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