[net-next-2.6.git] / net / ipv4 / ipvs / ip_vs_proto_udp.c

/*
 * ip_vs_proto_udp.c:	UDP load balancing support for IPVS
 *
 * Version:     $Id: ip_vs_proto_udp.c,v 1.3 2002/11/30 01:50:35 wensong Exp $
 *
 * Authors:     Wensong Zhang <wensong@linuxvirtualserver.org>
 *              Julian Anastasov <ja@ssi.bg>
 *
 *              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.
 *
 * Changes:
 *
 */

#include <linux/in.h>
#include <linux/ip.h>
#include <linux/kernel.h>
#include <linux/netfilter.h>
#include <linux/netfilter_ipv4.h>
#include <linux/udp.h>

#include <net/ip_vs.h>
#include <net/ip.h>

static struct ip_vs_conn *
udp_conn_in_get(const struct sk_buff *skb, struct ip_vs_protocol *pp,
		const struct iphdr *iph, unsigned int proto_off, int inverse)
{
	struct ip_vs_conn *cp;
	__be16 _ports[2], *pptr;

	pptr = skb_header_pointer(skb, proto_off, sizeof(_ports), _ports);
	if (pptr == NULL)
		return NULL;

	if (likely(!inverse)) {
		cp = ip_vs_conn_in_get(iph->protocol,
				       iph->saddr, pptr[0],
				       iph->daddr, pptr[1]);
	} else {
		cp = ip_vs_conn_in_get(iph->protocol,
				       iph->daddr, pptr[1],
				       iph->saddr, pptr[0]);
	}

	return cp;
}


static struct ip_vs_conn *
udp_conn_out_get(const struct sk_buff *skb, struct ip_vs_protocol *pp,
		 const struct iphdr *iph, unsigned int proto_off, int inverse)
{
	struct ip_vs_conn *cp;
	__be16 _ports[2], *pptr;

	pptr = skb_header_pointer(skb, ip_hdrlen(skb),
				  sizeof(_ports), _ports);
	if (pptr == NULL)
		return NULL;

	if (likely(!inverse)) {
		cp = ip_vs_conn_out_get(iph->protocol,
					iph->saddr, pptr[0],
					iph->daddr, pptr[1]);
	} else {
		cp = ip_vs_conn_out_get(iph->protocol,
					iph->daddr, pptr[1],
					iph->saddr, pptr[0]);
	}

	return cp;
}


static int
udp_conn_schedule(struct sk_buff *skb, struct ip_vs_protocol *pp,
		  int *verdict, struct ip_vs_conn **cpp)
{
	struct ip_vs_service *svc;
	struct udphdr _udph, *uh;

	uh = skb_header_pointer(skb, ip_hdrlen(skb),
				sizeof(_udph), &_udph);
	if (uh == NULL) {
		*verdict = NF_DROP;
		return 0;
	}

	if ((svc = ip_vs_service_get(skb->mark, ip_hdr(skb)->protocol,
				     ip_hdr(skb)->daddr, uh->dest))) {
		if (ip_vs_todrop()) {
			/*
			 * It seems that we are very loaded.
			 * We have to drop this packet :(
			 */
			ip_vs_service_put(svc);
			*verdict = NF_DROP;
			return 0;
		}

		/*
		 * Let the virtual server select a real server for the
		 * incoming connection, and create a connection entry.
		 */
		*cpp = ip_vs_schedule(svc, skb);
		if (!*cpp) {
			*verdict = ip_vs_leave(svc, skb, pp);
			return 0;
		}
		ip_vs_service_put(svc);
	}
	return 1;
}


static inline void
udp_fast_csum_update(struct udphdr *uhdr, __be32 oldip, __be32 newip,
		     __be16 oldport, __be16 newport)
{
	uhdr->check =
		csum_fold(ip_vs_check_diff4(oldip, newip,
				 ip_vs_check_diff2(oldport, newport,
					~csum_unfold(uhdr->check))));
	if (!uhdr->check)
		uhdr->check = CSUM_MANGLED_0;
}

static int
udp_snat_handler(struct sk_buff *skb,
		 struct ip_vs_protocol *pp, struct ip_vs_conn *cp)
{
	struct udphdr *udph;
	const unsigned int udphoff = ip_hdrlen(skb);

	/* csum_check requires unshared skb */
	if (!skb_make_writable(skb, udphoff+sizeof(*udph)))
		return 0;

	if (unlikely(cp->app != NULL)) {
		/* Some checks before mangling */
		if (pp->csum_check && !pp->csum_check(skb, pp))
			return 0;

		/*
		 *	Call application helper if needed
		 */
		if (!ip_vs_app_pkt_out(cp, skb))
			return 0;
	}

	udph = (void *)ip_hdr(skb) + udphoff;
	udph->source = cp->vport;

	/*
	 *	Adjust UDP checksums
	 */
	if (!cp->app && (udph->check != 0)) {
		/* Only port and addr are changed, do fast csum update */
		udp_fast_csum_update(udph, cp->daddr, cp->vaddr,
				     cp->dport, cp->vport);
		if (skb->ip_summed == CHECKSUM_COMPLETE)
			skb->ip_summed = CHECKSUM_NONE;
	} else {
		/* full checksum calculation */
		udph->check = 0;
		skb->csum = skb_checksum(skb, udphoff, skb->len - udphoff, 0);
		udph->check = csum_tcpudp_magic(cp->vaddr, cp->caddr,
						skb->len - udphoff,
						cp->protocol, skb->csum);
		if (udph->check == 0)
			udph->check = CSUM_MANGLED_0;
		IP_VS_DBG(11, "O-pkt: %s O-csum=%d (+%zd)\n",
			  pp->name, udph->check,
			  (char*)&(udph->check) - (char*)udph);
	}
	return 1;
}


static int
udp_dnat_handler(struct sk_buff *skb,
		 struct ip_vs_protocol *pp, struct ip_vs_conn *cp)
{
	struct udphdr *udph;
	unsigned int udphoff = ip_hdrlen(skb);

	/* csum_check requires unshared skb */
	if (!skb_make_writable(skb, udphoff+sizeof(*udph)))
		return 0;

	if (unlikely(cp->app != NULL)) {
		/* Some checks before mangling */
		if (pp->csum_check && !pp->csum_check(skb, pp))
			return 0;

		/*
		 *	Attempt ip_vs_app call.
		 *	It will fix ip_vs_conn
		 */
		if (!ip_vs_app_pkt_in(cp, skb))
			return 0;
	}

	udph = (void *)ip_hdr(skb) + udphoff;
	udph->dest = cp->dport;

	/*
	 *	Adjust UDP checksums
	 */
	if (!cp->app && (udph->check != 0)) {
		/* Only port and addr are changed, do fast csum update */
		udp_fast_csum_update(udph, cp->vaddr, cp->daddr,
				     cp->vport, cp->dport);
		if (skb->ip_summed == CHECKSUM_COMPLETE)
			skb->ip_summed = CHECKSUM_NONE;
	} else {
		/* full checksum calculation */
		udph->check = 0;
		skb->csum = skb_checksum(skb, udphoff, skb->len - udphoff, 0);
		udph->check = csum_tcpudp_magic(cp->caddr, cp->daddr,
						skb->len - udphoff,
						cp->protocol, skb->csum);
		if (udph->check == 0)
			udph->check = CSUM_MANGLED_0;
		skb->ip_summed = CHECKSUM_UNNECESSARY;
	}
	return 1;
}


static int
udp_csum_check(struct sk_buff *skb, struct ip_vs_protocol *pp)
{
	struct udphdr _udph, *uh;
	const unsigned int udphoff = ip_hdrlen(skb);

	uh = skb_header_pointer(skb, udphoff, sizeof(_udph), &_udph);
	if (uh == NULL)
		return 0;

	if (uh->check != 0) {
		switch (skb->ip_summed) {
		case CHECKSUM_NONE:
			skb->csum = skb_checksum(skb, udphoff,
						 skb->len - udphoff, 0);
		case CHECKSUM_COMPLETE:
			if (csum_tcpudp_magic(ip_hdr(skb)->saddr,
					      ip_hdr(skb)->daddr,
					      skb->len - udphoff,
					      ip_hdr(skb)->protocol,
					      skb->csum)) {
				IP_VS_DBG_RL_PKT(0, pp, skb, 0,
						 "Failed checksum for");
				return 0;
			}
			break;
		default:
			/* No need to checksum. */
			break;
		}
	}
	return 1;
}


/*
 *	Note: the caller guarantees that only one of register_app,
 *	unregister_app or app_conn_bind is called each time.
 */

#define	UDP_APP_TAB_BITS	4
#define	UDP_APP_TAB_SIZE	(1 << UDP_APP_TAB_BITS)
#define	UDP_APP_TAB_MASK	(UDP_APP_TAB_SIZE - 1)

static struct list_head udp_apps[UDP_APP_TAB_SIZE];
static DEFINE_SPINLOCK(udp_app_lock);

static inline __u16 udp_app_hashkey(__be16 port)
{
	return (((__force u16)port >> UDP_APP_TAB_BITS) ^ (__force u16)port)
		& UDP_APP_TAB_MASK;
}


static int udp_register_app(struct ip_vs_app *inc)
{
	struct ip_vs_app *i;
	__u16 hash;
	__be16 port = inc->port;
	int ret = 0;

	hash = udp_app_hashkey(port);


	spin_lock_bh(&udp_app_lock);
	list_for_each_entry(i, &udp_apps[hash], p_list) {
		if (i->port == port) {
			ret = -EEXIST;
			goto out;
		}
	}
	list_add(&inc->p_list, &udp_apps[hash]);
	atomic_inc(&ip_vs_protocol_udp.appcnt);

  out:
	spin_unlock_bh(&udp_app_lock);
	return ret;
}


static void
udp_unregister_app(struct ip_vs_app *inc)
{
	spin_lock_bh(&udp_app_lock);
	atomic_dec(&ip_vs_protocol_udp.appcnt);
	list_del(&inc->p_list);
	spin_unlock_bh(&udp_app_lock);
}


static int udp_app_conn_bind(struct ip_vs_conn *cp)
{
	int hash;
	struct ip_vs_app *inc;
	int result = 0;

	/* Default binding: bind app only for NAT */
	if (IP_VS_FWD_METHOD(cp) != IP_VS_CONN_F_MASQ)
		return 0;

	/* Lookup application incarnations and bind the right one */
	hash = udp_app_hashkey(cp->vport);

	spin_lock(&udp_app_lock);
	list_for_each_entry(inc, &udp_apps[hash], p_list) {
		if (inc->port == cp->vport) {
			if (unlikely(!ip_vs_app_inc_get(inc)))
				break;
			spin_unlock(&udp_app_lock);

			IP_VS_DBG(9, "%s: Binding conn %u.%u.%u.%u:%u->"
				  "%u.%u.%u.%u:%u to app %s on port %u\n",
				  __FUNCTION__,
				  NIPQUAD(cp->caddr), ntohs(cp->cport),
				  NIPQUAD(cp->vaddr), ntohs(cp->vport),
				  inc->name, ntohs(inc->port));
			cp->app = inc;
			if (inc->init_conn)
				result = inc->init_conn(inc, cp);
			goto out;
		}
	}
	spin_unlock(&udp_app_lock);

  out:
	return result;
}


static int udp_timeouts[IP_VS_UDP_S_LAST+1] = {
	[IP_VS_UDP_S_NORMAL]		=	5*60*HZ,
	[IP_VS_UDP_S_LAST]		=	2*HZ,
};

static char * udp_state_name_table[IP_VS_UDP_S_LAST+1] = {
	[IP_VS_UDP_S_NORMAL]		=	"UDP",
	[IP_VS_UDP_S_LAST]		=	"BUG!",
};


static int
udp_set_state_timeout(struct ip_vs_protocol *pp, char *sname, int to)
{
	return ip_vs_set_state_timeout(pp->timeout_table, IP_VS_UDP_S_LAST,
				       udp_state_name_table, sname, to);
}

static const char * udp_state_name(int state)
{
	if (state >= IP_VS_UDP_S_LAST)
		return "ERR!";
	return udp_state_name_table[state] ? udp_state_name_table[state] : "?";
}

static int
udp_state_transition(struct ip_vs_conn *cp, int direction,
		     const struct sk_buff *skb,
		     struct ip_vs_protocol *pp)
{
	cp->timeout = pp->timeout_table[IP_VS_UDP_S_NORMAL];
	return 1;
}

static void udp_init(struct ip_vs_protocol *pp)
{
	IP_VS_INIT_HASH_TABLE(udp_apps);
	pp->timeout_table = udp_timeouts;
}

static void udp_exit(struct ip_vs_protocol *pp)
{
}


struct ip_vs_protocol ip_vs_protocol_udp = {
	.name =			"UDP",
	.protocol =		IPPROTO_UDP,
	.dont_defrag =		0,
	.init =			udp_init,
	.exit =			udp_exit,
	.conn_schedule =	udp_conn_schedule,
	.conn_in_get =		udp_conn_in_get,
	.conn_out_get =		udp_conn_out_get,
	.snat_handler =		udp_snat_handler,
	.dnat_handler =		udp_dnat_handler,
	.csum_check =		udp_csum_check,
	.state_transition =	udp_state_transition,
	.state_name =		udp_state_name,
	.register_app =		udp_register_app,
	.unregister_app =	udp_unregister_app,
	.app_conn_bind =	udp_app_conn_bind,
	.debug_packet =		ip_vs_tcpudp_debug_packet,
	.timeout_change =	NULL,
	.set_state_timeout =	udp_set_state_timeout,
};
Commit	Line	Data
1da177e4 LT	1	/*
	2	* ip_vs_proto_udp.c: UDP load balancing support for IPVS
	3	*
	4	* Version: $Id: ip_vs_proto_udp.c,v 1.3 2002/11/30 01:50:35 wensong Exp $
	5	*
	6	* Authors: Wensong Zhang <wensong@linuxvirtualserver.org>
	7	* Julian Anastasov <ja@ssi.bg>
	8	*
	9	* This program is free software; you can redistribute it and/or
	10	* modify it under the terms of the GNU General Public License
	11	* as published by the Free Software Foundation; either version
	12	* 2 of the License, or (at your option) any later version.
	13	*
	14	* Changes:
	15	*
	16	*/
	17
14c85021 ACM	18	#include <linux/in.h>
14c85021 ACM	19	#include <linux/ip.h>
1da177e4	20	#include <linux/kernel.h>
af1e1cf0	21	#include <linux/netfilter.h>
1da177e4	22	#include <linux/netfilter_ipv4.h>
14c85021	23	#include <linux/udp.h>
1da177e4 LT	24
1da177e4 LT	25	#include <net/ip_vs.h>
c9bdd4b5	26	#include <net/ip.h>
1da177e4 LT	27
	28	static struct ip_vs_conn *
	29	udp_conn_in_get(const struct sk_buff skb, struct ip_vs_protocol pp,
	30	const struct iphdr *iph, unsigned int proto_off, int inverse)
	31	{
	32	struct ip_vs_conn *cp;
014d730d	33	__be16 _ports[2], *pptr;
1da177e4 LT	34
	35	pptr = skb_header_pointer(skb, proto_off, sizeof(_ports), _ports);
	36	if (pptr == NULL)
	37	return NULL;
	38
	39	if (likely(!inverse)) {
	40	cp = ip_vs_conn_in_get(iph->protocol,
	41	iph->saddr, pptr[0],
	42	iph->daddr, pptr[1]);
	43	} else {
	44	cp = ip_vs_conn_in_get(iph->protocol,
	45	iph->daddr, pptr[1],
	46	iph->saddr, pptr[0]);
	47	}
	48
	49	return cp;
	50	}
	51
	52
	53	static struct ip_vs_conn *
	54	udp_conn_out_get(const struct sk_buff skb, struct ip_vs_protocol pp,
	55	const struct iphdr *iph, unsigned int proto_off, int inverse)
	56	{
	57	struct ip_vs_conn *cp;
014d730d	58	__be16 _ports[2], *pptr;
1da177e4	59
c9bdd4b5	60	pptr = skb_header_pointer(skb, ip_hdrlen(skb),
1da177e4 LT	61	sizeof(_ports), _ports);
	62	if (pptr == NULL)
	63	return NULL;
	64
	65	if (likely(!inverse)) {
	66	cp = ip_vs_conn_out_get(iph->protocol,
	67	iph->saddr, pptr[0],
	68	iph->daddr, pptr[1]);
	69	} else {
	70	cp = ip_vs_conn_out_get(iph->protocol,
	71	iph->daddr, pptr[1],
	72	iph->saddr, pptr[0]);
	73	}
	74
	75	return cp;
	76	}
	77
	78
	79	static int
	80	udp_conn_schedule(struct sk_buff skb, struct ip_vs_protocol pp,
	81	int verdict, struct ip_vs_conn *cpp)
	82	{
	83	struct ip_vs_service *svc;
	84	struct udphdr _udph, *uh;
	85
c9bdd4b5	86	uh = skb_header_pointer(skb, ip_hdrlen(skb),
1da177e4 LT	87	sizeof(_udph), &_udph);
	88	if (uh == NULL) {
	89	*verdict = NF_DROP;
	90	return 0;
	91	}
	92
eddc9ec5 ACM	93	if ((svc = ip_vs_service_get(skb->mark, ip_hdr(skb)->protocol,
eddc9ec5 ACM	94	ip_hdr(skb)->daddr, uh->dest))) {
1da177e4 LT	95	if (ip_vs_todrop()) {
	96	/*
	97	* It seems that we are very loaded.
	98	* We have to drop this packet :(
	99	*/
	100	ip_vs_service_put(svc);
	101	*verdict = NF_DROP;
	102	return 0;
	103	}
	104
	105	/*
	106	* Let the virtual server select a real server for the
	107	* incoming connection, and create a connection entry.
	108	*/
	109	*cpp = ip_vs_schedule(svc, skb);
	110	if (!*cpp) {
	111	*verdict = ip_vs_leave(svc, skb, pp);
	112	return 0;
	113	}
	114	ip_vs_service_put(svc);
	115	}
	116	return 1;
	117	}
	118
	119
	120	static inline void
014d730d AV	121	udp_fast_csum_update(struct udphdr *uhdr, __be32 oldip, __be32 newip,
014d730d AV	122	__be16 oldport, __be16 newport)
1da177e4 LT	123	{
1da177e4 LT	124	uhdr->check =
f9214b26 AV	125	csum_fold(ip_vs_check_diff4(oldip, newip,
	126	ip_vs_check_diff2(oldport, newport,
	127	~csum_unfold(uhdr->check))));
1da177e4	128	if (!uhdr->check)
f6ab0288	129	uhdr->check = CSUM_MANGLED_0;
1da177e4 LT	130	}
	131
	132	static int
3db05fea	133	udp_snat_handler(struct sk_buff *skb,
1da177e4 LT	134	struct ip_vs_protocol pp, struct ip_vs_conn cp)
	135	{
	136	struct udphdr *udph;
3db05fea	137	const unsigned int udphoff = ip_hdrlen(skb);
1da177e4 LT	138
1da177e4 LT	139	/* csum_check requires unshared skb */
3db05fea	140	if (!skb_make_writable(skb, udphoff+sizeof(*udph)))
1da177e4 LT	141	return 0;
	142
	143	if (unlikely(cp->app != NULL)) {
	144	/* Some checks before mangling */
3db05fea	145	if (pp->csum_check && !pp->csum_check(skb, pp))
1da177e4 LT	146	return 0;
	147
	148	/*
	149	* Call application helper if needed
	150	*/
3db05fea	151	if (!ip_vs_app_pkt_out(cp, skb))
1da177e4 LT	152	return 0;
	153	}
	154
3db05fea	155	udph = (void *)ip_hdr(skb) + udphoff;
1da177e4 LT	156	udph->source = cp->vport;
	157
	158	/*
	159	* Adjust UDP checksums
	160	*/
	161	if (!cp->app && (udph->check != 0)) {
	162	/* Only port and addr are changed, do fast csum update */
	163	udp_fast_csum_update(udph, cp->daddr, cp->vaddr,
	164	cp->dport, cp->vport);
3db05fea HX	165	if (skb->ip_summed == CHECKSUM_COMPLETE)
3db05fea HX	166	skb->ip_summed = CHECKSUM_NONE;
1da177e4 LT	167	} else {
	168	/* full checksum calculation */
	169	udph->check = 0;
3db05fea	170	skb->csum = skb_checksum(skb, udphoff, skb->len - udphoff, 0);
1da177e4	171	udph->check = csum_tcpudp_magic(cp->vaddr, cp->caddr,
3db05fea HX	172	skb->len - udphoff,
3db05fea HX	173	cp->protocol, skb->csum);
1da177e4	174	if (udph->check == 0)
f6ab0288	175	udph->check = CSUM_MANGLED_0;
1da177e4 LT	176	IP_VS_DBG(11, "O-pkt: %s O-csum=%d (+%zd)\n",
	177	pp->name, udph->check,
	178	(char)&(udph->check) - (char)udph);
	179	}
	180	return 1;
	181	}
	182
	183
	184	static int
3db05fea	185	udp_dnat_handler(struct sk_buff *skb,
1da177e4 LT	186	struct ip_vs_protocol pp, struct ip_vs_conn cp)
	187	{
	188	struct udphdr *udph;
3db05fea	189	unsigned int udphoff = ip_hdrlen(skb);
1da177e4 LT	190
1da177e4 LT	191	/* csum_check requires unshared skb */
3db05fea	192	if (!skb_make_writable(skb, udphoff+sizeof(*udph)))
1da177e4 LT	193	return 0;
	194
	195	if (unlikely(cp->app != NULL)) {
	196	/* Some checks before mangling */
3db05fea	197	if (pp->csum_check && !pp->csum_check(skb, pp))
1da177e4 LT	198	return 0;
	199
	200	/*
	201	* Attempt ip_vs_app call.
	202	* It will fix ip_vs_conn
	203	*/
3db05fea	204	if (!ip_vs_app_pkt_in(cp, skb))
1da177e4 LT	205	return 0;
	206	}
	207
3db05fea	208	udph = (void *)ip_hdr(skb) + udphoff;
1da177e4 LT	209	udph->dest = cp->dport;
	210
	211	/*
	212	* Adjust UDP checksums
	213	*/
	214	if (!cp->app && (udph->check != 0)) {
	215	/* Only port and addr are changed, do fast csum update */
	216	udp_fast_csum_update(udph, cp->vaddr, cp->daddr,
	217	cp->vport, cp->dport);
3db05fea HX	218	if (skb->ip_summed == CHECKSUM_COMPLETE)
3db05fea HX	219	skb->ip_summed = CHECKSUM_NONE;
1da177e4 LT	220	} else {
	221	/* full checksum calculation */
	222	udph->check = 0;
3db05fea	223	skb->csum = skb_checksum(skb, udphoff, skb->len - udphoff, 0);
1da177e4	224	udph->check = csum_tcpudp_magic(cp->caddr, cp->daddr,
3db05fea HX	225	skb->len - udphoff,
3db05fea HX	226	cp->protocol, skb->csum);
1da177e4	227	if (udph->check == 0)
f6ab0288	228	udph->check = CSUM_MANGLED_0;
3db05fea	229	skb->ip_summed = CHECKSUM_UNNECESSARY;
1da177e4 LT	230	}
	231	return 1;
	232	}
	233
	234
	235	static int
	236	udp_csum_check(struct sk_buff skb, struct ip_vs_protocol pp)
	237	{
	238	struct udphdr _udph, *uh;
c9bdd4b5	239	const unsigned int udphoff = ip_hdrlen(skb);
1da177e4 LT	240
	241	uh = skb_header_pointer(skb, udphoff, sizeof(_udph), &_udph);
	242	if (uh == NULL)
	243	return 0;
	244
	245	if (uh->check != 0) {
	246	switch (skb->ip_summed) {
	247	case CHECKSUM_NONE:
	248	skb->csum = skb_checksum(skb, udphoff,
	249	skb->len - udphoff, 0);
84fa7933	250	case CHECKSUM_COMPLETE:
eddc9ec5 ACM	251	if (csum_tcpudp_magic(ip_hdr(skb)->saddr,
eddc9ec5 ACM	252	ip_hdr(skb)->daddr,
1da177e4	253	skb->len - udphoff,
eddc9ec5	254	ip_hdr(skb)->protocol,
1da177e4 LT	255	skb->csum)) {
	256	IP_VS_DBG_RL_PKT(0, pp, skb, 0,
	257	"Failed checksum for");
	258	return 0;
	259	}
	260	break;
	261	default:
84fa7933	262	/* No need to checksum. */
1da177e4 LT	263	break;
	264	}
	265	}
	266	return 1;
	267	}
	268
	269
	270	/*
	271	* Note: the caller guarantees that only one of register_app,
	272	* unregister_app or app_conn_bind is called each time.
	273	*/
	274
	275	#define UDP_APP_TAB_BITS 4
	276	#define UDP_APP_TAB_SIZE (1 << UDP_APP_TAB_BITS)
	277	#define UDP_APP_TAB_MASK (UDP_APP_TAB_SIZE - 1)
	278
	279	static struct list_head udp_apps[UDP_APP_TAB_SIZE];
	280	static DEFINE_SPINLOCK(udp_app_lock);
	281
75e7ce66	282	static inline __u16 udp_app_hashkey(__be16 port)
1da177e4	283	{
75e7ce66 AV	284	return (((__force u16)port >> UDP_APP_TAB_BITS) ^ (__force u16)port)
75e7ce66 AV	285	& UDP_APP_TAB_MASK;
1da177e4 LT	286	}
	287
	288
	289	static int udp_register_app(struct ip_vs_app *inc)
	290	{
	291	struct ip_vs_app *i;
75e7ce66 AV	292	__u16 hash;
75e7ce66 AV	293	__be16 port = inc->port;
1da177e4 LT	294	int ret = 0;
	295
	296	hash = udp_app_hashkey(port);
	297
	298
	299	spin_lock_bh(&udp_app_lock);
	300	list_for_each_entry(i, &udp_apps[hash], p_list) {
	301	if (i->port == port) {
	302	ret = -EEXIST;
	303	goto out;
	304	}
	305	}
	306	list_add(&inc->p_list, &udp_apps[hash]);
	307	atomic_inc(&ip_vs_protocol_udp.appcnt);
	308
	309	out:
	310	spin_unlock_bh(&udp_app_lock);
	311	return ret;
	312	}
	313
	314
	315	static void
	316	udp_unregister_app(struct ip_vs_app *inc)
	317	{
	318	spin_lock_bh(&udp_app_lock);
	319	atomic_dec(&ip_vs_protocol_udp.appcnt);
	320	list_del(&inc->p_list);
	321	spin_unlock_bh(&udp_app_lock);
	322	}
	323
	324
	325	static int udp_app_conn_bind(struct ip_vs_conn *cp)
	326	{
	327	int hash;
	328	struct ip_vs_app *inc;
	329	int result = 0;
	330
	331	/* Default binding: bind app only for NAT */
	332	if (IP_VS_FWD_METHOD(cp) != IP_VS_CONN_F_MASQ)
	333	return 0;
	334
	335	/* Lookup application incarnations and bind the right one */
	336	hash = udp_app_hashkey(cp->vport);
	337
	338	spin_lock(&udp_app_lock);
	339	list_for_each_entry(inc, &udp_apps[hash], p_list) {
	340	if (inc->port == cp->vport) {
	341	if (unlikely(!ip_vs_app_inc_get(inc)))
	342	break;
	343	spin_unlock(&udp_app_lock);
	344
	345	IP_VS_DBG(9, "%s: Binding conn %u.%u.%u.%u:%u->"
	346	"%u.%u.%u.%u:%u to app %s on port %u\n",
	347	__FUNCTION__,
	348	NIPQUAD(cp->caddr), ntohs(cp->cport),
	349	NIPQUAD(cp->vaddr), ntohs(cp->vport),
	350	inc->name, ntohs(inc->port));
	351	cp->app = inc;
	352	if (inc->init_conn)
	353	result = inc->init_conn(inc, cp);
	354	goto out;
	355	}
	356	}
	357	spin_unlock(&udp_app_lock);
358
359	out:
360	return result;
361	}
362
363
364	static int udp_timeouts[IP_VS_UDP_S_LAST+1] = {
365	[IP_VS_UDP_S_NORMAL] = 560HZ,
366	[IP_VS_UDP_S_LAST] = 2*HZ,
367	};
368
369	static char * udp_state_name_table[IP_VS_UDP_S_LAST+1] = {
370	[IP_VS_UDP_S_NORMAL] = "UDP",
371	[IP_VS_UDP_S_LAST] = "BUG!",
372	};
373
374
375	static int
376	udp_set_state_timeout(struct ip_vs_protocol pp, char sname, int to)
377	{
378	return ip_vs_set_state_timeout(pp->timeout_table, IP_VS_UDP_S_LAST,
379	udp_state_name_table, sname, to);
380	}
381
382	static const char * udp_state_name(int state)
383	{
384	if (state >= IP_VS_UDP_S_LAST)
385	return "ERR!";
386	return udp_state_name_table[state] ? udp_state_name_table[state] : "?";
387	}
388
389	static int
390	udp_state_transition(struct ip_vs_conn *cp, int direction,
391	const struct sk_buff *skb,
392	struct ip_vs_protocol *pp)
393	{
394	cp->timeout = pp->timeout_table[IP_VS_UDP_S_NORMAL];
395	return 1;
396	}
397
398	static void udp_init(struct ip_vs_protocol *pp)
399	{
400	IP_VS_INIT_HASH_TABLE(udp_apps);
401	pp->timeout_table = udp_timeouts;
402	}
403
404	static void udp_exit(struct ip_vs_protocol *pp)
405	{
406	}
407
408
409	struct ip_vs_protocol ip_vs_protocol_udp = {
410	.name = "UDP",
411	.protocol = IPPROTO_UDP,
412	.dont_defrag = 0,
413	.init = udp_init,
414	.exit = udp_exit,
415	.conn_schedule = udp_conn_schedule,
416	.conn_in_get = udp_conn_in_get,
417	.conn_out_get = udp_conn_out_get,
418	.snat_handler = udp_snat_handler,
419	.dnat_handler = udp_dnat_handler,
420	.csum_check = udp_csum_check,
421	.state_transition = udp_state_transition,
422	.state_name = udp_state_name,
423	.register_app = udp_register_app,
424	.unregister_app = udp_unregister_app,
425	.app_conn_bind = udp_app_conn_bind,
426	.debug_packet = ip_vs_tcpudp_debug_packet,
427	.timeout_change = NULL,
428	.set_state_timeout = udp_set_state_timeout,
429	};