vjcomp.c revision 32663
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 1.15 1998/01/11 17:50:46 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 "timer.h" 36#include "fsm.h" 37#include "lcpproto.h" 38#include "slcompress.h" 39#include "hdlc.h" 40#include "ipcp.h" 41#include "vjcomp.h" 42 43#define MAX_VJHEADER 16 /* Maximum size of compressed header */ 44 45static struct slcompress cslc; 46 47void 48VjInit(int max_state) 49{ 50 sl_compress_init(&cslc, max_state); 51} 52 53void 54SendPppFrame(struct mbuf * bp) 55{ 56 int type; 57 u_short proto; 58 u_short cproto = IpcpInfo.his_compproto >> 16; 59 60 LogPrintf(LogDEBUG, "SendPppFrame: proto = %x\n", IpcpInfo.his_compproto); 61 if (((struct ip *) MBUF_CTOP(bp))->ip_p == IPPROTO_TCP 62 && cproto == PROTO_VJCOMP) { 63 type = sl_compress_tcp(bp, (struct ip *)MBUF_CTOP(bp), &cslc, 64 IpcpInfo.his_compproto & 0xff); 65 LogPrintf(LogDEBUG, "SendPppFrame: type = %x\n", type); 66 switch (type) { 67 case TYPE_IP: 68 proto = PROTO_IP; 69 break; 70 case TYPE_UNCOMPRESSED_TCP: 71 proto = PROTO_VJUNCOMP; 72 break; 73 case TYPE_COMPRESSED_TCP: 74 proto = PROTO_VJCOMP; 75 break; 76 default: 77 LogPrintf(LogERROR, "Unknown frame type %x\n", type); 78 pfree(bp); 79 return; 80 } 81 } else 82 proto = PROTO_IP; 83 HdlcOutput(PRI_NORMAL, proto, bp); 84} 85 86static struct mbuf * 87VjUncompressTcp(struct mbuf * bp, u_char type) 88{ 89 u_char *bufp; 90 int len, olen, rlen; 91 struct mbuf *nbp; 92 u_char work[MAX_HDR + MAX_VJHEADER]; /* enough to hold TCP/IP header */ 93 94 olen = len = plength(bp); 95 if (type == TYPE_UNCOMPRESSED_TCP) { 96 97 /* 98 * Uncompressed packet does NOT change its size, so that we can use mbuf 99 * space for uncompression job. 100 */ 101 bufp = MBUF_CTOP(bp); 102 len = sl_uncompress_tcp(&bufp, len, type, &cslc); 103 if (len <= 0) { 104 pfree(bp); 105 bp = NULL; 106 } 107 return (bp); 108 } 109 110 /* 111 * Handle compressed packet. 1) Read upto MAX_VJHEADER bytes into work 112 * space. 2) Try to uncompress it. 3) Compute amount of necesary space. 4) 113 * Copy unread data info there. 114 */ 115 if (len > MAX_VJHEADER) 116 len = MAX_VJHEADER; 117 rlen = len; 118 bufp = work + MAX_HDR; 119 bp = mbread(bp, bufp, rlen); 120 len = sl_uncompress_tcp(&bufp, olen, type, &cslc); 121 if (len <= 0) { 122 pfree(bp); 123 return NULL; 124 } 125 len -= olen; 126 len += rlen; 127 nbp = mballoc(len, MB_VJCOMP); 128 memcpy(MBUF_CTOP(nbp), bufp, len); 129 nbp->next = bp; 130 return (nbp); 131} 132 133struct mbuf * 134VjCompInput(struct mbuf * bp, int proto) 135{ 136 u_char type; 137 138 LogPrintf(LogDEBUG, "VjCompInput: proto %02x\n", proto); 139 LogDumpBp(LogDEBUG, "Raw packet info:", bp); 140 141 switch (proto) { 142 case PROTO_VJCOMP: 143 type = TYPE_COMPRESSED_TCP; 144 break; 145 case PROTO_VJUNCOMP: 146 type = TYPE_UNCOMPRESSED_TCP; 147 break; 148 default: 149 LogPrintf(LogERROR, "VjCompInput...???\n"); 150 return (bp); 151 } 152 bp = VjUncompressTcp(bp, type); 153 return (bp); 154} 155 156const char * 157vj2asc(u_int32_t val) 158{ 159 static char asc[50]; 160 161 sprintf(asc, "%d VJ slots %s slot compression", 162 (int)((val>>8)&15)+1, val & 1 ? "with" : "without"); 163 return asc; 164} 165