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, u_int nb));
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 */
103 * Space allocation and freeing routines for use by zlib routines.
106 zalloc(notused, items, size)
112 MALLOC(ptr, void *, items * size, M_DEVBUF, M_NOWAIT);
117 zfree(notused, ptr, nbytes)
126 * Allocate space for a compressor.
129 z_comp_alloc(options, opt_len)
133 struct deflate_state *state;
136 if (opt_len != CILEN_DEFLATE || options[0] != CI_DEFLATE
137 || options[1] != CILEN_DEFLATE
138 || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
139 || options[3] != DEFLATE_CHK_SEQUENCE)
141 w_size = DEFLATE_SIZE(options[2]);
142 if (w_size < DEFLATE_MIN_SIZE || w_size > DEFLATE_MAX_SIZE)
145 MALLOC(state, struct deflate_state *, sizeof(struct deflate_state),
150 state->strm.next_in = NULL;
151 state->strm.zalloc = zalloc;
152 state->strm.zalloc_init = zalloc;
153 state->strm.zfree = zfree;
154 if (deflateInit2(&state->strm, Z_DEFAULT_COMPRESSION, DEFLATE_METHOD_VAL,
155 -w_size, 8, Z_DEFAULT_STRATEGY, DEFLATE_OVHD+2) != Z_OK) {
156 FREE(state, M_DEVBUF);
160 state->w_size = w_size;
161 bzero(&state->stats, sizeof(state->stats));
162 return (void *) state;
169 struct deflate_state *state = (struct deflate_state *) arg;
171 deflateEnd(&state->strm);
172 FREE(state, M_DEVBUF);
176 z_comp_init(arg, options, opt_len, unit, hdrlen, debug)
179 int opt_len, unit, hdrlen, debug;
181 struct deflate_state *state = (struct deflate_state *) arg;
183 if (opt_len < CILEN_DEFLATE || options[0] != CI_DEFLATE
184 || options[1] != CILEN_DEFLATE
185 || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
186 || DEFLATE_SIZE(options[2]) != state->w_size
187 || options[3] != DEFLATE_CHK_SEQUENCE)
192 state->hdrlen = hdrlen;
193 state->debug = debug;
195 deflateReset(&state->strm);
204 struct deflate_state *state = (struct deflate_state *) arg;
207 deflateReset(&state->strm);
211 z_compress(arg, mret, mp, orig_len, maxolen)
213 struct mbuf **mret; /* compressed packet (out) */
214 struct mbuf *mp; /* uncompressed packet (in) */
215 int orig_len, maxolen;
217 struct deflate_state *state = (struct deflate_state *) arg;
219 int proto, olen, wspace, r, flush;
223 * Check that the protocol is in the range we handle.
225 rptr = mtod(mp, u_char *);
226 proto = PPP_PROTOCOL(rptr);
227 if (proto > 0x3fff || proto == 0xfd || proto == 0xfb) {
232 /* Allocate one mbuf initially. */
233 if (maxolen > orig_len)
235 MGET(m, M_DONTWAIT, MT_DATA);
239 if (maxolen + state->hdrlen > MLEN)
240 MCLGET(m, M_DONTWAIT);
241 wspace = M_TRAILINGSPACE(m);
242 if (state->hdrlen + PPP_HDRLEN + 2 < wspace) {
243 m->m_data += state->hdrlen;
244 wspace -= state->hdrlen;
246 wptr = mtod(m, u_char *);
249 * Copy over the PPP header and store the 2-byte sequence number.
251 wptr[0] = PPP_ADDRESS(rptr);
252 wptr[1] = PPP_CONTROL(rptr);
253 wptr[2] = PPP_COMP >> 8;
256 wptr[0] = state->seqno >> 8;
257 wptr[1] = state->seqno;
259 state->strm.next_out = wptr;
260 state->strm.avail_out = wspace - (PPP_HDRLEN + 2);
262 state->strm.next_out = NULL;
263 state->strm.avail_out = 1000000;
269 rptr += (proto > 0xff)? 2: 3; /* skip 1st proto byte if 0 */
270 state->strm.next_in = rptr;
271 state->strm.avail_in = mtod(mp, u_char *) + mp->m_len - rptr;
273 flush = (mp == NULL)? Z_PACKET_FLUSH: Z_NO_FLUSH;
276 r = deflate(&state->strm, flush);
278 printf("z_compress: deflate returned %d (%s)\n",
279 r, (state->strm.msg? state->strm.msg: ""));
282 if (flush != Z_NO_FLUSH && state->strm.avail_out != 0)
283 break; /* all done */
284 if (state->strm.avail_in == 0 && mp != NULL) {
285 state->strm.next_in = mtod(mp, u_char *);
286 state->strm.avail_in = mp->m_len;
289 flush = Z_PACKET_FLUSH;
291 if (state->strm.avail_out == 0) {
295 MGET(m->m_next, M_DONTWAIT, MT_DATA);
299 if (maxolen - olen > MLEN)
300 MCLGET(m, M_DONTWAIT);
301 state->strm.next_out = mtod(m, u_char *);
302 state->strm.avail_out = wspace = M_TRAILINGSPACE(m);
306 state->strm.next_out = NULL;
307 state->strm.avail_out = 1000000;
312 olen += (m->m_len = wspace - state->strm.avail_out);
315 * See if we managed to reduce the size of the packet.
316 * If the compressor just gave us a single zero byte, it means
317 * the packet was incompressible.
319 if (m != NULL && olen < orig_len
320 && !(olen == PPP_HDRLEN + 3 && *wptr == 0)) {
321 state->stats.comp_bytes += olen;
322 state->stats.comp_packets++;
328 state->stats.inc_bytes += orig_len;
329 state->stats.inc_packets++;
332 state->stats.unc_bytes += orig_len;
333 state->stats.unc_packets++;
339 z_comp_stats(arg, stats)
341 struct compstat *stats;
343 struct deflate_state *state = (struct deflate_state *) arg;
346 *stats = state->stats;
347 stats->ratio = stats->unc_bytes;
348 out = stats->comp_bytes + stats->inc_bytes;
349 if (stats->ratio <= 0x7ffffff)
358 * Allocate space for a decompressor.
361 z_decomp_alloc(options, opt_len)
365 struct deflate_state *state;
368 if (opt_len != CILEN_DEFLATE || options[0] != CI_DEFLATE
369 || options[1] != CILEN_DEFLATE
370 || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
371 || options[3] != DEFLATE_CHK_SEQUENCE)
373 w_size = DEFLATE_SIZE(options[2]);
374 if (w_size < DEFLATE_MIN_SIZE || w_size > DEFLATE_MAX_SIZE)
377 MALLOC(state, struct deflate_state *, sizeof(struct deflate_state),
382 state->strm.next_out = NULL;
383 state->strm.zalloc = zalloc;
384 state->strm.zalloc_init = zalloc;
385 state->strm.zfree = zfree;
386 if (inflateInit2(&state->strm, -w_size) != Z_OK) {
387 FREE(state, M_DEVBUF);
391 state->w_size = w_size;
392 bzero(&state->stats, sizeof(state->stats));
393 return (void *) state;
400 struct deflate_state *state = (struct deflate_state *) arg;
402 inflateEnd(&state->strm);
403 FREE(state, M_DEVBUF);
407 z_decomp_init(arg, options, opt_len, unit, hdrlen, mru, debug)
410 int opt_len, unit, hdrlen, mru, debug;
412 struct deflate_state *state = (struct deflate_state *) arg;
414 if (opt_len < CILEN_DEFLATE || options[0] != CI_DEFLATE
415 || options[1] != CILEN_DEFLATE
416 || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
417 || DEFLATE_SIZE(options[2]) != state->w_size
418 || options[3] != DEFLATE_CHK_SEQUENCE)
423 state->hdrlen = hdrlen;
424 state->debug = debug;
427 inflateReset(&state->strm);
436 struct deflate_state *state = (struct deflate_state *) arg;
439 inflateReset(&state->strm);
443 * Decompress a Deflate-compressed packet.
445 * Because of patent problems, we return DECOMP_ERROR for errors
446 * found by inspecting the input data and for system problems, but
447 * DECOMP_FATALERROR for any errors which could possibly be said to
448 * be being detected "after" decompression. For DECOMP_ERROR,
449 * we can issue a CCP reset-request; for DECOMP_FATALERROR, we may be
450 * infringing a patent of Motorola's if we do, so we take CCP down
453 * Given that the frame has the correct sequence number and a good FCS,
454 * errors such as invalid codes in the input most likely indicate a
455 * bug, so we return DECOMP_FATALERROR for them in order to turn off
456 * compression, even though they are detected by inspecting the input.
459 z_decompress(arg, mi, mop)
461 struct mbuf *mi, **mop;
463 struct deflate_state *state = (struct deflate_state *) arg;
464 struct mbuf *mo, *mo_head;
466 int rlen, olen, ospace;
467 int seq, i, flush, r, decode_proto;
468 u_char hdr[PPP_HDRLEN + DEFLATE_OVHD];
471 rptr = mtod(mi, u_char *);
473 for (i = 0; i < PPP_HDRLEN + DEFLATE_OVHD; ++i) {
478 rptr = mtod(mi, u_char *);
485 /* Check the sequence number. */
486 seq = (hdr[PPP_HDRLEN] << 8) + hdr[PPP_HDRLEN+1];
487 if (seq != state->seqno) {
489 printf("z_decompress%d: bad seq # %d, expected %d\n",
490 state->unit, seq, state->seqno);
495 /* Allocate an output mbuf. */
496 MGETHDR(mo, M_DONTWAIT, MT_DATA);
502 MCLGET(mo, M_DONTWAIT);
503 ospace = M_TRAILINGSPACE(mo);
504 if (state->hdrlen + PPP_HDRLEN < ospace) {
505 mo->m_data += state->hdrlen;
506 ospace -= state->hdrlen;
510 * Fill in the first part of the PPP header. The protocol field
511 * comes from the decompressed data.
513 wptr = mtod(mo, u_char *);
514 wptr[0] = PPP_ADDRESS(hdr);
515 wptr[1] = PPP_CONTROL(hdr);
519 * Set up to call inflate. We set avail_out to 1 initially so we can
520 * look at the first byte of the output and decide whether we have
521 * a 1-byte or 2-byte protocol field.
523 state->strm.next_in = rptr;
524 state->strm.avail_in = rlen;
526 flush = (mi == NULL)? Z_PACKET_FLUSH: Z_NO_FLUSH;
527 rlen += PPP_HDRLEN + DEFLATE_OVHD;
528 state->strm.next_out = wptr + 3;
529 state->strm.avail_out = 1;
534 * Call inflate, supplying more input or output as needed.
537 r = inflate(&state->strm, flush);
542 printf("z_decompress%d: inflate returned %d (%s)\n",
543 state->unit, r, (state->strm.msg? state->strm.msg: ""));
545 return DECOMP_FATALERROR;
547 if (flush != Z_NO_FLUSH && state->strm.avail_out != 0)
548 break; /* all done */
549 if (state->strm.avail_in == 0 && mi != NULL) {
550 state->strm.next_in = mtod(mi, u_char *);
551 state->strm.avail_in = mi->m_len;
555 flush = Z_PACKET_FLUSH;
557 if (state->strm.avail_out == 0) {
559 state->strm.avail_out = ospace - PPP_HDRLEN;
560 if ((wptr[3] & 1) == 0) {
561 /* 2-byte protocol field */
563 --state->strm.next_out;
564 ++state->strm.avail_out;
571 MGET(mo->m_next, M_DONTWAIT, MT_DATA);
577 MCLGET(mo, M_DONTWAIT);
578 state->strm.next_out = mtod(mo, u_char *);
579 state->strm.avail_out = ospace = M_TRAILINGSPACE(mo);
587 olen += (mo->m_len = ospace - state->strm.avail_out);
589 if (olen > state->mru + PPP_HDRLEN)
590 printf("ppp_deflate%d: exceeded mru (%d > %d)\n",
591 state->unit, olen, state->mru + PPP_HDRLEN);
594 state->stats.unc_bytes += olen;
595 state->stats.unc_packets++;
596 state->stats.comp_bytes += rlen;
597 state->stats.comp_packets++;
604 * Incompressible data has arrived - add it to the history.
611 struct deflate_state *state = (struct deflate_state *) arg;
616 * Check that the protocol is one we handle.
618 rptr = mtod(mi, u_char *);
619 proto = PPP_PROTOCOL(rptr);
620 if (proto > 0x3fff || proto == 0xfd || proto == 0xfb)
626 * Iterate through the mbufs, adding the characters in them
627 * to the decompressor's history. For the first mbuf, we start
628 * at the either the 1st or 2nd byte of the protocol field,
629 * depending on whether the protocol value is compressible.
632 state->strm.next_in = rptr + 3;
633 state->strm.avail_in = rlen - 3;
635 --state->strm.next_in;
636 ++state->strm.avail_in;
639 r = inflateIncomp(&state->strm);
645 printf("z_incomp%d: inflateIncomp returned %d (%s)\n",
646 state->unit, r, (state->strm.msg? state->strm.msg: ""));
652 state->strm.next_in = mtod(mi, u_char *);
653 state->strm.avail_in = mi->m_len;
660 state->stats.inc_bytes += rlen;
661 state->stats.inc_packets++;
662 state->stats.unc_bytes += rlen;
663 state->stats.unc_packets++;
666 #endif /* DO_DEFLATE */