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/*
* Input/Output VJ Compressed packets
*
* Written by Toshiharu OHNO (tony-o@iij.ad.jp)
*
* Copyright (C) 1993, Internet Initiative Japan, Inc. All rights reserverd.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* advertising materials, and other materials related to such
* distribution and use acknowledge that the software was developed
* by the Internet Initiative Japan, Inc. The name of the
* IIJ may not be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*
* $Id: vjcomp.c,v 1.4 1998/01/21 02:13:44 brian Exp $
*
* TODO:
*/
#include <sys/types.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <stdio.h>
#include <string.h>
#include "command.h"
#include "mbuf.h"
#include "log.h"
#include "timer.h"
#include "fsm.h"
#include "lcpproto.h"
#include "slcompress.h"
#include "hdlc.h"
#include "ipcp.h"
#include "vjcomp.h"
#define MAX_VJHEADER 16 /* Maximum size of compressed header */
static struct slcompress cslc;
void
VjInit(int max_state)
{
sl_compress_init(&cslc, max_state);
}
void
SendPppFrame(struct mbuf * bp)
{
int type;
u_short proto;
u_short cproto = IpcpInfo.his_compproto >> 16;
LogPrintf(LogDEBUG, "SendPppFrame: proto = %x\n", IpcpInfo.his_compproto);
if (((struct ip *) MBUF_CTOP(bp))->ip_p == IPPROTO_TCP
&& cproto == PROTO_VJCOMP) {
type = sl_compress_tcp(bp, (struct ip *)MBUF_CTOP(bp), &cslc,
IpcpInfo.his_compproto & 0xff);
LogPrintf(LogDEBUG, "SendPppFrame: type = %x\n", type);
switch (type) {
case TYPE_IP:
proto = PROTO_IP;
break;
case TYPE_UNCOMPRESSED_TCP:
proto = PROTO_VJUNCOMP;
break;
case TYPE_COMPRESSED_TCP:
proto = PROTO_VJCOMP;
break;
default:
LogPrintf(LogERROR, "Unknown frame type %x\n", type);
pfree(bp);
return;
}
} else
proto = PROTO_IP;
HdlcOutput(PRI_NORMAL, proto, bp);
}
static struct mbuf *
VjUncompressTcp(struct mbuf * bp, u_char type)
{
u_char *bufp;
int len, olen, rlen;
struct mbuf *nbp;
u_char work[MAX_HDR + MAX_VJHEADER]; /* enough to hold TCP/IP header */
olen = len = plength(bp);
if (type == TYPE_UNCOMPRESSED_TCP) {
/*
* Uncompressed packet does NOT change its size, so that we can use mbuf
* space for uncompression job.
*/
bufp = MBUF_CTOP(bp);
len = sl_uncompress_tcp(&bufp, len, type, &cslc);
if (len <= 0) {
pfree(bp);
bp = NULL;
}
return (bp);
}
/*
* Handle compressed packet. 1) Read upto MAX_VJHEADER bytes into work
* space. 2) Try to uncompress it. 3) Compute amount of necesary space. 4)
* Copy unread data info there.
*/
if (len > MAX_VJHEADER)
len = MAX_VJHEADER;
rlen = len;
bufp = work + MAX_HDR;
bp = mbread(bp, bufp, rlen);
len = sl_uncompress_tcp(&bufp, olen, type, &cslc);
if (len <= 0) {
pfree(bp);
return NULL;
}
len -= olen;
len += rlen;
nbp = mballoc(len, MB_VJCOMP);
memcpy(MBUF_CTOP(nbp), bufp, len);
nbp->next = bp;
return (nbp);
}
struct mbuf *
VjCompInput(struct mbuf * bp, int proto)
{
u_char type;
LogPrintf(LogDEBUG, "VjCompInput: proto %02x\n", proto);
LogDumpBp(LogDEBUG, "Raw packet info:", bp);
switch (proto) {
case PROTO_VJCOMP:
type = TYPE_COMPRESSED_TCP;
break;
case PROTO_VJUNCOMP:
type = TYPE_UNCOMPRESSED_TCP;
break;
default:
LogPrintf(LogERROR, "VjCompInput...???\n");
return (bp);
}
bp = VjUncompressTcp(bp, type);
return (bp);
}
const char *
vj2asc(u_int32_t val)
{
static char asc[50];
sprintf(asc, "%d VJ slots %s slot compression",
(int)((val>>8)&15)+1, val & 1 ? "with" : "without");
return asc;
}
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