diff options
Diffstat (limited to 'extensions')
-rwxr-xr-x | extensions/.helper-test | 2 | ||||
-rw-r--r-- | extensions/libipt_helper.c | 109 |
2 files changed, 111 insertions, 0 deletions
diff --git a/extensions/.helper-test b/extensions/.helper-test new file mode 100755 index 00000000..a9a9b726 --- /dev/null +++ b/extensions/.helper-test @@ -0,0 +1,2 @@ +#! /bin/sh +[ -f $KERNEL_DIR/include/linux/netfilter_ipv4/ipt_helper.h ] && echo helper diff --git a/extensions/libipt_helper.c b/extensions/libipt_helper.c new file mode 100644 index 00000000..ddb42eea --- /dev/null +++ b/extensions/libipt_helper.c @@ -0,0 +1,109 @@ +/* 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 <iptables.h> +#include <linux/netfilter_ipv4/ipt_helper.h> + +/* Function which prints out usage message. */ +static void +help(void) +{ + printf( +"helper match v%s options:\n" +"[!] --helper value Match helper value\n" +"\n", +NETFILTER_VERSION); +} + +static struct option opts[] = { + { "helper", 1, 0, '1' }, + {0} +}; + +/* Initialize the match. */ +static void +init(struct ipt_entry_match *m, unsigned int *nfcache) +{ + /* Can't cache this. */ + *nfcache |= NFC_UNKNOWN; +} + +/* Function which parses command options; returns true if it + ate an option */ +static int +parse(int c, char **argv, int invert, unsigned int *flags, + const struct ipt_entry *entry, + unsigned int *nfcache, + struct ipt_entry_match **match) +{ + struct ipt_helper_info *info = (struct ipt_helper_info *)(*match)->data; + + switch (c) { + case '1': + if (check_inverse(optarg, &invert)) + optind++; + strncpy(info->name, optarg, 29); + if (invert) + info->invert = 1; + *flags = 1; + break; + + default: + return 0; + } + return 1; +} + +/* Final check; must have specified --helper. */ +static void +final_check(unsigned int flags) +{ + if (!flags) + exit_error(PARAMETER_PROBLEM, + "helper match: You must specify `--helper'"); +} + +/* Prints out the info. */ +static void +print(const struct ipt_ip *ip, + const struct ipt_entry_match *match, + int numeric) +{ + struct ipt_helper_info *info = (struct ipt_helper_info *)match->data; + + printf("helper match %s\"%s\" ", info->invert ? "! " : "", info->name); +} + +/* Saves the union ipt_info in parsable form to stdout. */ +static void +save(const struct ipt_ip *ip, const struct ipt_entry_match *match) +{ + struct ipt_helper_info *info = (struct ipt_helper_info *)match->data; + + printf("%s--helper \"%s\" ",info->invert ? "! " : "", info->name); +} + +static +struct iptables_match helper += { NULL, + "helper", + NETFILTER_VERSION, + IPT_ALIGN(sizeof(struct ipt_helper_info)), + IPT_ALIGN(sizeof(struct ipt_helper_info)), + &help, + &init, + &parse, + &final_check, + &print, + &save, + opts +}; + +void _init(void) +{ + register_match(&helper); +} |