diff options
| -rw-r--r-- | extensions/libxt_conntrack.c | 2 | ||||
| -rw-r--r-- | extensions/libxt_osf.c | 155 | ||||
| -rw-r--r-- | include/linux/netfilter/xt_osf.h | 135 |
3 files changed, 291 insertions, 1 deletions
diff --git a/extensions/libxt_conntrack.c b/extensions/libxt_conntrack.c index d30871fc..5ca734d2 100644 --- a/extensions/libxt_conntrack.c +++ b/extensions/libxt_conntrack.c @@ -273,7 +273,7 @@ conntrack_ps_expires(struct xt_conntrack_mtinfo2 *info, const char *s) xtables_param_act(XTF_BAD_VALUE, "conntrack", "--expires", s); max = min; if (*end == ':') - if (!xtables_strtoui(s, &end, &max, 0, UINT32_MAX)) + if (!xtables_strtoui(end + 1, &end, &max, 0, UINT32_MAX)) xtables_param_act(XTF_BAD_VALUE, "conntrack", "--expires", s); if (*end != '\0') xtables_param_act(XTF_BAD_VALUE, "conntrack", "--expires", s); diff --git a/extensions/libxt_osf.c b/extensions/libxt_osf.c new file mode 100644 index 00000000..3c0ea2dd --- /dev/null +++ b/extensions/libxt_osf.c @@ -0,0 +1,155 @@ +/* + * 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); +} diff --git a/include/linux/netfilter/xt_osf.h b/include/linux/netfilter/xt_osf.h new file mode 100644 index 00000000..18afa495 --- /dev/null +++ b/include/linux/netfilter/xt_osf.h @@ -0,0 +1,135 @@ +/* + * 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 */ |