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 *
hmap_pop_helper__(struct hmap * hmap,size_t * bucket)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
hmap_remove(struct hmap * hmap,struct hmap_node * node)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
conntrack_destroy(struct conntrack * ct)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 }
98