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      1 #include <stdbool.h>
      2 #include <stdlib.h>
      3 #include <stdio.h>
      4 #include <string.h>
      5 #include <getopt.h>
      6 #include <xtables.h>
      7 
      8 #include <linux/netfilter/x_tables.h>
      9 #include <linux/netfilter/xt_NFLOG.h>
     10 
     11 enum {
     12 	O_GROUP = 0,
     13 	O_PREFIX,
     14 	O_RANGE,
     15 	O_THRESHOLD,
     16 };
     17 
     18 #define s struct xt_nflog_info
     19 static const struct xt_option_entry NFLOG_opts[] = {
     20 	{.name = "nflog-group", .id = O_GROUP, .type = XTTYPE_UINT16,
     21 	 .flags = XTOPT_PUT, XTOPT_POINTER(s, group)},
     22 	{.name = "nflog-prefix", .id = O_PREFIX, .type = XTTYPE_STRING,
     23 	 .min = 1, .flags = XTOPT_PUT, XTOPT_POINTER(s, prefix)},
     24 	{.name = "nflog-range", .id = O_RANGE, .type = XTTYPE_UINT32,
     25 	 .flags = XTOPT_PUT, XTOPT_POINTER(s, len)},
     26 	{.name = "nflog-threshold", .id = O_THRESHOLD, .type = XTTYPE_UINT16,
     27 	 .flags = XTOPT_PUT, XTOPT_POINTER(s, threshold)},
     28 	XTOPT_TABLEEND,
     29 };
     30 #undef s
     31 
     32 static void NFLOG_help(void)
     33 {
     34 	printf("NFLOG target options:\n"
     35 	       " --nflog-group NUM		NETLINK group used for logging\n"
     36 	       " --nflog-range NUM		Number of byte to copy\n"
     37 	       " --nflog-threshold NUM		Message threshold of in-kernel queue\n"
     38 	       " --nflog-prefix STRING		Prefix string for log messages\n");
     39 }
     40 
     41 static void NFLOG_init(struct xt_entry_target *t)
     42 {
     43 	struct xt_nflog_info *info = (struct xt_nflog_info *)t->data;
     44 
     45 	info->threshold	= XT_NFLOG_DEFAULT_THRESHOLD;
     46 }
     47 
     48 static void NFLOG_parse(struct xt_option_call *cb)
     49 {
     50 	xtables_option_parse(cb);
     51 	switch (cb->entry->id) {
     52 	case O_PREFIX:
     53 		if (strchr(cb->arg, '\n') != NULL)
     54 			xtables_error(PARAMETER_PROBLEM,
     55 				   "Newlines not allowed in --log-prefix");
     56 		break;
     57 	}
     58 }
     59 
     60 static void nflog_print(const struct xt_nflog_info *info, char *prefix)
     61 {
     62 	if (info->prefix[0] != '\0') {
     63 		printf(" %snflog-prefix ", prefix);
     64 		xtables_save_string(info->prefix);
     65 	}
     66 	if (info->group)
     67 		printf(" %snflog-group %u", prefix, info->group);
     68 	if (info->len)
     69 		printf(" %snflog-range %u", prefix, info->len);
     70 	if (info->threshold != XT_NFLOG_DEFAULT_THRESHOLD)
     71 		printf(" %snflog-threshold %u", prefix, info->threshold);
     72 }
     73 
     74 static void NFLOG_print(const void *ip, const struct xt_entry_target *target,
     75                         int numeric)
     76 {
     77 	const struct xt_nflog_info *info = (struct xt_nflog_info *)target->data;
     78 
     79 	nflog_print(info, "");
     80 }
     81 
     82 static void NFLOG_save(const void *ip, const struct xt_entry_target *target)
     83 {
     84 	const struct xt_nflog_info *info = (struct xt_nflog_info *)target->data;
     85 
     86 	nflog_print(info, "--");
     87 }
     88 
     89 static struct xtables_target nflog_target = {
     90 	.family		= NFPROTO_UNSPEC,
     91 	.name		= "NFLOG",
     92 	.version	= XTABLES_VERSION,
     93 	.size		= XT_ALIGN(sizeof(struct xt_nflog_info)),
     94 	.userspacesize	= XT_ALIGN(sizeof(struct xt_nflog_info)),
     95 	.help		= NFLOG_help,
     96 	.init		= NFLOG_init,
     97 	.x6_parse	= NFLOG_parse,
     98 	.print		= NFLOG_print,
     99 	.save		= NFLOG_save,
    100 	.x6_options	= NFLOG_opts,
    101 };
    102 
    103 void _init(void)
    104 {
    105 	xtables_register_target(&nflog_target);
    106 }
    107