vjcomp.c revision 93465 
1/*-
2 * Copyright (c) 1996 - 2001 Brian Somers <brian@Awfulhak.org>
3 *          based on work by Toshiharu OHNO <tony-o@iij.ad.jp>
4 *                           Internet Initiative Japan, Inc (IIJ)
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: head/usr.sbin/ppp/vjcomp.c 93465 2002-03-31 01:57:06Z brian $
29 */
30
31#include <sys/param.h>
32#include <netinet/in.h>
33#include <netinet/in_systm.h>
34#include <netinet/ip.h>
35#include <sys/socket.h>
36#include <sys/un.h>
37
38#include <stdio.h>
39#include <string.h>		/* strlen/memcpy */
40#include <termios.h>
41
42#include "layer.h"
43#include "mbuf.h"
44#include "log.h"
45#include "timer.h"
46#include "fsm.h"
47#include "proto.h"
48#include "slcompress.h"
49#include "lqr.h"
50#include "hdlc.h"
51#include "defs.h"
52#include "iplist.h"
53#include "throughput.h"
54#include "ncpaddr.h"
55#include "ip.h"
56#include "ipcp.h"
57#include "lcp.h"
58#include "ccp.h"
59#include "link.h"
60#include "filter.h"
61#include "descriptor.h"
62#include "mp.h"
63#ifndef NORADIUS
64#include "radius.h"
65#endif
66#include "ipv6cp.h"
67#include "ncp.h"
68#include "bundle.h"
69#include "vjcomp.h"
70
71#define MAX_VJHEADER 16		/* Maximum size of compressed header */
72
73static struct mbuf *
74vj_LayerPush(struct bundle *bundle, struct link *l, struct mbuf *bp, int pri,
75             u_short *proto)
76{
77  int type;
78  struct ip *pip;
79  u_short cproto = bundle->ncp.ipcp.peer_compproto >> 16;
80
81  bp = m_pullup(bp);
82  pip = (struct ip *)MBUF_CTOP(bp);
83  if (*proto == PROTO_IP && pip->ip_p == IPPROTO_TCP &&
84      cproto == PROTO_VJCOMP) {
85    type = sl_compress_tcp(bp, pip, &bundle->ncp.ipcp.vj.cslc,
86                           &bundle->ncp.ipcp.vj.slstat,
87                           bundle->ncp.ipcp.peer_compproto & 0xff);
88    log_Printf(LogDEBUG, "vj_LayerWrite: type = %x\n", type);
89    switch (type) {
90    case TYPE_IP:
91      break;
92
93    case TYPE_UNCOMPRESSED_TCP:
94      *proto = PROTO_VJUNCOMP;
95      log_Printf(LogDEBUG, "vj_LayerPush: PROTO_IP -> PROTO_VJUNCOMP\n");
96      m_settype(bp, MB_VJOUT);
97      break;
98
99    case TYPE_COMPRESSED_TCP:
100      *proto = PROTO_VJCOMP;
101      log_Printf(LogDEBUG, "vj_LayerPush: PROTO_IP -> PROTO_VJUNCOMP\n");
102      m_settype(bp, MB_VJOUT);
103      break;
104
105    default:
106      log_Printf(LogERROR, "vj_LayerPush: Unknown frame type %x\n", type);
107      m_freem(bp);
108      return NULL;
109    }
110  }
111
112  return bp;
113}
114
115static struct mbuf *
116VjUncompressTcp(struct ipcp *ipcp, struct mbuf *bp, u_char type)
117{
118  u_char *bufp;
119  int len, olen, rlen;
120  u_char work[MAX_HDR + MAX_VJHEADER];	/* enough to hold TCP/IP header */
121
122  bp = m_pullup(bp);
123  olen = len = m_length(bp);
124  if (type == TYPE_UNCOMPRESSED_TCP) {
125    /*
126     * Uncompressed packet does NOT change its size, so that we can use mbuf
127     * space for uncompression job.
128     */
129    bufp = MBUF_CTOP(bp);
130    len = sl_uncompress_tcp(&bufp, len, type, &ipcp->vj.cslc, &ipcp->vj.slstat,
131                            (ipcp->my_compproto >> 8) & 255);
132    if (len <= 0) {
133      m_freem(bp);
134      bp = NULL;
135    } else
136      m_settype(bp, MB_VJIN);
137    return bp;
138  }
139
140  /*
141   * Handle compressed packet. 1) Read upto MAX_VJHEADER bytes into work
142   * space. 2) Try to uncompress it. 3) Compute amount of necessary space. 4)
143   * Copy unread data info there.
144   */
145  if (len > MAX_VJHEADER)
146    len = MAX_VJHEADER;
147  rlen = len;
148  bufp = work + MAX_HDR;
149  bp = mbuf_Read(bp, bufp, rlen);
150  len = sl_uncompress_tcp(&bufp, olen, type, &ipcp->vj.cslc, &ipcp->vj.slstat,
151                          (ipcp->my_compproto >> 8) & 255);
152  if (len <= 0) {
153    m_freem(bp);
154    return NULL;
155  }
156  len -= olen;
157  len += rlen;
158
159  bp = m_prepend(bp, bufp, len, 0);
160  m_settype(bp, MB_VJIN);
161
162  return bp;
163}
164
165static struct mbuf *
166vj_LayerPull(struct bundle *bundle, struct link *l, struct mbuf *bp,
167             u_short *proto)
168{
169  u_char type;
170
171  switch (*proto) {
172  case PROTO_VJCOMP:
173    type = TYPE_COMPRESSED_TCP;
174    log_Printf(LogDEBUG, "vj_LayerPull: PROTO_VJCOMP -> PROTO_IP\n");
175    break;
176  case PROTO_VJUNCOMP:
177    type = TYPE_UNCOMPRESSED_TCP;
178    log_Printf(LogDEBUG, "vj_LayerPull: PROTO_VJUNCOMP -> PROTO_IP\n");
179    break;
180  default:
181    return bp;
182  }
183
184  *proto = PROTO_IP;
185  return VjUncompressTcp(&bundle->ncp.ipcp, bp, type);
186}
187
188const char *
189vj2asc(u_int32_t val)
190{
191  static char asc[50];		/* The return value is used immediately */
192
193  if (val)
194    snprintf(asc, sizeof asc, "%d VJ slots with%s slot compression",
195            (int)((val>>8)&15)+1, val & 1 ?  "" : "out");
196  else
197    strcpy(asc, "VJ disabled");
198  return asc;
199}
200
201struct layer vjlayer = { LAYER_VJ, "vj", vj_LayerPush, vj_LayerPull };
202