freebsd-dev/usr.sbin/ppp/vjcomp.c
Doug Rabson 76bd0c0a9d Some patches to ppp which improve stability. I have been running a
ppp based on these patches for about 3 weeks with no downtime.

The original submitters comments:

Two features iijppp has over kernel ppp that I like are predictor1
compression and demand dialing.  Here are a few bug fixes.

I expanded the priority queueing scheme and discovered it was broken
due to the assignment at ip.c line 300.  All packets were being
queued at the same priority.

Fixing priority queueing broke predictor1 compression.  Packets
were compressed before being queued and predictor1 worked as long
as the packets were popped off the queue in the same order they
were pushed onto the queue.

There were a few byte order problems in IP header tests also.

There is a recursion problem in SendLqrReport().  LcpClose() is
called when "Too many echo packets are lost" which winds up in
SendLqrReport() again.  I believe the original intention was to
just stop the LQR timer with the call to StopLqr() but the side
effects hurt.

Submitted by:	John Capo <jc@irbs.com>
1996-01-30 11:08:50 +00:00

153 lines
3.5 KiB
C

/*
* 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 1.3 1995/05/30 03:51:02 rgrimes Exp $
*
* TODO:
*/
#include "fsm.h"
#include "lcpproto.h"
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include "slcompress.h"
#include "hdlc.h"
#include "ipcp.h"
#define MAX_VJHEADER 16 /* Maximum size of compressed header */
struct slcompress cslc;
void
VjInit()
{
sl_compress_init(&cslc);
}
void
SendPppFrame(bp)
struct mbuf *bp;
{
int type;
int proto;
int cproto = IpcpInfo.his_compproto >> 16;
#ifdef DEBUG
logprintf("SendPppFrame: proto = %x\n", IpcpInfo.his_compproto);
#endif
if (cproto== PROTO_VJCOMP) {
type = sl_compress_tcp(bp, (struct ip *)MBUF_CTOP(bp), &cslc, IpcpInfo.his_compproto & 0xff);
#ifdef DEBUG
logprintf("type = %x\n", type);
#endif
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("unknown type %x\n", type);
pfree(bp);
return;
}
} else
proto = PROTO_IP;
HdlcOutput(PRI_NORMAL, proto, bp);
}
static struct mbuf *
VjUncompressTcp(bp, type)
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 = NULLBUFF;
}
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 NULLBUFF;
}
len -= olen;
len += rlen;
nbp = mballoc(len, MB_VJCOMP);
bcopy(bufp, MBUF_CTOP(nbp), len);
nbp->next = bp;
return(nbp);
}
struct mbuf *
VjCompInput(bp, proto)
struct mbuf *bp;
int proto;
{
u_char type;
#ifdef DEBUG
logprintf("VjCompInput (%02x):\n", proto);
DumpBp(bp);
#endif
switch (proto) {
case PROTO_VJCOMP:
type = TYPE_COMPRESSED_TCP;
break;
case PROTO_VJUNCOMP:
type = TYPE_UNCOMPRESSED_TCP;
break;
default:
logprintf("???\n");
return(bp);
}
bp = VjUncompressTcp(bp, type);
return(bp);
}