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A couple xattr fixes for --fake-super.
[rsync.git] / xattrs.c
blob85341b37045eec01764c8566f538f0d660d24431
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) 2006-2008 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 "lib/sysxattrs.h"
25
26 #ifdef SUPPORT_XATTRS
27
28 extern int dry_run;
29 extern int am_root;
30 extern int am_sender;
31 extern int am_generator;
32 extern int read_only;
33 extern int list_only;
34 extern int preserve_xattrs;
35 extern int checksum_seed;
36
37 #define RSYNC_XAL_INITIAL 5
38 #define RSYNC_XAL_LIST_INITIAL 100
39
40 #define MAX_FULL_DATUM 32
41
42 #define HAS_PREFIX(str, prfx) (*(str) == *(prfx) \
43 && strncmp(str, prfx, sizeof (prfx) - 1) == 0)
44
45 #define XATTR_ABBREV(x) ((size_t)((x).name - (x).datum) < (x).datum_len)
46
47 #define XSTATE_ABBREV 1
48 #define XSTATE_DONE 2
49 #define XSTATE_TODO 3
50
51 #define USER_PREFIX "user."
52 #define UPRE_LEN ((int)sizeof USER_PREFIX - 1)
53 #define SYSTEM_PREFIX "system."
54 #define SPRE_LEN ((int)sizeof SYSTEM_PREFIX - 1)
55
56 #ifdef HAVE_LINUX_XATTRS
57 #define MIGHT_NEED_RPRE (am_root < 0)
58 #define RSYNC_PREFIX USER_PREFIX "rsync."
59 #else
60 #define MIGHT_NEED_RPRE am_root
61 #define RSYNC_PREFIX "rsync."
62 #endif
63 #define RPRE_LEN ((int)sizeof RSYNC_PREFIX - 1)
64
65 #define XSTAT_SUFFIX "stat"
66 #define XSTAT_ATTR RSYNC_PREFIX "%" XSTAT_SUFFIX
67 #define XACC_ACL_SUFFIX "aacl"
68 #define XACC_ACL_ATTR RSYNC_PREFIX "%" XACC_ACL_SUFFIX
69 #define XDEF_ACL_SUFFIX "dacl"
70 #define XDEF_ACL_ATTR RSYNC_PREFIX "%" XDEF_ACL_SUFFIX
71
72 typedef struct {
73 char *datum, *name;
74 size_t datum_len, name_len;
75 int num;
76 } rsync_xa;
77
78 static size_t namebuf_len = 0;
79 static char *namebuf = NULL;
80
81 static item_list empty_xattr = EMPTY_ITEM_LIST;
82 static item_list rsync_xal_l = EMPTY_ITEM_LIST;
83
84 /* ------------------------------------------------------------------------- */
85
86 static void rsync_xal_free(item_list *xalp)
87 {
88 size_t i;
89 rsync_xa *rxas = xalp->items;
90
91 for (i = 0; i < xalp->count; i++) {
92 free(rxas[i].datum);
93 /*free(rxas[i].name);*/
94 }
95 xalp->count = 0;
96 }
97
98 void free_xattr(stat_x *sxp)
99 {
100 if (!sxp->xattr)
101 return;
102 rsync_xal_free(sxp->xattr);
103 free(sxp->xattr);
104 sxp->xattr = NULL;
105 }
106
107 static int rsync_xal_compare_names(const void *x1, const void *x2)
108 {
109 const rsync_xa *xa1 = x1;
110 const rsync_xa *xa2 = x2;
111 return strcmp(xa1->name, xa2->name);
112 }
113
114 static ssize_t get_xattr_names(const char *fname)
115 {
116 ssize_t list_len;
117 double arg;
118
119 if (!namebuf) {
120 namebuf_len = 1024;
121 namebuf = new_array(char, namebuf_len);
122 if (!namebuf)
123 out_of_memory("get_xattr_names");
124 }
125
126 while (1) {
127 /* The length returned includes all the '\0' terminators. */
128 list_len = sys_llistxattr(fname, namebuf, namebuf_len);
129 if (list_len >= 0) {
130 if ((size_t)list_len <= namebuf_len)
131 break;
132 } else if (errno == ENOTSUP)
133 return 0;
134 else if (errno != ERANGE) {
135 arg = (double)namebuf_len;
136 got_error:
137 rsyserr(FERROR_XFER, errno,
138 "get_xattr_names: llistxattr(\"%s\",%.0f) failed",
139 fname, arg);
140 return -1;
141 }
142 list_len = sys_llistxattr(fname, NULL, 0);
143 if (list_len < 0) {
144 arg = 0;
145 goto got_error;
146 }
147 if (namebuf_len)
148 free(namebuf);
149 namebuf_len = list_len + 1024;
150 namebuf = new_array(char, namebuf_len);
151 if (!namebuf)
152 out_of_memory("get_xattr_names");
153 }
154
155 return list_len;
156 }
157
158 /* On entry, the *len_ptr parameter contains the size of the extra space we
159 * should allocate when we create a buffer for the data. On exit, it contains
160 * the length of the datum. */
161 static char *get_xattr_data(const char *fname, const char *name, size_t *len_ptr,
162 int no_missing_error)
163 {
164 size_t datum_len = sys_lgetxattr(fname, name, NULL, 0);
165 size_t extra_len = *len_ptr;
166 char *ptr;
167
168 *len_ptr = datum_len;
169
170 if (datum_len == (size_t)-1) {
171 if (errno == ENOTSUP || no_missing_error)
172 return NULL;
173 rsyserr(FERROR_XFER, errno,
174 "get_xattr_data: lgetxattr(\"%s\",\"%s\",0) failed",
175 fname, name);
176 return NULL;
177 }
178
179 if (!datum_len && !extra_len)
180 extra_len = 1; /* request non-zero amount of memory */
181 if (datum_len + extra_len < datum_len)
182 overflow_exit("get_xattr_data");
183 if (!(ptr = new_array(char, datum_len + extra_len)))
184 out_of_memory("get_xattr_data");
185
186 if (datum_len) {
187 size_t len = sys_lgetxattr(fname, name, ptr, datum_len);
188 if (len != datum_len) {
189 if (len == (size_t)-1) {
190 rsyserr(FERROR_XFER, errno,
191 "get_xattr_data: lgetxattr(\"%s\",\"%s\",%ld)"
192 " failed", fname, name, (long)datum_len);
193 } else {
194 rprintf(FERROR_XFER,
195 "get_xattr_data: lgetxattr(\"%s\",\"%s\",%ld)"
196 " returned %ld\n", fname, name,
197 (long)datum_len, (long)len);
198 }
199 free(ptr);
200 return NULL;
201 }
202 }
203
204 return ptr;
205 }
206
207 static int rsync_xal_get(const char *fname, item_list *xalp)
208 {
209 ssize_t list_len, name_len;
210 size_t datum_len, name_offset;
211 char *name, *ptr;
212 #ifdef HAVE_LINUX_XATTRS
213 int user_only = am_sender ? 0 : !am_root;
214 #endif
215 rsync_xa *rxa;
216 int count;
217
218 /* This puts the name list into the "namebuf" buffer. */
219 if ((list_len = get_xattr_names(fname)) < 0)
220 return -1;
221
222 for (name = namebuf; list_len > 0; name += name_len) {
223 name_len = strlen(name) + 1;
224 list_len -= name_len;
225
226 #ifdef HAVE_LINUX_XATTRS
227 /* We always ignore the system namespace, and non-root
228 * ignores everything but the user namespace. */
229 if (user_only ? !HAS_PREFIX(name, USER_PREFIX)
230 : HAS_PREFIX(name, SYSTEM_PREFIX))
231 continue;
232 #endif
233
234 /* No rsync.%FOO attributes are copied w/o 2 -X options. */
235 if (name_len > RPRE_LEN && name[RPRE_LEN] == '%'
236 && HAS_PREFIX(name, RSYNC_PREFIX)) {
237 if ((am_sender && preserve_xattrs < 2)
238 || (am_root < 0
239 && (strcmp(name+RPRE_LEN+1, XSTAT_SUFFIX) == 0
240 || strcmp(name+RPRE_LEN+1, XACC_ACL_SUFFIX) == 0
241 || strcmp(name+RPRE_LEN+1, XDEF_ACL_SUFFIX) == 0)))
242 continue;
243 }
244
245 datum_len = name_len; /* Pass extra size to get_xattr_data() */
246 if (!(ptr = get_xattr_data(fname, name, &datum_len, 0)))
247 return -1;
248
249 if (datum_len > MAX_FULL_DATUM) {
250 /* For large datums, we store a flag and a checksum. */
251 name_offset = 1 + MAX_DIGEST_LEN;
252 sum_init(checksum_seed);
253 sum_update(ptr, datum_len);
254 free(ptr);
255
256 if (!(ptr = new_array(char, name_offset + name_len)))
257 out_of_memory("rsync_xal_get");
258 *ptr = XSTATE_ABBREV;
259 sum_end(ptr + 1);
260 } else
261 name_offset = datum_len;
262
263 rxa = EXPAND_ITEM_LIST(xalp, rsync_xa, RSYNC_XAL_INITIAL);
264 rxa->name = ptr + name_offset;
265 memcpy(rxa->name, name, name_len);
266 rxa->datum = ptr;
267 rxa->name_len = name_len;
268 rxa->datum_len = datum_len;
269 }
270 count = xalp->count;
271 rxa = xalp->items;
272 if (count > 1)
273 qsort(rxa, count, sizeof (rsync_xa), rsync_xal_compare_names);
274 for (rxa += count-1; count; count--, rxa--)
275 rxa->num = count;
276 return 0;
277 }
278
279 /* Read the xattr(s) for this filename. */
280 int get_xattr(const char *fname, stat_x *sxp)
281 {
282 sxp->xattr = new(item_list);
283 *sxp->xattr = empty_xattr;
284 if (rsync_xal_get(fname, sxp->xattr) < 0) {
285 free_xattr(sxp);
286 return -1;
287 }
288 return 0;
289 }
290
291 int copy_xattrs(const char *source, const char *dest)
292 {
293 ssize_t list_len, name_len;
294 size_t datum_len;
295 char *name, *ptr;
296 #ifdef HAVE_LINUX_XATTRS
297 int user_only = am_sender ? 0 : am_root <= 0;
298 #endif
299
300 /* This puts the name list into the "namebuf" buffer. */
301 if ((list_len = get_xattr_names(source)) < 0)
302 return -1;
303
304 for (name = namebuf; list_len > 0; name += name_len) {
305 name_len = strlen(name) + 1;
306 list_len -= name_len;
307
308 #ifdef HAVE_LINUX_XATTRS
309 /* We always ignore the system namespace, and non-root
310 * ignores everything but the user namespace. */
311 if (user_only ? !HAS_PREFIX(name, USER_PREFIX)
312 : HAS_PREFIX(name, SYSTEM_PREFIX))
313 continue;
314 #endif
315
316 datum_len = 0;
317 if (!(ptr = get_xattr_data(source, name, &datum_len, 0)))
318 return -1;
319 if (sys_lsetxattr(dest, name, ptr, datum_len) < 0) {
320 int save_errno = errno ? errno : EINVAL;
321 rsyserr(FERROR_XFER, errno,
322 "rsync_xal_set: lsetxattr(\"%s\",\"%s\") failed",
323 dest, name);
324 errno = save_errno;
325 return -1;
326 }
327 free(ptr);
328 }
329
330 return 0;
331 }
332
333 static int find_matching_xattr(item_list *xalp)
334 {
335 size_t i, j;
336 item_list *lst = rsync_xal_l.items;
337
338 for (i = 0; i < rsync_xal_l.count; i++) {
339 rsync_xa *rxas1 = lst[i].items;
340 rsync_xa *rxas2 = xalp->items;
341
342 /* Wrong number of elements? */
343 if (lst[i].count != xalp->count)
344 continue;
345 /* any elements different? */
346 for (j = 0; j < xalp->count; j++) {
347 if (rxas1[j].name_len != rxas2[j].name_len
348 || rxas1[j].datum_len != rxas2[j].datum_len
349 || strcmp(rxas1[j].name, rxas2[j].name))
350 break;
351 if (rxas1[j].datum_len > MAX_FULL_DATUM) {
352 if (memcmp(rxas1[j].datum + 1,
353 rxas2[j].datum + 1,
354 MAX_DIGEST_LEN) != 0)
355 break;
356 } else {
357 if (memcmp(rxas1[j].datum, rxas2[j].datum,
358 rxas2[j].datum_len))
359 break;
360 }
361 }
362 /* no differences found. This is The One! */
363 if (j == xalp->count)
364 return i;
365 }
366
367 return -1;
368 }
369
370 /* Store *xalp on the end of rsync_xal_l */
371 static void rsync_xal_store(item_list *xalp)
372 {
373 item_list *new_lst = EXPAND_ITEM_LIST(&rsync_xal_l, item_list, RSYNC_XAL_LIST_INITIAL);
374 /* Since the following call starts a new list, we know it will hold the
375 * entire initial-count, not just enough space for one new item. */
376 *new_lst = empty_xattr;
377 (void)EXPAND_ITEM_LIST(new_lst, rsync_xa, xalp->count);
378 memcpy(new_lst->items, xalp->items, xalp->count * sizeof (rsync_xa));
379 new_lst->count = xalp->count;
380 xalp->count = 0;
381 }
382
383 /* Send the make_xattr()-generated xattr list for this flist entry. */
384 int send_xattr(stat_x *sxp, int f)
385 {
386 int ndx = find_matching_xattr(sxp->xattr);
387
388 /* Send 0 (-1 + 1) to indicate that literal xattr data follows. */
389 write_varint(f, ndx + 1);
390
391 if (ndx < 0) {
392 rsync_xa *rxa;
393 int count = sxp->xattr->count;
394 write_varint(f, count);
395 for (rxa = sxp->xattr->items; count--; rxa++) {
396 size_t name_len = rxa->name_len;
397 const char *name = rxa->name;
398 /* Strip the rsync prefix from disguised namespaces. */
399 if (name_len > RPRE_LEN
400 #ifdef HAVE_LINUX_XATTRS
401 && am_root < 0
402 #endif
403 && name[RPRE_LEN] != '%' && HAS_PREFIX(name, RSYNC_PREFIX)) {
404 name += RPRE_LEN;
405 name_len -= RPRE_LEN;
406 }
407 #ifndef HAVE_LINUX_XATTRS
408 else {
409 /* Put everything else in the user namespace. */
410 name_len += UPRE_LEN;
411 }
412 #endif
413 write_varint(f, name_len);
414 write_varint(f, rxa->datum_len);
415 #ifndef HAVE_LINUX_XATTRS
416 if (name_len > rxa->name_len) {
417 write_buf(f, USER_PREFIX, UPRE_LEN);
418 name_len -= UPRE_LEN;
419 }
420 #endif
421 write_buf(f, name, name_len);
422 if (rxa->datum_len > MAX_FULL_DATUM)
423 write_buf(f, rxa->datum + 1, MAX_DIGEST_LEN);
424 else
425 write_buf(f, rxa->datum, rxa->datum_len);
426 }
427 ndx = rsync_xal_l.count; /* pre-incremented count */
428 rsync_xal_store(sxp->xattr); /* adds item to rsync_xal_l */
429 }
430
431 return ndx;
432 }
433
434 /* Return a flag indicating if we need to change a file's xattrs. If
435 * "find_all" is specified, also mark any abbreviated xattrs that we
436 * need so that send_xattr_request() can tell the sender about them. */
437 int xattr_diff(struct file_struct *file, stat_x *sxp, int find_all)
438 {
439 item_list *lst = rsync_xal_l.items;
440 rsync_xa *snd_rxa, *rec_rxa;
441 int snd_cnt, rec_cnt;
442 int cmp, same, xattrs_equal = 1;
443
444 if (sxp && XATTR_READY(*sxp)) {
445 rec_rxa = sxp->xattr->items;
446 rec_cnt = sxp->xattr->count;
447 } else {
448 rec_rxa = NULL;
449 rec_cnt = 0;
450 }
451
452 if (F_XATTR(file) >= 0)
453 lst += F_XATTR(file);
454 else
455 lst = &empty_xattr;
456
457 snd_rxa = lst->items;
458 snd_cnt = lst->count;
459
460 /* If the count of the sender's xattrs is different from our
461 * (receiver's) xattrs, the lists are not the same. */
462 if (snd_cnt != rec_cnt) {
463 if (!find_all)
464 return 1;
465 xattrs_equal = 0;
466 }
467
468 while (snd_cnt) {
469 cmp = rec_cnt ? strcmp(snd_rxa->name, rec_rxa->name) : -1;
470 if (cmp > 0)
471 same = 0;
472 else if (snd_rxa->datum_len > MAX_FULL_DATUM) {
473 same = cmp == 0 && snd_rxa->datum_len == rec_rxa->datum_len
474 && memcmp(snd_rxa->datum + 1, rec_rxa->datum + 1,
475 MAX_DIGEST_LEN) == 0;
476 /* Flag unrequested items that we need. */
477 if (!same && find_all && snd_rxa->datum[0] == XSTATE_ABBREV)
478 snd_rxa->datum[0] = XSTATE_TODO;
479 } else {
480 same = cmp == 0 && snd_rxa->datum_len == rec_rxa->datum_len
481 && memcmp(snd_rxa->datum, rec_rxa->datum,
482 snd_rxa->datum_len) == 0;
483 }
484 if (!same) {
485 if (!find_all)
486 return 1;
487 xattrs_equal = 0;
488 }
489
490 if (cmp <= 0) {
491 snd_rxa++;
492 snd_cnt--;
493 }
494 if (cmp >= 0) {
495 rec_rxa++;
496 rec_cnt--;
497 }
498 }
499
500 if (rec_cnt)
501 xattrs_equal = 0;
502
503 return !xattrs_equal;
504 }
505
506 /* When called by the generator (with a NULL fname), this tells the sender
507 * all the abbreviated xattr values we need. When called by the sender
508 * (with a non-NULL fname), we send all the extra xattr data it needs.
509 * The generator may also call with f_out < 0 to just change all the
510 * XSTATE_ABBREV states into XSTATE_DONE. */
511 void send_xattr_request(const char *fname, struct file_struct *file, int f_out)
512 {
513 item_list *lst = rsync_xal_l.items;
514 int cnt, prior_req = 0;
515 rsync_xa *rxa;
516
517 lst += F_XATTR(file);
518 for (rxa = lst->items, cnt = lst->count; cnt--; rxa++) {
519 if (rxa->datum_len <= MAX_FULL_DATUM)
520 continue;
521 switch (rxa->datum[0]) {
522 case XSTATE_ABBREV:
523 /* Items left abbreviated matched the sender's checksum, so
524 * the receiver will cache the local data for future use. */
525 if (am_generator)
526 rxa->datum[0] = XSTATE_DONE;
527 continue;
528 case XSTATE_TODO:
529 assert(f_out >= 0);
530 break;
531 default:
532 continue;
533 }
534
535 /* Flag that we handled this abbreviated item. */
536 rxa->datum[0] = XSTATE_DONE;
537
538 write_varint(f_out, rxa->num - prior_req);
539 prior_req = rxa->num;
540
541 if (fname) {
542 size_t len = 0;
543 char *ptr;
544
545 /* Re-read the long datum. */
546 if (!(ptr = get_xattr_data(fname, rxa->name, &len, 0))) {
547 rprintf(FERROR_XFER, "failed to re-read xattr %s for %s\n", rxa->name, fname);
548 write_varint(f_out, 0);
549 continue;
550 }
551
552 write_varint(f_out, len); /* length might have changed! */
553 write_buf(f_out, ptr, len);
554 free(ptr);
555 }
556 }
557
558 if (f_out >= 0)
559 write_byte(f_out, 0); /* end the list */
560 }
561
562 /* When called by the sender, read the request from the generator and mark
563 * any needed xattrs with a flag that lets us know they need to be sent to
564 * the receiver. When called by the receiver, reads the sent data and
565 * stores it in place of its checksum. */
566 int recv_xattr_request(struct file_struct *file, int f_in)
567 {
568 item_list *lst = rsync_xal_l.items;
569 char *old_datum, *name;
570 rsync_xa *rxa;
571 int rel_pos, cnt, num, got_xattr_data = 0;
572
573 if (F_XATTR(file) < 0) {
574 rprintf(FERROR, "recv_xattr_request: internal data error!\n");
575 exit_cleanup(RERR_STREAMIO);
576 }
577 lst += F_XATTR(file);
578
579 cnt = lst->count;
580 rxa = lst->items;
581 num = 0;
582 while ((rel_pos = read_varint(f_in)) != 0) {
583 num += rel_pos;
584 while (cnt && rxa->num < num) {
585 rxa++;
586 cnt--;
587 }
588 if (!cnt || rxa->num != num) {
589 rprintf(FERROR, "[%s] could not find xattr #%d for %s\n",
590 who_am_i(), num, f_name(file, NULL));
591 exit_cleanup(RERR_STREAMIO);
592 }
593 if (!XATTR_ABBREV(*rxa) || rxa->datum[0] != XSTATE_ABBREV) {
594 rprintf(FERROR, "[%s] internal abbrev error on %s (%s, len=%ld)!\n",
595 who_am_i(), f_name(file, NULL), rxa->name, (long)rxa->datum_len);
596 exit_cleanup(RERR_STREAMIO);
597 }
598
599 if (am_sender) {
600 rxa->datum[0] = XSTATE_TODO;
601 continue;
602 }
603
604 old_datum = rxa->datum;
605 rxa->datum_len = read_varint(f_in);
606
607 if (rxa->name_len + rxa->datum_len < rxa->name_len)
608 overflow_exit("recv_xattr_request");
609 rxa->datum = new_array(char, rxa->datum_len + rxa->name_len);
610 if (!rxa->datum)
611 out_of_memory("recv_xattr_request");
612 name = rxa->datum + rxa->datum_len;
613 memcpy(name, rxa->name, rxa->name_len);
614 rxa->name = name;
615 free(old_datum);
616 read_buf(f_in, rxa->datum, rxa->datum_len);
617 got_xattr_data = 1;
618 }
619
620 return got_xattr_data;
621 }
622
623 /* ------------------------------------------------------------------------- */
624
625 /* receive and build the rsync_xattr_lists */
626 void receive_xattr(struct file_struct *file, int f)
627 {
628 static item_list temp_xattr = EMPTY_ITEM_LIST;
629 int count, num;
630 #ifdef HAVE_LINUX_XATTRS
631 int need_sort = 0;
632 #else
633 int need_sort = 1;
634 #endif
635 int ndx = read_varint(f);
636
637 if (ndx < 0 || (size_t)ndx > rsync_xal_l.count) {
638 rprintf(FERROR, "receive_xattr: xa index %d out of"
639 " range for %s\n", ndx, f_name(file, NULL));
640 exit_cleanup(RERR_STREAMIO);
641 }
642
643 if (ndx != 0) {
644 F_XATTR(file) = ndx - 1;
645 return;
646 }
647
648 if ((count = read_varint(f)) != 0) {
649 (void)EXPAND_ITEM_LIST(&temp_xattr, rsync_xa, count);
650 temp_xattr.count = 0;
651 }
652
653 for (num = 1; num <= count; num++) {
654 char *ptr, *name;
655 rsync_xa *rxa;
656 size_t name_len = read_varint(f);
657 size_t datum_len = read_varint(f);
658 size_t dget_len = datum_len > MAX_FULL_DATUM ? 1 + MAX_DIGEST_LEN : datum_len;
659 size_t extra_len = MIGHT_NEED_RPRE ? RPRE_LEN : 0;
660 if ((dget_len + extra_len < dget_len)
661 || (dget_len + extra_len + name_len < dget_len))
662 overflow_exit("receive_xattr");
663 ptr = new_array(char, dget_len + extra_len + name_len);
664 if (!ptr)
665 out_of_memory("receive_xattr");
666 name = ptr + dget_len + extra_len;
667 read_buf(f, name, name_len);
668 if (dget_len == datum_len)
669 read_buf(f, ptr, dget_len);
670 else {
671 *ptr = XSTATE_ABBREV;
672 read_buf(f, ptr + 1, MAX_DIGEST_LEN);
673 }
674 #ifdef HAVE_LINUX_XATTRS
675 /* Non-root can only save the user namespace. */
676 if (am_root <= 0 && !HAS_PREFIX(name, USER_PREFIX)) {
677 if (!am_root) {
678 free(ptr);
679 continue;
680 }
681 name -= RPRE_LEN;
682 name_len += RPRE_LEN;
683 memcpy(name, RSYNC_PREFIX, RPRE_LEN);
684 need_sort = 1;
685 }
686 #else
687 /* This OS only has a user namespace, so we either
688 * strip the user prefix, or we put a non-user
689 * namespace inside our rsync hierarchy. */
690 if (HAS_PREFIX(name, USER_PREFIX)) {
691 name += UPRE_LEN;
692 name_len -= UPRE_LEN;
693 } else if (am_root) {
694 name -= RPRE_LEN;
695 name_len += RPRE_LEN;
696 memcpy(name, RSYNC_PREFIX, RPRE_LEN);
697 } else {
698 free(ptr);
699 continue;
700 }
701 #endif
702 /* No rsync.%FOO attributes are copied w/o 2 -X options. */
703 if (preserve_xattrs < 2 && name_len > RPRE_LEN
704 && name[RPRE_LEN] == '%' && HAS_PREFIX(name, RSYNC_PREFIX)) {
705 free(ptr);
706 continue;
707 }
708 rxa = EXPAND_ITEM_LIST(&temp_xattr, rsync_xa, 1);
709 rxa->name = name;
710 rxa->datum = ptr;
711 rxa->name_len = name_len;
712 rxa->datum_len = datum_len;
713 rxa->num = num;
714 }
715
716 if (need_sort && count > 1)
717 qsort(temp_xattr.items, count, sizeof (rsync_xa), rsync_xal_compare_names);
718
719 ndx = rsync_xal_l.count; /* pre-incremented count */
720 rsync_xal_store(&temp_xattr); /* adds item to rsync_xal_l */
721
722 F_XATTR(file) = ndx;
723 }
724
725 /* Turn the xattr data in stat_x into cached xattr data, setting the index
726 * values in the file struct. */
727 void cache_xattr(struct file_struct *file, stat_x *sxp)
728 {
729 int ndx;
730
731 if (!sxp->xattr)
732 return;
733
734 ndx = find_matching_xattr(sxp->xattr);
735 if (ndx < 0)
736 rsync_xal_store(sxp->xattr); /* adds item to rsync_xal_l */
737
738 F_XATTR(file) = ndx;
739 }
740
741 static int rsync_xal_set(const char *fname, item_list *xalp,
742 const char *fnamecmp, stat_x *sxp)
743 {
744 rsync_xa *rxas = xalp->items;
745 ssize_t list_len;
746 size_t i, len;
747 char *name, *ptr, sum[MAX_DIGEST_LEN];
748 #ifdef HAVE_LINUX_XATTRS
749 int user_only = am_root <= 0;
750 #endif
751 size_t name_len;
752 int ret = 0;
753
754 /* This puts the current name list into the "namebuf" buffer. */
755 if ((list_len = get_xattr_names(fname)) < 0)
756 return -1;
757
758 for (i = 0; i < xalp->count; i++) {
759 name = rxas[i].name;
760
761 if (XATTR_ABBREV(rxas[i])) {
762 /* See if the fnamecmp version is identical. */
763 len = name_len = rxas[i].name_len;
764 if ((ptr = get_xattr_data(fnamecmp, name, &len, 1)) == NULL) {
765 still_abbrev:
766 if (am_generator)
767 continue;
768 rprintf(FERROR, "Missing abbreviated xattr value, %s, for %s\n",
769 rxas[i].name, full_fname(fname));
770 ret = -1;
771 continue;
772 }
773 if (len != rxas[i].datum_len) {
774 free(ptr);
775 goto still_abbrev;
776 }
777
778 sum_init(checksum_seed);
779 sum_update(ptr, len);
780 sum_end(sum);
781 if (memcmp(sum, rxas[i].datum + 1, MAX_DIGEST_LEN) != 0) {
782 free(ptr);
783 goto still_abbrev;
784 }
785
786 if (fname == fnamecmp)
787 ; /* Value is already set when identical */
788 else if (sys_lsetxattr(fname, name, ptr, len) < 0) {
789 rsyserr(FERROR_XFER, errno,
790 "rsync_xal_set: lsetxattr(\"%s\",\"%s\") failed",
791 fname, name);
792 ret = -1;
793 } else /* make sure caller sets mtime */
794 sxp->st.st_mtime = (time_t)-1;
795
796 if (am_generator) { /* generator items stay abbreviated */
797 free(ptr);
798 continue;
799 }
800
801 memcpy(ptr + len, name, name_len);
802 free(rxas[i].datum);
803
804 rxas[i].name = name = ptr + len;
805 rxas[i].datum = ptr;
806 continue;
807 }
808
809 if (sys_lsetxattr(fname, name, rxas[i].datum, rxas[i].datum_len) < 0) {
810 rsyserr(FERROR_XFER, errno,
811 "rsync_xal_set: lsetxattr(\"%s\",\"%s\") failed",
812 fname, name);
813 ret = -1;
814 } else /* make sure caller sets mtime */
815 sxp->st.st_mtime = (time_t)-1;
816 }
817
818 /* Remove any extraneous names. */
819 for (name = namebuf; list_len > 0; name += name_len) {
820 name_len = strlen(name) + 1;
821 list_len -= name_len;
822
823 #ifdef HAVE_LINUX_XATTRS
824 /* We always ignore the system namespace, and non-root
825 * ignores everything but the user namespace. */
826 if (user_only ? !HAS_PREFIX(name, USER_PREFIX)
827 : HAS_PREFIX(name, SYSTEM_PREFIX))
828 continue;
829 #endif
830 if (am_root < 0 && name_len > RPRE_LEN
831 && name[RPRE_LEN] == '%' && strcmp(name, XSTAT_ATTR) == 0)
832 continue;
833
834 for (i = 0; i < xalp->count; i++) {
835 if (strcmp(name, rxas[i].name) == 0)
836 break;
837 }
838 if (i == xalp->count) {
839 if (sys_lremovexattr(fname, name) < 0) {
840 rsyserr(FERROR_XFER, errno,
841 "rsync_xal_clear: lremovexattr(\"%s\",\"%s\") failed",
842 fname, name);
843 ret = -1;
844 } else /* make sure caller sets mtime */
845 sxp->st.st_mtime = (time_t)-1;
846 }
847 }
848
849 return ret;
850 }
851
852 /* Set extended attributes on indicated filename. */
853 int set_xattr(const char *fname, const struct file_struct *file,
854 const char *fnamecmp, stat_x *sxp)
855 {
856 int ndx;
857 item_list *lst = rsync_xal_l.items;
858
859 if (dry_run)
860 return 1; /* FIXME: --dry-run needs to compute this value */
861
862 if (read_only || list_only) {
863 errno = EROFS;
864 return -1;
865 }
866
867 ndx = F_XATTR(file);
868 return rsync_xal_set(fname, lst + ndx, fnamecmp, sxp);
869 }
870
871 #ifdef SUPPORT_ACLS
872 char *get_xattr_acl(const char *fname, int is_access_acl, size_t *len_p)
873 {
874 const char *name = is_access_acl ? XACC_ACL_ATTR : XDEF_ACL_ATTR;
875 *len_p = 0; /* no extra data alloc needed from get_xattr_data() */
876 return get_xattr_data(fname, name, len_p, 1);
877 }
878
879 int set_xattr_acl(const char *fname, int is_access_acl, const char *buf, size_t buf_len)
880 {
881 const char *name = is_access_acl ? XACC_ACL_ATTR : XDEF_ACL_ATTR;
882 if (sys_lsetxattr(fname, name, buf, buf_len) < 0) {
883 rsyserr(FERROR_XFER, errno,
884 "set_xattr_acl: lsetxattr(\"%s\",\"%s\") failed",
885 fname, name);
886 return -1;
887 }
888 return 0;
889 }
890
891 int del_def_xattr_acl(const char *fname)
892 {
893 return sys_lremovexattr(fname, XDEF_ACL_ATTR);
894 }
895 #endif
896
897 int get_stat_xattr(const char *fname, int fd, STRUCT_STAT *fst, STRUCT_STAT *xst)
898 {
899 int mode, rdev_major, rdev_minor, uid, gid, len;
900 char buf[256];
901
902 if (am_root >= 0 || IS_DEVICE(fst->st_mode) || IS_SPECIAL(fst->st_mode))
903 return -1;
904
905 if (xst)
906 *xst = *fst;
907 else
908 xst = fst;
909 if (fname) {
910 fd = -1;
911 len = sys_lgetxattr(fname, XSTAT_ATTR, buf, sizeof buf - 1);
912 } else {
913 fname = "fd";
914 len = sys_fgetxattr(fd, XSTAT_ATTR, buf, sizeof buf - 1);
915 }
916 if (len >= (int)sizeof buf) {
917 len = -1;
918 errno = ERANGE;
919 }
920 if (len < 0) {
921 if (errno == ENOTSUP || errno == ENOATTR)
922 return -1;
923 if (errno == EPERM && S_ISLNK(fst->st_mode)) {
924 xst->st_uid = 0;
925 xst->st_gid = 0;
926 return 0;
927 }
928 rsyserr(FERROR_XFER, errno, "failed to read xattr %s for %s",
929 XSTAT_ATTR, full_fname(fname));
930 return -1;
931 }
932 buf[len] = '\0';
933
934 if (sscanf(buf, "%o %d,%d %d:%d",
935 &mode, &rdev_major, &rdev_minor, &uid, &gid) != 5) {
936 rprintf(FERROR, "Corrupt %s xattr attached to %s: \"%s\"\n",
937 XSTAT_ATTR, full_fname(fname), buf);
938 exit_cleanup(RERR_FILEIO);
939 }
940
941 xst->st_mode = from_wire_mode(mode);
942 xst->st_rdev = MAKEDEV(rdev_major, rdev_minor);
943 xst->st_uid = uid;
944 xst->st_gid = gid;
945
946 return 0;
947 }
948
949 int set_stat_xattr(const char *fname, struct file_struct *file, mode_t new_mode)
950 {
951 STRUCT_STAT fst, xst;
952 dev_t rdev;
953 mode_t mode, fmode;
954
955 if (dry_run)
956 return 0;
957
958 if (read_only || list_only) {
959 rsyserr(FERROR_XFER, EROFS, "failed to write xattr %s for %s",
960 XSTAT_ATTR, full_fname(fname));
961 return -1;
962 }
963
964 if (x_lstat(fname, &fst, &xst) < 0) {
965 rsyserr(FERROR_XFER, errno, "failed to re-stat %s",
966 full_fname(fname));
967 return -1;
968 }
969
970 fst.st_mode &= (_S_IFMT | CHMOD_BITS);
971 fmode = new_mode & (_S_IFMT | CHMOD_BITS);
972
973 if (IS_DEVICE(fmode) || IS_SPECIAL(fmode)) {
974 uint32 *devp = F_RDEV_P(file);
975 rdev = MAKEDEV(DEV_MAJOR(devp), DEV_MINOR(devp));
976 } else
977 rdev = 0;
978
979 /* Dump the special permissions and enable full owner access. */
980 mode = (fst.st_mode & _S_IFMT) | (fmode & ACCESSPERMS)
981 | (S_ISDIR(fst.st_mode) ? 0700 : 0600);
982 if (fst.st_mode != mode)
983 do_chmod(fname, mode);
984 if (!IS_DEVICE(fst.st_mode) && !IS_SPECIAL(fst.st_mode))
985 fst.st_rdev = 0; /* just in case */
986
987 if (mode == fmode && fst.st_rdev == rdev
988 && fst.st_uid == F_OWNER(file) && fst.st_gid == F_GROUP(file)) {
989 /* xst.st_mode will be 0 if there's no current stat xattr */
990 if (xst.st_mode && sys_lremovexattr(fname, XSTAT_ATTR) < 0) {
991 rsyserr(FERROR_XFER, errno,
992 "delete of stat xattr failed for %s",
993 full_fname(fname));
994 return -1;
995 }
996 return 0;
997 }
998
999 if (xst.st_mode != fmode || xst.st_rdev != rdev
1000 || xst.st_uid != F_OWNER(file) || xst.st_gid != F_GROUP(file)) {
1001 char buf[256];
1002 int len = snprintf(buf, sizeof buf, "%o %u,%u %u:%u",
1003 to_wire_mode(fmode),
1004 (int)major(rdev), (int)minor(rdev),
1005 F_OWNER(file), F_GROUP(file));
1006 if (sys_lsetxattr(fname, XSTAT_ATTR, buf, len) < 0) {
1007 if (errno == EPERM && S_ISLNK(fst.st_mode))
1008 return 0;
1009 rsyserr(FERROR_XFER, errno,
1010 "failed to write xattr %s for %s",
1011 XSTAT_ATTR, full_fname(fname));
1012 return -1;
1013 }
1014 }
1015
1016 return 0;
1017 }
1018
1019 int x_stat(const char *fname, STRUCT_STAT *fst, STRUCT_STAT *xst)
1020 {
1021 int ret = do_stat(fname, fst);
1022 if ((ret < 0 || get_stat_xattr(fname, -1, fst, xst) < 0) && xst)
1023 xst->st_mode = 0;
1024 return ret;
1025 }
1026
1027 int x_lstat(const char *fname, STRUCT_STAT *fst, STRUCT_STAT *xst)
1028 {
1029 int ret = do_lstat(fname, fst);
1030 if ((ret < 0 || get_stat_xattr(fname, -1, fst, xst) < 0) && xst)
1031 xst->st_mode = 0;
1032 return ret;
1033 }
1034
1035 int x_fstat(int fd, STRUCT_STAT *fst, STRUCT_STAT *xst)
1036 {
1037 int ret = do_fstat(fd, fst);
1038 if ((ret < 0 || get_stat_xattr(NULL, fd, fst, xst) < 0) && xst)
1039 xst->st_mode = 0;
1040 return ret;
1041 }
1042
1043 #endif /* SUPPORT_XATTRS */
rsync: a fast, versatile, remote (and local) file-copying tool