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Commit bb9b18fb authored by Thomas Graf's avatar Thomas Graf Committed by Jesse Gross
Browse files

genl: Add genlmsg_new_unicast() for unicast message allocation 



Allocates a new sk_buff large enough to cover the specified payload
plus required Netlink headers. Will check receiving socket for
memory mapped i/o capability and use it if enabled. Will fall back
to non-mapped skb if message size exceeds the frame size of the ring.

Signed-of-by: default avatarThomas Graf <tgraf@suug.ch>
Reviewed-by: default avatarDaniel Borkmann <dborkman@redhat.com>
Signed-off-by: default avatarJesse Gross <jesse@nicira.com>
parent 663efa36

include/net/genetlink.h

+4 −0
Original line number Diff line number Diff line
@@ -73,6 +73,7 @@ struct genl_family { 
 * @attrs: netlink attributes

 * @_net: network namespace

 * @user_ptr: user pointers

 * @dst_sk: destination socket

 */

struct genl_info {

	u32			snd_seq;
@@ -85,6 +86,7 @@ struct genl_info { 
	struct net *		_net;

#endif

	void *			user_ptr[2];

	struct sock *		dst_sk;

};



static inline struct net *genl_info_net(struct genl_info *info)
@@ -177,6 +179,8 @@ void genl_notify(struct genl_family *family, 
		 struct sk_buff *skb, struct net *net, u32 portid,

		 u32 group, struct nlmsghdr *nlh, gfp_t flags);



struct sk_buff *genlmsg_new_unicast(size_t payload, struct genl_info *info,

				    gfp_t flags);

void *genlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,

		  struct genl_family *family, int flags, u8 cmd);

net/netlink/genetlink.c

+21 −0
Original line number Diff line number Diff line
@@ -453,6 +453,26 @@ int genl_unregister_family(struct genl_family *family) 
}

EXPORT_SYMBOL(genl_unregister_family);



/**

 * genlmsg_new_unicast - Allocate generic netlink message for unicast

 * @payload: size of the message payload

 * @info: information on destination

 * @flags: the type of memory to allocate

 *

 * Allocates a new sk_buff large enough to cover the specified payload

 * plus required Netlink headers. Will check receiving socket for

 * memory mapped i/o capability and use it if enabled. Will fall back

 * to non-mapped skb if message size exceeds the frame size of the ring.

 */

struct sk_buff *genlmsg_new_unicast(size_t payload, struct genl_info *info,

				    gfp_t flags)

{

	size_t len = nlmsg_total_size(genlmsg_total_size(payload));



	return netlink_alloc_skb(info->dst_sk, len, info->snd_portid, flags);

}

EXPORT_SYMBOL_GPL(genlmsg_new_unicast);



/**

 * genlmsg_put - Add generic netlink header to netlink message

 * @skb: socket buffer holding the message
@@ -593,6 +613,7 @@ static int genl_family_rcv_msg(struct genl_family *family, 
	info.genlhdr = nlmsg_data(nlh);

	info.userhdr = nlmsg_data(nlh) + GENL_HDRLEN;

	info.attrs = attrbuf;

	info.dst_sk = skb->sk;

	genl_info_net_set(&info, net);

	memset(&info.user_ptr, 0, sizeof(info.user_ptr));