xref: /freebsd/usr.sbin/ppp/lqr.c (revision ae77177087c655fc883075af4f425b37e032cd05)
1 /*-
2  * Copyright (c) 1996 - 2001 Brian Somers <brian@Awfulhak.org>
3  *          based on work by Toshiharu OHNO <tony-o@iij.ad.jp>
4  *                           Internet Initiative Japan, Inc (IIJ)
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  *
28  * $FreeBSD$
29  */
30 
31 #include <sys/param.h>
32 
33 #ifdef __FreeBSD__
34 #include <netinet/in.h>
35 #endif
36 #include <sys/un.h>
37 
38 #include <string.h>
39 #include <termios.h>
40 
41 #include "layer.h"
42 #include "mbuf.h"
43 #include "log.h"
44 #include "defs.h"
45 #include "timer.h"
46 #include "fsm.h"
47 #include "acf.h"
48 #include "proto.h"
49 #include "lqr.h"
50 #include "hdlc.h"
51 #include "lcp.h"
52 #include "async.h"
53 #include "throughput.h"
54 #include "ccp.h"
55 #include "link.h"
56 #include "descriptor.h"
57 #include "physical.h"
58 #include "mp.h"
59 #include "chat.h"
60 #include "auth.h"
61 #include "chap.h"
62 #include "command.h"
63 #include "cbcp.h"
64 #include "datalink.h"
65 
66 struct echolqr {
67   u_int32_t magic;
68   u_int32_t signature;
69   u_int32_t sequence;
70 };
71 
72 #define	SIGNATURE  0x594e4f54
73 
74 static void
75 SendEchoReq(struct lcp *lcp)
76 {
77   struct hdlc *hdlc = &link2physical(lcp->fsm.link)->hdlc;
78   struct echolqr echo;
79 
80   echo.magic = htonl(lcp->want_magic);
81   echo.signature = htonl(SIGNATURE);
82   echo.sequence = htonl(hdlc->lqm.echo.seq_sent);
83   fsm_Output(&lcp->fsm, CODE_ECHOREQ, hdlc->lqm.echo.seq_sent++,
84             (u_char *)&echo, sizeof echo, MB_ECHOOUT);
85 }
86 
87 struct mbuf *
88 lqr_RecvEcho(struct fsm *fp, struct mbuf *bp)
89 {
90   struct hdlc *hdlc = &link2physical(fp->link)->hdlc;
91   struct lcp *lcp = fsm2lcp(fp);
92   struct echolqr lqr;
93 
94   if (m_length(bp) >= sizeof lqr) {
95     m_freem(mbuf_Read(bp, &lqr, sizeof lqr));
96     bp = NULL;
97     lqr.magic = ntohl(lqr.magic);
98     lqr.signature = ntohl(lqr.signature);
99     lqr.sequence = ntohl(lqr.sequence);
100 
101     /* Tolerate echo replies with either magic number */
102     if (lqr.magic != 0 && lqr.magic != lcp->his_magic &&
103         lqr.magic != lcp->want_magic) {
104       log_Printf(LogWARN, "%s: lqr_RecvEcho: Bad magic: expected 0x%08x,"
105                  " got 0x%08x\n", fp->link->name, lcp->his_magic, lqr.magic);
106       /*
107        * XXX: We should send a terminate request. But poor implementations may
108        *      die as a result.
109        */
110     }
111     if (lqr.signature == SIGNATURE) {
112       /* careful not to update lqm.echo.seq_recv with older values */
113       if ((hdlc->lqm.echo.seq_recv > (u_int32_t)0 - 5 && lqr.sequence < 5) ||
114           (hdlc->lqm.echo.seq_recv <= (u_int32_t)0 - 5 &&
115            lqr.sequence > hdlc->lqm.echo.seq_recv))
116         hdlc->lqm.echo.seq_recv = lqr.sequence;
117     } else
118       log_Printf(LogWARN, "lqr_RecvEcho: Got sig 0x%08lx, not 0x%08lx !\n",
119                 (u_long)lqr.signature, (u_long)SIGNATURE);
120   } else
121     log_Printf(LogWARN, "lqr_RecvEcho: Got packet size %zd, expecting %ld !\n",
122               m_length(bp), (long)sizeof(struct echolqr));
123   return bp;
124 }
125 
126 void
127 lqr_ChangeOrder(struct lqrdata *src, struct lqrdata *dst)
128 {
129   u_int32_t *sp, *dp;
130   unsigned n;
131 
132   sp = (u_int32_t *) src;
133   dp = (u_int32_t *) dst;
134   for (n = 0; n < sizeof(struct lqrdata) / sizeof(u_int32_t); n++, sp++, dp++)
135     *dp = ntohl(*sp);
136 }
137 
138 static void
139 SendLqrData(struct lcp *lcp)
140 {
141   struct mbuf *bp;
142   int extra;
143 
144   extra = proto_WrapperOctets(lcp, PROTO_LQR) +
145           acf_WrapperOctets(lcp, PROTO_LQR);
146   bp = m_get(sizeof(struct lqrdata) + extra, MB_LQROUT);
147   bp->m_len -= extra;
148   bp->m_offset += extra;
149 
150   /*
151    * Send on the highest priority queue.  We send garbage - the real data
152    * is written by lqr_LayerPush() where we know how to fill in all the
153    * fields.  Note, lqr_LayerPush() ``knows'' that we're pushing onto the
154    * highest priority queue, and factors out packet & octet values from
155    * other queues!
156    */
157   link_PushPacket(lcp->fsm.link, bp, lcp->fsm.bundle,
158                   LINK_QUEUES(lcp->fsm.link) - 1, PROTO_LQR);
159 }
160 
161 static void
162 SendLqrReport(void *v)
163 {
164   struct lcp *lcp = (struct lcp *)v;
165   struct physical *p = link2physical(lcp->fsm.link);
166 
167   timer_Stop(&p->hdlc.lqm.timer);
168 
169   if (p->hdlc.lqm.method & LQM_LQR) {
170     if (p->hdlc.lqm.lqr.resent > 5) {
171       /* XXX: Should implement LQM strategy */
172       log_Printf(LogPHASE, "%s: ** Too many LQR packets lost **\n",
173                 lcp->fsm.link->name);
174       log_Printf(LogLQM, "%s: Too many LQR packets lost\n",
175                 lcp->fsm.link->name);
176       p->hdlc.lqm.method = 0;
177       datalink_Down(p->dl, CLOSE_NORMAL);
178     } else {
179       SendLqrData(lcp);
180       p->hdlc.lqm.lqr.resent++;
181     }
182   } else if (p->hdlc.lqm.method & LQM_ECHO) {
183     if ((p->hdlc.lqm.echo.seq_sent > 5 &&
184          p->hdlc.lqm.echo.seq_sent - 5 > p->hdlc.lqm.echo.seq_recv) ||
185         (p->hdlc.lqm.echo.seq_sent <= 5 &&
186          p->hdlc.lqm.echo.seq_sent > p->hdlc.lqm.echo.seq_recv + 5)) {
187       log_Printf(LogPHASE, "%s: ** Too many LCP ECHO packets lost **\n",
188                 lcp->fsm.link->name);
189       log_Printf(LogLQM, "%s: Too many LCP ECHO packets lost\n",
190                 lcp->fsm.link->name);
191       p->hdlc.lqm.method = 0;
192       datalink_Down(p->dl, CLOSE_NORMAL);
193     } else
194       SendEchoReq(lcp);
195   }
196   if (p->hdlc.lqm.method && p->hdlc.lqm.timer.load)
197     timer_Start(&p->hdlc.lqm.timer);
198 }
199 
200 struct mbuf *
201 lqr_Input(struct bundle *bundle __unused, struct link *l, struct mbuf *bp)
202 {
203   struct physical *p = link2physical(l);
204   struct lcp *lcp = p->hdlc.lqm.owner;
205   int len;
206 
207   if (p == NULL) {
208     log_Printf(LogERROR, "lqr_Input: Not a physical link - dropped\n");
209     m_freem(bp);
210     return NULL;
211   }
212 
213   len = m_length(bp);
214   if (len != sizeof(struct lqrdata))
215     log_Printf(LogWARN, "lqr_Input: Got packet size %d, expecting %ld !\n",
216               len, (long)sizeof(struct lqrdata));
217   else if (!IsAccepted(l->lcp.cfg.lqr) && !(p->hdlc.lqm.method & LQM_LQR)) {
218     bp = m_pullup(proto_Prepend(bp, PROTO_LQR, 0, 0));
219     lcp_SendProtoRej(lcp, MBUF_CTOP(bp), bp->m_len);
220   } else {
221     struct lqrdata *lqr;
222 
223     bp = m_pullup(bp);
224     lqr = (struct lqrdata *)MBUF_CTOP(bp);
225     if (ntohl(lqr->MagicNumber) != lcp->his_magic)
226       log_Printf(LogWARN, "lqr_Input: magic 0x%08lx is wrong,"
227                  " expecting 0x%08lx\n",
228 		 (u_long)ntohl(lqr->MagicNumber), (u_long)lcp->his_magic);
229     else {
230       struct lqrdata lastlqr;
231 
232       memcpy(&lastlqr, &p->hdlc.lqm.lqr.peer, sizeof lastlqr);
233       lqr_ChangeOrder(lqr, &p->hdlc.lqm.lqr.peer);
234       lqr_Dump(l->name, "Input", &p->hdlc.lqm.lqr.peer);
235       /* we have received an LQR from our peer */
236       p->hdlc.lqm.lqr.resent = 0;
237 
238       /* Snapshot our state when the LQR packet was received */
239       memcpy(&p->hdlc.lqm.lqr.prevSave, &p->hdlc.lqm.lqr.Save,
240              sizeof p->hdlc.lqm.lqr.prevSave);
241       p->hdlc.lqm.lqr.Save.InLQRs = ++p->hdlc.lqm.lqr.InLQRs;
242       p->hdlc.lqm.lqr.Save.InPackets = p->hdlc.lqm.ifInUniPackets;
243       p->hdlc.lqm.lqr.Save.InDiscards = p->hdlc.lqm.ifInDiscards;
244       p->hdlc.lqm.lqr.Save.InErrors = p->hdlc.lqm.ifInErrors;
245       p->hdlc.lqm.lqr.Save.InOctets = p->hdlc.lqm.lqr.InGoodOctets;
246 
247       lqr_Analyse(&p->hdlc, &lastlqr, &p->hdlc.lqm.lqr.peer);
248 
249       /*
250        * Generate an LQR response if we're not running an LQR timer OR
251        * two successive LQR's PeerInLQRs are the same.
252        */
253       if (p->hdlc.lqm.timer.load == 0 || !(p->hdlc.lqm.method & LQM_LQR) ||
254           (lastlqr.PeerInLQRs &&
255            lastlqr.PeerInLQRs == p->hdlc.lqm.lqr.peer.PeerInLQRs))
256         SendLqrData(lcp);
257     }
258   }
259   m_freem(bp);
260   return NULL;
261 }
262 
263 /*
264  *  When LCP is reached to opened state, We'll start LQM activity.
265  */
266 static void
267 lqr_Setup(struct lcp *lcp)
268 {
269   struct physical *physical = link2physical(lcp->fsm.link);
270   int period;
271 
272   physical->hdlc.lqm.lqr.resent = 0;
273   physical->hdlc.lqm.echo.seq_sent = 0;
274   physical->hdlc.lqm.echo.seq_recv = 0;
275   memset(&physical->hdlc.lqm.lqr.peer, '\0',
276          sizeof physical->hdlc.lqm.lqr.peer);
277 
278   physical->hdlc.lqm.method = lcp->cfg.echo ? LQM_ECHO : 0;
279   if (IsEnabled(lcp->cfg.lqr) && !REJECTED(lcp, TY_QUALPROTO))
280     physical->hdlc.lqm.method |= LQM_LQR;
281   timer_Stop(&physical->hdlc.lqm.timer);
282 
283   physical->hdlc.lqm.lqr.peer_timeout = lcp->his_lqrperiod;
284   if (lcp->his_lqrperiod)
285     log_Printf(LogLQM, "%s: Expecting LQR every %d.%02d secs\n",
286               physical->link.name, lcp->his_lqrperiod / 100,
287               lcp->his_lqrperiod % 100);
288 
289   period = lcp->want_lqrperiod ?
290     lcp->want_lqrperiod : lcp->cfg.lqrperiod * 100;
291   physical->hdlc.lqm.timer.func = SendLqrReport;
292   physical->hdlc.lqm.timer.name = "lqm";
293   physical->hdlc.lqm.timer.arg = lcp;
294 
295   if (lcp->want_lqrperiod || physical->hdlc.lqm.method & LQM_ECHO) {
296     log_Printf(LogLQM, "%s: Will send %s every %d.%02d secs\n",
297               physical->link.name, lcp->want_lqrperiod ? "LQR" : "LCP ECHO",
298               period / 100, period % 100);
299     physical->hdlc.lqm.timer.load = period * SECTICKS / 100;
300   } else {
301     physical->hdlc.lqm.timer.load = 0;
302     if (!lcp->his_lqrperiod)
303       log_Printf(LogLQM, "%s: LQR/LCP ECHO not negotiated\n",
304                  physical->link.name);
305   }
306 }
307 
308 void
309 lqr_Start(struct lcp *lcp)
310 {
311   struct physical *p = link2physical(lcp->fsm.link);
312 
313   lqr_Setup(lcp);
314   if (p->hdlc.lqm.timer.load)
315     SendLqrReport(lcp);
316 }
317 
318 void
319 lqr_reStart(struct lcp *lcp)
320 {
321   struct physical *p = link2physical(lcp->fsm.link);
322 
323   lqr_Setup(lcp);
324   if (p->hdlc.lqm.timer.load)
325     timer_Start(&p->hdlc.lqm.timer);
326 }
327 
328 void
329 lqr_StopTimer(struct physical *physical)
330 {
331   timer_Stop(&physical->hdlc.lqm.timer);
332 }
333 
334 void
335 lqr_Stop(struct physical *physical, int method)
336 {
337   if (method == LQM_LQR)
338     log_Printf(LogLQM, "%s: Stop sending LQR, Use LCP ECHO instead.\n",
339                physical->link.name);
340   if (method == LQM_ECHO)
341     log_Printf(LogLQM, "%s: Stop sending LCP ECHO.\n",
342                physical->link.name);
343   physical->hdlc.lqm.method &= ~method;
344   if (physical->hdlc.lqm.method)
345     SendLqrReport(physical->hdlc.lqm.owner);
346   else
347     timer_Stop(&physical->hdlc.lqm.timer);
348 }
349 
350 void
351 lqr_Dump(const char *link, const char *message, const struct lqrdata *lqr)
352 {
353   if (log_IsKept(LogLQM)) {
354     log_Printf(LogLQM, "%s: %s:\n", link, message);
355     log_Printf(LogLQM, "  Magic:          %08x   LastOutLQRs:    %08x\n",
356 	      lqr->MagicNumber, lqr->LastOutLQRs);
357     log_Printf(LogLQM, "  LastOutPackets: %08x   LastOutOctets:  %08x\n",
358 	      lqr->LastOutPackets, lqr->LastOutOctets);
359     log_Printf(LogLQM, "  PeerInLQRs:     %08x   PeerInPackets:  %08x\n",
360 	      lqr->PeerInLQRs, lqr->PeerInPackets);
361     log_Printf(LogLQM, "  PeerInDiscards: %08x   PeerInErrors:   %08x\n",
362 	      lqr->PeerInDiscards, lqr->PeerInErrors);
363     log_Printf(LogLQM, "  PeerInOctets:   %08x   PeerOutLQRs:    %08x\n",
364 	      lqr->PeerInOctets, lqr->PeerOutLQRs);
365     log_Printf(LogLQM, "  PeerOutPackets: %08x   PeerOutOctets:  %08x\n",
366 	      lqr->PeerOutPackets, lqr->PeerOutOctets);
367   }
368 }
369 
370 void
371 lqr_Analyse(const struct hdlc *hdlc, const struct lqrdata *oldlqr,
372             const struct lqrdata *newlqr)
373 {
374   u_int32_t LQRs, transitLQRs, pkts, octets, disc, err;
375 
376   if (!newlqr->PeerInLQRs)	/* No analysis possible yet! */
377     return;
378 
379   log_Printf(LogLQM, "Analysis:\n");
380 
381   LQRs = (newlqr->LastOutLQRs - oldlqr->LastOutLQRs) -
382          (newlqr->PeerInLQRs - oldlqr->PeerInLQRs);
383   transitLQRs = hdlc->lqm.lqr.OutLQRs - newlqr->LastOutLQRs;
384   pkts = (newlqr->LastOutPackets - oldlqr->LastOutPackets) -
385          (newlqr->PeerInPackets - oldlqr->PeerInPackets);
386   octets = (newlqr->LastOutOctets - oldlqr->LastOutOctets) -
387            (newlqr->PeerInOctets - oldlqr->PeerInOctets);
388   log_Printf(LogLQM, "  Outbound lossage: %d LQR%s (%d en route), %d packet%s,"
389              " %d octet%s\n", (int)LQRs, LQRs == 1 ? "" : "s", (int)transitLQRs,
390 	     (int)pkts, pkts == 1 ? "" : "s",
391 	     (int)octets, octets == 1 ? "" : "s");
392 
393   pkts = (newlqr->PeerOutPackets - oldlqr->PeerOutPackets) -
394     (hdlc->lqm.lqr.Save.InPackets - hdlc->lqm.lqr.prevSave.InPackets);
395   octets = (newlqr->PeerOutOctets - oldlqr->PeerOutOctets) -
396     (hdlc->lqm.lqr.Save.InOctets - hdlc->lqm.lqr.prevSave.InOctets);
397   log_Printf(LogLQM, "  Inbound lossage: %d packet%s, %d octet%s\n",
398 	     (int)pkts, pkts == 1 ? "" : "s",
399 	     (int)octets, octets == 1 ? "" : "s");
400 
401   disc = newlqr->PeerInDiscards - oldlqr->PeerInDiscards;
402   err = newlqr->PeerInErrors - oldlqr->PeerInErrors;
403   if (disc && err)
404     log_Printf(LogLQM, "                   Likely due to both peer congestion"
405                " and physical errors\n");
406   else if (disc)
407     log_Printf(LogLQM, "                   Likely due to peer congestion\n");
408   else if (err)
409     log_Printf(LogLQM, "                   Likely due to physical errors\n");
410   else if (pkts)
411     log_Printf(LogLQM, "                   Likely due to transport "
412 	       "congestion\n");
413 }
414 
415 static struct mbuf *
416 lqr_LayerPush(struct bundle *b __unused, struct link *l, struct mbuf *bp,
417               int pri __unused, u_short *proto)
418 {
419   struct physical *p = link2physical(l);
420   int len, layer;
421 
422   if (!p) {
423     /* Oops - can't happen :-] */
424     m_freem(bp);
425     return NULL;
426   }
427 
428   bp = m_pullup(bp);
429   len = m_length(bp);
430 
431   /*-
432    * From rfc1989:
433    *
434    *  All octets which are included in the FCS calculation MUST be counted,
435    *  including the packet header, the information field, and any padding.
436    *  The FCS octets MUST also be counted, and one flag octet per frame
437    *  MUST be counted.  All other octets (such as additional flag
438    *  sequences, and escape bits or octets) MUST NOT be counted.
439    *
440    * As we're stacked higher than the HDLC layer (otherwise HDLC wouldn't be
441    * able to calculate the FCS), we must not forget about these additional
442    * bytes when we're asynchronous.
443    *
444    * We're also expecting to be stacked *before* the likes of the proto and
445    * acf layers (to avoid alignment issues), so deal with this too.
446    */
447 
448   p->hdlc.lqm.ifOutUniPackets++;
449   p->hdlc.lqm.ifOutOctets += len + 1;		/* plus 1 flag octet! */
450   for (layer = 0; layer < l->nlayers; layer++)
451     switch (l->layer[layer]->type) {
452       case LAYER_ACF:
453         p->hdlc.lqm.ifOutOctets += acf_WrapperOctets(&l->lcp, *proto);
454         break;
455       case LAYER_ASYNC:
456         /* Not included - see rfc1989 */
457         break;
458       case LAYER_HDLC:
459         p->hdlc.lqm.ifOutOctets += hdlc_WrapperOctets();
460         break;
461       case LAYER_LQR:
462         layer = l->nlayers;
463         break;
464       case LAYER_PROTO:
465         p->hdlc.lqm.ifOutOctets += proto_WrapperOctets(&l->lcp, *proto);
466         break;
467       case LAYER_SYNC:
468         /* Nothing to add on */
469         break;
470       default:
471         log_Printf(LogWARN, "Oops, don't know how to do octets for %s layer\n",
472                    l->layer[layer]->name);
473         break;
474     }
475 
476   if (*proto == PROTO_LQR) {
477     /* Overwrite the entire packet (created in SendLqrData()) */
478     struct lqrdata lqr;
479     size_t pending_pkts, pending_octets;
480 
481     p->hdlc.lqm.lqr.OutLQRs++;
482 
483     /*
484      * We need to compensate for the fact that we're pushing our data
485      * onto the highest priority queue by factoring out packet & octet
486      * values from other queues!
487      */
488     link_PendingLowPriorityData(l, &pending_pkts, &pending_octets);
489 
490     memset(&lqr, '\0', sizeof lqr);
491     lqr.MagicNumber = p->link.lcp.want_magic;
492     lqr.LastOutLQRs = p->hdlc.lqm.lqr.peer.PeerOutLQRs;
493     lqr.LastOutPackets = p->hdlc.lqm.lqr.peer.PeerOutPackets;
494     lqr.LastOutOctets = p->hdlc.lqm.lqr.peer.PeerOutOctets;
495     lqr.PeerInLQRs = p->hdlc.lqm.lqr.Save.InLQRs;
496     lqr.PeerInPackets = p->hdlc.lqm.lqr.Save.InPackets;
497     lqr.PeerInDiscards = p->hdlc.lqm.lqr.Save.InDiscards;
498     lqr.PeerInErrors = p->hdlc.lqm.lqr.Save.InErrors;
499     lqr.PeerInOctets = p->hdlc.lqm.lqr.Save.InOctets;
500     lqr.PeerOutLQRs = p->hdlc.lqm.lqr.OutLQRs;
501     lqr.PeerOutPackets = p->hdlc.lqm.ifOutUniPackets - pending_pkts;
502     /* Don't forget our ``flag'' octets.... */
503     lqr.PeerOutOctets = p->hdlc.lqm.ifOutOctets - pending_octets - pending_pkts;
504     lqr_Dump(l->name, "Output", &lqr);
505     lqr_ChangeOrder(&lqr, (struct lqrdata *)MBUF_CTOP(bp));
506   }
507 
508   return bp;
509 }
510 
511 static struct mbuf *
512 lqr_LayerPull(struct bundle *b __unused, struct link *l __unused,
513 	      struct mbuf *bp, u_short *proto)
514 {
515   /*
516    * This is the ``Rx'' process from rfc1989, although a part of it is
517    * actually performed by sync_LayerPull() & hdlc_LayerPull() so that
518    * our octet counts are correct.
519    */
520 
521   if (*proto == PROTO_LQR)
522     m_settype(bp, MB_LQRIN);
523   return bp;
524 }
525 
526 /*
527  * Statistics for pulled packets are recorded either in hdlc_PullPacket()
528  * or sync_PullPacket()
529  */
530 
531 struct layer lqrlayer = { LAYER_LQR, "lqr", lqr_LayerPush, lqr_LayerPull };
532