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/*
* (C) 2009 by Pablo Neira Ayuso <pablo@netfilter.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "conntrackd.h"
#include "sync.h"
#include "log.h"
#include "cache.h"
#include "origin.h"
#include "external.h"
#include "netlink.h"
#include <libnetfilter_conntrack/libnetfilter_conntrack.h>
#include <errno.h>
#include <stdlib.h>
static struct nfct_handle *inject;
static int external_inject_init(void)
{
/* handler to directly inject conntracks into kernel-space */
inject = nfct_open(CONNTRACK, 0);
if (inject == NULL) {
dlog(LOG_ERR, "can't open netlink handler: %s",
strerror(errno));
dlog(LOG_ERR, "no ctnetlink kernel support?");
return -1;
}
/* we are directly injecting the entries into the kernel */
origin_register(inject, CTD_ORIGIN_INJECT);
return 0;
}
static void external_inject_close(void)
{
origin_unregister(inject);
nfct_close(inject);
}
static void external_inject_new(struct nf_conntrack *ct)
{
int ret, retry = 1;
retry:
if (nl_create_conntrack(inject, ct, 0) == -1) {
/* if the state entry exists, we delete and try again */
if (errno == EEXIST && retry == 1) {
ret = nl_destroy_conntrack(inject, ct);
if (ret == 0 || (ret == -1 && errno == ENOENT)) {
if (retry) {
retry = 0;
goto retry;
}
}
dlog(LOG_ERR, "inject-add1: %s", strerror(errno));
dlog_ct(STATE(log), ct, NFCT_O_PLAIN);
return;
}
dlog(LOG_ERR, "inject-add2: %s", strerror(errno));
dlog_ct(STATE(log), ct, NFCT_O_PLAIN);
}
}
static void external_inject_upd(struct nf_conntrack *ct)
{
int ret;
/* if we successfully update the entry, everything is OK */
if (nl_update_conntrack(inject, ct, 0) != -1)
return;
/* state entries does not exist, we have to create it */
if (errno == ENOENT) {
if (nl_create_conntrack(inject, ct, 0) == -1) {
dlog(LOG_ERR, "inject-upd1: %s", strerror(errno));
dlog_ct(STATE(log), ct, NFCT_O_PLAIN);
}
return;
}
/* we failed to update the entry, there are some operations that
* may trigger this error, eg. unset some status bits. Try harder,
* delete the existing entry and create a new one. */
ret = nl_destroy_conntrack(inject, ct);
if (ret == 0 || (ret == -1 && errno == ENOENT)) {
if (nl_create_conntrack(inject, ct, 0) == -1) {
dlog(LOG_ERR, "inject-upd2: %s", strerror(errno));
dlog_ct(STATE(log), ct, NFCT_O_PLAIN);
}
return;
}
dlog(LOG_ERR, "inject-upd3: %s", strerror(errno));
dlog_ct(STATE(log), ct, NFCT_O_PLAIN);
}
static void external_inject_del(struct nf_conntrack *ct)
{
if (nl_destroy_conntrack(inject, ct) == -1) {
if (errno != ENOENT) {
dlog(LOG_ERR, "inject-del: %s", strerror(errno));
dlog_ct(STATE(log), ct, NFCT_O_PLAIN);
}
}
}
static void external_inject_dump(int fd, int type)
{
}
static void external_inject_commit(struct nfct_handle *h, int fd)
{
}
static void external_inject_flush(void)
{
}
static void external_inject_stats(int fd)
{
}
static void external_inject_stats_ext(int fd)
{
}
struct external_handler external_inject = {
.init = external_inject_init,
.close = external_inject_close,
.new = external_inject_new,
.update = external_inject_upd,
.destroy = external_inject_del,
.dump = external_inject_dump,
.commit = external_inject_commit,
.flush = external_inject_flush,
.stats = external_inject_stats,
.stats_ext = external_inject_stats_ext,
};
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