Change in osmo-sgsn[master]: Fix nsei+bvci not updated on rx UL SNDCP data

[pespin]

pespin has uploaded this change for review. ( https://gerrit.osmocom.org/c/osmo-sgsn/+/22929 )


Change subject: Fix nsei+bvci not updated on rx UL SNDCP data
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Fix nsei+bvci not updated on rx UL SNDCP data

msgid2mmctx() was already being called for signalling messages in
gsm0408_gprs_rcvmsg_gb() before calling gprs_gb_recv_pdu(), but it was
not called in sndcp_llunitdata_ind().

Let's move msgid2mmctx() inside gprs_gb_recv_pdu() since we want to
always update the nsei+bvci, regardless of message containing data or
control content.

This commit fixes the scenario where an MS changes to a new cell (PCU)
and then continues transmitting UL data. Prior to this patch, the SGSN
kept sending DL content to the old cell (PCU nsei+bvci) instead of the
new one even after the MS transmitted Ul content fro mthe new cell.

Related: SYS#4909
Change-Id: I2c14e1d65575f54212924f7c5f0a2f4c1b76ec81
---
M include/osmocom/sgsn/gprs_gb.h
M src/sgsn/gprs_gb.c
M src/sgsn/gprs_sndcp.c
3 files changed, 5 insertions(+), 5 deletions(-)



  git pull ssh://gerrit.osmocom.org:29418/osmo-sgsn refs/changes/29/22929/1

diff --git a/include/osmocom/sgsn/gprs_gb.h b/include/osmocom/sgsn/gprs_gb.h
index c98dd34..9162367 100644
--- a/include/osmocom/sgsn/gprs_gb.h
+++ b/include/osmocom/sgsn/gprs_gb.h
@@ -8,7 +8,7 @@
 int gsm0408_gprs_rcvmsg_gb(struct msgb *msg, struct gprs_llc_llme *llme,
 			   bool drop_cipherable);
 /* Has to be called whenever any PDU (signaling, data, ...) has been received */
-void gprs_gb_recv_pdu(struct sgsn_mm_ctx *mmctx);
+void gprs_gb_recv_pdu(struct sgsn_mm_ctx *mmctx, const struct msgb *msg);
 
 /* page a MS in its routing area */
 int gprs_gb_page_ps_ra(struct sgsn_mm_ctx *mmctx);
diff --git a/src/sgsn/gprs_gb.c b/src/sgsn/gprs_gb.c
index 2585d6d..cddd1b1 100644
--- a/src/sgsn/gprs_gb.c
+++ b/src/sgsn/gprs_gb.c
@@ -38,7 +38,8 @@
 #include <osmocom/sgsn/debug.h>
 
 /* Has to be called whenever any PDU (signaling, data, ...) has been received */
-void gprs_gb_recv_pdu(struct sgsn_mm_ctx *mmctx) {
+void gprs_gb_recv_pdu(struct sgsn_mm_ctx *mmctx, const struct msgb *msg) {
+	msgid2mmctx(mmctx, msg);
 	if (mmctx->gb.llme)
 		osmo_fsm_inst_dispatch(mmctx->gb.mm_state_fsm, E_MM_PDU_RECEPTION, NULL);
 }
@@ -56,10 +57,9 @@
 	bssgp_parse_cell_id(&ra_id, msgb_bcid(msg));
 	mmctx = sgsn_mm_ctx_by_tlli(msgb_tlli(msg), &ra_id);
 	if (mmctx) {
-		msgid2mmctx(mmctx, msg);
 		rate_ctr_inc(&mmctx->ctrg->ctr[GMM_CTR_PKTS_SIG_IN]);
 		mmctx->gb.llme = llme;
-		gprs_gb_recv_pdu(mmctx);
+		gprs_gb_recv_pdu(mmctx, msg);
 	}
 
 	/* MMCTX can be NULL */
diff --git a/src/sgsn/gprs_sndcp.c b/src/sgsn/gprs_sndcp.c
index b237bf9..6692f1a 100644
--- a/src/sgsn/gprs_sndcp.c
+++ b/src/sgsn/gprs_sndcp.c
@@ -808,7 +808,7 @@
 				lle, lle->llme->tlli, lle->sapi, sch->nsapi);
 		return -EIO;
 	}
-	gprs_gb_recv_pdu(mmctx);
+	gprs_gb_recv_pdu(mmctx, msg);
 
 	if (scomph) {
 		sne->defrag.pcomp = scomph->pcomp;

-- 
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Gerrit-Project: osmo-sgsn
Gerrit-Branch: master
Gerrit-Change-Id: I2c14e1d65575f54212924f7c5f0a2f4c1b76ec81
Gerrit-Change-Number: 22929
Gerrit-PatchSet: 1
Gerrit-Owner: pespin <pespin at sysmocom.de>
Gerrit-MessageType: newchange
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