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#include <stdio.h>
#include <string.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 {
O_NOTRACK = 0,
O_HELPER,
O_CTEVENTS,
O_EXPEVENTS,
O_ZONE,
};
#define s struct xt_ct_target_info
static const struct xt_option_entry ct_opts[] = {
{.name = "notrack", .id = O_NOTRACK, .type = XTTYPE_NONE},
{.name = "helper", .id = O_HELPER, .type = XTTYPE_STRING,
.flags = XTOPT_PUT, XTOPT_POINTER(s, helper)},
{.name = "ctevents", .id = O_CTEVENTS, .type = XTTYPE_STRING},
{.name = "expevents", .id = O_EXPEVENTS, .type = XTTYPE_STRING},
{.name = "zone", .id = O_ZONE, .type = XTTYPE_UINT16,
.flags = XTOPT_PUT, XTOPT_POINTER(s, zone)},
XTOPT_TABLEEND,
};
#undef s
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 = ",";
}
}
}
static void ct_parse(struct xt_option_call *cb)
{
struct xt_ct_target_info *info = cb->data;
xtables_option_parse(cb);
switch (cb->entry->id) {
case O_NOTRACK:
info->flags |= XT_CT_NOTRACK;
break;
case O_CTEVENTS:
info->ct_events = ct_parse_events(ct_event_tbl, ARRAY_SIZE(ct_event_tbl), cb->arg);
break;
case O_EXPEVENTS:
info->exp_events = ct_parse_events(exp_event_tbl, ARRAY_SIZE(exp_event_tbl), cb->arg);
break;
}
}
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,
.print = ct_print,
.save = ct_save,
.x6_parse = ct_parse,
.x6_options = ct_opts,
};
void _init(void)
{
xtables_register_target(&ct_target);
}
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