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 * $Id:$ 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 SendPppFlame(pri, bp) 44 int pri; 45 struct mbuf *bp; 46 { 47 int type; 48 int proto; 49 int cproto = IpcpInfo.his_compproto >> 16; 50 51 #ifdef DEBUG 52 logprintf("SendPppFlame: proto = %x\n", IpcpInfo.his_compproto); 53 #endif 54 if (cproto== PROTO_VJCOMP) { 55 type = sl_compress_tcp(bp, MBUF_CTOP(bp), &cslc, IpcpInfo.his_compproto & 0xff); 56 57 #ifdef DEBUG 58 logprintf("type = %x\n", type); 59 #endif 60 switch (type) { 61 case TYPE_IP: 62 proto = PROTO_IP; 63 break; 64 case TYPE_UNCOMPRESSED_TCP: 65 proto = PROTO_VJUNCOMP; 66 break; 67 case TYPE_COMPRESSED_TCP: 68 proto = PROTO_VJCOMP; 69 break; 70 default: 71 logprintf("unknown type %x\n", type); 72 pfree(bp); 73 return; 74 } 75 } else 76 proto = PROTO_IP; 77 HdlcOutput(pri, proto, bp); 78 } 79 80 static struct mbuf * 81 VjUncompressTcp(bp, type) 82 struct mbuf *bp; 83 u_char type; 84 { 85 u_char *bufp; 86 int len, olen, rlen; 87 struct mbuf *nbp; 88 u_char work[MAX_HDR+MAX_VJHEADER]; /* enough to hold TCP/IP header */ 89 90 olen = len = plength(bp); 91 if (type == TYPE_UNCOMPRESSED_TCP) { 92 /* 93 * Uncompressed packet does NOT change its size, so that we can 94 * use mbuf space for uncompression job. 95 */ 96 bufp = MBUF_CTOP(bp); 97 len = sl_uncompress_tcp(&bufp, len, type, &cslc); 98 return(bp); 99 } 100 /* 101 * Handle compressed packet. 102 * 1) Read upto MAX_VJHEADER bytes into work space. 103 * 2) Try to uncompress it. 104 * 3) Compute amount of necesary space. 105 * 4) Copy unread data info there. 106 */ 107 if (len > MAX_VJHEADER) len = MAX_VJHEADER; 108 rlen = len; 109 bufp = work + MAX_HDR; 110 bp = mbread(bp, bufp, rlen); 111 len = sl_uncompress_tcp(&bufp, olen, type, &cslc); 112 len -= olen; 113 len += rlen; 114 nbp = mballoc(len, MB_VJCOMP); 115 bcopy(bufp, MBUF_CTOP(nbp), len); 116 nbp->next = bp; 117 return(nbp); 118 } 119 120 struct mbuf * 121 VjCompInput(bp, proto) 122 struct mbuf *bp; 123 int proto; 124 { 125 u_char type; 126 127 #ifdef DEBUG 128 logprintf("VjCompInput (%02x):\n", proto); 129 DumpBp(bp); 130 #endif 131 132 switch (proto) { 133 case PROTO_VJCOMP: 134 type = TYPE_COMPRESSED_TCP; 135 break; 136 case PROTO_VJUNCOMP: 137 type = TYPE_UNCOMPRESSED_TCP; 138 break; 139 default: 140 logprintf("???\n"); 141 return(bp); 142 } 143 bp = VjUncompressTcp(bp, type); 144 return(bp); 145 } 146