Fix the gateway example routing and lookups. Thanks, Sam! (#163)

Co-authored-by: Steve Karg <skarg@users.sourceforge.net>

apps/gateway/main.c

@@ -82,6 +82,9 @@ int DNET_list[2] = {
 /* current version of the BACnet stack */
 static const char *BACnet_Version = BACNET_VERSION_TEXT;
 
+/* routed devices - I-Am on startup */
+static unsigned Routed_Device_Index;
+
 /** Initialize the Device Objects and each of the child Object instances.
  * @param first_object_instance Set the first (gateway) Device to this
             instance number, and subsequent devices to incremented values.
@@ -107,6 +110,59 @@ static void Devices_Init(uint32_t first_object_instance)
     }
 }
 
+/** Initialize the BACnet Device Addresses for each Device object.
+ * The gateway has already gotten the normal address (eg, PC's IP for BIP) and
+ * the remote devices get
+ * - For BIP, the IP address reversed, and 4th byte equal to index.
+ * (Eg, 11.22.33.44 for the gateway becomes 44.33.22.01 for the first remote
+ * device.) This is sure to be unique! The port number stays the same.
+ * - For MS/TP, [Steve inserts a good idea here]
+ */
+static void Initialize_Device_Addresses(void)
+{
+    int i = 0; /* First entry is Gateway Device */
+    uint32_t virtual_mac = 0;
+    BACNET_ADDRESS virtual_address = {0};
+    DEVICE_OBJECT_DATA *pDev = NULL;
+    /* Setup info for the main gateway device first */
+    pDev = Get_Routed_Device_Object(i);
+
+    /* we can't use datalink_get_my_address() since it is
+       mapped to routed_get_my_address() in this app
+       to get the parent device address */
+#if defined(BACDL_BIP)
+    bip_get_my_address(&virtual_address);
+#elif defined(BACDL_MSTP)
+    dlmstp_get_my_address(&virtual_address);
+#elif defined(BACDL_ARCNET)
+    arcnet_get_my_address(&virtual_address);
+#elif defined(BACDL_ETHERNET)
+    ethernet_get_my_address(&virtual_address);
+#elif defined(BACDL_BIP6)
+    bip6_get_my_address(&virtual_address);
+#else
+#error "No support for this Data Link Layer type "
+#endif
+    bacnet_address_copy(&pDev->bacDevAddr, &virtual_address);
+    /* broadcast an I-Am on startup */
+    Send_I_Am(&Handler_Transmit_Buffer[0]);
+
+    for (i = 1; i < MAX_NUM_DEVICES; i++) {
+        pDev = Get_Routed_Device_Object(i);
+        if (pDev == NULL) {
+            continue;
+        }
+        /* start with the router address */
+        bacnet_address_copy(&pDev->bacDevAddr, &virtual_address);
+        /* add the network number to each gateway device */
+        pDev->bacDevAddr.net = VIRTUAL_DNET;
+        /* use a virtual MAC for each gateway device */
+        virtual_mac = pDev->bacObj.Object_Instance_Number;
+        encode_unsigned24(&pDev->bacDevAddr.adr[0], virtual_mac);
+        pDev->bacDevAddr.len = 3;
+    }
+}
+
 /** Initialize the handlers we will utilize.
  * @see Device_Init, apdu_set_unconfirmed_handler, apdu_set_confirmed_handler
  */
@@ -158,54 +214,6 @@ static void Init_Service_Handlers(uint32_t first_object_instance)
         handler_device_communication_control);
 }
 
-/** Initialize the BACnet Device Addresses for each Device object.
- * The gateway has already gotten the normal address (eg, PC's IP for BIP) and
- * the remote devices get
- * - For BIP, the IP address reversed, and 4th byte equal to index.
- * (Eg, 11.22.33.44 for the gateway becomes 44.33.22.01 for the first remote
- * device.) This is sure to be unique! The port number stays the same.
- * - For MS/TP, [Steve inserts a good idea here]
- */
-static void Initialize_Device_Addresses()
-{
-    int i = 0; /* First entry is Gateway Device */
-    uint32_t virtual_mac = 0;
-    DEVICE_OBJECT_DATA *pDev = NULL;
-    /* Setup info for the main gateway device first */
-    pDev = Get_Routed_Device_Object(i);
-
-    /* we can't use datalink_get_my_address() since it is
-       mapped to routed_get_my_address() in this app
-       to get the parent device address */
-#if defined(BACDL_BIP)
-    bip_get_my_address(&pDev->bacDevAddr);
-#elif defined(BACDL_MSTP)
-    dlmstp_get_my_address(&pDev->bacDevAddr);
-#elif defined(BACDL_ARCNET)
-    arcnet_get_my_address(&pDev->bacDevAddr);
-#elif defined(BACDL_ETHERNET)
-    ethernet_get_my_address(&pDev->bacDevAddr);
-#elif defined(BACDL_BIP6)
-    bip6_get_my_address&pDev->bacDevAddr);
-#else
-#error "No support for this Data Link Layer type "
-#endif
-    /* broadcast an I-Am on startup */
-    Send_I_Am(&Handler_Transmit_Buffer[0]);
-
-    for (i = 1; i < MAX_NUM_DEVICES; i++) {
-        pDev = Get_Routed_Device_Object(i);
-        if (pDev == NULL) {
-            continue;
-        }
-        virtual_mac = pDev->bacObj.Object_Instance_Number;
-        encode_unsigned24(&pDev->bacDevAddr.adr[0], virtual_mac);
-        pDev->bacDevAddr.len = 3;
-        /* broadcast an I-Am for each routed Device now */
-        Send_I_Am(&Handler_Transmit_Buffer[0]);
-    }
-}
-
 /** Main function of server demo.
  *
  * @see Device_Set_Object_Instance_Number, dlenv_init, Send_I_Am,
@@ -248,8 +256,9 @@ int main(int argc, char *argv[])
     printf("BACnet Router Demo\n"
            "BACnet Stack Version %s\n"
            "BACnet Device ID: %u\n"
-           "Max APDU: %d\n",
+           "Max APDU: %d\n"
-        BACnet_Version, first_object_instance, MAX_APDU);
+           "Max Devices: %d\n",
+        BACnet_Version, first_object_instance, MAX_APDU, MAX_NUM_DEVICES);
     Init_Service_Handlers(first_object_instance);
     dlenv_init();
     atexit(datalink_cleanup);
@@ -293,8 +302,12 @@ int main(int argc, char *argv[])
         }
         handler_cov_task();
         /* output */
-
+        if (Routed_Device_Index < MAX_NUM_DEVICES) {
-        /* blink LEDs, Turn on or off outputs, etc */
+            Routed_Device_Index++;
+            Get_Routed_Device_Object(Routed_Device_Index);
+            /* broadcast an I-Am for each routed Device now */
+            Send_I_Am(&Handler_Transmit_Buffer[0]);
+        }
     }
     /* Dummy return */
     return 0;

src/bacnet/basic/npdu/h_routed_npdu.c

@@ -206,6 +206,7 @@ static void routed_apdu_handler(BACNET_ADDRESS *src,
         /* If wasn't unicast to us, must have been one of the bcast types.
          * Drop it. */
         if (bvlc_get_function_code() != BVLC_ORIGINAL_UNICAST_NPDU) {
+            debug_printf("NPDU: not unicast - dropped!\n");
             return;
         }
 #endif
@@ -216,7 +217,10 @@ static void routed_apdu_handler(BACNET_ADDRESS *src,
         if (dest->len > 0) {
             Send_Reject_Message_To_Network(
                 src, NETWORK_REJECT_NO_ROUTE, dest->net);
-        } /* else, silently drop it */
+        } else {
+            /* silently drop it */
+            debug_printf("NPDU: broadcast - dropped!\n");
+        }
         return;
     }
 
@@ -229,6 +233,7 @@ static void routed_apdu_handler(BACNET_ADDRESS *src,
     }
     if (!bGotOne) {
         /* Just silently drop this packet. */
+        debug_printf("NPDU: dest not found - dropped!\n");
     }
 }
 
@@ -278,6 +283,7 @@ void routing_npdu_handler(
                 network_control_handler(src, DNET_list, &npdu_data,
                     &pdu[apdu_offset], (uint16_t)(pdu_len - apdu_offset));
             } else {
+                debug_printf("NPDU: message for our router? Discarded!\n");
                 /* The DNET is set, but we don't support downstream routers,
                  * so we just silently drop this network layer message,
                  * since only routers can handle it (even if for our DNET) */

src/bacnet/basic/object/gateway/gw_device.c

@@ -220,24 +220,24 @@ void routed_get_my_address(BACNET_ADDRESS *my_address)
  *         Else False if no match or invalid idx is given.
  */
 bool Routed_Device_Address_Lookup(
-    int idx, uint8_t address_len, uint8_t *mac_adress)
+    int idx, uint8_t dlen, uint8_t *dadr)
 {
     bool result = false;
     DEVICE_OBJECT_DATA *pDev = &Devices[idx];
     int i;
 
     if ((idx >= 0) && (idx < MAX_NUM_DEVICES)) {
-        if (address_len == 0) {
+        if (dlen == 0) {
             /* Automatic match */
             iCurrent_Device_Idx = idx;
             result = true;
-        } else if (mac_adress != NULL) {
+        } else if (dadr != NULL) {
-            for (i = 0; i < address_len; i++) {
+            for (i = 0; i < dlen; i++) {
-                if (pDev->bacDevAddr.mac[i] != mac_adress[i]) {
+                if (pDev->bacDevAddr.adr[i] != dadr[i]) {
                     break;
                 }
             }
-            if (i == address_len) { /* Success! */
+            if (i == dlen) { /* Success! */
                 iCurrent_Device_Idx = idx;
                 result = true;
             }
@@ -370,25 +370,51 @@ uint32_t Routed_Device_Index_To_Instance(unsigned index)
     return Devices[iCurrent_Device_Idx].bacObj.Object_Instance_Number;
 }
 
-/** See if the requested Object instance matches that for the currently
+/**
- * indexed Device Object.
+ * For a given object instance-number, determines a 1..N-1 index
- * iCurrent_Device_Idx must have been set to point to this Device Object
+ * of Device objects where N is MAX_NUM_DEVICES
- * before this function is called.
+ *
- * @param object_id [in] Object ID of the desired Device object.
+ * @param  object_instance - object-instance number of the object
- * 			If the wildcard value (BACNET_MAX_INSTANCE), always
+ * @return  index for the given instance-number, or 0 if not valid.
- * matches.
+ */
- * @return True if Object ID matches the present Device, else False.
+static uint32_t Routed_Device_Instance_To_Index(
+        uint32_t Instance_Number)
+{
+    int i;
+
+
+    for ( i=0; i < MAX_NUM_DEVICES; i++) {
+        if (Devices[i].bacObj.Object_Instance_Number == Instance_Number)
+        {
+            /* Found Instance, so return the Device Index Number */
+            return i;
+        }
+    }
+
+    /* We did not find instance... so simply return an Index of 0
+       All gateways will have at least a single root Device Object */
+    return 0;
+
+}
+
+/**
+ * Determines if a given Device instance is valid
+ *
+ * @param  object_id - object-instance number of the object
+ * @return  true if the instance is valid, and false if not
  */
 bool Routed_Device_Valid_Object_Instance_Number(uint32_t object_id)
 {
-    bool bResult = false;
+    bool valid = false;
-    DEVICE_OBJECT_DATA *pDev = &Devices[iCurrent_Device_Idx];
+    DEVICE_OBJECT_DATA *pDev = NULL;
 
+    iCurrent_Device_Idx = Routed_Device_Instance_To_Index(object_id);
+    pDev = &Devices[iCurrent_Device_Idx];
     if (pDev->bacObj.Object_Instance_Number == object_id) {
-        bResult = true;
+        valid = true;
     }
 
-    return bResult;
+    return valid;
 }
 
 bool Routed_Device_Name(

src/bacnet/config.h

@@ -62,7 +62,7 @@
 /* Enable the Gateway (Routing) functionality here, if desired. */
 #if !defined(MAX_NUM_DEVICES)
 #ifdef BAC_ROUTING
-#define MAX_NUM_DEVICES 3       /* Eg, Gateway + two remote devices */
+#define MAX_NUM_DEVICES 32       /* Eg, Gateway + 31 remote devices */
 #else
 #define MAX_NUM_DEVICES 1       /* Just the one normal BACnet Device Object */
 #endif