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 read_batch;
  50 extern int write_batch;
  51 extern int list_only;
  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                 char fnamecmpdest[MAXPATHLEN];
  83
  84                 if (compare_dest != NULL) {
  85                         if (access(fname, 0) != 0) {
  86                                 pathjoin(fnamecmpdest, sizeof fnamecmpdest,
  87                                          compare_dest, fname);
  88                                 fname = fnamecmpdest;
  89                         }
  90                 }
  91                 file_checksum(fname,sum,st->st_size);
  92                 return memcmp(sum, file->u.sum, protocol_version < 21 ? 2
  93                                                         : MD4_SUM_LENGTH) == 0;
  94         }
  95
  96         if (size_only)
  97                 return 1;
  98
  99         if (ignore_times)
 100                 return 0;
 101
 102         return cmp_modtime(st->st_mtime, file->modtime) == 0;
 103 }
 104
 105
 106 /*
 107  * NULL sum_struct means we have no checksums
 108  */
 109 void write_sum_head(int f, struct sum_struct *sum)
 110 {
 111         static struct sum_struct null_sum;
 112
 113         if (sum == NULL)
 114                 sum = &null_sum;
 115
 116         write_int(f, sum->count);
 117         write_int(f, sum->blength);
 118         if (protocol_version >= 27)
 119                 write_int(f, sum->s2length);
 120         write_int(f, sum->remainder);
 121 }
 122
 123 /*
 124  * set (initialize) the size entries in the per-file sum_struct
 125  * calculating dynamic block and checksum sizes.
 126  *
 127  * This is only called from generate_and_send_sums() but is a separate
 128  * function to encapsulate the logic.
 129  *
 130  * The block size is a rounded square root of file length.
 131  *
 132  * The checksum size is determined according to:
 133  *     blocksum_bits = BLOCKSUM_EXP + 2*log2(file_len) - log2(block_len)
 134  * provided by Donovan Baarda which gives a probability of rsync
 135  * algorithm corrupting data and falling back using the whole md4
 136  * checksums.
 137  *
 138  * This might be made one of several selectable heuristics.
 139  */
 140
 141 static void sum_sizes_sqroot(struct sum_struct *sum, uint64 len)
 142 {
 143         unsigned int blength;
 144         int s2length;
 145         uint32 c;
 146         uint64 l;
 147
 148         if (block_size) {
 149                 blength = block_size;
 150         } else if (len <= BLOCK_SIZE * BLOCK_SIZE) {
 151                 blength = BLOCK_SIZE;
 152         } else {
 153                 l = len;
 154                 c = 1;
 155                 while (l >>= 2) {
 156                         c <<= 1;
 157                 }
 158                 blength = 0;
 159                 do {
 160                         blength |= c;
 161                         if (len < (uint64)blength * blength)
 162                                 blength &= ~c;
 163                         c >>= 1;
 164                 } while (c >= 8);       /* round to multiple of 8 */
 165                 blength = MAX(blength, BLOCK_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  * Perhaps we want to just send an empty checksum set for this file,
 206  * which will force the whole thing to be literally transferred.
 207  *
 208  * When do we do this?  If the user's explicitly said they
 209  * want the whole thing, or if { they haven't explicitly
 210  * requested a delta, and it's local but not batch mode.}
 211  *
 212  * Whew. */
 213 static BOOL disable_deltas_p(void)
 214 {
 215         if (whole_file > 0)
 216                 return True;
 217         if (whole_file == 0 || write_batch || read_batch)
 218                 return False;
 219         return local_server;
 220 }
 221
 222
 223 /*
 224  * Generate and send a stream of signatures/checksums that describe a buffer
 225  *
 226  * Generate approximately one checksum every block_len bytes.
 227  */
 228 static void generate_and_send_sums(struct map_struct *buf, size_t len, int f_out)
 229 {
 230         size_t i;
 231         struct sum_struct sum;
 232         OFF_T offset = 0;
 233
 234         sum_sizes_sqroot(&sum, len);
 235
 236         write_sum_head(f_out, &sum);
 237
 238         for (i = 0; i < sum.count; i++) {
 239                 unsigned int n1 = MIN(len, sum.blength);
 240                 char *map = map_ptr(buf, offset, n1);
 241                 uint32 sum1 = get_checksum1(map, n1);
 242                 char sum2[SUM_LENGTH];
 243
 244                 get_checksum2(map, n1, sum2);
 245
 246                 if (verbose > 3) {
 247                         rprintf(FINFO,
 248                                 "chunk[%.0f] offset=%.0f len=%u sum1=%08lx\n",
 249                                 (double)i, (double)offset, n1,
 250                                 (unsigned long)sum1);
 251                 }
 252                 write_int(f_out, sum1);
 253                 write_buf(f_out, sum2, sum.s2length);
 254                 len -= n1;
 255                 offset += n1;
 256         }
 257 }
 258
 259
 260
 261 /*
 262  * Acts on file number @p i from @p flist, whose name is @p fname.
 263  *
 264  * First fixes up permissions, then generates checksums for the file.
 265  *
 266  * @note This comment was added later by mbp who was trying to work it
 267  * out.  It might be wrong.
 268  */
 269 static void recv_generator(char *fname, struct file_struct *file, int i,
 270                            int f_out)
 271 {
 272         int fd;
 273         STRUCT_STAT st;
 274         struct map_struct *mapbuf;
 275         int statret;
 276         char *fnamecmp;
 277         char fnamecmpbuf[MAXPATHLEN];
 278
 279         if (list_only)
 280                 return;
 281
 282         if (verbose > 2)
 283                 rprintf(FINFO,"recv_generator(%s,%d)\n",fname,i);
 284
 285         if (server_exclude_list.head
 286             && check_exclude(&server_exclude_list, fname,
 287                              S_ISDIR(file->mode)) < 0) {
 288                 if (verbose) {
 289                         rprintf(FINFO, "skipping server-excluded file \"%s\"\n",
 290                                 fname);
 291                 }
 292                 return;
 293         }
 294
 295         statret = link_stat(fname, &st, keep_dirlinks && S_ISDIR(file->mode));
 296
 297         if (only_existing && statret == -1 && errno == ENOENT) {
 298                 /* we only want to update existing files */
 299                 if (verbose > 1)
 300                         rprintf(FINFO, "not creating new file \"%s\"\n", fname);
 301                 return;
 302         }
 303
 304         if (statret == 0 &&
 305             !preserve_perms &&
 306             (S_ISDIR(st.st_mode) == S_ISDIR(file->mode))) {
 307                 /* if the file exists already and we aren't perserving
 308                  * permissions then act as though the remote end sent
 309                  * us the file permissions we already have */
 310                 file->mode = (file->mode & ~CHMOD_BITS)
 311                            | (st.st_mode & CHMOD_BITS);
 312         }
 313
 314         if (S_ISDIR(file->mode)) {
 315                 /* The file to be received is a directory, so we need
 316                  * to prepare appropriately.  If there is already a
 317                  * file of that name and it is *not* a directory, then
 318                  * we need to delete it.  If it doesn't exist, then
 319                  * recursively create it. */
 320
 321                 if (dry_run)
 322                         return; /* TODO: causes inaccuracies -- fix */
 323                 if (statret == 0 && !S_ISDIR(st.st_mode)) {
 324                         if (robust_unlink(fname) != 0) {
 325                                 rsyserr(FERROR, errno,
 326                                         "recv_generator: unlink %s to make room for directory",
 327                                         full_fname(fname));
 328                                 return;
 329                         }
 330                         statret = -1;
 331                 }
 332                 if (statret != 0 && do_mkdir(fname,file->mode) != 0 && errno != EEXIST) {
 333                         if (!(relative_paths && errno == ENOENT
 334                             && create_directory_path(fname, orig_umask) == 0
 335                             && do_mkdir(fname, file->mode) == 0)) {
 336                                 rsyserr(FERROR, errno,
 337                                         "recv_generator: mkdir %s failed",
 338                                         full_fname(fname));
 339                         }
 340                 }
 341                 /* f_out is set to -1 when doing final directory-permission
 342                  * and modification-time repair. */
 343                 if (set_perms(fname, file, statret ? NULL : &st, 0)
 344                     && verbose && f_out != -1)
 345                         rprintf(FINFO,"%s/\n",fname);
 346                 return;
 347         }
 348
 349         if (preserve_links && S_ISLNK(file->mode)) {
 350 #if SUPPORT_LINKS
 351                 char lnk[MAXPATHLEN];
 352                 int l;
 353
 354                 if (safe_symlinks && unsafe_symlink(file->u.link, fname)) {
 355                         if (verbose) {
 356                                 rprintf(FINFO, "ignoring unsafe symlink %s -> \"%s\"\n",
 357                                         full_fname(fname), file->u.link);
 358                         }
 359                         return;
 360                 }
 361                 if (statret == 0) {
 362                         l = readlink(fname,lnk,MAXPATHLEN-1);
 363                         if (l > 0) {
 364                                 lnk[l] = 0;
 365                                 /* A link already pointing to the
 366                                  * right place -- no further action
 367                                  * required. */
 368                                 if (strcmp(lnk,file->u.link) == 0) {
 369                                         set_perms(fname, file, &st,
 370                                                   PERMS_REPORT);
 371                                         return;
 372                                 }
 373                         }
 374                         /* Not a symlink, so delete whatever's
 375                          * already there and put a new symlink
 376                          * in place. */
 377                         delete_file(fname);
 378                 }
 379                 if (do_symlink(file->u.link,fname) != 0) {
 380                         rsyserr(FERROR, errno, "symlink %s -> \"%s\" failed",
 381                                 full_fname(fname), file->u.link);
 382                 } else {
 383                         set_perms(fname,file,NULL,0);
 384                         if (verbose) {
 385                                 rprintf(FINFO,"%s -> %s\n", fname,file->u.link);
 386                         }
 387                 }
 388 #endif
 389                 return;
 390         }
 391
 392 #ifdef HAVE_MKNOD
 393         if (am_root && preserve_devices && IS_DEVICE(file->mode)) {
 394                 if (statret != 0 ||
 395                     st.st_mode != file->mode ||
 396                     st.st_rdev != file->u.rdev) {
 397                         delete_file(fname);
 398                         if (verbose > 2) {
 399                                 rprintf(FINFO,"mknod(%s,0%o,0x%x)\n",
 400                                         fname,(int)file->mode,(int)file->u.rdev);
 401                         }
 402                         if (do_mknod(fname,file->mode,file->u.rdev) != 0) {
 403                                 rsyserr(FERROR, errno, "mknod %s failed",
 404                                         full_fname(fname));
 405                         } else {
 406                                 set_perms(fname,file,NULL,0);
 407                                 if (verbose)
 408                                         rprintf(FINFO,"%s\n",fname);
 409                         }
 410                 } else {
 411                         set_perms(fname, file, &st, PERMS_REPORT);
 412                 }
 413                 return;
 414         }
 415 #endif
 416
 417         if (preserve_hard_links && hard_link_check(file, HL_CHECK_MASTER))
 418                 return;
 419
 420         if (!S_ISREG(file->mode)) {
 421                 rprintf(FINFO, "skipping non-regular file \"%s\"\n",fname);
 422                 return;
 423         }
 424
 425         fnamecmp = fname;
 426
 427         if (statret == -1 && compare_dest != NULL) {
 428                 /* try the file at compare_dest instead */
 429                 int saveerrno = errno;
 430                 pathjoin(fnamecmpbuf, sizeof fnamecmpbuf, compare_dest, fname);
 431                 statret = link_stat(fnamecmpbuf, &st, 0);
 432                 if (!S_ISREG(st.st_mode))
 433                         statret = -1;
 434                 if (statret == -1)
 435                         errno = saveerrno;
 436 #if HAVE_LINK
 437                 else if (link_dest && !dry_run) {
 438                         if (do_link(fnamecmpbuf, fname) != 0) {
 439                                 if (verbose > 0) {
 440                                         rsyserr(FINFO, errno, "link %s => %s",
 441                                                 fnamecmpbuf, fname);
 442                                 }
 443                         }
 444                         fnamecmp = fnamecmpbuf;
 445                 }
 446 #endif
 447                 else
 448                         fnamecmp = fnamecmpbuf;
 449         }
 450
 451         if (statret == -1) {
 452                 if (preserve_hard_links && hard_link_check(file, HL_SKIP))
 453                         return;
 454                 if (errno == ENOENT) {
 455                         write_int(f_out,i);
 456                         if (!dry_run)
 457                                 write_sum_head(f_out, NULL);
 458                 } else if (verbose > 1) {
 459                         rsyserr(FERROR, errno,
 460                                 "recv_generator: failed to open %s",
 461                                 full_fname(fname));
 462                 }
 463                 return;
 464         }
 465
 466         if (!S_ISREG(st.st_mode)) {
 467                 if (delete_file(fname) != 0) {
 468                         return;
 469                 }
 470
 471                 /* now pretend the file didn't exist */
 472                 if (preserve_hard_links && hard_link_check(file, HL_SKIP))
 473                         return;
 474                 write_int(f_out,i);
 475                 if (!dry_run)
 476                         write_sum_head(f_out, NULL);
 477                 return;
 478         }
 479
 480         if (opt_ignore_existing && fnamecmp == fname) {
 481                 if (verbose > 1)
 482                         rprintf(FINFO,"%s exists\n",fname);
 483                 return;
 484         }
 485
 486         if (update_only && fnamecmp == fname
 487             && cmp_modtime(st.st_mtime, file->modtime) > 0) {
 488                 if (verbose > 1)
 489                         rprintf(FINFO,"%s is newer\n",fname);
 490                 return;
 491         }
 492
 493         if (skip_file(fname, file, &st)) {
 494                 if (fnamecmp == fname)
 495                         set_perms(fname, file, &st, PERMS_REPORT);
 496                 return;
 497         }
 498
 499         if (dry_run) {
 500                 write_int(f_out,i);
 501                 return;
 502         }
 503
 504         if (disable_deltas_p()) {
 505                 write_int(f_out,i);
 506                 write_sum_head(f_out, NULL);
 507                 return;
 508         }
 509
 510         /* open the file */
 511         fd = do_open(fnamecmp, O_RDONLY, 0);
 512
 513         if (fd == -1) {
 514                 rsyserr(FERROR, errno, "failed to open %s, continuing",
 515                         full_fname(fnamecmp));
 516                 /* pretend the file didn't exist */
 517                 if (preserve_hard_links && hard_link_check(file, HL_SKIP))
 518                         return;
 519                 write_int(f_out,i);
 520                 write_sum_head(f_out, NULL);
 521                 return;
 522         }
 523
 524         if (st.st_size > 0)
 525                 mapbuf = map_file(fd,st.st_size);
 526         else
 527                 mapbuf = NULL;
 528
 529         if (verbose > 3) {
 530                 rprintf(FINFO,"gen mapped %s of size %.0f\n", fnamecmp,
 531                         (double)st.st_size);
 532         }
 533
 534         if (verbose > 2)
 535                 rprintf(FINFO, "generating and sending sums for %d\n", i);
 536
 537         write_int(f_out,i);
 538         generate_and_send_sums(mapbuf, st.st_size, f_out);
 539
 540         close(fd);
 541         if (mapbuf)
 542                 unmap_file(mapbuf);
 543 }
 544
 545
 546 void generate_files(int f, struct file_list *flist, char *local_name)
 547 {
 548         int i;
 549         int phase=0;
 550         char fbuf[MAXPATHLEN];
 551
 552         if (verbose > 2) {
 553                 rprintf(FINFO, "generator starting pid=%ld count=%d\n",
 554                         (long)getpid(), flist->count);
 555         }
 556
 557         if (verbose >= 2) {
 558                 rprintf(FINFO,
 559                         disable_deltas_p()
 560                         ? "delta-transmission disabled for local transfer or --whole-file\n"
 561                         : "delta transmission enabled\n");
 562         }
 563
 564         /* we expect to just sit around now, so don't exit on a
 565            timeout. If we really get a timeout then the other process should
 566            exit */
 567         io_timeout = 0;
 568
 569         for (i = 0; i < flist->count; i++) {
 570                 struct file_struct *file = flist->files[i];
 571                 struct file_struct copy;
 572
 573                 if (!file->basename)
 574                         continue;
 575                 /* we need to ensure that any directories we create have writeable
 576                    permissions initially so that we can create the files within
 577                    them. This is then fixed after the files are transferred */
 578                 if (!am_root && S_ISDIR(file->mode) && !(file->mode & S_IWUSR)) {
 579                         copy = *file;
 580                         /* XXX: Could this be causing a problem on SCO?  Perhaps their
 581                          * handling of permissions is strange? */
 582                         copy.mode |= S_IWUSR; /* user write */
 583                         file = &copy;
 584                 }
 585
 586                 recv_generator(local_name ? local_name : f_name_to(file, fbuf),
 587                                file, i, f);
 588         }
 589
 590         phase++;
 591         csum_length = SUM_LENGTH;
 592         ignore_times=1;
 593
 594         if (verbose > 2)
 595                 rprintf(FINFO,"generate_files phase=%d\n",phase);
 596
 597         write_int(f,-1);
 598
 599         /* files can cycle through the system more than once
 600          * to catch initial checksum errors */
 601         while ((i = get_redo_num()) != -1) {
 602                 struct file_struct *file = flist->files[i];
 603                 recv_generator(local_name ? local_name : f_name_to(file, fbuf),
 604                                file, i, f);
 605         }
 606
 607         phase++;
 608         if (verbose > 2)
 609                 rprintf(FINFO,"generate_files phase=%d\n",phase);
 610
 611         write_int(f,-1);
 612
 613         if (preserve_hard_links)
 614                 do_hard_links();
 615
 616         /* now we need to fix any directory permissions that were
 617          * modified during the transfer */
 618         for (i = 0; i < flist->count; i++) {
 619                 struct file_struct *file = flist->files[i];
 620                 if (!file->basename || !S_ISDIR(file->mode))
 621                         continue;
 622                 recv_generator(local_name ? local_name : f_name(file),
 623                                file, i, -1);
 624         }
 625
 626         if (verbose > 2)
 627                 rprintf(FINFO,"generate_files finished\n");
 628 }