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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.
*
* Description: run and init functions
*/
#include "conntrackd.h"
#include <libnetfilter_conntrack/libnetfilter_conntrack.h>
#include <errno.h>
#include "us-conntrack.h"
#include <signal.h>
#include <stdlib.h>
#include <unistd.h>
void killer(int foo)
{
/* no signals while handling signals */
sigprocmask(SIG_BLOCK, &STATE(block), NULL);
nfct_close(STATE(event));
nfct_close(STATE(dump));
ignore_pool_destroy(STATE(ignore_pool));
local_server_destroy(STATE(local));
STATE(mode)->kill();
unlink(CONFIG(lockfile));
dlog(STATE(log), LOG_NOTICE, "---- shutdown received ----");
close_log();
sigprocmask(SIG_UNBLOCK, &STATE(block), NULL);
exit(0);
}
static void child(int foo)
{
while(wait(NULL) > 0);
}
void local_handler(int fd, void *data)
{
int ret;
int type;
ret = read(fd, &type, sizeof(type));
if (ret == -1) {
dlog(STATE(log), LOG_ERR, "can't read from unix socket");
return;
}
if (ret == 0)
return;
switch(type) {
case FLUSH_MASTER:
dlog(STATE(log), LOG_WARNING, "`conntrackd -F' is deprecated. "
"Use conntrack -F instead.");
if (fork() == 0) {
execlp("conntrack", "conntrack", "-F", NULL);
exit(EXIT_SUCCESS);
}
return;
case RESYNC_MASTER:
dlog(STATE(log), LOG_NOTICE, "resync with master table");
nl_dump_conntrack_table();
return;
}
if (!STATE(mode)->local(fd, type, data))
dlog(STATE(log), LOG_WARNING, "unknown local request %d", type);
}
int init(void)
{
if (CONFIG(flags) & CTD_STATS_MODE)
STATE(mode) = &stats_mode;
else if (CONFIG(flags) & CTD_SYNC_MODE)
STATE(mode) = &sync_mode;
else {
fprintf(stderr, "WARNING: No running mode specified. "
"Defaulting to statistics mode.\n");
CONFIG(flags) |= CTD_STATS_MODE;
STATE(mode) = &stats_mode;
}
/* Initialization */
if (STATE(mode)->init() == -1) {
dlog(STATE(log), LOG_ERR, "initialization failed");
return -1;
}
/* local UNIX socket */
STATE(local) = local_server_create(&CONFIG(local));
if (!STATE(local)) {
dlog(STATE(log), LOG_ERR, "can't open unix socket!");
return -1;
}
if (nl_init_event_handler() == -1) {
dlog(STATE(log), LOG_ERR, "can't open netlink handler! "
"no ctnetlink kernel support?");
return -1;
}
if (nl_init_dump_handler() == -1) {
dlog(STATE(log), LOG_ERR, "can't open netlink handler! "
"no ctnetlink kernel support?");
return -1;
}
/* Signals handling */
sigemptyset(&STATE(block));
sigaddset(&STATE(block), SIGTERM);
sigaddset(&STATE(block), SIGINT);
sigaddset(&STATE(block), SIGCHLD);
if (signal(SIGINT, killer) == SIG_ERR)
return -1;
if (signal(SIGTERM, killer) == SIG_ERR)
return -1;
/* ignore connection reset by peer */
if (signal(SIGPIPE, SIG_IGN) == SIG_ERR)
return -1;
if (signal(SIGCHLD, child) == SIG_ERR)
return -1;
dlog(STATE(log), LOG_NOTICE, "initialization completed");
return 0;
}
static int __run(struct timeval *next_alarm)
{
int max, ret;
fd_set readfds;
FD_ZERO(&readfds);
FD_SET(STATE(local), &readfds);
FD_SET(nfct_fd(STATE(event)), &readfds);
max = MAX(STATE(local), nfct_fd(STATE(event)));
if (STATE(mode)->add_fds_to_set)
max = MAX(max, STATE(mode)->add_fds_to_set(&readfds));
ret = select(max+1, &readfds, NULL, NULL, next_alarm);
if (ret == -1) {
/* interrupted syscall, retry */
if (errno == EINTR)
return;
dlog(STATE(log), LOG_WARNING,
"select failed: %s", strerror(errno));
return;
}
/* timeout expired, run the alarm list */
if (ret == 0)
return 1;
/* signals are racy */
sigprocmask(SIG_BLOCK, &STATE(block), NULL);
/* order received via UNIX socket */
if (FD_ISSET(STATE(local), &readfds))
do_local_server_step(STATE(local), NULL, local_handler);
/* conntrack event has happened */
if (FD_ISSET(nfct_fd(STATE(event)), &readfds)) {
while ((ret = nfct_catch(STATE(event))) != -1);
if (ret == -1) {
switch(errno) {
case ENOBUFS:
/*
* It seems that ctnetlink can't back off,
* it's likely that we're losing events.
* Solution: duplicate the socket buffer
* size and resync with master conntrack table.
*/
nl_resize_socket_buffer(STATE(event));
/* XXX: schedule overrun call via alarm */
STATE(mode)->overrun();
break;
case ENOENT:
/*
* We received a message from another
* netfilter subsystem that we are not
* interested in. Just ignore it.
*/
break;
case EAGAIN:
break;
default:
dlog(STATE(log), LOG_WARNING,
"event catch says: %s", strerror(errno));
break;
}
}
}
if (STATE(mode)->run)
STATE(mode)->run(&readfds);
sigprocmask(SIG_UNBLOCK, &STATE(block), NULL);
return 0;
}
void run(void)
{
struct timeval next_alarm;
struct timeval *next = &next_alarm;
struct timeval tv;
/* initialization: get the first alarm available */
gettimeofday(&tv, NULL);
if (!get_next_alarm(&tv, next))
next = NULL;
while(1) {
if (__run(next)) {
sigprocmask(SIG_BLOCK, &STATE(block), NULL);
next = &next_alarm;
if (!do_alarm_run(next))
next = NULL; /* no next alarms */
sigprocmask(SIG_UNBLOCK, &STATE(block), NULL);
}
}
}
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