xref: /freebsd/contrib/unbound/services/modstack.h (revision faf25f48d601ae39f5752602f3020e2e92605625)
1 /*
2  * services/modstack.h - stack of modules
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 maintain a stack of modules.
40  */
41 
42 #ifndef SERVICES_MODSTACK_H
43 #define SERVICES_MODSTACK_H
44 struct module_func_block;
45 struct module_env;
46 
47 /**
48  * Stack of modules.
49  */
50 struct module_stack {
51 	/** the number of modules */
52 	int num;
53 	/** the module callbacks, array of num_modules length (ref only) */
54 	struct module_func_block** mod;
55 };
56 
57 /**
58  * Init a stack of modules
59  * @param stack: initialised as empty.
60  */
61 void modstack_init(struct module_stack* stack);
62 
63 /**
64  * Read config file module settings and set up the modfunc block
65  * @param stack: the stack of modules (empty before call).
66  * @param module_conf: string what modules to insert.
67  * @return false on error
68  */
69 int modstack_config(struct module_stack* stack, const char* module_conf);
70 
71 /**
72  * Get funcblock for module name
73  * @param str: string with module name. Advanced to next value on success.
74  *	The string is assumed whitespace separated list of module names.
75  * @return funcblock or NULL on error.
76  */
77 struct module_func_block* module_factory(const char** str);
78 
79 /**
80  * Get list of modules available.
81  * @return list of modules available. Static strings, ends with NULL.
82  */
83 const char** module_list_avail(void);
84 
85 /**
86  * Setup modules. Assigns ids and calls module_init.
87  * @param stack: if not empty beforehand, it will be desetup()ed.
88  *	It is then modstack_configged().
89  * @param module_conf: string what modules to insert.
90  * @param env: module environment which is inited by the modules.
91  *	environment should have a superalloc, cfg,
92  *	env.need_to_validate is set by the modules.
93  * @return on false a module init failed.
94  */
95 int modstack_setup(struct module_stack* stack, const char* module_conf,
96 	struct module_env* env);
97 
98 /**
99  * Desetup the modules, deinit, delete.
100  * @param stack: made empty.
101  * @param env: module env for module deinit() calls.
102  */
103 void modstack_desetup(struct module_stack* stack, struct module_env* env);
104 
105 /**
106  * Find index of module by name.
107  * @param stack: to look in
108  * @param name: the name to look for
109  * @return -1 on failure, otherwise index number.
110  */
111 int modstack_find(struct module_stack* stack, const char* name);
112 
113 /** fetch memory for a module by name, returns 0 if module not there */
114 size_t mod_get_mem(struct module_env* env, const char* name);
115 
116 #endif /* SERVICES_MODSTACK_H */
117