inet/getnetgrent_r.c

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