[SCTP]: Implement SCTP_FRAGMENT_INTERLEAVE socket option

This option was introduced in draft-ietf-tsvwg-sctpsocket-13.  It
prevents head-of-line blocking in the case of one-to-many endpoint.
Applications enabling this option really must enable SCTP_SNDRCV event
so that they would know where the data belongs.  Based on an
earlier patch by Ivan Skytte Jørgensen.

Additionally, this functionality now permits multiple associations
on the same endpoint to enter Partial Delivery.  Applications should
be extra careful, when using this functionality, to track EOR indicators.

Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 1 deletions

diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index f431acf3dcea..fe7f5ae1c513 100644
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -304,10 +304,11 @@ struct sctp_sock {
         __u32 autoclose;
         __u8 nodelay;
         __u8 disable_fragments;
-        __u8 pd_mode;
         __u8 v4mapped;
+        __u8 frag_interleave;
         __u32 adaptation_ind;
 
+        atomic_t pd_mode;
         /* Receive to here while partial delivery is in effect. */
         struct sk_buff_head pd_lobby;
 };