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 1.10 1997/10/07 00:56:58 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 <string.h> 30 31 #include "mbuf.h" 32 #include "log.h" 33 #include "defs.h" 34 #include "timer.h" 35 #include "fsm.h" 36 #include "lcpproto.h" 37 #include "slcompress.h" 38 #include "hdlc.h" 39 #include "ipcp.h" 40 #include "vjcomp.h" 41 42 #define MAX_VJHEADER 16 /* Maximum size of compressed header */ 43 44 struct slcompress cslc; 45 46 void 47 VjInit(int max_state) 48 { 49 sl_compress_init(&cslc, max_state); 50 } 51 52 void 53 SendPppFrame(struct mbuf * bp) 54 { 55 int type; 56 int proto; 57 int cproto = IpcpInfo.his_compproto >> 16; 58 59 LogPrintf(LogDEBUG, "SendPppFrame: proto = %x\n", IpcpInfo.his_compproto); 60 if (((struct ip *) MBUF_CTOP(bp))->ip_p == IPPROTO_TCP 61 && cproto == PROTO_VJCOMP) { 62 type = sl_compress_tcp(bp, (struct ip *) MBUF_CTOP(bp), &cslc, IpcpInfo.his_compproto & 0xff); 63 64 LogPrintf(LogDEBUG, "SendPppFrame: type = %x\n", type); 65 switch (type) { 66 case TYPE_IP: 67 proto = PROTO_IP; 68 break; 69 case TYPE_UNCOMPRESSED_TCP: 70 proto = PROTO_VJUNCOMP; 71 break; 72 case TYPE_COMPRESSED_TCP: 73 proto = PROTO_VJCOMP; 74 break; 75 default: 76 LogPrintf(LogERROR, "Unknown frame type %x\n", type); 77 pfree(bp); 78 return; 79 } 80 } else 81 proto = PROTO_IP; 82 HdlcOutput(PRI_NORMAL, proto, bp); 83 } 84 85 static struct mbuf * 86 VjUncompressTcp(struct mbuf * bp, u_char type) 87 { 88 u_char *bufp; 89 int len, olen, rlen; 90 struct mbuf *nbp; 91 u_char work[MAX_HDR + MAX_VJHEADER]; /* enough to hold TCP/IP header */ 92 93 olen = len = plength(bp); 94 if (type == TYPE_UNCOMPRESSED_TCP) { 95 96 /* 97 * Uncompressed packet does NOT change its size, so that we can use mbuf 98 * space for uncompression job. 99 */ 100 bufp = MBUF_CTOP(bp); 101 len = sl_uncompress_tcp(&bufp, len, type, &cslc); 102 if (len <= 0) { 103 pfree(bp); 104 bp = NULLBUFF; 105 } 106 return (bp); 107 } 108 109 /* 110 * Handle compressed packet. 1) Read upto MAX_VJHEADER bytes into work 111 * space. 2) Try to uncompress it. 3) Compute amount of necesary space. 4) 112 * Copy unread data info there. 113 */ 114 if (len > MAX_VJHEADER) 115 len = MAX_VJHEADER; 116 rlen = len; 117 bufp = work + MAX_HDR; 118 bp = mbread(bp, bufp, rlen); 119 len = sl_uncompress_tcp(&bufp, olen, type, &cslc); 120 if (len <= 0) { 121 pfree(bp); 122 return NULLBUFF; 123 } 124 len -= olen; 125 len += rlen; 126 nbp = mballoc(len, MB_VJCOMP); 127 memcpy(MBUF_CTOP(nbp), bufp, len); 128 nbp->next = bp; 129 return (nbp); 130 } 131 132 struct mbuf * 133 VjCompInput(struct mbuf * bp, int proto) 134 { 135 u_char type; 136 137 LogPrintf(LogDEBUG, "VjCompInput: proto %02x\n", proto); 138 LogDumpBp(LogDEBUG, "Raw packet info:", bp); 139 140 switch (proto) { 141 case PROTO_VJCOMP: 142 type = TYPE_COMPRESSED_TCP; 143 break; 144 case PROTO_VJUNCOMP: 145 type = TYPE_UNCOMPRESSED_TCP; 146 break; 147 default: 148 LogPrintf(LogERROR, "VjCompInput...???\n"); 149 return (bp); 150 } 151 bp = VjUncompressTcp(bp, type); 152 return (bp); 153 } 154