SGSN: Avoid duplicate MM contexts in case MS and SGSN disagree on P-TMSI
diff --git a/openbsc/include/openbsc/gprs_sgsn.h b/openbsc/include/openbsc/gprs_sgsn.h
index fb1b288..b470c53 100644
--- a/openbsc/include/openbsc/gprs_sgsn.h
+++ b/openbsc/include/openbsc/gprs_sgsn.h
@@ -119,6 +119,7 @@
/* Allocate a new SGSN MM context */
struct sgsn_mm_ctx *sgsn_mm_ctx_alloc(uint32_t tlli,
const struct gprs_ra_id *raid);
+void sgsn_mm_ctx_free(struct sgsn_mm_ctx *mm);
enum pdp_ctx_state {
diff --git a/openbsc/src/gprs/gprs_gmm.c b/openbsc/src/gprs/gprs_gmm.c
index ee6e366..4f1fe05 100644
--- a/openbsc/src/gprs/gprs_gmm.c
+++ b/openbsc/src/gprs/gprs_gmm.c
@@ -594,6 +594,19 @@
/* we already have a mm context with current TLLI, but no
* P-TMSI / IMSI yet. What we now need to do is to fill
* this initial context with data from the HLR */
+ if (strlen(ctx->imsi) == 0) {
+ /* Check if we already have a MM context for this IMSI */
+ struct sgsn_mm_ctx *ictx;
+ ictx = sgsn_mm_ctx_by_imsi(mi_string);
+ if (ictx) {
+ DEBUGP(DMM, "Deleting old MM Context for same IMSI ",
+ "p_tmsi_old=0x%08x, p_tmsi_new=0x%08x\n",
+ ictx->p_tmsi, ctx->p_tmsi);
+ gprs_llgmm_assign(ictx->llme, ictx->tlli,
+ 0xffffffff, GPRS_ALGO_GEA0, NULL);
+ sgsn_mm_ctx_free(ictx);
+ }
+ }
strncpy(ctx->imsi, mi_string, sizeof(ctx->imei));
break;
case GSM_MI_TYPE_IMEI:
@@ -704,6 +717,8 @@
if (!ctx)
ctx = sgsn_mm_ctx_by_ptmsi(tmsi);
if (!ctx) {
+ /* Allocate a context as most of our code expects one.
+ * Context will not have an IMSI ultil ID RESP is received */
ctx = sgsn_mm_ctx_alloc(msgb_tlli(msg), &ra_id);
ctx->p_tmsi = tmsi;
}
diff --git a/openbsc/src/gprs/gprs_sgsn.c b/openbsc/src/gprs/gprs_sgsn.c
index f558003..142ff47 100644
--- a/openbsc/src/gprs/gprs_sgsn.c
+++ b/openbsc/src/gprs/gprs_sgsn.c
@@ -173,6 +173,21 @@
return ctx;
}
+void sgsn_mm_ctx_free(struct sgsn_mm_ctx *mm)
+{
+ struct sgsn_pdp_ctx *pdp, *pdp2;
+
+ /* Unlink from global list of MM contexts */
+ llist_del(&mm->list);
+
+ /* Free all PDP contexts */
+ llist_for_each_entry_safe(pdp, pdp2, &mm->pdp_list, list)
+ sgsn_pdp_ctx_free(pdp);
+
+ rate_ctr_group_free(mm->ctrg);
+
+ talloc_free(mm);
+}
/* look up PDP context by MM context and NSAPI */
struct sgsn_pdp_ctx *sgsn_pdp_ctx_by_nsapi(const struct sgsn_mm_ctx *mm,