1 /* $NetBSD: ppp-deflate.c,v 1.3 1996/10/13 02:11:08 christos Exp $ */
2 /* Id: ppp-deflate.c,v 1.5 1997/03/04 03:33:28 paulus Exp */
5 * ppp_deflate.c - interface the zlib procedures for Deflate compression
6 * and decompression (as used by gzip) to the PPP code.
7 * This version is for use with mbufs on BSD-derived systems.
9 * Copyright (c) 1994 The Australian National University.
10 * All rights reserved.
12 * Permission to use, copy, modify, and distribute this software and its
13 * documentation is hereby granted, provided that the above copyright
14 * notice appears in all copies. This software is provided without any
15 * warranty, express or implied. The Australian National University
16 * makes no representations about the suitability of this software for
19 * IN NO EVENT SHALL THE AUSTRALIAN NATIONAL UNIVERSITY BE LIABLE TO ANY
20 * PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
21 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
22 * THE AUSTRALIAN NATIONAL UNIVERSITY HAS BEEN ADVISED OF THE POSSIBILITY
25 * THE AUSTRALIAN NATIONAL UNIVERSITY SPECIFICALLY DISCLAIMS ANY WARRANTIES,
26 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
27 * AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
28 * ON AN "AS IS" BASIS, AND THE AUSTRALIAN NATIONAL UNIVERSITY HAS NO
29 * OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS,
33 #include <sys/param.h>
34 #include <sys/types.h>
35 #include <sys/systm.h>
37 #include <net/ppp_defs.h>
40 #define PACKETPTR struct mbuf *
41 #include <net/ppp-comp.h>
45 #define DEFLATE_DEBUG 1
48 * State for a Deflate (de)compressor.
50 struct deflate_state {
58 struct compstat stats;
61 #define DEFLATE_OVHD 2 /* Deflate overhead/packet */
63 static void *zalloc __P((void *, u_int items, u_int size));
64 static void zfree __P((void *, void *ptr));
65 static void *z_comp_alloc __P((u_char *options, int opt_len));
66 static void *z_decomp_alloc __P((u_char *options, int opt_len));
67 static void z_comp_free __P((void *state));
68 static void z_decomp_free __P((void *state));
69 static int z_comp_init __P((void *state, u_char *options, int opt_len,
70 int unit, int hdrlen, int debug));
71 static int z_decomp_init __P((void *state, u_char *options, int opt_len,
72 int unit, int hdrlen, int mru, int debug));
73 static int z_compress __P((void *state, struct mbuf **mret,
74 struct mbuf *mp, int slen, int maxolen));
75 static void z_incomp __P((void *state, struct mbuf *dmsg));
76 static int z_decompress __P((void *state, struct mbuf *cmp,
78 static void z_comp_reset __P((void *state));
79 static void z_decomp_reset __P((void *state));
80 static void z_comp_stats __P((void *state, struct compstat *stats));
83 * Procedures exported to if_ppp.c.
85 struct compressor ppp_deflate = {
86 CI_DEFLATE, /* compress_proto */
87 z_comp_alloc, /* comp_alloc */
88 z_comp_free, /* comp_free */
89 z_comp_init, /* comp_init */
90 z_comp_reset, /* comp_reset */
91 z_compress, /* compress */
92 z_comp_stats, /* comp_stat */
93 z_decomp_alloc, /* decomp_alloc */
94 z_decomp_free, /* decomp_free */
95 z_decomp_init, /* decomp_init */
96 z_decomp_reset, /* decomp_reset */
97 z_decompress, /* decompress */
98 z_incomp, /* incomp */
99 z_comp_stats, /* decomp_stat */
102 struct compressor ppp_deflate = {
103 CI_DEFLATE_DRAFT, /* compress_proto */
104 z_comp_alloc, /* comp_alloc */
105 z_comp_free, /* comp_free */
106 z_comp_init, /* comp_init */
107 z_comp_reset, /* comp_reset */
108 z_compress, /* compress */
109 z_comp_stats, /* comp_stat */
110 z_decomp_alloc, /* decomp_alloc */
111 z_decomp_free, /* decomp_free */
112 z_decomp_init, /* decomp_init */
113 z_decomp_reset, /* decomp_reset */
114 z_decompress, /* decompress */
115 z_incomp, /* incomp */
116 z_comp_stats, /* decomp_stat */
120 * Space allocation and freeing routines for use by zlib routines.
123 zalloc(notused, items, size)
129 MALLOC(ptr, void *, items * size, M_DEVBUF, M_NOWAIT);
142 * Allocate space for a compressor.
145 z_comp_alloc(options, opt_len)
149 struct deflate_state *state;
152 if (opt_len != CILEN_DEFLATE
153 || (options[0] != CI_DEFLATE && options[0] != CI_DEFLATE_DRAFT)
154 || options[1] != CILEN_DEFLATE
155 || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
156 || options[3] != DEFLATE_CHK_SEQUENCE)
158 w_size = DEFLATE_SIZE(options[2]);
159 if (w_size < DEFLATE_MIN_SIZE || w_size > DEFLATE_MAX_SIZE)
162 MALLOC(state, struct deflate_state *, sizeof(struct deflate_state),
167 state->strm.next_in = NULL;
168 state->strm.zalloc = zalloc;
169 state->strm.zfree = zfree;
170 if (deflateInit2(&state->strm, Z_DEFAULT_COMPRESSION, DEFLATE_METHOD_VAL,
171 -w_size, 8, Z_DEFAULT_STRATEGY) != Z_OK) {
172 FREE(state, M_DEVBUF);
176 state->w_size = w_size;
177 bzero(&state->stats, sizeof(state->stats));
178 return (void *) state;
185 struct deflate_state *state = (struct deflate_state *) arg;
187 deflateEnd(&state->strm);
188 FREE(state, M_DEVBUF);
192 z_comp_init(arg, options, opt_len, unit, hdrlen, debug)
195 int opt_len, unit, hdrlen, debug;
197 struct deflate_state *state = (struct deflate_state *) arg;
199 if (opt_len < CILEN_DEFLATE
200 || (options[0] != CI_DEFLATE && options[0] != CI_DEFLATE_DRAFT)
201 || options[1] != CILEN_DEFLATE
202 || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
203 || DEFLATE_SIZE(options[2]) != state->w_size
204 || options[3] != DEFLATE_CHK_SEQUENCE)
209 state->hdrlen = hdrlen;
210 state->debug = debug;
212 deflateReset(&state->strm);
221 struct deflate_state *state = (struct deflate_state *) arg;
224 deflateReset(&state->strm);
228 z_compress(arg, mret, mp, orig_len, maxolen)
230 struct mbuf **mret; /* compressed packet (out) */
231 struct mbuf *mp; /* uncompressed packet (in) */
232 int orig_len, maxolen;
234 struct deflate_state *state = (struct deflate_state *) arg;
236 int proto, olen, wspace, r, flush;
240 * Check that the protocol is in the range we handle.
242 rptr = mtod(mp, u_char *);
243 proto = PPP_PROTOCOL(rptr);
244 if (proto > 0x3fff || proto == 0xfd || proto == 0xfb) {
249 /* Allocate one mbuf initially. */
250 if (maxolen > orig_len)
252 MGET(m, M_DONTWAIT, MT_DATA);
256 if (maxolen + state->hdrlen > MLEN)
257 MCLGET(m, M_DONTWAIT);
258 wspace = M_TRAILINGSPACE(m);
259 if (state->hdrlen + PPP_HDRLEN + 2 < wspace) {
260 m->m_data += state->hdrlen;
261 wspace -= state->hdrlen;
263 wptr = mtod(m, u_char *);
266 * Copy over the PPP header and store the 2-byte sequence number.
268 wptr[0] = PPP_ADDRESS(rptr);
269 wptr[1] = PPP_CONTROL(rptr);
270 wptr[2] = PPP_COMP >> 8;
273 wptr[0] = state->seqno >> 8;
274 wptr[1] = state->seqno;
276 state->strm.next_out = wptr;
277 state->strm.avail_out = wspace - (PPP_HDRLEN + 2);
279 state->strm.next_out = NULL;
280 state->strm.avail_out = 1000000;
286 rptr += (proto > 0xff)? 2: 3; /* skip 1st proto byte if 0 */
287 state->strm.next_in = rptr;
288 state->strm.avail_in = mtod(mp, u_char *) + mp->m_len - rptr;
290 flush = (mp == NULL)? Z_PACKET_FLUSH: Z_NO_FLUSH;
293 r = deflate(&state->strm, flush);
295 printf("z_compress: deflate returned %d (%s)\n",
296 r, (state->strm.msg? state->strm.msg: ""));
299 if (flush != Z_NO_FLUSH && state->strm.avail_out != 0)
300 break; /* all done */
301 if (state->strm.avail_in == 0 && mp != NULL) {
302 state->strm.next_in = mtod(mp, u_char *);
303 state->strm.avail_in = mp->m_len;
306 flush = Z_PACKET_FLUSH;
308 if (state->strm.avail_out == 0) {
312 MGET(m->m_next, M_DONTWAIT, MT_DATA);
316 if (maxolen - olen > MLEN)
317 MCLGET(m, M_DONTWAIT);
318 state->strm.next_out = mtod(m, u_char *);
319 state->strm.avail_out = wspace = M_TRAILINGSPACE(m);
323 state->strm.next_out = NULL;
324 state->strm.avail_out = 1000000;
329 olen += (m->m_len = wspace - state->strm.avail_out);
332 * See if we managed to reduce the size of the packet.
334 if (m != NULL && olen < orig_len) {
335 state->stats.comp_bytes += olen;
336 state->stats.comp_packets++;
342 state->stats.inc_bytes += orig_len;
343 state->stats.inc_packets++;
346 state->stats.unc_bytes += orig_len;
347 state->stats.unc_packets++;
353 z_comp_stats(arg, stats)
355 struct compstat *stats;
357 struct deflate_state *state = (struct deflate_state *) arg;
360 *stats = state->stats;
361 stats->ratio = stats->unc_bytes;
362 out = stats->comp_bytes + stats->inc_bytes;
363 if (stats->ratio <= 0x7ffffff)
372 * Allocate space for a decompressor.
375 z_decomp_alloc(options, opt_len)
379 struct deflate_state *state;
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 || options[3] != DEFLATE_CHK_SEQUENCE)
388 w_size = DEFLATE_SIZE(options[2]);
389 if (w_size < DEFLATE_MIN_SIZE || w_size > DEFLATE_MAX_SIZE)
392 MALLOC(state, struct deflate_state *, sizeof(struct deflate_state),
397 state->strm.next_out = NULL;
398 state->strm.zalloc = zalloc;
399 state->strm.zfree = zfree;
400 if (inflateInit2(&state->strm, -w_size) != Z_OK) {
401 FREE(state, M_DEVBUF);
405 state->w_size = w_size;
406 bzero(&state->stats, sizeof(state->stats));
407 return (void *) state;
414 struct deflate_state *state = (struct deflate_state *) arg;
416 inflateEnd(&state->strm);
417 FREE(state, M_DEVBUF);
421 z_decomp_init(arg, options, opt_len, unit, hdrlen, mru, debug)
424 int opt_len, unit, hdrlen, mru, debug;
426 struct deflate_state *state = (struct deflate_state *) arg;
428 if (opt_len < CILEN_DEFLATE
429 || (options[0] != CI_DEFLATE && options[0] != CI_DEFLATE_DRAFT)
430 || options[1] != CILEN_DEFLATE
431 || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
432 || DEFLATE_SIZE(options[2]) != state->w_size
433 || options[3] != DEFLATE_CHK_SEQUENCE)
438 state->hdrlen = hdrlen;
439 state->debug = debug;
442 inflateReset(&state->strm);
451 struct deflate_state *state = (struct deflate_state *) arg;
454 inflateReset(&state->strm);
458 * Decompress a Deflate-compressed packet.
460 * Because of patent problems, we return DECOMP_ERROR for errors
461 * found by inspecting the input data and for system problems, but
462 * DECOMP_FATALERROR for any errors which could possibly be said to
463 * be being detected "after" decompression. For DECOMP_ERROR,
464 * we can issue a CCP reset-request; for DECOMP_FATALERROR, we may be
465 * infringing a patent of Motorola's if we do, so we take CCP down
468 * Given that the frame has the correct sequence number and a good FCS,
469 * errors such as invalid codes in the input most likely indicate a
470 * bug, so we return DECOMP_FATALERROR for them in order to turn off
471 * compression, even though they are detected by inspecting the input.
474 z_decompress(arg, mi, mop)
476 struct mbuf *mi, **mop;
478 struct deflate_state *state = (struct deflate_state *) arg;
479 struct mbuf *mo, *mo_head;
481 int rlen, olen, ospace;
482 int seq, i, flush, r, decode_proto;
483 u_char hdr[PPP_HDRLEN + DEFLATE_OVHD];
486 rptr = mtod(mi, u_char *);
488 for (i = 0; i < PPP_HDRLEN + DEFLATE_OVHD; ++i) {
493 rptr = mtod(mi, u_char *);
500 /* Check the sequence number. */
501 seq = (hdr[PPP_HDRLEN] << 8) + hdr[PPP_HDRLEN+1];
502 if (seq != state->seqno) {
504 printf("z_decompress%d: bad seq # %d, expected %d\n",
505 state->unit, seq, state->seqno);
510 /* Allocate an output mbuf. */
511 MGETHDR(mo, M_DONTWAIT, MT_DATA);
517 MCLGET(mo, M_DONTWAIT);
518 ospace = M_TRAILINGSPACE(mo);
519 if (state->hdrlen + PPP_HDRLEN < ospace) {
520 mo->m_data += state->hdrlen;
521 ospace -= state->hdrlen;
525 * Fill in the first part of the PPP header. The protocol field
526 * comes from the decompressed data.
528 wptr = mtod(mo, u_char *);
529 wptr[0] = PPP_ADDRESS(hdr);
530 wptr[1] = PPP_CONTROL(hdr);
534 * Set up to call inflate. We set avail_out to 1 initially so we can
535 * look at the first byte of the output and decide whether we have
536 * a 1-byte or 2-byte protocol field.
538 state->strm.next_in = rptr;
539 state->strm.avail_in = rlen;
541 flush = (mi == NULL)? Z_PACKET_FLUSH: Z_NO_FLUSH;
542 rlen += PPP_HDRLEN + DEFLATE_OVHD;
543 state->strm.next_out = wptr + 3;
544 state->strm.avail_out = 1;
549 * Call inflate, supplying more input or output as needed.
552 r = inflate(&state->strm, flush);
557 printf("z_decompress%d: inflate returned %d (%s)\n",
558 state->unit, r, (state->strm.msg? state->strm.msg: ""));
560 return DECOMP_FATALERROR;
562 if (flush != Z_NO_FLUSH && state->strm.avail_out != 0)
563 break; /* all done */
564 if (state->strm.avail_in == 0 && mi != NULL) {
565 state->strm.next_in = mtod(mi, u_char *);
566 state->strm.avail_in = mi->m_len;
570 flush = Z_PACKET_FLUSH;
572 if (state->strm.avail_out == 0) {
574 state->strm.avail_out = ospace - PPP_HDRLEN;
575 if ((wptr[3] & 1) == 0) {
576 /* 2-byte protocol field */
578 --state->strm.next_out;
579 ++state->strm.avail_out;
586 MGET(mo->m_next, M_DONTWAIT, MT_DATA);
592 MCLGET(mo, M_DONTWAIT);
593 state->strm.next_out = mtod(mo, u_char *);
594 state->strm.avail_out = ospace = M_TRAILINGSPACE(mo);
602 olen += (mo->m_len = ospace - state->strm.avail_out);
604 if (olen > state->mru + PPP_HDRLEN)
605 printf("ppp_deflate%d: exceeded mru (%d > %d)\n",
606 state->unit, olen, state->mru + PPP_HDRLEN);
609 state->stats.unc_bytes += olen;
610 state->stats.unc_packets++;
611 state->stats.comp_bytes += rlen;
612 state->stats.comp_packets++;
619 * Incompressible data has arrived - add it to the history.
626 struct deflate_state *state = (struct deflate_state *) arg;
631 * Check that the protocol is one we handle.
633 rptr = mtod(mi, u_char *);
634 proto = PPP_PROTOCOL(rptr);
635 if (proto > 0x3fff || proto == 0xfd || proto == 0xfb)
641 * Iterate through the mbufs, adding the characters in them
642 * to the decompressor's history. For the first mbuf, we start
643 * at the either the 1st or 2nd byte of the protocol field,
644 * depending on whether the protocol value is compressible.
647 state->strm.next_in = rptr + 3;
648 state->strm.avail_in = rlen - 3;
650 --state->strm.next_in;
651 ++state->strm.avail_in;
654 r = inflateIncomp(&state->strm);
660 printf("z_incomp%d: inflateIncomp returned %d (%s)\n",
661 state->unit, r, (state->strm.msg? state->strm.msg: ""));
667 state->strm.next_in = mtod(mi, u_char *);
668 state->strm.avail_in = mi->m_len;
675 state->stats.inc_bytes += rlen;
676 state->stats.inc_packets++;
677 state->stats.unc_bytes += rlen;
678 state->stats.unc_packets++;
681 #endif /* DO_DEFLATE */