nss/getXXbyYY_r.c

   1 /* Copyright (C) 1996,97,98,99,2000 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Library General Public License as
   7    published by the Free Software Foundation; either version 2 of the
   8    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    Library General Public License for more details.
  14
  15    You should have received a copy of the GNU Library General Public
  16    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  17    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18    Boston, MA 02111-1307, USA.  */
  19
  20 #include <assert.h>
  21 #include <errno.h>
  22 #include "nsswitch.h"
  23 #ifdef USE_NSCD
  24 # include <nscd/nscd_proto.h>
  25 #endif
  26 #ifdef NEED__RES_HCONF
  27 # include <resolv/res_hconf.h>
  28 #endif
  29 #ifdef NEED__RES
  30 # include <resolv.h>
  31 #endif
  32 /*******************************************************************\
  33 |* Here we assume several symbols to be defined:                   *|
  34 |*                                                                 *|
  35 |* LOOKUP_TYPE   - the return type of the function                 *|
  36 |*                                                                 *|
  37 |* FUNCTION_NAME - name of the non-reentrant function              *|
  38 |*                                                                 *|
  39 |* DATABASE_NAME - name of the database the function accesses      *|
  40 |*                 (e.g., host, services, ...)                     *|
  41 |*                                                                 *|
  42 |* ADD_PARAMS    - additional parameter, can vary in number        *|
  43 |*                                                                 *|
  44 |* ADD_VARIABLES - names of additional parameter                   *|
  45 |*                                                                 *|
  46 |* Optionally the following vars can be defined:                   *|
  47 |*                                                                 *|
  48 |* NEED_H_ERRNO  - an extra parameter will be passed to point to   *|
  49 |*                 the global `h_errno' variable.                  *|
  50 |*                                                                 *|
  51 |* NEED__RES     - the global _res variable might be used so we    *|
  52 |*                 will have to initialize it if necessary         *|
  53 |*                                                                 *|
  54 |* PREPROCESS    - code run before anything else                   *|
  55 |*                                                                 *|
  56 |* POSTPROCESS   - code run after the lookup                       *|
  57 |*                                                                 *|
  58 \*******************************************************************/
  59
  60 /* To make the real sources a bit prettier.  */
  61 #define REENTRANT_NAME APPEND_R (FUNCTION_NAME)
  62 #define APPEND_R(name) APPEND_R1 (name)
  63 #define APPEND_R1(name) name##_r
  64 #define INTERNAL(name) INTERNAL1 (name)
  65 #define INTERNAL1(name) __##name
  66
  67 #ifdef USE_NSCD
  68 # define NSCD_NAME ADD_NSCD (REENTRANT_NAME)
  69 # define ADD_NSCD(name) ADD_NSCD1 (name)
  70 # define ADD_NSCD1(name) __nscd_##name
  71 # define NOT_USENSCD_NAME ADD_NOT_NSCDUSE (DATABASE_NAME)
  72 # define ADD_NOT_NSCDUSE(name) ADD_NOT_NSCDUSE1 (name)
  73 # define ADD_NOT_NSCDUSE1(name) __nss_not_use_nscd_##name
  74 #endif
  75
  76 #define FUNCTION_NAME_STRING STRINGIZE (FUNCTION_NAME)
  77 #define REENTRANT_NAME_STRING STRINGIZE (REENTRANT_NAME)
  78 #define DATABASE_NAME_STRING STRINGIZE (DATABASE_NAME)
  79 #define STRINGIZE(name) STRINGIZE1 (name)
  80 #define STRINGIZE1(name) #name
  81
  82 #define DB_LOOKUP_FCT CONCAT3_1 (__nss_, DATABASE_NAME, _lookup)
  83 #define CONCAT3_1(Pre, Name, Post) CONCAT3_2 (Pre, Name, Post)
  84 #define CONCAT3_2(Pre, Name, Post) Pre##Name##Post
  85
  86 /* Sometimes we need to store error codes in the `h_errno' variable.  */
  87 #ifdef NEED_H_ERRNO
  88 # define H_ERRNO_PARM , int *h_errnop
  89 # define H_ERRNO_VAR , h_errnop
  90 #else
  91 # define H_ERRNO_PARM
  92 # define H_ERRNO_VAR
  93 #endif
  94
  95
  96 /* Type of the lookup function we need here.  */
  97 typedef enum nss_status (*lookup_function) (ADD_PARAMS, LOOKUP_TYPE *, char *,
  98                                             size_t, int * H_ERRNO_PARM);
  99
 100 /* The lookup function for the first entry of this service.  */
 101 extern int DB_LOOKUP_FCT (service_user **nip, const char *name, void **fctp);
 102
 103 /* Interval in which we transfer retry to contact the NSCD.  */
 104 #define NSS_NSCD_RETRY  100
 105
 106
 107 int
 108 INTERNAL (REENTRANT_NAME) (ADD_PARAMS, LOOKUP_TYPE *resbuf, char *buffer,
 109                            size_t buflen, LOOKUP_TYPE **result H_ERRNO_PARM)
 110 {
 111   static service_user *startp;
 112   static lookup_function start_fct;
 113   service_user *nip;
 114   lookup_function fct;
 115   int no_more;
 116   enum nss_status status = NSS_STATUS_UNAVAIL;
 117 #ifdef USE_NSCD
 118   int nscd_status;
 119 #endif
 120
 121 #ifdef PREPROCESS
 122   PREPROCESS;
 123 #endif
 124
 125 #ifdef HANDLE_DIGITS_DOTS
 126   /* We have to test for the use of IPv6 which can only be done by
 127      examining `_res'.  */
 128   if ((_res.options & RES_INIT) == 0 && __res_ninit (&_res) == -1)
 129     {
 130       *h_errnop = NETDB_INTERNAL;
 131       *result = NULL;
 132       return errno;
 133     }
 134 # define resbuf (*resbuf)
 135 # include "digits_dots.c"
 136 # undef resbuf
 137 #endif
 138
 139 #ifdef USE_NSCD
 140   if (NOT_USENSCD_NAME && ++NOT_USENSCD_NAME > NSS_NSCD_RETRY)
 141     NOT_USENSCD_NAME = 0;
 142
 143   if (!NOT_USENSCD_NAME)
 144     {
 145       nscd_status = NSCD_NAME (ADD_VARIABLES, resbuf, buffer, buflen
 146                                H_ERRNO_VAR);
 147       if (nscd_status >= 0)
 148         {
 149           *result = nscd_status == 0 ? resbuf : NULL;
 150           return nscd_status;
 151         }
 152     }
 153 #endif
 154
 155   if (startp == NULL)
 156     {
 157       no_more = DB_LOOKUP_FCT (&nip, REENTRANT_NAME_STRING, (void **) &fct);
 158       if (no_more)
 159         startp = (service_user *) -1l;
 160       else
 161         {
 162           startp = nip;
 163           start_fct = fct;
 164
 165 #ifdef NEED__RES
 166           /* The resolver code will really be used so we have to
 167              initialize it.  */
 168           if ((_res.options & RES_INIT) == 0 && __res_ninit (&_res) == -1)
 169             {
 170               *h_errnop = NETDB_INTERNAL;
 171               *result = NULL;
 172               return errno;
 173             }
 174 #endif /* need _res */
 175 #ifdef NEED__RES_HCONF
 176           if (!_res_hconf.initialized)
 177             _res_hconf_init ();
 178 #endif /* need _res_hconf */
 179         }
 180     }
 181   else
 182     {
 183       fct = start_fct;
 184       no_more = (nip = startp) == (service_user *) -1l;
 185     }
 186
 187   while (no_more == 0)
 188     {
 189       status = DL_CALL_FCT (fct, (ADD_VARIABLES, resbuf, buffer, buflen,
 190                                    &errno H_ERRNO_VAR));
 191
 192       /* The status is NSS_STATUS_TRYAGAIN and errno is ERANGE the
 193          provided buffer is too small.  In this case we should give
 194          the user the possibility to enlarge the buffer and we should
 195          not simply go on with the next service (even if the TRYAGAIN
 196          action tells us so).  */
 197       if (status == NSS_STATUS_TRYAGAIN
 198 #ifdef NEED_H_ERRNO
 199           && *h_errnop == NETDB_INTERNAL
 200 #endif
 201           && errno == ERANGE)
 202         break;
 203
 204       no_more = __nss_next (&nip, REENTRANT_NAME_STRING,
 205                             (void **) &fct, status, 0);
 206     }
 207
 208 #ifdef HANDLE_DIGITS_DOTS
 209 done:
 210 #endif
 211   *result = status == NSS_STATUS_SUCCESS ? resbuf : NULL;
 212 #ifdef POSTPROCESS
 213   POSTPROCESS;
 214 #endif
 215   return status == NSS_STATUS_SUCCESS ? 0 : errno;
 216 }
 217
 218
 219 #include <shlib-compat.h>
 220 #if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1_2)
 221 #define OLD(name) OLD1 (name)
 222 #define OLD1(name) __old_##name
 223
 224 int
 225 OLD (REENTRANT_NAME) (ADD_PARAMS, LOOKUP_TYPE *resbuf, char *buffer,
 226                       size_t buflen, LOOKUP_TYPE **result H_ERRNO_PARM)
 227 {
 228   int ret = INTERNAL (REENTRANT_NAME) (ADD_VARIABLES, resbuf, buffer,
 229                                        buflen, result H_ERRNO_VAR);
 230
 231   if (ret != 0)
 232     ret = -1;
 233
 234   return ret;
 235 }
 236
 237 #define do_symbol_version(real, name, version) \
 238   compat_symbol (libc, real, name, version)
 239 do_symbol_version (OLD (REENTRANT_NAME), REENTRANT_NAME, GLIBC_2_0);
 240
 241 #define do_default_symbol_version(real, name, version) \
 242   versioned_symbol (libc, real, name, version)
 243 do_default_symbol_version (INTERNAL (REENTRANT_NAME),
 244                            REENTRANT_NAME, GLIBC_2_1_2);
 245 #else
 246 #define do_weak_alias(n1, n2) weak_alias (n1, n2)
 247 do_weak_alias (INTERNAL (REENTRANT_NAME), REENTRANT_NAME)
 248 #endif