/*
 *      IP Virtual Server
 *      data structure and functionality definitions
 */

#ifndef _IP_VS_H
#define _IP_VS_H

#include <asm/types.h>          /* For __uXX types */

#define IP_VS_VERSION_CODE            0x01000A
#define NVERSION(version)                       \
	(version >> 16) & 0xFF,                 \
	(version >> 8) & 0xFF,                  \
	version & 0xFF

/*
 *      Virtual Service Flags
 */
#define IP_VS_SVC_F_PERSISTENT        0x0001    /* persistent port */
#define IP_VS_SVC_F_HASHED            0x0002    /* hashed entry */

/*
 *      Destination Server Flags
 */
#define IP_VS_DEST_F_AVAILABLE        0x0001    /* Available tag */

/*
 *      IPVS sync daemon states
 */
#define IP_VS_STATE_NONE    0           /* daemon is stopped */
#define IP_VS_STATE_MASTER  1           /* started as master */
#define IP_VS_STATE_BACKUP  2           /* started as backup */

/*
 *      IPVS socket options
 */
#define IP_VS_BASE_CTL		(64+1024+64)		/* base */

#define IP_VS_SO_SET_NONE	IP_VS_BASE_CTL	        /* just peek */
#define IP_VS_SO_SET_INSERT	(IP_VS_BASE_CTL+1)
#define IP_VS_SO_SET_ADD	(IP_VS_BASE_CTL+2)
#define IP_VS_SO_SET_EDIT	(IP_VS_BASE_CTL+3)
#define IP_VS_SO_SET_DEL	(IP_VS_BASE_CTL+4)
#define IP_VS_SO_SET_FLUSH	(IP_VS_BASE_CTL+5)
#define IP_VS_SO_SET_LIST	(IP_VS_BASE_CTL+6)
#define IP_VS_SO_SET_ADDDEST	(IP_VS_BASE_CTL+7)
#define IP_VS_SO_SET_DELDEST	(IP_VS_BASE_CTL+8)
#define IP_VS_SO_SET_EDITDEST	(IP_VS_BASE_CTL+9)
#define IP_VS_SO_SET_TIMEOUTS	(IP_VS_BASE_CTL+10)
#define IP_VS_SO_SET_STARTDAEMON (IP_VS_BASE_CTL+11)
#define IP_VS_SO_SET_STOPDAEMON (IP_VS_BASE_CTL+12)
#define IP_VS_SO_SET_RESTORE    (IP_VS_BASE_CTL+13)
#define IP_VS_SO_SET_SAVE       (IP_VS_BASE_CTL+14)
#define IP_VS_SO_SET_ZERO	(IP_VS_BASE_CTL+15)
#define IP_VS_SO_SET_MAX	IP_VS_SO_SET_ZERO

#define IP_VS_SO_GET_VERSION	IP_VS_BASE_CTL
#define IP_VS_SO_GET_INFO	(IP_VS_BASE_CTL+1)
#define IP_VS_SO_GET_SERVICES	(IP_VS_BASE_CTL+2)
#define IP_VS_SO_GET_SERVICE	(IP_VS_BASE_CTL+3)
#define IP_VS_SO_GET_DESTS	(IP_VS_BASE_CTL+4)
#define IP_VS_SO_GET_DEST	(IP_VS_BASE_CTL+5)	/* not used now */
#define IP_VS_SO_GET_TIMEOUTS	(IP_VS_BASE_CTL+6)
#define IP_VS_SO_GET_DAEMON	(IP_VS_BASE_CTL+7)
#define IP_VS_SO_GET_MAX	IP_VS_SO_GET_DAEMON


/*
 *      IPVS Connection Flags
 */
#define IP_VS_CONN_F_FWD_MASK         0x0007    /* mask for the fwd methods */
#define IP_VS_CONN_F_MASQ	      0x0000    /* masquerading */
#define IP_VS_CONN_F_LOCALNODE	      0x0001    /* local node */
#define IP_VS_CONN_F_TUNNEL	      0x0002    /* tunneling */
#define IP_VS_CONN_F_DROUTE           0x0003    /* direct routing */
#define IP_VS_CONN_F_BYPASS           0x0004    /* cache bypass */
#define IP_VS_CONN_F_HASHED	      0x0040	/* hashed entry */
#define IP_VS_CONN_F_NOOUTPUT         0x0080    /* no output packets */
#define IP_VS_CONN_F_INACTIVE         0x0100    /* not established */
#define IP_VS_CONN_F_OUT_SEQ          0x0200    /* must do output seq adjust */
#define IP_VS_CONN_F_IN_SEQ           0x0400    /* must do input seq adjust */
#define IP_VS_CONN_F_SEQ_MASK         0x0600    /* in/out sequence mask */
#define IP_VS_CONN_F_NO_CPORT         0x0800    /* no client port set yet */

/* Move it to better place one day, for now keep it unique */
#define NFC_IPVS_PROPERTY	0x10000

#define IP_VS_SCHEDNAME_MAXLEN         16
#define IP_VS_IFNAME_MAXLEN            16

struct ip_vs_rule_user {
	/* global options */
	int             tcp_timeout;    /* timeout values */
	int             tcp_fin_timeout;
	int             udp_timeout;
	int             state;          /* sync daemon state */
	char            mcast_ifn[IP_VS_IFNAME_MAXLEN];
					/* multicast interface name */

	/* virtual service options */
	u_int16_t	protocol;
	u_int32_t	vaddr;          /* virtual address */
	u_int16_t	vport;
	u_int32_t       vfwmark;        /* firwall mark of virtual service*/
	char            sched_name[IP_VS_SCHEDNAME_MAXLEN];
	unsigned	vs_flags;       /* virtual service flags */
	unsigned        timeout;        /* persistent timeout in ticks */
	u_int32_t	netmask;        /* persistent netmask */

	/* destination specific options */
	u_int32_t	daddr;          /* destination address */
	u_int16_t	dport;
	unsigned        conn_flags;     /* destination flags */
	int             weight;         /* destination weight */
};


/*
 *	IPVS statistics object (for user space)
 */
struct ip_vs_stats_user
{
	__u32                   conns;          /* connections scheduled */
	__u32                   inpkts;         /* incoming packets */
	__u32                   outpkts;        /* outgoing packets */
	__u64                   inbytes;        /* incoming bytes */
	__u64                   outbytes;       /* outgoing bytes */

	__u32			cps;		/* current connection rate */
	__u32			inpps;		/* current in packet rate */
	__u32			outpps;		/* current out packet rate */
	__u32			inbps;		/* current in byte rate */
	__u32			outbps;		/* current out byte rate */
};


/* The argument to IP_VS_SO_GET_INFO */
struct ip_vs_getinfo {
	/* version number */
	unsigned int	version;

	/* size of connection hash table */
	unsigned int	size;

	/* number of virtual services */
	unsigned int	num_services;
};

/* The argument to IP_VS_SO_GET_SERVICE */
struct ip_vs_service_user {
	/* which service: user fills this in */
	u_int16_t	protocol;
	u_int32_t	addr;           /* virtual address */
	u_int16_t	port;
	u_int32_t       fwmark;         /* firwall mark of virtual service */

	/* service options */
	char            sched_name[IP_VS_SCHEDNAME_MAXLEN];
	unsigned	flags;          /* virtual service flags */
	unsigned        timeout;        /* persistent timeout in ticks */
	u_int32_t	netmask;        /* persistent netmask */

	/* number of real servers */
	unsigned int    num_dests;

	/* statistics */
	struct ip_vs_stats_user stats;
};

struct ip_vs_dest_user {
	u_int32_t	addr;           /* destination address */
	u_int16_t	port;
	unsigned	flags;		/* destination flags */
	int		weight;         /* destination weight */
	u_int32_t	activeconns;	/* active connections */
	u_int32_t	inactconns;	/* inactive connections */

	/* statistics */
	struct ip_vs_stats_user stats;
};

/* The argument to IP_VS_SO_GET_DESTS */
struct ip_vs_get_dests {
	/* which service: user fills this in */
	u_int16_t	protocol;
	u_int32_t	addr;           /* virtual address */
	u_int16_t	port;
	u_int32_t       fwmark;         /* firwall mark of virtual service */

	/* number of real servers */
	unsigned int    num_dests;

	/* the real servers */
	struct ip_vs_dest_user entrytable[0];
};

/* The argument to IP_VS_SO_GET_SERVICES */
struct ip_vs_get_services {
	/* number of virtual services */
	unsigned int num_services;

	/* service table */
	struct ip_vs_service_user entrytable[0];
};

/* The argument to IP_VS_SO_GET_TIMEOUTS */
struct ip_vs_timeout_user {
	int             tcp_timeout;
	int             tcp_fin_timeout;
	int             udp_timeout;
};

/* The argument to IP_VS_SO_GET_DAEMON */
struct ip_vs_daemon_user {
	int	state;				/* sync daemon state */
	char	mcast_ifn[IP_VS_IFNAME_MAXLEN];	/* multicast interface name */
};


#ifdef __KERNEL__

#include <linux/config.h>
#include <linux/list.h>                 /* for struct list_head */
#include <linux/spinlock.h>             /* for struct rwlock_t */
#include <linux/skbuff.h>               /* for struct sk_buff */
#include <linux/ip.h>                   /* for struct iphdr */
#include <asm/atomic.h>                 /* for struct atomic_t */
#include <linux/netdevice.h>		/* for struct neighbour; */
#include <net/dst.h>			/* for struct dst_entry */
#include <net/route.h>			/* for ip_route_output */
#include <net/tcp.h>
#include <net/udp.h>


#ifdef CONFIG_IP_VS_DEBUG
extern int ip_vs_get_debug_level(void);
#define IP_VS_DBG(level, msg...)			\
    do {						\
	    if (level <= ip_vs_get_debug_level())	\
		    printk(KERN_DEBUG "IPVS: " msg);	\
    } while (0)
#define IP_VS_DBG_RL(msg...)				\
    do {						\
	    if (net_ratelimit())			\
		    printk(KERN_DEBUG "IPVS: " msg);	\
    } while (0)
#else	/* NO DEBUGGING at ALL */
#define IP_VS_DBG(level, msg...)  do {} while (0)
#define IP_VS_DBG_RL(msg...)  do {} while (0)
#endif

#define IP_VS_BUG() BUG()
#define IP_VS_ERR(msg...) printk(KERN_ERR "IPVS: " msg)
#define IP_VS_INFO(msg...) printk(KERN_INFO "IPVS: " msg)
#define IP_VS_WARNING(msg...) \
	printk(KERN_WARNING "IPVS: " msg)
#define IP_VS_ERR_RL(msg...)				\
    do {						\
	    if (net_ratelimit())			\
		    printk(KERN_ERR "IPVS: " msg);	\
    } while (0)

#ifdef CONFIG_IP_VS_DEBUG
#define EnterFunction(level)						\
    do {								\
	    if (level <= ip_vs_get_debug_level())			\
		    printk(KERN_DEBUG "Enter: %s, %s line %i\n",	\
			   __FUNCTION__, __FILE__, __LINE__);		\
    } while (0)
#define LeaveFunction(level)                                            \
    do {                                                                \
	    if (level <= ip_vs_get_debug_level())                       \
			printk(KERN_DEBUG "Leave: %s, %s line %i\n",    \
			       __FUNCTION__, __FILE__, __LINE__);       \
    } while (0)
#else
#define EnterFunction(level)   do {} while (0)
#define LeaveFunction(level)   do {} while (0)
#endif


/*
 *      The port number of FTP service (in network order).
 */
#define FTPPORT  __constant_htons(21)
#define FTPDATA  __constant_htons(20)


/*
 *      IPVS sysctl variables under the /proc/sys/net/ipv4/vs/
 */
#define NET_IPV4_VS              21

enum {
	NET_IPV4_VS_DEBUG_LEVEL=1,
	NET_IPV4_VS_AMEMTHRESH=2,
	NET_IPV4_VS_AMDROPRATE=3,
	NET_IPV4_VS_DROP_ENTRY=4,
	NET_IPV4_VS_DROP_PACKET=5,
	NET_IPV4_VS_SECURE_TCP=6,
	NET_IPV4_VS_TO_ES=7,
	NET_IPV4_VS_TO_SS=8,
	NET_IPV4_VS_TO_SR=9,
	NET_IPV4_VS_TO_FW=10,
	NET_IPV4_VS_TO_TW=11,
	NET_IPV4_VS_TO_CL=12,
	NET_IPV4_VS_TO_CW=13,
	NET_IPV4_VS_TO_LA=14,
	NET_IPV4_VS_TO_LI=15,
	NET_IPV4_VS_TO_SA=16,
	NET_IPV4_VS_TO_UDP=17,
	NET_IPV4_VS_TO_ICMP=18,
	NET_IPV4_VS_LBLC_EXPIRE=19,
	NET_IPV4_VS_LBLCR_EXPIRE=20,
	NET_IPV4_VS_CACHE_BYPASS=22,
	NET_IPV4_VS_EXPIRE_NODEST_CONN=23,
	NET_IPV4_VS_SYNC_THRESHOLD=24,
	NET_IPV4_VS_NAT_ICMP_SEND=25,
	NET_IPV4_VS_LAST
};


/*
 *      IPVS State Values
 */
enum {
	IP_VS_S_NONE = 0,
	IP_VS_S_ESTABLISHED,
	IP_VS_S_SYN_SENT,
	IP_VS_S_SYN_RECV,
	IP_VS_S_FIN_WAIT,
	IP_VS_S_TIME_WAIT,
	IP_VS_S_CLOSE,
	IP_VS_S_CLOSE_WAIT,
	IP_VS_S_LAST_ACK,
	IP_VS_S_LISTEN,
	IP_VS_S_SYNACK,
	IP_VS_S_UDP,
	IP_VS_S_ICMP,
	IP_VS_S_LAST
};


struct ip_vs_timeout_table {
	atomic_t refcnt;
	int scale;
	int timeout[IP_VS_S_LAST+1];
};


/*
 *	Transport protocol header
 */
union ip_vs_tphdr {
	unsigned char *raw;
	struct udphdr *uh;
	struct tcphdr *th;
	struct icmphdr *icmph;
	__u16 *portp;
};


/*
 *	Delta sequence info structure
 *	Each ip_vs_conn has 2 (output AND input seq. changes).
 *      Only used in the VS/NAT.
 */
struct ip_vs_seq {
	__u32           init_seq;       /* Add delta from this seq */
	__u32           delta;          /* Delta in sequence numbers */
	__u32           previous_delta; /* Delta in sequence numbers
					   before last resized pkt */
};


/*
 *	IPVS statistics object
 */
struct ip_vs_stats
{
	__u32                   conns;          /* connections scheduled */
	__u32                   inpkts;         /* incoming packets */
	__u32                   outpkts;        /* outgoing packets */
	__u64                   inbytes;        /* incoming bytes */
	__u64                   outbytes;       /* outgoing bytes */

	__u32			cps;		/* current connection rate */
	__u32			inpps;		/* current in packet rate */
	__u32			outpps;		/* current out packet rate */
	__u32			inbps;		/* current in byte rate */
	__u32			outbps;		/* current out byte rate */

	spinlock_t              lock;           /* spin lock */
};


/*
 *	IP_VS structure allocated for each dynamically scheduled connection
 */
struct ip_vs_conn {
	struct list_head        c_list;         /* hashed list heads */

	/* Protocol, addresses and port numbers */
	__u32                   caddr;          /* client address */
	__u32                   vaddr;          /* virtual address */
	__u32                   daddr;          /* destination address */
	__u16                   cport;
	__u16                   vport;
	__u16                   dport;
	__u16                   protocol;       /* Which protocol (TCP/UDP) */

	/* counter and timer */
	atomic_t		refcnt;		/* reference count */
	struct timer_list	timer;		/* Expiration timer */
	volatile unsigned long	timeout;	/* timeout */
	struct ip_vs_timeout_table *timeout_table;

	/* Flags and state transition */
	spinlock_t              lock;           /* lock for state transition */
	volatile __u16          flags;          /* status flags */
	volatile __u16          state;          /* state info */

	/* Control members */
	struct ip_vs_conn       *control;       /* Master control connection */
	atomic_t                n_control;      /* Number of controlled ones */
	struct ip_vs_dest       *dest;          /* real server */
	atomic_t                in_pkts;        /* incoming packet counter */

	/* packet transmitter for different forwarding methods */
	int (*packet_xmit)(struct sk_buff *skb, struct ip_vs_conn *cp);

	/* Note: we can group the following members into a structure,
	   in order to save more space, and the following members are
	   only used in VS/NAT anyway */
	struct ip_vs_app        *app;           /* bound ip_vs_app object */
	void                    *app_data;      /* Application private data */
	struct ip_vs_seq        in_seq;         /* incoming seq. struct */
	struct ip_vs_seq        out_seq;        /* outgoing seq. struct */
};


/*
 *	The information about the virtual service offered to the net
 *	and the forwarding entries
 */
struct ip_vs_service {
	struct list_head	s_list;   /* for normal service table */
	struct list_head	f_list;   /* for fwmark-based service table */
	atomic_t		refcnt;   /* reference counter */
	atomic_t		usecnt;   /* use counter */

	__u16			protocol; /* which protocol (TCP/UDP) */
	__u32			addr;	  /* IP address for virtual service */
	__u16			port;	  /* port number for the service */
	__u32                   fwmark;   /* firewall mark of the service */
	unsigned		flags;	  /* service status flags */
	unsigned		timeout;  /* persistent timeout in ticks */
	__u32			netmask;  /* grouping granularity */

	struct list_head	destinations;  /* real server d-linked list */
	__u32			num_dests;     /* number of servers */
	struct ip_vs_stats      stats;         /* statistics for the service */

	/* for scheduling */
	struct ip_vs_scheduler	*scheduler;    /* bound scheduler object */
	rwlock_t		sched_lock;    /* lock sched_data */
	void			*sched_data;   /* scheduler application data */
};


/*
 *	The real server destination forwarding entry
 *	with ip address, port number, and so on.
 */
struct ip_vs_dest {
	struct list_head	n_list;   /* for the dests in the service */
	struct list_head	d_list;   /* for table with all the dests */

	__u32			addr;	  /* IP address of real server */
	__u16			port;	  /* port number of the service */
	unsigned		flags;	  /* dest status flags */
	atomic_t		weight;	  /* server weight */
	atomic_t		conn_flags;	/* flags to copy to conn */
	atomic_t		activeconns;	/* active connections */
	atomic_t		inactconns;     /* inactive connections */
	atomic_t		refcnt;	        /* reference counter */
	struct ip_vs_stats      stats;          /* statistics */

	/* for destination cache */
	spinlock_t		dst_lock;	/* lock dst_cache */
	struct dst_entry	*dst_cache;	/* destination cache entry */
	u32			dst_rtos;	/* RT_TOS(tos) for dst */

	/* for virtual service */
	struct ip_vs_service    *svc;     /* service that it belongs to */
	__u16			protocol; /* which protocol (TCP/UDP) */
	__u32			vaddr;	  /* IP address for virtual service */
	__u16			vport;	  /* port number for the service */
	__u32                   vfwmark;  /* firewall mark of the service */
};


/*
 *	The scheduler object
 */
struct ip_vs_scheduler {
	struct list_head        n_list;   /* d-linked list head */
	char			*name;    /* scheduler name */
	atomic_t                refcnt;   /* reference counter */
	struct module		*module;  /* THIS_MODULE/NULL */

	/* scheduler initializing service */
	int (*init_service)(struct ip_vs_service *svc);
	/* scheduling service finish */
	int (*done_service)(struct ip_vs_service *svc);
	/* scheduler updating service */
	int (*update_service)(struct ip_vs_service *svc);

	/* selecting a server from the given service */
	struct ip_vs_dest* (*schedule)(struct ip_vs_service *svc,
				       struct iphdr *iph);
};


/*
 *	The application module object
 */
struct ip_vs_app
{
	struct list_head        n_list;   /* d-linked list head */
	char                    *name;    /* name of application module */
	unsigned                type;     /* type = proto<<16 | port
					     (host byte order)*/
	struct module		*module;  /* THIS_MODULE/NULL */

	/* ip_vs_app initializer */
	int (*init_conn)(struct ip_vs_app *, struct ip_vs_conn *);
	/* ip_vs_app finish */
	int (*done_conn)(struct ip_vs_app *, struct ip_vs_conn *);
	/* output hook */
	int (*pkt_out)(struct ip_vs_app *,
		       struct ip_vs_conn *, struct sk_buff *);
	/* input hook */
	int (*pkt_in)(struct ip_vs_app *,
		      struct ip_vs_conn *, struct sk_buff *);
};


/*
 *      IPVS core functions
 *      (from ip_vs_core.c)
 */
extern const char *ip_vs_proto_name(unsigned proto);
extern unsigned int check_for_ip_vs_out(struct sk_buff **skb_p,
					int (*okfn)(struct sk_buff *));


/*
 *     ip_vs_conn handling functions
 *     (from ip_vs_conn.c)
 */

/*
 *     IPVS connection entry hash table
 */
#ifndef CONFIG_IP_VS_TAB_BITS
#define CONFIG_IP_VS_TAB_BITS   12
#endif
/* make sure that IP_VS_CONN_TAB_BITS is located in [8, 20] */
#if CONFIG_IP_VS_TAB_BITS < 8
#define IP_VS_CONN_TAB_BITS	8
#endif
#if CONFIG_IP_VS_TAB_BITS > 20
#define IP_VS_CONN_TAB_BITS	20
#endif
#if 8 <= CONFIG_IP_VS_TAB_BITS && CONFIG_IP_VS_TAB_BITS <= 20
#define IP_VS_CONN_TAB_BITS	CONFIG_IP_VS_TAB_BITS
#endif
#define IP_VS_CONN_TAB_SIZE     (1 << IP_VS_CONN_TAB_BITS)
#define IP_VS_CONN_TAB_MASK     (IP_VS_CONN_TAB_SIZE - 1)

#define VS_STATE_INPUT	        0
#define VS_STATE_OUTPUT	        4
#define VS_STATE_INPUT_ONLY	8

extern struct ip_vs_timeout_table vs_timeout_table;
extern struct ip_vs_timeout_table vs_timeout_table_dos;

extern struct ip_vs_conn *ip_vs_conn_in_get
(int protocol, __u32 s_addr, __u16 s_port, __u32 d_addr, __u16 d_port);
extern struct ip_vs_conn *ip_vs_conn_out_get
(int protocol, __u32 s_addr, __u16 s_port, __u32 d_addr, __u16 d_port);

/* put back the conn without restarting its timer */
static inline void __ip_vs_conn_put(struct ip_vs_conn *cp)
{
	atomic_dec(&cp->refcnt);
}
extern void ip_vs_conn_put(struct ip_vs_conn *cp);

extern struct ip_vs_conn *
ip_vs_conn_new(int proto, __u32 caddr, __u16 cport, __u32 vaddr, __u16 vport,
	       __u32 daddr, __u16 dport, unsigned flags,
	       struct ip_vs_dest *dest);
extern void ip_vs_conn_expire_now(struct ip_vs_conn *cp);

extern const char * ip_vs_state_name(int state);
extern int ip_vs_set_state(struct ip_vs_conn *cp, int state_off,
			   struct iphdr *iph, void *tp);
extern int ip_vs_conn_listen(struct ip_vs_conn *cp);
extern int ip_vs_check_template(struct ip_vs_conn *ct);
extern void ip_vs_secure_tcp_set(int on);
extern void ip_vs_random_dropentry(void);
extern int ip_vs_conn_init(void);
extern void ip_vs_conn_cleanup(void);

static inline void ip_vs_control_del(struct ip_vs_conn *cp)
{
	struct ip_vs_conn *ctl_cp = cp->control;
	if (!ctl_cp) {
		IP_VS_ERR("request control DEL for uncontrolled: "
			  "%d.%d.%d.%d:%d to %d.%d.%d.%d:%d\n",
			  NIPQUAD(cp->caddr),ntohs(cp->cport),
			  NIPQUAD(cp->vaddr),ntohs(cp->vport));
		return;
	}

	IP_VS_DBG(7, "DELeting control for: "
		  "cp.dst=%d.%d.%d.%d:%d ctl_cp.dst=%d.%d.%d.%d:%d\n",
		  NIPQUAD(cp->caddr),ntohs(cp->cport),
		  NIPQUAD(ctl_cp->caddr),ntohs(ctl_cp->cport));

	cp->control = NULL;
	if (atomic_read(&ctl_cp->n_control) == 0) {
		IP_VS_ERR("BUG control DEL with n=0 : "
			  "%d.%d.%d.%d:%d to %d.%d.%d.%d:%d\n",
			  NIPQUAD(cp->caddr),ntohs(cp->cport),
			  NIPQUAD(cp->vaddr),ntohs(cp->vport));
		return;
	}
	atomic_dec(&ctl_cp->n_control);
}

static inline void
ip_vs_control_add(struct ip_vs_conn *cp, struct ip_vs_conn *ctl_cp)
{
	if (cp->control) {
		IP_VS_ERR("request control ADD for already controlled: "
			  "%d.%d.%d.%d:%d to %d.%d.%d.%d:%d\n",
			  NIPQUAD(cp->caddr),ntohs(cp->cport),
			  NIPQUAD(cp->vaddr),ntohs(cp->vport));
		ip_vs_control_del(cp);
	}

	IP_VS_DBG(7, "ADDing control for: "
		  "cp.dst=%d.%d.%d.%d:%d ctl_cp.dst=%d.%d.%d.%d:%d\n",
		  NIPQUAD(cp->caddr),ntohs(cp->cport),
		  NIPQUAD(ctl_cp->caddr),ntohs(ctl_cp->cport));

	cp->control = ctl_cp;
	atomic_inc(&ctl_cp->n_control);
}


/*
 *      IPVS application functions
 *      (from ip_vs_app.c)
 */
#define IP_VS_APP_MAX_PORTS  8
extern int register_ip_vs_app(struct ip_vs_app *mapp,
			      unsigned short proto, __u16 port);
extern int unregister_ip_vs_app(struct ip_vs_app *mapp);
extern struct ip_vs_app * ip_vs_bind_app(struct ip_vs_conn *cp);
extern int ip_vs_unbind_app(struct ip_vs_conn *cp);
extern int ip_vs_app_pkt_out(struct ip_vs_conn *, struct sk_buff *skb);
extern int ip_vs_app_pkt_in(struct ip_vs_conn *, struct sk_buff *skb);
extern int ip_vs_skb_replace(struct sk_buff *skb, int pri,
			     char *o_buf, int o_len, char *n_buf, int n_len);
extern int ip_vs_app_init(void);
extern void ip_vs_app_cleanup(void);


/*
 *      Registering/unregistering scheduler functions
 *      (from ip_vs_sched.c)
 */
extern int register_ip_vs_scheduler(struct ip_vs_scheduler *scheduler);
extern int unregister_ip_vs_scheduler(struct ip_vs_scheduler *scheduler);
extern int ip_vs_bind_scheduler(struct ip_vs_service *svc,
				struct ip_vs_scheduler *scheduler);
extern int ip_vs_unbind_scheduler(struct ip_vs_service *svc);
extern struct ip_vs_scheduler *ip_vs_scheduler_get(const char *sched_name);
extern void ip_vs_scheduler_put(struct ip_vs_scheduler *scheduler);


/*
 *      IPVS control data and functions
 *      (from ip_vs_ctl.c)
 */
extern int sysctl_ip_vs_cache_bypass;
extern int sysctl_ip_vs_expire_nodest_conn;
extern int sysctl_ip_vs_sync_threshold;
extern int sysctl_ip_vs_nat_icmp_send;
extern struct ip_vs_stats ip_vs_stats;

extern struct ip_vs_service *ip_vs_service_get(__u32 fwmark,
					       __u16 protocol,
					       __u32 vaddr, __u16 vport);
static inline void ip_vs_service_put(struct ip_vs_service *svc)
{
	atomic_dec(&svc->usecnt);
}

extern struct ip_vs_dest *
ip_vs_lookup_real_service(__u16 protocol, __u32 daddr, __u16 dport);
extern void ip_vs_random_dropentry(void);
extern int ip_vs_control_init(void);
extern void ip_vs_control_cleanup(void);


/*
 *      IPVS sync daemon data and function prototypes
 *      (from ip_vs_sync.c)
 */
extern volatile int ip_vs_sync_state;
extern char ip_vs_mcast_ifn[IP_VS_IFNAME_MAXLEN];
extern int start_sync_thread(int state, char *mcast_ifn);
extern int stop_sync_thread(void);
extern void ip_vs_sync_conn(struct ip_vs_conn *cp);


/*
 *      IPVS rate estimator prototypes (from ip_vs_est.c)
 */
extern int ip_vs_new_estimator(struct ip_vs_stats *stats);
extern void ip_vs_kill_estimator(struct ip_vs_stats *stats);
extern void ip_vs_zero_estimator(struct ip_vs_stats *stats);


/*
 *	This is a simple mechanism to ignore packets when
 *	we are loaded. Just set ip_vs_drop_rate to 'n' and
 *	we start to drop 1/rate of the packets
 */
extern int ip_vs_drop_rate;
extern int ip_vs_drop_counter;

static __inline__ int ip_vs_todrop(void)
{
	if (!ip_vs_drop_rate) return 0;
	if (--ip_vs_drop_counter > 0) return 0;
	ip_vs_drop_counter = ip_vs_drop_rate;
	return 1;
}


/*
 *      ip_vs_fwd_tag returns the forwarding tag of the connection
 */
#define IP_VS_FWD_METHOD(cp)  (cp->flags & IP_VS_CONN_F_FWD_MASK)

extern __inline__ char ip_vs_fwd_tag(struct ip_vs_conn *cp)
{
	char fwd;

	switch (IP_VS_FWD_METHOD(cp)) {
	case IP_VS_CONN_F_MASQ:
		fwd = 'M'; break;
	case IP_VS_CONN_F_LOCALNODE:
		fwd = 'L'; break;
	case IP_VS_CONN_F_TUNNEL:
		fwd = 'T'; break;
	case IP_VS_CONN_F_DROUTE:
		fwd = 'R'; break;
	case IP_VS_CONN_F_BYPASS:
		fwd = 'B'; break;
	default:
		fwd = '?'; break;
	}
	return fwd;
}


/*
 *	transport layer header checking
 */
extern inline int ip_vs_header_check(struct sk_buff *skb, int proto, int ihl)
{
	int len;

	switch (proto) {
	case IPPROTO_TCP:
		len = ihl + sizeof(struct tcphdr);
		/* we don't care about TCP options */
		break;
	case IPPROTO_UDP:
		len = ihl + sizeof(struct udphdr);
		break;
	default:
		len = 0;
	}

	/* guarantee protocol header available in skb data area */
	if (!pskb_may_pull(skb, len))
		return -1;
	else
		return 0;
}


/*
 *      Destination cache
 */
static inline void
__ip_vs_dst_set(struct ip_vs_dest *dest, u32 rtos, struct dst_entry *dst)
{
	struct dst_entry *old_dst;

	old_dst = dest->dst_cache;
	dest->dst_cache = dst;
	dest->dst_rtos = rtos;
	dst_release(old_dst);
}

static inline void
__ip_vs_dst_reset(struct ip_vs_dest *dest)
{
	struct dst_entry *old_dst;

	old_dst = dest->dst_cache;
	dest->dst_cache = NULL;
	dst_release(old_dst);
}

static inline struct dst_entry *
__ip_vs_dst_check(struct ip_vs_dest *dest, u32 rtos, u32 cookie)
{
	struct dst_entry *dst = dest->dst_cache;

	if (!dst)
		return NULL;
	if ((dst->obsolete || rtos != dest->dst_rtos) &&
	    dst->ops->check(dst, cookie) == NULL) {
		dest->dst_cache = 0;
		return NULL;
	}
	dst_hold(dst);
	return dst;
}

static inline struct rtable *
__ip_vs_get_out_rt(struct ip_vs_conn *cp, u32 rtos)
{
	struct rtable *rt;			/* Route to the other host */
	struct ip_vs_dest *dest = cp->dest;

	if (dest) {
		spin_lock(&dest->dst_lock);
		if (!(rt = (struct rtable *)
		      __ip_vs_dst_check(dest, rtos, 0))) {
			if (ip_route_output(&rt, dest->addr, 0, rtos, 0)) {
				spin_unlock(&dest->dst_lock);
				IP_VS_DBG_RL("ip_route_output error, "
					     "dest: %u.%u.%u.%u\n",
					     NIPQUAD(dest->addr));
				return NULL;
			}
			__ip_vs_dst_set(dest, rtos, dst_clone(&rt->u.dst));
			IP_VS_DBG(10, "new dst %u.%u.%u.%u, refcnt=%d, rtos=%X\n",
				  NIPQUAD(dest->addr),
				  atomic_read(&rt->u.dst.__refcnt), rtos);
		}
		spin_unlock(&dest->dst_lock);
	} else {
		if (ip_route_output(&rt, cp->daddr, 0, rtos, 0)) {
			IP_VS_DBG_RL("ip_route_output error, dest: "
				     "%u.%u.%u.%u\n", NIPQUAD(cp->daddr));
			return NULL;
		}
	}

	return rt;
}

static inline u16 ip_vs_check_diff(u32 old, u32 new, u16 oldsum)
{
	u32 diff[2] = { old, new };

	return csum_fold(csum_partial((char *) diff, sizeof(diff),
				      oldsum ^ 0xFFFF));
}

static inline void ip_vs_fast_check_update(union ip_vs_tphdr *h,
	u32 oldip, u32 newip, u16 oldport, u16 newport, u8 protocol)
{
	u16 *checkp;

	if (protocol == IPPROTO_TCP)
		checkp = &h->th->check;
	else
		checkp = &h->uh->check;
	*checkp = ip_vs_check_diff(~oldip, newip,
				   ip_vs_check_diff(oldport ^ 0xFFFF,
						    newport, *checkp));
	if (!*checkp && protocol == IPPROTO_UDP)
		*checkp = 0xFFFF;
}

static inline int
ip_vs_skb_cow(struct sk_buff *skb, unsigned int headroom,
	      struct iphdr **iph_p, unsigned char **t_p)
{
	int delta = (headroom > 16 ? headroom : 16) - skb_headroom(skb);

	if (delta < 0)
		delta = 0;

	if (delta || skb_cloned(skb)) {
		if (pskb_expand_head(skb, (delta+15)&~15, 0, GFP_ATOMIC))
			return -ENOMEM;

		/* skb data changed, update pointers */
		*iph_p = skb->nh.iph;
		*t_p = (char*) (*iph_p) + (*iph_p)->ihl * 4;
	}
	return 0;
}

#endif /* __KERNEL__ */

#endif	/* _IP_VS_H */
