src/main/valuepair.c

   1 /*
   2  * valuepair.c  Valuepair functions that are radiusd-specific
   3  *              and as such do not belong in the library.
   4  *
   5  * Version:     $Id$
   6  *
   7  *   This program is free software; you can redistribute it and/or modify
   8  *   it under the terms of the GNU General Public License as published by
   9  *   the Free Software Foundation; either version 2 of the License, or
  10  *   (at your option) any later version.
  11  *
  12  *   This program is distributed in the hope that it will be useful,
  13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *   GNU General Public License for more details.
  16  *
  17  *   You should have received a copy of the GNU General Public License
  18  *   along with this program; if not, write to the Free Software
  19  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  *
  21  * Copyright 2000  The FreeRADIUS server project
  22  * Copyright 2000  Alan DeKok <aland@ox.org>
  23  */
  24
  25 static const char rcsid[] = "$Id$";
  26
  27 #include "autoconf.h"
  28 #include "libradius.h"
  29
  30 #include <stdio.h>
  31 #include <stdlib.h>
  32 #include <string.h>
  33
  34 #ifdef HAVE_NETINET_IN_H
  35 #       include <netinet/in.h>
  36 #endif
  37
  38 #ifdef HAVE_REGEX_H
  39 #       include <regex.h>
  40
  41 /*
  42  *  For POSIX Regular expressions.
  43  *  (0) Means no extended regular expressions.
  44  *  REG_EXTENDED means use extended regular expressions.
  45  */
  46 #ifndef REG_EXTENDED
  47 #define REG_EXTENDED (0)
  48 #endif
  49
  50 #ifndef REG_NOSUB
  51 #define REG_NOSUB (0)
  52 #endif
  53 #endif
  54
  55 #include "radiusd.h"
  56
  57 struct cmp {
  58         int attribute;
  59         int otherattr;
  60         void *instance; /* module instance */
  61         RAD_COMPARE_FUNC compare;
  62         struct cmp *next;
  63 };
  64 static struct cmp *cmp;
  65
  66
  67 /*
  68  *      Compare 2 attributes. May call the attribute compare function.
  69  */
  70 static int paircompare(REQUEST *req, VALUE_PAIR *request, VALUE_PAIR *check,
  71                        VALUE_PAIR *check_pairs, VALUE_PAIR **reply_pairs)
  72 {
  73         int ret = -2;
  74         struct cmp *c;
  75
  76         /*
  77          *      Sanity check.
  78          */
  79 #if 0
  80         if (request->attribute != check->attribute)
  81                 return -2;
  82 #endif
  83
  84         /*
  85          *      Check for =* and !* and return appropriately
  86          */
  87         if( check->operator == T_OP_CMP_TRUE )
  88                  return 0;  /* always return 0/EQUAL */
  89         if( check->operator == T_OP_CMP_FALSE )
  90                  return 1;  /* always return 1/NOT EQUAL */
  91
  92         /*
  93          *      See if there is a special compare function.
  94          */
  95         for (c = cmp; c; c = c->next)
  96                 if (c->attribute == check->attribute)
  97                         return (c->compare)(c->instance, req, request, check,
  98                                 check_pairs, reply_pairs);
  99
 100         switch(check->type) {
 101 #ifdef ASCEND_BINARY
 102                 /*
 103                  *      Ascend binary attributes can be treated
 104                  *      as opaque objects, I guess...
 105                  */
 106                 case PW_TYPE_ABINARY:
 107 #endif
 108                 case PW_TYPE_OCTETS:
 109                         if (request->length != check->length) {
 110                                 ret = 1; /* NOT equal */
 111                                 break;
 112                         }
 113                         ret = memcmp(request->strvalue, check->strvalue,
 114                                         request->length);
 115                         break;
 116                 case PW_TYPE_STRING:
 117                         if (check->flags.caseless) {
 118                                 ret = strcasecmp((char *)request->strvalue,
 119                                                  (char *)check->strvalue);
 120                         } else {
 121                                 ret = strcmp((char *)request->strvalue,
 122                                              (char *)check->strvalue);
 123                         }
 124                         break;
 125                 case PW_TYPE_INTEGER:
 126                 case PW_TYPE_DATE:
 127                         ret = request->lvalue - check->lvalue;
 128                         break;
 129                 case PW_TYPE_IPADDR:
 130                         ret = ntohl(request->lvalue) - ntohl(check->lvalue);
 131                         break;
 132                 default:
 133                         break;
 134         }
 135
 136         return ret;
 137 }
 138
 139
 140 /*
 141  *      See what attribute we want to compare with.
 142  */
 143 static int otherattr(int attr)
 144 {
 145         struct cmp      *c;
 146
 147         for (c = cmp; c; c = c->next) {
 148                 if (c->attribute == attr)
 149                         return c->otherattr;
 150         }
 151
 152         return attr;
 153 }
 154
 155 /*
 156  *      Register a function as compare function.
 157  *      compare_attr is the attribute in the request we want to
 158  *      compare with. Normally this is the same as "attr".
 159  *      You can set this to:
 160  *
 161  *      -1   the same as "attr"
 162  *      0    always call compare function, not tied to request attribute
 163  *      >0   Attribute to compare with.
 164  *
 165  *      For example, PW_GROUP in a check item needs to be compared
 166  *      with PW_USER_NAME in the incoming request.
 167  */
 168 int paircompare_register(int attr, int compare_attr, RAD_COMPARE_FUNC fun, void *instance)
 169 {
 170         struct cmp      *c;
 171
 172         paircompare_unregister(attr, fun);
 173
 174         c = rad_malloc(sizeof(struct cmp));
 175
 176         if (compare_attr < 0)
 177                 compare_attr = attr;
 178         c->compare = fun;
 179         c->attribute = attr;
 180         c->otherattr = compare_attr;
 181         c->instance = instance;
 182         c->next = cmp;
 183         cmp = c;
 184
 185         return 0;
 186 }
 187
 188 /*
 189  *      Unregister a function.
 190  */
 191 void paircompare_unregister(int attr, RAD_COMPARE_FUNC fun)
 192 {
 193         struct cmp      *c, *last;
 194
 195         last = NULL;
 196         for (c = cmp; c; c = c->next) {
 197                 if (c->attribute == attr && c->compare == fun)
 198                         break;
 199                 last = c;
 200         }
 201
 202         if (c == NULL) return;
 203
 204         if (last != NULL)
 205                 last->next = c->next;
 206         else
 207                 cmp = c->next;
 208
 209         free(c);
 210 }
 211
 212 /*
 213  *      Compare two pair lists except for the password information.
 214  *      For every element in "check" at least one matching copy must
 215  *      be present in "reply".
 216  *
 217  *      Return 0 on match.
 218  */
 219 int paircmp(REQUEST *req, VALUE_PAIR *request, VALUE_PAIR *check, VALUE_PAIR **reply)
 220 {
 221         VALUE_PAIR *check_item;
 222         VALUE_PAIR *auth_item;
 223         int result = 0;
 224         int compare;
 225         int other;
 226 #ifdef HAVE_REGEX_H
 227         regex_t reg;
 228 #endif
 229
 230         for (check_item = check; check_item != NULL; check_item = check_item->next) {
 231                 /*
 232                  *      If the user is setting a configuration value,
 233                  *      then don't bother comparing it to any attributes
 234                  *      sent to us by the user.  It ALWAYS matches.
 235                  */
 236                 if ((check_item->operator == T_OP_SET) ||
 237                     (check_item->operator == T_OP_ADD)) {
 238                         continue;
 239                 }
 240
 241                 switch (check_item->attribute) {
 242                         /*
 243                          *      Attributes we skip during comparison.
 244                          *      These are "server" check items.
 245                          */
 246                         case PW_CRYPT_PASSWORD:
 247                         case PW_AUTH_TYPE:
 248                         case PW_AUTZ_TYPE:
 249                         case PW_ACCT_TYPE:
 250                         case PW_SESSION_TYPE:
 251                         case PW_STRIP_USER_NAME:
 252                                 continue;
 253                                 break;
 254
 255                         /*
 256                          *      IF the password attribute exists, THEN
 257                          *      we can do comparisons against it.  If not,
 258                          *      then the request did NOT contain a
 259                          *      User-Password attribute, so we CANNOT do
 260                          *      comparisons against it.
 261                          *
 262                          *      This hack makes CHAP-Password work..
 263                          */
 264                         case PW_PASSWORD:
 265                                 if (pairfind(request, PW_PASSWORD) == NULL) {
 266                                         continue;
 267                                 }
 268                                 break;
 269                 }
 270
 271                 /*
 272                  *      See if this item is present in the request.
 273                  */
 274                 other = otherattr(check_item->attribute);
 275
 276                 auth_item = request;
 277         try_again:
 278                 for (; auth_item != NULL; auth_item = auth_item->next) {
 279                         if (auth_item->attribute == other || other == 0)
 280                                 break;
 281                 }
 282
 283                 /*
 284                  *      Not found, it's not a match.
 285                  */
 286                 if (auth_item == NULL) {
 287                         /*
 288                          *      Didn't find it.  If we were *trying*
 289                          *      to not find it, then we succeeded.
 290                          */
 291                         if (check_item->operator == T_OP_CMP_FALSE)
 292                                 return 0;
 293                         else
 294                                 return -1;
 295                 }
 296
 297                 /*
 298                  *      Else we found it, but we were trying to not
 299                  *      find it, so we failed.
 300                  */
 301                 if (check_item->operator == T_OP_CMP_FALSE)
 302                         return -1;
 303
 304
 305                 /*
 306                  *      We've got to xlat the string before doing
 307                  *      the comparison.
 308                  */
 309                 if (check_item->flags.do_xlat) {
 310                         int rcode;
 311                         char buffer[sizeof(check_item->strvalue)];
 312
 313                         check_item->flags.do_xlat = 0;
 314                         rcode = radius_xlat(buffer, sizeof(buffer),
 315                                             check_item->strvalue,
 316                                             req, NULL);
 317
 318                         /*
 319                          *      Parse the string into a new value.
 320                          */
 321                         pairparsevalue(check_item, buffer);
 322                 }
 323
 324                 /*
 325                  *      OK it is present now compare them.
 326                  */
 327                 compare = paircompare(req, auth_item, check_item, check, reply);
 328
 329                 switch (check_item->operator) {
 330                         case T_OP_EQ:
 331                         default:
 332                                 radlog(L_INFO,  "Invalid operator for item %s: "
 333                                                 "reverting to '=='", check_item->name);
 334                                 /*FALLTHRU*/
 335                         case T_OP_CMP_TRUE:    /* compare always == 0 */
 336                         case T_OP_CMP_FALSE:   /* compare always == 1 */
 337                         case T_OP_CMP_EQ:
 338                                 if (compare != 0) result = -1;
 339                                 break;
 340
 341                         case T_OP_NE:
 342                                 if (compare == 0) result = -1;
 343                                 break;
 344
 345                         case T_OP_LT:
 346                                 if (compare >= 0) result = -1;
 347                                 break;
 348
 349                         case T_OP_GT:
 350                                 if (compare <= 0) result = -1;
 351                                 break;
 352
 353                         case T_OP_LE:
 354                                 if (compare > 0) result = -1;
 355                                 break;
 356
 357                         case T_OP_GE:
 358                                 if (compare < 0) result = -1;
 359                                 break;
 360
 361 #ifdef HAVE_REGEX_H
 362                         case T_OP_REG_EQ:
 363                         {
 364                                 int i;
 365                                 regmatch_t rxmatch[9];
 366
 367                                 /*
 368                                  *      Include substring matches.
 369                                  */
 370                                 regcomp(&reg, (char *)check_item->strvalue,
 371                                         REG_EXTENDED);
 372                                 compare = regexec(&reg,
 373                                                   (char *)auth_item->strvalue,
 374                                                   16, rxmatch, 0);
 375                                 regfree(&reg);
 376
 377                                 /*
 378                                  *      Add %{0}, %{1}, etc.
 379                                  */
 380                                 for (i = 0; i <= 8; i++) {
 381                                         char *p;
 382                                         char buffer[sizeof(check_item->strvalue)];
 383
 384                                         /*
 385                                          *      Didn't match: delete old
 386                                          *      match, if it existed.
 387                                          */
 388                                         if ((compare != 0) ||
 389                                             (rxmatch[i].rm_so == -1)) {
 390                                                 p = request_data_get(req, req,
 391                                                                      REQUEST_DATA_REGEX | i);
 392                                                 if (p) {
 393                                                         free(p);
 394                                                         continue;
 395                                                 }
 396
 397                                                 /*
 398                                                  *      No previous match
 399                                                  *      to delete, stop.
 400                                                  */
 401                                                 break;
 402                                         }
 403
 404                                         /*
 405                                          *      Copy substring into buffer.
 406                                          */
 407                                         memcpy(buffer,
 408                                                auth_item->strvalue + rxmatch[i].rm_so,
 409                                                rxmatch[i].rm_eo);
 410                                         buffer[rxmatch[i].rm_eo] = '\0';
 411
 412                                         /*
 413                                          *      Copy substring, and add it to
 414                                          *      the request.
 415                                          *
 416                                          *      Note that we don't check
 417                                          *      for out of memory, which is
 418                                          *      the only error we can get...
 419                                          */
 420                                         p = strdup(buffer);
 421                                         request_data_add(req,
 422                                                          req,
 423                                                          REQUEST_DATA_REGEX | i,
 424                                                          p, free);
 425                                 }
 426                         }
 427                                 if (compare != 0) result = -1;
 428                                 break;
 429
 430                         case T_OP_REG_NE:
 431                                 regcomp(&reg, (char *)check_item->strvalue, REG_EXTENDED|REG_NOSUB);
 432                                 compare = regexec(&reg, (char *)auth_item->strvalue,
 433                                                 0, NULL, 0);
 434                                 regfree(&reg);
 435                                 if (compare == 0) result = -1;
 436                                 break;
 437 #endif
 438
 439                 } /* switch over the operator of the check item */
 440
 441                 /*
 442                  *      This attribute didn't match, but maybe there's
 443                  *      another of the same attribute, which DOES match.
 444                  */
 445                 if (result != 0) {
 446                         auth_item = auth_item->next;
 447                         result = 0;
 448                         goto try_again;
 449                 }
 450
 451         } /* for every entry in the check item list */
 452
 453         return 0;               /* it matched */
 454 }
 455
 456 /*
 457  *      Compare two attributes simply.  Calls paircompare.
 458  */
 459
 460 int simplepaircmp(REQUEST *req, VALUE_PAIR *first, VALUE_PAIR *second)
 461 {
 462         return paircompare( req, first, second, NULL, NULL );
 463 }
 464
 465
 466 /*
 467  *      Compare a Connect-Info and a Connect-Rate
 468  */
 469 static int connectcmp(void *instance,
 470                       REQUEST *req UNUSED,
 471                       VALUE_PAIR *request,
 472                       VALUE_PAIR *check,
 473                       VALUE_PAIR *check_pairs,
 474                       VALUE_PAIR **reply_pairs)
 475 {
 476         int rate;
 477
 478         instance = instance;
 479         check_pairs = check_pairs; /* shut the compiler up */
 480         reply_pairs = reply_pairs;
 481
 482         rate = atoi((char *)request->strvalue);
 483         return rate - check->lvalue;
 484 }
 485
 486
 487 /*
 488  *      Compare a portno with a range.
 489  */
 490 static int portcmp(void *instance,
 491                    REQUEST *req UNUSED, VALUE_PAIR *request, VALUE_PAIR *check,
 492         VALUE_PAIR *check_pairs, VALUE_PAIR **reply_pairs)
 493 {
 494         char buf[MAX_STRING_LEN];
 495         char *s, *p;
 496         uint32_t lo, hi;
 497         uint32_t port = request->lvalue;
 498
 499         instance = instance;
 500         check_pairs = check_pairs; /* shut the compiler up */
 501         reply_pairs = reply_pairs;
 502
 503         if ((strchr((char *)check->strvalue, ',') == NULL) &&
 504                         (strchr((char *)check->strvalue, '-') == NULL)) {
 505                 return (request->lvalue - check->lvalue);
 506         }
 507
 508         /* Same size */
 509         strcpy(buf, (char *)check->strvalue);
 510         s = strtok(buf, ",");
 511
 512         while (s != NULL) {
 513                 if ((p = strchr(s, '-')) != NULL)
 514                         p++;
 515                 else
 516                         p = s;
 517                 lo = strtoul(s, NULL, 10);
 518                 hi = strtoul(p, NULL, 10);
 519                 if (lo <= port && port <= hi) {
 520                         return 0;
 521                 }
 522                 s = strtok(NULL, ",");
 523         }
 524
 525         return -1;
 526 }
 527
 528 /*
 529  *      Compare prefix/suffix.
 530  *
 531  *      If they compare:
 532  *      - if PW_STRIP_USER_NAME is present in check_pairs,
 533  *        strip the username of prefix/suffix.
 534  *      - if PW_STRIP_USER_NAME is not present in check_pairs,
 535  *        add a PW_STRIPPED_USER_NAME to the request.
 536  */
 537 static int presufcmp(void *instance,
 538                      REQUEST *req UNUSED,
 539                      VALUE_PAIR *request, VALUE_PAIR *check,
 540         VALUE_PAIR *check_pairs, VALUE_PAIR **reply_pairs)
 541 {
 542         VALUE_PAIR *vp;
 543         char *name = (char *)request->strvalue;
 544         char rest[MAX_STRING_LEN];
 545         int len, namelen;
 546         int ret = -1;
 547
 548         instance = instance;
 549         reply_pairs = reply_pairs; /* shut the compiler up */
 550
 551 #if 0 /* DEBUG */
 552         printf("Comparing %s and %s, check->attr is %d\n",
 553                 name, check->strvalue, check->attribute);
 554 #endif
 555
 556         len = strlen((char *)check->strvalue);
 557         switch (check->attribute) {
 558                 case PW_PREFIX:
 559                         ret = strncmp(name, (char *)check->strvalue, len);
 560                         if (ret == 0 && rest)
 561                                 strcpy(rest, name + len);
 562                         break;
 563                 case PW_SUFFIX:
 564                         namelen = strlen(name);
 565                         if (namelen < len)
 566                                 break;
 567                         ret = strcmp(name + namelen - len,
 568                                         (char *)check->strvalue);
 569                         if (ret == 0 && rest) {
 570                                 strNcpy(rest, name, namelen - len + 1);
 571                         }
 572                         break;
 573         }
 574         if (ret != 0)
 575                 return ret;
 576
 577         if (pairfind(check_pairs, PW_STRIP_USER_NAME)) {
 578                 /*
 579                  *      I don't think we want to update the User-Name
 580                  *      attribute in place... - atd
 581                  */
 582                 strcpy((char *)request->strvalue, rest);
 583                 request->length = strlen(rest);
 584         } else {
 585                 if ((vp = pairfind(check_pairs, PW_STRIPPED_USER_NAME)) != NULL){
 586                         strcpy((char *)vp->strvalue, rest);
 587                         vp->length = strlen(rest);
 588                 } else if ((vp = paircreate(PW_STRIPPED_USER_NAME,
 589                                 PW_TYPE_STRING)) != NULL) {
 590                         strcpy((char *)vp->strvalue, rest);
 591                         vp->length = strlen(rest);
 592                         pairadd(&request, vp);
 593                 } /* else no memory! Die, die!: FIXME!! */
 594         }
 595
 596         return ret;
 597 }
 598
 599
 600 /*
 601  *      Compare the current time to a range.
 602  */
 603 static int timecmp(void *instance,
 604                    REQUEST *req,
 605                    VALUE_PAIR *request, VALUE_PAIR *check,
 606         VALUE_PAIR *check_pairs, VALUE_PAIR **reply_pairs)
 607 {
 608         instance = instance;
 609         request = request;      /* shut the compiler up */
 610         check_pairs = check_pairs;
 611         reply_pairs = reply_pairs;
 612
 613         /*
 614          *      If there's a request, use that timestamp.
 615          */
 616         if (timestr_match((char *)check->strvalue,
 617                           req ? req->timestamp : time(NULL)) >= 0) {
 618                 return 0;
 619         }
 620         return -1;
 621 }
 622
 623 /*
 624  *      Matches if there is NO SUCH ATTRIBUTE as the one named
 625  *      in check->strvalue.  If there IS such an attribute, it
 626  *      doesn't match.
 627  *
 628  *      This is ugly, and definitely non-optimal.  We should be
 629  *      doing the lookup only ONCE, and storing the result
 630  *      in check->lvalue...
 631  */
 632 static int attrcmp(void *instance,
 633                    REQUEST *req UNUSED,
 634                    VALUE_PAIR *request, VALUE_PAIR *check,
 635                    VALUE_PAIR *check_pairs, VALUE_PAIR **reply_pairs)
 636 {
 637         VALUE_PAIR *pair;
 638         DICT_ATTR  *dict;
 639         int attr;
 640
 641         instance = instance;
 642         check_pairs = check_pairs; /* shut the compiler up */
 643         reply_pairs = reply_pairs;
 644
 645         if (check->lvalue == 0) {
 646                 dict = dict_attrbyname((char *)check->strvalue);
 647                 if (dict == NULL) {
 648                         return -1;
 649                 }
 650                 attr = dict->attr;
 651         } else {
 652                 attr = check->lvalue;
 653         }
 654
 655         /*
 656          *      If there's no such attribute, then return MATCH,
 657          *      else FAILURE.
 658          */
 659         pair = pairfind(request, attr);
 660         if (pair == NULL) {
 661                 return 0;
 662         }
 663
 664         return -1;
 665 }
 666
 667 /*
 668  *      Compare the expiration date.
 669  */
 670 static int expirecmp(void *instance, REQUEST *req UNUSED,
 671                      VALUE_PAIR *request, VALUE_PAIR *check,
 672                      VALUE_PAIR *check_pairs, VALUE_PAIR **reply_pairs)
 673 {
 674         time_t now;
 675
 676         instance = instance;
 677         request = request;      /* shut the compiler up */
 678         check_pairs = check_pairs;
 679         reply_pairs = reply_pairs;
 680
 681         /*
 682          *  FIXME!  This should be request->timestamp!
 683          */
 684         now = time(NULL);
 685
 686         if (now <= (signed)check->lvalue) {
 687                 return 0;
 688         }
 689
 690         return +1;
 691 }
 692
 693 /*
 694  *      Compare the request packet type.
 695  */
 696 static int packetcmp(void *instance UNUSED, REQUEST *req,
 697                      VALUE_PAIR *request UNUSED,
 698                      VALUE_PAIR *check,
 699                      VALUE_PAIR *check_pairs UNUSED,
 700                      VALUE_PAIR **reply_pairs UNUSED)
 701 {
 702         if (req->packet->code == check->lvalue) {
 703                 return 0;
 704         }
 705
 706         return 1;
 707 }
 708
 709 /*
 710  *      Compare the response packet type.
 711  */
 712 static int responsecmp(void *instance UNUSED,
 713                        REQUEST *req,
 714                        VALUE_PAIR *request UNUSED,
 715                        VALUE_PAIR *check,
 716                        VALUE_PAIR *check_pairs UNUSED,
 717                        VALUE_PAIR **reply_pairs UNUSED)
 718 {
 719         if (req->reply->code == check->lvalue) {
 720                 return 0;
 721         }
 722
 723         return 1;
 724 }
 725
 726 /*
 727  *      Register server-builtin special attributes.
 728  */
 729 void pair_builtincompare_init(void)
 730 {
 731         paircompare_register(PW_NAS_PORT, -1, portcmp, NULL);
 732         paircompare_register(PW_PREFIX, PW_USER_NAME, presufcmp, NULL);
 733         paircompare_register(PW_SUFFIX, PW_USER_NAME, presufcmp, NULL);
 734         paircompare_register(PW_CONNECT_RATE, PW_CONNECT_INFO, connectcmp, NULL);
 735         paircompare_register(PW_CURRENT_TIME, 0, timecmp, NULL);
 736         paircompare_register(PW_NO_SUCH_ATTRIBUTE, 0, attrcmp, NULL);
 737         paircompare_register(PW_EXPIRATION, 0, expirecmp, NULL);
 738         paircompare_register(PW_PACKET_TYPE, 0, packetcmp, NULL);
 739         paircompare_register(PW_RESPONSE_PACKET_TYPE, 0, responsecmp, NULL);
 740 }
 741
 742 /*
 743  *      Move pairs, replacing/over-writing them, and doing xlat.
 744  */
 745 /*
 746  *      Move attributes from one list to the other
 747  *      if not already present.
 748  */
 749 void pairxlatmove(REQUEST *req, VALUE_PAIR **to, VALUE_PAIR **from)
 750 {
 751         VALUE_PAIR **tailto, *i, *j, *next;
 752         VALUE_PAIR *tailfrom = NULL;
 753         VALUE_PAIR *found;
 754
 755         /*
 756          *      Point "tailto" to the end of the "to" list.
 757          */
 758         tailto = to;
 759         for(i = *to; i; i = i->next) {
 760                 tailto = &i->next;
 761         }
 762
 763         /*
 764          *      Loop over the "from" list.
 765          */
 766         for(i = *from; i; i = next) {
 767                 next = i->next;
 768
 769                 /*
 770                  *      Don't move 'fallthrough' over.
 771                  */
 772                 if (i->attribute == PW_FALL_THROUGH) {
 773                         continue;
 774                 }
 775
 776                 /*
 777                  *      We've got to xlat the string before moving
 778                  *      it over.
 779                  */
 780                 if (i->flags.do_xlat) {
 781                         int rcode;
 782                         char buffer[sizeof(i->strvalue)];
 783
 784                         i->flags.do_xlat = 0;
 785                         rcode = radius_xlat(buffer, sizeof(buffer),
 786                                             i->strvalue,
 787                                             req, NULL);
 788
 789                         /*
 790                          *      Parse the string into a new value.
 791                          */
 792                         pairparsevalue(i, buffer);
 793                 }
 794
 795                 found = pairfind(*to, i->attribute);
 796                 switch (i->operator) {
 797
 798                         /*
 799                          *  If a similar attribute is found,
 800                          *  delete it.
 801                          */
 802                 case T_OP_SUB:          /* -= */
 803                         if (found) {
 804                                 if (!i->strvalue[0] ||
 805                                     (strcmp((char *)found->strvalue,
 806                                             (char *)i->strvalue) == 0)){
 807                                         pairdelete(to, found->attribute);
 808
 809                                         /*
 810                                          *      'tailto' may have been
 811                                          *      deleted...
 812                                          */
 813                                         tailto = to;
 814                                         for(j = *to; j; j = j->next) {
 815                                                 tailto = &j->next;
 816                                         }
 817                                 }
 818                         }
 819                         tailfrom = i;
 820                         continue;
 821                         break;
 822
 823                         /*
 824                          *  Add it, if it's not already there.
 825                          */
 826                 case T_OP_EQ:           /* = */
 827                         if (found) {
 828                                 tailfrom = i;
 829                                 continue; /* with the loop */
 830                         }
 831                         break;
 832
 833                         /*
 834                          *  If a similar attribute is found,
 835                          *  replace it with the new one.  Otherwise,
 836                          *  add the new one to the list.
 837                          */
 838                 case T_OP_SET:          /* := */
 839                         if (found) {
 840                                 VALUE_PAIR *vp;
 841
 842                                 vp = found->next;
 843                                 memcpy(found, i, sizeof(*found));
 844                                 found->next = vp;
 845                                 continue;
 846                         }
 847                         break;
 848
 849                         /*
 850                          *  FIXME: Add support for <=, >=, <, >
 851                          *
 852                          *  which will mean (for integers)
 853                          *  'make the attribute the smaller, etc'
 854                          */
 855
 856                         /*
 857                          *  Add the new element to the list, even
 858                          *  if similar ones already exist.
 859                          */
 860                 default:
 861                 case T_OP_ADD:          /* += */
 862                         break;
 863                 }
 864
 865                 if (tailfrom)
 866                         tailfrom->next = next;
 867                 else
 868                         *from = next;
 869
 870                 /*
 871                  *      If ALL of the 'to' attributes have been deleted,
 872                  *      then ensure that the 'tail' is updated to point
 873                  *      to the head.
 874                  */
 875                 if (!*to) {
 876                         tailto = to;
 877                 }
 878                 *tailto = i;
 879                 if (i) {
 880                         i->next = NULL;
 881                         tailto = &i->next;
 882                 }
 883         } /* loop over the 'from' list */
 884 }