sctp: Add ASCONF operation on the single-homed host

In this case, the SCTP association transmits an ASCONF packet
including addition of the new IP address and deletion of the old
address.  This patch implements this functionality.
In this case, the ASCONF chunk is added to the beginning of the
queue, because the other chunks cannot be transmitted in this state.

Signed-off-by: Michio Honda <micchie@sfc.wide.ad.jp>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Acked-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 1 deletions

diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c
index 013c6136c546..af0a6b0fc9b6 100644
--- a/net/sctp/protocol.c
+++ b/net/sctp/protocol.c
@@ -503,7 +503,9 @@ static void sctp_v4_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
                 sctp_v4_dst_saddr(&dst_saddr, fl4, htons(bp->port));
                 rcu_read_lock();
                 list_for_each_entry_rcu(laddr, &bp->address_list, list) {
-                        if (!laddr->valid || (laddr->state != SCTP_ADDR_SRC))
+                        if (!laddr->valid || (laddr->state == SCTP_ADDR_DEL) ||
+                            (laddr->state != SCTP_ADDR_SRC &&
+                            !asoc->src_out_of_asoc_ok))
                                 continue;
                         if (sctp_v4_cmp_addr(&dst_saddr, &laddr->a))
                                 goto out_unlock;