xref: /openbmc/linux/include/uapi/linux/ppp-comp.h (revision e2be04c7)
1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2 /*
3  * ppp-comp.h - Definitions for doing PPP packet compression.
4  *
5  * Copyright 1994-1998 Paul Mackerras.
6  *
7  *  This program is free software; you can redistribute it and/or
8  *  modify it under the terms of the GNU General Public License
9  *  version 2 as published by the Free Software Foundation.
10  */
11 #ifndef _UAPI_NET_PPP_COMP_H
12 #define _UAPI_NET_PPP_COMP_H
13 
14 
15 /*
16  * CCP codes.
17  */
18 
19 #define CCP_CONFREQ	1
20 #define CCP_CONFACK	2
21 #define CCP_TERMREQ	5
22 #define CCP_TERMACK	6
23 #define CCP_RESETREQ	14
24 #define CCP_RESETACK	15
25 
26 /*
27  * Max # bytes for a CCP option
28  */
29 
30 #define CCP_MAX_OPTION_LENGTH	32
31 
32 /*
33  * Parts of a CCP packet.
34  */
35 
36 #define CCP_CODE(dp)		((dp)[0])
37 #define CCP_ID(dp)		((dp)[1])
38 #define CCP_LENGTH(dp)		(((dp)[2] << 8) + (dp)[3])
39 #define CCP_HDRLEN		4
40 
41 #define CCP_OPT_CODE(dp)	((dp)[0])
42 #define CCP_OPT_LENGTH(dp)	((dp)[1])
43 #define CCP_OPT_MINLEN		2
44 
45 /*
46  * Definitions for BSD-Compress.
47  */
48 
49 #define CI_BSD_COMPRESS		21	/* config. option for BSD-Compress */
50 #define CILEN_BSD_COMPRESS	3	/* length of config. option */
51 
52 /* Macros for handling the 3rd byte of the BSD-Compress config option. */
53 #define BSD_NBITS(x)		((x) & 0x1F)	/* number of bits requested */
54 #define BSD_VERSION(x)		((x) >> 5)	/* version of option format */
55 #define BSD_CURRENT_VERSION	1		/* current version number */
56 #define BSD_MAKE_OPT(v, n)	(((v) << 5) | (n))
57 
58 #define BSD_MIN_BITS		9	/* smallest code size supported */
59 #define BSD_MAX_BITS		15	/* largest code size supported */
60 
61 /*
62  * Definitions for Deflate.
63  */
64 
65 #define CI_DEFLATE		26	/* config option for Deflate */
66 #define CI_DEFLATE_DRAFT	24	/* value used in original draft RFC */
67 #define CILEN_DEFLATE		4	/* length of its config option */
68 
69 #define DEFLATE_MIN_SIZE	9
70 #define DEFLATE_MAX_SIZE	15
71 #define DEFLATE_METHOD_VAL	8
72 #define DEFLATE_SIZE(x)		(((x) >> 4) + 8)
73 #define DEFLATE_METHOD(x)	((x) & 0x0F)
74 #define DEFLATE_MAKE_OPT(w)	((((w) - 8) << 4) + DEFLATE_METHOD_VAL)
75 #define DEFLATE_CHK_SEQUENCE	0
76 
77 /*
78  * Definitions for MPPE.
79  */
80 
81 #define CI_MPPE                18      /* config option for MPPE */
82 #define CILEN_MPPE              6      /* length of config option */
83 
84 /*
85  * Definitions for other, as yet unsupported, compression methods.
86  */
87 
88 #define CI_PREDICTOR_1		1	/* config option for Predictor-1 */
89 #define CILEN_PREDICTOR_1	2	/* length of its config option */
90 #define CI_PREDICTOR_2		2	/* config option for Predictor-2 */
91 #define CILEN_PREDICTOR_2	2	/* length of its config option */
92 
93 
94 #endif /* _UAPI_NET_PPP_COMP_H */
95