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 1.10 2002/12/06 09:49:15 paulus Exp $ 36 */ 37 38/* 39 * ==FILEVERSION 20020319== 40 * 41 * NOTE TO MAINTAINERS: 42 * If you modify this file at all, please set the above date. 43 * ppp-comp.h is shipped with a PPP distribution as well as with the kernel; 44 * if everyone increases the FILEVERSION number above, then scripts 45 * can do the right thing when deciding whether to install a new ppp-comp.h 46 * file. Don't change the format of that line otherwise, so the 47 * installation script can recognize it. 48 */ 49 50#ifndef _NET_PPP_COMP_H 51#define _NET_PPP_COMP_H 52 53/* 54 * The following symbols control whether we include code for 55 * various compression methods. 56 */ 57 58#ifndef DO_BSD_COMPRESS 59#define DO_BSD_COMPRESS 1 /* by default, include BSD-Compress */ 60#endif 61#ifndef DO_DEFLATE 62#define DO_DEFLATE 1 /* by default, include Deflate */ 63#endif 64#define DO_PREDICTOR_1 0 65#define DO_PREDICTOR_2 0 66 67/* 68 * Structure giving methods for compression/decompression. 69 */ 70 71struct compressor { 72 int compress_proto; /* CCP compression protocol number */ 73 74 /* Allocate space for a compressor (transmit side) */ 75 void *(*comp_alloc) (unsigned char *options, int opt_len); 76 77 /* Free space used by a compressor */ 78 void (*comp_free) (void *state); 79 80 /* Initialize a compressor */ 81 int (*comp_init) (void *state, unsigned char *options, 82 int opt_len, int unit, int opthdr, int debug); 83 84 /* Reset a compressor */ 85 void (*comp_reset) (void *state); 86 87 /* Compress a packet */ 88 int (*compress) (void *state, unsigned char *rptr, 89 unsigned char *obuf, int isize, int osize); 90 91 /* Return compression statistics */ 92 void (*comp_stat) (void *state, struct compstat *stats); 93 94 /* Allocate space for a decompressor (receive side) */ 95 void *(*decomp_alloc) (unsigned char *options, int opt_len); 96 97 /* Free space used by a decompressor */ 98 void (*decomp_free) (void *state); 99 100 /* Initialize a decompressor */ 101 int (*decomp_init) (void *state, unsigned char *options, 102 int opt_len, int unit, int opthdr, int mru, 103 int debug); 104 105 /* Reset a decompressor */ 106 void (*decomp_reset) (void *state); 107 108 /* Decompress a packet. */ 109 int (*decompress) (void *state, unsigned char *ibuf, int isize, 110 unsigned char *obuf, int osize); 111 112 /* Update state for an incompressible packet received */ 113 void (*incomp) (void *state, unsigned char *ibuf, int icnt); 114 115 /* Return decompression statistics */ 116 void (*decomp_stat) (void *state, struct compstat *stats); 117}; 118 119/* 120 * The return value from decompress routine is the length of the 121 * decompressed packet if successful, otherwise DECOMP_ERROR 122 * or DECOMP_FATALERROR if an error occurred. 123 * 124 * We need to make this distinction so that we can disable certain 125 * useful functionality, namely sending a CCP reset-request as a result 126 * of an error detected after decompression. This is to avoid infringing 127 * a patent held by Motorola. 128 * Don't you just lurve software patents. 129 */ 130 131#define DECOMP_ERROR -1 /* error detected before decomp. */ 132#define DECOMP_FATALERROR -2 /* error detected after decomp. */ 133 134/* 135 * CCP codes. 136 */ 137 138#define CCP_CONFREQ 1 139#define CCP_CONFACK 2 140#define CCP_TERMREQ 5 141#define CCP_TERMACK 6 142#define CCP_RESETREQ 14 143#define CCP_RESETACK 15 144 145/* 146 * Max # bytes for a CCP option 147 */ 148 149#define CCP_MAX_OPTION_LENGTH 32 150 151/* 152 * Parts of a CCP packet. 153 */ 154 155#define CCP_CODE(dp) ((dp)[0]) 156#define CCP_ID(dp) ((dp)[1]) 157#define CCP_LENGTH(dp) (((dp)[2] << 8) + (dp)[3]) 158#define CCP_HDRLEN 4 159 160#define CCP_OPT_CODE(dp) ((dp)[0]) 161#define CCP_OPT_LENGTH(dp) ((dp)[1]) 162#define CCP_OPT_MINLEN 2 163 164/* 165 * Definitions for BSD-Compress. 166 */ 167 168#define CI_BSD_COMPRESS 21 /* config. option for BSD-Compress */ 169#define CILEN_BSD_COMPRESS 3 /* length of config. option */ 170 171/* Macros for handling the 3rd byte of the BSD-Compress config option. */ 172#define BSD_NBITS(x) ((x) & 0x1F) /* number of bits requested */ 173#define BSD_VERSION(x) ((x) >> 5) /* version of option format */ 174#define BSD_CURRENT_VERSION 1 /* current version number */ 175#define BSD_MAKE_OPT(v, n) (((v) << 5) | (n)) 176 177#define BSD_MIN_BITS 9 /* smallest code size supported */ 178#define BSD_MAX_BITS 15 /* largest code size supported */ 179 180/* 181 * Definitions for Deflate. 182 */ 183 184#define CI_DEFLATE 26 /* config option for Deflate */ 185#define CI_DEFLATE_DRAFT 24 /* value used in original draft RFC */ 186#define CILEN_DEFLATE 4 /* length of its config option */ 187 188#define DEFLATE_MIN_SIZE 8 189#define DEFLATE_MAX_SIZE 15 190#define DEFLATE_METHOD_VAL 8 191#define DEFLATE_SIZE(x) (((x) >> 4) + DEFLATE_MIN_SIZE) 192#define DEFLATE_METHOD(x) ((x) & 0x0F) 193#define DEFLATE_MAKE_OPT(w) ((((w) - DEFLATE_MIN_SIZE) << 4) \ 194 + DEFLATE_METHOD_VAL) 195#define DEFLATE_CHK_SEQUENCE 0 196 197/* 198 * Definitions for MPPE. 199 */ 200 201#define CI_MPPE 18 /* config option for MPPE */ 202#define CILEN_MPPE 6 /* length of config option */ 203 204#define MPPE_PAD 4 /* MPPE growth per frame */ 205#define MPPE_MAX_KEY_LEN 16 /* largest key length (128-bit) */ 206 207/* option bits for ccp_options.mppe */ 208#define MPPE_OPT_40 0x01 /* 40 bit */ 209#define MPPE_OPT_128 0x02 /* 128 bit */ 210#define MPPE_OPT_STATEFUL 0x04 /* stateful mode */ 211/* unsupported opts */ 212#define MPPE_OPT_56 0x08 /* 56 bit */ 213#define MPPE_OPT_MPPC 0x10 /* MPPC compression */ 214#define MPPE_OPT_D 0x20 /* Unknown */ 215#define MPPE_OPT_UNSUPPORTED (MPPE_OPT_56|MPPE_OPT_MPPC|MPPE_OPT_D) 216#define MPPE_OPT_UNKNOWN 0x40 /* Bits !defined in RFC 3078 were set */ 217 218/* 219 * This is not nice ... the alternative is a bitfield struct though. 220 * And unfortunately, we cannot share the same bits for the option 221 * names above since C and H are the same bit. We could do a u_int32 222 * but then we have to do a htonl() all the time and/or we still need 223 * to know which octet is which. 224 */ 225#define MPPE_C_BIT 0x01 /* MPPC */ 226#define MPPE_D_BIT 0x10 /* Obsolete, usage unknown */ 227#define MPPE_L_BIT 0x20 /* 40-bit */ 228#define MPPE_S_BIT 0x40 /* 128-bit */ 229#define MPPE_M_BIT 0x80 /* 56-bit, not supported */ 230#define MPPE_H_BIT 0x01 /* Stateless (in a different byte) */ 231 232/* Does not include H bit; used for least significant octet only. */ 233#define MPPE_ALL_BITS (MPPE_D_BIT|MPPE_L_BIT|MPPE_S_BIT|MPPE_M_BIT|MPPE_H_BIT) 234 235/* Build a CI from mppe opts (see RFC 3078) */ 236#define MPPE_OPTS_TO_CI(opts, ci) \ 237 do { \ 238 u_char *ptr = ci; /* u_char[4] */ \ 239 \ 240 /* H bit */ \ 241 if (opts & MPPE_OPT_STATEFUL) \ 242 *ptr++ = 0x0; \ 243 else \ 244 *ptr++ = MPPE_H_BIT; \ 245 *ptr++ = 0; \ 246 *ptr++ = 0; \ 247 \ 248 /* S,L bits */ \ 249 *ptr = 0; \ 250 if (opts & MPPE_OPT_128) \ 251 *ptr |= MPPE_S_BIT; \ 252 if (opts & MPPE_OPT_40) \ 253 *ptr |= MPPE_L_BIT; \ 254 /* M,D,C bits not supported */ \ 255 } while (/* CONSTCOND */ 0) 256 257/* The reverse of the above */ 258#define MPPE_CI_TO_OPTS(ci, opts) \ 259 do { \ 260 u_char *ptr = ci; /* u_char[4] */ \ 261 \ 262 opts = 0; \ 263 \ 264 /* H bit */ \ 265 if (!(ptr[0] & MPPE_H_BIT)) \ 266 opts |= MPPE_OPT_STATEFUL; \ 267 \ 268 /* S,L bits */ \ 269 if (ptr[3] & MPPE_S_BIT) \ 270 opts |= MPPE_OPT_128; \ 271 if (ptr[3] & MPPE_L_BIT) \ 272 opts |= MPPE_OPT_40; \ 273 \ 274 /* M,D,C bits */ \ 275 if (ptr[3] & MPPE_M_BIT) \ 276 opts |= MPPE_OPT_56; \ 277 if (ptr[3] & MPPE_D_BIT) \ 278 opts |= MPPE_OPT_D; \ 279 if (ptr[3] & MPPE_C_BIT) \ 280 opts |= MPPE_OPT_MPPC; \ 281 \ 282 /* Other bits */ \ 283 if (ptr[0] & ~MPPE_H_BIT) \ 284 opts |= MPPE_OPT_UNKNOWN; \ 285 if (ptr[1] || ptr[2]) \ 286 opts |= MPPE_OPT_UNKNOWN; \ 287 if (ptr[3] & ~MPPE_ALL_BITS) \ 288 opts |= MPPE_OPT_UNKNOWN; \ 289 } while (/* CONSTCOND */ 0) 290 291/* 292 * Definitions for other, as yet unsupported, compression methods. 293 */ 294 295#define CI_PREDICTOR_1 1 /* config option for Predictor-1 */ 296#define CILEN_PREDICTOR_1 2 /* length of its config option */ 297#define CI_PREDICTOR_2 2 /* config option for Predictor-2 */ 298#define CILEN_PREDICTOR_2 2 /* length of its config option */ 299 300#ifdef __KERNEL__ 301extern int ppp_register_compressor(struct compressor *); 302extern void ppp_unregister_compressor(struct compressor *); 303#endif /* __KERNEL__ */ 304 305#endif /* _NET_PPP_COMP_H */ 306