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 1.4 1996/08/28 06:34:56 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_free __P((void *, void *ptr, u_int nb));
73 static void *z_comp_alloc __P((u_char *options, int opt_len));
74 static void *z_decomp_alloc __P((u_char *options, int opt_len));
75 static void z_comp_free __P((void *state));
76 static void z_decomp_free __P((void *state));
77 static int z_comp_init __P((void *state, u_char *options, int opt_len,
78 int unit, int hdrlen, int debug));
79 static int z_decomp_init __P((void *state, u_char *options, int opt_len,
80 int unit, int hdrlen, int mru, int debug));
81 static int z_compress __P((void *state, mblk_t **mret,
82 mblk_t *mp, int slen, int maxolen));
83 static void z_incomp __P((void *state, mblk_t *dmsg));
84 static int z_decompress __P((void *state, mblk_t *cmp,
86 static void z_comp_reset __P((void *state));
87 static void z_decomp_reset __P((void *state));
88 static void z_comp_stats __P((void *state, struct compstat *stats));
91 * Procedures exported to if_ppp.c.
93 struct compressor ppp_deflate = {
94 CI_DEFLATE, /* compress_proto */
95 z_comp_alloc, /* comp_alloc */
96 z_comp_free, /* comp_free */
97 z_comp_init, /* comp_init */
98 z_comp_reset, /* comp_reset */
99 z_compress, /* compress */
100 z_comp_stats, /* comp_stat */
101 z_decomp_alloc, /* decomp_alloc */
102 z_decomp_free, /* decomp_free */
103 z_decomp_init, /* decomp_init */
104 z_decomp_reset, /* decomp_reset */
105 z_decompress, /* decompress */
106 z_incomp, /* incomp */
107 z_comp_stats, /* decomp_stat */
110 #define DECOMP_CHUNK 512
113 * Space allocation and freeing routines for use by zlib routines.
116 z_alloc(notused, items, size)
121 return ALLOC_SLEEP(items * size);
123 return ALLOC_NOSLEEP(items * size);
128 z_free(notused, ptr, nbytes)
137 * Allocate space for a compressor.
140 z_comp_alloc(options, opt_len)
144 struct deflate_state *state;
147 if (opt_len != CILEN_DEFLATE || options[0] != CI_DEFLATE
148 || options[1] != CILEN_DEFLATE
149 || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
150 || options[3] != DEFLATE_CHK_SEQUENCE)
152 w_size = DEFLATE_SIZE(options[2]);
153 if (w_size < DEFLATE_MIN_SIZE || w_size > DEFLATE_MAX_SIZE)
156 state = (struct deflate_state *) ALLOC_NOSLEEP(sizeof(*state));
160 state->strm.next_in = NULL;
161 state->strm.zalloc = (alloc_func) z_alloc;
162 state->strm.zfree = (free_func) z_free;
163 if (deflateInit2(&state->strm, Z_DEFAULT_COMPRESSION, DEFLATE_METHOD_VAL,
164 -w_size, 8, Z_DEFAULT_STRATEGY, DEFLATE_OVHD+2) != Z_OK) {
165 FREE(state, sizeof(*state));
169 state->w_size = w_size;
170 bzero(&state->stats, sizeof(state->stats));
171 return (void *) state;
178 struct deflate_state *state = (struct deflate_state *) arg;
180 deflateEnd(&state->strm);
181 FREE(state, sizeof(*state));
185 z_comp_init(arg, options, opt_len, unit, hdrlen, debug)
188 int opt_len, unit, hdrlen, debug;
190 struct deflate_state *state = (struct deflate_state *) arg;
192 if (opt_len < CILEN_DEFLATE || options[0] != CI_DEFLATE
193 || options[1] != CILEN_DEFLATE
194 || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
195 || DEFLATE_SIZE(options[2]) != state->w_size
196 || options[3] != DEFLATE_CHK_SEQUENCE)
201 state->hdrlen = hdrlen;
202 state->debug = debug;
204 deflateReset(&state->strm);
213 struct deflate_state *state = (struct deflate_state *) arg;
216 deflateReset(&state->strm);
220 z_compress(arg, mret, mp, orig_len, maxolen)
222 mblk_t **mret; /* compressed packet (out) */
223 mblk_t *mp; /* uncompressed packet (in) */
224 int orig_len, maxolen;
226 struct deflate_state *state = (struct deflate_state *) arg;
228 int proto, olen, wspace, r, flush;
232 * Check that the protocol is in the range we handle.
236 if (rptr + PPP_HDRLEN > mp->b_wptr) {
237 if (!pullupmsg(mp, PPP_HDRLEN))
241 proto = PPP_PROTOCOL(rptr);
242 if (proto > 0x3fff || proto == 0xfd || proto == 0xfb)
245 /* Allocate one mblk initially. */
246 if (maxolen > orig_len)
248 wspace = maxolen < 4096? maxolen: 4096;
249 m = allocb(wspace, BPRI_MED);
252 if (state->hdrlen + PPP_HDRLEN + 2 < wspace) {
253 m->b_rptr += state->hdrlen;
254 m->b_wptr = m->b_rptr;
255 wspace -= state->hdrlen;
260 * Copy over the PPP header and store the 2-byte sequence number.
262 wptr[0] = PPP_ADDRESS(rptr);
263 wptr[1] = PPP_CONTROL(rptr);
264 wptr[2] = PPP_COMP >> 8;
267 wptr[0] = state->seqno >> 8;
268 wptr[1] = state->seqno;
270 state->strm.next_out = wptr;
271 state->strm.avail_out = wspace - (PPP_HDRLEN + 2);
273 state->strm.next_out = NULL;
274 state->strm.avail_out = 1000000;
278 rptr += (proto > 0xff)? 2: 3; /* skip 1st proto byte if 0 */
279 state->strm.next_in = rptr;
280 state->strm.avail_in = mp->b_wptr - rptr;
282 flush = (mp == NULL)? Z_PACKET_FLUSH: Z_NO_FLUSH;
285 r = deflate(&state->strm, flush);
287 printf("z_compress: deflate returned %d (%s)\n",
288 r, (state->strm.msg? state->strm.msg: ""));
291 if (flush != Z_NO_FLUSH && state->strm.avail_out != 0)
292 break; /* all done */
293 if (state->strm.avail_in == 0 && mp != NULL) {
294 state->strm.next_in = mp->b_rptr;
295 state->strm.avail_in = mp->b_wptr - mp->b_rptr;
298 flush = Z_PACKET_FLUSH;
300 if (state->strm.avail_out == 0) {
304 wspace = maxolen - olen;
307 else if (wspace > 4096)
309 m->b_cont = allocb(wspace, BPRI_MED);
312 state->strm.next_out = m->b_wptr;
313 state->strm.avail_out = wspace;
317 state->strm.next_out = NULL;
318 state->strm.avail_out = 1000000;
322 m->b_wptr += wspace - state->strm.avail_out;
323 olen += wspace - state->strm.avail_out;
326 * See if we managed to reduce the size of the packet.
327 * If the compressor just gave us a single zero byte, it means
328 * the packet was incompressible.
330 if (olen < orig_len && m != NULL
331 && !(olen == PPP_HDRLEN + 3 && *wptr == 0)) {
332 state->stats.comp_bytes += olen;
333 state->stats.comp_packets++;
339 state->stats.inc_bytes += orig_len;
340 state->stats.inc_packets++;
343 state->stats.unc_bytes += orig_len;
344 state->stats.unc_packets++;
350 z_comp_stats(arg, stats)
352 struct compstat *stats;
354 struct deflate_state *state = (struct deflate_state *) arg;
357 *stats = state->stats;
358 stats->ratio = stats->unc_bytes;
359 out = stats->comp_bytes + stats->unc_bytes;
360 if (stats->ratio <= 0x7ffffff)
369 * Allocate space for a decompressor.
372 z_decomp_alloc(options, opt_len)
376 struct deflate_state *state;
379 if (opt_len != CILEN_DEFLATE || options[0] != CI_DEFLATE
380 || options[1] != CILEN_DEFLATE
381 || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
382 || options[3] != DEFLATE_CHK_SEQUENCE)
384 w_size = DEFLATE_SIZE(options[2]);
385 if (w_size < DEFLATE_MIN_SIZE || w_size > DEFLATE_MAX_SIZE)
388 state = (struct deflate_state *) ALLOC_NOSLEEP(sizeof(*state));
392 state->strm.next_out = NULL;
393 state->strm.zalloc = (alloc_func) z_alloc;
394 state->strm.zfree = (free_func) z_free;
395 if (inflateInit2(&state->strm, -w_size) != Z_OK) {
396 FREE(state, sizeof(*state));
400 state->w_size = w_size;
401 bzero(&state->stats, sizeof(state->stats));
402 return (void *) state;
409 struct deflate_state *state = (struct deflate_state *) arg;
411 inflateEnd(&state->strm);
412 FREE(state, sizeof(*state));
416 z_decomp_init(arg, options, opt_len, unit, hdrlen, mru, debug)
419 int opt_len, unit, hdrlen, mru, debug;
421 struct deflate_state *state = (struct deflate_state *) arg;
423 if (opt_len < CILEN_DEFLATE || options[0] != CI_DEFLATE
424 || options[1] != CILEN_DEFLATE
425 || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
426 || DEFLATE_SIZE(options[2]) != state->w_size
427 || options[3] != DEFLATE_CHK_SEQUENCE)
432 state->hdrlen = hdrlen;
433 state->debug = debug;
436 inflateReset(&state->strm);
445 struct deflate_state *state = (struct deflate_state *) arg;
448 inflateReset(&state->strm);
452 * Decompress a Deflate-compressed packet.
454 * Because of patent problems, we return DECOMP_ERROR for errors
455 * found by inspecting the input data and for system problems, but
456 * DECOMP_FATALERROR for any errors which could possibly be said to
457 * be being detected "after" decompression. For DECOMP_ERROR,
458 * we can issue a CCP reset-request; for DECOMP_FATALERROR, we may be
459 * infringing a patent of Motorola's if we do, so we take CCP down
462 * Given that the frame has the correct sequence number and a good FCS,
463 * errors such as invalid codes in the input most likely indicate a
464 * bug, so we return DECOMP_FATALERROR for them in order to turn off
465 * compression, even though they are detected by inspecting the input.
468 z_decompress(arg, mi, mop)
472 struct deflate_state *state = (struct deflate_state *) arg;
473 mblk_t *mo, *mo_head;
475 int rlen, olen, ospace;
476 int seq, i, flush, r, decode_proto;
477 u_char hdr[PPP_HDRLEN + DEFLATE_OVHD];
481 for (i = 0; i < PPP_HDRLEN + DEFLATE_OVHD; ++i) {
482 while (rptr >= mi->b_wptr) {
491 /* Check the sequence number. */
492 seq = (hdr[PPP_HDRLEN] << 8) + hdr[PPP_HDRLEN+1];
493 if (seq != state->seqno) {
497 printf("z_decompress%d: bad seq # %d, expected %d\n",
498 state->unit, seq, state->seqno);
503 /* Allocate an output message block. */
504 mo = allocb(DECOMP_CHUNK + state->hdrlen, BPRI_MED);
509 mo->b_rptr += state->hdrlen;
510 mo->b_wptr = wptr = mo->b_rptr;
511 ospace = DECOMP_CHUNK;
514 * Fill in the first part of the PPP header. The protocol field
515 * comes from the decompressed data.
517 wptr[0] = PPP_ADDRESS(hdr);
518 wptr[1] = PPP_CONTROL(hdr);
522 * Set up to call inflate. We set avail_out to 1 initially so we can
523 * look at the first byte of the output and decide whether we have
524 * a 1-byte or 2-byte protocol field.
526 state->strm.next_in = rptr;
527 state->strm.avail_in = mi->b_wptr - rptr;
529 flush = (mi == NULL)? Z_PACKET_FLUSH: Z_NO_FLUSH;
530 rlen = state->strm.avail_in + PPP_HDRLEN + DEFLATE_OVHD;
531 state->strm.next_out = wptr + 3;
532 state->strm.avail_out = 1;
537 * Call inflate, supplying more input or output as needed.
540 r = inflate(&state->strm, flush);
545 printf("z_decompress%d: inflate returned %d (%s)\n",
546 state->unit, r, (state->strm.msg? state->strm.msg: ""));
548 return DECOMP_FATALERROR;
550 if (flush != Z_NO_FLUSH && state->strm.avail_out != 0)
551 break; /* all done */
552 if (state->strm.avail_in == 0 && mi != NULL) {
553 state->strm.next_in = mi->b_rptr;
554 state->strm.avail_in = mi->b_wptr - mi->b_rptr;
555 rlen += state->strm.avail_in;
558 flush = Z_PACKET_FLUSH;
560 if (state->strm.avail_out == 0) {
562 state->strm.avail_out = ospace - PPP_HDRLEN;
563 if ((wptr[3] & 1) == 0) {
564 /* 2-byte protocol field */
566 --state->strm.next_out;
567 ++state->strm.avail_out;
572 mo->b_wptr += ospace;
574 mo->b_cont = allocb(DECOMP_CHUNK, BPRI_MED);
580 state->strm.next_out = mo->b_rptr;
581 state->strm.avail_out = ospace = DECOMP_CHUNK;
589 mo->b_wptr += ospace - state->strm.avail_out;
590 olen += ospace - state->strm.avail_out;
593 if (olen > state->mru + PPP_HDRLEN)
594 printf("ppp_deflate%d: exceeded mru (%d > %d)\n",
595 state->unit, olen, state->mru + PPP_HDRLEN);
598 state->stats.unc_bytes += olen;
599 state->stats.unc_packets++;
600 state->stats.comp_bytes += rlen;
601 state->stats.comp_packets++;
608 * Incompressible data has arrived - add it to the history.
615 struct deflate_state *state = (struct deflate_state *) arg;
620 * Check that the protocol is one we handle.
623 if (rptr + PPP_HDRLEN > mi->b_wptr) {
624 if (!pullupmsg(mi, PPP_HDRLEN))
628 proto = PPP_PROTOCOL(rptr);
629 if (proto > 0x3fff || proto == 0xfd || proto == 0xfb)
635 * Iterate through the message blocks, adding the characters in them
636 * to the decompressor's history. For the first block, we start
637 * at the either the 1st or 2nd byte of the protocol field,
638 * depending on whether the protocol value is compressible.
640 rlen = mi->b_wptr - mi->b_rptr;
641 state->strm.next_in = rptr + 3;
642 state->strm.avail_in = rlen - 3;
644 --state->strm.next_in;
645 ++state->strm.avail_in;
648 r = inflateIncomp(&state->strm);
654 printf("z_incomp%d: inflateIncomp returned %d (%s)\n",
655 state->unit, r, (state->strm.msg? state->strm.msg: ""));
661 state->strm.next_in = mi->b_rptr;
662 state->strm.avail_in = mi->b_wptr - mi->b_rptr;
663 rlen += state->strm.avail_in;
669 state->stats.inc_bytes += rlen;
670 state->stats.inc_packets++;
671 state->stats.unc_bytes += rlen;
672 state->stats.unc_packets++;
675 #endif /* DO_DEFLATE */