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/*
* (C) 2006-2007 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 "cache.h"
#include "hash.h"
#include "log.h"
#include "conntrackd.h"
#include "netlink.h"
#include "us-conntrack.h"
#include <libnetfilter_conntrack/libnetfilter_conntrack.h>
#include <sched.h>
#include <errno.h>
#include <string.h>
struct __dump_container {
int fd;
int type;
};
static int do_dump(void *data1, void *data2)
{
char buf[1024];
int size;
struct __dump_container *container = data1;
struct us_conntrack *u = data2;
char *data = u->data;
unsigned i;
/*
* XXX: Do not dump the entries that are scheduled to expire.
* These entries talk about already destroyed connections
* that we keep for some time just in case that we have to
* resent some lost messages. We do not show them to the
* user as he may think that the firewall replicas are not
* in sync. The branch below is a hack as it is quite
* specific and it breaks conntrackd modularity. Probably
* there's a nicer way to do this but until I come up with it...
*/
if (CONFIG(flags) & CTD_SYNC_FTFW && alarm_pending(&u->alarm))
return 0;
/* do not show cached timeout, this may confuse users */
if (nfct_attr_is_set(u->ct, ATTR_TIMEOUT))
nfct_attr_unset(u->ct, ATTR_TIMEOUT);
memset(buf, 0, sizeof(buf));
size = nfct_snprintf(buf,
sizeof(buf),
u->ct,
NFCT_T_UNKNOWN,
container->type,
0);
for (i = 0; i < u->cache->num_features; i++) {
if (u->cache->features[i]->dump) {
size += u->cache->features[i]->dump(u,
data,
buf+size,
container->type);
data += u->cache->features[i]->size;
}
}
size += sprintf(buf+size, "\n");
if (send(container->fd, buf, size, 0) == -1) {
if (errno != EPIPE)
return -1;
}
return 0;
}
void cache_dump(struct cache *c, int fd, int type)
{
struct __dump_container tmp = {
.fd = fd,
.type = type
};
hashtable_iterate(c->h, (void *) &tmp, do_dump);
}
/* no need to clone, called from child process */
static int do_commit(void *data1, void *data2)
{
int ret, retry = 1;
struct cache *c = data1;
struct us_conntrack *u = data2;
struct nf_conntrack *ct = u->ct;
/*
* Set a reduced timeout for candidate-to-be-committed
* conntracks that live in the external cache
*/
nfct_set_attr_u32(ct, ATTR_TIMEOUT, CONFIG(commit_timeout));
ret = nl_exist_conntrack(ct);
switch (ret) {
case -1:
dlog(LOG_ERR, "commit-exist: %s", strerror(errno));
dlog_ct(STATE(log), ct, NFCT_O_PLAIN);
break;
case 0:
try_again_create:
if (nl_create_conntrack(ct) == -1) {
if (errno == ENOMEM) {
if (retry) {
retry = 0;
sched_yield();
goto try_again_create;
}
}
dlog(LOG_ERR, "commit-create: %s", strerror(errno));
dlog_ct(STATE(log), ct, NFCT_O_PLAIN);
c->commit_fail++;
} else
c->commit_ok++;
break;
case 1:
c->commit_exist++;
try_again_update:
if (nl_update_conntrack(ct) == -1) {
if (errno == ENOMEM || errno == ETIME) {
if (retry) {
retry = 0;
sched_yield();
goto try_again_update;
}
}
dlog(LOG_ERR, "commit-update: %s", strerror(errno));
dlog_ct(STATE(log), ct, NFCT_O_PLAIN);
c->commit_fail++;
} else
c->commit_ok++;
break;
}
/* keep iterating even if we have found errors */
return 0;
}
void cache_commit(struct cache *c)
{
unsigned int commit_ok = c->commit_ok;
unsigned int commit_exist = c->commit_exist;
unsigned int commit_fail = c->commit_fail;
hashtable_iterate(c->h, c, do_commit);
/* calculate new entries committed */
commit_ok = c->commit_ok - commit_ok;
commit_fail = c->commit_fail - commit_fail;
commit_exist = c->commit_exist - commit_exist;
/* log results */
dlog(LOG_NOTICE, "Committed %u new entries", commit_ok);
if (commit_exist)
dlog(LOG_NOTICE, "%u entries updated, "
"already exist", commit_exist);
if (commit_fail)
dlog(LOG_NOTICE, "%u entries can't be "
"committed", commit_fail);
}
static int do_reset_timers(void *data1, void *data2)
{
int ret;
u_int32_t current_timeout;
struct us_conntrack *u = data2;
struct nf_conntrack *ct = u->ct;
ret = nl_get_conntrack(ct);
switch (ret) {
case -1:
/* the kernel table is not in sync with internal cache */
dlog(LOG_ERR, "reset-timers: %s", strerror(errno));
dlog_ct(STATE(log), ct, NFCT_O_PLAIN);
break;
case 1:
current_timeout = nfct_get_attr_u32(ct, ATTR_TIMEOUT);
/* already about to die, do not touch it */
if (current_timeout < CONFIG(purge_timeout))
break;
nfct_set_attr_u32(ct, ATTR_TIMEOUT, CONFIG(purge_timeout));
if (nl_update_conntrack(ct) == -1) {
if (errno == ETIME || errno == ENOENT)
break;
dlog(LOG_ERR, "reset-timers-upd: %s", strerror(errno));
dlog_ct(STATE(log), ct, NFCT_O_PLAIN);
}
break;
}
return 0;
}
void cache_reset_timers(struct cache *c)
{
hashtable_iterate(c->h, NULL, do_reset_timers);
}
static int do_flush(void *data1, void *data2)
{
struct cache *c = data1;
struct us_conntrack *u = data2;
cache_del(c, u->ct);
return 0;
}
void cache_flush(struct cache *c)
{
hashtable_iterate(c->h, c, do_flush);
c->flush++;
}
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