[SGSN] Fix processing of RA Update Request regarding TLLI
In case we get a RA UPD REQ on a new cell (both served by the same
SGSN), the LLC stack should not allocate a ne LLE/LLME, as the latter
would reset the V(u)sent / V(u)recv to zero and make the MS discard
our responses.
Instead, whenever the LLC stack sees a foreign TLLI, it should always
convert it to the local TLLI before doing any lookup for a LLE/LLME.
diff --git a/openbsc/src/gprs/gprs_llc.c b/openbsc/src/gprs/gprs_llc.c
index 002742b..7991f4c 100644
--- a/openbsc/src/gprs/gprs_llc.c
+++ b/openbsc/src/gprs/gprs_llc.c
@@ -106,11 +106,28 @@
LLIST_HEAD(gprs_llc_llmes);
void *llc_tall_ctx;
+/* If the TLLI is foreign, return its local version */
+static inline uint32_t tlli_foreign2local(uint32_t tlli)
+{
+ uint32_t new_tlli;
+
+ if (gprs_tlli_type(tlli) == TLLI_FOREIGN) {
+ new_tlli = tlli | 0x40000000;
+ DEBUGP(DLLC, "TLLI 0x%08x is foreign, converting to "
+ "local TLLI 0x%08x\n", tlli, new_tlli);
+ } else
+ new_tlli = tlli;
+
+ return new_tlli;
+}
+
/* lookup LLC Entity based on DLCI (TLLI+SAPI tuple) */
static struct gprs_llc_lle *lle_by_tlli_sapi(uint32_t tlli, uint8_t sapi)
{
struct gprs_llc_llme *llme;
+ tlli = tlli_foreign2local(tlli);
+
llist_for_each_entry(llme, &gprs_llc_llmes, list) {
if (llme->tlli == tlli || llme->old_tlli == tlli)
return &llme->lle[sapi];
@@ -321,6 +338,8 @@
lle = lle_by_tlli_sapi(msgb_tlli(msg), sapi);
if (!lle) {
struct gprs_llc_llme *llme;
+ LOGP(DLLC, LOGL_ERROR, "LLC TX: unknown TLLI 0x%08x, "
+ "creating LLME on the fly\n", msgb_tlli(msg));
llme = llme_alloc(msgb_tlli(msg));
lle = &llme->lle[sapi];
}
@@ -677,6 +696,8 @@
struct gprs_llc_llme *llme;
/* FIXME: don't use the TLLI but the 0xFFFF unassigned? */
llme = llme_alloc(msgb_tlli(msg));
+ LOGP(DLLC, LOGL_DEBUG, "LLC RX: unknown TLLI 0x08x, "
+ "creating LLME on the fly\n", msgb_tlli(msg));
lle = &llme->lle[llhp.sapi];
} else {
LOGP(DLLC, LOGL_NOTICE,