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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 "conntrackd.h"
#include "network.h"
#include "log.h"
#include "debug.h"
#include <stdlib.h>
#include <time.h>
#include <string.h>
#define NETHDR_ALIGNTO 4
static unsigned int seq_set, cur_seq;
int nethdr_align(int value)
{
return (value + NETHDR_ALIGNTO - 1) & ~(NETHDR_ALIGNTO - 1);
}
int nethdr_size(int len)
{
return NETHDR_SIZ + len;
}
static inline void __nethdr_set(struct nethdr *net, int len, int type)
{
if (!seq_set) {
seq_set = 1;
cur_seq = time(NULL);
}
net->version = CONNTRACKD_PROTOCOL_VERSION;
net->type = type;
net->len = len;
net->seq = cur_seq++;
}
void nethdr_set(struct nethdr *net, int type)
{
__nethdr_set(net, NETHDR_SIZ, type);
}
void nethdr_set_ack(struct nethdr *net)
{
__nethdr_set(net, NETHDR_ACK_SIZ, 0);
}
static size_t tx_buflenmax;
static size_t tx_buflen = 0;
static char *tx_buf;
#define HEADERSIZ 28 /* IP header (20 bytes) + UDP header 8 (bytes) */
int mcast_buffered_init(int if_mtu)
{
int mtu = if_mtu - HEADERSIZ;
/* default to Ethernet MTU 1500 bytes */
if (if_mtu == 0)
mtu = 1500 - HEADERSIZ;
tx_buf = malloc(mtu);
if (tx_buf == NULL)
return -1;
tx_buflenmax = mtu;
return 0;
}
void mcast_buffered_destroy(void)
{
free(tx_buf);
}
/* return 0 if it is not sent, otherwise return 1 */
int mcast_buffered_send_netmsg(struct mcast_sock *m, const struct nethdr *net)
{
int ret = 0, len = ntohs(net->len);
retry:
if (tx_buflen + len < tx_buflenmax) {
memcpy(tx_buf + tx_buflen, net, len);
tx_buflen += len;
} else {
mcast_send(m, tx_buf, tx_buflen);
ret = 1;
tx_buflen = 0;
goto retry;
}
return ret;
}
ssize_t mcast_buffered_pending_netmsg(struct mcast_sock *m)
{
ssize_t ret;
if (tx_buflen == 0)
return 0;
ret = mcast_send(m, tx_buf, tx_buflen);
tx_buflen = 0;
return ret;
}
static int local_seq_set = 0;
/* this function only tracks, it does not update the last sequence received */
int mcast_track_seq(uint32_t seq, uint32_t *exp_seq)
{
int ret = SEQ_UNKNOWN;
/* netlink sequence tracking initialization */
if (!local_seq_set) {
ret = SEQ_UNSET;
goto out;
}
/* fast path: we received the correct sequence */
if (seq == STATE_SYNC(last_seq_recv)+1) {
ret = SEQ_IN_SYNC;
goto out;
}
/* out of sequence: some messages got lost */
if (after(seq, STATE_SYNC(last_seq_recv)+1)) {
STATE_SYNC(packets_lost) += seq-STATE_SYNC(last_seq_recv)+1;
ret = SEQ_AFTER;
goto out;
}
/* out of sequence: replayed/delayed packet? */
if (before(seq, STATE_SYNC(last_seq_recv)+1))
ret = SEQ_BEFORE;
out:
*exp_seq = STATE_SYNC(last_seq_recv)+1;
return ret;
}
void mcast_track_update_seq(uint32_t seq)
{
if (!local_seq_set)
local_seq_set = 1;
STATE_SYNC(last_seq_recv) = seq;
}
int mcast_track_is_seq_set()
{
return local_seq_set;
}
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