/****************************************************************************** lcp.c - Network Link Control Protocol program file.** Copyright (c) 2003 by Marc Boucher, Services Informatiques (MBSI) inc.* portions Copyright (c) 1997 by Global Election Systems Inc.** The authors hereby grant permission to use, copy, modify, distribute,* and license this software and its documentation for any purpose, provided* that existing copyright notices are retained in all copies and that this* notice and the following disclaimer are included verbatim in any * distributions. No written agreement, license, or royalty fee is required* for any of the authorized uses.** THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS *AS IS* AND ANY EXPRESS OR* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.******************************************************************************** REVISION HISTORY** 03-01-01 Marc Boucher <marc@mbsi.ca>*   Ported to lwIP.* 97-12-01 Guy Lancaster <lancasterg@acm.org>, Global Election Systems Inc.*	Original.*****************************************************************************//* * 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. */ #include <string.h> #include "ppp.h"#if PPP_SUPPORT > 0#include "fsm.h"#include "chap.h"#include "magic.h"#include "auth.h"#include "lcp.h"#include "pppdebug.h"/*************************//*** LOCAL DEFINITIONS ***//*************************//* * Length of each type of configuration option (in octets) */#define CILEN_VOID	2#define CILEN_CHAR	3#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 CILEN_CBCP	3/***********************************//*** LOCAL FUNCTION DECLARATIONS ***//***********************************//* * Callbacks for fsm code.  (CI = Configuration Information) */static void lcp_resetci (fsm*);	        /* Reset our CI */static int  lcp_cilen (fsm*);		        /* Return length of our CI */static void lcp_addci (fsm*, u_char*, int*);       /* Add our CI to pkt */static int  lcp_ackci (fsm*, u_char*, int);/* Peer ack'd our CI */static int  lcp_nakci (fsm*, u_char*, int);/* Peer nak'd our CI */static int  lcp_rejci (fsm*, u_char*, int);/* Peer rej'd our CI */static int  lcp_reqci (fsm*, u_char*, int*, int);  /* Rcv peer CI */static void lcp_up (fsm*);		            /* We're UP */static void lcp_down (fsm*);	    	    /* We're DOWN */static void lcp_starting (fsm*);   	    /* We need lower layer up */static void lcp_finished (fsm*);	        /* We need lower layer down */static int  lcp_extcode (fsm*, int, u_char, u_char*, int);static void lcp_rprotrej (fsm*, u_char*, int);/* * routines to send LCP echos to peer */static void lcp_echo_lowerup (int);static void lcp_echo_lowerdown (int);static void LcpEchoTimeout (void*);static void lcp_received_echo_reply (fsm*, int, u_char*, int);static void LcpSendEchoRequest (fsm*);static void LcpLinkFailure (fsm*);static void LcpEchoCheck (fsm*);/* * Protocol entry points. * Some of these are called directly. */static void lcp_input (int, u_char *, int);static void lcp_protrej (int);#define CODENAME(x)	((x) == CONFACK ? "ACK" : \			 (x) == CONFNAK ? "NAK" : "REJ")/******************************//*** PUBLIC DATA STRUCTURES ***//******************************//* global vars */LinkPhase lcp_phase[NUM_PPP];			/* Phase of link session (RFC 1661) */lcp_options lcp_wantoptions[NUM_PPP];	/* Options that we want to request */lcp_options lcp_gotoptions[NUM_PPP];	/* Options that peer ack'd */lcp_options lcp_allowoptions[NUM_PPP];	/* Options we allow peer to request */lcp_options lcp_hisoptions[NUM_PPP];	/* Options that we ack'd */ext_accm xmit_accm[NUM_PPP];			/* extended transmit ACCM *//*****************************//*** LOCAL DATA STRUCTURES ***//*****************************/static fsm lcp_fsm[NUM_PPP];			/* LCP fsm structure (global)*/static u_int	 lcp_echo_interval = LCP_ECHOINTERVAL; /* Interval between LCP echo-requests */static u_int	 lcp_echo_fails = LCP_MAXECHOFAILS; /* Tolerance to unanswered echo-requests */static u32_t lcp_echos_pending = 0;	/* Number of outstanding echo msgs */static u32_t lcp_echo_number   = 0;	/* ID number of next echo frame */static u32_t lcp_echo_timer_running = 0;  /* TRUE if a timer is running */static u_char nak_buffer[PPP_MRU];	/* where we construct a nak packet */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 */};struct protent lcp_protent = {    PPP_LCP,    lcp_init,    lcp_input,    lcp_protrej,    lcp_lowerup,    lcp_lowerdown,    lcp_open,    lcp_close,#if 0    lcp_printpkt,    NULL,#endif    1,    "LCP",#if 0    NULL,    NULL,    NULL#endif};int lcp_loopbackfail = DEFLOOPBACKFAIL;/***********************************//*** PUBLIC FUNCTION DEFINITIONS ***//***********************************//* * lcp_init - Initialize LCP. */void lcp_init(int unit){	fsm *f = &lcp_fsm[unit];	lcp_options *wo = &lcp_wantoptions[unit];	lcp_options *ao = &lcp_allowoptions[unit];		f->unit = unit;	f->protocol = PPP_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 = PPP_DEFMRU;	wo->neg_asyncmap = 1;	wo->asyncmap = 0x00000000l;	/* Assume don't need to escape any ctl chars. */	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 */	wo->neg_cbcp = 0;		ao->neg_mru = 1;	ao->mru = PPP_MAXMRU;	ao->neg_asyncmap = 1;	ao->asyncmap = 0x00000000l;	/* Assume don't need to escape any ctl chars. */	ao->neg_chap = (CHAP_SUPPORT != 0);	ao->chap_mdtype = CHAP_DIGEST_MD5;	ao->neg_upap = (PAP_SUPPORT != 0);	ao->neg_magicnumber = 1;	ao->neg_pcompression = 1;	ao->neg_accompression = 1;	ao->neg_lqr = 0;			/* no LQR implementation yet */	ao->neg_cbcp = (CBCP_SUPPORT != 0);	/* 	 * Set transmit escape for the flag and escape characters plus anything	 * set for the allowable options.	 */	memset(xmit_accm[unit], 0, sizeof(xmit_accm[0]));	xmit_accm[unit][15] = 0x60;	xmit_accm[unit][0] = (u_char)(ao->asyncmap & 0xFF);	xmit_accm[unit][1] = (u_char)((ao->asyncmap >> 8) & 0xFF);	xmit_accm[unit][2] = (u_char)((ao->asyncmap >> 16) & 0xFF);	xmit_accm[unit][3] = (u_char)((ao->asyncmap >> 24) & 0xFF);	LCPDEBUG((LOG_INFO, "lcp_init: xmit_accm=%X %X %X %X\n",				xmit_accm[unit][0],				xmit_accm[unit][1],				xmit_accm[unit][2],				xmit_accm[unit][3]));		lcp_phase[unit] = PHASE_INITIALIZE;}/* * lcp_open - LCP is allowed to come up. */void lcp_open(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_phase[unit] = PHASE_ESTABLISH; }/* * lcp_close - Take LCP down. */void lcp_close(int unit, char *reason){	fsm *f = &lcp_fsm[unit];		if (lcp_phase[unit] != PHASE_DEAD)		lcp_phase[unit] = PHASE_TERMINATE;	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 an		 * lcp_close() in passive/silent mode when a connection hasn't		 * been established.		 */		f->state = CLOSED;		lcp_finished(f);	}	else		fsm_close(&lcp_fsm[unit], reason);}/* * lcp_lowerup - The lower layer is up. */void lcp_lowerup(int unit){	lcp_options *wo = &lcp_wantoptions[unit];		/*	* Don't use A/C or protocol compression on transmission,	* but accept A/C and protocol compressed packets	* if we are going to ask for A/C and protocol compression.	*/	ppp_set_xaccm(unit, &xmit_accm[unit]);	ppp_send_config(unit, PPP_MRU, 0xffffffffl, 0, 0);	ppp_recv_config(unit, PPP_MRU, 0x00000000l,					wo->neg_pcompression, wo->neg_accompression);	peer_mru[unit] = PPP_MRU;	lcp_allowoptions[unit].asyncmap 		= (u_long)xmit_accm[unit][0]			| ((u_long)xmit_accm[unit][1] << 8)			| ((u_long)xmit_accm[unit][2] << 16)			| ((u_long)xmit_accm[unit][3] << 24);	LCPDEBUG((LOG_INFO, "lcp_lowerup: asyncmap=%X %X %X %X\n",				xmit_accm[unit][3],				xmit_accm[unit][2],				xmit_accm[unit][1],				xmit_accm[unit][0]));		fsm_lowerup(&lcp_fsm[unit]);}/* * lcp_lowerdown - The lower layer is down. */void lcp_lowerdown(int unit){	fsm_lowerdown(&lcp_fsm[unit]);}/* * lcp_sprotrej - Send a Protocol-Reject for some protocol. */void lcp_sprotrej(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.	*/	fsm_sdata(&lcp_fsm[unit], PROTREJ, ++lcp_fsm[unit].id,				p, len);}/**********************************//*** LOCAL FUNCTION DEFINITIONS ***//**********************************//* * lcp_input - Input LCP packet. */static void lcp_input(int unit, u_char *p, int len){	fsm *f = &lcp_fsm[unit];		fsm_input(f, p, len);}/* * lcp_extcode - Handle a LCP-specific code. */static int lcp_extcode(fsm *f, int code, u_char 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\n", id));		magp = inp;		PUTLONG(lcp_gotoptions[f->unit].magicnumber, magp);		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(fsm *f, u_char *inp, int len){	int i;	struct protent *protp;	u_short prot;		if (len < sizeof (u_short)) {		LCPDEBUG((LOG_INFO,				"lcp_rprotrej: Rcvd short Protocol-Reject packet!\n"));		return;	}		GETSHORT(prot, inp);		LCPDEBUG((LOG_INFO,			"lcp_rprotrej: Rcvd Protocol-Reject packet for %x!\n",			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\n",				f->state));		return;	}		/*	* Upcall the proper Protocol-Reject routine.	*/	for (i = 0; (protp = ppp_protocols[i]) != NULL; ++i)		if (protp->protocol == prot && protp->enabled_flag) {			(*protp->protrej)(f->unit);			return;		}		LCPDEBUG((LOG_WARNING, "Protocol-Reject for unsupported protocol 0x%x\n",			prot));}/* * lcp_protrej - A Protocol-Reject was received. */static void lcp_protrej(int unit){	(void)unit;	/*	* Can't reject LCP!	*/	LCPDEBUG((LOG_WARNING,			"lcp_protrej: Received Protocol-Reject for LCP!\n"));	fsm_protreject(&lcp_fsm[unit]);}/* * lcp_resetci - Reset our CI. */static void lcp_resetci(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] = PPP_MRU;	auth_reset(f->unit);}/* * lcp_cilen - Return length of our CI. */static int lcp_cilen(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)#define LENCICBCP(neg)	((neg) ? CILEN_CBCP: 0)	/*	* NB: we only ask for one of CHAP and UPAP, even if we will	* accept either.