Commit 5aa51d9f authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

genetlink: add genlmsg_iput() API 



Add some APIs and helpers required for convenient construction
of replies and notifications based on struct genl_info.

Reviewed-by: default avatarJiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/20230814214723.2924989-8-kuba@kernel.org


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 5c670a01

include/net/genetlink.h

+53 −1
Original line number Diff line number Diff line
@@ -113,7 +113,7 @@ struct genl_info { 
	struct netlink_ext_ack *extack;

};



static inline struct net *genl_info_net(struct genl_info *info)

static inline struct net *genl_info_net(const struct genl_info *info)

{

	return read_pnet(&info->_net);

}
@@ -270,6 +270,32 @@ 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 void

genl_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;

}



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,
@@ -278,6 +304,32 @@ void genl_notify(const struct genl_family *family, struct sk_buff *skb, 
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()