vjcomp.c revision 31343
1/* 2 * Input/Output VJ Compressed packets 3 * 4 * Written by Toshiharu OHNO (tony-o@iij.ad.jp) 5 * 6 * Copyright (C) 1993, Internet Initiative Japan, Inc. All rights reserverd. 7 * 8 * Redistribution and use in source and binary forms are permitted 9 * provided that the above copyright notice and this paragraph are 10 * duplicated in all such forms and that any documentation, 11 * advertising materials, and other materials related to such 12 * distribution and use acknowledge that the software was developed 13 * by the Internet Initiative Japan, Inc. The name of the 14 * IIJ may not be used to endorse or promote products derived 15 * from this software without specific prior written permission. 16 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED 18 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. 19 * 20 * $Id: vjcomp.c,v 1.12 1997/11/09 06:22:49 brian Exp $ 21 * 22 * TODO: 23 */ 24#include <sys/types.h> 25#include <netinet/in.h> 26#include <netinet/in_systm.h> 27#include <netinet/ip.h> 28 29#include <stdio.h> 30#include <string.h> 31 32#include "command.h" 33#include "mbuf.h" 34#include "log.h" 35#include "defs.h" 36#include "timer.h" 37#include "fsm.h" 38#include "lcpproto.h" 39#include "slcompress.h" 40#include "hdlc.h" 41#include "ipcp.h" 42#include "vjcomp.h" 43 44#define MAX_VJHEADER 16 /* Maximum size of compressed header */ 45 46struct slcompress cslc; 47 48void 49VjInit(int max_state) 50{ 51 sl_compress_init(&cslc, max_state); 52} 53 54void 55SendPppFrame(struct mbuf * bp) 56{ 57 int type; 58 int proto; 59 int cproto = IpcpInfo.his_compproto >> 16; 60 61 LogPrintf(LogDEBUG, "SendPppFrame: proto = %x\n", IpcpInfo.his_compproto); 62 if (((struct ip *) MBUF_CTOP(bp))->ip_p == IPPROTO_TCP 63 && cproto == PROTO_VJCOMP) { 64 type = sl_compress_tcp(bp, (struct ip *) MBUF_CTOP(bp), &cslc, IpcpInfo.his_compproto & 0xff); 65 66 LogPrintf(LogDEBUG, "SendPppFrame: type = %x\n", type); 67 switch (type) { 68 case TYPE_IP: 69 proto = PROTO_IP; 70 break; 71 case TYPE_UNCOMPRESSED_TCP: 72 proto = PROTO_VJUNCOMP; 73 break; 74 case TYPE_COMPRESSED_TCP: 75 proto = PROTO_VJCOMP; 76 break; 77 default: 78 LogPrintf(LogERROR, "Unknown frame type %x\n", type); 79 pfree(bp); 80 return; 81 } 82 } else 83 proto = PROTO_IP; 84 HdlcOutput(PRI_NORMAL, proto, bp); 85} 86 87static struct mbuf * 88VjUncompressTcp(struct mbuf * bp, u_char type) 89{ 90 u_char *bufp; 91 int len, olen, rlen; 92 struct mbuf *nbp; 93 u_char work[MAX_HDR + MAX_VJHEADER]; /* enough to hold TCP/IP header */ 94 95 olen = len = plength(bp); 96 if (type == TYPE_UNCOMPRESSED_TCP) { 97 98 /* 99 * Uncompressed packet does NOT change its size, so that we can use mbuf 100 * space for uncompression job. 101 */ 102 bufp = MBUF_CTOP(bp); 103 len = sl_uncompress_tcp(&bufp, len, type, &cslc); 104 if (len <= 0) { 105 pfree(bp); 106 bp = NULLBUFF; 107 } 108 return (bp); 109 } 110 111 /* 112 * Handle compressed packet. 1) Read upto MAX_VJHEADER bytes into work 113 * space. 2) Try to uncompress it. 3) Compute amount of necesary space. 4) 114 * Copy unread data info there. 115 */ 116 if (len > MAX_VJHEADER) 117 len = MAX_VJHEADER; 118 rlen = len; 119 bufp = work + MAX_HDR; 120 bp = mbread(bp, bufp, rlen); 121 len = sl_uncompress_tcp(&bufp, olen, type, &cslc); 122 if (len <= 0) { 123 pfree(bp); 124 return NULLBUFF; 125 } 126 len -= olen; 127 len += rlen; 128 nbp = mballoc(len, MB_VJCOMP); 129 memcpy(MBUF_CTOP(nbp), bufp, len); 130 nbp->next = bp; 131 return (nbp); 132} 133 134struct mbuf * 135VjCompInput(struct mbuf * bp, int proto) 136{ 137 u_char type; 138 139 LogPrintf(LogDEBUG, "VjCompInput: proto %02x\n", proto); 140 LogDumpBp(LogDEBUG, "Raw packet info:", bp); 141 142 switch (proto) { 143 case PROTO_VJCOMP: 144 type = TYPE_COMPRESSED_TCP; 145 break; 146 case PROTO_VJUNCOMP: 147 type = TYPE_UNCOMPRESSED_TCP; 148 break; 149 default: 150 LogPrintf(LogERROR, "VjCompInput...???\n"); 151 return (bp); 152 } 153 bp = VjUncompressTcp(bp, type); 154 return (bp); 155} 156