diff options
Diffstat (limited to 'include/net/genetlink.h')
| -rw-r--r-- | include/net/genetlink.h | 310 |
1 files changed, 310 insertions, 0 deletions
diff --git a/include/net/genetlink.h b/include/net/genetlink.h new file mode 100644 index 00000000..d420f28b --- /dev/null +++ b/include/net/genetlink.h @@ -0,0 +1,310 @@ +#ifndef __NET_GENERIC_NETLINK_H +#define __NET_GENERIC_NETLINK_H + +#include <linux/genetlink.h> +#include <net/netlink.h> +#include <net/net_namespace.h> + +/** + * struct genl_multicast_group - generic netlink multicast group + * @name: name of the multicast group, names are per-family + * @id: multicast group ID, assigned by the core, to use with + * genlmsg_multicast(). + * @list: list entry for linking + * @family: pointer to family, need not be set before registering + */ +struct genl_multicast_group { + struct genl_family *family; /* private */ + struct list_head list; /* private */ + char name[GENL_NAMSIZ]; + u32 id; +}; + +struct genl_ops; +struct genl_info; + +/** + * struct genl_family - generic netlink family + * @id: protocol family idenfitier + * @hdrsize: length of user specific header in bytes + * @name: name of family + * @version: protocol version + * @maxattr: maximum number of attributes supported + * @netnsok: set to true if the family can handle network + * namespaces and should be presented in all of them + * @pre_doit: called before an operation's doit callback, it may + * do additional, common, filtering and return an error + * @post_doit: called after an operation's doit callback, it may + * undo operations done by pre_doit, for example release locks + * @attrbuf: buffer to store parsed attributes + * @ops_list: list of all assigned operations + * @family_list: family list + * @mcast_groups: multicast groups list + */ +struct genl_family { + unsigned int id; + unsigned int hdrsize; + char name[GENL_NAMSIZ]; + unsigned int version; + unsigned int maxattr; + bool netnsok; + int (*pre_doit)(struct genl_ops *ops, + struct sk_buff *skb, + struct genl_info *info); + void (*post_doit)(struct genl_ops *ops, + struct sk_buff *skb, + struct genl_info *info); + struct nlattr ** attrbuf; /* private */ + struct list_head ops_list; /* private */ + struct list_head family_list; /* private */ + struct list_head mcast_groups; /* private */ +}; + +/** + * struct genl_info - receiving information + * @snd_seq: sending sequence number + * @snd_pid: netlink pid of sender + * @nlhdr: netlink message header + * @genlhdr: generic netlink message header + * @userhdr: user specific header + * @attrs: netlink attributes + * @_net: network namespace + * @user_ptr: user pointers + */ +struct genl_info { + u32 snd_seq; + u32 snd_pid; + struct nlmsghdr * nlhdr; + struct genlmsghdr * genlhdr; + void * userhdr; + struct nlattr ** attrs; +#ifdef CONFIG_NET_NS + struct net * _net; +#endif + void * user_ptr[2]; +}; + +static inline struct net *genl_info_net(struct genl_info *info) +{ + return read_pnet(&info->_net); +} + +static inline void genl_info_net_set(struct genl_info *info, struct net *net) +{ + write_pnet(&info->_net, net); +} + +/** + * struct genl_ops - generic netlink operations + * @cmd: command identifier + * @internal_flags: flags used by the family + * @flags: flags + * @policy: attribute validation policy + * @doit: standard command callback + * @dumpit: callback for dumpers + * @done: completion callback for dumps + * @ops_list: operations list + */ +struct genl_ops { + u8 cmd; + u8 internal_flags; + unsigned int flags; + const struct nla_policy *policy; + int (*doit)(struct sk_buff *skb, + struct genl_info *info); + int (*dumpit)(struct sk_buff *skb, + struct netlink_callback *cb); + int (*done)(struct netlink_callback *cb); + struct list_head ops_list; +}; + +extern int genl_register_family(struct genl_family *family); +extern int genl_register_family_with_ops(struct genl_family *family, + struct genl_ops *ops, size_t n_ops); +extern int genl_unregister_family(struct genl_family *family); +extern int genl_register_ops(struct genl_family *, struct genl_ops *ops); +extern int genl_unregister_ops(struct genl_family *, struct genl_ops *ops); +extern int genl_register_mc_group(struct genl_family *family, + struct genl_multicast_group *grp); +extern void genl_unregister_mc_group(struct genl_family *family, + struct genl_multicast_group *grp); + +/** + * genlmsg_put - Add generic netlink header to netlink message + * @skb: socket buffer holding the message + * @pid: netlink pid the message is addressed to + * @seq: sequence number (usually the one of the sender) + * @family: generic netlink family + * @flags netlink message flags + * @cmd: generic netlink command + * + * Returns pointer to user specific header + */ +static inline void *genlmsg_put(struct sk_buff *skb, u32 pid, u32 seq, + struct genl_family *family, int flags, u8 cmd) +{ + struct nlmsghdr *nlh; + struct genlmsghdr *hdr; + + nlh = nlmsg_put(skb, pid, seq, family->id, GENL_HDRLEN + + family->hdrsize, flags); + if (nlh == NULL) + return NULL; + + hdr = nlmsg_data(nlh); + hdr->cmd = cmd; + hdr->version = family->version; + hdr->reserved = 0; + + return (char *) hdr + GENL_HDRLEN; +} + +/** + * genlmsg_put_reply - Add generic netlink header to a reply message + * @skb: socket buffer holding the message + * @info: receiver info + * @family: generic netlink family + * @flags: netlink message flags + * @cmd: generic netlink command + * + * Returns pointer to user specific header + */ +static inline void *genlmsg_put_reply(struct sk_buff *skb, + struct genl_info *info, + struct genl_family *family, + int flags, u8 cmd) +{ + return genlmsg_put(skb, info->snd_pid, info->snd_seq, family, + flags, cmd); +} + +/** + * genlmsg_end - Finalize a generic netlink message + * @skb: socket buffer the message is stored in + * @hdr: user specific header + */ +static inline int genlmsg_end(struct sk_buff *skb, void *hdr) +{ + return nlmsg_end(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN); +} + +/** + * genlmsg_cancel - Cancel construction of a generic netlink message + * @skb: socket buffer the message is stored in + * @hdr: generic netlink message header + */ +static inline void genlmsg_cancel(struct sk_buff *skb, void *hdr) +{ + if (hdr) + nlmsg_cancel(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN); +} + +/** + * genlmsg_multicast_netns - multicast a netlink message to a specific netns + * @net: the net namespace + * @skb: netlink message as socket buffer + * @pid: own netlink pid to avoid sending to yourself + * @group: multicast group id + * @flags: allocation flags + */ +static inline int genlmsg_multicast_netns(struct net *net, struct sk_buff *skb, + u32 pid, unsigned int group, gfp_t flags) +{ + return nlmsg_multicast(net->genl_sock, skb, pid, group, flags); +} + +/** + * genlmsg_multicast - multicast a netlink message to the default netns + * @skb: netlink message as socket buffer + * @pid: own netlink pid to avoid sending to yourself + * @group: multicast group id + * @flags: allocation flags + */ +static inline int genlmsg_multicast(struct sk_buff *skb, u32 pid, + unsigned int group, gfp_t flags) +{ + return genlmsg_multicast_netns(&init_net, skb, pid, group, flags); +} + +/** + * genlmsg_multicast_allns - multicast a netlink message to all net namespaces + * @skb: netlink message as socket buffer + * @pid: own netlink pid to avoid sending to yourself + * @group: multicast group id + * @flags: allocation flags + * + * This function must hold the RTNL or rcu_read_lock(). + */ +int genlmsg_multicast_allns(struct sk_buff *skb, u32 pid, + unsigned int group, gfp_t flags); + +/** + * genlmsg_unicast - unicast a netlink message + * @skb: netlink message as socket buffer + * @pid: netlink pid of the destination socket + */ +static inline int genlmsg_unicast(struct net *net, struct sk_buff *skb, u32 pid) +{ + return nlmsg_unicast(net->genl_sock, skb, pid); +} + +/** + * genlmsg_reply - reply to a request + * @skb: netlink message to be sent back + * @info: receiver information + */ +static inline int genlmsg_reply(struct sk_buff *skb, struct genl_info *info) +{ + return genlmsg_unicast(genl_info_net(info), skb, info->snd_pid); +} + +/** + * gennlmsg_data - head of message payload + * @gnlh: genetlink message header + */ +static inline void *genlmsg_data(const struct genlmsghdr *gnlh) +{ + return ((unsigned char *) gnlh + GENL_HDRLEN); +} + +/** + * genlmsg_len - length of message payload + * @gnlh: genetlink message header + */ +static inline int genlmsg_len(const struct genlmsghdr *gnlh) +{ + struct nlmsghdr *nlh = (struct nlmsghdr *)((unsigned char *)gnlh - + NLMSG_HDRLEN); + return (nlh->nlmsg_len - GENL_HDRLEN - NLMSG_HDRLEN); +} + +/** + * genlmsg_msg_size - length of genetlink message not including padding + * @payload: length of message payload + */ +static inline int genlmsg_msg_size(int payload) +{ + return GENL_HDRLEN + payload; +} + +/** + * genlmsg_total_size - length of genetlink message including padding + * @payload: length of message payload + */ +static inline int genlmsg_total_size(int payload) +{ + return NLMSG_ALIGN(genlmsg_msg_size(payload)); +} + +/** + * genlmsg_new - Allocate a new generic netlink message + * @payload: size of the message payload + * @flags: the type of memory to allocate. + */ +static inline struct sk_buff *genlmsg_new(size_t payload, gfp_t flags) +{ + return nlmsg_new(genlmsg_total_size(payload), flags); +} + + +#endif /* __NET_GENERIC_NETLINK_H */ |