1 /* $Id: ppp-deflate.c,v 1.9 2002/12/06 09:49:16 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 Paul Mackerras. All rights reserved.
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in
19 * the documentation and/or other materials provided with the
22 * 3. The name(s) of the authors of this software must not be used to
23 * endorse or promote products derived from this software without
24 * prior written permission.
26 * 4. Redistributions of any form whatsoever must retain the following
28 * "This product includes software developed by Paul Mackerras
29 * <paulus@samba.org>".
31 * THE AUTHORS OF THIS SOFTWARE DISCLAIM ALL WARRANTIES WITH REGARD TO
32 * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
33 * AND FITNESS, IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
34 * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
35 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
36 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
37 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
40 #include <sys/param.h>
41 #include <sys/types.h>
42 #include <sys/systm.h>
44 #include <net/ppp_defs.h>
47 #define PACKETPTR struct mbuf *
48 #include <net/ppp-comp.h>
52 #define DEFLATE_DEBUG 1
55 * State for a Deflate (de)compressor.
57 struct deflate_state {
65 struct compstat stats;
68 #define DEFLATE_OVHD 2 /* Deflate overhead/packet */
70 static void *zalloc __P((void *, u_int items, u_int size));
71 static void zfree __P((void *, void *ptr));
72 static void *z_comp_alloc __P((u_char *options, int opt_len));
73 static void *z_decomp_alloc __P((u_char *options, int opt_len));
74 static void z_comp_free __P((void *state));
75 static void z_decomp_free __P((void *state));
76 static int z_comp_init __P((void *state, u_char *options, int opt_len,
77 int unit, int hdrlen, int debug));
78 static int z_decomp_init __P((void *state, u_char *options, int opt_len,
79 int unit, int hdrlen, int mru, int debug));
80 static int z_compress __P((void *state, struct mbuf **mret,
81 struct mbuf *mp, int slen, int maxolen));
82 static void z_incomp __P((void *state, struct mbuf *dmsg));
83 static int z_decompress __P((void *state, struct mbuf *cmp,
85 static void z_comp_reset __P((void *state));
86 static void z_decomp_reset __P((void *state));
87 static void z_comp_stats __P((void *state, struct compstat *stats));
90 * Procedures exported to if_ppp.c.
92 struct compressor ppp_deflate = {
93 CI_DEFLATE, /* compress_proto */
94 z_comp_alloc, /* comp_alloc */
95 z_comp_free, /* comp_free */
96 z_comp_init, /* comp_init */
97 z_comp_reset, /* comp_reset */
98 z_compress, /* compress */
99 z_comp_stats, /* comp_stat */
100 z_decomp_alloc, /* decomp_alloc */
101 z_decomp_free, /* decomp_free */
102 z_decomp_init, /* decomp_init */
103 z_decomp_reset, /* decomp_reset */
104 z_decompress, /* decompress */
105 z_incomp, /* incomp */
106 z_comp_stats, /* decomp_stat */
109 struct compressor ppp_deflate = {
110 CI_DEFLATE_DRAFT, /* compress_proto */
111 z_comp_alloc, /* comp_alloc */
112 z_comp_free, /* comp_free */
113 z_comp_init, /* comp_init */
114 z_comp_reset, /* comp_reset */
115 z_compress, /* compress */
116 z_comp_stats, /* comp_stat */
117 z_decomp_alloc, /* decomp_alloc */
118 z_decomp_free, /* decomp_free */
119 z_decomp_init, /* decomp_init */
120 z_decomp_reset, /* decomp_reset */
121 z_decompress, /* decompress */
122 z_incomp, /* incomp */
123 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.
340 * If the compressor just gave us a single zero byte, it means
341 * the packet was incompressible.
343 if (m != NULL && olen < orig_len
344 && !(olen == PPP_HDRLEN + 3 && *wptr == 0)) {
345 state->stats.comp_bytes += olen;
346 state->stats.comp_packets++;
352 state->stats.inc_bytes += orig_len;
353 state->stats.inc_packets++;
356 state->stats.unc_bytes += orig_len;
357 state->stats.unc_packets++;
363 z_comp_stats(arg, stats)
365 struct compstat *stats;
367 struct deflate_state *state = (struct deflate_state *) arg;
370 *stats = state->stats;
371 stats->ratio = stats->unc_bytes;
372 out = stats->comp_bytes + stats->inc_bytes;
373 if (stats->ratio <= 0x7ffffff)
382 * Allocate space for a decompressor.
385 z_decomp_alloc(options, opt_len)
389 struct deflate_state *state;
392 if (opt_len != CILEN_DEFLATE
393 || (options[0] != CI_DEFLATE && options[0] != CI_DEFLATE_DRAFT)
394 || options[1] != CILEN_DEFLATE
395 || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
396 || options[3] != DEFLATE_CHK_SEQUENCE)
398 w_size = DEFLATE_SIZE(options[2]);
399 if (w_size < DEFLATE_MIN_SIZE || w_size > DEFLATE_MAX_SIZE)
402 MALLOC(state, struct deflate_state *, sizeof(struct deflate_state),
407 state->strm.next_out = NULL;
408 state->strm.zalloc = zalloc;
409 state->strm.zfree = zfree;
410 if (inflateInit2(&state->strm, -w_size) != Z_OK) {
411 FREE(state, M_DEVBUF);
415 state->w_size = w_size;
416 bzero(&state->stats, sizeof(state->stats));
417 return (void *) state;
424 struct deflate_state *state = (struct deflate_state *) arg;
426 inflateEnd(&state->strm);
427 FREE(state, M_DEVBUF);
431 z_decomp_init(arg, options, opt_len, unit, hdrlen, mru, debug)
434 int opt_len, unit, hdrlen, mru, debug;
436 struct deflate_state *state = (struct deflate_state *) arg;
438 if (opt_len < CILEN_DEFLATE
439 || (options[0] != CI_DEFLATE && options[0] != CI_DEFLATE_DRAFT)
440 || options[1] != CILEN_DEFLATE
441 || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
442 || DEFLATE_SIZE(options[2]) != state->w_size
443 || options[3] != DEFLATE_CHK_SEQUENCE)
448 state->hdrlen = hdrlen;
449 state->debug = debug;
452 inflateReset(&state->strm);
461 struct deflate_state *state = (struct deflate_state *) arg;
464 inflateReset(&state->strm);
468 * Decompress a Deflate-compressed packet.
470 * Because of patent problems, we return DECOMP_ERROR for errors
471 * found by inspecting the input data and for system problems, but
472 * DECOMP_FATALERROR for any errors which could possibly be said to
473 * be being detected "after" decompression. For DECOMP_ERROR,
474 * we can issue a CCP reset-request; for DECOMP_FATALERROR, we may be
475 * infringing a patent of Motorola's if we do, so we take CCP down
478 * Given that the frame has the correct sequence number and a good FCS,
479 * errors such as invalid codes in the input most likely indicate a
480 * bug, so we return DECOMP_FATALERROR for them in order to turn off
481 * compression, even though they are detected by inspecting the input.
484 z_decompress(arg, mi, mop)
486 struct mbuf *mi, **mop;
488 struct deflate_state *state = (struct deflate_state *) arg;
489 struct mbuf *mo, *mo_head;
491 int rlen, olen, ospace;
492 int seq, i, flush, r, decode_proto;
493 u_char hdr[PPP_HDRLEN + DEFLATE_OVHD];
496 rptr = mtod(mi, u_char *);
498 for (i = 0; i < PPP_HDRLEN + DEFLATE_OVHD; ++i) {
503 rptr = mtod(mi, u_char *);
510 /* Check the sequence number. */
511 seq = (hdr[PPP_HDRLEN] << 8) + hdr[PPP_HDRLEN+1];
512 if (seq != state->seqno) {
514 printf("z_decompress%d: bad seq # %d, expected %d\n",
515 state->unit, seq, state->seqno);
520 /* Allocate an output mbuf. */
521 MGETHDR(mo, M_DONTWAIT, MT_DATA);
527 MCLGET(mo, M_DONTWAIT);
528 ospace = M_TRAILINGSPACE(mo);
529 if (state->hdrlen + PPP_HDRLEN < ospace) {
530 mo->m_data += state->hdrlen;
531 ospace -= state->hdrlen;
535 * Fill in the first part of the PPP header. The protocol field
536 * comes from the decompressed data.
538 wptr = mtod(mo, u_char *);
539 wptr[0] = PPP_ADDRESS(hdr);
540 wptr[1] = PPP_CONTROL(hdr);
544 * Set up to call inflate. We set avail_out to 1 initially so we can
545 * look at the first byte of the output and decide whether we have
546 * a 1-byte or 2-byte protocol field.
548 state->strm.next_in = rptr;
549 state->strm.avail_in = rlen;
551 flush = (mi == NULL)? Z_PACKET_FLUSH: Z_NO_FLUSH;
552 rlen += PPP_HDRLEN + DEFLATE_OVHD;
553 state->strm.next_out = wptr + 3;
554 state->strm.avail_out = 1;
559 * Call inflate, supplying more input or output as needed.
562 r = inflate(&state->strm, flush);
567 printf("z_decompress%d: inflate returned %d (%s)\n",
568 state->unit, r, (state->strm.msg? state->strm.msg: ""));
570 return DECOMP_FATALERROR;
572 if (flush != Z_NO_FLUSH && state->strm.avail_out != 0)
573 break; /* all done */
574 if (state->strm.avail_in == 0 && mi != NULL) {
575 state->strm.next_in = mtod(mi, u_char *);
576 state->strm.avail_in = mi->m_len;
580 flush = Z_PACKET_FLUSH;
582 if (state->strm.avail_out == 0) {
584 state->strm.avail_out = ospace - PPP_HDRLEN;
585 if ((wptr[3] & 1) == 0) {
586 /* 2-byte protocol field */
588 --state->strm.next_out;
589 ++state->strm.avail_out;
596 MGET(mo->m_next, M_DONTWAIT, MT_DATA);
602 MCLGET(mo, M_DONTWAIT);
603 state->strm.next_out = mtod(mo, u_char *);
604 state->strm.avail_out = ospace = M_TRAILINGSPACE(mo);
612 olen += (mo->m_len = ospace - state->strm.avail_out);
614 if (olen > state->mru + PPP_HDRLEN)
615 printf("ppp_deflate%d: exceeded mru (%d > %d)\n",
616 state->unit, olen, state->mru + PPP_HDRLEN);
619 state->stats.unc_bytes += olen;
620 state->stats.unc_packets++;
621 state->stats.comp_bytes += rlen;
622 state->stats.comp_packets++;
629 * Incompressible data has arrived - add it to the history.
636 struct deflate_state *state = (struct deflate_state *) arg;
641 * Check that the protocol is one we handle.
643 rptr = mtod(mi, u_char *);
644 proto = PPP_PROTOCOL(rptr);
645 if (proto > 0x3fff || proto == 0xfd || proto == 0xfb)
651 * Iterate through the mbufs, adding the characters in them
652 * to the decompressor's history. For the first mbuf, we start
653 * at the either the 1st or 2nd byte of the protocol field,
654 * depending on whether the protocol value is compressible.
657 state->strm.next_in = rptr + 3;
658 state->strm.avail_in = rlen - 3;
660 --state->strm.next_in;
661 ++state->strm.avail_in;
664 r = inflateIncomp(&state->strm);
670 printf("z_incomp%d: inflateIncomp returned %d (%s)\n",
671 state->unit, r, (state->strm.msg? state->strm.msg: ""));
677 state->strm.next_in = mtod(mi, u_char *);
678 state->strm.avail_in = mi->m_len;
685 state->stats.inc_bytes += rlen;
686 state->stats.inc_packets++;
687 state->stats.unc_bytes += rlen;
688 state->stats.unc_packets++;
691 #endif /* DO_DEFLATE */