1  /* Minimized/hacked up from openvswitch lib/conntrack.c, which had this license
       2     header:  */
       3  /*
       4   * Copyright (c) 2015-2019 Nicira, Inc.
       5   *
       6   * Licensed under the Apache License, Version 2.0 (the "License");
       7   * you may not use this file except in compliance with the License.
       8   * You may obtain a copy of the License at:
       9   *
      10   *     http://www.apache.org/licenses/LICENSE-2.0
      11   *
      12   * Unless required by applicable law or agreed to in writing, software
      13   * distributed under the License is distributed on an "AS IS" BASIS,
      14   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
      15   * See the License for the specific language governing permissions and
      16   * limitations under the License.
      17   */
      18  
      19  typedef __SIZE_TYPE__ size_t;
      20  #define NULL ((void *)0)
      21  #define false 0
      22  
      23  #define OBJECT_OFFSETOF(OBJECT, MEMBER)\
      24      __builtin_offsetof(typeof(*(OBJECT)), MEMBER)
      25  
      26  #define OBJECT_CONTAINING(POINTER, OBJECT, MEMBER)                      \
      27      ((typeof(OBJECT)) (void *)                                      \
      28       ((char *) (POINTER) - OBJECT_OFFSETOF(OBJECT, MEMBER)))
      29  
      30  #define ASSIGN_CONTAINER(OBJECT, POINTER, MEMBER)			\
      31      ((OBJECT) = OBJECT_CONTAINING(POINTER, OBJECT, MEMBER), (void) 0)
      32  
      33  #define INIT_CONTAINER(OBJECT, POINTER, MEMBER)				\
      34      ((OBJECT) = NULL, ASSIGN_CONTAINER(OBJECT, POINTER, MEMBER))
      35  
      36  #define HMAP_FOR_EACH_POP(NODE, MEMBER, HMAP)				\
      37      for (size_t bucket__ = 0;                                               \
      38           INIT_CONTAINER(NODE, hmap_pop_helper__(HMAP, &bucket__), MEMBER),  \
      39           (NODE != OBJECT_CONTAINING(NULL, NODE, MEMBER))                    \
      40           || ((NODE = NULL), false);)
      41  
      42  struct hmap {
      43      struct hmap_node **buckets;
      44      struct hmap_node *one;
      45      size_t mask;
      46      size_t n;
      47  };
      48  
      49  struct hmap_node {
      50      size_t hash;
      51      struct hmap_node *next;
      52  };
      53  
      54  static inline void hmap_remove(struct hmap *, struct hmap_node *);
      55  
      56  struct hmap_node *
      57  hmap_pop_helper__(struct hmap *hmap, size_t *bucket) {
      58  
      59      for (; *bucket <= hmap->mask; (*bucket)++) {
      60          struct hmap_node *node = hmap->buckets[*bucket];
      61  
      62          if (node) {
      63              hmap_remove(hmap, node);
      64              return node;
      65          }
      66      }
      67  
      68      return NULL;
      69  }
      70  
      71  static inline void
      72  hmap_remove(struct hmap *hmap, struct hmap_node *node)
      73  {
      74      struct hmap_node **bucket = &hmap->buckets[node->hash & hmap->mask];
      75      while (*bucket != node) {
      76          bucket = &(*bucket)->next;
      77      }
      78      *bucket = node->next;
      79      hmap->n--;
      80  }
      81  
      82  struct conntrack {
      83      struct hmap zone_limits;
      84  };
      85  
      86  struct zone_limit {
      87      struct hmap_node node;
      88  };
      89  
      90  void
      91  conntrack_destroy(struct conntrack *ct)
      92  {
      93      struct zone_limit *zl;
      94      HMAP_FOR_EACH_POP (zl, node, &ct->zone_limits) {
      95        __builtin_free(zl);
      96      }
      97  }