tbf: Get the TLLI from the MS object

Since the synchronisation of the TBF's concerning the TLLIs has been
removed in 'Support new and old TLLI's', gprs_rlcmac_tbf::tlli() can
return the old TLLI which is probably different to ms()->tlli() in
that case. This can lead to a wrong TLLI being used in BSSGP messages.

This commit modifies the TBF's tlli() method to get the current TLLI
from the MS object.

Sponsored-by: On-Waves ehf

src/tbf.cpp

@@ -46,6 +46,11 @@ gprs_rlcmac_bts *gprs_rlcmac_tbf::bts_data() const
 	return bts->bts_data();
 }
 
+uint32_t gprs_rlcmac_tbf::tlli() const
+{
+	return m_ms ? m_ms->tlli() : m_tlli;
+}
+
 void gprs_rlcmac_tbf::assign_imsi(const char *imsi)
 {
 	strncpy(m_imsi, imsi, sizeof(m_imsi));

src/tbf.h

@@ -293,11 +293,6 @@ inline GprsMs *gprs_rlcmac_tbf::ms()
 	return m_ms;
 }
 
-inline uint32_t gprs_rlcmac_tbf::tlli() const
-{
-	return m_tlli;
-}
-
 inline bool gprs_rlcmac_tbf::is_tlli_valid() const
 {
 	return m_tlli_valid;