1/* Copyright (C) 1996-2017 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <http://www.gnu.org/licenses/>. */
17
18#ifndef _NSSWITCH_H
19#define _NSSWITCH_H 1
20
21/* This is an *internal* header. */
22
23#include <arpa/nameser.h>
24#include <netinet/in.h>
25#include <nss.h>
26#include <resolv.h>
27#include <search.h>
28#include <dlfcn.h>
29#include <stdbool.h>
30
31/* Actions performed after lookup finished. */
32typedef enum
33{
34 NSS_ACTION_CONTINUE,
35 NSS_ACTION_RETURN,
36 NSS_ACTION_MERGE
37} lookup_actions;
38
39
40typedef struct service_library
41{
42 /* Name of service (`files', `dns', `nis', ...). */
43 const char *name;
44 /* Pointer to the loaded shared library. */
45 void *lib_handle;
46 /* And the link to the next entry. */
47 struct service_library *next;
48} service_library;
49
50
51/* For mapping a function name to a function pointer. It is known in
52 nsswitch.c:nss_lookup_function that a string pointer for the lookup key
53 is the first member. */
54typedef struct
55{
56 const char *fct_name;
57 void *fct_ptr;
58} known_function;
59
60
61typedef struct service_user
62{
63 /* And the link to the next entry. */
64 struct service_user *next;
65 /* Action according to result. */
66 lookup_actions actions[5];
67 /* Link to the underlying library object. */
68 service_library *library;
69 /* Collection of known functions. */
70 void *known;
71 /* Name of the service (`files', `dns', `nis', ...). */
72 char name[0];
73} service_user;
74
75/* To access the action based on the status value use this macro. */
76#define nss_next_action(ni, status) ((ni)->actions[2 + status])
77
78
79typedef struct name_database_entry
80{
81 /* And the link to the next entry. */
82 struct name_database_entry *next;
83 /* List of service to be used. */
84 service_user *service;
85 /* Name of the database. */
86 char name[0];
87} name_database_entry;
88
89
90typedef struct name_database
91{
92 /* List of all known databases. */
93 name_database_entry *entry;
94 /* List of libraries with service implementation. */
95 service_library *library;
96} name_database;
97
98
99/* Indices into DATABASES in nsswitch.c and __NSS_DATABASE_CUSTOM. */
100enum
101 {
102#define DEFINE_DATABASE(arg) NSS_DBSIDX_##arg,
103#include "databases.def"
104#undef DEFINE_DATABASE
105 NSS_DBSIDX_max
106 };
107
108/* Flags whether custom rules for database is set. */
109extern bool __nss_database_custom[NSS_DBSIDX_max];
110
111/* Warning for NSS functions, which don't require dlopen if glibc
112 was built with --enable-static-nss. */
113#ifdef DO_STATIC_NSS
114# define nss_interface_function(name)
115#else
116# define nss_interface_function(name) static_link_warning (name)
117#endif
118
119
120/* Interface functions for NSS. */
121
122/* Get the data structure representing the specified database.
123 If there is no configuration for this database in the file,
124 parse a service list from DEFCONFIG and use that. More
125 than one function can use the database. */
126extern int __nss_database_lookup (const char *database,
127 const char *alternative_name,
128 const char *defconfig, service_user **ni);
129libc_hidden_proto (__nss_database_lookup)
130
131/* Put first function with name FCT_NAME for SERVICE in FCTP. The
132 position is remembered in NI. The function returns a value < 0 if
133 an error occurred or no such function exists. */
134extern int __nss_lookup (service_user **ni, const char *fct_name,
135 const char *fct2_name, void **fctp);
136libc_hidden_proto (__nss_lookup)
137
138/* Determine the next step in the lookup process according to the
139 result STATUS of the call to the last function returned by
140 `__nss_lookup' or `__nss_next'. NI specifies the last function
141 examined. The function return a value > 0 if the process should
142 stop with the last result of the last function call to be the
143 result of the entire lookup. The returned value is 0 if there is
144 another function to use and < 0 if an error occurred.
145
146 If ALL_VALUES is nonzero, the return value will not be > 0 as long as
147 there is a possibility the lookup process can ever use following
148 services. In other words, only if all four lookup results have
149 the action RETURN associated the lookup process stops before the
150 natural end. */
151extern int __nss_next2 (service_user **ni, const char *fct_name,
152 const char *fct2_name, void **fctp, int status,
153 int all_values) attribute_hidden;
154libc_hidden_proto (__nss_next2)
155extern int __nss_next (service_user **ni, const char *fct_name, void **fctp,
156 int status, int all_values);
157
158/* Search for the service described in NI for a function named FCT_NAME
159 and return a pointer to this function if successful. */
160extern void *__nss_lookup_function (service_user *ni, const char *fct_name);
161libc_hidden_proto (__nss_lookup_function)
162
163
164/* Called by NSCD to disable recursive calls and enable special handling
165 when used in nscd. */
166struct traced_file;
167extern void __nss_disable_nscd (void (*) (size_t, struct traced_file *));
168
169
170typedef int (*db_lookup_function) (service_user **, const char *, const char *,
171 void **)
172 internal_function;
173typedef enum nss_status (*setent_function) (int);
174typedef enum nss_status (*endent_function) (void);
175typedef enum nss_status (*getent_function) (void *, char *, size_t,
176 int *, int *);
177typedef int (*getent_r_function) (void *, char *, size_t,
178 void **result, int *);
179
180extern void __nss_setent (const char *func_name,
181 db_lookup_function lookup_fct,
182 service_user **nip, service_user **startp,
183 service_user **last_nip, int stayon,
184 int *stayon_tmp, int res);
185extern void __nss_endent (const char *func_name,
186 db_lookup_function lookup_fct,
187 service_user **nip, service_user **startp,
188 service_user **last_nip, int res);
189extern int __nss_getent_r (const char *getent_func_name,
190 const char *setent_func_name,
191 db_lookup_function lookup_fct,
192 service_user **nip, service_user **startp,
193 service_user **last_nip, int *stayon_tmp,
194 int res,
195 void *resbuf, char *buffer, size_t buflen,
196 void **result, int *h_errnop);
197extern void *__nss_getent (getent_r_function func,
198 void **resbuf, char **buffer, size_t buflen,
199 size_t *buffer_size, int *h_errnop);
200struct hostent;
201extern int __nss_hostname_digits_dots (const char *name,
202 struct hostent *resbuf, char **buffer,
203 size_t *buffer_size, size_t buflen,
204 struct hostent **result,
205 enum nss_status *status, int af,
206 int *h_errnop);
207libc_hidden_proto (__nss_hostname_digits_dots)
208
209/* Maximum number of aliases we allow. */
210#define MAX_NR_ALIASES 48
211#define MAX_NR_ADDRS 48
212
213#endif /* nsswitch.h */
214