xref: /freebsd/usr.sbin/ppp/vjcomp.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 1996 - 2001 Brian Somers <brian@Awfulhak.org>
5  *          based on work by Toshiharu OHNO <tony-o@iij.ad.jp>
6  *                           Internet Initiative Japan, Inc (IIJ)
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  *
30  * $FreeBSD$
31  */
32 
33 #include <sys/param.h>
34 #include <netinet/in.h>
35 #include <netinet/in_systm.h>
36 #include <netinet/ip.h>
37 #include <sys/socket.h>
38 #include <sys/un.h>
39 
40 #include <stdio.h>
41 #include <string.h>		/* strlen/memcpy */
42 #include <termios.h>
43 
44 #include "layer.h"
45 #include "mbuf.h"
46 #include "log.h"
47 #include "timer.h"
48 #include "fsm.h"
49 #include "proto.h"
50 #include "slcompress.h"
51 #include "lqr.h"
52 #include "hdlc.h"
53 #include "defs.h"
54 #include "iplist.h"
55 #include "throughput.h"
56 #include "ncpaddr.h"
57 #include "ipcp.h"
58 #include "lcp.h"
59 #include "ccp.h"
60 #include "link.h"
61 #include "filter.h"
62 #include "descriptor.h"
63 #include "mp.h"
64 #ifndef NORADIUS
65 #include "radius.h"
66 #endif
67 #include "ipv6cp.h"
68 #include "ncp.h"
69 #include "bundle.h"
70 #include "vjcomp.h"
71 
72 #define MAX_VJHEADER 16		/* Maximum size of compressed header */
73 
74 static struct mbuf *
75 vj_LayerPush(struct bundle *bundle, struct link *l __unused, struct mbuf *bp,
76 	     int pri __unused, u_short *proto)
77 {
78   int type;
79   struct ip *pip;
80   u_short cproto = bundle->ncp.ipcp.peer_compproto >> 16;
81 
82   bp = m_pullup(bp);
83   pip = (struct ip *)MBUF_CTOP(bp);
84   if (*proto == PROTO_IP && pip->ip_p == IPPROTO_TCP &&
85       cproto == PROTO_VJCOMP) {
86     type = sl_compress_tcp(bp, pip, &bundle->ncp.ipcp.vj.cslc,
87                            &bundle->ncp.ipcp.vj.slstat,
88                            bundle->ncp.ipcp.peer_compproto & 0xff);
89     log_Printf(LogDEBUG, "vj_LayerWrite: type = %x\n", type);
90     switch (type) {
91     case TYPE_IP:
92       break;
93 
94     case TYPE_UNCOMPRESSED_TCP:
95       *proto = PROTO_VJUNCOMP;
96       log_Printf(LogDEBUG, "vj_LayerPush: PROTO_IP -> PROTO_VJUNCOMP\n");
97       m_settype(bp, MB_VJOUT);
98       break;
99 
100     case TYPE_COMPRESSED_TCP:
101       *proto = PROTO_VJCOMP;
102       log_Printf(LogDEBUG, "vj_LayerPush: PROTO_IP -> PROTO_VJUNCOMP\n");
103       m_settype(bp, MB_VJOUT);
104       break;
105 
106     default:
107       log_Printf(LogERROR, "vj_LayerPush: Unknown frame type %x\n", type);
108       m_freem(bp);
109       return NULL;
110     }
111   }
112 
113   return bp;
114 }
115 
116 static struct mbuf *
117 VjUncompressTcp(struct ipcp *ipcp, struct mbuf *bp, u_char type)
118 {
119   u_char *bufp;
120   int len, olen, rlen;
121   u_char work[MAX_HDR + MAX_VJHEADER];	/* enough to hold TCP/IP header */
122 
123   bp = m_pullup(bp);
124   olen = len = m_length(bp);
125   if (type == TYPE_UNCOMPRESSED_TCP) {
126     /*
127      * Uncompressed packet does NOT change its size, so that we can use mbuf
128      * space for uncompression job.
129      */
130     bufp = MBUF_CTOP(bp);
131     len = sl_uncompress_tcp(&bufp, len, type, &ipcp->vj.cslc, &ipcp->vj.slstat,
132                             (ipcp->my_compproto >> 8) & 255);
133     if (len <= 0) {
134       m_freem(bp);
135       bp = NULL;
136     } else
137       m_settype(bp, MB_VJIN);
138     return bp;
139   }
140 
141   /*
142    * Handle compressed packet. 1) Read up to MAX_VJHEADER bytes into work
143    * space. 2) Try to uncompress it. 3) Compute amount of necessary space. 4)
144    * Copy unread data info there.
145    */
146   if (len > MAX_VJHEADER)
147     len = MAX_VJHEADER;
148   rlen = len;
149   bufp = work + MAX_HDR;
150   bp = mbuf_Read(bp, bufp, rlen);
151   len = sl_uncompress_tcp(&bufp, olen, type, &ipcp->vj.cslc, &ipcp->vj.slstat,
152                           (ipcp->my_compproto >> 8) & 255);
153   if (len <= 0) {
154     m_freem(bp);
155     return NULL;
156   }
157   len -= olen;
158   len += rlen;
159 
160   bp = m_prepend(bp, bufp, len, 0);
161   m_settype(bp, MB_VJIN);
162 
163   return bp;
164 }
165 
166 static struct mbuf *
167 vj_LayerPull(struct bundle *bundle, struct link *l __unused, struct mbuf *bp,
168              u_short *proto)
169 {
170   u_char type;
171 
172   switch (*proto) {
173   case PROTO_VJCOMP:
174     type = TYPE_COMPRESSED_TCP;
175     log_Printf(LogDEBUG, "vj_LayerPull: PROTO_VJCOMP -> PROTO_IP\n");
176     break;
177   case PROTO_VJUNCOMP:
178     type = TYPE_UNCOMPRESSED_TCP;
179     log_Printf(LogDEBUG, "vj_LayerPull: PROTO_VJUNCOMP -> PROTO_IP\n");
180     break;
181   default:
182     return bp;
183   }
184 
185   *proto = PROTO_IP;
186   return VjUncompressTcp(&bundle->ncp.ipcp, bp, type);
187 }
188 
189 const char *
190 vj2asc(u_int32_t val)
191 {
192   static char asc[50];		/* The return value is used immediately */
193 
194   if (val)
195     snprintf(asc, sizeof asc, "%d VJ slots with%s slot compression",
196             (int)((val>>8)&15)+1, val & 1 ?  "" : "out");
197   else
198     strcpy(asc, "VJ disabled");
199   return asc;
200 }
201 
202 struct layer vjlayer = { LAYER_VJ, "vj", vj_LayerPush, vj_LayerPull };
203