Diff: netif/ppp/fsm.c

Revision:

0:51ac1d130fd4

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/netif/ppp/fsm.c	Fri Jun 22 09:25:39 2012 +0000
@@ -0,0 +1,890 @@
+/*****************************************************************************
+* fsm.c - Network Control Protocol Finite State Machine 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 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 "lwip/opt.h"
+
+#if PPP_SUPPORT /* don't build if not configured for use in lwipopts.h */
+
+#include "ppp.h"
+#include "pppdebug.h"
+
+#include "fsm.h"
+
+#include <string.h>
+
+#if PPP_DEBUG
+static const char *ppperr_strerr[] = {
+           "LS_INITIAL",  /* LS_INITIAL  0 */
+           "LS_STARTING", /* LS_STARTING 1 */
+           "LS_CLOSED",   /* LS_CLOSED   2 */
+           "LS_STOPPED",  /* LS_STOPPED  3 */
+           "LS_CLOSING",  /* LS_CLOSING  4 */
+           "LS_STOPPING", /* LS_STOPPING 5 */
+           "LS_REQSENT",  /* LS_REQSENT  6 */
+           "LS_ACKRCVD",  /* LS_ACKRCVD  7 */
+           "LS_ACKSENT",  /* LS_ACKSENT  8 */
+           "LS_OPENED"    /* LS_OPENED   9 */
+};
+#endif /* PPP_DEBUG */
+
+static void fsm_timeout (void *);
+static void fsm_rconfreq (fsm *, u_char, u_char *, int);
+static void fsm_rconfack (fsm *, int, u_char *, int);
+static void fsm_rconfnakrej (fsm *, int, int, u_char *, int);
+static void fsm_rtermreq (fsm *, int, u_char *, int);
+static void fsm_rtermack (fsm *);
+static void fsm_rcoderej (fsm *, u_char *, int);
+static void fsm_sconfreq (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(fsm *f)
+{
+  f->state = LS_INITIAL;
+  f->flags = 0;
+  f->id = 0;        /* XXX Start with random id? */
+  f->timeouttime = FSM_DEFTIMEOUT;
+  f->maxconfreqtransmits = FSM_DEFMAXCONFREQS;
+  f->maxtermtransmits = FSM_DEFMAXTERMREQS;
+  f->maxnakloops = FSM_DEFMAXNAKLOOPS;
+  f->term_reason_len = 0;
+}
+
+
+/*
+ * fsm_lowerup - The lower layer is up.
+ */
+void
+fsm_lowerup(fsm *f)
+{
+  int oldState = f->state;
+
+  LWIP_UNUSED_ARG(oldState);
+
+  switch( f->state ) {
+    case LS_INITIAL:
+      f->state = LS_CLOSED;
+      break;
+
+    case LS_STARTING:
+      if( f->flags & OPT_SILENT ) {
+        f->state = LS_STOPPED;
+      } else {
+        /* Send an initial configure-request */
+        fsm_sconfreq(f, 0);
+        f->state = LS_REQSENT;
+      }
+    break;
+
+    default:
+      FSMDEBUG(LOG_INFO, ("%s: Up event in state %d (%s)!\n",
+          PROTO_NAME(f), f->state, ppperr_strerr[f->state]));
+  }
+
+  FSMDEBUG(LOG_INFO, ("%s: lowerup state %d (%s) -> %d (%s)\n",
+      PROTO_NAME(f), oldState, ppperr_strerr[oldState], f->state, ppperr_strerr[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;
+
+  LWIP_UNUSED_ARG(oldState);
+
+  switch( f->state ) {
+    case LS_CLOSED:
+      f->state = LS_INITIAL;
+      break;
+
+    case LS_STOPPED:
+      f->state = LS_STARTING;
+      if( f->callbacks->starting ) {
+        (*f->callbacks->starting)(f);
+      }
+      break;
+
+    case LS_CLOSING:
+      f->state = LS_INITIAL;
+      UNTIMEOUT(fsm_timeout, f);  /* Cancel timeout */
+      break;
+
+    case LS_STOPPING:
+    case LS_REQSENT:
+    case LS_ACKRCVD:
+    case LS_ACKSENT:
+      f->state = LS_STARTING;
+      UNTIMEOUT(fsm_timeout, f);  /* Cancel timeout */
+      break;
+
+    case LS_OPENED:
+      if( f->callbacks->down ) {
+        (*f->callbacks->down)(f);
+      }
+      f->state = LS_STARTING;
+      break;
+
+    default:
+      FSMDEBUG(LOG_INFO, ("%s: Down event in state %d (%s)!\n",
+          PROTO_NAME(f), f->state, ppperr_strerr[f->state]));
+  }
+
+  FSMDEBUG(LOG_INFO, ("%s: lowerdown state %d (%s) -> %d (%s)\n",
+      PROTO_NAME(f), oldState, ppperr_strerr[oldState], f->state, ppperr_strerr[f->state]));
+}
+
+
+/*
+ * fsm_open - Link is allowed to come up.
+ */
+void
+fsm_open(fsm *f)
+{
+  int oldState = f->state;
+
+  LWIP_UNUSED_ARG(oldState);
+
+  switch( f->state ) {
+    case LS_INITIAL:
+      f->state = LS_STARTING;
+      if( f->callbacks->starting ) {
+        (*f->callbacks->starting)(f);
+      }
+      break;
+
+    case LS_CLOSED:
+      if( f->flags & OPT_SILENT ) {
+        f->state = LS_STOPPED;
+      } else {
+        /* Send an initial configure-request */
+        fsm_sconfreq(f, 0);
+        f->state = LS_REQSENT;
+      }
+      break;
+  
+    case LS_CLOSING:
+      f->state = LS_STOPPING;
+      /* fall through */
+    case LS_STOPPED:
+    case LS_OPENED:
+      if( f->flags & OPT_RESTART ) {
+        fsm_lowerdown(f);
+        fsm_lowerup(f);
+      }
+      break;
+  }
+
+  FSMDEBUG(LOG_INFO, ("%s: open state %d (%s) -> %d (%s)\n",
+      PROTO_NAME(f), oldState, ppperr_strerr[oldState], f->state, ppperr_strerr[f->state]));
+}
+
+#if 0 /* backport pppd 2.4.4b1; */
+/*
+ * terminate_layer - Start process of shutting down the FSM
+ *
+ * Cancel any timeout running, notify upper layers we're done, and
+ * send a terminate-request message as configured.
+ */
+static void
+terminate_layer(fsm *f, int nextstate)
+{
+  /* @todo */
+}
+#endif
+
+/*
+ * fsm_close - Start closing connection.
+ *
+ * Cancel timeouts and either initiate close or possibly go directly to
+ * the LS_CLOSED state.
+ */
+void
+fsm_close(fsm *f, char *reason)
+{
+  int oldState = f->state;
+
+  LWIP_UNUSED_ARG(oldState);
+
+  f->term_reason = reason;
+  f->term_reason_len = (reason == NULL ? 0 : (int)strlen(reason));
+  switch( f->state ) {
+    case LS_STARTING:
+      f->state = LS_INITIAL;
+      break;
+    case LS_STOPPED:
+      f->state = LS_CLOSED;
+      break;
+    case LS_STOPPING:
+      f->state = LS_CLOSING;
+      break;
+
+    case LS_REQSENT:
+    case LS_ACKRCVD:
+    case LS_ACKSENT:
+    case LS_OPENED:
+      if( f->state != LS_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 = LS_CLOSING;
+      break;
+  }
+
+  FSMDEBUG(LOG_INFO, ("%s: close reason=%s state %d (%s) -> %d (%s)\n",
+      PROTO_NAME(f), reason, oldState, ppperr_strerr[oldState], f->state, ppperr_strerr[f->state]));
+}
+
+
+/*
+ * fsm_timeout - Timeout expired.
+ */
+static void
+fsm_timeout(void *arg)
+{
+  fsm *f = (fsm *) arg;
+
+  switch (f->state) {
+    case LS_CLOSING:
+    case LS_STOPPING:
+      if( f->retransmits <= 0 ) {
+        FSMDEBUG(LOG_WARNING, ("%s: timeout sending Terminate-Request state=%d (%s)\n",
+             PROTO_NAME(f), f->state, ppperr_strerr[f->state]));
+        /*
+         * We've waited for an ack long enough.  Peer probably heard us.
+         */
+        f->state = (f->state == LS_CLOSING)? LS_CLOSED: LS_STOPPED;
+        if( f->callbacks->finished ) {
+          (*f->callbacks->finished)(f);
+        }
+      } else {
+        FSMDEBUG(LOG_WARNING, ("%s: timeout resending Terminate-Requests state=%d (%s)\n",
+             PROTO_NAME(f), f->state, ppperr_strerr[f->state]));
+        /* 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 LS_REQSENT:
+    case LS_ACKRCVD:
+    case LS_ACKSENT:
+      if (f->retransmits <= 0) {
+        FSMDEBUG(LOG_WARNING, ("%s: timeout sending Config-Requests state=%d (%s)\n",
+         PROTO_NAME(f), f->state, ppperr_strerr[f->state]));
+        f->state = LS_STOPPED;
+        if( (f->flags & OPT_PASSIVE) == 0 && f->callbacks->finished ) {
+          (*f->callbacks->finished)(f);
+        }
+      } else {
+        FSMDEBUG(LOG_WARNING, ("%s: timeout resending Config-Request state=%d (%s)\n",
+         PROTO_NAME(f), f->state, ppperr_strerr[f->state]));
+        /* Retransmit the configure-request */
+        if (f->callbacks->retransmit) {
+          (*f->callbacks->retransmit)(f);
+        }
+        fsm_sconfreq(f, 1);    /* Re-send Configure-Request */
+        if( f->state == LS_ACKRCVD ) {
+          f->state = LS_REQSENT;
+        }
+      }
+      break;
+
+    default:
+      FSMDEBUG(LOG_INFO, ("%s: UNHANDLED timeout event in state %d (%s)!\n",
+          PROTO_NAME(f), f->state, ppperr_strerr[f->state]));
+  }
+}
+
+
+/*
+ * 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.\n",
+          f->protocol));
+    return;
+  }
+  GETCHAR(code, inp);
+  GETCHAR(id, inp);
+  GETSHORT(len, inp);
+  if (len < HEADERLEN) {
+    FSMDEBUG(LOG_INFO, ("fsm_input(%x): Rcvd illegal length.\n",
+        f->protocol));
+    return;
+  }
+  if (len > l) {
+    FSMDEBUG(LOG_INFO, ("fsm_input(%x): Rcvd short packet.\n",
+        f->protocol));
+    return;
+  }
+  len -= HEADERLEN;    /* subtract header length */
+
+  if( f->state == LS_INITIAL || f->state == LS_STARTING ) {
+    FSMDEBUG(LOG_INFO, ("fsm_input(%x): Rcvd packet in state %d (%s).\n",
+        f->protocol, f->state, ppperr_strerr[f->state]));
+    return;
+  }
+  FSMDEBUG(LOG_INFO, ("fsm_input(%s):%d,%d,%d\n", PROTO_NAME(f), code, id, l));
+  /*
+   * 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:
+      FSMDEBUG(LOG_INFO, ("fsm_input(%s): default: \n", PROTO_NAME(f)));
+      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(fsm *f, u_char id, u_char *inp, int len)
+{
+  int code, reject_if_disagree;
+
+  FSMDEBUG(LOG_INFO, ("fsm_rconfreq(%s): Rcvd id %d state=%d (%s)\n", 
+        PROTO_NAME(f), id, f->state, ppperr_strerr[f->state]));
+  switch( f->state ) {
+    case LS_CLOSED:
+      /* Go away, we're closed */
+      fsm_sdata(f, TERMACK, id, NULL, 0);
+      return;
+    case LS_CLOSING:
+    case LS_STOPPING:
+      return;
+
+    case LS_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 LS_STOPPED:
+      /* Negotiation started by our peer */
+      fsm_sconfreq(f, 0);    /* Send initial Configure-Request */
+      f->state = LS_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, (u_char)code, id, inp, len);
+  
+  if (code == CONFACK) {
+    if (f->state == LS_ACKRCVD) {
+      UNTIMEOUT(fsm_timeout, f);  /* Cancel timeout */
+      f->state = LS_OPENED;
+      if (f->callbacks->up) {
+        (*f->callbacks->up)(f);  /* Inform upper layers */
+      }
+    } else {
+      f->state = LS_ACKSENT;
+    }
+    f->nakloops = 0;
+  } else {
+    /* we sent CONFACK or CONFREJ */
+    if (f->state != LS_ACKRCVD) {
+      f->state = LS_REQSENT;
+    }
+    if( code == CONFNAK ) {
+      ++f->nakloops;
+    }
+  }
+}
+
+
+/*
+ * fsm_rconfack - Receive Configure-Ack.
+ */
+static void
+fsm_rconfack(fsm *f, int id, u_char *inp, int len)
+{
+  FSMDEBUG(LOG_INFO, ("fsm_rconfack(%s): Rcvd id %d state=%d (%s)\n",
+        PROTO_NAME(f), id, f->state, ppperr_strerr[f->state]));
+  
+  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 */
+    FSMDEBUG(LOG_INFO, ("%s: received bad Ack (length %d)\n",
+          PROTO_NAME(f), len));
+    return;
+  }
+  f->seen_ack = 1;
+  
+  switch (f->state) {
+    case LS_CLOSED:
+    case LS_STOPPED:
+      fsm_sdata(f, TERMACK, (u_char)id, NULL, 0);
+      break;
+    
+    case LS_REQSENT:
+      f->state = LS_ACKRCVD;
+      f->retransmits = f->maxconfreqtransmits;
+      break;
+    
+    case LS_ACKRCVD:
+      /* Huh? an extra valid Ack? oh well... */
+      UNTIMEOUT(fsm_timeout, f);  /* Cancel timeout */
+      fsm_sconfreq(f, 0);
+      f->state = LS_REQSENT;
+      break;
+    
+    case LS_ACKSENT:
+      UNTIMEOUT(fsm_timeout, f);  /* Cancel timeout */
+      f->state = LS_OPENED;
+      f->retransmits = f->maxconfreqtransmits;
+      if (f->callbacks->up) {
+        (*f->callbacks->up)(f);  /* Inform upper layers */
+      }
+      break;
+    
+    case LS_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 = LS_REQSENT;
+      break;
+  }
+}
+
+
+/*
+ * fsm_rconfnakrej - Receive Configure-Nak or Configure-Reject.
+ */
+static void
+fsm_rconfnakrej(fsm *f, int code, int id, u_char *inp, int len)
+{
+  int (*proc) (fsm *, u_char *, int);
+  int ret;
+
+  FSMDEBUG(LOG_INFO, ("fsm_rconfnakrej(%s): Rcvd id %d state=%d (%s)\n",
+        PROTO_NAME(f), id, f->state, ppperr_strerr[f->state]));
+
+  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 */
+    FSMDEBUG(LOG_INFO, ("%s: received bad %s (length %d)\n",
+          PROTO_NAME(f), (code==CONFNAK? "Nak": "reject"), len));
+    return;
+  }
+  f->seen_ack = 1;
+
+  switch (f->state) {
+    case LS_CLOSED:
+    case LS_STOPPED:
+      fsm_sdata(f, TERMACK, (u_char)id, NULL, 0);
+      break;
+    
+    case LS_REQSENT:
+    case LS_ACKSENT:
+      /* They didn't agree to what we wanted - try another request */
+      UNTIMEOUT(fsm_timeout, f);  /* Cancel timeout */
+      if (ret < 0) {
+        f->state = LS_STOPPED;    /* kludge for stopping CCP */
+      } else {
+        fsm_sconfreq(f, 0);    /* Send Configure-Request */
+      }
+      break;
+    
+    case LS_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 = LS_REQSENT;
+      break;
+    
+    case LS_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 = LS_REQSENT;
+      break;
+  }
+}
+
+
+/*
+ * fsm_rtermreq - Receive Terminate-Req.
+ */
+static void
+fsm_rtermreq(fsm *f, int id, u_char *p, int len)
+{
+  LWIP_UNUSED_ARG(p);
+
+  FSMDEBUG(LOG_INFO, ("fsm_rtermreq(%s): Rcvd id %d state=%d (%s)\n",
+        PROTO_NAME(f), id, f->state, ppperr_strerr[f->state]));
+
+  switch (f->state) {
+    case LS_ACKRCVD:
+    case LS_ACKSENT:
+      f->state = LS_REQSENT;    /* Start over but keep trying */
+      break;
+
+    case LS_OPENED:
+      if (len > 0) {
+        FSMDEBUG(LOG_INFO, ("%s terminated by peer (%p)\n", PROTO_NAME(f), p));
+      } else {
+        FSMDEBUG(LOG_INFO, ("%s terminated by peer\n", PROTO_NAME(f)));
+      }
+      if (f->callbacks->down) {
+        (*f->callbacks->down)(f);  /* Inform upper layers */
+      }
+      f->retransmits = 0;
+      f->state = LS_STOPPING;
+      TIMEOUT(fsm_timeout, f, f->timeouttime);
+      break;
+  }
+
+  fsm_sdata(f, TERMACK, (u_char)id, NULL, 0);
+}
+
+
+/*
+ * fsm_rtermack - Receive Terminate-Ack.
+ */
+static void
+fsm_rtermack(fsm *f)
+{
+  FSMDEBUG(LOG_INFO, ("fsm_rtermack(%s): state=%d (%s)\n", 
+        PROTO_NAME(f), f->state, ppperr_strerr[f->state]));
+  
+  switch (f->state) {
+    case LS_CLOSING:
+      UNTIMEOUT(fsm_timeout, f);
+      f->state = LS_CLOSED;
+      if( f->callbacks->finished ) {
+        (*f->callbacks->finished)(f);
+      }
+      break;
+
+    case LS_STOPPING:
+      UNTIMEOUT(fsm_timeout, f);
+      f->state = LS_STOPPED;
+      if( f->callbacks->finished ) {
+        (*f->callbacks->finished)(f);
+      }
+      break;
+    
+    case LS_ACKRCVD:
+      f->state = LS_REQSENT;
+      break;
+    
+    case LS_OPENED:
+      if (f->callbacks->down) {
+        (*f->callbacks->down)(f);  /* Inform upper layers */
+      }
+      fsm_sconfreq(f, 0);
+      break;
+    default:
+      FSMDEBUG(LOG_INFO, ("fsm_rtermack(%s): UNHANDLED state=%d (%s)!!!\n", 
+                PROTO_NAME(f), f->state, ppperr_strerr[f->state]));
+  }
+}
+
+
+/*
+ * fsm_rcoderej - Receive an Code-Reject.
+ */
+static void
+fsm_rcoderej(fsm *f, u_char *inp, int len)
+{
+  u_char code, id;
+  
+  FSMDEBUG(LOG_INFO, ("fsm_rcoderej(%s): state=%d (%s)\n", 
+        PROTO_NAME(f), f->state, ppperr_strerr[f->state]));
+  
+  if (len < HEADERLEN) {
+    FSMDEBUG(LOG_INFO, ("fsm_rcoderej: Rcvd short Code-Reject packet!\n"));
+    return;
+  }
+  GETCHAR(code, inp);
+  GETCHAR(id, inp);
+  FSMDEBUG(LOG_WARNING, ("%s: Rcvd Code-Reject for code %d, id %d\n",
+        PROTO_NAME(f), code, id));
+  
+  if( f->state == LS_ACKRCVD ) {
+    f->state = LS_REQSENT;
+  }
+}
+
+
+/*
+ * fsm_protreject - Peer doesn't speak this protocol.
+ *
+ * Treat this as a catastrophic error (RXJ-).
+ */
+void
+fsm_protreject(fsm *f)
+{
+  switch( f->state ) {
+    case LS_CLOSING:
+      UNTIMEOUT(fsm_timeout, f);  /* Cancel timeout */
+      /* fall through */
+    case LS_CLOSED:
+      f->state = LS_CLOSED;
+      if( f->callbacks->finished ) {
+        (*f->callbacks->finished)(f);
+      }
+      break;
+
+    case LS_STOPPING:
+    case LS_REQSENT:
+    case LS_ACKRCVD:
+    case LS_ACKSENT:
+      UNTIMEOUT(fsm_timeout, f);  /* Cancel timeout */
+      /* fall through */
+    case LS_STOPPED:
+      f->state = LS_STOPPED;
+      if( f->callbacks->finished ) {
+        (*f->callbacks->finished)(f);
+      }
+      break;
+    
+    case LS_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 = LS_STOPPING;
+      break;
+    
+    default:
+      FSMDEBUG(LOG_INFO, ("%s: Protocol-reject event in state %d (%s)!\n",
+            PROTO_NAME(f), f->state, ppperr_strerr[f->state]));
+    }
+}
+
+
+/*
+ * fsm_sconfreq - Send a Configure-Request.
+ */
+static void
+fsm_sconfreq(fsm *f, int retransmit)
+{
+  u_char *outp;
+  int cilen;
+  
+  if( f->state != LS_REQSENT && f->state != LS_ACKRCVD && f->state != LS_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[f->unit] + PPP_HDRLEN + HEADERLEN;
+  if( f->callbacks->cilen && f->callbacks->addci ) {
+    cilen = (*f->callbacks->cilen)(f);
+    if( cilen > peer_mru[f->unit] - (int)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\n",
+        PROTO_NAME(f), f->reqid));
+}
+
+
+/*
+ * 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.\n",
+        PROTO_NAME(f), code, id, outlen));
+}
+
+#endif /* PPP_SUPPORT */