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/* SPDX-License-Identifier: GPL-2.0 */#ifndef __NET_GENERIC_NETLINK_H#define __NET_GENERIC_NETLINK_H #include <linux/net.h>#include <net/netlink.h>#include <net/net_namespace.h>#include <uapi/linux/genetlink.h> #define GENLMSG_DEFAULT_SIZE (NLMSG_DEFAULT_SIZE - GENL_HDRLEN) /* Non-parallel generic netlink requests are serialized by a global lock. */void genl_lock(void);void genl_unlock(void); #define MODULE_ALIAS_GENL_FAMILY(family) \ MODULE_ALIAS_NET_PF_PROTO_NAME(PF_NETLINK, NETLINK_GENERIC, "-family-" family) /* Binding to multicast group requires %CAP_NET_ADMIN */#define GENL_MCAST_CAP_NET_ADMIN	BIT(0)/* Binding to multicast group requires %CAP_SYS_ADMIN */#define GENL_MCAST_CAP_SYS_ADMIN	BIT(1) /** * struct genl_multicast_group - generic netlink multicast group * @name: name of the multicast group, names are per-family * @flags: GENL_MCAST_* flags */struct genl_multicast_group {	char			name[GENL_NAMSIZ];	u8			flags;}; struct genl_split_ops;struct genl_info; /** * struct genl_family - generic netlink family * @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 * @bind: called when family multicast group is added to a netlink socket * @unbind: called when family multicast group is removed from a netlink socket * @module: pointer to the owning module (set to THIS_MODULE) * @mcgrps: multicast groups used by this family * @n_mcgrps: number of multicast groups * @resv_start_op: first operation for which reserved fields of the header *	can be validated and policies are required (see below); *	new families should leave this field at zero * @ops: the operations supported by this family * @n_ops: number of operations supported by this family * @small_ops: the small-struct operations supported by this family * @n_small_ops: number of small-struct operations supported by this family * @split_ops: the split do/dump form of operation definition * @n_split_ops: number of entries in @split_ops, note that with split do/dump *	ops the number of entries is not the same as number of commands * @sock_priv_size: the size of per-socket private memory * @sock_priv_init: the per-socket private memory initializer * @sock_priv_destroy: the per-socket private memory destructor * * Attribute policies (the combination of @policy and @maxattr fields) * can be attached at the family level or at the operation level. * If both are present the per-operation policy takes precedence. * For operations before @resv_start_op lack of policy means that the core * will perform no attribute parsing or validation. For newer operations * if policy is not provided core will reject all TLV attributes. */struct genl_family {	unsigned int		hdrsize;	char			name[GENL_NAMSIZ];	unsigned int		version;	unsigned int		maxattr;	u8			netnsok:1;	u8			parallel_ops:1;	u8			n_ops;	u8			n_small_ops;	u8			n_split_ops;	u8			n_mcgrps;	u8			resv_start_op;	const struct nla_policy *policy;	int			(*pre_doit)(const struct genl_split_ops *ops,					    struct sk_buff *skb,					    struct genl_info *info);	void			(*post_doit)(const struct genl_split_ops *ops,					     struct sk_buff *skb,					     struct genl_info *info);	int			(*bind)(int mcgrp);	void			(*unbind)(int mcgrp);	const struct genl_ops *	ops;	const struct genl_small_ops *small_ops;	const struct genl_split_ops *split_ops;	const struct genl_multicast_group *mcgrps;	struct module		*module; 	size_t			sock_priv_size;	void			(*sock_priv_init)(void *priv);	void			(*sock_priv_destroy)(void *priv); /* private: internal use only */	/* protocol family identifier */	int			id;	/* starting number of multicast group IDs in this family */	unsigned int		mcgrp_offset;	/* list of per-socket privs */	struct xarray		*sock_privs;}; /** * struct genl_info - receiving information * @snd_seq: sending sequence number * @snd_portid: netlink portid of sender * @family: generic netlink family * @nlhdr: netlink message header * @genlhdr: generic netlink message header * @attrs: netlink attributes * @_net: network namespace * @ctx: storage space for the use by the family * @user_ptr: user pointers (deprecated, use ctx instead) * @extack: extended ACK report struct */struct genl_info {	u32			snd_seq;	u32			snd_portid;	const struct genl_family *family;	const struct nlmsghdr *	nlhdr;	struct genlmsghdr *	genlhdr;	struct nlattr **	attrs;	possible_net_t		_net;	union {		u8		ctx[NETLINK_CTX_SIZE];		void *		user_ptr[2];	};	struct netlink_ext_ack *extack;}; static inline struct net *genl_info_net(const 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);} static inline void *genl_info_userhdr(const struct genl_info *info){	return (u8 *)info->genlhdr + GENL_HDRLEN;} #define GENL_SET_ERR_MSG(info, msg) NL_SET_ERR_MSG((info)->extack, msg) #define GENL_SET_ERR_MSG_FMT(info, msg, args...) \	NL_SET_ERR_MSG_FMT((info)->extack, msg, ##args) /* Report that a root attribute is missing */#define GENL_REQ_ATTR_CHECK(info, attr) ({				\	const struct genl_info *__info = (info);			\									\	NL_REQ_ATTR_CHECK(__info->extack, NULL, __info->attrs, (attr)); \}) 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_small_ops - generic netlink operations (small version) * @cmd: command identifier * @internal_flags: flags used by the family * @flags: GENL_* flags (%GENL_ADMIN_PERM or %GENL_UNS_ADMIN_PERM) * @validate: validation flags from enum genl_validate_flags * @doit: standard command callback * @dumpit: callback for dumpers * * This is a cut-down version of struct genl_ops for users who don't need * most of the ancillary infra and want to save space. */struct genl_small_ops {	int	(*doit)(struct sk_buff *skb, struct genl_info *info);	int	(*dumpit)(struct sk_buff *skb, struct netlink_callback *cb);	u8	cmd;	u8	internal_flags;	u8	flags;	u8	validate;}; /** * struct genl_ops - generic netlink operations * @cmd: command identifier * @internal_flags: flags used by the family * @flags: GENL_* flags (%GENL_ADMIN_PERM or %GENL_UNS_ADMIN_PERM) * @maxattr: maximum number of attributes supported * @policy: netlink policy (takes precedence over family policy) * @validate: validation flags from enum genl_validate_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);	const struct nla_policy *policy;	unsigned int		maxattr;	u8			cmd;	u8			internal_flags;	u8			flags;	u8			validate;}; /** * struct genl_split_ops - generic netlink operations (do/dump split version) * @cmd: command identifier * @internal_flags: flags used by the family * @flags: GENL_* flags (%GENL_ADMIN_PERM or %GENL_UNS_ADMIN_PERM) * @validate: validation flags from enum genl_validate_flags * @policy: netlink policy (takes precedence over family policy) * @maxattr: maximum number of attributes supported * * Do callbacks: * @pre_doit: called before an operation's @doit callback, it may *	do additional, common, filtering and return an error * @doit: standard command callback * @post_doit: called after an operation's @doit callback, it may *	undo operations done by pre_doit, for example release locks * * Dump callbacks: * @start: start callback for dumps * @dumpit: callback for dumpers * @done: completion callback for dumps * * Do callbacks can be used if %GENL_CMD_CAP_DO is set in @flags. * Dump callbacks can be used if %GENL_CMD_CAP_DUMP is set in @flags. * Exactly one of those flags must be set. */struct genl_split_ops {	union {		struct {			int (*pre_doit)(const struct genl_split_ops *ops,					struct sk_buff *skb,					struct genl_info *info);			int (*doit)(struct sk_buff *skb,				    struct genl_info *info);			void (*post_doit)(const struct genl_split_ops *ops,					  struct sk_buff *skb,					  struct genl_info *info);		};		struct {			int (*start)(struct netlink_callback *cb);			int (*dumpit)(struct sk_buff *skb,				      struct netlink_callback *cb);			int (*done)(struct netlink_callback *cb);		};	};	const struct nla_policy *policy;	unsigned int		maxattr;	u8			cmd;	u8			internal_flags;	u8			flags;	u8			validate;}; /** * struct genl_dumpit_info - info that is available during dumpit op call * @op: generic netlink ops - for internal genl code usage * @attrs: netlink attributes * @info: struct genl_info describing the request */struct genl_dumpit_info {	struct genl_split_ops op;	struct genl_info info;}; static inline const struct genl_dumpit_info *genl_dumpit_info(struct netlink_callback *cb){	return cb->data;} static inline const struct genl_info *genl_info_dump(struct netlink_callback *cb){	return &genl_dumpit_info(cb)->info;} /** * genl_info_init_ntf() - initialize genl_info for notifications * @info:   genl_info struct to set up * @family: pointer to the genetlink family * @cmd:    command to be used in the notification * * Initialize a locally declared struct genl_info to pass to various APIs. * Intended to be used when creating notifications. */static inline voidgenl_info_init_ntf(struct genl_info *info, const struct genl_family *family,		   u8 cmd){	struct genlmsghdr *hdr = (void *) &info->user_ptr[0]; 	memset(info, 0, sizeof(*info));	info->family = family;	info->genlhdr = hdr;	hdr->cmd = cmd;} static inline bool genl_info_is_ntf(const struct genl_info *info){	return !info->nlhdr;} void *__genl_sk_priv_get(struct genl_family *family, struct sock *sk);void *genl_sk_priv_get(struct genl_family *family, struct sock *sk);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); static inline void *__genlmsg_iput(struct sk_buff *skb, const struct genl_info *info, int flags){	return genlmsg_put(skb, info->snd_portid, info->snd_seq, info->family,			   flags, info->genlhdr->cmd);} /** * genlmsg_iput - start genetlink message based on genl_info * @skb: skb in which message header will be placed * @info: genl_info as provided to do/dump handlers * * Convenience wrapper which starts a genetlink message based on * information in user request. @info should be either the struct passed * by genetlink core to do/dump handlers (when constructing replies to * such requests) or a struct initialized by genl_info_init_ntf() * when constructing notifications. * * Returns: pointer to new genetlink header. */static inline void *genlmsg_iput(struct sk_buff *skb, const struct genl_info *info){	return __genlmsg_iput(skb, info, 0);} /** * 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_filtered - multicast a netlink message *				      to a specific netns with filter *				      function * @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 * @filter: filter function * @filter_data: filter function private data * * Return: 0 on success, negative error code for failure. */static inline intgenlmsg_multicast_netns_filtered(const struct genl_family *family,				 struct net *net, struct sk_buff *skb,				 u32 portid, unsigned int group, gfp_t flags,				 netlink_filter_fn filter,				 void *filter_data){	if (WARN_ON_ONCE(group >= family->n_mcgrps)) {		nlmsg_free(skb);		return -EINVAL;	}	group = family->mcgrp_offset + group;	return nlmsg_multicast_filtered(net->genl_sock, skb, portid, group,					flags, filter, filter_data);} 

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