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      1 /*
      2  * Copyright (c) 2003+ Evgeniy Polyakov <johnpol (at) 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 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