Added NAK functionality for BBMD commands when not supported.

Also record any BVLL Result returned to us (eg, for foreign device registration).

bacnet-stack/include/bvlc.h

@@ -52,11 +52,6 @@ extern "C" {
 #else
 #define bvlc_maintenance_timer(x)
 #endif
-    /* registers with a bbmd as a foreign device */
-    int bvlc_register_with_bbmd(
-        uint32_t bbmd_address,  /* in network byte order */
-        uint16_t bbmd_port,     /* in network byte order */
-        uint16_t time_to_live_seconds);
 
     uint16_t bvlc_receive(
         BACNET_ADDRESS * src,   /* returns the source address */
@@ -92,6 +87,20 @@ extern "C" {
         unsigned npdu_length);
 #endif
 
+    /* registers with a bbmd as a foreign device */
+    int bvlc_register_with_bbmd(
+        uint32_t bbmd_address,  /* in network byte order */
+        uint16_t bbmd_port,     /* in network byte order */
+        uint16_t time_to_live_seconds);
+
+struct sockaddr_in;     /* Defined elsewhere, needed here. */
+
+    /* Note any BVLC_RESULT code, or NAK the BVLL message in the unsupported cases. */
+    void bvlc_for_non_bbmd(     
+            struct sockaddr_in * sout,      
+            uint8_t * npdu,     
+            uint16_t received_bytes);
+
 #ifdef __cplusplus
 }
 #endif /* __cplusplus */

bacnet-stack/src/bip.c

@@ -37,6 +37,7 @@
 #include "bacdcode.h"
 #include "bacint.h"
 #include "bip.h"
+#include "bvlc.h"
 #include "net.h"        /* custom per port */
 #if PRINT_ENABLED
 #include <stdio.h>      /* for standard integer types uint8_t etc. */
@@ -337,9 +338,12 @@ uint16_t bip_receive(
             }
         }
     } else {
+        /* Handle, usually with a NACK. */
+        bvlc_for_non_bbmd(&sin, pdu, received_bytes);
 #if PRINT_ENABLED
         fprintf(stderr, "BIP: BVLC discarded!\n");
 #endif
+        pdu_len = 0;
     }
 
     return pdu_len;

bacnet-stack/src/bvlc.c

@@ -55,6 +55,9 @@
    remote BBMD address/port here in network byte order */
 static struct sockaddr_in Remote_BBMD;
 
+/* result from a client request */
+BACNET_BVLC_RESULT BVLC_Result_Code = BVLC_RESULT_SUCCESSFUL_COMPLETION;
+
 
 /* Define BBMD_ENABLED to get the functions that a
  * BBMD needs to handle its services.
@@ -105,9 +108,6 @@ typedef struct {
 #endif
 static FD_TABLE_ENTRY FD_Table[MAX_FD_ENTRIES];
 
-/* result from a client request */
-BACNET_BVLC_RESULT BVLC_Result_Code = BVLC_RESULT_SUCCESSFUL_COMPLETION;
-
 
 void bvlc_maintenance_timer(
     time_t seconds)
@@ -203,6 +203,8 @@ static int bvlc_encode_address_entry(
 
     return len;
 }
+#endif
+
 
 static int bvlc_encode_bvlc_result(
     uint8_t * pdu,
@@ -220,7 +222,6 @@ static int bvlc_encode_bvlc_result(
 
     return 6;
 }
-#endif
 
 #if defined(BBMD_CLIENT_ENABLED) && BBMD_CLIENT_ENABLED
 int bvlc_encode_write_bdt_init(
@@ -738,7 +739,7 @@ static void bvlc_fdt_forward_npdu(
 
     return;
 }
-
+#endif
 
 
 static void bvlc_send_result(
@@ -754,6 +755,7 @@ static void bvlc_send_result(
     return;
 }
 
+#if defined(BBMD_ENABLED) && BBMD_ENABLED
 static int bvlc_send_bdt(
     struct sockaddr_in *dest)
 {
@@ -1230,6 +1232,59 @@ int bvlc_register_with_bbmd(
 }
 
 
+/** Note any BVLC_RESULT code, or NAK the BVLL message in the unsupported cases.
+ * Use this handler when you are not a BBMD.
+ * @param sout  [in] Socket address to send any NAK back to.
+ * @param npdu  [in] The received buffer.
+ * @param received_bytes [in] How many bytes in npdu[].
+ */ 
+void bvlc_for_non_bbmd(     
+        struct sockaddr_in * sout,      
+        uint8_t * npdu,     
+        uint16_t received_bytes)
+{
+    uint16_t result_code = 0; /* aka, BVLC_RESULT_SUCCESSFUL_COMPLETION */
+    uint8_t function_type = npdu[1];    /* The BVLC function */
+    switch (function_type) {
+        case BVLC_RESULT:
+            if ( received_bytes >= 6) {
+                /* This is the result of our foreign device registration */
+                (void) decode_unsigned16(&npdu[4], &result_code);
+                BVLC_Result_Code = (BACNET_BVLC_RESULT) result_code;
+                debug_printf("BVLC: Result Code=%d\n", BVLC_Result_Code);
+                /* But don't send any response */
+                result_code = 0;
+            }
+            break;
+        case BVLC_WRITE_BROADCAST_DISTRIBUTION_TABLE:
+            result_code = BVLC_RESULT_WRITE_BROADCAST_DISTRIBUTION_TABLE_NAK;
+            break;
+        case BVLC_READ_BROADCAST_DIST_TABLE:
+            result_code = BVLC_RESULT_READ_BROADCAST_DISTRIBUTION_TABLE_NAK;
+            break;
+        /* case BVLC_READ_BROADCAST_DIST_TABLE_ACK: */
+        case BVLC_REGISTER_FOREIGN_DEVICE:
+            result_code = BVLC_RESULT_REGISTER_FOREIGN_DEVICE_NAK;
+            break;
+        case BVLC_READ_FOREIGN_DEVICE_TABLE:
+            result_code = BVLC_RESULT_READ_FOREIGN_DEVICE_TABLE_NAK;
+            break;
+        /* case BVLC_READ_FOREIGN_DEVICE_TABLE_ACK: */
+        case BVLC_DELETE_FOREIGN_DEVICE_TABLE_ENTRY:
+            result_code = BVLC_RESULT_DELETE_FOREIGN_DEVICE_TABLE_ENTRY_NAK;
+            break;
+        case BVLC_DISTRIBUTE_BROADCAST_TO_NETWORK:
+            break;
+        /* case BVLC_ORIGINAL_UNICAST_NPDU: */
+        /* case BVLC_ORIGINAL_BROADCAST_NPDU: */
+        default:
+            break;
+    }
+    if (result_code > 0) {
+        bvlc_send_result(sout, result_code);
+        debug_printf("BVLC: NAK code=%d\n", result_code);
+    }
+}
 
 #ifdef TEST
 #include <assert.h>