2 * ccp.c - PPP Compression Control Protocol.
4 * Copyright (c) 1994 The Australian National University.
7 * Permission to use, copy, modify, and distribute this software and its
8 * documentation is hereby granted, provided that the above copyright
9 * notice appears in all copies. This software is provided without any
10 * warranty, express or implied. The Australian National University
11 * makes no representations about the suitability of this software for
14 * IN NO EVENT SHALL THE AUSTRALIAN NATIONAL UNIVERSITY BE LIABLE TO ANY
15 * PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
16 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
17 * THE AUSTRALIAN NATIONAL UNIVERSITY HAVE BEEN ADVISED OF THE POSSIBILITY
20 * THE AUSTRALIAN NATIONAL UNIVERSITY SPECIFICALLY DISCLAIMS ANY WARRANTIES,
21 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
22 * AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
23 * ON AN "AS IS" BASIS, AND THE AUSTRALIAN NATIONAL UNIVERSITY HAS NO
24 * OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS,
29 static char rcsid[] = "$Id: ccp.c,v 1.9 1995/05/19 03:17:09 paulus Exp $";
33 #include <sys/ioctl.h>
34 #include <net/ppp-comp.h>
41 ccp_options ccp_wantoptions[NUM_PPP]; /* what to request the peer to use */
42 ccp_options ccp_gotoptions[NUM_PPP]; /* what the peer agreed to do */
43 ccp_options ccp_allowoptions[NUM_PPP]; /* what we'll agree to do */
44 ccp_options ccp_hisoptions[NUM_PPP]; /* what we agreed to do */
47 * Callbacks for fsm code.
49 static void ccp_resetci __P((fsm *));
50 static int ccp_cilen __P((fsm *));
51 static void ccp_addci __P((fsm *, u_char *, int *));
52 static int ccp_ackci __P((fsm *, u_char *, int));
53 static int ccp_nakci __P((fsm *, u_char *, int));
54 static int ccp_rejci __P((fsm *, u_char *, int));
55 static int ccp_reqci __P((fsm *, u_char *, int *, int));
56 static void ccp_up __P((fsm *));
57 static void ccp_down __P((fsm *));
58 static int ccp_extcode __P((fsm *, int, int, u_char *, int));
59 static void ccp_rack_timeout __P(());
61 static fsm_callbacks ccp_callbacks = {
80 * Do we want / did we get any compression?
82 #define ANY_COMPRESS(opt) ((opt).bsd_compress)
85 * Local state (mainly for handling reset-reqs and reset-acks
87 static int ccp_localstate[NUM_PPP];
88 #define RACK_PENDING 1 /* waiting for reset-ack */
89 #define RREQ_REPEAT 2 /* send another reset-req if no reset-ack */
91 #define RACKTIMEOUT 1 /* second */
94 * ccp_init - initialize CCP.
100 fsm *f = &ccp_fsm[unit];
103 f->protocol = PPP_CCP;
104 f->callbacks = &ccp_callbacks;
107 memset(&ccp_wantoptions[unit], 0, sizeof(ccp_options));
108 memset(&ccp_gotoptions[unit], 0, sizeof(ccp_options));
109 memset(&ccp_allowoptions[unit], 0, sizeof(ccp_options));
110 memset(&ccp_hisoptions[unit], 0, sizeof(ccp_options));
112 ccp_wantoptions[0].bsd_bits = 12; /* default value */
114 ccp_allowoptions[0].bsd_compress = 1;
115 ccp_allowoptions[0].bsd_bits = BSD_MAX_BITS;
119 * ccp_open - CCP is allowed to come up.
125 fsm *f = &ccp_fsm[unit];
127 if (f->state != OPENED)
128 ccp_flags_set(unit, 1, 0);
129 if (!ANY_COMPRESS(ccp_wantoptions[unit]))
130 f->flags |= OPT_SILENT;
135 * ccp_close - Terminate CCP.
141 ccp_flags_set(unit, 0, 0);
142 fsm_close(&ccp_fsm[unit]);
146 * ccp_lowerup - we may now transmit CCP packets.
152 fsm_lowerup(&ccp_fsm[unit]);
156 * ccp_lowerdown - we may not transmit CCP packets.
162 fsm_lowerdown(&ccp_fsm[unit]);
166 * ccp_input - process a received CCP packet.
169 ccp_input(unit, p, len)
174 fsm *f = &ccp_fsm[unit];
178 * Check for a terminate-request so we can print a message.
181 fsm_input(f, p, len);
182 if (oldstate == OPENED && p[0] == TERMREQ && f->state != OPENED)
183 syslog(LOG_NOTICE, "Compression disabled by peer.");
187 * Handle a CCP-specific code.
190 ccp_extcode(f, code, id, p, len)
198 if (f->state != OPENED)
200 /* send a reset-ack, which the transmitter will see and
201 reset its compression state. */
202 fsm_sdata(f, CCP_RESETACK, id, NULL, 0);
206 if (ccp_localstate[f->unit] & RACK_PENDING && id == f->reqid) {
207 ccp_localstate[f->unit] &= ~(RACK_PENDING | RREQ_REPEAT);
208 UNTIMEOUT(ccp_rack_timeout, (caddr_t) f);
220 * ccp_protrej - peer doesn't talk CCP.
226 ccp_flags_set(unit, 0, 0);
227 fsm_lowerdown(&ccp_fsm[unit]);
231 * ccp_resetci - initialize at start of negotiation.
237 ccp_options *go = &ccp_gotoptions[f->unit];
240 *go = ccp_wantoptions[f->unit];
241 if (go->bsd_compress) {
242 opt_buf[0] = CI_BSD_COMPRESS;
243 opt_buf[1] = CILEN_BSD_COMPRESS;
244 opt_buf[2] = BSD_MAKE_OPT(BSD_CURRENT_VERSION, go->bsd_bits);
245 if (!ccp_test(f->unit, opt_buf, CILEN_BSD_COMPRESS, 0))
246 go->bsd_compress = 0;
251 * ccp_cilen - Return total length of our configuration info.
257 ccp_options *go = &ccp_gotoptions[f->unit];
259 return (go->bsd_compress? CILEN_BSD_COMPRESS: 0);
263 * ccp_addci - put our requests in a packet.
266 ccp_addci(f, p, lenp)
271 ccp_options *go = &ccp_gotoptions[f->unit];
274 if (go->bsd_compress) {
275 p[0] = CI_BSD_COMPRESS;
276 p[1] = CILEN_BSD_COMPRESS;
277 p[2] = BSD_MAKE_OPT(BSD_CURRENT_VERSION, go->bsd_bits);
278 if (ccp_test(f->unit, p, CILEN_BSD_COMPRESS, 0))
279 p += CILEN_BSD_COMPRESS;
281 go->bsd_compress = 0;
287 * ccp_ackci - process a received configure-ack, and return
288 * 1 iff the packet was OK.
296 ccp_options *go = &ccp_gotoptions[f->unit];
298 if (go->bsd_compress) {
299 if (len < CILEN_BSD_COMPRESS
300 || p[0] != CI_BSD_COMPRESS || p[1] != CILEN_BSD_COMPRESS
301 || p[2] != BSD_MAKE_OPT(BSD_CURRENT_VERSION, go->bsd_bits))
303 p += CILEN_BSD_COMPRESS;
304 len -= CILEN_BSD_COMPRESS;
312 * ccp_nakci - process received configure-nak.
313 * Returns 1 iff the nak was OK.
321 ccp_options *go = &ccp_gotoptions[f->unit];
322 ccp_options no; /* options we've seen already */
323 ccp_options try; /* options to ask for next time */
325 memset(&no, 0, sizeof(no));
328 if (go->bsd_compress && !no.bsd_compress && len >= CILEN_BSD_COMPRESS
329 && p[0] == CI_BSD_COMPRESS && p[1] == CILEN_BSD_COMPRESS) {
332 * Peer wants us to use a different number of bits
333 * or a different version.
335 if (BSD_VERSION(p[2]) != BSD_CURRENT_VERSION)
336 try.bsd_compress = 0;
337 else if (BSD_NBITS(p[2]) < go->bsd_bits)
338 try.bsd_bits = BSD_NBITS(p[2]);
339 p += CILEN_BSD_COMPRESS;
340 len -= CILEN_BSD_COMPRESS;
344 * Have a look at any remaining options...???
350 if (f->state != OPENED)
356 * ccp_rejci - reject some of our suggested compression methods.
364 ccp_options *go = &ccp_gotoptions[f->unit];
365 ccp_options try; /* options to request next time */
369 if (go->bsd_compress && len >= CILEN_BSD_COMPRESS
370 && p[0] == CI_BSD_COMPRESS && p[1] == CILEN_BSD_COMPRESS) {
371 if (p[2] != BSD_MAKE_OPT(BSD_CURRENT_VERSION, go->bsd_bits))
373 try.bsd_compress = 0;
374 p += CILEN_BSD_COMPRESS;
375 len -= CILEN_BSD_COMPRESS;
381 if (f->state != OPENED)
388 * ccp_reqci - processed a received configure-request.
389 * Returns CONFACK, CONFNAK or CONFREJ and the packet modified
393 ccp_reqci(f, p, lenp, dont_nak)
401 int len, clen, type, nb;
402 ccp_options *ho = &ccp_hisoptions[f->unit];
403 ccp_options *ao = &ccp_allowoptions[f->unit];
409 memset(ho, 0, sizeof(ccp_options));
413 if (len < 2 || p[1] < 2 || p[1] > len) {
423 case CI_BSD_COMPRESS:
424 if (!ao->bsd_compress || clen != CILEN_BSD_COMPRESS) {
429 ho->bsd_compress = 1;
430 ho->bsd_bits = nb = BSD_NBITS(p[2]);
431 if (BSD_VERSION(p[2]) != BSD_CURRENT_VERSION
432 || nb > ao->bsd_bits) {
435 } else if (nb < BSD_MIN_BITS) {
437 } else if (!ccp_test(f->unit, p, CILEN_BSD_COMPRESS, 1)) {
438 if (nb > BSD_MIN_BITS) {
444 if (newret == CONFNAK && !dont_nak) {
445 p[2] = BSD_MAKE_OPT(BSD_CURRENT_VERSION, nb);
455 if (newret == CONFNAK && dont_nak)
457 if (!(newret == CONFACK || newret == CONFNAK && ret == CONFREJ)) {
458 /* we're returning this option */
459 if (newret == CONFREJ && ret == CONFNAK)
463 BCOPY(p, retp, clen);
477 * CCP has come up - inform the kernel driver.
483 ccp_options *go = &ccp_gotoptions[f->unit];
484 ccp_options *ho = &ccp_hisoptions[f->unit];
486 ccp_flags_set(f->unit, 1, 1);
487 if (go->bsd_compress || ho->bsd_compress)
488 syslog(LOG_NOTICE, "%s enabled",
489 go->bsd_compress? ho->bsd_compress? "Compression":
490 "Receive compression": "Transmit compression");
494 * CCP has gone down - inform the kernel driver.
500 if (ccp_localstate[f->unit] & RACK_PENDING)
501 UNTIMEOUT(ccp_rack_timeout, (caddr_t) f);
502 ccp_localstate[f->unit] = 0;
503 ccp_flags_set(f->unit, 1, 0);
507 * Print the contents of a CCP packet.
509 char *ccp_codenames[] = {
510 "ConfReq", "ConfAck", "ConfNak", "ConfRej",
511 "TermReq", "TermAck", "CodeRej",
512 NULL, NULL, NULL, NULL, NULL, NULL,
513 "ResetReq", "ResetAck",
517 ccp_printpkt(p, plen, printer, arg)
520 void (*printer) __P((void *, char *, ...));
528 if (plen < HEADERLEN)
532 len = (p[2] << 8) + p[3];
533 if (len < HEADERLEN || len > plen)
536 if (code >= 1 && code <= sizeof(ccp_codenames) / sizeof(char *)
537 && ccp_codenames[code-1] != NULL)
538 printer(arg, " %s", ccp_codenames[code-1]);
540 printer(arg, " code=0x%x", code);
541 printer(arg, " id=0x%x", id);
550 /* print list of possible compression methods */
554 if (optlen < 2 || optlen > len)
560 case CI_BSD_COMPRESS:
561 if (optlen >= CILEN_BSD_COMPRESS) {
562 printer(arg, "bsd v%d %d", BSD_VERSION(p[2]),
564 p += CILEN_BSD_COMPRESS;
569 printer(arg, " %.2x", *p++);
575 /* dump out the rest of the packet in hex */
577 printer(arg, " %.2x", *p++);
583 * We have received a packet that the decompressor failed to
584 * decompress. Here we would expect to issue a reset-request, but
585 * Motorola has a patent on resetting the compressor as a result of
586 * detecting an error in the decompressed data after decompression.
587 * (See US patent 5,130,993; international patent publication number
588 * WO 91/10289; Australian patent 73296/91.)
590 * So we ask the kernel whether the error was detected after
591 * decompression; if it was, we take CCP down, thus disabling
592 * compression :-(, otherwise we issue the reset-request.
595 ccp_datainput(unit, pkt, len)
603 if (f->state == OPENED) {
604 if (ccp_fatal_error(unit)) {
606 * Disable compression by taking CCP down.
608 syslog(LOG_ERR, "Lost compression sync: disabling compression");
612 * Send a reset-request to reset the peer's compressor.
613 * We don't do that if we are still waiting for an
614 * acknowledgement to a previous reset-request.
616 if (!(ccp_localstate[f->unit] & RACK_PENDING)) {
617 fsm_sdata(f, CCP_RESETREQ, f->reqid = ++f->id, NULL, 0);
618 TIMEOUT(ccp_rack_timeout, (caddr_t) f, RACKTIMEOUT);
619 ccp_localstate[f->unit] |= RACK_PENDING;
621 ccp_localstate[f->unit] |= RREQ_REPEAT;
627 * Timeout waiting for reset-ack.
630 ccp_rack_timeout(arg)
633 fsm *f = (fsm *) arg;
635 if (f->state == OPENED && ccp_localstate[f->unit] & RREQ_REPEAT) {
636 fsm_sdata(f, CCP_RESETREQ, f->reqid, NULL, 0);
637 TIMEOUT(ccp_rack_timeout, (caddr_t) f, RACKTIMEOUT);
638 ccp_localstate[f->unit] &= ~RREQ_REPEAT;
640 ccp_localstate[f->unit] &= ~RACK_PENDING;