/* Shared library add-on to iptables to add PSD support Copyright (C) 2000,2001 astaro AG This file is distributed under the terms of the GNU General Public License (GPL). Copies of the GPL can be obtained from: ftp://prep.ai.mit.edu/pub/gnu/GPL 2000-05-04 Markus Hennig <hennig@astaro.de> : initial 2000-08-18 Dennis Koslowski <koslowski@astaro.de> : first release 2000-12-01 Dennis Koslowski <koslowski@astaro.de> : UDP scans detection added 2001-02-04 Jan Rekorajski <baggins@pld.org.pl> : converted from target to match 2003-03-02 Harald Welte <laforge@netfilter.org>: fix 'storage' bug 2008-06-25 Luiz Capitulino <lcapitulino@mandriva.com.br>: converted from target to match again (target interface has been added back someway) */ #include <stdio.h> #include <netdb.h> #include <string.h> #include <stdlib.h> #include <syslog.h> #include <getopt.h> #include <iptables.h> #include <linux/netfilter_ipv4/ip_tables.h> #include <linux/netfilter_ipv4/ipt_psd.h> /* Function which prints out usage message. */ static void psd_help(void) { printf( "psd options:\n" " --psd-weight-threshold threshhold Portscan detection weight threshold\n\n" " --psd-delay-threshold delay Portscan detection delay threshold\n\n" " --psd-lo-ports-weight lo Privileged ports weight\n\n" " --psd-hi-ports-weight hi High ports weight\n\n"); } static struct option psd_opts[] = { { "psd-weight-threshold", 1, 0, '1' }, { "psd-delay-threshold", 1, 0, '2' }, { "psd-lo-ports-weight", 1, 0, '3' }, { "psd-hi-ports-weight", 1, 0, '4' }, { 0 } }; /* Initialize the target. */ static void psd_init(struct xt_entry_match *m) { struct ipt_psd_info *psdinfo = (struct ipt_psd_info *)m->data; psdinfo->weight_threshold = SCAN_WEIGHT_THRESHOLD; psdinfo->delay_threshold = SCAN_DELAY_THRESHOLD; psdinfo->lo_ports_weight = PORT_WEIGHT_PRIV; psdinfo->hi_ports_weight = PORT_WEIGHT_HIGH; } typedef struct _code { char *c_name; int c_val; } CODE; #define IPT_PSD_OPT_CTRESH 0x01 #define IPT_PSD_OPT_DTRESH 0x02 #define IPT_PSD_OPT_LPWEIGHT 0x04 #define IPT_PSD_OPT_HPWEIGHT 0x08 /* Function which parses command options; returns true if it ate an option */ static int psd_parse(int c, char **argv, int invert, unsigned int *flags, const void *entry, struct xt_entry_match **match) { struct ipt_psd_info *psdinfo = (struct ipt_psd_info *)(*match)->data; unsigned int num; switch (c) { /* PSD-weight-threshold */ case '1': if (*flags & IPT_PSD_OPT_CTRESH) xtables_error(PARAMETER_PROBLEM, "Can't specify --psd-weight-threshold " "twice"); if (xtables_strtoui(optarg, NULL, &num, 0, 10000) == -1) xtables_error(PARAMETER_PROBLEM, "bad --psd-weight-threshold `%s'", optarg); psdinfo->weight_threshold = num; *flags |= IPT_PSD_OPT_CTRESH; break; /* PSD-delay-threshold */ case '2': if (*flags & IPT_PSD_OPT_DTRESH) xtables_error(PARAMETER_PROBLEM, "Can't specify --psd-delay-threshold twice"); if (xtables_strtoui(optarg, NULL, &num, 0, 10000) == -1) xtables_error(PARAMETER_PROBLEM, "bad --psd-delay-threshold `%s'", optarg); psdinfo->delay_threshold = num; *flags |= IPT_PSD_OPT_DTRESH; break; /* PSD-lo-ports-weight */ case '3': if (*flags & IPT_PSD_OPT_LPWEIGHT) xtables_error(PARAMETER_PROBLEM, "Can't specify --psd-lo-ports-weight twice"); if (xtables_strtoui(optarg, NULL, &num, 0, 10000) == -1) xtables_error(PARAMETER_PROBLEM, "bad --psd-lo-ports-weight `%s'", optarg); psdinfo->lo_ports_weight = num; *flags |= IPT_PSD_OPT_LPWEIGHT; break; /* PSD-hi-ports-weight */ case '4': if (*flags & IPT_PSD_OPT_HPWEIGHT) xtables_error(PARAMETER_PROBLEM, "Can't specify --psd-hi-ports-weight twice"); if (xtables_strtoui(optarg, NULL, &num, 0, 10000) == -1) xtables_error(PARAMETER_PROBLEM, "bad --psd-hi-ports-weight `%s'", optarg); psdinfo->hi_ports_weight = num; *flags |= IPT_PSD_OPT_HPWEIGHT; break; default: return 0; } return 1; } /* Final check; nothing. */ static void psd_check(unsigned int flags) { return; } /* Prints out the targinfo. */ static void psd_print(const void *ip, const struct xt_entry_match *match, int numeric) { const struct ipt_psd_info *psdinfo = (const struct ipt_psd_info *)match->data; printf("psd "); printf("weight-threshold: %u ", psdinfo->weight_threshold); printf("delay-threshold: %u ", psdinfo->delay_threshold); printf("lo-ports-weight: %u ", psdinfo->lo_ports_weight); printf("hi-ports-weight: %u ", psdinfo->hi_ports_weight); } /* Saves the union ipt_targinfo in parsable form to stdout. */ static void psd_save(const void *ip, const struct xt_entry_match *match) { const struct ipt_psd_info *psdinfo = (const struct ipt_psd_info *)match->data; printf("--psd-weight-threshold %u ", psdinfo->weight_threshold); printf("--psd-delay-threshold %u ", psdinfo->delay_threshold); printf("--psd-lo-ports-weight %u ", psdinfo->lo_ports_weight); printf("--psd-hi-ports-weight %u ", psdinfo->hi_ports_weight); } static struct xtables_match psd_tg_reg = { .name = "psd", .version = XTABLES_VERSION, .size = XT_ALIGN(sizeof(struct ipt_psd_info)), .userspacesize = XT_ALIGN(sizeof(struct ipt_psd_info)), .help = psd_help, .init = psd_init, .parse = psd_parse, .final_check = psd_check, .print = psd_print, .save = psd_save, .extra_opts = psd_opts, }; void _init(void) { xtables_register_match(&psd_tg_reg); }