acf.c revision 46686 
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 *	$Id:$
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 "lcp.h"
43#include "throughput.h"
44#include "lqr.h"
45#include "hdlc.h"
46#include "ccp.h"
47#include "link.h"
48#include "descriptor.h"
49#include "async.h"
50#include "physical.h"
51
52int
53acf_WrapperOctets(struct lcp *lcp, u_short proto)
54{
55  return (proto == PROTO_LCP || lcp->his_acfcomp == 0) ? 2 : 0;
56}
57
58static struct mbuf *
59acf_LayerPush(struct bundle *b, struct link *l, struct mbuf *bp,
60              int pri, 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 = mbuf_Prepend(bp, cp, 2, 0);
66
67  return bp;
68}
69
70static struct mbuf *
71acf_LayerPull(struct bundle *b, struct link *l, struct mbuf *bp, u_short *proto)
72{
73  struct physical *p = link2physical(l);
74  u_char cp[2];
75
76  if (!p) {
77    log_Printf(LogERROR, "Can't Pull an acf packet from a logical link\n");
78    return bp;
79  }
80
81  if (mbuf_View(bp, cp, 2) == 2) {
82    if (!p->link.lcp.want_acfcomp) {
83      /* We expect the packet not to be compressed */
84      bp = mbuf_Read(bp, cp, 2);
85      if (cp[0] != HDLC_ADDR) {
86        p->hdlc.lqm.SaveInErrors++;
87        p->hdlc.stats.badaddr++;
88        log_Printf(LogDEBUG, "acf_LayerPull: addr 0x%02x\n", cp[0]);
89        mbuf_Free(bp);
90        return NULL;
91      }
92      if (cp[1] != HDLC_UI) {
93        p->hdlc.lqm.SaveInErrors++;
94        p->hdlc.stats.badcommand++;
95        log_Printf(LogDEBUG, "acf_LayerPull: control 0x%02x\n", cp[1]);
96        mbuf_Free(bp);
97        return NULL;
98      }
99    } else if (cp[0] == HDLC_ADDR && cp[1] == HDLC_UI) {
100      /*
101       * We can receive compressed packets, but the peer still sends
102       * uncompressed packets (or maybe this is a PROTO_LCP packet) !
103       */
104      bp = mbuf_Read(bp, cp, 2);
105    }
106  }
107
108  return bp;
109}
110
111struct layer acflayer = { LAYER_ACF, "acf", acf_LayerPush, acf_LayerPull };
112