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isdn4k-utils/ipppd/ccp.c

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/*
* ccp.c - PPP Compression Control Protocol.
*
* Copyright (c) 1994 The Australian National University.
* All rights reserved.
*
* Permission to use, copy, modify, and distribute this software and its
* documentation is hereby granted, provided that the above copyright
* notice appears in all copies. This software is provided without any
* warranty, express or implied. The Australian National University
* makes no representations about the suitability of this software for
* any purpose.
*
* IN NO EVENT SHALL THE AUSTRALIAN NATIONAL UNIVERSITY BE LIABLE TO ANY
* PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
* ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
* THE AUSTRALIAN NATIONAL UNIVERSITY HAVE BEEN ADVISED OF THE POSSIBILITY
* OF SUCH DAMAGE.
*
* THE AUSTRALIAN NATIONAL UNIVERSITY SPECIFICALLY DISCLAIMS ANY WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
* ON AN "AS IS" BASIS, AND THE AUSTRALIAN NATIONAL UNIVERSITY HAS NO
* OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS,
* OR MODIFICATIONS.
*/
#ifndef lint
static char rcsid[] = "$Id: ccp.c,v 1.1 1997/03/07 16:01:10 hipp Exp $";
#endif
#include <string.h>
#include <syslog.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <net/ppp_defs.h>
#include <linux/ppp-comp.h>
#include "fsm.h"
#include "pppd.h"
#include "ccp.h"
/*
* Protocol entry points from main code.
*/
static void ccp_init __P((int unit));
static void ccp_open __P((int unit));
static void ccp_close __P((int unit, char *));
static void ccp_lowerup __P((int unit));
static void ccp_lowerdown __P((int));
static void ccp_input __P((int unit, u_char *pkt, int len));
static void ccp_protrej __P((int unit));
static int ccp_printpkt __P((u_char *pkt, int len,
void (*printer) __P((void *, char *, ...)),
void *arg));
static void ccp_datainput __P((int unit, u_char *pkt, int len));
struct protent ccp_protent = {
PPP_CCP,
ccp_init,
ccp_input,
ccp_protrej,
ccp_lowerup,
ccp_lowerdown,
ccp_open,
ccp_close,
ccp_printpkt,
ccp_datainput,
1,
"CCP",
NULL,
NULL,
NULL
};
fsm ccp_fsm[NUM_PPP];
ccp_options ccp_wantoptions[NUM_PPP]; /* what to request the peer to use */
ccp_options ccp_gotoptions[NUM_PPP]; /* what the peer agreed to do */
ccp_options ccp_allowoptions[NUM_PPP]; /* what we'll agree to do */
ccp_options ccp_hisoptions[NUM_PPP]; /* what we agreed to do */
/*
* Callbacks for fsm code.
*/
static void ccp_resetci __P((fsm *));
static int ccp_cilen __P((fsm *));
static void ccp_addci __P((fsm *, u_char *, int *));
static int ccp_ackci __P((fsm *, u_char *, int));
static int ccp_nakci __P((fsm *, u_char *, int));
static int ccp_rejci __P((fsm *, u_char *, int));
static int ccp_reqci __P((fsm *, u_char *, int *, int));
static void ccp_up __P((fsm *));
static void ccp_down __P((fsm *));
static int ccp_extcode __P((fsm *, int, int, u_char *, int));
static void ccp_rack_timeout __P(());
static char *method_name __P((ccp_options *, ccp_options *));
static fsm_callbacks ccp_callbacks = {
ccp_resetci,
ccp_cilen,
ccp_addci,
ccp_ackci,
ccp_nakci,
ccp_rejci,
ccp_reqci,
ccp_up,
ccp_down,
NULL,
NULL,
NULL,
NULL,
ccp_extcode,
"CCP"
};
/*
* Do we want / did we get any compression?
*/
#define ANY_COMPRESS(opt) ((opt).deflate || (opt).bsd_compress \
|| (opt).predictor_1 || (opt).predictor_2)
/*
* Local state (mainly for handling reset-reqs and reset-acks).
*/
static int ccp_localstate[NUM_PPP];
#define RACK_PENDING 1 /* waiting for reset-ack */
#define RREQ_REPEAT 2 /* send another reset-req if no reset-ack */
#define RACKTIMEOUT 1 /* second */
static int all_rejected[NUM_PPP];
/*
* ccp_init - initialize CCP.
*/
static void ccp_init(int unit)
{
fsm *f = &ccp_fsm[unit];
f->unit = -1;
f->protocol = PPP_CCP;
f->callbacks = &ccp_callbacks;
fsm_init(f);
memset(&ccp_wantoptions[unit], 0, sizeof(ccp_options));
memset(&ccp_gotoptions[unit], 0, sizeof(ccp_options));
memset(&ccp_allowoptions[unit], 0, sizeof(ccp_options));
memset(&ccp_hisoptions[unit], 0, sizeof(ccp_options));
ccp_wantoptions[0].deflate = 1;
ccp_wantoptions[0].deflate_size = DEFLATE_MAX_SIZE;
ccp_allowoptions[0].deflate = 1;
ccp_allowoptions[0].deflate_size = DEFLATE_MAX_SIZE;
ccp_wantoptions[0].bsd_compress = 1;
ccp_wantoptions[0].bsd_bits = BSD_MAX_BITS;
ccp_allowoptions[unit].bsd_compress = 1;
ccp_allowoptions[unit].bsd_bits = BSD_MAX_BITS;
ccp_allowoptions[unit].predictor_1 = 1;
}
int ccp_getunit(int linkunit)
{
int i;
for(i=0;i<NUM_PPP;i++)
if(!ccp_fsm[i].inuse)
{
ccp_fsm[i].inuse = 1;
ccp_fsm[i].state = INITIAL;
ccp_fsm[i].flags = 0;
ccp_fsm[i].id = 0;
ccp_fsm[i].unit = linkunit;
return i;
}
syslog(LOG_ERR,"No more ccp_units available");
return -1;
}
void ccp_freeunit(int unit)
{
ccp_fsm[unit].inuse = 0;
ccp_fsm[unit].unit = -1;
}
/*
* ccp_open - CCP is allowed to come up.
*/
static void ccp_open(int unit)
{
fsm *f = &ccp_fsm[unit];
if (f->state != OPENED)
ccp_flags_set(unit, 1, 0);
/*
* Find out which compressors the kernel supports before
* deciding whether to open in silent mode.
*/
ccp_resetci(f);
if (!ANY_COMPRESS(ccp_gotoptions[unit]))
f->flags |= OPT_SILENT;
fsm_open(f);
}
/*
* ccp_close - Terminate CCP.
*/
static void ccp_close(int unit,char *reason)
{
ccp_flags_set(unit, 0, 0);
fsm_close(&ccp_fsm[unit],reason);
}
/*
* ccp_lowerup - we may now transmit CCP packets.
*/
static void ccp_lowerup(int unit)
{
fsm_lowerup(&ccp_fsm[unit]);
}
/*
* ccp_lowerdown - we may not transmit CCP packets.
*/
static void ccp_lowerdown(int unit)
{
fsm_lowerdown(&ccp_fsm[unit]);
}
/*
* ccp_input - process a received CCP packet.
*/
static void ccp_input(int linkunit,u_char *p,int len)
{
int unit = lns[linkunit].ccp_unit;
fsm *f = &ccp_fsm[unit];
int oldstate;
/*
* Check for a terminate-request so we can print a message.
*/
oldstate = f->state;
fsm_input(f, p, len);
if (oldstate == OPENED && p[0] == TERMREQ && f->state != OPENED)
syslog(LOG_NOTICE, "Compression disabled by peer.");
/*
* If we get a terminate-ack and we're not asking for compression,
* close CCP.
*/
if (oldstate == REQSENT && p[0] == TERMACK && !ANY_COMPRESS(ccp_gotoptions[unit]))
ccp_close(unit,"No compression negotiated");
}
/*
* Handle a CCP-specific code.
*/
static int ccp_extcode(fsm *f,int code,int id,u_char *p,int len)
{
switch (code) {
case CCP_RESETREQ:
if (f->state != OPENED)
break;
/* send a reset-ack, which the transmitter will see and
reset its compression state. */
fsm_sdata(f, CCP_RESETACK, id, NULL, 0);
break;
case CCP_RESETACK:
if (ccp_localstate[lns[f->unit].ccp_unit] & RACK_PENDING && id == f->reqid) {
ccp_localstate[lns[f->unit].ccp_unit] &= ~(RACK_PENDING | RREQ_REPEAT);
UNTIMEOUT(ccp_rack_timeout, (caddr_t) f);
}
break;
default:
return 0;
}
return 1;
}
/*
* ccp_protrej - peer doesn't talk CCP.
*/
static void ccp_protrej(int linkunit)
{
int unit = lns[linkunit].ccp_unit;
ccp_flags_set(unit, 0, 0);
fsm_lowerdown(&ccp_fsm[unit]);
}
/*
* ccp_resetci - initialize at start of negotiation.
*/
static void ccp_resetci(fsm *f)
{
ccp_options *go = &ccp_gotoptions[lns[f->unit].ccp_unit];
u_char opt_buf[16];
*go = ccp_wantoptions[lns[f->unit].ccp_unit];
all_rejected[lns[f->unit].ccp_unit] = 0;
/*
* Check whether the kernel knows about the various
* compression methods we might request.
*/
if (go->bsd_compress) {
opt_buf[0] = CI_BSD_COMPRESS;
opt_buf[1] = CILEN_BSD_COMPRESS;
opt_buf[2] = BSD_MAKE_OPT(BSD_CURRENT_VERSION, BSD_MIN_BITS);
if (ccp_test(lns[f->unit].ccp_unit, opt_buf, CILEN_BSD_COMPRESS, 0) <= 0)
go->bsd_compress = 0;
}
if (go->deflate) {
opt_buf[0] = CI_DEFLATE;
opt_buf[1] = CILEN_DEFLATE;
opt_buf[2] = DEFLATE_MAKE_OPT(DEFLATE_MIN_SIZE);
opt_buf[3] = DEFLATE_CHK_SEQUENCE;
if (ccp_test(lns[f->unit].ccp_unit, opt_buf, CILEN_DEFLATE, 0) <= 0)
go->deflate = 0;
}
if (go->predictor_1) {
opt_buf[0] = CI_PREDICTOR_1;
opt_buf[1] = CILEN_PREDICTOR_1;
if (ccp_test(lns[f->unit].ccp_unit, opt_buf, CILEN_PREDICTOR_1, 0) <= 0)
go->predictor_1 = 0;
}
if (go->predictor_2) {
opt_buf[0] = CI_PREDICTOR_2;
opt_buf[1] = CILEN_PREDICTOR_2;
if (ccp_test(lns[f->unit].ccp_unit, opt_buf, CILEN_PREDICTOR_2, 0) <= 0)
go->predictor_2 = 0;
}
}
/*
* ccp_cilen - Return total length of our configuration info.
*/
static int ccp_cilen(fsm *f)
{
ccp_options *go = &ccp_gotoptions[lns[f->unit].ccp_unit];
return (go->bsd_compress? CILEN_BSD_COMPRESS: 0)
+ (go->deflate? CILEN_DEFLATE: 0)
+ (go->predictor_1? CILEN_PREDICTOR_1: 0)
+ (go->predictor_2? CILEN_PREDICTOR_2: 0);
}
/*
* ccp_addci - put our requests in a packet.
*/
static void ccp_addci(fsm *f,u_char *p,int *lenp)
{
int res;
ccp_options *go = &ccp_gotoptions[lns[f->unit].ccp_unit];
u_char *p0 = p;
/*
* Add the compression types that we can receive, in decreasing
* preference order. Get the kernel to allocate the first one
* in case it gets Acked.
*/
if (go->deflate) {
p[0] = CI_DEFLATE;
p[1] = CILEN_DEFLATE;
p[2] = DEFLATE_MAKE_OPT(go->deflate_size);
p[3] = DEFLATE_CHK_SEQUENCE;
for (;;) {
res = ccp_test(lns[f->unit].ccp_unit, p, CILEN_DEFLATE, 0);
if (res > 0) {
p += CILEN_DEFLATE;
break;
}
if (res < 0 || go->deflate_size <= DEFLATE_MIN_SIZE) {
go->deflate = 0;
break;
}
--go->deflate_size;
p[2] = DEFLATE_MAKE_OPT(go->deflate_size);
}
}
if (go->bsd_compress) {
p[0] = CI_BSD_COMPRESS;
p[1] = CILEN_BSD_COMPRESS;
p[2] = BSD_MAKE_OPT(BSD_CURRENT_VERSION, go->bsd_bits);
if (p != p0) {
p += CILEN_BSD_COMPRESS; /* not the first option */
} else {
for (;;) {
res = ccp_test(lns[f->unit].ccp_unit, p, CILEN_BSD_COMPRESS, 0);
if (res > 0) {
p += CILEN_BSD_COMPRESS;
break;
}
if (res < 0 || go->bsd_bits <= BSD_MIN_BITS) {
go->bsd_compress = 0;
break;
}
--go->bsd_bits;
p[2] = BSD_MAKE_OPT(BSD_CURRENT_VERSION, go->bsd_bits);
}
}
}
/* XXX Should Predictor 2 be preferable to Predictor 1? */
if (go->predictor_1) {
p[0] = CI_PREDICTOR_1;
p[1] = CILEN_PREDICTOR_1;
if (p == p0 && ccp_test(lns[f->unit].ccp_unit, p, CILEN_PREDICTOR_1, 0) <= 0) {
go->predictor_1 = 0;
} else {
p += CILEN_PREDICTOR_1;
}
}
if (go->predictor_2) {
p[0] = CI_PREDICTOR_2;
p[1] = CILEN_PREDICTOR_2;
if (p == p0 && ccp_test(lns[f->unit].ccp_unit, p, CILEN_PREDICTOR_2, 0) <= 0) {
go->predictor_2 = 0;
} else {
p += CILEN_PREDICTOR_2;
}
}
go->method = (p > p0)? p0[0]: -1;
*lenp = p - p0;
}
/*
* ccp_ackci - process a received configure-ack, and return
* 1 iff the packet was OK.
*/
static int ccp_ackci(fsm *f,u_char *p,int len)
{
ccp_options *go = &ccp_gotoptions[lns[f->unit].ccp_unit];
u_char *p0 = p;
if (go->deflate) {
if (len < CILEN_DEFLATE
|| p[0] != CI_DEFLATE || p[1] != CILEN_DEFLATE
|| p[2] != DEFLATE_MAKE_OPT(go->deflate_size)
|| p[3] != DEFLATE_CHK_SEQUENCE)
return 0;
p += CILEN_DEFLATE;
len -= CILEN_DEFLATE;
/* XXX Cope with first/fast ack */
if (len == 0)
return 1;
}
if (go->bsd_compress) {
if (len < CILEN_BSD_COMPRESS
|| p[0] != CI_BSD_COMPRESS || p[1] != CILEN_BSD_COMPRESS
|| p[2] != BSD_MAKE_OPT(BSD_CURRENT_VERSION, go->bsd_bits))
return 0;
p += CILEN_BSD_COMPRESS;
len -= CILEN_BSD_COMPRESS;
/* XXX Cope with first/fast ack */
if (p == p0 && len == 0)
return 1;
}
if (go->predictor_1) {
if (len < CILEN_PREDICTOR_1
|| p[0] != CI_PREDICTOR_1 || p[1] != CILEN_PREDICTOR_1)
return 0;
p += CILEN_PREDICTOR_1;
len -= CILEN_PREDICTOR_1;
/* XXX Cope with first/fast ack */
if (p == p0 && len == 0)
return 1;
}
if (go->predictor_2) {
if (len < CILEN_PREDICTOR_2
|| p[0] != CI_PREDICTOR_2 || p[1] != CILEN_PREDICTOR_2)
return 0;
p += CILEN_PREDICTOR_2;
len -= CILEN_PREDICTOR_2;
/* XXX Cope with first/fast ack */
if (p == p0 && len == 0)
return 1;
}
if (len != 0)
return 0;
return 1;
}
/*
* ccp_nakci - process received configure-nak.
* Returns 1 iff the nak was OK.
*/
static int ccp_nakci(fsm *f,u_char *p,int len)
{
ccp_options *go = &ccp_gotoptions[lns[f->unit].ccp_unit];
ccp_options no; /* options we've seen already */
ccp_options try; /* options to ask for next time */
memset(&no, 0, sizeof(no));
try = *go;
if (go->deflate && len >= CILEN_DEFLATE
&& p[0] == CI_DEFLATE && p[1] == CILEN_DEFLATE) {
no.deflate = 1;
/*
* Peer wants us to use a different code size or something.
* Stop asking for Deflate if we don't understand his suggestion.
*/
if (DEFLATE_METHOD(p[2]) != DEFLATE_METHOD_VAL
|| DEFLATE_SIZE(p[2]) < DEFLATE_MIN_SIZE
|| p[3] != DEFLATE_CHK_SEQUENCE)
try.deflate = 0;
else if (DEFLATE_SIZE(p[2]) < go->deflate_size)
go->deflate_size = DEFLATE_SIZE(p[2]);
p += CILEN_DEFLATE;
len -= CILEN_DEFLATE;
}
if (go->bsd_compress && len >= CILEN_BSD_COMPRESS
&& p[0] == CI_BSD_COMPRESS && p[1] == CILEN_BSD_COMPRESS) {
no.bsd_compress = 1;
/*
* Peer wants us to use a different number of bits
* or a different version.
*/
if (BSD_VERSION(p[2]) != BSD_CURRENT_VERSION)
try.bsd_compress = 0;
else if (BSD_NBITS(p[2]) < go->bsd_bits)
try.bsd_bits = BSD_NBITS(p[2]);
p += CILEN_BSD_COMPRESS;
len -= CILEN_BSD_COMPRESS;
}
/*
* Predictor-1 and 2 have no options, so they can't be Naked.
*
* XXX What should we do with any remaining options?
*/
if (len != 0)
return 0;
if (f->state != OPENED)
*go = try;
return 1;
}
/*
* ccp_rejci - reject some of our suggested compression methods.
*/
static int ccp_rejci(fsm *f,u_char *p,int len)
{
ccp_options *go = &ccp_gotoptions[lns[f->unit].ccp_unit];
ccp_options try; /* options to request next time */
try = *go;
/*
* Cope with empty configure-rejects by ceasing to send
* configure-requests.
*/
if (len == 0 && all_rejected[lns[f->unit].ccp_unit])
return -1;
if (go->deflate && len >= CILEN_DEFLATE
&& p[0] == CI_DEFLATE && p[1] == CILEN_DEFLATE) {
if (p[2] != DEFLATE_MAKE_OPT(go->deflate_size)
|| p[3] != DEFLATE_CHK_SEQUENCE)
return 0; /* Rej is bad */
try.deflate = 0;
p += CILEN_DEFLATE;
len -= CILEN_DEFLATE;
}
if (go->bsd_compress && len >= CILEN_BSD_COMPRESS
&& p[0] == CI_BSD_COMPRESS && p[1] == CILEN_BSD_COMPRESS) {
if (p[2] != BSD_MAKE_OPT(BSD_CURRENT_VERSION, go->bsd_bits))
return 0;
try.bsd_compress = 0;
p += CILEN_BSD_COMPRESS;
len -= CILEN_BSD_COMPRESS;
}
if (go->predictor_1 && len >= CILEN_PREDICTOR_1
&& p[0] == CI_PREDICTOR_1 && p[1] == CILEN_PREDICTOR_1) {
try.predictor_1 = 0;
p += CILEN_PREDICTOR_1;
len -= CILEN_PREDICTOR_1;
}
if (go->predictor_2 && len >= CILEN_PREDICTOR_2
&& p[0] == CI_PREDICTOR_2 && p[1] == CILEN_PREDICTOR_2) {
try.predictor_2 = 0;
p += CILEN_PREDICTOR_2;
len -= CILEN_PREDICTOR_2;
}
if (len != 0)
return 0;
if (f->state != OPENED)
*go = try;
return 1;
}
/*
* ccp_reqci - processed a received configure-request.
* Returns CONFACK, CONFNAK or CONFREJ and the packet modified
* appropriately.
*/
static int ccp_reqci(fsm *f,u_char *p,int *lenp,int dont_nak)
{
int ret, newret, res;
u_char *p0, *retp;
int len, clen, type, nb;
ccp_options *ho = &ccp_hisoptions[lns[f->unit].ccp_unit];
ccp_options *ao = &ccp_allowoptions[lns[f->unit].ccp_unit];
ret = CONFACK;
retp = p0 = p;
len = *lenp;
memset(ho, 0, sizeof(ccp_options));
ho->method = (len > 0)? p[0]: -1;
while (len > 0) {
newret = CONFACK;
if (len < 2 || p[1] < 2 || p[1] > len) {
/* length is bad */
clen = len;
newret = CONFREJ;
} else {
type = p[0];
clen = p[1];
switch (type) {
case CI_DEFLATE:
if (!ao->deflate || clen != CILEN_DEFLATE) {
newret = CONFREJ;
break;
}
ho->deflate = 1;
ho->deflate_size = nb = DEFLATE_SIZE(p[2]);
if (DEFLATE_METHOD(p[2]) != DEFLATE_METHOD_VAL
|| p[3] != DEFLATE_CHK_SEQUENCE
|| nb > ao->deflate_size || nb < DEFLATE_MIN_SIZE) {
newret = CONFNAK;
if (!dont_nak) {
p[2] = DEFLATE_MAKE_OPT(ao->deflate_size);
p[3] = DEFLATE_CHK_SEQUENCE;
}
break;
}
/*
* Check whether we can do Deflate with the window
* size they want. If the window is too big, reduce
* it until the kernel can cope and nak with that.
* We only check this for the first option.
*/
if (p == p0) {
for (;;) {
res = ccp_test(f->unit, p, CILEN_DEFLATE, 1);
if (res > 0)
break; /* it's OK now */
if (res < 0 || nb == DEFLATE_MIN_SIZE || dont_nak) {
newret = CONFREJ;
p[2] = DEFLATE_MAKE_OPT(ho->deflate_size);
break;
}
newret = CONFNAK;
--nb;
p[2] = DEFLATE_MAKE_OPT(nb);
}
}
break;
case CI_BSD_COMPRESS:
if (!ao->bsd_compress || clen != CILEN_BSD_COMPRESS) {
newret = CONFREJ;
break;
}
ho->bsd_compress = 1;
ho->bsd_bits = nb = BSD_NBITS(p[2]);
if (BSD_VERSION(p[2]) != BSD_CURRENT_VERSION
|| nb > ao->bsd_bits || nb < BSD_MIN_BITS) {
newret = CONFNAK;
if (!dont_nak)
p[2] = BSD_MAKE_OPT(BSD_CURRENT_VERSION, ao->bsd_bits);
break;
}
/*
* Check whether we can do BSD-Compress with the code
* size they want. If the code size is too big, reduce
* it until the kernel can cope and nak with that.
* We only check this for the first option.
*/
if (p == p0) {
for (;;) {
res = ccp_test(f->unit, p, CILEN_BSD_COMPRESS, 1);
if (res > 0)
break;
if (res < 0 || nb == BSD_MIN_BITS || dont_nak) {
newret = CONFREJ;
p[2] = BSD_MAKE_OPT(BSD_CURRENT_VERSION,
ho->bsd_bits);
break;
}
newret = CONFNAK;
--nb;
p[2] = BSD_MAKE_OPT(BSD_CURRENT_VERSION, nb);
}
}
break;
case CI_PREDICTOR_1:
if (!ao->predictor_1 || clen != CILEN_PREDICTOR_1) {
newret = CONFREJ;
break;
}
ho->predictor_1 = 1;
if (p == p0 && ccp_test(lns[f->unit].ccp_unit, p, CILEN_PREDICTOR_1, 1) <= 0) {
newret = CONFREJ;
}
break;
case CI_PREDICTOR_2:
if (!ao->predictor_2 || clen != CILEN_PREDICTOR_2) {
newret = CONFREJ;
break;
}
ho->predictor_2 = 1;
if (p == p0 && ccp_test(lns[f->unit].ccp_unit, p, CILEN_PREDICTOR_2, 1) <= 0) {
newret = CONFREJ;
}
break;
default:
newret = CONFREJ;
}
}
if (newret == CONFNAK && dont_nak)
newret = CONFREJ;
if (!(newret == CONFACK || (newret == CONFNAK && ret == CONFREJ) )) {
/* we're returning this option */
if (newret == CONFREJ && ret == CONFNAK)
retp = p0;
ret = newret;
if (p != retp)
BCOPY(p, retp, clen);
retp += clen;
}
p += clen;
len -= clen;
}
if (ret != CONFACK) {
if (ret == CONFREJ && *lenp == retp - p0)
all_rejected[lns[f->unit].ccp_unit] = 1;
else
*lenp = retp - p0;
}
return ret;
}
/*
* Make a string name for a compression method (or 2).
*/
static char *method_name(ccp_options *opt,ccp_options *opt2)
{
static char result[64];
if (!ANY_COMPRESS(*opt))
return "(none)";
switch (opt->method) {
case CI_DEFLATE:
if (opt2 != NULL && opt2->deflate_size != opt->deflate_size)
sprintf(result, "Deflate (%d/%d)", opt->deflate_size,
opt2->deflate_size);
else
sprintf(result, "Deflate (%d)", opt->deflate_size);
break;
case CI_BSD_COMPRESS:
if (opt2 != NULL && opt2->bsd_bits != opt->bsd_bits)
sprintf(result, "BSD-Compress (%d/%d)", opt->bsd_bits,
opt2->bsd_bits);
else
sprintf(result, "BSD-Compress (%d)", opt->bsd_bits);
break;
case CI_PREDICTOR_1:
return "Predictor 1";
case CI_PREDICTOR_2:
return "Predictor 2";
default:
sprintf(result, "Method %d", opt->method);
}
return result;
}
/*
* CCP has come up - inform the kernel driver and log a message.
*/
static void ccp_up(fsm *f)
{
ccp_options *go = &ccp_gotoptions[lns[f->unit].ccp_unit];
ccp_options *ho = &ccp_hisoptions[lns[f->unit].ccp_unit];
char method1[64];
ccp_flags_set(lns[f->unit].ccp_unit, 1, 1);
if (ANY_COMPRESS(*go)) {
if (ANY_COMPRESS(*ho)) {
if (go->method == ho->method) {
syslog(LOG_NOTICE, "%s compression enabled",
method_name(go, ho));
} else {
strcpy(method1, method_name(go, NULL));
syslog(LOG_NOTICE, "%s / %s compression enabled",
method1, method_name(ho, NULL));
}
} else
syslog(LOG_NOTICE, "%s receive compression enabled",
method_name(go, NULL));
} else if (ANY_COMPRESS(*ho))
syslog(LOG_NOTICE, "%s transmit compression enabled",
method_name(ho, NULL));
}
/*
* CCP has gone down - inform the kernel driver.
*/
static void ccp_down(fsm *f)
{
if (ccp_localstate[lns[f->unit].ccp_unit] & RACK_PENDING)
UNTIMEOUT(ccp_rack_timeout, (caddr_t) f);
ccp_localstate[lns[f->unit].ccp_unit] = 0;
ccp_flags_set(lns[f->unit].ccp_unit, 1, 0);
}
/*
* Print the contents of a CCP packet.
*/
static char *ccp_codenames[] = {
"ConfReq", "ConfAck", "ConfNak", "ConfRej",
"TermReq", "TermAck", "CodeRej",
NULL, NULL, NULL, NULL, NULL, NULL,
"ResetReq", "ResetAck",
};
static int ccp_printpkt(u_char *p,int plen,void (*printer)(void*,char*,...),void *arg)
{
u_char *p0, *optend;
int code, id, len;
int optlen;
p0 = p;
if (plen < HEADERLEN)
return 0;
code = p[0];
id = p[1];
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_DEFLATE:
if (optlen >= CILEN_DEFLATE) {
printer(arg, "deflate %d", DEFLATE_SIZE(p[2]));
if (DEFLATE_METHOD(p[2]) != DEFLATE_METHOD_VAL)
printer(arg, " method %d", DEFLATE_METHOD(p[2]));
if (p[3] != DEFLATE_CHK_SEQUENCE)
printer(arg, " check %d", p[3]);
p += CILEN_DEFLATE;
}
break;
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;
case CI_PREDICTOR_1:
if (optlen >= CILEN_PREDICTOR_1) {
printer(arg, "predictor 1");
p += CILEN_PREDICTOR_1;
}
break;
case CI_PREDICTOR_2:
if (optlen >= CILEN_PREDICTOR_2) {
printer(arg, "predictor 2");
p += CILEN_PREDICTOR_2;
}
break;
}
while (p < optend)
printer(arg, " %.2x", *p++);
printer(arg, ">");
}
break;
case TERMACK:
case TERMREQ:
if (len > 0 && *p >= ' ' && *p < 0x7f) {
print_string(p, len, printer, arg);
p += len;
len = 0;
}
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.
*/
static void ccp_datainput(int linkunit,u_char *pkt,int len)
{
int unit = lns[linkunit].ccp_unit;
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,"Lost compression sync");
} 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[unit] & RACK_PENDING)) {
fsm_sdata(f, CCP_RESETREQ, f->reqid = ++f->id, NULL, 0);
TIMEOUT(ccp_rack_timeout, (caddr_t) f, RACKTIMEOUT);
ccp_localstate[unit] |= RACK_PENDING;
} else
ccp_localstate[unit] |= RREQ_REPEAT;
}
}
}
/*
* Timeout waiting for reset-ack.
*/
static void ccp_rack_timeout(caddr_t arg)
{
fsm *f = (fsm *) arg;
if (f->state == OPENED && ccp_localstate[lns[f->unit].ccp_unit] & RREQ_REPEAT) {
fsm_sdata(f, CCP_RESETREQ, f->reqid, NULL, 0);
TIMEOUT(ccp_rack_timeout, (caddr_t) f, RACKTIMEOUT);
ccp_localstate[lns[f->unit].ccp_unit] &= ~RREQ_REPEAT;
} else
ccp_localstate[lns[f->unit].ccp_unit] &= ~RACK_PENDING;
}
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