644 lines
14 KiB
C
644 lines
14 KiB
C
/*
|
|
* 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 1995/07/04 23:54:06 paulus Exp $";
|
|
#endif
|
|
|
|
#include <syslog.h>
|
|
#include <sys/ioctl.h>
|
|
#include <net/ppp-comp.h>
|
|
|
|
#include "pppd.h"
|
|
#include "fsm.h"
|
|
#include "ccp.h"
|
|
|
|
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 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).bsd_compress)
|
|
|
|
/*
|
|
* 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 */
|
|
|
|
/*
|
|
* ccp_init - initialize CCP.
|
|
*/
|
|
void
|
|
ccp_init(unit)
|
|
int unit;
|
|
{
|
|
fsm *f = &ccp_fsm[unit];
|
|
|
|
f->unit = unit;
|
|
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].bsd_compress = 1;
|
|
ccp_wantoptions[0].bsd_bits = 12; /* default value */
|
|
|
|
ccp_allowoptions[0].bsd_compress = 1;
|
|
ccp_allowoptions[0].bsd_bits = BSD_MAX_BITS;
|
|
}
|
|
|
|
/*
|
|
* ccp_open - CCP is allowed to come up.
|
|
*/
|
|
void
|
|
ccp_open(unit)
|
|
int unit;
|
|
{
|
|
fsm *f = &ccp_fsm[unit];
|
|
|
|
if (f->state != OPENED)
|
|
ccp_flags_set(unit, 1, 0);
|
|
if (!ANY_COMPRESS(ccp_wantoptions[unit]))
|
|
f->flags |= OPT_SILENT;
|
|
fsm_open(f);
|
|
}
|
|
|
|
/*
|
|
* ccp_close - Terminate CCP.
|
|
*/
|
|
void
|
|
ccp_close(unit)
|
|
int unit;
|
|
{
|
|
ccp_flags_set(unit, 0, 0);
|
|
fsm_close(&ccp_fsm[unit]);
|
|
}
|
|
|
|
/*
|
|
* ccp_lowerup - we may now transmit CCP packets.
|
|
*/
|
|
void
|
|
ccp_lowerup(unit)
|
|
int unit;
|
|
{
|
|
fsm_lowerup(&ccp_fsm[unit]);
|
|
}
|
|
|
|
/*
|
|
* ccp_lowerdown - we may not transmit CCP packets.
|
|
*/
|
|
void
|
|
ccp_lowerdown(unit)
|
|
int unit;
|
|
{
|
|
fsm_lowerdown(&ccp_fsm[unit]);
|
|
}
|
|
|
|
/*
|
|
* ccp_input - process a received CCP packet.
|
|
*/
|
|
void
|
|
ccp_input(unit, p, len)
|
|
int unit;
|
|
u_char *p;
|
|
int len;
|
|
{
|
|
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.");
|
|
}
|
|
|
|
/*
|
|
* Handle a CCP-specific code.
|
|
*/
|
|
static int
|
|
ccp_extcode(f, code, id, p, len)
|
|
fsm *f;
|
|
int code, 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[f->unit] & RACK_PENDING && id == f->reqid) {
|
|
ccp_localstate[f->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.
|
|
*/
|
|
void
|
|
ccp_protrej(unit)
|
|
int unit;
|
|
{
|
|
ccp_flags_set(unit, 0, 0);
|
|
fsm_lowerdown(&ccp_fsm[unit]);
|
|
}
|
|
|
|
/*
|
|
* ccp_resetci - initialize at start of negotiation.
|
|
*/
|
|
static void
|
|
ccp_resetci(f)
|
|
fsm *f;
|
|
{
|
|
ccp_options *go = &ccp_gotoptions[f->unit];
|
|
u_char opt_buf[16];
|
|
|
|
*go = ccp_wantoptions[f->unit];
|
|
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, go->bsd_bits);
|
|
if (!ccp_test(f->unit, opt_buf, CILEN_BSD_COMPRESS, 0))
|
|
go->bsd_compress = 0;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* ccp_cilen - Return total length of our configuration info.
|
|
*/
|
|
static int
|
|
ccp_cilen(f)
|
|
fsm *f;
|
|
{
|
|
ccp_options *go = &ccp_gotoptions[f->unit];
|
|
|
|
return (go->bsd_compress? CILEN_BSD_COMPRESS: 0);
|
|
}
|
|
|
|
/*
|
|
* ccp_addci - put our requests in a packet.
|
|
*/
|
|
static void
|
|
ccp_addci(f, p, lenp)
|
|
fsm *f;
|
|
u_char *p;
|
|
int *lenp;
|
|
{
|
|
ccp_options *go = &ccp_gotoptions[f->unit];
|
|
u_char *p0 = p;
|
|
|
|
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 (ccp_test(f->unit, p, CILEN_BSD_COMPRESS, 0))
|
|
p += CILEN_BSD_COMPRESS;
|
|
else
|
|
go->bsd_compress = 0;
|
|
}
|
|
*lenp = p - p0;
|
|
}
|
|
|
|
/*
|
|
* ccp_ackci - process a received configure-ack, and return
|
|
* 1 iff the packet was OK.
|
|
*/
|
|
static int
|
|
ccp_ackci(f, p, len)
|
|
fsm *f;
|
|
u_char *p;
|
|
int len;
|
|
{
|
|
ccp_options *go = &ccp_gotoptions[f->unit];
|
|
|
|
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;
|
|
}
|
|
if (len != 0)
|
|
return 0;
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* ccp_nakci - process received configure-nak.
|
|
* Returns 1 iff the nak was OK.
|
|
*/
|
|
static int
|
|
ccp_nakci(f, p, len)
|
|
fsm *f;
|
|
u_char *p;
|
|
int len;
|
|
{
|
|
ccp_options *go = &ccp_gotoptions[f->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->bsd_compress && !no.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;
|
|
}
|
|
|
|
/*
|
|
* Have a look at 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(f, p, len)
|
|
fsm *f;
|
|
u_char *p;
|
|
int len;
|
|
{
|
|
ccp_options *go = &ccp_gotoptions[f->unit];
|
|
ccp_options try; /* options to request next time */
|
|
|
|
try = *go;
|
|
|
|
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 (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(f, p, lenp, dont_nak)
|
|
fsm *f;
|
|
u_char *p;
|
|
int *lenp;
|
|
int dont_nak;
|
|
{
|
|
int ret, newret;
|
|
u_char *p0, *retp;
|
|
int len, clen, type, nb;
|
|
ccp_options *ho = &ccp_hisoptions[f->unit];
|
|
ccp_options *ao = &ccp_allowoptions[f->unit];
|
|
|
|
ret = CONFACK;
|
|
retp = p0 = p;
|
|
len = *lenp;
|
|
|
|
memset(ho, 0, sizeof(ccp_options));
|
|
|
|
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_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) {
|
|
newret = CONFNAK;
|
|
nb = ao->bsd_bits;
|
|
} else if (nb < BSD_MIN_BITS) {
|
|
newret = CONFREJ;
|
|
} else if (!ccp_test(f->unit, p, CILEN_BSD_COMPRESS, 1)) {
|
|
if (nb > BSD_MIN_BITS) {
|
|
--nb;
|
|
newret = CONFNAK;
|
|
} else
|
|
newret = CONFREJ;
|
|
}
|
|
if (newret == CONFNAK && !dont_nak) {
|
|
p[2] = BSD_MAKE_OPT(BSD_CURRENT_VERSION, nb);
|
|
}
|
|
|
|
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)
|
|
*lenp = retp - p0;
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* CCP has come up - inform the kernel driver.
|
|
*/
|
|
static void
|
|
ccp_up(f)
|
|
fsm *f;
|
|
{
|
|
ccp_options *go = &ccp_gotoptions[f->unit];
|
|
ccp_options *ho = &ccp_hisoptions[f->unit];
|
|
|
|
ccp_flags_set(f->unit, 1, 1);
|
|
if (go->bsd_compress || ho->bsd_compress)
|
|
syslog(LOG_NOTICE, "%s enabled",
|
|
go->bsd_compress? ho->bsd_compress? "Compression":
|
|
"Receive compression": "Transmit compression");
|
|
}
|
|
|
|
/*
|
|
* CCP has gone down - inform the kernel driver.
|
|
*/
|
|
static void
|
|
ccp_down(f)
|
|
fsm *f;
|
|
{
|
|
if (ccp_localstate[f->unit] & RACK_PENDING)
|
|
UNTIMEOUT(ccp_rack_timeout, (caddr_t) f);
|
|
ccp_localstate[f->unit] = 0;
|
|
ccp_flags_set(f->unit, 1, 0);
|
|
}
|
|
|
|
/*
|
|
* Print the contents of a CCP packet.
|
|
*/
|
|
char *ccp_codenames[] = {
|
|
"ConfReq", "ConfAck", "ConfNak", "ConfRej",
|
|
"TermReq", "TermAck", "CodeRej",
|
|
NULL, NULL, NULL, NULL, NULL, NULL,
|
|
"ResetReq", "ResetAck",
|
|
};
|
|
|
|
int
|
|
ccp_printpkt(p, plen, printer, arg)
|
|
u_char *p;
|
|
int plen;
|
|
void (*printer) __P((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_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;
|
|
}
|
|
|