/* SPDX-License-Identifier: GPL-2.0 */#ifndef __NET_GENERIC_NETLINK_H#define __NET_GENERIC_NETLINK_H #include <linux/genetlink.h>#include <net/netlink.h>#include <net/net_namespace.h> #define GENLMSG_DEFAULT_SIZE (NLMSG_DEFAULT_SIZE - GENL_HDRLEN) /** * struct genl_multicast_group - generic netlink multicast group * @name: name of the multicast group, names are per-family */struct genl_multicast_group {	char			name[GENL_NAMSIZ];}; struct genl_ops;struct genl_info; /** * struct genl_family - generic netlink family * @id: protocol family identifier (private) * @hdrsize: length of user specific header in bytes * @name: name of family * @version: protocol version * @maxattr: maximum number of attributes supported * @policy: netlink policy * @netnsok: set to true if the family can handle network *	namespaces and should be presented in all of them * @parallel_ops: operations can be called in parallel and aren't *	synchronized by the core genetlink code * @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 * @mcgrps: multicast groups used by this family * @n_mcgrps: number of multicast groups * @mcgrp_offset: starting number of multicast group IDs in this family *	(private) * @ops: the operations supported by this family * @n_ops: number of operations supported by this family */struct genl_family {	int			id;		/* private */	unsigned int		hdrsize;	char			name[GENL_NAMSIZ];	unsigned int		version;	unsigned int		maxattr;	bool			netnsok;	bool			parallel_ops;	const struct nla_policy *policy;	int			(*pre_doit)(const struct genl_ops *ops,					    struct sk_buff *skb,					    struct genl_info *info);	void			(*post_doit)(const struct genl_ops *ops,					     struct sk_buff *skb,					     struct genl_info *info);	const struct genl_ops *	ops;	const struct genl_multicast_group *mcgrps;	unsigned int		n_ops;	unsigned int		n_mcgrps;	unsigned int		mcgrp_offset;	/* private */	struct module		*module;}; /** * struct genl_info - receiving information * @snd_seq: sending sequence number * @snd_portid: netlink portid 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 * @extack: extended ACK report struct */struct genl_info {	u32			snd_seq;	u32			snd_portid;	struct nlmsghdr *	nlhdr;	struct genlmsghdr *	genlhdr;	void *			userhdr;	struct nlattr **	attrs;	possible_net_t		_net;	void *			user_ptr[2];	struct netlink_ext_ack *extack;}; 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);} #define GENL_SET_ERR_MSG(info, msg) NL_SET_ERR_MSG((info)->extack, msg) static inline int genl_err_attr(struct genl_info *info, int err,				const struct nlattr *attr){	info->extack->bad_attr = attr; 	return err;} enum genl_validate_flags {	GENL_DONT_VALIDATE_STRICT		= BIT(0),	GENL_DONT_VALIDATE_DUMP			= BIT(1),	GENL_DONT_VALIDATE_DUMP_STRICT		= BIT(2),}; /** * struct genl_info - info that is available during dumpit op call * @family: generic netlink family - for internal genl code usage * @ops: generic netlink ops - for internal genl code usage * @attrs: netlink attributes */struct genl_dumpit_info {	const struct genl_family *family;	const struct genl_ops *ops;	struct nlattr **attrs;}; static inline const struct genl_dumpit_info *genl_dumpit_info(struct netlink_callback *cb){	return cb->data;} /** * struct genl_ops - generic netlink operations * @cmd: command identifier * @internal_flags: flags used by the family * @flags: flags * @doit: standard command callback * @start: start callback for dumps * @dumpit: callback for dumpers * @done: completion callback for dumps */struct genl_ops {	int		       (*doit)(struct sk_buff *skb,				       struct genl_info *info);	int		       (*start)(struct netlink_callback *cb);	int		       (*dumpit)(struct sk_buff *skb,					 struct netlink_callback *cb);	int		       (*done)(struct netlink_callback *cb);	u8			cmd;	u8			internal_flags;	u8			flags;	u8			validate;}; int genl_register_family(struct genl_family *family);int genl_unregister_family(const struct genl_family *family);void genl_notify(const struct genl_family *family, struct sk_buff *skb,		 struct genl_info *info, u32 group, gfp_t flags); void *genlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,		  const struct genl_family *family, int flags, u8 cmd); /** * genlmsg_nlhdr - Obtain netlink header from user specified header * @user_hdr: user header as returned from genlmsg_put() * * Returns pointer to netlink header. */static inline struct nlmsghdr *genlmsg_nlhdr(void *user_hdr){	return (struct nlmsghdr *)((char *)user_hdr -				   GENL_HDRLEN -				   NLMSG_HDRLEN);} /** * genlmsg_parse_deprecated - parse attributes of a genetlink message * @nlh: netlink message header * @family: genetlink message family * @tb: destination array with maxtype+1 elements * @maxtype: maximum attribute type to be expected * @policy: validation policy * @extack: extended ACK report struct */static inline int genlmsg_parse_deprecated(const struct nlmsghdr *nlh,					   const struct genl_family *family,					   struct nlattr *tb[], int maxtype,					   const struct nla_policy *policy,					   struct netlink_ext_ack *extack){	return __nlmsg_parse(nlh, family->hdrsize + GENL_HDRLEN, tb, maxtype,			     policy, NL_VALIDATE_LIBERAL, extack);} /** * genlmsg_parse - parse attributes of a genetlink message * @nlh: netlink message header * @family: genetlink message family * @tb: destination array with maxtype+1 elements * @maxtype: maximum attribute type to be expected * @policy: validation policy * @extack: extended ACK report struct */static inline int genlmsg_parse(const struct nlmsghdr *nlh,				const struct genl_family *family,				struct nlattr *tb[], int maxtype,				const struct nla_policy *policy,				struct netlink_ext_ack *extack){	return __nlmsg_parse(nlh, family->hdrsize + GENL_HDRLEN, tb, maxtype,			     policy, NL_VALIDATE_STRICT, extack);} /** * 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() * * 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){	nl_dump_check_consistent(cb, genlmsg_nlhdr(user_hdr));} /** * 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,				      const struct genl_family *family,				      int flags, u8 cmd){	return genlmsg_put(skb, info->snd_portid, 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 void genlmsg_end(struct sk_buff *skb, void *hdr){	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 * @family: the generic netlink family * @net: the net namespace * @skb: netlink message as socket buffer * @portid: own netlink portid to avoid sending to yourself * @group: offset of multicast group in groups array * @flags: allocation flags */static inline int genlmsg_multicast_netns(const struct genl_family *family,					  struct net *net, struct sk_buff *skb,					  u32 portid, unsigned int group, gfp_t flags){	if (WARN_ON_ONCE(group >= family->n_mcgrps))		return -EINVAL;	group = family->mcgrp_offset + group;	return nlmsg_multicast(net->genl_sock, skb, portid, group, flags);} /** * genlmsg_multicast - multicast a netlink message to the default netns * @family: the generic netlink family * @skb: netlink message as socket buffer * @portid: own netlink portid to avoid sending to yourself * @group: offset of multicast group in groups array * @flags: allocation flags */static inline int genlmsg_multicast(const struct genl_family *family,				    struct sk_buff *skb, u32 portid,				    unsigned int group, gfp_t flags){	return genlmsg_multicast_netns(family, &init_net, skb,				       portid, group, flags);} /** * genlmsg_multicast_allns - multicast a netlink message to all net namespaces * @family: the generic netlink family * @skb: netlink message as socket buffer * @portid: own netlink portid to avoid sending to yourself * @group: offset of multicast group in groups array * @flags: allocation flags * * This function must hold the RTNL or rcu_read_lock(). */int genlmsg_multicast_allns(const struct genl_family *family,			    struct sk_buff *skb, u32 portid,			    unsigned int group, gfp_t flags); /** * genlmsg_unicast - unicast a netlink message * @skb: netlink message as socket buffer * @portid: netlink portid of the destination socket */static inline int genlmsg_unicast(struct net *net, struct sk_buff *skb, u32 portid){	return nlmsg_unicast(net->genl_sock, skb, portid);} /** * 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_portid);} /** * 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);} /** * genl_set_err - report error to genetlink broadcast listeners * @family: the generic netlink family * @net: the network namespace to report the error to * @portid: the PORTID of a process that we want to skip (if any) * @group: the broadcast group that will notice the error * 	(this is the offset of the multicast group in the groups array) * @code: error code, must be negative (as usual in kernelspace) * * This function returns the number of broadcast listeners that have set the * NETLINK_RECV_NO_ENOBUFS socket option. */static inline int genl_set_err(const struct genl_family *family,			       struct net *net, u32 portid,			       u32 group, int code){	if (WARN_ON_ONCE(group >= family->n_mcgrps))		return -EINVAL;	group = family->mcgrp_offset + group;	return netlink_set_err(net->genl_sock, portid, group, code);} static inline int genl_has_listeners(const struct genl_family *family,				     struct net *net, unsigned int group){	if (WARN_ON_ONCE(group >= family->n_mcgrps))		return -EINVAL;	group = family->mcgrp_offset + group;	return netlink_has_listeners(net->genl_sock, group);}#endif	/* __NET_GENERIC_NETLINK_H */