Added segmentation support for server reply. (#974)

Added segmentation support for server devices for some services. Configure BACNET_SEGMENTATION_ENABLED=1 to include in the library, and adjust BACNET_MAX_SEGMENTS_ACCEPTED for maximum number of segments.

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 +400,19 @@ bool address_get_by_device(
     return found;
 }
 
+/**
+ * @brief Return the cached addresBACNET_STACK_EXPORT
+s 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,