--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/include/linux/ppp-comp.h Sun Jan 11 20:20:11 2009 +0100
@@ -0,0 +1,214 @@
+/*
+ * ppp-comp.h - Definitions for doing PPP packet compression.
+ *
+ * Copyright (c) 1994 The Australian National University.
+ * All rights reserved.
+ *
+ * Permission to use, copy, modify, and distribute this software and its
+ * documentation is hereby granted, provided that the above copyright
+ * notice appears in all copies. This software is provided without any
+ * warranty, express or implied. The Australian National University
+ * makes no representations about the suitability of this software for
+ * any purpose.
+ *
+ * IN NO EVENT SHALL THE AUSTRALIAN NATIONAL UNIVERSITY BE LIABLE TO ANY
+ * PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
+ * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
+ * THE AUSTRALIAN NATIONAL UNIVERSITY HAVE BEEN ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * THE AUSTRALIAN NATIONAL UNIVERSITY SPECIFICALLY DISCLAIMS ANY WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
+ * ON AN "AS IS" BASIS, AND THE AUSTRALIAN NATIONAL UNIVERSITY HAS NO
+ * OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS,
+ * OR MODIFICATIONS.
+ */
+
+/*
+ * ==FILEVERSION 980319==
+ *
+ * NOTE TO MAINTAINERS:
+ * If you modify this file at all, please set the above date.
+ * ppp-comp.h is shipped with a PPP distribution as well as with the kernel;
+ * if everyone increases the FILEVERSION number above, then scripts
+ * can do the right thing when deciding whether to install a new ppp-comp.h
+ * file. Don't change the format of that line otherwise, so the
+ * installation script can recognize it.
+ */
+
+#ifndef _NET_PPP_COMP_H
+#define _NET_PPP_COMP_H
+
+struct module;
+
+/*
+ * 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
+
+/*
+ * Structure giving methods for compression/decompression.
+ */
+
+struct compressor {
+ int compress_proto; /* CCP compression protocol number */
+
+ /* Allocate space for a compressor (transmit side) */
+ void *(*comp_alloc) (unsigned char *options, int opt_len);
+
+ /* Free space used by a compressor */
+ void (*comp_free) (void *state);
+
+ /* Initialize a compressor */
+ int (*comp_init) (void *state, unsigned char *options,
+ int opt_len, int unit, int opthdr, int debug);
+
+ /* Reset a compressor */
+ void (*comp_reset) (void *state);
+
+ /* Compress a packet */
+ int (*compress) (void *state, unsigned char *rptr,
+ unsigned char *obuf, int isize, int osize);
+
+ /* Return compression statistics */
+ void (*comp_stat) (void *state, struct compstat *stats);
+
+ /* Allocate space for a decompressor (receive side) */
+ void *(*decomp_alloc) (unsigned char *options, int opt_len);
+
+ /* Free space used by a decompressor */
+ void (*decomp_free) (void *state);
+
+ /* Initialize a decompressor */
+ int (*decomp_init) (void *state, unsigned char *options,
+ int opt_len, int unit, int opthdr, int mru,
+ int debug);
+
+ /* Reset a decompressor */
+ void (*decomp_reset) (void *state);
+
+ /* Decompress a packet. */
+ int (*decompress) (void *state, unsigned char *ibuf, int isize,
+ unsigned char *obuf, int osize);
+
+ /* Update state for an incompressible packet received */
+ void (*incomp) (void *state, unsigned char *ibuf, int icnt);
+
+ /* Return decompression statistics */
+ void (*decomp_stat) (void *state, struct compstat *stats);
+
+ /* Used in locking compressor modules */
+ struct module *owner;
+ /* Extra skb space needed by the compressor algorithm */
+ unsigned int comp_extra;
+};
+
+/*
+ * The return value from decompress routine is the length of the
+ * decompressed packet if successful, otherwise DECOMP_ERROR
+ * or DECOMP_FATALERROR if an error occurred.
+ *
+ * We need to make this distinction 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_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_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 32
+
+/*
+ * 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 9
+#define DEFLATE_MAX_SIZE 15
+#define DEFLATE_METHOD_VAL 8
+#define DEFLATE_SIZE(x) (((x) >> 4) + 8)
+#define DEFLATE_METHOD(x) ((x) & 0x0F)
+#define DEFLATE_MAKE_OPT(w) ((((w) - 8) << 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 */
+
+/*
+ * 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 */
+
+#ifdef __KERNEL__
+extern int ppp_register_compressor(struct compressor *);
+extern void ppp_unregister_compressor(struct compressor *);
+#endif /* __KERNEL__ */
+
+#endif /* _NET_PPP_COMP_H */