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) 2003-2020 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.h>
  25
  26 extern int do_compression;
  27 extern int protocol_version;
  28 extern int module_id;
  29 extern int def_compress_level;
  30 extern char *skip_compress;
  31
  32 #ifndef Z_INSERT_ONLY
  33 #define Z_INSERT_ONLY Z_SYNC_FLUSH
  34 #endif
  35
  36 static int compression_level, per_file_default_level;
  37
  38 struct suffix_tree {
  39         struct suffix_tree *sibling;
  40         struct suffix_tree *child;
  41         char letter, word_end;
  42 };
  43
  44 static char *match_list;
  45 static struct suffix_tree *suftree;
  46
  47 static void add_suffix(struct suffix_tree **prior, char ltr, const char *str)
  48 {
  49         struct suffix_tree *node, *newnode;
  50
  51         if (ltr == '[') {
  52                 const char *after = strchr(str, ']');
  53                 /* Treat "[foo" and "[]" as having a literal '['. */
  54                 if (after && after++ != str+1) {
  55                         while ((ltr = *str++) != ']')
  56                                 add_suffix(prior, ltr, after);
  57                         return;
  58                 }
  59         }
  60
  61         for (node = *prior; node; prior = &node->sibling, node = node->sibling) {
  62                 if (node->letter == ltr) {
  63                         if (*str)
  64                                 add_suffix(&node->child, *str, str+1);
  65                         else
  66                                 node->word_end = 1;
  67                         return;
  68                 }
  69                 if (node->letter > ltr)
  70                         break;
  71         }
  72         if (!(newnode = new(struct suffix_tree)))
  73                 out_of_memory("add_suffix");
  74         newnode->sibling = node;
  75         newnode->child = NULL;
  76         newnode->letter = ltr;
  77         *prior = newnode;
  78         if (*str) {
  79                 add_suffix(&newnode->child, *str, str+1);
  80                 newnode->word_end = 0;
  81         } else
  82                 newnode->word_end = 1;
  83 }
  84
  85 static void add_nocompress_suffixes(const char *str)
  86 {
  87         char *buf, *t;
  88         const char *f = str;
  89
  90         if (!(buf = new_array(char, strlen(f) + 1)))
  91                 out_of_memory("add_nocompress_suffixes");
  92
  93         while (*f) {
  94                 if (*f == '/') {
  95                         f++;
  96                         continue;
  97                 }
  98
  99                 t = buf;
 100                 do {
 101                         if (isUpper(f))
 102                                 *t++ = toLower(f);
 103                         else
 104                                 *t++ = *f;
 105                 } while (*++f != '/' && *f);
 106                 *t++ = '\0';
 107
 108                 add_suffix(&suftree, *buf, buf+1);
 109         }
 110
 111         free(buf);
 112 }
 113
 114 static void init_set_compression(void)
 115 {
 116         const char *f;
 117         char *t, *start;
 118
 119         if (skip_compress)
 120                 add_nocompress_suffixes(skip_compress);
 121
 122         /* A non-daemon transfer skips the default suffix list if the
 123          * user specified --skip-compress. */
 124         if (skip_compress && module_id < 0)
 125                 f = "";
 126         else
 127                 f = lp_dont_compress(module_id);
 128
 129         if (!(match_list = t = new_array(char, strlen(f) + 2)))
 130                 out_of_memory("set_compression");
 131
 132         per_file_default_level = def_compress_level;
 133
 134         while (*f) {
 135                 if (*f == ' ') {
 136                         f++;
 137                         continue;
 138                 }
 139
 140                 start = t;
 141                 do {
 142                         if (isUpper(f))
 143                                 *t++ = toLower(f);
 144                         else
 145                                 *t++ = *f;
 146                 } while (*++f != ' ' && *f);
 147                 *t++ = '\0';
 148
 149                 if (t - start == 1+1 && *start == '*') {
 150                         /* Optimize a match-string of "*". */
 151                         *match_list = '\0';
 152                         suftree = NULL;
 153                         per_file_default_level = 0;
 154                         break;
 155                 }
 156
 157                 /* Move *.foo items into the stuffix tree. */
 158                 if (*start == '*' && start[1] == '.' && start[2]
 159                  && !strpbrk(start+2, ".?*")) {
 160                         add_suffix(&suftree, start[2], start+3);
 161                         t = start;
 162                 }
 163         }
 164         *t++ = '\0';
 165 }
 166
 167 /* determine the compression level based on a wildcard filename list */
 168 void set_compression(const char *fname)
 169 {
 170         const struct suffix_tree *node;
 171         const char *s;
 172         char ltr;
 173
 174         if (!do_compression)
 175                 return;
 176
 177         if (!match_list)
 178                 init_set_compression();
 179
 180         compression_level = per_file_default_level;
 181
 182         if (!*match_list && !suftree)
 183                 return;
 184
 185         if ((s = strrchr(fname, '/')) != NULL)
 186                 fname = s + 1;
 187
 188         for (s = match_list; *s; s += strlen(s) + 1) {
 189                 if (iwildmatch(s, fname)) {
 190                         compression_level = 0;
 191                         return;
 192                 }
 193         }
 194
 195         if (!(node = suftree) || !(s = strrchr(fname, '.'))
 196          || s == fname || !(ltr = *++s))
 197                 return;
 198
 199         while (1) {
 200                 if (isUpper(&ltr))
 201                         ltr = toLower(&ltr);
 202                 while (node->letter != ltr) {
 203                         if (node->letter > ltr)
 204                                 return;
 205                         if (!(node = node->sibling))
 206                                 return;
 207                 }
 208                 if ((ltr = *++s) == '\0') {
 209                         if (node->word_end)
 210                                 compression_level = 0;
 211                         return;
 212                 }
 213                 if (!(node = node->child))
 214                         return;
 215         }
 216 }
 217
 218 /* non-compressing recv token */
 219 static int32 simple_recv_token(int f, char **data)
 220 {
 221         static int32 residue;
 222         static char *buf;
 223         int32 n;
 224
 225         if (!buf) {
 226                 buf = new_array(char, CHUNK_SIZE);
 227                 if (!buf)
 228                         out_of_memory("simple_recv_token");
 229         }
 230
 231         if (residue == 0) {
 232                 int32 i = read_int(f);
 233                 if (i <= 0)
 234                         return i;
 235                 residue = i;
 236         }
 237
 238         *data = buf;
 239         n = MIN(CHUNK_SIZE,residue);
 240         residue -= n;
 241         read_buf(f,buf,n);
 242         return n;
 243 }
 244
 245 /* non-compressing send token */
 246 static void simple_send_token(int f, int32 token, struct map_struct *buf,
 247                               OFF_T offset, int32 n)
 248 {
 249         if (n > 0) {
 250                 int32 len = 0;
 251                 while (len < n) {
 252                         int32 n1 = MIN(CHUNK_SIZE, n-len);
 253                         write_int(f, n1);
 254                         write_buf(f, map_ptr(buf, offset+len, n1), n1);
 255                         len += n1;
 256                 }
 257         }
 258         /* a -2 token means to send data only and no token */
 259         if (token != -2)
 260                 write_int(f, -(token+1));
 261 }
 262
 263 /* Flag bytes in compressed stream are encoded as follows: */
 264 #define END_FLAG        0       /* that's all folks */
 265 #define TOKEN_LONG      0x20    /* followed by 32-bit token number */
 266 #define TOKENRUN_LONG   0x21    /* ditto with 16-bit run count */
 267 #define DEFLATED_DATA   0x40    /* + 6-bit high len, then low len byte */
 268 #define TOKEN_REL       0x80    /* + 6-bit relative token number */
 269 #define TOKENRUN_REL    0xc0    /* ditto with 16-bit run count */
 270
 271 #define MAX_DATA_COUNT  16383   /* fit 14 bit count into 2 bytes with flags */
 272
 273 /* zlib.h says that if we want to be able to compress something in a single
 274  * call, avail_out must be at least 0.1% larger than avail_in plus 12 bytes.
 275  * We'll add in 0.1%+16, just to be safe (and we'll avoid floating point,
 276  * to ensure that this is a compile-time value). */
 277 #define AVAIL_OUT_SIZE(avail_in_size) ((avail_in_size)*1001/1000+16)
 278
 279 /* For coding runs of tokens */
 280 static int32 last_token = -1;
 281 static int32 run_start;
 282 static int32 last_run_end;
 283
 284 /* Deflation state */
 285 static z_stream tx_strm;
 286
 287 /* Output buffer */
 288 static char *obuf;
 289
 290 /* We want obuf to be able to hold both MAX_DATA_COUNT+2 bytes as well as
 291  * AVAIL_OUT_SIZE(CHUNK_SIZE) bytes, so make sure that it's large enough. */
 292 #if MAX_DATA_COUNT+2 > AVAIL_OUT_SIZE(CHUNK_SIZE)
 293 #define OBUF_SIZE       (MAX_DATA_COUNT+2)
 294 #else
 295 #define OBUF_SIZE       AVAIL_OUT_SIZE(CHUNK_SIZE)
 296 #endif
 297
 298 /* Send a deflated token */
 299 static void
 300 send_deflated_token(int f, int32 token, struct map_struct *buf, OFF_T offset,
 301                     int32 nb, int32 toklen)
 302 {
 303         static int init_done, flush_pending;
 304         int32 n, r;
 305
 306         if (last_token == -1) {
 307                 /* initialization */
 308                 if (!init_done) {
 309                         tx_strm.next_in = NULL;
 310                         tx_strm.zalloc = NULL;
 311                         tx_strm.zfree = NULL;
 312                         if (deflateInit2(&tx_strm, compression_level,
 313                                          Z_DEFLATED, -15, 8,
 314                                          Z_DEFAULT_STRATEGY) != Z_OK) {
 315                                 rprintf(FERROR, "compression init failed\n");
 316                                 exit_cleanup(RERR_PROTOCOL);
 317                         }
 318                         if ((obuf = new_array(char, OBUF_SIZE)) == NULL)
 319                                 out_of_memory("send_deflated_token");
 320                         init_done = 1;
 321                 } else
 322                         deflateReset(&tx_strm);
 323                 last_run_end = 0;
 324                 run_start = token;
 325                 flush_pending = 0;
 326         } else if (last_token == -2) {
 327                 run_start = token;
 328         } else if (nb != 0 || token != last_token + 1
 329                    || token >= run_start + 65536) {
 330                 /* output previous run */
 331                 r = run_start - last_run_end;
 332                 n = last_token - run_start;
 333                 if (r >= 0 && r <= 63) {
 334                         write_byte(f, (n==0? TOKEN_REL: TOKENRUN_REL) + r);
 335                 } else {
 336                         write_byte(f, (n==0? TOKEN_LONG: TOKENRUN_LONG));
 337                         write_int(f, run_start);
 338                 }
 339                 if (n != 0) {
 340                         write_byte(f, n);
 341                         write_byte(f, n >> 8);
 342                 }
 343                 last_run_end = last_token;
 344                 run_start = token;
 345         }
 346
 347         last_token = token;
 348
 349         if (nb != 0 || flush_pending) {
 350                 /* deflate the data starting at offset */
 351                 int flush = Z_NO_FLUSH;
 352                 tx_strm.avail_in = 0;
 353                 tx_strm.avail_out = 0;
 354                 do {
 355                         if (tx_strm.avail_in == 0 && nb != 0) {
 356                                 /* give it some more input */
 357                                 n = MIN(nb, CHUNK_SIZE);
 358                                 tx_strm.next_in = (Bytef *)
 359                                         map_ptr(buf, offset, n);
 360                                 tx_strm.avail_in = n;
 361                                 nb -= n;
 362                                 offset += n;
 363                         }
 364                         if (tx_strm.avail_out == 0) {
 365                                 tx_strm.next_out = (Bytef *)(obuf + 2);
 366                                 tx_strm.avail_out = MAX_DATA_COUNT;
 367                                 if (flush != Z_NO_FLUSH) {
 368                                         /*
 369                                          * We left the last 4 bytes in the
 370                                          * buffer, in case they are the
 371                                          * last 4.  Move them to the front.
 372                                          */
 373                                         memcpy(tx_strm.next_out,
 374                                                obuf+MAX_DATA_COUNT-2, 4);
 375                                         tx_strm.next_out += 4;
 376                                         tx_strm.avail_out -= 4;
 377                                 }
 378                         }
 379                         if (nb == 0 && token != -2)
 380                                 flush = Z_SYNC_FLUSH;
 381                         r = deflate(&tx_strm, flush);
 382                         if (r != Z_OK) {
 383                                 rprintf(FERROR, "deflate returned %d\n", r);
 384                                 exit_cleanup(RERR_STREAMIO);
 385                         }
 386                         if (nb == 0 || tx_strm.avail_out == 0) {
 387                                 n = MAX_DATA_COUNT - tx_strm.avail_out;
 388                                 if (flush != Z_NO_FLUSH) {
 389                                         /*
 390                                          * We have to trim off the last 4
 391                                          * bytes of output when flushing
 392                                          * (they are just 0, 0, ff, ff).
 393                                          */
 394                                         n -= 4;
 395                                 }
 396                                 if (n > 0) {
 397                                         obuf[0] = DEFLATED_DATA + (n >> 8);
 398                                         obuf[1] = n;
 399                                         write_buf(f, obuf, n+2);
 400                                 }
 401                         }
 402                 } while (nb != 0 || tx_strm.avail_out == 0);
 403                 flush_pending = token == -2;
 404         }
 405
 406         if (token == -1) {
 407                 /* end of file - clean up */
 408                 write_byte(f, END_FLAG);
 409         } else if (token != -2 && do_compression == CPRES_ZLIB) {
 410                 /* Add the data in the current block to the compressor's
 411                  * history and hash table. */
 412                 do {
 413                         /* Break up long sections in the same way that
 414                          * see_deflate_token() does. */
 415                         int32 n1 = toklen > 0xffff ? 0xffff : toklen;
 416                         toklen -= n1;
 417                         tx_strm.next_in = (Bytef *)map_ptr(buf, offset, n1);
 418                         tx_strm.avail_in = n1;
 419                         if (protocol_version >= 31) /* Newer protocols avoid a data-duplicating bug */
 420                                 offset += n1;
 421                         tx_strm.next_out = (Bytef *) obuf;
 422                         tx_strm.avail_out = AVAIL_OUT_SIZE(CHUNK_SIZE);
 423                         r = deflate(&tx_strm, Z_INSERT_ONLY);
 424                         if (r != Z_OK || tx_strm.avail_in != 0) {
 425                                 rprintf(FERROR, "deflate on token returned %d (%d bytes left)\n",
 426                                         r, tx_strm.avail_in);
 427                                 exit_cleanup(RERR_STREAMIO);
 428                         }
 429                 } while (toklen > 0);
 430         }
 431 }
 432
 433 /* tells us what the receiver is in the middle of doing */
 434 static enum { r_init, r_idle, r_running, r_inflating, r_inflated } recv_state;
 435
 436 /* for inflating stuff */
 437 static z_stream rx_strm;
 438 static char *cbuf;
 439 static char *dbuf;
 440
 441 /* for decoding runs of tokens */
 442 static int32 rx_token;
 443 static int32 rx_run;
 444
 445 /* Receive a deflated token and inflate it */
 446 static int32 recv_deflated_token(int f, char **data)
 447 {
 448         static int init_done;
 449         static int32 saved_flag;
 450         int32 n, flag;
 451         int r;
 452
 453         for (;;) {
 454                 switch (recv_state) {
 455                 case r_init:
 456                         if (!init_done) {
 457                                 rx_strm.next_out = NULL;
 458                                 rx_strm.zalloc = NULL;
 459                                 rx_strm.zfree = NULL;
 460                                 if (inflateInit2(&rx_strm, -15) != Z_OK) {
 461                                         rprintf(FERROR, "inflate init failed\n");
 462                                         exit_cleanup(RERR_PROTOCOL);
 463                                 }
 464                                 if (!(cbuf = new_array(char, MAX_DATA_COUNT))
 465                                     || !(dbuf = new_array(char, AVAIL_OUT_SIZE(CHUNK_SIZE))))
 466                                         out_of_memory("recv_deflated_token");
 467                                 init_done = 1;
 468                         } else {
 469                                 inflateReset(&rx_strm);
 470                         }
 471                         recv_state = r_idle;
 472                         rx_token = 0;
 473                         break;
 474
 475                 case r_idle:
 476                 case r_inflated:
 477                         if (saved_flag) {
 478                                 flag = saved_flag & 0xff;
 479                                 saved_flag = 0;
 480                         } else
 481                                 flag = read_byte(f);
 482                         if ((flag & 0xC0) == DEFLATED_DATA) {
 483                                 n = ((flag & 0x3f) << 8) + read_byte(f);
 484                                 read_buf(f, cbuf, n);
 485                                 rx_strm.next_in = (Bytef *)cbuf;
 486                                 rx_strm.avail_in = n;
 487                                 recv_state = r_inflating;
 488                                 break;
 489                         }
 490                         if (recv_state == r_inflated) {
 491                                 /* check previous inflated stuff ended correctly */
 492                                 rx_strm.avail_in = 0;
 493                                 rx_strm.next_out = (Bytef *)dbuf;
 494                                 rx_strm.avail_out = AVAIL_OUT_SIZE(CHUNK_SIZE);
 495                                 r = inflate(&rx_strm, Z_SYNC_FLUSH);
 496                                 n = AVAIL_OUT_SIZE(CHUNK_SIZE) - rx_strm.avail_out;
 497                                 /*
 498                                  * Z_BUF_ERROR just means no progress was
 499                                  * made, i.e. the decompressor didn't have
 500                                  * any pending output for us.
 501                                  */
 502                                 if (r != Z_OK && r != Z_BUF_ERROR) {
 503                                         rprintf(FERROR, "inflate flush returned %d (%d bytes)\n",
 504                                                 r, n);
 505                                         exit_cleanup(RERR_STREAMIO);
 506                                 }
 507                                 if (n != 0 && r != Z_BUF_ERROR) {
 508                                         /* have to return some more data and
 509                                            save the flag for later. */
 510                                         saved_flag = flag + 0x10000;
 511                                         *data = dbuf;
 512                                         return n;
 513                                 }
 514                                 /*
 515                                  * At this point the decompressor should
 516                                  * be expecting to see the 0, 0, ff, ff bytes.
 517                                  */
 518                                 if (!inflateSyncPoint(&rx_strm)) {
 519                                         rprintf(FERROR, "decompressor lost sync!\n");
 520                                         exit_cleanup(RERR_STREAMIO);
 521                                 }
 522                                 rx_strm.avail_in = 4;
 523                                 rx_strm.next_in = (Bytef *)cbuf;
 524                                 cbuf[0] = cbuf[1] = 0;
 525                                 cbuf[2] = cbuf[3] = 0xff;
 526                                 inflate(&rx_strm, Z_SYNC_FLUSH);
 527                                 recv_state = r_idle;
 528                         }
 529                         if (flag == END_FLAG) {
 530                                 /* that's all folks */
 531                                 recv_state = r_init;
 532                                 return 0;
 533                         }
 534
 535                         /* here we have a token of some kind */
 536                         if (flag & TOKEN_REL) {
 537                                 rx_token += flag & 0x3f;
 538                                 flag >>= 6;
 539                         } else
 540                                 rx_token = read_int(f);
 541                         if (flag & 1) {
 542                                 rx_run = read_byte(f);
 543                                 rx_run += read_byte(f) << 8;
 544                                 recv_state = r_running;
 545                         }
 546                         return -1 - rx_token;
 547
 548                 case r_inflating:
 549                         rx_strm.next_out = (Bytef *)dbuf;
 550                         rx_strm.avail_out = AVAIL_OUT_SIZE(CHUNK_SIZE);
 551                         r = inflate(&rx_strm, Z_NO_FLUSH);
 552                         n = AVAIL_OUT_SIZE(CHUNK_SIZE) - rx_strm.avail_out;
 553                         if (r != Z_OK) {
 554                                 rprintf(FERROR, "inflate returned %d (%d bytes)\n", r, n);
 555                                 exit_cleanup(RERR_STREAMIO);
 556                         }
 557                         if (rx_strm.avail_in == 0)
 558                                 recv_state = r_inflated;
 559                         if (n != 0) {
 560                                 *data = dbuf;
 561                                 return n;
 562                         }
 563                         break;
 564
 565                 case r_running:
 566                         ++rx_token;
 567                         if (--rx_run == 0)
 568                                 recv_state = r_idle;
 569                         return -1 - rx_token;
 570                 }
 571         }
 572 }
 573
 574 /*
 575  * put the data corresponding to a token that we've just returned
 576  * from recv_deflated_token into the decompressor's history buffer.
 577  */
 578 static void see_deflate_token(char *buf, int32 len)
 579 {
 580         int r;
 581         int32 blklen;
 582         unsigned char hdr[5];
 583
 584         rx_strm.avail_in = 0;
 585         blklen = 0;
 586         hdr[0] = 0;
 587         do {
 588                 if (rx_strm.avail_in == 0 && len != 0) {
 589                         if (blklen == 0) {
 590                                 /* Give it a fake stored-block header. */
 591                                 rx_strm.next_in = (Bytef *)hdr;
 592                                 rx_strm.avail_in = 5;
 593                                 blklen = len;
 594                                 if (blklen > 0xffff)
 595                                         blklen = 0xffff;
 596                                 hdr[1] = blklen;
 597                                 hdr[2] = blklen >> 8;
 598                                 hdr[3] = ~hdr[1];
 599                                 hdr[4] = ~hdr[2];
 600                         } else {
 601                                 rx_strm.next_in = (Bytef *)buf;
 602                                 rx_strm.avail_in = blklen;
 603                                 if (protocol_version >= 31) /* Newer protocols avoid a data-duplicating bug */
 604                                         buf += blklen;
 605                                 len -= blklen;
 606                                 blklen = 0;
 607                         }
 608                 }
 609                 rx_strm.next_out = (Bytef *)dbuf;
 610                 rx_strm.avail_out = AVAIL_OUT_SIZE(CHUNK_SIZE);
 611                 r = inflate(&rx_strm, Z_SYNC_FLUSH);
 612                 if (r != Z_OK && r != Z_BUF_ERROR) {
 613                         rprintf(FERROR, "inflate (token) returned %d\n", r);
 614                         exit_cleanup(RERR_STREAMIO);
 615                 }
 616         } while (len || rx_strm.avail_out == 0);
 617 }
 618
 619 /**
 620  * Transmit a verbatim buffer of length @p n followed by a token.
 621  * If token == -1 then we have reached EOF
 622  * If n == 0 then don't send a buffer
 623  */
 624 void send_token(int f, int32 token, struct map_struct *buf, OFF_T offset,
 625                 int32 n, int32 toklen)
 626 {
 627         if (!do_compression)
 628                 simple_send_token(f, token, buf, offset, n);
 629         else
 630                 send_deflated_token(f, token, buf, offset, n, toklen);
 631 }
 632
 633 /*
 634  * receive a token or buffer from the other end. If the return value is >0 then
 635  * it is a data buffer of that length, and *data will point at the data.
 636  * if the return value is -i then it represents token i-1
 637  * if the return value is 0 then the end has been reached
 638  */
 639 int32 recv_token(int f, char **data)
 640 {
 641         int tok;
 642
 643         if (!do_compression)
 644                 tok = simple_recv_token(f,data);
 645         else /* CPRES_ZLIB & CPRES_ZLIBX */
 646                 tok = recv_deflated_token(f, data);
 647         return tok;
 648 }
 649
 650 /*
 651  * look at the data corresponding to a token, if necessary
 652  */
 653 void see_token(char *data, int32 toklen)
 654 {
 655         if (do_compression == CPRES_ZLIB)
 656                 see_deflate_token(data, toklen);
 657 }