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);
 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 SUPPORT_LINKS
 307         if (statret == 0 && keep_dirlinks
 308             && S_ISLNK(st.st_mode) && S_ISDIR(file->mode)) {
 309                 STRUCT_STAT st2;
 310                 if (do_stat(fname, &st2) == 0 && S_ISDIR(st2.st_mode))
 311                     st = st2;
 312         }
 313 #endif
 314
 315         if (statret == 0 &&
 316             !preserve_perms &&
 317             (S_ISDIR(st.st_mode) == S_ISDIR(file->mode))) {
 318                 /* if the file exists already and we aren't perserving
 319                  * permissions then act as though the remote end sent
 320                  * us the file permissions we already have */
 321                 file->mode = (file->mode & ~CHMOD_BITS)
 322                            | (st.st_mode & CHMOD_BITS);
 323         }
 324
 325         if (S_ISDIR(file->mode)) {
 326                 /* The file to be received is a directory, so we need
 327                  * to prepare appropriately.  If there is already a
 328                  * file of that name and it is *not* a directory, then
 329                  * we need to delete it.  If it doesn't exist, then
 330                  * recursively create it. */
 331
 332                 if (dry_run) return; /* XXXX -- might cause inaccuracies?? -- mbp */
 333                 if (statret == 0 && !S_ISDIR(st.st_mode)) {
 334                         if (robust_unlink(fname) != 0) {
 335                                 rsyserr(FERROR, errno,
 336                                         "recv_generator: unlink %s to make room for directory",
 337                                         full_fname(fname));
 338                                 return;
 339                         }
 340                         statret = -1;
 341                 }
 342                 if (statret != 0 && do_mkdir(fname,file->mode) != 0 && errno != EEXIST) {
 343                         if (!(relative_paths && errno == ENOENT
 344                             && create_directory_path(fname, orig_umask) == 0
 345                             && do_mkdir(fname, file->mode) == 0)) {
 346                                 rsyserr(FERROR, errno,
 347                                         "recv_generator: mkdir %s failed",
 348                                         full_fname(fname));
 349                         }
 350                 }
 351                 /* f_out is set to -1 when doing final directory-permission
 352                  * and modification-time repair. */
 353                 if (set_perms(fname, file, statret ? NULL : &st, 0)
 354                     && verbose && f_out != -1)
 355                         rprintf(FINFO,"%s/\n",fname);
 356                 return;
 357         }
 358
 359         if (preserve_links && S_ISLNK(file->mode)) {
 360 #if SUPPORT_LINKS
 361                 char lnk[MAXPATHLEN];
 362                 int l;
 363
 364                 if (safe_symlinks && unsafe_symlink(file->u.link, fname)) {
 365                         if (verbose) {
 366                                 rprintf(FINFO, "ignoring unsafe symlink %s -> \"%s\"\n",
 367                                         full_fname(fname), file->u.link);
 368                         }
 369                         return;
 370                 }
 371                 if (statret == 0) {
 372                         l = readlink(fname,lnk,MAXPATHLEN-1);
 373                         if (l > 0) {
 374                                 lnk[l] = 0;
 375                                 /* A link already pointing to the
 376                                  * right place -- no further action
 377                                  * required. */
 378                                 if (strcmp(lnk,file->u.link) == 0) {
 379                                         set_perms(fname, file, &st,
 380                                                   PERMS_REPORT);
 381                                         return;
 382                                 }
 383                         }
 384                         /* Not a symlink, so delete whatever's
 385                          * already there and put a new symlink
 386                          * in place. */
 387                         delete_file(fname);
 388                 }
 389                 if (do_symlink(file->u.link,fname) != 0) {
 390                         rsyserr(FERROR, errno, "symlink %s -> \"%s\" failed",
 391                                 full_fname(fname), file->u.link);
 392                 } else {
 393                         set_perms(fname,file,NULL,0);
 394                         if (verbose) {
 395                                 rprintf(FINFO,"%s -> %s\n", fname,file->u.link);
 396                         }
 397                 }
 398 #endif
 399                 return;
 400         }
 401
 402 #ifdef HAVE_MKNOD
 403         if (am_root && preserve_devices && IS_DEVICE(file->mode)) {
 404                 if (statret != 0 ||
 405                     st.st_mode != file->mode ||
 406                     st.st_rdev != file->u.rdev) {
 407                         delete_file(fname);
 408                         if (verbose > 2) {
 409                                 rprintf(FINFO,"mknod(%s,0%o,0x%x)\n",
 410                                         fname,(int)file->mode,(int)file->u.rdev);
 411                         }
 412                         if (do_mknod(fname,file->mode,file->u.rdev) != 0) {
 413                                 rsyserr(FERROR, errno, "mknod %s failed",
 414                                         full_fname(fname));
 415                         } else {
 416                                 set_perms(fname,file,NULL,0);
 417                                 if (verbose)
 418                                         rprintf(FINFO,"%s\n",fname);
 419                         }
 420                 } else {
 421                         set_perms(fname, file, &st, PERMS_REPORT);
 422                 }
 423                 return;
 424         }
 425 #endif
 426
 427         if (preserve_hard_links && hard_link_check(file, HL_CHECK_MASTER))
 428                 return;
 429
 430         if (!S_ISREG(file->mode)) {
 431                 rprintf(FINFO, "skipping non-regular file \"%s\"\n",fname);
 432                 return;
 433         }
 434
 435         fnamecmp = fname;
 436
 437         if (statret == -1 && compare_dest != NULL) {
 438                 /* try the file at compare_dest instead */
 439                 int saveerrno = errno;
 440                 pathjoin(fnamecmpbuf, sizeof fnamecmpbuf, compare_dest, fname);
 441                 statret = link_stat(fnamecmpbuf,&st);
 442                 if (!S_ISREG(st.st_mode))
 443                         statret = -1;
 444                 if (statret == -1)
 445                         errno = saveerrno;
 446 #if HAVE_LINK
 447                 else if (link_dest && !dry_run) {
 448                         if (do_link(fnamecmpbuf, fname) != 0) {
 449                                 if (verbose > 0) {
 450                                         rsyserr(FINFO, errno, "link %s => %s",
 451                                                 fnamecmpbuf, fname);
 452                                 }
 453                         }
 454                         fnamecmp = fnamecmpbuf;
 455                 }
 456 #endif
 457                 else
 458                         fnamecmp = fnamecmpbuf;
 459         }
 460
 461         if (statret == -1) {
 462                 if (preserve_hard_links && hard_link_check(file, HL_SKIP))
 463                         return;
 464                 if (errno == ENOENT) {
 465                         write_int(f_out,i);
 466                         if (!dry_run) write_sum_head(f_out, NULL);
 467                 } else if (verbose > 1) {
 468                         rsyserr(FERROR, errno,
 469                                 "recv_generator: failed to open %s",
 470                                 full_fname(fname));
 471                 }
 472                 return;
 473         }
 474
 475         if (!S_ISREG(st.st_mode)) {
 476                 if (delete_file(fname) != 0) {
 477                         return;
 478                 }
 479
 480                 /* now pretend the file didn't exist */
 481                 if (preserve_hard_links && hard_link_check(file, HL_SKIP))
 482                         return;
 483                 write_int(f_out,i);
 484                 if (!dry_run) write_sum_head(f_out, NULL);
 485                 return;
 486         }
 487
 488         if (opt_ignore_existing && fnamecmp == fname) {
 489                 if (verbose > 1)
 490                         rprintf(FINFO,"%s exists\n",fname);
 491                 return;
 492         }
 493
 494         if (update_only && cmp_modtime(st.st_mtime,file->modtime)>0 && fnamecmp == fname) {
 495                 if (verbose > 1)
 496                         rprintf(FINFO,"%s is newer\n",fname);
 497                 return;
 498         }
 499
 500         if (skip_file(fname, file, &st)) {
 501                 if (fnamecmp == fname)
 502                         set_perms(fname, file, &st, PERMS_REPORT);
 503                 return;
 504         }
 505
 506         if (dry_run) {
 507                 write_int(f_out,i);
 508                 return;
 509         }
 510
 511         if (disable_deltas_p()) {
 512                 write_int(f_out,i);
 513                 write_sum_head(f_out, NULL);
 514                 return;
 515         }
 516
 517         /* open the file */
 518         fd = do_open(fnamecmp, O_RDONLY, 0);
 519
 520         if (fd == -1) {
 521                 rsyserr(FERROR, errno, "failed to open %s, continuing",
 522                         full_fname(fnamecmp));
 523                 /* pretend the file didn't exist */
 524                 if (preserve_hard_links && hard_link_check(file, HL_SKIP))
 525                         return;
 526                 write_int(f_out,i);
 527                 write_sum_head(f_out, NULL);
 528                 return;
 529         }
 530
 531         if (st.st_size > 0)
 532                 mapbuf = map_file(fd,st.st_size);
 533         else
 534                 mapbuf = NULL;
 535
 536         if (verbose > 3) {
 537                 rprintf(FINFO,"gen mapped %s of size %.0f\n", fnamecmp,
 538                         (double)st.st_size);
 539         }
 540
 541         if (verbose > 2)
 542                 rprintf(FINFO, "generating and sending sums for %d\n", i);
 543
 544         write_int(f_out,i);
 545         generate_and_send_sums(mapbuf, st.st_size, f_out);
 546
 547         close(fd);
 548         if (mapbuf) unmap_file(mapbuf);
 549 }
 550
 551
 552 void generate_files(int f, struct file_list *flist, char *local_name)
 553 {
 554         int i;
 555         int phase=0;
 556         char fbuf[MAXPATHLEN];
 557
 558         if (verbose > 2) {
 559                 rprintf(FINFO, "generator starting pid=%ld count=%d\n",
 560                         (long)getpid(), flist->count);
 561         }
 562
 563         if (verbose >= 2) {
 564                 rprintf(FINFO,
 565                         disable_deltas_p()
 566                         ? "delta-transmission disabled for local transfer or --whole-file\n"
 567                         : "delta transmission enabled\n");
 568         }
 569
 570         /* we expect to just sit around now, so don't exit on a
 571            timeout. If we really get a timeout then the other process should
 572            exit */
 573         io_timeout = 0;
 574
 575         for (i = 0; i < flist->count; i++) {
 576                 struct file_struct *file = flist->files[i];
 577                 struct file_struct copy;
 578
 579                 if (!file->basename)
 580                         continue;
 581                 /* we need to ensure that any directories we create have writeable
 582                    permissions initially so that we can create the files within
 583                    them. This is then fixed after the files are transferred */
 584                 if (!am_root && S_ISDIR(file->mode) && !(file->mode & S_IWUSR)) {
 585                         copy = *file;
 586                         /* XXX: Could this be causing a problem on SCO?  Perhaps their
 587                          * handling of permissions is strange? */
 588                         copy.mode |= S_IWUSR; /* user write */
 589                         file = &copy;
 590                 }
 591
 592                 recv_generator(local_name ? local_name : f_name_to(file, fbuf),
 593                                file, i, f);
 594         }
 595
 596         phase++;
 597         csum_length = SUM_LENGTH;
 598         ignore_times=1;
 599
 600         if (verbose > 2)
 601                 rprintf(FINFO,"generate_files phase=%d\n",phase);
 602
 603         write_int(f,-1);
 604
 605         /* files can cycle through the system more than once
 606          * to catch initial checksum errors */
 607         while ((i = get_redo_num()) != -1) {
 608                 struct file_struct *file = flist->files[i];
 609                 recv_generator(local_name ? local_name : f_name_to(file, fbuf),
 610                                file, i, f);
 611         }
 612
 613         phase++;
 614         if (verbose > 2)
 615                 rprintf(FINFO,"generate_files phase=%d\n",phase);
 616
 617         write_int(f,-1);
 618
 619         if (preserve_hard_links)
 620                 do_hard_links();
 621
 622         /* now we need to fix any directory permissions that were
 623          * modified during the transfer */
 624         for (i = 0; i < flist->count; i++) {
 625                 struct file_struct *file = flist->files[i];
 626                 if (!file->basename || !S_ISDIR(file->mode)) continue;
 627                 recv_generator(local_name ? local_name : f_name(file),
 628                                file, i, -1);
 629         }
 630
 631         if (verbose > 2)
 632                 rprintf(FINFO,"generate_files finished\n");
 633 }