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 #include <asm/unaligned.h>
  45
  46 /*
  47  * State for a Deflate (de)compressor.
  48  */
  49 struct ppp_deflate_state {
  50     int         seqno;
  51     int         w_size;
  52     int         unit;
  53     int         mru;
  54     int         debug;
  55     z_stream    strm;
  56     struct compstat stats;
  57 };
  58
  59 #define DEFLATE_OVHD    2               /* Deflate overhead/packet */
  60
  61 static void     *z_comp_alloc(unsigned char *options, int opt_len);
  62 static void     *z_decomp_alloc(unsigned char *options, int opt_len);
  63 static void     z_comp_free(void *state);
  64 static void     z_decomp_free(void *state);
  65 static int      z_comp_init(void *state, unsigned char *options,
  66                                  int opt_len,
  67                                  int unit, int hdrlen, int debug);
  68 static int      z_decomp_init(void *state, unsigned char *options,
  69                                    int opt_len,
  70                                    int unit, int hdrlen, int mru, int debug);
  71 static int      z_compress(void *state, unsigned char *rptr,
  72                                 unsigned char *obuf,
  73                                 int isize, int osize);
  74 static void     z_incomp(void *state, unsigned char *ibuf, int icnt);
  75 static int      z_decompress(void *state, unsigned char *ibuf,
  76                                 int isize, unsigned char *obuf, int osize);
  77 static void     z_comp_reset(void *state);
  78 static void     z_decomp_reset(void *state);
  79 static void     z_comp_stats(void *state, struct compstat *stats);
  80
  81 /**
  82  *      z_comp_free - free the memory used by a compressor
  83  *      @arg:   pointer to the private state for the compressor.
  84  */
  85 static void z_comp_free(void *arg)
  86 {
  87         struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
  88
  89         if (state) {
  90                 zlib_deflateEnd(&state->strm);
  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 = kzalloc(sizeof(*state),
 126                                                      GFP_KERNEL);
 127         if (state == NULL)
 128                 return NULL;
 129
 130         state->strm.next_in   = NULL;
 131         state->w_size         = w_size;
 132         state->strm.workspace = vmalloc(zlib_deflate_workspacesize(-w_size, 8));
 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 static 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         put_unaligned_be16(PPP_COMP, wptr + 2);
 237         wptr += PPP_HDRLEN;
 238         put_unaligned_be16(state->seqno, wptr);
 239         wptr += DEFLATE_OVHD;
 240         olen = PPP_HDRLEN + DEFLATE_OVHD;
 241         state->strm.next_out = wptr;
 242         state->strm.avail_out = oavail = osize - olen;
 243         ++state->seqno;
 244
 245         off = (proto > 0xff) ? 2 : 3;   /* skip 1st proto byte if 0 */
 246         rptr += off;
 247         state->strm.next_in = rptr;
 248         state->strm.avail_in = (isize - off);
 249
 250         for (;;) {
 251                 r = zlib_deflate(&state->strm, Z_PACKET_FLUSH);
 252                 if (r != Z_OK) {
 253                         if (state->debug)
 254                                 printk(KERN_ERR
 255                                        "z_compress: deflate returned %d\n", r);
 256                         break;
 257                 }
 258                 if (state->strm.avail_out == 0) {
 259                         olen += oavail;
 260                         state->strm.next_out = NULL;
 261                         state->strm.avail_out = oavail = 1000000;
 262                 } else {
 263                         break;          /* all done */
 264                 }
 265         }
 266         olen += oavail - state->strm.avail_out;
 267
 268         /*
 269          * See if we managed to reduce the size of the packet.
 270          */
 271         if (olen < isize) {
 272                 state->stats.comp_bytes += olen;
 273                 state->stats.comp_packets++;
 274         } else {
 275                 state->stats.inc_bytes += isize;
 276                 state->stats.inc_packets++;
 277                 olen = 0;
 278         }
 279         state->stats.unc_bytes += isize;
 280         state->stats.unc_packets++;
 281
 282         return olen;
 283 }
 284
 285 /**
 286  *      z_comp_stats - return compression statistics for a compressor
 287  *              or decompressor.
 288  *      @arg:   pointer to private space for the (de)compressor
 289  *      @stats: pointer to a struct compstat to receive the result.
 290  */
 291 static void z_comp_stats(void *arg, struct compstat *stats)
 292 {
 293         struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
 294
 295         *stats = state->stats;
 296 }
 297
 298 /**
 299  *      z_decomp_free - Free the memory used by a decompressor.
 300  *      @arg:   pointer to private space for the decompressor.
 301  */
 302 static void z_decomp_free(void *arg)
 303 {
 304         struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
 305
 306         if (state) {
 307                 zlib_inflateEnd(&state->strm);
 308                 vfree(state->strm.workspace);
 309                 kfree(state);
 310         }
 311 }
 312
 313 /**
 314  *      z_decomp_alloc - allocate space for a decompressor.
 315  *      @options: pointer to CCP option data
 316  *      @opt_len: length of the CCP option at @options.
 317  *
 318  *      The @options pointer points to the a buffer containing the
 319  *      CCP option data for the compression being negotiated.  It is
 320  *      formatted according to RFC1979, and describes the window
 321  *      size that we are requesting the peer to use in compressing
 322  *      data to be sent to us.
 323  *
 324  *      Returns the pointer to the private state for the decompressor,
 325  *      or NULL if we could not allocate enough memory.
 326  */
 327 static void *z_decomp_alloc(unsigned char *options, int opt_len)
 328 {
 329         struct ppp_deflate_state *state;
 330         int w_size;
 331
 332         if (opt_len != CILEN_DEFLATE ||
 333             (options[0] != CI_DEFLATE && options[0] != CI_DEFLATE_DRAFT) ||
 334             options[1] != CILEN_DEFLATE ||
 335             DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL ||
 336             options[3] != DEFLATE_CHK_SEQUENCE)
 337                 return NULL;
 338         w_size = DEFLATE_SIZE(options[2]);
 339         if (w_size < DEFLATE_MIN_SIZE || w_size > DEFLATE_MAX_SIZE)
 340                 return NULL;
 341
 342         state = kzalloc(sizeof(*state), GFP_KERNEL);
 343         if (state == NULL)
 344                 return NULL;
 345
 346         state->w_size         = w_size;
 347         state->strm.next_out  = NULL;
 348         state->strm.workspace = vmalloc(zlib_inflate_workspacesize());
 349         if (state->strm.workspace == NULL)
 350                 goto out_free;
 351
 352         if (zlib_inflateInit2(&state->strm, -w_size) != Z_OK)
 353                 goto out_free;
 354         return (void *) state;
 355
 356 out_free:
 357         z_decomp_free(state);
 358         return NULL;
 359 }
 360
 361 /**
 362  *      z_decomp_init - initialize a previously-allocated decompressor.
 363  *      @arg:   pointer to the private state for the decompressor
 364  *      @options: pointer to the CCP option data describing the
 365  *              compression that was negotiated with the peer
 366  *      @opt_len: length of the CCP option data at @options
 367  *      @unit:  PPP unit number for diagnostic messages
 368  *      @hdrlen: ignored (present for backwards compatibility)
 369  *      @mru:   maximum length of decompressed packets
 370  *      @debug: debug flag; if non-zero, debug messages are printed.
 371  *
 372  *      The CCP options described by @options must match the options
 373  *      specified when the decompressor was allocated.  The decompressor
 374  *      history is reset.  Returns 0 for failure (CCP options don't
 375  *      match) or 1 for success.
 376  */
 377 static int z_decomp_init(void *arg, unsigned char *options, int opt_len,
 378                          int unit, int hdrlen, int mru, int debug)
 379 {
 380         struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
 381
 382         if (opt_len < CILEN_DEFLATE ||
 383             (options[0] != CI_DEFLATE && options[0] != CI_DEFLATE_DRAFT) ||
 384             options[1] != CILEN_DEFLATE ||
 385             DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL ||
 386             DEFLATE_SIZE(options[2]) != state->w_size ||
 387             options[3] != DEFLATE_CHK_SEQUENCE)
 388                 return 0;
 389
 390         state->seqno = 0;
 391         state->unit  = unit;
 392         state->debug = debug;
 393         state->mru   = mru;
 394
 395         zlib_inflateReset(&state->strm);
 396
 397         return 1;
 398 }
 399
 400 /**
 401  *      z_decomp_reset - reset a previously-allocated decompressor.
 402  *      @arg:   pointer to private state for the decompressor.
 403  *
 404  *      This clears the history for the decompressor and makes it
 405  *      ready to receive a new compressed stream.
 406  */
 407 static void z_decomp_reset(void *arg)
 408 {
 409         struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
 410
 411         state->seqno = 0;
 412         zlib_inflateReset(&state->strm);
 413 }
 414
 415 /**
 416  *      z_decompress - decompress a Deflate-compressed packet.
 417  *      @arg:   pointer to private state for the decompressor
 418  *      @ibuf:  pointer to input (compressed) packet data
 419  *      @isize: length of input packet
 420  *      @obuf:  pointer to space for output (decompressed) packet
 421  *      @osize: amount of space available at @obuf
 422  *
 423  * Because of patent problems, we return DECOMP_ERROR for errors
 424  * found by inspecting the input data and for system problems, but
 425  * DECOMP_FATALERROR for any errors which could possibly be said to
 426  * be being detected "after" decompression.  For DECOMP_ERROR,
 427  * we can issue a CCP reset-request; for DECOMP_FATALERROR, we may be
 428  * infringing a patent of Motorola's if we do, so we take CCP down
 429  * instead.
 430  *
 431  * Given that the frame has the correct sequence number and a good FCS,
 432  * errors such as invalid codes in the input most likely indicate a
 433  * bug, so we return DECOMP_FATALERROR for them in order to turn off
 434  * compression, even though they are detected by inspecting the input.
 435  */
 436 static int z_decompress(void *arg, unsigned char *ibuf, int isize,
 437                  unsigned char *obuf, int osize)
 438 {
 439         struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
 440         int olen, seq, r;
 441         int decode_proto, overflow;
 442         unsigned char overflow_buf[1];
 443
 444         if (isize <= PPP_HDRLEN + DEFLATE_OVHD) {
 445                 if (state->debug)
 446                         printk(KERN_DEBUG "z_decompress%d: short pkt (%d)\n",
 447                                state->unit, isize);
 448                 return DECOMP_ERROR;
 449         }
 450
 451         /* Check the sequence number. */
 452         seq = get_unaligned_be16(ibuf + PPP_HDRLEN);
 453         if (seq != (state->seqno & 0xffff)) {
 454                 if (state->debug)
 455                         printk(KERN_DEBUG "z_decompress%d: bad seq # %d, expected %d\n",
 456                                state->unit, seq, state->seqno & 0xffff);
 457                 return DECOMP_ERROR;
 458         }
 459         ++state->seqno;
 460
 461         /*
 462          * Fill in the first part of the PPP header.  The protocol field
 463          * comes from the decompressed data.
 464          */
 465         obuf[0] = PPP_ADDRESS(ibuf);
 466         obuf[1] = PPP_CONTROL(ibuf);
 467         obuf[2] = 0;
 468
 469         /*
 470          * Set up to call inflate.  We set avail_out to 1 initially so we can
 471          * look at the first byte of the output and decide whether we have
 472          * a 1-byte or 2-byte protocol field.
 473          */
 474         state->strm.next_in = ibuf + PPP_HDRLEN + DEFLATE_OVHD;
 475         state->strm.avail_in = isize - (PPP_HDRLEN + DEFLATE_OVHD);
 476         state->strm.next_out = obuf + 3;
 477         state->strm.avail_out = 1;
 478         decode_proto = 1;
 479         overflow = 0;
 480
 481         /*
 482          * Call inflate, supplying more input or output as needed.
 483          */
 484         for (;;) {
 485                 r = zlib_inflate(&state->strm, Z_PACKET_FLUSH);
 486                 if (r != Z_OK) {
 487                         if (state->debug)
 488                                 printk(KERN_DEBUG "z_decompress%d: inflate returned %d (%s)\n",
 489                                        state->unit, r, (state->strm.msg? state->strm.msg: ""));
 490                         return DECOMP_FATALERROR;
 491                 }
 492                 if (state->strm.avail_out != 0)
 493                         break;          /* all done */
 494                 if (decode_proto) {
 495                         state->strm.avail_out = osize - PPP_HDRLEN;
 496                         if ((obuf[3] & 1) == 0) {
 497                                 /* 2-byte protocol field */
 498                                 obuf[2] = obuf[3];
 499                                 --state->strm.next_out;
 500                                 ++state->strm.avail_out;
 501                         }
 502                         decode_proto = 0;
 503                 } else if (!overflow) {
 504                         /*
 505                          * We've filled up the output buffer; the only way to
 506                          * find out whether inflate has any more characters
 507                          * left is to give it another byte of output space.
 508                          */
 509                         state->strm.next_out = overflow_buf;
 510                         state->strm.avail_out = 1;
 511                         overflow = 1;
 512                 } else {
 513                         if (state->debug)
 514                                 printk(KERN_DEBUG "z_decompress%d: ran out of mru\n",
 515                                        state->unit);
 516                         return DECOMP_FATALERROR;
 517                 }
 518         }
 519
 520         if (decode_proto) {
 521                 if (state->debug)
 522                         printk(KERN_DEBUG "z_decompress%d: didn't get proto\n",
 523                                state->unit);
 524                 return DECOMP_ERROR;
 525         }
 526
 527         olen = osize + overflow - state->strm.avail_out;
 528         state->stats.unc_bytes += olen;
 529         state->stats.unc_packets++;
 530         state->stats.comp_bytes += isize;
 531         state->stats.comp_packets++;
 532
 533         return olen;
 534 }
 535
 536 /**
 537  *      z_incomp - add incompressible input data to the history.
 538  *      @arg:   pointer to private state for the decompressor
 539  *      @ibuf:  pointer to input packet data
 540  *      @icnt:  length of input data.
 541  */
 542 static void z_incomp(void *arg, unsigned char *ibuf, int icnt)
 543 {
 544         struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
 545         int proto, r;
 546
 547         /*
 548          * Check that the protocol is one we handle.
 549          */
 550         proto = PPP_PROTOCOL(ibuf);
 551         if (proto > 0x3fff || proto == 0xfd || proto == 0xfb)
 552                 return;
 553
 554         ++state->seqno;
 555
 556         /*
 557          * We start at the either the 1st or 2nd byte of the protocol field,
 558          * depending on whether the protocol value is compressible.
 559          */
 560         state->strm.next_in = ibuf + 3;
 561         state->strm.avail_in = icnt - 3;
 562         if (proto > 0xff) {
 563                 --state->strm.next_in;
 564                 ++state->strm.avail_in;
 565         }
 566
 567         r = zlib_inflateIncomp(&state->strm);
 568         if (r != Z_OK) {
 569                 /* gak! */
 570                 if (state->debug) {
 571                         printk(KERN_DEBUG "z_incomp%d: inflateIncomp returned %d (%s)\n",
 572                                state->unit, r, (state->strm.msg? state->strm.msg: ""));
 573                 }
 574                 return;
 575         }
 576
 577         /*
 578          * Update stats.
 579          */
 580         state->stats.inc_bytes += icnt;
 581         state->stats.inc_packets++;
 582         state->stats.unc_bytes += icnt;
 583         state->stats.unc_packets++;
 584 }
 585
 586 /*************************************************************
 587  * Module interface table
 588  *************************************************************/
 589
 590 /* These are in ppp_generic.c */
 591 extern int  ppp_register_compressor   (struct compressor *cp);
 592 extern void ppp_unregister_compressor (struct compressor *cp);
 593
 594 /*
 595  * Procedures exported to if_ppp.c.
 596  */
 597 static struct compressor ppp_deflate = {
 598         .compress_proto =       CI_DEFLATE,
 599         .comp_alloc =           z_comp_alloc,
 600         .comp_free =            z_comp_free,
 601         .comp_init =            z_comp_init,
 602         .comp_reset =           z_comp_reset,
 603         .compress =             z_compress,
 604         .comp_stat =            z_comp_stats,
 605         .decomp_alloc =         z_decomp_alloc,
 606         .decomp_free =          z_decomp_free,
 607         .decomp_init =          z_decomp_init,
 608         .decomp_reset =         z_decomp_reset,
 609         .decompress =           z_decompress,
 610         .incomp =               z_incomp,
 611         .decomp_stat =          z_comp_stats,
 612         .owner =                THIS_MODULE
 613 };
 614
 615 static struct compressor ppp_deflate_draft = {
 616         .compress_proto =       CI_DEFLATE_DRAFT,
 617         .comp_alloc =           z_comp_alloc,
 618         .comp_free =            z_comp_free,
 619         .comp_init =            z_comp_init,
 620         .comp_reset =           z_comp_reset,
 621         .compress =             z_compress,
 622         .comp_stat =            z_comp_stats,
 623         .decomp_alloc =         z_decomp_alloc,
 624         .decomp_free =          z_decomp_free,
 625         .decomp_init =          z_decomp_init,
 626         .decomp_reset =         z_decomp_reset,
 627         .decompress =           z_decompress,
 628         .incomp =               z_incomp,
 629         .decomp_stat =          z_comp_stats,
 630         .owner =                THIS_MODULE
 631 };
 632
 633 static int __init deflate_init(void)
 634 {
 635         int answer = ppp_register_compressor(&ppp_deflate);
 636         if (answer == 0)
 637                 printk(KERN_INFO
 638                        "PPP Deflate Compression module registered\n");
 639         ppp_register_compressor(&ppp_deflate_draft);
 640         return answer;
 641 }
 642
 643 static void __exit deflate_cleanup(void)
 644 {
 645         ppp_unregister_compressor(&ppp_deflate);
 646         ppp_unregister_compressor(&ppp_deflate_draft);
 647 }
 648
 649 module_init(deflate_init);
 650 module_exit(deflate_cleanup);
 651 MODULE_LICENSE("Dual BSD/GPL");
 652 MODULE_ALIAS("ppp-compress-" __stringify(CI_DEFLATE));
 653 MODULE_ALIAS("ppp-compress-" __stringify(CI_DEFLATE_DRAFT));