nss/getnssent_r.c

   1 /* Copyright (C) 2000,02 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 #include <errno.h>
  20 #include <netdb.h>
  21 #include "nsswitch.h"
  22
  23 /* Set up NIP to run through the services.  If ALL is zero, use NIP's
  24    current location if it's not nil.  Return nonzero if there are no
  25    services (left).  */
  26 static int
  27 setup (const char *func_name, db_lookup_function lookup_fct,
  28        void **fctp, service_user **nip, service_user **startp, int all)
  29 {
  30   int no_more;
  31   if (*startp == NULL)
  32     {
  33       no_more = lookup_fct (nip, func_name, fctp);
  34       *startp = no_more ? (service_user *) -1l : *nip;
  35     }
  36   else if (*startp == (service_user *) -1l)
  37     /* No services at all.  */
  38     return 1;
  39   else
  40     {
  41       if (all || !*nip)
  42         /* Reset to the beginning of the service list.  */
  43         *nip = *startp;
  44       /* Look up the first function.  */
  45       no_more = __nss_lookup (nip, func_name, fctp);
  46     }
  47   return no_more;
  48 }
  49 \f
  50 void
  51 __nss_setent (const char *func_name, db_lookup_function lookup_fct,
  52               service_user **nip, service_user **startp,
  53               service_user **last_nip, int stayopen, int *stayopen_tmp,
  54               int res)
  55 {
  56   union
  57   {
  58     setent_function f;
  59     void *ptr;
  60   } fct;
  61   int no_more;
  62
  63   if (res && (_res.options & RES_INIT) == 0
  64       && __res_ninit (&_res) == -1)
  65     {
  66       __set_h_errno (NETDB_INTERNAL);
  67       return;
  68     }
  69
  70   /* Cycle through the services and run their `setXXent' functions until
  71      we find an available service.  */
  72   no_more = setup (func_name, lookup_fct, &fct.ptr, nip,
  73                    startp, 1);
  74   while (! no_more)
  75     {
  76       int is_last_nip = *nip == *last_nip;
  77       enum nss_status status;
  78
  79       if (stayopen_tmp)
  80         status = DL_CALL_FCT (fct.f, (*stayopen_tmp));
  81       else
  82         status = DL_CALL_FCT (fct.f, (0));
  83
  84       no_more = __nss_next (nip, func_name, &fct.ptr,
  85                             status, 0);
  86       if (is_last_nip)
  87         *last_nip = *nip;
  88     }
  89
  90   if (stayopen_tmp)
  91     *stayopen_tmp = stayopen;
  92 }
  93
  94
  95 void
  96 __nss_endent (const char *func_name, db_lookup_function lookup_fct,
  97               service_user **nip, service_user **startp,
  98               service_user **last_nip, int res)
  99 {
 100   union
 101   {
 102     endent_function f;
 103     void *ptr;
 104   } fct;
 105   int no_more;
 106
 107   if (res && (_res.options & RES_INIT) == 0
 108       && __res_ninit (&_res) == -1)
 109     {
 110       __set_h_errno (NETDB_INTERNAL);
 111       return;
 112     }
 113
 114   /* Cycle through all the services and run their endXXent functions.  */
 115   no_more = setup (func_name, lookup_fct, &fct.ptr, nip, startp, 1);
 116   while (! no_more)
 117     {
 118       /* Ignore status, we force check in __NSS_NEXT.  */
 119       DL_CALL_FCT (fct.f, ());
 120
 121       if (*nip == *last_nip)
 122         /* We have processed all services which were used.  */
 123         break;
 124
 125       no_more = __nss_next (nip, func_name, &fct.ptr, 0, 1);
 126     }
 127   *last_nip = *nip = NULL;
 128 }
 129
 130
 131 int
 132 __nss_getent_r (const char *getent_func_name,
 133                 const char *setent_func_name,
 134                 db_lookup_function lookup_fct,
 135                 service_user **nip, service_user **startp,
 136                 service_user **last_nip, int *stayopen_tmp, int res,
 137                 void *resbuf, char *buffer, size_t buflen,
 138                 void **result, int *h_errnop)
 139 {
 140   union
 141   {
 142     getent_function f;
 143     void *ptr;
 144   } fct;
 145   int no_more;
 146   enum nss_status status;
 147
 148   if (res && (_res.options & RES_INIT) == 0
 149       && __res_ninit (&_res) == -1)
 150     {
 151       *h_errnop = NETDB_INTERNAL;
 152       *result = NULL;
 153       return errno;
 154     }
 155
 156   /* Initialize status to return if no more functions are found.  */
 157   status = NSS_STATUS_NOTFOUND;
 158
 159   /* Run through available functions, starting with the same function last
 160      run.  We will repeat each function as long as it succeeds, and then go
 161      on to the next service action.  */
 162   no_more = setup (getent_func_name, lookup_fct, &fct.ptr, nip,
 163                    startp, 0);
 164   while (! no_more)
 165     {
 166       int is_last_nip = *nip == *last_nip;
 167
 168       status = DL_CALL_FCT (fct.f,
 169                             (resbuf, buffer, buflen, &errno, &h_errno));
 170
 171       /* The the status is NSS_STATUS_TRYAGAIN and errno is ERANGE the
 172          provided buffer is too small.  In this case we should give
 173          the user the possibility to enlarge the buffer and we should
 174          not simply go on with the next service (even if the TRYAGAIN
 175          action tells us so).  */
 176       if (status == NSS_STATUS_TRYAGAIN
 177           && (h_errnop == NULL || *h_errnop == NETDB_INTERNAL)
 178           && errno == ERANGE)
 179         break;
 180
 181       do
 182         {
 183           no_more = __nss_next (nip, getent_func_name, &fct.ptr,
 184                                 status, 0);
 185
 186           if (is_last_nip)
 187             *last_nip = *nip;
 188
 189           if (! no_more)
 190             {
 191               /* Call the `setXXent' function.  This wasn't done before.  */
 192               union
 193               {
 194                 setent_function f;
 195                 void *ptr;
 196               } sfct;
 197
 198               no_more = __nss_lookup (nip, setent_func_name,
 199                                       &sfct.ptr);
 200
 201               if (! no_more)
 202                 {
 203                   if (stayopen_tmp)
 204                     status = DL_CALL_FCT (sfct.f, (*stayopen_tmp));
 205                   else
 206                     status = DL_CALL_FCT (sfct.f, (0));
 207                 }
 208               else
 209                 status = NSS_STATUS_NOTFOUND;
 210             }
 211         }
 212       while (! no_more && status != NSS_STATUS_SUCCESS);
 213     }
 214
 215   *result = status == NSS_STATUS_SUCCESS ? resbuf : NULL;
 216   return (status == NSS_STATUS_SUCCESS ? 0
 217           : status != NSS_STATUS_TRYAGAIN ? ENOENT
 218           /* h_errno functions only set errno if h_errno is NETDB_INTERNAL.  */
 219           : (h_errnop == NULL || *h_errnop == NETDB_INTERNAL) ? errno
 220           : EAGAIN);
 221 }