]>
Commit | Line | Data |
---|---|---|
171689da | 1 | /* Global list of NSS service modules. |
dff8da6b | 2 | Copyright (c) 2020-2024 Free Software Foundation, Inc. |
171689da FW |
3 | This file is part of the GNU C Library. |
4 | ||
5 | The GNU C Library is free software; you can redistribute it and/or | |
6 | modify it under the terms of the GNU Lesser General Public | |
7 | License as published by the Free Software Foundation; either | |
8 | version 2.1 of the License, or (at your option) any later version. | |
9 | ||
10 | The GNU C Library is distributed in the hope that it will be useful, | |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
13 | Lesser General Public License for more details. | |
14 | ||
15 | You should have received a copy of the GNU Lesser General Public | |
16 | License along with the GNU C Library; if not, see | |
17 | <https://www.gnu.org/licenses/>. */ | |
18 | ||
19 | #ifndef _NSS_MODULE_H | |
20 | #define _NSS_MODULE_H | |
21 | ||
22 | #include <nss.h> | |
23 | #include <stdbool.h> | |
24 | ||
25 | /* See nss_database.h for a summary of how this relates. */ | |
26 | ||
27 | /* Typed function pointers for all functions that can be defined by a | |
28 | service module. */ | |
29 | struct nss_module_functions | |
30 | { | |
31 | #undef DEFINE_NSS_FUNCTION | |
32 | #define DEFINE_NSS_FUNCTION(f) nss_##f *f; | |
33 | #include "function.def" | |
34 | }; | |
35 | ||
ee5ed999 FW |
36 | /* Number of elements of the nss_module_functions_untyped array. */ |
37 | enum | |
38 | { | |
39 | nss_module_functions_count = (sizeof (struct nss_module_functions) | |
40 | / sizeof (void *)) | |
41 | }; | |
42 | ||
171689da FW |
43 | /* Untyped version of struct nss_module_functions, for consistent |
44 | processing purposes. */ | |
ee5ed999 | 45 | typedef void *nss_module_functions_untyped[nss_module_functions_count]; |
171689da | 46 | |
f9c8b11e FW |
47 | /* Locate the nss_files functions, as if by dlopen/dlsym. */ |
48 | void __nss_files_functions (nss_module_functions_untyped pointers) | |
49 | attribute_hidden; | |
50 | ||
171689da FW |
51 | /* Initialization state of a NSS module. */ |
52 | enum nss_module_state | |
53 | { | |
54 | nss_module_uninitialized, | |
55 | nss_module_loaded, | |
56 | nss_module_failed, | |
57 | }; | |
58 | ||
59 | /* A NSS service module (potentially unloaded). Client code should | |
60 | use the functions below. */ | |
61 | struct nss_module | |
62 | { | |
63 | /* Actual type is enum nss_module_state. Use int due to atomic | |
64 | access. Used in a double-checked locking idiom. */ | |
65 | int state; | |
66 | ||
67 | /* The function pointers in the module. */ | |
68 | union | |
69 | { | |
70 | struct nss_module_functions typed; | |
71 | nss_module_functions_untyped untyped; | |
72 | } functions; | |
73 | ||
74 | /* Only used for __libc_freeres unloading. */ | |
75 | void *handle; | |
76 | ||
77 | /* The next module in the list. */ | |
78 | struct nss_module *next; | |
79 | ||
80 | /* The name of the module (as it appears in /etc/nsswitch.conf). */ | |
81 | char name[]; | |
82 | }; | |
83 | ||
84 | /* Allocates the NSS module NAME (of NAME_LENGTH bytes) and places it | |
85 | into the global list. If it already exists in the list, return the | |
86 | pre-existing module. This does not actually load the module. | |
87 | Returns NULL on memory allocation failure. */ | |
88 | struct nss_module *__nss_module_allocate (const char *name, | |
89 | size_t name_length) attribute_hidden; | |
90 | ||
91 | /* Ensures that MODULE is in a loaded or failed state. */ | |
92 | bool __nss_module_load (struct nss_module *module) attribute_hidden; | |
93 | ||
94 | /* Ensures that MODULE is loaded and returns a pointer to the function | |
95 | NAME defined in it. Returns NULL if MODULE could not be loaded, or | |
96 | if the function NAME is not defined in the module. */ | |
97 | void *__nss_module_get_function (struct nss_module *module, const char *name) | |
98 | attribute_hidden; | |
99 | ||
429029a7 DD |
100 | /* Block attempts to dlopen any module we haven't already opened. */ |
101 | void __nss_module_disable_loading (void); | |
102 | ||
171689da | 103 | #endif /* NSS_MODULE_H */ |