nss/getXXbyYY_r.c

   1 /* Copyright (C) 1996,97,98,99,2000,2001,2002 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 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 #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 #ifndef DB_LOOKUP_FCT
  83 # define DB_LOOKUP_FCT CONCAT3_1 (__nss_, DATABASE_NAME, _lookup)
  84 # define CONCAT3_1(Pre, Name, Post) CONCAT3_2 (Pre, Name, Post)
  85 # define CONCAT3_2(Pre, Name, Post) Pre##Name##Post
  86 #endif
  87
  88 /* Sometimes we need to store error codes in the `h_errno' variable.  */
  89 #ifdef NEED_H_ERRNO
  90 # define H_ERRNO_PARM , int *h_errnop
  91 # define H_ERRNO_VAR , h_errnop
  92 # define H_ERRNO_VAR_P h_errnop
  93 #else
  94 # define H_ERRNO_PARM
  95 # define H_ERRNO_VAR
  96 # define H_ERRNO_VAR_P NULL
  97 #endif
  98
  99 #ifndef HAVE_TYPE
 100 # define TYPE_VAR_P NULL
 101 # define FLAGS_VAR 0
 102 #endif
 103
 104 #ifdef HAVE_AF
 105 # define AF_VAR_P &af
 106 #else
 107 # define AF_VAR_P NULL
 108 #endif
 109
 110 /* Type of the lookup function we need here.  */
 111 typedef enum nss_status (*lookup_function) (ADD_PARAMS, LOOKUP_TYPE *, char *,
 112                                             size_t, int * H_ERRNO_PARM);
 113
 114 /* The lookup function for the first entry of this service.  */
 115 extern int DB_LOOKUP_FCT (service_user **nip, const char *name, void **fctp)
 116      internal_function;
 117
 118 /* Interval in which we transfer retry to contact the NSCD.  */
 119 #define NSS_NSCD_RETRY  100
 120
 121
 122 int
 123 INTERNAL (REENTRANT_NAME) (ADD_PARAMS, LOOKUP_TYPE *resbuf, char *buffer,
 124                            size_t buflen, LOOKUP_TYPE **result H_ERRNO_PARM)
 125 {
 126   static service_user *startp;
 127   static lookup_function start_fct;
 128   service_user *nip;
 129   lookup_function fct;
 130   int no_more;
 131   enum nss_status status = NSS_STATUS_UNAVAIL;
 132 #ifdef USE_NSCD
 133   int nscd_status;
 134 #endif
 135
 136 #ifdef PREPROCESS
 137   PREPROCESS;
 138 #endif
 139
 140 #ifdef HANDLE_DIGITS_DOTS
 141   switch (__nss_hostname_digits_dots (name, resbuf, &buffer, NULL,
 142                                       buflen, result, &status,
 143                                       TYPE_VAR_P, FLAGS_VAR, AF_VAR_P,
 144                                       H_ERRNO_VAR_P))
 145     {
 146     case -1:
 147       return errno;
 148     case 1:
 149       goto done;
 150     }
 151 #endif
 152
 153 #ifdef USE_NSCD
 154   if (NOT_USENSCD_NAME && ++NOT_USENSCD_NAME > NSS_NSCD_RETRY)
 155     NOT_USENSCD_NAME = 0;
 156
 157   if (!NOT_USENSCD_NAME)
 158     {
 159       nscd_status = NSCD_NAME (ADD_VARIABLES, resbuf, buffer, buflen
 160                                H_ERRNO_VAR);
 161       if (nscd_status >= 0)
 162         {
 163           *result = nscd_status == 0 ? resbuf : NULL;
 164           return nscd_status;
 165         }
 166     }
 167 #endif
 168
 169   if (startp == NULL)
 170     {
 171       no_more = DB_LOOKUP_FCT (&nip, REENTRANT_NAME_STRING, (void **) &fct);
 172       if (no_more)
 173         startp = (service_user *) -1l;
 174       else
 175         {
 176           startp = nip;
 177           start_fct = fct;
 178
 179 #ifdef NEED__RES
 180           /* The resolver code will really be used so we have to
 181              initialize it.  */
 182           if ((_res.options & RES_INIT) == 0 && __res_ninit (&_res) == -1)
 183             {
 184               *h_errnop = NETDB_INTERNAL;
 185               *result = NULL;
 186               return errno;
 187             }
 188 #endif /* need _res */
 189 #ifdef NEED__RES_HCONF
 190           if (!_res_hconf.initialized)
 191             _res_hconf_init ();
 192 #endif /* need _res_hconf */
 193         }
 194     }
 195   else
 196     {
 197       fct = start_fct;
 198       no_more = (nip = startp) == (service_user *) -1l;
 199     }
 200
 201   while (no_more == 0)
 202     {
 203       status = DL_CALL_FCT (fct, (ADD_VARIABLES, resbuf, buffer, buflen,
 204                                    &errno H_ERRNO_VAR));
 205
 206       /* The status is NSS_STATUS_TRYAGAIN and errno is ERANGE the
 207          provided buffer is too small.  In this case we should give
 208          the user the possibility to enlarge the buffer and we should
 209          not simply go on with the next service (even if the TRYAGAIN
 210          action tells us so).  */
 211       if (status == NSS_STATUS_TRYAGAIN
 212 #ifdef NEED_H_ERRNO
 213           && *h_errnop == NETDB_INTERNAL
 214 #endif
 215           && errno == ERANGE)
 216         break;
 217
 218       no_more = __nss_next (&nip, REENTRANT_NAME_STRING,
 219                             (void **) &fct, status, 0);
 220     }
 221
 222 #ifdef HANDLE_DIGITS_DOTS
 223 done:
 224 #endif
 225   *result = status == NSS_STATUS_SUCCESS ? resbuf : NULL;
 226 #ifdef POSTPROCESS
 227   POSTPROCESS;
 228 #endif
 229   return status == NSS_STATUS_SUCCESS ? 0 : errno;
 230 }
 231
 232
 233 #include <shlib-compat.h>
 234 #if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1_2)
 235 #define OLD(name) OLD1 (name)
 236 #define OLD1(name) __old_##name
 237
 238 int
 239 OLD (REENTRANT_NAME) (ADD_PARAMS, LOOKUP_TYPE *resbuf, char *buffer,
 240                       size_t buflen, LOOKUP_TYPE **result H_ERRNO_PARM)
 241 {
 242   int ret = INTERNAL (REENTRANT_NAME) (ADD_VARIABLES, resbuf, buffer,
 243                                        buflen, result H_ERRNO_VAR);
 244
 245   if (ret != 0)
 246     ret = -1;
 247
 248   return ret;
 249 }
 250
 251 #define do_symbol_version(real, name, version) \
 252   compat_symbol (libc, real, name, version)
 253 do_symbol_version (OLD (REENTRANT_NAME), REENTRANT_NAME, GLIBC_2_0);
 254 #endif
 255
 256 #define do_default_symbol_version(real, name, version) \
 257   versioned_symbol (libc, real, name, version)
 258 do_default_symbol_version (INTERNAL (REENTRANT_NAME),
 259                            REENTRANT_NAME, GLIBC_2_1_2);