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freebsd/usr.sbin/pppd/lcp.c
Garrett Wollman 08a0aca6e2 Initial revision
1994-09-25 02:11:26 +00:00

1645 lines
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/*
* lcp.c - PPP Link Control Protocol.
*
* Copyright (c) 1989 Carnegie Mellon University.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* advertising materials, and other materials related to such
* distribution and use acknowledge that the software was developed
* by Carnegie Mellon University. The name of the
* University may not be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
#ifndef lint
static char rcsid[] = "$Id: lcp.c,v 1.8 1994/05/30 02:38:49 paulus Exp $";
#endif
/*
* TODO:
*/
#include <stdio.h>
#include <string.h>
#include <syslog.h>
#include <assert.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <netinet/in.h>
#include "pppd.h"
#include "ppp.h"
#include "fsm.h"
#include "lcp.h"
#include "magic.h"
#include "chap.h"
#include "upap.h"
#include "ipcp.h"
#ifdef _linux_ /* Needs ppp ioctls */
#include <linux/ppp.h>
#endif
/* global vars */
fsm lcp_fsm[NPPP]; /* LCP fsm structure (global)*/
lcp_options lcp_wantoptions[NPPP]; /* Options that we want to request */
lcp_options lcp_gotoptions[NPPP]; /* Options that peer ack'd */
lcp_options lcp_allowoptions[NPPP]; /* Options we allow peer to request */
lcp_options lcp_hisoptions[NPPP]; /* Options that we ack'd */
u_long xmit_accm[NPPP][8]; /* extended transmit ACCM */
static u_long lcp_echos_pending = 0; /* Number of outstanding echo msgs */
static u_long lcp_echo_number = 0; /* ID number of next echo frame */
static u_long lcp_echo_timer_running = 0; /* TRUE if a timer is running */
u_long lcp_echo_interval = 0;
u_long lcp_echo_fails = 0;
/*
* Callbacks for fsm code. (CI = Configuration Information)
*/
static void lcp_resetci __ARGS((fsm *)); /* Reset our CI */
static int lcp_cilen __ARGS((fsm *)); /* Return length of our CI */
static void lcp_addci __ARGS((fsm *, u_char *, int *)); /* Add our CI to pkt */
static int lcp_ackci __ARGS((fsm *, u_char *, int)); /* Peer ack'd our CI */
static int lcp_nakci __ARGS((fsm *, u_char *, int)); /* Peer nak'd our CI */
static int lcp_rejci __ARGS((fsm *, u_char *, int)); /* Peer rej'd our CI */
static int lcp_reqci __ARGS((fsm *, u_char *, int *, int)); /* Rcv peer CI */
static void lcp_up __ARGS((fsm *)); /* We're UP */
static void lcp_down __ARGS((fsm *)); /* We're DOWN */
static void lcp_starting __ARGS((fsm *)); /* We need lower layer up */
static void lcp_finished __ARGS((fsm *)); /* We need lower layer down */
static int lcp_extcode __ARGS((fsm *, int, int, u_char *, int));
static void lcp_rprotrej __ARGS((fsm *, u_char *, int));
/*
* routines to send LCP echos to peer
*/
static void lcp_echo_lowerup __ARGS((int));
static void lcp_echo_lowerdown __ARGS((int));
static void LcpEchoTimeout __ARGS((caddr_t));
static void lcp_received_echo_reply __ARGS((fsm *, int, u_char *, int));
static void LcpSendEchoRequest __ARGS((fsm *));
static void LcpLinkFailure __ARGS((fsm *));
static fsm_callbacks lcp_callbacks = { /* LCP callback routines */
lcp_resetci, /* Reset our Configuration Information */
lcp_cilen, /* Length of our Configuration Information */
lcp_addci, /* Add our Configuration Information */
lcp_ackci, /* ACK our Configuration Information */
lcp_nakci, /* NAK our Configuration Information */
lcp_rejci, /* Reject our Configuration Information */
lcp_reqci, /* Request peer's Configuration Information */
lcp_up, /* Called when fsm reaches OPENED state */
lcp_down, /* Called when fsm leaves OPENED state */
lcp_starting, /* Called when we want the lower layer up */
lcp_finished, /* Called when we want the lower layer down */
NULL, /* Called when Protocol-Reject received */
NULL, /* Retransmission is necessary */
lcp_extcode, /* Called to handle LCP-specific codes */
"LCP" /* String name of protocol */
};
int lcp_warnloops = DEFWARNLOOPS; /* Warn about a loopback this often */
/*
* Length of each type of configuration option (in octets)
*/
#define CILEN_VOID 2
#define CILEN_SHORT 4 /* CILEN_VOID + sizeof(short) */
#define CILEN_CHAP 5 /* CILEN_VOID + sizeof(short) + 1 */
#define CILEN_LONG 6 /* CILEN_VOID + sizeof(long) */
#define CILEN_LQR 8 /* CILEN_VOID + sizeof(short) + sizeof(long) */
#define CODENAME(x) ((x) == CONFACK ? "ACK" : \
(x) == CONFNAK ? "NAK" : "REJ")
/*
* lcp_init - Initialize LCP.
*/
void
lcp_init(unit)
int unit;
{
fsm *f = &lcp_fsm[unit];
lcp_options *wo = &lcp_wantoptions[unit];
lcp_options *ao = &lcp_allowoptions[unit];
f->unit = unit;
f->protocol = LCP;
f->callbacks = &lcp_callbacks;
fsm_init(f);
wo->passive = 0;
wo->silent = 0;
wo->restart = 0; /* Set to 1 in kernels or multi-line
implementations */
wo->neg_mru = 1;
wo->mru = DEFMRU;
wo->neg_asyncmap = 0;
wo->asyncmap = 0;
wo->neg_chap = 0; /* Set to 1 on server */
wo->neg_upap = 0; /* Set to 1 on server */
wo->chap_mdtype = CHAP_DIGEST_MD5;
wo->neg_magicnumber = 1;
wo->neg_pcompression = 1;
wo->neg_accompression = 1;
wo->neg_lqr = 0; /* no LQR implementation yet */
ao->neg_mru = 1;
ao->mru = MAXMRU;
ao->neg_asyncmap = 1;
ao->asyncmap = 0;
ao->neg_chap = 1;
ao->chap_mdtype = CHAP_DIGEST_MD5;
ao->neg_upap = 1;
ao->neg_magicnumber = 1;
ao->neg_pcompression = 1;
ao->neg_accompression = 1;
ao->neg_lqr = 0; /* no LQR implementation yet */
memset(xmit_accm[unit], 0, sizeof(xmit_accm[0]));
xmit_accm[unit][3] = 0x60000000;
}
/*
* lcp_open - LCP is allowed to come up.
*/
void
lcp_open(unit)
int unit;
{
fsm *f = &lcp_fsm[unit];
lcp_options *wo = &lcp_wantoptions[unit];
f->flags = 0;
if (wo->passive)
f->flags |= OPT_PASSIVE;
if (wo->silent)
f->flags |= OPT_SILENT;
fsm_open(f);
}
/*
* lcp_close - Take LCP down.
*/
void
lcp_close(unit)
int unit;
{
fsm *f = &lcp_fsm[unit];
if (f->state == STOPPED && f->flags & (OPT_PASSIVE|OPT_SILENT)) {
/*
* This action is not strictly according to the FSM in RFC1548,
* but it does mean that the program terminates if you do a
* lcp_close(0) in passive/silent mode when a connection hasn't
* been established.
*/
f->state = CLOSED;
lcp_finished(f);
} else
fsm_close(&lcp_fsm[unit]);
}
/*
* lcp_lowerup - The lower layer is up.
*/
void
lcp_lowerup(unit)
int unit;
{
sifdown(unit);
ppp_set_xaccm(unit, xmit_accm[unit]);
ppp_send_config(unit, MTU, 0xffffffff, 0, 0);
ppp_recv_config(unit, MTU, 0x00000000, 0, 0);
peer_mru[unit] = MTU;
lcp_allowoptions[unit].asyncmap = xmit_accm[unit][0];
fsm_lowerup(&lcp_fsm[unit]);
}
/*
* lcp_lowerdown - The lower layer is down.
*/
void
lcp_lowerdown(unit)
int unit;
{
fsm_lowerdown(&lcp_fsm[unit]);
}
/*
* lcp_input - Input LCP packet.
*/
void
lcp_input(unit, p, len)
int unit;
u_char *p;
int len;
{
fsm_input(&lcp_fsm[unit], p, len);
}
/*
* lcp_extcode - Handle a LCP-specific code.
*/
static int
lcp_extcode(f, code, id, inp, len)
fsm *f;
int code, id;
u_char *inp;
int len;
{
u_char *magp;
switch( code ){
case PROTREJ:
lcp_rprotrej(f, inp, len);
break;
case ECHOREQ:
if (f->state != OPENED)
break;
LCPDEBUG((LOG_INFO, "lcp: Echo-Request, Rcvd id %d", id));
magp = inp;
PUTLONG(lcp_gotoptions[f->unit].magicnumber, magp);
if (len < CILEN_LONG)
len = CILEN_LONG;
fsm_sdata(f, ECHOREP, id, inp, len);
break;
case ECHOREP:
lcp_received_echo_reply(f, id, inp, len);
break;
case DISCREQ:
break;
default:
return 0;
}
return 1;
}
/*
* lcp_rprotrej - Receive an Protocol-Reject.
*
* Figure out which protocol is rejected and inform it.
*/
static void
lcp_rprotrej(f, inp, len)
fsm *f;
u_char *inp;
int len;
{
u_short prot;
LCPDEBUG((LOG_INFO, "lcp_rprotrej."));
if (len < sizeof (u_short)) {
LCPDEBUG((LOG_INFO,
"lcp_rprotrej: Rcvd short Protocol-Reject packet!"));
return;
}
GETSHORT(prot, inp);
LCPDEBUG((LOG_INFO,
"lcp_rprotrej: Rcvd Protocol-Reject packet for %x!",
prot));
/*
* Protocol-Reject packets received in any state other than the LCP
* OPENED state SHOULD be silently discarded.
*/
if( f->state != OPENED ){
LCPDEBUG((LOG_INFO, "Protocol-Reject discarded: LCP in state %d",
f->state));
return;
}
DEMUXPROTREJ(f->unit, prot); /* Inform protocol */
}
/*
* lcp_protrej - A Protocol-Reject was received.
*/
/*ARGSUSED*/
void
lcp_protrej(unit)
int unit;
{
/*
* Can't reject LCP!
*/
LCPDEBUG((LOG_WARNING,
"lcp_protrej: Received Protocol-Reject for LCP!"));
fsm_protreject(&lcp_fsm[unit]);
}
/*
* lcp_sprotrej - Send a Protocol-Reject for some protocol.
*/
void
lcp_sprotrej(unit, p, len)
int unit;
u_char *p;
int len;
{
/*
* Send back the protocol and the information field of the
* rejected packet. We only get here if LCP is in the OPENED state.
*/
p += 2;
len -= 2;
fsm_sdata(&lcp_fsm[unit], PROTREJ, ++lcp_fsm[unit].id,
p, len);
}
/*
* lcp_resetci - Reset our CI.
*/
static void
lcp_resetci(f)
fsm *f;
{
lcp_wantoptions[f->unit].magicnumber = magic();
lcp_wantoptions[f->unit].numloops = 0;
lcp_gotoptions[f->unit] = lcp_wantoptions[f->unit];
peer_mru[f->unit] = MTU;
}
/*
* lcp_cilen - Return length of our CI.
*/
static int
lcp_cilen(f)
fsm *f;
{
lcp_options *go = &lcp_gotoptions[f->unit];
#define LENCIVOID(neg) (neg ? CILEN_VOID : 0)
#define LENCICHAP(neg) (neg ? CILEN_CHAP : 0)
#define LENCISHORT(neg) (neg ? CILEN_SHORT : 0)
#define LENCILONG(neg) (neg ? CILEN_LONG : 0)
#define LENCILQR(neg) (neg ? CILEN_LQR: 0)
/*
* NB: we only ask for one of CHAP and UPAP, even if we will
* accept either.
*/
return (LENCISHORT(go->neg_mru) +
LENCILONG(go->neg_asyncmap) +
LENCICHAP(go->neg_chap) +
LENCISHORT(!go->neg_chap && go->neg_upap) +
LENCILQR(go->neg_lqr) +
LENCILONG(go->neg_magicnumber) +
LENCIVOID(go->neg_pcompression) +
LENCIVOID(go->neg_accompression));
}
/*
* lcp_addci - Add our desired CIs to a packet.
*/
static void
lcp_addci(f, ucp, lenp)
fsm *f;
u_char *ucp;
int *lenp;
{
lcp_options *go = &lcp_gotoptions[f->unit];
u_char *start_ucp = ucp;
#define ADDCIVOID(opt, neg) \
if (neg) { \
PUTCHAR(opt, ucp); \
PUTCHAR(CILEN_VOID, ucp); \
}
#define ADDCISHORT(opt, neg, val) \
if (neg) { \
PUTCHAR(opt, ucp); \
PUTCHAR(CILEN_SHORT, ucp); \
PUTSHORT(val, ucp); \
}
#define ADDCICHAP(opt, neg, val, digest) \
if (neg) { \
PUTCHAR(opt, ucp); \
PUTCHAR(CILEN_CHAP, ucp); \
PUTSHORT(val, ucp); \
PUTCHAR(digest, ucp); \
}
#define ADDCILONG(opt, neg, val) \
if (neg) { \
PUTCHAR(opt, ucp); \
PUTCHAR(CILEN_LONG, ucp); \
PUTLONG(val, ucp); \
}
#define ADDCILQR(opt, neg, val) \
if (neg) { \
PUTCHAR(opt, ucp); \
PUTCHAR(CILEN_LQR, ucp); \
PUTSHORT(LQR, ucp); \
PUTLONG(val, ucp); \
}
ADDCISHORT(CI_MRU, go->neg_mru, go->mru);
ADDCILONG(CI_ASYNCMAP, go->neg_asyncmap, go->asyncmap);
ADDCICHAP(CI_AUTHTYPE, go->neg_chap, CHAP, go->chap_mdtype);
ADDCISHORT(CI_AUTHTYPE, !go->neg_chap && go->neg_upap, UPAP);
ADDCILQR(CI_QUALITY, go->neg_lqr, go->lqr_period);
ADDCILONG(CI_MAGICNUMBER, go->neg_magicnumber, go->magicnumber);
ADDCIVOID(CI_PCOMPRESSION, go->neg_pcompression);
ADDCIVOID(CI_ACCOMPRESSION, go->neg_accompression);
if (ucp - start_ucp != *lenp) {
/* this should never happen, because peer_mtu should be 1500 */
syslog(LOG_ERR, "Bug in lcp_addci: wrong length");
}
}
/*
* lcp_ackci - Ack our CIs.
* This should not modify any state if the Ack is bad.
*
* Returns:
* 0 - Ack was bad.
* 1 - Ack was good.
*/
static int
lcp_ackci(f, p, len)
fsm *f;
u_char *p;
int len;
{
lcp_options *go = &lcp_gotoptions[f->unit];
u_char cilen, citype, cichar;
u_short cishort;
u_long cilong;
/*
* CIs must be in exactly the same order that we sent.
* Check packet length and CI length at each step.
* If we find any deviations, then this packet is bad.
*/
#define ACKCIVOID(opt, neg) \
if (neg) { \
if ((len -= CILEN_VOID) < 0) \
goto bad; \
GETCHAR(citype, p); \
GETCHAR(cilen, p); \
if (cilen != CILEN_VOID || \
citype != opt) \
goto bad; \
}
#define ACKCISHORT(opt, neg, val) \
if (neg) { \
if ((len -= CILEN_SHORT) < 0) \
goto bad; \
GETCHAR(citype, p); \
GETCHAR(cilen, p); \
if (cilen != CILEN_SHORT || \
citype != opt) \
goto bad; \
GETSHORT(cishort, p); \
if (cishort != val) \
goto bad; \
}
#define ACKCICHAP(opt, neg, val, digest) \
if (neg) { \
if ((len -= CILEN_CHAP) < 0) \
goto bad; \
GETCHAR(citype, p); \
GETCHAR(cilen, p); \
if (cilen != CILEN_CHAP || \
citype != opt) \
goto bad; \
GETSHORT(cishort, p); \
if (cishort != val) \
goto bad; \
GETCHAR(cichar, p); \
if (cichar != digest) \
goto bad; \
}
#define ACKCILONG(opt, neg, val) \
if (neg) { \
if ((len -= CILEN_LONG) < 0) \
goto bad; \
GETCHAR(citype, p); \
GETCHAR(cilen, p); \
if (cilen != CILEN_LONG || \
citype != opt) \
goto bad; \
GETLONG(cilong, p); \
if (cilong != val) \
goto bad; \
}
#define ACKCILQR(opt, neg, val) \
if (neg) { \
if ((len -= CILEN_LQR) < 0) \
goto bad; \
GETCHAR(citype, p); \
GETCHAR(cilen, p); \
if (cilen != CILEN_LQR || \
citype != opt) \
goto bad; \
GETSHORT(cishort, p); \
if (cishort != LQR) \
goto bad; \
GETLONG(cilong, p); \
if (cilong != val) \
goto bad; \
}
ACKCISHORT(CI_MRU, go->neg_mru, go->mru);
ACKCILONG(CI_ASYNCMAP, go->neg_asyncmap, go->asyncmap);
ACKCICHAP(CI_AUTHTYPE, go->neg_chap, CHAP, go->chap_mdtype);
ACKCISHORT(CI_AUTHTYPE, !go->neg_chap && go->neg_upap, UPAP);
ACKCILQR(CI_QUALITY, go->neg_lqr, go->lqr_period);
ACKCILONG(CI_MAGICNUMBER, go->neg_magicnumber, go->magicnumber);
ACKCIVOID(CI_PCOMPRESSION, go->neg_pcompression);
ACKCIVOID(CI_ACCOMPRESSION, go->neg_accompression);
/*
* If there are any remaining CIs, then this packet is bad.
*/
if (len != 0)
goto bad;
return (1);
bad:
LCPDEBUG((LOG_WARNING, "lcp_acki: received bad Ack!"));
return (0);
}
/*
* lcp_nakci - Peer has sent a NAK for some of our CIs.
* This should not modify any state if the Nak is bad
* or if LCP is in the OPENED state.
*
* Returns:
* 0 - Nak was bad.
* 1 - Nak was good.
*/
static int
lcp_nakci(f, p, len)
fsm *f;
u_char *p;
int len;
{
lcp_options *go = &lcp_gotoptions[f->unit];
lcp_options *wo = &lcp_wantoptions[f->unit];
u_char cilen, citype, cichar, *next;
u_short cishort;
u_long cilong;
lcp_options no; /* options we've seen Naks for */
lcp_options try; /* options to request next time */
int looped_back = 0;
BZERO(&no, sizeof(no));
try = *go;
/*
* Any Nak'd CIs must be in exactly the same order that we sent.
* Check packet length and CI length at each step.
* If we find any deviations, then this packet is bad.
*/
#define NAKCIVOID(opt, neg, code) \
if (go->neg && \
len >= CILEN_VOID && \
p[1] == CILEN_VOID && \
p[0] == opt) { \
len -= CILEN_VOID; \
INCPTR(CILEN_VOID, p); \
no.neg = 1; \
code \
}
#define NAKCICHAP(opt, neg, code) \
if (go->neg && \
len >= CILEN_CHAP && \
p[1] == CILEN_CHAP && \
p[0] == opt) { \
len -= CILEN_CHAP; \
INCPTR(2, p); \
GETSHORT(cishort, p); \
GETCHAR(cichar, p); \
no.neg = 1; \
code \
}
#define NAKCISHORT(opt, neg, code) \
if (go->neg && \
len >= CILEN_SHORT && \
p[1] == CILEN_SHORT && \
p[0] == opt) { \
len -= CILEN_SHORT; \
INCPTR(2, p); \
GETSHORT(cishort, p); \
no.neg = 1; \
code \
}
#define NAKCILONG(opt, neg, code) \
if (go->neg && \
len >= CILEN_LONG && \
p[1] == CILEN_LONG && \
p[0] == opt) { \
len -= CILEN_LONG; \
INCPTR(2, p); \
GETLONG(cilong, p); \
no.neg = 1; \
code \
}
#define NAKCILQR(opt, neg, code) \
if (go->neg && \
len >= CILEN_LQR && \
p[1] == CILEN_LQR && \
p[0] == opt) { \
len -= CILEN_LQR; \
INCPTR(2, p); \
GETSHORT(cishort, p); \
GETLONG(cilong, p); \
no.neg = 1; \
code \
}
/*
* We don't care if they want to send us smaller packets than
* we want. Therefore, accept any MRU less than what we asked for,
* but then ignore the new value when setting the MRU in the kernel.
* If they send us a bigger MRU than what we asked, accept it, up to
* the limit of the default MRU we'd get if we didn't negotiate.
*/
NAKCISHORT(CI_MRU, neg_mru,
if (cishort <= wo->mru || cishort < DEFMRU)
try.mru = cishort;
);
/*
* Add any characters they want to our (receive-side) asyncmap.
*/
NAKCILONG(CI_ASYNCMAP, neg_asyncmap,
try.asyncmap = go->asyncmap | cilong;
);
/*
* If they can't cope with our CHAP hash algorithm, we'll have
* to stop asking for CHAP. We haven't got any other algorithm.
*/
NAKCICHAP(CI_AUTHTYPE, neg_chap,
try.neg_chap = 0;
);
/*
* Peer shouldn't send Nak for UPAP, protocol compression or
* address/control compression requests; they should send
* a Reject instead. If they send a Nak, treat it as a Reject.
*/
if (!go->neg_chap ){
NAKCISHORT(CI_AUTHTYPE, neg_upap,
try.neg_upap = 0;
);
}
/*
* If they can't cope with our link quality protocol, we'll have
* to stop asking for LQR. We haven't got any other protocol.
* If they Nak the reporting period, take their value XXX ?
*/
NAKCILQR(CI_QUALITY, neg_lqr,
if (cishort != LQR)
try.neg_lqr = 0;
else
try.lqr_period = cilong;
);
/*
* Check for a looped-back line.
*/
NAKCILONG(CI_MAGICNUMBER, neg_magicnumber,
try.magicnumber = magic();
++try.numloops;
looped_back = 1;
);
NAKCIVOID(CI_PCOMPRESSION, neg_pcompression,
try.neg_pcompression = 0;
);
NAKCIVOID(CI_ACCOMPRESSION, neg_accompression,
try.neg_accompression = 0;
);
/*
* There may be remaining CIs, if the peer is requesting negotiation
* on an option that we didn't include in our request packet.
* If we see an option that we requested, or one we've already seen
* in this packet, then this packet is bad.
* If we wanted to respond by starting to negotiate on the requested
* option(s), we could, but we don't, because except for the
* authentication type and quality protocol, if we are not negotiating
* an option, it is because we were told not to.
* For the authentication type, the Nak from the peer means
* `let me authenticate myself with you' which is a bit pointless.
* For the quality protocol, the Nak means `ask me to send you quality
* reports', but if we didn't ask for them, we don't want them.
*/
while (len > CILEN_VOID) {
GETCHAR(citype, p);
GETCHAR(cilen, p);
if( (len -= cilen) < 0 )
goto bad;
next = p + cilen - 2;
switch (citype) {
case CI_MRU:
if (go->neg_mru || no.neg_mru || cilen != CILEN_SHORT)
goto bad;
break;
case CI_ASYNCMAP:
if (go->neg_asyncmap || no.neg_asyncmap || cilen != CILEN_LONG)
goto bad;
break;
case CI_AUTHTYPE:
if (go->neg_chap || no.neg_chap || go->neg_upap || no.neg_upap)
goto bad;
break;
case CI_MAGICNUMBER:
if (go->neg_magicnumber || no.neg_magicnumber ||
cilen != CILEN_LONG)
goto bad;
break;
case CI_PCOMPRESSION:
if (go->neg_pcompression || no.neg_pcompression
|| cilen != CILEN_VOID)
goto bad;
break;
case CI_ACCOMPRESSION:
if (go->neg_accompression || no.neg_accompression
|| cilen != CILEN_VOID)
goto bad;
break;
case CI_QUALITY:
if (go->neg_lqr || no.neg_lqr || cilen != CILEN_LQR)
goto bad;
break;
default:
goto bad;
}
p = next;
}
/* If there is still anything left, this packet is bad. */
if (len != 0)
goto bad;
/*
* OK, the Nak is good. Now we can update state.
*/
if (f->state != OPENED) {
*go = try;
if (looped_back && try.numloops % lcp_warnloops == 0)
LCPDEBUG((LOG_INFO, "The line appears to be looped back."));
}
return 1;
bad:
LCPDEBUG((LOG_WARNING, "lcp_nakci: received bad Nak!"));
return 0;
}
/*
* lcp_rejci - Peer has Rejected some of our CIs.
* This should not modify any state if the Reject is bad
* or if LCP is in the OPENED state.
*
* Returns:
* 0 - Reject was bad.
* 1 - Reject was good.
*/
static int
lcp_rejci(f, p, len)
fsm *f;
u_char *p;
int len;
{
lcp_options *go = &lcp_gotoptions[f->unit];
u_char cichar;
u_short cishort;
u_long cilong;
u_char *start = p;
int plen = len;
lcp_options try; /* options to request next time */
try = *go;
/*
* Any Rejected CIs must be in exactly the same order that we sent.
* Check packet length and CI length at each step.
* If we find any deviations, then this packet is bad.
*/
#define REJCIVOID(opt, neg) \
if (go->neg && \
len >= CILEN_VOID && \
p[1] == CILEN_VOID && \
p[0] == opt) { \
len -= CILEN_VOID; \
INCPTR(CILEN_VOID, p); \
try.neg = 0; \
LCPDEBUG((LOG_INFO, "lcp_rejci rejected void opt %d", opt)); \
}
#define REJCISHORT(opt, neg, val) \
if (go->neg && \
len >= CILEN_SHORT && \
p[1] == CILEN_SHORT && \
p[0] == opt) { \
len -= CILEN_SHORT; \
INCPTR(2, p); \
GETSHORT(cishort, p); \
/* Check rejected value. */ \
if (cishort != val) \
goto bad; \
try.neg = 0; \
LCPDEBUG((LOG_INFO,"lcp_rejci rejected short opt %d", opt)); \
}
#define REJCICHAP(opt, neg, val, digest) \
if (go->neg && \
len >= CILEN_CHAP && \
p[1] == CILEN_CHAP && \
p[0] == opt) { \
len -= CILEN_CHAP; \
INCPTR(2, p); \
GETSHORT(cishort, p); \
GETCHAR(cichar, p); \
/* Check rejected value. */ \
if (cishort != val || cichar != digest) \
goto bad; \
try.neg = 0; \
LCPDEBUG((LOG_INFO,"lcp_rejci rejected chap opt %d", opt)); \
}
#define REJCILONG(opt, neg, val) \
if (go->neg && \
len >= CILEN_LONG && \
p[1] == CILEN_LONG && \
p[0] == opt) { \
len -= CILEN_LONG; \
INCPTR(2, p); \
GETLONG(cilong, p); \
/* Check rejected value. */ \
if (cilong != val) \
goto bad; \
try.neg = 0; \
LCPDEBUG((LOG_INFO,"lcp_rejci rejected long opt %d", opt)); \
}
#define REJCILQR(opt, neg, val) \
if (go->neg && \
len >= CILEN_LQR && \
p[1] == CILEN_LQR && \
p[0] == opt) { \
len -= CILEN_LQR; \
INCPTR(2, p); \
GETSHORT(cishort, p); \
GETLONG(cilong, p); \
/* Check rejected value. */ \
if (cishort != LQR || cilong != val) \
goto bad; \
try.neg = 0; \
LCPDEBUG((LOG_INFO,"lcp_rejci rejected LQR opt %d", opt)); \
}
REJCISHORT(CI_MRU, neg_mru, go->mru);
REJCILONG(CI_ASYNCMAP, neg_asyncmap, go->asyncmap);
REJCICHAP(CI_AUTHTYPE, neg_chap, CHAP, go->chap_mdtype);
if (!go->neg_chap) {
REJCISHORT(CI_AUTHTYPE, neg_upap, UPAP);
}
REJCILQR(CI_QUALITY, neg_lqr, go->lqr_period);
REJCILONG(CI_MAGICNUMBER, neg_magicnumber, go->magicnumber);
REJCIVOID(CI_PCOMPRESSION, neg_pcompression);
REJCIVOID(CI_ACCOMPRESSION, neg_accompression);
/*
* If there are any remaining CIs, then this packet is bad.
*/
if (len != 0)
goto bad;
/*
* Now we can update state.
*/
if (f->state != OPENED)
*go = try;
return 1;
bad:
LCPDEBUG((LOG_WARNING, "lcp_rejci: received bad Reject!"));
LCPDEBUG((LOG_WARNING, "lcp_rejci: plen %d len %d off %d",
plen, len, p - start));
return 0;
}
/*
* lcp_reqci - Check the peer's requested CIs and send appropriate response.
*
* Returns: CONFACK, CONFNAK or CONFREJ and input packet modified
* appropriately. If reject_if_disagree is non-zero, doesn't return
* CONFNAK; returns CONFREJ if it can't return CONFACK.
*/
static int
lcp_reqci(f, inp, lenp, reject_if_disagree)
fsm *f;
u_char *inp; /* Requested CIs */
int *lenp; /* Length of requested CIs */
int reject_if_disagree;
{
lcp_options *go = &lcp_gotoptions[f->unit];
lcp_options *ho = &lcp_hisoptions[f->unit];
lcp_options *ao = &lcp_allowoptions[f->unit];
u_char *cip, *next; /* Pointer to current and next CIs */
u_char cilen, citype, cichar;/* Parsed len, type, char value */
u_short cishort; /* Parsed short value */
u_long cilong; /* Parse long value */
int rc = CONFACK; /* Final packet return code */
int orc; /* Individual option return code */
u_char *p; /* Pointer to next char to parse */
u_char *ucp = inp; /* Pointer to current output char */
int l = *lenp; /* Length left */
/*
* Reset all his options.
*/
BZERO(ho, sizeof(*ho));
/*
* Process all his options.
*/
next = inp;
while (l) {
orc = CONFACK; /* Assume success */
cip = p = next; /* Remember begining of CI */
if (l < 2 || /* Not enough data for CI header or */
p[1] < 2 || /* CI length too small or */
p[1] > l) { /* CI length too big? */
LCPDEBUG((LOG_WARNING, "lcp_reqci: bad CI length!"));
orc = CONFREJ; /* Reject bad CI */
cilen = l; /* Reject till end of packet */
l = 0; /* Don't loop again */
goto endswitch;
}
GETCHAR(citype, p); /* Parse CI type */
GETCHAR(cilen, p); /* Parse CI length */
l -= cilen; /* Adjust remaining length */
next += cilen; /* Step to next CI */
switch (citype) { /* Check CI type */
case CI_MRU:
LCPDEBUG((LOG_INFO, "lcp_reqci: rcvd MRU"));
if (!ao->neg_mru || /* Allow option? */
cilen != CILEN_SHORT) { /* Check CI length */
orc = CONFREJ; /* Reject CI */
break;
}
GETSHORT(cishort, p); /* Parse MRU */
LCPDEBUG((LOG_INFO, "(%d)", cishort));
/*
* He must be able to receive at least our minimum.
* No need to check a maximum. If he sends a large number,
* we'll just ignore it.
*/
if (cishort < MINMRU) {
orc = CONFNAK; /* Nak CI */
if( !reject_if_disagree ){
DECPTR(sizeof (short), p); /* Backup */
PUTSHORT(MINMRU, p); /* Give him a hint */
}
break;
}
ho->neg_mru = 1; /* Remember he sent MRU */
ho->mru = cishort; /* And remember value */
break;
case CI_ASYNCMAP:
LCPDEBUG((LOG_INFO, "lcp_reqci: rcvd ASYNCMAP"));
if (!ao->neg_asyncmap ||
cilen != CILEN_LONG) {
orc = CONFREJ;
break;
}
GETLONG(cilong, p);
LCPDEBUG((LOG_INFO, "(%lx)", cilong));
/*
* Asyncmap must have set at least the bits
* which are set in lcp_allowoptions[unit].asyncmap.
*/
if ((ao->asyncmap & ~cilong) != 0) {
orc = CONFNAK;
if( !reject_if_disagree ){
DECPTR(sizeof (long), p);
PUTLONG(ao->asyncmap | cilong, p);
}
break;
}
ho->neg_asyncmap = 1;
ho->asyncmap = cilong;
break;
case CI_AUTHTYPE:
LCPDEBUG((LOG_INFO, "lcp_reqci: rcvd AUTHTYPE"));
if (cilen < CILEN_SHORT ||
!(ao->neg_upap || ao->neg_chap)) {
orc = CONFREJ;
break;
}
GETSHORT(cishort, p);
LCPDEBUG((LOG_INFO, "(%x)", cishort));
/*
* Authtype must be UPAP or CHAP.
*
* Note: if both ao->neg_upap and ao->neg_chap are set,
* and the peer sends a Configure-Request with two
* authenticate-protocol requests, one for CHAP and one
* for UPAP, then we will reject the second request.
* Whether we end up doing CHAP or UPAP depends then on
* the ordering of the CIs in the peer's Configure-Request.
*/
if (cishort == UPAP) {
if (!ao->neg_upap || /* we don't want to do PAP */
ho->neg_chap || /* or we've already accepted CHAP */
cilen != CILEN_SHORT) {
LCPDEBUG((LOG_WARNING,
"lcp_reqci: rcvd AUTHTYPE PAP, rejecting..."));
orc = CONFREJ;
break;
}
ho->neg_upap = 1;
break;
}
if (cishort == CHAP) {
if (!ao->neg_chap || /* we don't want to do CHAP */
ho->neg_upap || /* or we've already accepted UPAP */
cilen != CILEN_CHAP) {
LCPDEBUG((LOG_INFO,
"lcp_reqci: rcvd AUTHTYPE CHAP, rejecting..."));
orc = CONFREJ;
break;
}
GETCHAR(cichar, p); /* get digest type*/
if (cichar != ao->chap_mdtype) {
orc = CONFNAK;
if( !reject_if_disagree ){
DECPTR(sizeof (u_char), p);
PUTCHAR(ao->chap_mdtype, p);
}
break;
}
ho->chap_mdtype = cichar; /* save md type */
ho->neg_chap = 1;
break;
}
/*
* We don't recognize the protocol they're asking for.
* Reject it.
*/
orc = CONFREJ;
break;
case CI_QUALITY:
LCPDEBUG((LOG_INFO, "lcp_reqci: rcvd QUALITY"));
if (!ao->neg_lqr ||
cilen != CILEN_LQR) {
orc = CONFREJ;
break;
}
GETSHORT(cishort, p);
GETLONG(cilong, p);
LCPDEBUG((LOG_INFO, "(%x %lx)", cishort, cilong));
if (cishort != LQR) {
orc = CONFREJ;
break;
}
/*
* Check the reporting period.
* XXX When should we Nak this, and what with?
*/
break;
case CI_MAGICNUMBER:
LCPDEBUG((LOG_INFO, "lcp_reqci: rcvd MAGICNUMBER"));
if (!(ao->neg_magicnumber || go->neg_magicnumber) ||
cilen != CILEN_LONG) {
orc = CONFREJ;
break;
}
GETLONG(cilong, p);
LCPDEBUG((LOG_INFO, "(%lx)", cilong));
/*
* He must have a different magic number.
*/
if (go->neg_magicnumber &&
cilong == go->magicnumber) {
orc = CONFNAK;
DECPTR(sizeof (long), p);
cilong = magic(); /* Don't put magic() inside macro! */
PUTLONG(cilong, p);
break;
}
ho->neg_magicnumber = 1;
ho->magicnumber = cilong;
break;
case CI_PCOMPRESSION:
LCPDEBUG((LOG_INFO, "lcp_reqci: rcvd PCOMPRESSION"));
if (!ao->neg_pcompression ||
cilen != CILEN_VOID) {
orc = CONFREJ;
break;
}
ho->neg_pcompression = 1;
break;
case CI_ACCOMPRESSION:
LCPDEBUG((LOG_INFO, "lcp_reqci: rcvd ACCOMPRESSION"));
if (!ao->neg_accompression ||
cilen != CILEN_VOID) {
orc = CONFREJ;
break;
}
ho->neg_accompression = 1;
break;
default:
LCPDEBUG((LOG_INFO, "lcp_reqci: rcvd unknown option %d",
citype));
orc = CONFREJ;
break;
}
endswitch:
LCPDEBUG((LOG_INFO, " (%s)", CODENAME(orc)));
if (orc == CONFACK && /* Good CI */
rc != CONFACK) /* but prior CI wasnt? */
continue; /* Don't send this one */
if (orc == CONFNAK) { /* Nak this CI? */
if (reject_if_disagree) /* Getting fed up with sending NAKs? */
orc = CONFREJ; /* Get tough if so */
else {
if (rc == CONFREJ) /* Rejecting prior CI? */
continue; /* Don't send this one */
if (rc == CONFACK) { /* Ack'd all prior CIs? */
rc = CONFNAK; /* Not anymore... */
ucp = inp; /* Backup */
}
}
}
if (orc == CONFREJ && /* Reject this CI */
rc != CONFREJ) { /* but no prior ones? */
rc = CONFREJ;
ucp = inp; /* Backup */
}
if (ucp != cip) /* Need to move CI? */
BCOPY(cip, ucp, cilen); /* Move it */
INCPTR(cilen, ucp); /* Update output pointer */
}
/*
* If we wanted to send additional NAKs (for unsent CIs), the
* code would go here. This must be done with care since it might
* require a longer packet than we received. At present there
* are no cases where we want to ask the peer to negotiate an option.
*/
*lenp = ucp - inp; /* Compute output length */
LCPDEBUG((LOG_INFO, "lcp_reqci: returning CONF%s.", CODENAME(rc)));
return (rc); /* Return final code */
}
/*
* lcp_up - LCP has come UP.
*
* Start UPAP, IPCP, etc.
*/
static void
lcp_up(f)
fsm *f;
{
lcp_options *wo = &lcp_wantoptions[f->unit];
lcp_options *ho = &lcp_hisoptions[f->unit];
lcp_options *go = &lcp_gotoptions[f->unit];
lcp_options *ao = &lcp_allowoptions[f->unit];
if (!go->neg_magicnumber)
go->magicnumber = 0;
if (!ho->neg_magicnumber)
ho->magicnumber = 0;
/*
* Set our MTU to the smaller of the MTU we wanted and
* the MRU our peer wanted. If we negotiated an MRU,
* set our MRU to the larger of value we wanted and
* the value we got in the negotiation.
*/
ppp_send_config(f->unit, MIN(ao->mru, (ho->neg_mru? ho->mru: MTU)),
(ho->neg_asyncmap? ho->asyncmap: 0xffffffff),
ho->neg_pcompression, ho->neg_accompression);
/*
* If the asyncmap hasn't been negotiated, we really should
* set the receive asyncmap to ffffffff, but we set it to 0
* for backwards contemptibility.
*/
ppp_recv_config(f->unit, (go->neg_mru? MAX(wo->mru, go->mru): MTU),
(go->neg_asyncmap? go->asyncmap: 0x00000000),
go->neg_pcompression, go->neg_accompression);
if (ho->neg_mru)
peer_mru[f->unit] = ho->mru;
ChapLowerUp(f->unit); /* Enable CHAP */
upap_lowerup(f->unit); /* Enable UPAP */
ipcp_lowerup(f->unit); /* Enable IPCP */
lcp_echo_lowerup(f->unit); /* Enable echo messages */
link_established(f->unit);
}
/*
* lcp_down - LCP has gone DOWN.
*
* Alert other protocols.
*/
static void
lcp_down(f)
fsm *f;
{
lcp_echo_lowerdown(f->unit);
ipcp_lowerdown(f->unit);
ChapLowerDown(f->unit);
upap_lowerdown(f->unit);
sifdown(f->unit);
ppp_send_config(f->unit, MTU, 0xffffffff, 0, 0);
ppp_recv_config(f->unit, MTU, 0x00000000, 0, 0);
peer_mru[f->unit] = MTU;
link_down(f->unit);
}
/*
* lcp_starting - LCP needs the lower layer up.
*/
static void
lcp_starting(f)
fsm *f;
{
link_required(f->unit);
}
/*
* lcp_finished - LCP has finished with the lower layer.
*/
static void
lcp_finished(f)
fsm *f;
{
link_terminated(f->unit);
}
/*
* lcp_printpkt - print the contents of an LCP packet.
*/
char *lcp_codenames[] = {
"ConfReq", "ConfAck", "ConfNak", "ConfRej",
"TermReq", "TermAck", "CodeRej", "ProtRej",
"EchoReq", "EchoRep", "DiscReq"
};
int
lcp_printpkt(p, plen, printer, arg)
u_char *p;
int plen;
void (*printer) __ARGS((void *, char *, ...));
void *arg;
{
int code, id, len, olen;
u_char *pstart, *optend;
u_short cishort;
u_long cilong;
if (plen < HEADERLEN)
return 0;
pstart = p;
GETCHAR(code, p);
GETCHAR(id, p);
GETSHORT(len, p);
if (len < HEADERLEN || len > plen)
return 0;
if (code >= 1 && code <= sizeof(lcp_codenames) / sizeof(char *))
printer(arg, " %s", lcp_codenames[code-1]);
else
printer(arg, " code=0x%x", code);
printer(arg, " id=0x%x", id);
len -= HEADERLEN;
switch (code) {
case CONFREQ:
case CONFACK:
case CONFNAK:
case CONFREJ:
/* print option list */
while (len >= 2) {
GETCHAR(code, p);
GETCHAR(olen, p);
p -= 2;
if (olen < 2 || olen > len) {
break;
}
printer(arg, " <");
len -= olen;
optend = p + olen;
switch (code) {
case CI_MRU:
if (olen == CILEN_SHORT) {
p += 2;
GETSHORT(cishort, p);
printer(arg, "mru %d", cishort);
}
break;
case CI_ASYNCMAP:
if (olen == CILEN_LONG) {
p += 2;
GETLONG(cilong, p);
printer(arg, "asyncmap 0x%x", cilong);
}
break;
case CI_AUTHTYPE:
if (olen >= CILEN_SHORT) {
p += 2;
printer(arg, "auth ");
GETSHORT(cishort, p);
switch (cishort) {
case UPAP:
printer(arg, "upap");
break;
case CHAP:
printer(arg, "chap");
break;
default:
printer(arg, "0x%x", cishort);
}
}
break;
case CI_QUALITY:
if (olen >= CILEN_SHORT) {
p += 2;
printer(arg, "quality ");
GETSHORT(cishort, p);
switch (cishort) {
case LQR:
printer(arg, "lqr");
break;
default:
printer(arg, "0x%x", cishort);
}
}
break;
case CI_MAGICNUMBER:
if (olen == CILEN_LONG) {
p += 2;
GETLONG(cilong, p);
printer(arg, "magic 0x%x", cilong);
}
break;
case CI_PCOMPRESSION:
if (olen == CILEN_VOID) {
p += 2;
printer(arg, "pcomp");
}
break;
case CI_ACCOMPRESSION:
if (olen == CILEN_VOID) {
p += 2;
printer(arg, "accomp");
}
break;
}
while (p < optend) {
GETCHAR(code, p);
printer(arg, " %.2x", code);
}
printer(arg, ">");
}
break;
}
/* print the rest of the bytes in the packet */
for (; len > 0; --len) {
GETCHAR(code, p);
printer(arg, " %.2x", code);
}
return p - pstart;
}
/*
* Time to shut down the link because there is nothing out there.
*/
static
void LcpLinkFailure (f)
fsm *f;
{
if (f->state == OPENED) {
syslog (LOG_NOTICE, "Excessive lack of response to LCP echo frames.");
lcp_lowerdown(f->unit); /* Reset connection */
}
}
/*
* Timer expired for the LCP echo requests from this process.
*/
static void
LcpEchoCheck (f)
fsm *f;
{
u_long delta;
#ifdef __linux__
struct ppp_ddinfo ddinfo;
u_long latest;
/*
* Read the time since the last packet was received.
*/
if (ioctl (fd, PPPIOCGTIME, &ddinfo) < 0) {
syslog (LOG_ERR, "ioctl(PPPIOCGTIME): %m");
die (1);
}
/*
* Choose the most recient frame received. It may be an IP or NON-IP frame.
*/
latest = ddinfo.nip_rjiffies < ddinfo.ip_rjiffies ? ddinfo.nip_rjiffies
: ddinfo.ip_rjiffies;
/*
* Compute the time since the last packet was received. If the timer
* has expired then send the echo request and reset the timer to maximum.
*/
delta = (lcp_echo_interval * HZ) - latest;
if (delta < HZ || latest < 0L) {
LcpSendEchoRequest (f);
delta = lcp_echo_interval * HZ;
}
delta /= HZ;
#else /* Other implementations do not have ability to find delta */
LcpSendEchoRequest (f);
delta = lcp_echo_interval;
#endif
/*
* Start the timer for the next interval.
*/
assert (lcp_echo_timer_running==0);
TIMEOUT (LcpEchoTimeout, (caddr_t) f, delta);
lcp_echo_timer_running = 1;
}
/*
* LcpEchoTimeout - Timer expired on the LCP echo
*/
static void
LcpEchoTimeout (arg)
caddr_t arg;
{
if (lcp_echo_timer_running != 0) {
lcp_echo_timer_running = 0;
LcpEchoCheck ((fsm *) arg);
}
}
/*
* LcpEchoReply - LCP has received a reply to the echo
*/
static void
lcp_received_echo_reply (f, id, inp, len)
fsm *f;
int id; u_char *inp; int len;
{
u_long magic;
/* Check the magic number - don't count replies from ourselves. */
if (len < CILEN_LONG)
return;
GETLONG(magic, inp);
if (lcp_gotoptions[f->unit].neg_magicnumber
&& magic == lcp_gotoptions[f->unit].magicnumber)
return;
/* Reset the number of outstanding echo frames */
lcp_echos_pending = 0;
}
/*
* LcpSendEchoRequest - Send an echo request frame to the peer
*/
static void
LcpSendEchoRequest (f)
fsm *f;
{
u_long lcp_magic;
u_char pkt[4], *pktp;
/*
* Detect the failure of the peer at this point.
*/
if (lcp_echo_fails != 0) {
if (lcp_echos_pending++ >= lcp_echo_fails) {
LcpLinkFailure(f);
lcp_echos_pending = 0;
}
}
/*
* Make and send the echo request frame.
*/
if (f->state == OPENED) {
lcp_magic = lcp_gotoptions[f->unit].neg_magicnumber
? lcp_gotoptions[f->unit].magicnumber
: 0L;
pktp = pkt;
PUTLONG(lcp_magic, pktp);
fsm_sdata(f, ECHOREQ,
lcp_echo_number++ & 0xFF, pkt, pktp - pkt);
}
}
/*
* lcp_echo_lowerup - Start the timer for the LCP frame
*/
static void
lcp_echo_lowerup (unit)
int unit;
{
fsm *f = &lcp_fsm[unit];
/* Clear the parameters for generating echo frames */
lcp_echos_pending = 0;
lcp_echo_number = 0;
lcp_echo_timer_running = 0;
/* If a timeout interval is specified then start the timer */
if (lcp_echo_interval != 0)
LcpEchoCheck (f);
}
/*
* lcp_echo_lowerdown - Stop the timer for the LCP frame
*/
static void
lcp_echo_lowerdown (unit)
int unit;
{
fsm *f = &lcp_fsm[unit];
if (lcp_echo_timer_running != 0) {
UNTIMEOUT (LcpEchoTimeout, (caddr_t) f);
lcp_echo_timer_running = 0;
}
}
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