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/autoconf.h>
  28
  29 #include <stdio.h>
  30 #include <stdlib.h>
  31 #include <string.h>
  32 #ifdef HAVE_REGEX_H
  33 #       include <regex.h>
  34 #endif
  35
  36 #include <freeradius-devel/radiusd.h>
  37 #include <freeradius-devel/modules.h>
  38
  39 #define RLM_REGEX_INPACKET 0
  40 #define RLM_REGEX_INCONFIG 1
  41 #define RLM_REGEX_INREPLY  2
  42 #define RLM_REGEX_INPROXY 3
  43 #define RLM_REGEX_INPROXYREPLY 4
  44
  45 typedef struct rlm_attr_rewrite_t {
  46         char *attribute;        /* The attribute to search for */
  47         int  attr_num;          /* The attribute number */
  48         char *search;           /* The pattern to search for */
  49         int search_len;         /* The length of the search pattern */
  50         char *searchin_str;     /* The VALUE_PAIR list to search in. Can be either packet,reply,proxy,proxy_reply or config */
  51         char searchin;          /* The same as above just coded as a number for speed */
  52         char *replace;          /* The replacement */
  53         int replace_len;        /* The length of the replacement string */
  54         int  append;            /* Switch to control append mode (1,0) */
  55         int  nocase;            /* Ignore case */
  56         int  new_attr;          /* Boolean. Do we create a new attribute or not? */
  57         int  num_matches;       /* Maximum number of matches */
  58         char *name;             /* The module name */
  59 } rlm_attr_rewrite_t;
  60
  61 static const CONF_PARSER module_config[] = {
  62   { "attribute", PW_TYPE_STRING_PTR, offsetof(rlm_attr_rewrite_t,attribute), NULL, NULL },
  63   { "searchfor", PW_TYPE_STRING_PTR, offsetof(rlm_attr_rewrite_t,search), NULL, NULL },
  64   { "searchin",  PW_TYPE_STRING_PTR, offsetof(rlm_attr_rewrite_t,searchin_str), NULL, "packet" },
  65   { "replacewith", PW_TYPE_STRING_PTR, offsetof(rlm_attr_rewrite_t,replace), NULL, NULL },
  66   { "append", PW_TYPE_BOOLEAN, offsetof(rlm_attr_rewrite_t,append),NULL, "no" },
  67   { "ignore_case", PW_TYPE_BOOLEAN, offsetof(rlm_attr_rewrite_t,nocase), NULL, "yes" },
  68   { "new_attribute", PW_TYPE_BOOLEAN, offsetof(rlm_attr_rewrite_t,new_attr), NULL, "no" },
  69   { "max_matches", PW_TYPE_INTEGER, offsetof(rlm_attr_rewrite_t,num_matches), NULL, "10" },
  70   { NULL, -1, 0, NULL, NULL }
  71 };
  72
  73 static int attr_rewrite_instantiate(CONF_SECTION *conf, void **instance)
  74 {
  75         rlm_attr_rewrite_t *data;
  76         DICT_ATTR *dattr;
  77         const char *instance_name = NULL;
  78
  79         /*
  80          *      Set up a storage area for instance data
  81          */
  82         data = rad_malloc(sizeof(*data));
  83         if (!data) {
  84                 return -1;
  85         }
  86         memset(data, 0, sizeof(*data));
  87
  88         /*
  89          *      If the configuration parameters can't be parsed, then
  90          *      fail.
  91          */
  92         if (cf_section_parse(conf, data, module_config) < 0) {
  93                 free(data);
  94                 return -1;
  95         }
  96
  97         /*
  98          *      Discover the attribute number of the key.
  99          */
 100         if (data->attribute == NULL) {
 101                 radlog(L_ERR, "rlm_attr_rewrite: 'attribute' must be set.");
 102                 return -1;
 103         }
 104         if (data->search == NULL || data->replace == NULL) {
 105                 radlog(L_ERR, "rlm_attr_rewrite: search/replace strings must be set.");
 106                 return -1;
 107         }
 108         data->search_len = strlen(data->search);
 109         data->replace_len = strlen(data->replace);
 110
 111         if (data->replace_len == 0 && data->new_attr){
 112                 radlog(L_ERR, "rlm_attr_rewrite: replace string must not be zero length in order to create new attribute.");
 113                 return -1;
 114         }
 115
 116         if (data->num_matches < 1 || data->num_matches > MAX_STRING_LEN) {
 117                 radlog(L_ERR, "rlm_attr_rewrite: Illegal range for match number.");
 118                 return -1;
 119         }
 120         if (data->searchin_str == NULL) {
 121                 radlog(L_ERR, "rlm_attr_rewrite: Illegal searchin directive given. Assuming packet.");
 122                 data->searchin = RLM_REGEX_INPACKET;
 123         }
 124         else{
 125                 if (strcmp(data->searchin_str, "packet") == 0)
 126                         data->searchin = RLM_REGEX_INPACKET;
 127                 else if (strcmp(data->searchin_str, "config") == 0)
 128                         data->searchin = RLM_REGEX_INCONFIG;
 129                 else if (strcmp(data->searchin_str, "reply") == 0)
 130                         data->searchin = RLM_REGEX_INREPLY;
 131                 else if (strcmp(data->searchin_str, "proxy") == 0)
 132                         data->searchin = RLM_REGEX_INPROXY;
 133                 else if (strcmp(data->searchin_str, "proxy_reply") == 0)
 134                         data->searchin = RLM_REGEX_INPROXYREPLY;
 135                 else {
 136                         radlog(L_ERR, "rlm_attr_rewrite: Illegal searchin directive given. Assuming packet.");
 137                         data->searchin = RLM_REGEX_INPACKET;
 138                 }
 139                 free((char *)data->searchin_str);
 140         }
 141         dattr = dict_attrbyname(data->attribute);
 142         if (dattr == NULL) {
 143                 radlog(L_ERR, "rlm_attr_rewrite: No such attribute %s",
 144                                 data->attribute);
 145                 return -1;
 146         }
 147         data->attr_num = dattr->attr;
 148         /* Add the module instance name */
 149         data->name = NULL;
 150         instance_name = cf_section_name2(conf);
 151         if (instance_name != NULL)
 152                 data->name = strdup(instance_name);
 153
 154
 155         *instance = data;
 156
 157         return 0;
 158 }
 159
 160 static int do_attr_rewrite(void *instance, REQUEST *request)
 161 {
 162         rlm_attr_rewrite_t *data = (rlm_attr_rewrite_t *) instance;
 163         int ret = RLM_MODULE_NOOP;
 164         VALUE_PAIR *attr_vp = NULL;
 165         VALUE_PAIR *tmp = NULL;
 166         regex_t preg;
 167         regmatch_t pmatch[9];
 168         int cflags = 0;
 169         int err = 0;
 170         char done_xlat = 0;
 171         unsigned int len = 0;
 172         char err_msg[MAX_STRING_LEN];
 173         unsigned int i = 0;
 174         unsigned int j = 0;
 175         unsigned int counter = 0;
 176         char new_str[MAX_STRING_LEN];
 177         char *ptr, *ptr2;
 178         char search_STR[MAX_STRING_LEN];
 179         char replace_STR[MAX_STRING_LEN];
 180         int replace_len = 0;
 181
 182         if ((attr_vp = pairfind(request->config_items, PW_REWRITE_RULE)) != NULL){
 183                 if (data->name == NULL || strcmp(data->name,attr_vp->vp_strvalue))
 184                         return RLM_MODULE_NOOP;
 185         }
 186
 187         if (data->new_attr){
 188                 /* new_attribute = yes */
 189                 if (!radius_xlat(replace_STR, sizeof(replace_STR), data->replace, request, NULL)) {
 190                         DEBUG2("rlm_attr_rewrite: xlat on replace string failed.");
 191                         return ret;
 192                 }
 193                 replace_len = strlen(replace_STR);
 194                 attr_vp = pairmake(data->attribute,replace_STR,0);
 195                 if (attr_vp == NULL){
 196                         DEBUG2("rlm_attr_rewrite: Could not add new attribute %s with value '%s'",
 197                                 data->attribute,replace_STR);
 198                         return ret;
 199                 }
 200                 switch(data->searchin){
 201                         case RLM_REGEX_INPACKET:
 202                                 pairadd(&request->packet->vps,attr_vp);
 203                                 break;
 204                         case RLM_REGEX_INCONFIG:
 205                                 pairadd(&request->config_items,attr_vp);
 206                                 break;
 207                         case RLM_REGEX_INREPLY:
 208                                 pairadd(&request->reply->vps,attr_vp);
 209                                 break;
 210                         case RLM_REGEX_INPROXY:
 211                                 if (!request->proxy) {
 212                                         pairbasicfree(attr_vp);
 213                                         return RLM_MODULE_NOOP;
 214                                 }
 215                                 pairadd(&request->proxy->vps, attr_vp);
 216                                 break;
 217                         case RLM_REGEX_INPROXYREPLY:
 218                                 if (!request->proxy_reply) {
 219                                         pairbasicfree(attr_vp);
 220                                         return RLM_MODULE_NOOP;
 221                                 }
 222                                 pairadd(&request->proxy_reply->vps, attr_vp);
 223                                 break;
 224                         default:
 225                                 radlog(L_ERR, "rlm_attr_rewrite: Illegal value for searchin. Changing to packet.");
 226                                 data->searchin = RLM_REGEX_INPACKET;
 227                                 pairadd(&request->packet->vps,attr_vp);
 228                                 break;
 229                 }
 230                 DEBUG2("rlm_attr_rewrite: Added attribute %s with value '%s'",data->attribute,replace_STR);
 231                 ret = RLM_MODULE_OK;
 232         } else {
 233                 /* new_attribute = no */
 234                 switch (data->searchin) {
 235                         case RLM_REGEX_INPACKET:
 236                                 if (data->attr_num == PW_USER_NAME)
 237                                         attr_vp = request->username;
 238                                 else if (data->attr_num == PW_USER_PASSWORD)
 239                                         attr_vp = request->password;
 240                                 else
 241                                         tmp = request->packet->vps;
 242                                 break;
 243                         case RLM_REGEX_INCONFIG:
 244                                 tmp = request->config_items;
 245                                 break;
 246                         case RLM_REGEX_INREPLY:
 247                                 tmp = request->reply->vps;
 248                                 break;
 249                         case RLM_REGEX_INPROXYREPLY:
 250                                 if (!request->proxy_reply)
 251                                         return RLM_MODULE_NOOP;
 252                                 tmp = request->proxy_reply->vps;
 253                                 break;
 254                         case RLM_REGEX_INPROXY:
 255                                 if (!request->proxy)
 256                                         return RLM_MODULE_NOOP;
 257                                 tmp = request->proxy->vps;
 258                                 break;
 259                         default:
 260                                 radlog(L_ERR, "rlm_attr_rewrite: Illegal value for searchin. Changing to packet.");
 261                                 data->searchin = RLM_REGEX_INPACKET;
 262                                 attr_vp = pairfind(request->packet->vps, data->attr_num);
 263                                 break;
 264                 }
 265 do_again:
 266                 if (tmp != NULL)
 267                         attr_vp = pairfind(tmp, data->attr_num);
 268                 if (attr_vp == NULL) {
 269                         DEBUG2("rlm_attr_rewrite: Could not find value pair for attribute %s",data->attribute);
 270                         return ret;
 271                 }
 272                 if (attr_vp->vp_strvalue == NULL || attr_vp->length == 0){
 273                         DEBUG2("rlm_attr_rewrite: Attribute %s string value NULL or of zero length",data->attribute);
 274                         return ret;
 275                 }
 276                 cflags |= REG_EXTENDED;
 277                 if (data->nocase)
 278                         cflags |= REG_ICASE;
 279
 280                 if (!radius_xlat(search_STR, sizeof(search_STR), data->search, request, NULL) && data->search_len != 0) {
 281                         DEBUG2("rlm_attr_rewrite: xlat on search string failed.");
 282                         return ret;
 283                 }
 284
 285                 if ((err = regcomp(&preg,search_STR,cflags))) {
 286                         regerror(err, &preg, err_msg, MAX_STRING_LEN);
 287                         DEBUG2("rlm_attr_rewrite: regcomp() returned error: %s",err_msg);
 288                         return ret;
 289                 }
 290
 291                 if ((attr_vp->type == PW_TYPE_IPADDR) &&
 292                     (attr_vp->vp_strvalue[0] == '\0')) {
 293                   inet_ntop(AF_INET, &(attr_vp->lvalue),
 294                             attr_vp->vp_strvalue,
 295                             sizeof(attr_vp->vp_strvalue));
 296                 }
 297
 298                 ptr = new_str;
 299                 ptr2 = attr_vp->vp_strvalue;
 300                 counter = 0;
 301
 302                 for ( i = 0 ;i < (unsigned)data->num_matches; i++) {
 303                         err = regexec(&preg, ptr2, REQUEST_MAX_REGEX, pmatch, 0);
 304                         if (err == REG_NOMATCH) {
 305                                 if (i == 0) {
 306                                         DEBUG2("rlm_attr_rewrite: No match found for attribute %s with value '%s'",
 307                                                         data->attribute, attr_vp->vp_strvalue);
 308                                         regfree(&preg);
 309                                         goto to_do_again;
 310                                 } else
 311                                         break;
 312                         }
 313                         if (err != 0) {
 314                                 regfree(&preg);
 315                                 radlog(L_ERR, "rlm_attr_rewrite: match failure for attribute %s with value '%s'",
 316                                                 data->attribute, attr_vp->vp_strvalue);
 317                                 return ret;
 318                         }
 319                         if (pmatch[0].rm_so == -1)
 320                                 break;
 321                         len = pmatch[0].rm_so;
 322                         if (data->append) {
 323                                 len = len + (pmatch[0].rm_eo - pmatch[0].rm_so);
 324                         }
 325                         counter += len;
 326                         if (counter >= MAX_STRING_LEN) {
 327                                 regfree(&preg);
 328                                 DEBUG2("rlm_attr_rewrite: Replacement out of limits for attribute %s with value '%s'",
 329                                                 data->attribute, attr_vp->vp_strvalue);
 330                                 return ret;
 331                         }
 332
 333                         strlcpy(ptr, ptr2,len);
 334                         ptr += len;
 335                         ptr2 += pmatch[0].rm_eo;
 336
 337                         if (i == 0){
 338                                 /*
 339                                  * We only run on the first match, sorry
 340                                  */
 341                                 for(j = 0; j <= REQUEST_MAX_REGEX; j++){
 342                                         char *p;
 343                                         char buffer[sizeof(attr_vp->vp_strvalue)];
 344
 345                                         /*
 346                                          * Stolen from src/main/valuepair.c, paircompare()
 347                                          */
 348
 349                                         /*
 350                                          * Delete old matches if the corresponding match does not
 351                                          * exist in the current regex
 352                                          */
 353                                         if (pmatch[j].rm_so == -1){
 354                                                 p = request_data_get(request,request,REQUEST_DATA_REGEX | j);
 355                                                 if (p){
 356                                                         free(p);
 357                                                         continue;
 358                                                 }
 359                                                 break;
 360                                         }
 361                                         memcpy(buffer,
 362                                                attr_vp->vp_strvalue + pmatch[j].rm_so,
 363                                                pmatch[j].rm_eo - pmatch[j].rm_so);
 364                                         buffer[pmatch[j].rm_eo - pmatch[j].rm_so] = '\0';
 365                                         p = strdup(buffer);
 366                                         request_data_add(request,request,REQUEST_DATA_REGEX | j,p,free);
 367                                 }
 368                         }
 369
 370                         if (!done_xlat){
 371                                 if (data->replace_len != 0 &&
 372                                 radius_xlat(replace_STR, sizeof(replace_STR), data->replace, request, NULL) == 0) {
 373                                         DEBUG2("rlm_attr_rewrite: xlat on replace string failed.");
 374                                         return ret;
 375                                 }
 376                                 replace_len = (data->replace_len != 0) ? strlen(replace_STR) : 0;
 377                                 done_xlat = 1;
 378                         }
 379
 380                         counter += replace_len;
 381                         if (counter >= MAX_STRING_LEN) {
 382                                 regfree(&preg);
 383                                 DEBUG2("rlm_attr_rewrite: Replacement out of limits for attribute %s with value '%s'",
 384                                                 data->attribute, attr_vp->vp_strvalue);
 385                                 return ret;
 386                         }
 387                         if (replace_len){
 388                                 strlcpy(ptr, replace_STR, replace_len);
 389                                 ptr += replace_len;
 390                         }
 391                 }
 392                 regfree(&preg);
 393                 len = strlen(ptr2) + 1;         /* We add the ending NULL */
 394                 counter += len;
 395                 if (counter >= MAX_STRING_LEN){
 396                         DEBUG2("rlm_attr_rewrite: Replacement out of limits for attribute %s with value '%s'",
 397                                         data->attribute, attr_vp->vp_strvalue);
 398                         return ret;
 399                 }
 400                 strlcpy(ptr, ptr2, len);
 401
 402                 DEBUG2("rlm_attr_rewrite: Changed value for attribute %s from '%s' to '%s'",
 403                                 data->attribute, attr_vp->vp_strvalue, new_str);
 404                 if (pairparsevalue(attr_vp, new_str) == NULL) {
 405                         DEBUG2("rlm_attr_rewrite: Could not write value '%s' into attribute %s: %s", new_str, data->attribute, librad_errstr);
 406                         return ret;
 407                 }
 408
 409 to_do_again:
 410                 ret = RLM_MODULE_OK;
 411
 412                 if (tmp != NULL){
 413                         tmp = attr_vp->next;
 414                         if (tmp != NULL)
 415                                 goto do_again;
 416                 }
 417         }
 418
 419         return ret;
 420 }
 421
 422 static int attr_rewrite_accounting(void *instance, REQUEST *request)
 423 {
 424         return do_attr_rewrite(instance, request);
 425 }
 426
 427 static int attr_rewrite_authorize(void *instance, REQUEST *request)
 428 {
 429         return do_attr_rewrite(instance, request);
 430 }
 431
 432 static int attr_rewrite_authenticate(void *instance, REQUEST *request)
 433 {
 434         return do_attr_rewrite(instance, request);
 435 }
 436
 437 static int attr_rewrite_preacct(void *instance, REQUEST *request)
 438 {
 439         return do_attr_rewrite(instance, request);
 440 }
 441
 442 static int attr_rewrite_checksimul(void *instance, REQUEST *request)
 443 {
 444         return do_attr_rewrite(instance, request);
 445 }
 446
 447 static int attr_rewrite_preproxy(void *instance, REQUEST *request)
 448 {
 449         return do_attr_rewrite(instance, request);
 450 }
 451
 452 static int attr_rewrite_postproxy(void *instance, REQUEST *request)
 453 {
 454         return do_attr_rewrite(instance, request);
 455 }
 456
 457 static int attr_rewrite_postauth(void *instance, REQUEST *request)
 458 {
 459         return do_attr_rewrite(instance, request);
 460 }
 461
 462 static int attr_rewrite_detach(void *instance)
 463 {
 464         rlm_attr_rewrite_t *data = (rlm_attr_rewrite_t *) instance;
 465
 466         if (data->name)
 467                 free(data->name);
 468
 469         free(instance);
 470         return 0;
 471 }
 472
 473 /*
 474  *      The module name should be the only globally exported symbol.
 475  *      That is, everything else should be 'static'.
 476  *
 477  *      If the module needs to temporarily modify it's instantiation
 478  *      data, the type should be changed to RLM_TYPE_THREAD_UNSAFE.
 479  *      The server will then take care of ensuring that the module
 480  *      is single-threaded.
 481  */
 482 module_t rlm_attr_rewrite = {
 483         RLM_MODULE_INIT,
 484         "attr_rewrite",
 485         RLM_TYPE_THREAD_UNSAFE,         /* type */
 486         attr_rewrite_instantiate,               /* instantiation */
 487         attr_rewrite_detach,                    /* detach */
 488         {
 489                 attr_rewrite_authenticate,      /* authentication */
 490                 attr_rewrite_authorize,         /* authorization */
 491                 attr_rewrite_preacct,           /* preaccounting */
 492                 attr_rewrite_accounting,        /* accounting */
 493                 attr_rewrite_checksimul,        /* checksimul */
 494                 attr_rewrite_preproxy,          /* pre-proxy */
 495                 attr_rewrite_postproxy,         /* post-proxy */
 496                 attr_rewrite_postauth           /* post-auth */
 497         },
 498 };