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