filter.c 18.3 KB
Newer Older
1 2 3 4 5 6
/*
 *	Filters: utility functions
 *
 *	Copyright 1998 Pavel Machek <pavel@ucw.cz>
 *
 *	Can be freely distributed and used under the terms of the GNU GPL.
7
 *
8 9
 */

10
#define LOCAL_DEBUG
11

12 13 14 15
#include "nest/bird.h"
#include "lib/lists.h"
#include "lib/resource.h"
#include "lib/socket.h"
16
#include "lib/string.h"
17
#include "lib/unaligned.h"
18 19 20
#include "nest/route.h"
#include "nest/protocol.h"
#include "nest/iface.h"
21
#include "nest/attrs.h"
22 23 24
#include "conf/conf.h"
#include "filter/filter.h"

25 26
#define P(a,b) ((a<<8) | b)

Pavel Machek's avatar
Pavel Machek committed
27
struct f_inst *startup_func = NULL, *test1_func, *test2_func;
28

29 30
#define CMP_ERROR 999

Pavel Machek's avatar
Pavel Machek committed
31
static int
32 33 34 35 36 37 38 39 40 41
pm_path_compare(struct f_path_mask *m1, struct f_path_mask *m2)
{
  while (1) {
    if ((!m1) || (!m2))
      return !((!m1) && (!m2));
    m1 = m1->next;
    m2 = m2->next;
  }
}

42 43 44 45
/* Compare two values, returns -1, 0, 1 compared, ERROR 999 */
int
val_compare(struct f_val v1, struct f_val v2)
{
Pavel Machek's avatar
Pavel Machek committed
46 47 48 49 50 51 52
  if ((v1.type == T_VOID) && (v2.type == T_VOID))
    return 0;
  if (v1.type == T_VOID)	/* Hack for else */
    return -1;
  if (v2.type == T_VOID)
    return 1;

53 54
  if (v1.type != v2.type) {
    debug( "Types do not match in val_compare\n" );
55
    return CMP_ERROR;
56
  }
57
  switch (v1.type) {
58
  case T_ENUM:
59
  case T_INT: 
60
  case T_PAIR:
61 62 63
    if (v1.val.i == v2.val.i) return 0;
    if (v1.val.i < v2.val.i) return -1;
    return 1;
64
  case T_IP:
65 66
  case T_PREFIX:
    return ipa_compare(v1.val.px.ip, v2.val.px.ip);
67 68
  case T_PATH_MASK:
    return pm_path_compare(v1.val.path_mask, v2.val.path_mask);
69
  default:
70
    debug( "Compare of unkown entities: %x\n", v1.type );
71
    return CMP_ERROR;
72 73 74
  }
}

75
int
76 77
val_simple_in_range(struct f_val v1, struct f_val v2)
{
78
  if ((v1.type == T_PATH) && (v2.type == T_PATH_MASK))
Pavel Machek's avatar
Pavel Machek committed
79
    return as_path_match(v1.val.ad, v2.val.path_mask);
80 81
  if ((v1.type == T_PAIR) && (v2.type == T_CLIST))
    return int_set_contains(v2.val.ad, v1.val.i);
82

83 84 85 86 87 88 89 90 91 92
  if ((v1.type == T_IP) && (v2.type == T_PREFIX))
    return !(ipa_compare(ipa_and(v2.val.px.ip, ipa_mkmask(v2.val.px.len)), ipa_and(v1.val.px.ip, ipa_mkmask(v2.val.px.len))));

  if ((v1.type == T_PREFIX) && (v2.type == T_PREFIX)) {
    ip_addr mask;
    if (v1.val.px.len & (LEN_PLUS | LEN_MINUS | LEN_RANGE))
      return CMP_ERROR;
    mask = ipa_mkmask( v2.val.px.len & LEN_MASK );
    if (ipa_compare(ipa_and(v2.val.px.ip, mask), ipa_and(v1.val.px.ip, mask)))
      return 0;
93

94 95 96 97 98 99 100 101 102 103 104 105
    if ((v2.val.px.len & LEN_MINUS) && (v1.val.px.len <= (v2.val.px.len & LEN_MASK)))
      return 0;
    if ((v2.val.px.len & LEN_PLUS) && (v1.val.px.len < (v2.val.px.len & LEN_MASK)))
      return 0;
    if ((v2.val.px.len & LEN_RANGE) && ((v1.val.px.len < (0xff & (v2.val.px.len >> 16)))
					|| (v1.val.px.len > (0xff & (v2.val.px.len >> 8)))))
      return 0;
    return 1;    
  }
  return CMP_ERROR;
}

106 107 108
int
val_in_range(struct f_val v1, struct f_val v2)
{
109 110 111 112 113 114 115
  int res;

  res = val_simple_in_range(v1, v2);

  if (res != CMP_ERROR)
    return res;

Pavel Machek's avatar
Pavel Machek committed
116
  if (((v1.type == T_INT) || ((v1.type == T_IP) || (v1.type == T_PREFIX)) && (v2.type == T_SET))) {
117 118 119 120 121 122
    struct f_tree *n;
    n = find_tree(v2.val.t, v1);
    if (!n)
      return 0;
    return !! (val_simple_in_range(v1, n->from));	/* We turn CMP_ERROR into compared ok, and that's fine */
  }
123 124 125
  return CMP_ERROR;
}

126 127 128 129
static void
tree_print(struct f_tree *t)
{
  if (!t) {
130
    debug( "() " );
131 132
    return;
  }
133
  debug( "[ " );
134
  tree_print( t->left );
135
  debug( ", " ); val_print( t->from ); debug( ".." ); val_print( t->to ); debug( ", " );
136
  tree_print( t->right );
137
  debug( "] " );
138 139 140 141 142 143
}

void
val_print(struct f_val v)
{
  char buf[2048];
144
  char buf2[1024];
145 146 147 148 149 150 151
#define PRINTF(a...) bsnprintf( buf, 2040, a )
  buf[0] = 0;
  switch (v.type) {
  case T_VOID: PRINTF( "(void)" ); break;
  case T_BOOL: PRINTF( v.val.i ? "TRUE" : "FALSE" ); break;
  case T_INT: PRINTF( "%d ", v.val.i ); break;
  case T_STRING: PRINTF( "%s", v.val.s ); break;
152
  case T_IP: PRINTF( "%I", v.val.px.ip ); break;
153 154
  case T_PREFIX: PRINTF( "%I/%d", v.val.px.ip, v.val.px.len ); break;
  case T_PAIR: PRINTF( "(%d,%d)", v.val.i >> 16, v.val.i & 0xffff ); break;
155
  case T_SET: tree_print( v.val.t ); PRINTF( "\n" ); break;
Pavel Machek's avatar
Pavel Machek committed
156
  case T_ENUM: PRINTF( "(enum %x)%d", v.type, v.val.i ); break;
157
  case T_PATH: as_path_format(v.val.ad, buf2, 1020); PRINTF( "(path %s)", buf2 ); break;
158
  case T_CLIST: int_set_format(v.val.ad, buf2, 1020); PRINTF( "(clist %s)", buf2 ); break;
159
  case T_PATH_MASK: debug( "(pathmask " ); { struct f_path_mask *p = v.val.s; while (p) { debug("%d ", p->val); p=p->next; } debug(")" ); } break;
160
  default: PRINTF( "[unknown type %x]", v.type );
161
#undef PRINTF
162
  }
163
  debug( buf );
164 165
}

166
static struct rte **f_rte, *f_rte_old;
167
static struct linpool *f_pool;
Pavel Machek's avatar
Pavel Machek committed
168
static struct ea_list **f_tmp_attrs;
169
static int f_flags;
170
static rta *f_rta_copy;
171

172 173 174 175 176 177 178 179 180
#define runtime(x) do { \
    log( L_ERR x ); \
    res.type = T_RETURN; \
    res.val.i = F_ERROR; \
    return res; \
  } while(0)

#define ARG(x,y) \
	x = interpret(what->y); \
181
	if (x.type & T_RETURN) \
182 183 184 185 186 187 188 189
		return x;

#define ONEARG ARG(v1, a1.p)
#define TWOARGS ARG(v1, a1.p) \
		ARG(v2, a2.p)
#define TWOARGS_C TWOARGS \
                  if (v1.type != v2.type) \
		    runtime( "Can not operate with values of incompatible types" );
190

191 192 193 194 195
static struct f_val
interpret(struct f_inst *what)
{
  struct symbol *sym;
  struct f_val v1, v2, res;
196
  int i,j,k;
197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228

  res.type = T_VOID;
  if (!what)
    return res;

  switch(what->code) {
  case ',':
    TWOARGS;
    break;

/* Binary operators */
  case '+':
    TWOARGS_C;
    switch (res.type = v1.type) {
    case T_VOID: runtime( "Can not operate with values of type void" );
    case T_INT: res.val.i = v1.val.i + v2.val.i; break;
    default: runtime( "Usage of unknown type" );
    }
    break;
  case '/':
    TWOARGS_C;
    switch (res.type = v1.type) {
    case T_VOID: runtime( "Can not operate with values of type void" );
    case T_INT: res.val.i = v1.val.i / v2.val.i; break;
    case T_IP: if (v2.type != T_INT)
                 runtime( "Operator / is <ip>/<int>" );
               break;
    default: runtime( "Usage of unknown type" );
    }
    break;

/* Relational operators */
229 230 231 232 233 234 235 236

#define COMPARE(x) \
    TWOARGS_C; \
    res.type = T_BOOL; \
    i = val_compare(v1, v2); \
    if (i==CMP_ERROR) \
      runtime( "Error in comparation" ); \
    res.val.i = (x); \
237
    break;
238

239 240
  case P('!','='): COMPARE(i!=0);
  case P('=','='): COMPARE(i==0);
241
  case '<': COMPARE(i==-1);
242
  case P('<','='): COMPARE(i!=1);
243

Pavel Machek's avatar
Pavel Machek committed
244 245 246 247 248 249 250 251
  case '!':
    ONEARG;
    if (v1.type != T_BOOL)
      runtime( "not applied to non-boolean" );
    res = v1;
    res.val.i = !res.val.i;
    break;

252 253
  case '~':
    TWOARGS;
254
    res.type = T_BOOL;
255 256 257
    res.val.i = val_in_range(v1, v2);
    if (res.val.i == CMP_ERROR)
      runtime( "~ applied on unknown type pair" );
258
    break;
259
  case P('d','e'):
260 261 262 263
    ONEARG;
    res.type = T_BOOL;
    res.val.i = (v1.type != T_VOID);
    break;
264

265
  /* Set to indirect value, a1 = variable, a2 = value */
266
  case 's':
Pavel Machek's avatar
Pavel Machek committed
267 268
    ARG(v2, a2.p);
    sym = what->a1.p;
269 270
    switch (res.type = v2.type) {
    case T_VOID: runtime( "Can not assign void values" );
271
    case T_ENUM:
272
    case T_INT: 
273 274 275
    case T_IP: 
    case T_PREFIX: 
    case T_PAIR: 
276 277
    case T_PATH:
    case T_CLIST:
278
    case T_PATH_MASK:
279
      if (sym->class != (SYM_VARIABLE | v2.type))
280
	runtime( "Variable of bad type" );
281
      * (struct f_val *) sym->aux2 = v2; 
282
      break;
283
    default:
284
      bug( "Set to invalid type" );
285 286 287
    }
    break;

288
  case 'c':	/* integer (or simple type) constant */
289
    res.type = what->aux;
290
    res.val.i = what->a2.i;
291
    break;
292 293 294
  case 'C':
    res = * ((struct f_val *) what->a1.p);
    break;
295 296
  case 'p':
    ONEARG;
297
    val_print(v1);
298 299 300 301 302 303
    break;
  case '?':	/* ? has really strange error value, so we can implement if ... else nicely :-) */
    ONEARG;
    if (v1.type != T_BOOL)
      runtime( "If requires bool expression" );
    if (v1.val.i) {
Pavel Machek's avatar
Pavel Machek committed
304
      ARG(res,a2.p);
305 306 307 308 309
      res.val.i = 0;
    } else res.val.i = 1;
    res.type = T_BOOL;
    break;
  case '0':
310
    debug( "No operation\n" );
311
    break;
312
  case P('p',','):
313
    ONEARG;
314
    if (what->a2.i == F_NOP || (what->a2.i != F_NONL && what->a1.p))
315
      debug( "\n" );
316

Pavel Machek's avatar
Pavel Machek committed
317
    switch (what->a2.i) {
318 319 320 321 322
    case F_QUITBIRD:
      die( "Filter asked me to die" );
    case F_ACCEPT:
      /* Should take care about turning ACCEPT into MODIFY */
    case F_ERROR:
323
    case F_REJECT:	/* FIXME (noncritical) Should print complete route along with reason to reject route */
324
      res.type = T_RETURN;
325
      res.val.i = what->a2.i;
326
      return res;	/* We have to return now, no more processing. */
327
    case F_NONL:
328 329 330 331 332 333
    case F_NOP:
      break;
    default:
      bug( "unknown return type: can not happen");
    }
    break;
334 335 336
  case 'a':	/* rta access */
    {
      struct rta *rta = (*f_rte)->attrs;
337
      res.type = what->aux;
338 339
      switch(res.type) {
      case T_IP:
340
	res.val.px.ip = * (ip_addr *) ((char *) rta + what->a2.i);
341
	break;
342 343 344
      case T_ENUM:
	res.val.i = * ((char *) rta + what->a2.i);
	break;
345 346 347 348 349 350 351
      case T_PREFIX:	/* Warning: this works only for prefix of network */
	{
	  res.val.px.ip = (*f_rte)->net->n.prefix;
	  res.val.px.len = (*f_rte)->net->n.pxlen;
	  break;
	}
      default:
352
	bug( "Invalid type for rta access (%x)", res.type );
353 354 355
      }
    }
    break;
356
  case P('e','a'):	/* Access to extended attributes */
357
    {
358
      eattr *e = NULL;
359
      if (!(f_flags & FF_FORCE_TMPATTR))
360
	e = ea_find( (*f_rte)->attrs->eattrs, what->a2.i );
Pavel Machek's avatar
Pavel Machek committed
361 362
      if (!e) 
	e = ea_find( (*f_tmp_attrs), what->a2.i );
363
      if ((!e) && (f_flags & FF_FORCE_TMPATTR))
364 365
	e = ea_find( (*f_rte)->attrs->eattrs, what->a2.i );
      
366 367 368 369
      if (!e) {
	res.type = T_VOID;
	break;
      }
370 371 372
      switch (what->aux & EAF_TYPE_MASK) {
      case EAF_TYPE_INT:
	res.type = T_INT;
373 374
	res.val.i = e->u.data;
	break;
375 376 377 378 379 380
      case EAF_TYPE_AS_PATH:
        res.type = T_PATH;
	res.val.ad = e->u.ptr;
	break;
      case EAF_TYPE_INT_SET:
	res.type = T_CLIST;
381 382
	res.val.ad = e->u.ptr;
	break;
Martin Mareš's avatar
Martin Mareš committed
383 384
      default:
	bug("Unknown type in e,a\n");
385 386
      }
    }
387
    break;
388
  case P('e','S'):
389 390 391 392 393 394 395 396
    ONEARG;
    {
      struct ea_list *l = lp_alloc(f_pool, sizeof(struct ea_list) + sizeof(eattr));

      l->next = NULL;
      l->flags = EALF_SORTED;
      l->count = 1;
      l->attrs[0].id = what->a2.i;
Pavel Machek's avatar
Pavel Machek committed
397 398
      l->attrs[0].flags = 0;
      l->attrs[0].type = what->aux | EAF_ORIGINATED;
Pavel Machek's avatar
Pavel Machek committed
399 400 401 402
      switch (what->aux & EAF_TYPE_MASK) {
      case EAF_TYPE_INT:
	if (v1.type != T_INT)
	  runtime( "Setting int attribute to non-int value" );
403 404
	l->attrs[0].u.data = v1.val.i;
	break;
405 406 407 408 409
      case EAF_TYPE_AS_PATH:
	if (v1.type != T_PATH)
	  runtime( "Setting path attribute to non-path value" );
	l->attrs[0].u.ptr = v1.val.ad;
	break;
410 411 412 413 414
      case EAF_TYPE_INT_SET:
	if (v1.type != T_CLIST)
	  runtime( "Setting int set  attribute to non-clist value" );
	l->attrs[0].u.ptr = v1.val.ad;
	break;
Pavel Machek's avatar
Pavel Machek committed
415 416 417
      case EAF_TYPE_UNDEF:
	if (v1.type != T_VOID)
	  runtime( "Setting void attribute to non-void value" );
418 419
	l->attrs[0].u.data = 0;
	break;
420
      default: bug("Unknown type in e,S");
421
      }
Pavel Machek's avatar
Pavel Machek committed
422

423
      if (!(what->aux & EAF_TEMP) && (!(f_flags & FF_FORCE_TMPATTR))) {
424 425 426 427 428 429 430 431 432
	if (!f_rta_copy) {
	  f_rta_copy = lp_alloc(f_pool, sizeof(rta));
	  memcpy(f_rta_copy, (*f_rte)->attrs, sizeof(rta));
	  f_rta_copy->aflags = 0;
	  *f_rte = rte_cow(*f_rte);
	  (*f_rte)->attrs = f_rta_copy;
	}
	l->next = f_rta_copy->eattrs;
	f_rta_copy->eattrs = l;
Pavel Machek's avatar
Pavel Machek committed
433 434 435 436
      } else {
	l->next = (*f_tmp_attrs);
	(*f_tmp_attrs) = l;
      }
437 438
    }
    break;
439

440 441 442 443 444 445 446 447 448
  case 'L':	/* Get length of */
    ONEARG;
    res.type = T_INT;
    switch(v1.type) {
    case T_PREFIX: res.val.i = v1.val.px.len; break;
    case T_PATH:   res.val.i = as_path_getlen(v1.val.ad); break;
    default: bug( "Length of what?" );
    }
    break;
449
  case P('c','p'):	/* Convert prefix to ... */
450 451 452
    ONEARG;
    if (v1.type != T_PREFIX)
      runtime( "Can not convert non-prefix this way" );
453
    res.type = what->aux;
454
    switch(res.type) {
455
      /*    case T_INT:	res.val.i = v1.val.px.len; break; Not needed any more */
456
    case T_IP: res.val.px.ip = v1.val.px.ip; break;
457
    default: bug( "Unknown prefix to conversion" );
458 459
    }
    break;
460 461 462 463 464 465
  case 'r':
    ONEARG;
    res = v1;
    res.type |= T_RETURN;
    break;
  case P('c','a'): /* CALL: this is special: if T_RETURN and returning some value, mask it out  */
466 467
    ONEARG;
    res = interpret(what->a2.p);
468 469 470
    if (res.type == T_RETURN)
      return res;
    res.type &= ~T_RETURN;    
471
    break;
472
  case P('S','W'):
473
    ONEARG;
Pavel Machek's avatar
Pavel Machek committed
474 475 476 477 478 479
    {
      struct f_tree *t = find_tree(what->a2.p, v1);
      if (!t) {
	v1.type = T_VOID;
	t = find_tree(what->a2.p, v1);
	if (!t) {
480
	  debug( "No else statement?\n ");
Pavel Machek's avatar
Pavel Machek committed
481 482 483 484
	  break;
	}
      }	
      if (!t->data)
485
	bug( "Impossible: no code associated!" );
Pavel Machek's avatar
Pavel Machek committed
486 487
      return interpret(t->data);
    }
488
    break;
489
  case P('i','M'): /* IP.MASK(val) */
490 491 492 493 494 495 496 497 498 499
    TWOARGS;
    if (v2.type != T_INT)
      runtime( "Can not use this type for mask.");
    if (v1.type != T_IP)
      runtime( "You can mask only IP addresses." );
    {
      ip_addr mask = ipa_mkmask(v2.val.i);
      res.type = T_IP;
      res.val.px.ip = ipa_and(mask, v1.val.px.ip);
    }
500
    break;
501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516

  case 'E':	/* Create empty attribute */
    res.type = what->aux;
    res.val.ad = adata_empty(f_pool);
    break;
  case P('A','p'):	/* Path prepend */
    TWOARGS;
    if (v1.type != T_PATH)
      runtime("Can't prepend to non-path");
    if (v2.type != T_INT)
      runtime("Can't prepend non-integer");

    res.type = T_PATH;
    res.val.ad = as_path_prepend(f_pool, v1.val.ad, v2.val.i);
    break;

517 518 519 520 521 522 523 524 525 526 527 528 529 530 531
  case P('C','a'):	/* Community list add or delete */
    TWOARGS;
    if (v1.type != T_CLIST)
      runtime("Can't add/delete to non-clist");
    if (v2.type != T_PAIR)
      runtime("Can't add/delete non-pair");

    res.type = T_CLIST;
    switch (what->aux) {
    case 'a': res.val.ad = int_set_add(f_pool, v1.val.ad, v2.val.i); break;
    case 'd': res.val.ad = int_set_del(f_pool, v1.val.ad, v2.val.i); break;
    default: bug("unknown Ca operation");
    }
    break;

532 533 534 535 536 537 538 539
  default:
    bug( "Unknown instruction %d (%c)", what->code, what->code & 0xff);
  }
  if (what->next)
    return interpret(what->next);
  return res;
}

540
#undef ARG
541 542 543 544 545 546 547 548 549 550 551 552 553 554 555
#define ARG(x,y) \
	if (!i_same(f1->y, f2->y)) \
		return 0;

#define ONEARG ARG(v1, a1.p)
#define TWOARGS ARG(v1, a1.p) \
		ARG(v2, a2.p)

#define A2_SAME if (f1->a2.i != f2->a2.i) return 0;

int
i_same(struct f_inst *f1, struct f_inst *f2)
{
  if ((!!f1) != (!!f2))
    return 0;
556 557
  if (!f1)
    return 1;
558 559 560 561
  if (f1->aux != f2->aux)
    return 0;
  if (f1->code != f2->code)
    return 0;
562 563
  if (f1 == f2)		/* It looks strange, but it is possible with call rewriting trickery */
    return 1;
564 565 566 567 568

  switch(f1->code) {
  case ',': /* fall through */
  case '+':
  case '/':
569 570
  case P('!','='):
  case P('=','='):
571
  case '<':
572
  case P('<','='): TWOARGS; break;
573

Pavel Machek's avatar
Pavel Machek committed
574
  case '!': ONEARG; break;
575
  case '~': TWOARGS; break;
576
  case P('d','e'): ONEARG; break;
577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592

  case 's':
    ARG(v2, a2.p);
    {
      struct symbol *s1, *s2;
      s1 = f1->a1.p;
      s2 = f2->a1.p;
      if (strcmp(s1->name, s2->name))
	return 0;
      if (s1->class != s2->class)
	return 0;
    }
    break;

  case 'c': A2_SAME; break;
  case 'C': 
593
    if (val_compare(* (struct f_val *) f1->a1.p, * (struct f_val *) f2->a1.p))
594 595
      return 0;
    break;
596
  case 'p': case 'L': ONEARG; break;
597
  case '?': TWOARGS; break;
598
  case '0': case 'E': break;
599
  case P('p',','): ONEARG; A2_SAME; break;
600
  case 'a': A2_SAME; break;
601 602
  case P('e','a'): A2_SAME; break;
  case P('e','S'): ONEARG; A2_SAME; break;
603

604 605
  case 'r': ONEARG; break;
  case P('c','p'): ONEARG; break;
606 607 608 609 610 611
  case P('c','a'): /* Call rewriting trickery to avoid exponential behaviour */
             ONEARG; 
	     if (!i_same(f1->a2.p, f2->a2.p))
	       return 0; 
	     f2->a2.p = f1->a2.p;
	     break;
612 613
  case P('S','W'): ONEARG; if (!same_tree(f1->a2.p, f2->a2.p)) return 0; break;
  case P('i','M'): TWOARGS; break;
614
  case P('A','p'): TWOARGS; break;
615
  case P('C','a'): TWOARGS; break;
616 617 618 619 620 621
  default:
    bug( "Unknown instruction %d in same (%c)", f1->code, f1->code & 0xff);
  }
  return i_same(f1->next, f2->next);
}

622 623 624 625 626 627 628 629 630 631 632 633
/**
 * f_run - external entry point to filters
 * @filter: pointer to filter to run
 * @rte: pointer to pointer to rte being filtered. When route is modified, this is changed with rte_cow.
 * @tmp_pool: all filter allocations go from this pool
 *
 * Filter consists of tree of &f_inst structures, one structure per
 * "instruction". Each &f_inst contains code, aux value which is
 * usually type of data this instruction operates on, and two generic
 * arguments (a1, a2). Some instructinos contain pointer(s) to other
 * instructions in their (a1, a2) fields.
 *
Pavel Machek's avatar
Pavel Machek committed
634 635 636 637 638 639 640 641
 * Filters use structure &f_val for its variables. Each &f_val
 * contains type and value. Types are constants prefixed with %T_. Few
 * of types are special; %T_RETURN can be or-ed with type to indicate
 * that return from function/from whole filter should be
 * forced. Important thing about &f_val s is that they may be copied
 * with simple =. That's fine for all currently defined types: strings
 * are read-only (and therefore okay), paths are copied for each
 * operation (okay too).
642
 */
643
int
644
f_run(struct filter *filter, struct rte **rte, struct ea_list **tmp_attrs, struct linpool *tmp_pool, int flags)
645 646 647
{
  struct f_inst *inst;
  struct f_val res;
648
  DBG( "Running filter `%s'...", filter->name );
649

650
  f_flags = flags;
Pavel Machek's avatar
Pavel Machek committed
651
  f_tmp_attrs = tmp_attrs;
652
  f_rte = rte;
653
  f_rte_old = *rte;
654
  f_rta_copy = NULL;
655
  f_pool = tmp_pool;
656 657 658 659
  inst = filter->root;
  res = interpret(inst);
  if (res.type != T_RETURN)
    return F_ERROR;
660
  DBG( "done (%d)\n", res.val.i );
661 662 663 664 665 666 667
  return res.val.i;
}

void
filters_postconfig(void)
{
  struct f_val res;
Pavel Machek's avatar
Pavel Machek committed
668

669
#if 1
Pavel Machek's avatar
Pavel Machek committed
670 671
  if (!i_same(test1_func, test2_func))
    bug("i_same does not work");
672
#endif
673
  if (startup_func) {
674
    debug( "Launching startup function...\n" );
675
    f_pool = lp_new(&root_pool, 1024);
676
    res = interpret(startup_func);
Pavel Machek's avatar
Pavel Machek committed
677
    if (res.type == F_ERROR)
678
      die( "Startup function resulted in error." );
679
    debug( "done\n" );
680
  }
681
} 
682

683 684 685 686 687 688 689 690 691 692
/**
 * filter_same - compare two filters
 * @new: first filter to be compared
 * @old: second filter to be compared, notice that this filter is
 * damaged while comparing.
 *
 * Returns 1 in case filters are same, otherwise 0. If there are
 * underlying bugs, it will rather say 0 on same filters than say
 * 1 on different.
 */
693 694 695
int
filter_same(struct filter *new, struct filter *old)
{
696 697 698 699 700
  if (old == new)	/* Handle FILTER_ACCEPT and FILTER_REJECT */
    return 1;
  if (old == FILTER_ACCEPT || old == FILTER_REJECT ||
      new == FILTER_ACCEPT || new == FILTER_REJECT)
    return 0;
701
  return i_same(new->root, old->root);
702
}
703 704

struct adata *
705
adata_empty(struct linpool *pool)
706 707 708 709 710
{
  struct adata *res = lp_alloc(pool, sizeof(struct adata));
  res->length = 0;
  return res;
}