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, void **fctp);
 114
 115 /* Determine the next step in the lookup process according to the
 116    result STATUS of the call to the last function returned by
 117    `__nss_lookup' or `__nss_next'.  NI specifies the last function
 118    examined.  The function return a value > 0 if the process should
 119    stop with the last result of the last function call to be the
 120    result of the entire lookup.  The returned value is 0 if there is
 121    another function to use and < 0 if an error occurred.
 122
 123    If ALL_VALUES is nonzero, the return value will not be > 0 as long as
 124    there is a possibility the lookup process can ever use following
 125    services.  In other words, only if all four lookup results have
 126    the action RETURN associated the lookup process stops before the
 127    natural end.  */
 128 extern int __nss_next (service_user **ni, const char *fct_name, void **fctp,
 129                        int status, int all_values);
 130 libc_hidden_proto (__nss_next)
 131
 132 /* Search for the service described in NI for a function named FCT_NAME
 133    and return a pointer to this function if successful.  */
 134 extern void *__nss_lookup_function (service_user *ni, const char *fct_name);
 135 libc_hidden_proto (__nss_lookup_function)
 136
 137
 138 /* Called by NSCD to disable recursive calls.  */
 139 extern void __nss_disable_nscd (void);
 140
 141
 142 typedef int (*db_lookup_function) (service_user **, const char *, void **)
 143      internal_function;
 144 typedef enum nss_status (*setent_function) (int);
 145 typedef enum nss_status (*endent_function) (void);
 146 typedef enum nss_status (*getent_function) (void *, char *, size_t,
 147                                             int *, int *);
 148 typedef int (*getent_r_function) (void *, char *, size_t,
 149                                   void **result, int *);
 150
 151 extern void __nss_setent (const char *func_name,
 152                           db_lookup_function lookup_fct,
 153                           service_user **nip, service_user **startp,
 154                           service_user **last_nip, int stayon,
 155                           int *stayon_tmp, int res);
 156 extern void __nss_endent (const char *func_name,
 157                           db_lookup_function lookup_fct,
 158                           service_user **nip, service_user **startp,
 159                           service_user **last_nip, int res);
 160 extern int __nss_getent_r (const char *getent_func_name,
 161                            const char *setent_func_name,
 162                            db_lookup_function lookup_fct,
 163                            service_user **nip, service_user **startp,
 164                            service_user **last_nip, int *stayon_tmp,
 165                            int res,
 166                            void *resbuf, char *buffer, size_t buflen,
 167                            void **result, int *h_errnop);
 168 extern void *__nss_getent (getent_r_function func,
 169                            void **resbuf, char **buffer, size_t buflen,
 170                            size_t *buffer_size, int *h_errnop);
 171 struct hostent;
 172 extern int __nss_hostname_digits_dots (const char *name,
 173                                        struct hostent *resbuf, char **buffer,
 174                                        size_t *buffer_size, size_t buflen,
 175                                        struct hostent **result,
 176                                        enum nss_status *status, int af,
 177                                        int *h_errnop);
 178 libc_hidden_proto (__nss_hostname_digits_dots)
 179
 180 #endif  /* nsswitch.h */