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
  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         }
  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
 100         if (ignore_times) {
 101                 return 0;
 102         }
 103
 104         return (cmp_modtime(st->st_mtime,file->modtime) == 0);
 105 }
 106
 107
 108 /*
 109  * NULL sum_struct means we have no checksums
 110  */
 111 void write_sum_head(int f, struct sum_struct *sum)
 112 {
 113         static struct sum_struct null_sum;
 114
 115         if (sum == NULL)
 116                 sum = &null_sum;
 117
 118         write_int(f, sum->count);
 119         write_int(f, sum->blength);
 120         if (protocol_version >= 27)
 121                 write_int(f, sum->s2length);
 122         write_int(f, sum->remainder);
 123 }
 124
 125 /*
 126  * set (initialize) the size entries in the per-file sum_struct
 127  * calulating dynamic block ans checksum sizes.
 128  *
 129  * This is only called from generate_and_send_sums() but is a seperate
 130  * function to encapsulate the logic.
 131  *
 132  * The block size is a rounded square root of file length.
 133  *
 134  * The checksum size is determined according to:
 135  *     blocksum_bits = BLOCKSUM_EXP + 2*log2(file_len) - log2(block_len)
 136  * provided by Donovan Baarda which gives a probability of rsync
 137  * algorithm corrupting data and falling back using the whole md4
 138  * checksums.
 139  *
 140  * This might be made one of several selectable heuristics.
 141  */
 142
 143 static void sum_sizes_sqroot(struct sum_struct *sum, uint64 len)
 144 {
 145         extern unsigned int block_size;
 146         unsigned int blength;
 147         int s2length;
 148         uint32 c;
 149         uint64 l;
 150
 151         if (block_size) {
 152                 blength = block_size;
 153         } else if (len <= BLOCK_SIZE * BLOCK_SIZE) {
 154                 blength = BLOCK_SIZE;
 155         } else {
 156                 l = len;
 157                 c = 1;
 158                 while (l >>= 2) {
 159                         c <<= 1;
 160                 }
 161                 blength = 0;
 162                 do {
 163                         blength |= c;
 164                         if (len < (uint64)blength * blength)
 165                                 blength &= ~c;
 166                         c >>= 1;
 167                 } while (c >= 8);       /* round to multiple of 8 */
 168                 blength = MAX(blength, BLOCK_SIZE);
 169         }
 170
 171         if (protocol_version < 27) {
 172                 s2length = csum_length;
 173         } else if (csum_length == SUM_LENGTH) {
 174                 s2length = SUM_LENGTH;
 175         } else {
 176                 int b = BLOCKSUM_BIAS;
 177                 l = len;
 178                 while (l >>= 1) {
 179                         b += 2;
 180                 }
 181                 c = blength;
 182                 while (c >>= 1 && b) {
 183                         b--;
 184                 }
 185                 s2length = (b + 1 - 32 + 7) / 8; /* add a bit,
 186                                                   * subtract rollsum,
 187                                                   * round up
 188                                                   *    --optimize in compiler--
 189                                                   */
 190                 s2length = MAX(s2length, csum_length);
 191                 s2length = MIN(s2length, SUM_LENGTH);
 192         }
 193
 194         sum->flength    = len;
 195         sum->blength    = blength;
 196         sum->s2length   = s2length;
 197         sum->count      = (len + (blength - 1)) / blength;
 198         sum->remainder  = (len % blength);
 199
 200         if (sum->count && verbose > 2) {
 201                 rprintf(FINFO, "count=%.0f rem=%u blength=%u s2length=%d flength=%.0f\n",
 202                         (double)sum->count, sum->remainder, sum->blength,
 203                         sum->s2length, (double)sum->flength);
 204         }
 205 }
 206
 207 /**
 208  * Perhaps we want to just send an empty checksum set for this file,
 209  * which will force the whole thing to be literally transferred.
 210  *
 211  * When do we do this?  If the user's explicitly said they
 212  * want the whole thing, or if { they haven't explicitly
 213  * requested a delta, and it's local but not batch mode.}
 214  *
 215  * Whew. */
 216 static BOOL disable_deltas_p(void)
 217 {
 218         if (whole_file > 0)
 219                 return True;
 220         if (whole_file == 0 || write_batch || read_batch)
 221                 return False;
 222         return local_server;
 223 }
 224
 225
 226 /*
 227  * Generate and send a stream of signatures/checksums that describe a buffer
 228  *
 229  * Generate approximately one checksum every block_len bytes.
 230  */
 231 static void generate_and_send_sums(struct map_struct *buf, size_t len, int f_out)
 232 {
 233         size_t i;
 234         struct sum_struct sum;
 235         OFF_T offset = 0;
 236
 237         sum_sizes_sqroot(&sum, len);
 238
 239         write_sum_head(f_out, &sum);
 240
 241         for (i = 0; i < sum.count; i++) {
 242                 unsigned int n1 = MIN(len, sum.blength);
 243                 char *map = map_ptr(buf, offset, n1);
 244                 uint32 sum1 = get_checksum1(map, n1);
 245                 char sum2[SUM_LENGTH];
 246
 247                 get_checksum2(map, n1, sum2);
 248
 249                 if (verbose > 3) {
 250                         rprintf(FINFO,
 251                                 "chunk[%.0f] offset=%.0f len=%u sum1=%08lx\n",
 252                                 (double)i, (double)offset, n1,
 253                                 (unsigned long)sum1);
 254                 }
 255                 write_int(f_out, sum1);
 256                 write_buf(f_out, sum2, sum.s2length);
 257                 len -= n1;
 258                 offset += n1;
 259         }
 260 }
 261
 262
 263
 264 /**
 265  * Acts on file number @p i from @p flist, whose name is @p fname.
 266  *
 267  * First fixes up permissions, then generates checksums for the file.
 268  *
 269  * @note This comment was added later by mbp who was trying to work it
 270  * out.  It might be wrong.
 271  **/
 272 void recv_generator(char *fname, struct file_struct *file, int i, int f_out)
 273 {
 274         int fd;
 275         STRUCT_STAT st;
 276         struct map_struct *mapbuf;
 277         int statret;
 278         char *fnamecmp;
 279         char fnamecmpbuf[MAXPATHLEN];
 280
 281         if (list_only)
 282                 return;
 283
 284         if (verbose > 2)
 285                 rprintf(FINFO,"recv_generator(%s,%d)\n",fname,i);
 286
 287         if (server_exclude_list.head
 288             && check_exclude(&server_exclude_list, fname,
 289                              S_ISDIR(file->mode)) < 0) {
 290                 if (verbose) {
 291                         rprintf(FINFO, "skipping server-excluded file \"%s\"\n",
 292                                 fname);
 293                 }
 294                 return;
 295         }
 296
 297         statret = link_stat(fname, &st, keep_dirlinks && S_ISDIR(file->mode));
 298
 299         if (only_existing && statret == -1 && errno == ENOENT) {
 300                 /* we only want to update existing files */
 301                 if (verbose > 1)
 302                         rprintf(FINFO, "not creating new file \"%s\"\n", fname);
 303                 return;
 304         }
 305
 306         if (statret == 0 &&
 307             !preserve_perms &&
 308             (S_ISDIR(st.st_mode) == S_ISDIR(file->mode))) {
 309                 /* if the file exists already and we aren't perserving
 310                  * permissions then act as though the remote end sent
 311                  * us the file permissions we already have */
 312                 file->mode = (file->mode & ~CHMOD_BITS)
 313                            | (st.st_mode & CHMOD_BITS);
 314         }
 315
 316         if (S_ISDIR(file->mode)) {
 317                 /* The file to be received is a directory, so we need
 318                  * to prepare appropriately.  If there is already a
 319                  * file of that name and it is *not* a directory, then
 320                  * we need to delete it.  If it doesn't exist, then
 321                  * recursively create it. */
 322
 323                 if (dry_run) return; /* XXXX -- might cause inaccuracies?? -- mbp */
 324                 if (statret == 0 && !S_ISDIR(st.st_mode)) {
 325                         if (robust_unlink(fname) != 0) {
 326                                 rsyserr(FERROR, errno,
 327                                         "recv_generator: unlink %s to make room for directory",
 328                                         full_fname(fname));
 329                                 return;
 330                         }
 331                         statret = -1;
 332                 }
 333                 if (statret != 0 && do_mkdir(fname,file->mode) != 0 && errno != EEXIST) {
 334                         if (!(relative_paths && errno == ENOENT
 335                             && create_directory_path(fname, orig_umask) == 0
 336                             && do_mkdir(fname, file->mode) == 0)) {
 337                                 rsyserr(FERROR, errno,
 338                                         "recv_generator: mkdir %s failed",
 339                                         full_fname(fname));
 340                         }
 341                 }
 342                 /* f_out is set to -1 when doing final directory-permission
 343                  * and modification-time repair. */
 344                 if (set_perms(fname, file, statret ? NULL : &st, 0)
 345                     && verbose && f_out != -1)
 346                         rprintf(FINFO,"%s/\n",fname);
 347                 return;
 348         }
 349
 350         if (preserve_links && S_ISLNK(file->mode)) {
 351 #if SUPPORT_LINKS
 352                 char lnk[MAXPATHLEN];
 353                 int l;
 354
 355                 if (safe_symlinks && unsafe_symlink(file->u.link, fname)) {
 356                         if (verbose) {
 357                                 rprintf(FINFO, "ignoring unsafe symlink %s -> \"%s\"\n",
 358                                         full_fname(fname), file->u.link);
 359                         }
 360                         return;
 361                 }
 362                 if (statret == 0) {
 363                         l = readlink(fname,lnk,MAXPATHLEN-1);
 364                         if (l > 0) {
 365                                 lnk[l] = 0;
 366                                 /* A link already pointing to the
 367                                  * right place -- no further action
 368                                  * required. */
 369                                 if (strcmp(lnk,file->u.link) == 0) {
 370                                         set_perms(fname, file, &st,
 371                                                   PERMS_REPORT);
 372                                         return;
 373                                 }
 374                         }
 375                         /* Not a symlink, so delete whatever's
 376                          * already there and put a new symlink
 377                          * in place. */
 378                         delete_file(fname);
 379                 }
 380                 if (do_symlink(file->u.link,fname) != 0) {
 381                         rsyserr(FERROR, errno, "symlink %s -> \"%s\" failed",
 382                                 full_fname(fname), file->u.link);
 383                 } else {
 384                         set_perms(fname,file,NULL,0);
 385                         if (verbose) {
 386                                 rprintf(FINFO,"%s -> %s\n", fname,file->u.link);
 387                         }
 388                 }
 389 #endif
 390                 return;
 391         }
 392
 393 #ifdef HAVE_MKNOD
 394         if (am_root && preserve_devices && IS_DEVICE(file->mode)) {
 395                 if (statret != 0 ||
 396                     st.st_mode != file->mode ||
 397                     st.st_rdev != file->u.rdev) {
 398                         delete_file(fname);
 399                         if (verbose > 2) {
 400                                 rprintf(FINFO,"mknod(%s,0%o,0x%x)\n",
 401                                         fname,(int)file->mode,(int)file->u.rdev);
 402                         }
 403                         if (do_mknod(fname,file->mode,file->u.rdev) != 0) {
 404                                 rsyserr(FERROR, errno, "mknod %s failed",
 405                                         full_fname(fname));
 406                         } else {
 407                                 set_perms(fname,file,NULL,0);
 408                                 if (verbose)
 409                                         rprintf(FINFO,"%s\n",fname);
 410                         }
 411                 } else {
 412                         set_perms(fname, file, &st, PERMS_REPORT);
 413                 }
 414                 return;
 415         }
 416 #endif
 417
 418         if (preserve_hard_links && hard_link_check(file, HL_CHECK_MASTER))
 419                 return;
 420
 421         if (!S_ISREG(file->mode)) {
 422                 rprintf(FINFO, "skipping non-regular file \"%s\"\n",fname);
 423                 return;
 424         }
 425
 426         fnamecmp = fname;
 427
 428         if (statret == -1 && compare_dest != NULL) {
 429                 /* try the file at compare_dest instead */
 430                 int saveerrno = errno;
 431                 pathjoin(fnamecmpbuf, sizeof fnamecmpbuf, compare_dest, fname);
 432                 statret = link_stat(fnamecmpbuf, &st, 0);
 433                 if (!S_ISREG(st.st_mode))
 434                         statret = -1;
 435                 if (statret == -1)
 436                         errno = saveerrno;
 437 #if HAVE_LINK
 438                 else if (link_dest && !dry_run) {
 439                         if (do_link(fnamecmpbuf, fname) != 0) {
 440                                 if (verbose > 0) {
 441                                         rsyserr(FINFO, errno, "link %s => %s",
 442                                                 fnamecmpbuf, fname);
 443                                 }
 444                         }
 445                         fnamecmp = fnamecmpbuf;
 446                 }
 447 #endif
 448                 else
 449                         fnamecmp = fnamecmpbuf;
 450         }
 451
 452         if (statret == -1) {
 453                 if (preserve_hard_links && hard_link_check(file, HL_SKIP))
 454                         return;
 455                 if (errno == ENOENT) {
 456                         write_int(f_out,i);
 457                         if (!dry_run) 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) write_sum_head(f_out, NULL);
 476                 return;
 477         }
 478
 479         if (opt_ignore_existing && fnamecmp == fname) {
 480                 if (verbose > 1)
 481                         rprintf(FINFO,"%s exists\n",fname);
 482                 return;
 483         }
 484
 485         if (update_only && cmp_modtime(st.st_mtime,file->modtime)>0 && fnamecmp == fname) {
 486                 if (verbose > 1)
 487                         rprintf(FINFO,"%s is newer\n",fname);
 488                 return;
 489         }
 490
 491         if (skip_file(fname, file, &st)) {
 492                 if (fnamecmp == fname)
 493                         set_perms(fname, file, &st, PERMS_REPORT);
 494                 return;
 495         }
 496
 497         if (dry_run) {
 498                 write_int(f_out,i);
 499                 return;
 500         }
 501
 502         if (disable_deltas_p()) {
 503                 write_int(f_out,i);
 504                 write_sum_head(f_out, NULL);
 505                 return;
 506         }
 507
 508         /* open the file */
 509         fd = do_open(fnamecmp, O_RDONLY, 0);
 510
 511         if (fd == -1) {
 512                 rsyserr(FERROR, errno, "failed to open %s, continuing",
 513                         full_fname(fnamecmp));
 514                 /* pretend the file didn't exist */
 515                 if (preserve_hard_links && hard_link_check(file, HL_SKIP))
 516                         return;
 517                 write_int(f_out,i);
 518                 write_sum_head(f_out, NULL);
 519                 return;
 520         }
 521
 522         if (st.st_size > 0)
 523                 mapbuf = map_file(fd,st.st_size);
 524         else
 525                 mapbuf = NULL;
 526
 527         if (verbose > 3) {
 528                 rprintf(FINFO,"gen mapped %s of size %.0f\n", fnamecmp,
 529                         (double)st.st_size);
 530         }
 531
 532         if (verbose > 2)
 533                 rprintf(FINFO, "generating and sending sums for %d\n", i);
 534
 535         write_int(f_out,i);
 536         generate_and_send_sums(mapbuf, st.st_size, f_out);
 537
 538         close(fd);
 539         if (mapbuf) unmap_file(mapbuf);
 540 }
 541
 542
 543 void generate_files(int f, struct file_list *flist, char *local_name)
 544 {
 545         int i;
 546         int phase=0;
 547         char fbuf[MAXPATHLEN];
 548
 549         if (verbose > 2) {
 550                 rprintf(FINFO, "generator starting pid=%ld count=%d\n",
 551                         (long)getpid(), flist->count);
 552         }
 553
 554         if (verbose >= 2) {
 555                 rprintf(FINFO,
 556                         disable_deltas_p()
 557                         ? "delta-transmission disabled for local transfer or --whole-file\n"
 558                         : "delta transmission enabled\n");
 559         }
 560
 561         /* we expect to just sit around now, so don't exit on a
 562            timeout. If we really get a timeout then the other process should
 563            exit */
 564         io_timeout = 0;
 565
 566         for (i = 0; i < flist->count; i++) {
 567                 struct file_struct *file = flist->files[i];
 568                 struct file_struct copy;
 569
 570                 if (!file->basename)
 571                         continue;
 572                 /* we need to ensure that any directories we create have writeable
 573                    permissions initially so that we can create the files within
 574                    them. This is then fixed after the files are transferred */
 575                 if (!am_root && S_ISDIR(file->mode) && !(file->mode & S_IWUSR)) {
 576                         copy = *file;
 577                         /* XXX: Could this be causing a problem on SCO?  Perhaps their
 578                          * handling of permissions is strange? */
 579                         copy.mode |= S_IWUSR; /* user write */
 580                         file = &copy;
 581                 }
 582
 583                 recv_generator(local_name ? local_name : f_name_to(file, fbuf),
 584                                file, i, f);
 585         }
 586
 587         phase++;
 588         csum_length = SUM_LENGTH;
 589         ignore_times=1;
 590
 591         if (verbose > 2)
 592                 rprintf(FINFO,"generate_files phase=%d\n",phase);
 593
 594         write_int(f,-1);
 595
 596         /* files can cycle through the system more than once
 597          * to catch initial checksum errors */
 598         while ((i = get_redo_num()) != -1) {
 599                 struct file_struct *file = flist->files[i];
 600                 recv_generator(local_name ? local_name : f_name_to(file, fbuf),
 601                                file, i, f);
 602         }
 603
 604         phase++;
 605         if (verbose > 2)
 606                 rprintf(FINFO,"generate_files phase=%d\n",phase);
 607
 608         write_int(f,-1);
 609
 610         if (preserve_hard_links)
 611                 do_hard_links();
 612
 613         /* now we need to fix any directory permissions that were
 614          * modified during the transfer */
 615         for (i = 0; i < flist->count; i++) {
 616                 struct file_struct *file = flist->files[i];
 617                 if (!file->basename || !S_ISDIR(file->mode)) continue;
 618                 recv_generator(local_name ? local_name : f_name(file),
 619                                file, i, -1);
 620         }
 621
 622         if (verbose > 2)
 623                 rprintf(FINFO,"generate_files finished\n");
 624 }