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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  *
  20  * Copyright 2002  The FreeRADIUS server project
  21  * Copyright 2002  Kostas Kalevras <kkalev@noc.ntua.gr>
  22  */
  23
  24 #include "autoconf.h"
  25 #include "libradius.h"
  26
  27 #include <stdio.h>
  28 #include <stdlib.h>
  29 #include <string.h>
  30 #ifdef HAVE_REGEX_H
  31 #       include <regex.h>
  32 #endif
  33
  34 #include "radiusd.h"
  35 #include "modules.h"
  36 #include "conffile.h"
  37
  38 #define RLM_REGEX_INPACKET 0
  39 #define RLM_REGEX_INCONFIG 1
  40 #define RLM_REGEX_INREPLY  2
  41 #define RLM_REGEX_INPROXY 3
  42 #define RLM_REGEX_INPROXYREPLY 4
  43
  44 static const char rcsid[] = "$Id$";
  45
  46 typedef struct rlm_attr_rewrite_t {
  47         char *attribute;        /* The attribute to search for */
  48         int  attr_num;          /* The attribute number */
  49         char *search;           /* The pattern to search for */
  50         int search_len;         /* The length of the search pattern */
  51         char *searchin_str;     /* The VALUE_PAIR list to search in. Can be either packet,reply,proxy,proxy_reply or config */
  52         char searchin;          /* The same as above just coded as a number for speed */
  53         char *replace;          /* The replacement */
  54         int replace_len;        /* The length of the replacement string */
  55         int  append;            /* Switch to control append mode (1,0) */
  56         int  nocase;            /* Ignore case */
  57         int  new_attr;          /* Boolean. Do we create a new attribute or not? */
  58         int  num_matches;       /* Maximum number of matches */
  59         char *name;             /* The module name */
  60 } rlm_attr_rewrite_t;
  61
  62
  63 static CONF_PARSER module_config[] = {
  64   { "attribute", PW_TYPE_STRING_PTR, offsetof(rlm_attr_rewrite_t,attribute), NULL, NULL },
  65   { "searchfor", PW_TYPE_STRING_PTR, offsetof(rlm_attr_rewrite_t,search), NULL, NULL },
  66   { "searchin",  PW_TYPE_STRING_PTR, offsetof(rlm_attr_rewrite_t,searchin_str), NULL, "packet" },
  67   { "replacewith", PW_TYPE_STRING_PTR, offsetof(rlm_attr_rewrite_t,replace), NULL, NULL },
  68   { "append", PW_TYPE_BOOLEAN, offsetof(rlm_attr_rewrite_t,append),NULL, "no" },
  69   { "ignore_case", PW_TYPE_BOOLEAN, offsetof(rlm_attr_rewrite_t,nocase), NULL, "yes" },
  70   { "new_attribute", PW_TYPE_BOOLEAN, offsetof(rlm_attr_rewrite_t,new_attr), NULL, "no" },
  71   { "max_matches", PW_TYPE_INTEGER, offsetof(rlm_attr_rewrite_t,num_matches), NULL, "10" },
  72   { NULL, -1, 0, NULL, NULL }
  73 };
  74
  75
  76 static int attr_rewrite_instantiate(CONF_SECTION *conf, void **instance)
  77 {
  78         rlm_attr_rewrite_t *data;
  79         DICT_ATTR *dattr;
  80         char *instance_name = NULL;
  81
  82         /*
  83          *      Set up a storage area for instance data
  84          */
  85         data = rad_malloc(sizeof(*data));
  86         if (!data) {
  87                 return -1;
  88         }
  89         memset(data, 0, sizeof(*data));
  90
  91         /*
  92          *      If the configuration parameters can't be parsed, then
  93          *      fail.
  94          */
  95         if (cf_section_parse(conf, data, module_config) < 0) {
  96                 free(data);
  97                 return -1;
  98         }
  99
 100         /*
 101          *      Discover the attribute number of the key.
 102          */
 103         if (data->attribute == NULL) {
 104                 radlog(L_ERR, "rlm_attr_rewrite: 'attribute' must be set.");
 105                 return -1;
 106         }
 107         if (data->search == NULL || data->replace == NULL) {
 108                 radlog(L_ERR, "rlm_attr_rewrite: search/replace strings must be set.");
 109                 return -1;
 110         }
 111         data->search_len = strlen(data->search);
 112         data->replace_len = strlen(data->replace);
 113
 114         if (data->replace_len == 0 && data->new_attr){
 115                 radlog(L_ERR, "rlm_attr_rewrite: replace string must not be zero length in order to create new attribute.");
 116                 return -1;
 117         }
 118
 119         if (data->num_matches < 1 || data->num_matches > MAX_STRING_LEN) {
 120                 radlog(L_ERR, "rlm_attr_rewrite: Illegal range for match number.");
 121                 return -1;
 122         }
 123         if (data->searchin_str == NULL) {
 124                 radlog(L_ERR, "rlm_attr_rewrite: Illegal searchin directive given. Assuming packet.");
 125                 data->searchin = RLM_REGEX_INPACKET;
 126         }
 127         else{
 128                 if (strcmp(data->searchin_str, "packet") == 0)
 129                         data->searchin = RLM_REGEX_INPACKET;
 130                 else if (strcmp(data->searchin_str, "config") == 0)
 131                         data->searchin = RLM_REGEX_INCONFIG;
 132                 else if (strcmp(data->searchin_str, "reply") == 0)
 133                         data->searchin = RLM_REGEX_INREPLY;
 134                 else if (strcmp(data->searchin_str, "proxy") == 0)
 135                         data->searchin = RLM_REGEX_INPROXY;
 136                 else if (strcmp(data->searchin_str, "proxy_reply") == 0)
 137                         data->searchin = RLM_REGEX_INPROXYREPLY;
 138                 else {
 139                         radlog(L_ERR, "rlm_attr_rewrite: Illegal searchin directive given. Assuming packet.");
 140                         data->searchin = RLM_REGEX_INPACKET;
 141                 }
 142                 free((char *)data->searchin_str);
 143         }
 144         dattr = dict_attrbyname(data->attribute);
 145         if (dattr == NULL) {
 146                 radlog(L_ERR, "rlm_attr_rewrite: No such attribute %s",
 147                                 data->attribute);
 148                 return -1;
 149         }
 150         data->attr_num = dattr->attr;
 151         /* Add the module instance name */
 152         data->name = NULL;
 153         instance_name = cf_section_name2(conf);
 154         if (instance_name != NULL)
 155                 data->name = strdup(instance_name);
 156
 157
 158         *instance = data;
 159
 160         return 0;
 161 }
 162
 163 static int do_attr_rewrite(void *instance, REQUEST *request)
 164 {
 165         rlm_attr_rewrite_t *data = (rlm_attr_rewrite_t *) instance;
 166         int ret = RLM_MODULE_NOOP;
 167         VALUE_PAIR *attr_vp = NULL;
 168         VALUE_PAIR *tmp = NULL;
 169         regex_t preg;
 170         regmatch_t pmatch[9];
 171         int cflags = 0;
 172         int err = 0;
 173         char done_xlat = 0;
 174         unsigned int len = 0;
 175         char err_msg[MAX_STRING_LEN];
 176         unsigned int i = 0;
 177         unsigned int j = 0;
 178         unsigned int counter = 0;
 179         char new_str[MAX_STRING_LEN];
 180         char *ptr, *ptr2;
 181         char search_STR[MAX_STRING_LEN];
 182         char replace_STR[MAX_STRING_LEN];
 183         int replace_len = 0;
 184
 185         if ((attr_vp = pairfind(request->config_items, PW_REWRITE_RULE)) != NULL){
 186                 if (data->name == NULL || strcmp(data->name,attr_vp->strvalue))
 187                         return RLM_MODULE_NOOP;
 188         }
 189
 190         if (data->new_attr){
 191                 /* new_attribute = yes */
 192                 if (!radius_xlat(replace_STR, sizeof(replace_STR), data->replace, request, NULL)) {
 193                         DEBUG2("rlm_attr_rewrite: xlat on replace string failed.");
 194                         return ret;
 195                 }
 196                 replace_len = strlen(replace_STR);
 197                 attr_vp = pairmake(data->attribute,replace_STR,0);
 198                 if (attr_vp == NULL){
 199                         DEBUG2("rlm_attr_rewrite: Could not add new attribute %s with value '%s'",
 200                                 data->attribute,replace_STR);
 201                         return ret;
 202                 }
 203                 switch(data->searchin){
 204                         case RLM_REGEX_INPACKET:
 205                                 pairadd(&request->packet->vps,attr_vp);
 206                                 break;
 207                         case RLM_REGEX_INCONFIG:
 208                                 pairadd(&request->config_items,attr_vp);
 209                                 break;
 210                         case RLM_REGEX_INREPLY:
 211                                 pairadd(&request->reply->vps,attr_vp);
 212                                 break;
 213                         case RLM_REGEX_INPROXY:
 214                                 if (!request->proxy)
 215                                         return RLM_MODULE_NOOP;
 216                                 pairadd(&request->proxy->vps, attr_vp);
 217                                 break;
 218                         case RLM_REGEX_INPROXYREPLY:
 219                                 if (!request->proxy_reply)
 220                                         return RLM_MODULE_NOOP;
 221                                 pairadd(&request->proxy_reply->vps, attr_vp);
 222                                 break;
 223                         default:
 224                                 radlog(L_ERR, "rlm_attr_rewrite: Illegal value for searchin. Changing to packet.");
 225                                 data->searchin = RLM_REGEX_INPACKET;
 226                                 pairadd(&request->packet->vps,attr_vp);
 227                                 break;
 228                 }
 229                 DEBUG2("rlm_attr_rewrite: Added attribute %s with value '%s'",data->attribute,replace_STR);
 230                 ret = RLM_MODULE_OK;
 231         } else {
 232                 /* new_attribute = no */
 233                 switch (data->searchin) {
 234                         case RLM_REGEX_INPACKET:
 235                                 if (data->attr_num == PW_USER_NAME)
 236                                         attr_vp = request->username;
 237                                 else if (data->attr_num == PW_PASSWORD)
 238                                         attr_vp = request->password;
 239                                 else
 240                                         tmp = request->packet->vps;
 241                                 break;
 242                         case RLM_REGEX_INCONFIG:
 243                                 tmp = request->config_items;
 244                                 break;
 245                         case RLM_REGEX_INREPLY:
 246                                 tmp = request->reply->vps;
 247                                 break;
 248                         case RLM_REGEX_INPROXYREPLY:
 249                                 if (!request->proxy_reply)
 250                                         return RLM_MODULE_NOOP;
 251                                 tmp = request->proxy_reply->vps;
 252                                 break;
 253                         case RLM_REGEX_INPROXY:
 254                                 if (!request->proxy)
 255                                         return RLM_MODULE_NOOP;
 256                                 tmp = request->proxy->vps;
 257                                 break;
 258                         default:
 259                                 radlog(L_ERR, "rlm_attr_rewrite: Illegal value for searchin. Changing to packet.");
 260                                 data->searchin = RLM_REGEX_INPACKET;
 261                                 attr_vp = pairfind(request->packet->vps, data->attr_num);
 262                                 break;
 263                 }
 264 do_again:
 265                 if (tmp != NULL)
 266                         attr_vp = pairfind(tmp, data->attr_num);
 267                 if (attr_vp == NULL) {
 268                         DEBUG2("rlm_attr_rewrite: Could not find value pair for attribute %s",data->attribute);
 269                         return ret;
 270                 }
 271                 if (attr_vp->strvalue == NULL || attr_vp->length == 0){
 272                         DEBUG2("rlm_attr_rewrite: Attribute %s string value NULL or of zero length",data->attribute);
 273                         return ret;
 274                 }
 275                 cflags |= REG_EXTENDED;
 276                 if (data->nocase)
 277                         cflags |= REG_ICASE;
 278
 279                 if (!radius_xlat(search_STR, sizeof(search_STR), data->search, request, NULL) && data->search_len != 0) {
 280                         DEBUG2("rlm_attr_rewrite: xlat on search string failed.");
 281                         return ret;
 282                 }
 283
 284                 if ((err = regcomp(&preg,search_STR,cflags))) {
 285                         regerror(err, &preg, err_msg, MAX_STRING_LEN);
 286                         DEBUG2("rlm_attr_rewrite: regcomp() returned error: %s",err_msg);
 287                         return ret;
 288                 }
 289                 ptr = new_str;
 290                 ptr2 = attr_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("rlm_attr_rewrite: No match found for attribute %s with value '%s'",
 298                                                         data->attribute, attr_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, "rlm_attr_rewrite: match failure for attribute %s with value '%s'",
 307                                                 data->attribute, attr_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("rlm_attr_rewrite: Replacement out of limits for attribute %s with value '%s'",
 320                                                 data->attribute, attr_vp->strvalue);
 321                                 return ret;
 322                         }
 323
 324                         strncpy(ptr, ptr2,len);
 325                         ptr += len;
 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->strvalue)];
 335
 336                                         /*
 337                                          * Stolen from src/main/valuepair.c, paircmp()
 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->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("rlm_attr_rewrite: xlat on replace string failed.");
 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("rlm_attr_rewrite: Replacement out of limits for attribute %s with value '%s'",
 375                                                 data->attribute, attr_vp->strvalue);
 376                                 return ret;
 377                         }
 378                         if (replace_len){
 379                                 strncpy(ptr, replace_STR, replace_len);
 380                                 ptr += replace_len;
 381                         }
 382                 }
 383                 regfree(&preg);
 384                 len = strlen(ptr2) + 1;         /* We add the ending NULL */
 385                 counter += len;
 386                 if (counter >= MAX_STRING_LEN){
 387                         DEBUG2("rlm_attr_rewrite: Replacement out of limits for attribute %s with value '%s'",
 388                                         data->attribute, attr_vp->strvalue);
 389                         return ret;
 390                 }
 391                 strncpy(ptr, ptr2, len);
 392
 393                 DEBUG2("rlm_attr_rewrite: Changed value for attribute %s from '%s' to '%s'",
 394                                 data->attribute, attr_vp->strvalue, new_str);
 395                 if (pairparsevalue(attr_vp, new_str) == NULL) {
 396                         DEBUG2("rlm_attr_rewrite: Could not write value '%s' into attribute %s: %s", new_str, data->attribute, librad_errstr);
 397                         return ret;
 398                 }
 399
 400 to_do_again:
 401                 ret = RLM_MODULE_OK;
 402
 403                 if (tmp != NULL){
 404                         tmp = attr_vp->next;
 405                         if (tmp != NULL)
 406                                 goto do_again;
 407                 }
 408         }
 409
 410         return ret;
 411 }
 412
 413
 414 static int attr_rewrite_accounting(void *instance, REQUEST *request)
 415 {
 416         return do_attr_rewrite(instance, request);
 417 }
 418
 419 static int attr_rewrite_authorize(void *instance, REQUEST *request)
 420 {
 421         return do_attr_rewrite(instance, request);
 422 }
 423 static int attr_rewrite_authenticate(void *instance, REQUEST *request)
 424 {
 425         return do_attr_rewrite(instance, request);
 426 }
 427 static int attr_rewrite_preacct(void *instance, REQUEST *request)
 428 {
 429         return do_attr_rewrite(instance, request);
 430 }
 431 static int attr_rewrite_ismul(void *instance, REQUEST *request)
 432 {
 433         return do_attr_rewrite(instance, request);
 434 }
 435
 436 static int attr_rewrite_preproxy(void *instance, REQUEST *request)
 437 {
 438         return do_attr_rewrite(instance, request);
 439 }
 440
 441 static int attr_rewrite_postproxy(void *instance, REQUEST *request)
 442 {
 443         return do_attr_rewrite(instance, request);
 444 }
 445
 446 static int attr_rewrite_postauth(void *instance, REQUEST *request)
 447 {
 448         return do_attr_rewrite(instance, request);
 449 }
 450
 451 static int attr_rewrite_detach(void *instance)
 452 {
 453         rlm_attr_rewrite_t *data = (rlm_attr_rewrite_t *) instance;
 454
 455         if (data->attribute)
 456                 free(data->attribute);
 457         if (data->search)
 458                 free(data->search);
 459         if (data->replace)
 460                 free(data->replace);
 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         "attr_rewrite",
 479         RLM_TYPE_THREAD_UNSAFE,         /* type */
 480         NULL,                           /* initialization */
 481         attr_rewrite_instantiate,               /* instantiation */
 482         {
 483                 attr_rewrite_authenticate,      /* authentication */
 484                 attr_rewrite_authorize,         /* authorization */
 485                 attr_rewrite_preacct,           /* preaccounting */
 486                 attr_rewrite_accounting,        /* accounting */
 487                 attr_rewrite_ismul,             /* checksimul */
 488                 attr_rewrite_preproxy,          /* pre-proxy */
 489                 attr_rewrite_postproxy,         /* post-proxy */
 490                 attr_rewrite_postauth           /* post-auth */
 491         },
 492         attr_rewrite_detach,                    /* detach */
 493         NULL,                           /* destroy */
 494 };