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

/*
 * ip_vs_proto_udp.c:	UDP load balancing support for IPVS
 *
 * 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:
 *
 */

#define KMSG_COMPONENT "IPVS"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt

#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>
#include <net/ip6_checksum.h>

static struct ip_vs_conn *
udp_conn_in_get(int af, const struct sk_buff *skb, struct ip_vs_protocol *pp,
		const struct ip_vs_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(af, iph->protocol,
				       &iph->saddr, pptr[0],
				       &iph->daddr, pptr[1]);
	} else {
		cp = ip_vs_conn_in_get(af, iph->protocol,
				       &iph->daddr, pptr[1],
				       &iph->saddr, pptr[0]);
	}

	return cp;
}


static struct ip_vs_conn *
udp_conn_out_get(int af, const struct sk_buff *skb, struct ip_vs_protocol *pp,
		 const struct ip_vs_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_out_get(af, iph->protocol,
					&iph->saddr, pptr[0],
					&iph->daddr, pptr[1]);
	} else {
		cp = ip_vs_conn_out_get(af, iph->protocol,
					&iph->daddr, pptr[1],
					&iph->saddr, pptr[0]);
	}

	return cp;
}


static int
udp_conn_schedule(int af, 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;
	struct ip_vs_iphdr iph;

	ip_vs_fill_iphdr(af, skb_network_header(skb), &iph);

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

	svc = ip_vs_service_get(af, skb->mark, iph.protocol,
				&iph.daddr, uh->dest);
	if (svc) {
		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(int af, struct udphdr *uhdr,
		     const union nf_inet_addr *oldip,
		     const union nf_inet_addr *newip,
		     __be16 oldport, __be16 newport)
{
#ifdef CONFIG_IP_VS_IPV6
	if (af == AF_INET6)
		uhdr->check =
			csum_fold(ip_vs_check_diff16(oldip->ip6, newip->ip6,
					 ip_vs_check_diff2(oldport, newport,
						~csum_unfold(uhdr->check))));
	else
#endif
		uhdr->check =
			csum_fold(ip_vs_check_diff4(oldip->ip, newip->ip,
					 ip_vs_check_diff2(oldport, newport,
						~csum_unfold(uhdr->check))));
	if (!uhdr->check)
		uhdr->check = CSUM_MANGLED_0;
}

static inline void
udp_partial_csum_update(int af, struct udphdr *uhdr,
		     const union nf_inet_addr *oldip,
		     const union nf_inet_addr *newip,
		     __be16 oldlen, __be16 newlen)
{
#ifdef CONFIG_IP_VS_IPV6
	if (af == AF_INET6)
		uhdr->check =
			csum_fold(ip_vs_check_diff16(oldip->ip6, newip->ip6,
					 ip_vs_check_diff2(oldlen, newlen,
						~csum_unfold(uhdr->check))));
	else
#endif
	uhdr->check =
		csum_fold(ip_vs_check_diff4(oldip->ip, newip->ip,
				ip_vs_check_diff2(oldlen, newlen,
						~csum_unfold(uhdr->check))));
}


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

#ifdef CONFIG_IP_VS_IPV6
	if (cp->af == AF_INET6)
		udphoff = sizeof(struct ipv6hdr);
	else
#endif
		udphoff = ip_hdrlen(skb);
	oldlen = skb->len - udphoff;

	/* 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(cp->af, skb, pp))
			return 0;

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

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

	/*
	 *	Adjust UDP checksums
	 */
	if (skb->ip_summed == CHECKSUM_PARTIAL) {
		udp_partial_csum_update(cp->af, udph, &cp->daddr, &cp->vaddr,
					htons(oldlen),
					htons(skb->len - udphoff));
	} else if (!cp->app && (udph->check != 0)) {
		/* Only port and addr are changed, do fast csum update */
		udp_fast_csum_update(cp->af, 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);
#ifdef CONFIG_IP_VS_IPV6
		if (cp->af == AF_INET6)
			udph->check = csum_ipv6_magic(&cp->vaddr.in6,
						      &cp->caddr.in6,
						      skb->len - udphoff,
						      cp->protocol, skb->csum);
		else
#endif
			udph->check = csum_tcpudp_magic(cp->vaddr.ip,
							cp->caddr.ip,
							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;
	int oldlen;

#ifdef CONFIG_IP_VS_IPV6
	if (cp->af == AF_INET6)
		udphoff = sizeof(struct ipv6hdr);
	else
#endif
		udphoff = ip_hdrlen(skb);
	oldlen = skb->len - udphoff;

	/* 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(cp->af, 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 *)skb_network_header(skb) + udphoff;
	udph->dest = cp->dport;

	/*
	 *	Adjust UDP checksums
	 */
	if (skb->ip_summed == CHECKSUM_PARTIAL) {
		udp_partial_csum_update(cp->af, udph, &cp->daddr, &cp->vaddr,
					htons(oldlen),
					htons(skb->len - udphoff));
	} else if (!cp->app && (udph->check != 0)) {
		/* Only port and addr are changed, do fast csum update */
		udp_fast_csum_update(cp->af, 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);
#ifdef CONFIG_IP_VS_IPV6
		if (cp->af == AF_INET6)
			udph->check = csum_ipv6_magic(&cp->caddr.in6,
						      &cp->daddr.in6,
						      skb->len - udphoff,
						      cp->protocol, skb->csum);
		else
#endif
			udph->check = csum_tcpudp_magic(cp->caddr.ip,
							cp->daddr.ip,
							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(int af, struct sk_buff *skb, struct ip_vs_protocol *pp)
{
	struct udphdr _udph, *uh;
	unsigned int udphoff;

#ifdef CONFIG_IP_VS_IPV6
	if (af == AF_INET6)
		udphoff = sizeof(struct ipv6hdr);
	else
#endif
		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:
#ifdef CONFIG_IP_VS_IPV6
			if (af == AF_INET6) {
				if (csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
						    &ipv6_hdr(skb)->daddr,
						    skb->len - udphoff,
						    ipv6_hdr(skb)->nexthdr,
						    skb->csum)) {
					IP_VS_DBG_RL_PKT(0, pp, skb, 0,
							 "Failed checksum for");
					return 0;
				}
			} else
#endif
				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_BUF(9, "%s: Binding conn %s:%u->"
				      "%s:%u to app %s on port %u\n",
				      __func__,
				      IP_VS_DBG_ADDR(cp->af, &cp->caddr),
				      ntohs(cp->cport),
				      IP_VS_DBG_ADDR(cp->af, &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,
	.num_states =		IP_VS_UDP_S_LAST,
	.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	*
1da177e4 LT	4	* Authors: Wensong Zhang <wensong@linuxvirtualserver.org>
	5	* Julian Anastasov <ja@ssi.bg>
	6	*
	7	* This program is free software; you can redistribute it and/or
	8	* modify it under the terms of the GNU General Public License
	9	* as published by the Free Software Foundation; either version
	10	* 2 of the License, or (at your option) any later version.
	11	*
	12	* Changes:
	13	*
	14	*/
	15
9aada7ac HE	16	#define KMSG_COMPONENT "IPVS"
	17	#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
	18
14c85021 ACM	19	#include <linux/in.h>
14c85021 ACM	20	#include <linux/ip.h>
1da177e4	21	#include <linux/kernel.h>
af1e1cf0	22	#include <linux/netfilter.h>
1da177e4	23	#include <linux/netfilter_ipv4.h>
14c85021	24	#include <linux/udp.h>
1da177e4 LT	25
1da177e4 LT	26	#include <net/ip_vs.h>
c9bdd4b5	27	#include <net/ip.h>
63f2c046	28	#include <net/ip6_checksum.h>
1da177e4 LT	29
1da177e4 LT	30	static struct ip_vs_conn *
51ef348b JV	31	udp_conn_in_get(int af, const struct sk_buff skb, struct ip_vs_protocol pp,
	32	const struct ip_vs_iphdr *iph, unsigned int proto_off,
	33	int inverse)
1da177e4 LT	34	{
1da177e4 LT	35	struct ip_vs_conn *cp;
014d730d	36	__be16 _ports[2], *pptr;
1da177e4 LT	37
	38	pptr = skb_header_pointer(skb, proto_off, sizeof(_ports), _ports);
	39	if (pptr == NULL)
	40	return NULL;
	41
	42	if (likely(!inverse)) {
28364a59 JV	43	cp = ip_vs_conn_in_get(af, iph->protocol,
	44	&iph->saddr, pptr[0],
	45	&iph->daddr, pptr[1]);
1da177e4	46	} else {
28364a59 JV	47	cp = ip_vs_conn_in_get(af, iph->protocol,
	48	&iph->daddr, pptr[1],
	49	&iph->saddr, pptr[0]);
1da177e4 LT	50	}
	51
	52	return cp;
	53	}
	54
	55
	56	static struct ip_vs_conn *
51ef348b JV	57	udp_conn_out_get(int af, const struct sk_buff skb, struct ip_vs_protocol pp,
	58	const struct ip_vs_iphdr *iph, unsigned int proto_off,
	59	int inverse)
1da177e4 LT	60	{
1da177e4 LT	61	struct ip_vs_conn *cp;
014d730d	62	__be16 _ports[2], *pptr;
1da177e4	63
51ef348b	64	pptr = skb_header_pointer(skb, proto_off, sizeof(_ports), _ports);
1da177e4 LT	65	if (pptr == NULL)
	66	return NULL;
	67
	68	if (likely(!inverse)) {
28364a59 JV	69	cp = ip_vs_conn_out_get(af, iph->protocol,
	70	&iph->saddr, pptr[0],
	71	&iph->daddr, pptr[1]);
1da177e4	72	} else {
28364a59 JV	73	cp = ip_vs_conn_out_get(af, iph->protocol,
	74	&iph->daddr, pptr[1],
	75	&iph->saddr, pptr[0]);
1da177e4 LT	76	}
	77
	78	return cp;
	79	}
	80
	81
	82	static int
51ef348b	83	udp_conn_schedule(int af, struct sk_buff skb, struct ip_vs_protocol pp,
1da177e4 LT	84	int verdict, struct ip_vs_conn *cpp)
	85	{
	86	struct ip_vs_service *svc;
	87	struct udphdr _udph, *uh;
3c2e0505	88	struct ip_vs_iphdr iph;
1da177e4	89
51ef348b	90	ip_vs_fill_iphdr(af, skb_network_header(skb), &iph);
3c2e0505 JV	91
3c2e0505 JV	92	uh = skb_header_pointer(skb, iph.len, sizeof(_udph), &_udph);
1da177e4 LT	93	if (uh == NULL) {
	94	*verdict = NF_DROP;
	95	return 0;
	96	}
	97
51ef348b	98	svc = ip_vs_service_get(af, skb->mark, iph.protocol,
3c2e0505 JV	99	&iph.daddr, uh->dest);
3c2e0505 JV	100	if (svc) {
1da177e4 LT	101	if (ip_vs_todrop()) {
	102	/*
	103	* It seems that we are very loaded.
	104	* We have to drop this packet :(
	105	*/
	106	ip_vs_service_put(svc);
	107	*verdict = NF_DROP;
	108	return 0;
	109	}
	110
	111	/*
	112	* Let the virtual server select a real server for the
	113	* incoming connection, and create a connection entry.
	114	*/
	115	*cpp = ip_vs_schedule(svc, skb);
	116	if (!*cpp) {
	117	*verdict = ip_vs_leave(svc, skb, pp);
	118	return 0;
	119	}
	120	ip_vs_service_put(svc);
	121	}
	122	return 1;
	123	}
	124
	125
	126	static inline void
0bbdd42b JV	127	udp_fast_csum_update(int af, struct udphdr *uhdr,
	128	const union nf_inet_addr *oldip,
	129	const union nf_inet_addr *newip,
014d730d	130	__be16 oldport, __be16 newport)
1da177e4	131	{
0bbdd42b JV	132	#ifdef CONFIG_IP_VS_IPV6
	133	if (af == AF_INET6)
	134	uhdr->check =
	135	csum_fold(ip_vs_check_diff16(oldip->ip6, newip->ip6,
	136	ip_vs_check_diff2(oldport, newport,
	137	~csum_unfold(uhdr->check))));
	138	else
	139	#endif
	140	uhdr->check =
	141	csum_fold(ip_vs_check_diff4(oldip->ip, newip->ip,
	142	ip_vs_check_diff2(oldport, newport,
	143	~csum_unfold(uhdr->check))));
1da177e4	144	if (!uhdr->check)
f6ab0288	145	uhdr->check = CSUM_MANGLED_0;
1da177e4 LT	146	}
1da177e4 LT	147
503e81f6 SH	148	static inline void
	149	udp_partial_csum_update(int af, struct udphdr *uhdr,
	150	const union nf_inet_addr *oldip,
	151	const union nf_inet_addr *newip,
	152	__be16 oldlen, __be16 newlen)
	153	{
	154	#ifdef CONFIG_IP_VS_IPV6
	155	if (af == AF_INET6)
	156	uhdr->check =
	157	csum_fold(ip_vs_check_diff16(oldip->ip6, newip->ip6,
	158	ip_vs_check_diff2(oldlen, newlen,
	159	~csum_unfold(uhdr->check))));
	160	else
	161	#endif
	162	uhdr->check =
	163	csum_fold(ip_vs_check_diff4(oldip->ip, newip->ip,
	164	ip_vs_check_diff2(oldlen, newlen,
	165	~csum_unfold(uhdr->check))));
	166	}
	167
	168
1da177e4	169	static int
3db05fea	170	udp_snat_handler(struct sk_buff *skb,
1da177e4 LT	171	struct ip_vs_protocol pp, struct ip_vs_conn cp)
	172	{
	173	struct udphdr *udph;
0bbdd42b	174	unsigned int udphoff;
503e81f6	175	int oldlen;
0bbdd42b JV	176
	177	#ifdef CONFIG_IP_VS_IPV6
	178	if (cp->af == AF_INET6)
	179	udphoff = sizeof(struct ipv6hdr);
	180	else
	181	#endif
	182	udphoff = ip_hdrlen(skb);
503e81f6	183	oldlen = skb->len - udphoff;
1da177e4 LT	184
1da177e4 LT	185	/* csum_check requires unshared skb */
3db05fea	186	if (!skb_make_writable(skb, udphoff+sizeof(*udph)))
1da177e4 LT	187	return 0;
	188
	189	if (unlikely(cp->app != NULL)) {
	190	/* Some checks before mangling */
0bbdd42b	191	if (pp->csum_check && !pp->csum_check(cp->af, skb, pp))
1da177e4 LT	192	return 0;
	193
	194	/*
	195	* Call application helper if needed
	196	*/
3db05fea	197	if (!ip_vs_app_pkt_out(cp, skb))
1da177e4 LT	198	return 0;
	199	}
	200
0bbdd42b	201	udph = (void *)skb_network_header(skb) + udphoff;
1da177e4 LT	202	udph->source = cp->vport;
	203
	204	/*
	205	* Adjust UDP checksums
	206	*/
503e81f6 SH	207	if (skb->ip_summed == CHECKSUM_PARTIAL) {
503e81f6 SH	208	udp_partial_csum_update(cp->af, udph, &cp->daddr, &cp->vaddr,
ca62059b HH	209	htons(oldlen),
ca62059b HH	210	htons(skb->len - udphoff));
503e81f6	211	} else if (!cp->app && (udph->check != 0)) {
1da177e4	212	/* Only port and addr are changed, do fast csum update */
0bbdd42b	213	udp_fast_csum_update(cp->af, udph, &cp->daddr, &cp->vaddr,
1da177e4	214	cp->dport, cp->vport);
3db05fea HX	215	if (skb->ip_summed == CHECKSUM_COMPLETE)
3db05fea HX	216	skb->ip_summed = CHECKSUM_NONE;
1da177e4 LT	217	} else {
	218	/* full checksum calculation */
	219	udph->check = 0;
3db05fea	220	skb->csum = skb_checksum(skb, udphoff, skb->len - udphoff, 0);
0bbdd42b JV	221	#ifdef CONFIG_IP_VS_IPV6
	222	if (cp->af == AF_INET6)
	223	udph->check = csum_ipv6_magic(&cp->vaddr.in6,
	224	&cp->caddr.in6,
	225	skb->len - udphoff,
	226	cp->protocol, skb->csum);
	227	else
	228	#endif
	229	udph->check = csum_tcpudp_magic(cp->vaddr.ip,
	230	cp->caddr.ip,
	231	skb->len - udphoff,
	232	cp->protocol,
	233	skb->csum);
1da177e4	234	if (udph->check == 0)
f6ab0288	235	udph->check = CSUM_MANGLED_0;
1da177e4 LT	236	IP_VS_DBG(11, "O-pkt: %s O-csum=%d (+%zd)\n",
	237	pp->name, udph->check,
	238	(char)&(udph->check) - (char)udph);
	239	}
	240	return 1;
	241	}
	242
	243
	244	static int
3db05fea	245	udp_dnat_handler(struct sk_buff *skb,
1da177e4 LT	246	struct ip_vs_protocol pp, struct ip_vs_conn cp)
	247	{
	248	struct udphdr *udph;
0bbdd42b	249	unsigned int udphoff;
503e81f6	250	int oldlen;
0bbdd42b JV	251
	252	#ifdef CONFIG_IP_VS_IPV6
	253	if (cp->af == AF_INET6)
	254	udphoff = sizeof(struct ipv6hdr);
	255	else
	256	#endif
	257	udphoff = ip_hdrlen(skb);
503e81f6	258	oldlen = skb->len - udphoff;
1da177e4 LT	259
1da177e4 LT	260	/* csum_check requires unshared skb */
3db05fea	261	if (!skb_make_writable(skb, udphoff+sizeof(*udph)))
1da177e4 LT	262	return 0;
	263
	264	if (unlikely(cp->app != NULL)) {
	265	/* Some checks before mangling */
0bbdd42b	266	if (pp->csum_check && !pp->csum_check(cp->af, skb, pp))
1da177e4 LT	267	return 0;
	268
	269	/*
	270	* Attempt ip_vs_app call.
	271	* It will fix ip_vs_conn
	272	*/
3db05fea	273	if (!ip_vs_app_pkt_in(cp, skb))
1da177e4 LT	274	return 0;
	275	}
	276
0bbdd42b	277	udph = (void *)skb_network_header(skb) + udphoff;
1da177e4 LT	278	udph->dest = cp->dport;
	279
	280	/*
	281	* Adjust UDP checksums
	282	*/
503e81f6 SH	283	if (skb->ip_summed == CHECKSUM_PARTIAL) {
503e81f6 SH	284	udp_partial_csum_update(cp->af, udph, &cp->daddr, &cp->vaddr,
ca62059b HH	285	htons(oldlen),
ca62059b HH	286	htons(skb->len - udphoff));
503e81f6	287	} else if (!cp->app && (udph->check != 0)) {
1da177e4	288	/* Only port and addr are changed, do fast csum update */
0bbdd42b	289	udp_fast_csum_update(cp->af, udph, &cp->vaddr, &cp->daddr,
1da177e4	290	cp->vport, cp->dport);
3db05fea HX	291	if (skb->ip_summed == CHECKSUM_COMPLETE)
3db05fea HX	292	skb->ip_summed = CHECKSUM_NONE;
1da177e4 LT	293	} else {
	294	/* full checksum calculation */
	295	udph->check = 0;
3db05fea	296	skb->csum = skb_checksum(skb, udphoff, skb->len - udphoff, 0);
0bbdd42b JV	297	#ifdef CONFIG_IP_VS_IPV6
	298	if (cp->af == AF_INET6)
	299	udph->check = csum_ipv6_magic(&cp->caddr.in6,
	300	&cp->daddr.in6,
	301	skb->len - udphoff,
	302	cp->protocol, skb->csum);
	303	else
	304	#endif
	305	udph->check = csum_tcpudp_magic(cp->caddr.ip,
	306	cp->daddr.ip,
	307	skb->len - udphoff,
	308	cp->protocol,
	309	skb->csum);
1da177e4	310	if (udph->check == 0)
f6ab0288	311	udph->check = CSUM_MANGLED_0;
3db05fea	312	skb->ip_summed = CHECKSUM_UNNECESSARY;
1da177e4 LT	313	}
	314	return 1;
	315	}
	316
	317
	318	static int
51ef348b	319	udp_csum_check(int af, struct sk_buff skb, struct ip_vs_protocol pp)
1da177e4 LT	320	{
1da177e4 LT	321	struct udphdr _udph, *uh;
51ef348b JV	322	unsigned int udphoff;
	323
	324	#ifdef CONFIG_IP_VS_IPV6
	325	if (af == AF_INET6)
	326	udphoff = sizeof(struct ipv6hdr);
	327	else
	328	#endif
	329	udphoff = ip_hdrlen(skb);
1da177e4 LT	330
	331	uh = skb_header_pointer(skb, udphoff, sizeof(_udph), &_udph);
	332	if (uh == NULL)
	333	return 0;
	334
	335	if (uh->check != 0) {
	336	switch (skb->ip_summed) {
	337	case CHECKSUM_NONE:
	338	skb->csum = skb_checksum(skb, udphoff,
	339	skb->len - udphoff, 0);
84fa7933	340	case CHECKSUM_COMPLETE:
51ef348b JV	341	#ifdef CONFIG_IP_VS_IPV6
	342	if (af == AF_INET6) {
	343	if (csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
	344	&ipv6_hdr(skb)->daddr,
	345	skb->len - udphoff,
	346	ipv6_hdr(skb)->nexthdr,
	347	skb->csum)) {
	348	IP_VS_DBG_RL_PKT(0, pp, skb, 0,
	349	"Failed checksum for");
	350	return 0;
	351	}
	352	} else
	353	#endif
	354	if (csum_tcpudp_magic(ip_hdr(skb)->saddr,
	355	ip_hdr(skb)->daddr,
	356	skb->len - udphoff,
	357	ip_hdr(skb)->protocol,
	358	skb->csum)) {
	359	IP_VS_DBG_RL_PKT(0, pp, skb, 0,
	360	"Failed checksum for");
	361	return 0;
	362	}
1da177e4 LT	363	break;
1da177e4 LT	364	default:
84fa7933	365	/* No need to checksum. */
1da177e4 LT	366	break;
	367	}
	368	}
	369	return 1;
	370	}
	371
	372
	373	/*
	374	* Note: the caller guarantees that only one of register_app,
	375	* unregister_app or app_conn_bind is called each time.
	376	*/
	377
	378	#define UDP_APP_TAB_BITS 4
	379	#define UDP_APP_TAB_SIZE (1 << UDP_APP_TAB_BITS)
	380	#define UDP_APP_TAB_MASK (UDP_APP_TAB_SIZE - 1)
	381
	382	static struct list_head udp_apps[UDP_APP_TAB_SIZE];
	383	static DEFINE_SPINLOCK(udp_app_lock);
	384
75e7ce66	385	static inline __u16 udp_app_hashkey(__be16 port)
1da177e4	386	{
75e7ce66 AV	387	return (((__force u16)port >> UDP_APP_TAB_BITS) ^ (__force u16)port)
75e7ce66 AV	388	& UDP_APP_TAB_MASK;
1da177e4 LT	389	}
	390
	391
	392	static int udp_register_app(struct ip_vs_app *inc)
	393	{
	394	struct ip_vs_app *i;
75e7ce66 AV	395	__u16 hash;
75e7ce66 AV	396	__be16 port = inc->port;
1da177e4 LT	397	int ret = 0;
	398
	399	hash = udp_app_hashkey(port);
	400
	401
	402	spin_lock_bh(&udp_app_lock);
	403	list_for_each_entry(i, &udp_apps[hash], p_list) {
	404	if (i->port == port) {
	405	ret = -EEXIST;
	406	goto out;
	407	}
	408	}
	409	list_add(&inc->p_list, &udp_apps[hash]);
	410	atomic_inc(&ip_vs_protocol_udp.appcnt);
	411
	412	out:
	413	spin_unlock_bh(&udp_app_lock);
	414	return ret;
	415	}
	416
	417
	418	static void
	419	udp_unregister_app(struct ip_vs_app *inc)
	420	{
	421	spin_lock_bh(&udp_app_lock);
	422	atomic_dec(&ip_vs_protocol_udp.appcnt);
	423	list_del(&inc->p_list);
	424	spin_unlock_bh(&udp_app_lock);
	425	}
	426
	427
	428	static int udp_app_conn_bind(struct ip_vs_conn *cp)
	429	{
	430	int hash;
	431	struct ip_vs_app *inc;
	432	int result = 0;
	433
	434	/* Default binding: bind app only for NAT */
	435	if (IP_VS_FWD_METHOD(cp) != IP_VS_CONN_F_MASQ)
	436	return 0;
	437
	438	/* Lookup application incarnations and bind the right one */
	439	hash = udp_app_hashkey(cp->vport);
	440
	441	spin_lock(&udp_app_lock);
	442	list_for_each_entry(inc, &udp_apps[hash], p_list) {
	443	if (inc->port == cp->vport) {
	444	if (unlikely(!ip_vs_app_inc_get(inc)))
	445	break;
	446	spin_unlock(&udp_app_lock);
	447
cfc78c5a JV	448	IP_VS_DBG_BUF(9, "%s: Binding conn %s:%u->"
	449	"%s:%u to app %s on port %u\n",
	450	__func__,
	451	IP_VS_DBG_ADDR(cp->af, &cp->caddr),
	452	ntohs(cp->cport),
	453	IP_VS_DBG_ADDR(cp->af, &cp->vaddr),
	454	ntohs(cp->vport),
	455	inc->name, ntohs(inc->port));
	456
1da177e4 LT	457	cp->app = inc;
	458	if (inc->init_conn)
	459	result = inc->init_conn(inc, cp);
	460	goto out;
	461	}
	462	}
	463	spin_unlock(&udp_app_lock);
	464
	465	out:
	466	return result;
	467	}
	468
	469
	470	static int udp_timeouts[IP_VS_UDP_S_LAST+1] = {
	471	[IP_VS_UDP_S_NORMAL] = 560HZ,
	472	[IP_VS_UDP_S_LAST] = 2*HZ,
	473	};
	474
	475	static char * udp_state_name_table[IP_VS_UDP_S_LAST+1] = {
	476	[IP_VS_UDP_S_NORMAL] = "UDP",
	477	[IP_VS_UDP_S_LAST] = "BUG!",
	478	};
	479
	480
	481	static int
	482	udp_set_state_timeout(struct ip_vs_protocol pp, char sname, int to)
	483	{
	484	return ip_vs_set_state_timeout(pp->timeout_table, IP_VS_UDP_S_LAST,
	485	udp_state_name_table, sname, to);
	486	}
	487
	488	static const char * udp_state_name(int state)
	489	{
	490	if (state >= IP_VS_UDP_S_LAST)
	491	return "ERR!";
	492	return udp_state_name_table[state] ? udp_state_name_table[state] : "?";
	493	}
	494
	495	static int
	496	udp_state_transition(struct ip_vs_conn *cp, int direction,
	497	const struct sk_buff *skb,
	498	struct ip_vs_protocol *pp)
	499	{
	500	cp->timeout = pp->timeout_table[IP_VS_UDP_S_NORMAL];
	501	return 1;
	502	}
	503
	504	static void udp_init(struct ip_vs_protocol *pp)
	505	{
	506	IP_VS_INIT_HASH_TABLE(udp_apps);
	507	pp->timeout_table = udp_timeouts;
	508	}
	509
	510	static void udp_exit(struct ip_vs_protocol *pp)
	511	{
	512	}
	513
	514
	515	struct ip_vs_protocol ip_vs_protocol_udp = {
	516	.name = "UDP",
	517	.protocol = IPPROTO_UDP,
2ad17def	518	.num_states = IP_VS_UDP_S_LAST,
1da177e4 LT	519	.dont_defrag = 0,
	520	.init = udp_init,
	521	.exit = udp_exit,
	522	.conn_schedule = udp_conn_schedule,
	523	.conn_in_get = udp_conn_in_get,
	524	.conn_out_get = udp_conn_out_get,
	525	.snat_handler = udp_snat_handler,
	526	.dnat_handler = udp_dnat_handler,
	527	.csum_check = udp_csum_check,
	528	.state_transition = udp_state_transition,
	529	.state_name = udp_state_name,
	530	.register_app = udp_register_app,
	531	.unregister_app = udp_unregister_app,
	532	.app_conn_bind = udp_app_conn_bind,
	533	.debug_packet = ip_vs_tcpudp_debug_packet,
	534	.timeout_change = NULL,
	535	.set_state_timeout = udp_set_state_timeout,
	536	};