/*
 *      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 */

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

#include <linux/list.h>                 /* for struct list_head */
#include <linux/spinlock.h>             /* for struct rwlock_t */
#include <linux/atomic.h>                 /* for struct atomic_t */
#include <linux/compiler.h>
#include <linux/timer.h>
#include <linux/bug.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>
#if IS_ENABLED(CONFIG_IP_VS_IPV6)
#include <linux/netfilter_ipv6/ip6_tables.h>
#endif
#if IS_ENABLED(CONFIG_NF_CONNTRACK)
#include <net/netfilter/nf_conntrack.h>
#endif
#include <net/net_namespace.h>          /* Netw namespace */

/*
 * Generic access of ipvs struct
 */
static inline struct netns_ipvs *net_ipvs(struct net* net)
{
        return net->ipvs;
}
/*
 * Get net ptr from skb in traffic cases
 * use skb_sknet when call is from userland (ioctl or netlink)
 */
static inline struct net *skb_net(const struct sk_buff *skb)
{
#ifdef CONFIG_NET_NS
#ifdef CONFIG_IP_VS_DEBUG
        /*
         * This is used for debug only.
         * Start with the most likely hit
         * End with BUG
         */
        if (likely(skb->dev && skb->dev->nd_net))
                return dev_net(skb->dev);
        if (skb_dst(skb) && skb_dst(skb)->dev)
                return dev_net(skb_dst(skb)->dev);
        WARN(skb->sk, "Maybe skb_sknet should be used in %s() at line:%d\n",
                      __func__, __LINE__);
        if (likely(skb->sk && skb->sk->sk_net))
                return sock_net(skb->sk);
        pr_err("There is no net ptr to find in the skb in %s() line:%d\n",
                __func__, __LINE__);
        BUG();
#else
        return dev_net(skb->dev ? : skb_dst(skb)->dev);
#endif
#else
        return &init_net;
#endif
}

static inline struct net *skb_sknet(const struct sk_buff *skb)
{
#ifdef CONFIG_NET_NS
#ifdef CONFIG_IP_VS_DEBUG
        /* Start with the most likely hit */
        if (likely(skb->sk && skb->sk->sk_net))
                return sock_net(skb->sk);
        WARN(skb->dev, "Maybe skb_net should be used instead in %s() line:%d\n",
                       __func__, __LINE__);
        if (likely(skb->dev && skb->dev->nd_net))
                return dev_net(skb->dev);
        pr_err("There is no net ptr to find in the skb in %s() line:%d\n",
                __func__, __LINE__);
        BUG();
#else
        return sock_net(skb->sk);
#endif
#else
        return &init_net;
#endif
}
/*
 * This one needed for single_open_net since net is stored directly in
 * private not as a struct i.e. seq_file_net can't be used.
 */
static inline struct net *seq_file_single_net(struct seq_file *seq)
{
#ifdef CONFIG_NET_NS
        return (struct net *)seq->private;
#else
        return &init_net;
#endif
}

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

struct ip_vs_iphdr {
        __u32 len;      /* IPv4 simply where L4 starts
                           IPv6 where L4 Transport Header starts */
        __u32 thoff_reasm; /* Transport Header Offset in nfct_reasm skb */
        __u16 fragoffs; /* IPv6 fragment offset, 0 if first frag (or not frag)*/
        __s16 protocol;
        __s32 flags;
        union nf_inet_addr saddr;
        union nf_inet_addr daddr;
};

/* Dependency to module: nf_defrag_ipv6 */
#if defined(CONFIG_NF_DEFRAG_IPV6) || defined(CONFIG_NF_DEFRAG_IPV6_MODULE)
static inline struct sk_buff *skb_nfct_reasm(const struct sk_buff *skb)
{
        return skb->nfct_reasm;
}
static inline void *frag_safe_skb_hp(const struct sk_buff *skb, int offset,
                                      int len, void *buffer,
                                      const struct ip_vs_iphdr *ipvsh)
{
        if (unlikely(ipvsh->fragoffs && skb_nfct_reasm(skb)))
                return skb_header_pointer(skb_nfct_reasm(skb),
                                          ipvsh->thoff_reasm, len, buffer);

        return skb_header_pointer(skb, offset, len, buffer);
}
#else
static inline struct sk_buff *skb_nfct_reasm(const struct sk_buff *skb)
{
        return NULL;
}
static inline void *frag_safe_skb_hp(const struct sk_buff *skb, int offset,
                                      int len, void *buffer,
                                      const struct ip_vs_iphdr *ipvsh)
{
        return skb_header_pointer(skb, offset, len, buffer);
}
#endif

static inline void
ip_vs_fill_ip4hdr(const void *nh, struct ip_vs_iphdr *iphdr)
{
        const struct iphdr *iph = nh;

        iphdr->len      = iph->ihl * 4;
        iphdr->fragoffs = 0;
        iphdr->protocol = iph->protocol;
        iphdr->saddr.ip = iph->saddr;
        iphdr->daddr.ip = iph->daddr;
}

/* This function handles filling *ip_vs_iphdr, both for IPv4 and IPv6.
 * IPv6 requires some extra work, as finding proper header position,
 * depend on the IPv6 extension headers.
 */
static inline void
ip_vs_fill_iph_skb(int af, const struct sk_buff *skb, struct ip_vs_iphdr *iphdr)
{
#ifdef CONFIG_IP_VS_IPV6
        if (af == AF_INET6) {
                const struct ipv6hdr *iph =
                        (struct ipv6hdr *)skb_network_header(skb);
                iphdr->saddr.in6 = iph->saddr;
                iphdr->daddr.in6 = iph->daddr;
                /* ipv6_find_hdr() updates len, flags, thoff_reasm */
                iphdr->thoff_reasm = 0;
                iphdr->len       = 0;
                iphdr->flags     = 0;
                iphdr->protocol  = ipv6_find_hdr(skb, &iphdr->len, -1,
                                                 &iphdr->fragoffs,
                                                 &iphdr->flags);
                /* get proto from re-assembled packet and it's offset */
                if (skb_nfct_reasm(skb))
                        iphdr->protocol = ipv6_find_hdr(skb_nfct_reasm(skb),
                                                        &iphdr->thoff_reasm,
                                                        -1, NULL, NULL);

        } else
#endif
        {
                const struct iphdr *iph =
                        (struct iphdr *)skb_network_header(skb);
                iphdr->len      = iph->ihl * 4;
                iphdr->fragoffs = 0;
                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)
                dst->in6 = src->in6;
        else
#endif
        dst->ip = src->ip;
}

static inline void ip_vs_addr_set(int af, union nf_inet_addr *dst,
                                  const union nf_inet_addr *src)
{
#ifdef CONFIG_IP_VS_IPV6
        if (af == AF_INET6) {
                dst->in6 = src->in6;
                return;
        }
#endif
        dst->ip = src->ip;
        dst->all[1] = 0;
        dst->all[2] = 0;
        dst->all[3] = 0;
}

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, "[%pI6c]",
                               &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


/*
 *      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_INIT1,
        IP_VS_SCTP_S_INIT,
        IP_VS_SCTP_S_COOKIE_SENT,
        IP_VS_SCTP_S_COOKIE_REPLIED,
        IP_VS_SCTP_S_COOKIE_WAIT,
        IP_VS_SCTP_S_COOKIE,
        IP_VS_SCTP_S_COOKIE_ECHOED,
        IP_VS_SCTP_S_ESTABLISHED,
        IP_VS_SCTP_S_SHUTDOWN_SENT,
        IP_VS_SCTP_S_SHUTDOWN_RECEIVED,
        IP_VS_SCTP_S_SHUTDOWN_ACK_SENT,
        IP_VS_SCTP_S_REJECTED,
        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 */
};

/*
 * counters per cpu
 */
struct ip_vs_counters {
        __u32           conns;          /* connections scheduled */
        __u32           inpkts;         /* incoming packets */
        __u32           outpkts;        /* outgoing packets */
        __u64           inbytes;        /* incoming bytes */
        __u64           outbytes;       /* outgoing bytes */
};
/*
 * Stats per cpu
 */
struct ip_vs_cpu_stats {
        struct ip_vs_counters   ustats;
        struct u64_stats_sync   syncp;
};

/*
 *      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 */
        struct ip_vs_cpu_stats __percpu *cpustats;      /* per cpu counters */
        spinlock_t              lock;           /* spin lock */
        struct ip_vs_stats_user ustats0;        /* reset values */
};

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

struct ip_vs_protocol {
        struct ip_vs_protocol   *next;
        char                    *name;
        u16                     protocol;
        u16                     num_states;
        int                     dont_defrag;

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

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

        int (*init_netns)(struct net *net, struct ip_vs_proto_data *pd);

        void (*exit_netns)(struct net *net, struct ip_vs_proto_data *pd);

        int (*conn_schedule)(int af, struct sk_buff *skb,
                             struct ip_vs_proto_data *pd,
                             int *verdict, struct ip_vs_conn **cpp,
                             struct ip_vs_iphdr *iph);

        struct ip_vs_conn *
        (*conn_in_get)(int af,
                       const struct sk_buff *skb,
                       const struct ip_vs_iphdr *iph,
                       int inverse);

        struct ip_vs_conn *
        (*conn_out_get)(int af,
                        const struct sk_buff *skb,
                        const struct ip_vs_iphdr *iph,
                        int inverse);

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

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

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

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

        void (*state_transition)(struct ip_vs_conn *cp, int direction,
                                 const struct sk_buff *skb,
                                 struct ip_vs_proto_data *pd);

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

        void (*unregister_app)(struct net *net, 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_proto_data *pd, int flags);
};

/*
 * protocol data per netns
 */
struct ip_vs_proto_data {
        struct ip_vs_proto_data *next;
        struct ip_vs_protocol   *pp;
        int                     *timeout_table; /* protocol timeout table */
        atomic_t                appcnt;         /* counter of proto app incs. */
        struct tcp_states_t     *tcp_state_table;
};

extern struct ip_vs_protocol   *ip_vs_proto_get(unsigned short proto);
extern struct ip_vs_proto_data *ip_vs_proto_data_get(struct net *net,
                                                     unsigned short proto);

struct ip_vs_conn_param {
        struct net                      *net;
        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 hlist_node       c_list;         /* hashed list heads */
        /* Protocol, addresses and port numbers */
        __be16                  cport;
        __be16                  dport;
        __be16                  vport;
        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 */
        __u16                   protocol;       /* Which protocol (TCP/UDP) */
#ifdef CONFIG_NET_NS
        struct net              *net;           /* Name space */
#endif

        /* 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
                                                 */
        __u32                   fwmark;         /* Fire wall mark from skb */
        unsigned long           sync_endtime;   /* jiffies + sent_retries */

        /* 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, struct ip_vs_iphdr *iph);

        /* 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 */

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

        struct rcu_head         rcu_head;
};

/*
 *  To save some memory in conn table when name space is disabled.
 */
static inline struct net *ip_vs_conn_net(const struct ip_vs_conn *cp)
{
#ifdef CONFIG_NET_NS
        return cp->net;
#else
        return &init_net;
#endif
}
static inline void ip_vs_conn_net_set(struct ip_vs_conn *cp, struct net *net)
{
#ifdef CONFIG_NET_NS
        cp->net = net;
#endif
}

static inline int ip_vs_conn_net_eq(const struct ip_vs_conn *cp,
                                    struct net *net)
{
#ifdef CONFIG_NET_NS
        return cp->net == net;
#else
        return 1;
#endif
}

/*
 *      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 */
        __be16                  port;
        u32                     fwmark;         /* firwall mark of service */

        /* virtual service options */
        char                    *sched_name;
        char                    *pe_name;
        unsigned int            flags;          /* virtual service flags */
        unsigned int            timeout;        /* persistent timeout in sec */
        __be32                  netmask;        /* persistent netmask or plen */
};


struct ip_vs_dest_user_kern {
        /* destination server address */
        union nf_inet_addr      addr;
        __be16                  port;

        /* real server options */
        unsigned int            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 hlist_node       s_list;   /* for normal service table */
        struct hlist_node       f_list;   /* for fwmark-based service table */
        atomic_t                refcnt;   /* reference 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 int            flags;    /* service status flags */
        unsigned int            timeout;  /* persistent timeout in ticks */
        __be32                  netmask;  /* grouping granularity, mask/plen */
        struct net              *net;

        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 __rcu *scheduler; /* bound scheduler object */
        spinlock_t              sched_lock;    /* lock sched_data */
        void                    *sched_data;   /* scheduler application data */

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

        struct rcu_head         rcu_head;
};

/* Information for cached dst */
struct ip_vs_dest_dst {
        struct dst_entry        *dst_cache;     /* destination cache entry */
        u32                     dst_cookie;
        union nf_inet_addr      dst_saddr;
        struct rcu_head         rcu_head;
};

/* In grace period after removing */
#define IP_VS_DEST_STATE_REMOVING       0x01
/*
 *      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 hlist_node       d_list;   /* for table with all the dests */

        u16                     af;             /* address family */
        __be16                  port;           /* port number of the server */
        union nf_inet_addr      addr;           /* IP address of the server */
        volatile unsigned int   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 */
        unsigned long           state;          /* state flags */

        /* 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 ip_vs_dest_dst __rcu *dest_dst;  /* cached dst info */

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

        struct list_head        t_list;         /* in dest_trash */
        struct rcu_head         rcu_head;
        unsigned int            in_rs_table:1;  /* we are in rs_table */
};


/*
 *      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 */
        void (*done_service)(struct ip_vs_service *svc);
        /* dest is linked */
        int (*add_dest)(struct ip_vs_service *svc, struct ip_vs_dest *dest);
        /* dest is unlinked */
        int (*del_dest)(struct ip_vs_service *svc, struct ip_vs_dest *dest);
        /* dest is updated */
        int (*upd_dest)(struct ip_vs_service *svc, struct ip_vs_dest *dest);

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

/* 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 */
        struct rcu_head         rcu_head;

        /*
         * 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, int inverse);

        struct ip_vs_conn *
        (*conn_out_get)(const struct sk_buff *skb, struct ip_vs_app *app,
                        const struct iphdr *iph, 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);
};

struct ipvs_master_sync_state {
        struct list_head        sync_queue;
        struct ip_vs_sync_buff  *sync_buff;
        unsigned long           sync_queue_len;
        unsigned int            sync_queue_delay;
        struct task_struct      *master_thread;
        struct delayed_work     master_wakeup_work;
        struct netns_ipvs       *ipvs;
};

/* How much time to keep dests in trash */
#define IP_VS_DEST_TRASH_PERIOD         (120 * HZ)

/* IPVS in network namespace */
struct netns_ipvs {
        int                     gen;            /* Generation */
        int                     enable;         /* enable like nf_hooks do */
        /*
         *      Hash table: for real service lookups
         */
        #define IP_VS_RTAB_BITS 4
        #define IP_VS_RTAB_SIZE (1 << IP_VS_RTAB_BITS)
        #define IP_VS_RTAB_MASK (IP_VS_RTAB_SIZE - 1)

        struct hlist_head       rs_table[IP_VS_RTAB_SIZE];
        /* ip_vs_app */
        struct list_head        app_list;
        /* ip_vs_proto */
        #define IP_VS_PROTO_TAB_SIZE    32      /* must be power of 2 */
        struct ip_vs_proto_data *proto_data_table[IP_VS_PROTO_TAB_SIZE];
        /* ip_vs_proto_tcp */
#ifdef CONFIG_IP_VS_PROTO_TCP
        #define TCP_APP_TAB_BITS        4
        #define TCP_APP_TAB_SIZE        (1 << TCP_APP_TAB_BITS)
        #define TCP_APP_TAB_MASK        (TCP_APP_TAB_SIZE - 1)
        struct list_head        tcp_apps[TCP_APP_TAB_SIZE];
#endif
        /* ip_vs_proto_udp */
#ifdef CONFIG_IP_VS_PROTO_UDP
        #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)
        struct list_head        udp_apps[UDP_APP_TAB_SIZE];
#endif
        /* ip_vs_proto_sctp */
#ifdef CONFIG_IP_VS_PROTO_SCTP
        #define SCTP_APP_TAB_BITS       4
        #define SCTP_APP_TAB_SIZE       (1 << SCTP_APP_TAB_BITS)
        #define SCTP_APP_TAB_MASK       (SCTP_APP_TAB_SIZE - 1)
        /* Hash table for SCTP application incarnations  */
        struct list_head        sctp_apps[SCTP_APP_TAB_SIZE];
#endif
        /* ip_vs_conn */
        atomic_t                conn_count;      /*  connection counter */

        /* ip_vs_ctl */
        struct ip_vs_stats              tot_stats;  /* Statistics & est. */

        int                     num_services;    /* no of virtual services */

        /* Trash for destinations */
        struct list_head        dest_trash;
        spinlock_t              dest_trash_lock;
        struct timer_list       dest_trash_timer; /* expiration timer */
        /* Service counters */
        atomic_t                ftpsvc_counter;
        atomic_t                nullsvc_counter;

#ifdef CONFIG_SYSCTL
        /* 1/rate drop and drop-entry variables */
        struct delayed_work     defense_work;   /* Work handler */
        int                     drop_rate;
        int                     drop_counter;
        atomic_t                dropentry;
        /* locks in ctl.c */
        spinlock_t              dropentry_lock;  /* drop entry handling */
        spinlock_t              droppacket_lock; /* drop packet handling */
        spinlock_t              securetcp_lock;  /* state and timeout tables */

        /* sys-ctl struct */
        struct ctl_table_header *sysctl_hdr;
        struct ctl_table        *sysctl_tbl;
#endif

        /* sysctl variables */
        int                     sysctl_amemthresh;
        int                     sysctl_am_droprate;
        int                     sysctl_drop_entry;
        int                     sysctl_drop_packet;
        int                     sysctl_secure_tcp;
#ifdef CONFIG_IP_VS_NFCT
        int                     sysctl_conntrack;
#endif
        int                     sysctl_snat_reroute;
        int                     sysctl_sync_ver;
        int                     sysctl_sync_ports;
        int                     sysctl_sync_persist_mode;
        unsigned long           sysctl_sync_qlen_max;
        int                     sysctl_sync_sock_size;
        int                     sysctl_cache_bypass;
        int                     sysctl_expire_nodest_conn;
        int                     sysctl_sloppy_tcp;
        int                     sysctl_sloppy_sctp;
        int                     sysctl_expire_quiescent_template;
        int                     sysctl_sync_threshold[2];
        unsigned int            sysctl_sync_refresh_period;
        int                     sysctl_sync_retries;
        int                     sysctl_nat_icmp_send;
        int                     sysctl_pmtu_disc;
        int                     sysctl_backup_only;

        /* ip_vs_lblc */
        int                     sysctl_lblc_expiration;
        struct ctl_table_header *lblc_ctl_header;
        struct ctl_table        *lblc_ctl_table;
        /* ip_vs_lblcr */
        int                     sysctl_lblcr_expiration;
        struct ctl_table_header *lblcr_ctl_header;
        struct ctl_table        *lblcr_ctl_table;

        /* ip_vs_est */
        struct list_head        est_list;       /* estimator list */
        spinlock_t              est_lock;
        struct timer_list       est_timer;      /* Estimation timer */
        /* ip_vs_sync */
        spinlock_t              sync_lock;
        struct ipvs_master_sync_state *ms;
        spinlock_t              sync_buff_lock;
        struct task_struct      **backup_threads;
        int                     threads_mask;
        int                     send_mesg_maxlen;
        int                     recv_mesg_maxlen;
        volatile int            sync_state;
        volatile int            master_syncid;
        volatile int            backup_syncid;
        struct mutex            sync_mutex;
        /* multicast interface name */
        char                    master_mcast_ifn[IP_VS_IFNAME_MAXLEN];
        char                    backup_mcast_ifn[IP_VS_IFNAME_MAXLEN];
        /* net name space ptr */
        struct net              *net;            /* Needed by timer routines */
};

#define DEFAULT_SYNC_THRESHOLD  3
#define DEFAULT_SYNC_PERIOD     50
#define DEFAULT_SYNC_VER        1
#define DEFAULT_SLOPPY_TCP      0
#define DEFAULT_SLOPPY_SCTP     0
#define DEFAULT_SYNC_REFRESH_PERIOD     (0U * HZ)
#define DEFAULT_SYNC_RETRIES            0
#define IPVS_SYNC_WAKEUP_RATE   8
#define IPVS_SYNC_QLEN_MAX      (IPVS_SYNC_WAKEUP_RATE * 4)
#define IPVS_SYNC_SEND_DELAY    (HZ / 50)
#define IPVS_SYNC_CHECK_PERIOD  HZ
#define IPVS_SYNC_FLUSH_TIME    (HZ * 2)
#define IPVS_SYNC_PORTS_MAX     (1 << 6)

#ifdef CONFIG_SYSCTL

static inline int sysctl_sync_threshold(struct netns_ipvs *ipvs)
{
        return ipvs->sysctl_sync_threshold[0];
}

static inline int sysctl_sync_period(struct netns_ipvs *ipvs)
{
        return ACCESS_ONCE(ipvs->sysctl_sync_threshold[1]);
}

static inline unsigned int sysctl_sync_refresh_period(struct netns_ipvs *ipvs)
{
        return ACCESS_ONCE(ipvs->sysctl_sync_refresh_period);
}

static inline int sysctl_sync_retries(struct netns_ipvs *ipvs)
{
        return ipvs->sysctl_sync_retries;
}

static inline int sysctl_sync_ver(struct netns_ipvs *ipvs)
{
        return ipvs->sysctl_sync_ver;
}

static inline int sysctl_sloppy_tcp(struct netns_ipvs *ipvs)
{
        return ipvs->sysctl_sloppy_tcp;
}

static inline int sysctl_sloppy_sctp(struct netns_ipvs *ipvs)
{
        return ipvs->sysctl_sloppy_sctp;
}

static inline int sysctl_sync_ports(struct netns_ipvs *ipvs)
{
        return ACCESS_ONCE(ipvs->sysctl_sync_ports);
}

static inline int sysctl_sync_persist_mode(struct netns_ipvs *ipvs)
{
        return ipvs->sysctl_sync_persist_mode;
}

static inline unsigned long sysctl_sync_qlen_max(struct netns_ipvs *ipvs)
{
        return ipvs->sysctl_sync_qlen_max;
}

static inline int sysctl_sync_sock_size(struct netns_ipvs *ipvs)
{
        return ipvs->sysctl_sync_sock_size;
}

static inline int sysctl_pmtu_disc(struct netns_ipvs *ipvs)
{
        return ipvs->sysctl_pmtu_disc;
}

static inline int sysctl_backup_only(struct netns_ipvs *ipvs)
{
        return ipvs->sync_state & IP_VS_STATE_BACKUP &&
               ipvs->sysctl_backup_only;
}

#else

static inline int sysctl_sync_threshold(struct netns_ipvs *ipvs)
{
        return DEFAULT_SYNC_THRESHOLD;
}

static inline int sysctl_sync_period(struct netns_ipvs *ipvs)
{
        return DEFAULT_SYNC_PERIOD;
}

static inline unsigned int sysctl_sync_refresh_period(struct netns_ipvs *ipvs)
{
        return DEFAULT_SYNC_REFRESH_PERIOD;
}

static inline int sysctl_sync_retries(struct netns_ipvs *ipvs)
{
        return DEFAULT_SYNC_RETRIES & 3;
}

static inline int sysctl_sync_ver(struct netns_ipvs *ipvs)
{
        return DEFAULT_SYNC_VER;
}

static inline int sysctl_sloppy_tcp(struct netns_ipvs *ipvs)
{
        return DEFAULT_SLOPPY_TCP;
}

static inline int sysctl_sloppy_sctp(struct netns_ipvs *ipvs)
{
        return DEFAULT_SLOPPY_SCTP;
}

static inline int sysctl_sync_ports(struct netns_ipvs *ipvs)
{
        return 1;
}

static inline int sysctl_sync_persist_mode(struct netns_ipvs *ipvs)
{
        return 0;
}

static inline unsigned long sysctl_sync_qlen_max(struct netns_ipvs *ipvs)
{
        return IPVS_SYNC_QLEN_MAX;
}

static inline int sysctl_sync_sock_size(struct netns_ipvs *ipvs)
{
        return 0;
}

static inline int sysctl_pmtu_disc(struct netns_ipvs *ipvs)
{
        return 1;
}

static inline int sysctl_backup_only(struct netns_ipvs *ipvs)
{
        return 0;
}

#endif

/*
 *      IPVS core functions
 *      (from ip_vs_core.c)
 */
extern const char *ip_vs_proto_name(unsigned int 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(struct net *net, 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->net = net;
        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,
                                            const struct ip_vs_iphdr *iph,
                                            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,
                                             const struct ip_vs_iphdr *iph,
                                             int inverse);

/* Get reference to gain full access to conn.
 * By default, RCU read-side critical sections have access only to
 * conn fields and its PE data, see ip_vs_conn_rcu_free() for reference.
 */
static inline bool __ip_vs_conn_get(struct ip_vs_conn *cp)
{
        return atomic_inc_not_zero(&cp->refcnt);
}

/* put back the conn without restarting its timer */
static inline void __ip_vs_conn_put(struct ip_vs_conn *cp)
{
        smp_mb__before_atomic_dec();
        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 int flags,
                                  struct ip_vs_dest *dest, __u32 fwmark);
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 net *net, struct ip_vs_conn *cp);
extern int ip_vs_check_template(struct ip_vs_conn *ct);
extern void ip_vs_random_dropentry(struct net *net);
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 netns init & cleanup functions
 */
extern int ip_vs_estimator_net_init(struct net *net);
extern int ip_vs_control_net_init(struct net *net);
extern int ip_vs_protocol_net_init(struct net *net);
extern int ip_vs_app_net_init(struct net *net);
extern int ip_vs_conn_net_init(struct net *net);
extern int ip_vs_sync_net_init(struct net *net);
extern void ip_vs_conn_net_cleanup(struct net *net);
extern void ip_vs_app_net_cleanup(struct net *net);
extern void ip_vs_protocol_net_cleanup(struct net *net);
extern void ip_vs_control_net_cleanup(struct net *net);
extern void ip_vs_estimator_net_cleanup(struct net *net);
extern void ip_vs_sync_net_cleanup(struct net *net);
extern void ip_vs_service_net_cleanup(struct net *net);

/*
 *      IPVS application functions
 *      (from ip_vs_app.c)
 */
#define IP_VS_APP_MAX_PORTS  8
extern struct ip_vs_app *register_ip_vs_app(struct net *net,
                                            struct ip_vs_app *app);
extern void unregister_ip_vs_app(struct net *net, 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 net *net, 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);

int register_ip_vs_pe(struct ip_vs_pe *pe);
int unregister_ip_vs_pe(struct ip_vs_pe *pe);
struct ip_vs_pe *ip_vs_pe_getbyname(const char *name);
struct ip_vs_pe *__ip_vs_pe_getbyname(const char *pe_name);

/*
 * Use a #define to avoid all of module.h just for these trivial ops
 */
#define ip_vs_pe_get(pe)                        \
        if (pe && pe->module)                   \
                __module_get(pe->module);

#define ip_vs_pe_put(pe)                        \
        if (pe && pe->module)                   \
                module_put(pe->module);

/*
 *      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(struct netns_ipvs *ipvs, 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 void ip_vs_unbind_scheduler(struct ip_vs_service *svc,
                                   struct ip_vs_scheduler *sched);
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_proto_data *pd, int *ignored,
               struct ip_vs_iphdr *iph);
extern int ip_vs_leave(struct ip_vs_service *svc, struct sk_buff *skb,
                        struct ip_vs_proto_data *pd, struct ip_vs_iphdr *iph);

extern void ip_vs_scheduler_err(struct ip_vs_service *svc, const char *msg);


/*
 *      IPVS control data and functions (from ip_vs_ctl.c)
 */
extern struct ip_vs_stats ip_vs_stats;
extern int sysctl_ip_vs_sync_ver;

extern struct ip_vs_service *
ip_vs_service_find(struct net *net, int af, __u32 fwmark, __u16 protocol,
                  const union nf_inet_addr *vaddr, __be16 vport);

extern bool
ip_vs_has_real_service(struct net *net, 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_register_nl_ioctl(void);
extern void ip_vs_unregister_nl_ioctl(void);
extern int ip_vs_control_init(void);
extern void ip_vs_control_cleanup(void);
extern struct ip_vs_dest *
ip_vs_find_dest(struct net *net, int af, const union nf_inet_addr *daddr,
                __be16 dport, const union nf_inet_addr *vaddr, __be16 vport,
                __u16 protocol, __u32 fwmark, __u32 flags);
extern void ip_vs_try_bind_dest(struct ip_vs_conn *cp);

static inline void ip_vs_dest_hold(struct ip_vs_dest *dest)
{
        atomic_inc(&dest->refcnt);
}

static inline void ip_vs_dest_put(struct ip_vs_dest *dest)
{
        smp_mb__before_atomic_dec();
        atomic_dec(&dest->refcnt);
}

/*
 *      IPVS sync daemon data and function prototypes
 *      (from ip_vs_sync.c)
 */
extern int start_sync_thread(struct net *net, int state, char *mcast_ifn,
                             __u8 syncid);
extern int stop_sync_thread(struct net *net, int state);
extern void ip_vs_sync_conn(struct net *net, struct ip_vs_conn *cp, int pkts);


/*
 *      IPVS rate estimator prototypes (from ip_vs_est.c)
 */
extern void ip_vs_start_estimator(struct net *net, struct ip_vs_stats *stats);
extern void ip_vs_stop_estimator(struct net *net, struct ip_vs_stats *stats);
extern void ip_vs_zero_estimator(struct ip_vs_stats *stats);
extern void ip_vs_read_estimator(struct ip_vs_stats_user *dst,
                                 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, struct ip_vs_iphdr *iph);
extern int ip_vs_bypass_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
                             struct ip_vs_protocol *pp,
                             struct ip_vs_iphdr *iph);
extern int ip_vs_nat_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
                          struct ip_vs_protocol *pp, struct ip_vs_iphdr *iph);
extern int ip_vs_tunnel_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
                             struct ip_vs_protocol *pp,
                             struct ip_vs_iphdr *iph);
extern int ip_vs_dr_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
                         struct ip_vs_protocol *pp, struct ip_vs_iphdr *iph);
extern int ip_vs_icmp_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
                           struct ip_vs_protocol *pp, int offset,
                           unsigned int hooknum, struct ip_vs_iphdr *iph);
extern void ip_vs_dest_dst_rcu_free(struct rcu_head *head);

#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,
                                struct ip_vs_iphdr *iph);
extern int ip_vs_nat_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp,
                             struct ip_vs_protocol *pp,
                             struct ip_vs_iphdr *iph);
extern int ip_vs_tunnel_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp,
                                struct ip_vs_protocol *pp,
                                struct ip_vs_iphdr *iph);
extern int ip_vs_dr_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp,
                            struct ip_vs_protocol *pp, struct ip_vs_iphdr *iph);
extern int ip_vs_icmp_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp,
                              struct ip_vs_protocol *pp, int offset,
                              unsigned int hooknum, struct ip_vs_iphdr *iph);
#endif

#ifdef CONFIG_SYSCTL
/*
 *      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
 */

static inline int ip_vs_todrop(struct netns_ipvs *ipvs)
{
        if (!ipvs->drop_rate)
                return 0;
        if (--ipvs->drop_counter > 0)
                return 0;
        ipvs->drop_counter = ipvs->drop_rate;
        return 1;
}
#else
static inline int ip_vs_todrop(struct netns_ipvs *ipvs) { return 0; }
#endif

/*
 *      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 = nf_ct_get(skb, &ctinfo);

        if (!ct || !nf_ct_is_untracked(ct)) {
                nf_conntrack_put(skb->nfct);
                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(struct netns_ipvs *ipvs)
{
#ifdef CONFIG_SYSCTL
        return ipvs->sysctl_conntrack;
#else
        return 0;
#endif
}

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);
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(struct netns_ipvs *ipvs)
{
        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)
{
        return NF_ACCEPT;
}

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

static inline unsigned int
ip_vs_dest_conn_overhead(struct ip_vs_dest *dest)
{
        /*
         * We think the overhead of processing active connections is 256
         * times higher than that of inactive connections in average. (This
         * 256 times might not be accurate, we will change it later) We
         * use the following formula to estimate the overhead now:
         *                dest->activeconns*256 + dest->inactconns
         */
        return (atomic_read(&dest->activeconns) << 8) +
                atomic_read(&dest->inactconns);
}

#endif  /* _NET_IP_VS_H */