hirifumi mikage / EthernetNetIf

EthernetNetIf

Dependents:   XBee_WiFi_EA_LPC4088

lwip/netif/ppp/vj.h@0:62580107d20c, 2014-11-19 (annotated)

Committer:
hmike
Date:
Wed Nov 19 12:00:42 2014 +0000
Revision:
0:62580107d20c
EthernetNetIf

Who changed what in which revision?

UserRevisionLine numberNew contents of line
hmike 0:62580107d20c 1 /*
hmike 0:62580107d20c 2 * Definitions for tcp compression routines.
hmike 0:62580107d20c 3 *
hmike 0:62580107d20c 4 * $Id: vj.h,v 1.7 2010/02/22 17:52:09 goldsimon Exp $
hmike 0:62580107d20c 5 *
hmike 0:62580107d20c 6 * Copyright (c) 1989 Regents of the University of California.
hmike 0:62580107d20c 7 * All rights reserved.
hmike 0:62580107d20c 8 *
hmike 0:62580107d20c 9 * Redistribution and use in source and binary forms are permitted
hmike 0:62580107d20c 10 * provided that the above copyright notice and this paragraph are
hmike 0:62580107d20c 11 * duplicated in all such forms and that any documentation,
hmike 0:62580107d20c 12 * advertising materials, and other materials related to such
hmike 0:62580107d20c 13 * distribution and use acknowledge that the software was developed
hmike 0:62580107d20c 14 * by the University of California, Berkeley. The name of the
hmike 0:62580107d20c 15 * University may not be used to endorse or promote products derived
hmike 0:62580107d20c 16 * from this software without specific prior written permission.
hmike 0:62580107d20c 17 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
hmike 0:62580107d20c 18 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
hmike 0:62580107d20c 19 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
hmike 0:62580107d20c 20 *
hmike 0:62580107d20c 21 * Van Jacobson (van@helios.ee.lbl.gov), Dec 31, 1989:
hmike 0:62580107d20c 22 * - Initial distribution.
hmike 0:62580107d20c 23 */
hmike 0:62580107d20c 24
hmike 0:62580107d20c 25 #ifndef VJ_H
hmike 0:62580107d20c 26 #define VJ_H
hmike 0:62580107d20c 27
hmike 0:62580107d20c 28 #include "lwip/ip.h"
hmike 0:62580107d20c 29 #include "lwip/tcp_impl.h"
hmike 0:62580107d20c 30
hmike 0:62580107d20c 31 #define MAX_SLOTS 16 /* must be > 2 and < 256 */
hmike 0:62580107d20c 32 #define MAX_HDR 128
hmike 0:62580107d20c 33
hmike 0:62580107d20c 34 /*
hmike 0:62580107d20c 35 * Compressed packet format:
hmike 0:62580107d20c 36 *
hmike 0:62580107d20c 37 * The first octet contains the packet type (top 3 bits), TCP
hmike 0:62580107d20c 38 * 'push' bit, and flags that indicate which of the 4 TCP sequence
hmike 0:62580107d20c 39 * numbers have changed (bottom 5 bits). The next octet is a
hmike 0:62580107d20c 40 * conversation number that associates a saved IP/TCP header with
hmike 0:62580107d20c 41 * the compressed packet. The next two octets are the TCP checksum
hmike 0:62580107d20c 42 * from the original datagram. The next 0 to 15 octets are
hmike 0:62580107d20c 43 * sequence number changes, one change per bit set in the header
hmike 0:62580107d20c 44 * (there may be no changes and there are two special cases where
hmike 0:62580107d20c 45 * the receiver implicitly knows what changed -- see below).
hmike 0:62580107d20c 46 *
hmike 0:62580107d20c 47 * There are 5 numbers which can change (they are always inserted
hmike 0:62580107d20c 48 * in the following order): TCP urgent pointer, window,
hmike 0:62580107d20c 49 * acknowlegement, sequence number and IP ID. (The urgent pointer
hmike 0:62580107d20c 50 * is different from the others in that its value is sent, not the
hmike 0:62580107d20c 51 * change in value.) Since typical use of SLIP links is biased
hmike 0:62580107d20c 52 * toward small packets (see comments on MTU/MSS below), changes
hmike 0:62580107d20c 53 * use a variable length coding with one octet for numbers in the
hmike 0:62580107d20c 54 * range 1 - 255 and 3 octets (0, MSB, LSB) for numbers in the
hmike 0:62580107d20c 55 * range 256 - 65535 or 0. (If the change in sequence number or
hmike 0:62580107d20c 56 * ack is more than 65535, an uncompressed packet is sent.)
hmike 0:62580107d20c 57 */
hmike 0:62580107d20c 58
hmike 0:62580107d20c 59 /*
hmike 0:62580107d20c 60 * Packet types (must not conflict with IP protocol version)
hmike 0:62580107d20c 61 *
hmike 0:62580107d20c 62 * The top nibble of the first octet is the packet type. There are
hmike 0:62580107d20c 63 * three possible types: IP (not proto TCP or tcp with one of the
hmike 0:62580107d20c 64 * control flags set); uncompressed TCP (a normal IP/TCP packet but
hmike 0:62580107d20c 65 * with the 8-bit protocol field replaced by an 8-bit connection id --
hmike 0:62580107d20c 66 * this type of packet syncs the sender & receiver); and compressed
hmike 0:62580107d20c 67 * TCP (described above).
hmike 0:62580107d20c 68 *
hmike 0:62580107d20c 69 * LSB of 4-bit field is TCP "PUSH" bit (a worthless anachronism) and
hmike 0:62580107d20c 70 * is logically part of the 4-bit "changes" field that follows. Top
hmike 0:62580107d20c 71 * three bits are actual packet type. For backward compatibility
hmike 0:62580107d20c 72 * and in the interest of conserving bits, numbers are chosen so the
hmike 0:62580107d20c 73 * IP protocol version number (4) which normally appears in this nibble
hmike 0:62580107d20c 74 * means "IP packet".
hmike 0:62580107d20c 75 */
hmike 0:62580107d20c 76
hmike 0:62580107d20c 77 /* packet types */
hmike 0:62580107d20c 78 #define TYPE_IP 0x40
hmike 0:62580107d20c 79 #define TYPE_UNCOMPRESSED_TCP 0x70
hmike 0:62580107d20c 80 #define TYPE_COMPRESSED_TCP 0x80
hmike 0:62580107d20c 81 #define TYPE_ERROR 0x00
hmike 0:62580107d20c 82
hmike 0:62580107d20c 83 /* Bits in first octet of compressed packet */
hmike 0:62580107d20c 84 #define NEW_C 0x40 /* flag bits for what changed in a packet */
hmike 0:62580107d20c 85 #define NEW_I 0x20
hmike 0:62580107d20c 86 #define NEW_S 0x08
hmike 0:62580107d20c 87 #define NEW_A 0x04
hmike 0:62580107d20c 88 #define NEW_W 0x02
hmike 0:62580107d20c 89 #define NEW_U 0x01
hmike 0:62580107d20c 90
hmike 0:62580107d20c 91 /* reserved, special-case values of above */
hmike 0:62580107d20c 92 #define SPECIAL_I (NEW_S|NEW_W|NEW_U) /* echoed interactive traffic */
hmike 0:62580107d20c 93 #define SPECIAL_D (NEW_S|NEW_A|NEW_W|NEW_U) /* unidirectional data */
hmike 0:62580107d20c 94 #define SPECIALS_MASK (NEW_S|NEW_A|NEW_W|NEW_U)
hmike 0:62580107d20c 95
hmike 0:62580107d20c 96 #define TCP_PUSH_BIT 0x10
hmike 0:62580107d20c 97
hmike 0:62580107d20c 98
hmike 0:62580107d20c 99 /*
hmike 0:62580107d20c 100 * "state" data for each active tcp conversation on the wire. This is
hmike 0:62580107d20c 101 * basically a copy of the entire IP/TCP header from the last packet
hmike 0:62580107d20c 102 * we saw from the conversation together with a small identifier
hmike 0:62580107d20c 103 * the transmit & receive ends of the line use to locate saved header.
hmike 0:62580107d20c 104 */
hmike 0:62580107d20c 105 struct cstate {
hmike 0:62580107d20c 106 struct cstate *cs_next; /* next most recently used state (xmit only) */
hmike 0:62580107d20c 107 u_short cs_hlen; /* size of hdr (receive only) */
hmike 0:62580107d20c 108 u_char cs_id; /* connection # associated with this state */
hmike 0:62580107d20c 109 u_char cs_filler;
hmike 0:62580107d20c 110 union {
hmike 0:62580107d20c 111 char csu_hdr[MAX_HDR];
hmike 0:62580107d20c 112 struct ip_hdr csu_ip; /* ip/tcp hdr from most recent packet */
hmike 0:62580107d20c 113 } vjcs_u;
hmike 0:62580107d20c 114 };
hmike 0:62580107d20c 115 #define cs_ip vjcs_u.csu_ip
hmike 0:62580107d20c 116 #define cs_hdr vjcs_u.csu_hdr
hmike 0:62580107d20c 117
hmike 0:62580107d20c 118
hmike 0:62580107d20c 119 struct vjstat {
hmike 0:62580107d20c 120 unsigned long vjs_packets; /* outbound packets */
hmike 0:62580107d20c 121 unsigned long vjs_compressed; /* outbound compressed packets */
hmike 0:62580107d20c 122 unsigned long vjs_searches; /* searches for connection state */
hmike 0:62580107d20c 123 unsigned long vjs_misses; /* times couldn't find conn. state */
hmike 0:62580107d20c 124 unsigned long vjs_uncompressedin; /* inbound uncompressed packets */
hmike 0:62580107d20c 125 unsigned long vjs_compressedin; /* inbound compressed packets */
hmike 0:62580107d20c 126 unsigned long vjs_errorin; /* inbound unknown type packets */
hmike 0:62580107d20c 127 unsigned long vjs_tossed; /* inbound packets tossed because of error */
hmike 0:62580107d20c 128 };
hmike 0:62580107d20c 129
hmike 0:62580107d20c 130 /*
hmike 0:62580107d20c 131 * all the state data for one serial line (we need one of these per line).
hmike 0:62580107d20c 132 */
hmike 0:62580107d20c 133 struct vjcompress {
hmike 0:62580107d20c 134 struct cstate *last_cs; /* most recently used tstate */
hmike 0:62580107d20c 135 u_char last_recv; /* last rcvd conn. id */
hmike 0:62580107d20c 136 u_char last_xmit; /* last sent conn. id */
hmike 0:62580107d20c 137 u_short flags;
hmike 0:62580107d20c 138 u_char maxSlotIndex;
hmike 0:62580107d20c 139 u_char compressSlot; /* Flag indicating OK to compress slot ID. */
hmike 0:62580107d20c 140 #if LINK_STATS
hmike 0:62580107d20c 141 struct vjstat stats;
hmike 0:62580107d20c 142 #endif
hmike 0:62580107d20c 143 struct cstate tstate[MAX_SLOTS]; /* xmit connection states */
hmike 0:62580107d20c 144 struct cstate rstate[MAX_SLOTS]; /* receive connection states */
hmike 0:62580107d20c 145 };
hmike 0:62580107d20c 146
hmike 0:62580107d20c 147 /* flag values */
hmike 0:62580107d20c 148 #define VJF_TOSS 1U /* tossing rcvd frames because of input err */
hmike 0:62580107d20c 149
hmike 0:62580107d20c 150 extern void vj_compress_init (struct vjcompress *comp);
hmike 0:62580107d20c 151 extern u_int vj_compress_tcp (struct vjcompress *comp, struct pbuf *pb);
hmike 0:62580107d20c 152 extern void vj_uncompress_err (struct vjcompress *comp);
hmike 0:62580107d20c 153 extern int vj_uncompress_uncomp(struct pbuf *nb, struct vjcompress *comp);
hmike 0:62580107d20c 154 extern int vj_uncompress_tcp (struct pbuf **nb, struct vjcompress *comp);
hmike 0:62580107d20c 155
hmike 0:62580107d20c 156 #endif /* VJ_H */