include/net/genetlink.h

   1 #ifndef __NET_GENERIC_NETLINK_H
   2 #define __NET_GENERIC_NETLINK_H
   3
   4 #include <linux/genetlink.h>
   5 #include <net/netlink.h>
   6
   7 /**
   8  * struct genl_family - generic netlink family
   9  * @id: protocol family idenfitier
  10  * @hdrsize: length of user specific header in bytes
  11  * @name: name of family
  12  * @version: protocol version
  13  * @maxattr: maximum number of attributes supported
  14  * @attrbuf: buffer to store parsed attributes
  15  * @ops_list: list of all assigned operations
  16  * @family_list: family list
  17  */
  18 struct genl_family
  19 {
  20         unsigned int            id;
  21         unsigned int            hdrsize;
  22         char                    name[GENL_NAMSIZ];
  23         unsigned int            version;
  24         unsigned int            maxattr;
  25         struct nlattr **        attrbuf;        /* private */
  26         struct list_head        ops_list;       /* private */
  27         struct list_head        family_list;    /* private */
  28 };
  29
  30 #define GENL_ADMIN_PERM         0x01
  31
  32 /**
  33  * struct genl_info - receiving information
  34  * @snd_seq: sending sequence number
  35  * @snd_pid: netlink pid of sender
  36  * @nlhdr: netlink message header
  37  * @genlhdr: generic netlink message header
  38  * @userhdr: user specific header
  39  * @attrs: netlink attributes
  40  */
  41 struct genl_info
  42 {
  43         u32                     snd_seq;
  44         u32                     snd_pid;
  45         struct nlmsghdr *       nlhdr;
  46         struct genlmsghdr *     genlhdr;
  47         void *                  userhdr;
  48         struct nlattr **        attrs;
  49 };
  50
  51 /**
  52  * struct genl_ops - generic netlink operations
  53  * @cmd: command identifier
  54  * @flags: flags
  55  * @policy: attribute validation policy
  56  * @doit: standard command callback
  57  * @dumpit: callback for dumpers
  58  * @ops_list: operations list
  59  */
  60 struct genl_ops
  61 {
  62         u8                      cmd;
  63         unsigned int            flags;
  64         struct nla_policy       *policy;
  65         int                    (*doit)(struct sk_buff *skb,
  66                                        struct genl_info *info);
  67         int                    (*dumpit)(struct sk_buff *skb,
  68                                          struct netlink_callback *cb);
  69         struct list_head        ops_list;
  70 };
  71
  72 extern int genl_register_family(struct genl_family *family);
  73 extern int genl_unregister_family(struct genl_family *family);
  74 extern int genl_register_ops(struct genl_family *, struct genl_ops *ops);
  75 extern int genl_unregister_ops(struct genl_family *, struct genl_ops *ops);
  76
  77 extern struct sock *genl_sock;
  78
  79 /**
  80  * genlmsg_put - Add generic netlink header to netlink message
  81  * @skb: socket buffer holding the message
  82  * @pid: netlink pid the message is addressed to
  83  * @seq: sequence number (usually the one of the sender)
  84  * @type: netlink message type
  85  * @hdrlen: length of the user specific header
  86  * @flags netlink message flags
  87  * @cmd: generic netlink command
  88  * @version: version
  89  *
  90  * Returns pointer to user specific header
  91  */
  92 static inline void *genlmsg_put(struct sk_buff *skb, u32 pid, u32 seq,
  93                                 int type, int hdrlen, int flags,
  94                                 u8 cmd, u8 version)
  95 {
  96         struct nlmsghdr *nlh;
  97         struct genlmsghdr *hdr;
  98
  99         nlh = nlmsg_put(skb, pid, seq, type, GENL_HDRLEN + hdrlen, flags);
 100         if (nlh == NULL)
 101                 return NULL;
 102
 103         hdr = nlmsg_data(nlh);
 104         hdr->cmd = cmd;
 105         hdr->version = version;
 106         hdr->reserved = 0;
 107
 108         return (char *) hdr + GENL_HDRLEN;
 109 }
 110
 111 /**
 112  * genlmsg_end - Finalize a generic netlink message
 113  * @skb: socket buffer the message is stored in
 114  * @hdr: user specific header
 115  */
 116 static inline int genlmsg_end(struct sk_buff *skb, void *hdr)
 117 {
 118         return nlmsg_end(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
 119 }
 120
 121 /**
 122  * genlmsg_cancel - Cancel construction of a generic netlink message
 123  * @skb: socket buffer the message is stored in
 124  * @hdr: generic netlink message header
 125  */
 126 static inline int genlmsg_cancel(struct sk_buff *skb, void *hdr)
 127 {
 128         return nlmsg_cancel(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
 129 }
 130
 131 /**
 132  * genlmsg_multicast - multicast a netlink message
 133  * @skb: netlink message as socket buffer
 134  * @pid: own netlink pid to avoid sending to yourself
 135  * @group: multicast group id
 136  * @flags: allocation flags
 137  */
 138 static inline int genlmsg_multicast(struct sk_buff *skb, u32 pid,
 139                                     unsigned int group, gfp_t flags)
 140 {
 141         return nlmsg_multicast(genl_sock, skb, pid, group, flags);
 142 }
 143
 144 /**
 145  * genlmsg_unicast - unicast a netlink message
 146  * @skb: netlink message as socket buffer
 147  * @pid: netlink pid of the destination socket
 148  */
 149 static inline int genlmsg_unicast(struct sk_buff *skb, u32 pid)
 150 {
 151         return nlmsg_unicast(genl_sock, skb, pid);
 152 }
 153
 154 /**
 155  * gennlmsg_data - head of message payload
 156  * @gnlh: genetlink messsage header
 157  */
 158 static inline void *genlmsg_data(const struct genlmsghdr *gnlh)
 159 {
 160         return ((unsigned char *) gnlh + GENL_HDRLEN);
 161 }
 162
 163 /**
 164  * genlmsg_len - length of message payload
 165  * @gnlh: genetlink message header
 166  */
 167 static inline int genlmsg_len(const struct genlmsghdr *gnlh)
 168 {
 169         struct nlmsghdr *nlh = (struct nlmsghdr *)((unsigned char *)gnlh -
 170                                                         NLMSG_HDRLEN);
 171         return (nlh->nlmsg_len - GENL_HDRLEN - NLMSG_HDRLEN);
 172 }
 173
 174 #endif  /* __NET_GENERIC_NETLINK_H */