--- /dev/null
+/*
+ * Copyright (c) 2003+ Evgeniy Polyakov <zbr@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);
+}
--- /dev/null
+/*
+ * Copyright (c) 2003+ Evgeniy Polyakov <johnpol@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 */
projects / thirdparty / iptables.git / commitdiff
