tbf: Handle TLLI change on DL

When doing an RA Update the network can request to change the TLLI.
In this case, there can be 2 MS objects with different TLLI for a
single real MS. The first is associated with the old TLLI and the
IMSI, while the second is associated with the new TLLI and no IMSI if
it had been created for the uplink TBF. When the first message with
the new TLLI and the IMSI arrives from the network, the PCU is able
to detect this.

Currently this is not handled properly. The TBFs of the old MS object
are not cleaned up properly, keeping the old MS from being deleted.

This patch modifies gprs_rlcmac_dl_tbf::handle to check for this and
if neccessary to move an existing DL TBF and to clean up the old MS
object to ensure its deletion.

Sponsored-by: On-Waves ehf

1 files changed, 14 insertions, 0 deletions

diff --git a/src/gprs_ms.cpp b/src/gprs_ms.cpp
index e0023e3d..82f17848 100644
--- a/src/gprs_ms.cpp
+++ b/src/gprs_ms.cpp
@@ -297,6 +297,20 @@ void GprsMs::update_status()
 	}
 }
 
+void GprsMs::reset()
+{
+	LOGP(DRLCMAC, LOGL_INFO,
+		"Clearing MS object, TLLI: 0x%08x, IMSI: '%s'\n",
+		tlli(), imsi());
+
+	stop_timer();
+
+	m_tlli = 0;
+	m_new_dl_tlli = 0;
+	m_new_ul_tlli = 0;
+	m_imsi[0] = '\0';
+}
+
 void GprsMs::set_tlli(uint32_t tlli)
 {
 	if (tlli == m_tlli || tlli == m_new_ul_tlli)