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      1 /*-
      2  * Copyright (c) 1999 Brian Somers <brian (at) Awfulhak.org>
      3  * All rights reserved.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions
      7  * are met:
      8  * 1. Redistributions of source code must retain the above copyright
      9  *    notice, this list of conditions and the following disclaimer.
     10  * 2. Redistributions in binary form must reproduce the above copyright
     11  *    notice, this list of conditions and the following disclaimer in the
     12  *    documentation and/or other materials provided with the distribution.
     13  *
     14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
     15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     24  * SUCH DAMAGE.
     25  *
     26  * $FreeBSD: src/usr.sbin/ppp/acf.c,v 1.7.26.1 2010/12/21 17:10:29 kensmith Exp $
     27  */
     28 
     29 #include <sys/types.h>
     30 
     31 #include <stdio.h>
     32 #include <termios.h>
     33 
     34 #include "defs.h"
     35 #include "layer.h"
     36 #include "timer.h"
     37 #include "fsm.h"
     38 #include "log.h"
     39 #include "mbuf.h"
     40 #include "acf.h"
     41 #include "proto.h"
     42 #include "throughput.h"
     43 #include "lqr.h"
     44 #include "hdlc.h"
     45 #include "lcp.h"
     46 #include "ccp.h"
     47 #include "link.h"
     48 #include "descriptor.h"
     49 #include "async.h"
     50 #include "physical.h"
     51 
     52 int
     53 acf_WrapperOctets(struct lcp *lcp, u_short proto)
     54 {
     55   return (proto == PROTO_LCP || lcp->his_acfcomp == 0) ? 2 : 0;
     56 }
     57 
     58 static struct mbuf *
     59 acf_LayerPush(struct bundle *b __unused, struct link *l, struct mbuf *bp,
     60               int pri __unused, u_short *proto)
     61 {
     62   const u_char cp[2] = { HDLC_ADDR, HDLC_UI };
     63 
     64   if (*proto == PROTO_LCP || l->lcp.his_acfcomp == 0) {
     65     bp = m_prepend(bp, cp, 2, 0);
     66     m_settype(bp, MB_ACFOUT);
     67   }
     68 
     69   return bp;
     70 }
     71 
     72 static struct mbuf *
     73 acf_LayerPull(struct bundle *b __unused, struct link *l, struct mbuf *bp,
     74 	      u_short *proto __unused)
     75 {
     76   struct physical *p = link2physical(l);
     77   u_char cp[2];
     78 
     79   if (!p) {
     80     log_Printf(LogERROR, "Can't Pull an acf packet from a logical link\n");
     81     return bp;
     82   }
     83 
     84   if (mbuf_View(bp, cp, 2) == 2) {
     85     if (!p->link.lcp.want_acfcomp) {
     86       /* We expect the packet not to be compressed */
     87       bp = mbuf_Read(bp, cp, 2);
     88       if (cp[0] != HDLC_ADDR) {
     89         p->hdlc.lqm.ifInErrors++;
     90         p->hdlc.stats.badaddr++;
     91         log_Printf(LogDEBUG, "acf_LayerPull: addr 0x%02x\n", cp[0]);
     92         m_freem(bp);
     93         return NULL;
     94       }
     95       if (cp[1] != HDLC_UI) {
     96         p->hdlc.lqm.ifInErrors++;
     97         p->hdlc.stats.badcommand++;
     98         log_Printf(LogDEBUG, "acf_LayerPull: control 0x%02x\n", cp[1]);
     99         m_freem(bp);
    100         return NULL;
    101       }
    102       m_settype(bp, MB_ACFIN);
    103     } else if (cp[0] == HDLC_ADDR && cp[1] == HDLC_UI) {
    104       /*
    105        * We can receive compressed packets, but the peer still sends
    106        * uncompressed packets (or maybe this is a PROTO_LCP packet) !
    107        */
    108       bp = mbuf_Read(bp, cp, 2);
    109       m_settype(bp, MB_ACFIN);
    110     }
    111   }
    112 
    113   return bp;
    114 }
    115 
    116 struct layer acflayer = { LAYER_ACF, "acf", acf_LayerPush, acf_LayerPull };
    117