Minor additions

Author: xuniq

doc/dev_guide/reference_capi/box.rst

@@ -284,16 +284,15 @@
     Sets an IPROTO request handler with the provided context for the given request type.
     The function yields.
 
-    Possible values:
+    :param uint32_t request_type: request type code from the ``iproto_type`` enumeration
+    :param iproto_handler_t handler: IPROTO request handler. To reset the request handler, set the ``handler`` parameter to ``NULL``.
 
-                                *   a type code from the :ref:`box.iproto.type <reference_lua-box_iproto_type>` (except
-                                    ``box.iproto.type.UNKNOWN``) -- override the existing request type.
+                                    See the full parameter description in the :ref:`Handler function <box_box_iproto_override-handler>` section.
 
-                                *   ``box.iproto.type.UNKNOWN`` -- override an unknown request type.
+    :param iproto_handler_destroy_t destroy: IPROTO request handler destructor. The destructor is called when the
+                                             corresponding handler is removed. See the full parameter description
+                                             in the :ref:`Handler destructor function <box_box_iproto_override-destroy>` section.
 
-    :param uint32_t request_type: request type code from the ``iproto_type`` enumeration
-    :param iproto_handler_t handler: IPROTO request handler. To reset the request handler, set the ``handler`` parameter to ``NULL``.
-    :param iproto_handler_destroy_t destroy: IPROTO request handler destructor
     :param void* ctx: a context passed to the ``handler`` and ``destroy`` callbacks
 
     :return: 0 on success
@@ -307,4 +306,49 @@
     *   :errcode:`ER_PROC_LUA` -- the exception is thrown, diagnostic is not set.
     *   diagnostics from ``src/box/errcode.h`` -- the exception is thrown, diagnostic is set.
 
-    For details, see `src/box/errcode.h <https://github.com/tarantool/tarantool/blob/master/src/box/errcode.h>`__.
+    For details, see `src/box/errcode.h <https://github.com/tarantool/tarantool/blob/master/src/box/errcode.h>`__.
+
+..  _box_box_iproto_override-handler:
+
+    **Handler function**
+
+    The signature of a handler function (the ``handler`` parameter):
+
+    ..  code-block:: c
+
+        enum iproto_handler_status {
+                IPROTO_HANDLER_OK,
+                IPROTO_HANDLER_ERROR,
+                IPROTO_HANDLER_FALLBACK,
+        }
+
+        typedef enum iproto_handler_status
+        (*iproto_handler_t)(const char *header, const char *header_end,
+                            const char *body, const char *body_end, void *ctx);
+
+    where:
+
+    *   ``header``(const char*) -- a MsgPack-encoded header
+    *   ``header_end``(const char*) -- end of a header encoded as MsgPack
+    *   ``body``(const char*) -- a MsgPack-encoded body
+    *   ``header_end``(const char*) -- end of a body encoded as MsgPack
+
+    The handler returns a status code. Possible statuses:
+
+    *  ``IPROTO_REQUEST_HANDLER_OK`` -- success
+    *  ``IPROTO_REQUEST_HANDLER_ERROR`` -- error, diagnostic must be set by handler
+    *  ``IPROTO_REQUEST_HANDLER_FALLBACK`` -- fallback to the system handler
+
+..  _box_box_iproto_override-destroy:
+
+    **Handler destructor function**
+
+    The signature of a destructor function (the ``destroy`` parameter):
+
+    ..  code-block:: c
+
+        typedef void (*iproto_handler_destroy_t)(void *ctx);
+
+    where:
+
+    *   ``ctx`` (void*): the context provided by ``box_iproto_override()`` function.

doc/reference/reference_lua/box_iproto.rst

@@ -108,7 +108,7 @@ The table lists all available functions and data of the submodule:
         *   - Name
             - Use
 
-        *   - :doc:`./box_iproto/keys`
+        *   - :doc:`./box_iproto/key`
             - Request keys
 
         *   - :doc:`./box_iproto/request_type`