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, see <http://www.gnu.org/licenses/>.
17 */
18
19#ifndef _XT_OSF_H
20#define _XT_OSF_H
21
22#include <linux/types.h>
23#include <linux/ip.h>
24#include <linux/tcp.h>
25
26#define MAXGENRELEN		32
27
28#define XT_OSF_GENRE		(1<<0)
29#define	XT_OSF_TTL		(1<<1)
30#define XT_OSF_LOG		(1<<2)
31#define XT_OSF_INVERT		(1<<3)
32
33#define XT_OSF_LOGLEVEL_ALL	0	/* log all matched fingerprints */
34#define XT_OSF_LOGLEVEL_FIRST	1	/* log only the first matced fingerprint */
35#define XT_OSF_LOGLEVEL_ALL_KNOWN	2 /* do not log unknown packets */
36
37#define XT_OSF_TTL_TRUE		0	/* True ip and fingerprint TTL comparison */
38#define XT_OSF_TTL_LESS		1	/* Check if ip TTL is less than fingerprint one */
39#define XT_OSF_TTL_NOCHECK	2	/* Do not compare ip and fingerprint TTL at all */
40
41struct xt_osf_info {
42	char			genre[MAXGENRELEN];
43	__u32			len;
44	__u32			flags;
45	__u32			loglevel;
46	__u32			ttl;
47};
48
49/*
50 * Wildcard MSS (kind of).
51 * It is used to implement a state machine for the different wildcard values
52 * of the MSS and window sizes.
53 */
54struct xt_osf_wc {
55	__u32			wc;
56	__u32			val;
57};
58
59/*
60 * This struct represents IANA options
61 * http://www.iana.org/assignments/tcp-parameters
62 */
63struct xt_osf_opt {
64	__u16			kind, length;
65	struct xt_osf_wc	wc;
66};
67
68struct xt_osf_user_finger {
69	struct xt_osf_wc	wss;
70
71	__u8			ttl, df;
72	__u16			ss, mss;
73	__u16			opt_num;
74
75	char			genre[MAXGENRELEN];
76	char			version[MAXGENRELEN];
77	char			subtype[MAXGENRELEN];
78
79	/* MAX_IPOPTLEN is maximum if all options are NOPs or EOLs */
80	struct xt_osf_opt	opt[MAX_IPOPTLEN];
81};
82
83struct xt_osf_nlmsg {
84	struct xt_osf_user_finger	f;
85	struct iphdr		ip;
86	struct tcphdr		tcp;
87};
88
89/* Defines for IANA option kinds */
90
91enum iana_options {
92	OSFOPT_EOL = 0,		/* End of options */
93	OSFOPT_NOP, 		/* NOP */
94	OSFOPT_MSS, 		/* Maximum segment size */
95	OSFOPT_WSO, 		/* Window scale option */
96	OSFOPT_SACKP,		/* SACK permitted */
97	OSFOPT_SACK,		/* SACK */
98	OSFOPT_ECHO,
99	OSFOPT_ECHOREPLY,
100	OSFOPT_TS,		/* Timestamp option */
101	OSFOPT_POCP,		/* Partial Order Connection Permitted */
102	OSFOPT_POSP,		/* Partial Order Service Profile */
103
104	/* Others are not used in the current OSF */
105	OSFOPT_EMPTY = 255,
106};
107
108/*
109 * Initial window size option state machine: multiple of mss, mtu or
110 * plain numeric value. Can also be made as plain numeric value which
111 * is not a multiple of specified value.
112 */
113enum xt_osf_window_size_options {
114	OSF_WSS_PLAIN	= 0,
115	OSF_WSS_MSS,
116	OSF_WSS_MTU,
117	OSF_WSS_MODULO,
118	OSF_WSS_MAX,
119};
120
121/*
122 * Add/remove fingerprint from the kernel.
123 */
124enum xt_osf_msg_types {
125	OSF_MSG_ADD,
126	OSF_MSG_REMOVE,
127	OSF_MSG_MAX,
128};
129
130enum xt_osf_attr_type {
131	OSF_ATTR_UNSPEC,
132	OSF_ATTR_FINGER,
133	OSF_ATTR_MAX,
134};
135
136#endif				/* _XT_OSF_H */
137