1 /* $NetBSD: ppp-deflate.c,v 1.24 2024/07/05 04:31:53 rin Exp $ */
2 /* Id: ppp-deflate.c,v 1.5 1997/03/04 03:33:28 paulus Exp */
3
4 /*
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.
8 *
9 * Copyright (c) 1989-2002 Paul Mackerras. All rights reserved.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 *
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 *
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
21 * distribution.
22 *
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.
26 *
27 * 4. Redistributions of any form whatsoever must retain the following
28 * acknowledgment:
29 * "This product includes software developed by Paul Mackerras
30 * <paulus@samba.org>".
31 *
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.
39 */
40
41 #include <sys/cdefs.h>
42 __KERNEL_RCSID(0, "$NetBSD: ppp-deflate.c,v 1.24 2024/07/05 04:31:53 rin Exp $");
43
44 #include <sys/param.h>
45 #include <sys/systm.h>
46 #include <sys/mbuf.h>
47 #include <sys/module.h>
48 #include <net/if.h>
49 #include <net/ppp_defs.h>
50 #include <net/if_ppp.h>
51 #include <net/zlib.h>
52
53 #define PACKETPTR struct mbuf *
54 #include <net/ppp-comp.h>
55
56 #if DO_DEFLATE
57
58 #define DEFLATE_DEBUG 1
59
60 /*
61 * State for a Deflate (de)compressor.
62 */
63 struct deflate_state {
64 int seqno;
65 int w_size;
66 int unit;
67 int hdrlen;
68 int mru;
69 int debug;
70 z_stream strm;
71 struct compstat stats;
72 };
73
74 #define DEFLATE_OVHD 2 /* Deflate overhead/packet */
75
76 static void *zalloc(void *, u_int items, u_int size);
77 static void zfree(void *, void *ptr);
78 static void *z_comp_alloc(u_char *options, int opt_len);
79 static void *z_decomp_alloc(u_char *options, int opt_len);
80 static void z_comp_free(void *state);
81 static void z_decomp_free(void *state);
82 static int z_comp_init(void *state, u_char *options, int opt_len,
83 int unit, int hdrlen, int debug);
84 static int z_decomp_init(void *state, u_char *options, int opt_len,
85 int unit, int hdrlen, int mru, int debug);
86 static int z_compress(void *state, struct mbuf **mret,
87 struct mbuf *mp, int slen, int maxolen);
88 static void z_incomp(void *state, struct mbuf *dmsg);
89 static int z_decompress(void *state, struct mbuf *cmp,
90 struct mbuf **dmpp);
91 static void z_comp_reset(void *state);
92 static void z_decomp_reset(void *state);
93 static void z_comp_stats(void *state, struct compstat *stats);
94
95 /*
96 * Procedures exported to if_ppp.c.
97 */
98 static struct compressor ppp_deflate[2] = { {
99 .compress_proto = CI_DEFLATE,
100 .comp_alloc = z_comp_alloc,
101 .comp_free = z_comp_free,
102 .comp_init = z_comp_init,
103 .comp_reset = z_comp_reset,
104 .compress = z_compress,
105 .comp_stat = z_comp_stats,
106 .decomp_alloc = z_decomp_alloc,
107 .decomp_free = z_decomp_free,
108 .decomp_init = z_decomp_init,
109 .decomp_reset = z_decomp_reset,
110 .decompress = z_decompress,
111 .incomp = z_incomp,
112 .decomp_stat = z_comp_stats,
113 },
114 {
115 .compress_proto = CI_DEFLATE_DRAFT,
116 .comp_alloc = z_comp_alloc,
117 .comp_free = z_comp_free,
118 .comp_init = z_comp_init,
119 .comp_reset = z_comp_reset,
120 .compress = z_compress,
121 .comp_stat = z_comp_stats,
122 .decomp_alloc = z_decomp_alloc,
123 .decomp_free = z_decomp_free,
124 .decomp_init = z_decomp_init,
125 .decomp_reset = z_decomp_reset,
126 .decompress = z_decompress,
127 .incomp = z_incomp,
128 .decomp_stat = z_comp_stats,
129 } };
130 /*
131 * Space allocation and freeing routines for use by zlib routines.
132 */
133 void *
zalloc(void * notused,u_int items,u_int size)134 zalloc(void *notused, u_int items, u_int size)
135 {
136 void *ptr;
137
138 ptr = malloc(items * size, M_DEVBUF, M_NOWAIT);
139 return ptr;
140 }
141
142 void
zfree(void * notused,void * ptr)143 zfree(void *notused, void *ptr)
144 {
145 free(ptr, M_DEVBUF);
146 }
147
148 /*
149 * Allocate space for a compressor.
150 */
151 static void *
z_comp_alloc(u_char * options,int opt_len)152 z_comp_alloc(u_char *options, int opt_len)
153 {
154 struct deflate_state *state;
155 int w_size;
156
157 if (opt_len != CILEN_DEFLATE
158 || (options[0] != CI_DEFLATE && options[0] != CI_DEFLATE_DRAFT)
159 || options[1] != CILEN_DEFLATE
160 || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
161 || options[3] != DEFLATE_CHK_SEQUENCE)
162 return NULL;
163 w_size = DEFLATE_SIZE(options[2]);
164 if (w_size < DEFLATE_MIN_SIZE || w_size > DEFLATE_MAX_SIZE)
165 return NULL;
166
167 state = malloc(sizeof(struct deflate_state), M_DEVBUF, M_NOWAIT);
168 if (state == NULL)
169 return NULL;
170
171 state->strm.next_in = NULL;
172 state->strm.zalloc = zalloc;
173 state->strm.zfree = zfree;
174 if (deflateInit2(&state->strm, Z_DEFAULT_COMPRESSION, DEFLATE_METHOD_VAL,
175 -w_size, 8, Z_DEFAULT_STRATEGY) != Z_OK) {
176 free(state, M_DEVBUF);
177 return NULL;
178 }
179
180 state->w_size = w_size;
181 memset(&state->stats, 0, sizeof(state->stats));
182 return (void *) state;
183 }
184
185 static void
z_comp_free(void * arg)186 z_comp_free(void *arg)
187 {
188 struct deflate_state *state = (struct deflate_state *) arg;
189
190 deflateEnd(&state->strm);
191 free(state, M_DEVBUF);
192 }
193
194 static int
z_comp_init(void * arg,u_char * options,int opt_len,int unit,int hdrlen,int debug)195 z_comp_init(void *arg, u_char *options, int opt_len, int unit, int hdrlen,
196 int debug)
197 {
198 struct deflate_state *state = (struct deflate_state *) arg;
199
200 if (opt_len < CILEN_DEFLATE
201 || (options[0] != CI_DEFLATE && options[0] != CI_DEFLATE_DRAFT)
202 || options[1] != CILEN_DEFLATE
203 || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
204 || DEFLATE_SIZE(options[2]) != state->w_size
205 || options[3] != DEFLATE_CHK_SEQUENCE)
206 return 0;
207
208 state->seqno = 0;
209 state->unit = unit;
210 state->hdrlen = hdrlen;
211 state->debug = debug;
212
213 deflateReset(&state->strm);
214
215 return 1;
216 }
217
218 static void
z_comp_reset(void * arg)219 z_comp_reset(void *arg)
220 {
221 struct deflate_state *state = (struct deflate_state *) arg;
222
223 state->seqno = 0;
224 deflateReset(&state->strm);
225 }
226
227 int
z_compress(void * arg,struct mbuf ** mret,struct mbuf * mp,int orig_len,int maxolen)228 z_compress(void *arg,
229 struct mbuf **mret /* compressed packet (out) */,
230 struct mbuf *mp /* uncompressed packet (in) */,
231 int orig_len, int maxolen)
232 {
233 struct deflate_state *state = (struct deflate_state *) arg;
234 u_char *rptr, *wptr;
235 int proto, olen, wspace, r, flush;
236 struct mbuf *m;
237
238 /*
239 * Check that the protocol is in the range we handle.
240 */
241 rptr = mtod(mp, u_char *);
242 proto = PPP_PROTOCOL(rptr);
243 if (proto > 0x3fff || proto == 0xfd || proto == 0xfb) {
244 *mret = NULL;
245 return orig_len;
246 }
247
248 /* Allocate one mbuf initially. */
249 if (maxolen > orig_len)
250 maxolen = orig_len;
251 MGET(m, M_DONTWAIT, MT_DATA);
252 *mret = m;
253 if (m != NULL) {
254 m->m_len = 0;
255 if (maxolen + state->hdrlen > MLEN)
256 MCLGET(m, M_DONTWAIT);
257 wspace = M_TRAILINGSPACE(m);
258 if (state->hdrlen + PPP_HDRLEN + 2 < wspace) {
259 m->m_data += state->hdrlen;
260 wspace -= state->hdrlen;
261 }
262 wptr = mtod(m, u_char *);
263
264 /*
265 * Copy over the PPP header and store the 2-byte sequence number.
266 */
267 wptr[0] = PPP_ADDRESS(rptr);
268 wptr[1] = PPP_CONTROL(rptr);
269 wptr[2] = PPP_COMP >> 8;
270 wptr[3] = PPP_COMP;
271 wptr += PPP_HDRLEN;
272 wptr[0] = state->seqno >> 8;
273 wptr[1] = state->seqno;
274 wptr += 2;
275 state->strm.next_out = wptr;
276 state->strm.avail_out = wspace - (PPP_HDRLEN + 2);
277 } else {
278 state->strm.next_out = NULL;
279 state->strm.avail_out = 1000000;
280 wptr = NULL;
281 wspace = 0;
282 }
283 ++state->seqno;
284
285 rptr += (proto > 0xff)? 2: 3; /* skip 1st proto byte if 0 */
286 state->strm.next_in = rptr;
287 state->strm.avail_in = mtod(mp, u_char *) + mp->m_len - rptr;
288 mp = mp->m_next;
289 flush = (mp == NULL)? Z_PACKET_FLUSH: Z_NO_FLUSH;
290 olen = 0;
291 for (;;) {
292 r = deflate(&state->strm, flush);
293 if (r != Z_OK) {
294 printf("z_compress: deflate returned %d (%s)\n",
295 r, (state->strm.msg? state->strm.msg: ""));
296 break;
297 }
298 if (flush != Z_NO_FLUSH && state->strm.avail_out != 0)
299 break; /* all done */
300 if (state->strm.avail_in == 0 && mp != NULL) {
301 state->strm.next_in = mtod(mp, u_char *);
302 state->strm.avail_in = mp->m_len;
303 mp = mp->m_next;
304 if (mp == NULL)
305 flush = Z_PACKET_FLUSH;
306 }
307 if (state->strm.avail_out == 0) {
308 if (m != NULL) {
309 m->m_len = wspace;
310 olen += wspace;
311 MGET(m->m_next, M_DONTWAIT, MT_DATA);
312 m = m->m_next;
313 if (m != NULL) {
314 m->m_len = 0;
315 if (maxolen - olen > MLEN)
316 MCLGET(m, M_DONTWAIT);
317 state->strm.next_out = mtod(m, u_char *);
318 state->strm.avail_out = wspace = M_TRAILINGSPACE(m);
319 }
320 }
321 if (m == NULL) {
322 state->strm.next_out = NULL;
323 state->strm.avail_out = 1000000;
324 }
325 }
326 }
327 if (m != NULL)
328 olen += (m->m_len = wspace - state->strm.avail_out);
329
330 /*
331 * See if we managed to reduce the size of the packet.
332 */
333 if (m != NULL && olen < orig_len) {
334 state->stats.comp_bytes += olen;
335 state->stats.comp_packets++;
336 } else {
337 m_freem(*mret);
338 *mret = NULL;
339 state->stats.inc_bytes += orig_len;
340 state->stats.inc_packets++;
341 olen = orig_len;
342 }
343 state->stats.unc_bytes += orig_len;
344 state->stats.unc_packets++;
345
346 return olen;
347 }
348
349 static void
z_comp_stats(void * arg,struct compstat * stats)350 z_comp_stats(void *arg, struct compstat *stats)
351 {
352 struct deflate_state *state = (struct deflate_state *) arg;
353 u_int out;
354
355 *stats = state->stats;
356 stats->ratio = stats->unc_bytes;
357 out = stats->comp_bytes + stats->inc_bytes;
358 if (stats->ratio <= 0x7ffffff)
359 stats->ratio <<= 8;
360 else
361 out >>= 8;
362 if (out != 0)
363 stats->ratio /= out;
364 }
365
366 /*
367 * Allocate space for a decompressor.
368 */
369 static void *
z_decomp_alloc(u_char * options,int opt_len)370 z_decomp_alloc(u_char *options, int opt_len)
371 {
372 struct deflate_state *state;
373 int w_size;
374
375 if (opt_len != CILEN_DEFLATE
376 || (options[0] != CI_DEFLATE && options[0] != CI_DEFLATE_DRAFT)
377 || options[1] != CILEN_DEFLATE
378 || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
379 || options[3] != DEFLATE_CHK_SEQUENCE)
380 return NULL;
381 w_size = DEFLATE_SIZE(options[2]);
382 if (w_size < DEFLATE_MIN_SIZE || w_size > DEFLATE_MAX_SIZE)
383 return NULL;
384
385 state = malloc(sizeof(struct deflate_state), M_DEVBUF, M_NOWAIT);
386 if (state == NULL)
387 return NULL;
388
389 state->strm.next_out = NULL;
390 state->strm.zalloc = zalloc;
391 state->strm.zfree = zfree;
392 if (inflateInit2(&state->strm, -w_size) != Z_OK) {
393 free(state, M_DEVBUF);
394 return NULL;
395 }
396
397 state->w_size = w_size;
398 memset(&state->stats, 0, sizeof(state->stats));
399 return (void *) state;
400 }
401
402 static void
z_decomp_free(void * arg)403 z_decomp_free(void *arg)
404 {
405 struct deflate_state *state = (struct deflate_state *) arg;
406
407 inflateEnd(&state->strm);
408 free(state, M_DEVBUF);
409 }
410
411 static int
z_decomp_init(void * arg,u_char * options,int opt_len,int unit,int hdrlen,int mru,int debug)412 z_decomp_init(void *arg, u_char *options, int opt_len, int unit, int hdrlen,
413 int mru, int debug)
414 {
415 struct deflate_state *state = (struct deflate_state *) arg;
416
417 if (opt_len < CILEN_DEFLATE
418 || (options[0] != CI_DEFLATE && options[0] != CI_DEFLATE_DRAFT)
419 || options[1] != CILEN_DEFLATE
420 || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
421 || DEFLATE_SIZE(options[2]) != state->w_size
422 || options[3] != DEFLATE_CHK_SEQUENCE)
423 return 0;
424
425 state->seqno = 0;
426 state->unit = unit;
427 state->hdrlen = hdrlen;
428 state->debug = debug;
429 state->mru = mru;
430
431 inflateReset(&state->strm);
432
433 return 1;
434 }
435
436 static void
z_decomp_reset(void * arg)437 z_decomp_reset(void *arg)
438 {
439 struct deflate_state *state = (struct deflate_state *) arg;
440
441 state->seqno = 0;
442 inflateReset(&state->strm);
443 }
444
445 /*
446 * Decompress a Deflate-compressed packet.
447 *
448 * Because of patent problems, we return DECOMP_ERROR for errors
449 * found by inspecting the input data and for system problems, but
450 * DECOMP_FATALERROR for any errors which could possibly be said to
451 * be being detected "after" decompression. For DECOMP_ERROR,
452 * we can issue a CCP reset-request; for DECOMP_FATALERROR, we may be
453 * infringing a patent of Motorola's if we do, so we take CCP down
454 * instead.
455 *
456 * Given that the frame has the correct sequence number and a good FCS,
457 * errors such as invalid codes in the input most likely indicate a
458 * bug, so we return DECOMP_FATALERROR for them in order to turn off
459 * compression, even though they are detected by inspecting the input.
460 */
461 int
z_decompress(void * arg,struct mbuf * mi,struct mbuf ** mop)462 z_decompress(void *arg, struct mbuf *mi, struct mbuf **mop)
463 {
464 struct deflate_state *state = (struct deflate_state *) arg;
465 struct mbuf *mo, *mo_head;
466 u_char *rptr, *wptr;
467 int rlen, olen, ospace;
468 int seq, i, flush, r, decode_proto;
469 u_char hdr[PPP_HDRLEN + DEFLATE_OVHD];
470
471 *mop = NULL;
472 rptr = mtod(mi, u_char *);
473 rlen = mi->m_len;
474 for (i = 0; i < PPP_HDRLEN + DEFLATE_OVHD; ++i) {
475 while (rlen <= 0) {
476 mi = mi->m_next;
477 if (mi == NULL)
478 return DECOMP_ERROR;
479 rptr = mtod(mi, u_char *);
480 rlen = mi->m_len;
481 }
482 hdr[i] = *rptr++;
483 --rlen;
484 }
485
486 /* Check the sequence number. */
487 seq = (hdr[PPP_HDRLEN] << 8) + hdr[PPP_HDRLEN+1];
488 if (seq != state->seqno) {
489 if (state->debug)
490 printf("z_decompress%d: bad seq # %d, expected %d\n",
491 state->unit, seq, state->seqno);
492 return DECOMP_ERROR;
493 }
494 ++state->seqno;
495
496 /* Allocate an output mbuf. */
497 MGETHDR(mo, M_DONTWAIT, MT_DATA);
498 if (mo == NULL)
499 return DECOMP_ERROR;
500 mo_head = mo;
501 mo->m_len = 0;
502 mo->m_next = NULL;
503 MCLGET(mo, M_DONTWAIT);
504 ospace = M_TRAILINGSPACE(mo);
505 if (state->hdrlen + PPP_HDRLEN < ospace) {
506 mo->m_data += state->hdrlen;
507 ospace -= state->hdrlen;
508 }
509
510 /*
511 * Fill in the first part of the PPP header. The protocol field
512 * comes from the decompressed data.
513 */
514 wptr = mtod(mo, u_char *);
515 wptr[0] = PPP_ADDRESS(hdr);
516 wptr[1] = PPP_CONTROL(hdr);
517 wptr[2] = 0;
518
519 /*
520 * Set up to call inflate. We set avail_out to 1 initially so we can
521 * look at the first byte of the output and decide whether we have
522 * a 1-byte or 2-byte protocol field.
523 */
524 state->strm.next_in = rptr;
525 state->strm.avail_in = rlen;
526 mi = mi->m_next;
527 flush = (mi == NULL)? Z_PACKET_FLUSH: Z_NO_FLUSH;
528 rlen += PPP_HDRLEN + DEFLATE_OVHD;
529 state->strm.next_out = wptr + 3;
530 state->strm.avail_out = 1;
531 decode_proto = 1;
532 olen = 0;
533
534 /*
535 * Call inflate, supplying more input or output as needed.
536 */
537 for (;;) {
538 r = inflate(&state->strm, flush);
539 if (r != Z_OK) {
540 #if !DEFLATE_DEBUG
541 if (state->debug)
542 #endif
543 printf("z_decompress%d: inflate returned %d (%s)\n",
544 state->unit, r, (state->strm.msg? state->strm.msg: ""));
545 m_freem(mo_head);
546 return DECOMP_FATALERROR;
547 }
548 if (flush != Z_NO_FLUSH && state->strm.avail_out != 0)
549 break; /* all done */
550 if (state->strm.avail_in == 0 && mi != NULL) {
551 state->strm.next_in = mtod(mi, u_char *);
552 state->strm.avail_in = mi->m_len;
553 rlen += mi->m_len;
554 mi = mi->m_next;
555 if (mi == NULL)
556 flush = Z_PACKET_FLUSH;
557 }
558 if (state->strm.avail_out == 0) {
559 if (decode_proto) {
560 state->strm.avail_out = ospace - PPP_HDRLEN;
561 if ((wptr[3] & 1) == 0) {
562 /* 2-byte protocol field */
563 wptr[2] = wptr[3];
564 --state->strm.next_out;
565 ++state->strm.avail_out;
566 --olen;
567 }
568 decode_proto = 0;
569 } else {
570 mo->m_len = ospace;
571 olen += ospace;
572 MGET(mo->m_next, M_DONTWAIT, MT_DATA);
573 mo = mo->m_next;
574 if (mo == NULL) {
575 m_freem(mo_head);
576 return DECOMP_ERROR;
577 }
578 MCLGET(mo, M_DONTWAIT);
579 state->strm.next_out = mtod(mo, u_char *);
580 state->strm.avail_out = ospace = M_TRAILINGSPACE(mo);
581 }
582 }
583 }
584 if (decode_proto) {
585 m_freem(mo_head);
586 return DECOMP_ERROR;
587 }
588 olen += (mo->m_len = ospace - state->strm.avail_out);
589 #if DEFLATE_DEBUG
590 if (olen > state->mru + PPP_HDRLEN)
591 printf("ppp_deflate%d: exceeded mru (%d > %d)\n",
592 state->unit, olen, state->mru + PPP_HDRLEN);
593 #endif
594
595 state->stats.unc_bytes += olen;
596 state->stats.unc_packets++;
597 state->stats.comp_bytes += rlen;
598 state->stats.comp_packets++;
599
600 *mop = mo_head;
601 return DECOMP_OK;
602 }
603
604 /*
605 * Incompressible data has arrived - add it to the history.
606 */
607 static void
z_incomp(void * arg,struct mbuf * mi)608 z_incomp(void *arg, struct mbuf *mi)
609 {
610 struct deflate_state *state = (struct deflate_state *) arg;
611 u_char *rptr;
612 int rlen, proto, r;
613
614 /*
615 * Check that the protocol is one we handle.
616 */
617 rptr = mtod(mi, u_char *);
618 proto = PPP_PROTOCOL(rptr);
619 if (proto > 0x3fff || proto == 0xfd || proto == 0xfb)
620 return;
621
622 ++state->seqno;
623
624 /*
625 * Iterate through the mbufs, adding the characters in them
626 * to the decompressor's history. For the first mbuf, we start
627 * at the either the 1st or 2nd byte of the protocol field,
628 * depending on whether the protocol value is compressible.
629 */
630 rlen = mi->m_len;
631 state->strm.next_in = rptr + 3;
632 state->strm.avail_in = rlen - 3;
633 if (proto > 0xff) {
634 --state->strm.next_in;
635 ++state->strm.avail_in;
636 }
637 for (;;) {
638 r = inflateIncomp(&state->strm);
639 if (r != Z_OK) {
640 /* gak! */
641 #if !DEFLATE_DEBUG
642 if (state->debug)
643 #endif
644 printf("z_incomp%d: inflateIncomp returned %d (%s)\n",
645 state->unit, r, (state->strm.msg? state->strm.msg: ""));
646 return;
647 }
648 mi = mi->m_next;
649 if (mi == NULL)
650 break;
651 state->strm.next_in = mtod(mi, u_char *);
652 state->strm.avail_in = mi->m_len;
653 rlen += mi->m_len;
654 }
655
656 /*
657 * Update stats.
658 */
659 state->stats.inc_bytes += rlen;
660 state->stats.inc_packets++;
661 state->stats.unc_bytes += rlen;
662 state->stats.unc_packets++;
663 }
664
665 MODULE(MODULE_CLASS_MISC, ppp_deflate, "zlib,if_ppp");
666
667 static int
ppp_deflate_modcmd(modcmd_t cmd,void * arg)668 ppp_deflate_modcmd(modcmd_t cmd, void *arg)
669 {
670
671 switch (cmd) {
672 case MODULE_CMD_INIT:
673 return ppp_register_compressor(ppp_deflate, 2);
674 case MODULE_CMD_FINI:
675 return ppp_unregister_compressor(ppp_deflate, 2);
676 case MODULE_CMD_STAT:
677 return 0;
678 default:
679 return ENOTTY;
680 }
681
682 return ENOTTY;
683 }
684 #endif /* DO_DEFLATE */
685