feat: Due to the deep modifications related to names and packet format,

this task cover a large part of the codebase and involves several changes:

- the library provides a name data structure (hicn_name_t ), which is composed
  of a name prefix (hicn_name_prefix_t) and a name suffix (hicn_name_suffix_t),
  and it has been extended to provide all support functions required for name
  manipulation, including common prefix computation, as required for the Longest
  Prefix Match (LPM)in the forwarder, in addition to Exact Prefix Match (EPM).
- all code has been rewritten to use this data structure instead of having for
  instance the forwarder define its own name class (used to be Name and NameBitVector)
  the code has been refactored to minimize name allocations and copies, one remaining
  aspect is the difference of name storage between PIT and CS entries (respectively
  in the PIT entry, and in the message buffer), which causes the packet cache
  index to be updated when a PIT entry is converted into a CS entry. By storing
  the name in the PIT/CS entry everytime, we might save on this operation).
- hicn-light FIB has been rewritten : code has been refactored and should now be
  shorter and documented; unit tests have been drafted but more would be required
  to cover all cases and match the algorithms to add/remove nodes, as specified in the doc.
  all protocol details and hICN header formats are now abstracted by the library
  for the forwarder (and thus header.h and  protocols/*.h have been removed from
  public includes, and replaced by packet.h providing protocol agnostic packet
  level functions, completely replacing the compat.h header that used to provide
  similar functions.
- this works by exposing a opaque buffer to the application (a kind of socket buffer)
  which is used by the lib to cache the packet format and offsets of the different
  layers in the buffer and provider efficient operations (the packet format is
  either defined for packet construction, or guessed at ingress, and this structure
  is updated accordingly only once).

Co-authored-by: Jordan Augé <jordan.auge+fdio@cisco.com>
Signed-off-by: Luca Muscariello <muscariello@ieee.org>
Change-Id: I31e321897f85f0267fe8ba4720363c180564492f

1 files changed, 210 insertions, 0 deletions

diff --git a/ctrl/libhicnctrl/src/request.c b/ctrl/libhicnctrl/src/request.c
new file mode 100644
index 000000000..0e1d07b04
--- /dev/null
+++ b/ctrl/libhicnctrl/src/request.c
@@ -0,0 +1,210 @@
+/*
+ * Copyright (c) 2021-2022 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * \file request.c
+ * \brief Implementation of pending requests.
+ */
+
+#include <assert.h>
+#include <stdlib.h>
+
+#include <hicn/util/log.h>
+
+#include "request.h"
+
+const char *hc_request_state_str[] = {
+#define _(x) [REQUEST_STATE_##x] = #x,
+    foreach_request_state
+#undef _
+};
+
+struct hc_request_s {
+  int seq;
+  hc_action_t action;
+  hc_object_type_t object_type;
+  hc_object_t *object;
+
+#if 0
+  int (*parse)(const uint8_t *src, uint8_t *dst);
+#endif
+
+  /* Callbacks */
+  hc_result_callback_t callback;
+  void *callback_data;
+
+  /* Temp data used for the execution of the request */
+  hc_data_t *data;
+
+  /* Nested requests support
+   *
+   * In order to answer complex requests, involving a combination of requests to
+   * the forwarder, we will allow maintaining a Finite State Machine in the
+   * requests (and a tree of requests)
+   *
+   * The entry point for the modules will always remain the initial request,
+   * however, we will chain nested requests in their parent fields, and point to
+   * the one currently under execution in current.
+   * */
+  hc_request_state_t state;
+  unsigned state_count; /* Usefor for iterative requests */
+  hc_request_t *parent;
+  hc_request_t *current;
+};
+
+hc_request_t *hc_request_create(int seq, hc_action_t action,
+                                hc_object_type_t object_type,
+                                hc_object_t *object,
+                                hc_result_callback_t callback,
+                                void *callback_data) {
+  hc_request_t *request = malloc(sizeof(hc_request_t));
+  if (!request) return NULL;
+  request->seq = seq;
+
+  request->action = action;
+  request->object_type = object_type;
+  request->object = object;
+
+  request->callback = callback;
+  request->callback_data = callback_data;
+
+  request->data = NULL;
+
+  request->state = REQUEST_STATE_INIT;
+  request->state_count = 0;
+  request->parent = NULL;
+  request->current = NULL;
+
+  return request;
+}
+
+void hc_request_free(hc_request_t *request) { free(request); }
+
+void hc_request_set(hc_request_t *request, hc_action_t action,
+                    hc_object_type_t object_type, hc_object_t *object) {
+  request->action = action;
+  request->object_type = object_type;
+  request->object = object;
+}
+
+int hc_request_get_seq(const hc_request_t *request) { return request->seq; }
+
+hc_request_t *hc_request_get_current(hc_request_t *request) {
+  return request->current ? request->current : request;
+}
+
+hc_request_t *hc_request_pop(hc_request_t *request) {
+  hc_request_t *current_request = hc_request_get_current(request);
+  hc_request_t *parent = current_request->parent;
+  request->current = parent;
+  if (parent) {
+    parent->data = current_request->data;
+    /* We only free the current_request if it was not the root */
+    hc_request_free(current_request);
+  }
+  return parent;
+}
+
+hc_request_state_t hc_request_get_state(const hc_request_t *request) {
+  return request->state;
+}
+
+void hc_request_set_state(hc_request_t *request, hc_request_state_t state) {
+  request->state = state;
+}
+
+int hc_request_get_state_count(const hc_request_t *request) {
+  return request->state_count;
+}
+
+void hc_request_set_state_count(hc_request_t *request, unsigned count) {
+  request->state_count = count;
+}
+
+hc_action_t hc_request_get_action(const hc_request_t *request) {
+  return request->action;
+}
+
+hc_object_type_t hc_request_get_object_type(const hc_request_t *request) {
+  return request->object_type;
+}
+
+hc_object_t *hc_request_get_object(const hc_request_t *request) {
+  return request->object;
+}
+
+hc_data_t *hc_request_get_data(const hc_request_t *request) {
+  return request->data;
+}
+
+void hc_request_set_data(hc_request_t *request, hc_data_t *data) {
+  assert(!request->data);
+  request->data = data;
+}
+
+void hc_request_reset_data(hc_request_t *request) {
+  if (!request->data) return;
+  hc_data_free(request->data);
+  request->data = NULL;
+}
+
+bool hc_request_is_subscription(const hc_request_t *request) {
+  hc_action_t action = hc_request_get_action(request);
+  hc_object_type_t object_type = hc_request_get_object_type(request);
+  return (action == ACTION_SUBSCRIBE) ||
+         (action == ACTION_CREATE && object_type == OBJECT_TYPE_SUBSCRIPTION);
+}
+
+bool hc_request_requires_object(const hc_request_t *request) {
+  hc_action_t action = hc_request_get_action(request);
+  return (action != ACTION_LIST) && (action != ACTION_SUBSCRIBE);
+}
+
+void hc_request_clear_data(hc_request_t *request) { request->data = NULL; }
+
+void hc_request_set_complete(hc_request_t *request) {
+  request->state = REQUEST_STATE_COMPLETE;
+}
+
+bool hc_request_is_complete(const hc_request_t *request) {
+  return request->state == REQUEST_STATE_COMPLETE;
+}
+
+void hc_request_on_complete(hc_request_t *request) {
+  // request->state = REQUEST_STATE_COMPLETE;
+  if (!request->callback) return;
+  request->callback(request->data, request->callback_data);
+}
+
+void hc_request_on_notification(hc_request_t *request) {
+  if (!request->callback) return;
+  request->callback(request->data, request->callback_data);
+}
+
+hc_request_t *hc_request_make_subrequest(hc_request_t *request,
+                                         hc_action_t action,
+                                         hc_object_type_t object_type,
+                                         hc_object_t *object) {
+  hc_request_t *sr =
+      hc_request_create(request->seq, action, object_type, object,
+                        request->callback, request->callback_data);
+
+  /* The parent is either the current one, or the request itself if NULL */
+  hc_request_t *current_request = hc_request_get_current(request);
+  hc_request_reset_data(current_request);
+  sr->parent = current_request;
+  request->current = sr;
+  return sr;
+}