154 lines
3.6 KiB
C
154 lines
3.6 KiB
C
/*
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* Input/Output VJ Compressed packets
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*
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* Written by Toshiharu OHNO (tony-o@iij.ad.jp)
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*
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* Copyright (C) 1993, Internet Initiative Japan, Inc. All rights reserverd.
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*
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* Redistribution and use in source and binary forms are permitted
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* provided that the above copyright notice and this paragraph are
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* duplicated in all such forms and that any documentation,
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* advertising materials, and other materials related to such
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* distribution and use acknowledge that the software was developed
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* by the Internet Initiative Japan, Inc. The name of the
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* IIJ may not be used to endorse or promote products derived
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* from this software without specific prior written permission.
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* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
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* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
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*
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* $Id: vjcomp.c,v 1.6 1997/02/22 16:11:05 peter Exp $
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*
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* TODO:
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*/
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#include "fsm.h"
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#include "lcpproto.h"
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#include <netinet/in_systm.h>
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#include <netinet/ip.h>
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#include "slcompress.h"
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#include "hdlc.h"
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#include "ipcp.h"
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#define MAX_VJHEADER 16 /* Maximum size of compressed header */
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struct slcompress cslc;
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void
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VjInit()
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{
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sl_compress_init(&cslc);
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}
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void
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SendPppFrame(bp)
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struct mbuf *bp;
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{
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int type;
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int proto;
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int cproto = IpcpInfo.his_compproto >> 16;
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#ifdef DEBUG
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logprintf("SendPppFrame: proto = %x\n", IpcpInfo.his_compproto);
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#endif
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if (((struct ip *)MBUF_CTOP(bp))->ip_p == IPPROTO_TCP
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&& cproto== PROTO_VJCOMP) {
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type = sl_compress_tcp(bp, (struct ip *)MBUF_CTOP(bp), &cslc, IpcpInfo.his_compproto & 0xff);
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#ifdef DEBUG
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logprintf("type = %x\n", type);
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#endif
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switch (type) {
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case TYPE_IP:
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proto = PROTO_IP;
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break;
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case TYPE_UNCOMPRESSED_TCP:
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proto = PROTO_VJUNCOMP;
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break;
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case TYPE_COMPRESSED_TCP:
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proto = PROTO_VJCOMP;
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break;
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default:
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logprintf("unknown type %x\n", type);
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pfree(bp);
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return;
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}
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} else
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proto = PROTO_IP;
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HdlcOutput(PRI_NORMAL, proto, bp);
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}
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static struct mbuf *
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VjUncompressTcp(bp, type)
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struct mbuf *bp;
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u_char type;
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{
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u_char *bufp;
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int len, olen, rlen;
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struct mbuf *nbp;
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u_char work[MAX_HDR+MAX_VJHEADER]; /* enough to hold TCP/IP header */
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olen = len = plength(bp);
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if (type == TYPE_UNCOMPRESSED_TCP) {
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/*
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* Uncompressed packet does NOT change its size, so that we can
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* use mbuf space for uncompression job.
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*/
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bufp = MBUF_CTOP(bp);
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len = sl_uncompress_tcp(&bufp, len, type, &cslc);
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if (len <= 0) {
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pfree(bp);
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bp = NULLBUFF;
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}
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return(bp);
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}
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/*
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* Handle compressed packet.
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* 1) Read upto MAX_VJHEADER bytes into work space.
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* 2) Try to uncompress it.
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* 3) Compute amount of necesary space.
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* 4) Copy unread data info there.
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*/
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if (len > MAX_VJHEADER) len = MAX_VJHEADER;
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rlen = len;
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bufp = work + MAX_HDR;
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bp = mbread(bp, bufp, rlen);
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len = sl_uncompress_tcp(&bufp, olen, type, &cslc);
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if (len <= 0) {
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pfree(bp);
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return NULLBUFF;
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}
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len -= olen;
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len += rlen;
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nbp = mballoc(len, MB_VJCOMP);
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bcopy(bufp, MBUF_CTOP(nbp), len);
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nbp->next = bp;
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return(nbp);
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}
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struct mbuf *
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VjCompInput(bp, proto)
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struct mbuf *bp;
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int proto;
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{
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u_char type;
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#ifdef DEBUG
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logprintf("VjCompInput (%02x):\n", proto);
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DumpBp(bp);
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#endif
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switch (proto) {
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case PROTO_VJCOMP:
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type = TYPE_COMPRESSED_TCP;
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break;
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case PROTO_VJUNCOMP:
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type = TYPE_UNCOMPRESSED_TCP;
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break;
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default:
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logprintf("???\n");
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return(bp);
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}
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bp = VjUncompressTcp(bp, type);
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return(bp);
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}
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