xref: /freebsd/usr.sbin/ppp/acf.c (revision 2be1a816b9ff69588e55be0a84cbe2a31efc0f2f)
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  * $FreeBSD$
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
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 *
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 *
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