usr.sbin/ppp/acf.c

   1 /*-
   2  * Copyright (c) 1999 Brian Somers <brian@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  * $FreeBSD$
  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 };