proto.c revision 330449 
1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 1999 Brian Somers <brian@Awfulhak.org>
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: stable/11/usr.sbin/ppp/proto.c 330449 2018-03-05 07:26:05Z eadler $
29 */
30
31#include <sys/types.h>
32
33#include <stdio.h>
34#include <termios.h>
35
36#include "layer.h"
37#include "acf.h"
38#include "defs.h"
39#include "log.h"
40#include "timer.h"
41#include "fsm.h"
42#include "mbuf.h"
43#include "proto.h"
44#include "throughput.h"
45#include "lqr.h"
46#include "hdlc.h"
47#include "lcp.h"
48#include "ccp.h"
49#include "link.h"
50
51int
52proto_WrapperOctets(struct lcp *lcp, u_short proto)
53{
54  return (lcp->his_protocomp && !(proto & 0xff00)) ? 1 : 2;
55}
56
57struct mbuf *
58proto_Prepend(struct mbuf *bp, u_short proto, unsigned comp, int extra)
59{
60  u_char cp[2];
61
62  cp[0] = proto >> 8;
63  cp[1] = proto & 0xff;
64
65  if (comp && cp[0] == 0)
66    bp = m_prepend(bp, cp + 1, 1, extra);
67  else
68    bp = m_prepend(bp, cp, 2, extra);
69
70  return bp;
71}
72
73static struct mbuf *
74proto_LayerPush(struct bundle *b __unused, struct link *l, struct mbuf *bp,
75                int pri __unused, u_short *proto)
76{
77  log_Printf(LogDEBUG, "proto_LayerPush: Using 0x%04x\n", *proto);
78  bp = proto_Prepend(bp, *proto, l->lcp.his_protocomp,
79                     acf_WrapperOctets(&l->lcp, *proto));
80  m_settype(bp, MB_PROTOOUT);
81  link_ProtocolRecord(l, *proto, PROTO_OUT);
82
83  return bp;
84}
85
86static struct mbuf *
87proto_LayerPull(struct bundle *b __unused, struct link *l, struct mbuf *bp,
88                u_short *proto)
89{
90  u_char cp[2];
91  size_t got;
92
93  if ((got = mbuf_View(bp, cp, 2)) == 0) {
94    m_freem(bp);
95    return NULL;
96  }
97
98  *proto = cp[0];
99  if (!(*proto & 1)) {
100    if (got == 1) {
101      m_freem(bp);
102      return NULL;
103    }
104    bp = mbuf_Read(bp, cp, 2);
105    *proto = (*proto << 8) | cp[1];
106  } else
107    bp = mbuf_Read(bp, cp, 1);
108
109  log_Printf(LogDEBUG, "proto_LayerPull: unknown -> 0x%04x\n", *proto);
110  m_settype(bp, MB_PROTOIN);
111  link_ProtocolRecord(l, *proto, PROTO_IN);
112
113  return bp;
114}
115
116struct layer protolayer =
117  { LAYER_PROTO, "proto", proto_LayerPush, proto_LayerPull };
118