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