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