inet/getnetgrent_r.c

   1 /* Copyright (C) 1996, 1997 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 Library General Public License as
   6    published by the Free Software Foundation; either version 2 of the
   7    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    Library General Public License for more details.
  13
  14    You should have received a copy of the GNU Library General Public
  15    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  16    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17    Boston, MA 02111-1307, USA.  */
  18
  19 #include <bits/libc-lock.h>
  20 #include <netdb.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include "netgroup.h"
  24 #include "nsswitch.h"
  25
  26
  27 /* Protect above variable against multiple uses at the same time.  */
  28 __libc_lock_define_initialized (static, lock)
  29
  30 /* This handle for the NSS data base is shared between all
  31    set/get/endXXXent functions.  */
  32 static service_user *nip;
  33
  34 /* The whole information for the set/get/endnetgrent functions are
  35    kept in this structure.  */
  36 static struct __netgrent dataset;
  37
  38 /* The lookup function for the first entry of this service.  */
  39 extern int __nss_netgroup_lookup (service_user **nip, const char *name,
  40                                   void **fctp);
  41
  42
  43 /* Set up NIP to run through the services.  If ALL is zero, use NIP's
  44    current location if it's not nil.  Return nonzero if there are no
  45    services (left).  */
  46 static enum nss_status
  47 setup (void **fctp, const char *func_name, int all)
  48 {
  49   /* Remember the first service_entry, it's always the same.  */
  50   static service_user *startp = NULL;
  51   int no_more;
  52
  53   if (startp == NULL)
  54     {
  55       no_more = __nss_netgroup_lookup (&nip, func_name, fctp);
  56       startp = no_more ? (service_user *) -1 : nip;
  57     }
  58   else if (startp == (service_user *) -1)
  59     /* No services at all.  */
  60     return 1;
  61   else
  62     {
  63       if (all || !nip)
  64         /* Reset to the beginning of the service list.  */
  65         nip = startp;
  66       /* Look up the first function.  */
  67       no_more = __nss_lookup (&nip, func_name, fctp);
  68     }
  69   return no_more;
  70 }
  71 \f
  72 /* Free used memory.  */
  73 static void
  74 free_memory (struct __netgrent *data)
  75 {
  76   while (data->known_groups != NULL)
  77     {
  78       struct name_list *tmp = data->known_groups;
  79       data->known_groups = data->known_groups->next;
  80       free ((void *) tmp->name);
  81       free (tmp);
  82     }
  83
  84   while (data->needed_groups != NULL)
  85     {
  86       struct name_list *tmp = data->needed_groups;
  87       data->needed_groups = data->needed_groups->next;
  88       free ((void *) tmp->name);
  89       free (tmp);
  90     }
  91 }
  92 \f
  93 static int
  94 internal_function
  95 __internal_setnetgrent_reuse (const char *group, struct __netgrent *datap)
  96 {
  97   enum nss_status (*fct) (const char *, struct __netgrent *);
  98   enum nss_status status = NSS_STATUS_UNAVAIL;
  99   struct name_list *new_elem;
 100   int no_more;
 101
 102   /* Cycle through all the services and run their setnetgrent functions.  */
 103   no_more = setup ((void **) &fct, "setnetgrent", 1);
 104   while (! no_more)
 105     {
 106       /* Ignore status, we force check in `__nss_next'.  */
 107       status = (*fct) (group, datap);
 108
 109       no_more = __nss_next (&nip, "setnetgrent", (void **) &fct, status, 0);
 110     }
 111
 112   /* Add the current group to the list of known groups.  */
 113   new_elem = (struct name_list *) malloc (sizeof (struct name_list));
 114   if (new_elem == NULL || (new_elem->name = __strdup (group)) == NULL)
 115     {
 116       if (new_elem != NULL)
 117         free (new_elem);
 118       status = NSS_STATUS_UNAVAIL;
 119     }
 120   else
 121     {
 122       new_elem->next = datap->known_groups;
 123       datap->known_groups = new_elem;
 124     }
 125
 126   return status == NSS_STATUS_SUCCESS;
 127 }
 128
 129 int
 130 __internal_setnetgrent (const char *group, struct __netgrent *datap)
 131 {
 132   /* Free list of all netgroup names from last run.  */
 133   free_memory (datap);
 134
 135   return __internal_setnetgrent_reuse (group, datap);
 136 }
 137
 138 int
 139 setnetgrent (const char *group)
 140 {
 141   int result;
 142
 143   __libc_lock_lock (lock);
 144
 145   result = __internal_setnetgrent (group, &dataset);
 146
 147   __libc_lock_unlock (lock);
 148
 149   return result;
 150 }
 151
 152
 153 void
 154 __internal_endnetgrent (struct __netgrent *datap)
 155 {
 156   service_user *old_nip;
 157   enum nss_status (*fct) (struct __netgrent *);
 158   int no_more;
 159
 160   /* Remember which was the last used service.  */
 161   old_nip = nip;
 162
 163   /* Cycle through all the services and run their endnetgrent functions.  */
 164   no_more = setup ((void **) &fct, "endnetgrent", 1);
 165   while (! no_more)
 166     {
 167       /* Ignore status, we force check in `__nss_next'.  */
 168       (void) (*fct) (datap);
 169
 170       no_more = (nip == old_nip
 171                  || __nss_next (&nip, "endnetgrent", (void **) &fct, 0, 1));
 172     }
 173
 174   /* Now free list of all netgroup names from last run.  */
 175   free_memory (datap);
 176 }
 177
 178
 179 void
 180 endnetgrent (void)
 181 {
 182   __libc_lock_lock (lock);
 183
 184   __internal_endnetgrent (&dataset);
 185
 186   __libc_lock_unlock (lock);
 187 }
 188
 189
 190 int
 191 __internal_getnetgrent_r (char **hostp, char **userp, char **domainp,
 192                           struct __netgrent *datap,
 193                           char *buffer, size_t buflen)
 194 {
 195   enum nss_status (*fct) (struct __netgrent *, char *, size_t);
 196   int no_more;
 197
 198   /* Initialize status to return if no more functions are found.  */
 199   enum nss_status status = NSS_STATUS_NOTFOUND;
 200
 201   /* Run through available functions, starting with the same function last
 202      run.  We will repeat each function as long as it succeeds, and then go
 203      on to the next service action.  */
 204   no_more = setup ((void **) &fct, "getnetgrent_r", 0);
 205   while (! no_more)
 206     {
 207       status = (*fct) (datap, buffer, buflen);
 208
 209       if (status == NSS_STATUS_RETURN)
 210         {
 211           /* This was the last one for this group.  Look at next group
 212              if available.  */
 213           int found = 0;
 214           while (datap->needed_groups != NULL && ! found)
 215             {
 216               struct name_list *tmp = datap->needed_groups;
 217               datap->needed_groups = datap->needed_groups->next;
 218               tmp->next = datap->known_groups;
 219               datap->known_groups = tmp;
 220
 221               found = __internal_setnetgrent_reuse (datap->known_groups->name,
 222                                                     datap);
 223             }
 224
 225           if (found)
 226             continue;
 227         }
 228       else if (status == NSS_STATUS_SUCCESS && datap->type == group_val)
 229         {
 230           /* The last entry was a name of another netgroup.  */
 231           struct name_list *namep;
 232
 233           /* Ignore if we've seen the name before.  */
 234           for (namep = datap->known_groups; namep != NULL;
 235                namep = namep->next)
 236             if (strcmp (datap->val.group, namep->name) == 0)
 237               break;
 238           if (namep != NULL)
 239             /* Really ignore.  */
 240             continue;
 241
 242           namep = (struct name_list *) malloc (sizeof (struct name_list));
 243           if (namep == NULL
 244               || (namep->name = __strdup (datap->val.group)) == NULL)
 245             {
 246               /* We are out of memory.  */
 247               if (namep != NULL)
 248                 free (namep);
 249               status = NSS_STATUS_RETURN;
 250             }
 251           else
 252             {
 253               namep->next = datap->needed_groups;
 254               datap->needed_groups = namep;
 255               /* And get the next entry.  */
 256               continue;
 257             }
 258         }
 259
 260       no_more = __nss_next (&nip, "getnetgrent_r", (void **) &fct, status, 0);
 261     }
 262
 263   if (status == NSS_STATUS_SUCCESS)
 264     {
 265       *hostp = (char *) datap->val.triple.host;
 266       *userp = (char *) datap->val.triple.user;
 267       *domainp = (char *) datap->val.triple.domain;
 268     }
 269
 270   return status == NSS_STATUS_SUCCESS ? 1 : 0;
 271 }
 272
 273 /* The real entry point.  */
 274 int
 275 __getnetgrent_r (char **hostp, char **userp, char **domainp,
 276                  char *buffer, size_t buflen)
 277 {
 278   enum nss_status status;
 279
 280   __libc_lock_lock (lock);
 281
 282   status = __internal_getnetgrent_r (hostp, userp, domainp, &dataset,
 283                                      buffer, buflen);
 284
 285   __libc_lock_unlock (lock);
 286
 287   return status;
 288 }
 289 weak_alias (__getnetgrent_r, getnetgrent_r)
 290 \f
 291 /* Test whether given (host,user,domain) triple is in NETGROUP.  */
 292 int
 293 innetgr (const char *netgroup, const char *host, const char *user,
 294          const char *domain)
 295 {
 296   int (*setfct) (const char *, struct __netgrent *);
 297   void (*endfct) (struct __netgrent *);
 298   int (*getfct) (struct __netgrent *, char *, size_t);
 299   struct name_list *known = NULL;
 300   struct name_list *needed = NULL;
 301   int result = 0;
 302   int no_more;
 303   const char *current_group = netgroup;
 304   int real_entry = 0;
 305
 306   /* Walk through the services until we found an answer or we shall
 307      not work further.  We can do some optimization here.  Since all
 308      services must provide the `setnetgrent' function we can do all
 309      the work during one walk through the service list.  */
 310   while (1)
 311     {
 312       no_more = setup ((void **) &setfct, "setnetgrent", 1);
 313       while (! no_more)
 314         {
 315           enum nss_status status;
 316           struct __netgrent entry;
 317
 318           /* Clear the space for the netgroup data.  */
 319           bzero (&entry, sizeof (entry));
 320
 321           /* Open netgroup.  */
 322           status = (*setfct) (current_group, &entry);
 323           if (status == NSS_STATUS_SUCCESS
 324               && __nss_lookup (&nip, "getnetgrent_r", (void **) &getfct) == 0)
 325             {
 326               char buffer[1024];
 327
 328               while ((*getfct) (&entry, buffer, sizeof buffer)
 329                      == NSS_STATUS_SUCCESS)
 330                 {
 331                   if (entry.type == group_val)
 332                     {
 333                       /* Make sure we haven't seen the name before.  */
 334                       struct name_list *namep;
 335
 336                       for (namep = known; namep != NULL; namep = namep->next)
 337                         if (strcmp (entry.val.group, namep->name) == 0)
 338                           break;
 339                       if (namep == NULL
 340                           && strcmp (netgroup, entry.val.group) != 0)
 341                         {
 342                           namep =
 343                             (struct name_list *) malloc (sizeof (*namep));
 344                           if (namep == NULL
 345                               || ((namep->name = __strdup (entry.val.group))
 346                                   == NULL))
 347                             {
 348                               /* Out of memory, simply return.  */
 349                               if (namep != NULL)
 350                                 free (namep);
 351                               result = -1;
 352                               break;
 353                             }
 354
 355                           namep->next = needed;
 356                           needed = namep;
 357                         }
 358                     }
 359                   else
 360                     {
 361                       real_entry = 1;
 362
 363                       if ((entry.val.triple.host == NULL || host == NULL
 364                            || strcmp (entry.val.triple.host, host) == 0)
 365                           && (entry.val.triple.user == NULL || user == NULL
 366                               || strcmp (entry.val.triple.user, user) == 0)
 367                           && (entry.val.triple.domain == NULL || domain == NULL
 368                               || strcmp (entry.val.triple.domain, domain) == 0))
 369                         {
 370                           result = 1;
 371                           break;
 372                         }
 373                     }
 374                 }
 375
 376               if (result != 0)
 377                 break;
 378
 379               /* If we found one service which does know the given
 380                  netgroup we don't try further.  */
 381               status = NSS_STATUS_RETURN;
 382             }
 383
 384           /* Free all resources of the service.  */
 385           if (__nss_lookup (&nip, "endnetgrent", (void **) &endfct) == 0)
 386             (*endfct) (&entry);
 387
 388           /* Look for the next service.  */
 389           no_more = __nss_next (&nip, "setnetgrent",
 390                                 (void **) &setfct, status, 0);
 391         }
 392
 393       if (result == 0 && needed != NULL)
 394         {
 395           struct name_list *tmp = needed;
 396           needed = tmp->next;
 397           tmp->next = known;
 398           known = tmp;
 399           current_group = known->name;
 400           continue;
 401         }
 402
 403       /* No way out.  */
 404       break;
 405     }
 406
 407   /* Free the memory.  */
 408   while (known != NULL)
 409     {
 410       struct name_list *tmp = known;
 411       known = known->next;
 412       free ((void *) tmp->name);
 413       free (tmp);
 414     }
 415   while (needed != NULL)
 416     {
 417       struct name_list *tmp = needed;
 418       needed = needed->next;
 419       free ((void *) tmp->name);
 420       free (tmp);
 421     }
 422
 423   return result == 1;
 424 }