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#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <stddef.h>
#include <getopt.h>
#include <xtables.h>
#include <linux/netfilter/nf_conntrack_common.h>
#include <linux/netfilter/xt_CT.h>
static void ct_help(void)
{
printf(
"CT target options:\n"
" --notrack Don't track connection\n"
" --helper name Use conntrack helper 'name' for connection\n"
" --ctevents event[,event...] Generate specified conntrack events for connection\n"
" --expevents event[,event...] Generate specified expectation events for connection\n"
" --zone ID Assign/Lookup connection in zone ID\n"
);
}
enum ct_options {
CT_OPT_NOTRACK = 0x1,
CT_OPT_HELPER = 0x2,
CT_OPT_CTEVENTS = 0x4,
CT_OPT_EXPEVENTS = 0x8,
CT_OPT_ZONE = 0x10,
};
static const struct option ct_opts[] = {
{ "notrack", 0, NULL, CT_OPT_NOTRACK },
{ "helper", 1, NULL, CT_OPT_HELPER },
{ "ctevents", 1, NULL, CT_OPT_CTEVENTS },
{ "expevents", 1, NULL, CT_OPT_EXPEVENTS },
{ "zone", 1, NULL, CT_OPT_ZONE },
{ .name = NULL },
};
struct event_tbl {
const char *name;
unsigned int event;
};
static const struct event_tbl ct_event_tbl[] = {
{ "new", IPCT_NEW },
{ "related", IPCT_RELATED },
{ "destroy", IPCT_DESTROY },
{ "reply", IPCT_REPLY },
{ "assured", IPCT_ASSURED },
{ "protoinfo", IPCT_PROTOINFO },
{ "helper", IPCT_HELPER },
{ "mark", IPCT_MARK },
{ "natseqinfo", IPCT_NATSEQADJ },
{ "secmark", IPCT_SECMARK },
};
static const struct event_tbl exp_event_tbl[] = {
{ "new", IPEXP_NEW },
};
static uint32_t ct_parse_events(const struct event_tbl *tbl, unsigned int size,
const char *events)
{
char str[strlen(events) + 1], *e = str, *t;
unsigned int mask = 0, i;
strcpy(str, events);
while ((t = strsep(&e, ","))) {
for (i = 0; i < size; i++) {
if (strcmp(t, tbl[i].name))
continue;
mask |= 1 << tbl[i].event;
break;
}
if (i == size)
xtables_error(PARAMETER_PROBLEM, "Unknown event type \"%s\"", t);
}
return mask;
}
static void ct_print_events(const char *pfx, const struct event_tbl *tbl,
unsigned int size, uint32_t mask)
{
const char *sep = "";
unsigned int i;
printf("%s ", pfx);
for (i = 0; i < size; i++) {
if (mask & (1 << tbl[i].event)) {
printf("%s%s", sep, tbl[i].name);
sep = ",";
}
}
printf(" ");
}
static int ct_parse(int c, char **argv, int invert, unsigned int *flags,
const void *entry, struct xt_entry_target **target)
{
struct xt_ct_target_info *info = (struct xt_ct_target_info *)(*target)->data;
unsigned int zone;
switch (c) {
case CT_OPT_NOTRACK:
xtables_param_act(XTF_ONLY_ONCE, "CT", "--notrack", *flags & CT_OPT_NOTRACK);
info->flags |= XT_CT_NOTRACK;
break;
case CT_OPT_HELPER:
xtables_param_act(XTF_ONLY_ONCE, "CT", "--helper", *flags & CT_OPT_HELPER);
strncpy(info->helper, optarg, sizeof(info->helper));
info->helper[sizeof(info->helper) - 1] = '\0';
break;
case CT_OPT_CTEVENTS:
xtables_param_act(XTF_ONLY_ONCE, "CT", "--ctevents", *flags & CT_OPT_CTEVENTS);
info->ct_events = ct_parse_events(ct_event_tbl, ARRAY_SIZE(ct_event_tbl), optarg);
break;
case CT_OPT_EXPEVENTS:
xtables_param_act(XTF_ONLY_ONCE, "CT", "--expevents", *flags & CT_OPT_EXPEVENTS);
info->exp_events = ct_parse_events(exp_event_tbl, ARRAY_SIZE(exp_event_tbl), optarg);
break;
case CT_OPT_ZONE:
xtables_param_act(XTF_ONLY_ONCE, "CT", "--zone", *flags & CT_OPT_ZONE);
if (!xtables_strtoui(optarg, NULL, &zone, 0, UINT16_MAX))
xtables_error(PARAMETER_PROBLEM, "Bad zone value \"%s\"", optarg);
info->zone = zone;
break;
default:
return 0;
}
*flags |= c;
return 1;
}
static void ct_print(const void *ip, const struct xt_entry_target *target, int numeric)
{
const struct xt_ct_target_info *info =
(const struct xt_ct_target_info *)target->data;
printf("CT ");
if (info->flags & XT_CT_NOTRACK)
printf("notrack ");
if (info->helper[0])
printf("helper %s ", info->helper);
if (info->ct_events)
ct_print_events("ctevents", ct_event_tbl,
ARRAY_SIZE(ct_event_tbl), info->ct_events);
if (info->exp_events)
ct_print_events("expevents", exp_event_tbl,
ARRAY_SIZE(exp_event_tbl), info->exp_events);
if (info->zone)
printf("zone %u ", info->zone);
}
static void ct_save(const void *ip, const struct xt_entry_target *target)
{
const struct xt_ct_target_info *info =
(const struct xt_ct_target_info *)target->data;
if (info->flags & XT_CT_NOTRACK)
printf("--notrack ");
if (info->helper[0])
printf("--helper %s ", info->helper);
if (info->ct_events)
ct_print_events("--ctevents", ct_event_tbl,
ARRAY_SIZE(ct_event_tbl), info->ct_events);
if (info->exp_events)
ct_print_events("--expevents", exp_event_tbl,
ARRAY_SIZE(exp_event_tbl), info->exp_events);
if (info->zone)
printf("--zone %u ", info->zone);
}
static struct xtables_target ct_target = {
.family = NFPROTO_UNSPEC,
.name = "CT",
.version = XTABLES_VERSION,
.size = XT_ALIGN(sizeof(struct xt_ct_target_info)),
.userspacesize = offsetof(struct xt_ct_target_info, ct),
.help = ct_help,
.parse = ct_parse,
.print = ct_print,
.save = ct_save,
.extra_opts = ct_opts,
};
void _init(void)
{
xtables_register_target(&ct_target);
}
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