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