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