Use F1 internally: RRC Message Transfer

First MR in a series of changes to use the F1 interface internally at the gNB.

• RRC Reject not handled yet via F1 message exchange
• Removes ITTISIM (which does not compile)
• Refactors code duplication of linear allocator of gNB/eNB RRC

common/utils/collection/linear_alloc.h

+/*
+ * Licensed to the OpenAirInterface (OAI) Software Alliance under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The OpenAirInterface Software Alliance licenses this file to You under
+ * the OAI Public License, Version 1.1  (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.openairinterface.org/?page_id=698
+ *
+ * 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.
+ *-------------------------------------------------------------------------------
+ * For more information about the OpenAirInterface (OAI) Software Alliance:
+ *      contact@openairinterface.org
+ */
+
+#ifndef LINEAR_ALLOC_H
+#define LINEAR_ALLOC_H
+
+#include <limits.h>
+
+typedef unsigned int uid_t;
+#define UID_LINEAR_ALLOCATOR_SIZE 1024
+#define UID_LINEAR_ALLOCATOR_BITMAP_SIZE (((UID_LINEAR_ALLOCATOR_SIZE/8)/sizeof(unsigned int)) + 1)
+typedef struct uid_linear_allocator_s {
+  unsigned int bitmap[UID_LINEAR_ALLOCATOR_BITMAP_SIZE];
+} uid_allocator_t;
+
+static inline void uid_linear_allocator_init(uid_allocator_t *uia) {
+  memset(uia, 0, sizeof(uid_allocator_t));
+}
+
+static inline uid_t uid_linear_allocator_new(uid_allocator_t *uia) {
+  unsigned int bit_index = 1;
+  uid_t        uid = 0;
+
+  for (unsigned int i = 0; i < UID_LINEAR_ALLOCATOR_BITMAP_SIZE; i++) {
+    if (uia->bitmap[i] != UINT_MAX) {
+      bit_index = 1;
+      uid       = 0;
+
+      while ((uia->bitmap[i] & bit_index) == bit_index) {
+        bit_index = bit_index << 1;
+        uid       += 1;
+      }
+
+      uia->bitmap[i] |= bit_index;
+      return uid + (i*sizeof(unsigned int)*8);
+    }
+  }
+
+  return UINT_MAX;
+}
+
+
+static inline void uid_linear_allocator_free(uid_allocator_t *uia, uid_t uid) {
+  const unsigned int i = uid/sizeof(unsigned int)/8;
+  const unsigned int bit = uid % (sizeof(unsigned int) * 8);
+  const unsigned int value = ~(1 << bit);
+
+  if (i < UID_LINEAR_ALLOCATOR_BITMAP_SIZE) {
+    uia->bitmap[i] &= value;
+  }
+}
+
+#endif /* LINEAR_ALLOC_H */