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 1.8 1997/06/09 03:27:43 brian Exp $ 21 * 22 * TODO: 23 */ 24 #include "fsm.h" 25 #include "lcpproto.h" 26 #include <netinet/in_systm.h> 27 #include <netinet/ip.h> 28 #include "slcompress.h" 29 #include "hdlc.h" 30 #include "ipcp.h" 31 32 #define MAX_VJHEADER 16 /* Maximum size of compressed header */ 33 34 struct slcompress cslc; 35 36 void 37 VjInit() 38 { 39 sl_compress_init(&cslc); 40 } 41 42 void 43 SendPppFrame(struct mbuf * bp) 44 { 45 int type; 46 int proto; 47 int cproto = IpcpInfo.his_compproto >> 16; 48 49 LogPrintf(LogDEBUG, "SendPppFrame: proto = %x\n", IpcpInfo.his_compproto); 50 if (((struct ip *) MBUF_CTOP(bp))->ip_p == IPPROTO_TCP 51 && cproto == PROTO_VJCOMP) { 52 type = sl_compress_tcp(bp, (struct ip *) MBUF_CTOP(bp), &cslc, IpcpInfo.his_compproto & 0xff); 53 54 LogPrintf(LogDEBUG, "SendPppFrame: type = %x\n", type); 55 switch (type) { 56 case TYPE_IP: 57 proto = PROTO_IP; 58 break; 59 case TYPE_UNCOMPRESSED_TCP: 60 proto = PROTO_VJUNCOMP; 61 break; 62 case TYPE_COMPRESSED_TCP: 63 proto = PROTO_VJCOMP; 64 break; 65 default: 66 LogPrintf(LogERROR, "Unknown frame type %x\n", type); 67 pfree(bp); 68 return; 69 } 70 } else 71 proto = PROTO_IP; 72 HdlcOutput(PRI_NORMAL, proto, bp); 73 } 74 75 static struct mbuf * 76 VjUncompressTcp(struct mbuf * bp, u_char type) 77 { 78 u_char *bufp; 79 int len, olen, rlen; 80 struct mbuf *nbp; 81 u_char work[MAX_HDR + MAX_VJHEADER]; /* enough to hold TCP/IP header */ 82 83 olen = len = plength(bp); 84 if (type == TYPE_UNCOMPRESSED_TCP) { 85 86 /* 87 * Uncompressed packet does NOT change its size, so that we can use mbuf 88 * space for uncompression job. 89 */ 90 bufp = MBUF_CTOP(bp); 91 len = sl_uncompress_tcp(&bufp, len, type, &cslc); 92 if (len <= 0) { 93 pfree(bp); 94 bp = NULLBUFF; 95 } 96 return (bp); 97 } 98 99 /* 100 * Handle compressed packet. 1) Read upto MAX_VJHEADER bytes into work 101 * space. 2) Try to uncompress it. 3) Compute amount of necesary space. 4) 102 * Copy unread data info there. 103 */ 104 if (len > MAX_VJHEADER) 105 len = MAX_VJHEADER; 106 rlen = len; 107 bufp = work + MAX_HDR; 108 bp = mbread(bp, bufp, rlen); 109 len = sl_uncompress_tcp(&bufp, olen, type, &cslc); 110 if (len <= 0) { 111 pfree(bp); 112 return NULLBUFF; 113 } 114 len -= olen; 115 len += rlen; 116 nbp = mballoc(len, MB_VJCOMP); 117 bcopy(bufp, MBUF_CTOP(nbp), len); 118 nbp->next = bp; 119 return (nbp); 120 } 121 122 struct mbuf * 123 VjCompInput(struct mbuf * bp, int proto) 124 { 125 u_char type; 126 127 LogPrintf(LogDEBUG, "VjCompInput: proto %02x\n", proto); 128 LogDumpBp(LogDEBUG, "Raw packet info:", bp); 129 130 switch (proto) { 131 case PROTO_VJCOMP: 132 type = TYPE_COMPRESSED_TCP; 133 break; 134 case PROTO_VJUNCOMP: 135 type = TYPE_UNCOMPRESSED_TCP; 136 break; 137 default: 138 LogPrintf(LogERROR, "VjCompInput...???\n"); 139 return (bp); 140 } 141 bp = VjUncompressTcp(bp, type); 142 return (bp); 143 } 144