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 /** 9 * struct genl_multicast_group - generic netlink multicast group 10 * @name: name of the multicast group, names are per-family 11 * @id: multicast group ID, assigned by the core, to use with 12 * genlmsg_multicast(). 13 * @list: list entry for linking 14 * @family: pointer to family, need not be set before registering 15 */ 16 struct genl_multicast_group 17 { 18 struct genl_family *family; /* private */ 19 struct list_head list; /* private */ 20 char name[GENL_NAMSIZ]; 21 u32 id; 22 }; 23 24 /** 25 * struct genl_family - generic netlink family 26 * @id: protocol family idenfitier 27 * @hdrsize: length of user specific header in bytes 28 * @name: name of family 29 * @version: protocol version 30 * @maxattr: maximum number of attributes supported 31 * @netnsok: set to true if the family can handle network 32 * namespaces and should be presented in all of them 33 * @attrbuf: buffer to store parsed attributes 34 * @ops_list: list of all assigned operations 35 * @family_list: family list 36 * @mcast_groups: multicast groups list 37 */ 38 struct genl_family 39 { 40 unsigned int id; 41 unsigned int hdrsize; 42 char name[GENL_NAMSIZ]; 43 unsigned int version; 44 unsigned int maxattr; 45 bool netnsok; 46 struct nlattr ** attrbuf; /* private */ 47 struct list_head ops_list; /* private */ 48 struct list_head family_list; /* private */ 49 struct list_head mcast_groups; /* private */ 50 }; 51 52 /** 53 * struct genl_info - receiving information 54 * @snd_seq: sending sequence number 55 * @snd_pid: netlink pid of sender 56 * @nlhdr: netlink message header 57 * @genlhdr: generic netlink message header 58 * @userhdr: user specific header 59 * @attrs: netlink attributes 60 */ 61 struct genl_info 62 { 63 u32 snd_seq; 64 u32 snd_pid; 65 struct nlmsghdr * nlhdr; 66 struct genlmsghdr * genlhdr; 67 void * userhdr; 68 struct nlattr ** attrs; 69 #ifdef CONFIG_NET_NS 70 struct net * _net; 71 #endif 72 }; 73 74 #ifdef CONFIG_NET_NS 75 static inline struct net *genl_info_net(struct genl_info *info) 76 { 77 return info->_net; 78 } 79 80 static inline void genl_info_net_set(struct genl_info *info, struct net *net) 81 { 82 info->_net = net; 83 } 84 #else 85 static inline struct net *genl_info_net(struct genl_info *info) 86 { 87 return &init_net; 88 } 89 90 static inline void genl_info_net_set(struct genl_info *info, struct net *net) 91 { 92 } 93 #endif 94 95 /** 96 * struct genl_ops - generic netlink operations 97 * @cmd: command identifier 98 * @flags: flags 99 * @policy: attribute validation policy 100 * @doit: standard command callback 101 * @dumpit: callback for dumpers 102 * @done: completion callback for dumps 103 * @ops_list: operations list 104 */ 105 struct genl_ops 106 { 107 u8 cmd; 108 unsigned int flags; 109 const struct nla_policy *policy; 110 int (*doit)(struct sk_buff *skb, 111 struct genl_info *info); 112 int (*dumpit)(struct sk_buff *skb, 113 struct netlink_callback *cb); 114 int (*done)(struct netlink_callback *cb); 115 struct list_head ops_list; 116 }; 117 118 extern int genl_register_family(struct genl_family *family); 119 extern int genl_register_family_with_ops(struct genl_family *family, 120 struct genl_ops *ops, size_t n_ops); 121 extern int genl_unregister_family(struct genl_family *family); 122 extern int genl_register_ops(struct genl_family *, struct genl_ops *ops); 123 extern int genl_unregister_ops(struct genl_family *, struct genl_ops *ops); 124 extern int genl_register_mc_group(struct genl_family *family, 125 struct genl_multicast_group *grp); 126 extern void genl_unregister_mc_group(struct genl_family *family, 127 struct genl_multicast_group *grp); 128 129 /** 130 * genlmsg_put - Add generic netlink header to netlink message 131 * @skb: socket buffer holding the message 132 * @pid: netlink pid the message is addressed to 133 * @seq: sequence number (usually the one of the sender) 134 * @family: generic netlink family 135 * @flags netlink message flags 136 * @cmd: generic netlink command 137 * 138 * Returns pointer to user specific header 139 */ 140 static inline void *genlmsg_put(struct sk_buff *skb, u32 pid, u32 seq, 141 struct genl_family *family, int flags, u8 cmd) 142 { 143 struct nlmsghdr *nlh; 144 struct genlmsghdr *hdr; 145 146 nlh = nlmsg_put(skb, pid, seq, family->id, GENL_HDRLEN + 147 family->hdrsize, flags); 148 if (nlh == NULL) 149 return NULL; 150 151 hdr = nlmsg_data(nlh); 152 hdr->cmd = cmd; 153 hdr->version = family->version; 154 hdr->reserved = 0; 155 156 return (char *) hdr + GENL_HDRLEN; 157 } 158 159 /** 160 * genlmsg_put_reply - Add generic netlink header to a reply message 161 * @skb: socket buffer holding the message 162 * @info: receiver info 163 * @family: generic netlink family 164 * @flags: netlink message flags 165 * @cmd: generic netlink command 166 * 167 * Returns pointer to user specific header 168 */ 169 static inline void *genlmsg_put_reply(struct sk_buff *skb, 170 struct genl_info *info, 171 struct genl_family *family, 172 int flags, u8 cmd) 173 { 174 return genlmsg_put(skb, info->snd_pid, info->snd_seq, family, 175 flags, cmd); 176 } 177 178 /** 179 * genlmsg_end - Finalize a generic netlink message 180 * @skb: socket buffer the message is stored in 181 * @hdr: user specific header 182 */ 183 static inline int genlmsg_end(struct sk_buff *skb, void *hdr) 184 { 185 return nlmsg_end(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN); 186 } 187 188 /** 189 * genlmsg_cancel - Cancel construction of a generic netlink message 190 * @skb: socket buffer the message is stored in 191 * @hdr: generic netlink message header 192 */ 193 static inline void genlmsg_cancel(struct sk_buff *skb, void *hdr) 194 { 195 nlmsg_cancel(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN); 196 } 197 198 /** 199 * genlmsg_multicast_netns - multicast a netlink message to a specific netns 200 * @net: the net namespace 201 * @skb: netlink message as socket buffer 202 * @pid: own netlink pid to avoid sending to yourself 203 * @group: multicast group id 204 * @flags: allocation flags 205 */ 206 static inline int genlmsg_multicast_netns(struct net *net, struct sk_buff *skb, 207 u32 pid, unsigned int group, gfp_t flags) 208 { 209 return nlmsg_multicast(net->genl_sock, skb, pid, group, flags); 210 } 211 212 /** 213 * genlmsg_multicast - multicast a netlink message to the default netns 214 * @skb: netlink message as socket buffer 215 * @pid: own netlink pid to avoid sending to yourself 216 * @group: multicast group id 217 * @flags: allocation flags 218 */ 219 static inline int genlmsg_multicast(struct sk_buff *skb, u32 pid, 220 unsigned int group, gfp_t flags) 221 { 222 return genlmsg_multicast_netns(&init_net, skb, pid, group, flags); 223 } 224 225 /** 226 * genlmsg_multicast_allns - multicast a netlink message to all net namespaces 227 * @skb: netlink message as socket buffer 228 * @pid: own netlink pid to avoid sending to yourself 229 * @group: multicast group id 230 * @flags: allocation flags 231 * 232 * This function must hold the RTNL or rcu_read_lock(). 233 */ 234 int genlmsg_multicast_allns(struct sk_buff *skb, u32 pid, 235 unsigned int group, gfp_t flags); 236 237 /** 238 * genlmsg_unicast - unicast a netlink message 239 * @skb: netlink message as socket buffer 240 * @pid: netlink pid of the destination socket 241 */ 242 static inline int genlmsg_unicast(struct net *net, struct sk_buff *skb, u32 pid) 243 { 244 return nlmsg_unicast(net->genl_sock, skb, pid); 245 } 246 247 /** 248 * genlmsg_reply - reply to a request 249 * @skb: netlink message to be sent back 250 * @info: receiver information 251 */ 252 static inline int genlmsg_reply(struct sk_buff *skb, struct genl_info *info) 253 { 254 return genlmsg_unicast(genl_info_net(info), skb, info->snd_pid); 255 } 256 257 /** 258 * gennlmsg_data - head of message payload 259 * @gnlh: genetlink messsage header 260 */ 261 static inline void *genlmsg_data(const struct genlmsghdr *gnlh) 262 { 263 return ((unsigned char *) gnlh + GENL_HDRLEN); 264 } 265 266 /** 267 * genlmsg_len - length of message payload 268 * @gnlh: genetlink message header 269 */ 270 static inline int genlmsg_len(const struct genlmsghdr *gnlh) 271 { 272 struct nlmsghdr *nlh = (struct nlmsghdr *)((unsigned char *)gnlh - 273 NLMSG_HDRLEN); 274 return (nlh->nlmsg_len - GENL_HDRLEN - NLMSG_HDRLEN); 275 } 276 277 /** 278 * genlmsg_msg_size - length of genetlink message not including padding 279 * @payload: length of message payload 280 */ 281 static inline int genlmsg_msg_size(int payload) 282 { 283 return GENL_HDRLEN + payload; 284 } 285 286 /** 287 * genlmsg_total_size - length of genetlink message including padding 288 * @payload: length of message payload 289 */ 290 static inline int genlmsg_total_size(int payload) 291 { 292 return NLMSG_ALIGN(genlmsg_msg_size(payload)); 293 } 294 295 /** 296 * genlmsg_new - Allocate a new generic netlink message 297 * @payload: size of the message payload 298 * @flags: the type of memory to allocate. 299 */ 300 static inline struct sk_buff *genlmsg_new(size_t payload, gfp_t flags) 301 { 302 return nlmsg_new(genlmsg_total_size(payload), flags); 303 } 304 305 306 #endif /* __NET_GENERIC_NETLINK_H */ 307