1 /*
2  * ppp-comp.h - Definitions for doing PPP packet compression.
3  *
4  * Copyright 1994-1998 Paul Mackerras.
5  *
6  *  This program is free software; you can redistribute it and/or
7  *  modify it under the terms of the GNU General Public License
8  *  version 2 as published by the Free Software Foundation.
9  */
10 #ifndef _UAPI_NET_PPP_COMP_H
11 #define _UAPI_NET_PPP_COMP_H
12 
13 
14 /*
15  * CCP codes.
16  */
17 
18 #define CCP_CONFREQ	1
19 #define CCP_CONFACK	2
20 #define CCP_TERMREQ	5
21 #define CCP_TERMACK	6
22 #define CCP_RESETREQ	14
23 #define CCP_RESETACK	15
24 
25 /*
26  * Max # bytes for a CCP option
27  */
28 
29 #define CCP_MAX_OPTION_LENGTH	32
30 
31 /*
32  * Parts of a CCP packet.
33  */
34 
35 #define CCP_CODE(dp)		((dp)[0])
36 #define CCP_ID(dp)		((dp)[1])
37 #define CCP_LENGTH(dp)		(((dp)[2] << 8) + (dp)[3])
38 #define CCP_HDRLEN		4
39 
40 #define CCP_OPT_CODE(dp)	((dp)[0])
41 #define CCP_OPT_LENGTH(dp)	((dp)[1])
42 #define CCP_OPT_MINLEN		2
43 
44 /*
45  * Definitions for BSD-Compress.
46  */
47 
48 #define CI_BSD_COMPRESS		21	/* config. option for BSD-Compress */
49 #define CILEN_BSD_COMPRESS	3	/* length of config. option */
50 
51 /* Macros for handling the 3rd byte of the BSD-Compress config option. */
52 #define BSD_NBITS(x)		((x) & 0x1F)	/* number of bits requested */
53 #define BSD_VERSION(x)		((x) >> 5)	/* version of option format */
54 #define BSD_CURRENT_VERSION	1		/* current version number */
55 #define BSD_MAKE_OPT(v, n)	(((v) << 5) | (n))
56 
57 #define BSD_MIN_BITS		9	/* smallest code size supported */
58 #define BSD_MAX_BITS		15	/* largest code size supported */
59 
60 /*
61  * Definitions for Deflate.
62  */
63 
64 #define CI_DEFLATE		26	/* config option for Deflate */
65 #define CI_DEFLATE_DRAFT	24	/* value used in original draft RFC */
66 #define CILEN_DEFLATE		4	/* length of its config option */
67 
68 #define DEFLATE_MIN_SIZE	9
69 #define DEFLATE_MAX_SIZE	15
70 #define DEFLATE_METHOD_VAL	8
71 #define DEFLATE_SIZE(x)		(((x) >> 4) + 8)
72 #define DEFLATE_METHOD(x)	((x) & 0x0F)
73 #define DEFLATE_MAKE_OPT(w)	((((w) - 8) << 4) + DEFLATE_METHOD_VAL)
74 #define DEFLATE_CHK_SEQUENCE	0
75 
76 /*
77  * Definitions for MPPE.
78  */
79 
80 #define CI_MPPE                18      /* config option for MPPE */
81 #define CILEN_MPPE              6      /* length of config option */
82 
83 /*
84  * Definitions for other, as yet unsupported, compression methods.
85  */
86 
87 #define CI_PREDICTOR_1		1	/* config option for Predictor-1 */
88 #define CILEN_PREDICTOR_1	2	/* length of its config option */
89 #define CI_PREDICTOR_2		2	/* config option for Predictor-2 */
90 #define CILEN_PREDICTOR_2	2	/* length of its config option */
91 
92 
93 #endif /* _UAPI_NET_PPP_COMP_H */
94