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[/] [openrisc/] [trunk/] [rtos/] [rtems/] [c/] [src/] [libnetworking/] [pppd/] [fsm.c] - Rev 173
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/* * 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. */ #ifndef lint /* static char rcsid[] = "$Id: fsm.c,v 1.2 2001-09-27 12:01:57 chris Exp $"; */ #endif #define log_packet(p, len, prefix, level) /* * TODO: * Randomize fsm id on link/init. * Deal with variable outgoing MTU. */ #include <stdio.h> #include <string.h> #include <sys/types.h> #include <syslog.h> #include "pppd.h" #include "fsm.h" static void fsm_timeout __P((void *)); static void fsm_rconfreq __P((fsm *, int, 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) int peer_mru[NUM_PPP]; /* * fsm_init - Initialize fsm. * * Initialize fsm state. */ void fsm_init(f) 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(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; 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)); } } /* * 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, reason) fsm *f; char *reason; { f->term_reason = reason; f->term_reason_len = (reason == NULL? 0: strlen(reason)); 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 ) 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; } } /* * fsm_timeout - Timeout expired. */ static void fsm_timeout(arg) void *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, (u_char *) f->term_reason, f->term_reason_len); TIMEOUT(fsm_timeout, 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, 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_rconfreq - Receive Configure-Request. */ static void fsm_rconfreq(f, id, inp, len) fsm *f; u_char id; u_char *inp; int len; { int code, 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) { UNTIMEOUT(fsm_timeout, 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; int id; u_char *inp; int len; { FSMDEBUG((LOG_INFO, "fsm_rconfack(%s): Rcvd id %d.", PROTO_NAME(f), id)); if (id != f->reqid || f->seen_ack) /* Expected id? */ return; /* Nope, toss... */ if( !(f->callbacks->ackci? (*f->callbacks->ackci)(f, inp, len): (len == 0)) ){ /* Ack is bad - ignore it */ log_packet(inp, len, "Received bad configure-ack: ", LOG_ERR); FSMDEBUG((LOG_INFO, "%s: received bad Ack (length %d)", PROTO_NAME(f), len)); return; } f->seen_ack = 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 valid Ack? oh well... */ UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */ fsm_sconfreq(f, 0); f->state = REQSENT; break; case ACKSENT: UNTIMEOUT(fsm_timeout, 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) __P((fsm *, u_char *, int)); int ret; FSMDEBUG((LOG_INFO, "fsm_rconfnakrej(%s): Rcvd id %d.", PROTO_NAME(f), id)); if (id != f->reqid || f->seen_ack) /* Expected id? */ return; /* Nope, toss... */ proc = (code == CONFNAK)? f->callbacks->nakci: f->callbacks->rejci; if (!proc || !(ret = proc(f, inp, len))) { /* Nak/reject is bad - ignore it */ log_packet(inp, len, "Received bad configure-nak/rej: ", LOG_ERR); FSMDEBUG((LOG_INFO, "%s: received bad %s (length %d)", PROTO_NAME(f), (code==CONFNAK? "Nak": "reject"), len)); return; } f->seen_ack = 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 */ UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */ if (ret < 0) f->state = STOPPED; /* kludge for stopping CCP */ else fsm_sconfreq(f, 0); /* Send Configure-Request */ break; case ACKRCVD: /* Got a Nak/reject when we had already had an Ack?? oh well... */ UNTIMEOUT(fsm_timeout, f); /* Cancel timeout */ 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, p, len) fsm *f; int id; u_char *p; int len; { char str[80]; 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: if (len > 0) { fmtmsg(str, sizeof(str), "%0.*v", len, p); syslog(LOG_INFO, "%s terminated by peer (%s)", PROTO_NAME(f), str); } else syslog(LOG_INFO, "%s terminated by peer", PROTO_NAME(f)); if (f->callbacks->down) (*f->callbacks->down)(f); /* Inform upper layers */ f->retransmits = 0; f->state = STOPPING; TIMEOUT(fsm_timeout, 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: UNTIMEOUT(fsm_timeout, f); f->state = CLOSED; if( f->callbacks->finished ) (*f->callbacks->finished)(f); break; case STOPPING: UNTIMEOUT(fsm_timeout, f); 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: 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: case ACKSENT: UNTIMEOUT(fsm_timeout, 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, (u_char *) f->term_reason, f->term_reason_len); TIMEOUT(fsm_timeout, 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)); } } /* * fsm_sconfreq - Send a Configure-Request. */ static void fsm_sconfreq(f, retransmit) fsm *f; int retransmit; { u_char *outp; int cilen; 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; } f->seen_ack = 0; /* * Make up the request packet */ outp = outpacket_buf + PPP_HDRLEN + HEADERLEN; if( f->callbacks->cilen && f->callbacks->addci ){ cilen = (*f->callbacks->cilen)(f); if( cilen > peer_mru[f->unit] - HEADERLEN ) cilen = peer_mru[f->unit] - 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; TIMEOUT(fsm_timeout, 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 = outpacket_buf; if (datalen > peer_mru[f->unit] - 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); output(f->unit, outpacket_buf, outlen + PPP_HDRLEN); FSMDEBUG((LOG_INFO, "fsm_sdata(%s): Sent code %d, id %d.", PROTO_NAME(f), code, id)); }