src/modules/rlm_policy/evaluate.c

   1 /*
   2  * evaluate.c           Evaluate a policy language
   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 2004  Alan DeKok <aland@ox.org>
  21  * Copyright 2006  The FreeRADIUS server project
  22  */
  23
  24 #include <freeradius-devel/ident.h>
  25 RCSID("$Id$")
  26
  27 #include "rlm_policy.h"
  28
  29 #ifdef HAVE_REGEX_H
  30 #include <regex.h>
  31 #endif
  32
  33 #define debug_evaluate if (0) printf
  34
  35 /*
  36  *      Print stuff we've parsed
  37  */
  38 static void policy_print(const policy_item_t *item, int indent)
  39 {
  40         if (!item) {
  41                 if (indent) printf("%*s", indent, " ");
  42                 printf("[NULL]\n");
  43                 return;
  44         }
  45
  46         while (item) {
  47                 switch (item->type) {
  48                 case POLICY_TYPE_BAD:
  49                         if (indent) printf("%*s", indent, " ");
  50                         printf("[BAD STATEMENT]");
  51                         break;
  52
  53                 case POLICY_TYPE_PRINT:
  54                         if (indent) printf("%*s", indent, " ");
  55                         {
  56                                 const policy_print_t *this;
  57
  58                                 this = (const policy_print_t *) item;
  59
  60                                 if (this->rhs_type == POLICY_LEX_BARE_WORD) {
  61                                         printf("print %s\n", this->rhs);
  62                                 } else {
  63                                         printf("print \"%s\"\n", this->rhs);
  64                                 }
  65                         }
  66                         break;
  67
  68                 case POLICY_TYPE_ASSIGNMENT:
  69                         {
  70                                 const policy_assignment_t *assign;
  71
  72                                 assign = (const policy_assignment_t *) item;
  73                                 if (indent) printf("%*s", indent, " ");
  74
  75                                 printf("\t%s %s ", assign->lhs,
  76                                        lrad_int2str(rlm_policy_tokens,
  77                                                     assign->assign, "?"));
  78                                 if (assign->rhs_type == POLICY_LEX_BARE_WORD) {
  79                                         printf("%s\n", assign->rhs);
  80                                 } else {
  81                                         /*
  82                                          *      FIXME: escape "
  83                                          */
  84                                         printf("\"%s\"\n", assign->rhs);
  85                                 }
  86                         }
  87                         break;
  88
  89                 case POLICY_TYPE_CONDITIONAL: /* no indentation here */
  90                         {
  91                                 const policy_condition_t *condition;
  92
  93                                 condition = (const policy_condition_t *) item;
  94
  95                                 printf("(");
  96
  97                                 /*
  98                                  *      Nested conditions.
  99                                  */
 100                                 if (condition->compare == POLICY_LEX_L_BRACKET) {
 101                                         policy_print(condition->child, indent);
 102                                         printf(")");
 103                                         break;
 104                                 }
 105
 106                                 if (condition->compare == POLICY_LEX_L_NOT) {
 107                                         printf("!");
 108                                         policy_print(condition->child, indent);
 109                                         printf(")");
 110                                         break;
 111                                 }
 112
 113                                 if (condition->compare == POLICY_LEX_CMP_TRUE) {
 114                                         printf("%s)", condition->lhs);
 115                                         break;
 116                                 }
 117
 118                                 if (condition->lhs_type == POLICY_LEX_FUNCTION) {
 119                                         printf("%s()", condition->lhs);
 120                                 } else {
 121                                         /*
 122                                          *      FIXME: escape ",
 123                                          *      and move all of this logic
 124                                          *      to a function.
 125                                          */
 126                                         printf("\"%s\"", condition->lhs);
 127                                 }
 128
 129                                 /*
 130                                  *      We always print this condition.
 131                                  */
 132                                 printf(" %s ", lrad_int2str(rlm_policy_tokens,
 133                                                             condition->compare,
 134                                                             "?"));
 135                                 if (condition->rhs_type == POLICY_LEX_BARE_WORD) {
 136                                         printf("%s", condition->rhs);
 137                                 } else {
 138                                         /*
 139                                          *      FIXME: escape ",
 140                                          *      and move all of this logic
 141                                          *      to a function.
 142                                          */
 143                                         printf("\"%s\"", condition->rhs);
 144                                 }
 145                                 printf(")");
 146
 147                                 if ((condition->child_condition != POLICY_LEX_BAD) &&
 148                                     (condition->child_condition != POLICY_LEX_BARE_WORD)) {
 149                                         printf(" %s ", lrad_int2str(rlm_policy_tokens, condition->child_condition, "?"));
 150                                         policy_print(condition->child, indent);
 151                                 }
 152                         }
 153                         break;
 154
 155                 case POLICY_TYPE_IF:
 156                         {
 157                                 const policy_if_t *statement;
 158
 159                                 statement = (const policy_if_t *) item;
 160
 161                                 if (indent) printf("%*s", indent, " ");
 162                                 printf("if ");
 163                                 policy_print(statement->condition, indent);
 164                                 printf(" {\n");
 165                                 policy_print(statement->if_true, indent + 1);
 166                                 if (indent) printf("%*s", indent, " ");
 167                                 if (statement->if_false) {
 168                                         printf("} else ");
 169                                         if (statement->if_false->type == POLICY_TYPE_ASSIGNMENT) {
 170                                                 printf(" { ");
 171                                                 policy_print(statement->if_false, indent + 1);
 172                                                 if (indent) printf("%*s", indent, " ");
 173                                                 printf(" }");
 174                                         } else {
 175                                                 policy_print(statement->if_false, indent + 1);
 176                                         }
 177                                 } else {
 178                                         printf("}\n");
 179                                 }
 180                         }
 181                         break;
 182
 183                 case POLICY_TYPE_ATTRIBUTE_LIST:
 184                         {
 185                                 const policy_attributes_t *this;
 186
 187                                 this = (const policy_attributes_t *) item;
 188
 189                                 if (indent) printf("%*s", indent, " ");
 190                                 printf("%s %s {\n",
 191                                        lrad_int2str(policy_reserved_words,
 192                                                     this->where, "?"),
 193                                        lrad_int2str(rlm_policy_tokens,
 194                                                     this->how, "?"));
 195                                 policy_print(this->attributes, indent + 1);
 196                                 if (indent) printf("%*s", indent, " ");
 197                                 printf("}\n");
 198                         }
 199                         break;
 200
 201                 case POLICY_TYPE_NAMED_POLICY:
 202                         {
 203                                 const policy_named_t *this;
 204
 205                                 this = (const policy_named_t *) item;
 206                                 if (indent) printf("%*s", indent, " ");
 207                                 printf("policy %s {\n", this->name);
 208                                 policy_print(this->policy, indent + 1);
 209                                 if (indent) printf("%*s", indent, " ");
 210                                 printf("}\n");
 211                         }
 212                         break;
 213
 214                 case POLICY_TYPE_CALL:
 215                         {
 216                                 const policy_call_t *this;
 217
 218                                 this = (const policy_call_t *) item;
 219                                 if (indent) printf("%*s", indent, " ");
 220                                 printf("call %s\n", this->name);
 221                         }
 222                         break;
 223
 224                 case POLICY_TYPE_RETURN:
 225                         {
 226                                 const policy_return_t *this;
 227
 228                                 this = (const policy_return_t *) item;
 229                                 if (indent) printf("%*s", indent, " ");
 230                                 printf("return %s\n",
 231                                        lrad_int2str(policy_return_codes,
 232                                                     this->rcode, "???"));
 233                         }
 234                         break;
 235
 236                 case POLICY_TYPE_MODULE:
 237                         {
 238                                 const policy_module_t *this;
 239
 240                                 this = (const policy_module_t *) item;
 241                                 if (indent) printf("%*s", indent, " ");
 242                                 printf("module %s <stuff>\n",
 243                                        lrad_int2str(policy_component_names,
 244                                                     this->component, "???"));
 245                         }
 246                         break;
 247
 248                 default:
 249                         if (indent) printf("%*s", indent, " ");
 250                         printf("[HUH?]\n");
 251                         break;
 252
 253                 }
 254
 255                 item = item->next;
 256         }
 257 }
 258
 259
 260 void rlm_policy_print(const policy_item_t *item)
 261 {
 262         printf("----------------------------------------------------------\n");
 263         policy_print(item, 0);
 264         printf("----------------------------------------------------------\n");
 265 }
 266
 267 /*
 268  *      Internal stack of things to do.  This lets us have function
 269  *      calls...
 270  *
 271  *      Yes, we should learn lex, yacc, etc.
 272  */
 273 #define POLICY_MAX_STACK 16
 274 typedef struct policy_state_t {
 275         rlm_policy_t    *inst;
 276         REQUEST         *request; /* so it's not passed on the C stack */
 277         int             rcode;  /* for functions, etc. */
 278         int             component; /* for calling other modules */
 279         int             depth;
 280         const policy_item_t *stack[POLICY_MAX_STACK];
 281 } policy_state_t;
 282
 283
 284 static int policy_evaluate_name(policy_state_t *state, const char *name);
 285
 286 /*
 287  *      Push an item onto the state.
 288  */
 289 static int policy_stack_push(policy_state_t *state, const policy_item_t *item)
 290 {
 291         rad_assert(state->depth >= 0);
 292
 293         /*
 294          *      Asked to push nothing.  Don't push it.
 295          */
 296         if (!item) return 1;
 297
 298         /*
 299          *      State is full.  Die.
 300          */
 301         if (state->depth >= POLICY_MAX_STACK) {
 302                 return 0;
 303         }
 304
 305         /*
 306          *      Walk back up the stack, looking for previous ocurrances
 307          *      of this name.  If found, we have infinite recursion,
 308          *      which we stop dead in the water!
 309          *
 310          *      This isn't strictly necessary right now, as we look up
 311          *      policies by name when they're first referenced.  This
 312          *      means that ALL references are backwards (to the start
 313          *      of the file), which means that there are no circular
 314          *      references.
 315          */
 316         if (item->type == POLICY_TYPE_NAMED_POLICY) {
 317                 int i;
 318
 319                 for (i = 0; i < state->depth; i++) {
 320                         /*
 321                          *      Check for circular references, by seeing
 322                          *      if the function is already on the stack.
 323                          *
 324                          *      Hmmm... do we want to do this for any type?
 325                          */
 326                         if (state->stack[i] == item) {
 327                                 debug_evaluate("Circular call to policy %s\n",
 328                                                ((const policy_named_t *) item)->name);
 329                                 return 0;
 330                         }
 331                 }
 332         }
 333
 334         debug_evaluate("push %d %p\n", state->depth, item);
 335
 336         state->stack[state->depth] = item;
 337         state->depth++;         /* points to unused entry */
 338
 339         return 1;
 340 }
 341
 342
 343 /*
 344  *      Pop an item from the state.
 345  */
 346 static int policy_stack_pop(policy_state_t *state, const policy_item_t **pitem)
 347 {
 348         rad_assert(pitem != NULL);
 349         rad_assert(state->depth >= 0);
 350
 351  redo:
 352         if (state->depth == 0) {
 353                 *pitem = NULL;
 354                 return 0;
 355         }
 356
 357         *pitem = state->stack[state->depth - 1];
 358
 359         /*
 360          *      Named policies are on the stack for catching recursion.
 361          */
 362         if ((*pitem)->type == POLICY_TYPE_NAMED_POLICY) {
 363                 state->depth--;
 364                 goto redo;
 365         }
 366
 367         /*
 368          *      Process the whole item list.
 369          */
 370         if ((*pitem)->next) {
 371                 state->stack[state->depth - 1] = (*pitem)->next;
 372                 debug_evaluate("pop/push %d %p\n", state->depth - 1, *pitem);
 373         } else {
 374                 state->depth--;         /* points to unused entry */
 375                 debug_evaluate("pop %d %p\n", state->depth, *pitem);
 376         }
 377
 378         return 1;
 379 }
 380
 381
 382 /*
 383  *      Evaluate a print statement
 384  */
 385 static int evaluate_print(policy_state_t *state, const policy_item_t *item)
 386 {
 387         const policy_print_t *this;
 388
 389         this = (const policy_print_t *) item;
 390
 391         if (this->rhs_type == POLICY_LEX_BARE_WORD) {
 392                 printf("%s\n", this->rhs);
 393         } else {
 394                 char buffer[1024];
 395
 396                 radius_xlat(buffer, sizeof(buffer), this->rhs,
 397                             state->request, NULL);
 398                 printf("%s", buffer);
 399         }
 400
 401         /*
 402          *      Doesn't change state->rcode
 403          */
 404
 405         return 1;
 406 }
 407
 408 /*
 409  *      Return a VALUE_PAIR, given an attribute name.
 410  *
 411  *      FIXME: Have it return the N'th one, too, like
 412  *      doc/variables.txt?
 413  *
 414  *      The amount of duplicated code is getting annoying...
 415  */
 416 static VALUE_PAIR *find_vp(REQUEST *request, const char *name)
 417 {
 418         const char *p;
 419         const DICT_ATTR *dattr;
 420         VALUE_PAIR *vps;
 421
 422         p = name;
 423         vps = request->packet->vps;;
 424
 425         /*
 426          *      FIXME: use names from reserved word list?
 427          */
 428         if (strncasecmp(name, "request:", 8) == 0) {
 429                 p += 8;
 430         } else if (strncasecmp(name, "reply:", 6) == 0) {
 431                 p += 6;
 432                 vps = request->reply->vps;
 433         } else if (strncasecmp(name, "proxy-request:", 14) == 0) {
 434                 p += 14;
 435                 if (request->proxy) {
 436                         vps = request->proxy->vps;
 437                 }
 438         } else if (strncasecmp(name, "proxy-reply:", 12) == 0) {
 439                 p += 12;
 440                 if (request->proxy_reply) {
 441                         vps = request->proxy_reply->vps;
 442                 }
 443         } else if (strncasecmp(name, "control:", 8) == 0) {
 444                 p += 8;
 445                 vps = request->config_items;
 446         } /* else it must be a bare attribute name */
 447
 448         if (!vps) {
 449                 return NULL;
 450         }
 451
 452         dattr = dict_attrbyname(p);
 453         if (!dattr) {
 454                 fprintf(stderr, "No such attribute %s\n", p);
 455                 return NULL;    /* no such attribute */
 456         }
 457
 458         return pairfind(vps, dattr->attr);
 459 }
 460
 461
 462 /*
 463  *      Evaluate an assignment
 464  *
 465  *      Not really used much...
 466  */
 467 static int evaluate_assignment(policy_state_t *state, const policy_item_t *item)
 468 {
 469         const policy_assignment_t *this;
 470 #if 0
 471         const DICT_ATTR *dattr;
 472 #endif
 473
 474         this = (const policy_assignment_t *) item;
 475
 476         rad_assert(this->lhs != NULL);
 477         rad_assert(this->rhs != NULL);
 478
 479 #if 0
 480         dattr = dict_attrbyname(this->lhs);
 481         if (!dattr) {
 482                 fprintf(stderr, "HUH?\n");
 483                 return 0;
 484         }
 485 #endif
 486
 487         return 1;
 488 }
 489
 490
 491 /*
 492  *      Evaluate a condition
 493  */
 494 static int evaluate_condition(policy_state_t *state, const policy_item_t *item)
 495 {
 496         int rcode;
 497         const policy_condition_t *this;
 498         VALUE_PAIR *vp = NULL;
 499         const char *data = NULL;
 500         int compare;
 501 #ifdef HAVE_REGEX_H
 502         regex_t reg;
 503 #endif
 504         char buffer[256];
 505         char lhs_buffer[2048];
 506
 507         this = (const policy_condition_t *) item;
 508
 509  redo:
 510         /*
 511          *      FIXME: Don't always do this...
 512          */
 513         if (this->compare != POLICY_LEX_L_BRACKET) {
 514                 if (this->lhs_type == POLICY_LEX_FUNCTION) {
 515                         /*
 516                          *      We can't call evaluate_call here,
 517                          *      because that just pushes stuff onto
 518                          *      the stack, and we want to actually
 519                          *      evaluate all of it...
 520                          */
 521                         rcode = policy_evaluate_name(state, this->lhs);
 522                         data = lrad_int2str(policy_return_codes, rcode, "???");
 523                         strlcpy(lhs_buffer, data, sizeof(lhs_buffer)); /* FIXME: yuck */
 524                 } else if (this->lhs_type == POLICY_LEX_DOUBLE_QUOTED_STRING) {
 525                         if (radius_xlat(lhs_buffer, sizeof(lhs_buffer), this->lhs,
 526                                         state->request, NULL) > 0) {
 527                                 data = lhs_buffer;
 528                         }
 529                 }
 530         }
 531
 532         switch (this->compare) {
 533         case POLICY_LEX_L_BRACKET: /* nested brackets are a special case */
 534                 rcode = evaluate_condition(state, this->child);
 535                 break;
 536
 537         case POLICY_LEX_L_NOT:
 538                 rcode = evaluate_condition(state, this->child);
 539                 rcode = (rcode == FALSE); /* reverse sense of test */
 540                 break;
 541
 542         case POLICY_LEX_CMP_FALSE: /* non-existence */
 543                 if (this->lhs_type == POLICY_LEX_BARE_WORD) {
 544                         vp = find_vp(state->request, this->lhs);
 545                         rcode = (vp == NULL);
 546                 } else {
 547                         rcode = (data == NULL);
 548                 }
 549                 break;
 550
 551         case POLICY_LEX_CMP_TRUE: /* existence */
 552                 if (this->lhs_type == POLICY_LEX_BARE_WORD) {
 553                         vp = find_vp(state->request, this->lhs);
 554                         rcode = (vp != NULL);
 555                 } else {
 556                         rcode = (data != NULL);
 557                 }
 558                 break;
 559
 560         default:                /* process other comparisons */
 561                 if ((this->compare != POLICY_LEX_CMP_EQUALS) &&
 562 #ifdef HAVE_REGEX_H
 563                     (this->compare != POLICY_LEX_RX_EQUALS) &&
 564                     (this->compare != POLICY_LEX_RX_NOT_EQUALS) &&
 565 #endif
 566                     (this->compare != POLICY_LEX_LT) &&
 567                     (this->compare != POLICY_LEX_GT) &&
 568                     (this->compare != POLICY_LEX_LE) &&
 569                     (this->compare != POLICY_LEX_GE) &&
 570                     (this->compare != POLICY_LEX_CMP_NOT_EQUALS)) {
 571                         fprintf(stderr, "%d: bad comparison\n",
 572                                 this->item.lineno);
 573                         return FALSE;
 574                 }
 575
 576                 if (this->lhs_type == POLICY_LEX_BARE_WORD) {
 577                         VALUE_PAIR *myvp;
 578
 579                         vp = find_vp(state->request, this->lhs);
 580
 581                         /*
 582                          *      A op B always returns FALSE if A doesn't
 583                          *      exist.
 584                          */
 585                         if (!vp) return FALSE; /* not in the request */
 586
 587                         /*
 588                          *      FIXME: Move sanity checks to
 589                          *      post-parse code, so we don't do
 590                          *      it on every packet.
 591                          */
 592                         vp_prints_value(buffer, sizeof(buffer), vp, 0);
 593                         myvp = pairmake(vp->name, this->rhs, T_OP_EQ);
 594                         data = buffer;
 595
 596                         /*
 597                          *      FIXME: What to do about comparisons
 598                          *      where vp doesn't exist?  Right now,
 599                          *      "simplepaircmp" returns -1, which is
 600                          *      probably a bad idea.  it should
 601                          *      instead take an operator, a pointer to
 602                          *      the comparison result, and return
 603                          *      "true/false" for "comparions
 604                          *      succeeded/failed", which are different
 605                          *      error codes than "comparison is less
 606                          *      than, equal to, or greater than zero".
 607                          */
 608                         compare = simplepaircmp(state->request,
 609                                                 vp, myvp);
 610                         pairfree(&myvp);
 611
 612                 } else {
 613                         /*
 614                          *      FIXME: Do something for RHS type?
 615                          */
 616                         printf("CMP %s %s\n", lhs_buffer, this->rhs);
 617                         compare = strcmp(lhs_buffer, this->rhs);
 618                 }
 619
 620                 debug_evaluate("CONDITION COMPARE %d\n", compare);
 621
 622                 switch (this->compare) {
 623                 case POLICY_LEX_CMP_EQUALS:
 624                         rcode = (compare == 0);
 625                         break;
 626
 627                 case POLICY_LEX_CMP_NOT_EQUALS:
 628                         rcode = (compare != 0);
 629                         break;
 630
 631                 case POLICY_LEX_LT:
 632                         rcode = (compare < 0);
 633                         break;
 634
 635                 case POLICY_LEX_GT:
 636                         rcode = (compare > 0);
 637                         break;
 638
 639                 case POLICY_LEX_LE:
 640                         rcode =(compare <= 0);
 641                         break;
 642
 643                 case POLICY_LEX_GE:
 644                         rcode = (compare >= 0);
 645                         break;
 646
 647 #ifdef HAVE_REGEX_H
 648                 case POLICY_LEX_RX_EQUALS:
 649                 { /* FIXME: copied from src/main/valuepair.c */
 650                         int i;
 651                         regmatch_t rxmatch[REQUEST_MAX_REGEX + 1];
 652
 653                         /*
 654                          *      Include substring matches.
 655                          */
 656                         if (regcomp(&reg, this->rhs,
 657                                     REG_EXTENDED) != 0) {
 658                                 return FALSE;
 659                         }
 660                         rad_assert(data != NULL);
 661                         rcode = regexec(&reg, data,
 662                                         REQUEST_MAX_REGEX + 1,
 663                                         rxmatch, 0);
 664                         rcode = (rcode == 0);
 665                         regfree(&reg);
 666
 667                         /*
 668                          *      Add %{0}, %{1}, etc.
 669                          */
 670                         for (i = 0; i <= REQUEST_MAX_REGEX; i++) {
 671                                 char *p;
 672                                 char rxbuffer[256];
 673
 674                                 /*
 675                                  *      Didn't match: delete old
 676                                  *      match, if it existed.
 677                                  */
 678                                 if (!rcode ||
 679                                     (rxmatch[i].rm_so == -1)) {
 680                                         p = request_data_get(state->request, state->request,
 681                                                              REQUEST_DATA_REGEX | i);
 682                                         if (p) {
 683                                                 free(p);
 684                                                 continue;
 685                                         }
 686
 687                                         /*
 688                                          *      No previous match
 689                                          *      to delete, stop.
 690                                          */
 691                                         break;
 692                                 }
 693
 694                                 /*
 695                                  *      Copy substring into buffer.
 696                                  */
 697                                 memcpy(rxbuffer,
 698                                        data + rxmatch[i].rm_so,
 699                                        rxmatch[i].rm_eo - rxmatch[i].rm_so);
 700                                 rxbuffer[rxmatch[i].rm_eo - rxmatch[i].rm_so] = '\0';
 701
 702                                 /*
 703                                  *      Copy substring, and add it to
 704                                  *      the request.
 705                                  *
 706                                  *      Note that we don't check
 707                                  *      for out of memory, which is
 708                                  *      the only error we can get...
 709                                  */
 710                                 p = strdup(rxbuffer);
 711                                 request_data_add(state->request,
 712                                                  state->request,
 713                                                  REQUEST_DATA_REGEX | i,
 714                                                  p, free);
 715                         }
 716
 717                 }
 718                 break;
 719
 720                 case POLICY_LEX_RX_NOT_EQUALS:
 721                         regcomp(&reg, this->rhs, REG_EXTENDED|REG_NOSUB);
 722                         rad_assert(data != NULL);
 723                         rcode = regexec(&reg, data,
 724                                         0, NULL, 0);
 725                         rcode = (rcode != 0);
 726                         regfree(&reg);
 727                                 break;
 728 #endif /* HAVE_REGEX_H */
 729                 default:
 730                         rcode = FALSE;
 731                         break;
 732                 } /* switch over comparison operators */
 733                 break;          /* default from first switch over compare */
 734         }
 735
 736         /*
 737          *      No trailing &&, ||
 738          */
 739         switch (this->child_condition) {
 740         default:
 741                 return rcode;
 742
 743         case POLICY_LEX_L_AND:
 744                 if (!rcode) return rcode; /* FALSE && x == FALSE */
 745                 break;
 746
 747         case POLICY_LEX_L_OR:
 748                 if (rcode) return rcode; /* TRUE && x == TRUE */
 749                 break;
 750         }
 751
 752         /*
 753          *      Tail recursion.
 754          */
 755         this = (const policy_condition_t *) this->child;
 756         goto redo;
 757
 758         return 1;               /* should never reach here */
 759 }
 760
 761
 762 /*
 763  *      Evaluate an 'if' statement
 764  */
 765 static int evaluate_if(policy_state_t *state, const policy_item_t *item)
 766 {
 767         int rcode;
 768         const policy_if_t *this;
 769
 770         this = (const policy_if_t *) item;
 771
 772         /*
 773          *      evaluate_condition calls itself recursively.
 774          *      We should probably allocate a new state, instead.
 775          */
 776         rcode = evaluate_condition(state, this->condition);
 777         debug_evaluate("IF condition returned %s\n",
 778                rcode ? "true" : "false");
 779         if (rcode) {
 780                 rcode = policy_stack_push(state, this->if_true);
 781                 if (!rcode) return rcode;
 782         } else if (this->if_false) {
 783                 rcode = policy_stack_push(state, this->if_false);
 784                 if (!rcode) return rcode;
 785         }
 786
 787         /*
 788          *      'if' can fail, if the block it's processing fails.
 789          */
 790         return 1;;
 791 }
 792
 793
 794 /*
 795  *      Make a VALUE_PAIR from a policy_assignment_t*
 796  *
 797  *      The assignment operator has to be '='.
 798  */
 799 static VALUE_PAIR *assign2vp(REQUEST *request,
 800                              const policy_assignment_t *assign)
 801 {
 802         VALUE_PAIR *vp;
 803         LRAD_TOKEN operator = T_OP_EQ;
 804         const char *value = assign->rhs;
 805         char buffer[2048];
 806
 807         if ((assign->rhs_type == POLICY_LEX_DOUBLE_QUOTED_STRING) &&
 808             (strchr(assign->rhs, '%') != NULL)) {
 809                 radius_xlat(buffer, sizeof(buffer), assign->rhs,
 810                             request, NULL);
 811                 value = buffer;
 812         }
 813
 814         /*
 815          *      This is crappy.. fix it.
 816          */
 817         switch (assign->assign) {
 818         case POLICY_LEX_ASSIGN:
 819                 operator = T_OP_EQ;
 820                 break;
 821
 822         case POLICY_LEX_SET_EQUALS:
 823                 operator = T_OP_SET;
 824                 break;
 825
 826         case POLICY_LEX_PLUS_EQUALS:
 827                 operator = T_OP_ADD;
 828                 break;
 829
 830         default:
 831                 fprintf(stderr, "Expected '=' for operator, not '%s' at line %d\n",
 832                         lrad_int2str(rlm_policy_tokens,
 833                                      assign->assign, "?"),
 834                         assign->item.lineno);
 835                 return NULL;
 836         }
 837
 838         vp = pairmake(assign->lhs, value, operator);
 839         if (!vp) {
 840                 fprintf(stderr, "SHIT: %s %s\n", value, librad_errstr);
 841         }
 842
 843         return vp;
 844 }
 845
 846
 847 /*
 848  *      Evaluate a 'packet .= {attrs}' statement
 849  */
 850 static int evaluate_attr_list(policy_state_t *state, const policy_item_t *item)
 851 {
 852         const policy_attributes_t *this;
 853         VALUE_PAIR **vps = NULL;
 854         VALUE_PAIR *vp, *head, **tail;
 855         const policy_item_t *attr;
 856
 857         this = (const policy_attributes_t *) item;
 858
 859         switch (this->where) {
 860         case POLICY_RESERVED_CONTROL:
 861                 vps = &(state->request->config_items);
 862                 break;
 863
 864         case POLICY_RESERVED_REQUEST:
 865                 vps = &(state->request->packet->vps);
 866                 break;
 867
 868         case POLICY_RESERVED_REPLY:
 869                 vps = &(state->request->reply->vps);
 870                 break;
 871
 872         case POLICY_RESERVED_PROXY_REQUEST:
 873                 if (!state->request->proxy) return 0; /* FIXME: print error */
 874                 vps = &(state->request->proxy->vps);
 875                 break;
 876
 877         case POLICY_RESERVED_PROXY_REPLY:
 878                 if (!state->request->proxy_reply) return 0; /* FIXME: print error */
 879                 vps = &(state->request->proxy_reply->vps);
 880                 break;
 881
 882         default:
 883                 return 0;
 884         }
 885
 886         head = NULL;
 887         tail = &head;
 888
 889         for (attr = this->attributes; attr != NULL; attr = attr->next) {
 890                 if (attr->type != POLICY_TYPE_ASSIGNMENT) {
 891                         fprintf(stderr, "bad assignment in attribute list at line %d\n", attr->lineno);
 892                         pairfree(&head);
 893                         return 0;
 894                 }
 895
 896                 vp = assign2vp(state->request, (const policy_assignment_t *) attr);
 897                 if (!vp) {
 898                         fprintf(stderr, "Failed to allocate VP\n");
 899                         pairfree(&head);
 900                         return 0;
 901                 }
 902                 *tail = vp;
 903                 tail = &(vp->next);
 904         }
 905
 906         switch (this->how) {
 907         case POLICY_LEX_SET_EQUALS: /* dangerous: removes all previous things! */
 908                 pairfree(vps);
 909                 *vps = head;
 910                 break;
 911
 912         case POLICY_LEX_ASSIGN: /* 'union' */
 913                 pairmove(vps, &head);
 914                 pairfree(&head);
 915                 break;
 916
 917         case POLICY_LEX_CONCAT_EQUALS:
 918                 pairadd(vps, head);
 919                 break;
 920
 921         default:
 922                 fprintf(stderr, "HUH?\n");
 923                 pairfree(&head);
 924                 return 0;
 925         }
 926
 927         state->rcode = RLM_MODULE_UPDATED; /* we did stuff */
 928
 929         return 1;
 930 }
 931
 932
 933 /*
 934  *      Evaluate a reference call to a module.
 935  */
 936 static int evaluate_call(policy_state_t *state, const policy_item_t *item)
 937 {
 938         int rcode;
 939         const policy_call_t *this;
 940         const policy_named_t *policy;
 941
 942         this = (const policy_call_t *) item;
 943
 944         policy = rlm_policy_find(state->inst->policies, this->name);
 945         if (!policy) return 0;  /* not found... */
 946
 947         DEBUG2("rlm_policy: Evaluating policy %s", this->name);
 948
 949         rad_assert(policy->policy->type != POLICY_TYPE_BAD);
 950         rad_assert(policy->policy->type < POLICY_TYPE_NUM_TYPES);
 951
 952         /*
 953          *      Push the name of the function onto the stack,
 954          *      so that we can catch recursive calls.
 955          *
 956          *      The "pop" function will skip over it when it sees it.
 957          */
 958         rcode = policy_stack_push(state, (const policy_item_t *) policy);
 959         if (!rcode) {
 960                 return rcode;
 961         }
 962
 963         /*
 964          *      Push it onto the stack.  Other code will take care of
 965          *      calling it.
 966          */
 967         rcode = policy_stack_push(state, policy->policy);
 968         if (!rcode) {
 969                 return rcode;
 970         }
 971
 972         return 1;
 973 }
 974
 975
 976 /*
 977  *      Evaluate a return statement
 978  */
 979 static int evaluate_return(policy_state_t *state, const policy_item_t *item)
 980 {
 981         const policy_return_t *this;
 982
 983         this = (const policy_return_t *) item;
 984         state->rcode = this->rcode;
 985
 986         return 1;               /* we succeeded */
 987 }
 988
 989
 990 /*
 991  *      Evaluate a module statement
 992  */
 993 static int evaluate_module(policy_state_t *state, const policy_item_t *item)
 994 {
 995         const policy_module_t *this;
 996
 997         this = (const policy_module_t *) item;
 998
 999         /*
1000          *      Just to be paranoid.  Maybe we want to loosen this
1001          *      restriction in the future?
1002          */
1003         if (this->component != state->component) {
1004                 DEBUG2("rlm_policy: Cannot mix & match components");
1005                 return 0;
1006         }
1007
1008         DEBUG2("rlm_policy: begin nested call");
1009         state->rcode = modcall(this->component, this->mc, state->request);
1010         DEBUG2("rlm_policy: end nested call");
1011
1012         return 1;               /* we succeeded */
1013 }
1014
1015
1016 /*
1017  *      State machine stuff.
1018  */
1019 typedef int (*policy_evaluate_type_t)(policy_state_t *, const policy_item_t *);
1020
1021
1022 /*
1023  *      MUST be kept in sync with policy_type_t
1024  */
1025 static policy_evaluate_type_t evaluate_functions[POLICY_TYPE_NUM_TYPES] = {
1026         NULL,                   /* POLICY_TYPE_BAD */
1027         evaluate_if,
1028         evaluate_condition,
1029         evaluate_assignment,
1030         evaluate_attr_list,
1031         evaluate_print,
1032         NULL,                   /* define a named policy.. */
1033         evaluate_call,
1034         evaluate_return,
1035         evaluate_module
1036 };
1037
1038
1039 /*
1040  *      Evaluate a policy, keyed by name.
1041  */
1042 static int policy_evaluate_name(policy_state_t *state, const char *name)
1043 {
1044         int rcode;
1045         const policy_item_t *this;
1046         policy_named_t mypolicy, *policy;
1047
1048         mypolicy.name = name;
1049         policy = rbtree_finddata(state->inst->policies, &mypolicy);
1050         if (!policy) return RLM_MODULE_FAIL;
1051
1052         DEBUG2("rlm_policy: Evaluating policy %s", name);
1053
1054         rad_assert(policy->item.type != POLICY_TYPE_BAD);
1055         rad_assert(policy->item.type < POLICY_TYPE_NUM_TYPES);
1056
1057         rcode = policy_stack_push(state, policy->policy);
1058         if (!rcode) {
1059                 return RLM_MODULE_FAIL;
1060         }
1061
1062         /*
1063          *      FIXME: Look for magic keywords like "return",
1064          *      where the packet gets accepted/rejected/whatever
1065          */
1066         while (policy_stack_pop(state, &this)) {
1067                 rad_assert(this != NULL);
1068                 rad_assert(this->type != POLICY_TYPE_BAD);
1069                 rad_assert(this->type < POLICY_TYPE_NUM_TYPES);
1070
1071                 debug_evaluate("Evaluating at line %d\n",
1072                                this->lineno);
1073                 rcode = (*evaluate_functions[this->type])(state,
1074                                                           this);
1075                 if (!rcode) {
1076                         return RLM_MODULE_FAIL;
1077                 }
1078         } /* loop until the stack is empty */
1079
1080         return state->rcode;
1081 }
1082
1083
1084 /*
1085  *      Evaluate, which is pretty close to print, but we look at what
1086  *      we're printing.
1087  */
1088 int rlm_policy_evaluate(rlm_policy_t *inst, REQUEST *request, const char *name)
1089 {
1090         int rcode;
1091         policy_state_t *state;
1092
1093         state = rad_malloc(sizeof(*state));
1094         memset(state, 0, sizeof(*state));
1095         state->request = request;
1096         state->inst = inst;
1097         state->rcode = RLM_MODULE_OK;
1098         state->component = lrad_str2int(policy_component_names, name,
1099                                         RLM_COMPONENT_COUNT);
1100
1101         rcode = policy_evaluate_name(state, name);
1102
1103         free(state);
1104
1105         return rcode;           /* evaluated OK. */
1106 }