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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 3 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>
static unsigned int seq_set, cur_seq;
static size_t __do_send(struct mcast_sock *m, void *data, size_t len)
{
struct nethdr *net = data;
#undef _TEST_DROP
#ifdef _TEST_DROP
static int drop = 0;
if (++drop >= 10) {
printf("drop sq: %u fl:%u len:%u\n",
ntohl(net->seq), ntohs(net->flags),
ntohs(net->len));
drop = 0;
return 0;
}
#endif
debug("send sq: %u fl:%u len:%u\n",
ntohl(net->seq), ntohs(net->flags),
ntohs(net->len));
return mcast_send(m, net, len);
}
static size_t __do_prepare(struct mcast_sock *m, void *data, size_t len)
{
struct nethdr *net = data;
if (!seq_set) {
seq_set = 1;
cur_seq = time(NULL);
net->flags |= NET_F_HELLO;
}
net->len = len;
net->seq = cur_seq++;
HDR_HOST2NETWORK(net);
return len;
}
static size_t __prepare_ctl(struct mcast_sock *m, void *data)
{
return __do_prepare(m, data, NETHDR_ACK_SIZ);
}
static size_t __prepare_data(struct mcast_sock *m, void *data)
{
struct nethdr *net = (struct nethdr *) data;
struct netpld *pld = NETHDR_DATA(net);
return __do_prepare(m, data, ntohs(pld->len) + NETPLD_SIZ + NETHDR_SIZ);
}
size_t prepare_send_netmsg(struct mcast_sock *m, void *data)
{
int ret = 0;
struct nethdr *net = (struct nethdr *) data;
if (IS_DATA(net))
ret = __prepare_data(m, data);
else if (IS_CTL(net))
ret = __prepare_ctl(m, data);
return ret;
}
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(struct mcast_conf *mconf)
{
int mtu = mconf->mtu - HEADERSIZ;
/* default to Ethernet MTU 1500 bytes */
if (mconf->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, void *data, size_t len)
{
int ret = 0;
struct nethdr *net = data;
retry:
if (tx_buflen + len < tx_buflenmax) {
memcpy(tx_buf + tx_buflen, net, len);
tx_buflen += len;
} else {
__do_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 = __do_send(m, tx_buf, tx_buflen);
tx_buflen = 0;
return ret;
}
int mcast_send_netmsg(struct mcast_sock *m, void *data)
{
int ret;
size_t len = prepare_send_netmsg(m, data);
ret = mcast_buffered_send_netmsg(m, data, len);
mcast_buffered_pending_netmsg(m);
return ret;
}
void build_netmsg(struct nf_conntrack *ct, int query, struct nethdr *net)
{
struct netpld *pld = NETHDR_DATA(net);
build_netpld(ct, pld, query);
}
int handle_netmsg(struct nethdr *net)
{
struct netpld *pld = NETHDR_DATA(net);
/* message too small: no room for the header */
if (ntohs(net->len) < NETHDR_ACK_SIZ)
return -1;
HDR_NETWORK2HOST(net);
if (IS_HELLO(net))
STATE_SYNC(last_seq_recv) = net->seq - 1;
if (IS_CTL(net))
return 0;
/* information received is too small */
if (net->len < sizeof(struct netpld))
return -1;
/* size mismatch! */
if (net->len < ntohs(pld->len) + NETHDR_SIZ)
return -1;
return 0;
}
int mcast_track_seq(uint32_t seq, uint32_t *exp_seq)
{
static int local_seq_set = 0;
int ret = 1;
/* netlink sequence tracking initialization */
if (!local_seq_set) {
local_seq_set = 1;
goto out;
}
/* fast path: we received the correct sequence */
if (seq == STATE_SYNC(last_seq_recv)+1)
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 = 0;
goto out;
}
/* out of sequence: replayed/delayed packet? */
if (before(seq, STATE_SYNC(last_seq_recv)+1))
dlog(LOG_WARNING, "delayed packet? exp=%u rcv=%u",
STATE_SYNC(last_seq_recv)+1, seq);
out:
*exp_seq = STATE_SYNC(last_seq_recv)+1;
/* update expected sequence */
STATE_SYNC(last_seq_recv) = seq;
return ret;
}
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