corrected data link receive of large packets that were reporting a actual PDU length but not loading the PDU.

bacnet-stack/ports/rtos32/bip.c

@@ -284,6 +284,8 @@ uint16_t bip_receive(
         pdu_len -= 4; /* BVLC header */
         if (pdu_len < max_pdu)
             memmove(&pdu[0],&buf[4],pdu_len);
+        // ignore packets that are too large
+        // clients should check my max-apdu first
         else
             pdu_len = 0;
     }

bacnet-stack/ports/rtos32/ethernet.c

@@ -257,6 +257,10 @@ uint16_t ethernet_receive(
     // copy the buffer into the PDU
     if (pdu_len < max_pdu)
       memmove(&pdu[0],&buf[17],pdu_len);
+    // ignore packets that are too large
+    // client should check my max apdu first
+    else
+      pdu_len = 0;
 
     return pdu_len;
 }