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