1 #ifndef __NET_GENERIC_NETLINK_H 2 #define __NET_GENERIC_NETLINK_H 3 4 #include <linux/genetlink.h> 5 #include <net/netlink.h> 6 #include <net/net_namespace.h> 7 8 #define GENLMSG_DEFAULT_SIZE (NLMSG_DEFAULT_SIZE - GENL_HDRLEN) 9 10 /** 11 * struct genl_multicast_group - generic netlink multicast group 12 * @name: name of the multicast group, names are per-family 13 * @id: multicast group ID, assigned by the core, to use with 14 * genlmsg_multicast(). 15 * @list: list entry for linking 16 * @family: pointer to family, need not be set before registering 17 */ 18 struct genl_multicast_group { 19 struct genl_family *family; /* private */ 20 struct list_head list; /* private */ 21 char name[GENL_NAMSIZ]; 22 u32 id; 23 }; 24 25 struct genl_ops; 26 struct genl_info; 27 28 /** 29 * struct genl_family - generic netlink family 30 * @id: protocol family idenfitier 31 * @hdrsize: length of user specific header in bytes 32 * @name: name of family 33 * @version: protocol version 34 * @maxattr: maximum number of attributes supported 35 * @netnsok: set to true if the family can handle network 36 * namespaces and should be presented in all of them 37 * @pre_doit: called before an operation's doit callback, it may 38 * do additional, common, filtering and return an error 39 * @post_doit: called after an operation's doit callback, it may 40 * undo operations done by pre_doit, for example release locks 41 * @attrbuf: buffer to store parsed attributes 42 * @ops_list: list of all assigned operations 43 * @family_list: family list 44 * @mcast_groups: multicast groups list 45 */ 46 struct genl_family { 47 unsigned int id; 48 unsigned int hdrsize; 49 char name[GENL_NAMSIZ]; 50 unsigned int version; 51 unsigned int maxattr; 52 bool netnsok; 53 bool parallel_ops; 54 int (*pre_doit)(struct genl_ops *ops, 55 struct sk_buff *skb, 56 struct genl_info *info); 57 void (*post_doit)(struct genl_ops *ops, 58 struct sk_buff *skb, 59 struct genl_info *info); 60 struct nlattr ** attrbuf; /* private */ 61 struct list_head ops_list; /* private */ 62 struct list_head family_list; /* private */ 63 struct list_head mcast_groups; /* private */ 64 }; 65 66 /** 67 * struct genl_info - receiving information 68 * @snd_seq: sending sequence number 69 * @snd_portid: netlink portid of sender 70 * @nlhdr: netlink message header 71 * @genlhdr: generic netlink message header 72 * @userhdr: user specific header 73 * @attrs: netlink attributes 74 * @_net: network namespace 75 * @user_ptr: user pointers 76 */ 77 struct genl_info { 78 u32 snd_seq; 79 u32 snd_portid; 80 struct nlmsghdr * nlhdr; 81 struct genlmsghdr * genlhdr; 82 void * userhdr; 83 struct nlattr ** attrs; 84 #ifdef CONFIG_NET_NS 85 struct net * _net; 86 #endif 87 void * user_ptr[2]; 88 }; 89 90 static inline struct net *genl_info_net(struct genl_info *info) 91 { 92 return read_pnet(&info->_net); 93 } 94 95 static inline void genl_info_net_set(struct genl_info *info, struct net *net) 96 { 97 write_pnet(&info->_net, net); 98 } 99 100 /** 101 * struct genl_ops - generic netlink operations 102 * @cmd: command identifier 103 * @internal_flags: flags used by the family 104 * @flags: flags 105 * @policy: attribute validation policy 106 * @doit: standard command callback 107 * @dumpit: callback for dumpers 108 * @done: completion callback for dumps 109 * @ops_list: operations list 110 */ 111 struct genl_ops { 112 u8 cmd; 113 u8 internal_flags; 114 unsigned int flags; 115 const struct nla_policy *policy; 116 int (*doit)(struct sk_buff *skb, 117 struct genl_info *info); 118 int (*dumpit)(struct sk_buff *skb, 119 struct netlink_callback *cb); 120 int (*done)(struct netlink_callback *cb); 121 struct list_head ops_list; 122 }; 123 124 extern int genl_register_family(struct genl_family *family); 125 extern int genl_register_family_with_ops(struct genl_family *family, 126 struct genl_ops *ops, size_t n_ops); 127 extern int genl_unregister_family(struct genl_family *family); 128 extern int genl_register_ops(struct genl_family *, struct genl_ops *ops); 129 extern int genl_unregister_ops(struct genl_family *, struct genl_ops *ops); 130 extern int genl_register_mc_group(struct genl_family *family, 131 struct genl_multicast_group *grp); 132 extern void genl_unregister_mc_group(struct genl_family *family, 133 struct genl_multicast_group *grp); 134 extern void genl_notify(struct sk_buff *skb, struct net *net, u32 portid, 135 u32 group, struct nlmsghdr *nlh, gfp_t flags); 136 137 void *genlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, 138 struct genl_family *family, int flags, u8 cmd); 139 140 /** 141 * genlmsg_nlhdr - Obtain netlink header from user specified header 142 * @user_hdr: user header as returned from genlmsg_put() 143 * @family: generic netlink family 144 * 145 * Returns pointer to netlink header. 146 */ 147 static inline struct nlmsghdr *genlmsg_nlhdr(void *user_hdr, 148 struct genl_family *family) 149 { 150 return (struct nlmsghdr *)((char *)user_hdr - 151 family->hdrsize - 152 GENL_HDRLEN - 153 NLMSG_HDRLEN); 154 } 155 156 /** 157 * genl_dump_check_consistent - check if sequence is consistent and advertise if not 158 * @cb: netlink callback structure that stores the sequence number 159 * @user_hdr: user header as returned from genlmsg_put() 160 * @family: generic netlink family 161 * 162 * Cf. nl_dump_check_consistent(), this just provides a wrapper to make it 163 * simpler to use with generic netlink. 164 */ 165 static inline void genl_dump_check_consistent(struct netlink_callback *cb, 166 void *user_hdr, 167 struct genl_family *family) 168 { 169 nl_dump_check_consistent(cb, genlmsg_nlhdr(user_hdr, family)); 170 } 171 172 /** 173 * genlmsg_put_reply - Add generic netlink header to a reply message 174 * @skb: socket buffer holding the message 175 * @info: receiver info 176 * @family: generic netlink family 177 * @flags: netlink message flags 178 * @cmd: generic netlink command 179 * 180 * Returns pointer to user specific header 181 */ 182 static inline void *genlmsg_put_reply(struct sk_buff *skb, 183 struct genl_info *info, 184 struct genl_family *family, 185 int flags, u8 cmd) 186 { 187 return genlmsg_put(skb, info->snd_portid, info->snd_seq, family, 188 flags, cmd); 189 } 190 191 /** 192 * genlmsg_end - Finalize a generic netlink message 193 * @skb: socket buffer the message is stored in 194 * @hdr: user specific header 195 */ 196 static inline int genlmsg_end(struct sk_buff *skb, void *hdr) 197 { 198 return nlmsg_end(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN); 199 } 200 201 /** 202 * genlmsg_cancel - Cancel construction of a generic netlink message 203 * @skb: socket buffer the message is stored in 204 * @hdr: generic netlink message header 205 */ 206 static inline void genlmsg_cancel(struct sk_buff *skb, void *hdr) 207 { 208 if (hdr) 209 nlmsg_cancel(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN); 210 } 211 212 /** 213 * genlmsg_multicast_netns - multicast a netlink message to a specific netns 214 * @net: the net namespace 215 * @skb: netlink message as socket buffer 216 * @portid: own netlink portid to avoid sending to yourself 217 * @group: multicast group id 218 * @flags: allocation flags 219 */ 220 static inline int genlmsg_multicast_netns(struct net *net, struct sk_buff *skb, 221 u32 portid, unsigned int group, gfp_t flags) 222 { 223 return nlmsg_multicast(net->genl_sock, skb, portid, group, flags); 224 } 225 226 /** 227 * genlmsg_multicast - multicast a netlink message to the default netns 228 * @skb: netlink message as socket buffer 229 * @portid: own netlink portid to avoid sending to yourself 230 * @group: multicast group id 231 * @flags: allocation flags 232 */ 233 static inline int genlmsg_multicast(struct sk_buff *skb, u32 portid, 234 unsigned int group, gfp_t flags) 235 { 236 return genlmsg_multicast_netns(&init_net, skb, portid, group, flags); 237 } 238 239 /** 240 * genlmsg_multicast_allns - multicast a netlink message to all net namespaces 241 * @skb: netlink message as socket buffer 242 * @portid: own netlink portid to avoid sending to yourself 243 * @group: multicast group id 244 * @flags: allocation flags 245 * 246 * This function must hold the RTNL or rcu_read_lock(). 247 */ 248 int genlmsg_multicast_allns(struct sk_buff *skb, u32 portid, 249 unsigned int group, gfp_t flags); 250 251 /** 252 * genlmsg_unicast - unicast a netlink message 253 * @skb: netlink message as socket buffer 254 * @portid: netlink portid of the destination socket 255 */ 256 static inline int genlmsg_unicast(struct net *net, struct sk_buff *skb, u32 portid) 257 { 258 return nlmsg_unicast(net->genl_sock, skb, portid); 259 } 260 261 /** 262 * genlmsg_reply - reply to a request 263 * @skb: netlink message to be sent back 264 * @info: receiver information 265 */ 266 static inline int genlmsg_reply(struct sk_buff *skb, struct genl_info *info) 267 { 268 return genlmsg_unicast(genl_info_net(info), skb, info->snd_portid); 269 } 270 271 /** 272 * gennlmsg_data - head of message payload 273 * @gnlh: genetlink message header 274 */ 275 static inline void *genlmsg_data(const struct genlmsghdr *gnlh) 276 { 277 return ((unsigned char *) gnlh + GENL_HDRLEN); 278 } 279 280 /** 281 * genlmsg_len - length of message payload 282 * @gnlh: genetlink message header 283 */ 284 static inline int genlmsg_len(const struct genlmsghdr *gnlh) 285 { 286 struct nlmsghdr *nlh = (struct nlmsghdr *)((unsigned char *)gnlh - 287 NLMSG_HDRLEN); 288 return (nlh->nlmsg_len - GENL_HDRLEN - NLMSG_HDRLEN); 289 } 290 291 /** 292 * genlmsg_msg_size - length of genetlink message not including padding 293 * @payload: length of message payload 294 */ 295 static inline int genlmsg_msg_size(int payload) 296 { 297 return GENL_HDRLEN + payload; 298 } 299 300 /** 301 * genlmsg_total_size - length of genetlink message including padding 302 * @payload: length of message payload 303 */ 304 static inline int genlmsg_total_size(int payload) 305 { 306 return NLMSG_ALIGN(genlmsg_msg_size(payload)); 307 } 308 309 /** 310 * genlmsg_new - Allocate a new generic netlink message 311 * @payload: size of the message payload 312 * @flags: the type of memory to allocate. 313 */ 314 static inline struct sk_buff *genlmsg_new(size_t payload, gfp_t flags) 315 { 316 return nlmsg_new(genlmsg_total_size(payload), flags); 317 } 318 319 320 #endif /* __NET_GENERIC_NETLINK_H */ 321