Ignore PDCP status PDUs, instead of passing them to the GW. Check on the GW if the packet is large enough to hold an IPv4 header.

lib/src/upper/pdcp_entity.cc

@@ -199,9 +199,17 @@ void pdcp_entity::write_pdu(unique_byte_buffer_t pdu)
     return;
   }
 
+
   pthread_mutex_lock(&mutex);
 
   if (cfg.is_data) {
+
+    // Check PDCP control messages
+    if ((pdu->msg[0] & 0x80) == 0) {
+      log->debug("Unhandled PDCP Control PDU\n");
+      goto exit; // TODO handle PDCP control PDUs
+    }
+
     // Handle DRB messages
     if (rlc->rb_is_um(lcid)) {
       handle_um_drb_pdu(pdu);

srsue/src/stack/upper/gw.cc

@@ -127,6 +127,9 @@ void gw::write_pdu(uint32_t lcid, srslte::unique_byte_buffer_t pdu)
   dl_tput_bytes += pdu->N_bytes;
   if (!if_up) {
     log.warning("TUN/TAP not up - dropping gw RX message\n");
+  } else if (pdu->N_bytes < 20) {
+    // Packet not large enough to hold IPv4 Header
+    log.warning("Packet to small to hold IPv4 header. Dropping packet with %d B\n", pdu->N_bytes);
   } else {
     // Only handle IPv4 and IPv6 packets
     struct iphdr*   ip_pkt  = (struct iphdr*)pdu->msg;