genetlink.h

Go to the documentation of this file.

#ifndef __NET_GENERIC_NETLINK_H
#define __NET_GENERIC_NETLINK_H

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

#define GENLMSG_DEFAULT_SIZE (NLMSG_DEFAULT_SIZE - GENL_HDRLEN)

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 {
    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 {
    u32         snd_seq;
    u32         snd_portid;
    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 {
    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);
extern void genl_notify(struct sk_buff *skb, struct net *net, u32 portid,
            u32 group, struct nlmsghdr *nlh, gfp_t flags);

void *genlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
                struct genl_family *family, int flags, u8 cmd);

static inline struct nlmsghdr *genlmsg_nlhdr(void *user_hdr,
                         struct genl_family *family)
{
    return (struct nlmsghdr *)((char *)user_hdr -
                   family->hdrsize -
                   GENL_HDRLEN -
                   NLMSG_HDRLEN);
}

static inline void genl_dump_check_consistent(struct netlink_callback *cb,
                          void *user_hdr,
                          struct genl_family *family)
{
    nl_dump_check_consistent(cb, genlmsg_nlhdr(user_hdr, family));
}

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_portid, info->snd_seq, family,
               flags, cmd);
}

static inline int genlmsg_end(struct sk_buff *skb, void *hdr)
{
    return nlmsg_end(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
}

static inline void genlmsg_cancel(struct sk_buff *skb, void *hdr)
{
    if (hdr)
        nlmsg_cancel(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
}

static inline int genlmsg_multicast_netns(struct net *net, struct sk_buff *skb,
                      u32 portid, unsigned int group, gfp_t flags)
{
    return nlmsg_multicast(net->genl_sock, skb, portid, group, flags);
}

static inline int genlmsg_multicast(struct sk_buff *skb, u32 portid,
                    unsigned int group, gfp_t flags)
{
    return genlmsg_multicast_netns(&init_net, skb, portid, group, flags);
}

int genlmsg_multicast_allns(struct sk_buff *skb, u32 portid,
                unsigned int group, gfp_t flags);

static inline int genlmsg_unicast(struct net *net, struct sk_buff *skb, u32 portid)
{
    return nlmsg_unicast(net->genl_sock, skb, portid);
}

static inline int genlmsg_reply(struct sk_buff *skb, struct genl_info *info)
{
    return genlmsg_unicast(genl_info_net(info), skb, info->snd_portid);
}

static inline void *genlmsg_data(const struct genlmsghdr *gnlh)
{
    return ((unsigned char *) gnlh + GENL_HDRLEN);
}

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);
}

static inline int genlmsg_msg_size(int payload)
{
    return GENL_HDRLEN + payload;
}

static inline int genlmsg_total_size(int payload)
{
    return NLMSG_ALIGN(genlmsg_msg_size(payload));
}

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 */