1 #ifndef _SLHC_H 1 #ifndef _SLHC_H
2 #define _SLHC_H 2 #define _SLHC_H
3 /* 3 /*
4 * Definitions for tcp compression routines. 4 * Definitions for tcp compression routines.
5 * 5 *
6 * $Header: slcompress.h,v 1.10 89/12/31 08:53 6 * $Header: slcompress.h,v 1.10 89/12/31 08:53:02 van Exp $
7 * 7 *
8 * Copyright (c) 1989 Regents of the Universit 8 * Copyright (c) 1989 Regents of the University of California.
9 * All rights reserved. 9 * All rights reserved.
10 * 10 *
11 * Redistribution and use in source and binary 11 * Redistribution and use in source and binary forms are permitted
12 * provided that the above copyright notice an 12 * provided that the above copyright notice and this paragraph are
13 * duplicated in all such forms and that any d 13 * duplicated in all such forms and that any documentation,
14 * advertising materials, and other materials 14 * advertising materials, and other materials related to such
15 * distribution and use acknowledge that the s 15 * distribution and use acknowledge that the software was developed
16 * by the University of California, Berkeley. 16 * by the University of California, Berkeley. The name of the
17 * University may not be used to endorse or pr 17 * University may not be used to endorse or promote products derived
18 * from this software without specific prior w 18 * from this software without specific prior written permission.
19 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WIT 19 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
20 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMI 20 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
21 * WARRANTIES OF MERCHANTABILITY AND FITNESS F 21 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
22 * 22 *
23 * Van Jacobson (van@helios.ee.lbl.gov), 23 * Van Jacobson (van@helios.ee.lbl.gov), Dec 31, 1989:
24 * - Initial distribution. 24 * - Initial distribution.
25 * 25 *
26 * 26 *
27 * modified for KA9Q Internet Software Package 27 * modified for KA9Q Internet Software Package by
28 * Katie Stevens (dkstevens@ucdavis.edu) 28 * Katie Stevens (dkstevens@ucdavis.edu)
29 * University of California, Davis 29 * University of California, Davis
30 * Computing Services 30 * Computing Services
31 * - 01-31-90 initial adaptation 31 * - 01-31-90 initial adaptation
32 * 32 *
33 * - Feb 1991 Bill_Simpson@um.cc.umi 33 * - Feb 1991 Bill_Simpson@um.cc.umich.edu
34 * variable number of con 34 * variable number of conversation slots
35 * allow zero or one slot 35 * allow zero or one slots
36 * separate routines 36 * separate routines
37 * status display 37 * status display
38 */ 38 */
39 39
40 /* 40 /*
41 * Compressed packet format: 41 * Compressed packet format:
42 * 42 *
43 * The first octet contains the packet type (t 43 * The first octet contains the packet type (top 3 bits), TCP
44 * 'push' bit, and flags that indicate which o 44 * 'push' bit, and flags that indicate which of the 4 TCP sequence
45 * numbers have changed (bottom 5 bits). The 45 * numbers have changed (bottom 5 bits). The next octet is a
46 * conversation number that associates a saved 46 * conversation number that associates a saved IP/TCP header with
47 * the compressed packet. The next two octets 47 * the compressed packet. The next two octets are the TCP checksum
48 * from the original datagram. The next 0 to 48 * from the original datagram. The next 0 to 15 octets are
49 * sequence number changes, one change per bit 49 * sequence number changes, one change per bit set in the header
50 * (there may be no changes and there are two 50 * (there may be no changes and there are two special cases where
51 * the receiver implicitly knows what changed 51 * the receiver implicitly knows what changed -- see below).
52 * 52 *
53 * There are 5 numbers which can change (they 53 * There are 5 numbers which can change (they are always inserted
54 * in the following order): TCP urgent pointer 54 * in the following order): TCP urgent pointer, window,
55 * acknowledgment, sequence number and IP ID. 55 * acknowledgment, sequence number and IP ID. (The urgent pointer
56 * is different from the others in that its va 56 * is different from the others in that its value is sent, not the
57 * change in value.) Since typical use of SLI 57 * change in value.) Since typical use of SLIP links is biased
58 * toward small packets (see comments on MTU/M 58 * toward small packets (see comments on MTU/MSS below), changes
59 * use a variable length coding with one octet 59 * use a variable length coding with one octet for numbers in the
60 * range 1 - 255 and 3 octets (0, MSB, LSB) fo 60 * range 1 - 255 and 3 octets (0, MSB, LSB) for numbers in the
61 * range 256 - 65535 or 0. (If the change in 61 * range 256 - 65535 or 0. (If the change in sequence number or
62 * ack is more than 65535, an uncompressed pac 62 * ack is more than 65535, an uncompressed packet is sent.)
63 */ 63 */
64 64
65 /* 65 /*
66 * Packet types (must not conflict with IP pro 66 * Packet types (must not conflict with IP protocol version)
67 * 67 *
68 * The top nibble of the first octet is the pa 68 * The top nibble of the first octet is the packet type. There are
69 * three possible types: IP (not proto TCP or 69 * three possible types: IP (not proto TCP or tcp with one of the
70 * control flags set); uncompressed TCP (a nor 70 * control flags set); uncompressed TCP (a normal IP/TCP packet but
71 * with the 8-bit protocol field replaced by a 71 * with the 8-bit protocol field replaced by an 8-bit connection id --
72 * this type of packet syncs the sender & rece 72 * this type of packet syncs the sender & receiver); and compressed
73 * TCP (described above). 73 * TCP (described above).
74 * 74 *
75 * LSB of 4-bit field is TCP "PUSH" bit (a wor 75 * LSB of 4-bit field is TCP "PUSH" bit (a worthless anachronism) and
76 * is logically part of the 4-bit "changes" fi 76 * is logically part of the 4-bit "changes" field that follows. Top
77 * three bits are actual packet type. For bac 77 * three bits are actual packet type. For backward compatibility
78 * and in the interest of conserving bits, num 78 * and in the interest of conserving bits, numbers are chosen so the
79 * IP protocol version number (4) which normal 79 * IP protocol version number (4) which normally appears in this nibble
80 * means "IP packet". 80 * means "IP packet".
81 */ 81 */
82 82
83 83
84 #include <linux/ip.h> 84 #include <linux/ip.h>
85 #include <linux/tcp.h> 85 #include <linux/tcp.h>
86 86
87 /* SLIP compression masks for len/vers byte */ 87 /* SLIP compression masks for len/vers byte */
88 #define SL_TYPE_IP 0x40 88 #define SL_TYPE_IP 0x40
89 #define SL_TYPE_UNCOMPRESSED_TCP 0x70 89 #define SL_TYPE_UNCOMPRESSED_TCP 0x70
90 #define SL_TYPE_COMPRESSED_TCP 0x80 90 #define SL_TYPE_COMPRESSED_TCP 0x80
91 #define SL_TYPE_ERROR 0x00 91 #define SL_TYPE_ERROR 0x00
92 92
93 /* Bits in first octet of compressed packet */ 93 /* Bits in first octet of compressed packet */
94 #define NEW_C 0x40 /* flag bits for what 94 #define NEW_C 0x40 /* flag bits for what changed in a packet */
95 #define NEW_I 0x20 95 #define NEW_I 0x20
96 #define NEW_S 0x08 96 #define NEW_S 0x08
97 #define NEW_A 0x04 97 #define NEW_A 0x04
98 #define NEW_W 0x02 98 #define NEW_W 0x02
99 #define NEW_U 0x01 99 #define NEW_U 0x01
100 100
101 /* reserved, special-case values of above */ 101 /* reserved, special-case values of above */
102 #define SPECIAL_I (NEW_S|NEW_W|NEW_U) 102 #define SPECIAL_I (NEW_S|NEW_W|NEW_U) /* echoed interactive traffic */
103 #define SPECIAL_D (NEW_S|NEW_A|NEW_W|NEW_U) 103 #define SPECIAL_D (NEW_S|NEW_A|NEW_W|NEW_U) /* unidirectional data */
104 #define SPECIALS_MASK (NEW_S|NEW_A|NEW_W|NEW_U 104 #define SPECIALS_MASK (NEW_S|NEW_A|NEW_W|NEW_U)
105 105
106 #define TCP_PUSH_BIT 0x10 106 #define TCP_PUSH_BIT 0x10
107 107
108 /* 108 /*
109 * data type and sizes conversion assumptions: 109 * data type and sizes conversion assumptions:
110 * 110 *
111 * VJ code KA9Q style generi 111 * VJ code KA9Q style generic
112 * u_char byte_t unsign 112 * u_char byte_t unsigned char 8 bits
113 * u_short int16 unsign 113 * u_short int16 unsigned short 16 bits
114 * u_int int16 unsign 114 * u_int int16 unsigned short 16 bits
115 * u_long unsigned long unsign 115 * u_long unsigned long unsigned long 32 bits
116 * int int32 long 116 * int int32 long 32 bits
117 */ 117 */
118 118
119 typedef __u8 byte_t; 119 typedef __u8 byte_t;
120 typedef __u32 int32; 120 typedef __u32 int32;
121 121
122 /* 122 /*
123 * "state" data for each active tcp conversati 123 * "state" data for each active tcp conversation on the wire. This is
124 * basically a copy of the entire IP/TCP heade 124 * basically a copy of the entire IP/TCP header from the last packet
125 * we saw from the conversation together with 125 * we saw from the conversation together with a small identifier
126 * the transmit & receive ends of the line use 126 * the transmit & receive ends of the line use to locate saved header.
127 */ 127 */
128 struct cstate { 128 struct cstate {
129 byte_t cs_this; /* connection 129 byte_t cs_this; /* connection id number (xmit) */
130 bool initialized; /* true if ini 130 bool initialized; /* true if initialized */
131 struct cstate *next; /* next in rin 131 struct cstate *next; /* next in ring (xmit) */
132 struct iphdr cs_ip; /* ip/tcp hdr 132 struct iphdr cs_ip; /* ip/tcp hdr from most recent packet */
133 struct tcphdr cs_tcp; 133 struct tcphdr cs_tcp;
134 unsigned char cs_ipopt[64]; 134 unsigned char cs_ipopt[64];
135 unsigned char cs_tcpopt[64]; 135 unsigned char cs_tcpopt[64];
136 int cs_hsize; 136 int cs_hsize;
137 }; 137 };
138 #define NULLSLSTATE (struct cstate *)0 138 #define NULLSLSTATE (struct cstate *)0
139 139
140 /* 140 /*
141 * all the state data for one serial line (we 141 * all the state data for one serial line (we need one of these per line).
142 */ 142 */
143 struct slcompress { 143 struct slcompress {
144 struct cstate *tstate; /* transmit co 144 struct cstate *tstate; /* transmit connection states (array)*/
145 struct cstate *rstate; /* receive con 145 struct cstate *rstate; /* receive connection states (array)*/
146 146
147 byte_t tslot_limit; /* highest tra 147 byte_t tslot_limit; /* highest transmit slot id (0-l)*/
148 byte_t rslot_limit; /* highest rec 148 byte_t rslot_limit; /* highest receive slot id (0-l)*/
149 149
150 byte_t xmit_oldest; /* oldest xmit 150 byte_t xmit_oldest; /* oldest xmit in ring */
151 byte_t xmit_current; /* most recent 151 byte_t xmit_current; /* most recent xmit id */
152 byte_t recv_current; /* most recent 152 byte_t recv_current; /* most recent rcvd id */
153 153
154 byte_t flags; 154 byte_t flags;
155 #define SLF_TOSS 0x01 /* tossing rcv 155 #define SLF_TOSS 0x01 /* tossing rcvd frames until id received */
156 156
157 int32 sls_o_nontcp; /* outbound no 157 int32 sls_o_nontcp; /* outbound non-TCP packets */
158 int32 sls_o_tcp; /* outbound TC 158 int32 sls_o_tcp; /* outbound TCP packets */
159 int32 sls_o_uncompressed; /* out 159 int32 sls_o_uncompressed; /* outbound uncompressed packets */
160 int32 sls_o_compressed; /* outbound co 160 int32 sls_o_compressed; /* outbound compressed packets */
161 int32 sls_o_searches; /* searches fo 161 int32 sls_o_searches; /* searches for connection state */
162 int32 sls_o_misses; /* times could 162 int32 sls_o_misses; /* times couldn't find conn. state */
163 163
164 int32 sls_i_uncompressed; /* inb 164 int32 sls_i_uncompressed; /* inbound uncompressed packets */
165 int32 sls_i_compressed; /* inbound com 165 int32 sls_i_compressed; /* inbound compressed packets */
166 int32 sls_i_error; /* inbound err 166 int32 sls_i_error; /* inbound error packets */
167 int32 sls_i_tossed; /* inbound pac 167 int32 sls_i_tossed; /* inbound packets tossed because of error */
168 168
169 int32 sls_i_runt; 169 int32 sls_i_runt;
170 int32 sls_i_badcheck; 170 int32 sls_i_badcheck;
171 }; 171 };
172 #define NULLSLCOMPR (struct slcompress *)0 172 #define NULLSLCOMPR (struct slcompress *)0
173 173
174 /* In slhc.c: */ 174 /* In slhc.c: */
175 struct slcompress *slhc_init(int rslots, int t 175 struct slcompress *slhc_init(int rslots, int tslots);
176 void slhc_free(struct slcompress *comp); 176 void slhc_free(struct slcompress *comp);
177 177
178 int slhc_compress(struct slcompress *comp, uns 178 int slhc_compress(struct slcompress *comp, unsigned char *icp, int isize,
179 unsigned char *ocp, unsigned 179 unsigned char *ocp, unsigned char **cpp, int compress_cid);
180 int slhc_uncompress(struct slcompress *comp, u 180 int slhc_uncompress(struct slcompress *comp, unsigned char *icp, int isize);
181 int slhc_remember(struct slcompress *comp, uns 181 int slhc_remember(struct slcompress *comp, unsigned char *icp, int isize);
182 int slhc_toss(struct slcompress *comp); 182 int slhc_toss(struct slcompress *comp);
183 183
184 #endif /* _SLHC_H */ 184 #endif /* _SLHC_H */
185 185
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