1 #include "first.h" 2 3 #include "stat_cache.h" 4 #include "log.h" 5 #include "fdevent.h" 6 #include "http_etag.h" 7 #include "algo_splaytree.h" 8 9 #include <sys/types.h> 10 #include <sys/stat.h> 11 12 #include <stdlib.h> 13 #include <string.h> 14 #include <errno.h> 15 #include <unistd.h> 16 #include <fcntl.h> 17 18 #if defined(HAVE_SYS_XATTR_H) 19 # include <sys/xattr.h> 20 #elif defined(HAVE_ATTR_ATTRIBUTES_H) 21 # include <attr/attributes.h> 22 #endif 23 24 #ifdef HAVE_SYS_EXTATTR_H 25 # include <sys/extattr.h> 26 #endif 27 28 #ifndef HAVE_LSTAT 29 #define lstat stat 30 #ifndef S_ISLNK 31 #define S_ISLNK(mode) (0) 32 #endif 33 #endif 34 35 /* 36 * stat-cache 37 * 38 * - a splay-tree is used as we can use the caching effect of it 39 */ 40 41 enum { 42 STAT_CACHE_ENGINE_SIMPLE = 0 /*(default)*/ 43 ,STAT_CACHE_ENGINE_NONE = 1 44 ,STAT_CACHE_ENGINE_FAM = 2 /* same as STAT_CACHE_ENGINE_INOTIFY */ 45 ,STAT_CACHE_ENGINE_INOTIFY = 2 /* same as STAT_CACHE_ENGINE_FAM */ 46 ,STAT_CACHE_ENGINE_KQUEUE = 2 /* same as STAT_CACHE_ENGINE_FAM */ 47 }; 48 49 struct stat_cache_fam; /* declaration */ 50 51 typedef struct stat_cache { 52 int stat_cache_engine; 53 splay_tree *files; /* nodes of tree are (stat_cache_entry *) */ 54 struct stat_cache_fam *scf; 55 } stat_cache; 56 57 static stat_cache sc; 58 59 60 static void * stat_cache_sptree_find(splay_tree ** const sptree, 61 const char * const name, 62 uint32_t len) 63 { 64 const int ndx = splaytree_djbhash(name, len); 65 *sptree = splaytree_splay(*sptree, ndx); 66 return (*sptree && (*sptree)->key == ndx) ? (*sptree)->data : NULL; 67 } 68 69 70 #if defined(HAVE_SYS_INOTIFY_H) \ 71 || (defined(HAVE_SYS_EVENT_H) && defined(HAVE_KQUEUE)) 72 #ifndef HAVE_FAM_H 73 #define HAVE_FAM_H 74 #endif 75 #endif 76 77 #ifdef HAVE_FAM_H 78 79 /* monitor changes in directories using FAM 80 * 81 * This implementation employing FAM monitors directories as they are used, 82 * and maintains a reference count for cache use within stat_cache.c. 83 * A periodic job runs in lighttpd every 32 seconds, expiring entries unused 84 * in last 64 seconds out of the cache and cancelling FAM monitoring. Items 85 * within the cache are checked against the filesystem upon use if last stat() 86 * was greater than or equal to 16 seconds ago. 87 * 88 * This implementation does not monitor every directory in a tree, and therefore 89 * the cache may get out-of-sync with the filesystem. Delays in receiving and 90 * processing events from FAM might also lead to stale cache entries. 91 * 92 * For many websites, a large number of files are seldom, if ever, modified, 93 * and a common practice with images is to create a new file with a new name 94 * when a new version is needed, in order for client browsers and CDNs to better 95 * cache the content. Given this, most use will see little difference in 96 * performance between server.stat-cache-engine = "fam" and "simple" (default). 97 * The default server.stat-cache-engine = "simple" calls stat() on a target once 98 * per second, and reuses that information until the next second. For use where 99 * changes must be immediately visible, server.stat-cache-engine = "disable" 100 * should be used. 101 * 102 * When considering use of server.stat-cache-engine = "fam", there are a few 103 * additional limitations for this cache implementation using FAM. 104 * - symlinks to files located outside of the current directory do not result 105 * in changes to that file being monitored (unless that file is in a directory 106 * which is monitored as a result of a different request). symlinks can be 107 * chained and can be circular. This implementation *does not* readlink() or 108 * realpath() to resolve the chains to find and monitor the ultimate target 109 * directory. While symlinks to files located outside the current directory 110 * are not monitored, symlinks to directories *are* monitored, though chains 111 * of symlinks to directories do not result in monitoring of the directories 112 * containing intermediate symlinks to the target directory. 113 * - directory rename of a directory which is not currently being monitored will 114 * result in stale information in the cache if there is a subdirectory that is 115 * being monitored. 116 * Even though lighttpd will not receive FAM events in the above cases, lighttpd 117 * does re-validate the information in the cache upon use if the cache entry has 118 * not been checked in 16 seconds, so that is the upper limit for use of stale 119 * data. 120 * 121 * Use of server.stat-cache-engine = "fam" is discouraged for extremely volatile 122 * directories such as temporary directories (e.g. /tmp and maybe /var/tmp) due 123 * to the overhead of processing the additional noise generated from changes. 124 * Related, server.stat-cache-engine = "fam" is not recommended on trees of 125 * untrusted files where a malicious user could generate an excess of change 126 * events. 127 * 128 * Internal note: lighttpd walks the caches to prune trees in stat_cache when an 129 * event is received for a directory (or symlink to a directory) which has been 130 * deleted or renamed. The splaytree data structure is suboptimal for frequent 131 * changes of large directories trees where there have been a large number of 132 * different files recently accessed and part of the stat_cache. 133 */ 134 135 #if defined(HAVE_SYS_INOTIFY_H) \ 136 && !(defined(HAVE_SYS_EVENT_H) && defined(HAVE_KQUEUE)) 137 138 #include <sys/inotify.h> 139 140 /*(translate FAM API to inotify; this is specific to stat_cache.c use of FAM)*/ 141 #define fam fd /*(translate struct stat_cache_fam scf->fam -> scf->fd)*/ 142 typedef int FAMRequest; /*(fr)*/ 143 #define FAMClose(fd) \ 144 close(*(fd)) 145 #define FAMCancelMonitor(fd, wd) \ 146 inotify_rm_watch(*(fd), *(wd)) 147 #define fam_watch_mask ( IN_ATTRIB | IN_CREATE | IN_DELETE | IN_DELETE_SELF \ 148 | IN_MODIFY | IN_MOVE_SELF | IN_MOVED_FROM \ 149 | IN_EXCL_UNLINK | IN_ONLYDIR ) 150 /*(note: follows symlinks; not providing IN_DONT_FOLLOW)*/ 151 #define FAMMonitorDirectory(fd, fn, wd, userData) \ 152 ((*(wd) = inotify_add_watch(*(fd), (fn), (fam_watch_mask))) < 0) 153 typedef enum FAMCodes { /*(copied from fam.h to define arbitrary enum values)*/ 154 FAMChanged=1, 155 FAMDeleted=2, 156 FAMCreated=5, 157 FAMMoved=6, 158 } FAMCodes; 159 160 #elif defined HAVE_SYS_EVENT_H && defined HAVE_KQUEUE 161 #undef HAVE_SYS_INOTIFY_H 162 163 #include <sys/event.h> 164 #include <sys/time.h> 165 166 /*(translate FAM API to inotify; this is specific to stat_cache.c use of FAM)*/ 167 #define fam fd /*(translate struct stat_cache_fam scf->fam -> scf->fd)*/ 168 typedef int FAMRequest; /*(fr)*/ 169 #define FAMClose(fd) \ 170 (-1 != (*(fd)) ? close(*(fd)) : 0) 171 static int FAMCancelMonitor (const int * const fd, int * const wd) 172 { 173 if (-1 == *fd) return 0; 174 if (-1 == *wd) return 0; 175 struct timespec t0 = { 0, 0 }; 176 struct kevent kev; 177 EV_SET(&kev, *wd, EVFILT_VNODE, EV_DELETE, 0, 0, 0); 178 int rc = kevent(*fd, &kev, 1, NULL, 0, &t0); 179 close(*wd); 180 *wd = -1; 181 return rc; 182 } 183 static int FAMMonitorDirectory (int * const fd, char * const fn, int * const wd, void * const userData) 184 { 185 *wd = fdevent_open_dirname(fn, 1); /*(note: follows symlinks)*/ 186 if (-1 == *wd) return -1; 187 struct timespec t0 = { 0, 0 }; 188 struct kevent kev; 189 unsigned short kev_flags = EV_ADD | EV_ENABLE | EV_CLEAR; 190 unsigned int kev_fflags = NOTE_ATTRIB | NOTE_EXTEND | NOTE_LINK | NOTE_WRITE 191 | NOTE_DELETE | NOTE_REVOKE | NOTE_RENAME; 192 EV_SET(&kev, *wd, EVFILT_VNODE, kev_flags, kev_fflags, 0, userData); 193 return kevent(*fd, &kev, 1, NULL, 0, &t0); 194 } 195 typedef enum FAMCodes { /*(copied from fam.h to define arbitrary enum values)*/ 196 FAMChanged=1, 197 FAMDeleted=2, 198 FAMCreated=5, 199 FAMMoved=6, 200 } FAMCodes; 201 202 #else 203 204 #include <fam.h> 205 206 #ifdef HAVE_FAMNOEXISTS 207 #ifndef LIGHTTPD_STATIC 208 #include <dlfcn.h> 209 #endif 210 #endif 211 212 #endif 213 214 typedef struct fam_dir_entry { 215 buffer *name; 216 int refcnt; 217 FAMRequest req; 218 time_t stat_ts; 219 dev_t st_dev; 220 ino_t st_ino; 221 struct fam_dir_entry *fam_parent; 222 } fam_dir_entry; 223 224 typedef struct stat_cache_fam { 225 splay_tree *dirs; /* indexed by path; node data is fam_dir_entry */ 226 #ifdef HAVE_SYS_INOTIFY_H 227 splay_tree *wds; /* indexed by inotify watch descriptor */ 228 #elif defined HAVE_SYS_EVENT_H && defined HAVE_KQUEUE 229 #else 230 FAMConnection fam; 231 #endif 232 log_error_st *errh; 233 fdevents *ev; 234 fdnode *fdn; 235 int fd; 236 } stat_cache_fam; 237 238 static fam_dir_entry * fam_dir_entry_init(const char *name, size_t len) 239 { 240 fam_dir_entry * const fam_dir = calloc(1, sizeof(*fam_dir)); 241 force_assert(NULL != fam_dir); 242 243 fam_dir->name = buffer_init(); 244 buffer_copy_string_len(fam_dir->name, name, len); 245 fam_dir->refcnt = 0; 246 #if defined HAVE_SYS_EVENT_H && defined HAVE_KQUEUE 247 fam_dir->req = -1; 248 #endif 249 250 return fam_dir; 251 } 252 253 static void fam_dir_entry_free(fam_dir_entry *fam_dir) 254 { 255 if (!fam_dir) return; 256 /*(fam_dir->parent might be invalid pointer here; ignore)*/ 257 buffer_free(fam_dir->name); 258 #if defined HAVE_SYS_EVENT_H && defined HAVE_KQUEUE 259 if (-1 != fam_dir->req) 260 close(fam_dir->req); 261 #endif 262 free(fam_dir); 263 } 264 265 static void fam_dir_invalidate_node(fam_dir_entry *fam_dir) 266 { 267 fam_dir->stat_ts = 0; 268 if (fam_dir->fam_parent) { 269 --fam_dir->fam_parent->refcnt; 270 fam_dir->fam_parent = NULL; 271 } 272 } 273 274 /* 275 * walk though splay_tree and collect contents of dir tree. 276 * remove tagged entries in a second loop 277 */ 278 279 static void fam_dir_tag_refcnt(splay_tree *t, int *keys, int *ndx) 280 { 281 if (*ndx == 512) return; /*(must match num array entries in keys[])*/ 282 if (t->left) fam_dir_tag_refcnt(t->left, keys, ndx); 283 if (t->right) fam_dir_tag_refcnt(t->right, keys, ndx); 284 if (*ndx == 512) return; /*(must match num array entries in keys[])*/ 285 286 fam_dir_entry * const fam_dir = t->data; 287 if (0 == fam_dir->refcnt) { 288 fam_dir_invalidate_node(fam_dir); 289 keys[(*ndx)++] = t->key; 290 } 291 } 292 293 __attribute_noinline__ 294 static void fam_dir_periodic_cleanup() { 295 stat_cache_fam * const scf = sc.scf; 296 int max_ndx, i; 297 int keys[512]; /* 2k size on stack */ 298 #if defined HAVE_SYS_EVENT_H && defined HAVE_KQUEUE 299 struct kevent kevl[512]; /* 32k size on stack to batch kevent EV_DELETE */ 300 #endif 301 do { 302 if (!scf->dirs) break; 303 max_ndx = 0; 304 fam_dir_tag_refcnt(scf->dirs, keys, &max_ndx); 305 for (i = 0; i < max_ndx; ++i) { 306 const int ndx = keys[i]; 307 splay_tree *node = scf->dirs = splaytree_splay(scf->dirs, ndx); 308 if (node && node->key == ndx) { 309 fam_dir_entry *fam_dir = node->data; 310 scf->dirs = splaytree_delete(scf->dirs, ndx); 311 #ifdef HAVE_SYS_INOTIFY_H 312 scf->wds = splaytree_delete(scf->wds, fam_dir->req); 313 #elif defined HAVE_SYS_EVENT_H && defined HAVE_KQUEUE 314 /* batch process kevent removal; defer cancel */ 315 EV_SET(kevl+i, fam_dir->req, EVFILT_VNODE, EV_DELETE, 0, 0, 0); 316 fam_dir->req = -1; /*(make FAMCancelMonitor() a no-op)*/ 317 #endif 318 FAMCancelMonitor(&scf->fam, &fam_dir->req); 319 fam_dir_entry_free(fam_dir); 320 } 321 } 322 #if defined HAVE_SYS_EVENT_H && defined HAVE_KQUEUE 323 /* batch process: kevent() to submit EV_DELETE, then close dir fds */ 324 if (0 == max_ndx) break; 325 struct timespec t0 = { 0, 0 }; 326 kevent(scf->fd, kevl, max_ndx, NULL, 0, &t0); 327 for (i = 0; i < max_ndx; ++i) 328 close((int)kevl[i].ident); 329 #endif 330 } while (max_ndx == sizeof(keys)/sizeof(int)); 331 } 332 333 static void fam_dir_invalidate_tree(splay_tree *t, const char *name, size_t len) 334 { 335 #ifdef __clang_analyzer__ 336 force_assert(name); 337 #endif 338 /*force_assert(t);*/ 339 if (t->left) fam_dir_invalidate_tree(t->left, name, len); 340 if (t->right) fam_dir_invalidate_tree(t->right, name, len); 341 342 fam_dir_entry * const fam_dir = t->data; 343 #ifdef __clang_analyzer__ 344 force_assert(fam_dir); 345 #endif 346 buffer *b = fam_dir->name; 347 size_t blen = buffer_string_length(b); 348 if (blen > len && b->ptr[len] == '/' && 0 == memcmp(b->ptr, name, len)) 349 fam_dir_invalidate_node(fam_dir); 350 } 351 352 /* declarations */ 353 static void stat_cache_delete_tree(const char *name, uint32_t len); 354 static void stat_cache_invalidate_dir_tree(const char *name, size_t len); 355 static void stat_cache_handle_fdevent_fn(stat_cache_fam * const scf, fam_dir_entry * const fam_dir, const char * const fn, const uint32_t fnlen, int code); 356 357 static void stat_cache_handle_fdevent_in(stat_cache_fam *scf) 358 { 359 #ifdef HAVE_SYS_INOTIFY_H 360 /*(inotify pads in->len to align struct following in->name[])*/ 361 char buf[4096] 362 __attribute__ ((__aligned__(__alignof__(struct inotify_event)))); 363 int rd; 364 do { 365 rd = (int)read(scf->fd, buf, sizeof(buf)); 366 if (rd <= 0) { 367 if (-1 == rd && errno != EINTR && errno != EAGAIN) { 368 log_perror(scf->errh, __FILE__, __LINE__, "inotify error"); 369 /* TODO: could flush cache, close scf->fd, and re-open inotify*/ 370 } 371 break; 372 } 373 for (int i = 0; i < rd; ) { 374 struct inotify_event * const in = 375 (struct inotify_event *)((uintptr_t)buf + i); 376 uint32_t len = in->len; 377 if (len > sizeof(buf)) break; /*(should not happen)*/ 378 i += sizeof(struct inotify_event) + len; 379 if (i > rd) break; /*(should not happen (partial record))*/ 380 if (in->mask & IN_CREATE) 381 continue; /*(see comment below for FAMCreated)*/ 382 if (in->mask & IN_Q_OVERFLOW) { 383 log_error(scf->errh, __FILE__, __LINE__, 384 "inotify queue overflow"); 385 continue; 386 } 387 /* ignore events which may have been pending for 388 * paths recently cancelled via FAMCancelMonitor() */ 389 scf->wds = splaytree_splay(scf->wds, in->wd); 390 if (!scf->wds || scf->wds->key != in->wd) 391 continue; 392 fam_dir_entry *fam_dir = scf->wds->data; 393 if (NULL == fam_dir) /*(should not happen)*/ 394 continue; 395 if (fam_dir->req != in->wd) /*(should not happen)*/ 396 continue; 397 /*(specific to use here in stat_cache.c)*/ 398 int code = 0; 399 if (in->mask & (IN_ATTRIB | IN_MODIFY)) 400 code = FAMChanged; 401 else if (in->mask & (IN_DELETE | IN_DELETE_SELF | IN_UNMOUNT)) 402 code = FAMDeleted; 403 else if (in->mask & (IN_MOVE_SELF | IN_MOVED_FROM)) 404 code = FAMMoved; 405 406 if (len) { 407 do { --len; } while (len && in->name[len-1] == '\0'); 408 } 409 stat_cache_handle_fdevent_fn(scf, fam_dir, in->name, len, code); 410 } 411 } while (rd + sizeof(struct inotify_event) + NAME_MAX + 1 > sizeof(buf)); 412 #elif defined HAVE_SYS_EVENT_H && defined HAVE_KQUEUE 413 struct kevent kevl[256]; 414 struct timespec t0 = { 0, 0 }; 415 int n; 416 do { 417 n = kevent(scf->fd, NULL, 0, kevl, sizeof(kevl)/sizeof(*kevl), &t0); 418 if (n <= 0) break; 419 for (int i = 0; i < n; ++i) { 420 const struct kevent * const kev = kevl+i; 421 /* ignore events which may have been pending for 422 * paths recently cancelled via FAMCancelMonitor() */ 423 int ndx = (int)(intptr_t)kev->udata; 424 scf->dirs = splaytree_splay(scf->dirs, ndx); 425 if (!scf->dirs || scf->dirs->key != ndx) 426 continue; 427 fam_dir_entry *fam_dir = scf->dirs->data; 428 if (fam_dir->req != (int)kev->ident) 429 continue; 430 /*(specific to use here in stat_cache.c)*/ 431 /* note: stat_cache only monitors on directories, 432 * so events here are only on directories 433 * note: changes are treated as FAMDeleted since 434 * it is unknown which file in dir was changed 435 * This is not efficient, but this stat_cache mechanism also 436 * should not be used on frequently modified directories. */ 437 int code = 0; 438 if (kev->fflags & (NOTE_WRITE|NOTE_ATTRIB|NOTE_EXTEND|NOTE_LINK)) 439 code = FAMDeleted; /*(not FAMChanged; see comment above)*/ 440 else if (kev->fflags & (NOTE_DELETE|NOTE_REVOKE)) 441 code = FAMDeleted; 442 else if (kev->fflags & NOTE_RENAME) 443 code = FAMMoved; 444 if (kev->flags & EV_ERROR) /*(not expected; treat as FAMDeleted)*/ 445 code = FAMDeleted; 446 stat_cache_handle_fdevent_fn(scf, fam_dir, NULL, 0, code); 447 } 448 } while (n == sizeof(kevl)/sizeof(*kevl)); 449 #else 450 for (int i = 0, ndx; i || (i = FAMPending(&scf->fam)) > 0; --i) { 451 FAMEvent fe; 452 if (FAMNextEvent(&scf->fam, &fe) < 0) break; 453 454 /* ignore events which may have been pending for 455 * paths recently cancelled via FAMCancelMonitor() */ 456 ndx = (int)(intptr_t)fe.userdata; 457 scf->dirs = splaytree_splay(scf->dirs, ndx); 458 if (!scf->dirs || scf->dirs->key != ndx) { 459 continue; 460 } 461 fam_dir_entry *fam_dir = scf->dirs->data; 462 if (FAMREQUEST_GETREQNUM(&fam_dir->req) 463 != FAMREQUEST_GETREQNUM(&fe.fr)) { 464 continue; 465 } 466 467 uint32_t fnlen = (fe.code != FAMCreated && fe.filename[0] != '/') 468 ? (uint32_t)strlen(fe.filename) 469 : 0; 470 stat_cache_handle_fdevent_fn(scf, fam_dir, fe.filename, fnlen, fe.code); 471 } 472 #endif 473 } 474 475 static void stat_cache_handle_fdevent_fn(stat_cache_fam * const scf, fam_dir_entry *fam_dir, const char * const fn, const uint32_t fnlen, int code) 476 { 477 if (fnlen) { 478 buffer * const n = fam_dir->name; 479 fam_dir_entry *fam_link; 480 uint32_t len; 481 switch (code) { 482 case FAMCreated: 483 /* file created in monitored dir modifies dir and 484 * we should get a separate FAMChanged event for dir. 485 * Therefore, ignore file FAMCreated event here. 486 * Also, if FAMNoExists() is used, might get spurious 487 * FAMCreated events as changes are made e.g. in monitored 488 * sub-sub-sub dirs and the library discovers new (already 489 * existing) dir entries */ 490 return; 491 case FAMChanged: 492 /* file changed in monitored dir does not modify dir */ 493 case FAMDeleted: 494 case FAMMoved: 495 /* file deleted or moved in monitored dir modifies dir, 496 * but FAM provides separate notification for that */ 497 498 /* temporarily append filename to dir in fam_dir->name to 499 * construct path, then delete stat_cache entry (if any)*/ 500 len = buffer_string_length(n); 501 buffer_append_path_len(n, fn, fnlen); 502 /* (alternatively, could chose to stat() and update)*/ 503 stat_cache_invalidate_entry(CONST_BUF_LEN(n)); 504 505 fam_link = /*(check if might be symlink to monitored dir)*/ 506 stat_cache_sptree_find(&scf->dirs, CONST_BUF_LEN(n)); 507 if (fam_link && !buffer_is_equal(fam_link->name, n)) 508 fam_link = NULL; 509 510 buffer_string_set_length(n, len); 511 512 if (fam_link) { 513 /* replaced symlink changes containing dir */ 514 stat_cache_invalidate_entry(CONST_BUF_LEN(n)); 515 /* handle symlink to dir as deleted dir below */ 516 code = FAMDeleted; 517 fam_dir = fam_link; 518 break; 519 } 520 return; 521 default: 522 return; 523 } 524 } 525 526 switch(code) { 527 case FAMChanged: 528 stat_cache_invalidate_entry(CONST_BUF_LEN(fam_dir->name)); 529 break; 530 case FAMDeleted: 531 case FAMMoved: 532 stat_cache_delete_tree(CONST_BUF_LEN(fam_dir->name)); 533 fam_dir_invalidate_node(fam_dir); 534 if (scf->dirs) 535 fam_dir_invalidate_tree(scf->dirs,CONST_BUF_LEN(fam_dir->name)); 536 fam_dir_periodic_cleanup(); 537 break; 538 default: 539 break; 540 } 541 } 542 543 static handler_t stat_cache_handle_fdevent(void *ctx, int revent) 544 { 545 stat_cache_fam * const scf = ctx; /* sc.scf */ 546 547 if (revent & FDEVENT_IN) { 548 stat_cache_handle_fdevent_in(scf); 549 } 550 551 if (revent & (FDEVENT_HUP|FDEVENT_RDHUP)) { 552 /* fam closed the connection */ 553 log_error(scf->errh, __FILE__, __LINE__, 554 "FAM connection closed; disabling stat_cache."); 555 /* (although effectively STAT_CACHE_ENGINE_NONE, 556 * do not change here so that periodic jobs clean up memory)*/ 557 /*sc.stat_cache_engine = STAT_CACHE_ENGINE_NONE; */ 558 fdevent_fdnode_event_del(scf->ev, scf->fdn); 559 fdevent_unregister(scf->ev, scf->fd); 560 scf->fdn = NULL; 561 562 FAMClose(&scf->fam); 563 scf->fd = -1; 564 } 565 566 return HANDLER_GO_ON; 567 } 568 569 static stat_cache_fam * stat_cache_init_fam(fdevents *ev, log_error_st *errh) { 570 stat_cache_fam *scf = calloc(1, sizeof(*scf)); 571 force_assert(scf); 572 scf->fd = -1; 573 scf->ev = ev; 574 scf->errh = errh; 575 576 #ifdef HAVE_SYS_INOTIFY_H 577 scf->fd = inotify_init1(IN_NONBLOCK|IN_CLOEXEC); 578 if (scf->fd < 0) { 579 log_perror(errh, __FILE__, __LINE__, "inotify_init1()"); 580 free(scf); 581 return NULL; 582 } 583 #elif defined HAVE_SYS_EVENT_H && defined HAVE_KQUEUE 584 #ifdef __NetBSD__ 585 scf->fd = kqueue1(O_NONBLOCK|O_CLOEXEC|O_NOSIGPIPE); 586 #else 587 scf->fd = kqueue(); 588 if (scf->fd >= 0) fdevent_setfd_cloexec(scf->fd); 589 #endif 590 if (scf->fd < 0) { 591 log_perror(errh, __FILE__, __LINE__, "kqueue()"); 592 free(scf); 593 return NULL; 594 } 595 #else 596 /* setup FAM */ 597 if (0 != FAMOpen2(&scf->fam, "lighttpd")) { 598 log_error(errh, __FILE__, __LINE__, 599 "could not open a fam connection, dying."); 600 free(scf); 601 return NULL; 602 } 603 #ifdef HAVE_FAMNOEXISTS 604 #ifdef LIGHTTPD_STATIC 605 FAMNoExists(&scf->fam); 606 #else 607 int (*FAMNoExists_fn)(FAMConnection *); 608 FAMNoExists_fn = 609 (int (*)(FAMConnection *))(intptr_t)dlsym(RTLD_DEFAULT,"FAMNoExists"); 610 if (FAMNoExists_fn) FAMNoExists_fn(&scf->fam); 611 #endif 612 #endif 613 614 scf->fd = FAMCONNECTION_GETFD(&scf->fam); 615 fdevent_setfd_cloexec(scf->fd); 616 #endif 617 scf->fdn = fdevent_register(scf->ev, scf->fd, stat_cache_handle_fdevent, scf); 618 fdevent_fdnode_event_set(scf->ev, scf->fdn, FDEVENT_IN | FDEVENT_RDHUP); 619 620 return scf; 621 } 622 623 static void stat_cache_free_fam(stat_cache_fam *scf) { 624 if (NULL == scf) return; 625 626 #ifdef HAVE_SYS_INOTIFY_H 627 while (scf->wds) { 628 splay_tree *node = scf->wds; 629 scf->wds = splaytree_delete(scf->wds, node->key); 630 } 631 #elif defined HAVE_SYS_EVENT_H && defined HAVE_KQUEUE 632 /*(quicker cleanup to close kqueue() before cancel per entry)*/ 633 close(scf->fd); 634 scf->fd = -1; 635 #endif 636 while (scf->dirs) { 637 /*(skip entry invalidation and FAMCancelMonitor())*/ 638 splay_tree *node = scf->dirs; 639 fam_dir_entry_free((fam_dir_entry *)node->data); 640 scf->dirs = splaytree_delete(scf->dirs, node->key); 641 } 642 643 if (-1 != scf->fd) { 644 /*scf->fdn already cleaned up in fdevent_free()*/ 645 FAMClose(&scf->fam); 646 /*scf->fd = -1;*/ 647 } 648 649 free(scf); 650 } 651 652 static fam_dir_entry * fam_dir_monitor(stat_cache_fam *scf, char *fn, uint32_t dirlen, struct stat *st) 653 { 654 if (NULL == scf->fdn) return NULL; /* FAM connection closed; do nothing */ 655 const int fn_is_dir = S_ISDIR(st->st_mode); 656 /*force_assert(0 != dirlen);*/ 657 /*force_assert(fn[0] == '/');*/ 658 /* consistency: ensure fn does not end in '/' unless root "/" 659 * FAM events will not end in '/', so easier to match this way */ 660 if (fn[dirlen-1] == '/') --dirlen; 661 if (0 == dirlen) dirlen = 1; /* root dir ("/") */ 662 /* Note: paths are expected to be normalized before calling stat_cache, 663 * e.g. without repeated '/' */ 664 if (!fn_is_dir) { 665 while (fn[--dirlen] != '/') ; 666 if (0 == dirlen) dirlen = 1; /*(should not happen for file)*/ 667 } 668 int dir_ndx = splaytree_djbhash(fn, dirlen); 669 fam_dir_entry *fam_dir = NULL; 670 671 scf->dirs = splaytree_splay(scf->dirs, dir_ndx); 672 if (NULL != scf->dirs && scf->dirs->key == dir_ndx) { 673 fam_dir = scf->dirs->data; 674 if (!buffer_is_equal_string(fam_dir->name, fn, dirlen)) { 675 /* hash collision; preserve existing 676 * do not monitor new to avoid cache thrashing */ 677 return NULL; 678 } 679 /* directory already registered */ 680 } 681 682 const time_t cur_ts = log_epoch_secs; 683 struct stat lst; 684 int ck_dir = fn_is_dir; 685 if (!fn_is_dir && (NULL==fam_dir || cur_ts - fam_dir->stat_ts >= 16)) { 686 ck_dir = 1; 687 /*(temporarily modify fn)*/ 688 fn[dirlen] = '\0'; 689 if (0 != lstat(fn, &lst)) { 690 fn[dirlen] = '/'; 691 return NULL; 692 } 693 if (!S_ISLNK(lst.st_mode)) { 694 st = &lst; 695 } 696 else if (0 != stat(fn, st)) { /*st passed in now is stat() of dir*/ 697 fn[dirlen] = '/'; 698 return NULL; 699 } 700 fn[dirlen] = '/'; 701 } 702 703 int ck_lnk = (NULL == fam_dir); 704 if (ck_dir && NULL != fam_dir) { 705 /* check stat() matches device and inode, just in case an external event 706 * not being monitored occurs (e.g. rename of unmonitored parent dir)*/ 707 if (st->st_dev != fam_dir->st_dev || st->st_ino != fam_dir->st_ino) { 708 ck_lnk = 1; 709 /*(modifies scf->dirs but no need to re-splay for dir_ndx since 710 * fam_dir is not NULL and so splaytree_insert not called below)*/ 711 if (scf->dirs) fam_dir_invalidate_tree(scf->dirs, fn, dirlen); 712 if (!fn_is_dir) /*(if dir, caller is updating stat_cache_entry)*/ 713 stat_cache_update_entry(fn, dirlen, st, NULL); 714 /*(must not delete tree since caller is holding a valid node)*/ 715 stat_cache_invalidate_dir_tree(fn, dirlen); 716 #ifdef HAVE_SYS_INOTIFY_H 717 scf->wds = splaytree_delete(scf->wds, fam_dir->req); 718 #endif 719 if (0 != FAMCancelMonitor(&scf->fam, &fam_dir->req) 720 || 0 != FAMMonitorDirectory(&scf->fam, fam_dir->name->ptr, 721 &fam_dir->req, 722 (void *)(intptr_t)dir_ndx)) { 723 fam_dir->stat_ts = 0; /* invalidate */ 724 return NULL; 725 } 726 fam_dir->st_dev = st->st_dev; 727 fam_dir->st_ino = st->st_ino; 728 #ifdef HAVE_SYS_INOTIFY_H 729 scf->wds = splaytree_insert(scf->wds, fam_dir->req, fam_dir); 730 #endif 731 } 732 fam_dir->stat_ts = cur_ts; 733 } 734 735 if (NULL == fam_dir) { 736 fam_dir = fam_dir_entry_init(fn, dirlen); 737 738 if (0 != FAMMonitorDirectory(&scf->fam,fam_dir->name->ptr,&fam_dir->req, 739 (void *)(intptr_t)dir_ndx)) { 740 #if defined(HAVE_SYS_INOTIFY_H) \ 741 || (defined HAVE_SYS_EVENT_H && defined HAVE_KQUEUE) 742 log_perror(scf->errh, __FILE__, __LINE__, 743 "monitoring dir failed: %s file: %s", 744 fam_dir->name->ptr, fn); 745 #else 746 log_error(scf->errh, __FILE__, __LINE__, 747 "monitoring dir failed: %s file: %s %s", 748 fam_dir->name->ptr, fn, FamErrlist[FAMErrno]); 749 #endif 750 fam_dir_entry_free(fam_dir); 751 return NULL; 752 } 753 754 scf->dirs = splaytree_insert(scf->dirs, dir_ndx, fam_dir); 755 #ifdef HAVE_SYS_INOTIFY_H 756 scf->wds = splaytree_insert(scf->wds, fam_dir->req, fam_dir); 757 #endif 758 fam_dir->stat_ts= cur_ts; 759 fam_dir->st_dev = st->st_dev; 760 fam_dir->st_ino = st->st_ino; 761 } 762 763 if (ck_lnk) { 764 if (fn_is_dir) { 765 /*(temporarily modify fn)*/ 766 char e = fn[dirlen]; 767 fn[dirlen] = '\0'; 768 if (0 != lstat(fn, &lst)) { 769 fn[dirlen] = e; 770 return NULL; 771 } 772 fn[dirlen] = e; 773 } 774 if (fam_dir->fam_parent) { 775 --fam_dir->fam_parent->refcnt; 776 fam_dir->fam_parent = NULL; 777 } 778 if (S_ISLNK(lst.st_mode)) { 779 fam_dir->fam_parent = fam_dir_monitor(scf, fn, dirlen, &lst); 780 } 781 } 782 783 ++fam_dir->refcnt; 784 return fam_dir; 785 } 786 787 #endif 788 789 790 static stat_cache_entry * stat_cache_entry_init(void) { 791 stat_cache_entry *sce = calloc(1, sizeof(*sce)); 792 force_assert(NULL != sce); 793 sce->fd = -1; 794 sce->refcnt = 1; 795 return sce; 796 } 797 798 static void stat_cache_entry_free(void *data) { 799 stat_cache_entry *sce = data; 800 if (!sce) return; 801 802 if (--sce->refcnt) return; 803 804 #ifdef HAVE_FAM_H 805 /*(decrement refcnt only; 806 * defer cancelling FAM monitor on dir even if refcnt reaches zero)*/ 807 if (sce->fam_dir) --((fam_dir_entry *)sce->fam_dir)->refcnt; 808 #endif 809 810 free(sce->name.ptr); 811 free(sce->etag.ptr); 812 if (sce->content_type.size) free(sce->content_type.ptr); 813 if (sce->fd >= 0) close(sce->fd); 814 815 free(sce); 816 } 817 818 void stat_cache_entry_refchg(void *data, int mod) { 819 /*(expect mod == -1 or mod == 1)*/ 820 stat_cache_entry * const sce = data; 821 if (mod < 0 && 1 == sce->refcnt) 822 stat_cache_entry_free(data); 823 else 824 sce->refcnt += mod; 825 } 826 827 #if defined(HAVE_XATTR) || defined(HAVE_EXTATTR) 828 829 static const char *attrname = "Content-Type"; 830 static char attrval[128]; 831 static buffer attrb = { attrval, 0, 0 }; 832 833 static int stat_cache_attr_get(const char *name) { 834 #if defined(HAVE_XATTR) 835 #if defined(HAVE_SYS_XATTR_H) 836 ssize_t attrlen; 837 if (0 < (attrlen = getxattr(name, attrname, 838 attrval, sizeof(attrval)-1))) 839 #else 840 int attrlen = sizeof(attrval)-1; 841 if (0 == attr_get(name, attrname, attrval, &attrlen, 0)) 842 #endif 843 #elif defined(HAVE_EXTATTR) 844 ssize_t attrlen; 845 if (0 < (attrlen = extattr_get_file(name, EXTATTR_NAMESPACE_USER, attrname, 846 attrval, sizeof(attrval)-1))) 847 #endif 848 { 849 attrval[attrlen] = '\0'; 850 attrb.used = (uint32_t)(attrlen + 1); 851 return 1; 852 } 853 return 0; 854 } 855 856 #endif 857 858 int stat_cache_init(fdevents *ev, log_error_st *errh) { 859 #ifdef HAVE_FAM_H 860 if (sc.stat_cache_engine == STAT_CACHE_ENGINE_FAM) { 861 sc.scf = stat_cache_init_fam(ev, errh); 862 if (NULL == sc.scf) return 0; 863 } 864 #else 865 UNUSED(ev); 866 UNUSED(errh); 867 #endif 868 869 return 1; 870 } 871 872 void stat_cache_free(void) { 873 splay_tree *sptree = sc.files; 874 while (sptree) { 875 stat_cache_entry_free(sptree->data); 876 sptree = splaytree_delete(sptree, sptree->key); 877 } 878 sc.files = NULL; 879 880 #ifdef HAVE_FAM_H 881 stat_cache_free_fam(sc.scf); 882 sc.scf = NULL; 883 #endif 884 885 #if defined(HAVE_XATTR) || defined(HAVE_EXTATTR) 886 attrname = "Content-Type"; 887 #endif 888 889 sc.stat_cache_engine = STAT_CACHE_ENGINE_SIMPLE; /*(default)*/ 890 } 891 892 void stat_cache_xattrname (const char *name) { 893 #if defined(HAVE_XATTR) || defined(HAVE_EXTATTR) 894 attrname = name; 895 #else 896 UNUSED(name); 897 #endif 898 } 899 900 int stat_cache_choose_engine (const buffer *stat_cache_string, log_error_st *errh) { 901 if (buffer_string_is_empty(stat_cache_string)) 902 sc.stat_cache_engine = STAT_CACHE_ENGINE_SIMPLE; 903 else if (buffer_eq_slen(stat_cache_string, CONST_STR_LEN("simple"))) 904 sc.stat_cache_engine = STAT_CACHE_ENGINE_SIMPLE; 905 #ifdef HAVE_SYS_INOTIFY_H 906 else if (buffer_eq_slen(stat_cache_string, CONST_STR_LEN("inotify"))) 907 sc.stat_cache_engine = STAT_CACHE_ENGINE_INOTIFY; 908 /*(STAT_CACHE_ENGINE_FAM == STAT_CACHE_ENGINE_INOTIFY)*/ 909 #elif defined HAVE_SYS_EVENT_H && defined HAVE_KQUEUE 910 else if (buffer_eq_slen(stat_cache_string, CONST_STR_LEN("kqueue"))) 911 sc.stat_cache_engine = STAT_CACHE_ENGINE_KQUEUE; 912 /*(STAT_CACHE_ENGINE_FAM == STAT_CACHE_ENGINE_KQUEUE)*/ 913 #endif 914 #ifdef HAVE_FAM_H 915 else if (buffer_eq_slen(stat_cache_string, CONST_STR_LEN("fam"))) 916 sc.stat_cache_engine = STAT_CACHE_ENGINE_FAM; 917 #endif 918 else if (buffer_eq_slen(stat_cache_string, CONST_STR_LEN("disable")) 919 || buffer_eq_slen(stat_cache_string, CONST_STR_LEN("none"))) 920 sc.stat_cache_engine = STAT_CACHE_ENGINE_NONE; 921 else { 922 log_error(errh, __FILE__, __LINE__, 923 "server.stat-cache-engine can be one of \"disable\", \"simple\"," 924 #ifdef HAVE_SYS_INOTIFY_H 925 " \"inotify\"," 926 #elif defined HAVE_SYS_EVENT_H && defined HAVE_KQUEUE 927 " \"kqueue\"," 928 #endif 929 #ifdef HAVE_FAM_H 930 " \"fam\"," 931 #endif 932 " but not: %s", stat_cache_string->ptr); 933 return -1; 934 } 935 return 0; 936 } 937 938 const buffer * stat_cache_mimetype_by_ext(const array * const mimetypes, const char * const name, const uint32_t nlen) 939 { 940 const char * const end = name + nlen; /*(end of string)*/ 941 const uint32_t used = mimetypes->used; 942 if (used < 16) { 943 for (uint32_t i = 0; i < used; ++i) { 944 /* suffix match */ 945 const data_string *ds = (data_string *)mimetypes->data[i]; 946 const size_t klen = buffer_string_length(&ds->key); 947 if (klen <= nlen && buffer_eq_icase_ssn(end-klen, ds->key.ptr, klen)) 948 return &ds->value; 949 } 950 } 951 else { 952 const char *s; 953 const data_string *ds; 954 if (nlen) { 955 for (s = end-1; s != name && *s != '/'; --s) ; /*(like memrchr())*/ 956 if (*s == '/') ++s; 957 } 958 else { 959 s = name; 960 } 961 /* search for basename, then longest .ext2.ext1, then .ext1, then "" */ 962 ds = (const data_string *)array_get_element_klen(mimetypes, s, end - s); 963 if (NULL != ds) return &ds->value; 964 while (++s < end) { 965 while (*s != '.' && ++s != end) ; 966 if (s == end) break; 967 /* search ".ext" then "ext" */ 968 ds = (const data_string *)array_get_element_klen(mimetypes, s, end - s); 969 if (NULL != ds) return &ds->value; 970 /* repeat search without leading '.' to handle situation where 971 * admin configured mimetype.assign keys without leading '.' */ 972 if (++s < end) { 973 if (*s == '.') { --s; continue; } 974 ds = (const data_string *)array_get_element_klen(mimetypes, s, end - s); 975 if (NULL != ds) return &ds->value; 976 } 977 } 978 /* search for ""; catchall */ 979 ds = (const data_string *)array_get_element_klen(mimetypes, CONST_STR_LEN("")); 980 if (NULL != ds) return &ds->value; 981 } 982 983 return NULL; 984 } 985 986 #if defined(HAVE_XATTR) || defined(HAVE_EXTATTR) 987 988 const buffer * stat_cache_mimetype_by_xattr(const char * const name) 989 { 990 return stat_cache_attr_get(name) ? &attrb : NULL; 991 } 992 993 const buffer * stat_cache_content_type_get_by_xattr(stat_cache_entry *sce, const array *mimetypes, int use_xattr) 994 { 995 /*(invalid caching if user config has multiple, different 996 * r->conf.mimetypes for same extension (not expected))*/ 997 if (!buffer_string_is_empty(&sce->content_type)) return &sce->content_type; 998 999 if (!S_ISREG(sce->st.st_mode)) return NULL; 1000 1001 /* cache mimetype */ 1002 const buffer *mtype = 1003 (use_xattr) ? stat_cache_mimetype_by_xattr(sce->name.ptr) : NULL; 1004 if (NULL == mtype) 1005 mtype = stat_cache_mimetype_by_ext(mimetypes,CONST_BUF_LEN(&sce->name)); 1006 if (NULL != mtype) { 1007 if (sce->content_type.size) { 1008 buffer_copy_buffer(&sce->content_type, mtype); 1009 } 1010 else if (mtype == &attrb) { 1011 sce->content_type.ptr = NULL; 1012 buffer_copy_buffer(&sce->content_type, mtype); 1013 } 1014 else { 1015 /*(copy pointers from mimetypes array; avoid allocation)*/ 1016 sce->content_type.ptr = mtype->ptr; 1017 sce->content_type.used = mtype->used; 1018 /*(leave sce->content_type.size = 0 to flag not-allocated)*/ 1019 } 1020 } 1021 else 1022 buffer_clear(&sce->content_type); 1023 1024 return &sce->content_type; 1025 } 1026 1027 #else 1028 1029 const buffer * stat_cache_content_type_get_by_ext(stat_cache_entry *sce, const array *mimetypes) 1030 { 1031 /*(invalid caching if user config has multiple, different 1032 * r->conf.mimetypes for same extension (not expected))*/ 1033 if (!buffer_string_is_empty(&sce->content_type)) return &sce->content_type; 1034 1035 if (!S_ISREG(sce->st.st_mode)) return NULL; 1036 1037 /* cache mimetype */ 1038 const buffer * const mtype = 1039 stat_cache_mimetype_by_ext(mimetypes, CONST_BUF_LEN(&sce->name)); 1040 if (NULL != mtype) { 1041 /*(copy pointers from mimetypes array; avoid allocation)*/ 1042 sce->content_type.ptr = mtype->ptr; 1043 sce->content_type.used = mtype->used; 1044 /*(leave sce->content_type.size = 0 to flag not-allocated)*/ 1045 } 1046 else 1047 buffer_clear(&sce->content_type); 1048 1049 return &sce->content_type; 1050 } 1051 1052 #endif 1053 1054 const buffer * stat_cache_etag_get(stat_cache_entry *sce, int flags) { 1055 /*(invalid caching if user cfg has multiple, different r->conf.etag_flags 1056 * for same path (not expected, since etag flags should be by filesystem))*/ 1057 if (!buffer_string_is_empty(&sce->etag)) return &sce->etag; 1058 1059 if (S_ISREG(sce->st.st_mode) || S_ISDIR(sce->st.st_mode)) { 1060 if (0 == flags) return NULL; 1061 http_etag_create(&sce->etag, &sce->st, flags); 1062 return &sce->etag; 1063 } 1064 1065 return NULL; 1066 } 1067 1068 __attribute_pure__ 1069 static int stat_cache_stat_eq(const struct stat * const sta, const struct stat * const stb) { 1070 return 1071 #ifdef st_mtime /* use high-precision timestamp if available */ 1072 #if defined(__APPLE__) && defined(__MACH__) 1073 sta->st_mtimespec.tv_nsec == stb->st_mtimespec.tv_nsec 1074 #else 1075 sta->st_mtim.tv_nsec == stb->st_mtim.tv_nsec 1076 #endif 1077 #else 1078 1 1079 #endif 1080 && sta->st_mtime == stb->st_mtime 1081 && sta->st_size == stb->st_size 1082 && sta->st_ino == stb->st_ino 1083 && sta->st_dev == stb->st_dev; 1084 } 1085 1086 void stat_cache_update_entry(const char *name, uint32_t len, 1087 struct stat *st, buffer *etagb) 1088 { 1089 if (sc.stat_cache_engine == STAT_CACHE_ENGINE_NONE) return; 1090 force_assert(0 != len); 1091 if (name[len-1] == '/') { if (0 == --len) len = 1; } 1092 splay_tree **sptree = &sc.files; 1093 stat_cache_entry *sce = 1094 stat_cache_sptree_find(sptree, name, len); 1095 if (sce && buffer_is_equal_string(&sce->name, name, len)) { 1096 if (!stat_cache_stat_eq(&sce->st, st)) { 1097 /* etagb might be NULL to clear etag (invalidate) */ 1098 buffer_copy_string_len(&sce->etag, CONST_BUF_LEN(etagb)); 1099 #if defined(HAVE_XATTR) || defined(HAVE_EXTATTR) 1100 buffer_clear(&sce->content_type); 1101 #endif 1102 if (sce->fd >= 0) { 1103 if (1 == sce->refcnt) { 1104 close(sce->fd); 1105 sce->fd = -1; 1106 } 1107 else { 1108 --sce->refcnt; /* stat_cache_entry_free(sce); */ 1109 (*sptree)->data = sce = stat_cache_entry_init(); 1110 buffer_copy_string_len(&sce->name, name, len); 1111 } 1112 } 1113 sce->st = *st; 1114 } 1115 sce->stat_ts = log_epoch_secs; 1116 } 1117 } 1118 1119 void stat_cache_delete_entry(const char *name, uint32_t len) 1120 { 1121 if (sc.stat_cache_engine == STAT_CACHE_ENGINE_NONE) return; 1122 force_assert(0 != len); 1123 if (name[len-1] == '/') { if (0 == --len) len = 1; } 1124 splay_tree **sptree = &sc.files; 1125 stat_cache_entry *sce = stat_cache_sptree_find(sptree, name, len); 1126 if (sce && buffer_is_equal_string(&sce->name, name, len)) { 1127 stat_cache_entry_free(sce); 1128 *sptree = splaytree_delete(*sptree, (*sptree)->key); 1129 } 1130 } 1131 1132 void stat_cache_invalidate_entry(const char *name, uint32_t len) 1133 { 1134 splay_tree **sptree = &sc.files; 1135 stat_cache_entry *sce = stat_cache_sptree_find(sptree, name, len); 1136 if (sce && buffer_is_equal_string(&sce->name, name, len)) { 1137 sce->stat_ts = 0; 1138 #ifdef HAVE_FAM_H 1139 if (sce->fam_dir != NULL) { 1140 --((fam_dir_entry *)sce->fam_dir)->refcnt; 1141 sce->fam_dir = NULL; 1142 } 1143 #endif 1144 } 1145 } 1146 1147 #ifdef HAVE_FAM_H 1148 1149 static void stat_cache_invalidate_dir_tree_walk(splay_tree *t, 1150 const char *name, size_t len) 1151 { 1152 if (t->left) stat_cache_invalidate_dir_tree_walk(t->left, name, len); 1153 if (t->right) stat_cache_invalidate_dir_tree_walk(t->right, name, len); 1154 1155 buffer *b = &((stat_cache_entry *)t->data)->name; 1156 size_t blen = buffer_string_length(b); 1157 if (blen > len && b->ptr[len] == '/' && 0 == memcmp(b->ptr, name, len)) { 1158 stat_cache_entry *sce = t->data; 1159 sce->stat_ts = 0; 1160 if (sce->fam_dir != NULL) { 1161 --((fam_dir_entry *)sce->fam_dir)->refcnt; 1162 sce->fam_dir = NULL; 1163 } 1164 } 1165 } 1166 1167 static void stat_cache_invalidate_dir_tree(const char *name, size_t len) 1168 { 1169 splay_tree * const sptree = sc.files; 1170 if (sptree) stat_cache_invalidate_dir_tree_walk(sptree, name, len); 1171 } 1172 1173 #endif 1174 1175 /* 1176 * walk though splay_tree and collect contents of dir tree. 1177 * remove tagged entries in a second loop 1178 */ 1179 1180 static void stat_cache_tag_dir_tree(splay_tree *t, const char *name, size_t len, 1181 int *keys, int *ndx) 1182 { 1183 if (*ndx == 8192) return; /*(must match num array entries in keys[])*/ 1184 if (t->left) stat_cache_tag_dir_tree(t->left, name, len, keys, ndx); 1185 if (t->right) stat_cache_tag_dir_tree(t->right, name, len, keys, ndx); 1186 if (*ndx == 8192) return; /*(must match num array entries in keys[])*/ 1187 1188 buffer *b = &((stat_cache_entry *)t->data)->name; 1189 size_t blen = buffer_string_length(b); 1190 if (blen > len && b->ptr[len] == '/' && 0 == memcmp(b->ptr, name, len)) 1191 keys[(*ndx)++] = t->key; 1192 } 1193 1194 __attribute_noinline__ 1195 static void stat_cache_prune_dir_tree(const char *name, size_t len) 1196 { 1197 splay_tree *sptree = sc.files; 1198 int max_ndx, i; 1199 int keys[8192]; /* 32k size on stack */ 1200 do { 1201 if (!sptree) break; 1202 max_ndx = 0; 1203 stat_cache_tag_dir_tree(sptree, name, len, keys, &max_ndx); 1204 for (i = 0; i < max_ndx; ++i) { 1205 const int ndx = keys[i]; 1206 splay_tree *node = sptree = splaytree_splay(sptree, ndx); 1207 if (node && node->key == ndx) { 1208 stat_cache_entry_free(node->data); 1209 sptree = splaytree_delete(sptree, ndx); 1210 } 1211 } 1212 } while (max_ndx == sizeof(keys)/sizeof(int)); 1213 sc.files = sptree; 1214 } 1215 1216 static void stat_cache_delete_tree(const char *name, uint32_t len) 1217 { 1218 stat_cache_delete_entry(name, len); 1219 stat_cache_prune_dir_tree(name, len); 1220 } 1221 1222 void stat_cache_delete_dir(const char *name, uint32_t len) 1223 { 1224 force_assert(0 != len); 1225 if (name[len-1] == '/') { if (0 == --len) len = 1; } 1226 stat_cache_delete_tree(name, len); 1227 #ifdef HAVE_FAM_H 1228 if (sc.stat_cache_engine == STAT_CACHE_ENGINE_FAM) { 1229 splay_tree **sptree = &sc.scf->dirs; 1230 fam_dir_entry *fam_dir = stat_cache_sptree_find(sptree, name, len); 1231 if (fam_dir && buffer_is_equal_string(fam_dir->name, name, len)) 1232 fam_dir_invalidate_node(fam_dir); 1233 if (*sptree) fam_dir_invalidate_tree(*sptree, name, len); 1234 fam_dir_periodic_cleanup(); 1235 } 1236 #endif 1237 } 1238 1239 /*** 1240 * 1241 * 1242 * 1243 * returns: 1244 * - HANDLER_FINISHED on cache-miss (don't forget to reopen the file) 1245 * - HANDLER_ERROR on stat() failed -> see errno for problem 1246 */ 1247 1248 stat_cache_entry * stat_cache_get_entry(const buffer *name) { 1249 stat_cache_entry *sce = NULL; 1250 struct stat st; 1251 int file_ndx; 1252 1253 /* consistency: ensure lookup name does not end in '/' unless root "/" 1254 * (but use full path given with stat(), even with trailing '/') */ 1255 int final_slash = 0; 1256 size_t len = buffer_string_length(name); 1257 force_assert(0 != len); 1258 if (name->ptr[len-1] == '/') { final_slash = 1; if (0 == --len) len = 1; } 1259 /* Note: paths are expected to be normalized before calling stat_cache, 1260 * e.g. without repeated '/' */ 1261 1262 if (name->ptr[0] != '/') { 1263 errno = EINVAL; 1264 return NULL; 1265 } 1266 1267 /* 1268 * check if the directory for this file has changed 1269 */ 1270 1271 const time_t cur_ts = log_epoch_secs; 1272 1273 file_ndx = splaytree_djbhash(name->ptr, len); 1274 splay_tree *sptree = sc.files = splaytree_splay(sc.files, file_ndx); 1275 1276 if (sptree && (sptree->key == file_ndx)) { 1277 /* we have seen this file already and 1278 * don't stat() it again in the same second */ 1279 1280 sce = sptree->data; 1281 1282 /* check if the name is the same, we might have a collision */ 1283 1284 if (buffer_is_equal_string(&sce->name, name->ptr, len)) { 1285 if (sc.stat_cache_engine == STAT_CACHE_ENGINE_SIMPLE) { 1286 if (sce->stat_ts == cur_ts) { 1287 if (final_slash && !S_ISDIR(sce->st.st_mode)) { 1288 errno = ENOTDIR; 1289 return NULL; 1290 } 1291 return sce; 1292 } 1293 } 1294 #ifdef HAVE_FAM_H 1295 else if (sc.stat_cache_engine == STAT_CACHE_ENGINE_FAM 1296 && sce->fam_dir) { /* entry is in monitored dir */ 1297 /* re-stat() periodically, even if monitoring for changes 1298 * (due to limitations in stat_cache.c use of FAM) 1299 * (gaps due to not continually monitoring an entire tree) */ 1300 if (cur_ts - sce->stat_ts < 16) { 1301 if (final_slash && !S_ISDIR(sce->st.st_mode)) { 1302 errno = ENOTDIR; 1303 return NULL; 1304 } 1305 return sce; 1306 } 1307 } 1308 #endif 1309 } else { 1310 /* collision, forget about the entry */ 1311 sce = NULL; 1312 } 1313 } 1314 1315 if (-1 == stat(name->ptr, &st)) { 1316 return NULL; 1317 } 1318 1319 if (S_ISREG(st.st_mode)) { 1320 /* fix broken stat/open for symlinks to reg files with appended slash on freebsd,osx */ 1321 if (name->ptr[buffer_string_length(name) - 1] == '/') { 1322 errno = ENOTDIR; 1323 return NULL; 1324 } 1325 } 1326 1327 if (NULL == sce) { 1328 1329 sce = stat_cache_entry_init(); 1330 buffer_copy_string_len(&sce->name, name->ptr, len); 1331 1332 /* already splayed file_ndx */ 1333 if (NULL != sptree && sptree->key == file_ndx) { 1334 /* hash collision: replace old entry */ 1335 stat_cache_entry_free(sptree->data); 1336 sptree->data = sce; 1337 } else { 1338 sptree = sc.files = splaytree_insert(sptree, file_ndx, sce); 1339 } 1340 1341 } else { 1342 1343 buffer_clear(&sce->etag); 1344 #if defined(HAVE_XATTR) || defined(HAVE_EXTATTR) 1345 buffer_clear(&sce->content_type); 1346 #endif 1347 1348 } 1349 1350 if (sce->fd >= 0) { 1351 /* close fd if file changed */ 1352 if (!stat_cache_stat_eq(&sce->st, &st)) { 1353 if (1 == sce->refcnt) { 1354 close(sce->fd); 1355 sce->fd = -1; 1356 } 1357 else { 1358 --sce->refcnt; /* stat_cache_entry_free(sce); */ 1359 sptree->data = sce = stat_cache_entry_init(); 1360 buffer_copy_string_len(&sce->name, name->ptr, len); 1361 } 1362 } 1363 } 1364 1365 sce->st = st; /*(copy prior to calling fam_dir_monitor())*/ 1366 1367 #ifdef HAVE_FAM_H 1368 if (sc.stat_cache_engine == STAT_CACHE_ENGINE_FAM) { 1369 if (sce->fam_dir) --((fam_dir_entry *)sce->fam_dir)->refcnt; 1370 sce->fam_dir = 1371 fam_dir_monitor(sc.scf, CONST_BUF_LEN(name), &st); 1372 #if 0 /*(performed below)*/ 1373 if (NULL != sce->fam_dir) { 1374 /*(may have been invalidated by dir change)*/ 1375 sce->stat_ts = cur_ts; 1376 } 1377 #endif 1378 } 1379 #endif 1380 1381 sce->stat_ts = cur_ts; 1382 return sce; 1383 } 1384 1385 stat_cache_entry * stat_cache_get_entry_open(const buffer * const name, const int symlinks) { 1386 stat_cache_entry * const sce = stat_cache_get_entry(name); 1387 if (NULL == sce) return NULL; 1388 if (sce->fd >= 0) return sce; 1389 if (sce->st.st_size > 0) 1390 sce->fd = stat_cache_open_rdonly_fstat(name, &sce->st, symlinks); 1391 return sce; /* (note: sce->fd might still be -1 if open() failed) */ 1392 } 1393 1394 const stat_cache_st * stat_cache_path_stat (const buffer * const name) { 1395 const stat_cache_entry * const sce = stat_cache_get_entry(name); 1396 return sce ? &sce->st : NULL; 1397 } 1398 1399 int stat_cache_path_isdir(const buffer *name) { 1400 const stat_cache_entry * const sce = stat_cache_get_entry(name); 1401 return (sce && (S_ISDIR(sce->st.st_mode) ? 1 : (errno = ENOTDIR, 0))); 1402 } 1403 1404 int stat_cache_path_contains_symlink(const buffer *name, log_error_st *errh) { 1405 /* caller should check for symlinks only if we should block symlinks. */ 1406 1407 /* catch the obvious symlinks 1408 * 1409 * this is not a secure check as we still have a race-condition between 1410 * the stat() and the open. We can only solve this by 1411 * 1. open() the file 1412 * 2. fstat() the fd 1413 * 1414 * and keeping the file open for the rest of the time. But this can 1415 * only be done at network level. 1416 * */ 1417 1418 #ifdef HAVE_LSTAT 1419 /* we assume "/" can not be symlink, 1420 * so skip the symlink stuff if path is "/" */ 1421 size_t len = buffer_string_length(name); 1422 force_assert(0 != len); 1423 force_assert(name->ptr[0] == '/'); 1424 if (1 == len) return 0; 1425 #ifndef PATH_MAX 1426 #define PATH_MAX 4096 1427 #endif 1428 if (len >= PATH_MAX) return -1; 1429 1430 char buf[PATH_MAX]; 1431 memcpy(buf, name->ptr, len); 1432 char *s_cur = buf+len; 1433 do { 1434 *s_cur = '\0'; 1435 struct stat st; 1436 if (0 == lstat(buf, &st)) { 1437 if (S_ISLNK(st.st_mode)) return 1; 1438 } 1439 else { 1440 log_perror(errh, __FILE__, __LINE__, "lstat failed for: %s", buf); 1441 return -1; 1442 } 1443 } while ((s_cur = strrchr(buf, '/')) > buf); /*(&buf[0]==buf; NULL < buf)*/ 1444 #endif 1445 1446 return 0; 1447 } 1448 1449 int stat_cache_open_rdonly_fstat (const buffer *name, struct stat *st, int symlinks) { 1450 /*(Note: O_NOFOLLOW affects only the final path segment, the target file, 1451 * not any intermediate symlinks along the path)*/ 1452 const int fd = fdevent_open_cloexec(name->ptr, symlinks, O_RDONLY, 0); 1453 if (fd >= 0) { 1454 if (0 == fstat(fd, st)) { 1455 return fd; 1456 } else { 1457 const int errnum = errno; 1458 close(fd); 1459 errno = errnum; 1460 } 1461 } 1462 return -1; 1463 } 1464 1465 /** 1466 * remove stat() from cache which haven't been stat()ed for 1467 * more than 2 seconds 1468 * 1469 * 1470 * walk though the stat-cache, collect the ids which are too old 1471 * and remove them in a second loop 1472 */ 1473 1474 static void stat_cache_tag_old_entries(splay_tree * const t, int * const keys, int * const ndx, const time_t max_age, const time_t cur_ts) { 1475 if (*ndx == 8192) return; /*(must match num array entries in keys[])*/ 1476 if (t->left) 1477 stat_cache_tag_old_entries(t->left, keys, ndx, max_age, cur_ts); 1478 if (t->right) 1479 stat_cache_tag_old_entries(t->right, keys, ndx, max_age, cur_ts); 1480 if (*ndx == 8192) return; /*(must match num array entries in keys[])*/ 1481 1482 const stat_cache_entry * const sce = t->data; 1483 if (cur_ts - sce->stat_ts > max_age) 1484 keys[(*ndx)++] = t->key; 1485 } 1486 1487 static void stat_cache_periodic_cleanup(const time_t max_age, const time_t cur_ts) { 1488 splay_tree *sptree = sc.files; 1489 int max_ndx, i; 1490 int keys[8192]; /* 32k size on stack */ 1491 do { 1492 if (!sptree) break; 1493 max_ndx = 0; 1494 stat_cache_tag_old_entries(sptree, keys, &max_ndx, max_age, cur_ts); 1495 for (i = 0; i < max_ndx; ++i) { 1496 int ndx = keys[i]; 1497 sptree = splaytree_splay(sptree, ndx); 1498 if (sptree && sptree->key == ndx) { 1499 stat_cache_entry_free(sptree->data); 1500 sptree = splaytree_delete(sptree, ndx); 1501 } 1502 } 1503 } while (max_ndx == sizeof(keys)/sizeof(int)); 1504 sc.files = sptree; 1505 } 1506 1507 void stat_cache_trigger_cleanup(void) { 1508 time_t max_age = 2; 1509 1510 #ifdef HAVE_FAM_H 1511 if (STAT_CACHE_ENGINE_FAM == sc.stat_cache_engine) { 1512 if (log_epoch_secs & 0x1F) return; 1513 /* once every 32 seconds (0x1F == 31) */ 1514 max_age = 32; 1515 fam_dir_periodic_cleanup(); 1516 /* By doing this before stat_cache_periodic_cleanup(), 1517 * entries used within the next max_age secs will remain 1518 * monitored, instead of effectively flushing and 1519 * rebuilding the FAM monitoring every max_age seconds */ 1520 } 1521 #endif 1522 1523 stat_cache_periodic_cleanup(max_age, log_epoch_secs); 1524 } 1525