nss/getnssent_r.c

   1 /* Copyright (C) 2000-2015 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, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 #include <errno.h>
  19 #include <netdb.h>
  20 #include "nsswitch.h"
  21
  22 /* Set up NIP to run through the services.  If ALL is zero, use NIP's
  23    current location if it's not nil.  Return nonzero if there are no
  24    services (left).  */
  25 static int
  26 setup (const char *func_name, db_lookup_function lookup_fct,
  27        void **fctp, service_user **nip, service_user **startp, int all)
  28 {
  29   int no_more;
  30   if (*startp == NULL)
  31     {
  32       no_more = lookup_fct (nip, func_name, NULL, fctp);
  33       *startp = no_more ? (service_user *) -1l : *nip;
  34     }
  35   else if (*startp == (service_user *) -1l)
  36     /* No services at all.  */
  37     return 1;
  38   else
  39     {
  40       if (all || !*nip)
  41         /* Reset to the beginning of the service list.  */
  42         *nip = *startp;
  43       /* Look up the first function.  */
  44       no_more = __nss_lookup (nip, func_name, NULL, fctp);
  45     }
  46   return no_more;
  47 }
  48 \f
  49 void
  50 __nss_setent (const char *func_name, db_lookup_function lookup_fct,
  51               service_user **nip, service_user **startp,
  52               service_user **last_nip, int stayopen, int *stayopen_tmp,
  53               int res)
  54 {
  55   union
  56   {
  57     setent_function f;
  58     void *ptr;
  59   } fct;
  60   int no_more;
  61
  62   if (res && __res_maybe_init (&_res, 0) == -1)
  63     {
  64       __set_h_errno (NETDB_INTERNAL);
  65       return;
  66     }
  67
  68   /* Cycle through the services and run their `setXXent' functions until
  69      we find an available service.  */
  70   no_more = setup (func_name, lookup_fct, &fct.ptr, nip,
  71                    startp, 1);
  72   while (! no_more)
  73     {
  74       int is_last_nip = *nip == *last_nip;
  75       enum nss_status status;
  76
  77       if (stayopen_tmp)
  78         status = DL_CALL_FCT (fct.f, (*stayopen_tmp));
  79       else
  80         status = DL_CALL_FCT (fct.f, (0));
  81
  82       no_more = __nss_next2 (nip, func_name, NULL, &fct.ptr, status, 0);
  83       if (is_last_nip)
  84         *last_nip = *nip;
  85     }
  86
  87   if (stayopen_tmp)
  88     *stayopen_tmp = stayopen;
  89 }
  90
  91
  92 void
  93 __nss_endent (const char *func_name, db_lookup_function lookup_fct,
  94               service_user **nip, service_user **startp,
  95               service_user **last_nip, int res)
  96 {
  97   union
  98   {
  99     endent_function f;
 100     void *ptr;
 101   } fct;
 102   int no_more;
 103
 104   if (res && __res_maybe_init (&_res, 0) == -1)
 105     {
 106       __set_h_errno (NETDB_INTERNAL);
 107       return;
 108     }
 109
 110   /* Cycle through all the services and run their endXXent functions.  */
 111   no_more = setup (func_name, lookup_fct, &fct.ptr, nip, startp, 1);
 112   while (! no_more)
 113     {
 114       /* Ignore status, we force check in __NSS_NEXT.  */
 115       DL_CALL_FCT (fct.f, ());
 116
 117       if (*nip == *last_nip)
 118         /* We have processed all services which were used.  */
 119         break;
 120
 121       no_more = __nss_next2 (nip, func_name, NULL, &fct.ptr, 0, 1);
 122     }
 123   *last_nip = *nip = NULL;
 124 }
 125
 126
 127 int
 128 __nss_getent_r (const char *getent_func_name,
 129                 const char *setent_func_name,
 130                 db_lookup_function lookup_fct,
 131                 service_user **nip, service_user **startp,
 132                 service_user **last_nip, int *stayopen_tmp, int res,
 133                 void *resbuf, char *buffer, size_t buflen,
 134                 void **result, int *h_errnop)
 135 {
 136   union
 137   {
 138     getent_function f;
 139     void *ptr;
 140   } fct;
 141   int no_more;
 142   enum nss_status status;
 143
 144   if (res && __res_maybe_init (&_res, 0) == -1)
 145     {
 146       *h_errnop = NETDB_INTERNAL;
 147       *result = NULL;
 148       return errno;
 149     }
 150
 151   /* Initialize status to return if no more functions are found.  */
 152   status = NSS_STATUS_NOTFOUND;
 153
 154   /* Run through available functions, starting with the same function last
 155      run.  We will repeat each function as long as it succeeds, and then go
 156      on to the next service action.  */
 157   no_more = setup (getent_func_name, lookup_fct, &fct.ptr, nip,
 158                    startp, 0);
 159   while (! no_more)
 160     {
 161       int is_last_nip = *nip == *last_nip;
 162
 163       status = DL_CALL_FCT (fct.f,
 164                             (resbuf, buffer, buflen, &errno, &h_errno));
 165
 166       /* The status is NSS_STATUS_TRYAGAIN and errno is ERANGE the
 167          provided buffer is too small.  In this case we should give
 168          the user the possibility to enlarge the buffer and we should
 169          not simply go on with the next service (even if the TRYAGAIN
 170          action tells us so).  */
 171       if (status == NSS_STATUS_TRYAGAIN
 172           && (h_errnop == NULL || *h_errnop == NETDB_INTERNAL)
 173           && errno == ERANGE)
 174         break;
 175
 176       do
 177         {
 178           no_more = __nss_next2 (nip, getent_func_name, NULL, &fct.ptr,
 179                                  status, 0);
 180
 181           if (is_last_nip)
 182             *last_nip = *nip;
 183
 184           if (! no_more)
 185             {
 186               /* Call the `setXXent' function.  This wasn't done before.  */
 187               union
 188               {
 189                 setent_function f;
 190                 void *ptr;
 191               } sfct;
 192
 193               no_more = __nss_lookup (nip, setent_func_name, NULL, &sfct.ptr);
 194
 195               if (! no_more)
 196                 {
 197                   if (stayopen_tmp)
 198                     status = DL_CALL_FCT (sfct.f, (*stayopen_tmp));
 199                   else
 200                     status = DL_CALL_FCT (sfct.f, (0));
 201                 }
 202               else
 203                 status = NSS_STATUS_NOTFOUND;
 204             }
 205         }
 206       while (! no_more && status != NSS_STATUS_SUCCESS);
 207     }
 208
 209   *result = status == NSS_STATUS_SUCCESS ? resbuf : NULL;
 210   return (status == NSS_STATUS_SUCCESS ? 0
 211           : status != NSS_STATUS_TRYAGAIN ? ENOENT
 212           /* h_errno functions only set errno if h_errno is NETDB_INTERNAL.  */
 213           : (h_errnop == NULL || *h_errnop == NETDB_INTERNAL) ? errno
 214           : EAGAIN);
 215 }