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