Added debugging.

bacnet-stack/demo/dcc/main.c

@@ -157,7 +157,6 @@ int main(
     bool found = false;
 
     if (argc < 3) {
-        /* note: priority 16 and 0 should produce the same end results... */
         printf("Usage: %s device-instance state timeout [password]\r\n"
             "Send BACnet DeviceCommunicationControl service to device.\r\n"
             "\r\n" "The device-instance can be 0 to %d.\r\n"

bacnet-stack/src/bip.c

@@ -231,6 +231,9 @@ uint16_t bip_receive(
         if ((sin.sin_addr.s_addr == htonl(BIP_Address.s_addr)) &&
             (sin.sin_port == htonl(BIP_Port))) {
             pdu_len = 0;
+#if PRINT_ENABLED
+            fprintf(stderr,"BIP: src is me. Discarded!\n");
+#endif
         } else {
             /* copy the source address
                FIXME: IPv6? */
@@ -244,16 +247,33 @@ uint16_t bip_receive(
             /* subtract off the BVLC header */
             pdu_len -= 4;
             if (pdu_len < max_pdu) {
+#if 0
+                fprintf(stderr,"BIP: NPDU[%hu]:",pdu_len);
+#endif
                 /* shift the buffer to return a valid PDU */
                 for (i = 0; i < pdu_len; i++) {
-                    pdu[i] = pdu[i + 4];
+                    pdu[i] = pdu[4 + i];
+#if 0
+                    fprintf(stderr,"%02X ",pdu[i]);
+#endif
                 }
+#if 0
+                fprintf(stderr,"\n");
+#endif
             }
             /* ignore packets that are too large */
             /* clients should check my max-apdu first */
-            else
+            else {
                 pdu_len = 0;
+#if PRINT_ENABLED
+            fprintf(stderr,"BIP: PDU too large. Discarded!.\n");
+#endif
+            }
         }
+    } else {
+#if PRINT_ENABLED
+        fprintf(stderr,"BIP: BVLC discarded!\n");
+#endif
     }
 
     return pdu_len;

bacnet-stack/src/npdu.c

@@ -41,6 +41,10 @@
 #include "npdu.h"
 #include "apdu.h"
 
+#if PRINT_ENABLED
+#include <stdio.h>
+#endif
+
 void npdu_copy_data(
     BACNET_NPDU_DATA * dest,
     BACNET_NPDU_DATA * src)
@@ -377,6 +381,9 @@ void npdu_handler(
     apdu_offset = npdu_decode(&pdu[0], &dest, src, &npdu_data);
     if (npdu_data.network_layer_message) {
         /*FIXME: network layer message received!  Handle it! */
+#if PRINT_ENABLED
+        fprintf(stderr,"NPDU: Network Layer Message discarded!\n");
+#endif
     } else if ((apdu_offset > 0) && (apdu_offset <= pdu_len)) {
         /* only handle the version that we know how to handle */
         if (npdu_data.protocol_version == BACNET_PROTOCOL_VERSION)