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  * @done: completion callback for dumps
  57  * @ops_list: operations list
  58  */
  59 struct genl_ops
  60 {
  61         u8                      cmd;
  62         unsigned int            flags;
  63         const struct nla_policy *policy;
  64         int                    (*doit)(struct sk_buff *skb,
  65                                        struct genl_info *info);
  66         int                    (*dumpit)(struct sk_buff *skb,
  67                                          struct netlink_callback *cb);
  68         int                    (*done)(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  * @family: generic netlink family
  85  * @flags netlink message flags
  86  * @cmd: generic netlink command
  87  *
  88  * Returns pointer to user specific header
  89  */
  90 static inline void *genlmsg_put(struct sk_buff *skb, u32 pid, u32 seq,
  91                                 struct genl_family *family, int flags, u8 cmd)
  92 {
  93         struct nlmsghdr *nlh;
  94         struct genlmsghdr *hdr;
  95
  96         nlh = nlmsg_put(skb, pid, seq, family->id, GENL_HDRLEN +
  97                         family->hdrsize, flags);
  98         if (nlh == NULL)
  99                 return NULL;
 100
 101         hdr = nlmsg_data(nlh);
 102         hdr->cmd = cmd;
 103         hdr->version = family->version;
 104         hdr->reserved = 0;
 105
 106         return (char *) hdr + GENL_HDRLEN;
 107 }
 108
 109 /**
 110  * genlmsg_put_reply - Add generic netlink header to a reply message
 111  * @skb: socket buffer holding the message
 112  * @info: receiver info
 113  * @family: generic netlink family
 114  * @flags: netlink message flags
 115  * @cmd: generic netlink command
 116  *
 117  * Returns pointer to user specific header
 118  */
 119 static inline void *genlmsg_put_reply(struct sk_buff *skb,
 120                                       struct genl_info *info,
 121                                       struct genl_family *family,
 122                                       int flags, u8 cmd)
 123 {
 124         return genlmsg_put(skb, info->snd_pid, info->snd_seq, family,
 125                            flags, cmd);
 126 }
 127
 128 /**
 129  * genlmsg_end - Finalize a generic netlink message
 130  * @skb: socket buffer the message is stored in
 131  * @hdr: user specific header
 132  */
 133 static inline int genlmsg_end(struct sk_buff *skb, void *hdr)
 134 {
 135         return nlmsg_end(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
 136 }
 137
 138 /**
 139  * genlmsg_cancel - Cancel construction of a generic netlink message
 140  * @skb: socket buffer the message is stored in
 141  * @hdr: generic netlink message header
 142  */
 143 static inline int genlmsg_cancel(struct sk_buff *skb, void *hdr)
 144 {
 145         return nlmsg_cancel(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
 146 }
 147
 148 /**
 149  * genlmsg_multicast - multicast a netlink message
 150  * @skb: netlink message as socket buffer
 151  * @pid: own netlink pid to avoid sending to yourself
 152  * @group: multicast group id
 153  * @flags: allocation flags
 154  */
 155 static inline int genlmsg_multicast(struct sk_buff *skb, u32 pid,
 156                                     unsigned int group, gfp_t flags)
 157 {
 158         return nlmsg_multicast(genl_sock, skb, pid, group, flags);
 159 }
 160
 161 /**
 162  * genlmsg_unicast - unicast a netlink message
 163  * @skb: netlink message as socket buffer
 164  * @pid: netlink pid of the destination socket
 165  */
 166 static inline int genlmsg_unicast(struct sk_buff *skb, u32 pid)
 167 {
 168         return nlmsg_unicast(genl_sock, skb, pid);
 169 }
 170
 171 /**
 172  * genlmsg_reply - reply to a request
 173  * @skb: netlink message to be sent back
 174  * @info: receiver information
 175  */
 176 static inline int genlmsg_reply(struct sk_buff *skb, struct genl_info *info)
 177 {
 178         return genlmsg_unicast(skb, info->snd_pid);
 179 }
 180
 181 /**
 182  * gennlmsg_data - head of message payload
 183  * @gnlh: genetlink messsage header
 184  */
 185 static inline void *genlmsg_data(const struct genlmsghdr *gnlh)
 186 {
 187         return ((unsigned char *) gnlh + GENL_HDRLEN);
 188 }
 189
 190 /**
 191  * genlmsg_len - length of message payload
 192  * @gnlh: genetlink message header
 193  */
 194 static inline int genlmsg_len(const struct genlmsghdr *gnlh)
 195 {
 196         struct nlmsghdr *nlh = (struct nlmsghdr *)((unsigned char *)gnlh -
 197                                                         NLMSG_HDRLEN);
 198         return (nlh->nlmsg_len - GENL_HDRLEN - NLMSG_HDRLEN);
 199 }
 200
 201 /**
 202  * genlmsg_msg_size - length of genetlink message not including padding
 203  * @payload: length of message payload
 204  */
 205 static inline int genlmsg_msg_size(int payload)
 206 {
 207         return GENL_HDRLEN + payload;
 208 }
 209
 210 /**
 211  * genlmsg_total_size - length of genetlink message including padding
 212  * @payload: length of message payload
 213  */
 214 static inline int genlmsg_total_size(int payload)
 215 {
 216         return NLMSG_ALIGN(genlmsg_msg_size(payload));
 217 }
 218
 219 /**
 220  * genlmsg_new - Allocate a new generic netlink message
 221  * @payload: size of the message payload
 222  * @flags: the type of memory to allocate.
 223  */
 224 static inline struct sk_buff *genlmsg_new(size_t payload, gfp_t flags)
 225 {
 226         return nlmsg_new(genlmsg_total_size(payload), flags);
 227 }
 228
 229
 230 #endif  /* __NET_GENERIC_NETLINK_H */