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_multicast_group - generic netlink multicast group
   9  * @name: name of the multicast group, names are per-family
  10  * @id: multicast group ID, assigned by the core, to use with
  11  *      genlmsg_multicast().
  12  * @list: list entry for linking
  13  * @family: pointer to family, need not be set before registering
  14  */
  15 struct genl_multicast_group
  16 {
  17         struct genl_family      *family;        /* private */
  18         struct list_head        list;           /* private */
  19         char                    name[GENL_NAMSIZ];
  20         u32                     id;
  21 };
  22
  23 /**
  24  * struct genl_family - generic netlink family
  25  * @id: protocol family idenfitier
  26  * @hdrsize: length of user specific header in bytes
  27  * @name: name of family
  28  * @version: protocol version
  29  * @maxattr: maximum number of attributes supported
  30  * @attrbuf: buffer to store parsed attributes
  31  * @ops_list: list of all assigned operations
  32  * @family_list: family list
  33  * @mcast_groups: multicast groups list
  34  */
  35 struct genl_family
  36 {
  37         unsigned int            id;
  38         unsigned int            hdrsize;
  39         char                    name[GENL_NAMSIZ];
  40         unsigned int            version;
  41         unsigned int            maxattr;
  42         struct nlattr **        attrbuf;        /* private */
  43         struct list_head        ops_list;       /* private */
  44         struct list_head        family_list;    /* private */
  45         struct list_head        mcast_groups;   /* private */
  46 };
  47
  48 /**
  49  * struct genl_info - receiving information
  50  * @snd_seq: sending sequence number
  51  * @snd_pid: netlink pid of sender
  52  * @nlhdr: netlink message header
  53  * @genlhdr: generic netlink message header
  54  * @userhdr: user specific header
  55  * @attrs: netlink attributes
  56  */
  57 struct genl_info
  58 {
  59         u32                     snd_seq;
  60         u32                     snd_pid;
  61         struct nlmsghdr *       nlhdr;
  62         struct genlmsghdr *     genlhdr;
  63         void *                  userhdr;
  64         struct nlattr **        attrs;
  65 };
  66
  67 /**
  68  * struct genl_ops - generic netlink operations
  69  * @cmd: command identifier
  70  * @flags: flags
  71  * @policy: attribute validation policy
  72  * @doit: standard command callback
  73  * @dumpit: callback for dumpers
  74  * @done: completion callback for dumps
  75  * @ops_list: operations list
  76  */
  77 struct genl_ops
  78 {
  79         u8                      cmd;
  80         unsigned int            flags;
  81         const struct nla_policy *policy;
  82         int                    (*doit)(struct sk_buff *skb,
  83                                        struct genl_info *info);
  84         int                    (*dumpit)(struct sk_buff *skb,
  85                                          struct netlink_callback *cb);
  86         int                    (*done)(struct netlink_callback *cb);
  87         struct list_head        ops_list;
  88 };
  89
  90 extern int genl_register_family(struct genl_family *family);
  91 extern int genl_register_family_with_ops(struct genl_family *family,
  92         struct genl_ops *ops, size_t n_ops);
  93 extern int genl_unregister_family(struct genl_family *family);
  94 extern int genl_register_ops(struct genl_family *, struct genl_ops *ops);
  95 extern int genl_unregister_ops(struct genl_family *, struct genl_ops *ops);
  96 extern int genl_register_mc_group(struct genl_family *family,
  97                                   struct genl_multicast_group *grp);
  98 extern void genl_unregister_mc_group(struct genl_family *family,
  99                                      struct genl_multicast_group *grp);
 100
 101 extern struct sock *genl_sock;
 102
 103 /**
 104  * genlmsg_put - Add generic netlink header to netlink message
 105  * @skb: socket buffer holding the message
 106  * @pid: netlink pid the message is addressed to
 107  * @seq: sequence number (usually the one of the sender)
 108  * @family: generic netlink family
 109  * @flags netlink message flags
 110  * @cmd: generic netlink command
 111  *
 112  * Returns pointer to user specific header
 113  */
 114 static inline void *genlmsg_put(struct sk_buff *skb, u32 pid, u32 seq,
 115                                 struct genl_family *family, int flags, u8 cmd)
 116 {
 117         struct nlmsghdr *nlh;
 118         struct genlmsghdr *hdr;
 119
 120         nlh = nlmsg_put(skb, pid, seq, family->id, GENL_HDRLEN +
 121                         family->hdrsize, flags);
 122         if (nlh == NULL)
 123                 return NULL;
 124
 125         hdr = nlmsg_data(nlh);
 126         hdr->cmd = cmd;
 127         hdr->version = family->version;
 128         hdr->reserved = 0;
 129
 130         return (char *) hdr + GENL_HDRLEN;
 131 }
 132
 133 /**
 134  * genlmsg_put_reply - Add generic netlink header to a reply message
 135  * @skb: socket buffer holding the message
 136  * @info: receiver info
 137  * @family: generic netlink family
 138  * @flags: netlink message flags
 139  * @cmd: generic netlink command
 140  *
 141  * Returns pointer to user specific header
 142  */
 143 static inline void *genlmsg_put_reply(struct sk_buff *skb,
 144                                       struct genl_info *info,
 145                                       struct genl_family *family,
 146                                       int flags, u8 cmd)
 147 {
 148         return genlmsg_put(skb, info->snd_pid, info->snd_seq, family,
 149                            flags, cmd);
 150 }
 151
 152 /**
 153  * genlmsg_end - Finalize a generic netlink message
 154  * @skb: socket buffer the message is stored in
 155  * @hdr: user specific header
 156  */
 157 static inline int genlmsg_end(struct sk_buff *skb, void *hdr)
 158 {
 159         return nlmsg_end(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
 160 }
 161
 162 /**
 163  * genlmsg_cancel - Cancel construction of a generic netlink message
 164  * @skb: socket buffer the message is stored in
 165  * @hdr: generic netlink message header
 166  */
 167 static inline void genlmsg_cancel(struct sk_buff *skb, void *hdr)
 168 {
 169         nlmsg_cancel(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
 170 }
 171
 172 /**
 173  * genlmsg_multicast - multicast a netlink message
 174  * @skb: netlink message as socket buffer
 175  * @pid: own netlink pid to avoid sending to yourself
 176  * @group: multicast group id
 177  * @flags: allocation flags
 178  */
 179 static inline int genlmsg_multicast(struct sk_buff *skb, u32 pid,
 180                                     unsigned int group, gfp_t flags)
 181 {
 182         return nlmsg_multicast(genl_sock, skb, pid, group, flags);
 183 }
 184
 185 /**
 186  * genlmsg_unicast - unicast a netlink message
 187  * @skb: netlink message as socket buffer
 188  * @pid: netlink pid of the destination socket
 189  */
 190 static inline int genlmsg_unicast(struct sk_buff *skb, u32 pid)
 191 {
 192         return nlmsg_unicast(genl_sock, skb, pid);
 193 }
 194
 195 /**
 196  * genlmsg_reply - reply to a request
 197  * @skb: netlink message to be sent back
 198  * @info: receiver information
 199  */
 200 static inline int genlmsg_reply(struct sk_buff *skb, struct genl_info *info)
 201 {
 202         return genlmsg_unicast(skb, info->snd_pid);
 203 }
 204
 205 /**
 206  * gennlmsg_data - head of message payload
 207  * @gnlh: genetlink messsage header
 208  */
 209 static inline void *genlmsg_data(const struct genlmsghdr *gnlh)
 210 {
 211         return ((unsigned char *) gnlh + GENL_HDRLEN);
 212 }
 213
 214 /**
 215  * genlmsg_len - length of message payload
 216  * @gnlh: genetlink message header
 217  */
 218 static inline int genlmsg_len(const struct genlmsghdr *gnlh)
 219 {
 220         struct nlmsghdr *nlh = (struct nlmsghdr *)((unsigned char *)gnlh -
 221                                                         NLMSG_HDRLEN);
 222         return (nlh->nlmsg_len - GENL_HDRLEN - NLMSG_HDRLEN);
 223 }
 224
 225 /**
 226  * genlmsg_msg_size - length of genetlink message not including padding
 227  * @payload: length of message payload
 228  */
 229 static inline int genlmsg_msg_size(int payload)
 230 {
 231         return GENL_HDRLEN + payload;
 232 }
 233
 234 /**
 235  * genlmsg_total_size - length of genetlink message including padding
 236  * @payload: length of message payload
 237  */
 238 static inline int genlmsg_total_size(int payload)
 239 {
 240         return NLMSG_ALIGN(genlmsg_msg_size(payload));
 241 }
 242
 243 /**
 244  * genlmsg_new - Allocate a new generic netlink message
 245  * @payload: size of the message payload
 246  * @flags: the type of memory to allocate.
 247  */
 248 static inline struct sk_buff *genlmsg_new(size_t payload, gfp_t flags)
 249 {
 250         return nlmsg_new(genlmsg_total_size(payload), flags);
 251 }
 252
 253
 254 #endif  /* __NET_GENERIC_NETLINK_H */