Add segmentation support functions (#1218)

* Added segmentation support functions and example changes, but no support for segmentation in the TSM or APDU handlers.

src/bacnet/basic/binding/address.c

@@ -45,6 +45,10 @@ static struct Address_Cache_Entry {
     uint8_t Flags;
     uint32_t device_id;
     unsigned max_apdu;
+#if BACNET_SEGMENTATION_ENABLED
+    uint8_t segmentation;
+    uint16_t maxsegments;
+#endif
     BACNET_ADDRESS address;
     uint32_t TimeToLive;
 } Address_Cache[MAX_ADDRESS_CACHE];
@@ -346,9 +350,16 @@ void address_set_device_TTL(
  * @param device_id  Device-Id
  * @param max_apdu  Pointer to a variable, taking the maximum APDU size.
  * @param src  Pointer to address structure for return.
+ * @param segmentation  Pointer to a variable, taking the BACNET_SEGMENTATION
+ * flag.
+ * @param maxsegments  Pointer to a variable, taking the maximum segments.
  */
-bool address_get_by_device(
-    uint32_t device_id, unsigned *max_apdu, BACNET_ADDRESS *src)
+bool address_segment_get_by_device(
+    uint32_t device_id,
+    unsigned *max_apdu,
+    BACNET_ADDRESS *src,
+    uint8_t *segmentation,
+    uint16_t *maxsegments)
 {
     struct Address_Cache_Entry *pMatch;
     bool found = false; /* return value */
@@ -364,6 +375,20 @@ bool address_get_by_device(
                 if (max_apdu) {
                     *max_apdu = pMatch->max_apdu;
                 }
+                if (segmentation) {
+#if BACNET_SEGMENTATION_ENABLED
+                    *segmentation = pMatch->segmentation;
+#else
+                    *segmentation = SEGMENTATION_NONE;
+#endif
+                }
+                if (maxsegments) {
+#if BACNET_SEGMENTATION_ENABLED
+                    *maxsegments = pMatch->maxsegments;
+#else
+                    *maxsegments = 1;
+#endif
+                }
                 /* Prove we found it */
                 found = true;
             }
@@ -375,6 +400,18 @@ bool address_get_by_device(
     return found;
 }
 
+/**
+ * @brief Return the cached address for the given device-id
+ * @param device_id  Device-Id
+ * @param max_apdu  Pointer to a variable, taking the maximum APDU size.
+ * @param src  Pointer to address structure for return.
+ */
+bool address_get_by_device(
+    uint32_t device_id, unsigned *max_apdu, BACNET_ADDRESS *src)
+{
+    return address_segment_get_by_device(device_id, max_apdu, src, NULL, NULL);
+}
+
 /**
  * Find a device id from a given MAC address.
  *

src/bacnet/basic/binding/address.h

@@ -43,6 +43,14 @@ BACNET_STACK_EXPORT
 bool address_get_by_device(
     uint32_t device_id, unsigned *max_apdu, BACNET_ADDRESS *src);
 
+BACNET_STACK_EXPORT
+bool address_segment_get_by_device(
+    uint32_t device_id,
+    unsigned *max_apdu,
+    BACNET_ADDRESS *src,
+    uint8_t *segmentation,
+    uint16_t *maxsegments);
+
 BACNET_STACK_EXPORT
 bool address_get_by_index(
     unsigned index,

src/bacnet/basic/object/device.c

@@ -1333,7 +1333,11 @@ uint8_t Device_Protocol_Revision(void)
 
 BACNET_SEGMENTATION Device_Segmentation_Supported(void)
 {
+#if BACNET_SEGMENTATION_ENABLED
+    return SEGMENTATION_BOTH;
+#else
     return SEGMENTATION_NONE;
+#endif
 }
 
 /**
@@ -1804,8 +1808,12 @@ int Device_Read_Property_Local(BACNET_READ_PROPERTY_DATA *rpdata)
                 rpdata->object_instance, rpdata->array_index,
                 Device_Object_List_Element_Encode, count, apdu, apdu_max);
             if (apdu_len == BACNET_STATUS_ABORT) {
+#if BACNET_SEGMENTATION_ENABLED
+                rpdata->error_code = ERROR_CODE_ABORT_BUFFER_OVERFLOW;
+#else
                 rpdata->error_code =
                     ERROR_CODE_ABORT_SEGMENTATION_NOT_SUPPORTED;
+#endif
             } else if (apdu_len == BACNET_STATUS_ERROR) {
                 rpdata->error_class = ERROR_CLASS_PROPERTY;
                 rpdata->error_code = ERROR_CODE_INVALID_ARRAY_INDEX;

src/bacnet/basic/service/s_iam.c

@@ -85,7 +85,7 @@ int iam_encode_pdu(
     /* encode the APDU portion of the packet */
     len = iam_encode_apdu(
         &buffer[pdu_len], Device_Object_Instance_Number(), MAX_APDU,
-        SEGMENTATION_NONE, Device_Vendor_Identifier());
+        Device_Segmentation_Supported(), Device_Vendor_Identifier());
     pdu_len += len;
 
     return pdu_len;
@@ -158,7 +158,7 @@ int iam_unicast_encode_pdu(
     /* encode the APDU portion of the packet */
     apdu_len = iam_encode_apdu(
         &buffer[npdu_len], Device_Object_Instance_Number(), MAX_APDU,
-        SEGMENTATION_NONE, Device_Vendor_Identifier());
+        Device_Segmentation_Supported(), Device_Vendor_Identifier());
     pdu_len = npdu_len + apdu_len;
 
     return pdu_len;