2 * ==FILEVERSION 980319==
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 Linux kernel 1.3.X and later.
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,
31 * From: deflate.c,v 1.1 1996/01/18 03:17:48 paulus Exp
34 #include <linux/module.h>
35 #include <linux/version.h>
36 #include <linux/kernel.h>
37 #include <linux/sched.h>
38 #include <linux/types.h>
39 #include <linux/fcntl.h>
40 #include <linux/interrupt.h>
41 #include <linux/ptrace.h>
42 #include <linux/ioport.h>
44 #include <linux/malloc.h>
47 /* a nice define to generate linux version numbers */
48 #define VERSION(major,minor,patch) (((((major)<<8)+(minor))<<8)+(patch))
50 #if LINUX_VERSION_CODE >= VERSION(2,1,4)
51 #include <linux/vmalloc.h>
54 #include <linux/errno.h>
55 #include <linux/sched.h> /* to get the struct task_struct */
56 #include <linux/string.h> /* used in new tty drivers */
57 #include <linux/signal.h> /* used in new tty drivers */
59 #include <asm/system.h>
61 #include <linux/netdevice.h>
62 #include <linux/skbuff.h>
63 #include <linux/inet.h>
64 #include <linux/ioctl.h>
66 #include <linux/ppp_defs.h>
67 #include <linux/ppp-comp.h>
72 * State for a Deflate (de)compressor.
74 struct ppp_deflate_state {
81 struct compstat stats;
84 #define DEFLATE_OVHD 2 /* Deflate overhead/packet */
86 static void *zalloc __P((void *, unsigned int items, unsigned int size));
87 static void *zalloc_init __P((void *, unsigned int items,
89 static void zfree __P((void *, void *ptr));
90 static void *z_comp_alloc __P((unsigned char *options, int opt_len));
91 static void *z_decomp_alloc __P((unsigned char *options, int opt_len));
92 static void z_comp_free __P((void *state));
93 static void z_decomp_free __P((void *state));
94 static int z_comp_init __P((void *state, unsigned char *options,
96 int unit, int hdrlen, int debug));
97 static int z_decomp_init __P((void *state, unsigned char *options,
99 int unit, int hdrlen, int mru, int debug));
100 static int z_compress __P((void *state, unsigned char *rptr,
102 int isize, int osize));
103 static void z_incomp __P((void *state, unsigned char *ibuf, int icnt));
104 static int z_decompress __P((void *state, unsigned char *ibuf,
105 int isize, unsigned char *obuf, int osize));
106 static void z_comp_reset __P((void *state));
107 static void z_decomp_reset __P((void *state));
108 static void z_comp_stats __P((void *state, struct compstat *stats));
110 struct chunk_header {
111 int valloced; /* allocated with valloc, not kmalloc */
112 int guard; /* check for overwritten header */
115 #define GUARD_MAGIC 0x77a8011a
116 #define MIN_VMALLOC 2048 /* use kmalloc for blocks < this */
119 * Space allocation and freeing routines for use by zlib routines.
126 struct chunk_header *hdr = ((struct chunk_header *)ptr) - 1;
128 if (hdr->guard != GUARD_MAGIC) {
129 printk(KERN_WARNING "zfree: header corrupted (%x %x) at %p\n",
130 hdr->valloced, hdr->guard, hdr);
140 zalloc(arg, items, size)
142 unsigned int items, size;
144 struct chunk_header *hdr;
147 nbytes = items * size + sizeof(*hdr);
148 hdr = kmalloc(nbytes, GFP_ATOMIC);
152 hdr->guard = GUARD_MAGIC;
153 return (void *) (hdr + 1);
157 zalloc_init(arg, items, size)
159 unsigned int items, size;
161 struct chunk_header *hdr;
164 nbytes = items * size + sizeof(*hdr);
165 if (nbytes >= MIN_VMALLOC)
166 hdr = vmalloc(nbytes);
168 hdr = kmalloc(nbytes, GFP_KERNEL);
171 hdr->valloced = nbytes >= MIN_VMALLOC;
172 hdr->guard = GUARD_MAGIC;
173 return (void *) (hdr + 1);
180 struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
183 deflateEnd(&state->strm);
190 * Allocate space for a compressor.
193 z_comp_alloc(options, opt_len)
194 unsigned char *options;
197 struct ppp_deflate_state *state;
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 || options[3] != DEFLATE_CHK_SEQUENCE)
206 w_size = DEFLATE_SIZE(options[2]);
207 if (w_size < DEFLATE_MIN_SIZE || w_size > DEFLATE_MAX_SIZE)
210 state = (struct ppp_deflate_state *) kmalloc(sizeof(*state), GFP_KERNEL);
215 memset (state, 0, sizeof (struct ppp_deflate_state));
216 state->strm.next_in = NULL;
217 state->strm.zalloc = zalloc_init;
218 state->strm.zfree = zfree;
219 state->w_size = w_size;
221 if (deflateInit2(&state->strm, Z_DEFAULT_COMPRESSION,
222 DEFLATE_METHOD_VAL, -w_size, 8, Z_DEFAULT_STRATEGY)
225 state->strm.zalloc = zalloc;
226 return (void *) state;
235 z_comp_init(arg, options, opt_len, unit, hdrlen, debug)
237 unsigned char *options;
238 int opt_len, unit, hdrlen, debug;
240 struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
242 if (opt_len < CILEN_DEFLATE
243 || (options[0] != CI_DEFLATE && options[0] != CI_DEFLATE_DRAFT)
244 || options[1] != CILEN_DEFLATE
245 || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
246 || DEFLATE_SIZE(options[2]) != state->w_size
247 || options[3] != DEFLATE_CHK_SEQUENCE)
252 state->debug = debug;
254 deflateReset(&state->strm);
263 struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
266 deflateReset(&state->strm);
270 z_compress(arg, rptr, obuf, isize, osize)
272 unsigned char *rptr; /* uncompressed packet (in) */
273 unsigned char *obuf; /* compressed packet (out) */
276 struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
277 int r, proto, off, olen, oavail;
281 * Check that the protocol is in the range we handle.
283 proto = PPP_PROTOCOL(rptr);
284 if (proto > 0x3fff || proto == 0xfd || proto == 0xfb)
287 /* Don't generate compressed packets which are larger than
288 the uncompressed packet. */
295 * Copy over the PPP header and store the 2-byte sequence number.
297 wptr[0] = PPP_ADDRESS(rptr);
298 wptr[1] = PPP_CONTROL(rptr);
299 wptr[2] = PPP_COMP >> 8;
302 wptr[0] = state->seqno >> 8;
303 wptr[1] = state->seqno;
304 wptr += DEFLATE_OVHD;
305 olen = PPP_HDRLEN + DEFLATE_OVHD;
306 state->strm.next_out = wptr;
307 state->strm.avail_out = oavail = osize - olen;
310 off = (proto > 0xff) ? 2 : 3; /* skip 1st proto byte if 0 */
312 state->strm.next_in = rptr;
313 state->strm.avail_in = (isize - off);
316 r = deflate(&state->strm, Z_PACKET_FLUSH);
320 "z_compress: deflate returned %d\n", r);
323 if (state->strm.avail_out == 0) {
325 state->strm.next_out = NULL;
326 state->strm.avail_out = oavail = 1000000;
328 break; /* all done */
331 olen += oavail - state->strm.avail_out;
334 * See if we managed to reduce the size of the packet.
337 state->stats.comp_bytes += olen;
338 state->stats.comp_packets++;
340 state->stats.inc_bytes += isize;
341 state->stats.inc_packets++;
344 state->stats.unc_bytes += isize;
345 state->stats.unc_packets++;
351 z_comp_stats(arg, stats)
353 struct compstat *stats;
355 struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
357 *stats = state->stats;
364 struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
367 inflateEnd(&state->strm);
374 * Allocate space for a decompressor.
377 z_decomp_alloc(options, opt_len)
378 unsigned char *options;
381 struct ppp_deflate_state *state;
384 if (opt_len != CILEN_DEFLATE
385 || (options[0] != CI_DEFLATE && options[0] != CI_DEFLATE_DRAFT)
386 || options[1] != CILEN_DEFLATE
387 || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
388 || options[3] != DEFLATE_CHK_SEQUENCE)
390 w_size = DEFLATE_SIZE(options[2]);
391 if (w_size < DEFLATE_MIN_SIZE || w_size > DEFLATE_MAX_SIZE)
394 state = (struct ppp_deflate_state *) kmalloc(sizeof(*state), GFP_KERNEL);
399 memset (state, 0, sizeof (struct ppp_deflate_state));
400 state->w_size = w_size;
401 state->strm.next_out = NULL;
402 state->strm.zalloc = zalloc_init;
403 state->strm.zfree = zfree;
405 if (inflateInit2(&state->strm, -w_size) != Z_OK)
407 state->strm.zalloc = zalloc;
408 return (void *) state;
411 z_decomp_free(state);
417 z_decomp_init(arg, options, opt_len, unit, hdrlen, mru, debug)
419 unsigned char *options;
420 int opt_len, unit, hdrlen, mru, debug;
422 struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
424 if (opt_len < CILEN_DEFLATE
425 || (options[0] != CI_DEFLATE && options[0] != CI_DEFLATE_DRAFT)
426 || options[1] != CILEN_DEFLATE
427 || DEFLATE_METHOD(options[2]) != DEFLATE_METHOD_VAL
428 || DEFLATE_SIZE(options[2]) != state->w_size
429 || options[3] != DEFLATE_CHK_SEQUENCE)
434 state->debug = debug;
437 inflateReset(&state->strm);
446 struct ppp_deflate_state *state = (struct ppp_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, ibuf, isize, obuf, osize)
476 struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
478 int decode_proto, overflow;
479 unsigned char overflow_buf[1];
481 if (isize <= PPP_HDRLEN + DEFLATE_OVHD) {
483 printk(KERN_DEBUG "z_decompress%d: short pkt (%d)\n",
488 /* Check the sequence number. */
489 seq = (ibuf[PPP_HDRLEN] << 8) + ibuf[PPP_HDRLEN+1];
490 if (seq != state->seqno) {
492 printk(KERN_DEBUG "z_decompress%d: bad seq # %d, expected %d\n",
493 state->unit, seq, state->seqno);
499 * Fill in the first part of the PPP header. The protocol field
500 * comes from the decompressed data.
502 obuf[0] = PPP_ADDRESS(ibuf);
503 obuf[1] = PPP_CONTROL(ibuf);
507 * Set up to call inflate. We set avail_out to 1 initially so we can
508 * look at the first byte of the output and decide whether we have
509 * a 1-byte or 2-byte protocol field.
511 state->strm.next_in = ibuf + PPP_HDRLEN + DEFLATE_OVHD;
512 state->strm.avail_in = isize - (PPP_HDRLEN + DEFLATE_OVHD);
513 state->strm.next_out = obuf + 3;
514 state->strm.avail_out = 1;
519 * Call inflate, supplying more input or output as needed.
522 r = inflate(&state->strm, Z_PACKET_FLUSH);
525 printk(KERN_DEBUG "z_decompress%d: inflate returned %d (%s)\n",
526 state->unit, r, (state->strm.msg? state->strm.msg: ""));
527 return DECOMP_FATALERROR;
529 if (state->strm.avail_out != 0)
530 break; /* all done */
532 state->strm.avail_out = osize - PPP_HDRLEN;
533 if ((obuf[3] & 1) == 0) {
534 /* 2-byte protocol field */
536 --state->strm.next_out;
537 ++state->strm.avail_out;
540 } else if (!overflow) {
542 * We've filled up the output buffer; the only way to
543 * find out whether inflate has any more characters
544 * left is to give it another byte of output space.
546 state->strm.next_out = overflow_buf;
547 state->strm.avail_out = 1;
551 printk(KERN_DEBUG "z_decompress%d: ran out of mru\n",
553 return DECOMP_FATALERROR;
559 printk(KERN_DEBUG "z_decompress%d: didn't get proto\n",
564 olen = osize + overflow - state->strm.avail_out;
565 state->stats.unc_bytes += olen;
566 state->stats.unc_packets++;
567 state->stats.comp_bytes += isize;
568 state->stats.comp_packets++;
574 * Incompressible data has arrived - add it to the history.
577 z_incomp(arg, ibuf, icnt)
582 struct ppp_deflate_state *state = (struct ppp_deflate_state *) arg;
586 * Check that the protocol is one we handle.
588 proto = PPP_PROTOCOL(ibuf);
589 if (proto > 0x3fff || proto == 0xfd || proto == 0xfb)
595 * We start at the either the 1st or 2nd byte of the protocol field,
596 * depending on whether the protocol value is compressible.
598 state->strm.next_in = ibuf + 3;
599 state->strm.avail_in = icnt - 3;
601 --state->strm.next_in;
602 ++state->strm.avail_in;
605 r = inflateIncomp(&state->strm);
609 printk(KERN_DEBUG "z_incomp%d: inflateIncomp returned %d (%s)\n",
610 state->unit, r, (state->strm.msg? state->strm.msg: ""));
618 state->stats.inc_bytes += icnt;
619 state->stats.inc_packets++;
620 state->stats.unc_bytes += icnt;
621 state->stats.unc_packets++;
624 /*************************************************************
625 * Module interface table
626 *************************************************************/
628 /* These are in ppp.c */
629 extern int ppp_register_compressor (struct compressor *cp);
630 extern void ppp_unregister_compressor (struct compressor *cp);
633 * Procedures exported to if_ppp.c.
635 struct compressor ppp_deflate = {
636 CI_DEFLATE, /* compress_proto */
637 z_comp_alloc, /* comp_alloc */
638 z_comp_free, /* comp_free */
639 z_comp_init, /* comp_init */
640 z_comp_reset, /* comp_reset */
641 z_compress, /* compress */
642 z_comp_stats, /* comp_stat */
643 z_decomp_alloc, /* decomp_alloc */
644 z_decomp_free, /* decomp_free */
645 z_decomp_init, /* decomp_init */
646 z_decomp_reset, /* decomp_reset */
647 z_decompress, /* decompress */
648 z_incomp, /* incomp */
649 z_comp_stats, /* decomp_stat */
652 struct compressor ppp_deflate_draft = {
653 CI_DEFLATE_DRAFT, /* compress_proto */
654 z_comp_alloc, /* comp_alloc */
655 z_comp_free, /* comp_free */
656 z_comp_init, /* comp_init */
657 z_comp_reset, /* comp_reset */
658 z_compress, /* compress */
659 z_comp_stats, /* comp_stat */
660 z_decomp_alloc, /* decomp_alloc */
661 z_decomp_free, /* decomp_free */
662 z_decomp_init, /* decomp_init */
663 z_decomp_reset, /* decomp_reset */
664 z_decompress, /* decompress */
665 z_incomp, /* incomp */
666 z_comp_stats, /* decomp_stat */
670 /*************************************************************
671 * Module support routines
672 *************************************************************/
677 int answer = ppp_register_compressor (&ppp_deflate);
680 "PPP Deflate Compression module registered\n");
681 ppp_register_compressor(&ppp_deflate_draft);
690 "Deflate Compression module busy, remove delayed\n");
692 ppp_unregister_compressor (&ppp_deflate);
693 ppp_unregister_compressor (&ppp_deflate_draft);