generator.c

   1 /* -*- c-file-style: "linux" -*-
   2
   3    rsync -- fast file replication program
   4
   5    Copyright (C) 1996-2000 by Andrew Tridgell
   6    Copyright (C) Paul Mackerras 1996
   7    Copyright (C) 2002 by Martin Pool <mbp@samba.org>
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 2 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program; if not, write to the Free Software
  21    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22 */
  23
  24 #include "rsync.h"
  25
  26 extern int verbose;
  27 extern int dry_run;
  28 extern int relative_paths;
  29 extern int keep_dirlinks;
  30 extern int preserve_links;
  31 extern int am_root;
  32 extern int preserve_devices;
  33 extern int preserve_hard_links;
  34 extern int preserve_perms;
  35 extern int preserve_uid;
  36 extern int preserve_gid;
  37 extern int update_only;
  38 extern int opt_ignore_existing;
  39 extern int inplace;
  40 extern int make_backups;
  41 extern int csum_length;
  42 extern int ignore_times;
  43 extern int size_only;
  44 extern int io_timeout;
  45 extern int protocol_version;
  46 extern int always_checksum;
  47 extern char *partial_dir;
  48 extern char *compare_dest;
  49 extern int link_dest;
  50 extern int whole_file;
  51 extern int local_server;
  52 extern int list_only;
  53 extern int read_batch;
  54 extern int only_existing;
  55 extern int orig_umask;
  56 extern int safe_symlinks;
  57 extern unsigned int block_size;
  58
  59 extern struct exclude_list_struct server_exclude_list;
  60
  61
  62 /* choose whether to skip a particular file */
  63 static int skip_file(char *fname, struct file_struct *file, STRUCT_STAT *st)
  64 {
  65         if (st->st_size != file->length)
  66                 return 0;
  67         if (link_dest) {
  68                 if (preserve_perms
  69                     && (st->st_mode & CHMOD_BITS) != (file->mode & CHMOD_BITS))
  70                         return 0;
  71
  72                 if (am_root && preserve_uid && st->st_uid != file->uid)
  73                         return 0;
  74
  75                 if (preserve_gid && file->gid != GID_NONE
  76                     && st->st_gid != file->gid)
  77                         return 0;
  78         }
  79
  80         /* if always checksum is set then we use the checksum instead
  81            of the file time to determine whether to sync */
  82         if (always_checksum && S_ISREG(st->st_mode)) {
  83                 char sum[MD4_SUM_LENGTH];
  84                 file_checksum(fname,sum,st->st_size);
  85                 return memcmp(sum, file->u.sum, protocol_version < 21 ? 2
  86                                                         : MD4_SUM_LENGTH) == 0;
  87         }
  88
  89         if (size_only)
  90                 return 1;
  91
  92         if (ignore_times)
  93                 return 0;
  94
  95         return cmp_modtime(st->st_mtime, file->modtime) == 0;
  96 }
  97
  98
  99 /*
 100  * NULL sum_struct means we have no checksums
 101  */
 102 void write_sum_head(int f, struct sum_struct *sum)
 103 {
 104         static struct sum_struct null_sum;
 105
 106         if (sum == NULL)
 107                 sum = &null_sum;
 108
 109         write_int(f, sum->count);
 110         write_int(f, sum->blength);
 111         if (protocol_version >= 27)
 112                 write_int(f, sum->s2length);
 113         write_int(f, sum->remainder);
 114 }
 115
 116 /*
 117  * set (initialize) the size entries in the per-file sum_struct
 118  * calculating dynamic block and checksum sizes.
 119  *
 120  * This is only called from generate_and_send_sums() but is a separate
 121  * function to encapsulate the logic.
 122  *
 123  * The block size is a rounded square root of file length.
 124  *
 125  * The checksum size is determined according to:
 126  *     blocksum_bits = BLOCKSUM_EXP + 2*log2(file_len) - log2(block_len)
 127  * provided by Donovan Baarda which gives a probability of rsync
 128  * algorithm corrupting data and falling back using the whole md4
 129  * checksums.
 130  *
 131  * This might be made one of several selectable heuristics.
 132  */
 133
 134 static void sum_sizes_sqroot(struct sum_struct *sum, uint64 len)
 135 {
 136         unsigned int blength;
 137         int s2length;
 138         uint32 c;
 139         uint64 l;
 140
 141         if (block_size) {
 142                 blength = block_size;
 143         } else if (len <= BLOCK_SIZE * BLOCK_SIZE) {
 144                 blength = BLOCK_SIZE;
 145         } else {
 146                 l = len;
 147                 c = 1;
 148                 while (l >>= 2) {
 149                         c <<= 1;
 150                 }
 151                 blength = 0;
 152                 do {
 153                         blength |= c;
 154                         if (len < (uint64)blength * blength)
 155                                 blength &= ~c;
 156                         c >>= 1;
 157                 } while (c >= 8);       /* round to multiple of 8 */
 158                 blength = MAX(blength, BLOCK_SIZE);
 159         }
 160
 161         if (protocol_version < 27) {
 162                 s2length = csum_length;
 163         } else if (csum_length == SUM_LENGTH) {
 164                 s2length = SUM_LENGTH;
 165         } else {
 166                 int b = BLOCKSUM_BIAS;
 167                 l = len;
 168                 while (l >>= 1) {
 169                         b += 2;
 170                 }
 171                 c = blength;
 172                 while (c >>= 1 && b) {
 173                         b--;
 174                 }
 175                 s2length = (b + 1 - 32 + 7) / 8; /* add a bit,
 176                                                   * subtract rollsum,
 177                                                   * round up
 178                                                   *    --optimize in compiler--
 179                                                   */
 180                 s2length = MAX(s2length, csum_length);
 181                 s2length = MIN(s2length, SUM_LENGTH);
 182         }
 183
 184         sum->flength    = len;
 185         sum->blength    = blength;
 186         sum->s2length   = s2length;
 187         sum->count      = (len + (blength - 1)) / blength;
 188         sum->remainder  = (len % blength);
 189
 190         if (sum->count && verbose > 2) {
 191                 rprintf(FINFO, "count=%.0f rem=%u blength=%u s2length=%d flength=%.0f\n",
 192                         (double)sum->count, sum->remainder, sum->blength,
 193                         sum->s2length, (double)sum->flength);
 194         }
 195 }
 196
 197
 198 /*
 199  * Generate and send a stream of signatures/checksums that describe a buffer
 200  *
 201  * Generate approximately one checksum every block_len bytes.
 202  */
 203 static void generate_and_send_sums(int fd, OFF_T len, int f_out, int f_copy)
 204 {
 205         size_t i;
 206         struct map_struct *mapbuf;
 207         struct sum_struct sum;
 208         OFF_T offset = 0;
 209
 210         sum_sizes_sqroot(&sum, len);
 211
 212         if (len > 0)
 213                 mapbuf = map_file(fd, len, MAX_MAP_SIZE, sum.blength);
 214         else
 215                 mapbuf = NULL;
 216
 217         write_sum_head(f_out, &sum);
 218
 219         for (i = 0; i < sum.count; i++) {
 220                 unsigned int n1 = MIN(len, sum.blength);
 221                 char *map = map_ptr(mapbuf, offset, n1);
 222                 uint32 sum1 = get_checksum1(map, n1);
 223                 char sum2[SUM_LENGTH];
 224
 225                 if (f_copy >= 0)
 226                         full_write(f_copy, map, n1);
 227
 228                 get_checksum2(map, n1, sum2);
 229
 230                 if (verbose > 3) {
 231                         rprintf(FINFO,
 232                                 "chunk[%.0f] offset=%.0f len=%u sum1=%08lx\n",
 233                                 (double)i, (double)offset, n1,
 234                                 (unsigned long)sum1);
 235                 }
 236                 write_int(f_out, sum1);
 237                 write_buf(f_out, sum2, sum.s2length);
 238                 len -= n1;
 239                 offset += n1;
 240         }
 241
 242         if (mapbuf)
 243                 unmap_file(mapbuf);
 244 }
 245
 246
 247
 248 /*
 249  * Acts on file number @p i from @p flist, whose name is @p fname.
 250  *
 251  * First fixes up permissions, then generates checksums for the file.
 252  *
 253  * @note This comment was added later by mbp who was trying to work it
 254  * out.  It might be wrong.
 255  */
 256 static void recv_generator(char *fname, struct file_struct *file, int i,
 257                            int f_out)
 258 {
 259         int fd, f_copy;
 260         STRUCT_STAT st, partial_st;
 261         struct file_struct *back_file;
 262         int statret, stat_errno;
 263         char *fnamecmp, *partialptr, *backupptr;
 264         char fnamecmpbuf[MAXPATHLEN];
 265
 266         if (list_only)
 267                 return;
 268
 269         if (verbose > 2)
 270                 rprintf(FINFO, "recv_generator(%s,%d)\n", safe_fname(fname), i);
 271
 272         if (server_exclude_list.head
 273             && check_exclude(&server_exclude_list, fname,
 274                              S_ISDIR(file->mode)) < 0) {
 275                 if (verbose) {
 276                         rprintf(FINFO, "skipping server-excluded file \"%s\"\n",
 277                                 safe_fname(fname));
 278                 }
 279                 return;
 280         }
 281
 282         if (dry_run > 1) {
 283                 statret = -1;
 284                 stat_errno = ENOENT;
 285         } else {
 286                 statret = link_stat(fname, &st,
 287                                     keep_dirlinks && S_ISDIR(file->mode));
 288                 stat_errno = errno;
 289         }
 290
 291         if (only_existing && statret == -1 && stat_errno == ENOENT) {
 292                 /* we only want to update existing files */
 293                 if (verbose > 1) {
 294                         rprintf(FINFO, "not creating new file \"%s\"\n",
 295                                 safe_fname(fname));
 296                 }
 297                 return;
 298         }
 299
 300         if (statret == 0 && !preserve_perms
 301             && S_ISDIR(st.st_mode) == S_ISDIR(file->mode)) {
 302                 /* if the file exists already and we aren't perserving
 303                  * permissions then act as though the remote end sent
 304                  * us the file permissions we already have */
 305                 file->mode = (file->mode & ~CHMOD_BITS)
 306                            | (st.st_mode & CHMOD_BITS);
 307         }
 308
 309         if (S_ISDIR(file->mode)) {
 310                 /* The file to be received is a directory, so we need
 311                  * to prepare appropriately.  If there is already a
 312                  * file of that name and it is *not* a directory, then
 313                  * we need to delete it.  If it doesn't exist, then
 314                  * recursively create it. */
 315
 316                 if (dry_run)
 317                         return; /* TODO: causes inaccuracies -- fix */
 318                 if (statret == 0 && !S_ISDIR(st.st_mode)) {
 319                         if (robust_unlink(fname) != 0) {
 320                                 rsyserr(FERROR, errno,
 321                                         "recv_generator: unlink %s to make room for directory",
 322                                         full_fname(fname));
 323                                 return;
 324                         }
 325                         statret = -1;
 326                 }
 327                 if (statret != 0 && do_mkdir(fname,file->mode) != 0 && errno != EEXIST) {
 328                         if (!(relative_paths && errno == ENOENT
 329                             && create_directory_path(fname, orig_umask) == 0
 330                             && do_mkdir(fname, file->mode) == 0)) {
 331                                 rsyserr(FERROR, errno,
 332                                         "recv_generator: mkdir %s failed",
 333                                         full_fname(fname));
 334                         }
 335                 }
 336                 /* f_out is set to -1 when doing final directory-permission
 337                  * and modification-time repair. */
 338                 if (set_perms(fname, file, statret ? NULL : &st, 0)
 339                     && verbose && f_out != -1)
 340                         rprintf(FINFO, "%s/\n", safe_fname(fname));
 341                 return;
 342         }
 343
 344         if (preserve_links && S_ISLNK(file->mode)) {
 345 #if SUPPORT_LINKS
 346                 char lnk[MAXPATHLEN];
 347                 int l;
 348
 349                 if (safe_symlinks && unsafe_symlink(file->u.link, fname)) {
 350                         if (verbose) {
 351                                 rprintf(FINFO, "ignoring unsafe symlink %s -> \"%s\"\n",
 352                                         full_fname(fname), file->u.link);
 353                         }
 354                         return;
 355                 }
 356                 if (statret == 0) {
 357                         l = readlink(fname,lnk,MAXPATHLEN-1);
 358                         if (l > 0) {
 359                                 lnk[l] = 0;
 360                                 /* A link already pointing to the
 361                                  * right place -- no further action
 362                                  * required. */
 363                                 if (strcmp(lnk,file->u.link) == 0) {
 364                                         set_perms(fname, file, &st,
 365                                                   PERMS_REPORT);
 366                                         return;
 367                                 }
 368                         }
 369                         /* Not a symlink, so delete whatever's
 370                          * already there and put a new symlink
 371                          * in place. */
 372                         delete_file(fname);
 373                 }
 374                 if (do_symlink(file->u.link,fname) != 0) {
 375                         rsyserr(FERROR, errno, "symlink %s -> \"%s\" failed",
 376                                 full_fname(fname), safe_fname(file->u.link));
 377                 } else {
 378                         set_perms(fname,file,NULL,0);
 379                         if (verbose) {
 380                                 rprintf(FINFO, "%s -> %s\n", safe_fname(fname),
 381                                         safe_fname(file->u.link));
 382                         }
 383                 }
 384 #endif
 385                 return;
 386         }
 387
 388         if (am_root && preserve_devices && IS_DEVICE(file->mode)) {
 389                 if (statret != 0 ||
 390                     st.st_mode != file->mode ||
 391                     st.st_rdev != file->u.rdev) {
 392                         delete_file(fname);
 393                         if (verbose > 2) {
 394                                 rprintf(FINFO,"mknod(%s,0%o,0x%x)\n",
 395                                         safe_fname(fname),
 396                                         (int)file->mode, (int)file->u.rdev);
 397                         }
 398                         if (do_mknod(fname,file->mode,file->u.rdev) != 0) {
 399                                 rsyserr(FERROR, errno, "mknod %s failed",
 400                                         full_fname(fname));
 401                         } else {
 402                                 set_perms(fname,file,NULL,0);
 403                                 if (verbose) {
 404                                         rprintf(FINFO, "%s\n",
 405                                                 safe_fname(fname));
 406                                 }
 407                         }
 408                 } else {
 409                         set_perms(fname, file, &st, PERMS_REPORT);
 410                 }
 411                 return;
 412         }
 413
 414         if (preserve_hard_links && hard_link_check(file, HL_CHECK_MASTER))
 415                 return;
 416
 417         if (!S_ISREG(file->mode)) {
 418                 rprintf(FINFO, "skipping non-regular file \"%s\"\n",
 419                         safe_fname(fname));
 420                 return;
 421         }
 422
 423         fnamecmp = fname;
 424
 425         if (statret == -1 && compare_dest != NULL) {
 426                 /* try the file at compare_dest instead */
 427                 pathjoin(fnamecmpbuf, sizeof fnamecmpbuf, compare_dest, fname);
 428                 if (link_stat(fnamecmpbuf, &st, 0) == 0
 429                     && S_ISREG(st.st_mode)) {
 430 #if HAVE_LINK
 431                         if (link_dest && !dry_run) {
 432                                 if (do_link(fnamecmpbuf, fname) < 0) {
 433                                         if (verbose) {
 434                                                 rsyserr(FINFO, errno,
 435                                                         "link %s => %s",
 436                                                         fnamecmpbuf,
 437                                                         safe_fname(fname));
 438                                         }
 439                                         fnamecmp = fnamecmpbuf;
 440                                 }
 441                         } else
 442 #endif
 443                                 fnamecmp = fnamecmpbuf;
 444                         statret = 0;
 445                 }
 446         }
 447
 448         if (statret == 0 && !S_ISREG(st.st_mode)) {
 449                 if (delete_file(fname) != 0)
 450                         return;
 451                 statret = -1;
 452                 stat_errno = ENOENT;
 453         }
 454
 455         if (partial_dir && (partialptr = partial_dir_fname(fname))
 456             && link_stat(partialptr, &partial_st, 0) == 0
 457             && S_ISREG(partial_st.st_mode)) {
 458                 if (statret == -1)
 459                         goto prepare_to_open;
 460         } else
 461                 partialptr = NULL;
 462
 463         if (statret == -1) {
 464                 if (preserve_hard_links && hard_link_check(file, HL_SKIP))
 465                         return;
 466                 if (stat_errno == ENOENT) {
 467                         write_int(f_out,i);
 468                         if (!dry_run && !read_batch)
 469                                 write_sum_head(f_out, NULL);
 470                 } else if (verbose > 1) {
 471                         rsyserr(FERROR, stat_errno,
 472                                 "recv_generator: failed to stat %s",
 473                                 full_fname(fname));
 474                 }
 475                 return;
 476         }
 477
 478         if (opt_ignore_existing && fnamecmp == fname) {
 479                 if (verbose > 1)
 480                         rprintf(FINFO, "%s exists\n", safe_fname(fname));
 481                 return;
 482         }
 483
 484         if (update_only && fnamecmp == fname
 485             && cmp_modtime(st.st_mtime, file->modtime) > 0) {
 486                 if (verbose > 1)
 487                         rprintf(FINFO, "%s is newer\n", safe_fname(fname));
 488                 return;
 489         }
 490
 491         if (skip_file(fnamecmp, file, &st)) {
 492                 if (fnamecmp == fname)
 493                         set_perms(fname, file, &st, PERMS_REPORT);
 494                 return;
 495         }
 496
 497 prepare_to_open:
 498         if (dry_run || read_batch) {
 499                 write_int(f_out,i);
 500                 return;
 501         }
 502
 503         if (whole_file > 0) {
 504                 write_int(f_out,i);
 505                 write_sum_head(f_out, NULL);
 506                 return;
 507         }
 508
 509         if (partialptr) {
 510                 st = partial_st;
 511                 fnamecmp = partialptr;
 512         }
 513
 514         /* open the file */
 515         fd = do_open(fnamecmp, O_RDONLY, 0);
 516
 517         if (fd == -1) {
 518                 rsyserr(FERROR, errno, "failed to open %s, continuing",
 519                         full_fname(fnamecmp));
 520             pretend_missing:
 521                 /* pretend the file didn't exist */
 522                 if (preserve_hard_links && hard_link_check(file, HL_SKIP))
 523                         return;
 524                 write_int(f_out,i);
 525                 write_sum_head(f_out, NULL);
 526                 return;
 527         }
 528
 529         if (inplace && make_backups) {
 530                 if (!(backupptr = get_backup_name(fname))) {
 531                         close(fd);
 532                         return;
 533                 }
 534                 if (!(back_file = make_file(fname, NULL, NO_EXCLUDES))) {
 535                         close(fd);
 536                         goto pretend_missing;
 537                 }
 538                 if (robust_unlink(backupptr) && errno != ENOENT) {
 539                         rsyserr(FERROR, errno, "unlink %s",
 540                                 full_fname(backupptr));
 541                         free(back_file);
 542                         close(fd);
 543                         return;
 544                 }
 545                 if ((f_copy = do_open(backupptr,
 546                     O_WRONLY | O_CREAT | O_TRUNC | O_EXCL, 0600)) < 0) {
 547                         rsyserr(FERROR, errno, "open %s",
 548                                 full_fname(backupptr));
 549                         free(back_file);
 550                         close(fd);
 551                         return;
 552                 }
 553         } else {
 554                 backupptr = NULL;
 555                 back_file = NULL;
 556                 f_copy = -1;
 557         }
 558
 559         if (verbose > 3) {
 560                 rprintf(FINFO, "gen mapped %s of size %.0f\n",
 561                         safe_fname(fnamecmp), (double)st.st_size);
 562         }
 563
 564         if (verbose > 2)
 565                 rprintf(FINFO, "generating and sending sums for %d\n", i);
 566
 567         write_int(f_out,i);
 568         generate_and_send_sums(fd, st.st_size, f_out, f_copy);
 569
 570         if (f_copy >= 0) {
 571                 close(f_copy);
 572                 set_perms(backupptr, back_file, NULL, 0);
 573                 if (verbose > 1)
 574                         rprintf(FINFO, "backed up %s to %s\n", fname, backupptr);
 575                 free(back_file);
 576         }
 577
 578         close(fd);
 579 }
 580
 581
 582 void generate_files(int f_out, struct file_list *flist, char *local_name)
 583 {
 584         int i;
 585         int phase = 0;
 586         char fbuf[MAXPATHLEN];
 587
 588         if (verbose > 2) {
 589                 rprintf(FINFO, "generator starting pid=%ld count=%d\n",
 590                         (long)getpid(), flist->count);
 591         }
 592
 593         if (verbose >= 2) {
 594                 rprintf(FINFO,
 595                         whole_file > 0
 596                         ? "delta-transmission disabled for local transfer or --whole-file\n"
 597                         : "delta transmission enabled\n");
 598         }
 599
 600         /* we expect to just sit around now, so don't exit on a
 601            timeout. If we really get a timeout then the other process should
 602            exit */
 603         io_timeout = 0;
 604
 605         for (i = 0; i < flist->count; i++) {
 606                 struct file_struct *file = flist->files[i];
 607                 struct file_struct copy;
 608
 609                 if (!file->basename)
 610                         continue;
 611                 /* we need to ensure that any directories we create have writeable
 612                    permissions initially so that we can create the files within
 613                    them. This is then fixed after the files are transferred */
 614                 if (!am_root && S_ISDIR(file->mode) && !(file->mode & S_IWUSR)) {
 615                         copy = *file;
 616                         /* XXX: Could this be causing a problem on SCO?  Perhaps their
 617                          * handling of permissions is strange? */
 618                         copy.mode |= S_IWUSR; /* user write */
 619                         file = &copy;
 620                 }
 621
 622                 recv_generator(local_name ? local_name : f_name_to(file, fbuf),
 623                                file, i, f_out);
 624         }
 625
 626         phase++;
 627         csum_length = SUM_LENGTH;
 628         ignore_times = 1;
 629
 630         if (verbose > 2)
 631                 rprintf(FINFO,"generate_files phase=%d\n",phase);
 632
 633         write_int(f_out, -1);
 634
 635         /* files can cycle through the system more than once
 636          * to catch initial checksum errors */
 637         while ((i = get_redo_num()) != -1) {
 638                 struct file_struct *file = flist->files[i];
 639                 recv_generator(local_name ? local_name : f_name_to(file, fbuf),
 640                                file, i, f_out);
 641         }
 642
 643         phase++;
 644         if (verbose > 2)
 645                 rprintf(FINFO,"generate_files phase=%d\n",phase);
 646
 647         write_int(f_out, -1);
 648
 649         if (preserve_hard_links)
 650                 do_hard_links();
 651
 652         /* now we need to fix any directory permissions that were
 653          * modified during the transfer */
 654         for (i = 0; i < flist->count; i++) {
 655                 struct file_struct *file = flist->files[i];
 656                 if (!file->basename || !S_ISDIR(file->mode))
 657                         continue;
 658                 recv_generator(local_name ? local_name : f_name(file),
 659                                file, i, -1);
 660         }
 661
 662         if (verbose > 2)
 663                 rprintf(FINFO,"generate_files finished\n");
 664 }