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lapdm: Append RSL_IE_OSMO_ABS_FRAME_NUMBER to RSLms msgs towards upper layers

This makes it possible to track GSM time in the upper layers.
The existing RSL_IE_FRAME_NUMBER and RSL_IE_STARTNG_TIME cannot be used
there, since those are 16bit fields containing Relative FN values.

The IE needs to be added before the L3_INFO one, because user code
usually assumes the msgb->l3 pointing to L3_INFO value extends until the
end of the message, using msgb3_len(msg). Regarding having an extra IE
at the middle, it's not a big problem since the libosmocore version
submitting this commit to the upper layers is the same which will also
be parsing it through rsl_tlv_parse() later on by the app.

Related: OS#3626
Change-Id: Id62c18f49f270449067b25b7104eb8b47f1955ec
---
M include/osmocom/gsm/rsl.h
M src/gsm/lapdm.c
M src/gsm/rsl.c
M tests/lapd/lapd_test.c
M tests/lapd/lapd_test.ok
5 files changed, 68 insertions(+), 13 deletions(-)

git pull ssh://gerrit.osmocom.org:29418/libosmocore refs/changes/32/34132/1
diff --git a/include/osmocom/gsm/rsl.h b/include/osmocom/gsm/rsl.h
index 285dbc2..b9d3282 100644
--- a/include/osmocom/gsm/rsl.h
+++ b/include/osmocom/gsm/rsl.h
@@ -51,6 +51,8 @@
/* Push a RSL RLL header with L3_INFO IE */
void rsl_rll_push_l3(struct msgb *msg, uint8_t msg_type, uint8_t chan_nr,
uint8_t link_id, int transparent);
+void rsl_rll_push_l3_with_fn(struct msgb *msg, uint8_t msg_type, uint8_t chan_nr,
+ uint8_t link_id, int transparent, uint32_t fn);

/* Allocate msgb and fill with simple RSL RLL header */
struct msgb *rsl_rll_simple(uint8_t msg_type, uint8_t chan_nr,
diff --git a/src/gsm/lapdm.c b/src/gsm/lapdm.c
index e96e218..a2e44a3 100644
--- a/src/gsm/lapdm.c
+++ b/src/gsm/lapdm.c
@@ -503,7 +503,7 @@
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, transparent);
+ rsl_rll_push_l3_with_fn(msg, msg_type, mctx->chan_nr, mctx->link_id, transparent, mctx->fn);

/* send off the RSLms message to L3 */
return rslms_sendmsg(msg, mctx->dl->entity);
@@ -517,6 +517,8 @@
/* Add the RSL + RLL header */
msgb_tv16_push(msg, RSL_IE_L3_INFO, l3_len);

+ msgb_tv32_push(msg, RSL_IE_OSMO_ABS_FRAME_NUMBER, mctx->fn);
+
/* Add two non-standard IEs carrying MS power and TA values for B4 (SACCH) */
if (mctx->lapdm_fmt == LAPDm_FMT_B4) {
msgb_tv_push(msg, RSL_IE_MS_POWER, mctx->tx_power_ind);
@@ -535,6 +537,8 @@
int transparent = rsl_is_transparent(msg_type);

msg = rsl_rll_simple(msg_type, mctx->chan_nr, mctx->link_id, transparent);
+ /* Add FN to the end to keep backward compat: */
+ msgb_tv32_put(msg, RSL_IE_OSMO_ABS_FRAME_NUMBER, mctx->fn);

/* send off the RSLms message to L3 */
return rslms_sendmsg(msg, mctx->dl->entity);
@@ -547,6 +551,9 @@
LOGDL(&mctx->dl->dl, LOGL_NOTICE, "sending MDL-ERROR-IND %d\n", cause);
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);
+ /* Add FN to the end to keep backward compat: */
+ msgb_tv32_put(msg, RSL_IE_OSMO_ABS_FRAME_NUMBER, mctx->fn);
+
return rslms_sendmsg(msg, mctx->dl->entity);
}

diff --git a/src/gsm/rsl.c b/src/gsm/rsl.c
index eac7fd8..a95d294 100644
--- a/src/gsm/rsl.c
+++ b/src/gsm/rsl.c
@@ -561,6 +561,31 @@
rsl_rll_push_hdr(msg, msg_type, chan_nr, link_id, transparent);
}

+/*! Wrap msgb in L3 Info IE and push a RSL RLL header
+ * \param[in] msg Message Buffer to which L3 Header shall be appended
+ * \param[in] msg_type RSL Message Type
+ * \param[in] chan_hr RSL Channel Number
+ * \param[in] link_id Link Identififer
+ * \param[in] transparent Transparent to BTS (1) or not (0)
+ * \param[in] fn Frame Number
+ */
+void rsl_rll_push_l3_with_fn(struct msgb *msg, uint8_t msg_type, uint8_t chan_nr,
+ uint8_t link_id, int transparent, uint32_t fn)
+{
+ uint8_t l3_len = msg->tail - (uint8_t *)msgb_l3(msg);
+
+ /* construct a RSLms RLL message (DATA INDICATION, UNIT DATA
+ * INDICATION) and send it off via RSLms */
+
+ /* Push the L3 IE tag and length */
+ msgb_tv16_push(msg, RSL_IE_L3_INFO, l3_len);
+
+ msgb_tv32_push(msg, RSL_IE_OSMO_ABS_FRAME_NUMBER, fn);
+
+ /* Then push the RSL header */
+ rsl_rll_push_hdr(msg, msg_type, chan_nr, link_id, transparent);
+}
+
/*! Create msgb with RSL RLL header
* \param[in] msg_type RSL Message Type
* \param[in] chan_nr RSL Channel Number
diff --git a/tests/lapd/lapd_test.c b/tests/lapd/lapd_test.c
index afea822..791edc8 100644
--- a/tests/lapd/lapd_test.c
+++ b/tests/lapd/lapd_test.c
@@ -360,7 +360,7 @@
struct abis_rsl_rll_hdr hdr;

printf("MS: Verifying incoming primitive.\n");
- OSMO_ASSERT(msg->len == sizeof(struct abis_rsl_rll_hdr));
+ OSMO_ASSERT(msg->len >= sizeof(struct abis_rsl_rll_hdr));

/* verify the header */
memset(&hdr, 0, sizeof(hdr));
diff --git a/tests/lapd/lapd_test.ok b/tests/lapd/lapd_test.ok
index a2e5ae3..9a3094f 100644
--- a/tests/lapd/lapd_test.ok
+++ b/tests/lapd/lapd_test.ok
@@ -1,28 +1,28 @@
I do some very simple LAPDm test.
Establishing link.
ms_to_bts_l1_cb: MS(us) -> BTS prim message
-bts_to_ms_tx_cb: MS->BTS(us) message 25
+bts_to_ms_tx_cb: MS->BTS(us) message 30
BTS: Verifying CM request.

Confirming
lapdm_phsap_dequeue_prim(): got rc 0: Success
Took message from DCCH queue: L2 header size 3, L3 size 20, SAP 0x1000000, 0/0, Link 0x00, FN 0
Message: [L2]> 01 73 41 [L3]> 05 24 31 03 50 18 93 08 29 47 80 00 00 00 00 80 2b 2b 2b 2b
-ms_to_bts_tx_cb: BTS->MS(us) message 6
+ms_to_bts_tx_cb: BTS->MS(us) message 11
MS: Verifying incoming primitive.

Sending back to MS
lapdm_phsap_dequeue_prim(): got rc 0: Success
Took message from DCCH queue: L2 header size 3, L3 size 20, SAP 0x1000000, 0/0, Link 0x00, FN 0
Message: [L2]> 03 00 0d [L3]> 05 04 0d 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b
-ms_to_bts_tx_cb: BTS->MS(us) message 12
+ms_to_bts_tx_cb: BTS->MS(us) message 17
MS: Verifying incoming MM message: 3
ms_to_bts_l1_cb: MS(us) -> BTS prim message
lapdm_phsap_dequeue_prim(): got rc -19: No such device

Sending back to BTS
ms_to_bts_l1_cb: MS(us) -> BTS prim message
-bts_to_ms_tx_cb: MS->BTS(us) message 14
+bts_to_ms_tx_cb: MS->BTS(us) message 19
BTS: Verifying dummy message.
lapdm_phsap_dequeue_prim(): got rc 0: Success
MSGB: L3 is undefined
@@ -32,7 +32,7 @@
lapdm_phsap_dequeue_prim(): got rc -19: No such device
I test RF channel release of an unestablished channel.
I test contention resultion by having two mobiles collide and first mobile repeating SABM.
-bts_to_ms_tx_cb: MS->BTS(us) message 25
+bts_to_ms_tx_cb: MS->BTS(us) message 30
BTS: Verifying CM request.
lapdm_phsap_dequeue_prim(): got rc 0: Success
Took message from DCCH queue: L2 header size 3, L3 size 20, SAP 0x1000000, 0/0, Link 0x00, FN 0
@@ -60,7 +60,7 @@
I test if desync problems exist in LAPDm

Establishing SAPI=0
-bts_to_ms_dummy_tx_cb: MS->BTS(us) message 25
+bts_to_ms_dummy_tx_cb: MS->BTS(us) message 30

Dumping queue:
00 00 17 [L2]> 01 73 41 [L3]> 05 24 31 03 50 18 93 08 29 47 80 00 00 00 00 80
@@ -70,7 +70,7 @@
Message: [L2]> 01 73 41 [L3]> 05 24 31 03 50 18 93 08 29 47 80 00 00 00 00 80 2b 2b 2b 2b

Sending Classmark Change
-bts_to_ms_dummy_tx_cb: MS->BTS(us) message 27
+bts_to_ms_dummy_tx_cb: MS->BTS(us) message 32

Dumping queue:
00 00 17 [L2]> 01 21 01
@@ -87,7 +87,7 @@


Sending GPRS Suspend Request
-bts_to_ms_dummy_tx_cb: MS->BTS(us) message 22
+bts_to_ms_dummy_tx_cb: MS->BTS(us) message 27

Dumping queue:
00 00 17 [L2]> 03 40 0d [L3]> 06 35 01
@@ -97,7 +97,7 @@
Message: [L2]> 03 40 0d [L3]> 06 35 01 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b

Sending Cipher Mode Complete
-bts_to_ms_dummy_tx_cb: MS->BTS(us) message 11
+bts_to_ms_dummy_tx_cb: MS->BTS(us) message 16

Dumping queue:
00 00 17 [L2]> 01 61 01
@@ -108,7 +108,7 @@
Message: [L2]> 01 61 01 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b 2b

Establishing SAPI=3
-bts_to_ms_dummy_tx_cb: MS->BTS(us) message 6
+bts_to_ms_dummy_tx_cb: MS->BTS(us) message 11

Dumping queue:

@@ -128,7 +128,7 @@
=== I test SAPI0/SAPI3 prioritization ===

MS is establishing a SAPI=0 link
-bts_to_ms_dummy_tx_cb: MS->BTS(us) message 22
+bts_to_ms_dummy_tx_cb: MS->BTS(us) message 27
BTS is establishing a SAPI=3 link
lapdm_phsap_dequeue_prim(): got rc 0: Success
Took message from DCCH queue: L2 header size 3, L3 size 20, SAP 0x1000000, 0/0, Link 0x00, FN 0

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Gerrit-Project: libosmocore
Gerrit-Branch: master
Gerrit-Change-Id: Id62c18f49f270449067b25b7104eb8b47f1955ec
Gerrit-Change-Number: 34132
Gerrit-PatchSet: 1
Gerrit-Owner: pespin <pespin@sysmocom.de>
Gerrit-MessageType: newchange