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, 2004, 2005, 2006, 2007 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 2 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, write to the Free Software Foundation, Inc.,
  20  * 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.
  21  */
  22
  23 #include "rsync.h"
  24 #include "zlib/zlib.h"
  25
  26 extern int do_compression;
  27 extern int module_id;
  28 extern int def_compress_level;
  29
  30 static int compression_level, per_file_default_level;
  31
  32 /* determine the compression level based on a wildcard filename list */
  33 void set_compression(char *fname)
  34 {
  35         static char *match_list;
  36         char *s;
  37
  38         if (!do_compression)
  39                 return;
  40
  41         if (!match_list) {
  42                 char *t, *f = lp_dont_compress(module_id);
  43                 int len = strlen(f);
  44                 if (!(match_list = t = new_array(char, len + 2)))
  45                         out_of_memory("set_compression");
  46                 while (*f) {
  47                         if (*f == ' ') {
  48                                 f++;
  49                                 continue;
  50                         }
  51                         do {
  52                                 if (isUpper(f))
  53                                         *t++ = toLower(f);
  54                                 else
  55                                         *t++ = *f;
  56                         } while (*++f != ' ' && *f);
  57                         *t++ = '\0';
  58                 }
  59                 /* Optimize a match-string of "*". */
  60                 if (t - match_list == 2 && match_list[0] == '*') {
  61                         t = match_list;
  62                         per_file_default_level = 0;
  63                 } else
  64                         per_file_default_level = def_compress_level;
  65                 *t++ = '\0';
  66         }
  67
  68         compression_level = per_file_default_level;
  69
  70         if (!*match_list)
  71                 return;
  72
  73         if ((s = strrchr(fname, '/')) != NULL)
  74                 fname = s + 1;
  75
  76         for (s = match_list; *s; s += strlen(s) + 1) {
  77                 if (iwildmatch(s, fname)) {
  78                         compression_level = 0;
  79                         break;
  80                 }
  81         }
  82 }
  83
  84 /* non-compressing recv token */
  85 static int32 simple_recv_token(int f, char **data)
  86 {
  87         static int32 residue;
  88         static char *buf;
  89         int32 n;
  90
  91         if (!buf) {
  92                 buf = new_array(char, CHUNK_SIZE);
  93                 if (!buf)
  94                         out_of_memory("simple_recv_token");
  95         }
  96
  97         if (residue == 0) {
  98                 int32 i = read_int(f);
  99                 if (i <= 0)
 100                         return i;
 101                 residue = i;
 102         }
 103
 104         *data = buf;
 105         n = MIN(CHUNK_SIZE,residue);
 106         residue -= n;
 107         read_buf(f,buf,n);
 108         return n;
 109 }
 110
 111 /* non-compressing send token */
 112 static void simple_send_token(int f, int32 token, struct map_struct *buf,
 113                               OFF_T offset, int32 n)
 114 {
 115         if (n > 0) {
 116                 int32 len = 0;
 117                 while (len < n) {
 118                         int32 n1 = MIN(CHUNK_SIZE, n-len);
 119                         write_int(f, n1);
 120                         write_buf(f, map_ptr(buf, offset+len, n1), n1);
 121                         len += n1;
 122                 }
 123         }
 124         /* a -2 token means to send data only and no token */
 125         if (token != -2)
 126                 write_int(f, -(token+1));
 127 }
 128
 129 /* Flag bytes in compressed stream are encoded as follows: */
 130 #define END_FLAG        0       /* that's all folks */
 131 #define TOKEN_LONG      0x20    /* followed by 32-bit token number */
 132 #define TOKENRUN_LONG   0x21    /* ditto with 16-bit run count */
 133 #define DEFLATED_DATA   0x40    /* + 6-bit high len, then low len byte */
 134 #define TOKEN_REL       0x80    /* + 6-bit relative token number */
 135 #define TOKENRUN_REL    0xc0    /* ditto with 16-bit run count */
 136
 137 #define MAX_DATA_COUNT  16383   /* fit 14 bit count into 2 bytes with flags */
 138
 139 /* zlib.h says that if we want to be able to compress something in a single
 140  * call, avail_out must be at least 0.1% larger than avail_in plus 12 bytes.
 141  * We'll add in 0.1%+16, just to be safe (and we'll avoid floating point,
 142  * to ensure that this is a compile-time value). */
 143 #define AVAIL_OUT_SIZE(avail_in_size) ((avail_in_size)*1001/1000+16)
 144
 145 /* For coding runs of tokens */
 146 static int32 last_token = -1;
 147 static int32 run_start;
 148 static int32 last_run_end;
 149
 150 /* Deflation state */
 151 static z_stream tx_strm;
 152
 153 /* Output buffer */
 154 static char *obuf;
 155
 156 /* We want obuf to be able to hold both MAX_DATA_COUNT+2 bytes as well as
 157  * AVAIL_OUT_SIZE(CHUNK_SIZE) bytes, so make sure that it's large enough. */
 158 #if MAX_DATA_COUNT+2 > AVAIL_OUT_SIZE(CHUNK_SIZE)
 159 #define OBUF_SIZE       (MAX_DATA_COUNT+2)
 160 #else
 161 #define OBUF_SIZE       AVAIL_OUT_SIZE(CHUNK_SIZE)
 162 #endif
 163
 164 /* Send a deflated token */
 165 static void
 166 send_deflated_token(int f, int32 token, struct map_struct *buf, OFF_T offset,
 167                     int32 nb, int32 toklen)
 168 {
 169         int32 n, r;
 170         static int init_done, flush_pending;
 171
 172         if (last_token == -1) {
 173                 /* initialization */
 174                 if (!init_done) {
 175                         tx_strm.next_in = NULL;
 176                         tx_strm.zalloc = NULL;
 177                         tx_strm.zfree = NULL;
 178                         if (deflateInit2(&tx_strm, compression_level,
 179                                          Z_DEFLATED, -15, 8,
 180                                          Z_DEFAULT_STRATEGY) != Z_OK) {
 181                                 rprintf(FERROR, "compression init failed\n");
 182                                 exit_cleanup(RERR_STREAMIO);
 183                         }
 184                         if ((obuf = new_array(char, OBUF_SIZE)) == NULL)
 185                                 out_of_memory("send_deflated_token");
 186                         init_done = 1;
 187                 } else
 188                         deflateReset(&tx_strm);
 189                 last_run_end = 0;
 190                 run_start = token;
 191                 flush_pending = 0;
 192         } else if (last_token == -2) {
 193                 run_start = token;
 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                 } else {
 202                         write_byte(f, (n==0? TOKEN_LONG: TOKENRUN_LONG));
 203                         write_int(f, run_start);
 204                 }
 205                 if (n != 0) {
 206                         write_byte(f, n);
 207                         write_byte(f, n >> 8);
 208                 }
 209                 last_run_end = last_token;
 210                 run_start = token;
 211         }
 212
 213         last_token = token;
 214
 215         if (nb != 0 || flush_pending) {
 216                 /* deflate the data starting at offset */
 217                 int flush = Z_NO_FLUSH;
 218                 tx_strm.avail_in = 0;
 219                 tx_strm.avail_out = 0;
 220                 do {
 221                         if (tx_strm.avail_in == 0 && nb != 0) {
 222                                 /* give it some more input */
 223                                 n = MIN(nb, CHUNK_SIZE);
 224                                 tx_strm.next_in = (Bytef *)
 225                                         map_ptr(buf, offset, n);
 226                                 tx_strm.avail_in = n;
 227                                 nb -= n;
 228                                 offset += n;
 229                         }
 230                         if (tx_strm.avail_out == 0) {
 231                                 tx_strm.next_out = (Bytef *)(obuf + 2);
 232                                 tx_strm.avail_out = MAX_DATA_COUNT;
 233                                 if (flush != Z_NO_FLUSH) {
 234                                         /*
 235                                          * We left the last 4 bytes in the
 236                                          * buffer, in case they are the
 237                                          * last 4.  Move them to the front.
 238                                          */
 239                                         memcpy(tx_strm.next_out,
 240                                                obuf+MAX_DATA_COUNT-2, 4);
 241                                         tx_strm.next_out += 4;
 242                                         tx_strm.avail_out -= 4;
 243                                 }
 244                         }
 245                         if (nb == 0 && token != -2)
 246                                 flush = Z_SYNC_FLUSH;
 247                         r = deflate(&tx_strm, flush);
 248                         if (r != Z_OK) {
 249                                 rprintf(FERROR, "deflate returned %d\n", r);
 250                                 exit_cleanup(RERR_STREAMIO);
 251                         }
 252                         if (nb == 0 || tx_strm.avail_out == 0) {
 253                                 n = MAX_DATA_COUNT - tx_strm.avail_out;
 254                                 if (flush != Z_NO_FLUSH) {
 255                                         /*
 256                                          * We have to trim off the last 4
 257                                          * bytes of output when flushing
 258                                          * (they are just 0, 0, ff, ff).
 259                                          */
 260                                         n -= 4;
 261                                 }
 262                                 if (n > 0) {
 263                                         obuf[0] = DEFLATED_DATA + (n >> 8);
 264                                         obuf[1] = n;
 265                                         write_buf(f, obuf, n+2);
 266                                 }
 267                         }
 268                 } while (nb != 0 || tx_strm.avail_out == 0);
 269                 flush_pending = token == -2;
 270         }
 271
 272         if (token == -1) {
 273                 /* end of file - clean up */
 274                 write_byte(f, END_FLAG);
 275         } else if (token != -2) {
 276                 /* Add the data in the current block to the compressor's
 277                  * history and hash table. */
 278                 do {
 279                         /* Break up long sections in the same way that
 280                          * see_deflate_token() does. */
 281                         int32 n1 = toklen > 0xffff ? 0xffff : toklen;
 282                         toklen -= n1;
 283                         tx_strm.next_in = (Bytef *)map_ptr(buf, offset, n1);
 284                         tx_strm.avail_in = n1;
 285                         tx_strm.next_out = (Bytef *) obuf;
 286                         tx_strm.avail_out = AVAIL_OUT_SIZE(CHUNK_SIZE);
 287                         r = deflate(&tx_strm, Z_INSERT_ONLY);
 288                         if (r != Z_OK || tx_strm.avail_in != 0) {
 289                                 rprintf(FERROR, "deflate on token returned %d (%d bytes left)\n",
 290                                         r, tx_strm.avail_in);
 291                                 exit_cleanup(RERR_STREAMIO);
 292                         }
 293                 } while (toklen > 0);
 294         }
 295 }
 296
 297 /* tells us what the receiver is in the middle of doing */
 298 static enum { r_init, r_idle, r_running, r_inflating, r_inflated } recv_state;
 299
 300 /* for inflating stuff */
 301 static z_stream rx_strm;
 302 static char *cbuf;
 303 static char *dbuf;
 304
 305 /* for decoding runs of tokens */
 306 static int32 rx_token;
 307 static int32 rx_run;
 308
 309 /* Receive a deflated token and inflate it */
 310 static int32 recv_deflated_token(int f, char **data)
 311 {
 312         static int init_done;
 313         static int32 saved_flag;
 314         int32 n, flag;
 315         int r;
 316
 317         for (;;) {
 318                 switch (recv_state) {
 319                 case r_init:
 320                         if (!init_done) {
 321                                 rx_strm.next_out = NULL;
 322                                 rx_strm.zalloc = NULL;
 323                                 rx_strm.zfree = NULL;
 324                                 if (inflateInit2(&rx_strm, -15) != Z_OK) {
 325                                         rprintf(FERROR, "inflate init failed\n");
 326                                         exit_cleanup(RERR_STREAMIO);
 327                                 }
 328                                 if (!(cbuf = new_array(char, MAX_DATA_COUNT))
 329                                     || !(dbuf = new_array(char, AVAIL_OUT_SIZE(CHUNK_SIZE))))
 330                                         out_of_memory("recv_deflated_token");
 331                                 init_done = 1;
 332                         } else {
 333                                 inflateReset(&rx_strm);
 334                         }
 335                         recv_state = r_idle;
 336                         rx_token = 0;
 337                         break;
 338
 339                 case r_idle:
 340                 case r_inflated:
 341                         if (saved_flag) {
 342                                 flag = saved_flag & 0xff;
 343                                 saved_flag = 0;
 344                         } else
 345                                 flag = read_byte(f);
 346                         if ((flag & 0xC0) == DEFLATED_DATA) {
 347                                 n = ((flag & 0x3f) << 8) + read_byte(f);
 348                                 read_buf(f, cbuf, n);
 349                                 rx_strm.next_in = (Bytef *)cbuf;
 350                                 rx_strm.avail_in = n;
 351                                 recv_state = r_inflating;
 352                                 break;
 353                         }
 354                         if (recv_state == r_inflated) {
 355                                 /* check previous inflated stuff ended correctly */
 356                                 rx_strm.avail_in = 0;
 357                                 rx_strm.next_out = (Bytef *)dbuf;
 358                                 rx_strm.avail_out = AVAIL_OUT_SIZE(CHUNK_SIZE);
 359                                 r = inflate(&rx_strm, Z_SYNC_FLUSH);
 360                                 n = AVAIL_OUT_SIZE(CHUNK_SIZE) - rx_strm.avail_out;
 361                                 /*
 362                                  * Z_BUF_ERROR just means no progress was
 363                                  * made, i.e. the decompressor didn't have
 364                                  * any pending output for us.
 365                                  */
 366                                 if (r != Z_OK && r != Z_BUF_ERROR) {
 367                                         rprintf(FERROR, "inflate flush returned %d (%d bytes)\n",
 368                                                 r, n);
 369                                         exit_cleanup(RERR_STREAMIO);
 370                                 }
 371                                 if (n != 0 && r != Z_BUF_ERROR) {
 372                                         /* have to return some more data and
 373                                            save the flag for later. */
 374                                         saved_flag = flag + 0x10000;
 375                                         *data = dbuf;
 376                                         return n;
 377                                 }
 378                                 /*
 379                                  * At this point the decompressor should
 380                                  * be expecting to see the 0, 0, ff, ff bytes.
 381                                  */
 382                                 if (!inflateSyncPoint(&rx_strm)) {
 383                                         rprintf(FERROR, "decompressor lost sync!\n");
 384                                         exit_cleanup(RERR_STREAMIO);
 385                                 }
 386                                 rx_strm.avail_in = 4;
 387                                 rx_strm.next_in = (Bytef *)cbuf;
 388                                 cbuf[0] = cbuf[1] = 0;
 389                                 cbuf[2] = cbuf[3] = 0xff;
 390                                 inflate(&rx_strm, Z_SYNC_FLUSH);
 391                                 recv_state = r_idle;
 392                         }
 393                         if (flag == END_FLAG) {
 394                                 /* that's all folks */
 395                                 recv_state = r_init;
 396                                 return 0;
 397                         }
 398
 399                         /* here we have a token of some kind */
 400                         if (flag & TOKEN_REL) {
 401                                 rx_token += flag & 0x3f;
 402                                 flag >>= 6;
 403                         } else
 404                                 rx_token = read_int(f);
 405                         if (flag & 1) {
 406                                 rx_run = read_byte(f);
 407                                 rx_run += read_byte(f) << 8;
 408                                 recv_state = r_running;
 409                         }
 410                         return -1 - rx_token;
 411
 412                 case r_inflating:
 413                         rx_strm.next_out = (Bytef *)dbuf;
 414                         rx_strm.avail_out = AVAIL_OUT_SIZE(CHUNK_SIZE);
 415                         r = inflate(&rx_strm, Z_NO_FLUSH);
 416                         n = AVAIL_OUT_SIZE(CHUNK_SIZE) - rx_strm.avail_out;
 417                         if (r != Z_OK) {
 418                                 rprintf(FERROR, "inflate returned %d (%d bytes)\n", r, n);
 419                                 exit_cleanup(RERR_STREAMIO);
 420                         }
 421                         if (rx_strm.avail_in == 0)
 422                                 recv_state = r_inflated;
 423                         if (n != 0) {
 424                                 *data = dbuf;
 425                                 return n;
 426                         }
 427                         break;
 428
 429                 case r_running:
 430                         ++rx_token;
 431                         if (--rx_run == 0)
 432                                 recv_state = r_idle;
 433                         return -1 - rx_token;
 434                 }
 435         }
 436 }
 437
 438 /*
 439  * put the data corresponding to a token that we've just returned
 440  * from recv_deflated_token into the decompressor's history buffer.
 441  */
 442 static void see_deflate_token(char *buf, int32 len)
 443 {
 444         int r;
 445         int32 blklen;
 446         unsigned char hdr[5];
 447
 448         rx_strm.avail_in = 0;
 449         blklen = 0;
 450         hdr[0] = 0;
 451         do {
 452                 if (rx_strm.avail_in == 0 && len != 0) {
 453                         if (blklen == 0) {
 454                                 /* Give it a fake stored-block header. */
 455                                 rx_strm.next_in = (Bytef *)hdr;
 456                                 rx_strm.avail_in = 5;
 457                                 blklen = len;
 458                                 if (blklen > 0xffff)
 459                                         blklen = 0xffff;
 460                                 hdr[1] = blklen;
 461                                 hdr[2] = blklen >> 8;
 462                                 hdr[3] = ~hdr[1];
 463                                 hdr[4] = ~hdr[2];
 464                         } else {
 465                                 rx_strm.next_in = (Bytef *)buf;
 466                                 rx_strm.avail_in = blklen;
 467                                 len -= blklen;
 468                                 blklen = 0;
 469                         }
 470                 }
 471                 rx_strm.next_out = (Bytef *)dbuf;
 472                 rx_strm.avail_out = AVAIL_OUT_SIZE(CHUNK_SIZE);
 473                 r = inflate(&rx_strm, Z_SYNC_FLUSH);
 474                 if (r != Z_OK) {
 475                         rprintf(FERROR, "inflate (token) returned %d\n", r);
 476                         exit_cleanup(RERR_STREAMIO);
 477                 }
 478         } while (len || rx_strm.avail_out == 0);
 479 }
 480
 481 /**
 482  * Transmit a verbatim buffer of length @p n followed by a token.
 483  * If token == -1 then we have reached EOF
 484  * If n == 0 then don't send a buffer
 485  */
 486 void send_token(int f, int32 token, struct map_struct *buf, OFF_T offset,
 487                 int32 n, int32 toklen)
 488 {
 489         if (!do_compression)
 490                 simple_send_token(f, token, buf, offset, n);
 491         else
 492                 send_deflated_token(f, token, buf, offset, n, toklen);
 493 }
 494
 495 /*
 496  * receive a token or buffer from the other end. If the reurn value is >0 then
 497  * it is a data buffer of that length, and *data will point at the data.
 498  * if the return value is -i then it represents token i-1
 499  * if the return value is 0 then the end has been reached
 500  */
 501 int32 recv_token(int f, char **data)
 502 {
 503         int tok;
 504
 505         if (!do_compression) {
 506                 tok = simple_recv_token(f,data);
 507         } else {
 508                 tok = recv_deflated_token(f, data);
 509         }
 510         return tok;
 511 }
 512
 513 /*
 514  * look at the data corresponding to a token, if necessary
 515  */
 516 void see_token(char *data, int32 toklen)
 517 {
 518         if (do_compression)
 519                 see_deflate_token(data, toklen);
 520 }