Added host_n_port_context_decode function.

src/bacnet/hostnport.c

@@ -245,6 +245,59 @@ int host_n_port_decode(uint8_t *apdu,
     return apdu_len;
 }
 
+/**
+ * @brief Decode a context encoded BACnetHostNPort complex data
+ * @param apdu - the APDU buffer
+ * @param apdu_size - the APDU buffer length
+ * @param tag_number - context tag number to be decoded
+ * @param error_code - error or reject or abort when error occurs
+ * @param address - IP address and port number
+ * @return length of the APDU buffer decoded, or ERROR, REJECT, or ABORT
+ */
+int host_n_port_context_decode(uint8_t *apdu,
+    uint32_t apdu_size,
+    uint8_t tag_number,
+    BACNET_ERROR_CODE *error_code,
+    BACNET_HOST_N_PORT *address)
+{
+    int len = 0;
+    int apdu_len = 0;
+
+    /* default reject code */
+    if (error_code) {
+        *error_code = ERROR_CODE_REJECT_MISSING_REQUIRED_PARAMETER;
+    }
+    if (!bacnet_is_opening_tag_number(
+            &apdu[apdu_len], apdu_size - apdu_len, tag_number, &len)) {
+        if (error_code) {
+            *error_code = ERROR_CODE_REJECT_INVALID_TAG;
+        }
+
+        return BACNET_STATUS_REJECT;
+    }
+    apdu_len += len;
+    len = host_n_port_decode(&apdu[apdu_len], apdu_size - apdu_len,
+            error_code, address);
+    if (len > 0) {
+        apdu_len += len;
+    } else {
+        if (error_code) {
+            *error_code = ERROR_CODE_REJECT_OTHER;
+        }
+        return BACNET_STATUS_REJECT;
+    }
+    if (!bacnet_is_closing_tag_number(
+            &apdu[apdu_len], apdu_size - apdu_len, tag_number, &len)) {
+        if (error_code) {
+            *error_code = ERROR_CODE_REJECT_INVALID_TAG;
+        }
+        return BACNET_STATUS_REJECT;
+    }
+    apdu_len += len;
+
+    return apdu_len;
+}
+
 /**
  * @brief Copy the BACnetHostNPort complex data from src to dst
  * @param dst - destination structure

src/bacnet/hostnport.h

@@ -61,6 +61,12 @@ extern "C" {
         BACNET_ERROR_CODE *error_code,
         BACNET_HOST_N_PORT *address);
     BACNET_STACK_EXPORT
+    int host_n_port_context_decode(uint8_t *apdu,
+        uint32_t apdu_size,
+        uint8_t tag_number,
+        BACNET_ERROR_CODE *error_code,
+        BACNET_HOST_N_PORT *address);
+    BACNET_STACK_EXPORT
     bool host_n_port_copy(
         BACNET_HOST_N_PORT * dst,
         BACNET_HOST_N_PORT * src);

test/bacnet/hostnport/src/main.c

@@ -41,19 +41,14 @@ static void test_HostNPortCodec(BACNET_HOST_N_PORT *data)
     zassert_equal(apdu_len, null_len, NULL);
     zassert_true(apdu_len != BACNET_STATUS_ERROR, NULL);
 
-    status = bacnet_is_opening_tag_number(apdu, apdu_len, tag_number, &len);
-    zassert_true(status, NULL);
-    zassert_true(len > 0, "len=%d", len);
-
-    null_len = host_n_port_decode(&apdu[len], apdu_len-len, NULL, NULL);
-    test_len = host_n_port_decode(&apdu[len], apdu_len-len, &error_code, &test_data);
+    null_len = host_n_port_context_decode(apdu, apdu_len, tag_number,
+        &error_code, NULL);
+    test_len = host_n_port_context_decode(apdu, apdu_len, tag_number,
+        &error_code, &test_data);
     zassert_equal(test_len, null_len, NULL);
     zassert_true(test_len > 0, "test_len=%d", len);
-    len += test_len;
-
-    status = bacnet_is_closing_tag_number(&apdu[len], apdu_len-len, tag_number, &len);
+    status = host_n_port_same(&test_data, data);
     zassert_true(status, NULL);
-    zassert_true(len > 0, "len=%d", len);
 
     status = host_n_port_copy(&test_data, data);
     zassert_true(status, NULL);