ip_conntrack_helper_h323.c

LINUX 2.6.17.4的源码

	return 0;
}

/****************************************************************************/
static int process_rcf(struct sk_buff **pskb, struct ip_conntrack *ct,
		       enum ip_conntrack_info ctinfo,
		       unsigned char **data, RegistrationConfirm * rcf)
{
	struct ip_ct_h323_master *info = &ct->help.ct_h323_info;
	int dir = CTINFO2DIR(ctinfo);
	int ret;
	struct ip_conntrack_expect *exp;

	DEBUGP("ip_ct_ras: RCF\n");

	if (set_sig_addr_hook) {
		ret = set_sig_addr_hook(pskb, ct, ctinfo, data,
					rcf->callSignalAddress.item,
					rcf->callSignalAddress.count);
		if (ret < 0)
			return -1;
	}

	if (rcf->options & eRegistrationConfirm_timeToLive) {
		DEBUGP("ip_ct_ras: RCF TTL = %u seconds\n", rcf->timeToLive);
		info->timeout = rcf->timeToLive;
	}

	if (info->timeout > 0) {
		DEBUGP
		    ("ip_ct_ras: set RAS connection timeout to %u seconds\n",
		     info->timeout);
		ip_ct_refresh_acct(ct, ctinfo, NULL, info->timeout * HZ);

		/* Set expect timeout */
		read_lock_bh(&ip_conntrack_lock);
		exp = find_expect(ct, ct->tuplehash[dir].tuple.dst.ip,
				  info->sig_port[!dir]);
		if (exp) {
			DEBUGP("ip_ct_ras: set Q.931 expect "
			       "(%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu) "
			       "timeout to %u seconds\n",
			       NIPQUAD(exp->tuple.src.ip),
			       ntohs(exp->tuple.src.u.tcp.port),
			       NIPQUAD(exp->tuple.dst.ip),
			       ntohs(exp->tuple.dst.u.tcp.port),
			       info->timeout);
			set_expect_timeout(exp, info->timeout);
		}
		read_unlock_bh(&ip_conntrack_lock);
	}

	return 0;
}

/****************************************************************************/
static int process_urq(struct sk_buff **pskb, struct ip_conntrack *ct,
		       enum ip_conntrack_info ctinfo,
		       unsigned char **data, UnregistrationRequest * urq)
{
	struct ip_ct_h323_master *info = &ct->help.ct_h323_info;
	int dir = CTINFO2DIR(ctinfo);
	int ret;

	DEBUGP("ip_ct_ras: URQ\n");

	if (set_sig_addr_hook) {
		ret = set_sig_addr_hook(pskb, ct, ctinfo, data,
					urq->callSignalAddress.item,
					urq->callSignalAddress.count);
		if (ret < 0)
			return -1;
	}

	/* Clear old expect */
	ip_ct_remove_expectations(ct);
	info->sig_port[dir] = 0;
	info->sig_port[!dir] = 0;

	/* Give it 30 seconds for UCF or URJ */
	ip_ct_refresh_acct(ct, ctinfo, NULL, 30 * HZ);

	return 0;
}

/****************************************************************************/
static int process_arq(struct sk_buff **pskb, struct ip_conntrack *ct,
		       enum ip_conntrack_info ctinfo,
		       unsigned char **data, AdmissionRequest * arq)
{
	struct ip_ct_h323_master *info = &ct->help.ct_h323_info;
	int dir = CTINFO2DIR(ctinfo);
	u_int32_t ip;
	u_int16_t port;

	DEBUGP("ip_ct_ras: ARQ\n");

	if ((arq->options & eAdmissionRequest_destCallSignalAddress) &&
	    get_h225_addr(*data, &arq->destCallSignalAddress, &ip, &port) &&
	    ip == ct->tuplehash[dir].tuple.src.ip &&
	    port == info->sig_port[dir] && set_h225_addr_hook) {
		/* Answering ARQ */
		return set_h225_addr_hook(pskb, data, 0,
					  &arq->destCallSignalAddress,
					  ct->tuplehash[!dir].tuple.dst.ip,
					  info->sig_port[!dir]);
	}

	if ((arq->options & eAdmissionRequest_srcCallSignalAddress) &&
	    get_h225_addr(*data, &arq->srcCallSignalAddress, &ip, &port) &&
	    ip == ct->tuplehash[dir].tuple.src.ip && set_h225_addr_hook) {
		/* Calling ARQ */
		return set_h225_addr_hook(pskb, data, 0,
					  &arq->srcCallSignalAddress,
					  ct->tuplehash[!dir].tuple.dst.ip,
					  port);
	}

	return 0;
}

/****************************************************************************/
static int process_acf(struct sk_buff **pskb, struct ip_conntrack *ct,
		       enum ip_conntrack_info ctinfo,
		       unsigned char **data, AdmissionConfirm * acf)
{
	int dir = CTINFO2DIR(ctinfo);
	int ret = 0;
	u_int32_t ip;
	u_int16_t port;
	struct ip_conntrack_expect *exp;

	DEBUGP("ip_ct_ras: ACF\n");

	if (!get_h225_addr(*data, &acf->destCallSignalAddress, &ip, &port))
		return 0;

	if (ip == ct->tuplehash[dir].tuple.dst.ip) {	/* Answering ACF */
		if (set_sig_addr_hook)
			return set_sig_addr_hook(pskb, ct, ctinfo, data,
						 &acf->destCallSignalAddress,
						 1);
		return 0;
	}

	/* Need new expect */
	if ((exp = ip_conntrack_expect_alloc(ct)) == NULL)
		return -1;
	exp->tuple.src.ip = ct->tuplehash[!dir].tuple.src.ip;
	exp->tuple.src.u.tcp.port = 0;
	exp->tuple.dst.ip = ip;
	exp->tuple.dst.u.tcp.port = htons(port);
	exp->tuple.dst.protonum = IPPROTO_TCP;
	exp->mask.src.ip = 0xFFFFFFFF;
	exp->mask.src.u.tcp.port = 0;
	exp->mask.dst.ip = 0xFFFFFFFF;
	exp->mask.dst.u.tcp.port = 0xFFFF;
	exp->mask.dst.protonum = 0xFF;
	exp->flags = IP_CT_EXPECT_PERMANENT;
	exp->expectfn = ip_conntrack_q931_expect;

	if (ip_conntrack_expect_related(exp) == 0) {
		DEBUGP("ip_ct_ras: expect Q.931 "
		       "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
		       NIPQUAD(exp->tuple.src.ip),
		       ntohs(exp->tuple.src.u.tcp.port),
		       NIPQUAD(exp->tuple.dst.ip),
		       ntohs(exp->tuple.dst.u.tcp.port));
	} else
		ret = -1;

	ip_conntrack_expect_put(exp);

	return ret;
}

/****************************************************************************/
static int process_lrq(struct sk_buff **pskb, struct ip_conntrack *ct,
		       enum ip_conntrack_info ctinfo,
		       unsigned char **data, LocationRequest * lrq)
{
	DEBUGP("ip_ct_ras: LRQ\n");

	if (set_ras_addr_hook)
		return set_ras_addr_hook(pskb, ct, ctinfo, data,
					 &lrq->replyAddress, 1);
	return 0;
}

/****************************************************************************/
static int process_lcf(struct sk_buff **pskb, struct ip_conntrack *ct,
		       enum ip_conntrack_info ctinfo,
		       unsigned char **data, LocationConfirm * lcf)
{
	int dir = CTINFO2DIR(ctinfo);
	int ret = 0;
	u_int32_t ip;
	u_int16_t port;
	struct ip_conntrack_expect *exp = NULL;

	DEBUGP("ip_ct_ras: LCF\n");

	if (!get_h225_addr(*data, &lcf->callSignalAddress, &ip, &port))
		return 0;

	/* Need new expect for call signal */
	if ((exp = ip_conntrack_expect_alloc(ct)) == NULL)
		return -1;
	exp->tuple.src.ip = ct->tuplehash[!dir].tuple.src.ip;
	exp->tuple.src.u.tcp.port = 0;
	exp->tuple.dst.ip = ip;
	exp->tuple.dst.u.tcp.port = htons(port);
	exp->tuple.dst.protonum = IPPROTO_TCP;
	exp->mask.src.ip = 0xFFFFFFFF;
	exp->mask.src.u.tcp.port = 0;
	exp->mask.dst.ip = 0xFFFFFFFF;
	exp->mask.dst.u.tcp.port = 0xFFFF;
	exp->mask.dst.protonum = 0xFF;
	exp->flags = IP_CT_EXPECT_PERMANENT;
	exp->expectfn = ip_conntrack_q931_expect;

	if (ip_conntrack_expect_related(exp) == 0) {
		DEBUGP("ip_ct_ras: expect Q.931 "
		       "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
		       NIPQUAD(exp->tuple.src.ip),
		       ntohs(exp->tuple.src.u.tcp.port),
		       NIPQUAD(exp->tuple.dst.ip),
		       ntohs(exp->tuple.dst.u.tcp.port));
	} else
		ret = -1;

	ip_conntrack_expect_put(exp);

	/* Ignore rasAddress */

	return ret;
}

/****************************************************************************/
static int process_irr(struct sk_buff **pskb, struct ip_conntrack *ct,
		       enum ip_conntrack_info ctinfo,
		       unsigned char **data, InfoRequestResponse * irr)
{
	int ret;

	DEBUGP("ip_ct_ras: IRR\n");

	if (set_ras_addr_hook) {
		ret = set_ras_addr_hook(pskb, ct, ctinfo, data,
					&irr->rasAddress, 1);
		if (ret < 0)
			return -1;
	}

	if (set_sig_addr_hook) {
		ret = set_sig_addr_hook(pskb, ct, ctinfo, data,
					irr->callSignalAddress.item,
					irr->callSignalAddress.count);
		if (ret < 0)
			return -1;
	}

	return 0;
}

/****************************************************************************/
static int process_ras(struct sk_buff **pskb, struct ip_conntrack *ct,
		       enum ip_conntrack_info ctinfo,
		       unsigned char **data, RasMessage * ras)
{
	switch (ras->choice) {
	case eRasMessage_gatekeeperRequest:
		return process_grq(pskb, ct, ctinfo, data,
				   &ras->gatekeeperRequest);
	case eRasMessage_gatekeeperConfirm:
		return process_gcf(pskb, ct, ctinfo, data,
				   &ras->gatekeeperConfirm);
	case eRasMessage_registrationRequest:
		return process_rrq(pskb, ct, ctinfo, data,
				   &ras->registrationRequest);
	case eRasMessage_registrationConfirm:
		return process_rcf(pskb, ct, ctinfo, data,
				   &ras->registrationConfirm);
	case eRasMessage_unregistrationRequest:
		return process_urq(pskb, ct, ctinfo, data,
				   &ras->unregistrationRequest);
	case eRasMessage_admissionRequest:
		return process_arq(pskb, ct, ctinfo, data,
				   &ras->admissionRequest);
	case eRasMessage_admissionConfirm:
		return process_acf(pskb, ct, ctinfo, data,
				   &ras->admissionConfirm);
	case eRasMessage_locationRequest:
		return process_lrq(pskb, ct, ctinfo, data,
				   &ras->locationRequest);
	case eRasMessage_locationConfirm:
		return process_lcf(pskb, ct, ctinfo, data,
				   &ras->locationConfirm);
	case eRasMessage_infoRequestResponse:
		return process_irr(pskb, ct, ctinfo, data,
				   &ras->infoRequestResponse);
	default:
		DEBUGP("ip_ct_ras: RAS message %d\n", ras->choice);
		break;
	}

	return 0;
}

/****************************************************************************/
static int ras_help(struct sk_buff **pskb, struct ip_conntrack *ct,
		    enum ip_conntrack_info ctinfo)
{
	static RasMessage ras;
	unsigned char *data;
	int datalen = 0;
	int ret;

	DEBUGP("ip_ct_ras: skblen = %u\n", (*pskb)->len);

	spin_lock_bh(&ip_h323_lock);

	/* Get UDP data */
	data = get_udp_data(pskb, &datalen);
	if (data == NULL)
		goto accept;
	DEBUGP("ip_ct_ras: RAS message %u.%u.%u.%u->%u.%u.%u.%u, len=%d\n",
	       NIPQUAD((*pskb)->nh.iph->saddr),
	       NIPQUAD((*pskb)->nh.iph->daddr), datalen);

	/* Decode RAS message */
	ret = DecodeRasMessage(data, datalen, &ras);
	if (ret < 0) {
		if (net_ratelimit())
			printk("ip_ct_ras: decoding error: %s\n",
			       ret == H323_ERROR_BOUND ?
			       "out of bound" : "out of range");
		goto accept;
	}

	/* Process RAS message */
	if (process_ras(pskb, ct, ctinfo, &data, &ras) < 0)
		goto drop;

      accept:
	spin_unlock_bh(&ip_h323_lock);
	return NF_ACCEPT;

      drop:
	spin_unlock_bh(&ip_h323_lock);
	if (net_ratelimit())
		printk("ip_ct_ras: packet dropped\n");
	return NF_DROP;
}

/****************************************************************************/
static struct ip_conntrack_helper ip_conntrack_helper_ras = {
	.name = "RAS",
	.me = THIS_MODULE,
	.max_expected = 32,
	.timeout = 240,
	.tuple = {.src = {.u = {__constant_htons(RAS_PORT)}},
		  .dst = {.protonum = IPPROTO_UDP}},
	.mask = {.src = {.u = {0xFFFE}},
		 .dst = {.protonum = 0xFF}},
	.help = ras_help,
};

/****************************************************************************/
static void ip_conntrack_ras_expect(struct ip_conntrack *new,
				    struct ip_conntrack_expect *this)
{
	write_lock_bh(&ip_conntrack_lock);
	new->helper = &ip_conntrack_helper_ras;
	write_unlock_bh(&ip_conntrack_lock);
}

/****************************************************************************/
/* Not __exit - called from init() */
static void fini(void)
{
	ip_conntrack_helper_unregister(&ip_conntrack_helper_ras);
	ip_conntrack_helper_unregister(&ip_conntrack_helper_q931);
	kfree(h323_buffer);
	DEBUGP("ip_ct_h323: fini\n");
}

/****************************************************************************/
static int __init init(void)
{
	int ret;

	h323_buffer = kmalloc(65536, GFP_KERNEL);
	if (!h323_buffer)
		return -ENOMEM;
	if ((ret = ip_conntrack_helper_register(&ip_conntrack_helper_q931)) ||
	    (ret = ip_conntrack_helper_register(&ip_conntrack_helper_ras))) {
		fini();
		return ret;
	}

	DEBUGP("ip_ct_h323: init success\n");
	return 0;
}

/****************************************************************************/
module_init(init);
module_exit(fini);

EXPORT_SYMBOL_GPL(get_h225_addr);
EXPORT_SYMBOL_GPL(ip_conntrack_h245_expect);
EXPORT_SYMBOL_GPL(ip_conntrack_q931_expect);
EXPORT_SYMBOL_GPL(set_h245_addr_hook);
EXPORT_SYMBOL_GPL(set_h225_addr_hook);
EXPORT_SYMBOL_GPL(set_sig_addr_hook);
EXPORT_SYMBOL_GPL(set_ras_addr_hook);
EXPORT_SYMBOL_GPL(nat_rtp_rtcp_hook);
EXPORT_SYMBOL_GPL(nat_t120_hook);
EXPORT_SYMBOL_GPL(nat_h245_hook);
EXPORT_SYMBOL_GPL(nat_q931_hook);

MODULE_AUTHOR("Jing Min Zhao <[e-mail]>");
MODULE_DESCRIPTION("H.323 connection tracking helper");
MODULE_LICENSE("GPL");