1 /* $Id: ppp-deflate.c,v 1.6 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 "../h/param.h"
41 #include "../h/types.h"
42 #include "../h/mbuf.h"
43 #include "../h/socket.h"
44 #include "../net/net/if.h"
48 #define PACKETPTR struct mbuf *
54 * State for a Deflate (de)compressor.
56 struct deflate_state {
64 struct compstat stats;
67 #define DEFLATE_OVHD 2 /* Deflate overhead/packet */
69 static void *zalloc __P((void *, u_int items, u_int size));
70 static void zfree __P((void *, void *ptr));
71 static void *z_comp_alloc __P((u_char *options, int opt_len));
72 static void *z_decomp_alloc __P((u_char *options, int opt_len));
73 static void z_comp_free __P((void *state));
74 static void z_decomp_free __P((void *state));
75 static int z_comp_init __P((void *state, u_char *options, int opt_len,
76 int unit, int hdrlen, int debug));
77 static int z_decomp_init __P((void *state, u_char *options, int opt_len,
78 int unit, int hdrlen, int mru, int debug));
79 static int z_compress __P((void *state, struct mbuf **mret,
80 struct mbuf *mp, int slen, int maxolen));
81 static void z_incomp __P((void *state, struct mbuf *dmsg));
82 static int z_decompress __P((void *state, struct mbuf *cmp,
84 static void z_comp_reset __P((void *state));
85 static void z_decomp_reset __P((void *state));
86 static void z_comp_stats __P((void *state, struct compstat *stats));
89 * Procedures exported to if_ppp.c.
91 struct compressor ppp_deflate = {
92 CI_DEFLATE, /* compress_proto */
93 z_comp_alloc, /* comp_alloc */
94 z_comp_free, /* comp_free */
95 z_comp_init, /* comp_init */
96 z_comp_reset, /* comp_reset */
97 z_compress, /* compress */
98 z_comp_stats, /* comp_stat */
99 z_decomp_alloc, /* decomp_alloc */
100 z_decomp_free, /* decomp_free */
101 z_decomp_init, /* decomp_init */
102 z_decomp_reset, /* decomp_reset */
103 z_decompress, /* decompress */
104 z_incomp, /* incomp */
105 z_comp_stats, /* decomp_stat */
108 struct compressor ppp_deflate_draft = {
109 CI_DEFLATE_DRAFT, /* compress_proto */
110 z_comp_alloc, /* comp_alloc */
111 z_comp_free, /* comp_free */
112 z_comp_init, /* comp_init */
113 z_comp_reset, /* comp_reset */
114 z_compress, /* compress */
115 z_comp_stats, /* comp_stat */
116 z_decomp_alloc, /* decomp_alloc */
117 z_decomp_free, /* decomp_free */
118 z_decomp_init, /* decomp_init */
119 z_decomp_reset, /* decomp_reset */
120 z_decompress, /* decompress */
121 z_incomp, /* incomp */
122 z_comp_stats, /* decomp_stat */
126 * Some useful mbuf macros not in mbuf.h.
128 #define M_IS_CLUSTER(m) ((m)->m_off > MMAXOFF)
130 #define M_TRAILINGSPACE(m) \
131 ((M_IS_CLUSTER(m) ? (u_int)(m)->m_clptr + M_CLUSTERSZ : MSIZE) \
132 - ((m)->m_off + (m)->m_len))
135 * Space allocation and freeing routines for use by zlib routines.
138 zalloc(notused, items, size)
144 KM_ALLOC(ptr, void *, items * size, KM_DEVBUF, KM_NOARG);
153 KM_FREE(ptr, KM_DEVBUF);
157 * Allocate space for a compressor.
160 z_comp_alloc(options, opt_len)
164 struct deflate_state *state;
167 if (opt_len != CILEN_DEFLATE
168 || (options[0] != CI_DEFLATE && options[0] != CI_DEFLATE_DRAFT)
169 || options[1] != CILEN_DEFLATE
170 || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
171 || options[3] != DEFLATE_CHK_SEQUENCE)
173 w_size = DEFLATE_SIZE(options[2]);
174 if (w_size < DEFLATE_MIN_SIZE || w_size > DEFLATE_MAX_SIZE)
177 KM_ALLOC(state, struct deflate_state *, sizeof(struct deflate_state),
178 KM_DEVBUF, KM_NOARG);
181 bzero(state, sizeof(struct deflate_state));
183 state->strm.next_in = NULL;
184 state->strm.zalloc = (alloc_func) zalloc;
185 state->strm.zfree = (free_func) zfree;
186 if (deflateInit2(&state->strm, Z_DEFAULT_COMPRESSION, DEFLATE_METHOD_VAL,
187 -w_size, 8, Z_DEFAULT_STRATEGY) != Z_OK) {
188 KM_FREE(state, KM_DEVBUF);
192 state->w_size = w_size;
193 bzero(&state->stats, sizeof(state->stats));
194 return (void *) state;
201 struct deflate_state *state = (struct deflate_state *) arg;
203 deflateEnd(&state->strm);
204 KM_FREE(state, KM_DEVBUF);
208 z_comp_init(arg, options, opt_len, unit, hdrlen, debug)
211 int opt_len, unit, hdrlen, debug;
213 struct deflate_state *state = (struct deflate_state *) arg;
215 if (opt_len < CILEN_DEFLATE
216 || (options[0] != CI_DEFLATE && options[0] != CI_DEFLATE_DRAFT)
217 || options[1] != CILEN_DEFLATE
218 || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
219 || DEFLATE_SIZE(options[2]) != state->w_size
220 || options[3] != DEFLATE_CHK_SEQUENCE)
225 state->hdrlen = hdrlen;
226 state->debug = debug;
228 deflateReset(&state->strm);
237 struct deflate_state *state = (struct deflate_state *) arg;
240 deflateReset(&state->strm);
244 z_compress(arg, mret, mp, orig_len, maxolen)
246 struct mbuf **mret; /* compressed packet (out) */
247 struct mbuf *mp; /* uncompressed packet (in) */
248 int orig_len, maxolen;
250 struct deflate_state *state = (struct deflate_state *) arg;
252 int proto, olen, wspace, r, flush;
253 struct mbuf *m, *clp;
256 * Check that the protocol is in the range we handle.
258 rptr = mtod(mp, u_char *);
259 proto = PPP_PROTOCOL(rptr);
260 if (proto > 0x3fff || proto == 0xfd || proto == 0xfb) {
265 /* Allocate one mbuf initially. */
266 if (maxolen > orig_len)
268 MGET(m, M_DONTWAIT, MT_DATA);
271 if (maxolen + state->hdrlen > MLEN) {
272 /* MCLGET is not a single statement!!! */
276 wspace = M_TRAILINGSPACE(m);
277 if (state->hdrlen > 0 && state->hdrlen + PPP_HDRLEN + 2 < wspace) {
278 m->m_off += state->hdrlen;
279 wspace -= state->hdrlen;
281 wptr = mtod(m, u_char *);
284 * Copy over the PPP header and store the 2-byte sequence number.
286 wptr[0] = PPP_ADDRESS(rptr);
287 wptr[1] = PPP_CONTROL(rptr);
288 wptr[2] = PPP_COMP >> 8;
291 wptr[0] = state->seqno >> 8;
292 wptr[1] = state->seqno;
294 state->strm.next_out = wptr;
295 state->strm.avail_out = wspace - (PPP_HDRLEN + 2);
297 state->strm.next_out = NULL;
298 state->strm.avail_out = 1000000;
304 rptr += (proto > 0xff)? 2: 3; /* skip 1st proto byte if 0 */
305 state->strm.next_in = rptr;
306 state->strm.avail_in = mtod(mp, u_char *) + mp->m_len - rptr;
308 flush = (mp == NULL)? Z_PACKET_FLUSH: Z_NO_FLUSH;
311 r = deflate(&state->strm, flush);
313 printf("z_compress: deflate returned %d (%s)\n",
314 r, (state->strm.msg? state->strm.msg: ""));
317 if (flush != Z_NO_FLUSH && state->strm.avail_out != 0)
318 break; /* all done */
319 if (state->strm.avail_in == 0 && mp != NULL) {
320 state->strm.next_in = mtod(mp, u_char *);
321 state->strm.avail_in = mp->m_len;
324 flush = Z_PACKET_FLUSH;
326 if (state->strm.avail_out == 0) {
330 MGET(m->m_next, M_DONTWAIT, MT_DATA);
333 if (maxolen - olen > MLEN) {
337 state->strm.next_out = mtod(m, u_char *);
338 state->strm.avail_out = wspace = M_TRAILINGSPACE(m);
342 state->strm.next_out = NULL;
343 state->strm.avail_out = 1000000;
348 olen += (m->m_len = wspace - state->strm.avail_out);
351 * See if we managed to reduce the size of the packet.
352 * If the compressor just gave us a single zero byte, it means
353 * the packet was incompressible.
355 if (m != NULL && olen < orig_len
356 && !(olen == PPP_HDRLEN + 3 && *wptr == 0)) {
357 state->stats.comp_bytes += olen;
358 state->stats.comp_packets++;
364 state->stats.inc_bytes += orig_len;
365 state->stats.inc_packets++;
368 state->stats.unc_bytes += orig_len;
369 state->stats.unc_packets++;
375 z_comp_stats(arg, stats)
377 struct compstat *stats;
379 struct deflate_state *state = (struct deflate_state *) arg;
382 *stats = state->stats;
383 stats->ratio = stats->unc_bytes;
384 out = stats->comp_bytes + stats->inc_bytes;
385 if (stats->ratio <= 0x7ffffff)
394 * Allocate space for a decompressor.
397 z_decomp_alloc(options, opt_len)
401 struct deflate_state *state;
404 if (opt_len != CILEN_DEFLATE
405 || (options[0] != CI_DEFLATE && options[0] != CI_DEFLATE_DRAFT)
406 || options[1] != CILEN_DEFLATE
407 || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
408 || options[3] != DEFLATE_CHK_SEQUENCE)
410 w_size = DEFLATE_SIZE(options[2]);
411 if (w_size < DEFLATE_MIN_SIZE || w_size > DEFLATE_MAX_SIZE)
414 KM_ALLOC(state, struct deflate_state *, sizeof(struct deflate_state),
415 KM_DEVBUF, KM_NOARG);
418 bzero(state, sizeof(struct deflate_state));
420 state->strm.next_out = NULL;
421 state->strm.zalloc = (alloc_func) zalloc;
422 state->strm.zfree = (free_func) zfree;
423 if (inflateInit2(&state->strm, -w_size) != Z_OK) {
424 KM_FREE(state, KM_DEVBUF);
428 state->w_size = w_size;
429 bzero(&state->stats, sizeof(state->stats));
430 return (void *) state;
437 struct deflate_state *state = (struct deflate_state *) arg;
439 inflateEnd(&state->strm);
440 KM_FREE(state, KM_DEVBUF);
444 z_decomp_init(arg, options, opt_len, unit, hdrlen, mru, debug)
447 int opt_len, unit, hdrlen, mru, debug;
449 struct deflate_state *state = (struct deflate_state *) arg;
451 if (opt_len < CILEN_DEFLATE
452 || (options[0] != CI_DEFLATE && options[0] != CI_DEFLATE_DRAFT)
453 || options[1] != CILEN_DEFLATE
454 || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
455 || DEFLATE_SIZE(options[2]) != state->w_size
456 || options[3] != DEFLATE_CHK_SEQUENCE)
461 state->hdrlen = hdrlen;
462 state->debug = debug;
465 inflateReset(&state->strm);
474 struct deflate_state *state = (struct deflate_state *) arg;
477 inflateReset(&state->strm);
481 * Decompress a Deflate-compressed packet.
483 * Because of patent problems, we return DECOMP_ERROR for errors
484 * found by inspecting the input data and for system problems, but
485 * DECOMP_FATALERROR for any errors which could possibly be said to
486 * be being detected "after" decompression. For DECOMP_ERROR,
487 * we can issue a CCP reset-request; for DECOMP_FATALERROR, we may be
488 * infringing a patent of Motorola's if we do, so we take CCP down
491 * Given that the frame has the correct sequence number and a good FCS,
492 * errors such as invalid codes in the input most likely indicate a
493 * bug, so we return DECOMP_FATALERROR for them in order to turn off
494 * compression, even though they are detected by inspecting the input.
497 z_decompress(arg, mi, mop)
499 struct mbuf *mi, **mop;
501 struct deflate_state *state = (struct deflate_state *) arg;
502 struct mbuf *mo, *mo_head, *clp;
504 int rlen, olen, ospace;
505 int seq, i, flush, r, decode_proto;
506 u_char hdr[PPP_HDRLEN + DEFLATE_OVHD];
509 rptr = mtod(mi, u_char *);
511 for (i = 0; i < PPP_HDRLEN + DEFLATE_OVHD; ++i) {
516 rptr = mtod(mi, u_char *);
523 /* Check the sequence number. */
524 seq = (hdr[PPP_HDRLEN] << 8) + hdr[PPP_HDRLEN+1];
525 if (seq != state->seqno) {
527 printf("z_decompress%d: bad seq # %d, expected %d\n",
528 state->unit, seq, state->seqno);
533 /* Allocate an output mbuf. */
534 MGET(mo, M_DONTWAIT, MT_DATA);
541 ospace = M_TRAILINGSPACE(mo);
542 if (state->hdrlen > 0 && state->hdrlen + PPP_HDRLEN < ospace) {
543 mo->m_off += state->hdrlen;
544 ospace -= state->hdrlen;
548 * Fill in the first part of the PPP header. The protocol field
549 * comes from the decompressed data.
551 wptr = mtod(mo, u_char *);
552 wptr[0] = PPP_ADDRESS(hdr);
553 wptr[1] = PPP_CONTROL(hdr);
557 * Set up to call inflate. We set avail_out to 1 initially so we can
558 * look at the first byte of the output and decide whether we have
559 * a 1-byte or 2-byte protocol field.
561 state->strm.next_in = rptr;
562 state->strm.avail_in = rlen;
564 flush = (mi == NULL)? Z_PACKET_FLUSH: Z_NO_FLUSH;
565 rlen += PPP_HDRLEN + DEFLATE_OVHD;
566 state->strm.next_out = wptr + 3;
567 state->strm.avail_out = 1;
572 * Call inflate, supplying more input or output as needed.
575 r = inflate(&state->strm, flush);
578 printf("z_decompress%d: inflate returned %d (%s)\n",
579 state->unit, r, (state->strm.msg? state->strm.msg: ""));
581 return DECOMP_FATALERROR;
583 if (flush != Z_NO_FLUSH && state->strm.avail_out != 0)
584 break; /* all done */
585 if (state->strm.avail_in == 0 && mi != NULL) {
586 state->strm.next_in = mtod(mi, u_char *);
587 state->strm.avail_in = mi->m_len;
591 flush = Z_PACKET_FLUSH;
593 if (state->strm.avail_out == 0) {
595 state->strm.avail_out = ospace - PPP_HDRLEN;
596 if ((wptr[3] & 1) == 0) {
597 /* 2-byte protocol field */
599 --state->strm.next_out;
600 ++state->strm.avail_out;
607 MGET(mo->m_next, M_DONTWAIT, MT_DATA);
615 state->strm.next_out = mtod(mo, u_char *);
616 state->strm.avail_out = ospace = M_TRAILINGSPACE(mo);
624 olen += (mo->m_len = ospace - state->strm.avail_out);
626 state->stats.unc_bytes += olen;
627 state->stats.unc_packets++;
628 state->stats.comp_bytes += rlen;
629 state->stats.comp_packets++;
636 * Incompressible data has arrived - add it to the history.
643 struct deflate_state *state = (struct deflate_state *) arg;
648 * Check that the protocol is one we handle.
650 rptr = mtod(mi, u_char *);
651 proto = PPP_PROTOCOL(rptr);
652 if (proto > 0x3fff || proto == 0xfd || proto == 0xfb)
658 * Iterate through the mbufs, adding the characters in them
659 * to the decompressor's history. For the first mbuf, we start
660 * at the either the 1st or 2nd byte of the protocol field,
661 * depending on whether the protocol value is compressible.
664 state->strm.next_in = rptr + 3;
665 state->strm.avail_in = rlen - 3;
667 --state->strm.next_in;
668 ++state->strm.avail_in;
671 r = inflateIncomp(&state->strm);
675 printf("z_incomp%d: inflateIncomp returned %d (%s)\n",
676 state->unit, r, (state->strm.msg? state->strm.msg: ""));
683 state->strm.next_in = mtod(mi, u_char *);
684 state->strm.avail_in = mi->m_len;
691 state->stats.inc_bytes += rlen;
692 state->stats.inc_packets++;
693 state->stats.unc_bytes += rlen;
694 state->stats.unc_packets++;
697 #endif /* DO_DEFLATE */