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Commit f88a10d6 authored by Thomas Graf's avatar Thomas Graf Committed by David S. Miller
Browse files

[NETLINK]: New message building macros 



 NLMSG_PUT_ANSWER(skb, nlcb, type, length)
   Start a new netlink message as answer to a request,
   returns the message header.

 NLMSG_END(skb, nlh)
   End a netlink message, fixes total message length,
   returns skb->len.

 NLMSG_CANCEL(skb, nlh)
   Cancel the building process and trim whole message
   from skb again, returns -1.

Signed-off-by: default avatarThomas Graf <tgraf@suug.ch>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent e52c1f17

include/linux/netlink.h

+15 −2
Original line number Diff line number Diff line
@@ -171,9 +171,22 @@ __nlmsg_put(struct sk_buff *skb, u32 pid, u32 seq, int type, int len) 
}



#define NLMSG_PUT(skb, pid, seq, type, len) \

({ if (skb_tailroom(skb) < (int)NLMSG_SPACE(len)) goto nlmsg_failure; \

({	if (skb_tailroom(skb) < (int)NLMSG_SPACE(len)) \

		goto nlmsg_failure; \

	__nlmsg_put(skb, pid, seq, type, len); })



#define NLMSG_PUT_ANSWER(skb, cb, type, len) \

	NLMSG_PUT(skb, NETLINK_CB((cb)->skb).pid, \

		  (cb)->nlh->nlmsg_seq, type, len)



#define NLMSG_END(skb, nlh) \

({	(nlh)->nlmsg_len = (skb)->tail - (unsigned char *) (nlh); \

	(skb)->len; })



#define NLMSG_CANCEL(skb, nlh) \

({	skb_trim(skb, (unsigned char *) (nlh) - (skb)->data); \

	-1; })



extern int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,

			      struct nlmsghdr *nlh,

			      int (*dump)(struct sk_buff *skb, struct netlink_callback*),