xattrs.c

   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) 2006-2015 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
  41 #define RSYNC_XAL_INITIAL 5
  42 #define RSYNC_XAL_LIST_INITIAL 100
  43
  44 #define MAX_FULL_DATUM 32
  45
  46 #define HAS_PREFIX(str, prfx) (*(str) == *(prfx) \
  47                             && 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 static size_t namebuf_len = 0;
  83 static char *namebuf = NULL;
  84
  85 static item_list empty_xattr = EMPTY_ITEM_LIST;
  86 static item_list rsync_xal_l = EMPTY_ITEM_LIST;
  87
  88 static size_t prior_xattr_count = (size_t)-1;
  89
  90 /* ------------------------------------------------------------------------- */
  91
  92 static void rsync_xal_free(item_list *xalp)
  93 {
  94         size_t i;
  95         rsync_xa *rxas = xalp->items;
  96
  97         if (!xalp->malloced)
  98                 return;
  99
 100         for (i = 0; i < xalp->count; i++) {
 101                 free(rxas[i].datum);
 102                 /*free(rxas[i].name);*/
 103         }
 104         free(xalp->items);
 105 }
 106
 107 void free_xattr(stat_x *sxp)
 108 {
 109         if (!sxp->xattr)
 110                 return;
 111         rsync_xal_free(sxp->xattr);
 112         free(sxp->xattr);
 113         sxp->xattr = NULL;
 114 }
 115
 116 static int rsync_xal_compare_names(const void *x1, const void *x2)
 117 {
 118         const rsync_xa *xa1 = x1;
 119         const rsync_xa *xa2 = x2;
 120         return strcmp(xa1->name, xa2->name);
 121 }
 122
 123 static ssize_t get_xattr_names(const char *fname)
 124 {
 125         ssize_t list_len;
 126         int64 arg;
 127
 128         if (!namebuf) {
 129                 namebuf_len = 1024;
 130                 namebuf = new_array(char, namebuf_len);
 131                 if (!namebuf)
 132                         out_of_memory("get_xattr_names");
 133         }
 134
 135         while (1) {
 136                 /* The length returned includes all the '\0' terminators. */
 137                 list_len = sys_llistxattr(fname, namebuf, namebuf_len);
 138                 if (list_len >= 0) {
 139                         if ((size_t)list_len <= namebuf_len)
 140                                 break;
 141                 } else if (errno == ENOTSUP)
 142                         return 0;
 143                 else if (errno != ERANGE) {
 144                         arg = namebuf_len;
 145                   got_error:
 146                         rsyserr(FERROR_XFER, errno,
 147                                 "get_xattr_names: llistxattr(\"%s\",%s) failed",
 148                                 full_fname(fname), big_num(arg));
 149                         return -1;
 150                 }
 151                 list_len = sys_llistxattr(fname, NULL, 0);
 152                 if (list_len < 0) {
 153                         arg = 0;
 154                         goto got_error;
 155                 }
 156                 if (namebuf_len)
 157                         free(namebuf);
 158                 namebuf_len = list_len + 1024;
 159                 namebuf = new_array(char, namebuf_len);
 160                 if (!namebuf)
 161                         out_of_memory("get_xattr_names");
 162         }
 163
 164         return list_len;
 165 }
 166
 167 /* On entry, the *len_ptr parameter contains the size of the extra space we
 168  * should allocate when we create a buffer for the data.  On exit, it contains
 169  * the length of the datum. */
 170 static char *get_xattr_data(const char *fname, const char *name, size_t *len_ptr,
 171                             int no_missing_error)
 172 {
 173         size_t datum_len = sys_lgetxattr(fname, name, NULL, 0);
 174         size_t extra_len = *len_ptr;
 175         char *ptr;
 176
 177         *len_ptr = datum_len;
 178
 179         if (datum_len == (size_t)-1) {
 180                 if (errno == ENOTSUP || no_missing_error)
 181                         return NULL;
 182                 rsyserr(FERROR_XFER, errno,
 183                         "get_xattr_data: lgetxattr(\"%s\",\"%s\",0) failed",
 184                         full_fname(fname), name);
 185                 return NULL;
 186         }
 187
 188         if (!datum_len && !extra_len)
 189                 extra_len = 1; /* request non-zero amount of memory */
 190         if (datum_len + extra_len < datum_len)
 191                 overflow_exit("get_xattr_data");
 192         if (!(ptr = new_array(char, datum_len + extra_len)))
 193                 out_of_memory("get_xattr_data");
 194
 195         if (datum_len) {
 196                 size_t len = sys_lgetxattr(fname, name, ptr, datum_len);
 197                 if (len != datum_len) {
 198                         if (len == (size_t)-1) {
 199                                 rsyserr(FERROR_XFER, errno,
 200                                     "get_xattr_data: lgetxattr(\"%s\",\"%s\",%ld)"
 201                                     " failed", full_fname(fname), name, (long)datum_len);
 202                         } else {
 203                                 rprintf(FERROR_XFER,
 204                                     "get_xattr_data: lgetxattr(\"%s\",\"%s\",%ld)"
 205                                     " returned %ld\n", full_fname(fname), name,
 206                                     (long)datum_len, (long)len);
 207                         }
 208                         free(ptr);
 209                         return NULL;
 210                 }
 211         }
 212
 213         return ptr;
 214 }
 215
 216 static int rsync_xal_get(const char *fname, item_list *xalp)
 217 {
 218         ssize_t list_len, name_len;
 219         size_t datum_len, name_offset;
 220         char *name, *ptr;
 221 #ifdef HAVE_LINUX_XATTRS
 222         int user_only = am_sender ? 0 : !am_root;
 223 #endif
 224         rsync_xa *rxa;
 225         int count;
 226
 227         /* This puts the name list into the "namebuf" buffer. */
 228         if ((list_len = get_xattr_names(fname)) < 0)
 229                 return -1;
 230
 231         for (name = namebuf; list_len > 0; name += name_len) {
 232                 name_len = strlen(name) + 1;
 233                 list_len -= name_len;
 234
 235 #ifdef HAVE_LINUX_XATTRS
 236                 /* We always ignore the system namespace, and non-root
 237                  * ignores everything but the user namespace. */
 238                 if (user_only ? !HAS_PREFIX(name, USER_PREFIX)
 239                               : HAS_PREFIX(name, SYSTEM_PREFIX))
 240                         continue;
 241 #endif
 242
 243                 /* No rsync.%FOO attributes are copied w/o 2 -X options. */
 244                 if (name_len > RPRE_LEN && name[RPRE_LEN] == '%'
 245                  && HAS_PREFIX(name, RSYNC_PREFIX)) {
 246                         if ((am_sender && preserve_xattrs < 2)
 247                          || (am_root < 0
 248                           && (strcmp(name+RPRE_LEN+1, XSTAT_SUFFIX) == 0
 249                            || strcmp(name+RPRE_LEN+1, XACC_ACL_SUFFIX) == 0
 250                            || strcmp(name+RPRE_LEN+1, XDEF_ACL_SUFFIX) == 0)))
 251                                 continue;
 252                 }
 253
 254                 datum_len = name_len; /* Pass extra size to get_xattr_data() */
 255                 if (!(ptr = get_xattr_data(fname, name, &datum_len, 0)))
 256                         return -1;
 257
 258                 if (datum_len > MAX_FULL_DATUM) {
 259                         /* For large datums, we store a flag and a checksum. */
 260                         name_offset = 1 + MAX_DIGEST_LEN;
 261                         sum_init(checksum_seed);
 262                         sum_update(ptr, datum_len);
 263                         free(ptr);
 264
 265                         if (!(ptr = new_array(char, name_offset + name_len)))
 266                                 out_of_memory("rsync_xal_get");
 267                         *ptr = XSTATE_ABBREV;
 268                         sum_end(ptr + 1);
 269                 } else
 270                         name_offset = datum_len;
 271
 272                 rxa = EXPAND_ITEM_LIST(xalp, rsync_xa, RSYNC_XAL_INITIAL);
 273                 rxa->name = ptr + name_offset;
 274                 memcpy(rxa->name, name, name_len);
 275                 rxa->datum = ptr;
 276                 rxa->name_len = name_len;
 277                 rxa->datum_len = datum_len;
 278         }
 279         count = xalp->count;
 280         rxa = xalp->items;
 281         if (count > 1)
 282                 qsort(rxa, count, sizeof (rsync_xa), rsync_xal_compare_names);
 283         for (rxa += count-1; count; count--, rxa--)
 284                 rxa->num = count;
 285         return 0;
 286 }
 287
 288 /* Read the xattr(s) for this filename. */
 289 int get_xattr(const char *fname, stat_x *sxp)
 290 {
 291         sxp->xattr = new(item_list);
 292         *sxp->xattr = empty_xattr;
 293
 294         if (S_ISREG(sxp->st.st_mode) || S_ISDIR(sxp->st.st_mode)) {
 295                 /* Everyone supports this. */
 296         } else if (S_ISLNK(sxp->st.st_mode)) {
 297 #ifndef NO_SYMLINK_XATTRS
 298                 if (!preserve_links)
 299 #endif
 300                         return 0;
 301         } else if (IS_SPECIAL(sxp->st.st_mode)) {
 302 #ifndef NO_SPECIAL_XATTRS
 303                 if (!preserve_specials)
 304 #endif
 305                         return 0;
 306         } else if (IS_DEVICE(sxp->st.st_mode)) {
 307 #ifndef NO_DEVICE_XATTRS
 308                 if (!preserve_devices)
 309 #endif
 310                         return 0;
 311         } else if (IS_MISSING_FILE(sxp->st))
 312                 return 0;
 313
 314         if (rsync_xal_get(fname, sxp->xattr) < 0) {
 315                 free_xattr(sxp);
 316                 return -1;
 317         }
 318         return 0;
 319 }
 320
 321 int copy_xattrs(const char *source, const char *dest)
 322 {
 323         ssize_t list_len, name_len;
 324         size_t datum_len;
 325         char *name, *ptr;
 326 #ifdef HAVE_LINUX_XATTRS
 327         int user_only = am_sender ? 0 : am_root <= 0;
 328 #endif
 329
 330         /* This puts the name list into the "namebuf" buffer. */
 331         if ((list_len = get_xattr_names(source)) < 0)
 332                 return -1;
 333
 334         for (name = namebuf; list_len > 0; name += name_len) {
 335                 name_len = strlen(name) + 1;
 336                 list_len -= name_len;
 337
 338 #ifdef HAVE_LINUX_XATTRS
 339                 /* We always ignore the system namespace, and non-root
 340                  * ignores everything but the user namespace. */
 341                 if (user_only ? !HAS_PREFIX(name, USER_PREFIX)
 342                               : HAS_PREFIX(name, SYSTEM_PREFIX))
 343                         continue;
 344 #endif
 345
 346                 datum_len = 0;
 347                 if (!(ptr = get_xattr_data(source, name, &datum_len, 0)))
 348                         return -1;
 349                 if (sys_lsetxattr(dest, name, ptr, datum_len) < 0) {
 350                         int save_errno = errno ? errno : EINVAL;
 351                         rsyserr(FERROR_XFER, errno,
 352                                 "copy_xattrs: lsetxattr(\"%s\",\"%s\") failed",
 353                                 full_fname(dest), name);
 354                         errno = save_errno;
 355                         return -1;
 356                 }
 357                 free(ptr);
 358         }
 359
 360         return 0;
 361 }
 362
 363 static int find_matching_xattr(item_list *xalp)
 364 {
 365         size_t i, j;
 366         item_list *lst = rsync_xal_l.items;
 367
 368         for (i = 0; i < rsync_xal_l.count; i++) {
 369                 rsync_xa *rxas1 = lst[i].items;
 370                 rsync_xa *rxas2 = xalp->items;
 371
 372                 /* Wrong number of elements? */
 373                 if (lst[i].count != xalp->count)
 374                         continue;
 375                 /* any elements different? */
 376                 for (j = 0; j < xalp->count; j++) {
 377                         if (rxas1[j].name_len != rxas2[j].name_len
 378                          || rxas1[j].datum_len != rxas2[j].datum_len
 379                          || strcmp(rxas1[j].name, rxas2[j].name))
 380                                 break;
 381                         if (rxas1[j].datum_len > MAX_FULL_DATUM) {
 382                                 if (memcmp(rxas1[j].datum + 1,
 383                                            rxas2[j].datum + 1,
 384                                            MAX_DIGEST_LEN) != 0)
 385                                         break;
 386                         } else {
 387                                 if (memcmp(rxas1[j].datum, rxas2[j].datum,
 388                                            rxas2[j].datum_len))
 389                                         break;
 390                         }
 391                 }
 392                 /* no differences found.  This is The One! */
 393                 if (j == xalp->count)
 394                         return i;
 395         }
 396
 397         return -1;
 398 }
 399
 400 /* Store *xalp on the end of rsync_xal_l */
 401 static void rsync_xal_store(item_list *xalp)
 402 {
 403         item_list *new_lst = EXPAND_ITEM_LIST(&rsync_xal_l, item_list, RSYNC_XAL_LIST_INITIAL);
 404         /* Since the following call starts a new list, we know it will hold the
 405          * entire initial-count, not just enough space for one new item. */
 406         *new_lst = empty_xattr;
 407         (void)EXPAND_ITEM_LIST(new_lst, rsync_xa, xalp->count);
 408         memcpy(new_lst->items, xalp->items, xalp->count * sizeof (rsync_xa));
 409         new_lst->count = xalp->count;
 410         xalp->count = 0;
 411 }
 412
 413 /* Send the make_xattr()-generated xattr list for this flist entry. */
 414 int send_xattr(int f, stat_x *sxp)
 415 {
 416         int ndx = find_matching_xattr(sxp->xattr);
 417
 418         /* Send 0 (-1 + 1) to indicate that literal xattr data follows. */
 419         write_varint(f, ndx + 1);
 420
 421         if (ndx < 0) {
 422                 rsync_xa *rxa;
 423                 int count = sxp->xattr->count;
 424                 write_varint(f, count);
 425                 for (rxa = sxp->xattr->items; count--; rxa++) {
 426                         size_t name_len = rxa->name_len;
 427                         const char *name = rxa->name;
 428                         /* Strip the rsync prefix from disguised namespaces. */
 429                         if (name_len > RPRE_LEN
 430 #ifdef HAVE_LINUX_XATTRS
 431                          && am_root < 0
 432 #endif
 433                          && name[RPRE_LEN] != '%' && HAS_PREFIX(name, RSYNC_PREFIX)) {
 434                                 name += RPRE_LEN;
 435                                 name_len -= RPRE_LEN;
 436                         }
 437 #ifndef HAVE_LINUX_XATTRS
 438                         else {
 439                                 /* Put everything else in the user namespace. */
 440                                 name_len += UPRE_LEN;
 441                         }
 442 #endif
 443                         write_varint(f, name_len);
 444                         write_varint(f, rxa->datum_len);
 445 #ifndef HAVE_LINUX_XATTRS
 446                         if (name_len > rxa->name_len) {
 447                                 write_buf(f, USER_PREFIX, UPRE_LEN);
 448                                 name_len -= UPRE_LEN;
 449                         }
 450 #endif
 451                         write_buf(f, name, name_len);
 452                         if (rxa->datum_len > MAX_FULL_DATUM)
 453                                 write_buf(f, rxa->datum + 1, MAX_DIGEST_LEN);
 454                         else
 455                                 write_bigbuf(f, rxa->datum, rxa->datum_len);
 456                 }
 457                 ndx = rsync_xal_l.count; /* pre-incremented count */
 458                 rsync_xal_store(sxp->xattr); /* adds item to rsync_xal_l */
 459         }
 460
 461         return ndx;
 462 }
 463
 464 /* Return a flag indicating if we need to change a file's xattrs.  If
 465  * "find_all" is specified, also mark any abbreviated xattrs that we
 466  * need so that send_xattr_request() can tell the sender about them. */
 467 int xattr_diff(struct file_struct *file, stat_x *sxp, int find_all)
 468 {
 469         item_list *lst = rsync_xal_l.items;
 470         rsync_xa *snd_rxa, *rec_rxa;
 471         int snd_cnt, rec_cnt;
 472         int cmp, same, xattrs_equal = 1;
 473
 474         if (sxp && XATTR_READY(*sxp)) {
 475                 rec_rxa = sxp->xattr->items;
 476                 rec_cnt = sxp->xattr->count;
 477         } else {
 478                 rec_rxa = NULL;
 479                 rec_cnt = 0;
 480         }
 481
 482         if (F_XATTR(file) >= 0)
 483                 lst += F_XATTR(file);
 484         else
 485                 lst = &empty_xattr;
 486
 487         snd_rxa = lst->items;
 488         snd_cnt = lst->count;
 489
 490         /* If the count of the sender's xattrs is different from our
 491          * (receiver's) xattrs, the lists are not the same. */
 492         if (snd_cnt != rec_cnt) {
 493                 if (!find_all)
 494                         return 1;
 495                 xattrs_equal = 0;
 496         }
 497
 498         while (snd_cnt) {
 499                 cmp = rec_cnt ? strcmp(snd_rxa->name, rec_rxa->name) : -1;
 500                 if (cmp > 0)
 501                         same = 0;
 502                 else if (snd_rxa->datum_len > MAX_FULL_DATUM) {
 503                         same = cmp == 0 && snd_rxa->datum_len == rec_rxa->datum_len
 504                             && memcmp(snd_rxa->datum + 1, rec_rxa->datum + 1,
 505                                       MAX_DIGEST_LEN) == 0;
 506                         /* Flag unrequested items that we need. */
 507                         if (!same && find_all && snd_rxa->datum[0] == XSTATE_ABBREV)
 508                                 snd_rxa->datum[0] = XSTATE_TODO;
 509                 } else {
 510                         same = cmp == 0 && snd_rxa->datum_len == rec_rxa->datum_len
 511                             && memcmp(snd_rxa->datum, rec_rxa->datum,
 512                                       snd_rxa->datum_len) == 0;
 513                 }
 514                 if (!same) {
 515                         if (!find_all)
 516                                 return 1;
 517                         xattrs_equal = 0;
 518                 }
 519
 520                 if (cmp <= 0) {
 521                         snd_rxa++;
 522                         snd_cnt--;
 523                 }
 524                 if (cmp >= 0) {
 525                         rec_rxa++;
 526                         rec_cnt--;
 527                 }
 528         }
 529
 530         if (rec_cnt)
 531                 xattrs_equal = 0;
 532
 533         return !xattrs_equal;
 534 }
 535
 536 /* When called by the generator (with a NULL fname), this tells the sender
 537  * all the abbreviated xattr values we need.  When called by the sender
 538  * (with a non-NULL fname), we send all the extra xattr data it needs.
 539  * The generator may also call with f_out < 0 to just change all the
 540  * XSTATE_ABBREV states into XSTATE_DONE. */
 541 void send_xattr_request(const char *fname, struct file_struct *file, int f_out)
 542 {
 543         item_list *lst = rsync_xal_l.items;
 544         int cnt, prior_req = 0;
 545         rsync_xa *rxa;
 546
 547         lst += F_XATTR(file);
 548         for (rxa = lst->items, cnt = lst->count; cnt--; rxa++) {
 549                 if (rxa->datum_len <= MAX_FULL_DATUM)
 550                         continue;
 551                 switch (rxa->datum[0]) {
 552                 case XSTATE_ABBREV:
 553                         /* Items left abbreviated matched the sender's checksum, so
 554                          * the receiver will cache the local data for future use. */
 555                         if (am_generator)
 556                                 rxa->datum[0] = XSTATE_DONE;
 557                         continue;
 558                 case XSTATE_TODO:
 559                         assert(f_out >= 0);
 560                         break;
 561                 default:
 562                         continue;
 563                 }
 564
 565                 /* Flag that we handled this abbreviated item. */
 566                 rxa->datum[0] = XSTATE_DONE;
 567
 568                 write_varint(f_out, rxa->num - prior_req);
 569                 prior_req = rxa->num;
 570
 571                 if (fname) {
 572                         size_t len = 0;
 573                         char *ptr;
 574
 575                         /* Re-read the long datum. */
 576                         if (!(ptr = get_xattr_data(fname, rxa->name, &len, 0))) {
 577                                 rprintf(FERROR_XFER, "failed to re-read xattr %s for %s\n", rxa->name, fname);
 578                                 write_varint(f_out, 0);
 579                                 continue;
 580                         }
 581
 582                         write_varint(f_out, len); /* length might have changed! */
 583                         write_bigbuf(f_out, ptr, len);
 584                         free(ptr);
 585                 }
 586         }
 587
 588         if (f_out >= 0)
 589                 write_byte(f_out, 0); /* end the list */
 590 }
 591
 592 /* When called by the sender, read the request from the generator and mark
 593  * any needed xattrs with a flag that lets us know they need to be sent to
 594  * the receiver.  When called by the receiver, reads the sent data and
 595  * stores it in place of its checksum. */
 596 int recv_xattr_request(struct file_struct *file, int f_in)
 597 {
 598         item_list *lst = rsync_xal_l.items;
 599         char *old_datum, *name;
 600         rsync_xa *rxa;
 601         int rel_pos, cnt, num, got_xattr_data = 0;
 602
 603         if (F_XATTR(file) < 0) {
 604                 rprintf(FERROR, "recv_xattr_request: internal data error!\n");
 605                 exit_cleanup(RERR_PROTOCOL);
 606         }
 607         lst += F_XATTR(file);
 608
 609         cnt = lst->count;
 610         rxa = lst->items;
 611         num = 0;
 612         while ((rel_pos = read_varint(f_in)) != 0) {
 613                 num += rel_pos;
 614                 /* Note that the sender-related num values may not be in order on the receiver! */
 615                 while (cnt && (am_sender ? rxa->num < num : rxa->num != num)) {
 616                         rxa++;
 617                         cnt--;
 618                 }
 619                 if (!cnt || rxa->num != num) {
 620                         rprintf(FERROR, "[%s] could not find xattr #%d for %s\n",
 621                                 who_am_i(), num, f_name(file, NULL));
 622                         exit_cleanup(RERR_PROTOCOL);
 623                 }
 624                 if (!XATTR_ABBREV(*rxa) || rxa->datum[0] != XSTATE_ABBREV) {
 625                         rprintf(FERROR, "[%s] internal abbrev error on %s (%s, len=%ld)!\n",
 626                                 who_am_i(), f_name(file, NULL), rxa->name, (long)rxa->datum_len);
 627                         exit_cleanup(RERR_PROTOCOL);
 628                 }
 629
 630                 if (am_sender) {
 631                         rxa->datum[0] = XSTATE_TODO;
 632                         continue;
 633                 }
 634
 635                 old_datum = rxa->datum;
 636                 rxa->datum_len = read_varint(f_in);
 637
 638                 if (rxa->name_len + rxa->datum_len < rxa->name_len)
 639                         overflow_exit("recv_xattr_request");
 640                 rxa->datum = new_array(char, rxa->datum_len + rxa->name_len);
 641                 if (!rxa->datum)
 642                         out_of_memory("recv_xattr_request");
 643                 name = rxa->datum + rxa->datum_len;
 644                 memcpy(name, rxa->name, rxa->name_len);
 645                 rxa->name = name;
 646                 free(old_datum);
 647                 read_buf(f_in, rxa->datum, rxa->datum_len);
 648                 got_xattr_data = 1;
 649         }
 650
 651         return got_xattr_data;
 652 }
 653
 654 /* ------------------------------------------------------------------------- */
 655
 656 /* receive and build the rsync_xattr_lists */
 657 void receive_xattr(int f, struct file_struct *file)
 658 {
 659         static item_list temp_xattr = EMPTY_ITEM_LIST;
 660         int count, num;
 661 #ifdef HAVE_LINUX_XATTRS
 662         int need_sort = 0;
 663 #else
 664         int need_sort = 1;
 665 #endif
 666         int ndx = read_varint(f);
 667
 668         if (ndx < 0 || (size_t)ndx > rsync_xal_l.count) {
 669                 rprintf(FERROR, "receive_xattr: xa index %d out of"
 670                         " range for %s\n", ndx, f_name(file, NULL));
 671                 exit_cleanup(RERR_STREAMIO);
 672         }
 673
 674         if (ndx != 0) {
 675                 F_XATTR(file) = ndx - 1;
 676                 return;
 677         }
 678
 679         if ((count = read_varint(f)) != 0) {
 680                 (void)EXPAND_ITEM_LIST(&temp_xattr, rsync_xa, count);
 681                 temp_xattr.count = 0;
 682         }
 683
 684         for (num = 1; num <= count; num++) {
 685                 char *ptr, *name;
 686                 rsync_xa *rxa;
 687                 size_t name_len = read_varint(f);
 688                 size_t datum_len = read_varint(f);
 689                 size_t dget_len = datum_len > MAX_FULL_DATUM ? 1 + MAX_DIGEST_LEN : datum_len;
 690                 size_t extra_len = MIGHT_NEED_RPRE ? RPRE_LEN : 0;
 691                 if ((dget_len + extra_len < dget_len)
 692                  || (dget_len + extra_len + name_len < dget_len))
 693                         overflow_exit("receive_xattr");
 694                 ptr = new_array(char, dget_len + extra_len + name_len);
 695                 if (!ptr)
 696                         out_of_memory("receive_xattr");
 697                 name = ptr + dget_len + extra_len;
 698                 read_buf(f, name, name_len);
 699                 if (dget_len == datum_len)
 700                         read_buf(f, ptr, dget_len);
 701                 else {
 702                         *ptr = XSTATE_ABBREV;
 703                         read_buf(f, ptr + 1, MAX_DIGEST_LEN);
 704                 }
 705 #ifdef HAVE_LINUX_XATTRS
 706                 /* Non-root can only save the user namespace. */
 707                 if (am_root <= 0 && !HAS_PREFIX(name, USER_PREFIX)) {
 708                         if (!am_root) {
 709                                 free(ptr);
 710                                 continue;
 711                         }
 712                         name -= RPRE_LEN;
 713                         name_len += RPRE_LEN;
 714                         memcpy(name, RSYNC_PREFIX, RPRE_LEN);
 715                         need_sort = 1;
 716                 }
 717 #else
 718                 /* This OS only has a user namespace, so we either
 719                  * strip the user prefix, or we put a non-user
 720                  * namespace inside our rsync hierarchy. */
 721                 if (HAS_PREFIX(name, USER_PREFIX)) {
 722                         name += UPRE_LEN;
 723                         name_len -= UPRE_LEN;
 724                 } else if (am_root) {
 725                         name -= RPRE_LEN;
 726                         name_len += RPRE_LEN;
 727                         memcpy(name, RSYNC_PREFIX, RPRE_LEN);
 728                 } else {
 729                         free(ptr);
 730                         continue;
 731                 }
 732 #endif
 733                 /* No rsync.%FOO attributes are copied w/o 2 -X options. */
 734                 if (preserve_xattrs < 2 && name_len > RPRE_LEN
 735                  && name[RPRE_LEN] == '%' && HAS_PREFIX(name, RSYNC_PREFIX)) {
 736                         free(ptr);
 737                         continue;
 738                 }
 739                 rxa = EXPAND_ITEM_LIST(&temp_xattr, rsync_xa, 1);
 740                 rxa->name = name;
 741                 rxa->datum = ptr;
 742                 rxa->name_len = name_len;
 743                 rxa->datum_len = datum_len;
 744                 rxa->num = num;
 745         }
 746
 747         if (need_sort && count > 1)
 748                 qsort(temp_xattr.items, count, sizeof (rsync_xa), rsync_xal_compare_names);
 749
 750         ndx = rsync_xal_l.count; /* pre-incremented count */
 751         rsync_xal_store(&temp_xattr); /* adds item to rsync_xal_l */
 752
 753         F_XATTR(file) = ndx;
 754 }
 755
 756 /* Turn the xattr data in stat_x into cached xattr data, setting the index
 757  * values in the file struct. */
 758 void cache_tmp_xattr(struct file_struct *file, stat_x *sxp)
 759 {
 760         int ndx;
 761
 762         if (!sxp->xattr)
 763                 return;
 764
 765         if (prior_xattr_count == (size_t)-1)
 766                 prior_xattr_count = rsync_xal_l.count;
 767         ndx = find_matching_xattr(sxp->xattr);
 768         if (ndx < 0)
 769                 rsync_xal_store(sxp->xattr); /* adds item to rsync_xal_l */
 770
 771         F_XATTR(file) = ndx;
 772 }
 773
 774 void uncache_tmp_xattrs(void)
 775 {
 776         if (prior_xattr_count != (size_t)-1) {
 777                 item_list *xattr_item = rsync_xal_l.items;
 778                 item_list *xattr_start = xattr_item + prior_xattr_count;
 779                 xattr_item += rsync_xal_l.count;
 780                 rsync_xal_l.count = prior_xattr_count;
 781                 while (xattr_item-- > xattr_start)
 782                         rsync_xal_free(xattr_item);
 783                 prior_xattr_count = (size_t)-1;
 784         }
 785 }
 786
 787 static int rsync_xal_set(const char *fname, item_list *xalp,
 788                          const char *fnamecmp, stat_x *sxp)
 789 {
 790         rsync_xa *rxas = xalp->items;
 791         ssize_t list_len;
 792         size_t i, len;
 793         char *name, *ptr, sum[MAX_DIGEST_LEN];
 794 #ifdef HAVE_LINUX_XATTRS
 795         int user_only = am_root <= 0;
 796 #endif
 797         size_t name_len;
 798         int ret = 0;
 799
 800         /* This puts the current name list into the "namebuf" buffer. */
 801         if ((list_len = get_xattr_names(fname)) < 0)
 802                 return -1;
 803
 804         for (i = 0; i < xalp->count; i++) {
 805                 name = rxas[i].name;
 806
 807                 if (XATTR_ABBREV(rxas[i])) {
 808                         /* See if the fnamecmp version is identical. */
 809                         len = name_len = rxas[i].name_len;
 810                         if ((ptr = get_xattr_data(fnamecmp, name, &len, 1)) == NULL) {
 811                           still_abbrev:
 812                                 if (am_generator)
 813                                         continue;
 814                                 rprintf(FERROR, "Missing abbreviated xattr value, %s, for %s\n",
 815                                         rxas[i].name, full_fname(fname));
 816                                 ret = -1;
 817                                 continue;
 818                         }
 819                         if (len != rxas[i].datum_len) {
 820                                 free(ptr);
 821                                 goto still_abbrev;
 822                         }
 823
 824                         sum_init(checksum_seed);
 825                         sum_update(ptr, len);
 826                         sum_end(sum);
 827                         if (memcmp(sum, rxas[i].datum + 1, MAX_DIGEST_LEN) != 0) {
 828                                 free(ptr);
 829                                 goto still_abbrev;
 830                         }
 831
 832                         if (fname == fnamecmp)
 833                                 ; /* Value is already set when identical */
 834                         else if (sys_lsetxattr(fname, name, ptr, len) < 0) {
 835                                 rsyserr(FERROR_XFER, errno,
 836                                         "rsync_xal_set: lsetxattr(\"%s\",\"%s\") failed",
 837                                         full_fname(fname), name);
 838                                 ret = -1;
 839                         } else /* make sure caller sets mtime */
 840                                 sxp->st.st_mtime = (time_t)-1;
 841
 842                         if (am_generator) { /* generator items stay abbreviated */
 843                                 free(ptr);
 844                                 continue;
 845                         }
 846
 847                         memcpy(ptr + len, name, name_len);
 848                         free(rxas[i].datum);
 849
 850                         rxas[i].name = name = ptr + len;
 851                         rxas[i].datum = ptr;
 852                         continue;
 853                 }
 854
 855                 if (sys_lsetxattr(fname, name, rxas[i].datum, rxas[i].datum_len) < 0) {
 856                         rsyserr(FERROR_XFER, errno,
 857                                 "rsync_xal_set: lsetxattr(\"%s\",\"%s\") failed",
 858                                 full_fname(fname), name);
 859                         ret = -1;
 860                 } else /* make sure caller sets mtime */
 861                         sxp->st.st_mtime = (time_t)-1;
 862         }
 863
 864         /* Remove any extraneous names. */
 865         for (name = namebuf; list_len > 0; name += name_len) {
 866                 name_len = strlen(name) + 1;
 867                 list_len -= name_len;
 868
 869 #ifdef HAVE_LINUX_XATTRS
 870                 /* We always ignore the system namespace, and non-root
 871                  * ignores everything but the user namespace. */
 872                 if (user_only ? !HAS_PREFIX(name, USER_PREFIX)
 873                               : HAS_PREFIX(name, SYSTEM_PREFIX))
 874                         continue;
 875 #endif
 876                 if (am_root < 0 && name_len > RPRE_LEN
 877                  && name[RPRE_LEN] == '%' && strcmp(name, XSTAT_ATTR) == 0)
 878                         continue;
 879
 880                 for (i = 0; i < xalp->count; i++) {
 881                         if (strcmp(name, rxas[i].name) == 0)
 882                                 break;
 883                 }
 884                 if (i == xalp->count) {
 885                         if (sys_lremovexattr(fname, name) < 0) {
 886                                 rsyserr(FERROR_XFER, errno,
 887                                         "rsync_xal_set: lremovexattr(\"%s\",\"%s\") failed",
 888                                         full_fname(fname), name);
 889                                 ret = -1;
 890                         } else /* make sure caller sets mtime */
 891                                 sxp->st.st_mtime = (time_t)-1;
 892                 }
 893         }
 894
 895         return ret;
 896 }
 897
 898 /* Set extended attributes on indicated filename. */
 899 int set_xattr(const char *fname, const struct file_struct *file,
 900               const char *fnamecmp, stat_x *sxp)
 901 {
 902         int ndx;
 903         item_list *lst = rsync_xal_l.items;
 904
 905         if (dry_run)
 906                 return 1; /* FIXME: --dry-run needs to compute this value */
 907
 908         if (read_only || list_only) {
 909                 errno = EROFS;
 910                 return -1;
 911         }
 912
 913 #ifdef NO_SPECIAL_XATTRS
 914         if (IS_SPECIAL(sxp->st.st_mode)) {
 915                 errno = ENOTSUP;
 916                 return -1;
 917         }
 918 #endif
 919 #ifdef NO_DEVICE_XATTRS
 920         if (IS_DEVICE(sxp->st.st_mode)) {
 921                 errno = ENOTSUP;
 922                 return -1;
 923         }
 924 #endif
 925 #ifdef NO_SYMLINK_XATTRS
 926         if (S_ISLNK(sxp->st.st_mode)) {
 927                 errno = ENOTSUP;
 928                 return -1;
 929         }
 930 #endif
 931
 932         ndx = F_XATTR(file);
 933         return rsync_xal_set(fname, lst + ndx, fnamecmp, sxp);
 934 }
 935
 936 #ifdef SUPPORT_ACLS
 937 char *get_xattr_acl(const char *fname, int is_access_acl, size_t *len_p)
 938 {
 939         const char *name = is_access_acl ? XACC_ACL_ATTR : XDEF_ACL_ATTR;
 940         *len_p = 0; /* no extra data alloc needed from get_xattr_data() */
 941         return get_xattr_data(fname, name, len_p, 1);
 942 }
 943
 944 int set_xattr_acl(const char *fname, int is_access_acl, const char *buf, size_t buf_len)
 945 {
 946         const char *name = is_access_acl ? XACC_ACL_ATTR : XDEF_ACL_ATTR;
 947         if (sys_lsetxattr(fname, name, buf, buf_len) < 0) {
 948                 rsyserr(FERROR_XFER, errno,
 949                         "set_xattr_acl: lsetxattr(\"%s\",\"%s\") failed",
 950                         full_fname(fname), name);
 951                 return -1;
 952         }
 953         return 0;
 954 }
 955
 956 int del_def_xattr_acl(const char *fname)
 957 {
 958         return sys_lremovexattr(fname, XDEF_ACL_ATTR);
 959 }
 960 #endif
 961
 962 int get_stat_xattr(const char *fname, int fd, STRUCT_STAT *fst, STRUCT_STAT *xst)
 963 {
 964         int mode, rdev_major, rdev_minor, uid, gid, len;
 965         char buf[256];
 966
 967         if (am_root >= 0 || IS_DEVICE(fst->st_mode) || IS_SPECIAL(fst->st_mode))
 968                 return -1;
 969
 970         if (xst)
 971                 *xst = *fst;
 972         else
 973                 xst = fst;
 974         if (fname) {
 975                 fd = -1;
 976                 len = sys_lgetxattr(fname, XSTAT_ATTR, buf, sizeof buf - 1);
 977         } else {
 978                 fname = "fd";
 979                 len = sys_fgetxattr(fd, XSTAT_ATTR, buf, sizeof buf - 1);
 980         }
 981         if (len >= (int)sizeof buf) {
 982                 len = -1;
 983                 errno = ERANGE;
 984         }
 985         if (len < 0) {
 986                 if (errno == ENOTSUP || errno == ENOATTR)
 987                         return -1;
 988                 if (errno == EPERM && S_ISLNK(fst->st_mode)) {
 989                         xst->st_uid = 0;
 990                         xst->st_gid = 0;
 991                         return 0;
 992                 }
 993                 rsyserr(FERROR_XFER, errno, "failed to read xattr %s for %s",
 994                         XSTAT_ATTR, full_fname(fname));
 995                 return -1;
 996         }
 997         buf[len] = '\0';
 998
 999         if (sscanf(buf, "%o %d,%d %d:%d",
1000                    &mode, &rdev_major, &rdev_minor, &uid, &gid) != 5) {
1001                 rprintf(FERROR, "Corrupt %s xattr attached to %s: \"%s\"\n",
1002                         XSTAT_ATTR, full_fname(fname), buf);
1003                 exit_cleanup(RERR_FILEIO);
1004         }
1005
1006         xst->st_mode = from_wire_mode(mode);
1007         xst->st_rdev = MAKEDEV(rdev_major, rdev_minor);
1008         xst->st_uid = uid;
1009         xst->st_gid = gid;
1010
1011         return 0;
1012 }
1013
1014 int set_stat_xattr(const char *fname, struct file_struct *file, mode_t new_mode)
1015 {
1016         STRUCT_STAT fst, xst;
1017         dev_t rdev;
1018         mode_t mode, fmode;
1019
1020         if (dry_run)
1021                 return 0;
1022
1023         if (read_only || list_only) {
1024                 rsyserr(FERROR_XFER, EROFS, "failed to write xattr %s for %s",
1025                         XSTAT_ATTR, full_fname(fname));
1026                 return -1;
1027         }
1028
1029         if (x_lstat(fname, &fst, &xst) < 0) {
1030                 rsyserr(FERROR_XFER, errno, "failed to re-stat %s",
1031                         full_fname(fname));
1032                 return -1;
1033         }
1034
1035         fst.st_mode &= (_S_IFMT | CHMOD_BITS);
1036         fmode = new_mode & (_S_IFMT | CHMOD_BITS);
1037
1038         if (IS_DEVICE(fmode)) {
1039                 uint32 *devp = F_RDEV_P(file);
1040                 rdev = MAKEDEV(DEV_MAJOR(devp), DEV_MINOR(devp));
1041         } else
1042                 rdev = 0;
1043
1044         /* Dump the special permissions and enable full owner access. */
1045         mode = (fst.st_mode & _S_IFMT) | (fmode & ACCESSPERMS)
1046              | (S_ISDIR(fst.st_mode) ? 0700 : 0600);
1047         if (fst.st_mode != mode)
1048                 do_chmod(fname, mode);
1049         if (!IS_DEVICE(fst.st_mode))
1050                 fst.st_rdev = 0; /* just in case */
1051
1052         if (mode == fmode && fst.st_rdev == rdev
1053          && fst.st_uid == F_OWNER(file) && fst.st_gid == F_GROUP(file)) {
1054                 /* xst.st_mode will be 0 if there's no current stat xattr */
1055                 if (xst.st_mode && sys_lremovexattr(fname, XSTAT_ATTR) < 0) {
1056                         rsyserr(FERROR_XFER, errno,
1057                                 "delete of stat xattr failed for %s",
1058                                 full_fname(fname));
1059                         return -1;
1060                 }
1061                 return 0;
1062         }
1063
1064         if (xst.st_mode != fmode || xst.st_rdev != rdev
1065          || xst.st_uid != F_OWNER(file) || xst.st_gid != F_GROUP(file)) {
1066                 char buf[256];
1067                 int len = snprintf(buf, sizeof buf, "%o %u,%u %u:%u",
1068                         to_wire_mode(fmode),
1069                         (int)major(rdev), (int)minor(rdev),
1070                         F_OWNER(file), F_GROUP(file));
1071                 if (sys_lsetxattr(fname, XSTAT_ATTR, buf, len) < 0) {
1072                         if (errno == EPERM && S_ISLNK(fst.st_mode))
1073                                 return 0;
1074                         rsyserr(FERROR_XFER, errno,
1075                                 "failed to write xattr %s for %s",
1076                                 XSTAT_ATTR, full_fname(fname));
1077                         return -1;
1078                 }
1079         }
1080
1081         return 0;
1082 }
1083
1084 int x_stat(const char *fname, STRUCT_STAT *fst, STRUCT_STAT *xst)
1085 {
1086         int ret = do_stat(fname, fst);
1087         if ((ret < 0 || get_stat_xattr(fname, -1, fst, xst) < 0) && xst)
1088                 xst->st_mode = 0;
1089         return ret;
1090 }
1091
1092 int x_lstat(const char *fname, STRUCT_STAT *fst, STRUCT_STAT *xst)
1093 {
1094         int ret = do_lstat(fname, fst);
1095         if ((ret < 0 || get_stat_xattr(fname, -1, fst, xst) < 0) && xst)
1096                 xst->st_mode = 0;
1097         return ret;
1098 }
1099
1100 int x_fstat(int fd, STRUCT_STAT *fst, STRUCT_STAT *xst)
1101 {
1102         int ret = do_fstat(fd, fst);
1103         if ((ret < 0 || get_stat_xattr(NULL, fd, fst, xst) < 0) && xst)
1104                 xst->st_mode = 0;
1105         return ret;
1106 }
1107
1108 #endif /* SUPPORT_XATTRS */