[SCTP]: ADDIP: Don't use an address as source until it is ASCONF-ACKed

This implements Rules D1 and D4 of Sec 4.3 in the ADDIP draft.

Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c
index 8ef0807..99c0cef 100644
--- a/net/sctp/ipv6.c
+++ b/net/sctp/ipv6.c
@@ -290,7 +290,8 @@
 	sctp_read_lock(addr_lock);
 	list_for_each(pos, &bp->address_list) {
 		laddr = list_entry(pos, struct sctp_sockaddr_entry, list);
-		if ((laddr->a.sa.sa_family == AF_INET6) &&
+		if ((laddr->use_as_src) &&
+		    (laddr->a.sa.sa_family == AF_INET6) &&
 		    (scope <= sctp_scope(&laddr->a))) {
 			bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
 			if (!baddr || (matchlen < bmatchlen)) {