1 /* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */ 2 /* 3 * Copyright (c) 2003+ Evgeniy Polyakov <johnpol@2ka.mxt.ru> 4 * 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, see <http://www.gnu.org/licenses/>. 18 */ 19 20 #ifndef _XT_OSF_H 21 #define _XT_OSF_H 22 23 #include <linux/types.h> 24 #include <linux/ip.h> 25 #include <linux/tcp.h> 26 27 #define MAXGENRELEN 32 28 29 #define XT_OSF_GENRE (1<<0) 30 #define XT_OSF_TTL (1<<1) 31 #define XT_OSF_LOG (1<<2) 32 #define XT_OSF_INVERT (1<<3) 33 34 #define XT_OSF_LOGLEVEL_ALL 0 /* log all matched fingerprints */ 35 #define XT_OSF_LOGLEVEL_FIRST 1 /* log only the first matced fingerprint */ 36 #define XT_OSF_LOGLEVEL_ALL_KNOWN 2 /* do not log unknown packets */ 37 38 #define XT_OSF_TTL_TRUE 0 /* True ip and fingerprint TTL comparison */ 39 #define XT_OSF_TTL_LESS 1 /* Check if ip TTL is less than fingerprint one */ 40 #define XT_OSF_TTL_NOCHECK 2 /* Do not compare ip and fingerprint TTL at all */ 41 42 struct xt_osf_info { 43 char genre[MAXGENRELEN]; 44 __u32 len; 45 __u32 flags; 46 __u32 loglevel; 47 __u32 ttl; 48 }; 49 50 /* 51 * Wildcard MSS (kind of). 52 * It is used to implement a state machine for the different wildcard values 53 * of the MSS and window sizes. 54 */ 55 struct xt_osf_wc { 56 __u32 wc; 57 __u32 val; 58 }; 59 60 /* 61 * This struct represents IANA options 62 * http://www.iana.org/assignments/tcp-parameters 63 */ 64 struct xt_osf_opt { 65 __u16 kind, length; 66 struct xt_osf_wc wc; 67 }; 68 69 struct xt_osf_user_finger { 70 struct xt_osf_wc wss; 71 72 __u8 ttl, df; 73 __u16 ss, mss; 74 __u16 opt_num; 75 76 char genre[MAXGENRELEN]; 77 char version[MAXGENRELEN]; 78 char subtype[MAXGENRELEN]; 79 80 /* MAX_IPOPTLEN is maximum if all options are NOPs or EOLs */ 81 struct xt_osf_opt opt[MAX_IPOPTLEN]; 82 }; 83 84 struct xt_osf_nlmsg { 85 struct xt_osf_user_finger f; 86 struct iphdr ip; 87 struct tcphdr tcp; 88 }; 89 90 /* Defines for IANA option kinds */ 91 92 enum iana_options { 93 OSFOPT_EOL = 0, /* End of options */ 94 OSFOPT_NOP, /* NOP */ 95 OSFOPT_MSS, /* Maximum segment size */ 96 OSFOPT_WSO, /* Window scale option */ 97 OSFOPT_SACKP, /* SACK permitted */ 98 OSFOPT_SACK, /* SACK */ 99 OSFOPT_ECHO, 100 OSFOPT_ECHOREPLY, 101 OSFOPT_TS, /* Timestamp option */ 102 OSFOPT_POCP, /* Partial Order Connection Permitted */ 103 OSFOPT_POSP, /* Partial Order Service Profile */ 104 105 /* Others are not used in the current OSF */ 106 OSFOPT_EMPTY = 255, 107 }; 108 109 /* 110 * Initial window size option state machine: multiple of mss, mtu or 111 * plain numeric value. Can also be made as plain numeric value which 112 * is not a multiple of specified value. 113 */ 114 enum xt_osf_window_size_options { 115 OSF_WSS_PLAIN = 0, 116 OSF_WSS_MSS, 117 OSF_WSS_MTU, 118 OSF_WSS_MODULO, 119 OSF_WSS_MAX, 120 }; 121 122 /* 123 * Add/remove fingerprint from the kernel. 124 */ 125 enum xt_osf_msg_types { 126 OSF_MSG_ADD, 127 OSF_MSG_REMOVE, 128 OSF_MSG_MAX, 129 }; 130 131 enum xt_osf_attr_type { 132 OSF_ATTR_UNSPEC, 133 OSF_ATTR_FINGER, 134 OSF_ATTR_MAX, 135 }; 136 137 #endif /* _XT_OSF_H */ 138