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         int  attr_num;          /* The attribute number */
  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 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         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         const char *instance_name = NULL;
  73
  74         /*
  75          *      Set up a storage area for instance data
  76          */
  77         data = rad_malloc(sizeof(*data));
  78         if (!data) {
  79                 return -1;
  80         }
  81         memset(data, 0, sizeof(*data));
  82
  83         /*
  84          *      If the configuration parameters can't be parsed, then
  85          *      fail.
  86          */
  87         if (cf_section_parse(conf, data, module_config) < 0) {
  88                 free(data);
  89                 return -1;
  90         }
  91
  92         /*
  93          *      Discover the attribute number of the key.
  94          */
  95         if (data->attribute == NULL) {
  96                 radlog(L_ERR, "rlm_attr_rewrite: 'attribute' must be set.");
  97                 return -1;
  98         }
  99         if (data->search == NULL || data->replace == NULL) {
 100                 radlog(L_ERR, "rlm_attr_rewrite: search/replace strings must be set.");
 101                 return -1;
 102         }
 103         data->search_len = strlen(data->search);
 104         data->replace_len = strlen(data->replace);
 105
 106         if (data->replace_len == 0 && data->new_attr){
 107                 radlog(L_ERR, "rlm_attr_rewrite: replace string must not be zero length in order to create new attribute.");
 108                 return -1;
 109         }
 110
 111         if (data->num_matches < 1 || data->num_matches > MAX_STRING_LEN) {
 112                 radlog(L_ERR, "rlm_attr_rewrite: Illegal range for match number.");
 113                 return -1;
 114         }
 115         if (data->searchin_str == NULL) {
 116                 radlog(L_ERR, "rlm_attr_rewrite: Illegal searchin directive given. Assuming packet.");
 117                 data->searchin = RLM_REGEX_INPACKET;
 118         }
 119         else{
 120                 if (strcmp(data->searchin_str, "packet") == 0)
 121                         data->searchin = RLM_REGEX_INPACKET;
 122                 else if (strcmp(data->searchin_str, "config") == 0)
 123                         data->searchin = RLM_REGEX_INCONFIG;
 124                 else if (strcmp(data->searchin_str, "reply") == 0)
 125                         data->searchin = RLM_REGEX_INREPLY;
 126                 else if (strcmp(data->searchin_str, "proxy") == 0)
 127                         data->searchin = RLM_REGEX_INPROXY;
 128                 else if (strcmp(data->searchin_str, "proxy_reply") == 0)
 129                         data->searchin = RLM_REGEX_INPROXYREPLY;
 130                 else {
 131                         radlog(L_ERR, "rlm_attr_rewrite: Illegal searchin directive given. Assuming packet.");
 132                         data->searchin = RLM_REGEX_INPACKET;
 133                 }
 134                 free((char *)data->searchin_str);
 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->attr_num = dattr->attr;
 143         /* Add the module instance name */
 144         data->name = NULL;
 145         instance_name = cf_section_name2(conf);
 146         if (instance_name != NULL)
 147                 data->name = strdup(instance_name);
 148
 149
 150         *instance = data;
 151
 152         return 0;
 153 }
 154
 155 static int do_attr_rewrite(void *instance, REQUEST *request)
 156 {
 157         rlm_attr_rewrite_t *data = (rlm_attr_rewrite_t *) instance;
 158         int ret = RLM_MODULE_NOOP;
 159         VALUE_PAIR *attr_vp = NULL;
 160         VALUE_PAIR *tmp = NULL;
 161         regex_t preg;
 162         regmatch_t pmatch[9];
 163         int cflags = 0;
 164         int err = 0;
 165         char done_xlat = 0;
 166         unsigned int len = 0;
 167         char err_msg[MAX_STRING_LEN];
 168         unsigned int i = 0;
 169         unsigned int j = 0;
 170         unsigned int counter = 0;
 171         char new_str[MAX_STRING_LEN];
 172         char *ptr, *ptr2;
 173         char search_STR[MAX_STRING_LEN];
 174         char replace_STR[MAX_STRING_LEN];
 175         int replace_len = 0;
 176
 177         if ((attr_vp = pairfind(request->config_items, PW_REWRITE_RULE)) != NULL){
 178                 if (data->name == NULL || strcmp(data->name,attr_vp->vp_strvalue))
 179                         return RLM_MODULE_NOOP;
 180         }
 181
 182         if (data->new_attr){
 183                 /* new_attribute = yes */
 184                 if (!radius_xlat(replace_STR, sizeof(replace_STR), data->replace, request, NULL)) {
 185                         DEBUG2("rlm_attr_rewrite: xlat on replace string failed.");
 186                         return ret;
 187                 }
 188                 replace_len = strlen(replace_STR);
 189                 attr_vp = pairmake(data->attribute,replace_STR,0);
 190                 if (attr_vp == NULL){
 191                         DEBUG2("rlm_attr_rewrite: Could not add new attribute %s with value '%s'",
 192                                 data->attribute,replace_STR);
 193                         return ret;
 194                 }
 195                 switch(data->searchin){
 196                         case RLM_REGEX_INPACKET:
 197                                 pairadd(&request->packet->vps,attr_vp);
 198                                 break;
 199                         case RLM_REGEX_INCONFIG:
 200                                 pairadd(&request->config_items,attr_vp);
 201                                 break;
 202                         case RLM_REGEX_INREPLY:
 203                                 pairadd(&request->reply->vps,attr_vp);
 204                                 break;
 205                         case RLM_REGEX_INPROXY:
 206                                 if (!request->proxy) {
 207                                         pairbasicfree(attr_vp);
 208                                         return RLM_MODULE_NOOP;
 209                                 }
 210                                 pairadd(&request->proxy->vps, attr_vp);
 211                                 break;
 212                         case RLM_REGEX_INPROXYREPLY:
 213                                 if (!request->proxy_reply) {
 214                                         pairbasicfree(attr_vp);
 215                                         return RLM_MODULE_NOOP;
 216                                 }
 217                                 pairadd(&request->proxy_reply->vps, attr_vp);
 218                                 break;
 219                         default:
 220                                 radlog(L_ERR, "rlm_attr_rewrite: Illegal value for searchin. Changing to packet.");
 221                                 data->searchin = RLM_REGEX_INPACKET;
 222                                 pairadd(&request->packet->vps,attr_vp);
 223                                 break;
 224                 }
 225                 DEBUG2("rlm_attr_rewrite: Added attribute %s with value '%s'",data->attribute,replace_STR);
 226                 ret = RLM_MODULE_OK;
 227         } else {
 228                 /* new_attribute = no */
 229                 switch (data->searchin) {
 230                         case RLM_REGEX_INPACKET:
 231                                 if (data->attr_num == PW_USER_NAME)
 232                                         attr_vp = request->username;
 233                                 else if (data->attr_num == PW_USER_PASSWORD)
 234                                         attr_vp = request->password;
 235                                 else
 236                                         tmp = request->packet->vps;
 237                                 break;
 238                         case RLM_REGEX_INCONFIG:
 239                                 tmp = request->config_items;
 240                                 break;
 241                         case RLM_REGEX_INREPLY:
 242                                 tmp = request->reply->vps;
 243                                 break;
 244                         case RLM_REGEX_INPROXYREPLY:
 245                                 if (!request->proxy_reply)
 246                                         return RLM_MODULE_NOOP;
 247                                 tmp = request->proxy_reply->vps;
 248                                 break;
 249                         case RLM_REGEX_INPROXY:
 250                                 if (!request->proxy)
 251                                         return RLM_MODULE_NOOP;
 252                                 tmp = request->proxy->vps;
 253                                 break;
 254                         default:
 255                                 radlog(L_ERR, "rlm_attr_rewrite: Illegal value for searchin. Changing to packet.");
 256                                 data->searchin = RLM_REGEX_INPACKET;
 257                                 attr_vp = pairfind(request->packet->vps, data->attr_num);
 258                                 break;
 259                 }
 260 do_again:
 261                 if (tmp != NULL)
 262                         attr_vp = pairfind(tmp, data->attr_num);
 263                 if (attr_vp == NULL) {
 264                         DEBUG2("rlm_attr_rewrite: Could not find value pair for attribute %s",data->attribute);
 265                         return ret;
 266                 }
 267                 if (attr_vp->vp_strvalue == NULL || attr_vp->length == 0){
 268                         DEBUG2("rlm_attr_rewrite: Attribute %s string value NULL or of zero length",data->attribute);
 269                         return ret;
 270                 }
 271                 cflags |= REG_EXTENDED;
 272                 if (data->nocase)
 273                         cflags |= REG_ICASE;
 274
 275                 if (!radius_xlat(search_STR, sizeof(search_STR), data->search, request, NULL) && data->search_len != 0) {
 276                         DEBUG2("rlm_attr_rewrite: xlat on search string failed.");
 277                         return ret;
 278                 }
 279
 280                 if ((err = regcomp(&preg,search_STR,cflags))) {
 281                         regerror(err, &preg, err_msg, MAX_STRING_LEN);
 282                         DEBUG2("rlm_attr_rewrite: regcomp() returned error: %s",err_msg);
 283                         return ret;
 284                 }
 285
 286                 if ((attr_vp->type == PW_TYPE_IPADDR) &&
 287                     (attr_vp->vp_strvalue[0] == '\0')) {
 288                   inet_ntop(AF_INET, &(attr_vp->vp_ipaddr),
 289                             attr_vp->vp_strvalue,
 290                             sizeof(attr_vp->vp_strvalue));
 291                 }
 292
 293                 ptr = new_str;
 294                 ptr2 = attr_vp->vp_strvalue;
 295                 counter = 0;
 296
 297                 for ( i = 0 ;i < (unsigned)data->num_matches; i++) {
 298                         err = regexec(&preg, ptr2, REQUEST_MAX_REGEX, pmatch, 0);
 299                         if (err == REG_NOMATCH) {
 300                                 if (i == 0) {
 301                                         DEBUG2("rlm_attr_rewrite: No match found for attribute %s with value '%s'",
 302                                                         data->attribute, attr_vp->vp_strvalue);
 303                                         regfree(&preg);
 304                                         goto to_do_again;
 305                                 } else
 306                                         break;
 307                         }
 308                         if (err != 0) {
 309                                 regfree(&preg);
 310                                 radlog(L_ERR, "rlm_attr_rewrite: match failure for attribute %s with value '%s'",
 311                                                 data->attribute, attr_vp->vp_strvalue);
 312                                 return ret;
 313                         }
 314                         if (pmatch[0].rm_so == -1)
 315                                 break;
 316                         len = pmatch[0].rm_so;
 317                         if (data->append) {
 318                                 len = len + (pmatch[0].rm_eo - pmatch[0].rm_so);
 319                         }
 320                         counter += len;
 321                         if (counter >= MAX_STRING_LEN) {
 322                                 regfree(&preg);
 323                                 DEBUG2("rlm_attr_rewrite: Replacement out of limits for attribute %s with value '%s'",
 324                                                 data->attribute, attr_vp->vp_strvalue);
 325                                 return ret;
 326                         }
 327
 328                         strlcpy(ptr, ptr2,len);
 329                         ptr += len;
 330                         ptr2 += pmatch[0].rm_eo;
 331
 332                         if (i == 0){
 333                                 /*
 334                                  * We only run on the first match, sorry
 335                                  */
 336                                 for(j = 0; j <= REQUEST_MAX_REGEX; j++){
 337                                         char *p;
 338                                         char buffer[sizeof(attr_vp->vp_strvalue)];
 339
 340                                         /*
 341                                          * Stolen from src/main/valuepair.c, paircompare()
 342                                          */
 343
 344                                         /*
 345                                          * Delete old matches if the corresponding match does not
 346                                          * exist in the current regex
 347                                          */
 348                                         if (pmatch[j].rm_so == -1){
 349                                                 p = request_data_get(request,request,REQUEST_DATA_REGEX | j);
 350                                                 if (p){
 351                                                         free(p);
 352                                                         continue;
 353                                                 }
 354                                                 break;
 355                                         }
 356                                         memcpy(buffer,
 357                                                attr_vp->vp_strvalue + pmatch[j].rm_so,
 358                                                pmatch[j].rm_eo - pmatch[j].rm_so);
 359                                         buffer[pmatch[j].rm_eo - pmatch[j].rm_so] = '\0';
 360                                         p = strdup(buffer);
 361                                         request_data_add(request,request,REQUEST_DATA_REGEX | j,p,free);
 362                                 }
 363                         }
 364
 365                         if (!done_xlat){
 366                                 if (data->replace_len != 0 &&
 367                                 radius_xlat(replace_STR, sizeof(replace_STR), data->replace, request, NULL) == 0) {
 368                                         DEBUG2("rlm_attr_rewrite: xlat on replace string failed.");
 369                                         return ret;
 370                                 }
 371                                 replace_len = (data->replace_len != 0) ? strlen(replace_STR) : 0;
 372                                 done_xlat = 1;
 373                         }
 374
 375                         counter += replace_len;
 376                         if (counter >= MAX_STRING_LEN) {
 377                                 regfree(&preg);
 378                                 DEBUG2("rlm_attr_rewrite: Replacement out of limits for attribute %s with value '%s'",
 379                                                 data->attribute, attr_vp->vp_strvalue);
 380                                 return ret;
 381                         }
 382                         if (replace_len){
 383                                 strlcpy(ptr, replace_STR, replace_len);
 384                                 ptr += replace_len;
 385                         }
 386                 }
 387                 regfree(&preg);
 388                 len = strlen(ptr2) + 1;         /* We add the ending NULL */
 389                 counter += len;
 390                 if (counter >= MAX_STRING_LEN){
 391                         DEBUG2("rlm_attr_rewrite: Replacement out of limits for attribute %s with value '%s'",
 392                                         data->attribute, attr_vp->vp_strvalue);
 393                         return ret;
 394                 }
 395                 strlcpy(ptr, ptr2, len);
 396
 397                 DEBUG2("rlm_attr_rewrite: Changed value for attribute %s from '%s' to '%s'",
 398                                 data->attribute, attr_vp->vp_strvalue, new_str);
 399                 if (pairparsevalue(attr_vp, new_str) == NULL) {
 400                         DEBUG2("rlm_attr_rewrite: Could not write value '%s' into attribute %s: %s", new_str, data->attribute, librad_errstr);
 401                         return ret;
 402                 }
 403
 404 to_do_again:
 405                 ret = RLM_MODULE_OK;
 406
 407                 if (tmp != NULL){
 408                         tmp = attr_vp->next;
 409                         if (tmp != NULL)
 410                                 goto do_again;
 411                 }
 412         }
 413
 414         return ret;
 415 }
 416
 417 static int attr_rewrite_accounting(void *instance, REQUEST *request)
 418 {
 419         return do_attr_rewrite(instance, request);
 420 }
 421
 422 static int attr_rewrite_authorize(void *instance, REQUEST *request)
 423 {
 424         return do_attr_rewrite(instance, request);
 425 }
 426
 427 static int attr_rewrite_authenticate(void *instance, REQUEST *request)
 428 {
 429         return do_attr_rewrite(instance, request);
 430 }
 431
 432 static int attr_rewrite_preacct(void *instance, REQUEST *request)
 433 {
 434         return do_attr_rewrite(instance, request);
 435 }
 436
 437 static int attr_rewrite_checksimul(void *instance, REQUEST *request)
 438 {
 439         return do_attr_rewrite(instance, request);
 440 }
 441
 442 static int attr_rewrite_preproxy(void *instance, REQUEST *request)
 443 {
 444         return do_attr_rewrite(instance, request);
 445 }
 446
 447 static int attr_rewrite_postproxy(void *instance, REQUEST *request)
 448 {
 449         return do_attr_rewrite(instance, request);
 450 }
 451
 452 static int attr_rewrite_postauth(void *instance, REQUEST *request)
 453 {
 454         return do_attr_rewrite(instance, request);
 455 }
 456
 457 static int attr_rewrite_detach(void *instance)
 458 {
 459         rlm_attr_rewrite_t *data = (rlm_attr_rewrite_t *) instance;
 460
 461         if (data->name)
 462                 free(data->name);
 463
 464         free(instance);
 465         return 0;
 466 }
 467
 468 /*
 469  *      The module name should be the only globally exported symbol.
 470  *      That is, everything else should be 'static'.
 471  *
 472  *      If the module needs to temporarily modify it's instantiation
 473  *      data, the type should be changed to RLM_TYPE_THREAD_UNSAFE.
 474  *      The server will then take care of ensuring that the module
 475  *      is single-threaded.
 476  */
 477 module_t rlm_attr_rewrite = {
 478         RLM_MODULE_INIT,
 479         "attr_rewrite",
 480         RLM_TYPE_THREAD_UNSAFE,         /* type */
 481         attr_rewrite_instantiate,               /* instantiation */
 482         attr_rewrite_detach,                    /* detach */
 483         {
 484                 attr_rewrite_authenticate,      /* authentication */
 485                 attr_rewrite_authorize,         /* authorization */
 486                 attr_rewrite_preacct,           /* preaccounting */
 487                 attr_rewrite_accounting,        /* accounting */
 488                 attr_rewrite_checksimul,        /* checksimul */
 489                 attr_rewrite_preproxy,          /* pre-proxy */
 490                 attr_rewrite_postproxy,         /* post-proxy */
 491                 attr_rewrite_postauth           /* post-auth */
 492         },
 493 };