/* $NetBSD: ppp-comp.h,v 1.17 2025/11/24 08:04:28 nia Exp $ */ /* * ppp-comp.h - Definitions for doing PPP packet compression. * * Copyright (c) 1989-2002 Paul Mackerras. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * * 3. The name(s) of the authors of this software must not be used to * endorse or promote products derived from this software without * prior written permission. * * THE AUTHORS OF THIS SOFTWARE DISCLAIM ALL WARRANTIES WITH REGARD TO * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY * AND FITNESS, IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ #ifndef _NET_PPP_COMP_H_ #define _NET_PPP_COMP_H_ /* * The following symbols control whether we include code for * various compression methods. */ #ifndef DO_BSD_COMPRESS #define DO_BSD_COMPRESS 1 /* by default, include BSD-Compress */ #endif #ifndef DO_DEFLATE #define DO_DEFLATE 1 /* by default, include Deflate */ #endif #define DO_PREDICTOR_1 0 #define DO_PREDICTOR_2 0 /* * How many entries to make available in the compressors table */ #ifndef PPP_COMPRESSORS_MAX #define PPP_COMPRESSORS_MAX 8 #endif /* * Structure giving methods for compression/decompression. */ #ifdef PACKETPTR #include <sys/queue.h> struct compressor { int compress_proto; /* CCP compression protocol number */ /* Allocate space for a compressor (transmit side) */ void *(*comp_alloc)(u_char *, int); /* Free space used by a compressor */ void (*comp_free)(void *); /* Initialize a compressor */ int (*comp_init)(void *, u_char *, int, int, int, int); /* Reset a compressor */ void (*comp_reset)(void *); /* Compress a packet */ int (*compress)(void *, PACKETPTR *, PACKETPTR, int, int); /* Return compression statistics */ void (*comp_stat)(void *, struct compstat *); /* Allocate space for a decompressor (receive side) */ void *(*decomp_alloc)(u_char *, int); /* Free space used by a decompressor */ void (*decomp_free)(void *); /* Initialize a decompressor */ int (*decomp_init)(void *, u_char *, int, int, int, int, int); /* Reset a decompressor */ void (*decomp_reset)(void *); /* Decompress a packet. */ int (*decompress)(void *, PACKETPTR, PACKETPTR *); /* Update state for an incompressible packet received */ void (*incomp)(void *, PACKETPTR); /* Return decompression statistics */ void (*decomp_stat)(void *, struct compstat *); LIST_ENTRY(compressor) comp_list; unsigned int comp_refcnt; }; #endif /* PACKETPTR */ /* * Return values for decompress routine. * We need to make these distinctions so that we can disable certain * useful functionality, namely sending a CCP reset-request as a result * of an error detected after decompression. This is to avoid infringing * a patent held by Motorola. * Don't you just lurve software patents. */ #define DECOMP_OK 0 /* everything went OK */ #define DECOMP_ERROR 1 /* error detected before decomp. */ #define DECOMP_FATALERROR 2 /* error detected after decomp. */ /* * CCP codes. */ #define CCP_CONFREQ 1 #define CCP_CONFACK 2 #define CCP_CONFNAK 3 #define CCP_CONFREJ 4 #define CCP_TERMREQ 5 #define CCP_TERMACK 6 #define CCP_RESETREQ 14 #define CCP_RESETACK 15 /* * Max # bytes for a CCP option */ #define CCP_MAX_OPTION_LENGTH 64 /* * Parts of a CCP packet. */ #define CCP_CODE(dp) ((dp)[0]) #define CCP_ID(dp) ((dp)[1]) #define CCP_LENGTH(dp) (((dp)[2] << 8) + (dp)[3]) #define CCP_HDRLEN 4 #define CCP_OPT_CODE(dp) ((dp)[0]) #define CCP_OPT_LENGTH(dp) ((dp)[1]) #define CCP_OPT_MINLEN 2 /* * Definitions for BSD-Compress. */ #define CI_BSD_COMPRESS 21 /* config. option for BSD-Compress */ #define CILEN_BSD_COMPRESS 3 /* length of config. option */ /* Macros for handling the 3rd byte of the BSD-Compress config option. */ #define BSD_NBITS(x) ((x) & 0x1F) /* number of bits requested */ #define BSD_VERSION(x) ((x) >> 5) /* version of option format */ #define BSD_CURRENT_VERSION 1 /* current version number */ #define BSD_MAKE_OPT(v, n) (((v) << 5) | (n)) #define BSD_MIN_BITS 9 /* smallest code size supported */ #define BSD_MAX_BITS 15 /* largest code size supported */ /* * Definitions for Deflate. */ #define CI_DEFLATE 26 /* config option for Deflate */ #define CI_DEFLATE_DRAFT 24 /* value used in original draft RFC */ #define CILEN_DEFLATE 4 /* length of its config option */ #define DEFLATE_MIN_SIZE 8 #define DEFLATE_MAX_SIZE 15 #define DEFLATE_METHOD_VAL 8 #define DEFLATE_SIZE(x) (((x) >> 4) + DEFLATE_MIN_SIZE) #define DEFLATE_METHOD(x) ((x) & 0x0F) #define DEFLATE_MAKE_OPT(w) ((((w) - DEFLATE_MIN_SIZE) << 4) \ + DEFLATE_METHOD_VAL) #define DEFLATE_CHK_SEQUENCE 0 /* * Definitions for MPPE. */ #define CI_MPPE 18 /* config option for MPPE */ #define CILEN_MPPE 6 /* length of config option */ #define MPPE_PAD 4 /* MPPE growth per frame */ #define MPPE_MAX_KEY_LEN 16 /* largest key length (128-bit) */ /* option bits for ccp_options.mppe */ #define MPPE_OPT_40 0x01 /* 40 bit */ #define MPPE_OPT_128 0x02 /* 128 bit */ #define MPPE_OPT_STATEFUL 0x04 /* stateful mode */ /* unsupported opts */ #define MPPE_OPT_56 0x08 /* 56 bit */ #define MPPE_OPT_MPPC 0x10 /* MPPC compression */ #define MPPE_OPT_D 0x20 /* Unknown */ #define MPPE_OPT_UNSUPPORTED (MPPE_OPT_56|MPPE_OPT_MPPC|MPPE_OPT_D) #define MPPE_OPT_UNKNOWN 0x40 /* Bits !defined in RFC 3078 were set */ /* * This is not nice ... the alternative is a bitfield struct though. * And unfortunately, we cannot share the same bits for the option * names above since C and H are the same bit. We could do a uint32_t * but then we have to do a htonl() all the time and/or we still need * to know which octet is which. */ #define MPPE_C_BIT 0x01 /* MPPC */ #define MPPE_D_BIT 0x10 /* Obsolete, usage unknown */ #define MPPE_L_BIT 0x20 /* 40-bit */ #define MPPE_S_BIT 0x40 /* 128-bit */ #define MPPE_M_BIT 0x80 /* 56-bit, not supported */ #define MPPE_H_BIT 0x01 /* Stateless (in a different byte) */ /* Does not include H bit; used for least significant octet only. */ #define MPPE_ALL_BITS (MPPE_D_BIT|MPPE_L_BIT|MPPE_S_BIT|MPPE_M_BIT|MPPE_H_BIT) /* Build a CI from mppe opts (see RFC 3078) */ #define MPPE_OPTS_TO_CI(opts, ci) \ do { \ u_char *ptr = ci; /* u_char[4] */ \ \ /* H bit */ \ if (opts & MPPE_OPT_STATEFUL) \ *ptr++ = 0x0; \ else \ *ptr++ = MPPE_H_BIT; \ *ptr++ = 0; \ *ptr++ = 0; \ \ /* S,L bits */ \ *ptr = 0; \ if (opts & MPPE_OPT_128) \ *ptr |= MPPE_S_BIT; \ if (opts & MPPE_OPT_40) \ *ptr |= MPPE_L_BIT; \ /* M,D,C bits not supported */ \ } while (/* CONSTCOND */ 0) /* The reverse of the above */ #define MPPE_CI_TO_OPTS(ci, opts) \ do { \ u_char *ptr = ci; /* u_char[4] */ \ \ opts = 0; \ \ /* H bit */ \ if (!(ptr[0] & MPPE_H_BIT)) \ opts |= MPPE_OPT_STATEFUL; \ \ /* S,L bits */ \ if (ptr[3] & MPPE_S_BIT) \ opts |= MPPE_OPT_128; \ if (ptr[3] & MPPE_L_BIT) \ opts |= MPPE_OPT_40; \ \ /* M,D,C bits */ \ if (ptr[3] & MPPE_M_BIT) \ opts |= MPPE_OPT_56; \ if (ptr[3] & MPPE_D_BIT) \ opts |= MPPE_OPT_D; \ if (ptr[3] & MPPE_C_BIT) \ opts |= MPPE_OPT_MPPC; \ \ /* Other bits */ \ if (ptr[0] & ~MPPE_H_BIT) \ opts |= MPPE_OPT_UNKNOWN; \ if (ptr[1] || ptr[2]) \ opts |= MPPE_OPT_UNKNOWN; \ if (ptr[3] & ~MPPE_ALL_BITS) \ opts |= MPPE_OPT_UNKNOWN; \ } while (/* CONSTCOND */ 0) /* * Definitions for other, as yet unsupported, compression methods. */ #define CI_PREDICTOR_1 1 /* config option for Predictor-1 */ #define CILEN_PREDICTOR_1 2 /* length of its config option */ #define CI_PREDICTOR_2 2 /* config option for Predictor-2 */ #define CILEN_PREDICTOR_2 2 /* length of its config option */ #endif /* !_NET_PPP_COMP_H_ */
