xref: /freebsd/usr.sbin/ppp/lqr.c (revision 9005607c8fa7317a759f1fc16cae4738f9a2fbb3)
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 	|| lqr.signature == lcp->want_magic) {			/* some implementations return the wrong magic */
113       /* careful not to update lqm.echo.seq_recv with older values */
114       if ((hdlc->lqm.echo.seq_recv > (u_int32_t)0 - 5 && lqr.sequence < 5) ||
115           (hdlc->lqm.echo.seq_recv <= (u_int32_t)0 - 5 &&
116            lqr.sequence > hdlc->lqm.echo.seq_recv))
117         hdlc->lqm.echo.seq_recv = lqr.sequence;
118     } else
119       log_Printf(LogWARN, "lqr_RecvEcho: Got sig 0x%08lx, not 0x%08lx !\n",
120                 (u_long)lqr.signature, (u_long)SIGNATURE);
121   } else
122     log_Printf(LogWARN, "lqr_RecvEcho: Got packet size %zd, expecting %ld !\n",
123               m_length(bp), (long)sizeof(struct echolqr));
124   return bp;
125 }
126 
127 void
128 lqr_ChangeOrder(struct lqrdata *src, struct lqrdata *dst)
129 {
130   u_int32_t *sp, *dp;
131   unsigned n;
132 
133   sp = (u_int32_t *) src;
134   dp = (u_int32_t *) dst;
135   for (n = 0; n < sizeof(struct lqrdata) / sizeof(u_int32_t); n++, sp++, dp++)
136     *dp = ntohl(*sp);
137 }
138 
139 static void
140 SendLqrData(struct lcp *lcp)
141 {
142   struct mbuf *bp;
143   int extra;
144 
145   extra = proto_WrapperOctets(lcp, PROTO_LQR) +
146           acf_WrapperOctets(lcp, PROTO_LQR);
147   bp = m_get(sizeof(struct lqrdata) + extra, MB_LQROUT);
148   bp->m_len -= extra;
149   bp->m_offset += extra;
150 
151   /*
152    * Send on the highest priority queue.  We send garbage - the real data
153    * is written by lqr_LayerPush() where we know how to fill in all the
154    * fields.  Note, lqr_LayerPush() ``knows'' that we're pushing onto the
155    * highest priority queue, and factors out packet & octet values from
156    * other queues!
157    */
158   link_PushPacket(lcp->fsm.link, bp, lcp->fsm.bundle,
159                   LINK_QUEUES(lcp->fsm.link) - 1, PROTO_LQR);
160 }
161 
162 static void
163 SendLqrReport(void *v)
164 {
165   struct lcp *lcp = (struct lcp *)v;
166   struct physical *p = link2physical(lcp->fsm.link);
167 
168   timer_Stop(&p->hdlc.lqm.timer);
169 
170   if (p->hdlc.lqm.method & LQM_LQR) {
171     if (p->hdlc.lqm.lqr.resent > 5) {
172       /* XXX: Should implement LQM strategy */
173       log_Printf(LogPHASE, "%s: ** Too many LQR packets lost **\n",
174                 lcp->fsm.link->name);
175       log_Printf(LogLQM, "%s: Too many LQR packets lost\n",
176                 lcp->fsm.link->name);
177       p->hdlc.lqm.method = 0;
178       datalink_Down(p->dl, CLOSE_NORMAL);
179     } else {
180       SendLqrData(lcp);
181       p->hdlc.lqm.lqr.resent++;
182     }
183   } else if (p->hdlc.lqm.method & LQM_ECHO) {
184     if ((p->hdlc.lqm.echo.seq_sent > 5 &&
185          p->hdlc.lqm.echo.seq_sent - 5 > p->hdlc.lqm.echo.seq_recv) ||
186         (p->hdlc.lqm.echo.seq_sent <= 5 &&
187          p->hdlc.lqm.echo.seq_sent > p->hdlc.lqm.echo.seq_recv + 5)) {
188       log_Printf(LogPHASE, "%s: ** Too many LCP ECHO packets lost **\n",
189                 lcp->fsm.link->name);
190       log_Printf(LogLQM, "%s: Too many LCP ECHO packets lost\n",
191                 lcp->fsm.link->name);
192       p->hdlc.lqm.method = 0;
193       datalink_Down(p->dl, CLOSE_NORMAL);
194     } else
195       SendEchoReq(lcp);
196   }
197   if (p->hdlc.lqm.method && p->hdlc.lqm.timer.load)
198     timer_Start(&p->hdlc.lqm.timer);
199 }
200 
201 struct mbuf *
202 lqr_Input(struct bundle *bundle __unused, struct link *l, struct mbuf *bp)
203 {
204   struct physical *p = link2physical(l);
205   struct lcp *lcp = p->hdlc.lqm.owner;
206   int len;
207 
208   if (p == NULL) {
209     log_Printf(LogERROR, "lqr_Input: Not a physical link - dropped\n");
210     m_freem(bp);
211     return NULL;
212   }
213 
214   len = m_length(bp);
215   if (len != sizeof(struct lqrdata))
216     log_Printf(LogWARN, "lqr_Input: Got packet size %d, expecting %ld !\n",
217               len, (long)sizeof(struct lqrdata));
218   else if (!IsAccepted(l->lcp.cfg.lqr) && !(p->hdlc.lqm.method & LQM_LQR)) {
219     bp = m_pullup(proto_Prepend(bp, PROTO_LQR, 0, 0));
220     lcp_SendProtoRej(lcp, MBUF_CTOP(bp), bp->m_len);
221   } else {
222     struct lqrdata *lqr;
223 
224     bp = m_pullup(bp);
225     lqr = (struct lqrdata *)MBUF_CTOP(bp);
226     if (ntohl(lqr->MagicNumber) != lcp->his_magic)
227       log_Printf(LogWARN, "lqr_Input: magic 0x%08lx is wrong,"
228                  " expecting 0x%08lx\n",
229 		 (u_long)ntohl(lqr->MagicNumber), (u_long)lcp->his_magic);
230     else {
231       struct lqrdata lastlqr;
232 
233       memcpy(&lastlqr, &p->hdlc.lqm.lqr.peer, sizeof lastlqr);
234       lqr_ChangeOrder(lqr, &p->hdlc.lqm.lqr.peer);
235       lqr_Dump(l->name, "Input", &p->hdlc.lqm.lqr.peer);
236       /* we have received an LQR from our peer */
237       p->hdlc.lqm.lqr.resent = 0;
238 
239       /* Snapshot our state when the LQR packet was received */
240       memcpy(&p->hdlc.lqm.lqr.prevSave, &p->hdlc.lqm.lqr.Save,
241              sizeof p->hdlc.lqm.lqr.prevSave);
242       p->hdlc.lqm.lqr.Save.InLQRs = ++p->hdlc.lqm.lqr.InLQRs;
243       p->hdlc.lqm.lqr.Save.InPackets = p->hdlc.lqm.ifInUniPackets;
244       p->hdlc.lqm.lqr.Save.InDiscards = p->hdlc.lqm.ifInDiscards;
245       p->hdlc.lqm.lqr.Save.InErrors = p->hdlc.lqm.ifInErrors;
246       p->hdlc.lqm.lqr.Save.InOctets = p->hdlc.lqm.lqr.InGoodOctets;
247 
248       lqr_Analyse(&p->hdlc, &lastlqr, &p->hdlc.lqm.lqr.peer);
249 
250       /*
251        * Generate an LQR response if we're not running an LQR timer OR
252        * two successive LQR's PeerInLQRs are the same.
253        */
254       if (p->hdlc.lqm.timer.load == 0 || !(p->hdlc.lqm.method & LQM_LQR) ||
255           (lastlqr.PeerInLQRs &&
256            lastlqr.PeerInLQRs == p->hdlc.lqm.lqr.peer.PeerInLQRs))
257         SendLqrData(lcp);
258     }
259   }
260   m_freem(bp);
261   return NULL;
262 }
263 
264 /*
265  *  When LCP is reached to opened state, We'll start LQM activity.
266  */
267 static void
268 lqr_Setup(struct lcp *lcp)
269 {
270   struct physical *physical = link2physical(lcp->fsm.link);
271   int period;
272 
273   physical->hdlc.lqm.lqr.resent = 0;
274   physical->hdlc.lqm.echo.seq_sent = 0;
275   physical->hdlc.lqm.echo.seq_recv = 0;
276   memset(&physical->hdlc.lqm.lqr.peer, '\0',
277          sizeof physical->hdlc.lqm.lqr.peer);
278 
279   physical->hdlc.lqm.method = lcp->cfg.echo ? LQM_ECHO : 0;
280   if (IsEnabled(lcp->cfg.lqr) && !REJECTED(lcp, TY_QUALPROTO))
281     physical->hdlc.lqm.method |= LQM_LQR;
282   timer_Stop(&physical->hdlc.lqm.timer);
283 
284   physical->hdlc.lqm.lqr.peer_timeout = lcp->his_lqrperiod;
285   if (lcp->his_lqrperiod)
286     log_Printf(LogLQM, "%s: Expecting LQR every %d.%02d secs\n",
287               physical->link.name, lcp->his_lqrperiod / 100,
288               lcp->his_lqrperiod % 100);
289 
290   period = lcp->want_lqrperiod ?
291     lcp->want_lqrperiod : lcp->cfg.lqrperiod * 100;
292   physical->hdlc.lqm.timer.func = SendLqrReport;
293   physical->hdlc.lqm.timer.name = "lqm";
294   physical->hdlc.lqm.timer.arg = lcp;
295 
296   if (lcp->want_lqrperiod || physical->hdlc.lqm.method & LQM_ECHO) {
297     log_Printf(LogLQM, "%s: Will send %s every %d.%02d secs\n",
298               physical->link.name, lcp->want_lqrperiod ? "LQR" : "LCP ECHO",
299               period / 100, period % 100);
300     physical->hdlc.lqm.timer.load = period * SECTICKS / 100;
301   } else {
302     physical->hdlc.lqm.timer.load = 0;
303     if (!lcp->his_lqrperiod)
304       log_Printf(LogLQM, "%s: LQR/LCP ECHO not negotiated\n",
305                  physical->link.name);
306   }
307 }
308 
309 void
310 lqr_Start(struct lcp *lcp)
311 {
312   struct physical *p = link2physical(lcp->fsm.link);
313 
314   lqr_Setup(lcp);
315   if (p->hdlc.lqm.timer.load)
316     SendLqrReport(lcp);
317 }
318 
319 void
320 lqr_reStart(struct lcp *lcp)
321 {
322   struct physical *p = link2physical(lcp->fsm.link);
323 
324   lqr_Setup(lcp);
325   if (p->hdlc.lqm.timer.load)
326     timer_Start(&p->hdlc.lqm.timer);
327 }
328 
329 void
330 lqr_StopTimer(struct physical *physical)
331 {
332   timer_Stop(&physical->hdlc.lqm.timer);
333 }
334 
335 void
336 lqr_Stop(struct physical *physical, int method)
337 {
338   if (method == LQM_LQR)
339     log_Printf(LogLQM, "%s: Stop sending LQR, Use LCP ECHO instead.\n",
340                physical->link.name);
341   if (method == LQM_ECHO)
342     log_Printf(LogLQM, "%s: Stop sending LCP ECHO.\n",
343                physical->link.name);
344   physical->hdlc.lqm.method &= ~method;
345   if (physical->hdlc.lqm.method)
346     SendLqrReport(physical->hdlc.lqm.owner);
347   else
348     timer_Stop(&physical->hdlc.lqm.timer);
349 }
350 
351 void
352 lqr_Dump(const char *link, const char *message, const struct lqrdata *lqr)
353 {
354   if (log_IsKept(LogLQM)) {
355     log_Printf(LogLQM, "%s: %s:\n", link, message);
356     log_Printf(LogLQM, "  Magic:          %08x   LastOutLQRs:    %08x\n",
357 	      lqr->MagicNumber, lqr->LastOutLQRs);
358     log_Printf(LogLQM, "  LastOutPackets: %08x   LastOutOctets:  %08x\n",
359 	      lqr->LastOutPackets, lqr->LastOutOctets);
360     log_Printf(LogLQM, "  PeerInLQRs:     %08x   PeerInPackets:  %08x\n",
361 	      lqr->PeerInLQRs, lqr->PeerInPackets);
362     log_Printf(LogLQM, "  PeerInDiscards: %08x   PeerInErrors:   %08x\n",
363 	      lqr->PeerInDiscards, lqr->PeerInErrors);
364     log_Printf(LogLQM, "  PeerInOctets:   %08x   PeerOutLQRs:    %08x\n",
365 	      lqr->PeerInOctets, lqr->PeerOutLQRs);
366     log_Printf(LogLQM, "  PeerOutPackets: %08x   PeerOutOctets:  %08x\n",
367 	      lqr->PeerOutPackets, lqr->PeerOutOctets);
368   }
369 }
370 
371 void
372 lqr_Analyse(const struct hdlc *hdlc, const struct lqrdata *oldlqr,
373             const struct lqrdata *newlqr)
374 {
375   u_int32_t LQRs, transitLQRs, pkts, octets, disc, err;
376 
377   if (!newlqr->PeerInLQRs)	/* No analysis possible yet! */
378     return;
379 
380   log_Printf(LogLQM, "Analysis:\n");
381 
382   LQRs = (newlqr->LastOutLQRs - oldlqr->LastOutLQRs) -
383          (newlqr->PeerInLQRs - oldlqr->PeerInLQRs);
384   transitLQRs = hdlc->lqm.lqr.OutLQRs - newlqr->LastOutLQRs;
385   pkts = (newlqr->LastOutPackets - oldlqr->LastOutPackets) -
386          (newlqr->PeerInPackets - oldlqr->PeerInPackets);
387   octets = (newlqr->LastOutOctets - oldlqr->LastOutOctets) -
388            (newlqr->PeerInOctets - oldlqr->PeerInOctets);
389   log_Printf(LogLQM, "  Outbound lossage: %d LQR%s (%d en route), %d packet%s,"
390              " %d octet%s\n", (int)LQRs, LQRs == 1 ? "" : "s", (int)transitLQRs,
391 	     (int)pkts, pkts == 1 ? "" : "s",
392 	     (int)octets, octets == 1 ? "" : "s");
393 
394   pkts = (newlqr->PeerOutPackets - oldlqr->PeerOutPackets) -
395     (hdlc->lqm.lqr.Save.InPackets - hdlc->lqm.lqr.prevSave.InPackets);
396   octets = (newlqr->PeerOutOctets - oldlqr->PeerOutOctets) -
397     (hdlc->lqm.lqr.Save.InOctets - hdlc->lqm.lqr.prevSave.InOctets);
398   log_Printf(LogLQM, "  Inbound lossage: %d packet%s, %d octet%s\n",
399 	     (int)pkts, pkts == 1 ? "" : "s",
400 	     (int)octets, octets == 1 ? "" : "s");
401 
402   disc = newlqr->PeerInDiscards - oldlqr->PeerInDiscards;
403   err = newlqr->PeerInErrors - oldlqr->PeerInErrors;
404   if (disc && err)
405     log_Printf(LogLQM, "                   Likely due to both peer congestion"
406                " and physical errors\n");
407   else if (disc)
408     log_Printf(LogLQM, "                   Likely due to peer congestion\n");
409   else if (err)
410     log_Printf(LogLQM, "                   Likely due to physical errors\n");
411   else if (pkts)
412     log_Printf(LogLQM, "                   Likely due to transport "
413 	       "congestion\n");
414 }
415 
416 static struct mbuf *
417 lqr_LayerPush(struct bundle *b __unused, struct link *l, struct mbuf *bp,
418               int pri __unused, u_short *proto)
419 {
420   struct physical *p = link2physical(l);
421   int len, layer;
422 
423   if (!p) {
424     /* Oops - can't happen :-] */
425     m_freem(bp);
426     return NULL;
427   }
428 
429   bp = m_pullup(bp);
430   len = m_length(bp);
431 
432   /*-
433    * From rfc1989:
434    *
435    *  All octets which are included in the FCS calculation MUST be counted,
436    *  including the packet header, the information field, and any padding.
437    *  The FCS octets MUST also be counted, and one flag octet per frame
438    *  MUST be counted.  All other octets (such as additional flag
439    *  sequences, and escape bits or octets) MUST NOT be counted.
440    *
441    * As we're stacked higher than the HDLC layer (otherwise HDLC wouldn't be
442    * able to calculate the FCS), we must not forget about these additional
443    * bytes when we're asynchronous.
444    *
445    * We're also expecting to be stacked *before* the likes of the proto and
446    * acf layers (to avoid alignment issues), so deal with this too.
447    */
448 
449   p->hdlc.lqm.ifOutUniPackets++;
450   p->hdlc.lqm.ifOutOctets += len + 1;		/* plus 1 flag octet! */
451   for (layer = 0; layer < l->nlayers; layer++)
452     switch (l->layer[layer]->type) {
453       case LAYER_ACF:
454         p->hdlc.lqm.ifOutOctets += acf_WrapperOctets(&l->lcp, *proto);
455         break;
456       case LAYER_ASYNC:
457         /* Not included - see rfc1989 */
458         break;
459       case LAYER_HDLC:
460         p->hdlc.lqm.ifOutOctets += hdlc_WrapperOctets();
461         break;
462       case LAYER_LQR:
463         layer = l->nlayers;
464         break;
465       case LAYER_PROTO:
466         p->hdlc.lqm.ifOutOctets += proto_WrapperOctets(&l->lcp, *proto);
467         break;
468       case LAYER_SYNC:
469         /* Nothing to add on */
470         break;
471       default:
472         log_Printf(LogWARN, "Oops, don't know how to do octets for %s layer\n",
473                    l->layer[layer]->name);
474         break;
475     }
476 
477   if (*proto == PROTO_LQR) {
478     /* Overwrite the entire packet (created in SendLqrData()) */
479     struct lqrdata lqr;
480     size_t pending_pkts, pending_octets;
481 
482     p->hdlc.lqm.lqr.OutLQRs++;
483 
484     /*
485      * We need to compensate for the fact that we're pushing our data
486      * onto the highest priority queue by factoring out packet & octet
487      * values from other queues!
488      */
489     link_PendingLowPriorityData(l, &pending_pkts, &pending_octets);
490 
491     memset(&lqr, '\0', sizeof lqr);
492     lqr.MagicNumber = p->link.lcp.want_magic;
493     lqr.LastOutLQRs = p->hdlc.lqm.lqr.peer.PeerOutLQRs;
494     lqr.LastOutPackets = p->hdlc.lqm.lqr.peer.PeerOutPackets;
495     lqr.LastOutOctets = p->hdlc.lqm.lqr.peer.PeerOutOctets;
496     lqr.PeerInLQRs = p->hdlc.lqm.lqr.Save.InLQRs;
497     lqr.PeerInPackets = p->hdlc.lqm.lqr.Save.InPackets;
498     lqr.PeerInDiscards = p->hdlc.lqm.lqr.Save.InDiscards;
499     lqr.PeerInErrors = p->hdlc.lqm.lqr.Save.InErrors;
500     lqr.PeerInOctets = p->hdlc.lqm.lqr.Save.InOctets;
501     lqr.PeerOutLQRs = p->hdlc.lqm.lqr.OutLQRs;
502     lqr.PeerOutPackets = p->hdlc.lqm.ifOutUniPackets - pending_pkts;
503     /* Don't forget our ``flag'' octets.... */
504     lqr.PeerOutOctets = p->hdlc.lqm.ifOutOctets - pending_octets - pending_pkts;
505     lqr_Dump(l->name, "Output", &lqr);
506     lqr_ChangeOrder(&lqr, (struct lqrdata *)MBUF_CTOP(bp));
507   }
508 
509   return bp;
510 }
511 
512 static struct mbuf *
513 lqr_LayerPull(struct bundle *b __unused, struct link *l __unused,
514 	      struct mbuf *bp, u_short *proto)
515 {
516   /*
517    * This is the ``Rx'' process from rfc1989, although a part of it is
518    * actually performed by sync_LayerPull() & hdlc_LayerPull() so that
519    * our octet counts are correct.
520    */
521 
522   if (*proto == PROTO_LQR)
523     m_settype(bp, MB_LQRIN);
524   return bp;
525 }
526 
527 /*
528  * Statistics for pulled packets are recorded either in hdlc_PullPacket()
529  * or sync_PullPacket()
530  */
531 
532 struct layer lqrlayer = { LAYER_LQR, "lqr", lqr_LayerPush, lqr_LayerPull };
533