4 Jan
2016
4 Jan
'16
5:43 p.m.
If an MM context cannot be found based on BBSGP info and a RA UPDATE
REQUEST is received, try to find an MM context with an P-TMSI from
which the TLLI could have been derived. This also checks, whether the
routing area matches.
This is similar to the old behaviour removed by the commits
"sgsn: Only look at TLLIs in sgsn_mm_ctx_by_tlli" and
"sgsn: Remove tlli_foreign2local", except that this will only
be done for RA UPDATE REQUESTs now.
Sponsored-by: On-Waves ehf
---
openbsc/include/openbsc/gprs_sgsn.h | 4 ++++
openbsc/src/gprs/gprs_gmm.c | 26 ++++++++++++++++++---
openbsc/src/gprs/gprs_sgsn.c | 25 ++++++++++++++++++++
openbsc/tests/sgsn/sgsn_test.c | 46 ++-----------------------------------
openbsc/tests/sgsn/sgsn_test.ok | 1 -
5 files changed, 54 insertions(+), 48 deletions(-)
diff --git a/openbsc/include/openbsc/gprs_sgsn.h b/openbsc/include/openbsc/gprs_sgsn.h
index 61120b1..74f0735 100644
--- a/openbsc/include/openbsc/gprs_sgsn.h
+++ b/openbsc/include/openbsc/gprs_sgsn.h
@@ -178,6 +178,10 @@ struct sgsn_mm_ctx *sgsn_mm_ctx_by_tlli(uint32_t tlli,
struct sgsn_mm_ctx *sgsn_mm_ctx_by_ptmsi(uint32_t tmsi);
struct sgsn_mm_ctx *sgsn_mm_ctx_by_imsi(const char *imsi);
+/* look-up by matching TLLI and P-TMSI (think twice before using this) */
+struct sgsn_mm_ctx *sgsn_mm_ctx_by_tlli_and_ptmsi(uint32_t tlli,
+ const struct gprs_ra_id *raid);
+
/* Allocate a new SGSN MM context */
struct sgsn_mm_ctx *sgsn_mm_ctx_alloc(uint32_t tlli,
const struct gprs_ra_id *raid);
diff --git a/openbsc/src/gprs/gprs_gmm.c b/openbsc/src/gprs/gprs_gmm.c
index 6e7e5f1..212c7d7 100644
--- a/openbsc/src/gprs/gprs_gmm.c
+++ b/openbsc/src/gprs/gprs_gmm.c
@@ -1172,13 +1172,33 @@ static int gsm48_rx_gmm_ra_upd_req(struct sgsn_mm_ctx *mmctx,
struct msgb *msg,
* if the TLLI matches foreign_tlli (P-TMSI). Note that this
* is an optimization to avoid the RA reject (impl detached)
* below, which will cause a new attach cycle. */
- }
-
- if (!mmctx || !gprs_ra_id_equals(&mmctx->ra, &old_ra_id) ||
+ /* Look-up the MM context based on old RA-ID and TLLI */
+ mmctx = sgsn_mm_ctx_by_tlli_and_ptmsi(msgb_tlli(msg), &old_ra_id);
+ if (mmctx) {
+ LOGMMCTXP(LOGL_INFO, mmctx,
+ "Looked up by matching TLLI and P_TMSI. "
+ "BSSGP TLLI: %08x, P-TMSI: %08x (%08x), "
+ "TLLI: %08x (%08x), RA: %d-%d-%d-%d\n",
+ msgb_tlli(msg),
+ mmctx->p_tmsi, mmctx->p_tmsi_old,
+ mmctx->tlli, mmctx->tlli_new,
+ mmctx->ra.mcc, mmctx->ra.mnc,
+ mmctx->ra.lac, mmctx->ra.rac);
+
+ mmctx->mm_state = GMM_COMMON_PROC_INIT;
+ }
+ } else if (!gprs_ra_id_equals(&mmctx->ra, &old_ra_id) ||
mmctx->mm_state == GMM_DEREGISTERED)
{
/* We cannot use the mmctx */
+ LOGMMCTXP(LOGL_INFO, mmctx,
+ "The MM context cannot be used, RA: %d-%d-%d-%d\n",
+ mmctx->ra.mcc, mmctx->ra.mnc,
+ mmctx->ra.lac, mmctx->ra.rac);
+ mmctx = NULL;
+ }
+ if (!mmctx) {
/* send a XID reset to re-set all LLC sequence numbers
* in the MS */
LOGMMCTXP(LOGL_NOTICE, mmctx, "LLC XID RESET\n");
diff --git a/openbsc/src/gprs/gprs_sgsn.c b/openbsc/src/gprs/gprs_sgsn.c
index f71066d..b7bda49 100644
--- a/openbsc/src/gprs/gprs_sgsn.c
+++ b/openbsc/src/gprs/gprs_sgsn.c
@@ -105,6 +105,31 @@ struct sgsn_mm_ctx *sgsn_mm_ctx_by_tlli(uint32_t tlli,
return NULL;
}
+struct sgsn_mm_ctx *sgsn_mm_ctx_by_tlli_and_ptmsi(uint32_t tlli,
+ const struct gprs_ra_id *raid)
+{
+ struct sgsn_mm_ctx *ctx;
+ int tlli_type;
+
+ /* TODO: Also check the P_TMSI signature to be safe. That signature
+ * should be different (at least with a sufficiently high probability)
+ * after SGSN restarts and for multiple SGSN instances.
+ */
+
+ tlli_type = gprs_tlli_type(tlli);
+ if (tlli_type != TLLI_FOREIGN && tlli_type != TLLI_LOCAL)
+ return NULL;
+
+ llist_for_each_entry(ctx, &sgsn_mm_ctxts, list) {
+ if ((gprs_tmsi2tlli(ctx->p_tmsi, tlli_type) == tlli ||
+ gprs_tmsi2tlli(ctx->p_tmsi_old, tlli_type) == tlli) &&
+ gprs_ra_id_equals(raid, &ctx->ra))
+ return ctx;
+ }
+
+ return NULL;
+}
+
struct sgsn_mm_ctx *sgsn_mm_ctx_by_ptmsi(uint32_t p_tmsi)
{
struct sgsn_mm_ctx *ctx;
diff --git a/openbsc/tests/sgsn/sgsn_test.c b/openbsc/tests/sgsn/sgsn_test.c
index d27b755..1acd6f2 100644
--- a/openbsc/tests/sgsn/sgsn_test.c
+++ b/openbsc/tests/sgsn/sgsn_test.c
@@ -1995,7 +1995,6 @@ static void test_gmm_routing_areas(void)
OSMO_ASSERT(ctx->p_tmsi == ptmsi1);
OSMO_ASSERT(ctx->tlli == ms_tlli);
-
printf(" - RA Update Request (RA 1 -> RA 2)\n");
/* inject the RA update request */
@@ -2005,50 +2004,9 @@ static void test_gmm_routing_areas(void)
send_0408_message(ctx->llme, ms_tlli, &raid2,
ra_upd_req1, ARRAY_SIZE(ra_upd_req1));
- /* we expect an RA update reject (and a LLC XID RESET) */
- OSMO_ASSERT(sgsn_tx_counter == 2);
- OSMO_ASSERT(last_dl_parse_ctx.g48_hdr->msg_type == GSM48_MT_GMM_RA_UPD_REJ);
- /* this has killed the LLE/LLME */
-
- printf(" - Attach Request (RA 2)\n");
-
- /* Create a LLE/LLME */
- OSMO_ASSERT(count(gprs_llme_list()) == 1);
- lle = gprs_lle_get_or_create(ms_tlli, 3);
- OSMO_ASSERT(count(gprs_llme_list()) == 1);
-
- /* inject the attach request */
- send_0408_message(lle->llme, ms_tlli, &raid2,
- attach_req2, ARRAY_SIZE(attach_req2));
-
- ctx = sgsn_mm_ctx_by_tlli(ms_tlli, &raid2);
- OSMO_ASSERT(ctx != NULL);
- OSMO_ASSERT(ctx->mm_state == GMM_COMMON_PROC_INIT);
- OSMO_ASSERT(ctx->p_tmsi != GSM_RESERVED_TMSI);
-
- /* we expect an attach accept */
+ /* we expect an RA update accept */
OSMO_ASSERT(sgsn_tx_counter == 1);
- OSMO_ASSERT(last_dl_parse_ctx.g48_hdr->msg_type == GSM48_MT_GMM_ATTACH_ACK);
-
- received_ptmsi = get_new_ptmsi(&last_dl_parse_ctx);
- OSMO_ASSERT(received_ptmsi == ctx->p_tmsi);
- ptmsi1 = received_ptmsi;
-
- /* inject the attach complete */
- ms_tlli = gprs_tmsi2tlli(ptmsi1, TLLI_LOCAL);
- ictx = sgsn_mm_ctx_by_tlli(ms_tlli, &raid2);
- OSMO_ASSERT(ictx != NULL);
- OSMO_ASSERT(ictx == ctx);
-
- send_0408_message(ctx->llme, ms_tlli, &raid2,
- attach_compl, ARRAY_SIZE(attach_compl));
-
- /* we don't expect a response */
- OSMO_ASSERT(sgsn_tx_counter == 0);
-
- OSMO_ASSERT(ctx->mm_state == GMM_REGISTERED_NORMAL);
- OSMO_ASSERT(ctx->p_tmsi_old == 0);
- OSMO_ASSERT(ctx->p_tmsi == ptmsi1);
+ OSMO_ASSERT(last_dl_parse_ctx.g48_hdr->msg_type == GSM48_MT_GMM_RA_UPD_ACK);
printf(" - RA Update Request (RA other -> RA 2)\n");
diff --git a/openbsc/tests/sgsn/sgsn_test.ok b/openbsc/tests/sgsn/sgsn_test.ok
index 5b8fc40..cdd2006 100644
--- a/openbsc/tests/sgsn/sgsn_test.ok
+++ b/openbsc/tests/sgsn/sgsn_test.ok
@@ -29,7 +29,6 @@ Testing routing area changes
- Attach Request (RA 1)
- RA Update Request (RA 1 -> RA 1)
- RA Update Request (RA 1 -> RA 2)
- - Attach Request (RA 2)
- RA Update Request (RA other -> RA 2)
- Attach Request (RA 2)
- RA Update Request (RA 2 -> RA 2)
--
1.9.1