/* $OpenBSD: pfvar.h,v 1.171 2003/09/26 21:44:09 cedric Exp $ */ /* * Copyright (c) 2001 Daniel Hartmeier * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * - Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * - Redistributions in binary form must reproduce the above * copyright notice, this list of conditions and the following * disclaimer in the documentation and/or other materials provided * with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * */ #ifndef _NET_PFVAR_H_ #define _NET_PFVAR_H_ #include #include #include /* A packed Operating System description for fingerprinting */ typedef u_int32_t pf_osfp_t; #define PF_OSFP_ANY ((pf_osfp_t)0) #define PF_OSFP_UNKNOWN ((pf_osfp_t)-1) #define PF_OSFP_NOMATCH ((pf_osfp_t)-2) struct pf_osfp_entry { SLIST_ENTRY(pf_osfp_entry) fp_entry; pf_osfp_t fp_os; int fp_enflags; #define PF_OSFP_EXPANDED 0x001 /* expanded entry */ #define PF_OSFP_GENERIC 0x002 /* generic signature */ #define PF_OSFP_NODETAIL 0x004 /* no p0f details */ #define PF_OSFP_LEN 32 char fp_class_nm[PF_OSFP_LEN]; char fp_version_nm[PF_OSFP_LEN]; char fp_subtype_nm[PF_OSFP_LEN]; }; #define PF_OSFP_ENTRY_EQ(a, b) \ ((a)->fp_os == (b)->fp_os && \ memcmp((a)->fp_class_nm, (b)->fp_class_nm, PF_OSFP_LEN) == 0 && \ memcmp((a)->fp_version_nm, (b)->fp_version_nm, PF_OSFP_LEN) == 0 && \ memcmp((a)->fp_subtype_nm, (b)->fp_subtype_nm, PF_OSFP_LEN) == 0) /* handle pf_osfp_t packing */ #define _FP_RESERVED_BIT 1 /* For the special negative #defines */ #define _FP_UNUSED_BITS 1 #define _FP_CLASS_BITS 10 /* OS Class (Windows, Linux) */ #define _FP_VERSION_BITS 10 /* OS version (95, 98, NT, 2.4.54, 3.2) */ #define _FP_SUBTYPE_BITS 10 /* patch level (NT SP4, SP3, ECN patch) */ #define PF_OSFP_UNPACK(osfp, class, version, subtype) do { \ (class) = ((osfp) >> (_FP_VERSION_BITS+_FP_SUBTYPE_BITS)) & \ ((1 << _FP_CLASS_BITS) - 1); \ (version) = ((osfp) >> _FP_SUBTYPE_BITS) & \ ((1 << _FP_VERSION_BITS) - 1);\ (subtype) = (osfp) & ((1 << _FP_SUBTYPE_BITS) - 1); \ } while(0) #define PF_OSFP_PACK(osfp, class, version, subtype) do { \ (osfp) = ((class) & ((1 << _FP_CLASS_BITS) - 1)) << (_FP_VERSION_BITS \ + _FP_SUBTYPE_BITS); \ (osfp) |= ((version) & ((1 << _FP_VERSION_BITS) - 1)) << \ _FP_SUBTYPE_BITS; \ (osfp) |= (subtype) & ((1 << _FP_SUBTYPE_BITS) - 1); \ } while(0) /* the fingerprint of an OSes TCP SYN packet */ typedef u_int64_t pf_tcpopts_t; struct pf_os_fingerprint { SLIST_HEAD(pf_osfp_enlist, pf_osfp_entry) fp_oses; /* list of matches */ pf_tcpopts_t fp_tcpopts; /* packed TCP options */ u_int16_t fp_wsize; /* TCP window size */ u_int16_t fp_psize; /* ip->ip_len */ u_int16_t fp_mss; /* TCP MSS */ u_int16_t fp_flags; #define PF_OSFP_WSIZE_MOD 0x0001 /* Window modulus */ #define PF_OSFP_WSIZE_DC 0x0002 /* Window don't care */ #define PF_OSFP_WSIZE_MSS 0x0004 /* Window multiple of MSS */ #define PF_OSFP_WSIZE_MTU 0x0008 /* Window multiple of MTU */ #define PF_OSFP_PSIZE_MOD 0x0010 /* packet size modulus */ #define PF_OSFP_PSIZE_DC 0x0020 /* packet size don't care */ #define PF_OSFP_WSCALE 0x0040 /* TCP window scaling */ #define PF_OSFP_WSCALE_MOD 0x0080 /* TCP window scale modulus */ #define PF_OSFP_WSCALE_DC 0x0100 /* TCP window scale dont-care */ #define PF_OSFP_MSS 0x0200 /* TCP MSS */ #define PF_OSFP_MSS_MOD 0x0400 /* TCP MSS modulus */ #define PF_OSFP_MSS_DC 0x0800 /* TCP MSS dont-care */ #define PF_OSFP_DF 0x1000 /* IPv4 don't fragment bit */ #define PF_OSFP_TS0 0x2000 /* Zero timestamp */ u_int8_t fp_optcnt; /* TCP option count */ u_int8_t fp_wscale; /* TCP window scaling */ u_int8_t fp_ttl; /* IPv4 TTL */ #define PF_OSFP_MAXTTL_OFFSET 40 /* TCP options packing */ #define PF_OSFP_TCPOPT_NOP 0x0 /* TCP NOP option */ #define PF_OSFP_TCPOPT_WSCALE 0x1 /* TCP window scaling option */ #define PF_OSFP_TCPOPT_MSS 0x2 /* TCP max segment size opt */ #define PF_OSFP_TCPOPT_SACK 0x3 /* TCP SACK OK option */ #define PF_OSFP_TCPOPT_TS 0x4 /* TCP timestamp option */ #define PF_OSFP_TCPOPT_BITS 3 /* bits used by each option */ #define PF_OSFP_MAX_OPTS \ (sizeof(((struct pf_os_fingerprint *)0)->fp_tcpopts) * 8) \ / PF_OSFP_TCPOPT_BITS SLIST_ENTRY(pf_os_fingerprint) fp_next; }; struct pf_osfp_ioctl { struct pf_osfp_entry fp_os; pf_tcpopts_t fp_tcpopts; /* packed TCP options */ u_int16_t fp_wsize; /* TCP window size */ u_int16_t fp_psize; /* ip->ip_len */ u_int16_t fp_mss; /* TCP MSS */ u_int16_t fp_flags; u_int8_t fp_optcnt; /* TCP option count */ u_int8_t fp_wscale; /* TCP window scaling */ u_int8_t fp_ttl; /* IPv4 TTL */ int fp_getnum; /* DIOCOSFPGET number */ }; /* The fingerprint functions can be linked into userland programs (tcpdump) */ int pf_osfp_add(struct pf_osfp_ioctl *); struct pf_osfp_enlist * pf_osfp_fingerprint_hdr(const struct ip_hdr *, const struct tcp_hdr *); void pf_osfp_flush(void); int pf_osfp_get(struct pf_osfp_ioctl *); void pf_osfp_initialize(void); int pf_osfp_match(struct pf_osfp_enlist *, pf_osfp_t); struct pf_os_fingerprint * pf_osfp_validate(void); #endif /* _NET_PFVAR_H_ */