1 /*
2  * Copyright (c) 2003+ Evgeniy Polyakov <johnpol@2ka.mxt.ru>
3  *
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License as published by
7  * the Free Software Foundation; either version 2 of the License, or
8  * (at your option) any later version.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, write to the Free Software
17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18  */
19 
20 #ifndef _XT_OSF_H
21 #define _XT_OSF_H
22 
23 #include <linux/types.h>
24 
25 #define MAXGENRELEN		32
26 
27 #define XT_OSF_GENRE		(1<<0)
28 #define	XT_OSF_TTL		(1<<1)
29 #define XT_OSF_LOG		(1<<2)
30 #define XT_OSF_INVERT		(1<<3)
31 
32 #define XT_OSF_LOGLEVEL_ALL	0	/* log all matched fingerprints */
33 #define XT_OSF_LOGLEVEL_FIRST	1	/* log only the first matced fingerprint */
34 #define XT_OSF_LOGLEVEL_ALL_KNOWN	2 /* do not log unknown packets */
35 
36 #define XT_OSF_TTL_TRUE		0	/* True ip and fingerprint TTL comparison */
37 #define XT_OSF_TTL_LESS		1	/* Check if ip TTL is less than fingerprint one */
38 #define XT_OSF_TTL_NOCHECK	2	/* Do not compare ip and fingerprint TTL at all */
39 
40 struct xt_osf_info {
41 	char			genre[MAXGENRELEN];
42 	__u32			len;
43 	__u32			flags;
44 	__u32			loglevel;
45 	__u32			ttl;
46 };
47 
48 /*
49  * Wildcard MSS (kind of).
50  * It is used to implement a state machine for the different wildcard values
51  * of the MSS and window sizes.
52  */
53 struct xt_osf_wc {
54 	__u32			wc;
55 	__u32			val;
56 };
57 
58 /*
59  * This struct represents IANA options
60  * http://www.iana.org/assignments/tcp-parameters
61  */
62 struct xt_osf_opt {
63 	__u16			kind, length;
64 	struct xt_osf_wc	wc;
65 };
66 
67 struct xt_osf_user_finger {
68 	struct xt_osf_wc	wss;
69 
70 	__u8			ttl, df;
71 	__u16			ss, mss;
72 	__u16			opt_num;
73 
74 	char			genre[MAXGENRELEN];
75 	char			version[MAXGENRELEN];
76 	char			subtype[MAXGENRELEN];
77 
78 	/* MAX_IPOPTLEN is maximum if all options are NOPs or EOLs */
79 	struct xt_osf_opt	opt[MAX_IPOPTLEN];
80 };
81 
82 struct xt_osf_nlmsg {
83 	struct xt_osf_user_finger	f;
84 	struct iphdr		ip;
85 	struct tcphdr		tcp;
86 };
87 
88 /* Defines for IANA option kinds */
89 
90 enum iana_options {
91 	OSFOPT_EOL = 0,		/* End of options */
92 	OSFOPT_NOP, 		/* NOP */
93 	OSFOPT_MSS, 		/* Maximum segment size */
94 	OSFOPT_WSO, 		/* Window scale option */
95 	OSFOPT_SACKP,		/* SACK permitted */
96 	OSFOPT_SACK,		/* SACK */
97 	OSFOPT_ECHO,
98 	OSFOPT_ECHOREPLY,
99 	OSFOPT_TS,		/* Timestamp option */
100 	OSFOPT_POCP,		/* Partial Order Connection Permitted */
101 	OSFOPT_POSP,		/* Partial Order Service Profile */
102 
103 	/* Others are not used in the current OSF */
104 	OSFOPT_EMPTY = 255,
105 };
106 
107 /*
108  * Initial window size option state machine: multiple of mss, mtu or
109  * plain numeric value. Can also be made as plain numeric value which
110  * is not a multiple of specified value.
111  */
112 enum xt_osf_window_size_options {
113 	OSF_WSS_PLAIN	= 0,
114 	OSF_WSS_MSS,
115 	OSF_WSS_MTU,
116 	OSF_WSS_MODULO,
117 	OSF_WSS_MAX,
118 };
119 
120 /*
121  * Add/remove fingerprint from the kernel.
122  */
123 enum xt_osf_msg_types {
124 	OSF_MSG_ADD,
125 	OSF_MSG_REMOVE,
126 	OSF_MSG_MAX,
127 };
128 
129 enum xt_osf_attr_type {
130 	OSF_ATTR_UNSPEC,
131 	OSF_ATTR_FINGER,
132 	OSF_ATTR_MAX,
133 };
134 
135 #endif				/* _XT_OSF_H */
136