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ccp.c
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ccp.c
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/* $OpenBSD: ccp.c,v 1.13 2009/10/27 23:59:53 deraadt Exp $ */
/*
* ccp.c - PPP Compression Control Protocol.
*
* Copyright (c) 1989-2002 Paul Mackerras. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The name(s) of the authors of this software must not be used to
* endorse or promote products derived from this software without
* prior written permission.
*
* 4. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by Paul Mackerras
* <[email protected]>".
*
* THE AUTHORS OF THIS SOFTWARE DISCLAIM ALL WARRANTIES WITH REGARD TO
* THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS, IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
* SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
* AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
* OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <string.h>
#include <syslog.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include "pppd.h"
#include "fsm.h"
#include "ccp.h"
#include <net/ppp-comp.h>
/*
* Protocol entry points from main code.
*/
static void ccp_init(int unit);
static void ccp_open(int unit);
static void ccp_close(int unit, char *);
static void ccp_lowerup(int unit);
static void ccp_lowerdown(int);
static void ccp_input(int unit, u_char *pkt, int len);
static void ccp_protrej(int unit);
static int ccp_printpkt(u_char *pkt, int len,
void (*printer)(void *, char *, ...), void *arg);
static void ccp_datainput(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(fsm *);
static int ccp_cilen(fsm *);
static void ccp_addci(fsm *, u_char *, int *);
static int ccp_ackci(fsm *, u_char *, int);
static int ccp_nakci(fsm *, u_char *, int);
static int ccp_rejci(fsm *, u_char *, int);
static int ccp_reqci(fsm *, u_char *, int *, int);
static void ccp_up(fsm *);
static void ccp_down(fsm *);
static int ccp_extcode(fsm *, int, int, u_char *, int);
static void ccp_rack_timeout(void *);
static char *method_name(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]; /* we rejected all peer's options */
/*
* ccp_init - initialize CCP.
*/
static 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].deflate = 1;
ccp_wantoptions[0].deflate_size = DEFLATE_MAX_SIZE;
ccp_wantoptions[0].deflate_correct = 1;
ccp_wantoptions[0].deflate_draft = 1;
ccp_allowoptions[0].deflate = 1;
ccp_allowoptions[0].deflate_size = DEFLATE_MAX_SIZE;
ccp_allowoptions[0].deflate_correct = 1;
ccp_allowoptions[0].deflate_draft = 1;
ccp_wantoptions[0].bsd_compress = 1;
ccp_wantoptions[0].bsd_bits = BSD_MAX_BITS;
ccp_allowoptions[0].bsd_compress = 1;
ccp_allowoptions[0].bsd_bits = BSD_MAX_BITS;
ccp_allowoptions[0].predictor_1 = 1;
}
/*
* ccp_open - CCP is allowed to come up.
*/
static void
ccp_open(unit)
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(unit, reason)
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(unit)
int unit;
{
fsm_lowerup(&ccp_fsm[unit]);
}
/*
* ccp_lowerdown - we may not transmit CCP packets.
*/
static void
ccp_lowerdown(unit)
int unit;
{
fsm_lowerdown(&ccp_fsm[unit]);
}
/*
* ccp_input - process a received CCP packet.
*/
static 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.");
/*
* 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(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, f);
}
break;
default:
return 0;
}
return 1;
}
/*
* ccp_protrej - peer doesn't talk CCP.
*/
static 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];
all_rejected[f->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(f->unit, opt_buf, CILEN_BSD_COMPRESS, 0) <= 0)
go->bsd_compress = 0;
}
if (go->deflate) {
if (go->deflate_correct) {
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(f->unit, opt_buf, CILEN_DEFLATE, 0) <= 0)
go->deflate_correct = 0;
}
if (go->deflate_draft) {
opt_buf[0] = CI_DEFLATE_DRAFT;
opt_buf[1] = CILEN_DEFLATE;
opt_buf[2] = DEFLATE_MAKE_OPT(DEFLATE_MIN_SIZE);
opt_buf[3] = DEFLATE_CHK_SEQUENCE;
if (ccp_test(f->unit, opt_buf, CILEN_DEFLATE, 0) <= 0)
go->deflate_draft = 0;
}
if (!go->deflate_correct && !go->deflate_draft)
go->deflate = 0;
}
if (go->predictor_1) {
opt_buf[0] = CI_PREDICTOR_1;
opt_buf[1] = CILEN_PREDICTOR_1;
if (ccp_test(f->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(f->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(f)
fsm *f;
{
ccp_options *go = &ccp_gotoptions[f->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(f, p, lenp)
fsm *f;
u_char *p;
int *lenp;
{
int res;
ccp_options *go = &ccp_gotoptions[f->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] = go->deflate_correct? CI_DEFLATE: CI_DEFLATE_DRAFT;
p[1] = CILEN_DEFLATE;
p[2] = DEFLATE_MAKE_OPT(go->deflate_size);
p[3] = DEFLATE_CHK_SEQUENCE;
for (;;) {
res = ccp_test(f->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 (p != p0 && go->deflate_correct && go->deflate_draft) {
p[0] = CI_DEFLATE_DRAFT;
p[1] = CILEN_DEFLATE;
p[2] = p[2 - CILEN_DEFLATE];
p[3] = DEFLATE_CHK_SEQUENCE;
p += CILEN_DEFLATE;
}
}
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(f->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(f->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(f->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(f, p, len)
fsm *f;
u_char *p;
int len;
{
ccp_options *go = &ccp_gotoptions[f->unit];
u_char *p0 = p;
if (go->deflate) {
if (len < CILEN_DEFLATE
|| p[0] != (go->deflate_correct? CI_DEFLATE: CI_DEFLATE_DRAFT)
|| 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->deflate_correct && go->deflate_draft) {
if (len < CILEN_DEFLATE
|| p[0] != CI_DEFLATE_DRAFT
|| 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;
}
}
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(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->deflate && len >= CILEN_DEFLATE
&& p[0] == (go->deflate_correct? CI_DEFLATE: CI_DEFLATE_DRAFT)
&& 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)
try.deflate_size = DEFLATE_SIZE(p[2]);
p += CILEN_DEFLATE;
len -= CILEN_DEFLATE;
if (go->deflate_correct && go->deflate_draft
&& len >= CILEN_DEFLATE && p[0] == CI_DEFLATE_DRAFT
&& p[1] == CILEN_DEFLATE) {
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(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;
/*
* Cope with empty configure-rejects by ceasing to send
* configure-requests.
*/
if (len == 0 && all_rejected[f->unit])
return -1;
if (go->deflate && len >= CILEN_DEFLATE
&& p[0] == (go->deflate_correct? CI_DEFLATE: CI_DEFLATE_DRAFT)
&& p[1] == CILEN_DEFLATE) {
if (p[2] != DEFLATE_MAKE_OPT(go->deflate_size)
|| p[3] != DEFLATE_CHK_SEQUENCE)
return 0; /* Rej is bad */
if (go->deflate_correct)
try.deflate_correct = 0;
else
try.deflate_draft = 0;
p += CILEN_DEFLATE;
len -= CILEN_DEFLATE;
if (go->deflate_correct && go->deflate_draft
&& len >= CILEN_DEFLATE && p[0] == CI_DEFLATE_DRAFT
&& 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_draft = 0;
p += CILEN_DEFLATE;
len -= CILEN_DEFLATE;
}
if (!try.deflate_correct && !try.deflate_draft)
try.deflate = 0;
}
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(f, p, lenp, dont_nak)
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[f->unit];
ccp_options *ao = &ccp_allowoptions[f->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:
case CI_DEFLATE_DRAFT:
if (!ao->deflate || clen != CILEN_DEFLATE
|| (!ao->deflate_correct && type == CI_DEFLATE)
|| (!ao->deflate_draft && type == CI_DEFLATE_DRAFT)) {
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;
/* fall through to test this #bits below */
} else
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);
/* fall through to test this #bits below */
} else
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(f->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(f->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[f->unit] = 1;
else
*lenp = retp - p0;
}
return ret;
}
/*
* Make a string name for a compression method (or 2).
*/
static char *
method_name(opt, opt2)
ccp_options *opt, *opt2;
{
static char result[64];
if (!ANY_COMPRESS(*opt))
return "(none)";
switch (opt->method) {
case CI_DEFLATE:
case CI_DEFLATE_DRAFT:
if (opt2 != NULL && opt2->deflate_size != opt->deflate_size)
snprintf(result, sizeof result, "Deflate%s (%d/%d)",
(opt->method == CI_DEFLATE_DRAFT? "(old#)": ""),
opt->deflate_size, opt2->deflate_size);
else
snprintf(result, sizeof result, "Deflate%s (%d)",
(opt->method == CI_DEFLATE_DRAFT? "(old#)": ""),
opt->deflate_size);
break;
case CI_BSD_COMPRESS:
if (opt2 != NULL && opt2->bsd_bits != opt->bsd_bits)
snprintf(result, sizeof result,
"BSD-Compress (%d/%d)", opt->bsd_bits,
opt2->bsd_bits);
else
snprintf(result, sizeof result, "BSD-Compress (%d)", opt->bsd_bits);
break;
case CI_PREDICTOR_1:
return "Predictor 1";
case CI_PREDICTOR_2:
return "Predictor 2";
default:
snprintf(result, sizeof result, "Method %d", opt->method);
}
return result;
}
/*
* CCP has come up - inform the kernel driver and log a message.
*/
static void
ccp_up(f)
fsm *f;
{
ccp_options *go = &ccp_gotoptions[f->unit];
ccp_options *ho = &ccp_hisoptions[f->unit];
char method1[64];
ccp_flags_set(f->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 {
strncpy(method1, method_name(go, NULL), sizeof method1);
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(f)
fsm *f;
{
if (ccp_localstate[f->unit] & RACK_PENDING)
UNTIMEOUT(ccp_rack_timeout, f);
ccp_localstate[f->unit] = 0;
ccp_flags_set(f->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(p, plen, printer, arg)
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;