drivers/net/ppp_deflate.c

   1 /*
   2  *  ==FILEVERSION 980319==
   3  *
   4  * ppp_deflate.c - interface the zlib procedures for Deflate compression
   5  * and decompression (as used by gzip) to the PPP code.
   6  * This version is for use with Linux kernel 1.3.X.
   7  *
   8  * Copyright (c) 1994 The Australian National University.
   9  * All rights reserved.
  10  *
  11  * Permission to use, copy, modify, and distribute this software and its
  12  * documentation is hereby granted, provided that the above copyright
  13  * notice appears in all copies.  This software is provided without any
  14  * warranty, express or implied. The Australian National University
  15  * makes no representations about the suitability of this software for
  16  * any purpose.
  17  *
  18  * IN NO EVENT SHALL THE AUSTRALIAN NATIONAL UNIVERSITY BE LIABLE TO ANY
  19  * PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
  20  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
  21  * THE AUSTRALIAN NATIONAL UNIVERSITY HAS BEEN ADVISED OF THE POSSIBILITY
  22  * OF SUCH DAMAGE.
  23  *
  24  * THE AUSTRALIAN NATIONAL UNIVERSITY SPECIFICALLY DISCLAIMS ANY WARRANTIES,
  25  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
  26  * AND FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
  27  * ON AN "AS IS" BASIS, AND THE AUSTRALIAN NATIONAL UNIVERSITY HAS NO
  28  * OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS,
  29  * OR MODIFICATIONS.
  30  *
  31  * From: deflate.c,v 1.1 1996/01/18 03:17:48 paulus Exp
  32  */
  33
  34 #include <linux/module.h>
  35 #include <linux/slab.h>
  36 #include <linux/vmalloc.h>
  37 #include <linux/init.h>
  38 #include <linux/string.h>
  39
  40 #include <linux/ppp_defs.h>
  41 #include <linux/ppp-comp.h>
  42
  43 #include <linux/zlib.h>
  44
  45 /*
  46  * State for a Deflate (de)compressor.
  47  */
  48 struct ppp_deflate_state {
  49     int         seqno;
  50     int         w_size;
  51     int         unit;
  52     int         mru;
  53     int         debug;
  54     z_stream    strm;
  55     struct compstat stats;
  56 };
  57
  58 #define DEFLATE_OVHD    2               /* Deflate overhead/packet */
  59
  60 static void     *z_comp_alloc(unsigned char *options, int opt_len);
  61 static void     *z_decomp_alloc(unsigned char *options, int opt_len);
  62 static void     z_comp_free(void *state);
  63 static void     z_decomp_free(void *state);
  64 static int      z_comp_init(void *state, unsigned char *options,
  65                                  int opt_len,
  66                                  int unit, int hdrlen, int debug);
  67 static int      z_decomp_init(void *state, unsigned char *options,
  68                                    int opt_len,
  69                                    int unit, int hdrlen, int mru, int debug);
  70 static int      z_compress(void *state, unsigned char *rptr,
  71                                 unsigned char *obuf,
  72                                 int isize, int osize);
  73 static void     z_incomp(void *state, unsigned char *ibuf, int icnt);
  74 static int      z_decompress(void *state, unsigned char *ibuf,
  75                                 int isize, unsigned char *obuf, int osize);
  76 static void     z_comp_reset(void *state);
  77 static void     z_decomp_reset(void *state);
  78 static void     z_comp_stats(void *state, struct compstat *stats);
  79
  80 /**
  81  *      z_comp_free - free the memory used by a compressor
  82  *      @arg:   pointer to the private state for the compressor.
  83  */
  84 static void z_comp_free(void *arg)
  85 {
  86         struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
  87
  88         if (state) {
  89                 zlib_deflateEnd(&state->strm);
  90                 if (state->strm.workspace)
  91                         vfree(state->strm.workspace);
  92                 kfree(state);
  93         }
  94 }
  95
  96 /**
  97  *      z_comp_alloc - allocate space for a compressor.
  98  *      @options: pointer to CCP option data
  99  *      @opt_len: length of the CCP option at @options.
 100  *
 101  *      The @options pointer points to the a buffer containing the
 102  *      CCP option data for the compression being negotiated.  It is
 103  *      formatted according to RFC1979, and describes the window
 104  *      size that the peer is requesting that we use in compressing
 105  *      data to be sent to it.
 106  *
 107  *      Returns the pointer to the private state for the compressor,
 108  *      or NULL if we could not allocate enough memory.
 109  */
 110 static void *z_comp_alloc(unsigned char *options, int opt_len)
 111 {
 112         struct ppp_deflate_state *state;
 113         int w_size;
 114
 115         if (opt_len != CILEN_DEFLATE
 116             || (options[0] != CI_DEFLATE && options[0] != CI_DEFLATE_DRAFT)
 117             || options[1] != CILEN_DEFLATE
 118             || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
 119             || options[3] != DEFLATE_CHK_SEQUENCE)
 120                 return NULL;
 121         w_size = DEFLATE_SIZE(options[2]);
 122         if (w_size < DEFLATE_MIN_SIZE || w_size > DEFLATE_MAX_SIZE)
 123                 return NULL;
 124
 125         state = (struct ppp_deflate_state *) kmalloc(sizeof(*state),
 126                                                      GFP_KERNEL);
 127         if (state == NULL)
 128                 return NULL;
 129
 130         memset (state, 0, sizeof (struct ppp_deflate_state));
 131         state->strm.next_in   = NULL;
 132         state->w_size         = w_size;
 133         state->strm.workspace = vmalloc(zlib_deflate_workspacesize());
 134         if (state->strm.workspace == NULL)
 135                 goto out_free;
 136
 137         if (zlib_deflateInit2(&state->strm, Z_DEFAULT_COMPRESSION,
 138                          DEFLATE_METHOD_VAL, -w_size, 8, Z_DEFAULT_STRATEGY)
 139             != Z_OK)
 140                 goto out_free;
 141         return (void *) state;
 142
 143 out_free:
 144         z_comp_free(state);
 145         return NULL;
 146 }
 147
 148 /**
 149  *      z_comp_init - initialize a previously-allocated compressor.
 150  *      @arg:   pointer to the private state for the compressor
 151  *      @options: pointer to the CCP option data describing the
 152  *              compression that was negotiated with the peer
 153  *      @opt_len: length of the CCP option data at @options
 154  *      @unit:  PPP unit number for diagnostic messages
 155  *      @hdrlen: ignored (present for backwards compatibility)
 156  *      @debug: debug flag; if non-zero, debug messages are printed.
 157  *
 158  *      The CCP options described by @options must match the options
 159  *      specified when the compressor was allocated.  The compressor
 160  *      history is reset.  Returns 0 for failure (CCP options don't
 161  *      match) or 1 for success.
 162  */
 163 static int z_comp_init(void *arg, unsigned char *options, int opt_len,
 164                        int unit, int hdrlen, int debug)
 165 {
 166         struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
 167
 168         if (opt_len < CILEN_DEFLATE
 169             || (options[0] != CI_DEFLATE && options[0] != CI_DEFLATE_DRAFT)
 170             || options[1] != CILEN_DEFLATE
 171             || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
 172             || DEFLATE_SIZE(options[2]) != state->w_size
 173             || options[3] != DEFLATE_CHK_SEQUENCE)
 174                 return 0;
 175
 176         state->seqno = 0;
 177         state->unit  = unit;
 178         state->debug = debug;
 179
 180         zlib_deflateReset(&state->strm);
 181
 182         return 1;
 183 }
 184
 185 /**
 186  *      z_comp_reset - reset a previously-allocated compressor.
 187  *      @arg:   pointer to private state for the compressor.
 188  *
 189  *      This clears the history for the compressor and makes it
 190  *      ready to start emitting a new compressed stream.
 191  */
 192 static void z_comp_reset(void *arg)
 193 {
 194         struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
 195
 196         state->seqno = 0;
 197         zlib_deflateReset(&state->strm);
 198 }
 199
 200 /**
 201  *      z_compress - compress a PPP packet with Deflate compression.
 202  *      @arg:   pointer to private state for the compressor
 203  *      @rptr:  uncompressed packet (input)
 204  *      @obuf:  compressed packet (output)
 205  *      @isize: size of uncompressed packet
 206  *      @osize: space available at @obuf
 207  *
 208  *      Returns the length of the compressed packet, or 0 if the
 209  *      packet is incompressible.
 210  */
 211 int z_compress(void *arg, unsigned char *rptr, unsigned char *obuf,
 212                int isize, int osize)
 213 {
 214         struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
 215         int r, proto, off, olen, oavail;
 216         unsigned char *wptr;
 217
 218         /*
 219          * Check that the protocol is in the range we handle.
 220          */
 221         proto = PPP_PROTOCOL(rptr);
 222         if (proto > 0x3fff || proto == 0xfd || proto == 0xfb)
 223                 return 0;
 224
 225         /* Don't generate compressed packets which are larger than
 226            the uncompressed packet. */
 227         if (osize > isize)
 228                 osize = isize;
 229
 230         wptr = obuf;
 231
 232         /*
 233          * Copy over the PPP header and store the 2-byte sequence number.
 234          */
 235         wptr[0] = PPP_ADDRESS(rptr);
 236         wptr[1] = PPP_CONTROL(rptr);
 237         wptr[2] = PPP_COMP >> 8;
 238         wptr[3] = PPP_COMP;
 239         wptr += PPP_HDRLEN;
 240         wptr[0] = state->seqno >> 8;
 241         wptr[1] = state->seqno;
 242         wptr += DEFLATE_OVHD;
 243         olen = PPP_HDRLEN + DEFLATE_OVHD;
 244         state->strm.next_out = wptr;
 245         state->strm.avail_out = oavail = osize - olen;
 246         ++state->seqno;
 247
 248         off = (proto > 0xff) ? 2 : 3;   /* skip 1st proto byte if 0 */
 249         rptr += off;
 250         state->strm.next_in = rptr;
 251         state->strm.avail_in = (isize - off);
 252
 253         for (;;) {
 254                 r = zlib_deflate(&state->strm, Z_PACKET_FLUSH);
 255                 if (r != Z_OK) {
 256                         if (state->debug)
 257                                 printk(KERN_ERR
 258                                        "z_compress: deflate returned %d\n", r);
 259                         break;
 260                 }
 261                 if (state->strm.avail_out == 0) {
 262                         olen += oavail;
 263                         state->strm.next_out = NULL;
 264                         state->strm.avail_out = oavail = 1000000;
 265                 } else {
 266                         break;          /* all done */
 267                 }
 268         }
 269         olen += oavail - state->strm.avail_out;
 270
 271         /*
 272          * See if we managed to reduce the size of the packet.
 273          */
 274         if (olen < isize) {
 275                 state->stats.comp_bytes += olen;
 276                 state->stats.comp_packets++;
 277         } else {
 278                 state->stats.inc_bytes += isize;
 279                 state->stats.inc_packets++;
 280                 olen = 0;
 281         }
 282         state->stats.unc_bytes += isize;
 283         state->stats.unc_packets++;
 284
 285         return olen;
 286 }
 287
 288 /**
 289  *      z_comp_stats - return compression statistics for a compressor
 290  *              or decompressor.
 291  *      @arg:   pointer to private space for the (de)compressor
 292  *      @stats: pointer to a struct compstat to receive the result.
 293  */
 294 static void z_comp_stats(void *arg, struct compstat *stats)
 295 {
 296         struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
 297
 298         *stats = state->stats;
 299 }
 300
 301 /**
 302  *      z_decomp_free - Free the memory used by a decompressor.
 303  *      @arg:   pointer to private space for the decompressor.
 304  */
 305 static void z_decomp_free(void *arg)
 306 {
 307         struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
 308
 309         if (state) {
 310                 zlib_inflateEnd(&state->strm);
 311                 if (state->strm.workspace)
 312                         kfree(state->strm.workspace);
 313                 kfree(state);
 314         }
 315 }
 316
 317 /**
 318  *      z_decomp_alloc - allocate space for a decompressor.
 319  *      @options: pointer to CCP option data
 320  *      @opt_len: length of the CCP option at @options.
 321  *
 322  *      The @options pointer points to the a buffer containing the
 323  *      CCP option data for the compression being negotiated.  It is
 324  *      formatted according to RFC1979, and describes the window
 325  *      size that we are requesting the peer to use in compressing
 326  *      data to be sent to us.
 327  *
 328  *      Returns the pointer to the private state for the decompressor,
 329  *      or NULL if we could not allocate enough memory.
 330  */
 331 static void *z_decomp_alloc(unsigned char *options, int opt_len)
 332 {
 333         struct ppp_deflate_state *state;
 334         int w_size;
 335
 336         if (opt_len != CILEN_DEFLATE
 337             || (options[0] != CI_DEFLATE && options[0] != CI_DEFLATE_DRAFT)
 338             || options[1] != CILEN_DEFLATE
 339             || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
 340             || options[3] != DEFLATE_CHK_SEQUENCE)
 341                 return NULL;
 342         w_size = DEFLATE_SIZE(options[2]);
 343         if (w_size < DEFLATE_MIN_SIZE || w_size > DEFLATE_MAX_SIZE)
 344                 return NULL;
 345
 346         state = (struct ppp_deflate_state *) kmalloc(sizeof(*state), GFP_KERNEL);
 347         if (state == NULL)
 348                 return NULL;
 349
 350         memset (state, 0, sizeof (struct ppp_deflate_state));
 351         state->w_size         = w_size;
 352         state->strm.next_out  = NULL;
 353         state->strm.workspace = kmalloc(zlib_inflate_workspacesize(),
 354                                         GFP_KERNEL|__GFP_REPEAT);
 355         if (state->strm.workspace == NULL)
 356                 goto out_free;
 357
 358         if (zlib_inflateInit2(&state->strm, -w_size) != Z_OK)
 359                 goto out_free;
 360         return (void *) state;
 361
 362 out_free:
 363         z_decomp_free(state);
 364         return NULL;
 365 }
 366
 367 /**
 368  *      z_decomp_init - initialize a previously-allocated decompressor.
 369  *      @arg:   pointer to the private state for the decompressor
 370  *      @options: pointer to the CCP option data describing the
 371  *              compression that was negotiated with the peer
 372  *      @opt_len: length of the CCP option data at @options
 373  *      @unit:  PPP unit number for diagnostic messages
 374  *      @hdrlen: ignored (present for backwards compatibility)
 375  *      @mru:   maximum length of decompressed packets
 376  *      @debug: debug flag; if non-zero, debug messages are printed.
 377  *
 378  *      The CCP options described by @options must match the options
 379  *      specified when the decompressor was allocated.  The decompressor
 380  *      history is reset.  Returns 0 for failure (CCP options don't
 381  *      match) or 1 for success.
 382  */
 383 static int z_decomp_init(void *arg, unsigned char *options, int opt_len,
 384                          int unit, int hdrlen, int mru, int debug)
 385 {
 386         struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
 387
 388         if (opt_len < CILEN_DEFLATE
 389             || (options[0] != CI_DEFLATE && options[0] != CI_DEFLATE_DRAFT)
 390             || options[1] != CILEN_DEFLATE
 391             || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
 392             || DEFLATE_SIZE(options[2]) != state->w_size
 393             || options[3] != DEFLATE_CHK_SEQUENCE)
 394                 return 0;
 395
 396         state->seqno = 0;
 397         state->unit  = unit;
 398         state->debug = debug;
 399         state->mru   = mru;
 400
 401         zlib_inflateReset(&state->strm);
 402
 403         return 1;
 404 }
 405
 406 /**
 407  *      z_decomp_reset - reset a previously-allocated decompressor.
 408  *      @arg:   pointer to private state for the decompressor.
 409  *
 410  *      This clears the history for the decompressor and makes it
 411  *      ready to receive a new compressed stream.
 412  */
 413 static void z_decomp_reset(void *arg)
 414 {
 415         struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
 416
 417         state->seqno = 0;
 418         zlib_inflateReset(&state->strm);
 419 }
 420
 421 /**
 422  *      z_decompress - decompress a Deflate-compressed packet.
 423  *      @arg:   pointer to private state for the decompressor
 424  *      @ibuf:  pointer to input (compressed) packet data
 425  *      @isize: length of input packet
 426  *      @obuf:  pointer to space for output (decompressed) packet
 427  *      @osize: amount of space available at @obuf
 428  *
 429  * Because of patent problems, we return DECOMP_ERROR for errors
 430  * found by inspecting the input data and for system problems, but
 431  * DECOMP_FATALERROR for any errors which could possibly be said to
 432  * be being detected "after" decompression.  For DECOMP_ERROR,
 433  * we can issue a CCP reset-request; for DECOMP_FATALERROR, we may be
 434  * infringing a patent of Motorola's if we do, so we take CCP down
 435  * instead.
 436  *
 437  * Given that the frame has the correct sequence number and a good FCS,
 438  * errors such as invalid codes in the input most likely indicate a
 439  * bug, so we return DECOMP_FATALERROR for them in order to turn off
 440  * compression, even though they are detected by inspecting the input.
 441  */
 442 int z_decompress(void *arg, unsigned char *ibuf, int isize,
 443                  unsigned char *obuf, int osize)
 444 {
 445         struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
 446         int olen, seq, r;
 447         int decode_proto, overflow;
 448         unsigned char overflow_buf[1];
 449
 450         if (isize <= PPP_HDRLEN + DEFLATE_OVHD) {
 451                 if (state->debug)
 452                         printk(KERN_DEBUG "z_decompress%d: short pkt (%d)\n",
 453                                state->unit, isize);
 454                 return DECOMP_ERROR;
 455         }
 456
 457         /* Check the sequence number. */
 458         seq = (ibuf[PPP_HDRLEN] << 8) + ibuf[PPP_HDRLEN+1];
 459         if (seq != (state->seqno & 0xffff)) {
 460                 if (state->debug)
 461                         printk(KERN_DEBUG "z_decompress%d: bad seq # %d, expected %d\n",
 462                                state->unit, seq, state->seqno & 0xffff);
 463                 return DECOMP_ERROR;
 464         }
 465         ++state->seqno;
 466
 467         /*
 468          * Fill in the first part of the PPP header.  The protocol field
 469          * comes from the decompressed data.
 470          */
 471         obuf[0] = PPP_ADDRESS(ibuf);
 472         obuf[1] = PPP_CONTROL(ibuf);
 473         obuf[2] = 0;
 474
 475         /*
 476          * Set up to call inflate.  We set avail_out to 1 initially so we can
 477          * look at the first byte of the output and decide whether we have
 478          * a 1-byte or 2-byte protocol field.
 479          */
 480         state->strm.next_in = ibuf + PPP_HDRLEN + DEFLATE_OVHD;
 481         state->strm.avail_in = isize - (PPP_HDRLEN + DEFLATE_OVHD);
 482         state->strm.next_out = obuf + 3;
 483         state->strm.avail_out = 1;
 484         decode_proto = 1;
 485         overflow = 0;
 486
 487         /*
 488          * Call inflate, supplying more input or output as needed.
 489          */
 490         for (;;) {
 491                 r = zlib_inflate(&state->strm, Z_PACKET_FLUSH);
 492                 if (r != Z_OK) {
 493                         if (state->debug)
 494                                 printk(KERN_DEBUG "z_decompress%d: inflate returned %d (%s)\n",
 495                                        state->unit, r, (state->strm.msg? state->strm.msg: ""));
 496                         return DECOMP_FATALERROR;
 497                 }
 498                 if (state->strm.avail_out != 0)
 499                         break;          /* all done */
 500                 if (decode_proto) {
 501                         state->strm.avail_out = osize - PPP_HDRLEN;
 502                         if ((obuf[3] & 1) == 0) {
 503                                 /* 2-byte protocol field */
 504                                 obuf[2] = obuf[3];
 505                                 --state->strm.next_out;
 506                                 ++state->strm.avail_out;
 507                         }
 508                         decode_proto = 0;
 509                 } else if (!overflow) {
 510                         /*
 511                          * We've filled up the output buffer; the only way to
 512                          * find out whether inflate has any more characters
 513                          * left is to give it another byte of output space.
 514                          */
 515                         state->strm.next_out = overflow_buf;
 516                         state->strm.avail_out = 1;
 517                         overflow = 1;
 518                 } else {
 519                         if (state->debug)
 520                                 printk(KERN_DEBUG "z_decompress%d: ran out of mru\n",
 521                                        state->unit);
 522                         return DECOMP_FATALERROR;
 523                 }
 524         }
 525
 526         if (decode_proto) {
 527                 if (state->debug)
 528                         printk(KERN_DEBUG "z_decompress%d: didn't get proto\n",
 529                                state->unit);
 530                 return DECOMP_ERROR;
 531         }
 532
 533         olen = osize + overflow - state->strm.avail_out;
 534         state->stats.unc_bytes += olen;
 535         state->stats.unc_packets++;
 536         state->stats.comp_bytes += isize;
 537         state->stats.comp_packets++;
 538
 539         return olen;
 540 }
 541
 542 /**
 543  *      z_incomp - add incompressible input data to the history.
 544  *      @arg:   pointer to private state for the decompressor
 545  *      @ibuf:  pointer to input packet data
 546  *      @icnt:  length of input data.
 547  */
 548 static void z_incomp(void *arg, unsigned char *ibuf, int icnt)
 549 {
 550         struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
 551         int proto, r;
 552
 553         /*
 554          * Check that the protocol is one we handle.
 555          */
 556         proto = PPP_PROTOCOL(ibuf);
 557         if (proto > 0x3fff || proto == 0xfd || proto == 0xfb)
 558                 return;
 559
 560         ++state->seqno;
 561
 562         /*
 563          * We start at the either the 1st or 2nd byte of the protocol field,
 564          * depending on whether the protocol value is compressible.
 565          */
 566         state->strm.next_in = ibuf + 3;
 567         state->strm.avail_in = icnt - 3;
 568         if (proto > 0xff) {
 569                 --state->strm.next_in;
 570                 ++state->strm.avail_in;
 571         }
 572
 573         r = zlib_inflateIncomp(&state->strm);
 574         if (r != Z_OK) {
 575                 /* gak! */
 576                 if (state->debug) {
 577                         printk(KERN_DEBUG "z_incomp%d: inflateIncomp returned %d (%s)\n",
 578                                state->unit, r, (state->strm.msg? state->strm.msg: ""));
 579                 }
 580                 return;
 581         }
 582
 583         /*
 584          * Update stats.
 585          */
 586         state->stats.inc_bytes += icnt;
 587         state->stats.inc_packets++;
 588         state->stats.unc_bytes += icnt;
 589         state->stats.unc_packets++;
 590 }
 591
 592 /*************************************************************
 593  * Module interface table
 594  *************************************************************/
 595
 596 /* These are in ppp_generic.c */
 597 extern int  ppp_register_compressor   (struct compressor *cp);
 598 extern void ppp_unregister_compressor (struct compressor *cp);
 599
 600 /*
 601  * Procedures exported to if_ppp.c.
 602  */
 603 struct compressor ppp_deflate = {
 604         .compress_proto =       CI_DEFLATE,
 605         .comp_alloc =           z_comp_alloc,
 606         .comp_free =            z_comp_free,
 607         .comp_init =            z_comp_init,
 608         .comp_reset =           z_comp_reset,
 609         .compress =             z_compress,
 610         .comp_stat =            z_comp_stats,
 611         .decomp_alloc =         z_decomp_alloc,
 612         .decomp_free =          z_decomp_free,
 613         .decomp_init =          z_decomp_init,
 614         .decomp_reset =         z_decomp_reset,
 615         .decompress =           z_decompress,
 616         .incomp =               z_incomp,
 617         .decomp_stat =          z_comp_stats,
 618         .owner =                THIS_MODULE
 619 };
 620
 621 struct compressor ppp_deflate_draft = {
 622         .compress_proto =       CI_DEFLATE_DRAFT,
 623         .comp_alloc =           z_comp_alloc,
 624         .comp_free =            z_comp_free,
 625         .comp_init =            z_comp_init,
 626         .comp_reset =           z_comp_reset,
 627         .compress =             z_compress,
 628         .comp_stat =            z_comp_stats,
 629         .decomp_alloc =         z_decomp_alloc,
 630         .decomp_free =          z_decomp_free,
 631         .decomp_init =          z_decomp_init,
 632         .decomp_reset =         z_decomp_reset,
 633         .decompress =           z_decompress,
 634         .incomp =               z_incomp,
 635         .decomp_stat =          z_comp_stats,
 636         .owner =                THIS_MODULE
 637 };
 638
 639 int __init deflate_init(void)
 640 {
 641         int answer = ppp_register_compressor(&ppp_deflate);
 642         if (answer == 0)
 643                 printk(KERN_INFO
 644                        "PPP Deflate Compression module registered\n");
 645         ppp_register_compressor(&ppp_deflate_draft);
 646         return answer;
 647 }
 648
 649 void __exit deflate_cleanup(void)
 650 {
 651         ppp_unregister_compressor(&ppp_deflate);
 652         ppp_unregister_compressor(&ppp_deflate_draft);
 653 }
 654
 655 module_init(deflate_init);
 656 module_exit(deflate_cleanup);
 657 MODULE_LICENSE("Dual BSD/GPL");
 658 MODULE_ALIAS("ppp-compress-" __stringify(CI_DEFLATE));
 659 MODULE_ALIAS("ppp-compress-" __stringify(CI_DEFLATE_DRAFT));