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 "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
acf_WrapperOctets(struct lcp * lcp,u_short proto)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 *
acf_LayerPush(struct bundle * b __unused,struct link * l,struct mbuf * bp,int pri __unused,u_short * proto)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 *
acf_LayerPull(struct bundle * b __unused,struct link * l,struct mbuf * bp,u_short * proto __unused)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 };
117