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