xref: /freebsd/crypto/krb5/src/util/verto/module.h (revision 7f2fe78b9dd5f51c821d771b63d2e096f6fd49e9)
1 /*
2  * Copyright 2011 Red Hat, Inc.
3  *
4  * Permission is hereby granted, free of charge, to any person
5  * obtaining a copy of this software and associated documentation files
6  * (the "Software"), to deal in the Software without restriction,
7  * including without limitation the rights to use, copy, modify, merge,
8  * publish, distribute, sublicense, and/or sell copies of the Software,
9  * and to permit persons to whom the Software is furnished to do so,
10  * subject to the following conditions:
11  *
12  * The above copyright notice and this permission notice shall be
13  * included in all copies or substantial portions of the Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
18  * NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
19  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
20  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
21  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
22  * SOFTWARE.
23  */
24 
25 /* Determines if a symbol is present in a given module.
26  *
27  * @param modname The name of the module.
28  * @param symbname The name of the symbol.
29  * @return Non-zero if found, zero if not found.
30  */
31 int
32 module_symbol_is_present(const char *modname, const char *symbname);
33 
34 /* Finds the file for a given symbol.
35  *
36  * If filename is non-null, the name of the file will be stored. This must
37  * be freed with free().
38  *
39  * @param addr The address to resolve.
40  * @param filename Where to store the name of the file.
41  * @return 0 on error, non-zero on success.
42  */
43 int
44 module_get_filename_for_symbol(void *addr, char **filename);
45 
46 /* Closes a module.
47  *
48  * Does nothing if dll is NULL.
49  *
50  * @param dll The module to close.
51  */
52 void
53 module_close(void *dll);
54 
55 
56 /* Loads a module and extracts the given symbol.
57  *
58  * This function loads the module specified by filename, but does not resolve
59  * any of its symbol dependencies. Next is gets the symbol symbname and calls
60  * shouldload(). If shouldload() returns non-zero, the module is reloaded
61  * with full symbol resolution and stores the results in dll and symb.
62  *
63  * The job of shouldload() is to determine, based on the metadata in the
64  * symbol fetched, if the module should be fully loaded. The shouldload()
65  * callback MUST NOT attempt to call any functions in the module. This will
66  * crash on WIN32.
67  *
68  * If an error occurs, an error string will be allocated and returned. If
69  * allocation of this string fails, NULL will be returned. Since this is the
70  * same as the non-error case, you should additionally check if dll or symb
71  * is NULL.
72  *
73  * @param filename Path to the module
74  * @param symbname Symbol name to load from the file and pass to shouldload()
75  * @param shouldload Callback to determine whether to fullly load the module
76  * @param misc Opaque pointer to pass to shouldload()
77  * @param dll Where the module will be stored (can be NULL)
78  * @param symb Where the symbol will be stored (can be NULL)
79  * @return An error string.
80  */
81 char *
82 module_load(const char *filename, const char *symbname,
83             int (*shouldload)(void *symb, void *misc, char **err), void *misc,
84             void **dll, void **symb);
85