+++ /dev/null
-/* $NetBSD: slcompress.h,v 1.12 1998/02/09 17:43:56 perry Exp $ */
-/* Id: slcompress.h,v 1.4 1994/09/21 06:50:08 paulus Exp */
-
-/*
- * Copyright (c) 1989, 1993
- * The Regents of the University of California. 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. All advertising materials mentioning features or use of this software
- * must display the following acknowledgement:
- * This product includes software developed by the University of
- * California, Berkeley and its contributors.
- * 4. Neither the name of the University nor the names of its contributors
- * may be used to endorse or promote products derived from this software
- * without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- *
- * @(#)slcompress.h 8.1 (Berkeley) 6/10/93
- */
-
-/*
- * Definitions for tcp compression routines.
- *
- * Van Jacobson (van@helios.ee.lbl.gov), Dec 31, 1989:
- * - Initial distribution.
- */
-
-#ifndef _NET_SLCOMPRESS_H_
-#define _NET_SLCOMPRESS_H_
-
-#define MAX_STATES 16 /* must be > 2 and < 256 */
-#define MAX_HDR MLEN /* XXX 4bsd-ism: should really be 128 */
-
-/*
- * Compressed packet format:
- *
- * The first octet contains the packet type (top 3 bits), TCP
- * 'push' bit, and flags that indicate which of the 4 TCP sequence
- * numbers have changed (bottom 5 bits). The next octet is a
- * conversation number that associates a saved IP/TCP header with
- * the compressed packet. The next two octets are the TCP checksum
- * from the original datagram. The next 0 to 15 octets are
- * sequence number changes, one change per bit set in the header
- * (there may be no changes and there are two special cases where
- * the receiver implicitly knows what changed -- see below).
- *
- * There are 5 numbers which can change (they are always inserted
- * in the following order): TCP urgent pointer, window,
- * acknowlegement, sequence number and IP ID. (The urgent pointer
- * is different from the others in that its value is sent, not the
- * change in value.) Since typical use of SLIP links is biased
- * toward small packets (see comments on MTU/MSS below), changes
- * use a variable length coding with one octet for numbers in the
- * range 1 - 255 and 3 octets (0, MSB, LSB) for numbers in the
- * range 256 - 65535 or 0. (If the change in sequence number or
- * ack is more than 65535, an uncompressed packet is sent.)
- */
-
-/*
- * Packet types (must not conflict with IP protocol version)
- *
- * The top nibble of the first octet is the packet type. There are
- * three possible types: IP (not proto TCP or tcp with one of the
- * control flags set); uncompressed TCP (a normal IP/TCP packet but
- * with the 8-bit protocol field replaced by an 8-bit connection id --
- * this type of packet syncs the sender & receiver); and compressed
- * TCP (described above).
- *
- * LSB of 4-bit field is TCP "PUSH" bit (a worthless anachronism) and
- * is logically part of the 4-bit "changes" field that follows. Top
- * three bits are actual packet type. For backward compatibility
- * and in the interest of conserving bits, numbers are chosen so the
- * IP protocol version number (4) which normally appears in this nibble
- * means "IP packet".
- */
-
-/* packet types */
-#define TYPE_IP 0x40
-#define TYPE_UNCOMPRESSED_TCP 0x70
-#define TYPE_COMPRESSED_TCP 0x80
-#define TYPE_ERROR 0x00
-
-/* Bits in first octet of compressed packet */
-#define NEW_C 0x40 /* flag bits for what changed in a packet */
-#define NEW_I 0x20
-#define NEW_S 0x08
-#define NEW_A 0x04
-#define NEW_W 0x02
-#define NEW_U 0x01
-
-/* reserved, special-case values of above */
-#define SPECIAL_I (NEW_S|NEW_W|NEW_U) /* echoed interactive traffic */
-#define SPECIAL_D (NEW_S|NEW_A|NEW_W|NEW_U) /* unidirectional data */
-#define SPECIALS_MASK (NEW_S|NEW_A|NEW_W|NEW_U)
-
-#define TCP_PUSH_BIT 0x10
-
-
-/*
- * "state" data for each active tcp conversation on the wire. This is
- * basically a copy of the entire IP/TCP header from the last packet
- * we saw from the conversation together with a small identifier
- * the transmit & receive ends of the line use to locate saved header.
- */
-struct cstate {
- struct cstate *cs_next; /* next most recently used cstate (xmit only) */
- u_int16_t cs_hlen; /* size of hdr (receive only) */
- u_char cs_id; /* connection # associated with this state */
- u_char cs_filler;
- union {
- char csu_hdr[MAX_HDR];
- struct ip csu_ip; /* ip/tcp hdr from most recent packet */
- } slcs_u;
-};
-#define cs_ip slcs_u.csu_ip
-#define cs_hdr slcs_u.csu_hdr
-
-/*
- * all the state data for one serial line (we need one of these
- * per line).
- */
-struct slcompress {
- struct cstate *last_cs; /* most recently used tstate */
- u_char last_recv; /* last rcvd conn. id */
- u_char last_xmit; /* last sent conn. id */
- u_int16_t flags;
-#ifndef SL_NO_STATS
- int sls_packets; /* outbound packets */
- int sls_compressed; /* outbound compressed packets */
- int sls_searches; /* searches for connection state */
- int sls_misses; /* times couldn't find conn. state */
- int sls_uncompressedin; /* inbound uncompressed packets */
- int sls_compressedin; /* inbound compressed packets */
- int sls_errorin; /* inbound unknown type packets */
- int sls_tossed; /* inbound packets tossed because of error */
-#endif
- struct cstate tstate[MAX_STATES]; /* xmit connection states */
- struct cstate rstate[MAX_STATES]; /* receive connection states */
-};
-/* flag values */
-#define SLF_TOSS 1 /* tossing rcvd frames because of input err */
-
-void sl_compress_init __P((struct slcompress *));
-void sl_compress_setup __P((struct slcompress *, int));
-u_int sl_compress_tcp __P((struct mbuf *,
- struct ip *, struct slcompress *, int));
-int sl_uncompress_tcp __P((u_char **, int, u_int, struct slcompress *));
-int sl_uncompress_tcp_core __P((u_char *, int, int, u_int,
- struct slcompress *, u_char **, u_int *));
-
-#endif /* _NET_SLCOMPRESS_H_ */
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