nss/getnssent_r.c

   1 /* Copyright (C) 2000, 2002, 2004 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_maybe_init (&_res, 0) == -1)
  64     {
  65       __set_h_errno (NETDB_INTERNAL);
  66       return;
  67     }
  68
  69   /* Cycle through the services and run their `setXXent' functions until
  70      we find an available service.  */
  71   no_more = setup (func_name, lookup_fct, &fct.ptr, nip,
  72                    startp, 1);
  73   while (! no_more)
  74     {
  75       int is_last_nip = *nip == *last_nip;
  76       enum nss_status status;
  77
  78       if (stayopen_tmp)
  79         status = DL_CALL_FCT (fct.f, (*stayopen_tmp));
  80       else
  81         status = DL_CALL_FCT (fct.f, (0));
  82
  83       no_more = __nss_next (nip, func_name, &fct.ptr,
  84                             status, 0);
  85       if (is_last_nip)
  86         *last_nip = *nip;
  87     }
  88
  89   if (stayopen_tmp)
  90     *stayopen_tmp = stayopen;
  91 }
  92
  93
  94 void
  95 __nss_endent (const char *func_name, db_lookup_function lookup_fct,
  96               service_user **nip, service_user **startp,
  97               service_user **last_nip, int res)
  98 {
  99   union
 100   {
 101     endent_function f;
 102     void *ptr;
 103   } fct;
 104   int no_more;
 105
 106   if (res && __res_maybe_init (&_res, 0) == -1)
 107     {
 108       __set_h_errno (NETDB_INTERNAL);
 109       return;
 110     }
 111
 112   /* Cycle through all the services and run their endXXent functions.  */
 113   no_more = setup (func_name, lookup_fct, &fct.ptr, nip, startp, 1);
 114   while (! no_more)
 115     {
 116       /* Ignore status, we force check in __NSS_NEXT.  */
 117       DL_CALL_FCT (fct.f, ());
 118
 119       if (*nip == *last_nip)
 120         /* We have processed all services which were used.  */
 121         break;
 122
 123       no_more = __nss_next (nip, func_name, &fct.ptr, 0, 1);
 124     }
 125   *last_nip = *nip = NULL;
 126 }
 127
 128
 129 int
 130 __nss_getent_r (const char *getent_func_name,
 131                 const char *setent_func_name,
 132                 db_lookup_function lookup_fct,
 133                 service_user **nip, service_user **startp,
 134                 service_user **last_nip, int *stayopen_tmp, int res,
 135                 void *resbuf, char *buffer, size_t buflen,
 136                 void **result, int *h_errnop)
 137 {
 138   union
 139   {
 140     getent_function f;
 141     void *ptr;
 142   } fct;
 143   int no_more;
 144   enum nss_status status;
 145
 146   if (res && __res_maybe_init (&_res, 0) == -1)
 147     {
 148       *h_errnop = NETDB_INTERNAL;
 149       *result = NULL;
 150       return errno;
 151     }
 152
 153   /* Initialize status to return if no more functions are found.  */
 154   status = NSS_STATUS_NOTFOUND;
 155
 156   /* Run through available functions, starting with the same function last
 157      run.  We will repeat each function as long as it succeeds, and then go
 158      on to the next service action.  */
 159   no_more = setup (getent_func_name, lookup_fct, &fct.ptr, nip,
 160                    startp, 0);
 161   while (! no_more)
 162     {
 163       int is_last_nip = *nip == *last_nip;
 164
 165       status = DL_CALL_FCT (fct.f,
 166                             (resbuf, buffer, buflen, &errno, &h_errno));
 167
 168       /* The the status is NSS_STATUS_TRYAGAIN and errno is ERANGE the
 169          provided buffer is too small.  In this case we should give
 170          the user the possibility to enlarge the buffer and we should
 171          not simply go on with the next service (even if the TRYAGAIN
 172          action tells us so).  */
 173       if (status == NSS_STATUS_TRYAGAIN
 174           && (h_errnop == NULL || *h_errnop == NETDB_INTERNAL)
 175           && errno == ERANGE)
 176         break;
 177
 178       do
 179         {
 180           no_more = __nss_next (nip, getent_func_name, &fct.ptr,
 181                                 status, 0);
 182
 183           if (is_last_nip)
 184             *last_nip = *nip;
 185
 186           if (! no_more)
 187             {
 188               /* Call the `setXXent' function.  This wasn't done before.  */
 189               union
 190               {
 191                 setent_function f;
 192                 void *ptr;
 193               } sfct;
 194
 195               no_more = __nss_lookup (nip, setent_func_name,
 196                                       &sfct.ptr);
 197
 198               if (! no_more)
 199                 {
 200                   if (stayopen_tmp)
 201                     status = DL_CALL_FCT (sfct.f, (*stayopen_tmp));
 202                   else
 203                     status = DL_CALL_FCT (sfct.f, (0));
 204                 }
 205               else
 206                 status = NSS_STATUS_NOTFOUND;
 207             }
 208         }
 209       while (! no_more && status != NSS_STATUS_SUCCESS);
 210     }
 211
 212   *result = status == NSS_STATUS_SUCCESS ? resbuf : NULL;
 213   return (status == NSS_STATUS_SUCCESS ? 0
 214           : status != NSS_STATUS_TRYAGAIN ? ENOENT
 215           /* h_errno functions only set errno if h_errno is NETDB_INTERNAL.  */
 216           : (h_errnop == NULL || *h_errnop == NETDB_INTERNAL) ? errno
 217           : EAGAIN);
 218 }