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   setent_function fct;
  57   int no_more;
  58
  59   if (res && (_res.options & RES_INIT) == 0
  60       && __res_ninit (&_res) == -1)
  61     {
  62       __set_h_errno (NETDB_INTERNAL);
  63       return;
  64     }
  65
  66   /* Cycle through the services and run their `setXXent' functions until
  67      we find an available service.  */
  68   no_more = setup (func_name, lookup_fct, (void **) &fct, nip,
  69                    startp, 1);
  70   while (! no_more)
  71     {
  72       int is_last_nip = *nip == *last_nip;
  73       enum nss_status status;
  74
  75       if (stayopen_tmp)
  76         status = DL_CALL_FCT (fct, (*stayopen_tmp));
  77       else
  78         status = DL_CALL_FCT (fct, (0));
  79
  80       no_more = __nss_next (nip, func_name, (void **) &fct,
  81                             status, 0);
  82       if (is_last_nip)
  83         *last_nip = *nip;
  84     }
  85
  86   if (stayopen_tmp)
  87     *stayopen_tmp = stayopen;
  88 }
  89
  90
  91 void
  92 __nss_endent (const char *func_name, db_lookup_function lookup_fct,
  93               service_user **nip, service_user **startp,
  94               service_user **last_nip, int res)
  95 {
  96   endent_function fct;
  97   int no_more;
  98
  99   if (res && (_res.options & RES_INIT) == 0
 100       && __res_ninit (&_res) == -1)
 101     {
 102       __set_h_errno (NETDB_INTERNAL);
 103       return;
 104     }
 105
 106   /* Cycle through all the services and run their endXXent functions.  */
 107   no_more = setup (func_name, lookup_fct, (void **) &fct, nip, startp, 1);
 108   while (! no_more)
 109     {
 110       /* Ignore status, we force check in __NSS_NEXT.  */
 111       DL_CALL_FCT (fct, ());
 112
 113       if (*nip == *last_nip)
 114         /* We have processed all services which were used.  */
 115         break;
 116
 117       no_more = __nss_next (nip, func_name, (void **) &fct, 0, 1);
 118     }
 119   *last_nip = *nip = NULL;
 120 }
 121
 122
 123 int
 124 __nss_getent_r (const char *getent_func_name,
 125                 const char *setent_func_name,
 126                 db_lookup_function lookup_fct,
 127                 service_user **nip, service_user **startp,
 128                 service_user **last_nip, int *stayopen_tmp, int res,
 129                 void *resbuf, char *buffer, size_t buflen,
 130                 void **result, int *h_errnop)
 131 {
 132   getent_function fct;
 133   int no_more;
 134   enum nss_status status;
 135
 136   if (res && (_res.options & RES_INIT) == 0
 137       && __res_ninit (&_res) == -1)
 138     {
 139       *h_errnop = NETDB_INTERNAL;
 140       *result = NULL;
 141       return errno;
 142     }
 143
 144   /* Initialize status to return if no more functions are found.  */
 145   status = NSS_STATUS_NOTFOUND;
 146
 147   /* Run through available functions, starting with the same function last
 148      run.  We will repeat each function as long as it succeeds, and then go
 149      on to the next service action.  */
 150   no_more = setup (getent_func_name, lookup_fct, (void **) &fct, nip,
 151                    startp, 0);
 152   while (! no_more)
 153     {
 154       int is_last_nip = *nip == *last_nip;
 155
 156       status = DL_CALL_FCT (fct,
 157                              (resbuf, buffer, buflen, &errno, &h_errno));
 158
 159       /* The the status is NSS_STATUS_TRYAGAIN and errno is ERANGE the
 160          provided buffer is too small.  In this case we should give
 161          the user the possibility to enlarge the buffer and we should
 162          not simply go on with the next service (even if the TRYAGAIN
 163          action tells us so).  */
 164       if (status == NSS_STATUS_TRYAGAIN
 165           && (h_errnop == NULL || *h_errnop == NETDB_INTERNAL)
 166           && errno == ERANGE)
 167         break;
 168
 169       do
 170         {
 171           no_more = __nss_next (nip, getent_func_name, (void **) &fct,
 172                                 status, 0);
 173
 174           if (is_last_nip)
 175             *last_nip = *nip;
 176
 177           if (! no_more)
 178             {
 179               /* Call the `setXXent' function.  This wasn't done before.  */
 180               setent_function sfct;
 181
 182               no_more = __nss_lookup (nip, setent_func_name,
 183                                       (void **) &sfct);
 184
 185               if (! no_more)
 186                 {
 187                   if (stayopen_tmp)
 188                     status = DL_CALL_FCT (sfct, (*stayopen_tmp));
 189                   else
 190                     status = DL_CALL_FCT (sfct, (0));
 191                 }
 192               else
 193                 status = NSS_STATUS_NOTFOUND;
 194             }
 195         }
 196       while (! no_more && status != NSS_STATUS_SUCCESS);
 197     }
 198
 199   *result = status == NSS_STATUS_SUCCESS ? resbuf : NULL;
 200   return (status == NSS_STATUS_SUCCESS
 201           ? 0 : status == NSS_STATUS_TRYAGAIN ? errno : ENOENT);
 202 }