/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _AF_NETLINK_H
#define _AF_NETLINK_H

#include <linux/rhashtable.h>
#include <linux/atomic.h>
#include <net/sock.h>

/* flags */
enum {
        NETLINK_F_KERNEL_SOCKET,
        NETLINK_F_RECV_PKTINFO,
        NETLINK_F_BROADCAST_SEND_ERROR,
        NETLINK_F_RECV_NO_ENOBUFS,
        NETLINK_F_LISTEN_ALL_NSID,
        NETLINK_F_CAP_ACK,
        NETLINK_F_EXT_ACK,
        NETLINK_F_STRICT_CHK,
};

#define NLGRPSZ(x)      (ALIGN(x, sizeof(unsigned long) * 8) / 8)
#define NLGRPLONGS(x)   (NLGRPSZ(x)/sizeof(unsigned long))

struct netlink_sock {
        /* struct sock has to be the first member of netlink_sock */
        struct sock             sk;
        unsigned long           flags;
        u32                     portid;
        u32                     dst_portid;
        u32                     dst_group;
        u32                     subscriptions;
        u32                     ngroups;
        unsigned long           *groups;
        unsigned long           state;
        size_t                  max_recvmsg_len;
        wait_queue_head_t       wait;
        bool                    bound;
        bool                    cb_running;
        int                     dump_done_errno;
        struct netlink_callback cb;
        struct mutex            nl_cb_mutex;

        void                    (*netlink_rcv)(struct sk_buff *skb);
        int                     (*netlink_bind)(struct net *net, int group);
        void                    (*netlink_unbind)(struct net *net, int group);
        void                    (*netlink_release)(struct sock *sk,
                                                   unsigned long *groups);
        struct module           *module;

        struct rhash_head       node;
        struct rcu_head         rcu;
};

static inline struct netlink_sock *nlk_sk(struct sock *sk)
{
        return container_of(sk, struct netlink_sock, sk);
}

#define nlk_test_bit(nr, sk) test_bit(NETLINK_F_##nr, &nlk_sk(sk)->flags)

struct netlink_table {
        struct rhashtable       hash;
        struct hlist_head       mc_list;
        struct listeners __rcu  *listeners;
        unsigned int            flags;
        unsigned int            groups;
        struct mutex            *cb_mutex;
        struct module           *module;
        int                     (*bind)(struct net *net, int group);
        void                    (*unbind)(struct net *net, int group);
        void                    (*release)(struct sock *sk,
                                           unsigned long *groups);
        int                     registered;
};

extern struct netlink_table *nl_table;
extern rwlock_t nl_table_lock;

#endif