src/modules/rlm_attr_filter/rlm_attr_filter.c

   1 /*
   2  * rlm_attr_filter.c  - Filter A/V Pairs received back from proxy reqs
   3  *                      before sending reply to the NAS/Server that sent
   4  *                      it to us.
   5  *
   6  * Version:      $Id$
   7  *
   8  *   This program is is free software; you can redistribute it and/or modify
   9  *   it under the terms of the GNU General Public License, version 2 if the
  10  *   License as published by the Free Software Foundation.
  11  *
  12  *   This program is distributed in the hope that it will be useful,
  13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *   GNU General Public License for more details.
  16  *
  17  *   You should have received a copy of the GNU General Public License
  18  *   along with this program; if not, write to the Free Software
  19  *   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  20  *
  21  * Copyright (C) 2001,2006 The FreeRADIUS server project
  22  * Copyright (C) 2001 Chris Parker <cparker@starnetusa.net>
  23  */
  24
  25 #include        <freeradius-devel/ident.h>
  26 RCSID("$Id$")
  27
  28 #include        <freeradius-devel/radiusd.h>
  29 #include        <freeradius-devel/modules.h>
  30 #include        <freeradius-devel/rad_assert.h>
  31
  32 #include        <sys/stat.h>
  33
  34 #include        <ctype.h>
  35 #include        <fcntl.h>
  36 #include        <limits.h>
  37
  38
  39 /*
  40  *      Define a structure with the module configuration, so it can
  41  *      be used as the instance handle.
  42  */
  43 struct attr_filter_instance {
  44         char *file;
  45         char *key;
  46         int relaxed;
  47         PAIR_LIST *attrs;
  48 };
  49
  50 static const CONF_PARSER module_config[] = {
  51         { "file",     PW_TYPE_FILENAME,
  52           offsetof(struct attr_filter_instance,file), NULL, "${raddbdir}/attrs" },
  53         { "key",     PW_TYPE_STRING_PTR,
  54           offsetof(struct attr_filter_instance,key), NULL, "%{Realm}" },
  55         { "relaxed",    PW_TYPE_BOOLEAN,
  56                 offsetof(struct attr_filter_instance,relaxed), NULL, "no" },
  57         { NULL, -1, 0, NULL, NULL }
  58 };
  59
  60 static void check_pair(VALUE_PAIR *check_item, VALUE_PAIR *reply_item,
  61                       int *pass, int *fail)
  62 {
  63         int compare;
  64
  65         if (check_item->operator == T_OP_SET) return;
  66
  67         compare = paircmp(check_item, reply_item);
  68         if (compare == 1) {
  69                 ++*(pass);
  70         } else {
  71                 ++*(fail);
  72         }
  73
  74         return;
  75 }
  76
  77
  78 static int attr_filter_getfile(const char *filename, PAIR_LIST **pair_list)
  79 {
  80         int rcode;
  81         PAIR_LIST *attrs = NULL;
  82         PAIR_LIST *entry;
  83         VALUE_PAIR *vp;
  84
  85         rcode = pairlist_read(filename, &attrs, 1);
  86         if (rcode < 0) {
  87                 return -1;
  88         }
  89
  90         /*
  91          * Walk through the 'attrs' file list.
  92          */
  93
  94         entry = attrs;
  95         while (entry) {
  96
  97                 entry->check = entry->reply;
  98                 entry->reply = NULL;
  99
 100                 for (vp = entry->check; vp != NULL; vp = vp->next) {
 101
 102                     /*
 103                      * If it's NOT a vendor attribute,
 104                      * and it's NOT a wire protocol
 105                      * and we ignore Fall-Through,
 106                      * then bitch about it, giving a good warning message.
 107                      */
 108                      if ((vp->vendor == 0) &&
 109                          (vp->attribute > 0xff) &&
 110                          (vp->attribute > 1000)) {
 111                         log_debug("[%s]:%d WARNING! Check item \"%s\"\n"
 112                                   "\tfound in filter list for realm \"%s\".\n",
 113                                   filename, entry->lineno, vp->name,
 114                                   entry->name);
 115                     }
 116                 }
 117
 118                 entry = entry->next;
 119         }
 120
 121         *pair_list = attrs;
 122         return 0;
 123 }
 124
 125
 126 /*
 127  *      Clean up.
 128  */
 129 static int attr_filter_detach(void *instance)
 130 {
 131         struct attr_filter_instance *inst = instance;
 132         pairlist_free(&inst->attrs);
 133         free(inst);
 134         return 0;
 135 }
 136
 137
 138 /*
 139  *      (Re-)read the "attrs" file into memory.
 140  */
 141 static int attr_filter_instantiate(CONF_SECTION *conf, void **instance)
 142 {
 143         struct attr_filter_instance *inst;
 144         int rcode;
 145
 146         inst = rad_malloc(sizeof *inst);
 147         if (!inst) {
 148                 return -1;
 149         }
 150         memset(inst, 0, sizeof(*inst));
 151
 152         if (cf_section_parse(conf, inst, module_config) < 0) {
 153                 attr_filter_detach(inst);
 154                 return -1;
 155         }
 156
 157         rcode = attr_filter_getfile(inst->file, &inst->attrs);
 158         if (rcode != 0) {
 159                 radlog(L_ERR|L_CONS, "Errors reading %s", inst->file);
 160                 attr_filter_detach(inst);
 161                 return -1;
 162         }
 163         *instance = inst;
 164         return 0;
 165 }
 166
 167
 168 /*
 169  *      Common attr_filter checks
 170  */
 171 static int attr_filter_common(void *instance, REQUEST *request,
 172                               RADIUS_PACKET *packet)
 173 {
 174         struct attr_filter_instance *inst = instance;
 175         VALUE_PAIR      *vp;
 176         VALUE_PAIR      *output;
 177         VALUE_PAIR      **output_tail;
 178         VALUE_PAIR      *check_item;
 179         PAIR_LIST       *pl;
 180         int             found = 0;
 181         int             pass, fail = 0;
 182         char            *keyname = NULL;
 183         VALUE_PAIR      **input;
 184         char            buffer[256];
 185
 186         if (!packet) return RLM_MODULE_NOOP;
 187
 188         input = &(packet->vps);
 189
 190         if (!inst->key) {
 191                 VALUE_PAIR      *namepair;
 192
 193                 namepair = pairfind(request->packet->vps, PW_REALM, 0);
 194                 if (!namepair) {
 195                         return (RLM_MODULE_NOOP);
 196                 }
 197                 keyname = namepair->vp_strvalue;
 198         } else {
 199                 int len;
 200
 201                 len = radius_xlat(buffer, sizeof(buffer), inst->key,
 202                                   request, NULL, NULL);
 203                 if (!len) {
 204                         return RLM_MODULE_NOOP;
 205                 }
 206                 keyname = buffer;
 207         }
 208
 209         output = NULL;
 210         output_tail = &output;
 211
 212         /*
 213          *      Find the attr_filter profile entry for the entry.
 214          */
 215         for (pl = inst->attrs; pl; pl = pl->next) {
 216                 int fall_through = 0;
 217                 int relax_filter = inst->relaxed;
 218
 219                 /*
 220                  *  If the current entry is NOT a default,
 221                  *  AND the realm does NOT match the current entry,
 222                  *  then skip to the next entry.
 223                  */
 224                 if ((strcmp(pl->name, "DEFAULT") != 0) &&
 225                     (strcmp(keyname, pl->name) != 0))  {
 226                     continue;
 227                 }
 228
 229                 RDEBUG2("Matched entry %s at line %d", pl->name,
 230                        pl->lineno);
 231                 found = 1;
 232
 233                 for (check_item = pl->check;
 234                         check_item != NULL;
 235                         check_item = check_item->next) {
 236                         if ((check_item->attribute == PW_FALL_THROUGH) &&
 237                                 (check_item->vp_integer == 1)) {
 238                                 fall_through = 1;
 239                                 continue;
 240                         }
 241                         else if (check_item->attribute == PW_RELAX_FILTER) {
 242                                 relax_filter = check_item->vp_integer;
 243                                 continue;
 244                         }
 245
 246                         /*
 247                          *    If it is a SET operator, add the attribute to
 248                          *    the output list without checking it.
 249                          */
 250                         if (check_item->operator == T_OP_SET ) {
 251                                 vp = paircopyvp(check_item);
 252                                 if (!vp) {
 253                                         pairfree(&output);
 254                                         return RLM_MODULE_FAIL;
 255                                 }
 256                                 pairxlatmove(request, output_tail, &vp);
 257                                 output_tail = &((*output_tail)->next);
 258                         }
 259                 }
 260
 261                 /*
 262                  *      Iterate through the input items, comparing
 263                  *      each item to every rule, then moving it to the
 264                  *      output list only if it matches all rules
 265                  *      for that attribute.  IE, Idle-Timeout is moved
 266                  *      only if it matches all rules that describe an
 267                  *      Idle-Timeout.
 268                  */
 269                 for (vp = *input; vp != NULL; vp = vp->next ) {
 270                         /* reset the pass,fail vars for each reply item */
 271                         pass = fail = 0;
 272
 273                         /*
 274                          *      reset the check_item pointer to
 275                          *      beginning of the list
 276                          */
 277                         for (check_item = pl->check;
 278                              check_item != NULL;
 279                              check_item = check_item->next) {
 280                                 /*
 281                                  *      Vendor-Specific is special, and
 282                                  *      matches any VSA if the comparison
 283                                  *      is always true.
 284                                  */
 285                                 if ((check_item->attribute == PW_VENDOR_SPECIFIC) &&
 286                                         (vp->vendor != 0) &&
 287                                         (check_item->operator == T_OP_CMP_TRUE)) {
 288                                         pass++;
 289                                         continue;
 290                                 }
 291
 292                                 if (vp->attribute == check_item->attribute) {
 293                                         check_pair(check_item, vp,
 294                                                    &pass, &fail);
 295                                 }
 296                         }
 297
 298                         /*
 299                          *  Only move attribute if it passed all rules,
 300                          *  or if the config says we should copy unmatched
 301                          *  attributes ('relaxed' mode).
 302                          */
 303                         if (fail == 0 && (pass > 0 || relax_filter)) {
 304                                 if (!pass) {
 305                                         RDEBUG3("Attribute (%s) allowed by relaxed mode", vp->name);
 306                                 }
 307                                 *output_tail = paircopyvp(vp);
 308                                 if (!*output_tail) {
 309                                         pairfree(&output);
 310                                         return RLM_MODULE_FAIL;
 311                                 }
 312                                 output_tail = &((*output_tail)->next);
 313                         }
 314                 }
 315
 316                 /* If we shouldn't fall through, break */
 317                 if (!fall_through)
 318                         break;
 319         }
 320
 321         /*
 322          *      No entry matched.  We didn't do anything.
 323          */
 324         if (!found) {
 325                 rad_assert(output == NULL);
 326                 return RLM_MODULE_NOOP;
 327         }
 328
 329         pairfree(input);
 330         *input = output;
 331
 332         if (request->packet->code == PW_AUTHENTICATION_REQUEST) {
 333                 request->username = pairfind(request->packet->vps,
 334                                              PW_STRIPPED_USER_NAME, 0);
 335                 if (!request->username)
 336                         request->username = pairfind(request->packet->vps,
 337                                                      PW_USER_NAME, 0);
 338                 request->password = pairfind(request->packet->vps,
 339                                              PW_USER_PASSWORD, 0);
 340         }
 341
 342         return RLM_MODULE_UPDATED;
 343 }
 344
 345 static int attr_filter_preacct(void *instance, REQUEST *request)
 346 {
 347         return attr_filter_common(instance, request, request->packet);
 348 }
 349
 350 static int attr_filter_accounting(void *instance, REQUEST *request)
 351 {
 352         return attr_filter_common(instance, request, request->reply);
 353 }
 354
 355 #ifdef WITH_PROXY
 356 static int attr_filter_preproxy(void *instance, REQUEST *request)
 357 {
 358         return attr_filter_common(instance, request, request->proxy);
 359 }
 360
 361 static int attr_filter_postproxy(void *instance, REQUEST *request)
 362 {
 363         return attr_filter_common(instance, request, request->proxy_reply);
 364 }
 365 #endif
 366
 367 static int attr_filter_postauth(void *instance, REQUEST *request)
 368 {
 369         return attr_filter_common(instance, request, request->reply);
 370 }
 371
 372 static int attr_filter_authorize(void *instance, REQUEST *request)
 373 {
 374         return attr_filter_common(instance, request, request->packet);
 375 }
 376
 377
 378 /* globally exported name */
 379 module_t rlm_attr_filter = {
 380         RLM_MODULE_INIT,
 381         "attr_filter",
 382         RLM_TYPE_CHECK_CONFIG_SAFE | RLM_TYPE_HUP_SAFE,         /* type */
 383         attr_filter_instantiate,        /* instantiation */
 384         attr_filter_detach,             /* detach */
 385         {
 386                 NULL,                   /* authentication */
 387                 attr_filter_authorize,  /* authorization */
 388                 attr_filter_preacct,    /* pre-acct */
 389                 attr_filter_accounting, /* accounting */
 390                 NULL,                   /* checksimul */
 391 #ifdef WITH_PROXY
 392                 attr_filter_preproxy,   /* pre-proxy */
 393                 attr_filter_postproxy,  /* post-proxy */
 394 #else
 395                 NULL, NULL,
 396 #endif
 397                 attr_filter_postauth    /* post-auth */
 398         },
 399 };
 400