1 /* Shared library add-on to iptables to add related packet matching support. */
9 #include <linux/netfilter_ipv4/ipt_helper.h>
11 /* Function which prints out usage message. */
16 "helper match v%s options:\n"
17 "[!] --helper string Match helper identified by string\n"
22 static struct option opts[] = {
23 { "helper", 1, 0, '1' },
27 /* Function which parses command options; returns true if it
30 parse(int c, char **argv, int invert, unsigned int *flags,
31 const struct ipt_entry *entry,
32 unsigned int *nfcache,
33 struct ipt_entry_match **match)
35 struct ipt_helper_info *info = (struct ipt_helper_info *)(*match)->data;
40 exit_error(PARAMETER_PROBLEM,
41 "helper match: Only use --helper ONCE!");
42 check_inverse(optarg, &invert, &invert, 0);
43 strncpy(info->name, optarg, 29);
44 info->name[29] = '\0';
56 /* Final check; must have specified --helper. */
58 final_check(unsigned int flags)
61 exit_error(PARAMETER_PROBLEM,
62 "helper match: You must specify `--helper'");
65 /* Prints out the info. */
67 print(const struct ipt_ip *ip,
68 const struct ipt_entry_match *match,
71 struct ipt_helper_info *info = (struct ipt_helper_info *)match->data;
73 printf("helper match %s\"%s\" ", info->invert ? "! " : "", info->name);
76 /* Saves the union ipt_info in parsable form to stdout. */
78 save(const struct ipt_ip *ip, const struct ipt_entry_match *match)
80 struct ipt_helper_info *info = (struct ipt_helper_info *)match->data;
82 printf("%s--helper \"%s\" ",info->invert ? "! " : "", info->name);
85 static struct iptables_match helper = {
88 .version = IPTABLES_VERSION,
89 .size = IPT_ALIGN(sizeof(struct ipt_helper_info)),
92 .final_check = &final_check,
100 register_match(&helper);