#ifndef __NET_GENERIC_NETLINK_H
#define __NET_GENERIC_NETLINK_H

#include <linux/genetlink.h>
#include <net/netlink.h>
#include <net/net_namespace.h>

/**
 * struct genl_multicast_group - generic netlink multicast group
 * @name: name of the multicast group, names are per-family
 * @id: multicast group ID, assigned by the core, to use with
 *      genlmsg_multicast().
 * @list: list entry for linking
 * @family: pointer to family, need not be set before registering
 */
struct genl_multicast_group {
        struct genl_family      *family;        /* private */
        struct list_head        list;           /* private */
        char                    name[GENL_NAMSIZ];
        u32                     id;
};

struct genl_ops;
struct genl_info;

/**
 * struct genl_family - generic netlink family
 * @id: protocol family idenfitier
 * @hdrsize: length of user specific header in bytes
 * @name: name of family
 * @version: protocol version
 * @maxattr: maximum number of attributes supported
 * @netnsok: set to true if the family can handle network
 *      namespaces and should be presented in all of them
 * @pre_doit: called before an operation's doit callback, it may
 *      do additional, common, filtering and return an error
 * @post_doit: called after an operation's doit callback, it may
 *      undo operations done by pre_doit, for example release locks
 * @attrbuf: buffer to store parsed attributes
 * @ops_list: list of all assigned operations
 * @family_list: family list
 * @mcast_groups: multicast groups list
 */
struct genl_family {
        unsigned int            id;
        unsigned int            hdrsize;
        char                    name[GENL_NAMSIZ];
        unsigned int            version;
        unsigned int            maxattr;
        bool                    netnsok;
        int                     (*pre_doit)(struct genl_ops *ops,
                                            struct sk_buff *skb,
                                            struct genl_info *info);
        void                    (*post_doit)(struct genl_ops *ops,
                                             struct sk_buff *skb,
                                             struct genl_info *info);
        struct nlattr **        attrbuf;        /* private */
        struct list_head        ops_list;       /* private */
        struct list_head        family_list;    /* private */
        struct list_head        mcast_groups;   /* private */
};

/**
 * struct genl_info - receiving information
 * @snd_seq: sending sequence number
 * @snd_pid: netlink pid of sender
 * @nlhdr: netlink message header
 * @genlhdr: generic netlink message header
 * @userhdr: user specific header
 * @attrs: netlink attributes
 * @_net: network namespace
 * @user_ptr: user pointers
 */
struct genl_info {
        u32                     snd_seq;
        u32                     snd_pid;
        struct nlmsghdr *       nlhdr;
        struct genlmsghdr *     genlhdr;
        void *                  userhdr;
        struct nlattr **        attrs;
#ifdef CONFIG_NET_NS
        struct net *            _net;
#endif
        void *                  user_ptr[2];
};

static inline struct net *genl_info_net(struct genl_info *info)
{
        return read_pnet(&info->_net);
}

static inline void genl_info_net_set(struct genl_info *info, struct net *net)
{
        write_pnet(&info->_net, net);
}

/**
 * struct genl_ops - generic netlink operations
 * @cmd: command identifier
 * @internal_flags: flags used by the family
 * @flags: flags
 * @policy: attribute validation policy
 * @doit: standard command callback
 * @dumpit: callback for dumpers
 * @done: completion callback for dumps
 * @ops_list: operations list
 */
struct genl_ops {
        u8                      cmd;
        u8                      internal_flags;
        unsigned int            flags;
        const struct nla_policy *policy;
        int                    (*doit)(struct sk_buff *skb,
                                       struct genl_info *info);
        int                    (*dumpit)(struct sk_buff *skb,
                                         struct netlink_callback *cb);
        int                    (*done)(struct netlink_callback *cb);
        struct list_head        ops_list;
};

extern int genl_register_family(struct genl_family *family);
extern int genl_register_family_with_ops(struct genl_family *family,
        struct genl_ops *ops, size_t n_ops);
extern int genl_unregister_family(struct genl_family *family);
extern int genl_register_ops(struct genl_family *, struct genl_ops *ops);
extern int genl_unregister_ops(struct genl_family *, struct genl_ops *ops);
extern int genl_register_mc_group(struct genl_family *family,
                                  struct genl_multicast_group *grp);
extern void genl_unregister_mc_group(struct genl_family *family,
                                     struct genl_multicast_group *grp);

/**
 * genlmsg_put - Add generic netlink header to netlink message
 * @skb: socket buffer holding the message
 * @pid: netlink pid the message is addressed to
 * @seq: sequence number (usually the one of the sender)
 * @family: generic netlink family
 * @flags netlink message flags
 * @cmd: generic netlink command
 *
 * Returns pointer to user specific header
 */
static inline void *genlmsg_put(struct sk_buff *skb, u32 pid, u32 seq,
                                struct genl_family *family, int flags, u8 cmd)
{
        struct nlmsghdr *nlh;
        struct genlmsghdr *hdr;

        nlh = nlmsg_put(skb, pid, seq, family->id, GENL_HDRLEN +
                        family->hdrsize, flags);
        if (nlh == NULL)
                return NULL;

        hdr = nlmsg_data(nlh);
        hdr->cmd = cmd;
        hdr->version = family->version;
        hdr->reserved = 0;

        return (char *) hdr + GENL_HDRLEN;
}

/**
 * genlmsg_put_reply - Add generic netlink header to a reply message
 * @skb: socket buffer holding the message
 * @info: receiver info
 * @family: generic netlink family
 * @flags: netlink message flags
 * @cmd: generic netlink command
 *
 * Returns pointer to user specific header
 */
static inline void *genlmsg_put_reply(struct sk_buff *skb,
                                      struct genl_info *info,
                                      struct genl_family *family,
                                      int flags, u8 cmd)
{
        return genlmsg_put(skb, info->snd_pid, info->snd_seq, family,
                           flags, cmd);
}

/**
 * genlmsg_end - Finalize a generic netlink message
 * @skb: socket buffer the message is stored in
 * @hdr: user specific header
 */
static inline int genlmsg_end(struct sk_buff *skb, void *hdr)
{
        return nlmsg_end(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
}

/**
 * genlmsg_cancel - Cancel construction of a generic netlink message
 * @skb: socket buffer the message is stored in
 * @hdr: generic netlink message header
 */
static inline void genlmsg_cancel(struct sk_buff *skb, void *hdr)
{
        if (hdr)
                nlmsg_cancel(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
}

/**
 * genlmsg_multicast_netns - multicast a netlink message to a specific netns
 * @net: the net namespace
 * @skb: netlink message as socket buffer
 * @pid: own netlink pid to avoid sending to yourself
 * @group: multicast group id
 * @flags: allocation flags
 */
static inline int genlmsg_multicast_netns(struct net *net, struct sk_buff *skb,
                                          u32 pid, unsigned int group, gfp_t flags)
{
        return nlmsg_multicast(net->genl_sock, skb, pid, group, flags);
}

/**
 * genlmsg_multicast - multicast a netlink message to the default netns
 * @skb: netlink message as socket buffer
 * @pid: own netlink pid to avoid sending to yourself
 * @group: multicast group id
 * @flags: allocation flags
 */
static inline int genlmsg_multicast(struct sk_buff *skb, u32 pid,
                                    unsigned int group, gfp_t flags)
{
        return genlmsg_multicast_netns(&init_net, skb, pid, group, flags);
}

/**
 * genlmsg_multicast_allns - multicast a netlink message to all net namespaces
 * @skb: netlink message as socket buffer
 * @pid: own netlink pid to avoid sending to yourself
 * @group: multicast group id
 * @flags: allocation flags
 *
 * This function must hold the RTNL or rcu_read_lock().
 */
int genlmsg_multicast_allns(struct sk_buff *skb, u32 pid,
                            unsigned int group, gfp_t flags);

/**
 * genlmsg_unicast - unicast a netlink message
 * @skb: netlink message as socket buffer
 * @pid: netlink pid of the destination socket
 */
static inline int genlmsg_unicast(struct net *net, struct sk_buff *skb, u32 pid)
{
        return nlmsg_unicast(net->genl_sock, skb, pid);
}

/**
 * genlmsg_reply - reply to a request
 * @skb: netlink message to be sent back
 * @info: receiver information
 */
static inline int genlmsg_reply(struct sk_buff *skb, struct genl_info *info)
{
        return genlmsg_unicast(genl_info_net(info), skb, info->snd_pid);
}

/**
 * gennlmsg_data - head of message payload
 * @gnlh: genetlink messsage header
 */
static inline void *genlmsg_data(const struct genlmsghdr *gnlh)
{
        return ((unsigned char *) gnlh + GENL_HDRLEN);
}

/**
 * genlmsg_len - length of message payload
 * @gnlh: genetlink message header
 */
static inline int genlmsg_len(const struct genlmsghdr *gnlh)
{
        struct nlmsghdr *nlh = (struct nlmsghdr *)((unsigned char *)gnlh -
                                                        NLMSG_HDRLEN);
        return (nlh->nlmsg_len - GENL_HDRLEN - NLMSG_HDRLEN);
}

/**
 * genlmsg_msg_size - length of genetlink message not including padding
 * @payload: length of message payload
 */
static inline int genlmsg_msg_size(int payload)
{
        return GENL_HDRLEN + payload;
}

/**
 * genlmsg_total_size - length of genetlink message including padding
 * @payload: length of message payload
 */
static inline int genlmsg_total_size(int payload)
{
        return NLMSG_ALIGN(genlmsg_msg_size(payload));
}

/**
 * genlmsg_new - Allocate a new generic netlink message
 * @payload: size of the message payload
 * @flags: the type of memory to allocate.
 */
static inline struct sk_buff *genlmsg_new(size_t payload, gfp_t flags)
{
        return nlmsg_new(genlmsg_total_size(payload), flags);
}


#endif  /* __NET_GENERIC_NETLINK_H */