token.c

   1 /*
   2    Copyright (C) Andrew Tridgell 1996
   3    Copyright (C) Paul Mackerras 1996
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 2 of the License, or
   8    (at your option) any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program; if not, write to the Free Software
  17    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  18 */
  19
  20 #include "rsync.h"
  21 #include "zlib/zlib.h"
  22
  23 extern int do_compression;
  24 extern int module_id;
  25 extern int def_compress_level;
  26
  27 static int compression_level, per_file_default_level;
  28
  29 /* determine the compression level based on a wildcard filename list */
  30 void set_compression(char *fname)
  31 {
  32         static char *match_list;
  33         char *s;
  34
  35         if (!do_compression)
  36                 return;
  37
  38         if (!match_list) {
  39                 char *t, *f = lp_dont_compress(module_id);
  40                 int len = strlen(f);
  41                 if (!(match_list = t = new_array(char, len + 2)))
  42                         out_of_memory("set_compression");
  43                 while (*f) {
  44                         if (*f == ' ') {
  45                                 f++;
  46                                 continue;
  47                         }
  48                         do {
  49                                 if (isupper(*(unsigned char *)f))
  50                                         *t++ = tolower(*(unsigned char *)f);
  51                                 else
  52                                         *t++ = *f;
  53                         } while (*++f != ' ' && *f);
  54                         *t++ = '\0';
  55                 }
  56                 /* Optimize a match-string of "*". */
  57                 if (t - match_list == 2 && match_list[0] == '*') {
  58                         t = match_list;
  59                         per_file_default_level = 0;
  60                 } else
  61                         per_file_default_level = def_compress_level;
  62                 *t++ = '\0';
  63         }
  64
  65         compression_level = per_file_default_level;
  66
  67         if (!*match_list)
  68                 return;
  69
  70         if ((s = strrchr(fname, '/')) != NULL)
  71                 fname = s + 1;
  72
  73         for (s = match_list; *s; s += strlen(s) + 1) {
  74                 if (iwildmatch(s, fname)) {
  75                         compression_level = 0;
  76                         break;
  77                 }
  78         }
  79 }
  80
  81 /* non-compressing recv token */
  82 static int32 simple_recv_token(int f, char **data)
  83 {
  84         static int32 residue;
  85         static char *buf;
  86         int32 n;
  87
  88         if (!buf) {
  89                 buf = new_array(char, CHUNK_SIZE);
  90                 if (!buf)
  91                         out_of_memory("simple_recv_token");
  92         }
  93
  94         if (residue == 0) {
  95                 int32 i = read_int(f);
  96                 if (i <= 0)
  97                         return i;
  98                 residue = i;
  99         }
 100
 101         *data = buf;
 102         n = MIN(CHUNK_SIZE,residue);
 103         residue -= n;
 104         read_buf(f,buf,n);
 105         return n;
 106 }
 107
 108
 109 /* non-compressing send token */
 110 static void simple_send_token(int f, int32 token, struct map_struct *buf,
 111                               OFF_T offset, int32 n)
 112 {
 113         if (n > 0) {
 114                 int32 len = 0;
 115                 while (len < n) {
 116                         int32 n1 = MIN(CHUNK_SIZE, n-len);
 117                         write_int(f, n1);
 118                         write_buf(f, map_ptr(buf, offset+len, n1), n1);
 119                         len += n1;
 120                 }
 121         }
 122         /* a -2 token means to send data only and no token */
 123         if (token != -2)
 124                 write_int(f, -(token+1));
 125 }
 126
 127
 128 /* Flag bytes in compressed stream are encoded as follows: */
 129 #define END_FLAG        0       /* that's all folks */
 130 #define TOKEN_LONG      0x20    /* followed by 32-bit token number */
 131 #define TOKENRUN_LONG   0x21    /* ditto with 16-bit run count */
 132 #define DEFLATED_DATA   0x40    /* + 6-bit high len, then low len byte */
 133 #define TOKEN_REL       0x80    /* + 6-bit relative token number */
 134 #define TOKENRUN_REL    0xc0    /* ditto with 16-bit run count */
 135
 136 #define MAX_DATA_COUNT  16383   /* fit 14 bit count into 2 bytes with flags */
 137
 138 /* zlib.h says that if we want to be able to compress something in a single
 139  * call, avail_out must be at least 0.1% larger than avail_in plus 12 bytes.
 140  * We'll add in 0.1%+16, just to be safe (and we'll avoid floating point,
 141  * to ensure that this is a compile-time value). */
 142 #define AVAIL_OUT_SIZE(avail_in_size) ((avail_in_size)*1001/1000+16)
 143
 144 /* For coding runs of tokens */
 145 static int32 last_token = -1;
 146 static int32 run_start;
 147 static int32 last_run_end;
 148
 149 /* Deflation state */
 150 static z_stream tx_strm;
 151
 152 /* Output buffer */
 153 static char *obuf;
 154
 155 /* We want obuf to be able to hold both MAX_DATA_COUNT+2 bytes as well as
 156  * AVAIL_OUT_SIZE(CHUNK_SIZE) bytes, so make sure that it's large enough. */
 157 #if MAX_DATA_COUNT+2 > AVAIL_OUT_SIZE(CHUNK_SIZE)
 158 #define OBUF_SIZE       (MAX_DATA_COUNT+2)
 159 #else
 160 #define OBUF_SIZE       AVAIL_OUT_SIZE(CHUNK_SIZE)
 161 #endif
 162
 163 /* Send a deflated token */
 164 static void
 165 send_deflated_token(int f, int32 token, struct map_struct *buf, OFF_T offset,
 166                     int32 nb, int32 toklen)
 167 {
 168         int32 n, r;
 169         static int init_done, flush_pending;
 170
 171         if (last_token == -1) {
 172                 /* initialization */
 173                 if (!init_done) {
 174                         tx_strm.next_in = NULL;
 175                         tx_strm.zalloc = NULL;
 176                         tx_strm.zfree = NULL;
 177                         if (deflateInit2(&tx_strm, compression_level,
 178                                          Z_DEFLATED, -15, 8,
 179                                          Z_DEFAULT_STRATEGY) != Z_OK) {
 180                                 rprintf(FERROR, "compression init failed\n");
 181                                 exit_cleanup(RERR_STREAMIO);
 182                         }
 183                         if ((obuf = new_array(char, OBUF_SIZE)) == NULL)
 184                                 out_of_memory("send_deflated_token");
 185                         init_done = 1;
 186                 } else
 187                         deflateReset(&tx_strm);
 188                 last_run_end = 0;
 189                 run_start = token;
 190                 flush_pending = 0;
 191
 192         } else if (last_token == -2) {
 193                 run_start = token;
 194
 195         } else if (nb != 0 || token != last_token + 1
 196                    || token >= run_start + 65536) {
 197                 /* output previous run */
 198                 r = run_start - last_run_end;
 199                 n = last_token - run_start;
 200                 if (r >= 0 && r <= 63) {
 201                         write_byte(f, (n==0? TOKEN_REL: TOKENRUN_REL) + r);
 202                 } else {
 203                         write_byte(f, (n==0? TOKEN_LONG: TOKENRUN_LONG));
 204                         write_int(f, run_start);
 205                 }
 206                 if (n != 0) {
 207                         write_byte(f, n);
 208                         write_byte(f, n >> 8);
 209                 }
 210                 last_run_end = last_token;
 211                 run_start = token;
 212         }
 213
 214         last_token = token;
 215
 216         if (nb != 0 || flush_pending) {
 217                 /* deflate the data starting at offset */
 218                 int flush = Z_NO_FLUSH;
 219                 tx_strm.avail_in = 0;
 220                 tx_strm.avail_out = 0;
 221                 do {
 222                         if (tx_strm.avail_in == 0 && nb != 0) {
 223                                 /* give it some more input */
 224                                 n = MIN(nb, CHUNK_SIZE);
 225                                 tx_strm.next_in = (Bytef *)
 226                                         map_ptr(buf, offset, n);
 227                                 tx_strm.avail_in = n;
 228                                 nb -= n;
 229                                 offset += n;
 230                         }
 231                         if (tx_strm.avail_out == 0) {
 232                                 tx_strm.next_out = (Bytef *)(obuf + 2);
 233                                 tx_strm.avail_out = MAX_DATA_COUNT;
 234                                 if (flush != Z_NO_FLUSH) {
 235                                         /*
 236                                          * We left the last 4 bytes in the
 237                                          * buffer, in case they are the
 238                                          * last 4.  Move them to the front.
 239                                          */
 240                                         memcpy(tx_strm.next_out,
 241                                                obuf+MAX_DATA_COUNT-2, 4);
 242                                         tx_strm.next_out += 4;
 243                                         tx_strm.avail_out -= 4;
 244                                 }
 245                         }
 246                         if (nb == 0 && token != -2)
 247                                 flush = Z_SYNC_FLUSH;
 248                         r = deflate(&tx_strm, flush);
 249                         if (r != Z_OK) {
 250                                 rprintf(FERROR, "deflate returned %d\n", r);
 251                                 exit_cleanup(RERR_STREAMIO);
 252                         }
 253                         if (nb == 0 || tx_strm.avail_out == 0) {
 254                                 n = MAX_DATA_COUNT - tx_strm.avail_out;
 255                                 if (flush != Z_NO_FLUSH) {
 256                                         /*
 257                                          * We have to trim off the last 4
 258                                          * bytes of output when flushing
 259                                          * (they are just 0, 0, ff, ff).
 260                                          */
 261                                         n -= 4;
 262                                 }
 263                                 if (n > 0) {
 264                                         obuf[0] = DEFLATED_DATA + (n >> 8);
 265                                         obuf[1] = n;
 266                                         write_buf(f, obuf, n+2);
 267                                 }
 268                         }
 269                 } while (nb != 0 || tx_strm.avail_out == 0);
 270                 flush_pending = token == -2;
 271         }
 272
 273         if (token == -1) {
 274                 /* end of file - clean up */
 275                 write_byte(f, END_FLAG);
 276         } else if (token != -2) {
 277                 /* Add the data in the current block to the compressor's
 278                  * history and hash table. */
 279                 do {
 280                         /* Break up long sections in the same way that
 281                          * see_deflate_token() does. */
 282                         int32 n1 = toklen > 0xffff ? 0xffff : toklen;
 283                         toklen -= n1;
 284                         tx_strm.next_in = (Bytef *)map_ptr(buf, offset, n1);
 285                         tx_strm.avail_in = n1;
 286                         tx_strm.next_out = (Bytef *) obuf;
 287                         tx_strm.avail_out = AVAIL_OUT_SIZE(CHUNK_SIZE);
 288                         r = deflate(&tx_strm, Z_INSERT_ONLY);
 289                         if (r != Z_OK || tx_strm.avail_in != 0) {
 290                                 rprintf(FERROR, "deflate on token returned %d (%d bytes left)\n",
 291                                         r, tx_strm.avail_in);
 292                                 exit_cleanup(RERR_STREAMIO);
 293                         }
 294                 } while (toklen > 0);
 295         }
 296 }
 297
 298
 299 /* tells us what the receiver is in the middle of doing */
 300 static enum { r_init, r_idle, r_running, r_inflating, r_inflated } recv_state;
 301
 302 /* for inflating stuff */
 303 static z_stream rx_strm;
 304 static char *cbuf;
 305 static char *dbuf;
 306
 307 /* for decoding runs of tokens */
 308 static int32 rx_token;
 309 static int32 rx_run;
 310
 311 /* Receive a deflated token and inflate it */
 312 static int32 recv_deflated_token(int f, char **data)
 313 {
 314         static int init_done;
 315         static int32 saved_flag;
 316         int32 n, flag;
 317         int r;
 318
 319         for (;;) {
 320                 switch (recv_state) {
 321                 case r_init:
 322                         if (!init_done) {
 323                                 rx_strm.next_out = NULL;
 324                                 rx_strm.zalloc = NULL;
 325                                 rx_strm.zfree = NULL;
 326                                 if (inflateInit2(&rx_strm, -15) != Z_OK) {
 327                                         rprintf(FERROR, "inflate init failed\n");
 328                                         exit_cleanup(RERR_STREAMIO);
 329                                 }
 330                                 if (!(cbuf = new_array(char, MAX_DATA_COUNT))
 331                                     || !(dbuf = new_array(char, AVAIL_OUT_SIZE(CHUNK_SIZE))))
 332                                         out_of_memory("recv_deflated_token");
 333                                 init_done = 1;
 334                         } else {
 335                                 inflateReset(&rx_strm);
 336                         }
 337                         recv_state = r_idle;
 338                         rx_token = 0;
 339                         break;
 340
 341                 case r_idle:
 342                 case r_inflated:
 343                         if (saved_flag) {
 344                                 flag = saved_flag & 0xff;
 345                                 saved_flag = 0;
 346                         } else
 347                                 flag = read_byte(f);
 348                         if ((flag & 0xC0) == DEFLATED_DATA) {
 349                                 n = ((flag & 0x3f) << 8) + read_byte(f);
 350                                 read_buf(f, cbuf, n);
 351                                 rx_strm.next_in = (Bytef *)cbuf;
 352                                 rx_strm.avail_in = n;
 353                                 recv_state = r_inflating;
 354                                 break;
 355                         }
 356                         if (recv_state == r_inflated) {
 357                                 /* check previous inflated stuff ended correctly */
 358                                 rx_strm.avail_in = 0;
 359                                 rx_strm.next_out = (Bytef *)dbuf;
 360                                 rx_strm.avail_out = AVAIL_OUT_SIZE(CHUNK_SIZE);
 361                                 r = inflate(&rx_strm, Z_SYNC_FLUSH);
 362                                 n = AVAIL_OUT_SIZE(CHUNK_SIZE) - rx_strm.avail_out;
 363                                 /*
 364                                  * Z_BUF_ERROR just means no progress was
 365                                  * made, i.e. the decompressor didn't have
 366                                  * any pending output for us.
 367                                  */
 368                                 if (r != Z_OK && r != Z_BUF_ERROR) {
 369                                         rprintf(FERROR, "inflate flush returned %d (%d bytes)\n",
 370                                                 r, n);
 371                                         exit_cleanup(RERR_STREAMIO);
 372                                 }
 373                                 if (n != 0 && r != Z_BUF_ERROR) {
 374                                         /* have to return some more data and
 375                                            save the flag for later. */
 376                                         saved_flag = flag + 0x10000;
 377                                         *data = dbuf;
 378                                         return n;
 379                                 }
 380                                 /*
 381                                  * At this point the decompressor should
 382                                  * be expecting to see the 0, 0, ff, ff bytes.
 383                                  */
 384                                 if (!inflateSyncPoint(&rx_strm)) {
 385                                         rprintf(FERROR, "decompressor lost sync!\n");
 386                                         exit_cleanup(RERR_STREAMIO);
 387                                 }
 388                                 rx_strm.avail_in = 4;
 389                                 rx_strm.next_in = (Bytef *)cbuf;
 390                                 cbuf[0] = cbuf[1] = 0;
 391                                 cbuf[2] = cbuf[3] = 0xff;
 392                                 inflate(&rx_strm, Z_SYNC_FLUSH);
 393                                 recv_state = r_idle;
 394                         }
 395                         if (flag == END_FLAG) {
 396                                 /* that's all folks */
 397                                 recv_state = r_init;
 398                                 return 0;
 399                         }
 400
 401                         /* here we have a token of some kind */
 402                         if (flag & TOKEN_REL) {
 403                                 rx_token += flag & 0x3f;
 404                                 flag >>= 6;
 405                         } else
 406                                 rx_token = read_int(f);
 407                         if (flag & 1) {
 408                                 rx_run = read_byte(f);
 409                                 rx_run += read_byte(f) << 8;
 410                                 recv_state = r_running;
 411                         }
 412                         return -1 - rx_token;
 413
 414                 case r_inflating:
 415                         rx_strm.next_out = (Bytef *)dbuf;
 416                         rx_strm.avail_out = AVAIL_OUT_SIZE(CHUNK_SIZE);
 417                         r = inflate(&rx_strm, Z_NO_FLUSH);
 418                         n = AVAIL_OUT_SIZE(CHUNK_SIZE) - rx_strm.avail_out;
 419                         if (r != Z_OK) {
 420                                 rprintf(FERROR, "inflate returned %d (%d bytes)\n", r, n);
 421                                 exit_cleanup(RERR_STREAMIO);
 422                         }
 423                         if (rx_strm.avail_in == 0)
 424                                 recv_state = r_inflated;
 425                         if (n != 0) {
 426                                 *data = dbuf;
 427                                 return n;
 428                         }
 429                         break;
 430
 431                 case r_running:
 432                         ++rx_token;
 433                         if (--rx_run == 0)
 434                                 recv_state = r_idle;
 435                         return -1 - rx_token;
 436                 }
 437         }
 438 }
 439
 440 /*
 441  * put the data corresponding to a token that we've just returned
 442  * from recv_deflated_token into the decompressor's history buffer.
 443  */
 444 static void see_deflate_token(char *buf, int32 len)
 445 {
 446         int r;
 447         int32 blklen;
 448         unsigned char hdr[5];
 449
 450         rx_strm.avail_in = 0;
 451         blklen = 0;
 452         hdr[0] = 0;
 453         do {
 454                 if (rx_strm.avail_in == 0 && len != 0) {
 455                         if (blklen == 0) {
 456                                 /* Give it a fake stored-block header. */
 457                                 rx_strm.next_in = (Bytef *)hdr;
 458                                 rx_strm.avail_in = 5;
 459                                 blklen = len;
 460                                 if (blklen > 0xffff)
 461                                         blklen = 0xffff;
 462                                 hdr[1] = blklen;
 463                                 hdr[2] = blklen >> 8;
 464                                 hdr[3] = ~hdr[1];
 465                                 hdr[4] = ~hdr[2];
 466                         } else {
 467                                 rx_strm.next_in = (Bytef *)buf;
 468                                 rx_strm.avail_in = blklen;
 469                                 len -= blklen;
 470                                 blklen = 0;
 471                         }
 472                 }
 473                 rx_strm.next_out = (Bytef *)dbuf;
 474                 rx_strm.avail_out = AVAIL_OUT_SIZE(CHUNK_SIZE);
 475                 r = inflate(&rx_strm, Z_SYNC_FLUSH);
 476                 if (r != Z_OK) {
 477                         rprintf(FERROR, "inflate (token) returned %d\n", r);
 478                         exit_cleanup(RERR_STREAMIO);
 479                 }
 480         } while (len || rx_strm.avail_out == 0);
 481 }
 482
 483 /**
 484  * Transmit a verbatim buffer of length @p n followed by a token.
 485  * If token == -1 then we have reached EOF
 486  * If n == 0 then don't send a buffer
 487  */
 488 void send_token(int f, int32 token, struct map_struct *buf, OFF_T offset,
 489                 int32 n, int32 toklen)
 490 {
 491         if (!do_compression)
 492                 simple_send_token(f, token, buf, offset, n);
 493         else
 494                 send_deflated_token(f, token, buf, offset, n, toklen);
 495 }
 496
 497
 498 /*
 499  * receive a token or buffer from the other end. If the reurn value is >0 then
 500  * it is a data buffer of that length, and *data will point at the data.
 501  * if the return value is -i then it represents token i-1
 502  * if the return value is 0 then the end has been reached
 503  */
 504 int32 recv_token(int f, char **data)
 505 {
 506         int tok;
 507
 508         if (!do_compression) {
 509                 tok = simple_recv_token(f,data);
 510         } else {
 511                 tok = recv_deflated_token(f, data);
 512         }
 513         return tok;
 514 }
 515
 516 /*
 517  * look at the data corresponding to a token, if necessary
 518  */
 519 void see_token(char *data, int32 toklen)
 520 {
 521         if (do_compression)
 522                 see_deflate_token(data, toklen);
 523 }