nss/getXXbyYY_r.c

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