Add PDCP per-bearer reestablish

lib/include/srslte/interfaces/ue_interfaces.h

@@ -239,6 +239,7 @@ class pdcp_interface_rrc
 {
 public:
   virtual void reestablish() = 0;
+  virtual void     reestablish(uint32_t lcid)                                                                    = 0;
   virtual void reset() = 0;
   virtual void     write_sdu(uint32_t lcid, srslte::unique_byte_buffer_t sdu, bool blocking = true)              = 0;
   virtual void add_bearer(uint32_t lcid, srslte::srslte_pdcp_config_t cnfg = srslte::srslte_pdcp_config_t()) = 0;

lib/include/srslte/upper/pdcp.h

@@ -50,6 +50,7 @@ public:
 
   // RRC interface
   void reestablish();
+  void     reestablish(uint32_t lcid);
   void reset();
   void     write_sdu(uint32_t lcid, unique_byte_buffer_t sdu, bool blocking = true);
   void     write_sdu_mch(uint32_t lcid, unique_byte_buffer_t sdu);

lib/src/upper/pdcp.cc

@@ -88,6 +88,15 @@ void pdcp::reestablish() {
   pthread_rwlock_unlock(&rwlock);
 }
 
+void pdcp::reestablish(uint32_t lcid)
+{
+  pthread_rwlock_rdlock(&rwlock);
+  if (valid_lcid(lcid)) {
+    pdcp_array.at(lcid)->reestablish();
+  }
+  pthread_rwlock_unlock(&rwlock);
+}
+
 void pdcp::reset()
 {
   // destroy all bearers