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authorThe Android Open Source Project <initial-contribution@android.com>2009-03-03 19:30:31 -0800
committerThe Android Open Source Project <initial-contribution@android.com>2009-03-03 19:30:31 -0800
commit8ad0dd2a5c5f23cd210aedba72a43e48026e7436 (patch)
treeb4293a1636331777f640f43f814667a9e1b0bbb7 /pppd/fsm.c
parent7ec1262af43ee60f9e61973439fce12a471b4f99 (diff)
downloadppp-8ad0dd2a5c5f23cd210aedba72a43e48026e7436.tar.gz
Diffstat (limited to 'pppd/fsm.c')
-rw-r--r--pppd/fsm.c817
1 files changed, 817 insertions, 0 deletions
diff --git a/pppd/fsm.c b/pppd/fsm.c
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--- /dev/null
+++ b/pppd/fsm.c
@@ -0,0 +1,817 @@
+/*
+ * fsm.c - {Link, IP} Control Protocol Finite State Machine.
+ *
+ * Copyright (c) 1984-2000 Carnegie Mellon University. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ *
+ * 3. The name "Carnegie Mellon University" must not be used to
+ * endorse or promote products derived from this software without
+ * prior written permission. For permission or any legal
+ * details, please contact
+ * Office of Technology Transfer
+ * Carnegie Mellon University
+ * 5000 Forbes Avenue
+ * Pittsburgh, PA 15213-3890
+ * (412) 268-4387, fax: (412) 268-7395
+ * tech-transfer@andrew.cmu.edu
+ *
+ * 4. Redistributions of any form whatsoever must retain the following
+ * acknowledgment:
+ * "This product includes software developed by Computing Services
+ * at Carnegie Mellon University (http://www.cmu.edu/computing/)."
+ *
+ * CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
+ * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
+ * FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
+ * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
+ * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#define RCSID "$Id: fsm.c,v 1.23 2004/11/13 02:28:15 paulus Exp $"
+
+/*
+ * TODO:
+ * Randomize fsm id on link/init.
+ * Deal with variable outgoing MTU.
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <sys/types.h>
+
+#include "pppd.h"
+#include "fsm.h"
+
+static const char rcsid[] = RCSID;
+
+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(("%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(("%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;
+ }
+}
+
+/*
+ * 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(f, nextstate)
+ fsm *f;
+ int nextstate;
+{
+ 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 and send Terminate-Request */
+ f->retransmits = f->maxtermtransmits;
+ fsm_sdata(f, TERMREQ, f->reqid = ++f->id,
+ (u_char *) f->term_reason, f->term_reason_len);
+
+ if (f->retransmits == 0) {
+ /*
+ * User asked for no terminate requests at all; just close it.
+ * We've already fired off one Terminate-Request just to be nice
+ * to the peer, but we're not going to wait for a reply.
+ */
+ f->state = nextstate == CLOSING ? CLOSED : STOPPED;
+ if( f->callbacks->finished )
+ (*f->callbacks->finished)(f);
+ return;
+ }
+
+ TIMEOUT(fsm_timeout, f, f->timeouttime);
+ --f->retransmits;
+
+ f->state = nextstate;
+}
+
+/*
+ * 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:
+ terminate_layer(f, 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) {
+ warn("%s: timeout sending Config-Requests\n", 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(("%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(("fsm_input(%x): Rcvd short header.", f->protocol));
+ return;
+ }
+ GETCHAR(code, inp);
+ GETCHAR(id, inp);
+ GETSHORT(len, inp);
+ if (len < HEADERLEN) {
+ FSMDEBUG(("fsm_input(%x): Rcvd illegal length.", f->protocol));
+ return;
+ }
+ if (len > l) {
+ FSMDEBUG(("fsm_input(%x): Rcvd short packet.", f->protocol));
+ return;
+ }
+ len -= HEADERLEN; /* subtract header length */
+
+ if( f->state == INITIAL || f->state == STARTING ){
+ FSMDEBUG(("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;
+
+ 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 */
+ f->state = REQSENT;
+ 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;
+{
+ 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 */
+ error("Received bad configure-ack: %P", inp, len);
+ return;
+ }
+ f->seen_ack = 1;
+ f->rnakloops = 0;
+
+ 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 ret;
+ int treat_as_reject;
+
+ if (id != f->reqid || f->seen_ack) /* Expected id? */
+ return; /* Nope, toss... */
+
+ if (code == CONFNAK) {
+ ++f->rnakloops;
+ treat_as_reject = (f->rnakloops >= f->maxnakloops);
+ if (f->callbacks->nakci == NULL
+ || !(ret = f->callbacks->nakci(f, inp, len, treat_as_reject))) {
+ error("Received bad configure-nak: %P", inp, len);
+ return;
+ }
+ } else {
+ f->rnakloops = 0;
+ if (f->callbacks->rejci == NULL
+ || !(ret = f->callbacks->rejci(f, inp, len))) {
+ error("Received bad configure-rej: %P", inp, 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;
+{
+ switch (f->state) {
+ case ACKRCVD:
+ case ACKSENT:
+ f->state = REQSENT; /* Start over but keep trying */
+ break;
+
+ case OPENED:
+ if (len > 0) {
+ info("%s terminated by peer (%0.*v)", PROTO_NAME(f), len, p);
+ } else
+ info("%s terminated by peer", PROTO_NAME(f));
+ f->retransmits = 0;
+ f->state = STOPPING;
+ if (f->callbacks->down)
+ (*f->callbacks->down)(f); /* Inform upper layers */
+ 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;
+{
+ 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);
+ f->state = REQSENT;
+ 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;
+
+ if (len < HEADERLEN) {
+ FSMDEBUG(("fsm_rcoderej: Rcvd short Code-Reject packet!"));
+ return;
+ }
+ GETCHAR(code, inp);
+ GETCHAR(id, inp);
+ warn("%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:
+ terminate_layer(f, STOPPING);
+ break;
+
+ default:
+ FSMDEBUG(("%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;
+ f->rnakloops = 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);
+}
+
+
+/*
+ * 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);
+}