fsm.c
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上传日期:2007-01-17
资源大小:4983k
文件大小:17k
- /* fsm.c - {Link, IP} Control Protocol Finite State Machine */
- /* Copyright 1995 Wind River Systems, Inc. */
- #include "copyright_wrs.h"
- /*
- * 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.
- */
- /*
- modification history
- --------------------
- 01d,10sep98,sgv Added fix for interoperating with Windows
- 01c,16jun95,dzb header file consolidation.
- changed [UN]TIMEOUT macros to PPP_[UN]TIMEOUT.
- 01b,16jan95,dzb warnings cleanup.
- 01a,21dec94,dab VxWorks port - first WRS version.
- +dzb added: path for ppp header files, WRS copyright, strLib.h.
- */
- /*
- * TODO:
- * Deal with variable outgoing MTU.
- */
- #include "vxWorks.h"
- #include "stdio.h"
- #include "strLib.h"
- #include "sys/types.h"
- #include "socket.h"
- #include "net/if.h"
- #include "pppLib.h"
- extern char *proto_name();
- static void fsm_timeout __ARGS((caddr_t));
- static void fsm_rconfreq __ARGS((fsm *, int, u_char *, int));
- static void fsm_rconfack __ARGS((fsm *, int, u_char *, int));
- static void fsm_rconfnakrej __ARGS((fsm *, int, int, u_char *, int));
- static void fsm_rtermreq __ARGS((fsm *, int));
- static void fsm_rtermack __ARGS((fsm *));
- static void fsm_rcoderej __ARGS((fsm *, u_char *, int));
- static void fsm_sconfreq __ARGS((fsm *, int));
- #define PROTO_NAME(f) ((f)->callbacks->proto_name)
- /*
- * fsm_init - Initialize fsm.
- *
- * Initialize fsm state.
- */
- void
- fsm_init(f)
- fsm *f;
- {
- f->state = INITIAL;
- f->flags = 0;
- f->id = (u_char)random();
- f->timeouttime = DEFTIMEOUT;
- f->maxconfreqtransmits = DEFMAXCONFREQS;
- f->maxtermtransmits = DEFMAXTERMREQS;
- f->maxnakloops = DEFMAXNAKLOOPS;
- }
- /*
- * fsm_lowerup - The lower layer is up.
- */
- void
- fsm_lowerup(f)
- fsm *f;
- {
- switch( 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));
- }
- }
- /*
- * fsm_lowerdown - The lower layer is down.
- *
- * Cancel all timeouts and inform upper layers.
- */
- void
- fsm_lowerdown(f)
- fsm *f;
- {
- switch( 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;
- PPP_UNTIMEOUT(fsm_timeout, (caddr_t) f); /* Cancel timeout */
- break;
- case STOPPING:
- case REQSENT:
- case ACKRCVD:
- case ACKSENT:
- f->state = STARTING;
- PPP_UNTIMEOUT(fsm_timeout, (caddr_t) 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));
- }
- }
- /*
- * fsm_open - Link is allowed to come up.
- */
- void
- fsm_open(f)
- fsm *f;
- {
- switch( 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;
- }
- }
- /*
- * fsm_close - Start closing connection.
- *
- * Cancel timeouts and either initiate close or possibly go directly to
- * the CLOSED state.
- */
- void
- fsm_close(f)
- fsm *f;
- {
- switch( 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 )
- PPP_UNTIMEOUT(fsm_timeout, (caddr_t) 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, NULL, 0);
- PPP_TIMEOUT(fsm_timeout, (caddr_t) f, f->timeouttime);
- --f->retransmits;
- f->state = CLOSING;
- break;
- }
- }
- /*
- * fsm_timeout - Timeout expired.
- */
- static void
- fsm_timeout(arg)
- caddr_t arg;
- {
- fsm *f = (fsm *) arg;
- switch (f->state) {
- case CLOSING:
- case STOPPING:
- if( f->retransmits <= 0 ){
- /*
- * We've waited for an ack long enough. Peer probably heard us.
- */
- f->state = (f->state == CLOSING)? CLOSED: STOPPED;
- if( f->callbacks->finished )
- (*f->callbacks->finished)(f);
- } else {
- /* Send Terminate-Request */
- fsm_sdata(f, TERMREQ, f->reqid = ++f->id, NULL, 0);
- PPP_TIMEOUT(fsm_timeout, (caddr_t) f, f->timeouttime);
- --f->retransmits;
- }
- break;
- case REQSENT:
- case ACKRCVD:
- case ACKSENT:
- if (f->retransmits <= 0) {
- syslog(LOG_WARNING, "%s: timeout sending Config-Requests",
- PROTO_NAME(f));
- f->state = STOPPED;
- if( (f->flags & OPT_PASSIVE) == 0 && f->callbacks->finished )
- (*f->callbacks->finished)(f);
- } else {
- /* Retransmit the configure-request */
- if (f->callbacks->retransmit)
- (*f->callbacks->retransmit)(f);
- fsm_sconfreq(f, 1); /* Re-send Configure-Request */
- if( f->state == ACKRCVD )
- f->state = REQSENT;
- }
- break;
- default:
- FSMDEBUG((LOG_INFO, "%s: Timeout event in state %d!",
- PROTO_NAME(f), f->state));
- }
- }
- /*
- * fsm_input - Input packet.
- */
- void
- fsm_input(f, inpacket, l)
- fsm *f;
- u_char *inpacket;
- int l;
- {
- u_char *inp;
- u_char code, id;
- int len;
- /*
- * Parse header (code, id and length).
- * If packet too short, drop it.
- */
- inp = inpacket;
- 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;
- }
- /*
- * 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);
- 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_rconfreq - Receive Configure-Request.
- */
- static void
- fsm_rconfreq(f, id, inp, len)
- fsm *f;
- u_char id;
- u_char *inp;
- int len;
- {
- int code = 0, reject_if_disagree;
- FSMDEBUG((LOG_INFO, "fsm_rconfreq(%s): Rcvd id %d.", PROTO_NAME(f), id));
- switch( f->state ){
- case CLOSED:
- /* Go away, we're closed */
- fsm_sdata(f, TERMACK, id, NULL, 0);
- return;
- case CLOSING:
- case STOPPING:
- return;
- case OPENED:
- /* Go down and restart negotiation */
- if( f->callbacks->down )
- (*f->callbacks->down)(f); /* Inform upper layers */
- fsm_sconfreq(f, 0); /* Send initial Configure-Request */
- break;
- case STOPPED:
- /* Negotiation started by our peer */
- fsm_sconfreq(f, 0); /* Send initial Configure-Request */
- f->state = REQSENT;
- break;
- }
- /*
- * Pass the requested configuration options
- * to protocol-specific code for checking.
- */
- if (f->callbacks->reqci){ /* Check CI */
- reject_if_disagree = (f->nakloops >= f->maxnakloops);
- code = (*f->callbacks->reqci)(f, inp, &len, reject_if_disagree);
- } else if (len)
- code = CONFREJ; /* Reject all CI */
- else
- code = CONFACK;
- /* send the Ack, Nak or Rej to the peer */
- fsm_sdata(f, code, id, inp, len);
- if (code == CONFACK) {
- if (f->state == ACKRCVD) {
- PPP_UNTIMEOUT(fsm_timeout, (caddr_t) f); /* Cancel timeout */
- f->state = OPENED;
- if (f->callbacks->up)
- (*f->callbacks->up)(f); /* Inform upper layers */
- } else
- f->state = ACKSENT;
- f->nakloops = 0;
- } else {
- /* we sent CONFACK or CONFREJ */
- if (f->state != ACKRCVD)
- f->state = REQSENT;
- if( code == CONFNAK )
- ++f->nakloops;
- }
- }
- /*
- * fsm_rconfack - Receive Configure-Ack.
- */
- static void
- fsm_rconfack(f, id, inp, len)
- fsm *f;
- u_char id;
- u_char *inp;
- int len;
- {
- FSMDEBUG((LOG_INFO, "fsm_rconfack(%s): Rcvd id %d.",
- PROTO_NAME(f), id));
- if (id != f->reqid) /* Expected id? */
- return; /* Nope, toss... */
- if( !(f->callbacks->ackci? (*f->callbacks->ackci)(f, inp, len): (len == 0)) ){
- /* Ack is bad - ignore it */
- FSMDEBUG((LOG_INFO, "%s: received bad Ack (length %d)",
- PROTO_NAME(f), len));
- return;
- }
- f->reqid = -1;
- switch (f->state) {
- case CLOSED:
- case STOPPED:
- fsm_sdata(f, TERMACK, id, NULL, 0);
- break;
- case REQSENT:
- f->state = ACKRCVD;
- f->retransmits = f->maxconfreqtransmits;
- break;
- case ACKRCVD:
- /* Huh? an extra Ack? oh well... */
- fsm_sconfreq(f, 0);
- f->state = REQSENT;
- break;
- case ACKSENT:
- PPP_UNTIMEOUT(fsm_timeout, (caddr_t) f); /* Cancel timeout */
- f->state = OPENED;
- f->retransmits = f->maxconfreqtransmits;
- if (f->callbacks->up)
- (*f->callbacks->up)(f); /* Inform upper layers */
- break;
- case OPENED:
- /* Go down and restart negotiation */
- if (f->callbacks->down)
- (*f->callbacks->down)(f); /* Inform upper layers */
- fsm_sconfreq(f, 0); /* Send initial Configure-Request */
- f->state = REQSENT;
- break;
- }
- }
- /*
- * fsm_rconfnakrej - Receive Configure-Nak or Configure-Reject.
- */
- static void
- fsm_rconfnakrej(f, code, id, inp, len)
- fsm *f;
- int code, id;
- u_char *inp;
- int len;
- {
- int (*proc)();
- FSMDEBUG((LOG_INFO, "fsm_rconfnakrej(%s): Rcvd id %d.",
- PROTO_NAME(f), id));
- if (id != f->reqid) /* Expected id? */
- return; /* Nope, toss... */
- proc = (code == CONFNAK)? f->callbacks->nakci: f->callbacks->rejci;
- if( !proc || !proc(f, inp, len) ){
- /* Nak/reject is bad - ignore it */
- FSMDEBUG((LOG_INFO, "%s: received bad %s (length %d)",
- PROTO_NAME(f), (code==CONFNAK? "Nak": "reject"), len));
- return;
- }
- f->reqid = -1;
- switch (f->state) {
- case CLOSED:
- case STOPPED:
- fsm_sdata(f, TERMACK, id, NULL, 0);
- break;
- case REQSENT:
- case ACKSENT:
- /* They didn't agree to what we wanted - try another request */
- PPP_UNTIMEOUT(fsm_timeout, (caddr_t) f); /* Cancel timeout */
- fsm_sconfreq(f, 0); /* Send Configure-Request */
- break;
- case ACKRCVD:
- /* Got a Nak/reject when we had already had an Ack?? oh well... */
- fsm_sconfreq(f, 0);
- f->state = REQSENT;
- break;
- case OPENED:
- /* Go down and restart negotiation */
- if (f->callbacks->down)
- (*f->callbacks->down)(f); /* Inform upper layers */
- fsm_sconfreq(f, 0); /* Send initial Configure-Request */
- f->state = REQSENT;
- break;
- }
- }
- /*
- * fsm_rtermreq - Receive Terminate-Req.
- */
- static void
- fsm_rtermreq(f, id)
- fsm *f;
- int id;
- {
- FSMDEBUG((LOG_INFO, "fsm_rtermreq(%s): Rcvd id %d.",
- PROTO_NAME(f), id));
- switch (f->state) {
- case ACKRCVD:
- case ACKSENT:
- f->state = REQSENT; /* Start over but keep trying */
- break;
- case OPENED:
- syslog(LOG_INFO, "%s terminated at peer's request", PROTO_NAME(f));
- if (f->callbacks->down)
- (*f->callbacks->down)(f); /* Inform upper layers */
- f->retransmits = 0;
- f->state = STOPPING;
- PPP_TIMEOUT(fsm_timeout, (caddr_t) f, f->timeouttime);
- break;
- }
- fsm_sdata(f, TERMACK, id, NULL, 0);
- }
- /*
- * fsm_rtermack - Receive Terminate-Ack.
- */
- static void
- fsm_rtermack(f)
- fsm *f;
- {
- FSMDEBUG((LOG_INFO, "fsm_rtermack(%s).", PROTO_NAME(f)));
- switch (f->state) {
- case CLOSING:
- f->state = CLOSED;
- if( f->callbacks->finished )
- (*f->callbacks->finished)(f);
- break;
- case STOPPING:
- f->state = STOPPED;
- if( f->callbacks->finished )
- (*f->callbacks->finished)(f);
- break;
- case ACKRCVD:
- f->state = REQSENT;
- break;
- case OPENED:
- if (f->callbacks->down)
- (*f->callbacks->down)(f); /* Inform upper layers */
- fsm_sconfreq(f, 0);
- break;
- }
- }
- /*
- * fsm_rcoderej - Receive an Code-Reject.
- */
- static void
- fsm_rcoderej(f, inp, len)
- fsm *f;
- u_char *inp;
- int len;
- {
- u_char code, id;
- FSMDEBUG((LOG_INFO, "fsm_rcoderej(%s).", PROTO_NAME(f)));
- if (len < HEADERLEN) {
- FSMDEBUG((LOG_INFO, "fsm_rcoderej: Rcvd short Code-Reject packet!"));
- return;
- }
- GETCHAR(code, inp);
- GETCHAR(id, inp);
- syslog(LOG_WARNING, "%s: Rcvd Code-Reject for code %d, id %d",
- PROTO_NAME(f), code, id);
- if( f->state == ACKRCVD )
- f->state = REQSENT;
- }
- /*
- * fsm_protreject - Peer doesn't speak this protocol.
- *
- * Treat this as a catastrophic error (RXJ-).
- */
- void
- fsm_protreject(f)
- fsm *f;
- {
- switch( f->state ){
- case CLOSING:
- PPP_UNTIMEOUT(fsm_timeout, (caddr_t) 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:
- case ACKSENT:
- PPP_UNTIMEOUT(fsm_timeout, (caddr_t) f); /* Cancel timeout */
- /* fall through */
- case STOPPED:
- f->state = STOPPED;
- if( f->callbacks->finished )
- (*f->callbacks->finished)(f);
- break;
- case OPENED:
- if( f->callbacks->down )
- (*f->callbacks->down)(f);
- /* Init restart counter, send Terminate-Request */
- f->retransmits = f->maxtermtransmits;
- fsm_sdata(f, TERMREQ, f->reqid = ++f->id, NULL, 0);
- PPP_TIMEOUT(fsm_timeout, (caddr_t) f, f->timeouttime);
- --f->retransmits;
- f->state = STOPPING;
- break;
- default:
- FSMDEBUG((LOG_INFO, "%s: Protocol-reject event in state %d!",
- PROTO_NAME(f), f->state));
- }
- }
- extern struct ppp_softc *ppp_softc[ ];
- /*
- * fsm_sconfreq - Send a Configure-Request.
- */
- static void
- fsm_sconfreq(f, retransmit)
- fsm *f;
- int retransmit;
- {
- u_char *outp;
- int cilen;
- register struct ppp_softc *sc = ppp_softc[f->unit];
- if( f->state != REQSENT && f->state != ACKRCVD && f->state != ACKSENT ){
- /* Not currently negotiating - reset options */
- if( f->callbacks->resetci )
- (*f->callbacks->resetci)(f);
- f->nakloops = 0;
- }
- if( !retransmit ){
- /* New request - reset retransmission counter, use new ID */
- f->retransmits = f->maxconfreqtransmits;
- f->reqid = ++f->id;
- }
- /* Write the string "CLIENT" to the remote peer */
- if (((ppp_if[ppp_unit]->lcp_wantoptions.passive) == 1) ||
- (ppp_if[ppp_unit]->lcp_wantoptions.silent == 1))
- {
- char buf[7];
- strncpy(buf,"CLIENT",strlen("CLIENT"));
- output(f->unit, buf, strlen("CLIENT"));
- taskDelay(sysClkRateGet());
- }
- /*
- * Make up the request packet
- */
- outp = ppp_if[f->unit]->outpacket_buf + DLLHEADERLEN + HEADERLEN;
- if( f->callbacks->cilen && f->callbacks->addci ){
- cilen = (*f->callbacks->cilen)(f);
- if( cilen > ppp_if[f->unit]->peer_mru - HEADERLEN )
- cilen = ppp_if[f->unit]->peer_mru - HEADERLEN;
- if (f->callbacks->addci)
- (*f->callbacks->addci)(f, outp, &cilen);
- } else
- cilen = 0;
- /* send the request to our peer */
- fsm_sdata(f, CONFREQ, f->reqid, outp, cilen);
- /* start the retransmit timer */
- --f->retransmits;
- PPP_TIMEOUT(fsm_timeout, (caddr_t) f, f->timeouttime);
- FSMDEBUG((LOG_INFO, "%s: sending Configure-Request, id %d",
- PROTO_NAME(f), f->reqid));
- }
- /*
- * fsm_sdata - Send some data.
- *
- * Used for all packets sent to our peer by this module.
- */
- void
- fsm_sdata(f, code, id, data, datalen)
- fsm *f;
- u_char code, id;
- u_char *data;
- int datalen;
- {
- u_char *outp;
- int outlen;
- /* Adjust length to be smaller than MTU */
- outp = ppp_if[f->unit]->outpacket_buf;
- if (datalen > ppp_if[f->unit]->peer_mru - HEADERLEN)
- datalen = ppp_if[f->unit]->peer_mru - HEADERLEN;
- if (datalen && data != outp + DLLHEADERLEN + HEADERLEN)
- BCOPY((char *)data, (char *)(outp + DLLHEADERLEN + HEADERLEN), datalen);
- outlen = datalen + HEADERLEN;
- MAKEHEADER(outp, f->protocol);
- PUTCHAR(code, outp);
- PUTCHAR(id, outp);
- PUTSHORT(outlen, outp);
- output(f->unit, ppp_if[f->unit]->outpacket_buf, outlen + DLLHEADERLEN);
- FSMDEBUG((LOG_INFO, "fsm_sdata(%s): Sent code %d, id %d.",
- PROTO_NAME(f), code, id));
- }