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/autoconf.h>
  29
  30 #include        <sys/stat.h>
  31
  32 #include        <stdlib.h>
  33 #include        <string.h>
  34 #include        <netdb.h>
  35 #include        <ctype.h>
  36 #include        <fcntl.h>
  37 #include        <limits.h>
  38
  39 #include        <freeradius-devel/radiusd.h>
  40 #include        <freeradius-devel/rad_assert.h>
  41 #include        <freeradius-devel/modules.h>
  42
  43 /*
  44  *      Define a structure with the module configuration, so it can
  45  *      be used as the instance handle.
  46  */
  47 struct attr_filter_instance {
  48         char *attrsfile;
  49         char *key;
  50         PAIR_LIST *attrs;
  51 };
  52
  53 static const CONF_PARSER module_config[] = {
  54         { "attrsfile",     PW_TYPE_FILENAME,
  55           offsetof(struct attr_filter_instance,attrsfile), NULL, "${raddbdir}/attrs" },
  56         { "key",     PW_TYPE_STRING_PTR,
  57           offsetof(struct attr_filter_instance,key), NULL, "%{Realm}" },
  58         { NULL, -1, 0, NULL, NULL }
  59 };
  60
  61 static void check_pair(VALUE_PAIR *check_item, VALUE_PAIR *reply_item,
  62                       int *pass, int *fail)
  63 {
  64         int compare;
  65
  66         if (check_item->operator == T_OP_SET) return;
  67
  68         compare = paircmp(check_item, reply_item);
  69         if (compare == 1) {
  70                 ++*(pass);
  71         } else {
  72                 ++*(fail);
  73         }
  74
  75         return;
  76 }
  77
  78 /*
  79  *      Copy the specified attribute to the specified list
  80  */
  81 static int mypairappend(VALUE_PAIR *item, VALUE_PAIR **to)
  82 {
  83         VALUE_PAIR *tmp;
  84         tmp = paircreate(item->attribute, item->type);
  85         if (!tmp) {
  86                 radlog(L_ERR|L_CONS, "no memory");
  87                 return -1;
  88         }
  89
  90         /*
  91          *      Copy EVERYTHING.
  92          */
  93         memcpy(tmp, item, sizeof(*tmp));
  94         tmp->next = NULL;
  95         *to = tmp;
  96
  97         return 0;
  98 }
  99
 100 static int getattrsfile(const char *filename, PAIR_LIST **pair_list)
 101 {
 102         int rcode;
 103         PAIR_LIST *attrs = NULL;
 104         PAIR_LIST *entry;
 105         VALUE_PAIR *vp;
 106
 107         rcode = pairlist_read(filename, &attrs, 1);
 108         if (rcode < 0) {
 109                 return -1;
 110         }
 111
 112         /*
 113          * Walk through the 'attrs' file list.
 114          */
 115
 116         entry = attrs;
 117         while (entry) {
 118
 119                 entry->check = entry->reply;
 120                 entry->reply = NULL;
 121
 122                 for (vp = entry->check; vp != NULL; vp = vp->next) {
 123
 124                     /*
 125                      * If it's NOT a vendor attribute,
 126                      * and it's NOT a wire protocol
 127                      * and we ignore Fall-Through,
 128                      * then bitch about it, giving a good warning message.
 129                      */
 130                     if (!(vp->attribute & ~0xffff) &&
 131                          (vp->attribute > 0xff) &&
 132                          (vp->attribute > 1000)) {
 133                         log_debug("[%s]:%d WARNING! Check item \"%s\"\n"
 134                                   "\tfound in filter list for realm \"%s\".\n",
 135                                   filename, entry->lineno, vp->name,
 136                                   entry->name);
 137                     }
 138                 }
 139
 140                 entry = entry->next;
 141         }
 142
 143         *pair_list = attrs;
 144         return 0;
 145 }
 146
 147
 148 /*
 149  *      Clean up.
 150  */
 151 static int attr_filter_detach(void *instance)
 152 {
 153         struct attr_filter_instance *inst = instance;
 154         pairlist_free(&inst->attrs);
 155         free(inst);
 156         return 0;
 157 }
 158
 159
 160 /*
 161  *      (Re-)read the "attrs" file into memory.
 162  */
 163 static int attr_filter_instantiate(CONF_SECTION *conf, void **instance)
 164 {
 165         struct attr_filter_instance *inst;
 166         int rcode;
 167
 168         inst = rad_malloc(sizeof *inst);
 169         if (!inst) {
 170                 return -1;
 171         }
 172         memset(inst, 0, sizeof(*inst));
 173
 174         if (cf_section_parse(conf, inst, module_config) < 0) {
 175                 attr_filter_detach(inst);
 176                 return -1;
 177         }
 178
 179         rcode = getattrsfile(inst->attrsfile, &inst->attrs);
 180         if (rcode != 0) {
 181                 radlog(L_ERR|L_CONS, "Errors reading %s", inst->attrsfile);
 182                 attr_filter_detach(inst);
 183                 return -1;
 184         }
 185         *instance = inst;
 186         return 0;
 187 }
 188
 189
 190 /*
 191  *      Common attr_filter checks
 192  */
 193 static int attr_filter_common(void *instance, REQUEST *request,
 194                               VALUE_PAIR **input)
 195 {
 196         struct attr_filter_instance *inst = instance;
 197         VALUE_PAIR      *vp;
 198         VALUE_PAIR      *output = NULL;
 199         VALUE_PAIR      **output_tail;
 200         VALUE_PAIR      *check_item;
 201         PAIR_LIST       *pl;
 202         int             found = 0;
 203         int             pass, fail = 0;
 204         char            *keyname = NULL;
 205         char            buffer[256];
 206
 207         if (!inst->key) {
 208                 VALUE_PAIR      *namepair;
 209
 210                 namepair = pairfind(request->packet->vps, PW_REALM);
 211                 if (!namepair) {
 212                         return (RLM_MODULE_NOOP);
 213                 }
 214                 keyname = namepair->vp_strvalue;
 215         } else {
 216                 int len;
 217
 218                 len = radius_xlat(buffer, sizeof(buffer), inst->key,
 219                                   request, NULL);
 220                 if (!len) {
 221                         return RLM_MODULE_NOOP;
 222                 }
 223                 keyname = buffer;
 224         }
 225
 226         output_tail = &output;
 227
 228         /*
 229          *      Find the attr_filter profile entry for the entry.
 230          */
 231         for (pl = inst->attrs; pl; pl = pl->next) {
 232                 int fall_through = 0;
 233
 234                 /*
 235                  *  If the current entry is NOT a default,
 236                  *  AND the realm does NOT match the current entry,
 237                  *  then skip to the next entry.
 238                  */
 239                 if ((strcmp(pl->name, "DEFAULT") != 0) &&
 240                     (strcmp(keyname, pl->name) != 0))  {
 241                     continue;
 242                 }
 243
 244                 DEBUG2(" attr_filter: Matched entry %s at line %d", pl->name,
 245                        pl->lineno);
 246                 found = 1;
 247
 248                 for (check_item = pl->check;
 249                      check_item != NULL;
 250                      check_item = check_item->next) {
 251                         if (check_item->attribute == PW_FALL_THROUGH) {
 252                                 fall_through = 1;
 253                                 continue;
 254                         }
 255
 256                         /*
 257                          *    If it is a SET operator, add the attribute to
 258                          *    the output list without checking it.
 259                          */
 260                         if (check_item->operator == T_OP_SET ) {
 261                                 if (mypairappend(check_item, output_tail) < 0) {
 262                                         pairfree(&output);
 263                                         return RLM_MODULE_FAIL;
 264                                 }
 265                                 output_tail = &((*output_tail)->next);
 266                         }
 267                 }
 268
 269                 /*
 270                  *      Iterate through the input items, comparing
 271                  *      each item to every rule, then moving it to the
 272                  *      output list only if it matches all rules
 273                  *      for that attribute.  IE, Idle-Timeout is moved
 274                  *      only if it matches all rules that describe an
 275                  *      Idle-Timeout.
 276                  */
 277                 for (vp = *input; vp != NULL; vp = vp->next ) {
 278                         /* reset the pass,fail vars for each reply item */
 279                         pass = fail = 0;
 280
 281                         /*
 282                          *      reset the check_item pointer to
 283                          *      beginning of the list
 284                          */
 285                         for (check_item = pl->check;
 286                              check_item != NULL;
 287                              check_item = check_item->next) {
 288                                 /*
 289                                  *      Vendor-Specific is special, and
 290                                  *      matches any VSA if the comparison
 291                                  *      is always true.
 292                                  */
 293                                 if ((check_item->attribute == PW_VENDOR_SPECIFIC) &&
 294                                     (VENDOR(vp->attribute) != 0) &&
 295                                     (check_item->operator == T_OP_CMP_TRUE)) {
 296                                         pass++;
 297                                         continue;
 298                                 }
 299
 300                                 if (vp->attribute == check_item->attribute) {
 301                                         check_pair(check_item, vp,
 302                                                    &pass, &fail);
 303                                 }
 304                         }
 305
 306                         /* only move attribute if it passed all rules */
 307                         if (fail == 0 && pass > 0) {
 308                                 if (mypairappend(vp, output_tail) < 0) {
 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         return RLM_MODULE_UPDATED;
 333 }
 334
 335 static int attr_filter_accounting(void *instance, REQUEST *request)
 336 {
 337         return attr_filter_common(instance, request, &request->packet->vps);
 338 }
 339
 340 static int attr_filter_preproxy(void *instance, REQUEST *request)
 341 {
 342         return attr_filter_common(instance, request, &request->proxy->vps);
 343 }
 344
 345 static int attr_filter_postproxy(void *instance, REQUEST *request)
 346 {
 347         return attr_filter_common(instance, request, &request->proxy_reply->vps);
 348 }
 349
 350 static int attr_filter_postauth(void *instance, REQUEST *request)
 351 {
 352         return attr_filter_common(instance, request, &request->reply->vps);
 353 }
 354
 355
 356 /* globally exported name */
 357 module_t rlm_attr_filter = {
 358         RLM_MODULE_INIT,
 359         "attr_filter",
 360         0,                              /* type: reserved */
 361         attr_filter_instantiate,        /* instantiation */
 362         attr_filter_detach,             /* detach */
 363         {
 364                 NULL,                   /* authentication */
 365                 NULL,                   /* authorization */
 366                 NULL,                   /* preaccounting */
 367                 attr_filter_accounting, /* accounting */
 368                 NULL,                   /* checksimul */
 369                 attr_filter_preproxy,   /* pre-proxy */
 370                 attr_filter_postproxy,  /* post-proxy */
 371                 attr_filter_postauth    /* post-auth */
 372         },
 373 };
 374