2 * ppp_deflate.c - interface the zlib procedures for Deflate compression
3 * and decompression (as used by gzip) to the PPP code.
4 * This version is for use with STREAMS under SunOS 4.x, Solaris 2,
5 * SVR4, OSF/1 and AIX 4.x.
7 * Copyright (c) 1994 The Australian National University.
10 * Permission to use, copy, modify, and distribute this software and its
11 * documentation is hereby granted, provided that the above copyright
12 * notice appears in all copies. This software is provided without any
13 * warranty, express or implied. The Australian National University
14 * makes no representations about the suitability of this software for
17 * IN NO EVENT SHALL THE AUSTRALIAN NATIONAL UNIVERSITY BE LIABLE TO ANY
18 * PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
19 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
20 * THE AUSTRALIAN NATIONAL UNIVERSITY HAS BEEN ADVISED OF THE POSSIBILITY
23 * THE AUSTRALIAN NATIONAL UNIVERSITY SPECIFICALLY DISCLAIMS ANY WARRANTIES,
24 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
25 * AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
26 * ON AN "AS IS" BASIS, AND THE AUSTRALIAN NATIONAL UNIVERSITY HAS NO
27 * OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS,
30 * $Id: deflate.c,v 1.5 1997/04/30 05:43:39 paulus Exp $
34 #include <net/net_globals.h>
36 #include <sys/param.h>
37 #include <sys/types.h>
38 #include <sys/stream.h>
39 #include <net/ppp_defs.h>
42 #define PACKETPTR mblk_t *
43 #include <net/ppp-comp.h>
48 #include "common/zlib.h"
53 #define DEFLATE_DEBUG 1
56 * State for a Deflate (de)compressor.
58 struct deflate_state {
66 struct compstat stats;
69 #define DEFLATE_OVHD 2 /* Deflate overhead/packet */
71 static void *z_alloc __P((void *, u_int items, u_int size));
72 static void *z_alloc_init __P((void *, u_int items, u_int size));
73 static void z_free __P((void *, void *ptr, u_int nb));
74 static void *z_comp_alloc __P((u_char *options, int opt_len));
75 static void *z_decomp_alloc __P((u_char *options, int opt_len));
76 static void z_comp_free __P((void *state));
77 static void z_decomp_free __P((void *state));
78 static int z_comp_init __P((void *state, u_char *options, int opt_len,
79 int unit, int hdrlen, int debug));
80 static int z_decomp_init __P((void *state, u_char *options, int opt_len,
81 int unit, int hdrlen, int mru, int debug));
82 static int z_compress __P((void *state, mblk_t **mret,
83 mblk_t *mp, int slen, int maxolen));
84 static void z_incomp __P((void *state, mblk_t *dmsg));
85 static int z_decompress __P((void *state, mblk_t *cmp,
87 static void z_comp_reset __P((void *state));
88 static void z_decomp_reset __P((void *state));
89 static void z_comp_stats __P((void *state, struct compstat *stats));
92 * Procedures exported to if_ppp.c.
94 struct compressor ppp_deflate = {
95 CI_DEFLATE, /* compress_proto */
96 z_comp_alloc, /* comp_alloc */
97 z_comp_free, /* comp_free */
98 z_comp_init, /* comp_init */
99 z_comp_reset, /* comp_reset */
100 z_compress, /* compress */
101 z_comp_stats, /* comp_stat */
102 z_decomp_alloc, /* decomp_alloc */
103 z_decomp_free, /* decomp_free */
104 z_decomp_init, /* decomp_init */
105 z_decomp_reset, /* decomp_reset */
106 z_decompress, /* decompress */
107 z_incomp, /* incomp */
108 z_comp_stats, /* decomp_stat */
111 #define DECOMP_CHUNK 512
114 * Space allocation and freeing routines for use by zlib routines.
117 z_alloc_init(notused, items, size)
122 return ALLOC_SLEEP(items * size);
124 return ALLOC_NOSLEEP(items * size);
129 z_alloc(notused, items, size)
133 return ALLOC_NOSLEEP(items * size);
137 z_free(notused, ptr, nbytes)
146 * Allocate space for a compressor.
149 z_comp_alloc(options, opt_len)
153 struct deflate_state *state;
156 if (opt_len != CILEN_DEFLATE || options[0] != CI_DEFLATE
157 || options[1] != CILEN_DEFLATE
158 || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
159 || options[3] != DEFLATE_CHK_SEQUENCE)
161 w_size = DEFLATE_SIZE(options[2]);
162 if (w_size < DEFLATE_MIN_SIZE || w_size > DEFLATE_MAX_SIZE)
167 state = (struct deflate_state *) ALLOC_SLEEP(sizeof(*state));
169 state = (struct deflate_state *) ALLOC_NOSLEEP(sizeof(*state));
175 state->strm.next_in = NULL;
176 state->strm.zalloc = (alloc_func) z_alloc;
177 state->strm.zalloc_init = (alloc_func) z_alloc_init;
178 state->strm.zfree = (free_func) z_free;
179 if (deflateInit2(&state->strm, Z_DEFAULT_COMPRESSION, DEFLATE_METHOD_VAL,
180 -w_size, 8, Z_DEFAULT_STRATEGY, DEFLATE_OVHD+2) != Z_OK) {
181 FREE(state, sizeof(*state));
185 state->w_size = w_size;
186 bzero(&state->stats, sizeof(state->stats));
187 return (void *) state;
194 struct deflate_state *state = (struct deflate_state *) arg;
196 deflateEnd(&state->strm);
197 FREE(state, sizeof(*state));
201 z_comp_init(arg, options, opt_len, unit, hdrlen, debug)
204 int opt_len, unit, hdrlen, debug;
206 struct deflate_state *state = (struct deflate_state *) arg;
208 if (opt_len < CILEN_DEFLATE || options[0] != CI_DEFLATE
209 || options[1] != CILEN_DEFLATE
210 || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
211 || DEFLATE_SIZE(options[2]) != state->w_size
212 || options[3] != DEFLATE_CHK_SEQUENCE)
217 state->hdrlen = hdrlen;
218 state->debug = debug;
220 deflateReset(&state->strm);
229 struct deflate_state *state = (struct deflate_state *) arg;
232 deflateReset(&state->strm);
236 z_compress(arg, mret, mp, orig_len, maxolen)
238 mblk_t **mret; /* compressed packet (out) */
239 mblk_t *mp; /* uncompressed packet (in) */
240 int orig_len, maxolen;
242 struct deflate_state *state = (struct deflate_state *) arg;
244 int proto, olen, wspace, r, flush;
248 * Check that the protocol is in the range we handle.
252 if (rptr + PPP_HDRLEN > mp->b_wptr) {
253 if (!pullupmsg(mp, PPP_HDRLEN))
257 proto = PPP_PROTOCOL(rptr);
258 if (proto > 0x3fff || proto == 0xfd || proto == 0xfb)
261 /* Allocate one mblk initially. */
262 if (maxolen > orig_len)
264 wspace = maxolen < 4096? maxolen: 4096;
265 m = allocb(wspace, BPRI_MED);
268 if (state->hdrlen + PPP_HDRLEN + 2 < wspace) {
269 m->b_rptr += state->hdrlen;
270 m->b_wptr = m->b_rptr;
271 wspace -= state->hdrlen;
276 * Copy over the PPP header and store the 2-byte sequence number.
278 wptr[0] = PPP_ADDRESS(rptr);
279 wptr[1] = PPP_CONTROL(rptr);
280 wptr[2] = PPP_COMP >> 8;
283 wptr[0] = state->seqno >> 8;
284 wptr[1] = state->seqno;
286 state->strm.next_out = wptr;
287 state->strm.avail_out = wspace - (PPP_HDRLEN + 2);
289 state->strm.next_out = NULL;
290 state->strm.avail_out = 1000000;
294 rptr += (proto > 0xff)? 2: 3; /* skip 1st proto byte if 0 */
295 state->strm.next_in = rptr;
296 state->strm.avail_in = mp->b_wptr - rptr;
298 flush = (mp == NULL)? Z_PACKET_FLUSH: Z_NO_FLUSH;
301 r = deflate(&state->strm, flush);
303 printf("z_compress: deflate returned %d (%s)\n",
304 r, (state->strm.msg? state->strm.msg: ""));
307 if (flush != Z_NO_FLUSH && state->strm.avail_out != 0)
308 break; /* all done */
309 if (state->strm.avail_in == 0 && mp != NULL) {
310 state->strm.next_in = mp->b_rptr;
311 state->strm.avail_in = mp->b_wptr - mp->b_rptr;
314 flush = Z_PACKET_FLUSH;
316 if (state->strm.avail_out == 0) {
320 wspace = maxolen - olen;
323 else if (wspace > 4096)
325 m->b_cont = allocb(wspace, BPRI_MED);
328 state->strm.next_out = m->b_wptr;
329 state->strm.avail_out = wspace;
333 state->strm.next_out = NULL;
334 state->strm.avail_out = 1000000;
338 m->b_wptr += wspace - state->strm.avail_out;
339 olen += wspace - state->strm.avail_out;
342 * See if we managed to reduce the size of the packet.
343 * If the compressor just gave us a single zero byte, it means
344 * the packet was incompressible.
346 if (olen < orig_len && m != NULL
347 && !(olen == PPP_HDRLEN + 3 && *wptr == 0)) {
348 state->stats.comp_bytes += olen;
349 state->stats.comp_packets++;
355 state->stats.inc_bytes += orig_len;
356 state->stats.inc_packets++;
359 state->stats.unc_bytes += orig_len;
360 state->stats.unc_packets++;
366 z_comp_stats(arg, stats)
368 struct compstat *stats;
370 struct deflate_state *state = (struct deflate_state *) arg;
373 *stats = state->stats;
374 stats->ratio = stats->unc_bytes;
375 out = stats->comp_bytes + stats->unc_bytes;
376 if (stats->ratio <= 0x7ffffff)
385 * Allocate space for a decompressor.
388 z_decomp_alloc(options, opt_len)
392 struct deflate_state *state;
395 if (opt_len != CILEN_DEFLATE || options[0] != CI_DEFLATE
396 || options[1] != CILEN_DEFLATE
397 || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
398 || options[3] != DEFLATE_CHK_SEQUENCE)
400 w_size = DEFLATE_SIZE(options[2]);
401 if (w_size < DEFLATE_MIN_SIZE || w_size > DEFLATE_MAX_SIZE)
405 state = (struct deflate_state *) ALLOC_SLEEP(sizeof(*state));
407 state = (struct deflate_state *) ALLOC_NOSLEEP(sizeof(*state));
412 state->strm.next_out = NULL;
413 state->strm.zalloc = (alloc_func) z_alloc;
414 state->strm.zalloc_init = (alloc_func) z_alloc_init;
415 state->strm.zfree = (free_func) z_free;
416 if (inflateInit2(&state->strm, -w_size) != Z_OK) {
417 FREE(state, sizeof(*state));
421 state->w_size = w_size;
422 bzero(&state->stats, sizeof(state->stats));
423 return (void *) state;
430 struct deflate_state *state = (struct deflate_state *) arg;
432 inflateEnd(&state->strm);
433 FREE(state, sizeof(*state));
437 z_decomp_init(arg, options, opt_len, unit, hdrlen, mru, debug)
440 int opt_len, unit, hdrlen, mru, debug;
442 struct deflate_state *state = (struct deflate_state *) arg;
444 if (opt_len < CILEN_DEFLATE || options[0] != CI_DEFLATE
445 || options[1] != CILEN_DEFLATE
446 || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
447 || DEFLATE_SIZE(options[2]) != state->w_size
448 || options[3] != DEFLATE_CHK_SEQUENCE)
453 state->hdrlen = hdrlen;
454 state->debug = debug;
457 inflateReset(&state->strm);
466 struct deflate_state *state = (struct deflate_state *) arg;
469 inflateReset(&state->strm);
473 * Decompress a Deflate-compressed packet.
475 * Because of patent problems, we return DECOMP_ERROR for errors
476 * found by inspecting the input data and for system problems, but
477 * DECOMP_FATALERROR for any errors which could possibly be said to
478 * be being detected "after" decompression. For DECOMP_ERROR,
479 * we can issue a CCP reset-request; for DECOMP_FATALERROR, we may be
480 * infringing a patent of Motorola's if we do, so we take CCP down
483 * Given that the frame has the correct sequence number and a good FCS,
484 * errors such as invalid codes in the input most likely indicate a
485 * bug, so we return DECOMP_FATALERROR for them in order to turn off
486 * compression, even though they are detected by inspecting the input.
489 z_decompress(arg, mi, mop)
493 struct deflate_state *state = (struct deflate_state *) arg;
494 mblk_t *mo, *mo_head;
496 int rlen, olen, ospace;
497 int seq, i, flush, r, decode_proto;
498 u_char hdr[PPP_HDRLEN + DEFLATE_OVHD];
502 for (i = 0; i < PPP_HDRLEN + DEFLATE_OVHD; ++i) {
503 while (rptr >= mi->b_wptr) {
512 /* Check the sequence number. */
513 seq = (hdr[PPP_HDRLEN] << 8) + hdr[PPP_HDRLEN+1];
514 if (seq != state->seqno) {
518 printf("z_decompress%d: bad seq # %d, expected %d\n",
519 state->unit, seq, state->seqno);
524 /* Allocate an output message block. */
525 mo = allocb(DECOMP_CHUNK + state->hdrlen, BPRI_MED);
530 mo->b_rptr += state->hdrlen;
531 mo->b_wptr = wptr = mo->b_rptr;
532 ospace = DECOMP_CHUNK;
535 * Fill in the first part of the PPP header. The protocol field
536 * comes from the decompressed data.
538 wptr[0] = PPP_ADDRESS(hdr);
539 wptr[1] = PPP_CONTROL(hdr);
543 * Set up to call inflate. We set avail_out to 1 initially so we can
544 * look at the first byte of the output and decide whether we have
545 * a 1-byte or 2-byte protocol field.
547 state->strm.next_in = rptr;
548 state->strm.avail_in = mi->b_wptr - rptr;
550 flush = (mi == NULL)? Z_PACKET_FLUSH: Z_NO_FLUSH;
551 rlen = state->strm.avail_in + PPP_HDRLEN + DEFLATE_OVHD;
552 state->strm.next_out = wptr + 3;
553 state->strm.avail_out = 1;
558 * Call inflate, supplying more input or output as needed.
561 r = inflate(&state->strm, flush);
566 printf("z_decompress%d: inflate returned %d (%s)\n",
567 state->unit, r, (state->strm.msg? state->strm.msg: ""));
569 return DECOMP_FATALERROR;
571 if (flush != Z_NO_FLUSH && state->strm.avail_out != 0)
572 break; /* all done */
573 if (state->strm.avail_in == 0 && mi != NULL) {
574 state->strm.next_in = mi->b_rptr;
575 state->strm.avail_in = mi->b_wptr - mi->b_rptr;
576 rlen += state->strm.avail_in;
579 flush = Z_PACKET_FLUSH;
581 if (state->strm.avail_out == 0) {
583 state->strm.avail_out = ospace - PPP_HDRLEN;
584 if ((wptr[3] & 1) == 0) {
585 /* 2-byte protocol field */
587 --state->strm.next_out;
588 ++state->strm.avail_out;
593 mo->b_wptr += ospace;
595 mo->b_cont = allocb(DECOMP_CHUNK, BPRI_MED);
601 state->strm.next_out = mo->b_rptr;
602 state->strm.avail_out = ospace = DECOMP_CHUNK;
610 mo->b_wptr += ospace - state->strm.avail_out;
611 olen += ospace - state->strm.avail_out;
614 if (olen > state->mru + PPP_HDRLEN)
615 printf("ppp_deflate%d: exceeded mru (%d > %d)\n",
616 state->unit, olen, state->mru + PPP_HDRLEN);
619 state->stats.unc_bytes += olen;
620 state->stats.unc_packets++;
621 state->stats.comp_bytes += rlen;
622 state->stats.comp_packets++;
629 * Incompressible data has arrived - add it to the history.
636 struct deflate_state *state = (struct deflate_state *) arg;
641 * Check that the protocol is one we handle.
644 if (rptr + PPP_HDRLEN > mi->b_wptr) {
645 if (!pullupmsg(mi, PPP_HDRLEN))
649 proto = PPP_PROTOCOL(rptr);
650 if (proto > 0x3fff || proto == 0xfd || proto == 0xfb)
656 * Iterate through the message blocks, adding the characters in them
657 * to the decompressor's history. For the first block, we start
658 * at the either the 1st or 2nd byte of the protocol field,
659 * depending on whether the protocol value is compressible.
661 rlen = mi->b_wptr - mi->b_rptr;
662 state->strm.next_in = rptr + 3;
663 state->strm.avail_in = rlen - 3;
665 --state->strm.next_in;
666 ++state->strm.avail_in;
669 r = inflateIncomp(&state->strm);
675 printf("z_incomp%d: inflateIncomp returned %d (%s)\n",
676 state->unit, r, (state->strm.msg? state->strm.msg: ""));
682 state->strm.next_in = mi->b_rptr;
683 state->strm.avail_in = mi->b_wptr - mi->b_rptr;
684 rlen += state->strm.avail_in;
690 state->stats.inc_bytes += rlen;
691 state->stats.inc_packets++;
692 state->stats.unc_bytes += rlen;
693 state->stats.unc_packets++;
696 #endif /* DO_DEFLATE */