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[rsync.git] / xattrs.c
blobbbe003b97749a1a008c2afe488684435e91f820e
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) 2006-2020 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 #define RSYNC_XAL_INITIAL 5
43 #define RSYNC_XAL_LIST_INITIAL 100
44
45 #define MAX_FULL_DATUM 32
46
47 #define HAS_PREFIX(str, prfx) (*(str) == *(prfx) && strncmp(str, prfx, sizeof (prfx) - 1) == 0)
48
49 #define XATTR_ABBREV(x) ((size_t)((x).name - (x).datum) < (x).datum_len)
50
51 #define XSTATE_ABBREV 1
52 #define XSTATE_DONE 2
53 #define XSTATE_TODO 3
54
55 #define USER_PREFIX "user."
56 #define UPRE_LEN ((int)sizeof USER_PREFIX - 1)
57 #define SYSTEM_PREFIX "system."
58 #define SPRE_LEN ((int)sizeof SYSTEM_PREFIX - 1)
59
60 #ifdef HAVE_LINUX_XATTRS
61 #define MIGHT_NEED_RPRE (am_root < 0)
62 #define RSYNC_PREFIX USER_PREFIX "rsync."
63 #else
64 #define MIGHT_NEED_RPRE am_root
65 #define RSYNC_PREFIX "rsync."
66 #endif
67 #define RPRE_LEN ((int)sizeof RSYNC_PREFIX - 1)
68
69 #define XSTAT_SUFFIX "stat"
70 #define XSTAT_ATTR RSYNC_PREFIX "%" XSTAT_SUFFIX
71 #define XACC_ACL_SUFFIX "aacl"
72 #define XACC_ACL_ATTR RSYNC_PREFIX "%" XACC_ACL_SUFFIX
73 #define XDEF_ACL_SUFFIX "dacl"
74 #define XDEF_ACL_ATTR RSYNC_PREFIX "%" XDEF_ACL_SUFFIX
75
76 typedef struct {
77 char *datum, *name;
78 size_t datum_len, name_len;
79 int num;
80 } rsync_xa;
81
82 struct _rsync_xa_list;
83
84 typedef struct _rsync_xa_list_ref {
85 struct _rsync_xa_list_ref *next;
86 int ndx;
87 } rsync_xa_list_ref;
88
89 typedef struct _rsync_xa_list {
90 int ndx;
91 int64 key;
92 item_list xa_items;
93 } rsync_xa_list;
94
95 static size_t namebuf_len = 0;
96 static char *namebuf = NULL;
97
98 static const rsync_xa_list empty_xa_list = {
99 .xa_items = EMPTY_ITEM_LIST,
100 };
101 static const item_list empty_xattr = EMPTY_ITEM_LIST;
102 static item_list rsync_xal_l = EMPTY_ITEM_LIST;
103 static struct hashtable *rsync_xal_h = NULL;
104
105 static size_t prior_xattr_count = (size_t)-1;
106
107 /* ------------------------------------------------------------------------- */
108
109 static void rsync_xal_free(item_list *xalp)
110 {
111 size_t i;
112 rsync_xa *rxas = xalp->items;
113
114 if (!xalp->malloced)
115 return;
116
117 for (i = 0; i < xalp->count; i++) {
118 free(rxas[i].datum);
119 /*free(rxas[i].name);*/
120 }
121 free(xalp->items);
122 }
123
124 void free_xattr(stat_x *sxp)
125 {
126 if (!sxp->xattr)
127 return;
128 rsync_xal_free(sxp->xattr);
129 free(sxp->xattr);
130 sxp->xattr = NULL;
131 }
132
133 static int rsync_xal_compare_names(const void *x1, const void *x2)
134 {
135 const rsync_xa *xa1 = x1;
136 const rsync_xa *xa2 = x2;
137 return strcmp(xa1->name, xa2->name);
138 }
139
140 static ssize_t get_xattr_names(const char *fname)
141 {
142 ssize_t list_len;
143 int64 arg;
144
145 if (!namebuf) {
146 namebuf_len = 1024;
147 namebuf = new_array(char, namebuf_len);
148 if (!namebuf)
149 out_of_memory("get_xattr_names");
150 }
151
152 while (1) {
153 /* The length returned includes all the '\0' terminators. */
154 list_len = sys_llistxattr(fname, namebuf, namebuf_len);
155 if (list_len >= 0) {
156 if ((size_t)list_len <= namebuf_len)
157 break;
158 } else if (errno == ENOTSUP)
159 return 0;
160 else if (errno != ERANGE) {
161 arg = namebuf_len;
162 got_error:
163 rsyserr(FERROR_XFER, errno,
164 "get_xattr_names: llistxattr(%s,%s) failed",
165 full_fname(fname), big_num(arg));
166 return -1;
167 }
168 list_len = sys_llistxattr(fname, NULL, 0);
169 if (list_len < 0) {
170 arg = 0;
171 goto got_error;
172 }
173 if (namebuf_len)
174 free(namebuf);
175 namebuf_len = list_len + 1024;
176 namebuf = new_array(char, namebuf_len);
177 if (!namebuf)
178 out_of_memory("get_xattr_names");
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 (datum_len + extra_len < datum_len)
207 overflow_exit("get_xattr_data");
208 if (!(ptr = new_array(char, datum_len + extra_len)))
209 out_of_memory("get_xattr_data");
210
211 if (datum_len) {
212 size_t len = sys_lgetxattr(fname, name, ptr, datum_len);
213 if (len != datum_len) {
214 if (len == (size_t)-1) {
215 rsyserr(FERROR_XFER, errno,
216 "get_xattr_data: lgetxattr(%s,\"%s\",%ld) failed",
217 full_fname(fname), name, (long)datum_len);
218 } else {
219 rprintf(FERROR_XFER,
220 "get_xattr_data: lgetxattr(%s,\"%s\",%ld) returned %ld\n",
221 full_fname(fname), name,
222 (long)datum_len, (long)len);
223 }
224 free(ptr);
225 return NULL;
226 }
227 }
228
229 return ptr;
230 }
231
232 static int rsync_xal_get(const char *fname, item_list *xalp)
233 {
234 ssize_t list_len, name_len;
235 size_t datum_len, name_offset;
236 char *name, *ptr;
237 #ifdef HAVE_LINUX_XATTRS
238 int user_only = am_sender ? 0 : !am_root;
239 #endif
240 rsync_xa *rxa;
241 int count;
242
243 /* This puts the name list into the "namebuf" buffer. */
244 if ((list_len = get_xattr_names(fname)) < 0)
245 return -1;
246
247 for (name = namebuf; list_len > 0; name += name_len) {
248 name_len = strlen(name) + 1;
249 list_len -= name_len;
250
251 if (saw_xattr_filter) {
252 if (name_is_excluded(name, NAME_IS_XATTR, ALL_FILTERS))
253 continue;
254 }
255 #ifdef HAVE_LINUX_XATTRS
256 /* Choose between ignoring the system namespace or (non-root) ignoring any non-user namespace. */
257 else if (user_only ? !HAS_PREFIX(name, USER_PREFIX) : HAS_PREFIX(name, SYSTEM_PREFIX))
258 continue;
259 #endif
260
261 /* No rsync.%FOO attributes are copied w/o 2 -X options. */
262 if (name_len > RPRE_LEN && name[RPRE_LEN] == '%' && HAS_PREFIX(name, RSYNC_PREFIX)) {
263 if ((am_sender && preserve_xattrs < 2)
264 || (am_root < 0
265 && (strcmp(name+RPRE_LEN+1, XSTAT_SUFFIX) == 0
266 || strcmp(name+RPRE_LEN+1, XACC_ACL_SUFFIX) == 0
267 || strcmp(name+RPRE_LEN+1, XDEF_ACL_SUFFIX) == 0)))
268 continue;
269 }
270
271 datum_len = name_len; /* Pass extra size to get_xattr_data() */
272 if (!(ptr = get_xattr_data(fname, name, &datum_len, 0)))
273 return -1;
274
275 if (datum_len > MAX_FULL_DATUM) {
276 /* For large datums, we store a flag and a checksum. */
277 name_offset = 1 + MAX_DIGEST_LEN;
278 sum_init(-1, checksum_seed);
279 sum_update(ptr, datum_len);
280 free(ptr);
281
282 if (!(ptr = new_array(char, name_offset + name_len)))
283 out_of_memory("rsync_xal_get");
284 *ptr = XSTATE_ABBREV;
285 sum_end(ptr + 1);
286 } else
287 name_offset = datum_len;
288
289 rxa = EXPAND_ITEM_LIST(xalp, rsync_xa, RSYNC_XAL_INITIAL);
290 rxa->name = ptr + name_offset;
291 memcpy(rxa->name, name, name_len);
292 rxa->datum = ptr;
293 rxa->name_len = name_len;
294 rxa->datum_len = datum_len;
295 }
296 count = xalp->count;
297 rxa = xalp->items;
298 if (count > 1)
299 qsort(rxa, count, sizeof (rsync_xa), rsync_xal_compare_names);
300 for (rxa += count-1; count; count--, rxa--)
301 rxa->num = count;
302 return 0;
303 }
304
305 /* Read the xattr(s) for this filename. */
306 int get_xattr(const char *fname, stat_x *sxp)
307 {
308 sxp->xattr = new(item_list);
309 *sxp->xattr = empty_xattr;
310
311 if (S_ISREG(sxp->st.st_mode) || S_ISDIR(sxp->st.st_mode)) {
312 /* Everyone supports this. */
313 } else if (S_ISLNK(sxp->st.st_mode)) {
314 #ifndef NO_SYMLINK_XATTRS
315 if (!preserve_links)
316 #endif
317 return 0;
318 } else if (IS_SPECIAL(sxp->st.st_mode)) {
319 #ifndef NO_SPECIAL_XATTRS
320 if (!preserve_specials)
321 #endif
322 return 0;
323 } else if (IS_DEVICE(sxp->st.st_mode)) {
324 #ifndef NO_DEVICE_XATTRS
325 if (!preserve_devices)
326 #endif
327 return 0;
328 } else if (IS_MISSING_FILE(sxp->st))
329 return 0;
330
331 if (rsync_xal_get(fname, sxp->xattr) < 0) {
332 free_xattr(sxp);
333 return -1;
334 }
335 return 0;
336 }
337
338 int copy_xattrs(const char *source, const char *dest)
339 {
340 ssize_t list_len, name_len;
341 size_t datum_len;
342 char *name, *ptr;
343 #ifdef HAVE_LINUX_XATTRS
344 int user_only = am_sender ? 0 : am_root <= 0;
345 #endif
346
347 /* This puts the name list into the "namebuf" buffer. */
348 if ((list_len = get_xattr_names(source)) < 0)
349 return -1;
350
351 for (name = namebuf; list_len > 0; name += name_len) {
352 name_len = strlen(name) + 1;
353 list_len -= name_len;
354
355 if (saw_xattr_filter) {
356 if (name_is_excluded(name, NAME_IS_XATTR, ALL_FILTERS))
357 continue;
358 }
359 #ifdef HAVE_LINUX_XATTRS
360 /* Choose between ignoring the system namespace or (non-root) ignoring any non-user namespace. */
361 else if (user_only ? !HAS_PREFIX(name, USER_PREFIX) : HAS_PREFIX(name, SYSTEM_PREFIX))
362 continue;
363 #endif
364
365 datum_len = 0;
366 if (!(ptr = get_xattr_data(source, name, &datum_len, 0)))
367 return -1;
368 if (sys_lsetxattr(dest, name, ptr, datum_len) < 0) {
369 int save_errno = errno ? errno : EINVAL;
370 rsyserr(FERROR_XFER, errno,
371 "copy_xattrs: lsetxattr(%s,\"%s\") failed",
372 full_fname(dest), name);
373 errno = save_errno;
374 return -1;
375 }
376 free(ptr);
377 }
378
379 return 0;
380 }
381
382 static int64 xattr_lookup_hash(const item_list *xalp)
383 {
384 const rsync_xa *rxas = xalp->items;
385 size_t i;
386 int64 key = hashlittle(&xalp->count, sizeof xalp->count);
387
388 for (i = 0; i < xalp->count; i++) {
389 key += hashlittle(rxas[i].name, rxas[i].name_len);
390 if (rxas[i].datum_len > MAX_FULL_DATUM)
391 key += hashlittle(rxas[i].datum, MAX_DIGEST_LEN);
392 else
393 key += hashlittle(rxas[i].datum, rxas[i].datum_len);
394 }
395
396 if (key == 0) {
397 /* This is very unlikely, but we should never
398 * return 0 as hashtable_find() doesn't like it. */
399 return 1;
400 }
401
402 return key;
403 }
404
405 static int find_matching_xattr(const item_list *xalp)
406 {
407 const struct ht_int64_node *node;
408 const rsync_xa_list_ref *ref;
409 int64 key;
410
411 if (rsync_xal_h == NULL)
412 return -1;
413
414 key = xattr_lookup_hash(xalp);
415
416 node = hashtable_find(rsync_xal_h, key, NULL);
417 if (node == NULL)
418 return -1;
419
420 if (node->data == NULL)
421 return -1;
422
423 for (ref = node->data; ref != NULL; ref = ref->next) {
424 const rsync_xa_list *ptr = rsync_xal_l.items;
425 const rsync_xa *rxas1;
426 const rsync_xa *rxas2 = xalp->items;
427 size_t j;
428
429 ptr += ref->ndx;
430 rxas1 = ptr->xa_items.items;
431
432 /* Wrong number of elements? */
433 if (ptr->xa_items.count != xalp->count)
434 continue;
435 /* any elements different? */
436 for (j = 0; j < xalp->count; j++) {
437 if (rxas1[j].name_len != rxas2[j].name_len
438 || rxas1[j].datum_len != rxas2[j].datum_len
439 || strcmp(rxas1[j].name, rxas2[j].name))
440 break;
441 if (rxas1[j].datum_len > MAX_FULL_DATUM) {
442 if (memcmp(rxas1[j].datum + 1,
443 rxas2[j].datum + 1,
444 MAX_DIGEST_LEN) != 0)
445 break;
446 } else {
447 if (memcmp(rxas1[j].datum, rxas2[j].datum,
448 rxas2[j].datum_len))
449 break;
450 }
451 }
452 /* no differences found. This is The One! */
453 if (j == xalp->count)
454 return ref->ndx;
455 }
456
457 return -1;
458 }
459
460 /* Store *xalp on the end of rsync_xal_l */
461 static int rsync_xal_store(item_list *xalp)
462 {
463 struct ht_int64_node *node;
464 int ndx = rsync_xal_l.count; /* pre-incremented count */
465 rsync_xa_list *new_list = EXPAND_ITEM_LIST(&rsync_xal_l, rsync_xa_list, RSYNC_XAL_LIST_INITIAL);
466 rsync_xa_list_ref *new_ref;
467 /* Since the following call starts a new list, we know it will hold the
468 * entire initial-count, not just enough space for one new item. */
469 *new_list = empty_xa_list;
470 (void)EXPAND_ITEM_LIST(&new_list->xa_items, rsync_xa, xalp->count);
471 memcpy(new_list->xa_items.items, xalp->items, xalp->count * sizeof (rsync_xa));
472 new_list->xa_items.count = xalp->count;
473 xalp->count = 0;
474
475 new_list->ndx = ndx;
476 new_list->key = xattr_lookup_hash(&new_list->xa_items);
477
478 if (rsync_xal_h == NULL)
479 rsync_xal_h = hashtable_create(512, HT_KEY64);
480 if (rsync_xal_h == NULL)
481 out_of_memory("rsync_xal_h hashtable_create()");
482
483 new_ref = new0(rsync_xa_list_ref);
484 if (new_ref == NULL)
485 out_of_memory("new0(rsync_xa_list_ref)");
486 new_ref->ndx = ndx;
487
488 node = hashtable_find(rsync_xal_h, new_list->key, new_ref);
489 if (node->data != (void*)new_ref) {
490 rsync_xa_list_ref *ref = node->data;
491
492 while (ref != NULL) {
493 if (ref->next != NULL) {
494 ref = ref->next;
495 continue;
496 }
497
498 ref->next = new_ref;
499 break;
500 }
501 }
502
503 return ndx;
504 }
505
506 /* Send the make_xattr()-generated xattr list for this flist entry. */
507 int send_xattr(int f, stat_x *sxp)
508 {
509 int ndx = find_matching_xattr(sxp->xattr);
510
511 /* Send 0 (-1 + 1) to indicate that literal xattr data follows. */
512 write_varint(f, ndx + 1);
513
514 if (ndx < 0) {
515 rsync_xa *rxa;
516 int count = sxp->xattr->count;
517 write_varint(f, count);
518 for (rxa = sxp->xattr->items; count--; rxa++) {
519 size_t name_len = rxa->name_len;
520 const char *name = rxa->name;
521 /* Strip the rsync prefix from disguised namespaces. */
522 if (name_len > RPRE_LEN
523 #ifdef HAVE_LINUX_XATTRS
524 && am_root < 0
525 #endif
526 && name[RPRE_LEN] != '%' && HAS_PREFIX(name, RSYNC_PREFIX)) {
527 name += RPRE_LEN;
528 name_len -= RPRE_LEN;
529 }
530 #ifndef HAVE_LINUX_XATTRS
531 else {
532 /* Put everything else in the user namespace. */
533 name_len += UPRE_LEN;
534 }
535 #endif
536 write_varint(f, name_len);
537 write_varint(f, rxa->datum_len);
538 #ifndef HAVE_LINUX_XATTRS
539 if (name_len > rxa->name_len) {
540 write_buf(f, USER_PREFIX, UPRE_LEN);
541 name_len -= UPRE_LEN;
542 }
543 #endif
544 write_buf(f, name, name_len);
545 if (rxa->datum_len > MAX_FULL_DATUM)
546 write_buf(f, rxa->datum + 1, MAX_DIGEST_LEN);
547 else
548 write_bigbuf(f, rxa->datum, rxa->datum_len);
549 }
550 ndx = rsync_xal_store(sxp->xattr); /* adds item to rsync_xal_l */
551 }
552
553 return ndx;
554 }
555
556 /* Return a flag indicating if we need to change a file's xattrs. If
557 * "find_all" is specified, also mark any abbreviated xattrs that we
558 * need so that send_xattr_request() can tell the sender about them. */
559 int xattr_diff(struct file_struct *file, stat_x *sxp, int find_all)
560 {
561 const rsync_xa_list *glst = rsync_xal_l.items;
562 const item_list *lst;
563 rsync_xa *snd_rxa, *rec_rxa;
564 int snd_cnt, rec_cnt;
565 int cmp, same, xattrs_equal = 1;
566
567 if (sxp && XATTR_READY(*sxp)) {
568 rec_rxa = sxp->xattr->items;
569 rec_cnt = sxp->xattr->count;
570 } else {
571 rec_rxa = NULL;
572 rec_cnt = 0;
573 }
574
575 if (F_XATTR(file) >= 0) {
576 glst += F_XATTR(file);
577 lst = &glst->xa_items;
578 } else
579 lst = &empty_xattr;
580
581 snd_rxa = lst->items;
582 snd_cnt = lst->count;
583
584 /* If the count of the sender's xattrs is different from our
585 * (receiver's) xattrs, the lists are not the same. */
586 if (snd_cnt != rec_cnt) {
587 if (!find_all)
588 return 1;
589 xattrs_equal = 0;
590 }
591
592 while (snd_cnt) {
593 cmp = rec_cnt ? strcmp(snd_rxa->name, rec_rxa->name) : -1;
594 if (cmp > 0)
595 same = 0;
596 else if (snd_rxa->datum_len > MAX_FULL_DATUM) {
597 same = cmp == 0 && snd_rxa->datum_len == rec_rxa->datum_len
598 && memcmp(snd_rxa->datum + 1, rec_rxa->datum + 1,
599 MAX_DIGEST_LEN) == 0;
600 /* Flag unrequested items that we need. */
601 if (!same && find_all && snd_rxa->datum[0] == XSTATE_ABBREV)
602 snd_rxa->datum[0] = XSTATE_TODO;
603 } else {
604 same = cmp == 0 && snd_rxa->datum_len == rec_rxa->datum_len
605 && memcmp(snd_rxa->datum, rec_rxa->datum,
606 snd_rxa->datum_len) == 0;
607 }
608 if (!same) {
609 if (!find_all)
610 return 1;
611 xattrs_equal = 0;
612 }
613
614 if (cmp <= 0) {
615 snd_rxa++;
616 snd_cnt--;
617 }
618 if (cmp >= 0) {
619 rec_rxa++;
620 rec_cnt--;
621 }
622 }
623
624 if (rec_cnt)
625 xattrs_equal = 0;
626
627 return !xattrs_equal;
628 }
629
630 /* When called by the generator (with a NULL fname), this tells the sender
631 * all the abbreviated xattr values we need. When called by the sender
632 * (with a non-NULL fname), we send all the extra xattr data it needs.
633 * The generator may also call with f_out < 0 to just change all the
634 * XSTATE_ABBREV states into XSTATE_DONE. */
635 void send_xattr_request(const char *fname, struct file_struct *file, int f_out)
636 {
637 const rsync_xa_list *glst = rsync_xal_l.items;
638 const item_list *lst;
639 int cnt, prior_req = 0;
640 rsync_xa *rxa;
641
642 glst += F_XATTR(file);
643 lst = &glst->xa_items;
644
645 for (rxa = lst->items, cnt = lst->count; cnt--; rxa++) {
646 if (rxa->datum_len <= MAX_FULL_DATUM)
647 continue;
648 switch (rxa->datum[0]) {
649 case XSTATE_ABBREV:
650 /* Items left abbreviated matched the sender's checksum, so
651 * the receiver will cache the local data for future use. */
652 if (am_generator)
653 rxa->datum[0] = XSTATE_DONE;
654 continue;
655 case XSTATE_TODO:
656 assert(f_out >= 0);
657 break;
658 default:
659 continue;
660 }
661
662 /* Flag that we handled this abbreviated item. */
663 rxa->datum[0] = XSTATE_DONE;
664
665 write_varint(f_out, rxa->num - prior_req);
666 prior_req = rxa->num;
667
668 if (fname) {
669 size_t len = 0;
670 char *ptr;
671
672 /* Re-read the long datum. */
673 if (!(ptr = get_xattr_data(fname, rxa->name, &len, 0))) {
674 rprintf(FERROR_XFER, "failed to re-read xattr %s for %s\n", rxa->name, fname);
675 write_varint(f_out, 0);
676 continue;
677 }
678
679 write_varint(f_out, len); /* length might have changed! */
680 write_bigbuf(f_out, ptr, len);
681 free(ptr);
682 }
683 }
684
685 if (f_out >= 0)
686 write_byte(f_out, 0); /* end the list */
687 }
688
689 /* When called by the sender, read the request from the generator and mark
690 * any needed xattrs with a flag that lets us know they need to be sent to
691 * the receiver. When called by the receiver, reads the sent data and
692 * stores it in place of its checksum. */
693 int recv_xattr_request(struct file_struct *file, int f_in)
694 {
695 const rsync_xa_list *glst = rsync_xal_l.items;
696 const item_list *lst;
697 char *old_datum, *name;
698 rsync_xa *rxa;
699 int rel_pos, cnt, num, got_xattr_data = 0;
700
701 if (F_XATTR(file) < 0) {
702 rprintf(FERROR, "recv_xattr_request: internal data error!\n");
703 exit_cleanup(RERR_PROTOCOL);
704 }
705 glst += F_XATTR(file);
706 lst = &glst->xa_items;
707
708 cnt = lst->count;
709 rxa = lst->items;
710 num = 0;
711 while ((rel_pos = read_varint(f_in)) != 0) {
712 num += rel_pos;
713 if (am_sender) {
714 /* The sender-related num values are only in order on the sender.
715 * We use that order here to scan forward or backward as needed. */
716 if (rel_pos < 0) {
717 while (cnt < (int)lst->count && rxa->num > num) {
718 rxa--;
719 cnt++;
720 }
721 } else {
722 while (cnt > 1 && rxa->num < num) {
723 rxa++;
724 cnt--;
725 }
726 }
727 } else {
728 int j;
729 /* The receiving side has no known num order, so we just scan
730 * forward (w/wrap) and hope that the next value is near by. */
731 for (j = lst->count; j > 1 && rxa->num != num; j--) {
732 if (--cnt)
733 rxa++;
734 else {
735 cnt = lst->count;
736 rxa = lst->items;
737 }
738 }
739 }
740 if (!cnt || rxa->num != num) {
741 rprintf(FERROR, "[%s] could not find xattr #%d for %s\n",
742 who_am_i(), num, f_name(file, NULL));
743 exit_cleanup(RERR_PROTOCOL);
744 }
745 if (!XATTR_ABBREV(*rxa) || rxa->datum[0] != XSTATE_ABBREV) {
746 rprintf(FERROR, "[%s] internal abbrev error on %s (%s, len=%ld)!\n",
747 who_am_i(), f_name(file, NULL), rxa->name, (long)rxa->datum_len);
748 exit_cleanup(RERR_PROTOCOL);
749 }
750
751 if (am_sender) {
752 rxa->datum[0] = XSTATE_TODO;
753 continue;
754 }
755
756 old_datum = rxa->datum;
757 rxa->datum_len = read_varint(f_in);
758
759 if (rxa->name_len + rxa->datum_len < rxa->name_len)
760 overflow_exit("recv_xattr_request");
761 rxa->datum = new_array(char, rxa->datum_len + rxa->name_len);
762 if (!rxa->datum)
763 out_of_memory("recv_xattr_request");
764 name = rxa->datum + rxa->datum_len;
765 memcpy(name, rxa->name, rxa->name_len);
766 rxa->name = name;
767 free(old_datum);
768 read_buf(f_in, rxa->datum, rxa->datum_len);
769 got_xattr_data = 1;
770 }
771
772 return got_xattr_data;
773 }
774
775 /* ------------------------------------------------------------------------- */
776
777 /* receive and build the rsync_xattr_lists */
778 void receive_xattr(int f, struct file_struct *file)
779 {
780 static item_list temp_xattr = EMPTY_ITEM_LIST;
781 int count, num;
782 #ifdef HAVE_LINUX_XATTRS
783 int need_sort = 0;
784 #else
785 int need_sort = 1;
786 #endif
787 int ndx = read_varint(f);
788
789 if (ndx < 0 || (size_t)ndx > rsync_xal_l.count) {
790 rprintf(FERROR, "receive_xattr: xa index %d out of"
791 " range for %s\n", ndx, f_name(file, NULL));
792 exit_cleanup(RERR_STREAMIO);
793 }
794
795 if (ndx != 0) {
796 F_XATTR(file) = ndx - 1;
797 return;
798 }
799
800 if ((count = read_varint(f)) != 0) {
801 (void)EXPAND_ITEM_LIST(&temp_xattr, rsync_xa, count);
802 temp_xattr.count = 0;
803 }
804
805 for (num = 1; num <= count; num++) {
806 char *ptr, *name;
807 rsync_xa *rxa;
808 size_t name_len = read_varint(f);
809 size_t datum_len = read_varint(f);
810 size_t dget_len = datum_len > MAX_FULL_DATUM ? 1 + MAX_DIGEST_LEN : datum_len;
811 size_t extra_len = MIGHT_NEED_RPRE ? RPRE_LEN : 0;
812 if ((dget_len + extra_len < dget_len)
813 || (dget_len + extra_len + name_len < dget_len + extra_len))
814 overflow_exit("receive_xattr");
815 ptr = new_array(char, dget_len + extra_len + name_len);
816 if (!ptr)
817 out_of_memory("receive_xattr");
818 name = ptr + dget_len + extra_len;
819 read_buf(f, name, name_len);
820 if (name_len < 1 || name[name_len-1] != '\0') {
821 rprintf(FERROR, "Invalid xattr name received (missing trailing \\0).\n");
822 exit_cleanup(RERR_FILEIO);
823 }
824 if (dget_len == datum_len)
825 read_buf(f, ptr, dget_len);
826 else {
827 *ptr = XSTATE_ABBREV;
828 read_buf(f, ptr + 1, MAX_DIGEST_LEN);
829 }
830
831 if (saw_xattr_filter) {
832 if (name_is_excluded(name, NAME_IS_XATTR, ALL_FILTERS)) {
833 free(ptr);
834 continue;
835 }
836 }
837 #ifdef HAVE_LINUX_XATTRS
838 /* Non-root can only save the user namespace. */
839 if (am_root <= 0 && !HAS_PREFIX(name, USER_PREFIX)) {
840 if (!am_root && !saw_xattr_filter) {
841 free(ptr);
842 continue;
843 }
844 name -= RPRE_LEN;
845 name_len += RPRE_LEN;
846 memcpy(name, RSYNC_PREFIX, RPRE_LEN);
847 need_sort = 1;
848 }
849 #else
850 /* This OS only has a user namespace, so we either
851 * strip the user prefix, or we put a non-user
852 * namespace inside our rsync hierarchy. */
853 if (HAS_PREFIX(name, USER_PREFIX)) {
854 name += UPRE_LEN;
855 name_len -= UPRE_LEN;
856 } else if (am_root) {
857 name -= RPRE_LEN;
858 name_len += RPRE_LEN;
859 memcpy(name, RSYNC_PREFIX, RPRE_LEN);
860 } else {
861 free(ptr);
862 continue;
863 }
864 #endif
865 /* No rsync.%FOO attributes are copied w/o 2 -X options. */
866 if (preserve_xattrs < 2 && name_len > RPRE_LEN
867 && name[RPRE_LEN] == '%' && HAS_PREFIX(name, RSYNC_PREFIX)) {
868 free(ptr);
869 continue;
870 }
871
872 rxa = EXPAND_ITEM_LIST(&temp_xattr, rsync_xa, 1);
873 rxa->name = name;
874 rxa->datum = ptr;
875 rxa->name_len = name_len;
876 rxa->datum_len = datum_len;
877 rxa->num = num;
878 }
879
880 if (need_sort && count > 1)
881 qsort(temp_xattr.items, count, sizeof (rsync_xa), rsync_xal_compare_names);
882
883 ndx = rsync_xal_store(&temp_xattr); /* adds item to rsync_xal_l */
884
885 F_XATTR(file) = ndx;
886 }
887
888 /* Turn the xattr data in stat_x into cached xattr data, setting the index
889 * values in the file struct. */
890 void cache_tmp_xattr(struct file_struct *file, stat_x *sxp)
891 {
892 int ndx;
893
894 if (!sxp->xattr)
895 return;
896
897 if (prior_xattr_count == (size_t)-1)
898 prior_xattr_count = rsync_xal_l.count;
899 ndx = find_matching_xattr(sxp->xattr);
900 if (ndx < 0)
901 rsync_xal_store(sxp->xattr); /* adds item to rsync_xal_l */
902
903 F_XATTR(file) = ndx;
904 }
905
906 void uncache_tmp_xattrs(void)
907 {
908 if (prior_xattr_count != (size_t)-1) {
909 rsync_xa_list *xa_list_item = rsync_xal_l.items;
910 rsync_xa_list *xa_list_start = xa_list_item + prior_xattr_count;
911 xa_list_item += rsync_xal_l.count;
912 rsync_xal_l.count = prior_xattr_count;
913 while (xa_list_item-- > xa_list_start) {
914 struct ht_int64_node *node;
915 rsync_xa_list_ref *ref;
916
917 rsync_xal_free(&xa_list_item->xa_items);
918
919 if (rsync_xal_h == NULL)
920 continue;
921
922 node = hashtable_find(rsync_xal_h, xa_list_item->key, NULL);
923 if (node == NULL)
924 continue;
925
926 if (node->data == NULL)
927 continue;
928
929 ref = node->data;
930 if (xa_list_item->ndx == ref->ndx) {
931 /* xa_list_item is the first in the list. */
932 node->data = ref->next;
933 free(ref);
934 continue;
935 }
936
937 while (ref != NULL) {
938 if (ref->next == NULL) {
939 ref = NULL;
940 break;
941 }
942 if (xa_list_item->ndx == ref->next->ndx) {
943 ref->next = ref->next->next;
944 free(ref);
945 break;
946 }
947 ref = ref->next;
948 }
949 }
950 prior_xattr_count = (size_t)-1;
951 }
952 }
953
954 static int rsync_xal_set(const char *fname, item_list *xalp,
955 const char *fnamecmp, stat_x *sxp)
956 {
957 rsync_xa *rxas = xalp->items;
958 ssize_t list_len;
959 size_t i, len;
960 char *name, *ptr, sum[MAX_DIGEST_LEN];
961 #ifdef HAVE_LINUX_XATTRS
962 int user_only = am_root <= 0;
963 #endif
964 size_t name_len;
965 int ret = 0;
966
967 /* This puts the current name list into the "namebuf" buffer. */
968 if ((list_len = get_xattr_names(fname)) < 0)
969 return -1;
970
971 for (i = 0; i < xalp->count; i++) {
972 name = rxas[i].name;
973
974 if (XATTR_ABBREV(rxas[i])) {
975 int sum_len;
976 /* See if the fnamecmp version is identical. */
977 len = name_len = rxas[i].name_len;
978 if ((ptr = get_xattr_data(fnamecmp, name, &len, 1)) == NULL) {
979 still_abbrev:
980 if (am_generator)
981 continue;
982 rprintf(FERROR, "Missing abbreviated xattr value, %s, for %s\n",
983 rxas[i].name, full_fname(fname));
984 ret = -1;
985 continue;
986 }
987 if (len != rxas[i].datum_len) {
988 free(ptr);
989 goto still_abbrev;
990 }
991
992 sum_init(-1, checksum_seed);
993 sum_update(ptr, len);
994 sum_len = sum_end(sum);
995 if (memcmp(sum, rxas[i].datum + 1, sum_len) != 0) {
996 free(ptr);
997 goto still_abbrev;
998 }
999
1000 if (fname == fnamecmp)
1001 ; /* Value is already set when identical */
1002 else if (sys_lsetxattr(fname, name, ptr, len) < 0) {
1003 rsyserr(FERROR_XFER, errno,
1004 "rsync_xal_set: lsetxattr(%s,\"%s\") failed",
1005 full_fname(fname), name);
1006 ret = -1;
1007 } else /* make sure caller sets mtime */
1008 sxp->st.st_mtime = (time_t)-1;
1009
1010 if (am_generator) { /* generator items stay abbreviated */
1011 free(ptr);
1012 continue;
1013 }
1014
1015 memcpy(ptr + len, name, name_len);
1016 free(rxas[i].datum);
1017
1018 rxas[i].name = name = ptr + len;
1019 rxas[i].datum = ptr;
1020 continue;
1021 }
1022
1023 if (sys_lsetxattr(fname, name, rxas[i].datum, rxas[i].datum_len) < 0) {
1024 rsyserr(FERROR_XFER, errno,
1025 "rsync_xal_set: lsetxattr(%s,\"%s\") failed",
1026 full_fname(fname), name);
1027 ret = -1;
1028 } else /* make sure caller sets mtime */
1029 sxp->st.st_mtime = (time_t)-1;
1030 }
1031
1032 /* Remove any extraneous names. */
1033 for (name = namebuf; list_len > 0; name += name_len) {
1034 name_len = strlen(name) + 1;
1035 list_len -= name_len;
1036
1037 if (saw_xattr_filter) {
1038 if (name_is_excluded(name, NAME_IS_XATTR, ALL_FILTERS))
1039 continue;
1040 }
1041 #ifdef HAVE_LINUX_XATTRS
1042 /* Choose between ignoring the system namespace or (non-root) ignoring any non-user namespace. */
1043 else if (user_only ? !HAS_PREFIX(name, USER_PREFIX) : HAS_PREFIX(name, SYSTEM_PREFIX))
1044 continue;
1045 #endif
1046 if (am_root < 0 && name_len > RPRE_LEN && name[RPRE_LEN] == '%' && strcmp(name, XSTAT_ATTR) == 0)
1047 continue;
1048
1049 for (i = 0; i < xalp->count; i++) {
1050 if (strcmp(name, rxas[i].name) == 0)
1051 break;
1052 }
1053 if (i == xalp->count) {
1054 if (sys_lremovexattr(fname, name) < 0) {
1055 rsyserr(FERROR_XFER, errno,
1056 "rsync_xal_set: lremovexattr(%s,\"%s\") failed",
1057 full_fname(fname), name);
1058 ret = -1;
1059 } else /* make sure caller sets mtime */
1060 sxp->st.st_mtime = (time_t)-1;
1061 }
1062 }
1063
1064 return ret;
1065 }
1066
1067 /* Set extended attributes on indicated filename. */
1068 int set_xattr(const char *fname, const struct file_struct *file, const char *fnamecmp, stat_x *sxp)
1069 {
1070 rsync_xa_list *glst = rsync_xal_l.items;
1071 item_list *lst;
1072 int ndx;
1073
1074 if (dry_run)
1075 return 1; /* FIXME: --dry-run needs to compute this value */
1076
1077 if (read_only || list_only) {
1078 errno = EROFS;
1079 return -1;
1080 }
1081
1082 #ifdef NO_SPECIAL_XATTRS
1083 if (IS_SPECIAL(sxp->st.st_mode)) {
1084 errno = ENOTSUP;
1085 return -1;
1086 }
1087 #endif
1088 #ifdef NO_DEVICE_XATTRS
1089 if (IS_DEVICE(sxp->st.st_mode)) {
1090 errno = ENOTSUP;
1091 return -1;
1092 }
1093 #endif
1094 #ifdef NO_SYMLINK_XATTRS
1095 if (S_ISLNK(sxp->st.st_mode)) {
1096 errno = ENOTSUP;
1097 return -1;
1098 }
1099 #endif
1100
1101 ndx = F_XATTR(file);
1102 glst += ndx;
1103 lst = &glst->xa_items;
1104 return rsync_xal_set(fname, lst, fnamecmp, sxp);
1105 }
1106
1107 #ifdef SUPPORT_ACLS
1108 char *get_xattr_acl(const char *fname, int is_access_acl, size_t *len_p)
1109 {
1110 const char *name = is_access_acl ? XACC_ACL_ATTR : XDEF_ACL_ATTR;
1111 *len_p = 0; /* no extra data alloc needed from get_xattr_data() */
1112 return get_xattr_data(fname, name, len_p, 1);
1113 }
1114
1115 int set_xattr_acl(const char *fname, int is_access_acl, const char *buf, size_t buf_len)
1116 {
1117 const char *name = is_access_acl ? XACC_ACL_ATTR : XDEF_ACL_ATTR;
1118 if (sys_lsetxattr(fname, name, buf, buf_len) < 0) {
1119 rsyserr(FERROR_XFER, errno,
1120 "set_xattr_acl: lsetxattr(%s,\"%s\") failed",
1121 full_fname(fname), name);
1122 return -1;
1123 }
1124 return 0;
1125 }
1126
1127 int del_def_xattr_acl(const char *fname)
1128 {
1129 return sys_lremovexattr(fname, XDEF_ACL_ATTR);
1130 }
1131 #endif
1132
1133 int get_stat_xattr(const char *fname, int fd, STRUCT_STAT *fst, STRUCT_STAT *xst)
1134 {
1135 int mode, rdev_major, rdev_minor, uid, gid, len;
1136 char buf[256];
1137
1138 if (am_root >= 0 || IS_DEVICE(fst->st_mode) || IS_SPECIAL(fst->st_mode))
1139 return -1;
1140
1141 if (xst)
1142 *xst = *fst;
1143 else
1144 xst = fst;
1145 if (fname) {
1146 fd = -1;
1147 len = sys_lgetxattr(fname, XSTAT_ATTR, buf, sizeof buf - 1);
1148 } else {
1149 fname = "fd";
1150 len = sys_fgetxattr(fd, XSTAT_ATTR, buf, sizeof buf - 1);
1151 }
1152 if (len >= (int)sizeof buf) {
1153 len = -1;
1154 errno = ERANGE;
1155 }
1156 if (len < 0) {
1157 if (errno == ENOTSUP || errno == ENOATTR)
1158 return -1;
1159 if (errno == EPERM && S_ISLNK(fst->st_mode)) {
1160 xst->st_uid = 0;
1161 xst->st_gid = 0;
1162 return 0;
1163 }
1164 rsyserr(FERROR_XFER, errno, "failed to read xattr %s for %s",
1165 XSTAT_ATTR, full_fname(fname));
1166 return -1;
1167 }
1168 buf[len] = '\0';
1169
1170 if (sscanf(buf, "%o %d,%d %d:%d",
1171 &mode, &rdev_major, &rdev_minor, &uid, &gid) != 5) {
1172 rprintf(FERROR, "Corrupt %s xattr attached to %s: \"%s\"\n",
1173 XSTAT_ATTR, full_fname(fname), buf);
1174 exit_cleanup(RERR_FILEIO);
1175 }
1176
1177 xst->st_mode = from_wire_mode(mode);
1178 xst->st_rdev = MAKEDEV(rdev_major, rdev_minor);
1179 xst->st_uid = uid;
1180 xst->st_gid = gid;
1181
1182 return 0;
1183 }
1184
1185 int set_stat_xattr(const char *fname, struct file_struct *file, mode_t new_mode)
1186 {
1187 STRUCT_STAT fst, xst;
1188 dev_t rdev;
1189 mode_t mode, fmode;
1190
1191 if (dry_run)
1192 return 0;
1193
1194 if (read_only || list_only) {
1195 rsyserr(FERROR_XFER, EROFS, "failed to write xattr %s for %s",
1196 XSTAT_ATTR, full_fname(fname));
1197 return -1;
1198 }
1199
1200 if (x_lstat(fname, &fst, &xst) < 0) {
1201 rsyserr(FERROR_XFER, errno, "failed to re-stat %s",
1202 full_fname(fname));
1203 return -1;
1204 }
1205
1206 fst.st_mode &= (_S_IFMT | CHMOD_BITS);
1207 fmode = new_mode & (_S_IFMT | CHMOD_BITS);
1208
1209 if (IS_DEVICE(fmode)) {
1210 uint32 *devp = F_RDEV_P(file);
1211 rdev = MAKEDEV(DEV_MAJOR(devp), DEV_MINOR(devp));
1212 } else
1213 rdev = 0;
1214
1215 /* Dump the special permissions and enable full owner access. */
1216 mode = (fst.st_mode & _S_IFMT) | (fmode & ACCESSPERMS)
1217 | (S_ISDIR(fst.st_mode) ? 0700 : 0600);
1218 if (fst.st_mode != mode)
1219 do_chmod(fname, mode);
1220 if (!IS_DEVICE(fst.st_mode))
1221 fst.st_rdev = 0; /* just in case */
1222
1223 if (mode == fmode && fst.st_rdev == rdev
1224 && fst.st_uid == F_OWNER(file) && fst.st_gid == F_GROUP(file)) {
1225 /* xst.st_mode will be 0 if there's no current stat xattr */
1226 if (xst.st_mode && sys_lremovexattr(fname, XSTAT_ATTR) < 0) {
1227 rsyserr(FERROR_XFER, errno,
1228 "delete of stat xattr failed for %s",
1229 full_fname(fname));
1230 return -1;
1231 }
1232 return 0;
1233 }
1234
1235 if (xst.st_mode != fmode || xst.st_rdev != rdev
1236 || xst.st_uid != F_OWNER(file) || xst.st_gid != F_GROUP(file)) {
1237 char buf[256];
1238 int len = snprintf(buf, sizeof buf, "%o %u,%u %u:%u",
1239 to_wire_mode(fmode),
1240 (int)major(rdev), (int)minor(rdev),
1241 F_OWNER(file), F_GROUP(file));
1242 if (sys_lsetxattr(fname, XSTAT_ATTR, buf, len) < 0) {
1243 if (errno == EPERM && S_ISLNK(fst.st_mode))
1244 return 0;
1245 rsyserr(FERROR_XFER, errno,
1246 "failed to write xattr %s for %s",
1247 XSTAT_ATTR, full_fname(fname));
1248 return -1;
1249 }
1250 }
1251
1252 return 0;
1253 }
1254
1255 int x_stat(const char *fname, STRUCT_STAT *fst, STRUCT_STAT *xst)
1256 {
1257 int ret = do_stat(fname, fst);
1258 if ((ret < 0 || get_stat_xattr(fname, -1, fst, xst) < 0) && xst)
1259 xst->st_mode = 0;
1260 return ret;
1261 }
1262
1263 int x_lstat(const char *fname, STRUCT_STAT *fst, STRUCT_STAT *xst)
1264 {
1265 int ret = do_lstat(fname, fst);
1266 if ((ret < 0 || get_stat_xattr(fname, -1, fst, xst) < 0) && xst)
1267 xst->st_mode = 0;
1268 return ret;
1269 }
1270
1271 int x_fstat(int fd, STRUCT_STAT *fst, STRUCT_STAT *xst)
1272 {
1273 int ret = do_fstat(fd, fst);
1274 if ((ret < 0 || get_stat_xattr(NULL, fd, fst, xst) < 0) && xst)
1275 xst->st_mode = 0;
1276 return ret;
1277 }
1278
1279 #endif /* SUPPORT_XATTRS */
rsync: a fast, versatile, remote (and local) file-copying tool