nss/nsswitch.h

   1 /* Copyright (C) 1996-1999,2001,2002,2003,2004,2007
   2    Free Software Foundation, Inc.
   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, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #ifndef _NSSWITCH_H
  21 #define _NSSWITCH_H     1
  22
  23 /* This is an *internal* header.  */
  24
  25 #include <arpa/nameser.h>
  26 #include <netinet/in.h>
  27 #include <nss.h>
  28 #include <resolv.h>
  29 #include <search.h>
  30 #include <dlfcn.h>
  31
  32 /* Actions performed after lookup finished.  */
  33 typedef enum
  34 {
  35   NSS_ACTION_CONTINUE,
  36   NSS_ACTION_RETURN
  37 } lookup_actions;
  38
  39
  40 typedef 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.  */
  54 typedef struct
  55 {
  56   const char *fct_name;
  57   void *fct_ptr;
  58 } known_function;
  59
  60
  61 typedef 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
  79 typedef 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
  90 typedef 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 /* Interface functions for NSS.  */
 100
 101 /* Get the data structure representing the specified database.
 102    If there is no configuration for this database in the file,
 103    parse a service list from DEFCONFIG and use that.  More
 104    than one function can use the database.  */
 105 extern int __nss_database_lookup (const char *database,
 106                                   const char *alternative_name,
 107                                   const char *defconfig, service_user **ni);
 108 libc_hidden_proto (__nss_database_lookup)
 109
 110 /* Put first function with name FCT_NAME for SERVICE in FCTP.  The
 111    position is remembered in NI.  The function returns a value < 0 if
 112    an error occurred or no such function exists.  */
 113 extern int __nss_lookup (service_user **ni, const char *fct_name,
 114                          const char *fct2_name, void **fctp) attribute_hidden;
 115
 116 /* Determine the next step in the lookup process according to the
 117    result STATUS of the call to the last function returned by
 118    `__nss_lookup' or `__nss_next'.  NI specifies the last function
 119    examined.  The function return a value > 0 if the process should
 120    stop with the last result of the last function call to be the
 121    result of the entire lookup.  The returned value is 0 if there is
 122    another function to use and < 0 if an error occurred.
 123
 124    If ALL_VALUES is nonzero, the return value will not be > 0 as long as
 125    there is a possibility the lookup process can ever use following
 126    services.  In other words, only if all four lookup results have
 127    the action RETURN associated the lookup process stops before the
 128    natural end.  */
 129 extern int __nss_next2 (service_user **ni, const char *fct_name,
 130                         const char *fct2_name, void **fctp, int status,
 131                         int all_values) attribute_hidden;
 132 libc_hidden_proto (__nss_next2)
 133 extern int __nss_next (service_user **ni, const char *fct_name, void **fctp,
 134                        int status, int all_values);
 135
 136 /* Search for the service described in NI for a function named FCT_NAME
 137    and return a pointer to this function if successful.  */
 138 extern void *__nss_lookup_function (service_user *ni, const char *fct_name);
 139 libc_hidden_proto (__nss_lookup_function)
 140
 141
 142 /* Called by NSCD to disable recursive calls.  */
 143 extern void __nss_disable_nscd (void);
 144
 145
 146 typedef int (*db_lookup_function) (service_user **, const char *, const char *,
 147                                    void **)
 148      internal_function;
 149 typedef enum nss_status (*setent_function) (int);
 150 typedef enum nss_status (*endent_function) (void);
 151 typedef enum nss_status (*getent_function) (void *, char *, size_t,
 152                                             int *, int *);
 153 typedef int (*getent_r_function) (void *, char *, size_t,
 154                                   void **result, int *);
 155
 156 extern void __nss_setent (const char *func_name,
 157                           db_lookup_function lookup_fct,
 158                           service_user **nip, service_user **startp,
 159                           service_user **last_nip, int stayon,
 160                           int *stayon_tmp, int res);
 161 extern void __nss_endent (const char *func_name,
 162                           db_lookup_function lookup_fct,
 163                           service_user **nip, service_user **startp,
 164                           service_user **last_nip, int res);
 165 extern int __nss_getent_r (const char *getent_func_name,
 166                            const char *setent_func_name,
 167                            db_lookup_function lookup_fct,
 168                            service_user **nip, service_user **startp,
 169                            service_user **last_nip, int *stayon_tmp,
 170                            int res,
 171                            void *resbuf, char *buffer, size_t buflen,
 172                            void **result, int *h_errnop);
 173 extern void *__nss_getent (getent_r_function func,
 174                            void **resbuf, char **buffer, size_t buflen,
 175                            size_t *buffer_size, int *h_errnop);
 176 struct hostent;
 177 extern int __nss_hostname_digits_dots (const char *name,
 178                                        struct hostent *resbuf, char **buffer,
 179                                        size_t *buffer_size, size_t buflen,
 180                                        struct hostent **result,
 181                                        enum nss_status *status, int af,
 182                                        int *h_errnop);
 183 libc_hidden_proto (__nss_hostname_digits_dots)
 184
 185 #endif  /* nsswitch.h */