652 lines
14 KiB
C
652 lines
14 KiB
C
/*
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* ccp.c - PPP Compression Control Protocol.
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*
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* Copyright (c) 1994 The Australian National University.
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* All rights reserved.
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*
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* Permission to use, copy, modify, and distribute this software and its
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* documentation is hereby granted, provided that the above copyright
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* notice appears in all copies. This software is provided without any
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* warranty, express or implied. The Australian National University
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* makes no representations about the suitability of this software for
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* any purpose.
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*
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* IN NO EVENT SHALL THE AUSTRALIAN NATIONAL UNIVERSITY BE LIABLE TO ANY
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* PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
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* ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
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* THE AUSTRALIAN NATIONAL UNIVERSITY HAVE BEEN ADVISED OF THE POSSIBILITY
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* OF SUCH DAMAGE.
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*
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* THE AUSTRALIAN NATIONAL UNIVERSITY SPECIFICALLY DISCLAIMS ANY WARRANTIES,
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* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
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* AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
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* ON AN "AS IS" BASIS, AND THE AUSTRALIAN NATIONAL UNIVERSITY HAS NO
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* OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS,
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* OR MODIFICATIONS.
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*/
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#ifndef lint
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static char rcsid[] = "$Id: ccp.c,v 1.2 1995/10/31 21:20:49 peter Exp $";
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#endif
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#include <syslog.h>
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#include <sys/ioctl.h>
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#include <net/ppp_comp.h>
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#include "pppd.h"
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#include "fsm.h"
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#include "ccp.h"
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fsm ccp_fsm[NUM_PPP];
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ccp_options ccp_wantoptions[NUM_PPP]; /* what to request the peer to use */
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ccp_options ccp_gotoptions[NUM_PPP]; /* what the peer agreed to do */
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ccp_options ccp_allowoptions[NUM_PPP]; /* what we'll agree to do */
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ccp_options ccp_hisoptions[NUM_PPP]; /* what we agreed to do */
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/*
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* Callbacks for fsm code.
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*/
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static void ccp_resetci __P((fsm *));
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static int ccp_cilen __P((fsm *));
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static void ccp_addci __P((fsm *, u_char *, int *));
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static int ccp_ackci __P((fsm *, u_char *, int));
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static int ccp_nakci __P((fsm *, u_char *, int));
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static int ccp_rejci __P((fsm *, u_char *, int));
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static int ccp_reqci __P((fsm *, u_char *, int *, int));
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static void ccp_up __P((fsm *));
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static void ccp_down __P((fsm *));
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static int ccp_extcode __P((fsm *, int, int, u_char *, int));
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static void ccp_rack_timeout __P(());
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static fsm_callbacks ccp_callbacks = {
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ccp_resetci,
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ccp_cilen,
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ccp_addci,
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ccp_ackci,
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ccp_nakci,
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ccp_rejci,
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ccp_reqci,
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ccp_up,
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ccp_down,
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NULL,
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NULL,
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NULL,
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NULL,
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ccp_extcode,
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"CCP"
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};
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/*
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* Do we want / did we get any compression?
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*/
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#define ANY_COMPRESS(opt) ((opt).bsd_compress)
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/*
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* Local state (mainly for handling reset-reqs and reset-acks
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*/
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static int ccp_localstate[NUM_PPP];
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#define RACK_PENDING 1 /* waiting for reset-ack */
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#define RREQ_REPEAT 2 /* send another reset-req if no reset-ack */
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#define RACKTIMEOUT 1 /* second */
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/*
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* ccp_init - initialize CCP.
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*/
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void
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ccp_init(unit)
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int unit;
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{
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fsm *f = &ccp_fsm[unit];
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f->unit = unit;
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f->protocol = PPP_CCP;
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f->callbacks = &ccp_callbacks;
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fsm_init(f);
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memset(&ccp_wantoptions[unit], 0, sizeof(ccp_options));
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memset(&ccp_gotoptions[unit], 0, sizeof(ccp_options));
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memset(&ccp_allowoptions[unit], 0, sizeof(ccp_options));
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memset(&ccp_hisoptions[unit], 0, sizeof(ccp_options));
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ccp_wantoptions[0].bsd_compress = 1;
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ccp_wantoptions[0].bsd_bits = 12; /* default value */
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ccp_allowoptions[0].bsd_compress = 1;
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ccp_allowoptions[0].bsd_bits = BSD_MAX_BITS;
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}
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/*
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* ccp_open - CCP is allowed to come up.
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*/
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void
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ccp_open(unit)
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int unit;
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{
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fsm *f = &ccp_fsm[unit];
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if (f->state != OPENED)
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ccp_flags_set(unit, 1, 0);
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if (!ANY_COMPRESS(ccp_wantoptions[unit]))
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f->flags |= OPT_SILENT;
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fsm_open(f);
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}
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/*
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* ccp_close - Terminate CCP.
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*/
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void
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ccp_close(unit)
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int unit;
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{
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ccp_flags_set(unit, 0, 0);
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fsm_close(&ccp_fsm[unit]);
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}
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/*
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* ccp_lowerup - we may now transmit CCP packets.
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*/
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void
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ccp_lowerup(unit)
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int unit;
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{
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fsm_lowerup(&ccp_fsm[unit]);
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}
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/*
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* ccp_lowerdown - we may not transmit CCP packets.
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*/
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void
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ccp_lowerdown(unit)
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int unit;
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{
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fsm_lowerdown(&ccp_fsm[unit]);
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}
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/*
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* ccp_input - process a received CCP packet.
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*/
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void
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ccp_input(unit, p, len)
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int unit;
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u_char *p;
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int len;
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{
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fsm *f = &ccp_fsm[unit];
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int oldstate;
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/*
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* Check for a terminate-request so we can print a message.
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*/
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oldstate = f->state;
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fsm_input(f, p, len);
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if (oldstate == OPENED && p[0] == TERMREQ && f->state != OPENED)
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syslog(LOG_NOTICE, "Compression disabled by peer.");
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/*
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* If we get a terminate-ack and we're not asking for compression,
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* close CCP.
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*/
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if (oldstate == REQSENT && p[0] == TERMACK
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&& !ANY_COMPRESS(ccp_gotoptions[unit]))
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ccp_close(unit);
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}
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/*
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* Handle a CCP-specific code.
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*/
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static int
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ccp_extcode(f, code, id, p, len)
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fsm *f;
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int code, id;
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u_char *p;
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int len;
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{
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switch (code) {
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case CCP_RESETREQ:
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if (f->state != OPENED)
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break;
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/* send a reset-ack, which the transmitter will see and
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reset its compression state. */
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fsm_sdata(f, CCP_RESETACK, id, NULL, 0);
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break;
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case CCP_RESETACK:
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if (ccp_localstate[f->unit] & RACK_PENDING && id == f->reqid) {
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ccp_localstate[f->unit] &= ~(RACK_PENDING | RREQ_REPEAT);
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UNTIMEOUT(ccp_rack_timeout, (caddr_t) f);
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}
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break;
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default:
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return 0;
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}
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return 1;
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}
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/*
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* ccp_protrej - peer doesn't talk CCP.
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*/
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void
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ccp_protrej(unit)
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int unit;
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{
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ccp_flags_set(unit, 0, 0);
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fsm_lowerdown(&ccp_fsm[unit]);
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}
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/*
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* ccp_resetci - initialize at start of negotiation.
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*/
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static void
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ccp_resetci(f)
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fsm *f;
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{
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ccp_options *go = &ccp_gotoptions[f->unit];
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u_char opt_buf[16];
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*go = ccp_wantoptions[f->unit];
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if (go->bsd_compress) {
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opt_buf[0] = CI_BSD_COMPRESS;
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opt_buf[1] = CILEN_BSD_COMPRESS;
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opt_buf[2] = BSD_MAKE_OPT(BSD_CURRENT_VERSION, go->bsd_bits);
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if (!ccp_test(f->unit, opt_buf, CILEN_BSD_COMPRESS, 0))
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go->bsd_compress = 0;
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}
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}
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/*
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* ccp_cilen - Return total length of our configuration info.
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*/
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static int
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ccp_cilen(f)
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fsm *f;
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{
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ccp_options *go = &ccp_gotoptions[f->unit];
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return (go->bsd_compress? CILEN_BSD_COMPRESS: 0);
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}
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/*
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* ccp_addci - put our requests in a packet.
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*/
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static void
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ccp_addci(f, p, lenp)
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fsm *f;
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u_char *p;
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int *lenp;
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{
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ccp_options *go = &ccp_gotoptions[f->unit];
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u_char *p0 = p;
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if (go->bsd_compress) {
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p[0] = CI_BSD_COMPRESS;
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p[1] = CILEN_BSD_COMPRESS;
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p[2] = BSD_MAKE_OPT(BSD_CURRENT_VERSION, go->bsd_bits);
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if (ccp_test(f->unit, p, CILEN_BSD_COMPRESS, 0))
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p += CILEN_BSD_COMPRESS;
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else
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go->bsd_compress = 0;
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}
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*lenp = p - p0;
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}
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/*
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* ccp_ackci - process a received configure-ack, and return
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* 1 iff the packet was OK.
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*/
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static int
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ccp_ackci(f, p, len)
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fsm *f;
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u_char *p;
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int len;
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{
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ccp_options *go = &ccp_gotoptions[f->unit];
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if (go->bsd_compress) {
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if (len < CILEN_BSD_COMPRESS
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|| p[0] != CI_BSD_COMPRESS || p[1] != CILEN_BSD_COMPRESS
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|| p[2] != BSD_MAKE_OPT(BSD_CURRENT_VERSION, go->bsd_bits))
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return 0;
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p += CILEN_BSD_COMPRESS;
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len -= CILEN_BSD_COMPRESS;
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}
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if (len != 0)
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return 0;
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return 1;
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}
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/*
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* ccp_nakci - process received configure-nak.
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* Returns 1 iff the nak was OK.
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*/
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static int
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ccp_nakci(f, p, len)
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fsm *f;
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u_char *p;
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int len;
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{
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ccp_options *go = &ccp_gotoptions[f->unit];
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ccp_options no; /* options we've seen already */
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ccp_options try; /* options to ask for next time */
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memset(&no, 0, sizeof(no));
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try = *go;
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if (go->bsd_compress && !no.bsd_compress && len >= CILEN_BSD_COMPRESS
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&& p[0] == CI_BSD_COMPRESS && p[1] == CILEN_BSD_COMPRESS) {
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no.bsd_compress = 1;
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/*
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* Peer wants us to use a different number of bits
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* or a different version.
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*/
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if (BSD_VERSION(p[2]) != BSD_CURRENT_VERSION)
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try.bsd_compress = 0;
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else if (BSD_NBITS(p[2]) < go->bsd_bits)
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try.bsd_bits = BSD_NBITS(p[2]);
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p += CILEN_BSD_COMPRESS;
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len -= CILEN_BSD_COMPRESS;
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}
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/*
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* Have a look at any remaining options...???
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*/
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if (len != 0)
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return 0;
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if (f->state != OPENED)
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*go = try;
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return 1;
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}
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/*
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* ccp_rejci - reject some of our suggested compression methods.
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*/
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static int
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ccp_rejci(f, p, len)
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fsm *f;
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u_char *p;
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int len;
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{
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ccp_options *go = &ccp_gotoptions[f->unit];
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ccp_options try; /* options to request next time */
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try = *go;
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if (go->bsd_compress && len >= CILEN_BSD_COMPRESS
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&& p[0] == CI_BSD_COMPRESS && p[1] == CILEN_BSD_COMPRESS) {
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if (p[2] != BSD_MAKE_OPT(BSD_CURRENT_VERSION, go->bsd_bits))
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return 0;
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try.bsd_compress = 0;
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p += CILEN_BSD_COMPRESS;
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len -= CILEN_BSD_COMPRESS;
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}
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if (len != 0)
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return 0;
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if (f->state != OPENED)
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*go = try;
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return 1;
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}
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/*
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* ccp_reqci - processed a received configure-request.
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* Returns CONFACK, CONFNAK or CONFREJ and the packet modified
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* appropriately.
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*/
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static int
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ccp_reqci(f, p, lenp, dont_nak)
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fsm *f;
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u_char *p;
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int *lenp;
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int dont_nak;
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{
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int ret, newret;
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u_char *p0, *retp;
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int len, clen, type, nb;
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ccp_options *ho = &ccp_hisoptions[f->unit];
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ccp_options *ao = &ccp_allowoptions[f->unit];
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ret = CONFACK;
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retp = p0 = p;
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len = *lenp;
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memset(ho, 0, sizeof(ccp_options));
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while (len > 0) {
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newret = CONFACK;
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if (len < 2 || p[1] < 2 || p[1] > len) {
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/* length is bad */
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clen = len;
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newret = CONFREJ;
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} else {
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type = p[0];
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clen = p[1];
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switch (type) {
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case CI_BSD_COMPRESS:
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if (!ao->bsd_compress || clen != CILEN_BSD_COMPRESS) {
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newret = CONFREJ;
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break;
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}
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ho->bsd_compress = 1;
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ho->bsd_bits = nb = BSD_NBITS(p[2]);
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if (BSD_VERSION(p[2]) != BSD_CURRENT_VERSION
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|| nb > ao->bsd_bits) {
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newret = CONFNAK;
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nb = ao->bsd_bits;
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} else if (nb < BSD_MIN_BITS) {
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newret = CONFREJ;
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} else if (!ccp_test(f->unit, p, CILEN_BSD_COMPRESS, 1)) {
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if (nb > BSD_MIN_BITS) {
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--nb;
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newret = CONFNAK;
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} else
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newret = CONFREJ;
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}
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if (newret == CONFNAK && !dont_nak) {
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p[2] = BSD_MAKE_OPT(BSD_CURRENT_VERSION, nb);
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}
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break;
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default:
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newret = CONFREJ;
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}
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}
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if (newret == CONFNAK && dont_nak)
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newret = CONFREJ;
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if (!(newret == CONFACK || newret == CONFNAK && ret == CONFREJ)) {
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/* we're returning this option */
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if (newret == CONFREJ && ret == CONFNAK)
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retp = p0;
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ret = newret;
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if (p != retp)
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BCOPY(p, retp, clen);
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retp += clen;
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}
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p += clen;
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len -= clen;
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}
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if (ret != CONFACK)
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*lenp = retp - p0;
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return ret;
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}
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/*
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* CCP has come up - inform the kernel driver.
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*/
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static void
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ccp_up(f)
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fsm *f;
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{
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ccp_options *go = &ccp_gotoptions[f->unit];
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ccp_options *ho = &ccp_hisoptions[f->unit];
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ccp_flags_set(f->unit, 1, 1);
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if (go->bsd_compress || ho->bsd_compress)
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syslog(LOG_NOTICE, "%s enabled",
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go->bsd_compress? ho->bsd_compress? "Compression":
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"Receive compression": "Transmit compression");
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}
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/*
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* CCP has gone down - inform the kernel driver.
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*/
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static void
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ccp_down(f)
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fsm *f;
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{
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if (ccp_localstate[f->unit] & RACK_PENDING)
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UNTIMEOUT(ccp_rack_timeout, (caddr_t) f);
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ccp_localstate[f->unit] = 0;
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ccp_flags_set(f->unit, 1, 0);
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}
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/*
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* Print the contents of a CCP packet.
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*/
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char *ccp_codenames[] = {
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"ConfReq", "ConfAck", "ConfNak", "ConfRej",
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"TermReq", "TermAck", "CodeRej",
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NULL, NULL, NULL, NULL, NULL, NULL,
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"ResetReq", "ResetAck",
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};
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int
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ccp_printpkt(p, plen, printer, arg)
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u_char *p;
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int plen;
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void (*printer) __P((void *, char *, ...));
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void *arg;
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{
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u_char *p0, *optend;
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int code, id, len;
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int optlen;
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p0 = p;
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if (plen < HEADERLEN)
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return 0;
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code = p[0];
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id = p[1];
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len = (p[2] << 8) + p[3];
|
|
if (len < HEADERLEN || len > plen)
|
|
return 0;
|
|
|
|
if (code >= 1 && code <= sizeof(ccp_codenames) / sizeof(char *)
|
|
&& ccp_codenames[code-1] != NULL)
|
|
printer(arg, " %s", ccp_codenames[code-1]);
|
|
else
|
|
printer(arg, " code=0x%x", code);
|
|
printer(arg, " id=0x%x", id);
|
|
len -= HEADERLEN;
|
|
p += HEADERLEN;
|
|
|
|
switch (code) {
|
|
case CONFREQ:
|
|
case CONFACK:
|
|
case CONFNAK:
|
|
case CONFREJ:
|
|
/* print list of possible compression methods */
|
|
while (len >= 2) {
|
|
code = p[0];
|
|
optlen = p[1];
|
|
if (optlen < 2 || optlen > len)
|
|
break;
|
|
printer(arg, " <");
|
|
len -= optlen;
|
|
optend = p + optlen;
|
|
switch (code) {
|
|
case CI_BSD_COMPRESS:
|
|
if (optlen >= CILEN_BSD_COMPRESS) {
|
|
printer(arg, "bsd v%d %d", BSD_VERSION(p[2]),
|
|
BSD_NBITS(p[2]));
|
|
p += CILEN_BSD_COMPRESS;
|
|
}
|
|
break;
|
|
}
|
|
while (p < optend)
|
|
printer(arg, " %.2x", *p++);
|
|
printer(arg, ">");
|
|
}
|
|
break;
|
|
}
|
|
|
|
/* dump out the rest of the packet in hex */
|
|
while (--len >= 0)
|
|
printer(arg, " %.2x", *p++);
|
|
|
|
return p - p0;
|
|
}
|
|
|
|
/*
|
|
* We have received a packet that the decompressor failed to
|
|
* decompress. Here we would expect to issue a reset-request, but
|
|
* Motorola has a patent on resetting the compressor as a result of
|
|
* detecting an error in the decompressed data after decompression.
|
|
* (See US patent 5,130,993; international patent publication number
|
|
* WO 91/10289; Australian patent 73296/91.)
|
|
*
|
|
* So we ask the kernel whether the error was detected after
|
|
* decompression; if it was, we take CCP down, thus disabling
|
|
* compression :-(, otherwise we issue the reset-request.
|
|
*/
|
|
void
|
|
ccp_datainput(unit, pkt, len)
|
|
int unit;
|
|
u_char *pkt;
|
|
int len;
|
|
{
|
|
fsm *f;
|
|
|
|
f = &ccp_fsm[unit];
|
|
if (f->state == OPENED) {
|
|
if (ccp_fatal_error(unit)) {
|
|
/*
|
|
* Disable compression by taking CCP down.
|
|
*/
|
|
syslog(LOG_ERR, "Lost compression sync: disabling compression");
|
|
ccp_close(unit);
|
|
} else {
|
|
/*
|
|
* Send a reset-request to reset the peer's compressor.
|
|
* We don't do that if we are still waiting for an
|
|
* acknowledgement to a previous reset-request.
|
|
*/
|
|
if (!(ccp_localstate[f->unit] & RACK_PENDING)) {
|
|
fsm_sdata(f, CCP_RESETREQ, f->reqid = ++f->id, NULL, 0);
|
|
TIMEOUT(ccp_rack_timeout, (caddr_t) f, RACKTIMEOUT);
|
|
ccp_localstate[f->unit] |= RACK_PENDING;
|
|
} else
|
|
ccp_localstate[f->unit] |= RREQ_REPEAT;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Timeout waiting for reset-ack.
|
|
*/
|
|
static void
|
|
ccp_rack_timeout(arg)
|
|
caddr_t arg;
|
|
{
|
|
fsm *f = (fsm *) arg;
|
|
|
|
if (f->state == OPENED && ccp_localstate[f->unit] & RREQ_REPEAT) {
|
|
fsm_sdata(f, CCP_RESETREQ, f->reqid, NULL, 0);
|
|
TIMEOUT(ccp_rack_timeout, (caddr_t) f, RACKTIMEOUT);
|
|
ccp_localstate[f->unit] &= ~RREQ_REPEAT;
|
|
} else
|
|
ccp_localstate[f->unit] &= ~RACK_PENDING;
|
|
}
|
|
|