1/* 2 * ppp-comp.h - Definitions for doing PPP packet compression. 3 * 4 * Copyright (c) 1984 Paul Mackerras. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in 15 * the documentation and/or other materials provided with the 16 * distribution. 17 * 18 * 3. The name(s) of the authors of this software must not be used to 19 * endorse or promote products derived from this software without 20 * prior written permission. 21 * 22 * 4. Redistributions of any form whatsoever must retain the following 23 * acknowledgment: 24 * "This product includes software developed by Paul Mackerras 25 * <paulus@samba.org>". 26 * 27 * THE AUTHORS OF THIS SOFTWARE DISCLAIM ALL WARRANTIES WITH REGARD TO 28 * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY 29 * AND FITNESS, IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY 30 * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 31 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN 32 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING 33 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 34 * 35 * $Id: ppp-comp.h,v 1.13 2002/12/06 09:49:15 paulus Exp $ 36 */ 37 38#ifndef _NET_PPP_COMP_H 39#define _NET_PPP_COMP_H 40 41/* 42 * The following symbols control whether we include code for 43 * various compression methods. 44 */ 45#ifndef DO_BSD_COMPRESS 46#define DO_BSD_COMPRESS 1 /* by default, include BSD-Compress */ 47#endif 48#ifndef DO_DEFLATE 49#define DO_DEFLATE 1 /* by default, include Deflate */ 50#endif 51#define DO_PREDICTOR_1 0 52#define DO_PREDICTOR_2 0 53 54/* 55 * Structure giving methods for compression/decompression. 56 */ 57#ifdef PACKETPTR 58struct compressor { 59 int compress_proto; /* CCP compression protocol number */ 60 61 /* Allocate space for a compressor (transmit side) */ 62 void *(*comp_alloc) __P((u_char *options, int opt_len)); 63 /* Free space used by a compressor */ 64 void (*comp_free) __P((void *state)); 65 /* Initialize a compressor */ 66 int (*comp_init) __P((void *state, u_char *options, int opt_len, 67 int unit, int hdrlen, int debug)); 68 /* Reset a compressor */ 69 void (*comp_reset) __P((void *state)); 70 /* Compress a packet */ 71 int (*compress) __P((void *state, PACKETPTR *mret, 72 PACKETPTR mp, int orig_len, int max_len)); 73 /* Return compression statistics */ 74 void (*comp_stat) __P((void *state, struct compstat *stats)); 75 76 /* Allocate space for a decompressor (receive side) */ 77 void *(*decomp_alloc) __P((u_char *options, int opt_len)); 78 /* Free space used by a decompressor */ 79 void (*decomp_free) __P((void *state)); 80 /* Initialize a decompressor */ 81 int (*decomp_init) __P((void *state, u_char *options, int opt_len, 82 int unit, int hdrlen, int mru, int debug)); 83 /* Reset a decompressor */ 84 void (*decomp_reset) __P((void *state)); 85 /* Decompress a packet. */ 86 int (*decompress) __P((void *state, PACKETPTR mp, 87 PACKETPTR *dmpp)); 88 /* Update state for an incompressible packet received */ 89 void (*incomp) __P((void *state, PACKETPTR mp)); 90 /* Return decompression statistics */ 91 void (*decomp_stat) __P((void *state, struct compstat *stats)); 92}; 93#endif /* PACKETPTR */ 94 95/* 96 * Return values for decompress routine. 97 * We need to make these distinctions so that we can disable certain 98 * useful functionality, namely sending a CCP reset-request as a result 99 * of an error detected after decompression. This is to avoid infringing 100 * a patent held by Motorola. 101 * Don't you just lurve software patents. 102 */ 103#define DECOMP_OK 0 /* everything went OK */ 104#define DECOMP_ERROR 1 /* error detected before decomp. */ 105#define DECOMP_FATALERROR 2 /* error detected after decomp. */ 106 107/* 108 * CCP codes. 109 */ 110#define CCP_CONFREQ 1 111#define CCP_CONFACK 2 112#define CCP_TERMREQ 5 113#define CCP_TERMACK 6 114#define CCP_RESETREQ 14 115#define CCP_RESETACK 15 116 117/* 118 * Max # bytes for a CCP option 119 */ 120#define CCP_MAX_OPTION_LENGTH 32 121 122/* 123 * Parts of a CCP packet. 124 */ 125#define CCP_CODE(dp) ((dp)[0]) 126#define CCP_ID(dp) ((dp)[1]) 127#define CCP_LENGTH(dp) (((dp)[2] << 8) + (dp)[3]) 128#define CCP_HDRLEN 4 129 130#define CCP_OPT_CODE(dp) ((dp)[0]) 131#define CCP_OPT_LENGTH(dp) ((dp)[1]) 132#define CCP_OPT_MINLEN 2 133 134/* 135 * Definitions for BSD-Compress. 136 */ 137#define CI_BSD_COMPRESS 21 /* config. option for BSD-Compress */ 138#define CILEN_BSD_COMPRESS 3 /* length of config. option */ 139 140/* Macros for handling the 3rd byte of the BSD-Compress config option. */ 141#define BSD_NBITS(x) ((x) & 0x1F) /* number of bits requested */ 142#define BSD_VERSION(x) ((x) >> 5) /* version of option format */ 143#define BSD_CURRENT_VERSION 1 /* current version number */ 144#define BSD_MAKE_OPT(v, n) (((v) << 5) | (n)) 145 146#define BSD_MIN_BITS 9 /* smallest code size supported */ 147#define BSD_MAX_BITS 15 /* largest code size supported */ 148 149/* 150 * Definitions for Deflate. 151 */ 152#define CI_DEFLATE 26 /* config option for Deflate */ 153#define CI_DEFLATE_DRAFT 24 /* value used in original draft RFC */ 154#define CILEN_DEFLATE 4 /* length of its config option */ 155 156#define DEFLATE_MIN_SIZE 8 157#define DEFLATE_MAX_SIZE 15 158#define DEFLATE_METHOD_VAL 8 159#define DEFLATE_SIZE(x) (((x) >> 4) + DEFLATE_MIN_SIZE) 160#define DEFLATE_METHOD(x) ((x) & 0x0F) 161#define DEFLATE_MAKE_OPT(w) ((((w) - DEFLATE_MIN_SIZE) << 4) \ 162 + DEFLATE_METHOD_VAL) 163#define DEFLATE_CHK_SEQUENCE 0 164 165/* 166 * Definitions for MPPE. 167 */ 168#define CI_MPPE 18 /* config option for MPPE */ 169#define CILEN_MPPE 6 /* length of config option */ 170 171#define MPPE_PAD 4 /* MPPE growth per frame */ 172#define MPPE_MAX_KEY_LEN 16 /* largest key length (128-bit) */ 173 174/* option bits for ccp_options.mppe */ 175#define MPPE_OPT_40 0x01 /* 40 bit */ 176#define MPPE_OPT_128 0x02 /* 128 bit */ 177#define MPPE_OPT_STATEFUL 0x04 /* stateful mode */ 178/* unsupported opts */ 179#define MPPE_OPT_56 0x08 /* 56 bit */ 180#define MPPE_OPT_MPPC 0x10 /* MPPC compression */ 181#define MPPE_OPT_D 0x20 /* Unknown */ 182#define MPPE_OPT_UNSUPPORTED (MPPE_OPT_56|MPPE_OPT_MPPC|MPPE_OPT_D) 183#define MPPE_OPT_UNKNOWN 0x40 /* Bits !defined in RFC 3078 were set */ 184 185/* 186 * This is not nice ... the alternative is a bitfield struct though. 187 * And unfortunately, we cannot share the same bits for the option 188 * names above since C and H are the same bit. We could do a u_int32 189 * but then we have to do a htonl() all the time and/or we still need 190 * to know which octet is which. 191 */ 192#define MPPE_C_BIT 0x01 /* MPPC */ 193#define MPPE_D_BIT 0x10 /* Obsolete, usage unknown */ 194#define MPPE_L_BIT 0x20 /* 40-bit */ 195#define MPPE_S_BIT 0x40 /* 128-bit */ 196#define MPPE_M_BIT 0x80 /* 56-bit, not supported */ 197#define MPPE_H_BIT 0x01 /* Stateless (in a different byte) */ 198 199/* Does not include H bit; used for least significant octet only. */ 200#define MPPE_ALL_BITS (MPPE_D_BIT|MPPE_L_BIT|MPPE_S_BIT|MPPE_M_BIT|MPPE_H_BIT) 201 202/* Build a CI from mppe opts (see RFC 3078) */ 203#define MPPE_OPTS_TO_CI(opts, ci) \ 204 do { \ 205 u_char *ptr = ci; /* u_char[4] */ \ 206 \ 207 /* H bit */ \ 208 if (opts & MPPE_OPT_STATEFUL) \ 209 *ptr++ = 0x0; \ 210 else \ 211 *ptr++ = MPPE_H_BIT; \ 212 *ptr++ = 0; \ 213 *ptr++ = 0; \ 214 \ 215 /* S,L bits */ \ 216 *ptr = 0; \ 217 if (opts & MPPE_OPT_128) \ 218 *ptr |= MPPE_S_BIT; \ 219 if (opts & MPPE_OPT_40) \ 220 *ptr |= MPPE_L_BIT; \ 221 /* M,D,C bits not supported */ \ 222 } while (/* CONSTCOND */ 0) 223 224/* The reverse of the above */ 225#define MPPE_CI_TO_OPTS(ci, opts) \ 226 do { \ 227 u_char *ptr = ci; /* u_char[4] */ \ 228 \ 229 opts = 0; \ 230 \ 231 /* H bit */ \ 232 if (!(ptr[0] & MPPE_H_BIT)) \ 233 opts |= MPPE_OPT_STATEFUL; \ 234 \ 235 /* S,L bits */ \ 236 if (ptr[3] & MPPE_S_BIT) \ 237 opts |= MPPE_OPT_128; \ 238 if (ptr[3] & MPPE_L_BIT) \ 239 opts |= MPPE_OPT_40; \ 240 \ 241 /* M,D,C bits */ \ 242 if (ptr[3] & MPPE_M_BIT) \ 243 opts |= MPPE_OPT_56; \ 244 if (ptr[3] & MPPE_D_BIT) \ 245 opts |= MPPE_OPT_D; \ 246 if (ptr[3] & MPPE_C_BIT) \ 247 opts |= MPPE_OPT_MPPC; \ 248 \ 249 /* Other bits */ \ 250 if (ptr[0] & ~MPPE_H_BIT) \ 251 opts |= MPPE_OPT_UNKNOWN; \ 252 if (ptr[1] || ptr[2]) \ 253 opts |= MPPE_OPT_UNKNOWN; \ 254 if (ptr[3] & ~MPPE_ALL_BITS) \ 255 opts |= MPPE_OPT_UNKNOWN; \ 256 } while (/* CONSTCOND */ 0) 257 258/* 259 * Definitions for other, as yet unsupported, compression methods. 260 */ 261#define CI_PREDICTOR_1 1 /* config option for Predictor-1 */ 262#define CILEN_PREDICTOR_1 2 /* length of its config option */ 263#define CI_PREDICTOR_2 2 /* config option for Predictor-2 */ 264#define CILEN_PREDICTOR_2 2 /* length of its config option */ 265 266#endif /* _NET_PPP_COMP_H */ 267