[GitHub/mt8127/android_kernel_alcatel_ttab.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:
 *
 */

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