| /* Shared library add-on to iptables to add related packet matching support. */ |
| #include <stdio.h> |
| #include <netdb.h> |
| #include <string.h> |
| #include <stdlib.h> |
| #include <getopt.h> |
| |
| #include <xtables.h> |
| #include <linux/netfilter/xt_helper.h> |
| |
| static void helper_help(void) |
| { |
| printf( |
| "helper match options:\n" |
| "[!] --helper string Match helper identified by string\n"); |
| } |
| |
| static const struct option helper_opts[] = { |
| { "helper", 1, NULL, '1' }, |
| { .name = NULL } |
| }; |
| |
| static int |
| helper_parse(int c, char **argv, int invert, unsigned int *flags, |
| const void *entry, struct xt_entry_match **match) |
| { |
| struct xt_helper_info *info = (struct xt_helper_info *)(*match)->data; |
| |
| switch (c) { |
| case '1': |
| if (*flags) |
| xtables_error(PARAMETER_PROBLEM, |
| "helper match: Only use --helper ONCE!"); |
| xtables_check_inverse(optarg, &invert, &optind, 0); |
| strncpy(info->name, optarg, 29); |
| info->name[29] = '\0'; |
| if (invert) |
| info->invert = 1; |
| *flags = 1; |
| break; |
| |
| default: |
| return 0; |
| } |
| return 1; |
| } |
| |
| static void helper_check(unsigned int flags) |
| { |
| if (!flags) |
| xtables_error(PARAMETER_PROBLEM, |
| "helper match: You must specify `--helper'"); |
| } |
| |
| static void |
| helper_print(const void *ip, const struct xt_entry_match *match, int numeric) |
| { |
| const struct xt_helper_info *info = (const void *)match->data; |
| |
| printf("helper match %s\"%s\" ", info->invert ? "! " : "", info->name); |
| } |
| |
| static void helper_save(const void *ip, const struct xt_entry_match *match) |
| { |
| const struct xt_helper_info *info = (const void *)match->data; |
| |
| printf("%s--helper ",info->invert ? "! " : ""); |
| xtables_save_string(info->name); |
| } |
| |
| static struct xtables_match helper_match = { |
| .family = NFPROTO_UNSPEC, |
| .name = "helper", |
| .version = XTABLES_VERSION, |
| .size = XT_ALIGN(sizeof(struct xt_helper_info)), |
| .help = helper_help, |
| .parse = helper_parse, |
| .final_check = helper_check, |
| .print = helper_print, |
| .save = helper_save, |
| .extra_opts = helper_opts, |
| }; |
| |
| void _init(void) |
| { |
| xtables_register_match(&helper_match); |
| } |