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) 2006-2009 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 checksum_seed;
  37
  38 #define RSYNC_XAL_INITIAL 5
  39 #define RSYNC_XAL_LIST_INITIAL 100
  40
  41 #define MAX_FULL_DATUM 32
  42
  43 #define HAS_PREFIX(str, prfx) (*(str) == *(prfx) \
  44                             && strncmp(str, prfx, sizeof (prfx) - 1) == 0)
  45
  46 #define XATTR_ABBREV(x) ((size_t)((x).name - (x).datum) < (x).datum_len)
  47
  48 #define XSTATE_ABBREV   1
  49 #define XSTATE_DONE     2
  50 #define XSTATE_TODO     3
  51
  52 #define USER_PREFIX "user."
  53 #define UPRE_LEN ((int)sizeof USER_PREFIX - 1)
  54 #define SYSTEM_PREFIX "system."
  55 #define SPRE_LEN ((int)sizeof SYSTEM_PREFIX - 1)
  56
  57 #ifdef HAVE_LINUX_XATTRS
  58 #define MIGHT_NEED_RPRE (am_root < 0)
  59 #define RSYNC_PREFIX USER_PREFIX "rsync."
  60 #else
  61 #define MIGHT_NEED_RPRE am_root
  62 #define RSYNC_PREFIX "rsync."
  63 #endif
  64 #define RPRE_LEN ((int)sizeof RSYNC_PREFIX - 1)
  65
  66 #define XSTAT_SUFFIX "stat"
  67 #define XSTAT_ATTR RSYNC_PREFIX "%" XSTAT_SUFFIX
  68 #define XACC_ACL_SUFFIX "aacl"
  69 #define XACC_ACL_ATTR RSYNC_PREFIX "%" XACC_ACL_SUFFIX
  70 #define XDEF_ACL_SUFFIX "dacl"
  71 #define XDEF_ACL_ATTR RSYNC_PREFIX "%" XDEF_ACL_SUFFIX
  72
  73 typedef struct {
  74         char *datum, *name;
  75         size_t datum_len, name_len;
  76         int num;
  77 } rsync_xa;
  78
  79 static size_t namebuf_len = 0;
  80 static char *namebuf = NULL;
  81
  82 static item_list empty_xattr = EMPTY_ITEM_LIST;
  83 static item_list rsync_xal_l = EMPTY_ITEM_LIST;
  84
  85 static size_t prior_xattr_count = (size_t)-1;
  86
  87 /* ------------------------------------------------------------------------- */
  88
  89 static void rsync_xal_free(item_list *xalp)
  90 {
  91         size_t i;
  92         rsync_xa *rxas = xalp->items;
  93
  94         for (i = 0; i < xalp->count; i++) {
  95                 free(rxas[i].datum);
  96                 /*free(rxas[i].name);*/
  97         }
  98         xalp->count = 0;
  99 }
 100
 101 void free_xattr(stat_x *sxp)
 102 {
 103         if (!sxp->xattr)
 104                 return;
 105         rsync_xal_free(sxp->xattr);
 106         free(sxp->xattr);
 107         sxp->xattr = NULL;
 108 }
 109
 110 static int rsync_xal_compare_names(const void *x1, const void *x2)
 111 {
 112         const rsync_xa *xa1 = x1;
 113         const rsync_xa *xa2 = x2;
 114         return strcmp(xa1->name, xa2->name);
 115 }
 116
 117 static ssize_t get_xattr_names(const char *fname)
 118 {
 119         ssize_t list_len;
 120         int64 arg;
 121
 122         if (!namebuf) {
 123                 namebuf_len = 1024;
 124                 namebuf = new_array(char, namebuf_len);
 125                 if (!namebuf)
 126                         out_of_memory("get_xattr_names");
 127         }
 128
 129         while (1) {
 130                 /* The length returned includes all the '\0' terminators. */
 131                 list_len = sys_llistxattr(fname, namebuf, namebuf_len);
 132                 if (list_len >= 0) {
 133                         if ((size_t)list_len <= namebuf_len)
 134                                 break;
 135                 } else if (errno == ENOTSUP)
 136                         return 0;
 137                 else if (errno != ERANGE) {
 138                         arg = namebuf_len;
 139                   got_error:
 140                         rsyserr(FERROR_XFER, errno,
 141                                 "get_xattr_names: llistxattr(\"%s\",%s) failed",
 142                                 fname, big_num(arg));
 143                         return -1;
 144                 }
 145                 list_len = sys_llistxattr(fname, NULL, 0);
 146                 if (list_len < 0) {
 147                         arg = 0;
 148                         goto got_error;
 149                 }
 150                 if (namebuf_len)
 151                         free(namebuf);
 152                 namebuf_len = list_len + 1024;
 153                 namebuf = new_array(char, namebuf_len);
 154                 if (!namebuf)
 155                         out_of_memory("get_xattr_names");
 156         }
 157
 158         return list_len;
 159 }
 160
 161 /* On entry, the *len_ptr parameter contains the size of the extra space we
 162  * should allocate when we create a buffer for the data.  On exit, it contains
 163  * the length of the datum. */
 164 static char *get_xattr_data(const char *fname, const char *name, size_t *len_ptr,
 165                             int no_missing_error)
 166 {
 167         size_t datum_len = sys_lgetxattr(fname, name, NULL, 0);
 168         size_t extra_len = *len_ptr;
 169         char *ptr;
 170
 171         *len_ptr = datum_len;
 172
 173         if (datum_len == (size_t)-1) {
 174                 if (errno == ENOTSUP || no_missing_error)
 175                         return NULL;
 176                 rsyserr(FERROR_XFER, errno,
 177                         "get_xattr_data: lgetxattr(\"%s\",\"%s\",0) failed",
 178                         fname, name);
 179                 return NULL;
 180         }
 181
 182         if (!datum_len && !extra_len)
 183                 extra_len = 1; /* request non-zero amount of memory */
 184         if (datum_len + extra_len < datum_len)
 185                 overflow_exit("get_xattr_data");
 186         if (!(ptr = new_array(char, datum_len + extra_len)))
 187                 out_of_memory("get_xattr_data");
 188
 189         if (datum_len) {
 190                 size_t len = sys_lgetxattr(fname, name, ptr, datum_len);
 191                 if (len != datum_len) {
 192                         if (len == (size_t)-1) {
 193                                 rsyserr(FERROR_XFER, errno,
 194                                     "get_xattr_data: lgetxattr(\"%s\",\"%s\",%ld)"
 195                                     " failed", fname, name, (long)datum_len);
 196                         } else {
 197                                 rprintf(FERROR_XFER,
 198                                     "get_xattr_data: lgetxattr(\"%s\",\"%s\",%ld)"
 199                                     " returned %ld\n", fname, name,
 200                                     (long)datum_len, (long)len);
 201                         }
 202                         free(ptr);
 203                         return NULL;
 204                 }
 205         }
 206
 207         return ptr;
 208 }
 209
 210 static int rsync_xal_get(const char *fname, item_list *xalp)
 211 {
 212         ssize_t list_len, name_len;
 213         size_t datum_len, name_offset;
 214         char *name, *ptr;
 215 #ifdef HAVE_LINUX_XATTRS
 216         int user_only = am_sender ? 0 : !am_root;
 217 #endif
 218         rsync_xa *rxa;
 219         int count;
 220
 221         /* This puts the name list into the "namebuf" buffer. */
 222         if ((list_len = get_xattr_names(fname)) < 0)
 223                 return -1;
 224
 225         for (name = namebuf; list_len > 0; name += name_len) {
 226                 name_len = strlen(name) + 1;
 227                 list_len -= name_len;
 228
 229 #ifdef HAVE_LINUX_XATTRS
 230                 /* We always ignore the system namespace, and non-root
 231                  * ignores everything but the user namespace. */
 232                 if (user_only ? !HAS_PREFIX(name, USER_PREFIX)
 233                               : HAS_PREFIX(name, SYSTEM_PREFIX))
 234                         continue;
 235 #endif
 236
 237                 /* No rsync.%FOO attributes are copied w/o 2 -X options. */
 238                 if (name_len > RPRE_LEN && name[RPRE_LEN] == '%'
 239                  && HAS_PREFIX(name, RSYNC_PREFIX)) {
 240                         if ((am_sender && preserve_xattrs < 2)
 241                          || (am_root < 0
 242                           && (strcmp(name+RPRE_LEN+1, XSTAT_SUFFIX) == 0
 243                            || strcmp(name+RPRE_LEN+1, XACC_ACL_SUFFIX) == 0
 244                            || strcmp(name+RPRE_LEN+1, XDEF_ACL_SUFFIX) == 0)))
 245                                 continue;
 246                 }
 247
 248                 datum_len = name_len; /* Pass extra size to get_xattr_data() */
 249                 if (!(ptr = get_xattr_data(fname, name, &datum_len, 0)))
 250                         return -1;
 251
 252                 if (datum_len > MAX_FULL_DATUM) {
 253                         /* For large datums, we store a flag and a checksum. */
 254                         name_offset = 1 + MAX_DIGEST_LEN;
 255                         sum_init(checksum_seed);
 256                         sum_update(ptr, datum_len);
 257                         free(ptr);
 258
 259                         if (!(ptr = new_array(char, name_offset + name_len)))
 260                                 out_of_memory("rsync_xal_get");
 261                         *ptr = XSTATE_ABBREV;
 262                         sum_end(ptr + 1);
 263                 } else
 264                         name_offset = datum_len;
 265
 266                 rxa = EXPAND_ITEM_LIST(xalp, rsync_xa, RSYNC_XAL_INITIAL);
 267                 rxa->name = ptr + name_offset;
 268                 memcpy(rxa->name, name, name_len);
 269                 rxa->datum = ptr;
 270                 rxa->name_len = name_len;
 271                 rxa->datum_len = datum_len;
 272         }
 273         count = xalp->count;
 274         rxa = xalp->items;
 275         if (count > 1)
 276                 qsort(rxa, count, sizeof (rsync_xa), rsync_xal_compare_names);
 277         for (rxa += count-1; count; count--, rxa--)
 278                 rxa->num = count;
 279         return 0;
 280 }
 281
 282 /* Read the xattr(s) for this filename. */
 283 int get_xattr(const char *fname, stat_x *sxp)
 284 {
 285         sxp->xattr = new(item_list);
 286         *sxp->xattr = empty_xattr;
 287
 288 #ifdef NO_SPECIAL_XATTRS
 289         if (IS_SPECIAL(sxp->st.st_mode))
 290                 return 0;
 291 #endif
 292 #ifdef NO_DEVICE_XATTRS
 293         if (IS_DEVICE(sxp->st.st_mode))
 294                 return 0;
 295 #endif
 296 #ifdef NO_SYMLINK_XATTRS
 297         if (S_ISLNK(sxp->st.st_mode))
 298                 return 0;
 299 #endif
 300
 301         if (rsync_xal_get(fname, sxp->xattr) < 0) {
 302                 free_xattr(sxp);
 303                 return -1;
 304         }
 305         return 0;
 306 }
 307
 308 int copy_xattrs(const char *source, const char *dest)
 309 {
 310         ssize_t list_len, name_len;
 311         size_t datum_len;
 312         char *name, *ptr;
 313 #ifdef HAVE_LINUX_XATTRS
 314         int user_only = am_sender ? 0 : am_root <= 0;
 315 #endif
 316
 317         /* This puts the name list into the "namebuf" buffer. */
 318         if ((list_len = get_xattr_names(source)) < 0)
 319                 return -1;
 320
 321         for (name = namebuf; list_len > 0; name += name_len) {
 322                 name_len = strlen(name) + 1;
 323                 list_len -= name_len;
 324
 325 #ifdef HAVE_LINUX_XATTRS
 326                 /* We always ignore the system namespace, and non-root
 327                  * ignores everything but the user namespace. */
 328                 if (user_only ? !HAS_PREFIX(name, USER_PREFIX)
 329                               : HAS_PREFIX(name, SYSTEM_PREFIX))
 330                         continue;
 331 #endif
 332
 333                 datum_len = 0;
 334                 if (!(ptr = get_xattr_data(source, name, &datum_len, 0)))
 335                         return -1;
 336                 if (sys_lsetxattr(dest, name, ptr, datum_len) < 0) {
 337                         int save_errno = errno ? errno : EINVAL;
 338                         rsyserr(FERROR_XFER, errno,
 339                                 "copy_xattrs: lsetxattr(\"%s\",\"%s\") failed",
 340                                 dest, name);
 341                         errno = save_errno;
 342                         return -1;
 343                 }
 344                 free(ptr);
 345         }
 346
 347         return 0;
 348 }
 349
 350 static int find_matching_xattr(item_list *xalp)
 351 {
 352         size_t i, j;
 353         item_list *lst = rsync_xal_l.items;
 354
 355         for (i = 0; i < rsync_xal_l.count; i++) {
 356                 rsync_xa *rxas1 = lst[i].items;
 357                 rsync_xa *rxas2 = xalp->items;
 358
 359                 /* Wrong number of elements? */
 360                 if (lst[i].count != xalp->count)
 361                         continue;
 362                 /* any elements different? */
 363                 for (j = 0; j < xalp->count; j++) {
 364                         if (rxas1[j].name_len != rxas2[j].name_len
 365                          || rxas1[j].datum_len != rxas2[j].datum_len
 366                          || strcmp(rxas1[j].name, rxas2[j].name))
 367                                 break;
 368                         if (rxas1[j].datum_len > MAX_FULL_DATUM) {
 369                                 if (memcmp(rxas1[j].datum + 1,
 370                                            rxas2[j].datum + 1,
 371                                            MAX_DIGEST_LEN) != 0)
 372                                         break;
 373                         } else {
 374                                 if (memcmp(rxas1[j].datum, rxas2[j].datum,
 375                                            rxas2[j].datum_len))
 376                                         break;
 377                         }
 378                 }
 379                 /* no differences found.  This is The One! */
 380                 if (j == xalp->count)
 381                         return i;
 382         }
 383
 384         return -1;
 385 }
 386
 387 /* Store *xalp on the end of rsync_xal_l */
 388 static void rsync_xal_store(item_list *xalp)
 389 {
 390         item_list *new_lst = EXPAND_ITEM_LIST(&rsync_xal_l, item_list, RSYNC_XAL_LIST_INITIAL);
 391         /* Since the following call starts a new list, we know it will hold the
 392          * entire initial-count, not just enough space for one new item. */
 393         *new_lst = empty_xattr;
 394         (void)EXPAND_ITEM_LIST(new_lst, rsync_xa, xalp->count);
 395         memcpy(new_lst->items, xalp->items, xalp->count * sizeof (rsync_xa));
 396         new_lst->count = xalp->count;
 397         xalp->count = 0;
 398 }
 399
 400 /* Send the make_xattr()-generated xattr list for this flist entry. */
 401 int send_xattr(int f, stat_x *sxp)
 402 {
 403         int ndx = find_matching_xattr(sxp->xattr);
 404
 405         /* Send 0 (-1 + 1) to indicate that literal xattr data follows. */
 406         write_varint(f, ndx + 1);
 407
 408         if (ndx < 0) {
 409                 rsync_xa *rxa;
 410                 int count = sxp->xattr->count;
 411                 write_varint(f, count);
 412                 for (rxa = sxp->xattr->items; count--; rxa++) {
 413                         size_t name_len = rxa->name_len;
 414                         const char *name = rxa->name;
 415                         /* Strip the rsync prefix from disguised namespaces. */
 416                         if (name_len > RPRE_LEN
 417 #ifdef HAVE_LINUX_XATTRS
 418                          && am_root < 0
 419 #endif
 420                          && name[RPRE_LEN] != '%' && HAS_PREFIX(name, RSYNC_PREFIX)) {
 421                                 name += RPRE_LEN;
 422                                 name_len -= RPRE_LEN;
 423                         }
 424 #ifndef HAVE_LINUX_XATTRS
 425                         else {
 426                                 /* Put everything else in the user namespace. */
 427                                 name_len += UPRE_LEN;
 428                         }
 429 #endif
 430                         write_varint(f, name_len);
 431                         write_varint(f, rxa->datum_len);
 432 #ifndef HAVE_LINUX_XATTRS
 433                         if (name_len > rxa->name_len) {
 434                                 write_buf(f, USER_PREFIX, UPRE_LEN);
 435                                 name_len -= UPRE_LEN;
 436                         }
 437 #endif
 438                         write_buf(f, name, name_len);
 439                         if (rxa->datum_len > MAX_FULL_DATUM)
 440                                 write_buf(f, rxa->datum + 1, MAX_DIGEST_LEN);
 441                         else
 442                                 write_buf(f, rxa->datum, rxa->datum_len);
 443                 }
 444                 ndx = rsync_xal_l.count; /* pre-incremented count */
 445                 rsync_xal_store(sxp->xattr); /* adds item to rsync_xal_l */
 446         }
 447
 448         return ndx;
 449 }
 450
 451 /* Return a flag indicating if we need to change a file's xattrs.  If
 452  * "find_all" is specified, also mark any abbreviated xattrs that we
 453  * need so that send_xattr_request() can tell the sender about them. */
 454 int xattr_diff(struct file_struct *file, stat_x *sxp, int find_all)
 455 {
 456         item_list *lst = rsync_xal_l.items;
 457         rsync_xa *snd_rxa, *rec_rxa;
 458         int snd_cnt, rec_cnt;
 459         int cmp, same, xattrs_equal = 1;
 460
 461         if (sxp && XATTR_READY(*sxp)) {
 462                 rec_rxa = sxp->xattr->items;
 463                 rec_cnt = sxp->xattr->count;
 464         } else {
 465                 rec_rxa = NULL;
 466                 rec_cnt = 0;
 467         }
 468
 469         if (F_XATTR(file) >= 0)
 470                 lst += F_XATTR(file);
 471         else
 472                 lst = &empty_xattr;
 473
 474         snd_rxa = lst->items;
 475         snd_cnt = lst->count;
 476
 477         /* If the count of the sender's xattrs is different from our
 478          * (receiver's) xattrs, the lists are not the same. */
 479         if (snd_cnt != rec_cnt) {
 480                 if (!find_all)
 481                         return 1;
 482                 xattrs_equal = 0;
 483         }
 484
 485         while (snd_cnt) {
 486                 cmp = rec_cnt ? strcmp(snd_rxa->name, rec_rxa->name) : -1;
 487                 if (cmp > 0)
 488                         same = 0;
 489                 else if (snd_rxa->datum_len > MAX_FULL_DATUM) {
 490                         same = cmp == 0 && snd_rxa->datum_len == rec_rxa->datum_len
 491                             && memcmp(snd_rxa->datum + 1, rec_rxa->datum + 1,
 492                                       MAX_DIGEST_LEN) == 0;
 493                         /* Flag unrequested items that we need. */
 494                         if (!same && find_all && snd_rxa->datum[0] == XSTATE_ABBREV)
 495                                 snd_rxa->datum[0] = XSTATE_TODO;
 496                 } else {
 497                         same = cmp == 0 && snd_rxa->datum_len == rec_rxa->datum_len
 498                             && memcmp(snd_rxa->datum, rec_rxa->datum,
 499                                       snd_rxa->datum_len) == 0;
 500                 }
 501                 if (!same) {
 502                         if (!find_all)
 503                                 return 1;
 504                         xattrs_equal = 0;
 505                 }
 506
 507                 if (cmp <= 0) {
 508                         snd_rxa++;
 509                         snd_cnt--;
 510                 }
 511                 if (cmp >= 0) {
 512                         rec_rxa++;
 513                         rec_cnt--;
 514                 }
 515         }
 516
 517         if (rec_cnt)
 518                 xattrs_equal = 0;
 519
 520         return !xattrs_equal;
 521 }
 522
 523 /* When called by the generator (with a NULL fname), this tells the sender
 524  * all the abbreviated xattr values we need.  When called by the sender
 525  * (with a non-NULL fname), we send all the extra xattr data it needs.
 526  * The generator may also call with f_out < 0 to just change all the
 527  * XSTATE_ABBREV states into XSTATE_DONE. */
 528 void send_xattr_request(const char *fname, struct file_struct *file, int f_out)
 529 {
 530         item_list *lst = rsync_xal_l.items;
 531         int cnt, prior_req = 0;
 532         rsync_xa *rxa;
 533
 534         lst += F_XATTR(file);
 535         for (rxa = lst->items, cnt = lst->count; cnt--; rxa++) {
 536                 if (rxa->datum_len <= MAX_FULL_DATUM)
 537                         continue;
 538                 switch (rxa->datum[0]) {
 539                 case XSTATE_ABBREV:
 540                         /* Items left abbreviated matched the sender's checksum, so
 541                          * the receiver will cache the local data for future use. */
 542                         if (am_generator)
 543                                 rxa->datum[0] = XSTATE_DONE;
 544                         continue;
 545                 case XSTATE_TODO:
 546                         assert(f_out >= 0);
 547                         break;
 548                 default:
 549                         continue;
 550                 }
 551
 552                 /* Flag that we handled this abbreviated item. */
 553                 rxa->datum[0] = XSTATE_DONE;
 554
 555                 write_varint(f_out, rxa->num - prior_req);
 556                 prior_req = rxa->num;
 557
 558                 if (fname) {
 559                         size_t len = 0;
 560                         char *ptr;
 561
 562                         /* Re-read the long datum. */
 563                         if (!(ptr = get_xattr_data(fname, rxa->name, &len, 0))) {
 564                                 rprintf(FERROR_XFER, "failed to re-read xattr %s for %s\n", rxa->name, fname);
 565                                 write_varint(f_out, 0);
 566                                 continue;
 567                         }
 568
 569                         write_varint(f_out, len); /* length might have changed! */
 570                         write_buf(f_out, ptr, len);
 571                         free(ptr);
 572                 }
 573         }
 574
 575         if (f_out >= 0)
 576                 write_byte(f_out, 0); /* end the list */
 577 }
 578
 579 /* When called by the sender, read the request from the generator and mark
 580  * any needed xattrs with a flag that lets us know they need to be sent to
 581  * the receiver.  When called by the receiver, reads the sent data and
 582  * stores it in place of its checksum. */
 583 int recv_xattr_request(struct file_struct *file, int f_in)
 584 {
 585         item_list *lst = rsync_xal_l.items;
 586         char *old_datum, *name;
 587         rsync_xa *rxa;
 588         int rel_pos, cnt, num, got_xattr_data = 0;
 589
 590         if (F_XATTR(file) < 0) {
 591                 rprintf(FERROR, "recv_xattr_request: internal data error!\n");
 592                 exit_cleanup(RERR_PROTOCOL);
 593         }
 594         lst += F_XATTR(file);
 595
 596         cnt = lst->count;
 597         rxa = lst->items;
 598         num = 0;
 599         while ((rel_pos = read_varint(f_in)) != 0) {
 600                 num += rel_pos;
 601                 while (cnt && rxa->num < num) {
 602                     rxa++;
 603                     cnt--;
 604                 }
 605                 if (!cnt || rxa->num != num) {
 606                         rprintf(FERROR, "[%s] could not find xattr #%d for %s\n",
 607                                 who_am_i(), num, f_name(file, NULL));
 608                         exit_cleanup(RERR_PROTOCOL);
 609                 }
 610                 if (!XATTR_ABBREV(*rxa) || rxa->datum[0] != XSTATE_ABBREV) {
 611                         rprintf(FERROR, "[%s] internal abbrev error on %s (%s, len=%ld)!\n",
 612                                 who_am_i(), f_name(file, NULL), rxa->name, (long)rxa->datum_len);
 613                         exit_cleanup(RERR_PROTOCOL);
 614                 }
 615
 616                 if (am_sender) {
 617                         rxa->datum[0] = XSTATE_TODO;
 618                         continue;
 619                 }
 620
 621                 old_datum = rxa->datum;
 622                 rxa->datum_len = read_varint(f_in);
 623
 624                 if (rxa->name_len + rxa->datum_len < rxa->name_len)
 625                         overflow_exit("recv_xattr_request");
 626                 rxa->datum = new_array(char, rxa->datum_len + rxa->name_len);
 627                 if (!rxa->datum)
 628                         out_of_memory("recv_xattr_request");
 629                 name = rxa->datum + rxa->datum_len;
 630                 memcpy(name, rxa->name, rxa->name_len);
 631                 rxa->name = name;
 632                 free(old_datum);
 633                 read_buf(f_in, rxa->datum, rxa->datum_len);
 634                 got_xattr_data = 1;
 635         }
 636
 637         return got_xattr_data;
 638 }
 639
 640 /* ------------------------------------------------------------------------- */
 641
 642 /* receive and build the rsync_xattr_lists */
 643 void receive_xattr(int f, struct file_struct *file)
 644 {
 645         static item_list temp_xattr = EMPTY_ITEM_LIST;
 646         int count, num;
 647 #ifdef HAVE_LINUX_XATTRS
 648         int need_sort = 0;
 649 #else
 650         int need_sort = 1;
 651 #endif
 652         int ndx = read_varint(f);
 653
 654         if (ndx < 0 || (size_t)ndx > rsync_xal_l.count) {
 655                 rprintf(FERROR, "receive_xattr: xa index %d out of"
 656                         " range for %s\n", ndx, f_name(file, NULL));
 657                 exit_cleanup(RERR_STREAMIO);
 658         }
 659
 660         if (ndx != 0) {
 661                 F_XATTR(file) = ndx - 1;
 662                 return;
 663         }
 664
 665         if ((count = read_varint(f)) != 0) {
 666                 (void)EXPAND_ITEM_LIST(&temp_xattr, rsync_xa, count);
 667                 temp_xattr.count = 0;
 668         }
 669
 670         for (num = 1; num <= count; num++) {
 671                 char *ptr, *name;
 672                 rsync_xa *rxa;
 673                 size_t name_len = read_varint(f);
 674                 size_t datum_len = read_varint(f);
 675                 size_t dget_len = datum_len > MAX_FULL_DATUM ? 1 + MAX_DIGEST_LEN : datum_len;
 676                 size_t extra_len = MIGHT_NEED_RPRE ? RPRE_LEN : 0;
 677                 if ((dget_len + extra_len < dget_len)
 678                  || (dget_len + extra_len + name_len < dget_len))
 679                         overflow_exit("receive_xattr");
 680                 ptr = new_array(char, dget_len + extra_len + name_len);
 681                 if (!ptr)
 682                         out_of_memory("receive_xattr");
 683                 name = ptr + dget_len + extra_len;
 684                 read_buf(f, name, name_len);
 685                 if (dget_len == datum_len)
 686                         read_buf(f, ptr, dget_len);
 687                 else {
 688                         *ptr = XSTATE_ABBREV;
 689                         read_buf(f, ptr + 1, MAX_DIGEST_LEN);
 690                 }
 691 #ifdef HAVE_LINUX_XATTRS
 692                 /* Non-root can only save the user namespace. */
 693                 if (am_root <= 0 && !HAS_PREFIX(name, USER_PREFIX)) {
 694                         if (!am_root) {
 695                                 free(ptr);
 696                                 continue;
 697                         }
 698                         name -= RPRE_LEN;
 699                         name_len += RPRE_LEN;
 700                         memcpy(name, RSYNC_PREFIX, RPRE_LEN);
 701                         need_sort = 1;
 702                 }
 703 #else
 704                 /* This OS only has a user namespace, so we either
 705                  * strip the user prefix, or we put a non-user
 706                  * namespace inside our rsync hierarchy. */
 707                 if (HAS_PREFIX(name, USER_PREFIX)) {
 708                         name += UPRE_LEN;
 709                         name_len -= UPRE_LEN;
 710                 } else if (am_root) {
 711                         name -= RPRE_LEN;
 712                         name_len += RPRE_LEN;
 713                         memcpy(name, RSYNC_PREFIX, RPRE_LEN);
 714                 } else {
 715                         free(ptr);
 716                         continue;
 717                 }
 718 #endif
 719                 /* No rsync.%FOO attributes are copied w/o 2 -X options. */
 720                 if (preserve_xattrs < 2 && name_len > RPRE_LEN
 721                  && name[RPRE_LEN] == '%' && HAS_PREFIX(name, RSYNC_PREFIX)) {
 722                         free(ptr);
 723                         continue;
 724                 }
 725                 rxa = EXPAND_ITEM_LIST(&temp_xattr, rsync_xa, 1);
 726                 rxa->name = name;
 727                 rxa->datum = ptr;
 728                 rxa->name_len = name_len;
 729                 rxa->datum_len = datum_len;
 730                 rxa->num = num;
 731         }
 732
 733         if (need_sort && count > 1)
 734                 qsort(temp_xattr.items, count, sizeof (rsync_xa), rsync_xal_compare_names);
 735
 736         ndx = rsync_xal_l.count; /* pre-incremented count */
 737         rsync_xal_store(&temp_xattr); /* adds item to rsync_xal_l */
 738
 739         F_XATTR(file) = ndx;
 740 }
 741
 742 /* Turn the xattr data in stat_x into cached xattr data, setting the index
 743  * values in the file struct. */
 744 void cache_tmp_xattr(struct file_struct *file, stat_x *sxp)
 745 {
 746         int ndx;
 747
 748         if (!sxp->xattr)
 749                 return;
 750
 751         if (prior_xattr_count == (size_t)-1)
 752                 prior_xattr_count = rsync_xal_l.count;
 753         ndx = find_matching_xattr(sxp->xattr);
 754         if (ndx < 0)
 755                 rsync_xal_store(sxp->xattr); /* adds item to rsync_xal_l */
 756
 757         F_XATTR(file) = ndx;
 758 }
 759
 760 void uncache_tmp_xattrs(void)
 761 {
 762         if (prior_xattr_count != (size_t)-1) {
 763                 item_list *xattr_item = rsync_xal_l.items;
 764                 item_list *xattr_start = xattr_item + prior_xattr_count;
 765                 xattr_item += rsync_xal_l.count;
 766                 rsync_xal_l.count = prior_xattr_count;
 767                 while (xattr_item-- > xattr_start) {
 768                         rsync_xal_free(xattr_item);
 769                         free(xattr_item->items);
 770                 }
 771                 prior_xattr_count = (size_t)-1;
 772         }
 773 }
 774
 775 static int rsync_xal_set(const char *fname, item_list *xalp,
 776                          const char *fnamecmp, stat_x *sxp)
 777 {
 778         rsync_xa *rxas = xalp->items;
 779         ssize_t list_len;
 780         size_t i, len;
 781         char *name, *ptr, sum[MAX_DIGEST_LEN];
 782 #ifdef HAVE_LINUX_XATTRS
 783         int user_only = am_root <= 0;
 784 #endif
 785         size_t name_len;
 786         int ret = 0;
 787
 788         /* This puts the current name list into the "namebuf" buffer. */
 789         if ((list_len = get_xattr_names(fname)) < 0)
 790                 return -1;
 791
 792         for (i = 0; i < xalp->count; i++) {
 793                 name = rxas[i].name;
 794
 795                 if (XATTR_ABBREV(rxas[i])) {
 796                         /* See if the fnamecmp version is identical. */
 797                         len = name_len = rxas[i].name_len;
 798                         if ((ptr = get_xattr_data(fnamecmp, name, &len, 1)) == NULL) {
 799                           still_abbrev:
 800                                 if (am_generator)
 801                                         continue;
 802                                 rprintf(FERROR, "Missing abbreviated xattr value, %s, for %s\n",
 803                                         rxas[i].name, full_fname(fname));
 804                                 ret = -1;
 805                                 continue;
 806                         }
 807                         if (len != rxas[i].datum_len) {
 808                                 free(ptr);
 809                                 goto still_abbrev;
 810                         }
 811
 812                         sum_init(checksum_seed);
 813                         sum_update(ptr, len);
 814                         sum_end(sum);
 815                         if (memcmp(sum, rxas[i].datum + 1, MAX_DIGEST_LEN) != 0) {
 816                                 free(ptr);
 817                                 goto still_abbrev;
 818                         }
 819
 820                         if (fname == fnamecmp)
 821                                 ; /* Value is already set when identical */
 822                         else if (sys_lsetxattr(fname, name, ptr, len) < 0) {
 823                                 rsyserr(FERROR_XFER, errno,
 824                                         "rsync_xal_set: lsetxattr(\"%s\",\"%s\") failed",
 825                                         fname, name);
 826                                 ret = -1;
 827                         } else /* make sure caller sets mtime */
 828                                 sxp->st.st_mtime = (time_t)-1;
 829
 830                         if (am_generator) { /* generator items stay abbreviated */
 831                                 free(ptr);
 832                                 continue;
 833                         }
 834
 835                         memcpy(ptr + len, name, name_len);
 836                         free(rxas[i].datum);
 837
 838                         rxas[i].name = name = ptr + len;
 839                         rxas[i].datum = ptr;
 840                         continue;
 841                 }
 842
 843                 if (sys_lsetxattr(fname, name, rxas[i].datum, rxas[i].datum_len) < 0) {
 844                         rsyserr(FERROR_XFER, errno,
 845                                 "rsync_xal_set: lsetxattr(\"%s\",\"%s\") failed",
 846                                 fname, name);
 847                         ret = -1;
 848                 } else /* make sure caller sets mtime */
 849                         sxp->st.st_mtime = (time_t)-1;
 850         }
 851
 852         /* Remove any extraneous names. */
 853         for (name = namebuf; list_len > 0; name += name_len) {
 854                 name_len = strlen(name) + 1;
 855                 list_len -= name_len;
 856
 857 #ifdef HAVE_LINUX_XATTRS
 858                 /* We always ignore the system namespace, and non-root
 859                  * ignores everything but the user namespace. */
 860                 if (user_only ? !HAS_PREFIX(name, USER_PREFIX)
 861                               : HAS_PREFIX(name, SYSTEM_PREFIX))
 862                         continue;
 863 #endif
 864                 if (am_root < 0 && name_len > RPRE_LEN
 865                  && name[RPRE_LEN] == '%' && strcmp(name, XSTAT_ATTR) == 0)
 866                         continue;
 867
 868                 for (i = 0; i < xalp->count; i++) {
 869                         if (strcmp(name, rxas[i].name) == 0)
 870                                 break;
 871                 }
 872                 if (i == xalp->count) {
 873                         if (sys_lremovexattr(fname, name) < 0) {
 874                                 rsyserr(FERROR_XFER, errno,
 875                                         "rsync_xal_clear: lremovexattr(\"%s\",\"%s\") failed",
 876                                         fname, name);
 877                                 ret = -1;
 878                         } else /* make sure caller sets mtime */
 879                                 sxp->st.st_mtime = (time_t)-1;
 880                 }
 881         }
 882
 883         return ret;
 884 }
 885
 886 /* Set extended attributes on indicated filename. */
 887 int set_xattr(const char *fname, const struct file_struct *file,
 888               const char *fnamecmp, stat_x *sxp)
 889 {
 890         int ndx;
 891         item_list *lst = rsync_xal_l.items;
 892
 893         if (dry_run)
 894                 return 1; /* FIXME: --dry-run needs to compute this value */
 895
 896         if (read_only || list_only) {
 897                 errno = EROFS;
 898                 return -1;
 899         }
 900
 901 #ifdef NO_SPECIAL_XATTRS
 902         if (IS_SPECIAL(sxp->st.st_mode)) {
 903                 errno = ENOTSUP;
 904                 return -1;
 905         }
 906 #endif
 907 #ifdef NO_DEVICE_XATTRS
 908         if (IS_DEVICE(sxp->st.st_mode)) {
 909                 errno = ENOTSUP;
 910                 return -1;
 911         }
 912 #endif
 913 #ifdef NO_SYMLINK_XATTRS
 914         if (S_ISLNK(sxp->st.st_mode)) {
 915                 errno = ENOTSUP;
 916                 return -1;
 917         }
 918 #endif
 919
 920         ndx = F_XATTR(file);
 921         return rsync_xal_set(fname, lst + ndx, fnamecmp, sxp);
 922 }
 923
 924 #ifdef SUPPORT_ACLS
 925 char *get_xattr_acl(const char *fname, int is_access_acl, size_t *len_p)
 926 {
 927         const char *name = is_access_acl ? XACC_ACL_ATTR : XDEF_ACL_ATTR;
 928         *len_p = 0; /* no extra data alloc needed from get_xattr_data() */
 929         return get_xattr_data(fname, name, len_p, 1);
 930 }
 931
 932 int set_xattr_acl(const char *fname, int is_access_acl, const char *buf, size_t buf_len)
 933 {
 934         const char *name = is_access_acl ? XACC_ACL_ATTR : XDEF_ACL_ATTR;
 935         if (sys_lsetxattr(fname, name, buf, buf_len) < 0) {
 936                 rsyserr(FERROR_XFER, errno,
 937                         "set_xattr_acl: lsetxattr(\"%s\",\"%s\") failed",
 938                         fname, name);
 939                 return -1;
 940         }
 941         return 0;
 942 }
 943
 944 int del_def_xattr_acl(const char *fname)
 945 {
 946         return sys_lremovexattr(fname, XDEF_ACL_ATTR);
 947 }
 948 #endif
 949
 950 int get_stat_xattr(const char *fname, int fd, STRUCT_STAT *fst, STRUCT_STAT *xst)
 951 {
 952         int mode, rdev_major, rdev_minor, uid, gid, len;
 953         char buf[256];
 954
 955         if (am_root >= 0 || IS_DEVICE(fst->st_mode) || IS_SPECIAL(fst->st_mode))
 956                 return -1;
 957
 958         if (xst)
 959                 *xst = *fst;
 960         else
 961                 xst = fst;
 962         if (fname) {
 963                 fd = -1;
 964                 len = sys_lgetxattr(fname, XSTAT_ATTR, buf, sizeof buf - 1);
 965         } else {
 966                 fname = "fd";
 967                 len = sys_fgetxattr(fd, XSTAT_ATTR, buf, sizeof buf - 1);
 968         }
 969         if (len >= (int)sizeof buf) {
 970                 len = -1;
 971                 errno = ERANGE;
 972         }
 973         if (len < 0) {
 974                 if (errno == ENOTSUP || errno == ENOATTR)
 975                         return -1;
 976                 if (errno == EPERM && S_ISLNK(fst->st_mode)) {
 977                         xst->st_uid = 0;
 978                         xst->st_gid = 0;
 979                         return 0;
 980                 }
 981                 rsyserr(FERROR_XFER, errno, "failed to read xattr %s for %s",
 982                         XSTAT_ATTR, full_fname(fname));
 983                 return -1;
 984         }
 985         buf[len] = '\0';
 986
 987         if (sscanf(buf, "%o %d,%d %d:%d",
 988                    &mode, &rdev_major, &rdev_minor, &uid, &gid) != 5) {
 989                 rprintf(FERROR, "Corrupt %s xattr attached to %s: \"%s\"\n",
 990                         XSTAT_ATTR, full_fname(fname), buf);
 991                 exit_cleanup(RERR_FILEIO);
 992         }
 993
 994         xst->st_mode = from_wire_mode(mode);
 995         xst->st_rdev = MAKEDEV(rdev_major, rdev_minor);
 996         xst->st_uid = uid;
 997         xst->st_gid = gid;
 998
 999         return 0;
1000 }
1001
1002 int set_stat_xattr(const char *fname, struct file_struct *file, mode_t new_mode)
1003 {
1004         STRUCT_STAT fst, xst;
1005         dev_t rdev;
1006         mode_t mode, fmode;
1007
1008         if (dry_run)
1009                 return 0;
1010
1011         if (read_only || list_only) {
1012                 rsyserr(FERROR_XFER, EROFS, "failed to write xattr %s for %s",
1013                         XSTAT_ATTR, full_fname(fname));
1014                 return -1;
1015         }
1016
1017         if (x_lstat(fname, &fst, &xst) < 0) {
1018                 rsyserr(FERROR_XFER, errno, "failed to re-stat %s",
1019                         full_fname(fname));
1020                 return -1;
1021         }
1022
1023         fst.st_mode &= (_S_IFMT | CHMOD_BITS);
1024         fmode = new_mode & (_S_IFMT | CHMOD_BITS);
1025
1026         if (IS_DEVICE(fmode)) {
1027                 uint32 *devp = F_RDEV_P(file);
1028                 rdev = MAKEDEV(DEV_MAJOR(devp), DEV_MINOR(devp));
1029         } else
1030                 rdev = 0;
1031
1032         /* Dump the special permissions and enable full owner access. */
1033         mode = (fst.st_mode & _S_IFMT) | (fmode & ACCESSPERMS)
1034              | (S_ISDIR(fst.st_mode) ? 0700 : 0600);
1035         if (fst.st_mode != mode)
1036                 do_chmod(fname, mode);
1037         if (!IS_DEVICE(fst.st_mode))
1038                 fst.st_rdev = 0; /* just in case */
1039
1040         if (mode == fmode && fst.st_rdev == rdev
1041          && fst.st_uid == F_OWNER(file) && fst.st_gid == F_GROUP(file)) {
1042                 /* xst.st_mode will be 0 if there's no current stat xattr */
1043                 if (xst.st_mode && sys_lremovexattr(fname, XSTAT_ATTR) < 0) {
1044                         rsyserr(FERROR_XFER, errno,
1045                                 "delete of stat xattr failed for %s",
1046                                 full_fname(fname));
1047                         return -1;
1048                 }
1049                 return 0;
1050         }
1051
1052         if (xst.st_mode != fmode || xst.st_rdev != rdev
1053          || xst.st_uid != F_OWNER(file) || xst.st_gid != F_GROUP(file)) {
1054                 char buf[256];
1055                 int len = snprintf(buf, sizeof buf, "%o %u,%u %u:%u",
1056                         to_wire_mode(fmode),
1057                         (int)major(rdev), (int)minor(rdev),
1058                         F_OWNER(file), F_GROUP(file));
1059                 if (sys_lsetxattr(fname, XSTAT_ATTR, buf, len) < 0) {
1060                         if (errno == EPERM && S_ISLNK(fst.st_mode))
1061                                 return 0;
1062                         rsyserr(FERROR_XFER, errno,
1063                                 "failed to write xattr %s for %s",
1064                                 XSTAT_ATTR, full_fname(fname));
1065                         return -1;
1066                 }
1067         }
1068
1069         return 0;
1070 }
1071
1072 int x_stat(const char *fname, STRUCT_STAT *fst, STRUCT_STAT *xst)
1073 {
1074         int ret = do_stat(fname, fst);
1075         if ((ret < 0 || get_stat_xattr(fname, -1, fst, xst) < 0) && xst)
1076                 xst->st_mode = 0;
1077         return ret;
1078 }
1079
1080 int x_lstat(const char *fname, STRUCT_STAT *fst, STRUCT_STAT *xst)
1081 {
1082         int ret = do_lstat(fname, fst);
1083         if ((ret < 0 || get_stat_xattr(fname, -1, fst, xst) < 0) && xst)
1084                 xst->st_mode = 0;
1085         return ret;
1086 }
1087
1088 int x_fstat(int fd, STRUCT_STAT *fst, STRUCT_STAT *xst)
1089 {
1090         int ret = do_fstat(fd, fst);
1091         if ((ret < 0 || get_stat_xattr(NULL, fd, fst, xst) < 0) && xst)
1092                 xst->st_mode = 0;
1093         return ret;
1094 }
1095
1096 #endif /* SUPPORT_XATTRS */