inet/getnetgrent_r.c

   1 /* Copyright (C) 1996, 1997, 1998 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 <errno.h>
  21 #include <netdb.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include "netgroup.h"
  25 #include "nsswitch.h"
  26
  27
  28 /* Protect above variable against multiple uses at the same time.  */
  29 __libc_lock_define_initialized (static, lock)
  30
  31 /* This handle for the NSS data base is shared between all
  32    set/get/endXXXent functions.  */
  33 static service_user *nip;
  34
  35 /* The whole information for the set/get/endnetgrent functions are
  36    kept in this structure.  */
  37 static struct __netgrent dataset;
  38
  39 /* The lookup function for the first entry of this service.  */
  40 extern int __nss_netgroup_lookup (service_user **nip, const char *name,
  41                                   void **fctp);
  42
  43
  44 /* Set up NIP to run through the services.  If ALL is zero, use NIP's
  45    current location if it's not nil.  Return nonzero if there are no
  46    services (left).  */
  47 static enum nss_status
  48 setup (void **fctp, const char *func_name, int all)
  49 {
  50   /* Remember the first service_entry, it's always the same.  */
  51   static service_user *startp = NULL;
  52   int no_more;
  53
  54   if (startp == NULL)
  55     {
  56       no_more = __nss_netgroup_lookup (&nip, func_name, fctp);
  57       startp = no_more ? (service_user *) -1 : nip;
  58     }
  59   else if (startp == (service_user *) -1)
  60     /* No services at all.  */
  61     return 1;
  62   else
  63     {
  64       if (all || !nip)
  65         /* Reset to the beginning of the service list.  */
  66         nip = startp;
  67       /* Look up the first function.  */
  68       no_more = __nss_lookup (&nip, func_name, fctp);
  69     }
  70   return no_more;
  71 }
  72 \f
  73 /* Free used memory.  */
  74 static void
  75 free_memory (struct __netgrent *data)
  76 {
  77   while (data->known_groups != NULL)
  78     {
  79       struct name_list *tmp = data->known_groups;
  80       data->known_groups = data->known_groups->next;
  81       free ((void *) tmp->name);
  82       free (tmp);
  83     }
  84
  85   while (data->needed_groups != NULL)
  86     {
  87       struct name_list *tmp = data->needed_groups;
  88       data->needed_groups = data->needed_groups->next;
  89       free ((void *) tmp->name);
  90       free (tmp);
  91     }
  92 }
  93 \f
  94 static int
  95 internal_function
  96 __internal_setnetgrent_reuse (const char *group, struct __netgrent *datap,
  97                               int *errnop)
  98 {
  99   enum nss_status (*fct) (const char *, struct __netgrent *);
 100   enum nss_status status = NSS_STATUS_UNAVAIL;
 101   struct name_list *new_elem;
 102   int no_more;
 103
 104   /* Cycle through all the services and run their setnetgrent functions.  */
 105   no_more = setup ((void **) &fct, "setnetgrent", 1);
 106   while (! no_more)
 107     {
 108       /* Ignore status, we force check in `__nss_next'.  */
 109       status = (*fct) (group, datap);
 110
 111       no_more = __nss_next (&nip, "setnetgrent", (void **) &fct, status, 0);
 112     }
 113
 114   /* Add the current group to the list of known groups.  */
 115   new_elem = (struct name_list *) malloc (sizeof (struct name_list));
 116   if (new_elem == NULL || (new_elem->name = __strdup (group)) == NULL)
 117     {
 118       if (new_elem != NULL)
 119         free (new_elem);
 120       *errnop = errno;
 121       status = NSS_STATUS_TRYAGAIN;
 122     }
 123   else
 124     {
 125       new_elem->next = datap->known_groups;
 126       datap->known_groups = new_elem;
 127     }
 128
 129   return status == NSS_STATUS_SUCCESS;
 130 }
 131
 132 int
 133 __internal_setnetgrent (const char *group, struct __netgrent *datap)
 134 {
 135   /* Free list of all netgroup names from last run.  */
 136   free_memory (datap);
 137
 138   return __internal_setnetgrent_reuse (group, datap, &errno);
 139 }
 140
 141 int
 142 setnetgrent (const char *group)
 143 {
 144   int result;
 145
 146   __libc_lock_lock (lock);
 147
 148   result = __internal_setnetgrent (group, &dataset);
 149
 150   __libc_lock_unlock (lock);
 151
 152   return result;
 153 }
 154
 155
 156 void
 157 __internal_endnetgrent (struct __netgrent *datap)
 158 {
 159   service_user *old_nip;
 160   enum nss_status (*fct) (struct __netgrent *);
 161   int no_more;
 162
 163   /* Remember which was the last used service.  */
 164   old_nip = nip;
 165
 166   /* Cycle through all the services and run their endnetgrent functions.  */
 167   no_more = setup ((void **) &fct, "endnetgrent", 1);
 168   while (! no_more)
 169     {
 170       /* Ignore status, we force check in `__nss_next'.  */
 171       (void) (*fct) (datap);
 172
 173       no_more = (nip == old_nip
 174                  || __nss_next (&nip, "endnetgrent", (void **) &fct, 0, 1));
 175     }
 176
 177   /* Now free list of all netgroup names from last run.  */
 178   free_memory (datap);
 179 }
 180
 181
 182 void
 183 endnetgrent (void)
 184 {
 185   __libc_lock_lock (lock);
 186
 187   __internal_endnetgrent (&dataset);
 188
 189   __libc_lock_unlock (lock);
 190 }
 191
 192
 193 int
 194 __internal_getnetgrent_r (char **hostp, char **userp, char **domainp,
 195                           struct __netgrent *datap,
 196                           char *buffer, size_t buflen, int *errnop)
 197 {
 198   enum nss_status (*fct) (struct __netgrent *, char *, size_t);
 199   int no_more;
 200
 201   /* Initialize status to return if no more functions are found.  */
 202   enum nss_status status = NSS_STATUS_NOTFOUND;
 203
 204   /* Run through available functions, starting with the same function last
 205      run.  We will repeat each function as long as it succeeds, and then go
 206      on to the next service action.  */
 207   no_more = setup ((void **) &fct, "getnetgrent_r", 0);
 208   while (! no_more)
 209     {
 210       status = (*fct) (datap, buffer, buflen);
 211
 212       if (status == NSS_STATUS_RETURN)
 213         {
 214           /* This was the last one for this group.  Look at next group
 215              if available.  */
 216           int found = 0;
 217           while (datap->needed_groups != NULL && ! found)
 218             {
 219               struct name_list *tmp = datap->needed_groups;
 220               datap->needed_groups = datap->needed_groups->next;
 221               tmp->next = datap->known_groups;
 222               datap->known_groups = tmp;
 223
 224               found = __internal_setnetgrent_reuse (datap->known_groups->name,
 225                                                     datap, errnop);
 226             }
 227
 228           if (found)
 229             continue;
 230         }
 231       else if (status == NSS_STATUS_SUCCESS && datap->type == group_val)
 232         {
 233           /* The last entry was a name of another netgroup.  */
 234           struct name_list *namep;
 235
 236           /* Ignore if we've seen the name before.  */
 237           for (namep = datap->known_groups; namep != NULL;
 238                namep = namep->next)
 239             if (strcmp (datap->val.group, namep->name) == 0)
 240               break;
 241           if (namep != NULL)
 242             /* Really ignore.  */
 243             continue;
 244
 245           namep = (struct name_list *) malloc (sizeof (struct name_list));
 246           if (namep == NULL
 247               || (namep->name = __strdup (datap->val.group)) == NULL)
 248             {
 249               /* We are out of memory.  */
 250               if (namep != NULL)
 251                 free (namep);
 252               status = NSS_STATUS_RETURN;
 253             }
 254           else
 255             {
 256               namep->next = datap->needed_groups;
 257               datap->needed_groups = namep;
 258               /* And get the next entry.  */
 259               continue;
 260             }
 261         }
 262
 263       no_more = __nss_next (&nip, "getnetgrent_r", (void **) &fct, status, 0);
 264     }
 265
 266   if (status == NSS_STATUS_SUCCESS)
 267     {
 268       *hostp = (char *) datap->val.triple.host;
 269       *userp = (char *) datap->val.triple.user;
 270       *domainp = (char *) datap->val.triple.domain;
 271     }
 272
 273   return status == NSS_STATUS_SUCCESS ? 1 : 0;
 274 }
 275
 276 /* The real entry point.  */
 277 int
 278 __getnetgrent_r (char **hostp, char **userp, char **domainp,
 279                  char *buffer, size_t buflen)
 280 {
 281   enum nss_status status;
 282
 283   __libc_lock_lock (lock);
 284
 285   status = __internal_getnetgrent_r (hostp, userp, domainp, &dataset,
 286                                      buffer, buflen, &errno);
 287
 288   __libc_lock_unlock (lock);
 289
 290   return status;
 291 }
 292 weak_alias (__getnetgrent_r, getnetgrent_r)
 293 \f
 294 /* Test whether given (host,user,domain) triple is in NETGROUP.  */
 295 int
 296 innetgr (const char *netgroup, const char *host, const char *user,
 297          const char *domain)
 298 {
 299   int (*setfct) (const char *, struct __netgrent *);
 300   void (*endfct) (struct __netgrent *);
 301   int (*getfct) (struct __netgrent *, char *, size_t);
 302   struct name_list *known = NULL;
 303   struct name_list *needed = NULL;
 304   int result = 0;
 305   int no_more;
 306   const char *current_group = netgroup;
 307   int real_entry = 0;
 308
 309   /* Walk through the services until we found an answer or we shall
 310      not work further.  We can do some optimization here.  Since all
 311      services must provide the `setnetgrent' function we can do all
 312      the work during one walk through the service list.  */
 313   while (1)
 314     {
 315       no_more = setup ((void **) &setfct, "setnetgrent", 1);
 316       while (! no_more)
 317         {
 318           enum nss_status status;
 319           struct __netgrent entry;
 320
 321           /* Clear the space for the netgroup data.  */
 322           __bzero (&entry, sizeof (entry));
 323
 324           /* Open netgroup.  */
 325           status = (*setfct) (current_group, &entry);
 326           if (status == NSS_STATUS_SUCCESS
 327               && __nss_lookup (&nip, "getnetgrent_r", (void **) &getfct) == 0)
 328             {
 329               char buffer[1024];
 330
 331               while ((*getfct) (&entry, buffer, sizeof buffer)
 332                      == NSS_STATUS_SUCCESS)
 333                 {
 334                   if (entry.type == group_val)
 335                     {
 336                       /* Make sure we haven't seen the name before.  */
 337                       struct name_list *namep;
 338
 339                       for (namep = known; namep != NULL; namep = namep->next)
 340                         if (strcmp (entry.val.group, namep->name) == 0)
 341                           break;
 342                       if (namep == NULL
 343                           && strcmp (netgroup, entry.val.group) != 0)
 344                         {
 345                           namep =
 346                             (struct name_list *) malloc (sizeof (*namep));
 347                           if (namep == NULL
 348                               || ((namep->name = __strdup (entry.val.group))
 349                                   == NULL))
 350                             {
 351                               /* Out of memory, simply return.  */
 352                               if (namep != NULL)
 353                                 free (namep);
 354                               result = -1;
 355                               break;
 356                             }
 357
 358                           namep->next = needed;
 359                           needed = namep;
 360                         }
 361                     }
 362                   else
 363                     {
 364                       real_entry = 1;
 365
 366                       if ((entry.val.triple.host == NULL || host == NULL
 367                            || strcmp (entry.val.triple.host, host) == 0)
 368                           && (entry.val.triple.user == NULL || user == NULL
 369                               || strcmp (entry.val.triple.user, user) == 0)
 370                           && (entry.val.triple.domain == NULL || domain == NULL
 371                               || strcmp (entry.val.triple.domain, domain) == 0))
 372                         {
 373                           result = 1;
 374                           break;
 375                         }
 376                     }
 377                 }
 378
 379               if (result != 0)
 380                 break;
 381
 382               /* If we found one service which does know the given
 383                  netgroup we don't try further.  */
 384               status = NSS_STATUS_RETURN;
 385             }
 386
 387           /* Free all resources of the service.  */
 388           if (__nss_lookup (&nip, "endnetgrent", (void **) &endfct) == 0)
 389             (*endfct) (&entry);
 390
 391           /* Look for the next service.  */
 392           no_more = __nss_next (&nip, "setnetgrent",
 393                                 (void **) &setfct, status, 0);
 394         }
 395
 396       if (result == 0 && needed != NULL)
 397         {
 398           struct name_list *tmp = needed;
 399           needed = tmp->next;
 400           tmp->next = known;
 401           known = tmp;
 402           current_group = known->name;
 403           continue;
 404         }
 405
 406       /* No way out.  */
 407       break;
 408     }
 409
 410   /* Free the memory.  */
 411   while (known != NULL)
 412     {
 413       struct name_list *tmp = known;
 414       known = known->next;
 415       free ((void *) tmp->name);
 416       free (tmp);
 417     }
 418   while (needed != NULL)
 419     {
 420       struct name_list *tmp = needed;
 421       needed = needed->next;
 422       free ((void *) tmp->name);
 423       free (tmp);
 424     }
 425
 426   return result == 1;
 427 }