1 /* $NetBSD: ppp-deflate.c,v 1.6 1998/05/02 14:34:25 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 Paul Mackerras. All rights reserved.
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
18 * 2. Redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in
20 * the documentation and/or other materials provided with the
23 * 3. The name(s) of the authors of this software must not be used to
24 * endorse or promote products derived from this software without
25 * prior written permission.
27 * 4. Redistributions of any form whatsoever must retain the following
29 * "This product includes software developed by Paul Mackerras
30 * <paulus@samba.org>".
32 * THE AUTHORS OF THIS SOFTWARE DISCLAIM ALL WARRANTIES WITH REGARD TO
33 * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
34 * AND FITNESS, IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
35 * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
36 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
37 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
38 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
41 #include <sys/param.h>
42 #include <sys/types.h>
43 #include <sys/systm.h>
45 #include <net/ppp_defs.h>
48 #define PACKETPTR struct mbuf *
49 #include <net/ppp-comp.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 *zalloc __P((void *, u_int items, u_int size));
72 static void zfree __P((void *, void *ptr));
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, struct mbuf **mret,
82 struct mbuf *mp, int slen, int maxolen));
83 static void z_incomp __P((void *state, struct mbuf *dmsg));
84 static int z_decompress __P((void *state, struct mbuf *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 struct compressor ppp_deflate_draft = {
111 CI_DEFLATE_DRAFT, /* compress_proto */
112 z_comp_alloc, /* comp_alloc */
113 z_comp_free, /* comp_free */
114 z_comp_init, /* comp_init */
115 z_comp_reset, /* comp_reset */
116 z_compress, /* compress */
117 z_comp_stats, /* comp_stat */
118 z_decomp_alloc, /* decomp_alloc */
119 z_decomp_free, /* decomp_free */
120 z_decomp_init, /* decomp_init */
121 z_decomp_reset, /* decomp_reset */
122 z_decompress, /* decompress */
123 z_incomp, /* incomp */
124 z_comp_stats, /* decomp_stat */
127 * Space allocation and freeing routines for use by zlib routines.
130 zalloc(notused, items, size)
136 MALLOC(ptr, void *, items * size, M_DEVBUF, M_NOWAIT);
149 * Allocate space for a compressor.
152 z_comp_alloc(options, opt_len)
156 struct deflate_state *state;
159 if (opt_len != CILEN_DEFLATE
160 || (options[0] != CI_DEFLATE && options[0] != CI_DEFLATE_DRAFT)
161 || options[1] != CILEN_DEFLATE
162 || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
163 || options[3] != DEFLATE_CHK_SEQUENCE)
165 w_size = DEFLATE_SIZE(options[2]);
166 if (w_size < DEFLATE_MIN_SIZE || w_size > DEFLATE_MAX_SIZE)
169 MALLOC(state, struct deflate_state *, sizeof(struct deflate_state),
174 state->strm.next_in = NULL;
175 state->strm.zalloc = zalloc;
176 state->strm.zfree = zfree;
177 if (deflateInit2(&state->strm, Z_DEFAULT_COMPRESSION, DEFLATE_METHOD_VAL,
178 -w_size, 8, Z_DEFAULT_STRATEGY) != Z_OK) {
179 FREE(state, M_DEVBUF);
183 state->w_size = w_size;
184 bzero(&state->stats, sizeof(state->stats));
185 return (void *) state;
192 struct deflate_state *state = (struct deflate_state *) arg;
194 deflateEnd(&state->strm);
195 FREE(state, M_DEVBUF);
199 z_comp_init(arg, options, opt_len, unit, hdrlen, debug)
202 int opt_len, unit, hdrlen, debug;
204 struct deflate_state *state = (struct deflate_state *) arg;
206 if (opt_len < CILEN_DEFLATE
207 || (options[0] != CI_DEFLATE && options[0] != CI_DEFLATE_DRAFT)
208 || options[1] != CILEN_DEFLATE
209 || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
210 || DEFLATE_SIZE(options[2]) != state->w_size
211 || options[3] != DEFLATE_CHK_SEQUENCE)
216 state->hdrlen = hdrlen;
217 state->debug = debug;
219 deflateReset(&state->strm);
228 struct deflate_state *state = (struct deflate_state *) arg;
231 deflateReset(&state->strm);
235 z_compress(arg, mret, mp, orig_len, maxolen)
237 struct mbuf **mret; /* compressed packet (out) */
238 struct mbuf *mp; /* uncompressed packet (in) */
239 int orig_len, maxolen;
241 struct deflate_state *state = (struct deflate_state *) arg;
243 int proto, olen, wspace, r, flush;
247 * Check that the protocol is in the range we handle.
249 rptr = mtod(mp, u_char *);
250 proto = PPP_PROTOCOL(rptr);
251 if (proto > 0x3fff || proto == 0xfd || proto == 0xfb) {
256 /* Allocate one mbuf initially. */
257 if (maxolen > orig_len)
259 MGET(m, M_DONTWAIT, MT_DATA);
263 if (maxolen + state->hdrlen > MLEN)
264 MCLGET(m, M_DONTWAIT);
265 wspace = M_TRAILINGSPACE(m);
266 if (state->hdrlen + PPP_HDRLEN + 2 < wspace) {
267 m->m_data += state->hdrlen;
268 wspace -= state->hdrlen;
270 wptr = mtod(m, u_char *);
273 * Copy over the PPP header and store the 2-byte sequence number.
275 wptr[0] = PPP_ADDRESS(rptr);
276 wptr[1] = PPP_CONTROL(rptr);
277 wptr[2] = PPP_COMP >> 8;
280 wptr[0] = state->seqno >> 8;
281 wptr[1] = state->seqno;
283 state->strm.next_out = wptr;
284 state->strm.avail_out = wspace - (PPP_HDRLEN + 2);
286 state->strm.next_out = NULL;
287 state->strm.avail_out = 1000000;
293 rptr += (proto > 0xff)? 2: 3; /* skip 1st proto byte if 0 */
294 state->strm.next_in = rptr;
295 state->strm.avail_in = mtod(mp, u_char *) + mp->m_len - rptr;
297 flush = (mp == NULL)? Z_PACKET_FLUSH: Z_NO_FLUSH;
300 r = deflate(&state->strm, flush);
302 printf("z_compress: deflate returned %d (%s)\n",
303 r, (state->strm.msg? state->strm.msg: ""));
306 if (flush != Z_NO_FLUSH && state->strm.avail_out != 0)
307 break; /* all done */
308 if (state->strm.avail_in == 0 && mp != NULL) {
309 state->strm.next_in = mtod(mp, u_char *);
310 state->strm.avail_in = mp->m_len;
313 flush = Z_PACKET_FLUSH;
315 if (state->strm.avail_out == 0) {
319 MGET(m->m_next, M_DONTWAIT, MT_DATA);
323 if (maxolen - olen > MLEN)
324 MCLGET(m, M_DONTWAIT);
325 state->strm.next_out = mtod(m, u_char *);
326 state->strm.avail_out = wspace = M_TRAILINGSPACE(m);
330 state->strm.next_out = NULL;
331 state->strm.avail_out = 1000000;
336 olen += (m->m_len = wspace - state->strm.avail_out);
339 * See if we managed to reduce the size of the packet.
341 if (m != NULL && olen < orig_len) {
342 state->stats.comp_bytes += olen;
343 state->stats.comp_packets++;
349 state->stats.inc_bytes += orig_len;
350 state->stats.inc_packets++;
353 state->stats.unc_bytes += orig_len;
354 state->stats.unc_packets++;
360 z_comp_stats(arg, stats)
362 struct compstat *stats;
364 struct deflate_state *state = (struct deflate_state *) arg;
367 *stats = state->stats;
368 stats->ratio = stats->unc_bytes;
369 out = stats->comp_bytes + stats->inc_bytes;
370 if (stats->ratio <= 0x7ffffff)
379 * Allocate space for a decompressor.
382 z_decomp_alloc(options, opt_len)
386 struct deflate_state *state;
389 if (opt_len != CILEN_DEFLATE
390 || (options[0] != CI_DEFLATE && options[0] != CI_DEFLATE_DRAFT)
391 || options[1] != CILEN_DEFLATE
392 || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
393 || options[3] != DEFLATE_CHK_SEQUENCE)
395 w_size = DEFLATE_SIZE(options[2]);
396 if (w_size < DEFLATE_MIN_SIZE || w_size > DEFLATE_MAX_SIZE)
399 MALLOC(state, struct deflate_state *, sizeof(struct deflate_state),
404 state->strm.next_out = NULL;
405 state->strm.zalloc = zalloc;
406 state->strm.zfree = zfree;
407 if (inflateInit2(&state->strm, -w_size) != Z_OK) {
408 FREE(state, M_DEVBUF);
412 state->w_size = w_size;
413 bzero(&state->stats, sizeof(state->stats));
414 return (void *) state;
421 struct deflate_state *state = (struct deflate_state *) arg;
423 inflateEnd(&state->strm);
424 FREE(state, M_DEVBUF);
428 z_decomp_init(arg, options, opt_len, unit, hdrlen, mru, debug)
431 int opt_len, unit, hdrlen, mru, debug;
433 struct deflate_state *state = (struct deflate_state *) arg;
435 if (opt_len < CILEN_DEFLATE
436 || (options[0] != CI_DEFLATE && options[0] != CI_DEFLATE_DRAFT)
437 || options[1] != CILEN_DEFLATE
438 || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
439 || DEFLATE_SIZE(options[2]) != state->w_size
440 || options[3] != DEFLATE_CHK_SEQUENCE)
445 state->hdrlen = hdrlen;
446 state->debug = debug;
449 inflateReset(&state->strm);
458 struct deflate_state *state = (struct deflate_state *) arg;
461 inflateReset(&state->strm);
465 * Decompress a Deflate-compressed packet.
467 * Because of patent problems, we return DECOMP_ERROR for errors
468 * found by inspecting the input data and for system problems, but
469 * DECOMP_FATALERROR for any errors which could possibly be said to
470 * be being detected "after" decompression. For DECOMP_ERROR,
471 * we can issue a CCP reset-request; for DECOMP_FATALERROR, we may be
472 * infringing a patent of Motorola's if we do, so we take CCP down
475 * Given that the frame has the correct sequence number and a good FCS,
476 * errors such as invalid codes in the input most likely indicate a
477 * bug, so we return DECOMP_FATALERROR for them in order to turn off
478 * compression, even though they are detected by inspecting the input.
481 z_decompress(arg, mi, mop)
483 struct mbuf *mi, **mop;
485 struct deflate_state *state = (struct deflate_state *) arg;
486 struct mbuf *mo, *mo_head;
488 int rlen, olen, ospace;
489 int seq, i, flush, r, decode_proto;
490 u_char hdr[PPP_HDRLEN + DEFLATE_OVHD];
493 rptr = mtod(mi, u_char *);
495 for (i = 0; i < PPP_HDRLEN + DEFLATE_OVHD; ++i) {
500 rptr = mtod(mi, u_char *);
507 /* Check the sequence number. */
508 seq = (hdr[PPP_HDRLEN] << 8) + hdr[PPP_HDRLEN+1];
509 if (seq != state->seqno) {
511 printf("z_decompress%d: bad seq # %d, expected %d\n",
512 state->unit, seq, state->seqno);
517 /* Allocate an output mbuf. */
518 MGETHDR(mo, M_DONTWAIT, MT_DATA);
524 MCLGET(mo, M_DONTWAIT);
525 ospace = M_TRAILINGSPACE(mo);
526 if (state->hdrlen + PPP_HDRLEN < ospace) {
527 mo->m_data += state->hdrlen;
528 ospace -= state->hdrlen;
532 * Fill in the first part of the PPP header. The protocol field
533 * comes from the decompressed data.
535 wptr = mtod(mo, u_char *);
536 wptr[0] = PPP_ADDRESS(hdr);
537 wptr[1] = PPP_CONTROL(hdr);
541 * Set up to call inflate. We set avail_out to 1 initially so we can
542 * look at the first byte of the output and decide whether we have
543 * a 1-byte or 2-byte protocol field.
545 state->strm.next_in = rptr;
546 state->strm.avail_in = rlen;
548 flush = (mi == NULL)? Z_PACKET_FLUSH: Z_NO_FLUSH;
549 rlen += PPP_HDRLEN + DEFLATE_OVHD;
550 state->strm.next_out = wptr + 3;
551 state->strm.avail_out = 1;
556 * Call inflate, supplying more input or output as needed.
559 r = inflate(&state->strm, flush);
564 printf("z_decompress%d: inflate returned %d (%s)\n",
565 state->unit, r, (state->strm.msg? state->strm.msg: ""));
567 return DECOMP_FATALERROR;
569 if (flush != Z_NO_FLUSH && state->strm.avail_out != 0)
570 break; /* all done */
571 if (state->strm.avail_in == 0 && mi != NULL) {
572 state->strm.next_in = mtod(mi, u_char *);
573 state->strm.avail_in = mi->m_len;
577 flush = Z_PACKET_FLUSH;
579 if (state->strm.avail_out == 0) {
581 state->strm.avail_out = ospace - PPP_HDRLEN;
582 if ((wptr[3] & 1) == 0) {
583 /* 2-byte protocol field */
585 --state->strm.next_out;
586 ++state->strm.avail_out;
593 MGET(mo->m_next, M_DONTWAIT, MT_DATA);
599 MCLGET(mo, M_DONTWAIT);
600 state->strm.next_out = mtod(mo, u_char *);
601 state->strm.avail_out = ospace = M_TRAILINGSPACE(mo);
609 olen += (mo->m_len = ospace - state->strm.avail_out);
611 if (olen > state->mru + PPP_HDRLEN)
612 printf("ppp_deflate%d: exceeded mru (%d > %d)\n",
613 state->unit, olen, state->mru + PPP_HDRLEN);
616 state->stats.unc_bytes += olen;
617 state->stats.unc_packets++;
618 state->stats.comp_bytes += rlen;
619 state->stats.comp_packets++;
626 * Incompressible data has arrived - add it to the history.
633 struct deflate_state *state = (struct deflate_state *) arg;
638 * Check that the protocol is one we handle.
640 rptr = mtod(mi, u_char *);
641 proto = PPP_PROTOCOL(rptr);
642 if (proto > 0x3fff || proto == 0xfd || proto == 0xfb)
648 * Iterate through the mbufs, adding the characters in them
649 * to the decompressor's history. For the first mbuf, we start
650 * at the either the 1st or 2nd byte of the protocol field,
651 * depending on whether the protocol value is compressible.
654 state->strm.next_in = rptr + 3;
655 state->strm.avail_in = rlen - 3;
657 --state->strm.next_in;
658 ++state->strm.avail_in;
661 r = inflateIncomp(&state->strm);
667 printf("z_incomp%d: inflateIncomp returned %d (%s)\n",
668 state->unit, r, (state->strm.msg? state->strm.msg: ""));
674 state->strm.next_in = mtod(mi, u_char *);
675 state->strm.avail_in = mi->m_len;
682 state->stats.inc_bytes += rlen;
683 state->stats.inc_packets++;
684 state->stats.unc_bytes += rlen;
685 state->stats.unc_packets++;
688 #endif /* DO_DEFLATE */