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 *attrsfile;
  45         char *key;
  46         PAIR_LIST *attrs;
  47 };
  48
  49 static const CONF_PARSER module_config[] = {
  50         { "attrsfile",     PW_TYPE_FILENAME,
  51           offsetof(struct attr_filter_instance,attrsfile), NULL, "${raddbdir}/attrs" },
  52         { "key",     PW_TYPE_STRING_PTR,
  53           offsetof(struct attr_filter_instance,key), NULL, "%{Realm}" },
  54         { NULL, -1, 0, NULL, NULL }
  55 };
  56
  57 static void check_pair(VALUE_PAIR *check_item, VALUE_PAIR *reply_item,
  58                       int *pass, int *fail)
  59 {
  60         int compare;
  61
  62         if (check_item->operator == T_OP_SET) return;
  63
  64         compare = paircmp(check_item, reply_item);
  65         if (compare == 1) {
  66                 ++*(pass);
  67         } else {
  68                 ++*(fail);
  69         }
  70
  71         return;
  72 }
  73
  74 /*
  75  *      Copy the specified attribute to the specified list
  76  */
  77 static int mypairappend(VALUE_PAIR *item, VALUE_PAIR **to)
  78 {
  79         VALUE_PAIR *tmp;
  80         tmp = paircreate(item->attribute, item->type);
  81         if (!tmp) {
  82                 radlog(L_ERR|L_CONS, "no memory");
  83                 return -1;
  84         }
  85
  86         /*
  87          *      Copy EVERYTHING.
  88          */
  89         memcpy(tmp, item, sizeof(*tmp));
  90         tmp->next = NULL;
  91         *to = tmp;
  92
  93         return 0;
  94 }
  95
  96 static int getattrsfile(const char *filename, PAIR_LIST **pair_list)
  97 {
  98         int rcode;
  99         PAIR_LIST *attrs = NULL;
 100         PAIR_LIST *entry;
 101         VALUE_PAIR *vp;
 102
 103         rcode = pairlist_read(filename, &attrs, 1);
 104         if (rcode < 0) {
 105                 return -1;
 106         }
 107
 108         /*
 109          * Walk through the 'attrs' file list.
 110          */
 111
 112         entry = attrs;
 113         while (entry) {
 114
 115                 entry->check = entry->reply;
 116                 entry->reply = NULL;
 117
 118                 for (vp = entry->check; vp != NULL; vp = vp->next) {
 119
 120                     /*
 121                      * If it's NOT a vendor attribute,
 122                      * and it's NOT a wire protocol
 123                      * and we ignore Fall-Through,
 124                      * then bitch about it, giving a good warning message.
 125                      */
 126                     if (!(vp->attribute & ~0xffff) &&
 127                          (vp->attribute > 0xff) &&
 128                          (vp->attribute > 1000)) {
 129                         log_debug("[%s]:%d WARNING! Check item \"%s\"\n"
 130                                   "\tfound in filter list for realm \"%s\".\n",
 131                                   filename, entry->lineno, vp->name,
 132                                   entry->name);
 133                     }
 134                 }
 135
 136                 entry = entry->next;
 137         }
 138
 139         *pair_list = attrs;
 140         return 0;
 141 }
 142
 143
 144 /*
 145  *      Clean up.
 146  */
 147 static int attr_filter_detach(void *instance)
 148 {
 149         struct attr_filter_instance *inst = instance;
 150         pairlist_free(&inst->attrs);
 151         free(inst);
 152         return 0;
 153 }
 154
 155
 156 /*
 157  *      (Re-)read the "attrs" file into memory.
 158  */
 159 static int attr_filter_instantiate(CONF_SECTION *conf, void **instance)
 160 {
 161         struct attr_filter_instance *inst;
 162         int rcode;
 163
 164         inst = rad_malloc(sizeof *inst);
 165         if (!inst) {
 166                 return -1;
 167         }
 168         memset(inst, 0, sizeof(*inst));
 169
 170         if (cf_section_parse(conf, inst, module_config) < 0) {
 171                 attr_filter_detach(inst);
 172                 return -1;
 173         }
 174
 175         rcode = getattrsfile(inst->attrsfile, &inst->attrs);
 176         if (rcode != 0) {
 177                 radlog(L_ERR|L_CONS, "Errors reading %s", inst->attrsfile);
 178                 attr_filter_detach(inst);
 179                 return -1;
 180         }
 181         *instance = inst;
 182         return 0;
 183 }
 184
 185
 186 /*
 187  *      Common attr_filter checks
 188  */
 189 static int attr_filter_common(void *instance, REQUEST *request,
 190                               VALUE_PAIR **input)
 191 {
 192         struct attr_filter_instance *inst = instance;
 193         VALUE_PAIR      *vp;
 194         VALUE_PAIR      *output = NULL;
 195         VALUE_PAIR      **output_tail;
 196         VALUE_PAIR      *check_item;
 197         PAIR_LIST       *pl;
 198         int             found = 0;
 199         int             pass, fail = 0;
 200         char            *keyname = NULL;
 201         char            buffer[256];
 202
 203         if (!inst->key) {
 204                 VALUE_PAIR      *namepair;
 205
 206                 namepair = pairfind(request->packet->vps, PW_REALM);
 207                 if (!namepair) {
 208                         return (RLM_MODULE_NOOP);
 209                 }
 210                 keyname = namepair->vp_strvalue;
 211         } else {
 212                 int len;
 213
 214                 len = radius_xlat(buffer, sizeof(buffer), inst->key,
 215                                   request, NULL);
 216                 if (!len) {
 217                         return RLM_MODULE_NOOP;
 218                 }
 219                 keyname = buffer;
 220         }
 221
 222         output_tail = &output;
 223
 224         /*
 225          *      Find the attr_filter profile entry for the entry.
 226          */
 227         for (pl = inst->attrs; pl; pl = pl->next) {
 228                 int fall_through = 0;
 229
 230                 /*
 231                  *  If the current entry is NOT a default,
 232                  *  AND the realm does NOT match the current entry,
 233                  *  then skip to the next entry.
 234                  */
 235                 if ((strcmp(pl->name, "DEFAULT") != 0) &&
 236                     (strcmp(keyname, pl->name) != 0))  {
 237                     continue;
 238                 }
 239
 240                 DEBUG2(" attr_filter: Matched entry %s at line %d", pl->name,
 241                        pl->lineno);
 242                 found = 1;
 243
 244                 for (check_item = pl->check;
 245                      check_item != NULL;
 246                      check_item = check_item->next) {
 247                         if (check_item->attribute == PW_FALL_THROUGH) {
 248                                 fall_through = 1;
 249                                 continue;
 250                         }
 251
 252                         /*
 253                          *    If it is a SET operator, add the attribute to
 254                          *    the output list without checking it.
 255                          */
 256                         if (check_item->operator == T_OP_SET ) {
 257                                 if (mypairappend(check_item, output_tail) < 0) {
 258                                         pairfree(&output);
 259                                         return RLM_MODULE_FAIL;
 260                                 }
 261                                 output_tail = &((*output_tail)->next);
 262                         }
 263                 }
 264
 265                 /*
 266                  *      Iterate through the input items, comparing
 267                  *      each item to every rule, then moving it to the
 268                  *      output list only if it matches all rules
 269                  *      for that attribute.  IE, Idle-Timeout is moved
 270                  *      only if it matches all rules that describe an
 271                  *      Idle-Timeout.
 272                  */
 273                 for (vp = *input; vp != NULL; vp = vp->next ) {
 274                         /* reset the pass,fail vars for each reply item */
 275                         pass = fail = 0;
 276
 277                         /*
 278                          *      reset the check_item pointer to
 279                          *      beginning of the list
 280                          */
 281                         for (check_item = pl->check;
 282                              check_item != NULL;
 283                              check_item = check_item->next) {
 284                                 /*
 285                                  *      Vendor-Specific is special, and
 286                                  *      matches any VSA if the comparison
 287                                  *      is always true.
 288                                  */
 289                                 if ((check_item->attribute == PW_VENDOR_SPECIFIC) &&
 290                                     (VENDOR(vp->attribute) != 0) &&
 291                                     (check_item->operator == T_OP_CMP_TRUE)) {
 292                                         pass++;
 293                                         continue;
 294                                 }
 295
 296                                 if (vp->attribute == check_item->attribute) {
 297                                         check_pair(check_item, vp,
 298                                                    &pass, &fail);
 299                                 }
 300                         }
 301
 302                         /* only move attribute if it passed all rules */
 303                         if (fail == 0 && pass > 0) {
 304                                 if (mypairappend(vp, output_tail) < 0) {
 305                                         pairfree(&output);
 306                                         return RLM_MODULE_FAIL;
 307                                 }
 308                                 output_tail = &((*output_tail)->next);
 309                         }
 310                 }
 311
 312                 /* If we shouldn't fall through, break */
 313                 if (!fall_through)
 314                         break;
 315         }
 316
 317         /*
 318          *      No entry matched.  We didn't do anything.
 319          */
 320         if (!found) {
 321                 rad_assert(output == NULL);
 322                 return RLM_MODULE_NOOP;
 323         }
 324
 325         pairfree(input);
 326         *input = output;
 327
 328         return RLM_MODULE_UPDATED;
 329 }
 330
 331 static int attr_filter_accounting(void *instance, REQUEST *request)
 332 {
 333         return attr_filter_common(instance, request, &request->packet->vps);
 334 }
 335
 336 static int attr_filter_preproxy(void *instance, REQUEST *request)
 337 {
 338         return attr_filter_common(instance, request, &request->proxy->vps);
 339 }
 340
 341 static int attr_filter_postproxy(void *instance, REQUEST *request)
 342 {
 343         return attr_filter_common(instance, request, &request->proxy_reply->vps);
 344 }
 345
 346 static int attr_filter_postauth(void *instance, REQUEST *request)
 347 {
 348         return attr_filter_common(instance, request, &request->reply->vps);
 349 }
 350
 351
 352 /* globally exported name */
 353 module_t rlm_attr_filter = {
 354         RLM_MODULE_INIT,
 355         "attr_filter",
 356         0,                              /* type: reserved */
 357         attr_filter_instantiate,        /* instantiation */
 358         attr_filter_detach,             /* detach */
 359         {
 360                 NULL,                   /* authentication */
 361                 NULL,                   /* authorization */
 362                 NULL,                   /* preaccounting */
 363                 attr_filter_accounting, /* accounting */
 364                 NULL,                   /* checksimul */
 365                 attr_filter_preproxy,   /* pre-proxy */
 366                 attr_filter_postproxy,  /* post-proxy */
 367                 attr_filter_postauth    /* post-auth */
 368         },
 369 };
 370