1 /* $Id: ppp-deflate.c,v 1.2 1996/09/26 06:19:18 paulus Exp $ */
4 * ppp_deflate.c - interface the zlib procedures for Deflate compression
5 * and decompression (as used by gzip) to the PPP code.
6 * This version is for use with mbufs on BSD-derived systems.
8 * Copyright (c) 1994 The Australian National University.
11 * Permission to use, copy, modify, and distribute this software and its
12 * documentation is hereby granted, provided that the above copyright
13 * notice appears in all copies. This software is provided without any
14 * warranty, express or implied. The Australian National University
15 * makes no representations about the suitability of this software for
18 * IN NO EVENT SHALL THE AUSTRALIAN NATIONAL UNIVERSITY BE LIABLE TO ANY
19 * PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
20 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
21 * THE AUSTRALIAN NATIONAL UNIVERSITY HAS BEEN ADVISED OF THE POSSIBILITY
24 * THE AUSTRALIAN NATIONAL UNIVERSITY SPECIFICALLY DISCLAIMS ANY WARRANTIES,
25 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
26 * AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
27 * ON AN "AS IS" BASIS, AND THE AUSTRALIAN NATIONAL UNIVERSITY HAS NO
28 * OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS,
32 #include "../h/param.h"
33 #include "../h/types.h"
34 #include "../h/mbuf.h"
35 #include "../h/socket.h"
36 #include "../net/net/if.h"
40 #define PACKETPTR struct mbuf *
46 * State for a Deflate (de)compressor.
48 struct deflate_state {
56 struct compstat stats;
59 #define DEFLATE_OVHD 2 /* Deflate overhead/packet */
61 static void *zalloc __P((void *, u_int items, u_int size));
62 static void zfree __P((void *, void *ptr, u_int nb));
63 static void *z_comp_alloc __P((u_char *options, int opt_len));
64 static void *z_decomp_alloc __P((u_char *options, int opt_len));
65 static void z_comp_free __P((void *state));
66 static void z_decomp_free __P((void *state));
67 static int z_comp_init __P((void *state, u_char *options, int opt_len,
68 int unit, int hdrlen, int debug));
69 static int z_decomp_init __P((void *state, u_char *options, int opt_len,
70 int unit, int hdrlen, int mru, int debug));
71 static int z_compress __P((void *state, struct mbuf **mret,
72 struct mbuf *mp, int slen, int maxolen));
73 static void z_incomp __P((void *state, struct mbuf *dmsg));
74 static int z_decompress __P((void *state, struct mbuf *cmp,
76 static void z_comp_reset __P((void *state));
77 static void z_decomp_reset __P((void *state));
78 static void z_comp_stats __P((void *state, struct compstat *stats));
81 * Procedures exported to if_ppp.c.
83 struct compressor ppp_deflate = {
84 CI_DEFLATE, /* compress_proto */
85 z_comp_alloc, /* comp_alloc */
86 z_comp_free, /* comp_free */
87 z_comp_init, /* comp_init */
88 z_comp_reset, /* comp_reset */
89 z_compress, /* compress */
90 z_comp_stats, /* comp_stat */
91 z_decomp_alloc, /* decomp_alloc */
92 z_decomp_free, /* decomp_free */
93 z_decomp_init, /* decomp_init */
94 z_decomp_reset, /* decomp_reset */
95 z_decompress, /* decompress */
96 z_incomp, /* incomp */
97 z_comp_stats, /* decomp_stat */
101 * Some useful mbuf macros not in mbuf.h.
103 #define M_IS_CLUSTER(m) ((m)->m_off > MMAXOFF)
105 #define M_TRAILINGSPACE(m) \
106 ((M_IS_CLUSTER(m) ? (u_int)(m)->m_clptr + M_CLUSTERSZ : MSIZE) \
107 - ((m)->m_off + (m)->m_len))
110 * Space allocation and freeing routines for use by zlib routines.
113 zalloc(notused, items, size)
119 KM_ALLOC(ptr, void *, items * size, KM_DEVBUF, KM_NOARG);
124 zfree(notused, ptr, nbytes)
129 KM_FREE(ptr, KM_DEVBUF);
133 * Allocate space for a compressor.
136 z_comp_alloc(options, opt_len)
140 struct deflate_state *state;
143 if (opt_len != CILEN_DEFLATE || options[0] != CI_DEFLATE
144 || options[1] != CILEN_DEFLATE
145 || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
146 || options[3] != DEFLATE_CHK_SEQUENCE)
148 w_size = DEFLATE_SIZE(options[2]);
149 if (w_size < DEFLATE_MIN_SIZE || w_size > DEFLATE_MAX_SIZE)
152 KM_ALLOC(state, struct deflate_state *, sizeof(struct deflate_state),
153 KM_DEVBUF, KM_NOARG);
156 bzero(state, sizeof(struct deflate_state));
158 state->strm.next_in = NULL;
159 state->strm.zalloc = (alloc_func) zalloc;
160 state->strm.zfree = (free_func) zfree;
161 if (deflateInit2(&state->strm, Z_DEFAULT_COMPRESSION, DEFLATE_METHOD_VAL,
162 -w_size, 8, Z_DEFAULT_STRATEGY, DEFLATE_OVHD+2) != Z_OK) {
163 KM_FREE(state, KM_DEVBUF);
167 state->w_size = w_size;
168 bzero(&state->stats, sizeof(state->stats));
169 return (void *) state;
176 struct deflate_state *state = (struct deflate_state *) arg;
178 deflateEnd(&state->strm);
179 KM_FREE(state, KM_DEVBUF);
183 z_comp_init(arg, options, opt_len, unit, hdrlen, debug)
186 int opt_len, unit, hdrlen, debug;
188 struct deflate_state *state = (struct deflate_state *) arg;
190 if (opt_len < CILEN_DEFLATE || options[0] != CI_DEFLATE
191 || options[1] != CILEN_DEFLATE
192 || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
193 || DEFLATE_SIZE(options[2]) != state->w_size
194 || options[3] != DEFLATE_CHK_SEQUENCE)
199 state->hdrlen = hdrlen;
200 state->debug = debug;
202 deflateReset(&state->strm);
211 struct deflate_state *state = (struct deflate_state *) arg;
214 deflateReset(&state->strm);
218 z_compress(arg, mret, mp, orig_len, maxolen)
220 struct mbuf **mret; /* compressed packet (out) */
221 struct mbuf *mp; /* uncompressed packet (in) */
222 int orig_len, maxolen;
224 struct deflate_state *state = (struct deflate_state *) arg;
226 int proto, olen, wspace, r, flush;
227 struct mbuf *m, *clp;
230 * Check that the protocol is in the range we handle.
232 rptr = mtod(mp, u_char *);
233 proto = PPP_PROTOCOL(rptr);
234 if (proto > 0x3fff || proto == 0xfd || proto == 0xfb) {
239 /* Allocate one mbuf initially. */
240 if (maxolen > orig_len)
242 MGET(m, M_DONTWAIT, MT_DATA);
245 if (maxolen + state->hdrlen > MLEN) {
246 /* MCLGET is not a single statement!!! */
250 wspace = M_TRAILINGSPACE(m);
251 if (state->hdrlen > 0 && state->hdrlen + PPP_HDRLEN + 2 < wspace) {
252 m->m_off += state->hdrlen;
253 wspace -= state->hdrlen;
255 wptr = mtod(m, u_char *);
258 * Copy over the PPP header and store the 2-byte sequence number.
260 wptr[0] = PPP_ADDRESS(rptr);
261 wptr[1] = PPP_CONTROL(rptr);
262 wptr[2] = PPP_COMP >> 8;
265 wptr[0] = state->seqno >> 8;
266 wptr[1] = state->seqno;
268 state->strm.next_out = wptr;
269 state->strm.avail_out = wspace - (PPP_HDRLEN + 2);
271 state->strm.next_out = NULL;
272 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 = mtod(mp, u_char *) + mp->m_len - 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 = mtod(mp, u_char *);
295 state->strm.avail_in = mp->m_len;
298 flush = Z_PACKET_FLUSH;
300 if (state->strm.avail_out == 0) {
304 MGET(m->m_next, M_DONTWAIT, MT_DATA);
307 if (maxolen - olen > MLEN) {
311 state->strm.next_out = mtod(m, u_char *);
312 state->strm.avail_out = wspace = M_TRAILINGSPACE(m);
316 state->strm.next_out = NULL;
317 state->strm.avail_out = 1000000;
322 olen += (m->m_len = wspace - state->strm.avail_out);
325 * See if we managed to reduce the size of the packet.
326 * If the compressor just gave us a single zero byte, it means
327 * the packet was incompressible.
329 if (m != NULL && olen < orig_len
330 && !(olen == PPP_HDRLEN + 3 && *wptr == 0)) {
331 state->stats.comp_bytes += olen;
332 state->stats.comp_packets++;
338 state->stats.inc_bytes += orig_len;
339 state->stats.inc_packets++;
342 state->stats.unc_bytes += orig_len;
343 state->stats.unc_packets++;
349 z_comp_stats(arg, stats)
351 struct compstat *stats;
353 struct deflate_state *state = (struct deflate_state *) arg;
356 *stats = state->stats;
357 stats->ratio = stats->unc_bytes;
358 out = stats->comp_bytes + stats->inc_bytes;
359 if (stats->ratio <= 0x7ffffff)
368 * Allocate space for a decompressor.
371 z_decomp_alloc(options, opt_len)
375 struct deflate_state *state;
378 if (opt_len != CILEN_DEFLATE || options[0] != CI_DEFLATE
379 || options[1] != CILEN_DEFLATE
380 || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
381 || options[3] != DEFLATE_CHK_SEQUENCE)
383 w_size = DEFLATE_SIZE(options[2]);
384 if (w_size < DEFLATE_MIN_SIZE || w_size > DEFLATE_MAX_SIZE)
387 KM_ALLOC(state, struct deflate_state *, sizeof(struct deflate_state),
388 KM_DEVBUF, KM_NOARG);
391 bzero(state, sizeof(struct deflate_state));
393 state->strm.next_out = NULL;
394 state->strm.zalloc = (alloc_func) zalloc;
395 state->strm.zfree = (free_func) zfree;
396 if (inflateInit2(&state->strm, -w_size) != Z_OK) {
397 KM_FREE(state, KM_DEVBUF);
401 state->w_size = w_size;
402 bzero(&state->stats, sizeof(state->stats));
403 return (void *) state;
410 struct deflate_state *state = (struct deflate_state *) arg;
412 inflateEnd(&state->strm);
413 KM_FREE(state, KM_DEVBUF);
417 z_decomp_init(arg, options, opt_len, unit, hdrlen, mru, debug)
420 int opt_len, unit, hdrlen, mru, debug;
422 struct deflate_state *state = (struct deflate_state *) arg;
424 if (opt_len < CILEN_DEFLATE || options[0] != CI_DEFLATE
425 || options[1] != CILEN_DEFLATE
426 || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
427 || DEFLATE_SIZE(options[2]) != state->w_size
428 || options[3] != DEFLATE_CHK_SEQUENCE)
433 state->hdrlen = hdrlen;
434 state->debug = debug;
437 inflateReset(&state->strm);
446 struct deflate_state *state = (struct deflate_state *) arg;
449 inflateReset(&state->strm);
453 * Decompress a Deflate-compressed packet.
455 * Because of patent problems, we return DECOMP_ERROR for errors
456 * found by inspecting the input data and for system problems, but
457 * DECOMP_FATALERROR for any errors which could possibly be said to
458 * be being detected "after" decompression. For DECOMP_ERROR,
459 * we can issue a CCP reset-request; for DECOMP_FATALERROR, we may be
460 * infringing a patent of Motorola's if we do, so we take CCP down
463 * Given that the frame has the correct sequence number and a good FCS,
464 * errors such as invalid codes in the input most likely indicate a
465 * bug, so we return DECOMP_FATALERROR for them in order to turn off
466 * compression, even though they are detected by inspecting the input.
469 z_decompress(arg, mi, mop)
471 struct mbuf *mi, **mop;
473 struct deflate_state *state = (struct deflate_state *) arg;
474 struct mbuf *mo, *mo_head, *clp;
476 int rlen, olen, ospace;
477 int seq, i, flush, r, decode_proto;
478 u_char hdr[PPP_HDRLEN + DEFLATE_OVHD];
481 rptr = mtod(mi, u_char *);
483 for (i = 0; i < PPP_HDRLEN + DEFLATE_OVHD; ++i) {
488 rptr = mtod(mi, u_char *);
495 /* Check the sequence number. */
496 seq = (hdr[PPP_HDRLEN] << 8) + hdr[PPP_HDRLEN+1];
497 if (seq != state->seqno) {
499 printf("z_decompress%d: bad seq # %d, expected %d\n",
500 state->unit, seq, state->seqno);
505 /* Allocate an output mbuf. */
506 MGET(mo, M_DONTWAIT, MT_DATA);
513 ospace = M_TRAILINGSPACE(mo);
514 if (state->hdrlen > 0 && state->hdrlen + PPP_HDRLEN < ospace) {
515 mo->m_off += state->hdrlen;
516 ospace -= state->hdrlen;
520 * Fill in the first part of the PPP header. The protocol field
521 * comes from the decompressed data.
523 wptr = mtod(mo, u_char *);
524 wptr[0] = PPP_ADDRESS(hdr);
525 wptr[1] = PPP_CONTROL(hdr);
529 * Set up to call inflate. We set avail_out to 1 initially so we can
530 * look at the first byte of the output and decide whether we have
531 * a 1-byte or 2-byte protocol field.
533 state->strm.next_in = rptr;
534 state->strm.avail_in = rlen;
536 flush = (mi == NULL)? Z_PACKET_FLUSH: Z_NO_FLUSH;
537 rlen += PPP_HDRLEN + DEFLATE_OVHD;
538 state->strm.next_out = wptr + 3;
539 state->strm.avail_out = 1;
544 * Call inflate, supplying more input or output as needed.
547 r = inflate(&state->strm, flush);
550 printf("z_decompress%d: inflate returned %d (%s)\n",
551 state->unit, r, (state->strm.msg? state->strm.msg: ""));
553 return DECOMP_FATALERROR;
555 if (flush != Z_NO_FLUSH && state->strm.avail_out != 0)
556 break; /* all done */
557 if (state->strm.avail_in == 0 && mi != NULL) {
558 state->strm.next_in = mtod(mi, u_char *);
559 state->strm.avail_in = mi->m_len;
563 flush = Z_PACKET_FLUSH;
565 if (state->strm.avail_out == 0) {
567 state->strm.avail_out = ospace - PPP_HDRLEN;
568 if ((wptr[3] & 1) == 0) {
569 /* 2-byte protocol field */
571 --state->strm.next_out;
572 ++state->strm.avail_out;
579 MGET(mo->m_next, M_DONTWAIT, MT_DATA);
587 state->strm.next_out = mtod(mo, u_char *);
588 state->strm.avail_out = ospace = M_TRAILINGSPACE(mo);
596 olen += (mo->m_len = ospace - state->strm.avail_out);
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.
622 rptr = mtod(mi, u_char *);
623 proto = PPP_PROTOCOL(rptr);
624 if (proto > 0x3fff || proto == 0xfd || proto == 0xfb)
630 * Iterate through the mbufs, adding the characters in them
631 * to the decompressor's history. For the first mbuf, we start
632 * at the either the 1st or 2nd byte of the protocol field,
633 * depending on whether the protocol value is compressible.
636 state->strm.next_in = rptr + 3;
637 state->strm.avail_in = rlen - 3;
639 --state->strm.next_in;
640 ++state->strm.avail_in;
643 r = inflateIncomp(&state->strm);
647 printf("z_incomp%d: inflateIncomp returned %d (%s)\n",
648 state->unit, r, (state->strm.msg? state->strm.msg: ""));
655 state->strm.next_in = mtod(mi, u_char *);
656 state->strm.avail_in = mi->m_len;
663 state->stats.inc_bytes += rlen;
664 state->stats.inc_packets++;
665 state->stats.unc_bytes += rlen;
666 state->stats.unc_packets++;
669 #endif /* DO_DEFLATE */