No subject


Sat Jun 20 14:05:19 CEST 2009


Signed-off-by: Patrick McHardy <kaber at trash.net>

diff --git a/extensions/libxt_osf.c b/extensions/libxt_osf.c
new file mode 100644
index 0000000..3c0ea2d
--- /dev/null
+++ b/extensions/libxt_osf.c
@@ -0,0 +1,155 @@
+/*
+ * Copyright (c) 2003+ Evgeniy Polyakov <zbr at ioremap.net>
+ *
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+/*
+ * xtables interface for OS fingerprint matching module.
+ */
+
+#include <stdio.h>
+#include <netdb.h>
+#include <string.h>
+#include <stdlib.h>
+#include <getopt.h>
+#include <ctype.h>
+
+#include <linux/types.h>
+
+#include <xtables.h>
+
+#include <netinet/ip.h>
+#include <netinet/tcp.h>
+
+#include <linux/netfilter/xt_osf.h>
+
+static void osf_help(void)
+{
+	printf("OS fingerprint match options:\n"
+		"--genre [!] string         Match a OS genre by passive fingerprinting.\n"
+		"--ttl                  Use some TTL check extensions to determine OS:\n"
+		"       0                       true ip and fingerprint TTL comparison. Works for LAN.\n"
+		"       1                       check if ip TTL is less than fingerprint one. Works for global addresses.\n"
+		"       2                       do not compare TTL at all. Allows to detect NMAP, but can produce false results.\n"
+		"--log level            Log determined genres into dmesg even if they do not match desired one:\n"
+		"       0                       log all matched or unknown signatures.\n"
+		"       1                       log only first one.\n"
+		"       2                       log all known matched signatures.\n"
+		);
+}
+
+
+static const struct option osf_opts[] = {
+	{ .name = "genre",	.has_arg = true, .val = '1' },
+	{ .name = "ttl",	.has_arg = true, .val = '2' },
+	{ .name = "log",	.has_arg = true, .val = '3' },
+	{ .name = NULL }
+};
+
+
+static void osf_parse_string(const char *s, struct xt_osf_info *info)
+{
+	if (strlen(s) < MAXGENRELEN)
+		strcpy(info->genre, s);
+	else
+		xtables_error(PARAMETER_PROBLEM,
+			      "Genre string too long `%s' [%zd], max=%d",
+			      s, strlen(s), MAXGENRELEN);
+}
+
+static int osf_parse(int c, char **argv, int invert, unsigned int *flags,
+      			const void *entry,
+      			struct xt_entry_match **match)
+{
+	struct xt_osf_info *info = (struct xt_osf_info *)(*match)->data;
+
+	switch(c) {
+		case '1': /* --genre */
+			if (*flags & XT_OSF_GENRE)
+				xtables_error(PARAMETER_PROBLEM,
+					      "Can't specify multiple genre parameter");
+			xtables_check_inverse(optarg, &invert, &optind, 0, argv);
+			osf_parse_string(argv[optind-1], info);
+			if (invert)
+				info->flags |= XT_OSF_INVERT;
+			info->len=strlen(info->genre);
+			*flags |= XT_OSF_GENRE;
+			break;
+		case '2': /* --ttl */
+			if (*flags & XT_OSF_TTL)
+				xtables_error(PARAMETER_PROBLEM,
+					      "Can't specify multiple ttl parameter");
+			*flags |= XT_OSF_TTL;
+			info->flags |= XT_OSF_TTL;
+			if (!xtables_strtoui(argv[optind-1], NULL, &info->ttl, 0, 2))
+				xtables_error(PARAMETER_PROBLEM, "TTL parameter is too big");
+			break;
+		case '3': /* --log */
+			if (*flags & XT_OSF_LOG)
+				xtables_error(PARAMETER_PROBLEM,
+					      "Can't specify multiple log parameter");
+			*flags |= XT_OSF_LOG;
+			if (!xtables_strtoui(argv[optind-1], NULL, &info->loglevel, 0, 2))
+				xtables_error(PARAMETER_PROBLEM, "Log level parameter is too big");
+			info->flags |= XT_OSF_LOG;
+			break;
+		default:
+			return 0;
+	}
+
+	return 1;
+}
+
+static void osf_final_check(unsigned int flags)
+{
+	if (!flags)
+		xtables_error(PARAMETER_PROBLEM,
+			      "OS fingerprint match: You must specify `--genre'");
+}
+
+static void osf_print(const void *ip, const struct xt_entry_match *match, int numeric)
+{
+	const struct xt_osf_info *info = (const struct xt_osf_info*) match->data;
+
+	printf("OS fingerprint match %s%s ", (info->flags & XT_OSF_INVERT) ? "! " : "", info->genre);
+}
+
+static void osf_save(const void *ip, const struct xt_entry_match *match)
+{
+	const struct xt_osf_info *info = (const struct xt_osf_info*) match->data;
+
+	printf("--genre %s%s ", (info->flags & XT_OSF_INVERT) ? "! ": "", info->genre);
+}
+
+static struct xtables_match osf_match = {
+	.name		= "osf",
+	.version	= XTABLES_VERSION,
+	.size		= XT_ALIGN(sizeof(struct xt_osf_info)),
+	.userspacesize	= XT_ALIGN(sizeof(struct xt_osf_info)),
+	.help		= osf_help,
+	.parse		= osf_parse,
+	.print		= osf_print,
+	.final_check	= osf_final_check,
+	.save		= osf_save,
+	.extra_opts	= osf_opts,
+	.family		= NFPROTO_IPV4
+};
+
+void _init(void)
+{
+	xtables_register_match(&osf_match);
+}
diff --git a/include/linux/netfilter/xt_osf.h b/include/linux/netfilter/xt_osf.h
new file mode 100644
index 0000000..18afa49
--- /dev/null
+++ b/include/linux/netfilter/xt_osf.h
@@ -0,0 +1,135 @@
+/*
+ * Copyright (c) 2003+ Evgeniy Polyakov <johnpol at 2ka.mxt.ru>
+ *
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#ifndef _XT_OSF_H
+#define _XT_OSF_H
+
+#include <linux/types.h>
+
+#define MAXGENRELEN		32
+
+#define XT_OSF_GENRE		(1<<0)
+#define	XT_OSF_TTL		(1<<1)
+#define XT_OSF_LOG		(1<<2)
+#define XT_OSF_INVERT		(1<<3)
+
+#define XT_OSF_LOGLEVEL_ALL	0	/* log all matched fingerprints */
+#define XT_OSF_LOGLEVEL_FIRST	1	/* log only the first matced fingerprint */
+#define XT_OSF_LOGLEVEL_ALL_KNOWN	2 /* do not log unknown packets */
+
+#define XT_OSF_TTL_TRUE		0	/* True ip and fingerprint TTL comparison */
+#define XT_OSF_TTL_LESS		1	/* Check if ip TTL is less than fingerprint one */
+#define XT_OSF_TTL_NOCHECK	2	/* Do not compare ip and fingerprint TTL at all */
+
+struct xt_osf_info {
+	char			genre[MAXGENRELEN];
+	__u32			len;
+	__u32			flags;
+	__u32			loglevel;
+	__u32			ttl;
+};
+
+/*
+ * Wildcard MSS (kind of).
+ * It is used to implement a state machine for the different wildcard values
+ * of the MSS and window sizes.
+ */
+struct xt_osf_wc {
+	__u32			wc;
+	__u32			val;
+};
+
+/*
+ * This struct represents IANA options
+ * http://www.iana.org/assignments/tcp-parameters
+ */
+struct xt_osf_opt {
+	__u16			kind, length;
+	struct xt_osf_wc	wc;
+};
+
+struct xt_osf_user_finger {
+	struct xt_osf_wc	wss;
+
+	__u8			ttl, df;
+	__u16			ss, mss;
+	__u16			opt_num;
+
+	char			genre[MAXGENRELEN];
+	char			version[MAXGENRELEN];
+	char			subtype[MAXGENRELEN];
+
+	/* MAX_IPOPTLEN is maximum if all options are NOPs or EOLs */
+	struct xt_osf_opt	opt[MAX_IPOPTLEN];
+};
+
+struct xt_osf_nlmsg {
+	struct xt_osf_user_finger	f;
+	struct iphdr		ip;
+	struct tcphdr		tcp;
+};
+
+/* Defines for IANA option kinds */
+
+enum iana_options {
+	OSFOPT_EOL = 0,		/* End of options */
+	OSFOPT_NOP, 		/* NOP */
+	OSFOPT_MSS, 		/* Maximum segment size */
+	OSFOPT_WSO, 		/* Window scale option */
+	OSFOPT_SACKP,		/* SACK permitted */
+	OSFOPT_SACK,		/* SACK */
+	OSFOPT_ECHO,
+	OSFOPT_ECHOREPLY,
+	OSFOPT_TS,		/* Timestamp option */
+	OSFOPT_POCP,		/* Partial Order Connection Permitted */
+	OSFOPT_POSP,		/* Partial Order Service Profile */
+
+	/* Others are not used in the current OSF */
+	OSFOPT_EMPTY = 255,
+};
+
+/*
+ * Initial window size option state machine: multiple of mss, mtu or
+ * plain numeric value. Can also be made as plain numeric value which
+ * is not a multiple of specified value.
+ */
+enum xt_osf_window_size_options {
+	OSF_WSS_PLAIN	= 0,
+	OSF_WSS_MSS,
+	OSF_WSS_MTU,
+	OSF_WSS_MODULO,
+	OSF_WSS_MAX,
+};
+
+/*
+ * Add/remove fingerprint from the kernel.
+ */
+enum xt_osf_msg_types {
+	OSF_MSG_ADD,
+	OSF_MSG_REMOVE,
+	OSF_MSG_MAX,
+};
+
+enum xt_osf_attr_type {
+	OSF_ATTR_UNSPEC,
+	OSF_ATTR_FINGER,
+	OSF_ATTR_MAX,
+};
+
+#endif				/* _XT_OSF_H */



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