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