token.c

   1 /*
   2  * Routines used by the file-transfer code.
   3  *
   4  * Copyright (C) 1996 Andrew Tridgell
   5  * Copyright (C) 1996 Paul Mackerras
   6  * Copyright (C) 2003-2009 Wayne Davison
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 3 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License along
  19  * with this program; if not, visit the http://fsf.org website.
  20  */
  21
  22 #include "rsync.h"
  23 #include "itypes.h"
  24 #include "zlib/zlib.h"
  25
  26 extern int do_compression;
  27 extern int module_id;
  28 extern int def_compress_level;
  29 extern char *skip_compress;
  30
  31 static int compression_level, per_file_default_level;
  32
  33 struct suffix_tree {
  34         struct suffix_tree *sibling;
  35         struct suffix_tree *child;
  36         char letter, word_end;
  37 };
  38
  39 static char *match_list;
  40 static struct suffix_tree *suftree;
  41
  42 static void add_suffix(struct suffix_tree **prior, char ltr, const char *str)
  43 {
  44         struct suffix_tree *node, *newnode;
  45
  46         if (ltr == '[') {
  47                 const char *after = strchr(str, ']');
  48                 /* Treat "[foo" and "[]" as having a literal '['. */
  49                 if (after && after++ != str+1) {
  50                         while ((ltr = *str++) != ']')
  51                                 add_suffix(prior, ltr, after);
  52                         return;
  53                 }
  54         }
  55
  56         for (node = *prior; node; prior = &node->sibling, node = node->sibling) {
  57                 if (node->letter == ltr) {
  58                         if (*str)
  59                                 add_suffix(&node->child, *str, str+1);
  60                         else
  61                                 node->word_end = 1;
  62                         return;
  63                 }
  64                 if (node->letter > ltr)
  65                         break;
  66         }
  67         if (!(newnode = new(struct suffix_tree)))
  68                 out_of_memory("add_suffix");
  69         newnode->sibling = node;
  70         newnode->child = NULL;
  71         newnode->letter = ltr;
  72         *prior = newnode;
  73         if (*str) {
  74                 add_suffix(&newnode->child, *str, str+1);
  75                 newnode->word_end = 0;
  76         } else
  77                 newnode->word_end = 1;
  78 }
  79
  80 static void add_nocompress_suffixes(const char *str)
  81 {
  82         char *buf, *t;
  83         const char *f = str;
  84
  85         if (!(buf = new_array(char, strlen(f) + 1)))
  86                 out_of_memory("add_nocompress_suffixes");
  87
  88         while (*f) {
  89                 if (*f == '/') {
  90                         f++;
  91                         continue;
  92                 }
  93
  94                 t = buf;
  95                 do {
  96                         if (isUpper(f))
  97                                 *t++ = toLower(f);
  98                         else
  99                                 *t++ = *f;
 100                 } while (*++f != '/' && *f);
 101                 *t++ = '\0';
 102
 103                 add_suffix(&suftree, *buf, buf+1);
 104         }
 105
 106         free(buf);
 107 }
 108
 109 static void init_set_compression(void)
 110 {
 111         const char *f;
 112         char *t, *start;
 113
 114         if (skip_compress)
 115                 add_nocompress_suffixes(skip_compress);
 116
 117         /* A non-daemon transfer skips the default suffix list if the
 118          * user specified --skip-compress. */
 119         if (skip_compress && module_id < 0)
 120                 f = "";
 121         else
 122                 f = lp_dont_compress(module_id);
 123
 124         if (!(match_list = t = new_array(char, strlen(f) + 2)))
 125                 out_of_memory("set_compression");
 126
 127         per_file_default_level = def_compress_level;
 128
 129         while (*f) {
 130                 if (*f == ' ') {
 131                         f++;
 132                         continue;
 133                 }
 134
 135                 start = t;
 136                 do {
 137                         if (isUpper(f))
 138                                 *t++ = toLower(f);
 139                         else
 140                                 *t++ = *f;
 141                 } while (*++f != ' ' && *f);
 142                 *t++ = '\0';
 143
 144                 if (t - start == 1+1 && *start == '*') {
 145                         /* Optimize a match-string of "*". */
 146                         *match_list = '\0';
 147                         suftree = NULL;
 148                         per_file_default_level = 0;
 149                         break;
 150                 }
 151
 152                 /* Move *.foo items into the stuffix tree. */
 153                 if (*start == '*' && start[1] == '.' && start[2]
 154                  && !strpbrk(start+2, ".?*")) {
 155                         add_suffix(&suftree, start[2], start+3);
 156                         t = start;
 157                 }
 158         }
 159         *t++ = '\0';
 160 }
 161
 162 /* determine the compression level based on a wildcard filename list */
 163 void set_compression(const char *fname)
 164 {
 165         const struct suffix_tree *node;
 166         const char *s;
 167         char ltr;
 168
 169         if (!do_compression)
 170                 return;
 171
 172         if (!match_list)
 173                 init_set_compression();
 174
 175         compression_level = per_file_default_level;
 176
 177         if (!*match_list && !suftree)
 178                 return;
 179
 180         if ((s = strrchr(fname, '/')) != NULL)
 181                 fname = s + 1;
 182
 183         for (s = match_list; *s; s += strlen(s) + 1) {
 184                 if (iwildmatch(s, fname)) {
 185                         compression_level = 0;
 186                         return;
 187                 }
 188         }
 189
 190         if (!(node = suftree) || !(s = strrchr(fname, '.'))
 191          || s == fname || !(ltr = *++s))
 192                 return;
 193
 194         while (1) {
 195                 if (isUpper(&ltr))
 196                         ltr = toLower(&ltr);
 197                 while (node->letter != ltr) {
 198                         if (node->letter > ltr)
 199                                 return;
 200                         if (!(node = node->sibling))
 201                                 return;
 202                 }
 203                 if ((ltr = *++s) == '\0') {
 204                         if (node->word_end)
 205                                 compression_level = 0;
 206                         return;
 207                 }
 208                 if (!(node = node->child))
 209                         return;
 210         }
 211 }
 212
 213 /* non-compressing recv token */
 214 static int32 simple_recv_token(int f, char **data)
 215 {
 216         static int32 residue;
 217         static char *buf;
 218         int32 n;
 219
 220         if (!buf) {
 221                 buf = new_array(char, CHUNK_SIZE);
 222                 if (!buf)
 223                         out_of_memory("simple_recv_token");
 224         }
 225
 226         if (residue == 0) {
 227                 int32 i = read_int(f);
 228                 if (i <= 0)
 229                         return i;
 230                 residue = i;
 231         }
 232
 233         *data = buf;
 234         n = MIN(CHUNK_SIZE,residue);
 235         residue -= n;
 236         read_buf(f,buf,n);
 237         return n;
 238 }
 239
 240 /* non-compressing send token */
 241 static void simple_send_token(int f, int32 token, struct map_struct *buf,
 242                               OFF_T offset, int32 n)
 243 {
 244         if (n > 0) {
 245                 int32 len = 0;
 246                 while (len < n) {
 247                         int32 n1 = MIN(CHUNK_SIZE, n-len);
 248                         write_int(f, n1);
 249                         write_buf(f, map_ptr(buf, offset+len, n1), n1);
 250                         len += n1;
 251                 }
 252         }
 253         /* a -2 token means to send data only and no token */
 254         if (token != -2)
 255                 write_int(f, -(token+1));
 256 }
 257
 258 /* Flag bytes in compressed stream are encoded as follows: */
 259 #define END_FLAG        0       /* that's all folks */
 260 #define TOKEN_LONG      0x20    /* followed by 32-bit token number */
 261 #define TOKENRUN_LONG   0x21    /* ditto with 16-bit run count */
 262 #define DEFLATED_DATA   0x40    /* + 6-bit high len, then low len byte */
 263 #define TOKEN_REL       0x80    /* + 6-bit relative token number */
 264 #define TOKENRUN_REL    0xc0    /* ditto with 16-bit run count */
 265
 266 #define MAX_DATA_COUNT  16383   /* fit 14 bit count into 2 bytes with flags */
 267
 268 /* zlib.h says that if we want to be able to compress something in a single
 269  * call, avail_out must be at least 0.1% larger than avail_in plus 12 bytes.
 270  * We'll add in 0.1%+16, just to be safe (and we'll avoid floating point,
 271  * to ensure that this is a compile-time value). */
 272 #define AVAIL_OUT_SIZE(avail_in_size) ((avail_in_size)*1001/1000+16)
 273
 274 /* For coding runs of tokens */
 275 static int32 last_token = -1;
 276 static int32 run_start;
 277 static int32 last_run_end;
 278
 279 /* Deflation state */
 280 static z_stream tx_strm;
 281
 282 /* Output buffer */
 283 static char *obuf;
 284
 285 /* We want obuf to be able to hold both MAX_DATA_COUNT+2 bytes as well as
 286  * AVAIL_OUT_SIZE(CHUNK_SIZE) bytes, so make sure that it's large enough. */
 287 #if MAX_DATA_COUNT+2 > AVAIL_OUT_SIZE(CHUNK_SIZE)
 288 #define OBUF_SIZE       (MAX_DATA_COUNT+2)
 289 #else
 290 #define OBUF_SIZE       AVAIL_OUT_SIZE(CHUNK_SIZE)
 291 #endif
 292
 293 /* Send a deflated token */
 294 static void
 295 send_deflated_token(int f, int32 token, struct map_struct *buf, OFF_T offset,
 296                     int32 nb, int32 toklen)
 297 {
 298         int32 n, r;
 299         static int init_done, flush_pending;
 300
 301         if (last_token == -1) {
 302                 /* initialization */
 303                 if (!init_done) {
 304                         tx_strm.next_in = NULL;
 305                         tx_strm.zalloc = NULL;
 306                         tx_strm.zfree = NULL;
 307                         if (deflateInit2(&tx_strm, compression_level,
 308                                          Z_DEFLATED, -15, 8,
 309                                          Z_DEFAULT_STRATEGY) != Z_OK) {
 310                                 rprintf(FERROR, "compression init failed\n");
 311                                 exit_cleanup(RERR_PROTOCOL);
 312                         }
 313                         if ((obuf = new_array(char, OBUF_SIZE)) == NULL)
 314                                 out_of_memory("send_deflated_token");
 315                         init_done = 1;
 316                 } else
 317                         deflateReset(&tx_strm);
 318                 last_run_end = 0;
 319                 run_start = token;
 320                 flush_pending = 0;
 321         } else if (last_token == -2) {
 322                 run_start = token;
 323         } else if (nb != 0 || token != last_token + 1
 324                    || token >= run_start + 65536) {
 325                 /* output previous run */
 326                 r = run_start - last_run_end;
 327                 n = last_token - run_start;
 328                 if (r >= 0 && r <= 63) {
 329                         write_byte(f, (n==0? TOKEN_REL: TOKENRUN_REL) + r);
 330                 } else {
 331                         write_byte(f, (n==0? TOKEN_LONG: TOKENRUN_LONG));
 332                         write_int(f, run_start);
 333                 }
 334                 if (n != 0) {
 335                         write_byte(f, n);
 336                         write_byte(f, n >> 8);
 337                 }
 338                 last_run_end = last_token;
 339                 run_start = token;
 340         }
 341
 342         last_token = token;
 343
 344         if (nb != 0 || flush_pending) {
 345                 /* deflate the data starting at offset */
 346                 int flush = Z_NO_FLUSH;
 347                 tx_strm.avail_in = 0;
 348                 tx_strm.avail_out = 0;
 349                 do {
 350                         if (tx_strm.avail_in == 0 && nb != 0) {
 351                                 /* give it some more input */
 352                                 n = MIN(nb, CHUNK_SIZE);
 353                                 tx_strm.next_in = (Bytef *)
 354                                         map_ptr(buf, offset, n);
 355                                 tx_strm.avail_in = n;
 356                                 nb -= n;
 357                                 offset += n;
 358                         }
 359                         if (tx_strm.avail_out == 0) {
 360                                 tx_strm.next_out = (Bytef *)(obuf + 2);
 361                                 tx_strm.avail_out = MAX_DATA_COUNT;
 362                                 if (flush != Z_NO_FLUSH) {
 363                                         /*
 364                                          * We left the last 4 bytes in the
 365                                          * buffer, in case they are the
 366                                          * last 4.  Move them to the front.
 367                                          */
 368                                         memcpy(tx_strm.next_out,
 369                                                obuf+MAX_DATA_COUNT-2, 4);
 370                                         tx_strm.next_out += 4;
 371                                         tx_strm.avail_out -= 4;
 372                                 }
 373                         }
 374                         if (nb == 0 && token != -2)
 375                                 flush = Z_SYNC_FLUSH;
 376                         r = deflate(&tx_strm, flush);
 377                         if (r != Z_OK) {
 378                                 rprintf(FERROR, "deflate returned %d\n", r);
 379                                 exit_cleanup(RERR_STREAMIO);
 380                         }
 381                         if (nb == 0 || tx_strm.avail_out == 0) {
 382                                 n = MAX_DATA_COUNT - tx_strm.avail_out;
 383                                 if (flush != Z_NO_FLUSH) {
 384                                         /*
 385                                          * We have to trim off the last 4
 386                                          * bytes of output when flushing
 387                                          * (they are just 0, 0, ff, ff).
 388                                          */
 389                                         n -= 4;
 390                                 }
 391                                 if (n > 0) {
 392                                         obuf[0] = DEFLATED_DATA + (n >> 8);
 393                                         obuf[1] = n;
 394                                         write_buf(f, obuf, n+2);
 395                                 }
 396                         }
 397                 } while (nb != 0 || tx_strm.avail_out == 0);
 398                 flush_pending = token == -2;
 399         }
 400
 401         if (token == -1) {
 402                 /* end of file - clean up */
 403                 write_byte(f, END_FLAG);
 404         } else if (token != -2) {
 405                 /* Add the data in the current block to the compressor's
 406                  * history and hash table. */
 407                 do {
 408                         /* Break up long sections in the same way that
 409                          * see_deflate_token() does. */
 410                         int32 n1 = toklen > 0xffff ? 0xffff : toklen;
 411                         toklen -= n1;
 412                         tx_strm.next_in = (Bytef *)map_ptr(buf, offset, n1);
 413                         tx_strm.avail_in = n1;
 414                         tx_strm.next_out = (Bytef *) obuf;
 415                         tx_strm.avail_out = AVAIL_OUT_SIZE(CHUNK_SIZE);
 416                         r = deflate(&tx_strm, Z_INSERT_ONLY);
 417                         if (r != Z_OK || tx_strm.avail_in != 0) {
 418                                 rprintf(FERROR, "deflate on token returned %d (%d bytes left)\n",
 419                                         r, tx_strm.avail_in);
 420                                 exit_cleanup(RERR_STREAMIO);
 421                         }
 422                 } while (toklen > 0);
 423         }
 424 }
 425
 426 /* tells us what the receiver is in the middle of doing */
 427 static enum { r_init, r_idle, r_running, r_inflating, r_inflated } recv_state;
 428
 429 /* for inflating stuff */
 430 static z_stream rx_strm;
 431 static char *cbuf;
 432 static char *dbuf;
 433
 434 /* for decoding runs of tokens */
 435 static int32 rx_token;
 436 static int32 rx_run;
 437
 438 /* Receive a deflated token and inflate it */
 439 static int32 recv_deflated_token(int f, char **data)
 440 {
 441         static int init_done;
 442         static int32 saved_flag;
 443         int32 n, flag;
 444         int r;
 445
 446         for (;;) {
 447                 switch (recv_state) {
 448                 case r_init:
 449                         if (!init_done) {
 450                                 rx_strm.next_out = NULL;
 451                                 rx_strm.zalloc = NULL;
 452                                 rx_strm.zfree = NULL;
 453                                 if (inflateInit2(&rx_strm, -15) != Z_OK) {
 454                                         rprintf(FERROR, "inflate init failed\n");
 455                                         exit_cleanup(RERR_PROTOCOL);
 456                                 }
 457                                 if (!(cbuf = new_array(char, MAX_DATA_COUNT))
 458                                     || !(dbuf = new_array(char, AVAIL_OUT_SIZE(CHUNK_SIZE))))
 459                                         out_of_memory("recv_deflated_token");
 460                                 init_done = 1;
 461                         } else {
 462                                 inflateReset(&rx_strm);
 463                         }
 464                         recv_state = r_idle;
 465                         rx_token = 0;
 466                         break;
 467
 468                 case r_idle:
 469                 case r_inflated:
 470                         if (saved_flag) {
 471                                 flag = saved_flag & 0xff;
 472                                 saved_flag = 0;
 473                         } else
 474                                 flag = read_byte(f);
 475                         if ((flag & 0xC0) == DEFLATED_DATA) {
 476                                 n = ((flag & 0x3f) << 8) + read_byte(f);
 477                                 read_buf(f, cbuf, n);
 478                                 rx_strm.next_in = (Bytef *)cbuf;
 479                                 rx_strm.avail_in = n;
 480                                 recv_state = r_inflating;
 481                                 break;
 482                         }
 483                         if (recv_state == r_inflated) {
 484                                 /* check previous inflated stuff ended correctly */
 485                                 rx_strm.avail_in = 0;
 486                                 rx_strm.next_out = (Bytef *)dbuf;
 487                                 rx_strm.avail_out = AVAIL_OUT_SIZE(CHUNK_SIZE);
 488                                 r = inflate(&rx_strm, Z_SYNC_FLUSH);
 489                                 n = AVAIL_OUT_SIZE(CHUNK_SIZE) - rx_strm.avail_out;
 490                                 /*
 491                                  * Z_BUF_ERROR just means no progress was
 492                                  * made, i.e. the decompressor didn't have
 493                                  * any pending output for us.
 494                                  */
 495                                 if (r != Z_OK && r != Z_BUF_ERROR) {
 496                                         rprintf(FERROR, "inflate flush returned %d (%d bytes)\n",
 497                                                 r, n);
 498                                         exit_cleanup(RERR_STREAMIO);
 499                                 }
 500                                 if (n != 0 && r != Z_BUF_ERROR) {
 501                                         /* have to return some more data and
 502                                            save the flag for later. */
 503                                         saved_flag = flag + 0x10000;
 504                                         *data = dbuf;
 505                                         return n;
 506                                 }
 507                                 /*
 508                                  * At this point the decompressor should
 509                                  * be expecting to see the 0, 0, ff, ff bytes.
 510                                  */
 511                                 if (!inflateSyncPoint(&rx_strm)) {
 512                                         rprintf(FERROR, "decompressor lost sync!\n");
 513                                         exit_cleanup(RERR_STREAMIO);
 514                                 }
 515                                 rx_strm.avail_in = 4;
 516                                 rx_strm.next_in = (Bytef *)cbuf;
 517                                 cbuf[0] = cbuf[1] = 0;
 518                                 cbuf[2] = cbuf[3] = 0xff;
 519                                 inflate(&rx_strm, Z_SYNC_FLUSH);
 520                                 recv_state = r_idle;
 521                         }
 522                         if (flag == END_FLAG) {
 523                                 /* that's all folks */
 524                                 recv_state = r_init;
 525                                 return 0;
 526                         }
 527
 528                         /* here we have a token of some kind */
 529                         if (flag & TOKEN_REL) {
 530                                 rx_token += flag & 0x3f;
 531                                 flag >>= 6;
 532                         } else
 533                                 rx_token = read_int(f);
 534                         if (flag & 1) {
 535                                 rx_run = read_byte(f);
 536                                 rx_run += read_byte(f) << 8;
 537                                 recv_state = r_running;
 538                         }
 539                         return -1 - rx_token;
 540
 541                 case r_inflating:
 542                         rx_strm.next_out = (Bytef *)dbuf;
 543                         rx_strm.avail_out = AVAIL_OUT_SIZE(CHUNK_SIZE);
 544                         r = inflate(&rx_strm, Z_NO_FLUSH);
 545                         n = AVAIL_OUT_SIZE(CHUNK_SIZE) - rx_strm.avail_out;
 546                         if (r != Z_OK) {
 547                                 rprintf(FERROR, "inflate returned %d (%d bytes)\n", r, n);
 548                                 exit_cleanup(RERR_STREAMIO);
 549                         }
 550                         if (rx_strm.avail_in == 0)
 551                                 recv_state = r_inflated;
 552                         if (n != 0) {
 553                                 *data = dbuf;
 554                                 return n;
 555                         }
 556                         break;
 557
 558                 case r_running:
 559                         ++rx_token;
 560                         if (--rx_run == 0)
 561                                 recv_state = r_idle;
 562                         return -1 - rx_token;
 563                 }
 564         }
 565 }
 566
 567 /*
 568  * put the data corresponding to a token that we've just returned
 569  * from recv_deflated_token into the decompressor's history buffer.
 570  */
 571 static void see_deflate_token(char *buf, int32 len)
 572 {
 573         int r;
 574         int32 blklen;
 575         unsigned char hdr[5];
 576
 577         rx_strm.avail_in = 0;
 578         blklen = 0;
 579         hdr[0] = 0;
 580         do {
 581                 if (rx_strm.avail_in == 0 && len != 0) {
 582                         if (blklen == 0) {
 583                                 /* Give it a fake stored-block header. */
 584                                 rx_strm.next_in = (Bytef *)hdr;
 585                                 rx_strm.avail_in = 5;
 586                                 blklen = len;
 587                                 if (blklen > 0xffff)
 588                                         blklen = 0xffff;
 589                                 hdr[1] = blklen;
 590                                 hdr[2] = blklen >> 8;
 591                                 hdr[3] = ~hdr[1];
 592                                 hdr[4] = ~hdr[2];
 593                         } else {
 594                                 rx_strm.next_in = (Bytef *)buf;
 595                                 rx_strm.avail_in = blklen;
 596                                 len -= blklen;
 597                                 blklen = 0;
 598                         }
 599                 }
 600                 rx_strm.next_out = (Bytef *)dbuf;
 601                 rx_strm.avail_out = AVAIL_OUT_SIZE(CHUNK_SIZE);
 602                 r = inflate(&rx_strm, Z_SYNC_FLUSH);
 603                 if (r != Z_OK && r != Z_BUF_ERROR) {
 604                         rprintf(FERROR, "inflate (token) returned %d\n", r);
 605                         exit_cleanup(RERR_STREAMIO);
 606                 }
 607         } while (len || rx_strm.avail_out == 0);
 608 }
 609
 610 /**
 611  * Transmit a verbatim buffer of length @p n followed by a token.
 612  * If token == -1 then we have reached EOF
 613  * If n == 0 then don't send a buffer
 614  */
 615 void send_token(int f, int32 token, struct map_struct *buf, OFF_T offset,
 616                 int32 n, int32 toklen)
 617 {
 618         if (!do_compression)
 619                 simple_send_token(f, token, buf, offset, n);
 620         else
 621                 send_deflated_token(f, token, buf, offset, n, toklen);
 622 }
 623
 624 /*
 625  * receive a token or buffer from the other end. If the reurn value is >0 then
 626  * it is a data buffer of that length, and *data will point at the data.
 627  * if the return value is -i then it represents token i-1
 628  * if the return value is 0 then the end has been reached
 629  */
 630 int32 recv_token(int f, char **data)
 631 {
 632         int tok;
 633
 634         if (!do_compression) {
 635                 tok = simple_recv_token(f,data);
 636         } else {
 637                 tok = recv_deflated_token(f, data);
 638         }
 639         return tok;
 640 }
 641
 642 /*
 643  * look at the data corresponding to a token, if necessary
 644  */
 645 void see_token(char *data, int32 toklen)
 646 {
 647         if (do_compression)
 648                 see_deflate_token(data, toklen);
 649 }