#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_nlhdr - Obtain netlink header from user specified header
* @user_hdr: user header as returned from genlmsg_put()
* @family: generic netlink family
*
* Returns pointer to netlink header.
*/
static inline struct nlmsghdr *genlmsg_nlhdr(void *user_hdr,
struct genl_family *family)
{
return (struct nlmsghdr *)((char *)user_hdr -
family->hdrsize -
GENL_HDRLEN -
NLMSG_HDRLEN);
}
/**
* genl_dump_check_consistent - check if sequence is consistent and advertise if not
* @cb: netlink callback structure that stores the sequence number
* @user_hdr: user header as returned from genlmsg_put()
* @family: generic netlink family
*
* Cf. nl_dump_check_consistent(), this just provides a wrapper to make it
* simpler to use with generic netlink.
*/
static inline void genl_dump_check_consistent(struct netlink_callback *cb,
void *user_hdr,
struct genl_family *family)
{
nl_dump_check_consistent(cb, genlmsg_nlhdr(user_hdr, family));
}
/**
* 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 */
