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

#include <linux/rtnetlink.h>
#include <linux/srcu.h>
#include <net/netlink.h>

typedef int (*rtnl_doit_func)(struct sk_buff *, struct nlmsghdr *,
                              struct netlink_ext_ack *);
typedef int (*rtnl_dumpit_func)(struct sk_buff *, struct netlink_callback *);

enum rtnl_link_flags {
        RTNL_FLAG_DOIT_UNLOCKED         = BIT(0),
#define RTNL_FLAG_DOIT_PERNET           RTNL_FLAG_DOIT_UNLOCKED
#define RTNL_FLAG_DOIT_PERNET_WIP       RTNL_FLAG_DOIT_UNLOCKED
        RTNL_FLAG_BULK_DEL_SUPPORTED    = BIT(1),
        RTNL_FLAG_DUMP_UNLOCKED         = BIT(2),
        RTNL_FLAG_DUMP_SPLIT_NLM_DONE   = BIT(3),       /* legacy behavior */
};

enum rtnl_kinds {
        RTNL_KIND_NEW,
        RTNL_KIND_DEL,
        RTNL_KIND_GET,
        RTNL_KIND_SET
};
#define RTNL_KIND_MASK 0x3

static inline enum rtnl_kinds rtnl_msgtype_kind(int msgtype)
{
        return msgtype & RTNL_KIND_MASK;
}

/**
 *      struct rtnl_msg_handler - rtnetlink message type and handlers
 *
 *      @owner: NULL for built-in, THIS_MODULE for module
 *      @protocol: Protocol family or PF_UNSPEC
 *      @msgtype: rtnetlink message type
 *      @doit: Function pointer called for each request message
 *      @dumpit: Function pointer called for each dump request (NLM_F_DUMP) message
 *      @flags: rtnl_link_flags to modify behaviour of doit/dumpit functions
 */
struct rtnl_msg_handler {
        struct module *owner;
        int protocol;
        int msgtype;
        rtnl_doit_func doit;
        rtnl_dumpit_func dumpit;
        int flags;
};

void rtnl_unregister_all(int protocol);

int __rtnl_register_many(const struct rtnl_msg_handler *handlers, int n);
void __rtnl_unregister_many(const struct rtnl_msg_handler *handlers, int n);

#define rtnl_register_many(handlers)                            \
        __rtnl_register_many(handlers, ARRAY_SIZE(handlers))
#define rtnl_unregister_many(handlers)                          \
        __rtnl_unregister_many(handlers, ARRAY_SIZE(handlers))

static inline int rtnl_msg_family(const struct nlmsghdr *nlh)
{
        if (nlmsg_len(nlh) >= sizeof(struct rtgenmsg))
                return ((struct rtgenmsg *) nlmsg_data(nlh))->rtgen_family;
        else
                return AF_UNSPEC;
}

/**
 * struct rtnl_newlink_params - parameters of rtnl_link_ops::newlink()
 *
 * @src_net: Source netns of rtnetlink socket
 * @link_net: Link netns by IFLA_LINK_NETNSID, NULL if not specified
 * @peer_net: Peer netns
 * @tb: IFLA_* attributes
 * @data: IFLA_INFO_DATA attributes
 */
struct rtnl_newlink_params {
        struct net *src_net;
        struct net *link_net;
        struct net *peer_net;
        struct nlattr **tb;
        struct nlattr **data;
};

/* Get effective link netns from newlink params. Generally, this is link_net
 * and falls back to src_net. But for compatibility, a driver may * choose to
 * use dev_net(dev) instead.
 */
static inline struct net *rtnl_newlink_link_net(struct rtnl_newlink_params *p)
{
        return p->link_net ? : p->src_net;
}

/* Get peer netns from newlink params. Fallback to link netns if peer netns is
 * not specified explicitly.
 */
static inline struct net *rtnl_newlink_peer_net(struct rtnl_newlink_params *p)
{
        return p->peer_net ? : rtnl_newlink_link_net(p);
}

/**
 *      struct rtnl_link_ops - rtnetlink link operations
 *
 *      @list: Used internally, protected by link_ops_mutex and SRCU
 *      @srcu: Used internally
 *      @kind: Identifier
 *      @netns_refund: Physical device, move to init_net on netns exit
 *      @peer_type: Peer device specific netlink attribute number (e.g. VETH_INFO_PEER)
 *      @maxtype: Highest device specific netlink attribute number
 *      @policy: Netlink policy for device specific attribute validation
 *      @validate: Optional validation function for netlink/changelink parameters
 *      @alloc: netdev allocation function, can be %NULL and is then used
 *              in place of alloc_netdev_mqs(), in this case @priv_size
 *              and @setup are unused. Returns a netdev or ERR_PTR().
 *      @priv_size: sizeof net_device private space
 *      @setup: net_device setup function
 *      @newlink: Function for configuring and registering a new device
 *      @changelink: Function for changing parameters of an existing device
 *      @dellink: Function to remove a device
 *      @get_size: Function to calculate required room for dumping device
 *                 specific netlink attributes
 *      @fill_info: Function to dump device specific netlink attributes
 *      @get_xstats_size: Function to calculate required room for dumping device
 *                        specific statistics
 *      @fill_xstats: Function to dump device specific statistics
 *      @get_num_tx_queues: Function to determine number of transmit queues
 *                          to create when creating a new device.
 *      @get_num_rx_queues: Function to determine number of receive queues
 *                          to create when creating a new device.
 *      @get_link_net: Function to get the i/o netns of the device
 *      @get_linkxstats_size: Function to calculate the required room for
 *                            dumping device-specific extended link stats
 *      @fill_linkxstats: Function to dump device-specific extended link stats
 */
struct rtnl_link_ops {
        struct list_head        list;
        struct srcu_struct      srcu;

        const char              *kind;

        size_t                  priv_size;
        struct net_device       *(*alloc)(struct nlattr *tb[],
                                          const char *ifname,
                                          unsigned char name_assign_type,
                                          unsigned int num_tx_queues,
                                          unsigned int num_rx_queues);
        void                    (*setup)(struct net_device *dev);

        bool                    netns_refund;
        const u16               peer_type;
        unsigned int            maxtype;
        const struct nla_policy *policy;
        int                     (*validate)(struct nlattr *tb[],
                                            struct nlattr *data[],
                                            struct netlink_ext_ack *extack);

        int                     (*newlink)(struct net_device *dev,
                                           struct rtnl_newlink_params *params,
                                           struct netlink_ext_ack *extack);
        int                     (*changelink)(struct net_device *dev,
                                              struct nlattr *tb[],
                                              struct nlattr *data[],
                                              struct netlink_ext_ack *extack);
        void                    (*dellink)(struct net_device *dev,
                                           struct list_head *head);

        size_t                  (*get_size)(const struct net_device *dev);
        int                     (*fill_info)(struct sk_buff *skb,
                                             const struct net_device *dev);

        size_t                  (*get_xstats_size)(const struct net_device *dev);
        int                     (*fill_xstats)(struct sk_buff *skb,
                                               const struct net_device *dev);
        unsigned int            (*get_num_tx_queues)(void);
        unsigned int            (*get_num_rx_queues)(void);

        unsigned int            slave_maxtype;
        const struct nla_policy *slave_policy;
        int                     (*slave_changelink)(struct net_device *dev,
                                                    struct net_device *slave_dev,
                                                    struct nlattr *tb[],
                                                    struct nlattr *data[],
                                                    struct netlink_ext_ack *extack);
        size_t                  (*get_slave_size)(const struct net_device *dev,
                                                  const struct net_device *slave_dev);
        int                     (*fill_slave_info)(struct sk_buff *skb,
                                                   const struct net_device *dev,
                                                   const struct net_device *slave_dev);
        struct net              *(*get_link_net)(const struct net_device *dev);
        size_t                  (*get_linkxstats_size)(const struct net_device *dev,
                                                       int attr);
        int                     (*fill_linkxstats)(struct sk_buff *skb,
                                                   const struct net_device *dev,
                                                   int *prividx, int attr);
};

int rtnl_link_register(struct rtnl_link_ops *ops);
void rtnl_link_unregister(struct rtnl_link_ops *ops);

/**
 *      struct rtnl_af_ops - rtnetlink address family operations
 *
 *      @list: Used internally, protected by RTNL and SRCU
 *      @srcu: Used internally
 *      @family: Address family
 *      @fill_link_af: Function to fill IFLA_AF_SPEC with address family
 *                     specific netlink attributes.
 *      @get_link_af_size: Function to calculate size of address family specific
 *                         netlink attributes.
 *      @validate_link_af: Validate a IFLA_AF_SPEC attribute, must check attr
 *                         for invalid configuration settings.
 *      @set_link_af: Function to parse a IFLA_AF_SPEC attribute and modify
 *                    net_device accordingly.
 */
struct rtnl_af_ops {
        struct list_head        list;
        struct srcu_struct      srcu;

        int                     family;

        int                     (*fill_link_af)(struct sk_buff *skb,
                                                const struct net_device *dev,
                                                u32 ext_filter_mask);
        size_t                  (*get_link_af_size)(const struct net_device *dev,
                                                    u32 ext_filter_mask);

        int                     (*validate_link_af)(const struct net_device *dev,
                                                    const struct nlattr *attr,
                                                    struct netlink_ext_ack *extack);
        int                     (*set_link_af)(struct net_device *dev,
                                               const struct nlattr *attr,
                                               struct netlink_ext_ack *extack);
        int                     (*fill_stats_af)(struct sk_buff *skb,
                                                 const struct net_device *dev);
        size_t                  (*get_stats_af_size)(const struct net_device *dev);
};

int rtnl_af_register(struct rtnl_af_ops *ops);
void rtnl_af_unregister(struct rtnl_af_ops *ops);

struct net *rtnl_link_get_net(struct net *src_net, struct nlattr *tb[]);
struct net_device *rtnl_create_link(struct net *net, const char *ifname,
                                    unsigned char name_assign_type,
                                    const struct rtnl_link_ops *ops,
                                    struct nlattr *tb[],
                                    struct netlink_ext_ack *extack);
int rtnl_delete_link(struct net_device *dev, u32 portid, const struct nlmsghdr *nlh);
int rtnl_configure_link(struct net_device *dev, const struct ifinfomsg *ifm,
                        u32 portid, const struct nlmsghdr *nlh);

int rtnl_nla_parse_ifinfomsg(struct nlattr **tb, const struct nlattr *nla_peer,
                             struct netlink_ext_ack *exterr);
struct net *rtnl_get_net_ns_capable(struct sock *sk, int netnsid);

#define MODULE_ALIAS_RTNL_LINK(kind) MODULE_ALIAS("rtnl-link-" kind)

#endif