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