xref: /freebsd/usr.sbin/ppp/proto.c (revision eda14cbc264d6969b02f2b1994cef11148e914f1)
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  * $FreeBSD$
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 
51 int
52 proto_WrapperOctets(struct lcp *lcp, u_short proto)
53 {
54   return (lcp->his_protocomp && !(proto & 0xff00)) ? 1 : 2;
55 }
56 
57 struct mbuf *
58 proto_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 
73 static struct mbuf *
74 proto_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 
86 static struct mbuf *
87 proto_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 
116 struct layer protolayer =
117   { LAYER_PROTO, "proto", proto_LayerPush, proto_LayerPull };
118