO_ASSERT(rc == 0 || rc == -EBUSY);
@@ -206,6 +207,7 @@
/* LAPDm requires those... */
pp.u.data.chan_nr = 0;
pp.u.data.link_id = 0;
+ pp.u.data.fn = 0;
/* feed into the LAPDm code of libosmogsm */
rc = lapdm_phsap_up(&pp.oph, &chan->lapdm_dcch);
OSMO_ASSERT(rc == 0 || rc == -EBUSY);