nss/nsswitch.h

   1 /* Copyright (C) 1996-1999,2001,2002,2003 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, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #ifndef _NSSWITCH_H
  20 #define _NSSWITCH_H     1
  21
  22 /* This is an *internal* header.  */
  23
  24 #include <arpa/nameser.h>
  25 #include <netinet/in.h>
  26 #include <nss.h>
  27 #include <resolv.h>
  28 #include <search.h>
  29 #include <dlfcn.h>
  30
  31 /* Actions performed after lookup finished.  */
  32 typedef enum
  33 {
  34   NSS_ACTION_CONTINUE,
  35   NSS_ACTION_RETURN
  36 } lookup_actions;
  37
  38
  39 typedef struct service_library
  40 {
  41   /* Name of service (`files', `dns', `nis', ...).  */
  42   const char *name;
  43   /* Pointer to the loaded shared library.  */
  44   void *lib_handle;
  45   /* And the link to the next entry.  */
  46   struct service_library *next;
  47 } service_library;
  48
  49
  50 /* For mapping a function name to a function pointer.  It is known in
  51    nsswitch.c:nss_lookup_function that a string pointer for the lookup key
  52    is the first member.  */
  53 typedef struct
  54 {
  55   const char *fct_name;
  56   void *fct_ptr;
  57 } known_function;
  58
  59
  60 typedef struct service_user
  61 {
  62   /* And the link to the next entry.  */
  63   struct service_user *next;
  64   /* Action according to result.  */
  65   lookup_actions actions[5];
  66   /* Link to the underlying library object.  */
  67   service_library *library;
  68   /* Collection of known functions.  */
  69   struct entry *known;
  70   /* Name of the service (`files', `dns', `nis', ...).  */
  71   char name[0];
  72 } service_user;
  73
  74 /* To access the action based on the status value use this macro.  */
  75 #define nss_next_action(ni, status) ((ni)->actions[2 + status])
  76
  77
  78 typedef struct name_database_entry
  79 {
  80   /* And the link to the next entry.  */
  81   struct name_database_entry *next;
  82   /* List of service to be used.  */
  83   service_user *service;
  84   /* Name of the database.  */
  85   char name[0];
  86 } name_database_entry;
  87
  88
  89 typedef struct name_database
  90 {
  91   /* List of all known databases.  */
  92   name_database_entry *entry;
  93   /* List of libraries with service implementation.  */
  94   service_library *library;
  95 } name_database;
  96
  97
  98 /* Interface functions for NSS.  */
  99
 100 /* Get the data structure representing the specified database.
 101    If there is no configuration for this database in the file,
 102    parse a service list from DEFCONFIG and use that.  More
 103    than one function can use the database.  */
 104 extern int __nss_database_lookup (const char *database,
 105                                   const char *alternative_name,
 106                                   const char *defconfig, service_user **ni);
 107 libc_hidden_proto (__nss_database_lookup)
 108
 109 /* Put first function with name FCT_NAME for SERVICE in FCTP.  The
 110    position is remembered in NI.  The function returns a value < 0 if
 111    an error occurred or no such function exists.  */
 112 extern int __nss_lookup (service_user **ni, const char *fct_name, void **fctp);
 113
 114 /* Determine the next step in the lookup process according to the
 115    result STATUS of the call to the last function returned by
 116    `__nss_lookup' or `__nss_next'.  NI specifies the last function
 117    examined.  The function return a value > 0 if the process should
 118    stop with the last result of the last function call to be the
 119    result of the entire lookup.  The returned value is 0 if there is
 120    another function to use and < 0 if an error occurred.
 121
 122    If ALL_VALUES is nonzero, the return value will not be > 0 as long as
 123    there is a possibility the lookup process can ever use following
 124    services.  In other words, only if all four lookup results have
 125    the action RETURN associated the lookup process stops before the
 126    natural end.  */
 127 extern int __nss_next (service_user **ni, const char *fct_name, void **fctp,
 128                        int status, int all_values);
 129 libc_hidden_proto (__nss_next)
 130
 131 /* Search for the service described in NI for a function named FCT_NAME
 132    and return a pointer to this function if successful.  */
 133 extern void *__nss_lookup_function (service_user *ni, const char *fct_name);
 134
 135
 136 /* Called by NSCD to disable recursive calls.  */
 137 extern void __nss_disable_nscd (void);
 138
 139
 140 typedef int (*db_lookup_function) (service_user **, const char *, void **)
 141      internal_function;
 142 typedef enum nss_status (*setent_function) (int);
 143 typedef enum nss_status (*endent_function) (void);
 144 typedef enum nss_status (*getent_function) (void *, char *, size_t,
 145                                             int *, int *);
 146 typedef int (*getent_r_function) (void *, char *, size_t,
 147                                   void **result, int *);
 148
 149 extern void __nss_setent (const char *func_name,
 150                           db_lookup_function lookup_fct,
 151                           service_user **nip, service_user **startp,
 152                           service_user **last_nip, int stayon,
 153                           int *stayon_tmp, int res);
 154 extern void __nss_endent (const char *func_name,
 155                           db_lookup_function lookup_fct,
 156                           service_user **nip, service_user **startp,
 157                           service_user **last_nip, int res);
 158 extern int __nss_getent_r (const char *getent_func_name,
 159                            const char *setent_func_name,
 160                            db_lookup_function lookup_fct,
 161                            service_user **nip, service_user **startp,
 162                            service_user **last_nip, int *stayon_tmp,
 163                            int res,
 164                            void *resbuf, char *buffer, size_t buflen,
 165                            void **result, int *h_errnop);
 166 extern void *__nss_getent (getent_r_function func,
 167                            void **resbuf, char **buffer, size_t buflen,
 168                            size_t *buffer_size, int *h_errnop);
 169 struct hostent;
 170 extern int __nss_hostname_digits_dots (const char *name,
 171                                        struct hostent *resbuf, char **buffer,
 172                                        size_t *buffer_size, size_t buflen,
 173                                        struct hostent **result,
 174                                        enum nss_status *status, int *typep,
 175                                        int flags, int *afp, int *h_errnop);
 176 libc_hidden_proto (__nss_hostname_digits_dots)
 177
 178 #endif  /* nsswitch.h */