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