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Mention smart-make in a comment.
[rsync.git] / xattrs.c
blob26e50a6f9ccb48e0496da3126363ac5f61d6494b
1 /*
2 * Extended Attribute support for rsync.
3 * Written by Jay Fenlason, vaguely based on the ACLs patch.
4 *
5 * Copyright (C) 2004 Red Hat, Inc.
6 * Copyright (C) 2006-2022 Wayne Davison
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 3 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License along
19 * with this program; if not, visit the http://fsf.org website.
20 */
21
22 #include "rsync.h"
23 #include "ifuncs.h"
24 #include "inums.h"
25 #include "lib/sysxattrs.h"
26
27 #ifdef SUPPORT_XATTRS
28
29 extern int dry_run;
30 extern int am_root;
31 extern int am_sender;
32 extern int am_generator;
33 extern int read_only;
34 extern int list_only;
35 extern int preserve_xattrs;
36 extern int preserve_links;
37 extern int preserve_devices;
38 extern int preserve_specials;
39 extern int checksum_seed;
40 extern int saw_xattr_filter;
41
42 extern struct name_num_item *xattr_sum_nni;
43 extern int xattr_sum_len;
44
45 #define RSYNC_XAL_INITIAL 5
46 #define RSYNC_XAL_LIST_INITIAL 100
47
48 #define MAX_XATTR_DIGEST_LEN MD5_DIGEST_LEN
49 #define MAX_FULL_DATUM 32
50
51 #define HAS_PREFIX(str, prfx) (*(str) == *(prfx) && strncmp(str, prfx, sizeof (prfx) - 1) == 0)
52
53 #define XATTR_ABBREV(x) ((size_t)((x).name - (x).datum) < (x).datum_len)
54
55 #define XSTATE_ABBREV 1
56 #define XSTATE_DONE 2
57 #define XSTATE_TODO 3
58
59 #define USER_PREFIX "user."
60 #define UPRE_LEN ((int)sizeof USER_PREFIX - 1)
61 #define SYSTEM_PREFIX "system."
62 #define SPRE_LEN ((int)sizeof SYSTEM_PREFIX - 1)
63
64 #ifdef HAVE_LINUX_XATTRS
65 #define MIGHT_NEED_RPRE (am_root <= 0)
66 #define RSYNC_PREFIX USER_PREFIX "rsync."
67 #else
68 #define MIGHT_NEED_RPRE am_root
69 #define RSYNC_PREFIX "rsync."
70 #endif
71 #define RPRE_LEN ((int)sizeof RSYNC_PREFIX - 1)
72
73 #define XSTAT_SUFFIX "stat"
74 #define XSTAT_ATTR RSYNC_PREFIX "%" XSTAT_SUFFIX
75 #define XACC_ACL_SUFFIX "aacl"
76 #define XACC_ACL_ATTR RSYNC_PREFIX "%" XACC_ACL_SUFFIX
77 #define XDEF_ACL_SUFFIX "dacl"
78 #define XDEF_ACL_ATTR RSYNC_PREFIX "%" XDEF_ACL_SUFFIX
79
80 typedef struct {
81 char *datum, *name;
82 size_t datum_len, name_len;
83 int num;
84 } rsync_xa;
85
86 struct _rsync_xa_list;
87
88 typedef struct _rsync_xa_list_ref {
89 struct _rsync_xa_list_ref *next;
90 int ndx;
91 } rsync_xa_list_ref;
92
93 typedef struct _rsync_xa_list {
94 int ndx;
95 int64 key;
96 item_list xa_items;
97 } rsync_xa_list;
98
99 static size_t namebuf_len = 0;
100 static char *namebuf = NULL;
101
102 static const rsync_xa_list empty_xa_list = {
103 .xa_items = EMPTY_ITEM_LIST,
104 };
105 static const item_list empty_xattr = EMPTY_ITEM_LIST;
106 static item_list rsync_xal_l = EMPTY_ITEM_LIST;
107 static struct hashtable *rsync_xal_h = NULL;
108
109 static size_t prior_xattr_count = (size_t)-1;
110
111 /* ------------------------------------------------------------------------- */
112
113 static void rsync_xal_free(item_list *xalp)
114 {
115 size_t i;
116 rsync_xa *rxas = xalp->items;
117
118 if (!xalp->malloced)
119 return;
120
121 for (i = 0; i < xalp->count; i++) {
122 free(rxas[i].datum);
123 /*free(rxas[i].name);*/
124 }
125 free(xalp->items);
126 }
127
128 void free_xattr(stat_x *sxp)
129 {
130 if (!sxp->xattr)
131 return;
132 rsync_xal_free(sxp->xattr);
133 free(sxp->xattr);
134 sxp->xattr = NULL;
135 }
136
137 static int rsync_xal_compare_names(const void *x1, const void *x2)
138 {
139 const rsync_xa *xa1 = x1;
140 const rsync_xa *xa2 = x2;
141 return strcmp(xa1->name, xa2->name);
142 }
143
144 static ssize_t get_xattr_names(const char *fname)
145 {
146 ssize_t list_len;
147 int64 arg;
148
149 if (!namebuf) {
150 namebuf_len = 1024;
151 namebuf = new_array(char, namebuf_len);
152 }
153
154 while (1) {
155 /* The length returned includes all the '\0' terminators. */
156 list_len = sys_llistxattr(fname, namebuf, namebuf_len);
157 if (list_len >= 0) {
158 if ((size_t)list_len <= namebuf_len)
159 break;
160 } else if (errno == ENOTSUP)
161 return 0;
162 else if (errno != ERANGE) {
163 arg = namebuf_len;
164 got_error:
165 rsyserr(FERROR_XFER, errno,
166 "get_xattr_names: llistxattr(%s,%s) failed",
167 full_fname(fname), big_num(arg));
168 return -1;
169 }
170 list_len = sys_llistxattr(fname, NULL, 0);
171 if (list_len < 0) {
172 arg = 0;
173 goto got_error;
174 }
175 if (namebuf_len)
176 free(namebuf);
177 namebuf_len = list_len + 1024;
178 namebuf = new_array(char, namebuf_len);
179 }
180
181 return list_len;
182 }
183
184 /* On entry, the *len_ptr parameter contains the size of the extra space we
185 * should allocate when we create a buffer for the data. On exit, it contains
186 * the length of the datum. */
187 static char *get_xattr_data(const char *fname, const char *name, size_t *len_ptr, int no_missing_error)
188 {
189 size_t datum_len = sys_lgetxattr(fname, name, NULL, 0);
190 size_t extra_len = *len_ptr;
191 char *ptr;
192
193 *len_ptr = datum_len;
194
195 if (datum_len == (size_t)-1) {
196 if (errno == ENOTSUP || no_missing_error)
197 return NULL;
198 rsyserr(FERROR_XFER, errno,
199 "get_xattr_data: lgetxattr(%s,\"%s\",0) failed",
200 full_fname(fname), name);
201 return NULL;
202 }
203
204 if (!datum_len && !extra_len)
205 extra_len = 1; /* request non-zero amount of memory */
206 if (SIZE_MAX - datum_len < extra_len)
207 overflow_exit("get_xattr_data");
208 ptr = new_array(char, datum_len + extra_len);
209
210 if (datum_len) {
211 size_t len = sys_lgetxattr(fname, name, ptr, datum_len);
212 if (len != datum_len) {
213 if (len == (size_t)-1) {
214 rsyserr(FERROR_XFER, errno,
215 "get_xattr_data: lgetxattr(%s,\"%s\",%ld) failed",
216 full_fname(fname), name, (long)datum_len);
217 } else {
218 rprintf(FERROR_XFER,
219 "get_xattr_data: lgetxattr(%s,\"%s\",%ld) returned %ld\n",
220 full_fname(fname), name,
221 (long)datum_len, (long)len);
222 }
223 free(ptr);
224 return NULL;
225 }
226 }
227
228 return ptr;
229 }
230
231 static int rsync_xal_get(const char *fname, item_list *xalp)
232 {
233 ssize_t list_len, name_len;
234 size_t datum_len, name_offset;
235 char *name, *ptr;
236 #ifdef HAVE_LINUX_XATTRS
237 int user_only = am_sender ? 0 : !am_root;
238 #endif
239 rsync_xa *rxa;
240 int count;
241
242 /* This puts the name list into the "namebuf" buffer. */
243 if ((list_len = get_xattr_names(fname)) < 0)
244 return -1;
245
246 for (name = namebuf; list_len > 0; name += name_len) {
247 name_len = strlen(name) + 1;
248 list_len -= name_len;
249
250 if (saw_xattr_filter) {
251 if (name_is_excluded(name, NAME_IS_XATTR, ALL_FILTERS))
252 continue;
253 }
254 #ifdef HAVE_LINUX_XATTRS
255 /* Choose between ignoring the system namespace or (non-root) ignoring any non-user namespace. */
256 else if (user_only ? !HAS_PREFIX(name, USER_PREFIX) : HAS_PREFIX(name, SYSTEM_PREFIX))
257 continue;
258 #endif
259
260 /* No rsync.%FOO attributes are copied w/o 2 -X options. */
261 if (name_len > RPRE_LEN && name[RPRE_LEN] == '%' && HAS_PREFIX(name, RSYNC_PREFIX)) {
262 if ((am_sender && preserve_xattrs < 2)
263 || (am_root < 0
264 && (strcmp(name+RPRE_LEN+1, XSTAT_SUFFIX) == 0
265 || strcmp(name+RPRE_LEN+1, XACC_ACL_SUFFIX) == 0
266 || strcmp(name+RPRE_LEN+1, XDEF_ACL_SUFFIX) == 0)))
267 continue;
268 }
269
270 datum_len = name_len; /* Pass extra size to get_xattr_data() */
271 if (!(ptr = get_xattr_data(fname, name, &datum_len, 0)))
272 return -1;
273
274 if (datum_len > MAX_FULL_DATUM) {
275 /* For large datums, we store a flag and a checksum. */
276 name_offset = 1 + MAX_XATTR_DIGEST_LEN;
277 sum_init(xattr_sum_nni, checksum_seed);
278 sum_update(ptr, datum_len);
279 free(ptr);
280
281 ptr = new_array(char, name_offset + name_len);
282 *ptr = XSTATE_ABBREV;
283 sum_end(ptr + 1);
284 } else
285 name_offset = datum_len;
286
287 rxa = EXPAND_ITEM_LIST(xalp, rsync_xa, RSYNC_XAL_INITIAL);
288 rxa->name = ptr + name_offset;
289 memcpy(rxa->name, name, name_len);
290 rxa->datum = ptr;
291 rxa->name_len = name_len;
292 rxa->datum_len = datum_len;
293 }
294 count = xalp->count;
295 rxa = xalp->items;
296 if (count > 1)
297 qsort(rxa, count, sizeof (rsync_xa), rsync_xal_compare_names);
298 for (rxa += count-1; count; count--, rxa--)
299 rxa->num = count;
300 return 0;
301 }
302
303 /* Read the xattr(s) for this filename. */
304 int get_xattr(const char *fname, stat_x *sxp)
305 {
306 sxp->xattr = new(item_list);
307 *sxp->xattr = empty_xattr;
308
309 if (S_ISREG(sxp->st.st_mode) || S_ISDIR(sxp->st.st_mode)) {
310 /* Everyone supports this. */
311 } else if (S_ISLNK(sxp->st.st_mode)) {
312 #ifndef NO_SYMLINK_XATTRS
313 if (!preserve_links)
314 #endif
315 return 0;
316 } else if (IS_SPECIAL(sxp->st.st_mode)) {
317 #ifndef NO_SPECIAL_XATTRS
318 if (!preserve_specials)
319 #endif
320 return 0;
321 } else if (IS_DEVICE(sxp->st.st_mode)) {
322 #ifndef NO_DEVICE_XATTRS
323 if (!preserve_devices)
324 #endif
325 return 0;
326 } else if (IS_MISSING_FILE(sxp->st))
327 return 0;
328
329 if (rsync_xal_get(fname, sxp->xattr) < 0) {
330 free_xattr(sxp);
331 return -1;
332 }
333 return 0;
334 }
335
336 int copy_xattrs(const char *source, const char *dest)
337 {
338 ssize_t list_len, name_len;
339 size_t datum_len;
340 char *name, *ptr;
341 #ifdef HAVE_LINUX_XATTRS
342 int user_only = am_sender ? 0 : am_root <= 0;
343 #endif
344
345 /* This puts the name list into the "namebuf" buffer. */
346 if ((list_len = get_xattr_names(source)) < 0)
347 return -1;
348
349 for (name = namebuf; list_len > 0; name += name_len) {
350 name_len = strlen(name) + 1;
351 list_len -= name_len;
352
353 if (saw_xattr_filter) {
354 if (name_is_excluded(name, NAME_IS_XATTR, ALL_FILTERS))
355 continue;
356 }
357 #ifdef HAVE_LINUX_XATTRS
358 /* Choose between ignoring the system namespace or (non-root) ignoring any non-user namespace. */
359 else if (user_only ? !HAS_PREFIX(name, USER_PREFIX) : HAS_PREFIX(name, SYSTEM_PREFIX))
360 continue;
361 #endif
362
363 datum_len = 0;
364 if (!(ptr = get_xattr_data(source, name, &datum_len, 0)))
365 return -1;
366 if (sys_lsetxattr(dest, name, ptr, datum_len) < 0) {
367 int save_errno = errno ? errno : EINVAL;
368 rsyserr(FERROR_XFER, errno,
369 "copy_xattrs: lsetxattr(%s,\"%s\") failed",
370 full_fname(dest), name);
371 errno = save_errno;
372 return -1;
373 }
374 free(ptr);
375 }
376
377 return 0;
378 }
379
380 static int64 xattr_lookup_hash(const item_list *xalp)
381 {
382 const rsync_xa *rxas = xalp->items;
383 size_t i;
384 int64 key = hashlittle2(&xalp->count, sizeof xalp->count);
385
386 for (i = 0; i < xalp->count; i++) {
387 key += hashlittle2(rxas[i].name, rxas[i].name_len);
388 if (rxas[i].datum_len > MAX_FULL_DATUM)
389 key += hashlittle2(rxas[i].datum, xattr_sum_len);
390 else
391 key += hashlittle2(rxas[i].datum, rxas[i].datum_len);
392 }
393
394 return key;
395 }
396
397 static int find_matching_xattr(const item_list *xalp)
398 {
399 const struct ht_int64_node *node;
400 const rsync_xa_list_ref *ref;
401 int64 key;
402
403 if (rsync_xal_h == NULL)
404 return -1;
405
406 key = xattr_lookup_hash(xalp);
407
408 node = hashtable_find(rsync_xal_h, key, NULL);
409 if (node == NULL)
410 return -1;
411
412 if (node->data == NULL)
413 return -1;
414
415 for (ref = node->data; ref != NULL; ref = ref->next) {
416 const rsync_xa_list *ptr = rsync_xal_l.items;
417 const rsync_xa *rxas1;
418 const rsync_xa *rxas2 = xalp->items;
419 size_t j;
420
421 ptr += ref->ndx;
422 rxas1 = ptr->xa_items.items;
423
424 /* Wrong number of elements? */
425 if (ptr->xa_items.count != xalp->count)
426 continue;
427 /* any elements different? */
428 for (j = 0; j < xalp->count; j++) {
429 if (rxas1[j].name_len != rxas2[j].name_len
430 || rxas1[j].datum_len != rxas2[j].datum_len
431 || strcmp(rxas1[j].name, rxas2[j].name))
432 break;
433 if (rxas1[j].datum_len > MAX_FULL_DATUM) {
434 if (memcmp(rxas1[j].datum + 1,
435 rxas2[j].datum + 1,
436 xattr_sum_len) != 0)
437 break;
438 } else {
439 if (memcmp(rxas1[j].datum, rxas2[j].datum,
440 rxas2[j].datum_len))
441 break;
442 }
443 }
444 /* no differences found. This is The One! */
445 if (j == xalp->count)
446 return ref->ndx;
447 }
448
449 return -1;
450 }
451
452 /* Store *xalp on the end of rsync_xal_l */
453 static int rsync_xal_store(item_list *xalp)
454 {
455 struct ht_int64_node *node;
456 int ndx = rsync_xal_l.count; /* pre-incremented count */
457 rsync_xa_list *new_list = EXPAND_ITEM_LIST(&rsync_xal_l, rsync_xa_list, RSYNC_XAL_LIST_INITIAL);
458 rsync_xa_list_ref *new_ref;
459 /* Since the following call starts a new list, we know it will hold the
460 * entire initial-count, not just enough space for one new item. */
461 *new_list = empty_xa_list;
462 (void)EXPAND_ITEM_LIST(&new_list->xa_items, rsync_xa, xalp->count);
463 memcpy(new_list->xa_items.items, xalp->items, xalp->count * sizeof (rsync_xa));
464 new_list->xa_items.count = xalp->count;
465 xalp->count = 0;
466
467 new_list->ndx = ndx;
468 new_list->key = xattr_lookup_hash(&new_list->xa_items);
469
470 if (rsync_xal_h == NULL)
471 rsync_xal_h = hashtable_create(512, HT_KEY64);
472
473 new_ref = new0(rsync_xa_list_ref);
474 new_ref->ndx = ndx;
475
476 node = hashtable_find(rsync_xal_h, new_list->key, new_ref);
477 if (node->data != (void*)new_ref) {
478 rsync_xa_list_ref *ref = node->data;
479
480 while (ref != NULL) {
481 if (ref->next != NULL) {
482 ref = ref->next;
483 continue;
484 }
485
486 ref->next = new_ref;
487 break;
488 }
489 }
490
491 return ndx;
492 }
493
494 /* Send the make_xattr()-generated xattr list for this flist entry. */
495 int send_xattr(int f, stat_x *sxp)
496 {
497 int ndx = find_matching_xattr(sxp->xattr);
498
499 /* Send 0 (-1 + 1) to indicate that literal xattr data follows. */
500 write_varint(f, ndx + 1);
501
502 if (ndx < 0) {
503 rsync_xa *rxa;
504 int count = sxp->xattr->count;
505 write_varint(f, count);
506 for (rxa = sxp->xattr->items; count--; rxa++) {
507 size_t name_len = rxa->name_len;
508 const char *name = rxa->name;
509 /* Strip the rsync prefix from disguised namespaces. */
510 if (name_len > RPRE_LEN
511 #ifdef HAVE_LINUX_XATTRS
512 && am_root < 0
513 #endif
514 && name[RPRE_LEN] != '%' && HAS_PREFIX(name, RSYNC_PREFIX)) {
515 name += RPRE_LEN;
516 name_len -= RPRE_LEN;
517 }
518 #ifndef HAVE_LINUX_XATTRS
519 else {
520 /* Put everything else in the user namespace. */
521 name_len += UPRE_LEN;
522 }
523 #endif
524 write_varint(f, name_len);
525 write_varint(f, rxa->datum_len);
526 #ifndef HAVE_LINUX_XATTRS
527 if (name_len > rxa->name_len) {
528 write_buf(f, USER_PREFIX, UPRE_LEN);
529 name_len -= UPRE_LEN;
530 }
531 #endif
532 write_buf(f, name, name_len);
533 if (rxa->datum_len > MAX_FULL_DATUM)
534 write_buf(f, rxa->datum + 1, xattr_sum_len);
535 else
536 write_bigbuf(f, rxa->datum, rxa->datum_len);
537 }
538 ndx = rsync_xal_store(sxp->xattr); /* adds item to rsync_xal_l */
539 }
540
541 return ndx;
542 }
543
544 /* Return a flag indicating if we need to change a file's xattrs. If
545 * "find_all" is specified, also mark any abbreviated xattrs that we
546 * need so that send_xattr_request() can tell the sender about them. */
547 int xattr_diff(struct file_struct *file, stat_x *sxp, int find_all)
548 {
549 const rsync_xa_list *glst = rsync_xal_l.items;
550 const item_list *lst;
551 rsync_xa *snd_rxa, *rec_rxa;
552 int snd_cnt, rec_cnt;
553 int cmp, same, xattrs_equal = 1;
554
555 if (sxp && XATTR_READY(*sxp)) {
556 rec_rxa = sxp->xattr->items;
557 rec_cnt = sxp->xattr->count;
558 } else {
559 rec_rxa = NULL;
560 rec_cnt = 0;
561 }
562
563 if (F_XATTR(file) >= 0) {
564 glst += F_XATTR(file);
565 lst = &glst->xa_items;
566 } else
567 lst = &empty_xattr;
568
569 snd_rxa = lst->items;
570 snd_cnt = lst->count;
571
572 /* If the count of the sender's xattrs is different from our
573 * (receiver's) xattrs, the lists are not the same. */
574 if (snd_cnt != rec_cnt) {
575 if (!find_all)
576 return 1;
577 xattrs_equal = 0;
578 }
579
580 while (snd_cnt) {
581 cmp = rec_cnt ? strcmp(snd_rxa->name, rec_rxa->name) : -1;
582 if (cmp > 0)
583 same = 0;
584 else if (snd_rxa->datum_len > MAX_FULL_DATUM) {
585 same = cmp == 0 && snd_rxa->datum_len == rec_rxa->datum_len
586 && memcmp(snd_rxa->datum + 1, rec_rxa->datum + 1,
587 xattr_sum_len) == 0;
588 /* Flag unrequested items that we need. */
589 if (!same && find_all && snd_rxa->datum[0] == XSTATE_ABBREV)
590 snd_rxa->datum[0] = XSTATE_TODO;
591 } else {
592 same = cmp == 0 && snd_rxa->datum_len == rec_rxa->datum_len
593 && memcmp(snd_rxa->datum, rec_rxa->datum,
594 snd_rxa->datum_len) == 0;
595 }
596 if (!same) {
597 if (!find_all)
598 return 1;
599 xattrs_equal = 0;
600 }
601
602 if (cmp <= 0) {
603 snd_rxa++;
604 snd_cnt--;
605 }
606 if (cmp >= 0) {
607 rec_rxa++;
608 rec_cnt--;
609 }
610 }
611
612 if (rec_cnt)
613 xattrs_equal = 0;
614
615 return !xattrs_equal;
616 }
617
618 /* When called by the generator (with a NULL fname), this tells the sender
619 * all the abbreviated xattr values we need. When called by the sender
620 * (with a non-NULL fname), we send all the extra xattr data it needs.
621 * The generator may also call with f_out < 0 to just change all the
622 * XSTATE_ABBREV states into XSTATE_DONE. */
623 void send_xattr_request(const char *fname, struct file_struct *file, int f_out)
624 {
625 const rsync_xa_list *glst = rsync_xal_l.items;
626 const item_list *lst;
627 int cnt, prior_req = 0;
628 rsync_xa *rxa;
629
630 glst += F_XATTR(file);
631 lst = &glst->xa_items;
632
633 for (rxa = lst->items, cnt = lst->count; cnt--; rxa++) {
634 if (rxa->datum_len <= MAX_FULL_DATUM)
635 continue;
636 switch (rxa->datum[0]) {
637 case XSTATE_ABBREV:
638 /* Items left abbreviated matched the sender's checksum, so
639 * the receiver will cache the local data for future use. */
640 if (am_generator)
641 rxa->datum[0] = XSTATE_DONE;
642 continue;
643 case XSTATE_TODO:
644 assert(f_out >= 0);
645 break;
646 default:
647 continue;
648 }
649
650 /* Flag that we handled this abbreviated item. */
651 rxa->datum[0] = XSTATE_DONE;
652
653 write_varint(f_out, rxa->num - prior_req);
654 prior_req = rxa->num;
655
656 if (fname) {
657 size_t len = 0;
658 char *ptr;
659
660 /* Re-read the long datum. */
661 if (!(ptr = get_xattr_data(fname, rxa->name, &len, 0))) {
662 rprintf(FERROR_XFER, "failed to re-read xattr %s for %s\n", rxa->name, fname);
663 write_varint(f_out, 0);
664 continue;
665 }
666
667 write_varint(f_out, len); /* length might have changed! */
668 write_bigbuf(f_out, ptr, len);
669 free(ptr);
670 }
671 }
672
673 if (f_out >= 0)
674 write_byte(f_out, 0); /* end the list */
675 }
676
677 /* When called by the sender, read the request from the generator and mark
678 * any needed xattrs with a flag that lets us know they need to be sent to
679 * the receiver. When called by the receiver, reads the sent data and
680 * stores it in place of its checksum. */
681 int recv_xattr_request(struct file_struct *file, int f_in)
682 {
683 const rsync_xa_list *glst = rsync_xal_l.items;
684 const item_list *lst;
685 char *old_datum, *name;
686 rsync_xa *rxa;
687 int rel_pos, cnt, num, got_xattr_data = 0;
688
689 if (F_XATTR(file) < 0) {
690 rprintf(FERROR, "recv_xattr_request: internal data error!\n");
691 exit_cleanup(RERR_PROTOCOL);
692 }
693 glst += F_XATTR(file);
694 lst = &glst->xa_items;
695
696 cnt = lst->count;
697 rxa = lst->items;
698 num = 0;
699 while ((rel_pos = read_varint(f_in)) != 0) {
700 num += rel_pos;
701 if (am_sender) {
702 /* The sender-related num values are only in order on the sender.
703 * We use that order here to scan forward or backward as needed. */
704 if (rel_pos < 0) {
705 while (cnt < (int)lst->count && rxa->num > num) {
706 rxa--;
707 cnt++;
708 }
709 } else {
710 while (cnt > 1 && rxa->num < num) {
711 rxa++;
712 cnt--;
713 }
714 }
715 } else {
716 int j;
717 /* The receiving side has no known num order, so we just scan
718 * forward (w/wrap) and hope that the next value is near by. */
719 for (j = lst->count; j > 1 && rxa->num != num; j--) {
720 if (--cnt)
721 rxa++;
722 else {
723 cnt = lst->count;
724 rxa = lst->items;
725 }
726 }
727 }
728 if (!cnt || rxa->num != num) {
729 rprintf(FERROR, "[%s] could not find xattr #%d for %s\n",
730 who_am_i(), num, f_name(file, NULL));
731 exit_cleanup(RERR_PROTOCOL);
732 }
733 if (!XATTR_ABBREV(*rxa) || rxa->datum[0] != XSTATE_ABBREV) {
734 rprintf(FERROR, "[%s] internal abbrev error on %s (%s, len=%ld)!\n",
735 who_am_i(), f_name(file, NULL), rxa->name, (long)rxa->datum_len);
736 exit_cleanup(RERR_PROTOCOL);
737 }
738
739 if (am_sender) {
740 rxa->datum[0] = XSTATE_TODO;
741 continue;
742 }
743
744 old_datum = rxa->datum;
745 rxa->datum_len = read_varint(f_in);
746
747 if (SIZE_MAX - rxa->name_len < rxa->datum_len)
748 overflow_exit("recv_xattr_request");
749 rxa->datum = new_array(char, rxa->datum_len + rxa->name_len);
750 name = rxa->datum + rxa->datum_len;
751 memcpy(name, rxa->name, rxa->name_len);
752 rxa->name = name;
753 free(old_datum);
754 read_buf(f_in, rxa->datum, rxa->datum_len);
755 got_xattr_data = 1;
756 }
757
758 return got_xattr_data;
759 }
760
761 /* ------------------------------------------------------------------------- */
762
763 /* receive and build the rsync_xattr_lists */
764 void receive_xattr(int f, struct file_struct *file)
765 {
766 static item_list temp_xattr = EMPTY_ITEM_LIST;
767 int count, num;
768 #ifdef HAVE_LINUX_XATTRS
769 int need_sort = 0;
770 #else
771 int need_sort = 1;
772 #endif
773 int ndx = read_varint(f);
774
775 if (ndx < 0 || (size_t)ndx > rsync_xal_l.count) {
776 rprintf(FERROR, "receive_xattr: xa index %d out of"
777 " range for %s\n", ndx, f_name(file, NULL));
778 exit_cleanup(RERR_STREAMIO);
779 }
780
781 if (ndx != 0) {
782 F_XATTR(file) = ndx - 1;
783 return;
784 }
785
786 if ((count = read_varint(f)) != 0) {
787 (void)EXPAND_ITEM_LIST(&temp_xattr, rsync_xa, count);
788 temp_xattr.count = 0;
789 }
790
791 for (num = 1; num <= count; num++) {
792 char *ptr, *name;
793 rsync_xa *rxa;
794 size_t name_len = read_varint(f);
795 size_t datum_len = read_varint(f);
796 size_t dget_len = datum_len > MAX_FULL_DATUM ? 1 + (size_t)xattr_sum_len : datum_len;
797 size_t extra_len = MIGHT_NEED_RPRE ? RPRE_LEN : 0;
798 if (SIZE_MAX - dget_len < extra_len || SIZE_MAX - dget_len - extra_len < name_len)
799 overflow_exit("receive_xattr");
800 ptr = new_array(char, dget_len + extra_len + name_len);
801 name = ptr + dget_len + extra_len;
802 read_buf(f, name, name_len);
803 if (name_len < 1 || name[name_len-1] != '\0') {
804 rprintf(FERROR, "Invalid xattr name received (missing trailing \\0).\n");
805 exit_cleanup(RERR_FILEIO);
806 }
807 if (dget_len == datum_len)
808 read_buf(f, ptr, dget_len);
809 else {
810 *ptr = XSTATE_ABBREV;
811 read_buf(f, ptr + 1, xattr_sum_len);
812 }
813
814 if (saw_xattr_filter) {
815 if (name_is_excluded(name, NAME_IS_XATTR, ALL_FILTERS)) {
816 free(ptr);
817 continue;
818 }
819 }
820 #ifdef HAVE_LINUX_XATTRS
821 /* Non-root can only save the user namespace. */
822 if (am_root <= 0 && !HAS_PREFIX(name, USER_PREFIX)) {
823 if (!am_root && !saw_xattr_filter) {
824 free(ptr);
825 continue;
826 }
827 name -= RPRE_LEN;
828 name_len += RPRE_LEN;
829 memcpy(name, RSYNC_PREFIX, RPRE_LEN);
830 need_sort = 1;
831 }
832 #else
833 /* This OS only has a user namespace, so we either
834 * strip the user prefix, or we put a non-user
835 * namespace inside our rsync hierarchy. */
836 if (HAS_PREFIX(name, USER_PREFIX)) {
837 name += UPRE_LEN;
838 name_len -= UPRE_LEN;
839 } else if (am_root) {
840 name -= RPRE_LEN;
841 name_len += RPRE_LEN;
842 memcpy(name, RSYNC_PREFIX, RPRE_LEN);
843 } else {
844 free(ptr);
845 continue;
846 }
847 #endif
848 /* No rsync.%FOO attributes are copied w/o 2 -X options. */
849 if (preserve_xattrs < 2 && name_len > RPRE_LEN
850 && name[RPRE_LEN] == '%' && HAS_PREFIX(name, RSYNC_PREFIX)) {
851 free(ptr);
852 continue;
853 }
854
855 rxa = EXPAND_ITEM_LIST(&temp_xattr, rsync_xa, 1);
856 rxa->name = name;
857 rxa->datum = ptr;
858 rxa->name_len = name_len;
859 rxa->datum_len = datum_len;
860 rxa->num = num;
861 }
862
863 if (need_sort && count > 1)
864 qsort(temp_xattr.items, count, sizeof (rsync_xa), rsync_xal_compare_names);
865
866 ndx = rsync_xal_store(&temp_xattr); /* adds item to rsync_xal_l */
867
868 F_XATTR(file) = ndx;
869 }
870
871 /* Turn the xattr data in stat_x into cached xattr data, setting the index
872 * values in the file struct. */
873 void cache_tmp_xattr(struct file_struct *file, stat_x *sxp)
874 {
875 int ndx;
876
877 if (!sxp->xattr)
878 return;
879
880 if (prior_xattr_count == (size_t)-1)
881 prior_xattr_count = rsync_xal_l.count;
882 ndx = find_matching_xattr(sxp->xattr);
883 if (ndx < 0)
884 rsync_xal_store(sxp->xattr); /* adds item to rsync_xal_l */
885
886 F_XATTR(file) = ndx;
887 }
888
889 void uncache_tmp_xattrs(void)
890 {
891 if (prior_xattr_count != (size_t)-1) {
892 rsync_xa_list *xa_list_item = rsync_xal_l.items;
893 rsync_xa_list *xa_list_start = xa_list_item + prior_xattr_count;
894 xa_list_item += rsync_xal_l.count;
895 rsync_xal_l.count = prior_xattr_count;
896 while (xa_list_item-- > xa_list_start) {
897 struct ht_int64_node *node;
898 rsync_xa_list_ref *ref;
899
900 rsync_xal_free(&xa_list_item->xa_items);
901
902 if (rsync_xal_h == NULL)
903 continue;
904
905 node = hashtable_find(rsync_xal_h, xa_list_item->key, NULL);
906 if (node == NULL)
907 continue;
908
909 if (node->data == NULL)
910 continue;
911
912 ref = node->data;
913 if (xa_list_item->ndx == ref->ndx) {
914 /* xa_list_item is the first in the list. */
915 node->data = ref->next;
916 free(ref);
917 continue;
918 }
919
920 while (1) {
921 rsync_xa_list_ref *next = ref->next;
922 if (next == NULL)
923 break;
924 if (xa_list_item->ndx == next->ndx) {
925 ref->next = next->next;
926 free(next);
927 break;
928 }
929 ref = next;
930 }
931 }
932 prior_xattr_count = (size_t)-1;
933 }
934 }
935
936 static int rsync_xal_set(const char *fname, item_list *xalp,
937 const char *fnamecmp, stat_x *sxp)
938 {
939 rsync_xa *rxas = xalp->items;
940 ssize_t list_len;
941 size_t i, len;
942 char *name, *ptr, sum[MAX_XATTR_DIGEST_LEN];
943 #ifdef HAVE_LINUX_XATTRS
944 int user_only = am_root <= 0;
945 #endif
946 size_t name_len;
947 int ret = 0;
948
949 /* This puts the current name list into the "namebuf" buffer. */
950 if ((list_len = get_xattr_names(fname)) < 0)
951 return -1;
952
953 for (i = 0; i < xalp->count; i++) {
954 name = rxas[i].name;
955
956 if (XATTR_ABBREV(rxas[i])) {
957 /* See if the fnamecmp version is identical. */
958 len = name_len = rxas[i].name_len;
959 if ((ptr = get_xattr_data(fnamecmp, name, &len, 1)) == NULL) {
960 still_abbrev:
961 if (am_generator)
962 continue;
963 rprintf(FERROR, "Missing abbreviated xattr value, %s, for %s\n",
964 rxas[i].name, full_fname(fname));
965 ret = -1;
966 continue;
967 }
968 if (len != rxas[i].datum_len) {
969 free(ptr);
970 goto still_abbrev;
971 }
972
973 sum_init(xattr_sum_nni, checksum_seed);
974 sum_update(ptr, len);
975 sum_end(sum);
976 if (memcmp(sum, rxas[i].datum + 1, xattr_sum_len) != 0) {
977 free(ptr);
978 goto still_abbrev;
979 }
980
981 if (fname == fnamecmp)
982 ; /* Value is already set when identical */
983 else if (sys_lsetxattr(fname, name, ptr, len) < 0) {
984 rsyserr(FERROR_XFER, errno,
985 "rsync_xal_set: lsetxattr(%s,\"%s\") failed",
986 full_fname(fname), name);
987 ret = -1;
988 } else /* make sure caller sets mtime */
989 sxp->st.st_mtime = (time_t)-1;
990
991 if (am_generator) { /* generator items stay abbreviated */
992 free(ptr);
993 continue;
994 }
995
996 memcpy(ptr + len, name, name_len);
997 free(rxas[i].datum);
998
999 rxas[i].name = name = ptr + len;
1000 rxas[i].datum = ptr;
1001 continue;
1002 }
1003
1004 if (sys_lsetxattr(fname, name, rxas[i].datum, rxas[i].datum_len) < 0) {
1005 rsyserr(FERROR_XFER, errno,
1006 "rsync_xal_set: lsetxattr(%s,\"%s\") failed",
1007 full_fname(fname), name);
1008 ret = -1;
1009 } else /* make sure caller sets mtime */
1010 sxp->st.st_mtime = (time_t)-1;
1011 }
1012
1013 /* Remove any extraneous names. */
1014 for (name = namebuf; list_len > 0; name += name_len) {
1015 name_len = strlen(name) + 1;
1016 list_len -= name_len;
1017
1018 if (saw_xattr_filter) {
1019 if (name_is_excluded(name, NAME_IS_XATTR, ALL_FILTERS))
1020 continue;
1021 }
1022 #ifdef HAVE_LINUX_XATTRS
1023 /* Choose between ignoring the system namespace or (non-root) ignoring any non-user namespace. */
1024 else if (user_only ? !HAS_PREFIX(name, USER_PREFIX) : HAS_PREFIX(name, SYSTEM_PREFIX))
1025 continue;
1026 #endif
1027 if (am_root < 0 && name_len > RPRE_LEN && name[RPRE_LEN] == '%' && strcmp(name, XSTAT_ATTR) == 0)
1028 continue;
1029
1030 for (i = 0; i < xalp->count; i++) {
1031 if (strcmp(name, rxas[i].name) == 0)
1032 break;
1033 }
1034 if (i == xalp->count) {
1035 if (sys_lremovexattr(fname, name) < 0) {
1036 rsyserr(FERROR_XFER, errno,
1037 "rsync_xal_set: lremovexattr(%s,\"%s\") failed",
1038 full_fname(fname), name);
1039 ret = -1;
1040 } else /* make sure caller sets mtime */
1041 sxp->st.st_mtime = (time_t)-1;
1042 }
1043 }
1044
1045 return ret;
1046 }
1047
1048 /* Set extended attributes on indicated filename. */
1049 int set_xattr(const char *fname, const struct file_struct *file, const char *fnamecmp, stat_x *sxp)
1050 {
1051 rsync_xa_list *glst = rsync_xal_l.items;
1052 item_list *lst;
1053 int ndx, added_write_perm = 0;
1054
1055 if (dry_run)
1056 return 1; /* FIXME: --dry-run needs to compute this value */
1057
1058 if (read_only || list_only) {
1059 errno = EROFS;
1060 return -1;
1061 }
1062
1063 #ifdef NO_SPECIAL_XATTRS
1064 if (IS_SPECIAL(sxp->st.st_mode)) {
1065 errno = ENOTSUP;
1066 return -1;
1067 }
1068 #endif
1069 #ifdef NO_DEVICE_XATTRS
1070 if (IS_DEVICE(sxp->st.st_mode)) {
1071 errno = ENOTSUP;
1072 return -1;
1073 }
1074 #endif
1075 #ifdef NO_SYMLINK_XATTRS
1076 if (S_ISLNK(sxp->st.st_mode)) {
1077 errno = ENOTSUP;
1078 return -1;
1079 }
1080 #endif
1081
1082 /* If the target file lacks write permission, we try to add it
1083 * temporarily so we can change the extended attributes. */
1084 if (!am_root
1085 #ifdef SUPPORT_LINKS
1086 && !S_ISLNK(sxp->st.st_mode)
1087 #endif
1088 && access(fname, W_OK) < 0
1089 && do_chmod(fname, (sxp->st.st_mode & CHMOD_BITS) | S_IWUSR) == 0)
1090 added_write_perm = 1;
1091
1092 ndx = F_XATTR(file);
1093 glst += ndx;
1094 lst = &glst->xa_items;
1095 int return_value = rsync_xal_set(fname, lst, fnamecmp, sxp);
1096 if (added_write_perm) /* remove the temporary write permission */
1097 do_chmod(fname, sxp->st.st_mode);
1098 return return_value;
1099 }
1100
1101 #ifdef SUPPORT_ACLS
1102 char *get_xattr_acl(const char *fname, int is_access_acl, size_t *len_p)
1103 {
1104 const char *name = is_access_acl ? XACC_ACL_ATTR : XDEF_ACL_ATTR;
1105 *len_p = 0; /* no extra data alloc needed from get_xattr_data() */
1106 return get_xattr_data(fname, name, len_p, 1);
1107 }
1108
1109 int set_xattr_acl(const char *fname, int is_access_acl, const char *buf, size_t buf_len)
1110 {
1111 const char *name = is_access_acl ? XACC_ACL_ATTR : XDEF_ACL_ATTR;
1112 if (sys_lsetxattr(fname, name, buf, buf_len) < 0) {
1113 rsyserr(FERROR_XFER, errno,
1114 "set_xattr_acl: lsetxattr(%s,\"%s\") failed",
1115 full_fname(fname), name);
1116 return -1;
1117 }
1118 return 0;
1119 }
1120
1121 int del_def_xattr_acl(const char *fname)
1122 {
1123 return sys_lremovexattr(fname, XDEF_ACL_ATTR);
1124 }
1125 #endif
1126
1127 int get_stat_xattr(const char *fname, int fd, STRUCT_STAT *fst, STRUCT_STAT *xst)
1128 {
1129 unsigned int mode;
1130 int rdev_major, rdev_minor, uid, gid, len;
1131 char buf[256];
1132
1133 if (am_root >= 0 || IS_DEVICE(fst->st_mode) || IS_SPECIAL(fst->st_mode))
1134 return -1;
1135
1136 if (xst)
1137 *xst = *fst;
1138 else
1139 xst = fst;
1140 if (fname) {
1141 fd = -1;
1142 len = sys_lgetxattr(fname, XSTAT_ATTR, buf, sizeof buf - 1);
1143 } else {
1144 fname = "fd";
1145 len = sys_fgetxattr(fd, XSTAT_ATTR, buf, sizeof buf - 1);
1146 }
1147 if (len >= (int)sizeof buf) {
1148 len = -1;
1149 errno = ERANGE;
1150 }
1151 if (len < 0) {
1152 if (errno == ENOTSUP || errno == ENOATTR)
1153 return -1;
1154 if (errno == EPERM && S_ISLNK(fst->st_mode)) {
1155 xst->st_uid = 0;
1156 xst->st_gid = 0;
1157 return 0;
1158 }
1159 rsyserr(FERROR_XFER, errno, "failed to read xattr %s for %s",
1160 XSTAT_ATTR, full_fname(fname));
1161 return -1;
1162 }
1163 buf[len] = '\0';
1164
1165 if (sscanf(buf, "%o %d,%d %d:%d",
1166 &mode, &rdev_major, &rdev_minor, &uid, &gid) != 5) {
1167 rprintf(FERROR, "Corrupt %s xattr attached to %s: \"%s\"\n",
1168 XSTAT_ATTR, full_fname(fname), buf);
1169 exit_cleanup(RERR_FILEIO);
1170 }
1171
1172 xst->st_mode = from_wire_mode(mode);
1173 xst->st_rdev = MAKEDEV(rdev_major, rdev_minor);
1174 xst->st_uid = uid;
1175 xst->st_gid = gid;
1176
1177 return 0;
1178 }
1179
1180 int set_stat_xattr(const char *fname, struct file_struct *file, mode_t new_mode)
1181 {
1182 STRUCT_STAT fst, xst;
1183 dev_t rdev;
1184 mode_t mode, fmode;
1185
1186 if (dry_run)
1187 return 0;
1188
1189 if (read_only || list_only) {
1190 rsyserr(FERROR_XFER, EROFS, "failed to write xattr %s for %s",
1191 XSTAT_ATTR, full_fname(fname));
1192 return -1;
1193 }
1194
1195 if (x_lstat(fname, &fst, &xst) < 0) {
1196 rsyserr(FERROR_XFER, errno, "failed to re-stat %s",
1197 full_fname(fname));
1198 return -1;
1199 }
1200
1201 fst.st_mode &= (_S_IFMT | CHMOD_BITS);
1202 fmode = new_mode & (_S_IFMT | CHMOD_BITS);
1203
1204 if (IS_DEVICE(fmode)) {
1205 uint32 *devp = F_RDEV_P(file);
1206 rdev = MAKEDEV(DEV_MAJOR(devp), DEV_MINOR(devp));
1207 } else
1208 rdev = 0;
1209
1210 /* Dump the special permissions and enable full owner access. */
1211 mode = (fst.st_mode & _S_IFMT) | (fmode & ACCESSPERMS)
1212 | (S_ISDIR(fst.st_mode) ? 0700 : 0600);
1213 if (fst.st_mode != mode)
1214 do_chmod(fname, mode);
1215 if (!IS_DEVICE(fst.st_mode))
1216 fst.st_rdev = 0; /* just in case */
1217
1218 if (mode == fmode && fst.st_rdev == rdev
1219 && fst.st_uid == F_OWNER(file) && fst.st_gid == F_GROUP(file)) {
1220 /* xst.st_mode will be 0 if there's no current stat xattr */
1221 if (xst.st_mode && sys_lremovexattr(fname, XSTAT_ATTR) < 0) {
1222 rsyserr(FERROR_XFER, errno,
1223 "delete of stat xattr failed for %s",
1224 full_fname(fname));
1225 return -1;
1226 }
1227 return 0;
1228 }
1229
1230 if (xst.st_mode != fmode || xst.st_rdev != rdev
1231 || xst.st_uid != F_OWNER(file) || xst.st_gid != F_GROUP(file)) {
1232 char buf[256];
1233 int len = snprintf(buf, sizeof buf, "%o %u,%u %u:%u",
1234 to_wire_mode(fmode),
1235 (int)major(rdev), (int)minor(rdev),
1236 F_OWNER(file), F_GROUP(file));
1237 if (sys_lsetxattr(fname, XSTAT_ATTR, buf, len) < 0) {
1238 if (errno == EPERM && S_ISLNK(fst.st_mode))
1239 return 0;
1240 rsyserr(FERROR_XFER, errno,
1241 "failed to write xattr %s for %s",
1242 XSTAT_ATTR, full_fname(fname));
1243 return -1;
1244 }
1245 }
1246
1247 return 0;
1248 }
1249
1250 int x_stat(const char *fname, STRUCT_STAT *fst, STRUCT_STAT *xst)
1251 {
1252 int ret = do_stat(fname, fst);
1253 if ((ret < 0 || get_stat_xattr(fname, -1, fst, xst) < 0) && xst)
1254 xst->st_mode = 0;
1255 return ret;
1256 }
1257
1258 int x_lstat(const char *fname, STRUCT_STAT *fst, STRUCT_STAT *xst)
1259 {
1260 int ret = do_lstat(fname, fst);
1261 if ((ret < 0 || get_stat_xattr(fname, -1, fst, xst) < 0) && xst)
1262 xst->st_mode = 0;
1263 return ret;
1264 }
1265
1266 int x_fstat(int fd, STRUCT_STAT *fst, STRUCT_STAT *xst)
1267 {
1268 int ret = do_fstat(fd, fst);
1269 if ((ret < 0 || get_stat_xattr(NULL, fd, fst, xst) < 0) && xst)
1270 xst->st_mode = 0;
1271 return ret;
1272 }
1273
1274 #endif /* SUPPORT_XATTRS */
rsync: a fast, versatile, remote (and local) file-copying tool