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 #define NEW(name) NEW1 (name)
  67 #define NEW1(name) __new_##name
  68
  69 #ifdef USE_NSCD
  70 # define NSCD_NAME ADD_NSCD (REENTRANT_NAME)
  71 # define ADD_NSCD(name) ADD_NSCD1 (name)
  72 # define ADD_NSCD1(name) __nscd_##name
  73 # define NOT_USENSCD_NAME ADD_NOT_NSCDUSE (DATABASE_NAME)
  74 # define ADD_NOT_NSCDUSE(name) ADD_NOT_NSCDUSE1 (name)
  75 # define ADD_NOT_NSCDUSE1(name) __nss_not_use_nscd_##name
  76 #endif
  77
  78 #define FUNCTION_NAME_STRING STRINGIZE (FUNCTION_NAME)
  79 #define REENTRANT_NAME_STRING STRINGIZE (REENTRANT_NAME)
  80 #define DATABASE_NAME_STRING STRINGIZE (DATABASE_NAME)
  81 #define STRINGIZE(name) STRINGIZE1 (name)
  82 #define STRINGIZE1(name) #name
  83
  84 #ifndef DB_LOOKUP_FCT
  85 # define DB_LOOKUP_FCT CONCAT3_1 (__nss_, DATABASE_NAME, _lookup)
  86 # define CONCAT3_1(Pre, Name, Post) CONCAT3_2 (Pre, Name, Post)
  87 # define CONCAT3_2(Pre, Name, Post) Pre##Name##Post
  88 #endif
  89
  90 /* Sometimes we need to store error codes in the `h_errno' variable.  */
  91 #ifdef NEED_H_ERRNO
  92 # define H_ERRNO_PARM , int *h_errnop
  93 # define H_ERRNO_VAR , h_errnop
  94 # define H_ERRNO_VAR_P h_errnop
  95 #else
  96 # define H_ERRNO_PARM
  97 # define H_ERRNO_VAR
  98 # define H_ERRNO_VAR_P NULL
  99 #endif
 100
 101 #ifndef HAVE_TYPE
 102 # define TYPE_VAR_P NULL
 103 # define FLAGS_VAR 0
 104 #endif
 105
 106 #ifdef HAVE_AF
 107 # define AF_VAR_P &af
 108 #else
 109 # define AF_VAR_P NULL
 110 #endif
 111
 112 /* Type of the lookup function we need here.  */
 113 typedef enum nss_status (*lookup_function) (ADD_PARAMS, LOOKUP_TYPE *, char *,
 114                                             size_t, int * H_ERRNO_PARM);
 115
 116 /* The lookup function for the first entry of this service.  */
 117 extern int DB_LOOKUP_FCT (service_user **nip, const char *name, void **fctp)
 118      internal_function;
 119 libc_hidden_proto (DB_LOOKUP_FCT)
 120
 121 /* Interval in which we transfer retry to contact the NSCD.  */
 122 #define NSS_NSCD_RETRY  100
 123
 124
 125 int
 126 INTERNAL (REENTRANT_NAME) (ADD_PARAMS, LOOKUP_TYPE *resbuf, char *buffer,
 127                            size_t buflen, LOOKUP_TYPE **result H_ERRNO_PARM)
 128 {
 129   static service_user *startp;
 130   static lookup_function start_fct;
 131   service_user *nip;
 132   lookup_function fct;
 133   int no_more;
 134   enum nss_status status = NSS_STATUS_UNAVAIL;
 135 #ifdef USE_NSCD
 136   int nscd_status;
 137 #endif
 138
 139 #ifdef PREPROCESS
 140   PREPROCESS;
 141 #endif
 142
 143 #ifdef HANDLE_DIGITS_DOTS
 144   switch (__nss_hostname_digits_dots (name, resbuf, &buffer, NULL,
 145                                       buflen, result, &status,
 146                                       TYPE_VAR_P, FLAGS_VAR, AF_VAR_P,
 147                                       H_ERRNO_VAR_P))
 148     {
 149     case -1:
 150       return errno;
 151     case 1:
 152       goto done;
 153     }
 154 #endif
 155
 156 #ifdef USE_NSCD
 157   if (NOT_USENSCD_NAME && ++NOT_USENSCD_NAME > NSS_NSCD_RETRY)
 158     NOT_USENSCD_NAME = 0;
 159
 160   if (!NOT_USENSCD_NAME)
 161     {
 162       nscd_status = NSCD_NAME (ADD_VARIABLES, resbuf, buffer, buflen
 163                                H_ERRNO_VAR);
 164       if (nscd_status >= 0)
 165         {
 166           *result = nscd_status == 0 ? resbuf : NULL;
 167           return nscd_status;
 168         }
 169     }
 170 #endif
 171
 172   if (startp == NULL)
 173     {
 174       no_more = DB_LOOKUP_FCT (&nip, REENTRANT_NAME_STRING, (void **) &fct);
 175       if (no_more)
 176         startp = (service_user *) -1l;
 177       else
 178         {
 179           startp = nip;
 180           start_fct = fct;
 181
 182 #ifdef NEED__RES
 183           /* The resolver code will really be used so we have to
 184              initialize it.  */
 185           if ((_res.options & RES_INIT) == 0 && __res_ninit (&_res) == -1)
 186             {
 187               *h_errnop = NETDB_INTERNAL;
 188               *result = NULL;
 189               return errno;
 190             }
 191 #endif /* need _res */
 192 #ifdef NEED__RES_HCONF
 193           if (!_res_hconf.initialized)
 194             _res_hconf_init ();
 195 #endif /* need _res_hconf */
 196         }
 197     }
 198   else
 199     {
 200       fct = start_fct;
 201       no_more = (nip = startp) == (service_user *) -1l;
 202     }
 203
 204   while (no_more == 0)
 205     {
 206       status = DL_CALL_FCT (fct, (ADD_VARIABLES, resbuf, buffer, buflen,
 207                                    &errno H_ERRNO_VAR));
 208
 209       /* The status is NSS_STATUS_TRYAGAIN and errno is ERANGE the
 210          provided buffer is too small.  In this case we should give
 211          the user the possibility to enlarge the buffer and we should
 212          not simply go on with the next service (even if the TRYAGAIN
 213          action tells us so).  */
 214       if (status == NSS_STATUS_TRYAGAIN
 215 #ifdef NEED_H_ERRNO
 216           && *h_errnop == NETDB_INTERNAL
 217 #endif
 218           && errno == ERANGE)
 219         break;
 220
 221       no_more = __nss_next (&nip, REENTRANT_NAME_STRING,
 222                             (void **) &fct, status, 0);
 223     }
 224
 225 #ifdef HANDLE_DIGITS_DOTS
 226 done:
 227 #endif
 228   *result = status == NSS_STATUS_SUCCESS ? resbuf : NULL;
 229 #ifdef POSTPROCESS
 230   POSTPROCESS;
 231 #endif
 232   return status == NSS_STATUS_SUCCESS ? 0 : errno;
 233 }
 234
 235
 236 #include <shlib-compat.h>
 237 #if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1_2)
 238 #define OLD(name) OLD1 (name)
 239 #define OLD1(name) __old_##name
 240
 241 int
 242 OLD (REENTRANT_NAME) (ADD_PARAMS, LOOKUP_TYPE *resbuf, char *buffer,
 243                       size_t buflen, LOOKUP_TYPE **result H_ERRNO_PARM)
 244 {
 245   int ret = INTERNAL (REENTRANT_NAME) (ADD_VARIABLES, resbuf, buffer,
 246                                        buflen, result H_ERRNO_VAR);
 247
 248   if (ret != 0)
 249     ret = -1;
 250
 251   return ret;
 252 }
 253
 254 #define do_symbol_version(real, name, version) \
 255   compat_symbol (libc, real, name, version)
 256 do_symbol_version (OLD (REENTRANT_NAME), REENTRANT_NAME, GLIBC_2_0);
 257 #endif
 258
 259 /* As INTERNAL (REENTRANT_NAME) may be hidden, we need an alias
 260    in between so that the REENTRANT_NAME@@GLIBC_2.1.2 is not
 261    hidden too.  */
 262 strong_alias (INTERNAL (REENTRANT_NAME), NEW (REENTRANT_NAME));
 263
 264 #define do_default_symbol_version(real, name, version) \
 265   versioned_symbol (libc, real, name, version)
 266 do_default_symbol_version (NEW (REENTRANT_NAME),
 267                            REENTRANT_NAME, GLIBC_2_1_2);