| 1 | /* $NetBSD: ppp-comp.h,v 1.16 2008/11/29 23:15:20 cube Exp $ */ |
| 2 | |
| 3 | /* |
| 4 | * ppp-comp.h - Definitions for doing PPP packet compression. |
| 5 | * |
| 6 | * Copyright (c) 1989-2002 Paul Mackerras. All rights reserved. |
| 7 | * |
| 8 | * Redistribution and use in source and binary forms, with or without |
| 9 | * modification, are permitted provided that the following conditions |
| 10 | * are met: |
| 11 | * |
| 12 | * 1. Redistributions of source code must retain the above copyright |
| 13 | * notice, this list of conditions and the following disclaimer. |
| 14 | * |
| 15 | * 2. Redistributions in binary form must reproduce the above copyright |
| 16 | * notice, this list of conditions and the following disclaimer in |
| 17 | * the documentation and/or other materials provided with the |
| 18 | * distribution. |
| 19 | * |
| 20 | * 3. The name(s) of the authors of this software must not be used to |
| 21 | * endorse or promote products derived from this software without |
| 22 | * prior written permission. |
| 23 | * |
| 24 | * 4. Redistributions of any form whatsoever must retain the following |
| 25 | * acknowledgment: |
| 26 | * "This product includes software developed by Paul Mackerras |
| 27 | * <paulus@samba.org>". |
| 28 | * |
| 29 | * THE AUTHORS OF THIS SOFTWARE DISCLAIM ALL WARRANTIES WITH REGARD TO |
| 30 | * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY |
| 31 | * AND FITNESS, IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY |
| 32 | * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
| 33 | * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN |
| 34 | * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING |
| 35 | * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
| 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 | * How many entries to make available in the compressors table |
| 56 | */ |
| 57 | #ifndef PPP_COMPRESSORS_MAX |
| 58 | #define PPP_COMPRESSORS_MAX 8 |
| 59 | #endif |
| 60 | |
| 61 | /* |
| 62 | * Structure giving methods for compression/decompression. |
| 63 | */ |
| 64 | #ifdef PACKETPTR |
| 65 | #include <sys/queue.h> |
| 66 | |
| 67 | struct compressor { |
| 68 | int compress_proto; /* CCP compression protocol number */ |
| 69 | |
| 70 | /* Allocate space for a compressor (transmit side) */ |
| 71 | void *(*comp_alloc)(u_char *, int); |
| 72 | /* Free space used by a compressor */ |
| 73 | void (*comp_free)(void *); |
| 74 | /* Initialize a compressor */ |
| 75 | int (*comp_init)(void *, u_char *, int, int, int, int); |
| 76 | /* Reset a compressor */ |
| 77 | void (*comp_reset)(void *); |
| 78 | /* Compress a packet */ |
| 79 | int (*compress)(void *, PACKETPTR *, PACKETPTR, int, int); |
| 80 | /* Return compression statistics */ |
| 81 | void (*comp_stat)(void *, struct compstat *); |
| 82 | |
| 83 | /* Allocate space for a decompressor (receive side) */ |
| 84 | void *(*decomp_alloc)(u_char *, int); |
| 85 | /* Free space used by a decompressor */ |
| 86 | void (*decomp_free)(void *); |
| 87 | /* Initialize a decompressor */ |
| 88 | int (*decomp_init)(void *, u_char *, int, int, int, int, int); |
| 89 | /* Reset a decompressor */ |
| 90 | void (*decomp_reset)(void *); |
| 91 | /* Decompress a packet. */ |
| 92 | int (*decompress)(void *, PACKETPTR, PACKETPTR *); |
| 93 | /* Update state for an incompressible packet received */ |
| 94 | void (*incomp)(void *, PACKETPTR); |
| 95 | /* Return decompression statistics */ |
| 96 | void (*decomp_stat)(void *, struct compstat *); |
| 97 | |
| 98 | LIST_ENTRY(compressor) comp_list; |
| 99 | unsigned int comp_refcnt; |
| 100 | }; |
| 101 | #endif /* PACKETPTR */ |
| 102 | |
| 103 | /* |
| 104 | * Return values for decompress routine. |
| 105 | * We need to make these distinctions so that we can disable certain |
| 106 | * useful functionality, namely sending a CCP reset-request as a result |
| 107 | * of an error detected after decompression. This is to avoid infringing |
| 108 | * a patent held by Motorola. |
| 109 | * Don't you just lurve software patents. |
| 110 | */ |
| 111 | #define DECOMP_OK 0 /* everything went OK */ |
| 112 | #define DECOMP_ERROR 1 /* error detected before decomp. */ |
| 113 | #define DECOMP_FATALERROR 2 /* error detected after decomp. */ |
| 114 | |
| 115 | /* |
| 116 | * CCP codes. |
| 117 | */ |
| 118 | #define CCP_CONFREQ 1 |
| 119 | #define CCP_CONFACK 2 |
| 120 | #define CCP_CONFNAK 3 |
| 121 | #define CCP_CONFREJ 4 |
| 122 | #define CCP_TERMREQ 5 |
| 123 | #define CCP_TERMACK 6 |
| 124 | #define CCP_RESETREQ 14 |
| 125 | #define CCP_RESETACK 15 |
| 126 | |
| 127 | /* |
| 128 | * Max # bytes for a CCP option |
| 129 | */ |
| 130 | #define CCP_MAX_OPTION_LENGTH 64 |
| 131 | |
| 132 | /* |
| 133 | * Parts of a CCP packet. |
| 134 | */ |
| 135 | #define CCP_CODE(dp) ((dp)[0]) |
| 136 | #define CCP_ID(dp) ((dp)[1]) |
| 137 | #define CCP_LENGTH(dp) (((dp)[2] << 8) + (dp)[3]) |
| 138 | #define CCP_HDRLEN 4 |
| 139 | |
| 140 | #define CCP_OPT_CODE(dp) ((dp)[0]) |
| 141 | #define CCP_OPT_LENGTH(dp) ((dp)[1]) |
| 142 | #define CCP_OPT_MINLEN 2 |
| 143 | |
| 144 | /* |
| 145 | * Definitions for BSD-Compress. |
| 146 | */ |
| 147 | #define CI_BSD_COMPRESS 21 /* config. option for BSD-Compress */ |
| 148 | #define CILEN_BSD_COMPRESS 3 /* length of config. option */ |
| 149 | |
| 150 | /* Macros for handling the 3rd byte of the BSD-Compress config option. */ |
| 151 | #define BSD_NBITS(x) ((x) & 0x1F) /* number of bits requested */ |
| 152 | #define BSD_VERSION(x) ((x) >> 5) /* version of option format */ |
| 153 | #define BSD_CURRENT_VERSION 1 /* current version number */ |
| 154 | #define BSD_MAKE_OPT(v, n) (((v) << 5) | (n)) |
| 155 | |
| 156 | #define BSD_MIN_BITS 9 /* smallest code size supported */ |
| 157 | #define BSD_MAX_BITS 15 /* largest code size supported */ |
| 158 | |
| 159 | /* |
| 160 | * Definitions for Deflate. |
| 161 | */ |
| 162 | #define CI_DEFLATE 26 /* config option for Deflate */ |
| 163 | #define CI_DEFLATE_DRAFT 24 /* value used in original draft RFC */ |
| 164 | |
| 165 | #define CILEN_DEFLATE 4 /* length of its config option */ |
| 166 | |
| 167 | #define DEFLATE_MIN_SIZE 8 |
| 168 | #define DEFLATE_MAX_SIZE 15 |
| 169 | #define DEFLATE_METHOD_VAL 8 |
| 170 | #define DEFLATE_SIZE(x) (((x) >> 4) + DEFLATE_MIN_SIZE) |
| 171 | #define DEFLATE_METHOD(x) ((x) & 0x0F) |
| 172 | #define DEFLATE_MAKE_OPT(w) ((((w) - DEFLATE_MIN_SIZE) << 4) \ |
| 173 | + DEFLATE_METHOD_VAL) |
| 174 | #define DEFLATE_CHK_SEQUENCE 0 |
| 175 | |
| 176 | /* |
| 177 | * Definitions for MPPE. |
| 178 | */ |
| 179 | #define CI_MPPE 18 /* config option for MPPE */ |
| 180 | #define CILEN_MPPE 6 /* length of config option */ |
| 181 | |
| 182 | #define MPPE_PAD 4 /* MPPE growth per frame */ |
| 183 | #define MPPE_MAX_KEY_LEN 16 /* largest key length (128-bit) */ |
| 184 | |
| 185 | /* option bits for ccp_options.mppe */ |
| 186 | #define MPPE_OPT_40 0x01 /* 40 bit */ |
| 187 | #define MPPE_OPT_128 0x02 /* 128 bit */ |
| 188 | #define MPPE_OPT_STATEFUL 0x04 /* stateful mode */ |
| 189 | /* unsupported opts */ |
| 190 | #define MPPE_OPT_56 0x08 /* 56 bit */ |
| 191 | #define MPPE_OPT_MPPC 0x10 /* MPPC compression */ |
| 192 | #define MPPE_OPT_D 0x20 /* Unknown */ |
| 193 | #define MPPE_OPT_UNSUPPORTED (MPPE_OPT_56|MPPE_OPT_MPPC|MPPE_OPT_D) |
| 194 | #define MPPE_OPT_UNKNOWN 0x40 /* Bits !defined in RFC 3078 were set */ |
| 195 | |
| 196 | /* |
| 197 | * This is not nice ... the alternative is a bitfield struct though. |
| 198 | * And unfortunately, we cannot share the same bits for the option |
| 199 | * names above since C and H are the same bit. We could do a uint32_t |
| 200 | * but then we have to do a htonl() all the time and/or we still need |
| 201 | * to know which octet is which. |
| 202 | */ |
| 203 | #define MPPE_C_BIT 0x01 /* MPPC */ |
| 204 | #define MPPE_D_BIT 0x10 /* Obsolete, usage unknown */ |
| 205 | #define MPPE_L_BIT 0x20 /* 40-bit */ |
| 206 | #define MPPE_S_BIT 0x40 /* 128-bit */ |
| 207 | #define MPPE_M_BIT 0x80 /* 56-bit, not supported */ |
| 208 | #define MPPE_H_BIT 0x01 /* Stateless (in a different byte) */ |
| 209 | |
| 210 | /* Does not include H bit; used for least significant octet only. */ |
| 211 | #define MPPE_ALL_BITS (MPPE_D_BIT|MPPE_L_BIT|MPPE_S_BIT|MPPE_M_BIT|MPPE_H_BIT) |
| 212 | |
| 213 | /* Build a CI from mppe opts (see RFC 3078) */ |
| 214 | #define MPPE_OPTS_TO_CI(opts, ci) \ |
| 215 | do { \ |
| 216 | u_char *ptr = ci; /* u_char[4] */ \ |
| 217 | \ |
| 218 | /* H bit */ \ |
| 219 | if (opts & MPPE_OPT_STATEFUL) \ |
| 220 | *ptr++ = 0x0; \ |
| 221 | else \ |
| 222 | *ptr++ = MPPE_H_BIT; \ |
| 223 | *ptr++ = 0; \ |
| 224 | *ptr++ = 0; \ |
| 225 | \ |
| 226 | /* S,L bits */ \ |
| 227 | *ptr = 0; \ |
| 228 | if (opts & MPPE_OPT_128) \ |
| 229 | *ptr |= MPPE_S_BIT; \ |
| 230 | if (opts & MPPE_OPT_40) \ |
| 231 | *ptr |= MPPE_L_BIT; \ |
| 232 | /* M,D,C bits not supported */ \ |
| 233 | } while (/* CONSTCOND */ 0) |
| 234 | |
| 235 | /* The reverse of the above */ |
| 236 | #define MPPE_CI_TO_OPTS(ci, opts) \ |
| 237 | do { \ |
| 238 | u_char *ptr = ci; /* u_char[4] */ \ |
| 239 | \ |
| 240 | opts = 0; \ |
| 241 | \ |
| 242 | /* H bit */ \ |
| 243 | if (!(ptr[0] & MPPE_H_BIT)) \ |
| 244 | opts |= MPPE_OPT_STATEFUL; \ |
| 245 | \ |
| 246 | /* S,L bits */ \ |
| 247 | if (ptr[3] & MPPE_S_BIT) \ |
| 248 | opts |= MPPE_OPT_128; \ |
| 249 | if (ptr[3] & MPPE_L_BIT) \ |
| 250 | opts |= MPPE_OPT_40; \ |
| 251 | \ |
| 252 | /* M,D,C bits */ \ |
| 253 | if (ptr[3] & MPPE_M_BIT) \ |
| 254 | opts |= MPPE_OPT_56; \ |
| 255 | if (ptr[3] & MPPE_D_BIT) \ |
| 256 | opts |= MPPE_OPT_D; \ |
| 257 | if (ptr[3] & MPPE_C_BIT) \ |
| 258 | opts |= MPPE_OPT_MPPC; \ |
| 259 | \ |
| 260 | /* Other bits */ \ |
| 261 | if (ptr[0] & ~MPPE_H_BIT) \ |
| 262 | opts |= MPPE_OPT_UNKNOWN; \ |
| 263 | if (ptr[1] || ptr[2]) \ |
| 264 | opts |= MPPE_OPT_UNKNOWN; \ |
| 265 | if (ptr[3] & ~MPPE_ALL_BITS) \ |
| 266 | opts |= MPPE_OPT_UNKNOWN; \ |
| 267 | } while (/* CONSTCOND */ 0) |
| 268 | |
| 269 | /* |
| 270 | * Definitions for other, as yet unsupported, compression methods. |
| 271 | */ |
| 272 | #define CI_PREDICTOR_1 1 /* config option for Predictor-1 */ |
| 273 | #define CILEN_PREDICTOR_1 2 /* length of its config option */ |
| 274 | #define CI_PREDICTOR_2 2 /* config option for Predictor-2 */ |
| 275 | #define CILEN_PREDICTOR_2 2 /* length of its config option */ |
| 276 | |
| 277 | #endif /* !_NET_PPP_COMP_H_ */ |
| 278 | |