genetlink.h 9.2 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318
  1. #ifndef __NET_GENERIC_NETLINK_H
  2. #define __NET_GENERIC_NETLINK_H
  3. #include <linux/genetlink.h>
  4. #include <net/netlink.h>
  5. #include <net/net_namespace.h>
  6. /**
  7. * struct genl_multicast_group - generic netlink multicast group
  8. * @name: name of the multicast group, names are per-family
  9. * @id: multicast group ID, assigned by the core, to use with
  10. * genlmsg_multicast().
  11. * @list: list entry for linking
  12. * @family: pointer to family, need not be set before registering
  13. */
  14. struct genl_multicast_group {
  15. struct genl_family *family; /* private */
  16. struct list_head list; /* private */
  17. char name[GENL_NAMSIZ];
  18. u32 id;
  19. };
  20. struct genl_ops;
  21. struct genl_info;
  22. /**
  23. * struct genl_family - generic netlink family
  24. * @id: protocol family idenfitier
  25. * @hdrsize: length of user specific header in bytes
  26. * @name: name of family
  27. * @version: protocol version
  28. * @maxattr: maximum number of attributes supported
  29. * @netnsok: set to true if the family can handle network
  30. * namespaces and should be presented in all of them
  31. * @pre_doit: called before an operation's doit callback, it may
  32. * do additional, common, filtering and return an error
  33. * @post_doit: called after an operation's doit callback, it may
  34. * undo operations done by pre_doit, for example release locks
  35. * @attrbuf: buffer to store parsed attributes
  36. * @ops_list: list of all assigned operations
  37. * @family_list: family list
  38. * @mcast_groups: multicast groups list
  39. */
  40. struct genl_family {
  41. unsigned int id;
  42. unsigned int hdrsize;
  43. char name[GENL_NAMSIZ];
  44. unsigned int version;
  45. unsigned int maxattr;
  46. bool netnsok;
  47. int (*pre_doit)(struct genl_ops *ops,
  48. struct sk_buff *skb,
  49. struct genl_info *info);
  50. void (*post_doit)(struct genl_ops *ops,
  51. struct sk_buff *skb,
  52. struct genl_info *info);
  53. struct nlattr ** attrbuf; /* private */
  54. struct list_head ops_list; /* private */
  55. struct list_head family_list; /* private */
  56. struct list_head mcast_groups; /* private */
  57. };
  58. /**
  59. * struct genl_info - receiving information
  60. * @snd_seq: sending sequence number
  61. * @snd_pid: netlink pid of sender
  62. * @nlhdr: netlink message header
  63. * @genlhdr: generic netlink message header
  64. * @userhdr: user specific header
  65. * @attrs: netlink attributes
  66. * @_net: network namespace
  67. * @user_ptr: user pointers
  68. */
  69. struct genl_info {
  70. u32 snd_seq;
  71. u32 snd_pid;
  72. struct nlmsghdr * nlhdr;
  73. struct genlmsghdr * genlhdr;
  74. void * userhdr;
  75. struct nlattr ** attrs;
  76. #ifdef CONFIG_NET_NS
  77. struct net * _net;
  78. #endif
  79. void * user_ptr[2];
  80. };
  81. static inline struct net *genl_info_net(struct genl_info *info)
  82. {
  83. return read_pnet(&info->_net);
  84. }
  85. static inline void genl_info_net_set(struct genl_info *info, struct net *net)
  86. {
  87. write_pnet(&info->_net, net);
  88. }
  89. /**
  90. * struct genl_ops - generic netlink operations
  91. * @cmd: command identifier
  92. * @internal_flags: flags used by the family
  93. * @flags: flags
  94. * @policy: attribute validation policy
  95. * @doit: standard command callback
  96. * @dumpit: callback for dumpers
  97. * @done: completion callback for dumps
  98. * @ops_list: operations list
  99. */
  100. struct genl_ops {
  101. u8 cmd;
  102. u8 internal_flags;
  103. unsigned int flags;
  104. const struct nla_policy *policy;
  105. int (*doit)(struct sk_buff *skb,
  106. struct genl_info *info);
  107. int (*dumpit)(struct sk_buff *skb,
  108. struct netlink_callback *cb);
  109. int (*done)(struct netlink_callback *cb);
  110. struct list_head ops_list;
  111. };
  112. extern int genl_register_family(struct genl_family *family);
  113. extern int genl_register_family_with_ops(struct genl_family *family,
  114. struct genl_ops *ops, size_t n_ops);
  115. extern int genl_unregister_family(struct genl_family *family);
  116. extern int genl_register_ops(struct genl_family *, struct genl_ops *ops);
  117. extern int genl_unregister_ops(struct genl_family *, struct genl_ops *ops);
  118. extern int genl_register_mc_group(struct genl_family *family,
  119. struct genl_multicast_group *grp);
  120. extern void genl_unregister_mc_group(struct genl_family *family,
  121. struct genl_multicast_group *grp);
  122. extern void genl_notify(struct sk_buff *skb, struct net *net, u32 pid,
  123. u32 group, struct nlmsghdr *nlh, gfp_t flags);
  124. void *genlmsg_put(struct sk_buff *skb, u32 pid, u32 seq,
  125. struct genl_family *family, int flags, u8 cmd);
  126. /**
  127. * genlmsg_nlhdr - Obtain netlink header from user specified header
  128. * @user_hdr: user header as returned from genlmsg_put()
  129. * @family: generic netlink family
  130. *
  131. * Returns pointer to netlink header.
  132. */
  133. static inline struct nlmsghdr *genlmsg_nlhdr(void *user_hdr,
  134. struct genl_family *family)
  135. {
  136. return (struct nlmsghdr *)((char *)user_hdr -
  137. family->hdrsize -
  138. GENL_HDRLEN -
  139. NLMSG_HDRLEN);
  140. }
  141. /**
  142. * genl_dump_check_consistent - check if sequence is consistent and advertise if not
  143. * @cb: netlink callback structure that stores the sequence number
  144. * @user_hdr: user header as returned from genlmsg_put()
  145. * @family: generic netlink family
  146. *
  147. * Cf. nl_dump_check_consistent(), this just provides a wrapper to make it
  148. * simpler to use with generic netlink.
  149. */
  150. static inline void genl_dump_check_consistent(struct netlink_callback *cb,
  151. void *user_hdr,
  152. struct genl_family *family)
  153. {
  154. nl_dump_check_consistent(cb, genlmsg_nlhdr(user_hdr, family));
  155. }
  156. /**
  157. * genlmsg_put_reply - Add generic netlink header to a reply message
  158. * @skb: socket buffer holding the message
  159. * @info: receiver info
  160. * @family: generic netlink family
  161. * @flags: netlink message flags
  162. * @cmd: generic netlink command
  163. *
  164. * Returns pointer to user specific header
  165. */
  166. static inline void *genlmsg_put_reply(struct sk_buff *skb,
  167. struct genl_info *info,
  168. struct genl_family *family,
  169. int flags, u8 cmd)
  170. {
  171. return genlmsg_put(skb, info->snd_pid, info->snd_seq, family,
  172. flags, cmd);
  173. }
  174. /**
  175. * genlmsg_end - Finalize a generic netlink message
  176. * @skb: socket buffer the message is stored in
  177. * @hdr: user specific header
  178. */
  179. static inline int genlmsg_end(struct sk_buff *skb, void *hdr)
  180. {
  181. return nlmsg_end(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
  182. }
  183. /**
  184. * genlmsg_cancel - Cancel construction of a generic netlink message
  185. * @skb: socket buffer the message is stored in
  186. * @hdr: generic netlink message header
  187. */
  188. static inline void genlmsg_cancel(struct sk_buff *skb, void *hdr)
  189. {
  190. if (hdr)
  191. nlmsg_cancel(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
  192. }
  193. /**
  194. * genlmsg_multicast_netns - multicast a netlink message to a specific netns
  195. * @net: the net namespace
  196. * @skb: netlink message as socket buffer
  197. * @pid: own netlink pid to avoid sending to yourself
  198. * @group: multicast group id
  199. * @flags: allocation flags
  200. */
  201. static inline int genlmsg_multicast_netns(struct net *net, struct sk_buff *skb,
  202. u32 pid, unsigned int group, gfp_t flags)
  203. {
  204. return nlmsg_multicast(net->genl_sock, skb, pid, group, flags);
  205. }
  206. /**
  207. * genlmsg_multicast - multicast a netlink message to the default netns
  208. * @skb: netlink message as socket buffer
  209. * @pid: own netlink pid to avoid sending to yourself
  210. * @group: multicast group id
  211. * @flags: allocation flags
  212. */
  213. static inline int genlmsg_multicast(struct sk_buff *skb, u32 pid,
  214. unsigned int group, gfp_t flags)
  215. {
  216. return genlmsg_multicast_netns(&init_net, skb, pid, group, flags);
  217. }
  218. /**
  219. * genlmsg_multicast_allns - multicast a netlink message to all net namespaces
  220. * @skb: netlink message as socket buffer
  221. * @pid: own netlink pid to avoid sending to yourself
  222. * @group: multicast group id
  223. * @flags: allocation flags
  224. *
  225. * This function must hold the RTNL or rcu_read_lock().
  226. */
  227. int genlmsg_multicast_allns(struct sk_buff *skb, u32 pid,
  228. unsigned int group, gfp_t flags);
  229. /**
  230. * genlmsg_unicast - unicast a netlink message
  231. * @skb: netlink message as socket buffer
  232. * @pid: netlink pid of the destination socket
  233. */
  234. static inline int genlmsg_unicast(struct net *net, struct sk_buff *skb, u32 pid)
  235. {
  236. return nlmsg_unicast(net->genl_sock, skb, pid);
  237. }
  238. /**
  239. * genlmsg_reply - reply to a request
  240. * @skb: netlink message to be sent back
  241. * @info: receiver information
  242. */
  243. static inline int genlmsg_reply(struct sk_buff *skb, struct genl_info *info)
  244. {
  245. return genlmsg_unicast(genl_info_net(info), skb, info->snd_pid);
  246. }
  247. /**
  248. * gennlmsg_data - head of message payload
  249. * @gnlh: genetlink message header
  250. */
  251. static inline void *genlmsg_data(const struct genlmsghdr *gnlh)
  252. {
  253. return ((unsigned char *) gnlh + GENL_HDRLEN);
  254. }
  255. /**
  256. * genlmsg_len - length of message payload
  257. * @gnlh: genetlink message header
  258. */
  259. static inline int genlmsg_len(const struct genlmsghdr *gnlh)
  260. {
  261. struct nlmsghdr *nlh = (struct nlmsghdr *)((unsigned char *)gnlh -
  262. NLMSG_HDRLEN);
  263. return (nlh->nlmsg_len - GENL_HDRLEN - NLMSG_HDRLEN);
  264. }
  265. /**
  266. * genlmsg_msg_size - length of genetlink message not including padding
  267. * @payload: length of message payload
  268. */
  269. static inline int genlmsg_msg_size(int payload)
  270. {
  271. return GENL_HDRLEN + payload;
  272. }
  273. /**
  274. * genlmsg_total_size - length of genetlink message including padding
  275. * @payload: length of message payload
  276. */
  277. static inline int genlmsg_total_size(int payload)
  278. {
  279. return NLMSG_ALIGN(genlmsg_msg_size(payload));
  280. }
  281. /**
  282. * genlmsg_new - Allocate a new generic netlink message
  283. * @payload: size of the message payload
  284. * @flags: the type of memory to allocate.
  285. */
  286. static inline struct sk_buff *genlmsg_new(size_t payload, gfp_t flags)
  287. {
  288. return nlmsg_new(genlmsg_total_size(payload), flags);
  289. }
  290. #endif /* __NET_GENERIC_NETLINK_H */