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2 * Copyright (C) 1997, 2000 Kunihiro Ishiguro
4 * This file is part of GNU Zebra.
6 * GNU Zebra is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the
8 * Free Software Foundation; either version 2, or (at your option) any
11 * GNU Zebra is distributed in the hope that it will be useful, but
12 * WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * General Public License for more details.
16 * You should have received a copy of the GNU General Public License along
17 * with this program; see the file COPYING; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
21 #ifndef _ZEBRA_LINKLIST_H
22 #define _ZEBRA_LINKLIST_H
24 /* listnodes must always contain data to be valid. Adding an empty node
25 * to a list is invalid
28 struct listnode
*next
;
29 struct listnode
*prev
;
31 /* private member, use getdata() to retrieve, do not access directly */
36 struct listnode
*head
;
37 struct listnode
*tail
;
39 /* invariant: count is the number of listnodes in the list */
43 * Returns -1 if val1 < val2, 0 if equal?, 1 if val1 > val2.
44 * Used as definition of sorted for listnode_add_sort
46 int (*cmp
)(void *val1
, void *val2
);
48 /* callback to free user-owned data when listnode is deleted. supplying
49 * this callback is very much encouraged!
51 void (*del
)(void *val
);
54 #define listnextnode(X) ((X) ? ((X)->next) : NULL)
55 #define listhead(X) ((X) ? ((X)->head) : NULL)
56 #define listtail(X) ((X) ? ((X)->tail) : NULL)
57 #define listcount(X) ((X)->count)
58 #define list_isempty(X) ((X)->head == NULL && (X)->tail == NULL)
59 /* return X->data only if X and X->data are not NULL */
60 #define listgetdata(X) (assert(X), assert((X)->data != NULL), (X)->data)
64 list_new(void); /* encouraged: set list.del callback on new lists */
66 extern void listnode_add(struct list
*, void *);
67 extern void listnode_add_sort(struct list
*, void *);
68 extern struct listnode
*listnode_add_after(struct list
*, struct listnode
*,
70 extern struct listnode
*listnode_add_before(struct list
*, struct listnode
*,
72 extern void listnode_move_to_tail(struct list
*, struct listnode
*);
73 extern void listnode_delete(struct list
*, void *);
74 extern struct listnode
*listnode_lookup(struct list
*, void *);
75 extern void *listnode_head(struct list
*);
78 * The usage of list_delete is being transitioned to pass in
79 * the double pointer to remove use after free's.
80 * list_free usage is deprecated, it leads to memory leaks
81 * of the linklist nodes. Please use list_delete_and_null
83 * In Oct of 2018, rename list_delete_and_null to list_delete
84 * and remove list_delete_original and the list_delete #define
85 * Additionally remove list_free entirely
87 #if CONFDATE > 20181001
88 CPP_NOTICE("list_delete without double pointer is deprecated, please fixup")
90 extern void list_delete_and_null(struct list
**);
91 extern void list_delete_original(struct list
*);
92 #define list_delete(X) \
93 list_delete_original((X)) \
94 CPP_WARN("Please transition to using list_delete_and_null")
95 #define list_free(X) \
96 list_delete_original((X)) \
97 CPP_WARN("Please transition tousing list_delete_and_null")
99 extern void list_delete_all_node(struct list
*);
101 /* For ospfd and ospf6d. */
102 extern void list_delete_node(struct list
*, struct listnode
*);
105 extern void list_add_list(struct list
*, struct list
*);
107 /* List iteration macro.
108 * Usage: for (ALL_LIST_ELEMENTS (...) { ... }
109 * It is safe to delete the listnode using this macro.
111 #define ALL_LIST_ELEMENTS(list, node, nextnode, data) \
112 (node) = listhead(list), ((data) = NULL); \
114 && ((data) = listgetdata(node), (nextnode) = node->next, 1); \
115 (node) = (nextnode), ((data) = NULL)
117 /* read-only list iteration macro.
118 * Usage: as per ALL_LIST_ELEMENTS, but not safe to delete the listnode Only
119 * use this macro when it is *immediately obvious* the listnode is not
120 * deleted in the body of the loop. Does not have forward-reference overhead
123 #define ALL_LIST_ELEMENTS_RO(list, node, data) \
124 (node) = listhead(list), ((data) = NULL); \
125 (node) != NULL && ((data) = listgetdata(node), 1); \
126 (node) = listnextnode(node), ((data) = NULL)
128 /* these *do not* cleanup list nodes and referenced data, as the functions
129 * do - these macros simply {de,at}tach a listnode from/to a list.
132 /* List node attach macro. */
133 #define LISTNODE_ATTACH(L, N) \
135 (N)->prev = (L)->tail; \
137 if ((L)->head == NULL) \
140 (L)->tail->next = (N); \
145 /* List node detach macro. */
146 #define LISTNODE_DETACH(L, N) \
149 (N)->prev->next = (N)->next; \
151 (L)->head = (N)->next; \
153 (N)->next->prev = (N)->prev; \
155 (L)->tail = (N)->prev; \
159 #endif /* _ZEBRA_LINKLIST_H */