1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668
|
/* $OpenLDAP: pkg/ldap/libraries/libldap/cache.c,v 1.13.6.5 2002/01/05 02:27:48 kurt Exp $ */
/*
* Copyright 1998-2002 The OpenLDAP Foundation, All Rights Reserved.
* COPYING RESTRICTIONS APPLY, see COPYRIGHT file
*/
/* Portions
* Copyright (c) 1993 The Regents of the University of Michigan.
* All rights reserved.
*
* cache.c - local caching support for LDAP
*/
#include "portable.h"
#include <stdio.h>
#include <ac/stdlib.h>
#include <ac/socket.h>
#include <ac/string.h>
#include <ac/time.h>
#include "ldap-int.h"
#ifndef LDAP_NOCACHE
static int cache_hash LDAP_P(( BerElement *ber ));
static LDAPMessage *msg_dup LDAP_P(( LDAPMessage *msg ));
static int request_cmp LDAP_P(( BerElement *req1, BerElement *req2 ));
static int chain_contains_dn LDAP_P(( LDAPMessage *msg, LDAP_CONST char *dn ));
static ber_len_t msg_size LDAP_P(( LDAPMessage *msg ));
static void check_cache_memused LDAP_P(( LDAPCache *lc ));
static void uncache_entry_or_req LDAP_P(( LDAP *ld, LDAP_CONST char *dn, ber_int_t msgid ));
#endif
int
ldap_enable_cache( LDAP *ld, long timeout, ber_len_t maxmem )
{
#ifndef LDAP_NOCACHE
if ( ld->ld_cache == NULL ) {
if (( ld->ld_cache = (LDAPCache *)LDAP_MALLOC( sizeof( LDAPCache )))
== NULL ) {
ld->ld_errno = LDAP_NO_MEMORY;
return( -1 );
}
(void) memset( ld->ld_cache, '\0', sizeof( LDAPCache ));
ld->ld_cache->lc_memused = sizeof( LDAPCache );
}
ld->ld_cache->lc_timeout = timeout;
ld->ld_cache->lc_maxmem = maxmem;
check_cache_memused( ld->ld_cache );
ld->ld_cache->lc_enabled = 1;
return( 0 );
#else
return( -1 );
#endif
}
void
ldap_disable_cache( LDAP *ld )
{
#ifndef LDAP_NOCACHE
if ( ld->ld_cache != NULL ) {
ld->ld_cache->lc_enabled = 0;
}
#endif
}
void
ldap_set_cache_options( LDAP *ld, unsigned long opts )
{
#ifndef LDAP_NOCACHE
if ( ld->ld_cache != NULL ) {
ld->ld_cache->lc_options = opts;
}
#endif
}
void
ldap_destroy_cache( LDAP *ld )
{
#ifndef LDAP_NOCACHE
if ( ld->ld_cache != NULL ) {
ldap_flush_cache( ld );
LDAP_FREE( (char *)ld->ld_cache );
ld->ld_cache = NULL;
}
#endif
}
void
ldap_flush_cache( LDAP *ld )
{
#ifndef LDAP_NOCACHE
int i;
LDAPMessage *m, *next;
Debug( LDAP_DEBUG_TRACE, "ldap_flush_cache\n", 0, 0, 0 );
if ( ld->ld_cache != NULL ) {
/* delete all requests in the queue */
for ( m = ld->ld_cache->lc_requests; m != NULL; m = next ) {
next = m->lm_next;
ldap_msgfree( m );
}
ld->ld_cache->lc_requests = NULL;
/* delete all messages in the cache */
for ( i = 0; i < LDAP_CACHE_BUCKETS; ++i ) {
for ( m = ld->ld_cache->lc_buckets[ i ];
m != NULL; m = next ) {
next = m->lm_next;
ldap_msgfree( m );
}
ld->ld_cache->lc_buckets[ i ] = NULL;
}
ld->ld_cache->lc_memused = sizeof( LDAPCache );
}
#endif
}
void
ldap_uncache_request( LDAP *ld, int msgid )
{
#ifndef LDAP_NOCACHE
Debug( LDAP_DEBUG_TRACE, "ldap_uncache_request %d ld_cache %lx\n",
msgid, (long) ld->ld_cache, 0 );
uncache_entry_or_req( ld, NULL, msgid );
#endif
}
void
ldap_uncache_entry( LDAP *ld, LDAP_CONST char *dn )
{
#ifndef LDAP_NOCACHE
Debug( LDAP_DEBUG_TRACE, "ldap_uncache_entry %s ld_cache %lx\n",
dn, (long) ld->ld_cache, 0 );
uncache_entry_or_req( ld, dn, 0 );
#endif
}
#ifndef LDAP_NOCACHE
static void
uncache_entry_or_req( LDAP *ld,
const char *dn, /* if non-NULL, uncache entry */
ber_int_t msgid ) /* request to uncache (if dn == NULL) */
{
int i;
LDAPMessage *m, *prev, *next;
Debug( LDAP_DEBUG_TRACE,
"ldap_uncache_entry_or_req dn %s msgid %ld ld_cache %lx\n",
dn, (long) msgid, (long) ld->ld_cache );
if ( ld->ld_cache == NULL ) {
return;
}
/* first check the request queue */
prev = NULL;
for ( m = ld->ld_cache->lc_requests; m != NULL; m = next ) {
next = m->lm_next;
if (( dn != NULL && chain_contains_dn( m, dn )) ||
( dn == NULL && m->lm_msgid == msgid )) {
if ( prev == NULL ) {
ld->ld_cache->lc_requests = next;
} else {
prev->lm_next = next;
}
ld->ld_cache->lc_memused -= msg_size( m );
ldap_msgfree( m );
} else {
prev = m;
}
}
/* now check the rest of the cache */
for ( i = 0; i < LDAP_CACHE_BUCKETS; ++i ) {
prev = NULL;
for ( m = ld->ld_cache->lc_buckets[ i ]; m != NULL;
m = next ) {
next = m->lm_next;
if (( dn != NULL && chain_contains_dn( m, dn )) ||
( dn == NULL && m->lm_msgid == msgid )) {
if ( prev == NULL ) {
ld->ld_cache->lc_buckets[ i ] = next;
} else {
prev->lm_next = next;
}
ld->ld_cache->lc_memused -= msg_size( m );
ldap_msgfree( m );
} else {
prev = m;
}
}
}
}
#endif
void
ldap_add_request_to_cache( LDAP *ld, ber_tag_t msgtype, BerElement *request )
{
#ifndef LDAP_NOCACHE
LDAPMessage *new;
ber_len_t len;
Debug( LDAP_DEBUG_TRACE, "ldap_add_request_to_cache\n", 0, 0, 0 );
ld->ld_errno = LDAP_SUCCESS;
if ( ld->ld_cache == NULL ||
( ld->ld_cache->lc_enabled == 0 )) {
return;
}
if (( new = (LDAPMessage *) LDAP_CALLOC( 1, sizeof(LDAPMessage) ))
!= NULL ) {
if (( new->lm_ber = ldap_alloc_ber_with_options( ld )) == NULL ) {
LDAP_FREE( (char *)new );
return;
}
len = request->ber_ptr - request->ber_buf;
if (( new->lm_ber->ber_buf = (char *) ber_memalloc( (size_t)len ))
== NULL ) {
ber_free( new->lm_ber, 0 );
LDAP_FREE( (char *)new );
ld->ld_errno = LDAP_NO_MEMORY;
return;
}
AC_MEMCPY( new->lm_ber->ber_buf, request->ber_buf,
(size_t)len );
new->lm_ber->ber_ptr = new->lm_ber->ber_buf;
new->lm_ber->ber_end = new->lm_ber->ber_buf + len;
new->lm_msgid = ld->ld_msgid;
new->lm_msgtype = msgtype;;
new->lm_next = ld->ld_cache->lc_requests;
ld->ld_cache->lc_requests = new;
} else {
ld->ld_errno = LDAP_NO_MEMORY;
}
#endif
}
void
ldap_add_result_to_cache( LDAP *ld, LDAPMessage *result )
{
#ifndef LDAP_NOCACHE
LDAPMessage *m, **mp, *req, *new, *prev;
int err, keep;
Debug( LDAP_DEBUG_TRACE, "ldap_add_result_to_cache: id %ld, type %ld\n",
(long) result->lm_msgid, (long) result->lm_msgtype, 0 );
if ( ld->ld_cache == NULL ||
( ld->ld_cache->lc_enabled == 0 )) {
Debug( LDAP_DEBUG_TRACE, "artc: cache disabled\n", 0, 0, 0 );
return;
}
if ( result->lm_msgtype != LDAP_RES_SEARCH_ENTRY &&
result->lm_msgtype != LDAP_RES_SEARCH_REFERENCE &&
result->lm_msgtype != LDAP_RES_SEARCH_RESULT &&
result->lm_msgtype != LDAP_RES_COMPARE ) {
/*
* only cache search and compare operations
*/
Debug( LDAP_DEBUG_TRACE,
"artc: only caching search & compare operations\n", 0, 0, 0 );
return;
}
/*
* if corresponding request is in the lc_requests list, add this
* result to it. if this result completes the results for the
* request, add the request/result chain to the cache proper.
*/
prev = NULL;
for ( m = ld->ld_cache->lc_requests; m != NULL; m = m->lm_next ) {
if ( m->lm_msgid == result->lm_msgid ) {
break;
}
prev = m;
}
if ( m != NULL ) { /* found request; add to end of chain */
req = m;
for ( ; m->lm_chain != NULL; m = m->lm_chain )
;
if (( new = msg_dup( result )) != NULL ) {
new->lm_chain = NULL;
m->lm_chain = new;
Debug( LDAP_DEBUG_TRACE,
"artc: result added to cache request chain\n",
0, 0, 0 );
}
if ( result->lm_msgtype == LDAP_RES_SEARCH_RESULT ||
result->lm_msgtype == LDAP_RES_COMPARE ) {
/*
* this result completes the chain of results
* add to cache proper if appropriate
*/
keep = 0; /* pessimistic */
err = ldap_result2error( ld, result, 0 );
if ( err == LDAP_SUCCESS ||
( result->lm_msgtype == LDAP_RES_COMPARE &&
( err == LDAP_COMPARE_FALSE ||
err == LDAP_COMPARE_TRUE ||
err == LDAP_NO_SUCH_ATTRIBUTE ))) {
keep = 1;
}
if ( ld->ld_cache->lc_options == 0 ) {
if ( err == LDAP_SIZELIMIT_EXCEEDED ) {
keep = 1;
}
} else if (( ld->ld_cache->lc_options &
LDAP_CACHE_OPT_CACHEALLERRS ) != 0 ) {
keep = 1;
}
if ( prev == NULL ) {
ld->ld_cache->lc_requests = req->lm_next;
} else {
prev->lm_next = req->lm_next;
}
if ( !keep ) {
Debug( LDAP_DEBUG_TRACE,
"artc: not caching result with error %d\n",
err, 0, 0 );
ldap_msgfree( req );
} else {
mp = &ld->ld_cache->lc_buckets[
cache_hash( req->lm_ber ) ];
req->lm_next = *mp;
*mp = req;
req->lm_time = (long) time( NULL );
ld->ld_cache->lc_memused += msg_size( req );
check_cache_memused( ld->ld_cache );
Debug( LDAP_DEBUG_TRACE,
"artc: cached result with error %d\n",
err, 0, 0 );
}
}
} else {
Debug( LDAP_DEBUG_TRACE, "artc: msgid not in request list\n",
0, 0, 0 );
}
#endif
}
/*
* look in the cache for this request
* return 0 if found, -1 if not
* if found, the corresponding result messages are added to the incoming
* queue with the correct (new) msgid so that subsequent ldap_result calls
* will find them.
*/
int
ldap_check_cache( LDAP *ld, ber_tag_t msgtype, BerElement *request )
{
#ifndef LDAP_NOCACHE
LDAPMessage *m, *new, *prev, *next;
BerElement reqber;
int first, hash;
time_t c_time;
Debug( LDAP_DEBUG_TRACE, "ldap_check_cache\n", 0, 0, 0 );
if ( ld->ld_cache == NULL ||
( ld->ld_cache->lc_enabled == 0 )) {
return( -1 );
}
memset( &reqber, '\0', sizeof(reqber) );
reqber.ber_valid = LBER_VALID_BERELEMENT;
reqber.ber_buf = reqber.ber_ptr = request->ber_buf;
reqber.ber_end = request->ber_ptr;
reqber.ber_debug = ber_int_debug;
c_time = time( NULL );
prev = NULL;
hash = cache_hash( &reqber );
for ( m = ld->ld_cache->lc_buckets[ hash ]; m != NULL; m = next ) {
Debug( LDAP_DEBUG_TRACE,"cc: examining id %ld,type %ld\n",
(long) m->lm_msgid, (long) m->lm_msgtype, 0 );
if ( difftime(c_time, m->lm_time) > ld->ld_cache->lc_timeout ) {
/* delete expired message */
next = m->lm_next;
if ( prev == NULL ) {
ld->ld_cache->lc_buckets[ hash ] = next;
} else {
prev->lm_next = next;
}
Debug( LDAP_DEBUG_TRACE, "cc: expired id %d\n",
m->lm_msgid, 0, 0 );
ld->ld_cache->lc_memused -= msg_size( m );
ldap_msgfree( m );
} else {
if ( m->lm_msgtype == (int)msgtype &&
request_cmp( m->lm_ber, &reqber ) == 0 ) {
break;
}
next = m->lm_next;
prev = m;
}
}
if ( m == NULL ) {
return( -1 );
}
/*
* add duplicates of responses to incoming queue
*/
first = 1;
for ( m = m->lm_chain; m != NULL; m = m->lm_chain ) {
if (( new = msg_dup( m )) == NULL ) {
return( -1 );
}
new->lm_msgid = ld->ld_msgid;
new->lm_chain = NULL;
if ( first ) {
new->lm_next = ld->ld_responses;
ld->ld_responses = new;
first = 0;
} else {
prev->lm_chain = new;
}
prev = new;
Debug( LDAP_DEBUG_TRACE, "cc: added type %ld\n",
(long) new->lm_msgtype, 0, 0 );
}
Debug( LDAP_DEBUG_TRACE, "cc: result returned from cache\n", 0, 0, 0 );
return( 0 );
#else
return( -1 );
#endif
}
#ifndef LDAP_NOCACHE
static int
cache_hash( BerElement *ber )
{
BerElement bercpy;
ber_len_t len;
/*
* just take the length of the packet and mod with # of buckets
*/
bercpy = *ber;
if ( ber_skip_tag( &bercpy, &len ) == LBER_ERROR
|| ber_scanf( &bercpy, "x" ) == LBER_ERROR ) {
len = 0; /* punt: just return zero */
} else {
len = bercpy.ber_end - bercpy.ber_ptr;
}
Debug( LDAP_DEBUG_TRACE, "cache_hash: len is %ld, returning %ld\n",
len, len % LDAP_CACHE_BUCKETS, 0 );
return( (int) ( len % LDAP_CACHE_BUCKETS ));
}
static LDAPMessage *
msg_dup( LDAPMessage *msg )
{
LDAPMessage *new;
ber_len_t len;
if (( new = (LDAPMessage *)LDAP_MALLOC( sizeof(LDAPMessage))) != NULL ) {
*new = *msg; /* struct copy */
if (( new->lm_ber = ber_dup( msg->lm_ber )) == NULL ) {
LDAP_FREE( (char *)new );
return( NULL );
}
len = msg->lm_ber->ber_end - msg->lm_ber->ber_buf;
if (( new->lm_ber->ber_buf = (char *) ber_memalloc(
(size_t)len )) == NULL ) {
ber_free( new->lm_ber, 0 );
LDAP_FREE( (char *)new );
return( NULL );
}
AC_MEMCPY( new->lm_ber->ber_buf, msg->lm_ber->ber_buf,
(size_t)len );
new->lm_ber->ber_ptr = new->lm_ber->ber_buf +
( msg->lm_ber->ber_ptr - msg->lm_ber->ber_buf );
new->lm_ber->ber_end = new->lm_ber->ber_buf + len;
}
return( new );
}
static int
request_cmp( BerElement *req1, BerElement *req2 )
{
ber_len_t len;
BerElement r1, r2;
r1 = *req1; /* struct copies */
r2 = *req2;
/*
* skip the enclosing tags (sequence markers) and the msg ids
*/
if ( ber_skip_tag( &r1, &len ) == LBER_ERROR || ber_scanf( &r1, "x" )
== LBER_ERROR ) {
return( -1 );
}
if ( ber_skip_tag( &r2, &len ) == LBER_ERROR || ber_scanf( &r2, "x" )
== LBER_ERROR ) {
return( -1 );
}
/*
* check remaining length and bytes if necessary
*/
if (( len = r1.ber_end - r1.ber_ptr ) !=
(ber_len_t) (r2.ber_end - r2.ber_ptr) )
{
return( -1 ); /* different lengths */
}
return( memcmp( r1.ber_ptr, r2.ber_ptr, (size_t)len ));
}
static int
chain_contains_dn( LDAPMessage *msg, const char *dn )
{
LDAPMessage *m;
BerElement ber;
ber_int_t msgid;
char *s;
int rc;
/*
* first check the base or dn of the request
*/
ber = *msg->lm_ber; /* struct copy */
if ( ber_scanf( &ber, "{i{a" /*}}*/, &msgid, &s ) != LBER_ERROR ) {
rc = ( strcasecmp( dn, s ) == 0 ) ? 1 : 0;
LDAP_FREE( s );
if ( rc != 0 ) {
return( rc );
}
}
if ( msg->lm_msgtype == LDAP_REQ_COMPARE ) {
return( 0 );
}
/*
* now check the dn of each search result
*/
rc = 0;
for ( m = msg->lm_chain; m != NULL && rc == 0 ; m = m->lm_chain ) {
if ( m->lm_msgtype != LDAP_RES_SEARCH_ENTRY ) {
continue;
}
ber = *m->lm_ber; /* struct copy */
if ( ber_scanf( &ber, "{a" /*}*/, &s ) != LBER_ERROR ) {
rc = ( strcasecmp( dn, s ) == 0 ) ? 1 : 0;
LDAP_FREE( s );
}
}
return( rc );
}
static ber_len_t
msg_size( LDAPMessage *msg )
{
LDAPMessage *m;
ber_len_t size;
size = 0;
for ( m = msg; m != NULL; m = m->lm_chain ) {
size += ( sizeof( LDAPMessage ) + m->lm_ber->ber_end -
m->lm_ber->ber_buf );
}
return( size );
}
#define THRESHOLD_FACTOR 3 / 4
#define SIZE_FACTOR 2 / 3
static void
check_cache_memused( LDAPCache *lc )
{
/*
* this routine is called to check if the cache is too big (lc_maxmem >
* minimum cache size and lc_memused > lc_maxmem). If too big, it reduces
* the cache size to < SIZE_FACTOR * lc_maxmem. The algorithm is as follows:
* remove_threshold = lc_timeout seconds;
* do {
* remove everything older than remove_threshold seconds;
* remove_threshold = remove_threshold * THRESHOLD_FACTOR;
* } while ( cache size is > SIZE_FACTOR * lc_maxmem )
*/
int i;
unsigned long remove_threshold;
time_t c_time;
LDAPMessage *m, *prev, *next;
Debug( LDAP_DEBUG_TRACE, "check_cache_memused: %ld bytes in use (%ld max)\n",
lc->lc_memused, lc->lc_maxmem, 0 );
if ( (unsigned) lc->lc_maxmem <= sizeof( LDAPCache )
|| lc->lc_memused <= lc->lc_maxmem * SIZE_FACTOR ) {
return;
}
remove_threshold = lc->lc_timeout;
while ( lc->lc_memused > lc->lc_maxmem * SIZE_FACTOR ) {
c_time = time( NULL );
for ( i = 0; i < LDAP_CACHE_BUCKETS; ++i ) {
prev = NULL;
for ( m = lc->lc_buckets[ i ]; m != NULL;
m = next ) {
next = m->lm_next;
if ( difftime(c_time, m->lm_time) > remove_threshold) {
if ( prev == NULL ) {
lc->lc_buckets[ i ] = next;
} else {
prev->lm_next = next;
}
lc->lc_memused -= msg_size( m );
Debug( LDAP_DEBUG_TRACE,
"ccm: removed %d\n",
m->lm_msgid, 0, 0 );
ldap_msgfree( m );
} else {
prev = m;
}
}
}
remove_threshold *= THRESHOLD_FACTOR;
}
Debug( LDAP_DEBUG_TRACE, "ccm: reduced usage to %ld bytes\n",
lc->lc_memused, 0, 0 );
}
#endif /* !NO_CACHE */
|