src/modules/rlm_attr_rewrite/rlm_attr_rewrite.c

   1 /*
   2  * rlm_attr_rewrite.c
   3  *
   4  * Version:  $Id$
   5  *
   6  *   This program is free software; you can redistribute it and/or modify
   7  *   it under the terms of the GNU General Public License as published by
   8  *   the Free Software Foundation; either version 2 of the License, or
   9  *   (at your option) any later version.
  10  *
  11  *   This program is distributed in the hope that it will be useful,
  12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *   GNU General Public License for more details.
  15  *
  16  *   You should have received a copy of the GNU General Public License
  17  *   along with this program; if not, write to the Free Software
  18  *   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  19  *
  20  * Copyright 2002,2006  The FreeRADIUS server project
  21  * Copyright 2002  Kostas Kalevras <kkalev@noc.ntua.gr>
  22  */
  23
  24 #include <freeradius-devel/ident.h>
  25 RCSID("$Id$")
  26
  27 #include <freeradius-devel/radiusd.h>
  28 #include <freeradius-devel/modules.h>
  29
  30 #ifdef HAVE_REGEX_H
  31 #       include <regex.h>
  32 #endif
  33
  34 #define RLM_REGEX_INPACKET 0
  35 #define RLM_REGEX_INCONFIG 1
  36 #define RLM_REGEX_INREPLY  2
  37 #define RLM_REGEX_INPROXY 3
  38 #define RLM_REGEX_INPROXYREPLY 4
  39
  40 typedef struct rlm_attr_rewrite_t {
  41         char *attribute;        /* The attribute to search for */
  42         DICT_ATTR *da;          /* The attribute definition */
  43         char *search;           /* The pattern to search for */
  44         int search_len;         /* The length of the search pattern */
  45         char *searchin_str;     /* The VALUE_PAIR list to search in. Can be either packet,reply,proxy,proxy_reply or control (plus it's alias 'config') */
  46         char searchin;          /* The same as above just coded as a number for speed */
  47         char *replace;          /* The replacement */
  48         int replace_len;        /* The length of the replacement string */
  49         int  append;            /* Switch to control append mode (1,0) */
  50         int  nocase;            /* Ignore case */
  51         int  new_attr;          /* Boolean. Do we create a new attribute or not? */
  52         int  num_matches;       /* Maximum number of matches */
  53         const char *name;       /* The module name */
  54 } rlm_attr_rewrite_t;
  55
  56 static const CONF_PARSER module_config[] = {
  57   { "attribute", PW_TYPE_STRING_PTR, offsetof(rlm_attr_rewrite_t,attribute), NULL, NULL },
  58   { "searchfor", PW_TYPE_STRING_PTR, offsetof(rlm_attr_rewrite_t,search), NULL, NULL },
  59   { "searchin",  PW_TYPE_STRING_PTR, offsetof(rlm_attr_rewrite_t,searchin_str), NULL, "packet" },
  60   { "replacewith", PW_TYPE_STRING_PTR, offsetof(rlm_attr_rewrite_t,replace), NULL, NULL },
  61   { "append", PW_TYPE_BOOLEAN, offsetof(rlm_attr_rewrite_t,append),NULL, "no" },
  62   { "ignore_case", PW_TYPE_BOOLEAN, offsetof(rlm_attr_rewrite_t,nocase), NULL, "yes" },
  63   { "new_attribute", PW_TYPE_BOOLEAN, offsetof(rlm_attr_rewrite_t,new_attr), NULL, "no" },
  64   { "max_matches", PW_TYPE_INTEGER, offsetof(rlm_attr_rewrite_t,num_matches), NULL, "10" },
  65   { NULL, -1, 0, NULL, NULL }
  66 };
  67
  68 static int attr_rewrite_instantiate(CONF_SECTION *conf, void **instance)
  69 {
  70         rlm_attr_rewrite_t *data;
  71         DICT_ATTR *dattr;
  72
  73         /*
  74          *      Set up a storage area for instance data
  75          */
  76         data = rad_malloc(sizeof(*data));
  77         if (!data) {
  78                 return -1;
  79         }
  80         memset(data, 0, sizeof(*data));
  81
  82         /*
  83          *      If the configuration parameters can't be parsed, then
  84          *      fail.
  85          */
  86         if (cf_section_parse(conf, data, module_config) < 0) {
  87                 free(data);
  88                 return -1;
  89         }
  90
  91         /*
  92          *      Discover the attribute number of the key.
  93          */
  94         if (data->attribute == NULL) {
  95                 radlog(L_ERR, "rlm_attr_rewrite: 'attribute' must be set.");
  96                 return -1;
  97         }
  98         if (data->search == NULL || data->replace == NULL) {
  99                 radlog(L_ERR, "rlm_attr_rewrite: search/replace strings must be set.");
 100                 return -1;
 101         }
 102         data->search_len = strlen(data->search);
 103         data->replace_len = strlen(data->replace);
 104
 105         if (data->replace_len == 0 && data->new_attr){
 106                 radlog(L_ERR, "rlm_attr_rewrite: replace string must not be zero length in order to create new attribute.");
 107                 return -1;
 108         }
 109
 110         if (data->num_matches < 1 || data->num_matches > MAX_STRING_LEN) {
 111                 radlog(L_ERR, "rlm_attr_rewrite: Illegal range for match number.");
 112                 return -1;
 113         }
 114         if (data->searchin_str == NULL) {
 115                 radlog(L_ERR, "rlm_attr_rewrite: Illegal searchin directive given. Assuming packet.");
 116                 data->searchin = RLM_REGEX_INPACKET;
 117         }
 118         else{
 119                 if (strcmp(data->searchin_str, "packet") == 0)
 120                         data->searchin = RLM_REGEX_INPACKET;
 121                 else if (strcmp(data->searchin_str, "config") == 0)
 122                         data->searchin = RLM_REGEX_INCONFIG;
 123                 else if (strcmp(data->searchin_str, "control") == 0)
 124                         data->searchin = RLM_REGEX_INCONFIG;
 125                 else if (strcmp(data->searchin_str, "reply") == 0)
 126                         data->searchin = RLM_REGEX_INREPLY;
 127                 else if (strcmp(data->searchin_str, "proxy") == 0)
 128                         data->searchin = RLM_REGEX_INPROXY;
 129                 else if (strcmp(data->searchin_str, "proxy_reply") == 0)
 130                         data->searchin = RLM_REGEX_INPROXYREPLY;
 131                 else {
 132                         radlog(L_ERR, "rlm_attr_rewrite: Illegal searchin directive given. Assuming packet.");
 133                         data->searchin = RLM_REGEX_INPACKET;
 134                 }
 135         }
 136         dattr = dict_attrbyname(data->attribute);
 137         if (dattr == NULL) {
 138                 radlog(L_ERR, "rlm_attr_rewrite: No such attribute %s",
 139                                 data->attribute);
 140                 return -1;
 141         }
 142         data->da = dattr;
 143         /* Add the module instance name */
 144         data->name = cf_section_name2(conf); /* may be NULL */
 145
 146         *instance = data;
 147
 148         return 0;
 149 }
 150
 151 static int do_attr_rewrite(void *instance, REQUEST *request)
 152 {
 153         rlm_attr_rewrite_t *data = (rlm_attr_rewrite_t *) instance;
 154         int ret = RLM_MODULE_NOOP;
 155         VALUE_PAIR *attr_vp = NULL;
 156         VALUE_PAIR *tmp = NULL;
 157         regex_t preg;
 158         regmatch_t pmatch[9];
 159         int cflags = 0;
 160         int err = 0;
 161         char done_xlat = 0;
 162         unsigned int len = 0;
 163         char err_msg[MAX_STRING_LEN];
 164         unsigned int i = 0;
 165         unsigned int j = 0;
 166         unsigned int counter = 0;
 167         char new_str[MAX_STRING_LEN];
 168         char *ptr, *ptr2;
 169         char search_STR[MAX_STRING_LEN];
 170         char replace_STR[MAX_STRING_LEN];
 171
 172         if ((attr_vp = pairfind(request->config_items, PW_REWRITE_RULE, 0)) != NULL){
 173                 if (data->name == NULL || strcmp(data->name,attr_vp->vp_strvalue))
 174                         return RLM_MODULE_NOOP;
 175         }
 176
 177         if (data->new_attr){
 178                 /* new_attribute = yes */
 179                 if (!radius_xlat(replace_STR, sizeof(replace_STR), data->replace, request, NULL)) {
 180                         DEBUG2("%s: xlat on replace string failed.", data->name);
 181                         return ret;
 182                 }
 183                 attr_vp = pairmake(data->attribute,replace_STR,0);
 184                 if (attr_vp == NULL){
 185                         DEBUG2("%s: Could not add new attribute %s with value '%s'", data->name,
 186                                 data->attribute,replace_STR);
 187                         return ret;
 188                 }
 189                 switch(data->searchin){
 190                         case RLM_REGEX_INPACKET:
 191                                 pairadd(&request->packet->vps,attr_vp);
 192                                 break;
 193                         case RLM_REGEX_INCONFIG:
 194                                 pairadd(&request->config_items,attr_vp);
 195                                 break;
 196                         case RLM_REGEX_INREPLY:
 197                                 pairadd(&request->reply->vps,attr_vp);
 198                                 break;
 199                         case RLM_REGEX_INPROXY:
 200                                 if (!request->proxy) {
 201                                         pairbasicfree(attr_vp);
 202                                         return RLM_MODULE_NOOP;
 203                                 }
 204                                 pairadd(&request->proxy->vps, attr_vp);
 205                                 break;
 206                         case RLM_REGEX_INPROXYREPLY:
 207                                 if (!request->proxy_reply) {
 208                                         pairbasicfree(attr_vp);
 209                                         return RLM_MODULE_NOOP;
 210                                 }
 211                                 pairadd(&request->proxy_reply->vps, attr_vp);
 212                                 break;
 213                         default:
 214                                 radlog(L_ERR, "%s: Illegal value for searchin. Changing to packet.", data->name);
 215                                 data->searchin = RLM_REGEX_INPACKET;
 216                                 pairadd(&request->packet->vps,attr_vp);
 217                                 break;
 218                 }
 219                 DEBUG2("%s: Added attribute %s with value '%s'", data->name,data->attribute,replace_STR);
 220                 ret = RLM_MODULE_OK;
 221         } else {
 222                 int replace_len = 0;
 223
 224                 /* new_attribute = no */
 225                 switch (data->searchin) {
 226                         case RLM_REGEX_INPACKET:
 227                                 if (!data->da->vendor && (data->da->attr == PW_USER_NAME))
 228                                         attr_vp = request->username;
 229                                 else if (!data->da->vendor && (data->da->attr == PW_USER_PASSWORD))
 230                                         attr_vp = request->password;
 231                                 else
 232                                         tmp = request->packet->vps;
 233                                 break;
 234                         case RLM_REGEX_INCONFIG:
 235                                 tmp = request->config_items;
 236                                 break;
 237                         case RLM_REGEX_INREPLY:
 238                                 tmp = request->reply->vps;
 239                                 break;
 240                         case RLM_REGEX_INPROXYREPLY:
 241                                 if (!request->proxy_reply)
 242                                         return RLM_MODULE_NOOP;
 243                                 tmp = request->proxy_reply->vps;
 244                                 break;
 245                         case RLM_REGEX_INPROXY:
 246                                 if (!request->proxy)
 247                                         return RLM_MODULE_NOOP;
 248                                 tmp = request->proxy->vps;
 249                                 break;
 250                         default:
 251                                 radlog(L_ERR, "%s: Illegal value for searchin. Changing to packet.", data->name);
 252                                 data->searchin = RLM_REGEX_INPACKET;
 253                                 attr_vp = pairfind(request->packet->vps, data->da->attr, data->da->vendor);
 254                                 break;
 255                 }
 256 do_again:
 257                 if (tmp != NULL)
 258                         attr_vp = pairfind(tmp, data->da->attr, data->da->vendor);
 259                 if (attr_vp == NULL) {
 260                         DEBUG2("%s: Could not find value pair for attribute %s", data->name,data->attribute);
 261                         return ret;
 262                 }
 263                 if (attr_vp->vp_strvalue == NULL || attr_vp->length == 0){
 264                         DEBUG2("%s: Attribute %s string value NULL or of zero length", data->name,data->attribute);
 265                         return ret;
 266                 }
 267                 cflags |= REG_EXTENDED;
 268                 if (data->nocase)
 269                         cflags |= REG_ICASE;
 270
 271                 if (!radius_xlat(search_STR, sizeof(search_STR), data->search, request, NULL) && data->search_len != 0) {
 272                         DEBUG2("%s: xlat on search string failed.", data->name);
 273                         return ret;
 274                 }
 275
 276                 if ((err = regcomp(&preg,search_STR,cflags))) {
 277                         regerror(err, &preg, err_msg, MAX_STRING_LEN);
 278                         DEBUG2("%s: regcomp() returned error: %s", data->name,err_msg);
 279                         return ret;
 280                 }
 281
 282                 if ((attr_vp->type == PW_TYPE_IPADDR) &&
 283                     (attr_vp->vp_strvalue[0] == '\0')) {
 284                         inet_ntop(AF_INET, &(attr_vp->vp_ipaddr),
 285                                   attr_vp->vp_strvalue,
 286                                   sizeof(attr_vp->vp_strvalue));
 287                 }
 288
 289                 ptr = new_str;
 290                 ptr2 = attr_vp->vp_strvalue;
 291                 counter = 0;
 292
 293                 for ( i = 0 ;i < (unsigned)data->num_matches; i++) {
 294                         err = regexec(&preg, ptr2, REQUEST_MAX_REGEX, pmatch, 0);
 295                         if (err == REG_NOMATCH) {
 296                                 if (i == 0) {
 297                                         DEBUG2("%s: Does not match: %s = %s", data->name,
 298                                                         data->attribute, attr_vp->vp_strvalue);
 299                                         regfree(&preg);
 300                                         goto to_do_again;
 301                                 } else
 302                                         break;
 303                         }
 304                         if (err != 0) {
 305                                 regfree(&preg);
 306                                 radlog(L_ERR, "%s: match failure for attribute %s with value '%s'", data->name,
 307                                                 data->attribute, attr_vp->vp_strvalue);
 308                                 return ret;
 309                         }
 310                         if (pmatch[0].rm_so == -1)
 311                                 break;
 312                         len = pmatch[0].rm_so;
 313                         if (data->append) {
 314                                 len = len + (pmatch[0].rm_eo - pmatch[0].rm_so);
 315                         }
 316                         counter += len;
 317                         if (counter >= MAX_STRING_LEN) {
 318                                 regfree(&preg);
 319                                 DEBUG2("%s: Replacement out of limits for attribute %s with value '%s'", data->name,
 320                                                 data->attribute, attr_vp->vp_strvalue);
 321                                 return ret;
 322                         }
 323
 324                         memcpy(ptr, ptr2,len);
 325                         ptr += len;
 326                         *ptr = '\0';
 327                         ptr2 += pmatch[0].rm_eo;
 328
 329                         if (i == 0){
 330                                 /*
 331                                  * We only run on the first match, sorry
 332                                  */
 333                                 for(j = 0; j <= REQUEST_MAX_REGEX; j++){
 334                                         char *p;
 335                                         char buffer[sizeof(attr_vp->vp_strvalue)];
 336
 337                                         /*
 338                                          * Stolen from src/main/valuepair.c, paircompare()
 339                                          */
 340
 341                                         /*
 342                                          * Delete old matches if the corresponding match does not
 343                                          * exist in the current regex
 344                                          */
 345                                         if (pmatch[j].rm_so == -1){
 346                                                 p = request_data_get(request,request,REQUEST_DATA_REGEX | j);
 347                                                 if (p){
 348                                                         free(p);
 349                                                         continue;
 350                                                 }
 351                                                 break;
 352                                         }
 353                                         memcpy(buffer,
 354                                                attr_vp->vp_strvalue + pmatch[j].rm_so,
 355                                                pmatch[j].rm_eo - pmatch[j].rm_so);
 356                                         buffer[pmatch[j].rm_eo - pmatch[j].rm_so] = '\0';
 357                                         p = strdup(buffer);
 358                                         request_data_add(request,request,REQUEST_DATA_REGEX | j,p,free);
 359                                 }
 360                         }
 361
 362                         if (!done_xlat){
 363                                 if (data->replace_len != 0 &&
 364                                 radius_xlat(replace_STR, sizeof(replace_STR), data->replace, request, NULL) == 0) {
 365                                         DEBUG2("%s: xlat on replace string failed.", data->name);
 366                                         return ret;
 367                                 }
 368                                 replace_len = (data->replace_len != 0) ? strlen(replace_STR) : 0;
 369                                 done_xlat = 1;
 370                         }
 371
 372                         counter += replace_len;
 373                         if (counter >= MAX_STRING_LEN) {
 374                                 regfree(&preg);
 375                                 DEBUG2("%s: Replacement out of limits for attribute %s with value '%s'", data->name,
 376                                                 data->attribute, attr_vp->vp_strvalue);
 377                                 return ret;
 378                         }
 379                         if (replace_len){
 380                                 memcpy(ptr, replace_STR, replace_len);
 381                                 ptr += replace_len;
 382                                 *ptr = '\0';
 383                         }
 384                 }
 385                 regfree(&preg);
 386                 len = strlen(ptr2) + 1;         /* We add the ending NULL */
 387                 counter += len;
 388                 if (counter >= MAX_STRING_LEN){
 389                         DEBUG2("%s: Replacement out of limits for attribute %s with value '%s'", data->name,
 390                                         data->attribute, attr_vp->vp_strvalue);
 391                         return ret;
 392                 }
 393                 memcpy(ptr, ptr2, len);
 394                 ptr[len] = '\0';
 395
 396                 DEBUG2("%s: Changed value for attribute %s from '%s' to '%s'", data->name,
 397                                 data->attribute, attr_vp->vp_strvalue, new_str);
 398                 if (pairparsevalue(attr_vp, new_str) == NULL) {
 399                         DEBUG2("%s: Could not write value '%s' into attribute %s: %s", data->name, new_str, data->attribute, fr_strerror());
 400                         return ret;
 401                 }
 402
 403 to_do_again:
 404                 ret = RLM_MODULE_OK;
 405
 406                 if (tmp != NULL){
 407                         tmp = attr_vp->next;
 408                         if (tmp != NULL)
 409                                 goto do_again;
 410                 }
 411         }
 412
 413         return ret;
 414 }
 415
 416 static int attr_rewrite_accounting(void *instance, REQUEST *request)
 417 {
 418         return do_attr_rewrite(instance, request);
 419 }
 420
 421 static int attr_rewrite_authorize(void *instance, REQUEST *request)
 422 {
 423         return do_attr_rewrite(instance, request);
 424 }
 425
 426 static int attr_rewrite_authenticate(void *instance, REQUEST *request)
 427 {
 428         return do_attr_rewrite(instance, request);
 429 }
 430
 431 static int attr_rewrite_preacct(void *instance, REQUEST *request)
 432 {
 433         return do_attr_rewrite(instance, request);
 434 }
 435
 436 static int attr_rewrite_checksimul(void *instance, REQUEST *request)
 437 {
 438         return do_attr_rewrite(instance, request);
 439 }
 440
 441 static int attr_rewrite_preproxy(void *instance, REQUEST *request)
 442 {
 443         return do_attr_rewrite(instance, request);
 444 }
 445
 446 static int attr_rewrite_postproxy(void *instance, REQUEST *request)
 447 {
 448         return do_attr_rewrite(instance, request);
 449 }
 450
 451 static int attr_rewrite_postauth(void *instance, REQUEST *request)
 452 {
 453         return do_attr_rewrite(instance, request);
 454 }
 455
 456 static int attr_rewrite_detach(void *instance)
 457 {
 458         free(instance);
 459         return 0;
 460 }
 461
 462 /*
 463  *      The module name should be the only globally exported symbol.
 464  *      That is, everything else should be 'static'.
 465  *
 466  *      If the module needs to temporarily modify it's instantiation
 467  *      data, the type should be changed to RLM_TYPE_THREAD_UNSAFE.
 468  *      The server will then take care of ensuring that the module
 469  *      is single-threaded.
 470  */
 471 module_t rlm_attr_rewrite = {
 472         RLM_MODULE_INIT,
 473         "attr_rewrite",
 474         RLM_TYPE_THREAD_UNSAFE,         /* type */
 475         attr_rewrite_instantiate,               /* instantiation */
 476         attr_rewrite_detach,                    /* detach */
 477         {
 478                 attr_rewrite_authenticate,      /* authentication */
 479                 attr_rewrite_authorize,         /* authorization */
 480                 attr_rewrite_preacct,           /* preaccounting */
 481                 attr_rewrite_accounting,        /* accounting */
 482                 attr_rewrite_checksimul,        /* checksimul */
 483                 attr_rewrite_preproxy,          /* pre-proxy */
 484                 attr_rewrite_postproxy,         /* post-proxy */
 485                 attr_rewrite_postauth           /* post-auth */
 486         },
 487 };