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

#ifndef _NET_IP_VS_H
#define _NET_IP_VS_H

#include <linux/ip_vs.h>                /* definitions shared with userland */

/* old ipvsadm versions still include this file directly */
#ifdef __KERNEL__

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

#include <linux/sysctl.h>               /* for ctl_path */
#include <linux/list.h>                 /* for struct list_head */
#include <linux/spinlock.h>             /* for struct rwlock_t */
#include <asm/atomic.h>                 /* for struct atomic_t */
#include <linux/compiler.h>
#include <linux/timer.h>

#include <net/checksum.h>
#include <linux/netfilter.h>            /* for union nf_inet_addr */
#include <linux/ip.h>
#include <linux/ipv6.h>                 /* for struct ipv6hdr */
#include <net/ipv6.h>                   /* for ipv6_addr_copy */
#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
#include <net/netfilter/nf_conntrack.h>
#endif

/* Connections' size value needed by ip_vs_ctl.c */
extern int ip_vs_conn_tab_size;


struct ip_vs_iphdr {
        int len;
        __u8 protocol;
        union nf_inet_addr saddr;
        union nf_inet_addr daddr;
};

static inline void
ip_vs_fill_iphdr(int af, const void *nh, struct ip_vs_iphdr *iphdr)
{
#ifdef CONFIG_IP_VS_IPV6
        if (af == AF_INET6) {
                const struct ipv6hdr *iph = nh;
                iphdr->len = sizeof(struct ipv6hdr);
                iphdr->protocol = iph->nexthdr;
                ipv6_addr_copy(&iphdr->saddr.in6, &iph->saddr);
                ipv6_addr_copy(&iphdr->daddr.in6, &iph->daddr);
        } else
#endif
        {
                const struct iphdr *iph = nh;
                iphdr->len = iph->ihl * 4;
                iphdr->protocol = iph->protocol;
                iphdr->saddr.ip = iph->saddr;
                iphdr->daddr.ip = iph->daddr;
        }
}

static inline void ip_vs_addr_copy(int af, union nf_inet_addr *dst,
                                   const union nf_inet_addr *src)
{
#ifdef CONFIG_IP_VS_IPV6
        if (af == AF_INET6)
                ipv6_addr_copy(&dst->in6, &src->in6);
        else
#endif
        dst->ip = src->ip;
}

static inline int ip_vs_addr_equal(int af, const union nf_inet_addr *a,
                                   const union nf_inet_addr *b)
{
#ifdef CONFIG_IP_VS_IPV6
        if (af == AF_INET6)
                return ipv6_addr_equal(&a->in6, &b->in6);
#endif
        return a->ip == b->ip;
}

#ifdef CONFIG_IP_VS_DEBUG
#include <linux/net.h>

extern int ip_vs_get_debug_level(void);

static inline const char *ip_vs_dbg_addr(int af, char *buf, size_t buf_len,
                                         const union nf_inet_addr *addr,
                                         int *idx)
{
        int len;
#ifdef CONFIG_IP_VS_IPV6
        if (af == AF_INET6)
                len = snprintf(&buf[*idx], buf_len - *idx, "[%pI6]",
                               &addr->in6) + 1;
        else
#endif
                len = snprintf(&buf[*idx], buf_len - *idx, "%pI4",
                               &addr->ip) + 1;

        *idx += len;
        BUG_ON(*idx > buf_len + 1);
        return &buf[*idx - len];
}

#define IP_VS_DBG_BUF(level, msg, ...)                                  \
        do {                                                            \
                char ip_vs_dbg_buf[160];                                \
                int ip_vs_dbg_idx = 0;                                  \
                if (level <= ip_vs_get_debug_level())                   \
                        printk(KERN_DEBUG pr_fmt(msg), ##__VA_ARGS__);  \
        } while (0)
#define IP_VS_ERR_BUF(msg...)                                           \
        do {                                                            \
                char ip_vs_dbg_buf[160];                                \
                int ip_vs_dbg_idx = 0;                                  \
                pr_err(msg);                                            \
        } while (0)

/* Only use from within IP_VS_DBG_BUF() or IP_VS_ERR_BUF macros */
#define IP_VS_DBG_ADDR(af, addr)                                        \
        ip_vs_dbg_addr(af, ip_vs_dbg_buf,                               \
                       sizeof(ip_vs_dbg_buf), addr,                     \
                       &ip_vs_dbg_idx)

#define IP_VS_DBG(level, msg, ...)                                      \
        do {                                                            \
                if (level <= ip_vs_get_debug_level())                   \
                        printk(KERN_DEBUG pr_fmt(msg), ##__VA_ARGS__);  \
        } while (0)
#define IP_VS_DBG_RL(msg, ...)                                          \
        do {                                                            \
                if (net_ratelimit())                                    \
                        printk(KERN_DEBUG pr_fmt(msg), ##__VA_ARGS__);  \
        } while (0)
#define IP_VS_DBG_PKT(level, af, pp, skb, ofs, msg)                     \
        do {                                                            \
                if (level <= ip_vs_get_debug_level())                   \
                        pp->debug_packet(af, pp, skb, ofs, msg);        \
        } while (0)
#define IP_VS_DBG_RL_PKT(level, af, pp, skb, ofs, msg)                  \
        do {                                                            \
                if (level <= ip_vs_get_debug_level() &&                 \
                    net_ratelimit())                                    \
                        pp->debug_packet(af, pp, skb, ofs, msg);        \
        } while (0)
#else   /* NO DEBUGGING at ALL */
#define IP_VS_DBG_BUF(level, msg...)  do {} while (0)
#define IP_VS_ERR_BUF(msg...)  do {} while (0)
#define IP_VS_DBG(level, msg...)  do {} while (0)
#define IP_VS_DBG_RL(msg...)  do {} while (0)
#define IP_VS_DBG_PKT(level, af, pp, skb, ofs, msg)     do {} while (0)
#define IP_VS_DBG_RL_PKT(level, af, pp, skb, ofs, msg)  do {} while (0)
#endif

#define IP_VS_BUG() BUG()
#define IP_VS_ERR_RL(msg, ...)                                          \
        do {                                                            \
                if (net_ratelimit())                                    \
                        pr_err(msg, ##__VA_ARGS__);                     \
        } while (0)

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

#define IP_VS_WAIT_WHILE(expr)  while (expr) { cpu_relax(); }


/*
 *      The port number of FTP service (in network order).
 */
#define FTPPORT  cpu_to_be16(21)
#define FTPDATA  cpu_to_be16(20)

/*
 *      TCP State Values
 */
enum {
        IP_VS_TCP_S_NONE = 0,
        IP_VS_TCP_S_ESTABLISHED,
        IP_VS_TCP_S_SYN_SENT,
        IP_VS_TCP_S_SYN_RECV,
        IP_VS_TCP_S_FIN_WAIT,
        IP_VS_TCP_S_TIME_WAIT,
        IP_VS_TCP_S_CLOSE,
        IP_VS_TCP_S_CLOSE_WAIT,
        IP_VS_TCP_S_LAST_ACK,
        IP_VS_TCP_S_LISTEN,
        IP_VS_TCP_S_SYNACK,
        IP_VS_TCP_S_LAST
};

/*
 *      UDP State Values
 */
enum {
        IP_VS_UDP_S_NORMAL,
        IP_VS_UDP_S_LAST,
};

/*
 *      ICMP State Values
 */
enum {
        IP_VS_ICMP_S_NORMAL,
        IP_VS_ICMP_S_LAST,
};

/*
 *      SCTP State Values
 */
enum ip_vs_sctp_states {
        IP_VS_SCTP_S_NONE,
        IP_VS_SCTP_S_INIT_CLI,
        IP_VS_SCTP_S_INIT_SER,
        IP_VS_SCTP_S_INIT_ACK_CLI,
        IP_VS_SCTP_S_INIT_ACK_SER,
        IP_VS_SCTP_S_ECHO_CLI,
        IP_VS_SCTP_S_ECHO_SER,
        IP_VS_SCTP_S_ESTABLISHED,
        IP_VS_SCTP_S_SHUT_CLI,
        IP_VS_SCTP_S_SHUT_SER,
        IP_VS_SCTP_S_SHUT_ACK_CLI,
        IP_VS_SCTP_S_SHUT_ACK_SER,
        IP_VS_SCTP_S_CLOSED,
        IP_VS_SCTP_S_LAST
};

/*
 *      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 objects
 */
struct ip_vs_estimator {
        struct list_head        list;

        u64                     last_inbytes;
        u64                     last_outbytes;
        u32                     last_conns;
        u32                     last_inpkts;
        u32                     last_outpkts;

        u32                     cps;
        u32                     inpps;
        u32                     outpps;
        u32                     inbps;
        u32                     outbps;
};

struct ip_vs_stats {
        struct ip_vs_stats_user ustats;         /* statistics */
        struct ip_vs_estimator  est;            /* estimator */

        spinlock_t              lock;           /* spin lock */
};

struct dst_entry;
struct iphdr;
struct ip_vs_conn;
struct ip_vs_app;
struct sk_buff;

struct ip_vs_protocol {
        struct ip_vs_protocol   *next;
        char                    *name;
        u16                     protocol;
        u16                     num_states;
        int                     dont_defrag;
        atomic_t                appcnt;         /* counter of proto app incs */
        int                     *timeout_table; /* protocol timeout table */

        void (*init)(struct ip_vs_protocol *pp);

        void (*exit)(struct ip_vs_protocol *pp);

        int (*conn_schedule)(int af, struct sk_buff *skb,
                             struct ip_vs_protocol *pp,
                             int *verdict, struct ip_vs_conn **cpp);

        struct ip_vs_conn *
        (*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 *
        (*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);

        int (*snat_handler)(struct sk_buff *skb,
                            struct ip_vs_protocol *pp, struct ip_vs_conn *cp);

        int (*dnat_handler)(struct sk_buff *skb,
                            struct ip_vs_protocol *pp, struct ip_vs_conn *cp);

        int (*csum_check)(int af, struct sk_buff *skb,
                          struct ip_vs_protocol *pp);

        const char *(*state_name)(int state);

        int (*state_transition)(struct ip_vs_conn *cp, int direction,
                                const struct sk_buff *skb,
                                struct ip_vs_protocol *pp);

        int (*register_app)(struct ip_vs_app *inc);

        void (*unregister_app)(struct ip_vs_app *inc);

        int (*app_conn_bind)(struct ip_vs_conn *cp);

        void (*debug_packet)(int af, struct ip_vs_protocol *pp,
                             const struct sk_buff *skb,
                             int offset,
                             const char *msg);

        void (*timeout_change)(struct ip_vs_protocol *pp, int flags);

        int (*set_state_timeout)(struct ip_vs_protocol *pp, char *sname, int to);
};

extern struct ip_vs_protocol * ip_vs_proto_get(unsigned short proto);

struct ip_vs_conn_param {
        const union nf_inet_addr        *caddr;
        const union nf_inet_addr        *vaddr;
        __be16                          cport;
        __be16                          vport;
        __u16                           protocol;
        u16                             af;

        const struct ip_vs_pe           *pe;
        char                            *pe_data;
        __u8                            pe_data_len;
};

/*
 *      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 */
        u16                      af;            /* address family */
        union nf_inet_addr       caddr;          /* client address */
        union nf_inet_addr       vaddr;          /* virtual address */
        union nf_inet_addr       daddr;          /* destination address */
        volatile __u32           flags;          /* status flags */
        __be16                   cport;
        __be16                   vport;
        __be16                   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 */

        /* Flags and state transition */
        spinlock_t              lock;           /* lock for state transition */
        volatile __u16          state;          /* state info */
        volatile __u16          old_state;      /* old state, to be used for
                                                 * state transition triggerd
                                                 * synchronization
                                                 */

        /* 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.  If it
           mangles the packet, it must return NF_DROP or better NF_STOLEN,
           otherwise this must be changed to a sk_buff **.
           NF_ACCEPT can be returned when destination is local.
         */
        int (*packet_xmit)(struct sk_buff *skb, struct ip_vs_conn *cp,
                           struct ip_vs_protocol *pp);

        /* 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 */

        char                    *pe_data;
        __u8                    pe_data_len;
};


/*
 *      Extended internal versions of struct ip_vs_service_user and
 *      ip_vs_dest_user for IPv6 support.
 *
 *      We need these to conveniently pass around service and destination
 *      options, but unfortunately, we also need to keep the old definitions to
 *      maintain userspace backwards compatibility for the setsockopt interface.
 */
struct ip_vs_service_user_kern {
        /* virtual service addresses */
        u16                     af;
        u16                     protocol;
        union nf_inet_addr      addr;           /* virtual ip address */
        u16                     port;
        u32                     fwmark;         /* firwall mark of service */

        /* virtual service options */
        char                    *sched_name;
        char                    *pe_name;
        unsigned                flags;          /* virtual service flags */
        unsigned                timeout;        /* persistent timeout in sec */
        u32                     netmask;        /* persistent netmask */
};


struct ip_vs_dest_user_kern {
        /* destination server address */
        union nf_inet_addr      addr;
        u16                     port;

        /* real server options */
        unsigned                conn_flags;     /* connection flags */
        int                     weight;         /* destination weight */

        /* thresholds for active connections */
        u32                     u_threshold;    /* upper threshold */
        u32                     l_threshold;    /* lower threshold */
};


/*
 *      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                     af;       /* address family */
        __u16                   protocol; /* which protocol (TCP/UDP) */
        union nf_inet_addr      addr;     /* IP address for virtual service */
        __be16                  port;     /* port number for the service */
        __u32                   fwmark;   /* firewall mark of the service */
        unsigned                flags;    /* service status flags */
        unsigned                timeout;  /* persistent timeout in ticks */
        __be32                  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 */
        struct ip_vs_app        *inc;     /* bind conns to this app inc */

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

        /* alternate persistence engine */
        struct ip_vs_pe         *pe;
};


/*
 *      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 */

        u16                     af;             /* address family */
        union nf_inet_addr      addr;           /* IP address of the server */
        __be16                  port;           /* port number of the server */
        volatile unsigned       flags;          /* dest status flags */
        atomic_t                conn_flags;     /* flags to copy to conn */
        atomic_t                weight;         /* server weight */

        atomic_t                refcnt;         /* reference counter */
        struct ip_vs_stats      stats;          /* statistics */

        /* connection counters and thresholds */
        atomic_t                activeconns;    /* active connections */
        atomic_t                inactconns;     /* inactive connections */
        atomic_t                persistconns;   /* persistent connections */
        __u32                   u_threshold;    /* upper threshold */
        __u32                   l_threshold;    /* lower threshold */

        /* for destination cache */
        spinlock_t              dst_lock;       /* lock of dst_cache */
        struct dst_entry        *dst_cache;     /* destination cache entry */
        u32                     dst_rtos;       /* RT_TOS(tos) for dst */
        u32                     dst_cookie;
#ifdef CONFIG_IP_VS_IPV6
        struct in6_addr         dst_saddr;
#endif

        /* for virtual service */
        struct ip_vs_service    *svc;           /* service it belongs to */
        __u16                   protocol;       /* which protocol (TCP/UDP) */
        union nf_inet_addr      vaddr;          /* virtual IP address */
        __be16                  vport;          /* virtual port number */
        __u32                   vfwmark;        /* firewall mark of 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,
                                       const struct sk_buff *skb);
};

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

        /* get the connection template, if any */
        int (*fill_param)(struct ip_vs_conn_param *p, struct sk_buff *skb);
        bool (*ct_match)(const struct ip_vs_conn_param *p,
                         struct ip_vs_conn *ct);
        u32 (*hashkey_raw)(const struct ip_vs_conn_param *p, u32 initval,
                           bool inverse);
        int (*show_pe_data)(const struct ip_vs_conn *cp, char *buf);
};

/*
 *      The application module object (a.k.a. app incarnation)
 */
struct ip_vs_app {
        struct list_head        a_list;         /* member in app list */
        int                     type;           /* IP_VS_APP_TYPE_xxx */
        char                    *name;          /* application module name */
        __u16                   protocol;
        struct module           *module;        /* THIS_MODULE/NULL */
        struct list_head        incs_list;      /* list of incarnations */

        /* members for application incarnations */
        struct list_head        p_list;         /* member in proto app list */
        struct ip_vs_app        *app;           /* its real application */
        __be16                  port;           /* port number in net order */
        atomic_t                usecnt;         /* usage counter */

        /*
         * output hook: Process packet in inout direction, diff set for TCP.
         * Return: 0=Error, 1=Payload Not Mangled/Mangled but checksum is ok,
         *         2=Mangled but checksum was not updated
         */
        int (*pkt_out)(struct ip_vs_app *, struct ip_vs_conn *,
                       struct sk_buff *, int *diff);

        /*
         * input hook: Process packet in outin direction, diff set for TCP.
         * Return: 0=Error, 1=Payload Not Mangled/Mangled but checksum is ok,
         *         2=Mangled but checksum was not updated
         */
        int (*pkt_in)(struct ip_vs_app *, struct ip_vs_conn *,
                      struct sk_buff *, int *diff);

        /* 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 *);


        /* not used now */
        int (*bind_conn)(struct ip_vs_app *, struct ip_vs_conn *,
                         struct ip_vs_protocol *);

        void (*unbind_conn)(struct ip_vs_app *, struct ip_vs_conn *);

        int *                   timeout_table;
        int *                   timeouts;
        int                     timeouts_size;

        int (*conn_schedule)(struct sk_buff *skb, struct ip_vs_app *app,
                             int *verdict, struct ip_vs_conn **cpp);

        struct ip_vs_conn *
        (*conn_in_get)(const struct sk_buff *skb, struct ip_vs_app *app,
                       const struct iphdr *iph, unsigned int proto_off,
                       int inverse);

        struct ip_vs_conn *
        (*conn_out_get)(const struct sk_buff *skb, struct ip_vs_app *app,
                        const struct iphdr *iph, unsigned int proto_off,
                        int inverse);

        int (*state_transition)(struct ip_vs_conn *cp, int direction,
                                const struct sk_buff *skb,
                                struct ip_vs_app *app);

        void (*timeout_change)(struct ip_vs_app *app, int flags);
};


/*
 *      IPVS core functions
 *      (from ip_vs_core.c)
 */
extern const char *ip_vs_proto_name(unsigned proto);
extern void ip_vs_init_hash_table(struct list_head *table, int rows);
#define IP_VS_INIT_HASH_TABLE(t) ip_vs_init_hash_table((t), ARRAY_SIZE((t)))

#define IP_VS_APP_TYPE_FTP      1

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

enum {
        IP_VS_DIR_INPUT = 0,
        IP_VS_DIR_OUTPUT,
        IP_VS_DIR_INPUT_ONLY,
        IP_VS_DIR_LAST,
};

static inline void ip_vs_conn_fill_param(int af, int protocol,
                                         const union nf_inet_addr *caddr,
                                         __be16 cport,
                                         const union nf_inet_addr *vaddr,
                                         __be16 vport,
                                         struct ip_vs_conn_param *p)
{
        p->af = af;
        p->protocol = protocol;
        p->caddr = caddr;
        p->cport = cport;
        p->vaddr = vaddr;
        p->vport = vport;
        p->pe = NULL;
        p->pe_data = NULL;
}

struct ip_vs_conn *ip_vs_conn_in_get(const struct ip_vs_conn_param *p);
struct ip_vs_conn *ip_vs_ct_in_get(const struct ip_vs_conn_param *p);

struct ip_vs_conn * ip_vs_conn_in_get_proto(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 *ip_vs_conn_out_get(const struct ip_vs_conn_param *p);

struct ip_vs_conn * ip_vs_conn_out_get_proto(int af, const struct sk_buff *skb,
                                             struct ip_vs_protocol *pp,
                                             const struct ip_vs_iphdr *iph,
                                             unsigned int proto_off,
                                             int inverse);

/* 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 void ip_vs_conn_fill_cport(struct ip_vs_conn *cp, __be16 cport);

struct ip_vs_conn *ip_vs_conn_new(const struct ip_vs_conn_param *p,
                                  const union nf_inet_addr *daddr,
                                  __be16 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(__u16 proto, int state);

extern void ip_vs_tcp_conn_listen(struct ip_vs_conn *cp);
extern int ip_vs_check_template(struct ip_vs_conn *ct);
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_BUF("request control DEL for uncontrolled: "
                              "%s:%d to %s:%d\n",
                              IP_VS_DBG_ADDR(cp->af, &cp->caddr),
                              ntohs(cp->cport),
                              IP_VS_DBG_ADDR(cp->af, &cp->vaddr),
                              ntohs(cp->vport));

                return;
        }

        IP_VS_DBG_BUF(7, "DELeting control for: "
                      "cp.dst=%s:%d ctl_cp.dst=%s:%d\n",
                      IP_VS_DBG_ADDR(cp->af, &cp->caddr),
                      ntohs(cp->cport),
                      IP_VS_DBG_ADDR(cp->af, &ctl_cp->caddr),
                      ntohs(ctl_cp->cport));

        cp->control = NULL;
        if (atomic_read(&ctl_cp->n_control) == 0) {
                IP_VS_ERR_BUF("BUG control DEL with n=0 : "
                              "%s:%d to %s:%d\n",
                              IP_VS_DBG_ADDR(cp->af, &cp->caddr),
                              ntohs(cp->cport),
                              IP_VS_DBG_ADDR(cp->af, &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_BUF("request control ADD for already controlled: "
                              "%s:%d to %s:%d\n",
                              IP_VS_DBG_ADDR(cp->af, &cp->caddr),
                              ntohs(cp->cport),
                              IP_VS_DBG_ADDR(cp->af, &cp->vaddr),
                              ntohs(cp->vport));

                ip_vs_control_del(cp);
        }

        IP_VS_DBG_BUF(7, "ADDing control for: "
                      "cp.dst=%s:%d ctl_cp.dst=%s:%d\n",
                      IP_VS_DBG_ADDR(cp->af, &cp->caddr),
                      ntohs(cp->cport),
                      IP_VS_DBG_ADDR(cp->af, &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 *app);
extern void unregister_ip_vs_app(struct ip_vs_app *app);
extern int ip_vs_bind_app(struct ip_vs_conn *cp, struct ip_vs_protocol *pp);
extern void ip_vs_unbind_app(struct ip_vs_conn *cp);
extern int
register_ip_vs_app_inc(struct ip_vs_app *app, __u16 proto, __u16 port);
extern int ip_vs_app_inc_get(struct ip_vs_app *inc);
extern void ip_vs_app_inc_put(struct ip_vs_app *inc);

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_app_init(void);
extern void ip_vs_app_cleanup(void);

void ip_vs_bind_pe(struct ip_vs_service *svc, struct ip_vs_pe *pe);
void ip_vs_unbind_pe(struct ip_vs_service *svc);
int register_ip_vs_pe(struct ip_vs_pe *pe);
int unregister_ip_vs_pe(struct ip_vs_pe *pe);
extern struct ip_vs_pe *ip_vs_pe_get(const char *name);
extern void ip_vs_pe_put(struct ip_vs_pe *pe);

/*
 *      IPVS protocol functions (from ip_vs_proto.c)
 */
extern int ip_vs_protocol_init(void);
extern void ip_vs_protocol_cleanup(void);
extern void ip_vs_protocol_timeout_change(int flags);
extern int *ip_vs_create_timeout_table(int *table, int size);
extern int
ip_vs_set_state_timeout(int *table, int num, const char *const *names,
                        const char *name, int to);
extern void
ip_vs_tcpudp_debug_packet(int af, struct ip_vs_protocol *pp,
                          const struct sk_buff *skb,
                          int offset, const char *msg);

extern struct ip_vs_protocol ip_vs_protocol_tcp;
extern struct ip_vs_protocol ip_vs_protocol_udp;
extern struct ip_vs_protocol ip_vs_protocol_icmp;
extern struct ip_vs_protocol ip_vs_protocol_esp;
extern struct ip_vs_protocol ip_vs_protocol_ah;
extern struct ip_vs_protocol ip_vs_protocol_sctp;

/*
 *      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);
extern struct ip_vs_conn *
ip_vs_schedule(struct ip_vs_service *svc, struct sk_buff *skb,
               struct ip_vs_protocol *pp, int *ignored);
extern int ip_vs_leave(struct ip_vs_service *svc, struct sk_buff *skb,
                        struct ip_vs_protocol *pp);


/*
 *      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_expire_quiescent_template;
extern int sysctl_ip_vs_sync_threshold[2];
extern int sysctl_ip_vs_nat_icmp_send;
extern int sysctl_ip_vs_conntrack;
extern int sysctl_ip_vs_snat_reroute;
extern struct ip_vs_stats ip_vs_stats;
extern const struct ctl_path net_vs_ctl_path[];

extern struct ip_vs_service *
ip_vs_service_get(int af, __u32 fwmark, __u16 protocol,
                  const union nf_inet_addr *vaddr, __be16 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(int af, __u16 protocol,
                          const union nf_inet_addr *daddr, __be16 dport);

extern int ip_vs_use_count_inc(void);
extern void ip_vs_use_count_dec(void);
extern int ip_vs_control_init(void);
extern void ip_vs_control_cleanup(void);
extern struct ip_vs_dest *
ip_vs_find_dest(int af, const union nf_inet_addr *daddr, __be16 dport,
                const union nf_inet_addr *vaddr, __be16 vport, __u16 protocol);
extern struct ip_vs_dest *ip_vs_try_bind_dest(struct ip_vs_conn *cp);


/*
 *      IPVS sync daemon data and function prototypes
 *      (from ip_vs_sync.c)
 */
extern volatile int ip_vs_sync_state;
extern volatile int ip_vs_master_syncid;
extern volatile int ip_vs_backup_syncid;
extern char ip_vs_master_mcast_ifn[IP_VS_IFNAME_MAXLEN];
extern char ip_vs_backup_mcast_ifn[IP_VS_IFNAME_MAXLEN];
extern int start_sync_thread(int state, char *mcast_ifn, __u8 syncid);
extern int stop_sync_thread(int state);
extern void ip_vs_sync_conn(struct ip_vs_conn *cp);


/*
 *      IPVS rate estimator prototypes (from ip_vs_est.c)
 */
extern int ip_vs_estimator_init(void);
extern void ip_vs_estimator_cleanup(void);
extern void 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);

/*
 *      Various IPVS packet transmitters (from ip_vs_xmit.c)
 */
extern int ip_vs_null_xmit
(struct sk_buff *skb, struct ip_vs_conn *cp, struct ip_vs_protocol *pp);
extern int ip_vs_bypass_xmit
(struct sk_buff *skb, struct ip_vs_conn *cp, struct ip_vs_protocol *pp);
extern int ip_vs_nat_xmit
(struct sk_buff *skb, struct ip_vs_conn *cp, struct ip_vs_protocol *pp);
extern int ip_vs_tunnel_xmit
(struct sk_buff *skb, struct ip_vs_conn *cp, struct ip_vs_protocol *pp);
extern int ip_vs_dr_xmit
(struct sk_buff *skb, struct ip_vs_conn *cp, struct ip_vs_protocol *pp);
extern int ip_vs_icmp_xmit
(struct sk_buff *skb, struct ip_vs_conn *cp, struct ip_vs_protocol *pp, int offset);
extern void ip_vs_dst_reset(struct ip_vs_dest *dest);

#ifdef CONFIG_IP_VS_IPV6
extern int ip_vs_bypass_xmit_v6
(struct sk_buff *skb, struct ip_vs_conn *cp, struct ip_vs_protocol *pp);
extern int ip_vs_nat_xmit_v6
(struct sk_buff *skb, struct ip_vs_conn *cp, struct ip_vs_protocol *pp);
extern int ip_vs_tunnel_xmit_v6
(struct sk_buff *skb, struct ip_vs_conn *cp, struct ip_vs_protocol *pp);
extern int ip_vs_dr_xmit_v6
(struct sk_buff *skb, struct ip_vs_conn *cp, struct ip_vs_protocol *pp);
extern int ip_vs_icmp_xmit_v6
(struct sk_buff *skb, struct ip_vs_conn *cp, struct ip_vs_protocol *pp,
 int offset);
#endif

/*
 *      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)

static 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;
}

extern void ip_vs_nat_icmp(struct sk_buff *skb, struct ip_vs_protocol *pp,
                           struct ip_vs_conn *cp, int dir);

#ifdef CONFIG_IP_VS_IPV6
extern void ip_vs_nat_icmp_v6(struct sk_buff *skb, struct ip_vs_protocol *pp,
                              struct ip_vs_conn *cp, int dir);
#endif

extern __sum16 ip_vs_checksum_complete(struct sk_buff *skb, int offset);

static inline __wsum ip_vs_check_diff4(__be32 old, __be32 new, __wsum oldsum)
{
        __be32 diff[2] = { ~old, new };

        return csum_partial(diff, sizeof(diff), oldsum);
}

#ifdef CONFIG_IP_VS_IPV6
static inline __wsum ip_vs_check_diff16(const __be32 *old, const __be32 *new,
                                        __wsum oldsum)
{
        __be32 diff[8] = { ~old[3], ~old[2], ~old[1], ~old[0],
                            new[3],  new[2],  new[1],  new[0] };

        return csum_partial(diff, sizeof(diff), oldsum);
}
#endif

static inline __wsum ip_vs_check_diff2(__be16 old, __be16 new, __wsum oldsum)
{
        __be16 diff[2] = { ~old, new };

        return csum_partial(diff, sizeof(diff), oldsum);
}

/*
 * Forget current conntrack (unconfirmed) and attach notrack entry
 */
static inline void ip_vs_notrack(struct sk_buff *skb)
{
#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
        enum ip_conntrack_info ctinfo;
        struct nf_conn *ct = ct = nf_ct_get(skb, &ctinfo);

        if (!ct || !nf_ct_is_untracked(ct)) {
                nf_reset(skb);
                skb->nfct = &nf_ct_untracked_get()->ct_general;
                skb->nfctinfo = IP_CT_NEW;
                nf_conntrack_get(skb->nfct);
        }
#endif
}

#ifdef CONFIG_IP_VS_NFCT
/*
 *      Netfilter connection tracking
 *      (from ip_vs_nfct.c)
 */
static inline int ip_vs_conntrack_enabled(void)
{
        return sysctl_ip_vs_conntrack;
}

extern void ip_vs_update_conntrack(struct sk_buff *skb, struct ip_vs_conn *cp,
                                   int outin);
extern int ip_vs_confirm_conntrack(struct sk_buff *skb, struct ip_vs_conn *cp);
extern void ip_vs_nfct_expect_related(struct sk_buff *skb, struct nf_conn *ct,
                                      struct ip_vs_conn *cp, u_int8_t proto,
                                      const __be16 port, int from_rs);
extern void ip_vs_conn_drop_conntrack(struct ip_vs_conn *cp);

#else

static inline int ip_vs_conntrack_enabled(void)
{
        return 0;
}

static inline void ip_vs_update_conntrack(struct sk_buff *skb,
                                          struct ip_vs_conn *cp, int outin)
{
}

static inline int ip_vs_confirm_conntrack(struct sk_buff *skb,
                                          struct ip_vs_conn *cp)
{
        return NF_ACCEPT;
}

static inline void ip_vs_conn_drop_conntrack(struct ip_vs_conn *cp)
{
}
/* CONFIG_IP_VS_NFCT */
#endif

#endif /* __KERNEL__ */

#endif  /* _NET_IP_VS_H */