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         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, "reply") == 0)
 124                         data->searchin = RLM_REGEX_INREPLY;
 125                 else if (strcmp(data->searchin_str, "proxy") == 0)
 126                         data->searchin = RLM_REGEX_INPROXY;
 127                 else if (strcmp(data->searchin_str, "proxy_reply") == 0)
 128                         data->searchin = RLM_REGEX_INPROXYREPLY;
 129                 else {
 130                         radlog(L_ERR, "rlm_attr_rewrite: Illegal searchin directive given. Assuming packet.");
 131                         data->searchin = RLM_REGEX_INPACKET;
 132                 }
 133                 free((char *)data->searchin_str);
 134         }
 135         dattr = dict_attrbyname(data->attribute);
 136         if (dattr == NULL) {
 137                 radlog(L_ERR, "rlm_attr_rewrite: No such attribute %s",
 138                                 data->attribute);
 139                 return -1;
 140         }
 141         data->attr_num = dattr->attr;
 142         /* Add the module instance name */
 143         data->name = cf_section_name2(conf); /* may be NULL */
 144
 145         *instance = data;
 146
 147         return 0;
 148 }
 149
 150 static int do_attr_rewrite(void *instance, REQUEST *request)
 151 {
 152         rlm_attr_rewrite_t *data = (rlm_attr_rewrite_t *) instance;
 153         int ret = RLM_MODULE_NOOP;
 154         VALUE_PAIR *attr_vp = NULL;
 155         VALUE_PAIR *tmp = NULL;
 156         regex_t preg;
 157         regmatch_t pmatch[9];
 158         int cflags = 0;
 159         int err = 0;
 160         char done_xlat = 0;
 161         unsigned int len = 0;
 162         char err_msg[MAX_STRING_LEN];
 163         unsigned int i = 0;
 164         unsigned int j = 0;
 165         unsigned int counter = 0;
 166         char new_str[MAX_STRING_LEN];
 167         char *ptr, *ptr2;
 168         char search_STR[MAX_STRING_LEN];
 169         char replace_STR[MAX_STRING_LEN];
 170         int replace_len = 0;
 171
 172         if ((attr_vp = pairfind(request->config_items, PW_REWRITE_RULE)) != 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                 replace_len = strlen(replace_STR);
 184                 attr_vp = pairmake(data->attribute,replace_STR,0);
 185                 if (attr_vp == NULL){
 186                         DEBUG2("%s: Could not add new attribute %s with value '%s'", data->name,
 187                                 data->attribute,replace_STR);
 188                         return ret;
 189                 }
 190                 switch(data->searchin){
 191                         case RLM_REGEX_INPACKET:
 192                                 pairadd(&request->packet->vps,attr_vp);
 193                                 break;
 194                         case RLM_REGEX_INCONFIG:
 195                                 pairadd(&request->config_items,attr_vp);
 196                                 break;
 197                         case RLM_REGEX_INREPLY:
 198                                 pairadd(&request->reply->vps,attr_vp);
 199                                 break;
 200                         case RLM_REGEX_INPROXY:
 201                                 if (!request->proxy) {
 202                                         pairbasicfree(attr_vp);
 203                                         return RLM_MODULE_NOOP;
 204                                 }
 205                                 pairadd(&request->proxy->vps, attr_vp);
 206                                 break;
 207                         case RLM_REGEX_INPROXYREPLY:
 208                                 if (!request->proxy_reply) {
 209                                         pairbasicfree(attr_vp);
 210                                         return RLM_MODULE_NOOP;
 211                                 }
 212                                 pairadd(&request->proxy_reply->vps, attr_vp);
 213                                 break;
 214                         default:
 215                                 radlog(L_ERR, "%s: Illegal value for searchin. Changing to packet.", data->name);
 216                                 data->searchin = RLM_REGEX_INPACKET;
 217                                 pairadd(&request->packet->vps,attr_vp);
 218                                 break;
 219                 }
 220                 DEBUG2("%s: Added attribute %s with value '%s'", data->name,data->attribute,replace_STR);
 221                 ret = RLM_MODULE_OK;
 222         } else {
 223                 /* new_attribute = no */
 224                 switch (data->searchin) {
 225                         case RLM_REGEX_INPACKET:
 226                                 if (data->attr_num == PW_USER_NAME)
 227                                         attr_vp = request->username;
 228                                 else if (data->attr_num == PW_USER_PASSWORD)
 229                                         attr_vp = request->password;
 230                                 else
 231                                         tmp = request->packet->vps;
 232                                 break;
 233                         case RLM_REGEX_INCONFIG:
 234                                 tmp = request->config_items;
 235                                 break;
 236                         case RLM_REGEX_INREPLY:
 237                                 tmp = request->reply->vps;
 238                                 break;
 239                         case RLM_REGEX_INPROXYREPLY:
 240                                 if (!request->proxy_reply)
 241                                         return RLM_MODULE_NOOP;
 242                                 tmp = request->proxy_reply->vps;
 243                                 break;
 244                         case RLM_REGEX_INPROXY:
 245                                 if (!request->proxy)
 246                                         return RLM_MODULE_NOOP;
 247                                 tmp = request->proxy->vps;
 248                                 break;
 249                         default:
 250                                 radlog(L_ERR, "%s: Illegal value for searchin. Changing to packet.", data->name);
 251                                 data->searchin = RLM_REGEX_INPACKET;
 252                                 attr_vp = pairfind(request->packet->vps, data->attr_num);
 253                                 break;
 254                 }
 255 do_again:
 256                 if (tmp != NULL)
 257                         attr_vp = pairfind(tmp, data->attr_num);
 258                 if (attr_vp == NULL) {
 259                         DEBUG2("%s: Could not find value pair for attribute %s", data->name,data->attribute);
 260                         return ret;
 261                 }
 262                 if (attr_vp->vp_strvalue == NULL || attr_vp->length == 0){
 263                         DEBUG2("%s: Attribute %s string value NULL or of zero length", data->name,data->attribute);
 264                         return ret;
 265                 }
 266                 cflags |= REG_EXTENDED;
 267                 if (data->nocase)
 268                         cflags |= REG_ICASE;
 269
 270                 if (!radius_xlat(search_STR, sizeof(search_STR), data->search, request, NULL) && data->search_len != 0) {
 271                         DEBUG2("%s: xlat on search string failed.", data->name);
 272                         return ret;
 273                 }
 274
 275                 if ((err = regcomp(&preg,search_STR,cflags))) {
 276                         regerror(err, &preg, err_msg, MAX_STRING_LEN);
 277                         DEBUG2("%s: regcomp() returned error: %s", data->name,err_msg);
 278                         return ret;
 279                 }
 280
 281                 if ((attr_vp->type == PW_TYPE_IPADDR) &&
 282                     (attr_vp->vp_strvalue[0] == '\0')) {
 283                         inet_ntop(AF_INET, &(attr_vp->vp_ipaddr),
 284                                   attr_vp->vp_strvalue,
 285                                   sizeof(attr_vp->vp_strvalue));
 286                 }
 287
 288                 ptr = new_str;
 289                 ptr2 = attr_vp->vp_strvalue;
 290                 counter = 0;
 291
 292                 for ( i = 0 ;i < (unsigned)data->num_matches; i++) {
 293                         err = regexec(&preg, ptr2, REQUEST_MAX_REGEX, pmatch, 0);
 294                         if (err == REG_NOMATCH) {
 295                                 if (i == 0) {
 296                                         DEBUG2("%s: Does not match: %s = %s", data->name,
 297                                                         data->attribute, attr_vp->vp_strvalue);
 298                                         regfree(&preg);
 299                                         goto to_do_again;
 300                                 } else
 301                                         break;
 302                         }
 303                         if (err != 0) {
 304                                 regfree(&preg);
 305                                 radlog(L_ERR, "%s: match failure for attribute %s with value '%s'", data->name,
 306                                                 data->attribute, attr_vp->vp_strvalue);
 307                                 return ret;
 308                         }
 309                         if (pmatch[0].rm_so == -1)
 310                                 break;
 311                         len = pmatch[0].rm_so;
 312                         if (data->append) {
 313                                 len = len + (pmatch[0].rm_eo - pmatch[0].rm_so);
 314                         }
 315                         counter += len;
 316                         if (counter >= MAX_STRING_LEN) {
 317                                 regfree(&preg);
 318                                 DEBUG2("%s: Replacement out of limits for attribute %s with value '%s'", data->name,
 319                                                 data->attribute, attr_vp->vp_strvalue);
 320                                 return ret;
 321                         }
 322
 323                         memcpy(ptr, ptr2,len);
 324                         ptr += len;
 325                         *ptr = '\0';
 326                         ptr2 += pmatch[0].rm_eo;
 327
 328                         if (i == 0){
 329                                 /*
 330                                  * We only run on the first match, sorry
 331                                  */
 332                                 for(j = 0; j <= REQUEST_MAX_REGEX; j++){
 333                                         char *p;
 334                                         char buffer[sizeof(attr_vp->vp_strvalue)];
 335
 336                                         /*
 337                                          * Stolen from src/main/valuepair.c, paircompare()
 338                                          */
 339
 340                                         /*
 341                                          * Delete old matches if the corresponding match does not
 342                                          * exist in the current regex
 343                                          */
 344                                         if (pmatch[j].rm_so == -1){
 345                                                 p = request_data_get(request,request,REQUEST_DATA_REGEX | j);
 346                                                 if (p){
 347                                                         free(p);
 348                                                         continue;
 349                                                 }
 350                                                 break;
 351                                         }
 352                                         memcpy(buffer,
 353                                                attr_vp->vp_strvalue + pmatch[j].rm_so,
 354                                                pmatch[j].rm_eo - pmatch[j].rm_so);
 355                                         buffer[pmatch[j].rm_eo - pmatch[j].rm_so] = '\0';
 356                                         p = strdup(buffer);
 357                                         request_data_add(request,request,REQUEST_DATA_REGEX | j,p,free);
 358                                 }
 359                         }
 360
 361                         if (!done_xlat){
 362                                 if (data->replace_len != 0 &&
 363                                 radius_xlat(replace_STR, sizeof(replace_STR), data->replace, request, NULL) == 0) {
 364                                         DEBUG2("%s: xlat on replace string failed.", data->name);
 365                                         return ret;
 366                                 }
 367                                 replace_len = (data->replace_len != 0) ? strlen(replace_STR) : 0;
 368                                 done_xlat = 1;
 369                         }
 370
 371                         counter += replace_len;
 372                         if (counter >= MAX_STRING_LEN) {
 373                                 regfree(&preg);
 374                                 DEBUG2("%s: Replacement out of limits for attribute %s with value '%s'", data->name,
 375                                                 data->attribute, attr_vp->vp_strvalue);
 376                                 return ret;
 377                         }
 378                         if (replace_len){
 379                                 memcpy(ptr, replace_STR, replace_len);
 380                                 ptr += replace_len;
 381                                 *ptr = '\0';
 382                         }
 383                 }
 384                 regfree(&preg);
 385                 len = strlen(ptr2) + 1;         /* We add the ending NULL */
 386                 counter += len;
 387                 if (counter >= MAX_STRING_LEN){
 388                         DEBUG2("%s: Replacement out of limits for attribute %s with value '%s'", data->name,
 389                                         data->attribute, attr_vp->vp_strvalue);
 390                         return ret;
 391                 }
 392                 memcpy(ptr, ptr2, len);
 393                 ptr[len] = '\0';
 394
 395                 DEBUG2("%s: Changed value for attribute %s from '%s' to '%s'", data->name,
 396                                 data->attribute, attr_vp->vp_strvalue, new_str);
 397                 if (pairparsevalue(attr_vp, new_str) == NULL) {
 398                         DEBUG2("%s: Could not write value '%s' into attribute %s: %s", data->name, new_str, data->attribute, fr_strerror);
 399                         return ret;
 400                 }
 401
 402 to_do_again:
 403                 ret = RLM_MODULE_OK;
 404
 405                 if (tmp != NULL){
 406                         tmp = attr_vp->next;
 407                         if (tmp != NULL)
 408                                 goto do_again;
 409                 }
 410         }
 411
 412         return ret;
 413 }
 414
 415 static int attr_rewrite_accounting(void *instance, REQUEST *request)
 416 {
 417         return do_attr_rewrite(instance, request);
 418 }
 419
 420 static int attr_rewrite_authorize(void *instance, REQUEST *request)
 421 {
 422         return do_attr_rewrite(instance, request);
 423 }
 424
 425 static int attr_rewrite_authenticate(void *instance, REQUEST *request)
 426 {
 427         return do_attr_rewrite(instance, request);
 428 }
 429
 430 static int attr_rewrite_preacct(void *instance, REQUEST *request)
 431 {
 432         return do_attr_rewrite(instance, request);
 433 }
 434
 435 static int attr_rewrite_checksimul(void *instance, REQUEST *request)
 436 {
 437         return do_attr_rewrite(instance, request);
 438 }
 439
 440 static int attr_rewrite_preproxy(void *instance, REQUEST *request)
 441 {
 442         return do_attr_rewrite(instance, request);
 443 }
 444
 445 static int attr_rewrite_postproxy(void *instance, REQUEST *request)
 446 {
 447         return do_attr_rewrite(instance, request);
 448 }
 449
 450 static int attr_rewrite_postauth(void *instance, REQUEST *request)
 451 {
 452         return do_attr_rewrite(instance, request);
 453 }
 454
 455 static int attr_rewrite_detach(void *instance)
 456 {
 457         free(instance);
 458         return 0;
 459 }
 460
 461 /*
 462  *      The module name should be the only globally exported symbol.
 463  *      That is, everything else should be 'static'.
 464  *
 465  *      If the module needs to temporarily modify it's instantiation
 466  *      data, the type should be changed to RLM_TYPE_THREAD_UNSAFE.
 467  *      The server will then take care of ensuring that the module
 468  *      is single-threaded.
 469  */
 470 module_t rlm_attr_rewrite = {
 471         RLM_MODULE_INIT,
 472         "attr_rewrite",
 473         RLM_TYPE_THREAD_UNSAFE,         /* type */
 474         attr_rewrite_instantiate,               /* instantiation */
 475         attr_rewrite_detach,                    /* detach */
 476         {
 477                 attr_rewrite_authenticate,      /* authentication */
 478                 attr_rewrite_authorize,         /* authorization */
 479                 attr_rewrite_preacct,           /* preaccounting */
 480                 attr_rewrite_accounting,        /* accounting */
 481                 attr_rewrite_checksimul,        /* checksimul */
 482                 attr_rewrite_preproxy,          /* pre-proxy */
 483                 attr_rewrite_postproxy,         /* post-proxy */
 484                 attr_rewrite_postauth           /* post-auth */
 485         },
 486 };