[PATCH] Wrong calcultation in nla_reserve

[Emmanuel Thierry]

Hello

There seams to be an error in the calculation of needed space for the message in nla_reserve. The current size of the message is counted twice: Once in NLMSG_ALIGN, once in the condition below.
This causes nla_put_* calls to be rejected if the allocation size of the message has been strictly calculated by the caller.

Best regards.
Emmanuel Thierry

Note: please keep me in cc in answers.

diff --git a/lib/attr.c b/lib/attr.c
index e6efe4e..8d27494 100644
--- a/lib/attr.c
+++ b/lib/attr.c
@@ -464,7 +464,7 @@ struct nlattr *nla_reserve(struct nl_msg *msg, int attrtype, int attrlen)
 	
 	tlen = NLMSG_ALIGN(msg->nm_nlh->nlmsg_len) + nla_total_size(attrlen);
 
-	if ((tlen + msg->nm_nlh->nlmsg_len) > msg->nm_size)
+	if (tlen > msg->nm_size)
 		return NULL;
 
 	nla = (struct nlattr *) nlmsg_tail(msg->nm_nlh);