1 /*
2 * Copyright (c) 1997-2014 Erez Zadok
3 * Copyright (c) 1990 Jan-Simon Pendry
4 * Copyright (c) 1990 Imperial College of Science, Technology & Medicine
5 * Copyright (c) 1990 The Regents of the University of California.
6 * All rights reserved.
7 *
8 * This code is derived from software contributed to Berkeley by
9 * Jan-Simon Pendry at Imperial College, London.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 *
35 *
36 * File: am-utils/amd/readdir.c
37 *
38 */
39
40
41 #include <stdint.h>
42 #ifdef HAVE_CONFIG_H
43 # include <config.h>
44 #endif /* HAVE_CONFIG_H */
45 #include <am_defs.h>
46 #include <amd.h>
47
48
49 /****************************************************************************
50 *** MACROS ***
51 ****************************************************************************/
52 #define DOT_DOT_COOKIE (u_int) 1
53 #define MAX_CHAIN 2048
54
55
56 /****************************************************************************
57 *** FORWARD DEFINITIONS ***
58 ****************************************************************************/
59 static int key_already_in_chain(char *keyname, const nfsentry *chain);
60 static nfsentry *make_entry_chain(am_node *mp, const nfsentry *current_chain, int fully_browsable);
61 static int amfs_readdir_browsable(am_node *mp, nfscookie cookie, nfsdirlist *dp, nfsentry *ep, u_int count, int fully_browsable);
62
63 static const u_int dotdotcookie = DOT_DOT_COOKIE;
64
65 /****************************************************************************
66 *** FUNCTIONS ***
67 ****************************************************************************/
68 /*
69 * Was: NEW_TOPLVL_READDIR
70 * Search a chain for an entry with some name.
71 * -Erez Zadok <ezk@cs.columbia.edu>
72 */
73 static int
key_already_in_chain(char * keyname,const nfsentry * chain)74 key_already_in_chain(char *keyname, const nfsentry *chain)
75 {
76 const nfsentry *tmpchain = chain;
77
78 while (tmpchain) {
79 if (keyname && tmpchain->ne_name && STREQ(keyname, tmpchain->ne_name))
80 return 1;
81 tmpchain = tmpchain->ne_nextentry;
82 }
83
84 return 0;
85 }
86
87
88 /*
89 * Create a chain of entries which are not linked.
90 * -Erez Zadok <ezk@cs.columbia.edu>
91 */
92 static nfsentry *
make_entry_chain(am_node * mp,const nfsentry * current_chain,int fully_browsable)93 make_entry_chain(am_node *mp, const nfsentry *current_chain, int fully_browsable)
94 {
95 static u_int last_cookie = (u_int) 2; /* monotonically increasing */
96 static nfsentry chain[MAX_CHAIN];
97 static int max_entries = MAX_CHAIN;
98 char *key;
99 int num_entries = 0, i;
100 u_int preflen = 0;
101 nfsentry *retval = (nfsentry *) NULL;
102 mntfs *mf;
103 mnt_map *mmp;
104
105 if (!mp) {
106 plog(XLOG_DEBUG, "make_entry_chain: mp is (NULL)");
107 return retval;
108 }
109 mf = mp->am_al->al_mnt;
110 if (!mf) {
111 plog(XLOG_DEBUG, "make_entry_chain: mp->am_al->al_mnt is (NULL)");
112 return retval;
113 }
114 mmp = (mnt_map *) mf->mf_private;
115 if (!mmp) {
116 plog(XLOG_DEBUG, "make_entry_chain: mp->am_al->al_mnt->mf_private is (NULL)");
117 return retval;
118 }
119
120 if (mp->am_pref)
121 preflen = strlen(mp->am_pref);
122
123 /* iterate over keys */
124 for (i = 0; i < NKVHASH; i++) {
125 kv *k;
126 for (k = mmp->kvhash[i]; k ; k = k->next) {
127
128 /*
129 * Skip unwanted entries which are either not real entries or
130 * very difficult to interpret (wildcards...) This test needs
131 * lots of improvement. Any takers?
132 */
133 key = k->key;
134 if (!key)
135 continue;
136
137 /* Skip '/defaults' */
138 if (STREQ(key, "/defaults"))
139 continue;
140
141 /* Skip '*' */
142 if (!fully_browsable && strchr(key, '*'))
143 continue;
144
145 /*
146 * If the map has a prefix-string then check if the key starts with
147 * this string, and if it does, skip over this prefix. If it has a
148 * prefix and it doesn't match the start of the key, skip it.
149 */
150 if (preflen) {
151 if (preflen > strlen(key))
152 continue;
153 if (!NSTREQ(key, mp->am_pref, preflen))
154 continue;
155 key += preflen;
156 }
157
158 /* no more '/' are allowed, unless browsable_dirs=full was used */
159 if (!fully_browsable && strchr(key, '/'))
160 continue;
161
162 /* no duplicates allowed */
163 if (key_already_in_chain(key, current_chain))
164 continue;
165
166 /* fill in a cell and link the entry */
167 if (num_entries >= max_entries) {
168 /* out of space */
169 plog(XLOG_DEBUG, "make_entry_chain: no more space in chain");
170 if (num_entries > 0) {
171 chain[num_entries - 1].ne_nextentry = NULL;
172 retval = &chain[0];
173 }
174 return retval;
175 }
176
177 /* we have space. put entry in next cell */
178 ++last_cookie;
179 chain[num_entries].ne_fileid = last_cookie;
180 (void)memcpy(chain[num_entries].ne_cookie, &last_cookie,
181 sizeof(last_cookie));
182 chain[num_entries].ne_name = key;
183 if (num_entries < max_entries - 1) { /* link to next one */
184 chain[num_entries].ne_nextentry = &chain[num_entries + 1];
185 }
186 ++num_entries;
187 } /* end of "while (k)" */
188 } /* end of "for (i ... NKVHASH ..." */
189
190 /* terminate chain */
191 if (num_entries > 0) {
192 chain[num_entries - 1].ne_nextentry = NULL;
193 retval = &chain[0];
194 }
195
196 return retval;
197 }
198
199
200
201 /* This one is called only if map is browsable */
202 static int
amfs_readdir_browsable(am_node * mp,nfscookie cookie,nfsdirlist * dp,nfsentry * ep,u_int count,int fully_browsable)203 amfs_readdir_browsable(am_node *mp, nfscookie cookie, nfsdirlist *dp, nfsentry *ep, u_int count, int fully_browsable)
204 {
205 u_int gen = *(u_int *) (uintptr_t) cookie;
206 int chain_length, i;
207 static nfsentry *te, *te_next;
208 static int j;
209
210 dp->dl_eof = FALSE; /* assume readdir not done */
211
212 if (amuDebug(D_READDIR))
213 plog(XLOG_DEBUG, "amfs_readdir_browsable gen=%u, count=%d",
214 gen, count);
215
216 if (gen == 0) {
217 /*
218 * In the default instance (which is used to start a search) we return
219 * "." and "..".
220 *
221 * This assumes that the count is big enough to allow both "." and ".."
222 * to be returned in a single packet. If it isn't (which would be
223 * fairly unbelievable) then tough.
224 */
225 dlog("%s: default search", __func__);
226 /*
227 * Check for enough room. This is extremely approximate but is more
228 * than enough space. Really need 2 times:
229 * 4byte fileid
230 * 4byte cookie
231 * 4byte name length
232 * 4byte name
233 * plus the dirlist structure */
234 if (count < (2 * (2 * (sizeof(*ep) + sizeof("..") + 4) + sizeof(*dp))))
235 return EINVAL;
236
237 /*
238 * compute # of entries to send in this chain.
239 * heuristics: 128 bytes per entry.
240 * This is too much probably, but it seems to work better because
241 * of the re-entrant nature of nfs_readdir, and esp. on systems
242 * like OpenBSD 2.2.
243 */
244 chain_length = count / 128;
245
246 /* reset static state counters */
247 te = te_next = NULL;
248
249 dp->dl_entries = ep;
250
251 /* construct "." */
252 ep[0].ne_fileid = mp->am_gen;
253 ep[0].ne_name = ".";
254 ep[0].ne_nextentry = &ep[1];
255 (void)memset(ep[0].ne_cookie, 0, sizeof(u_int));
256
257 /* construct ".." */
258 if (mp->am_parent)
259 ep[1].ne_fileid = mp->am_parent->am_gen;
260 else
261 ep[1].ne_fileid = mp->am_gen;
262
263 ep[1].ne_name = "..";
264 ep[1].ne_nextentry = NULL;
265 (void)memcpy(ep[1].ne_cookie, &dotdotcookie, sizeof(dotdotcookie));
266
267 /*
268 * If map is browsable, call a function make_entry_chain() to construct
269 * a linked list of unmounted keys, and return it. Then link the chain
270 * to the regular list. Get the chain only once, but return
271 * chunks of it each time.
272 */
273 te = make_entry_chain(mp, dp->dl_entries, fully_browsable);
274 if (!te)
275 return 0;
276 if (amuDebug(D_READDIR)) {
277 nfsentry *ne;
278 for (j = 0, ne = te; ne; ne = ne->ne_nextentry)
279 plog(XLOG_DEBUG, "gen1 key %4d \"%s\"", j++, ne->ne_name);
280 }
281
282 /* return only "chain_length" entries */
283 te_next = te;
284 for (i=1; i<chain_length; ++i) {
285 te_next = te_next->ne_nextentry;
286 if (!te_next)
287 break;
288 }
289 if (te_next) {
290 nfsentry *te_saved = te_next->ne_nextentry;
291 te_next->ne_nextentry = NULL; /* terminate "te" chain */
292 te_next = te_saved; /* save rest of "te" for next iteration */
293 dp->dl_eof = FALSE; /* tell readdir there's more */
294 } else {
295 dp->dl_eof = TRUE; /* tell readdir that's it */
296 }
297 ep[1].ne_nextentry = te; /* append this chunk of "te" chain */
298 if (amuDebug(D_READDIR)) {
299 nfsentry *ne;
300 for (j = 0, ne = te; ne; ne = ne->ne_nextentry)
301 plog(XLOG_DEBUG, "gen2 key %4d \"%s\"", j++, ne->ne_name);
302 for (j = 0, ne = ep; ne; ne = ne->ne_nextentry) {
303 u_int cookie;
304 (void)memcpy(&cookie, ne->ne_cookie, sizeof(cookie));
305 plog(XLOG_DEBUG, "gen2+ key %4d \"%s\" fi=%d ck=%d",
306 j++, ne->ne_name, ne->ne_fileid, cookie);
307 }
308 plog(XLOG_DEBUG, "EOF is %d", dp->dl_eof);
309 }
310 return 0;
311 } /* end of "if (gen == 0)" statement */
312
313 dlog("%s: real child", __func__);
314
315 if (gen == DOT_DOT_COOKIE) {
316 dlog("%s: End of readdir in %s", __func__, mp->am_path);
317 dp->dl_eof = TRUE;
318 dp->dl_entries = NULL;
319 return 0;
320 }
321
322 /*
323 * If browsable directories, then continue serving readdir() with another
324 * chunk of entries, starting from where we left off (when gen was equal
325 * to 0). Once again, assume last chunk served to readdir.
326 */
327 dp->dl_eof = TRUE;
328 dp->dl_entries = ep;
329
330 te = te_next; /* reset 'te' from last saved te_next */
331 if (!te) { /* another indicator of end of readdir */
332 dp->dl_entries = NULL;
333 return 0;
334 }
335 /*
336 * compute # of entries to send in this chain.
337 * heuristics: 128 bytes per entry.
338 */
339 chain_length = count / 128;
340
341 /* return only "chain_length" entries */
342 for (i = 1; i < chain_length; ++i) {
343 te_next = te_next->ne_nextentry;
344 if (!te_next)
345 break;
346 }
347 if (te_next) {
348 nfsentry *te_saved = te_next->ne_nextentry;
349 te_next->ne_nextentry = NULL; /* terminate "te" chain */
350 te_next = te_saved; /* save rest of "te" for next iteration */
351 dp->dl_eof = FALSE; /* tell readdir there's more */
352 }
353 ep = te; /* send next chunk of "te" chain */
354 dp->dl_entries = ep;
355 if (amuDebug(D_READDIR)) {
356 nfsentry *ne;
357 plog(XLOG_DEBUG, "dl_entries=%p, te_next=%p, dl_eof=%d",
358 dp->dl_entries, te_next, dp->dl_eof);
359 for (ne = te; ne; ne = ne->ne_nextentry)
360 plog(XLOG_DEBUG, "gen3 key %4d \"%s\"", j++, ne->ne_name);
361 }
362 return 0;
363 }
364
365 static int
amfs_readdir(am_node * mp,nfscookie cookie,nfsdirlist * dp,nfsentry * ep,u_int count)366 amfs_readdir(am_node *mp, nfscookie cookie, nfsdirlist *dp, nfsentry *ep, u_int count)
367 {
368 u_int gen = *(u_int *) (uintptr_t) cookie;
369 am_node *xp;
370
371 dp->dl_eof = FALSE; /* assume readdir not done */
372
373 /* when gen is 0, we start reading from the beginning of the directory */
374 if (gen == 0) {
375 /*
376 * In the default instance (which is used to start a search) we return
377 * "." and "..".
378 *
379 * This assumes that the count is big enough to allow both "." and ".."
380 * to be returned in a single packet. If it isn't (which would be
381 * fairly unbelievable) then tough.
382 */
383 dlog("%s: default search", __func__);
384 /*
385 * Check for enough room. This is extremely approximate but is more
386 * than enough space. Really need 2 times:
387 * 4byte fileid
388 * 4byte cookie
389 * 4byte name length
390 * 4byte name
391 * plus the dirlist structure */
392 #define NEEDROOM (2 * (2 * (sizeof(*ep) + sizeof("..") + 4) + sizeof(*dp)))
393 if (count < NEEDROOM) {
394 dlog("%s: not enough room %u < %zu", __func__, count, NEEDROOM);
395 return EINVAL;
396 }
397
398 xp = next_nonerror_node(mp->am_child);
399 dp->dl_entries = ep;
400
401 /* construct "." */
402 ep[0].ne_fileid = mp->am_gen;
403 ep[0].ne_name = ".";
404 ep[0].ne_nextentry = &ep[1];
405 (void)memset(ep[0].ne_cookie, 0, sizeof(u_int));
406
407 /* construct ".." */
408 if (mp->am_parent)
409 ep[1].ne_fileid = mp->am_parent->am_gen;
410 else
411 ep[1].ne_fileid = mp->am_gen;
412 ep[1].ne_name = "..";
413 ep[1].ne_nextentry = NULL;
414 (void)memcpy(ep[1].ne_cookie, (xp ? &xp->am_gen : &dotdotcookie),
415 sizeof(dotdotcookie));
416
417 if (!xp)
418 dp->dl_eof = TRUE; /* by default assume readdir done */
419
420 if (amuDebug(D_READDIR)) {
421 nfsentry *ne;
422 int j;
423 for (j = 0, ne = ep; ne; ne = ne->ne_nextentry) {
424 u_int cookie;
425 (void)memcpy(&cookie, ne->ne_cookie, sizeof(cookie));
426 plog(XLOG_DEBUG, "gen1 key %4d \"%s\" fi=%d ck=%d",
427 j++, ne->ne_name, ne->ne_fileid, cookie);
428 }
429 }
430 return 0;
431 }
432 dlog("%s: real child", __func__);
433
434 if (gen == DOT_DOT_COOKIE) {
435 dlog("%s: End of readdir in %s", __func__, mp->am_path);
436 dp->dl_eof = TRUE;
437 dp->dl_entries = NULL;
438 if (amuDebug(D_READDIR))
439 plog(XLOG_DEBUG, "end of readdir eof=TRUE, dl_entries=0\n");
440 return 0;
441 }
442
443 /* non-browsable directories code */
444 xp = mp->am_child;
445 while (xp && xp->am_gen != gen)
446 xp = xp->am_osib;
447
448 if (xp) {
449 int nbytes = count / 2; /* conservative */
450 int todo = MAX_READDIR_ENTRIES;
451
452 dp->dl_entries = ep;
453 do {
454 am_node *xp_next = next_nonerror_node(xp->am_osib);
455
456 if (xp_next) {
457 (void)memcpy(ep->ne_cookie, &xp_next->am_gen, sizeof(xp_next->am_gen));
458 } else {
459 (void)memcpy(ep->ne_cookie, &dotdotcookie, sizeof(dotdotcookie));
460 dp->dl_eof = TRUE;
461 }
462
463 ep->ne_fileid = xp->am_gen;
464 ep->ne_name = xp->am_name;
465 nbytes -= sizeof(*ep) + 1;
466 if (xp->am_name)
467 nbytes -= strlen(xp->am_name);
468
469 xp = xp_next;
470
471 if (nbytes > 0 && !dp->dl_eof && todo > 1) {
472 ep->ne_nextentry = ep + 1;
473 ep++;
474 --todo;
475 } else {
476 todo = 0;
477 }
478 } while (todo > 0);
479
480 ep->ne_nextentry = NULL;
481
482 if (amuDebug(D_READDIR)) {
483 nfsentry *ne;
484 int j;
485 for (j=0,ne=ep; ne; ne=ne->ne_nextentry) {
486 u_int cookie;
487 (void)memcpy(&cookie, ne->ne_cookie, sizeof(cookie));
488 plog(XLOG_DEBUG, "gen2 key %4d \"%s\" fi=%d ck=%d",
489 j++, ne->ne_name, ne->ne_fileid, cookie);
490 }
491 }
492 return 0;
493 }
494 return ESTALE;
495 }
496
497 /*
498 * Search a chain for an entry with some name.
499 */
500 static int
key_already_in_chain3(char * keyname,const am_entry3 * chain)501 key_already_in_chain3(char *keyname, const am_entry3 *chain)
502 {
503 const am_entry3 *tmpchain = chain;
504
505 while (tmpchain) {
506 if (keyname && tmpchain->name && STREQ(keyname, tmpchain->name))
507 return 1;
508 tmpchain = tmpchain->nextentry;
509 }
510
511 return 0;
512 }
513
514 /*
515 * Create a chain of entries which are not linked.
516 */
517 static am_entry3 *
make_entry_chain3(am_node * mp,const am_entry3 * current_chain,int fully_browsable)518 make_entry_chain3(am_node *mp, const am_entry3 *current_chain, int fully_browsable)
519 {
520 static uint64 last_cookie = (uint64) 2; /* monotonically increasing */
521 static am_entry3 chain[MAX_CHAIN];
522 static int max_entries = MAX_CHAIN;
523 char *key;
524 int num_entries = 0, i;
525 u_int preflen = 0;
526 am_entry3 *retval = (am_entry3 *) NULL;
527 mntfs *mf;
528 mnt_map *mmp;
529
530 if (!mp) {
531 plog(XLOG_DEBUG, "make_entry_chain3: mp is (NULL)");
532 return retval;
533 }
534 mf = mp->am_al->al_mnt;
535 if (!mf) {
536 plog(XLOG_DEBUG, "make_entry_chain3: mp->am_al->al_mnt is (NULL)");
537 return retval;
538 }
539 mmp = (mnt_map *) mf->mf_private;
540 if (!mmp) {
541 plog(XLOG_DEBUG, "make_entry_chain3: mp->am_al->al_mnt->mf_private is (NULL)");
542 return retval;
543 }
544
545 if (mp->am_pref)
546 preflen = strlen(mp->am_pref);
547
548 /* iterate over keys */
549 for (i = 0; i < NKVHASH; i++) {
550 kv *k;
551 for (k = mmp->kvhash[i]; k ; k = k->next) {
552
553 /*
554 * Skip unwanted entries which are either not real entries or
555 * very difficult to interpret (wildcards...) This test needs
556 * lots of improvement. Any takers?
557 */
558 key = k->key;
559 if (!key)
560 continue;
561
562 /* Skip '/defaults' */
563 if (STREQ(key, "/defaults"))
564 continue;
565
566 /* Skip '*' */
567 if (!fully_browsable && strchr(key, '*'))
568 continue;
569
570 /*
571 * If the map has a prefix-string then check if the key starts with
572 * this string, and if it does, skip over this prefix. If it has a
573 * prefix and it doesn't match the start of the key, skip it.
574 */
575 if (preflen) {
576 if (preflen > strlen(key))
577 continue;
578 if (!NSTREQ(key, mp->am_pref, preflen))
579 continue;
580 key += preflen;
581 }
582
583 /* no more '/' are allowed, unless browsable_dirs=full was used */
584 if (!fully_browsable && strchr(key, '/'))
585 continue;
586
587 /* no duplicates allowed */
588 if (key_already_in_chain3(key, current_chain))
589 continue;
590
591 /* fill in a cell and link the entry */
592 if (num_entries >= max_entries) {
593 /* out of space */
594 plog(XLOG_DEBUG, "make_entry_chain3: no more space in chain");
595 if (num_entries > 0) {
596 chain[num_entries - 1].nextentry = NULL;
597 retval = &chain[0];
598 }
599 return retval;
600 }
601
602 /* we have space. put entry in next cell */
603 ++last_cookie;
604 chain[num_entries].fileid = last_cookie;
605 chain[num_entries].cookie = last_cookie;
606 chain[num_entries].name = key;
607 if (num_entries < max_entries - 1) { /* link to next one */
608 chain[num_entries].nextentry = &chain[num_entries + 1];
609 }
610 ++num_entries;
611 } /* end of "while (k)" */
612 } /* end of "for (i ... NKVHASH ..." */
613
614 /* terminate chain */
615 if (num_entries > 0) {
616 chain[num_entries - 1].nextentry = NULL;
617 retval = &chain[0];
618 }
619
620 return retval;
621 }
622
needroom3(void)623 static size_t needroom3(void)
624 {
625 /*
626 * Check for enough room. This is extremely approximate but should
627 * be enough space. Really need 2 times:
628 * (8byte fileid
629 * 8byte cookie
630 * 8byte name pointer
631 * 8byte next entry addres) = sizeof(am_entry3)
632 * 2byte name + 1byte terminator
633 * plus the size of the am_dirlist3 structure */
634 return ((2 * ((sizeof(am_entry3) + sizeof("..") + 1))) + sizeof(am_dirlist3));
635 }
636
637 /* This one is called only if map is browsable */
638 static int
amfs_readdir3_browsable(am_node * mp,am_cookie3 cookie,am_dirlist3 * dp,am_entry3 * ep,u_int count,int fully_browsable)639 amfs_readdir3_browsable(am_node *mp, am_cookie3 cookie,
640 am_dirlist3 *dp, am_entry3 *ep, u_int count,
641 int fully_browsable)
642 {
643 uint64 gen = *(uint64 *) (uintptr_t) cookie;
644 int chain_length, i;
645 static am_entry3 *te, *te_next;
646 static int j;
647
648 dp->eof = FALSE; /* assume readdir not done */
649
650 if (amuDebug(D_READDIR))
651 plog(XLOG_DEBUG, "amfs_readdir3_browsable gen=%lu, count=%d", (long unsigned) gen, count);
652
653 if (gen == 0) {
654 size_t needed = needroom3();
655 /*
656 * In the default instance (which is used to start a search) we return
657 * "." and "..".
658 *
659 * This assumes that the count is big enough to allow both "." and ".."
660 * to be returned in a single packet. If it isn't (which would be
661 * fairly unbelievable) then tough.
662 */
663 dlog("%s: default search", __func__);
664
665 if (count < needed) {
666 dlog("%s: not enough room %u < %zu", __func__, count, needed);
667 return EINVAL;
668 }
669
670 /*
671 * compute # of entries to send in this chain.
672 * heuristics: 128 bytes per entry.
673 * This is too much probably, but it seems to work better because
674 * of the re-entrant nature of nfs_readdir, and esp. on systems
675 * like OpenBSD 2.2.
676 */
677 chain_length = count / 128;
678
679 /* reset static state counters */
680 te = te_next = NULL;
681
682 dp->entries = ep;
683
684 /* construct "." */
685 ep[0].fileid = mp->am_gen;
686 ep[0].name = ".";
687 ep[0].nextentry = &ep[1];
688 ep[0].cookie = 0;
689
690 /* construct ".." */
691 if (mp->am_parent)
692 ep[1].fileid = mp->am_parent->am_gen;
693 else
694 ep[1].fileid = mp->am_gen;
695
696 ep[1].name = "..";
697 ep[1].nextentry = NULL;
698 ep[1].cookie = dotdotcookie;
699
700 /*
701 * If map is browsable, call a function make_entry_chain() to construct
702 * a linked list of unmounted keys, and return it. Then link the chain
703 * to the regular list. Get the chain only once, but return
704 * chunks of it each time.
705 */
706 te = make_entry_chain3(mp, dp->entries, fully_browsable);
707 if (!te)
708 return 0;
709 if (amuDebug(D_READDIR)) {
710 am_entry3 *ne;
711 for (j = 0, ne = te; ne; ne = ne->ne_nextentry)
712 plog(XLOG_DEBUG, "gen1 key %4d \"%s\"", j++, ne->ne_name);
713 }
714
715 /* return only "chain_length" entries */
716 te_next = te;
717 for (i=1; i<chain_length; ++i) {
718 te_next = te_next->nextentry;
719 if (!te_next)
720 break;
721 }
722 if (te_next) {
723 am_entry3 *te_saved = te_next->nextentry;
724 te_next->nextentry = NULL; /* terminate "te" chain */
725 te_next = te_saved; /* save rest of "te" for next iteration */
726 dp->eof = FALSE; /* tell readdir there's more */
727 } else {
728 dp->eof = TRUE; /* tell readdir that's it */
729 }
730 ep[1].nextentry = te; /* append this chunk of "te" chain */
731 if (amuDebug(D_READDIR)) {
732 am_entry3 *ne;
733 for (j = 0, ne = te; ne; ne = ne->ne_nextentry)
734 plog(XLOG_DEBUG, "gen2 key %4d \"%s\"", j++, ne->name);
735 for (j = 0, ne = ep; ne; ne = ne->ne_nextentry) {
736 plog(XLOG_DEBUG, "gen2+ key %4d \"%s\" fi=%lu ck=%lu",
737 j++, ne->name, (long unsigned) ne->fileid, (long unsigned) ne->cookie);
738 }
739 plog(XLOG_DEBUG, "EOF is %d", dp->eof);
740 }
741 return 0;
742 } /* end of "if (gen == 0)" statement */
743
744 dlog("%s: real child", __func__);
745
746 if (gen == DOT_DOT_COOKIE) {
747 dlog("%s: End of readdir in %s", __func__, mp->am_path);
748 dp->eof = TRUE;
749 dp->entries = NULL;
750 return 0;
751 }
752
753 /*
754 * If browsable directories, then continue serving readdir() with another
755 * chunk of entries, starting from where we left off (when gen was equal
756 * to 0). Once again, assume last chunk served to readdir.
757 */
758 dp->eof = TRUE;
759 dp->entries = ep;
760
761 te = te_next; /* reset 'te' from last saved te_next */
762 if (!te) { /* another indicator of end of readdir */
763 dp->entries = NULL;
764 return 0;
765 }
766 /*
767 * compute # of entries to send in this chain.
768 * heuristics: 128 bytes per entry.
769 */
770 chain_length = count / 128;
771
772 /* return only "chain_length" entries */
773 for (i = 1; i < chain_length; ++i) {
774 te_next = te_next->nextentry;
775 if (!te_next)
776 break;
777 }
778 if (te_next) {
779 am_entry3 *te_saved = te_next->nextentry;
780 te_next->nextentry = NULL; /* terminate "te" chain */
781 te_next = te_saved; /* save rest of "te" for next iteration */
782 dp->eof = FALSE; /* tell readdir there's more */
783 }
784 ep = te; /* send next chunk of "te" chain */
785 dp->entries = ep;
786 if (amuDebug(D_READDIR)) {
787 am_entry3 *ne;
788 plog(XLOG_DEBUG,
789 "entries=%p, te_next=%p, eof=%d", dp->entries, te_next, dp->eof);
790 for (ne = te; ne; ne = ne->nextentry)
791 plog(XLOG_DEBUG, "gen3 key %4d \"%s\"", j++, ne->name);
792 }
793 return 0;
794 }
795
796 static int
amfs_readdir3(am_node * mp,am_cookie3 cookie,am_dirlist3 * dp,am_entry3 * ep,u_int count)797 amfs_readdir3(am_node *mp, am_cookie3 cookie,
798 am_dirlist3 *dp, am_entry3 *ep, u_int count)
799 {
800 uint64 gen = *(uint64 *) (uintptr_t) cookie;
801 am_node *xp;
802
803 if (amuDebug(D_READDIR))
804 plog(XLOG_DEBUG, "amfs_readdir3 gen=%lu, count=%d", (long unsigned) gen, count);
805
806 dp->eof = FALSE; /* assume readdir not done */
807
808 /* when gen is 0, we start reading from the beginning of the directory */
809 if (gen == 0) {
810 size_t needed = needroom3();
811 /*
812 * In the default instance (which is used to start a search) we return
813 * "." and "..".
814 *
815 * This assumes that the count is big enough to allow both "." and ".."
816 * to be returned in a single packet. If it isn't (which would be
817 * fairly unbelievable) then tough.
818 */
819 dlog("%s: default search", __func__);
820
821 if (count < needed) {
822 dlog("%s: not enough room %u < %zu", __func__, count, needed);
823 return EINVAL;
824 }
825
826 xp = next_nonerror_node(mp->am_child);
827 dp->entries = ep;
828
829 /* construct "." */
830 ep[0].fileid = mp->am_gen;
831 ep[0].name = ".";
832 ep[0].cookie = 0;
833 ep[0].nextentry = &ep[1];
834
835 /* construct ".." */
836 if (mp->am_parent)
837 ep[1].fileid = mp->am_parent->am_gen;
838 else
839 ep[1].fileid = mp->am_gen;
840 ep[1].name = "..";
841 ep[1].nextentry = NULL;
842 ep[1].cookie = (xp ? xp->am_gen : dotdotcookie);
843
844 if (!xp)
845 dp->eof = TRUE; /* by default assume readdir done */
846
847 if (amuDebug(D_READDIR)) {
848 am_entry3 *ne;
849 int j;
850 for (j = 0, ne = ep; ne; ne = ne->nextentry) {
851 plog(XLOG_DEBUG, "gen1 key %4d \"%s\" fi=%lu ck=%lu",
852 j++, ne->name, (long unsigned) ne->fileid, (long unsigned) ne->cookie);
853 }
854 }
855 return 0;
856 }
857 dlog("%s: real child", __func__);
858
859 if (gen == (uint64) DOT_DOT_COOKIE) {
860 dlog("%s: End of readdir in %s", __func__, mp->am_path);
861 dp->eof = TRUE;
862 dp->entries = NULL;
863 if (amuDebug(D_READDIR))
864 plog(XLOG_DEBUG, "end of readdir eof=TRUE, dl_entries=0\n");
865 return 0;
866 }
867
868 /* non-browsable directories code */
869 xp = mp->am_child;
870 while (xp && xp->am_gen != gen)
871 xp = xp->am_osib;
872
873 if (xp) {
874 int nbytes = count / 2; /* conservative */
875 int todo = MAX_READDIR_ENTRIES;
876
877 dp->entries = ep;
878 do {
879 am_node *xp_next = next_nonerror_node(xp->am_osib);
880
881 if (xp_next) {
882 ep->cookie = xp_next->am_gen;
883 } else {
884 ep->cookie = (uint64) dotdotcookie;
885 dp->eof = TRUE;
886 }
887
888 ep->fileid = xp->am_gen;
889 ep->name = xp->am_name;
890 nbytes -= sizeof(*ep) + 1;
891 if (xp->am_name)
892 nbytes -= strlen(xp->am_name);
893
894 xp = xp_next;
895
896 if (nbytes > 0 && !dp->dl_eof && todo > 1) {
897 ep->nextentry = ep + 1;
898 ep++;
899 --todo;
900 } else {
901 todo = 0;
902 }
903 } while (todo > 0);
904
905 ep->nextentry = NULL;
906
907 if (amuDebug(D_READDIR)) {
908 am_entry3 *ne;
909 int j;
910 for (j = 0, ne = ep; ne; ne = ne->nextentry) {
911 plog(XLOG_DEBUG, "gen2 key %4d \"%s\" fi=%lu ck=%lu",
912 j++, ne->name, (long unsigned) ne->fileid, (long unsigned) ne->cookie);
913 }
914 }
915 return 0;
916 }
917 return ESTALE;
918 }
919
920 /*
921 * This readdir function which call a special version of it that allows
922 * browsing if browsable_dirs=yes was set on the map.
923 */
924 int
amfs_generic_readdir(am_node * mp,voidp cookie,voidp dp,voidp ep,u_int count)925 amfs_generic_readdir(am_node *mp, voidp cookie, voidp dp, voidp ep, u_int count)
926 {
927 int browsable, full;
928
929 /* check if map is browsable */
930 browsable = 0;
931 if (mp->am_al->al_mnt && mp->am_al->al_mnt->mf_mopts) {
932 mntent_t mnt;
933 mnt.mnt_opts = mp->am_al->al_mnt->mf_mopts;
934 if (amu_hasmntopt(&mnt, "fullybrowsable"))
935 browsable = 2;
936 else if (amu_hasmntopt(&mnt, "browsable"))
937 browsable = 1;
938 }
939 full = (browsable == 2);
940
941 if (nfs_dispatcher == nfs_program_2) {
942 if (browsable)
943 return amfs_readdir_browsable(mp, cookie, dp, ep, count, full);
944 else
945 return amfs_readdir(mp, cookie, dp, ep, count);
946 } else {
947 if (browsable)
948 return amfs_readdir3_browsable(mp, (am_cookie3) (uintptr_t) cookie, dp, ep, count, full);
949 else
950 return amfs_readdir3(mp, (am_cookie3) (uintptr_t) cookie, dp, ep, count);
951 }
952 }
953