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 static inline struct net *genl_info_net(struct genl_info *info) 72 { 73 return read_pnet(&info->_net); 74 } 75 76 static inline void genl_info_net_set(struct genl_info *info, struct net *net) 77 { 78 write_pnet(&info->_net, net); 79 } 80 81 /** 82 * struct genl_ops - generic netlink operations 83 * @cmd: command identifier 84 * @flags: flags 85 * @policy: attribute validation policy 86 * @doit: standard command callback 87 * @dumpit: callback for dumpers 88 * @done: completion callback for dumps 89 * @ops_list: operations list 90 */ 91 struct genl_ops { 92 u8 cmd; 93 unsigned int flags; 94 const struct nla_policy *policy; 95 int (*doit)(struct sk_buff *skb, 96 struct genl_info *info); 97 int (*dumpit)(struct sk_buff *skb, 98 struct netlink_callback *cb); 99 int (*done)(struct netlink_callback *cb); 100 struct list_head ops_list; 101 }; 102 103 extern int genl_register_family(struct genl_family *family); 104 extern int genl_register_family_with_ops(struct genl_family *family, 105 struct genl_ops *ops, size_t n_ops); 106 extern int genl_unregister_family(struct genl_family *family); 107 extern int genl_register_ops(struct genl_family *, struct genl_ops *ops); 108 extern int genl_unregister_ops(struct genl_family *, struct genl_ops *ops); 109 extern int genl_register_mc_group(struct genl_family *family, 110 struct genl_multicast_group *grp); 111 extern void genl_unregister_mc_group(struct genl_family *family, 112 struct genl_multicast_group *grp); 113 114 /** 115 * genlmsg_put - Add generic netlink header to netlink message 116 * @skb: socket buffer holding the message 117 * @pid: netlink pid the message is addressed to 118 * @seq: sequence number (usually the one of the sender) 119 * @family: generic netlink family 120 * @flags netlink message flags 121 * @cmd: generic netlink command 122 * 123 * Returns pointer to user specific header 124 */ 125 static inline void *genlmsg_put(struct sk_buff *skb, u32 pid, u32 seq, 126 struct genl_family *family, int flags, u8 cmd) 127 { 128 struct nlmsghdr *nlh; 129 struct genlmsghdr *hdr; 130 131 nlh = nlmsg_put(skb, pid, seq, family->id, GENL_HDRLEN + 132 family->hdrsize, flags); 133 if (nlh == NULL) 134 return NULL; 135 136 hdr = nlmsg_data(nlh); 137 hdr->cmd = cmd; 138 hdr->version = family->version; 139 hdr->reserved = 0; 140 141 return (char *) hdr + GENL_HDRLEN; 142 } 143 144 /** 145 * genlmsg_put_reply - Add generic netlink header to a reply message 146 * @skb: socket buffer holding the message 147 * @info: receiver info 148 * @family: generic netlink family 149 * @flags: netlink message flags 150 * @cmd: generic netlink command 151 * 152 * Returns pointer to user specific header 153 */ 154 static inline void *genlmsg_put_reply(struct sk_buff *skb, 155 struct genl_info *info, 156 struct genl_family *family, 157 int flags, u8 cmd) 158 { 159 return genlmsg_put(skb, info->snd_pid, info->snd_seq, family, 160 flags, cmd); 161 } 162 163 /** 164 * genlmsg_end - Finalize a generic netlink message 165 * @skb: socket buffer the message is stored in 166 * @hdr: user specific header 167 */ 168 static inline int genlmsg_end(struct sk_buff *skb, void *hdr) 169 { 170 return nlmsg_end(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN); 171 } 172 173 /** 174 * genlmsg_cancel - Cancel construction of a generic netlink message 175 * @skb: socket buffer the message is stored in 176 * @hdr: generic netlink message header 177 */ 178 static inline void genlmsg_cancel(struct sk_buff *skb, void *hdr) 179 { 180 nlmsg_cancel(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN); 181 } 182 183 /** 184 * genlmsg_multicast_netns - multicast a netlink message to a specific netns 185 * @net: the net namespace 186 * @skb: netlink message as socket buffer 187 * @pid: own netlink pid to avoid sending to yourself 188 * @group: multicast group id 189 * @flags: allocation flags 190 */ 191 static inline int genlmsg_multicast_netns(struct net *net, struct sk_buff *skb, 192 u32 pid, unsigned int group, gfp_t flags) 193 { 194 return nlmsg_multicast(net->genl_sock, skb, pid, group, flags); 195 } 196 197 /** 198 * genlmsg_multicast - multicast a netlink message to the default netns 199 * @skb: netlink message as socket buffer 200 * @pid: own netlink pid to avoid sending to yourself 201 * @group: multicast group id 202 * @flags: allocation flags 203 */ 204 static inline int genlmsg_multicast(struct sk_buff *skb, u32 pid, 205 unsigned int group, gfp_t flags) 206 { 207 return genlmsg_multicast_netns(&init_net, skb, pid, group, flags); 208 } 209 210 /** 211 * genlmsg_multicast_allns - multicast a netlink message to all net namespaces 212 * @skb: netlink message as socket buffer 213 * @pid: own netlink pid to avoid sending to yourself 214 * @group: multicast group id 215 * @flags: allocation flags 216 * 217 * This function must hold the RTNL or rcu_read_lock(). 218 */ 219 int genlmsg_multicast_allns(struct sk_buff *skb, u32 pid, 220 unsigned int group, gfp_t flags); 221 222 /** 223 * genlmsg_unicast - unicast a netlink message 224 * @skb: netlink message as socket buffer 225 * @pid: netlink pid of the destination socket 226 */ 227 static inline int genlmsg_unicast(struct net *net, struct sk_buff *skb, u32 pid) 228 { 229 return nlmsg_unicast(net->genl_sock, skb, pid); 230 } 231 232 /** 233 * genlmsg_reply - reply to a request 234 * @skb: netlink message to be sent back 235 * @info: receiver information 236 */ 237 static inline int genlmsg_reply(struct sk_buff *skb, struct genl_info *info) 238 { 239 return genlmsg_unicast(genl_info_net(info), skb, info->snd_pid); 240 } 241 242 /** 243 * gennlmsg_data - head of message payload 244 * @gnlh: genetlink messsage header 245 */ 246 static inline void *genlmsg_data(const struct genlmsghdr *gnlh) 247 { 248 return ((unsigned char *) gnlh + GENL_HDRLEN); 249 } 250 251 /** 252 * genlmsg_len - length of message payload 253 * @gnlh: genetlink message header 254 */ 255 static inline int genlmsg_len(const struct genlmsghdr *gnlh) 256 { 257 struct nlmsghdr *nlh = (struct nlmsghdr *)((unsigned char *)gnlh - 258 NLMSG_HDRLEN); 259 return (nlh->nlmsg_len - GENL_HDRLEN - NLMSG_HDRLEN); 260 } 261 262 /** 263 * genlmsg_msg_size - length of genetlink message not including padding 264 * @payload: length of message payload 265 */ 266 static inline int genlmsg_msg_size(int payload) 267 { 268 return GENL_HDRLEN + payload; 269 } 270 271 /** 272 * genlmsg_total_size - length of genetlink message including padding 273 * @payload: length of message payload 274 */ 275 static inline int genlmsg_total_size(int payload) 276 { 277 return NLMSG_ALIGN(genlmsg_msg_size(payload)); 278 } 279 280 /** 281 * genlmsg_new - Allocate a new generic netlink message 282 * @payload: size of the message payload 283 * @flags: the type of memory to allocate. 284 */ 285 static inline struct sk_buff *genlmsg_new(size_t payload, gfp_t flags) 286 { 287 return nlmsg_new(genlmsg_total_size(payload), flags); 288 } 289 290 291 #endif /* __NET_GENERIC_NETLINK_H */ 292