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