outbound_list.h revision 269257 
1/*
2 * services/outbound_list.h - keep list of outbound serviced queries.
3 *
4 * Copyright (c) 2007, NLnet Labs. All rights reserved.
5 *
6 * This software is open source.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * Redistributions of source code must retain the above copyright notice,
13 * this list of conditions and the following disclaimer.
14 *
15 * Redistributions in binary form must reproduce the above copyright notice,
16 * this list of conditions and the following disclaimer in the documentation
17 * and/or other materials provided with the distribution.
18 *
19 * Neither the name of the NLNET LABS nor the names of its contributors may
20 * be used to endorse or promote products derived from this software without
21 * specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
24 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
25 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
26 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
27 * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
28 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
29 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
30 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
31 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
32 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
33 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34 */
35
36/**
37 * \file
38 *
39 * This file contains functions to help a module keep track of the
40 * queries it has outstanding to authoritative servers.
41 */
42#ifndef SERVICES_OUTBOUND_LIST_H
43#define SERVICES_OUTBOUND_LIST_H
44struct outbound_entry;
45struct serviced_query;
46struct module_qstate;
47
48/**
49 * The outbound list. This structure is part of the module specific query
50 * state.
51 */
52struct outbound_list {
53	/** The linked list of outbound query entries. */
54	struct outbound_entry* first;
55};
56
57/**
58 * Outbound list entry. A serviced query sent by a module processing the
59 * query from the qstate. Double linked list to aid removal.
60 */
61struct outbound_entry {
62	/** next in list */
63	struct outbound_entry* next;
64	/** prev in list */
65	struct outbound_entry* prev;
66	/** The query that was sent out */
67	struct serviced_query* qsent;
68	/** the module query state that sent it */
69	struct module_qstate* qstate;
70};
71
72/**
73 * Init the user allocated outbound list structure
74 * @param list: the list structure.
75 */
76void outbound_list_init(struct outbound_list* list);
77
78/**
79 * Clear the user owner outbound list structure.
80 * Deletes serviced queries.
81 * @param list: the list structure. It is cleared, but the list struct itself
82 * 	is callers responsability to delete.
83 */
84void outbound_list_clear(struct outbound_list* list);
85
86/**
87 * Insert new entry into the list. Caller must allocate the entry with malloc.
88 * qstate and qsent are set by caller.
89 * @param list: the list to add to.
90 * @param e: entry to add, it is only half initialised at call start, fully
91 *	initialised at call end.
92 */
93void outbound_list_insert(struct outbound_list* list,
94	struct outbound_entry* e);
95
96/**
97 * Remove an entry from the list, and deletes it.
98 * Deletes serviced query in the entry.
99 * @param list: the list to remove from.
100 * @param e: the entry to remove.
101 */
102void outbound_list_remove(struct outbound_list* list,
103	struct outbound_entry* e);
104
105#endif /* SERVICES_OUTBOUND_LIST_H */
106