📄 netfsm.c
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/*****************************************************************************
* netfsm.c - Network Control Protocol Finite State Machine program file.
*
* 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
*
* 97-12-01 Guy Lancaster <lancasterg@acm.org>, Global Election Systems Inc.
* Original based on BSD fsm.c.
*****************************************************************************/
/*
* fsm.c - {Link, IP} Control Protocol Finite State Machine.
*
* 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.
*/
/*
* TODO:
* Randomize fsm id on link/init.
* Deal with variable outgoing MTU.
*/
#include "netconf.h"
#include <string.h>
#include "net.h"
#include "nettimer.h"
#include "netbuf.h"
#include "netppp.h"
#include "netfsm.h"
#include <stdio.h>
#include "netdebug.h"
/*************************/
/*** LOCAL DEFINITIONS ***/
/*************************/
/************************/
/*** LOCAL DATA TYPES ***/
/************************/
/***********************************/
/*** LOCAL FUNCTION DECLARATIONS ***/
/***********************************/
static void fsm_timeout __P((void *));
static void fsm_rconfreq __P((fsm *, u_char, u_char *, int));
static void fsm_rconfack __P((fsm *, int, u_char *, int));
static void fsm_rconfnakrej __P((fsm *, int, int, u_char *, int));
static void fsm_rtermreq __P((fsm *, int, u_char *, int));
static void fsm_rtermack __P((fsm *));
static void fsm_rcoderej __P((fsm *, u_char *, int));
static void fsm_sconfreq __P((fsm *, int));
#define PROTO_NAME(f) ((f)->callbacks->proto_name)
/******************************/
/*** PUBLIC DATA STRUCTURES ***/
/******************************/
/*****************************/
/*** LOCAL DATA STRUCTURES ***/
/*****************************/
int peer_mru[NUM_PPP];
/***********************************/
/*** PUBLIC FUNCTION DEFINITIONS ***/
/***********************************/
/*
* fsm_init - Initialize fsm.
*
* Initialize fsm state.
*/
void fsm_init(fsm *f)
{
f->state = INITIAL;
f->flags = 0;
f->id = 0; /* XXX Start with random id? */
f->timeouttime = DEFTIMEOUT;
f->maxconfreqtransmits = DEFMAXCONFREQS;
f->maxtermtransmits = DEFMAXTERMREQS;
f->maxnakloops = DEFMAXNAKLOOPS;
f->term_reason_len = 0;
}
/*
* fsm_lowerup - The lower layer is up.
*/
void fsm_lowerup(fsm *f)
{
int oldState = f->state;
switch(oldState){ /***********修改osdState 取代 f->state******/
case INITIAL:
f->state = CLOSED;
break;
case STARTING:
if( f->flags & OPT_SILENT )
f->state = STOPPED;
else {
/* Send an initial configure-request */
fsm_sconfreq(f, 0);
f->state = REQSENT;
}
break;
default:
FSMDEBUG((LOG_INFO, "%s: Up event in state %d!",
PROTO_NAME(f), f->state));
}
FSMDEBUG((LOG_INFO, "%s: lowerup state %d -> %d",
PROTO_NAME(f), oldState, f->state));
}
/*
* fsm_lowerdown - The lower layer is down.
*
* Cancel all timeouts and inform upper layers.
*/
void fsm_lowerdown(fsm *f)
{
int oldState = f->state;
switch( oldState ){ /***********修改osdState 取代 f->state******/
case CLOSED:
f->state = INITIAL;
break;
case STOPPED:
f->state = STARTING;
if( f->callbacks->starting )
(*f->callbacks->starting)(f);
break;
case CLOSING:
f->state = INITIAL;
UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
break;
case STOPPING:
case REQSENT:
case ACKRCVD:
case ACKSENT:
f->state = STARTING;
UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
break;
case OPENED:
if( f->callbacks->down )
(*f->callbacks->down)(f);
f->state = STARTING;
break;
default:
FSMDEBUG((LOG_INFO, "%s: Down event in state %d!",
PROTO_NAME(f), f->state));
}
FSMDEBUG((LOG_INFO, "%s: lowerdown state %d -> %d",
PROTO_NAME(f), oldState, f->state));
}
/*
* fsm_open - Link is allowed to come up.
*/
void fsm_open(fsm *f)
{
int oldState = f->state;
switch( oldState ){ /***********修改osdState 取代 f->state******/
case INITIAL:
f->state = STARTING;
if( f->callbacks->starting )
(*f->callbacks->starting)(f);
break;
case CLOSED:
if( f->flags & OPT_SILENT )
f->state = STOPPED;
else {
/* Send an initial configure-request */
fsm_sconfreq(f, 0);
f->state = REQSENT;
}
break;
case CLOSING:
f->state = STOPPING;
/* fall through */
case STOPPED:
case OPENED:
if( f->flags & OPT_RESTART ){
fsm_lowerdown(f);
fsm_lowerup(f);
}
break;
}
FSMDEBUG((LOG_INFO, "%s: open state %d -> %d",
PROTO_NAME(f), oldState, f->state));
}
/*************************************************************************************************/
/*
* fsm_close - Start closing connection.
*
* Cancel timeouts and either initiate close or possibly go directly to
* the CLOSED state.
*/
void fsm_close(fsm *f, char *reason)
{
int oldState = f->state;
f->term_reason = reason;
f->term_reason_len = (reason == NULL? 0: strlen(reason));
switch( oldState ){ /***********修改osdState 取代 f->state******/
case STARTING:
f->state = INITIAL;
break;
case STOPPED:
f->state = CLOSED;
break;
case STOPPING:
f->state = CLOSING;
break;
case REQSENT:
case ACKRCVD:
case ACKSENT:
case OPENED:
if( f->state != OPENED )
UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
else if( f->callbacks->down )
(*f->callbacks->down)(f); /* Inform upper layers we're down */
/* Init restart counter, send Terminate-Request */
f->retransmits = f->maxtermtransmits;
fsm_sdata(f, TERMREQ, f->reqid = ++f->id, (u_char *) f->term_reason, f->term_reason_len);
TIMEOUT(fsm_timeout, f, f->timeouttime);
--f->retransmits;
f->state = CLOSING;
break;
}
FSMDEBUG((LOG_INFO, "%s: close reason=%s state %d -> %d",
PROTO_NAME(f), reason, oldState, f->state));
}
/**********************************************************************************************************/
/*
* fsm_sdata - Send some data.
*
* Used for all packets sent to our peer by this module.
*/
void fsm_sdata(
fsm *f,
u_char code,
u_char id,
u_char *data,
int datalen
)
{
u_char *outp;
int outlen;
/* Adjust length to be smaller than MTU */
outp = outpacket_buf[f->unit];
if (datalen > peer_mru[f->unit] - (int)HEADERLEN)
datalen = peer_mru[f->unit] - HEADERLEN;
if (datalen && data != outp + PPP_HDRLEN + HEADERLEN)
BCOPY(data, outp + PPP_HDRLEN + HEADERLEN, datalen);
outlen = datalen + HEADERLEN;
MAKEHEADER(outp, f->protocol);
PUTCHAR(code, outp);
PUTCHAR(id, outp);
PUTSHORT(outlen, outp);
pppWrite(f->unit, outpacket_buf[f->unit], outlen + PPP_HDRLEN);
FSMDEBUG((LOG_INFO, "fsm_sdata(%s): Sent code %d,%d,%d:%.40Z.",
PROTO_NAME(f), code, id, outlen,
&outpacket_buf[f->unit][PPP_HDRLEN + HEADERLEN]));
}
/*
* fsm_input - Input packet.
*/
void fsm_input(fsm *f, u_char *inpacket, int l)
{
u_char *inp = inpacket;
u_char code, id;
int len;
/*
* Parse header (code, id and length).
* If packet too short, drop it.
*/
if (l < HEADERLEN) {
FSMDEBUG((LOG_WARNING, "fsm_input(%x): Rcvd short header.",
f->protocol));
return;
}
GETCHAR(code, inp);
GETCHAR(id, inp);
GETSHORT(len, inp);
if (len < HEADERLEN) {
FSMDEBUG((LOG_INFO, "fsm_input(%x): Rcvd illegal length.",
f->protocol));
return;
}
if (len > l) {
FSMDEBUG((LOG_INFO, "fsm_input(%x): Rcvd short packet.",
f->protocol));
return;
}
len -= HEADERLEN; /* subtract header length */
if( f->state == INITIAL || f->state == STARTING ){
FSMDEBUG((LOG_INFO, "fsm_input(%x): Rcvd packet in state %d.",
f->protocol, f->state));
return;
}
FSMDEBUG((LOG_INFO, "fsm_input(%s):%d,%d,%d:%.40Z",
PROTO_NAME(f), code, id, l, inp));
/*
* Action depends on code.
*/
switch (code) {
case CONFREQ:
fsm_rconfreq(f, id, inp, len);
break;
case CONFACK:
fsm_rconfack(f, id, inp, len);
break;
case CONFNAK:
case CONFREJ:
fsm_rconfnakrej(f, code, id, inp, len);
break;
case TERMREQ:
fsm_rtermreq(f, id, inp, len);
break;
case TERMACK:
fsm_rtermack(f);
break;
case CODEREJ:
fsm_rcoderej(f, inp, len);
break;
default:
if( !f->callbacks->extcode
|| !(*f->callbacks->extcode)(f, code, id, inp, len) )
fsm_sdata(f, CODEREJ, ++f->id, inpacket, len + HEADERLEN);
break;
}
}
/*
* fsm_protreject - Peer doesn't speak this protocol.
*
* Treat this as a catastrophic error (RXJ-).
*/
void fsm_protreject(fsm *f)
{
switch( f->state ){
case CLOSING:
UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */
/* fall through */
case CLOSED:
f->state = CLOSED;
if( f->callbacks->finished )
(*f->callbacks->finished)(f);
break;
case STOPPING:
case REQSENT:
case ACKRCVD:
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