tipc: add SYN bit to connection setup messages

Messages intended for intitating a connection are currently
indistinguishable from regular datagram messages. The TIPC
protocol specification defines bit 17 in word 0 as a SYN bit
to allow sanity check of such messages in the listening socket,
but this has so far never been implemented.

We do that in this commit.

Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 7 insertions, 5 deletions

diff --git a/net/tipc/node.h b/net/tipc/node.h
index 48b3298a248d..03f5efb62cfb 100644
--- a/net/tipc/node.h
+++ b/net/tipc/node.h
@@ -45,6 +45,7 @@
 /* Optional capabilities supported by this code version
  */
 enum {
+        TIPC_SYN_BIT          = (1),
         TIPC_BCAST_SYNCH      = (1 << 1),
         TIPC_BCAST_STATE_NACK = (1 << 2),
         TIPC_BLOCK_FLOWCTL    = (1 << 3),
@@ -53,11 +54,12 @@ enum {
         TIPC_LINK_PROTO_SEQNO = (1 << 6)
 };
 
-#define TIPC_NODE_CAPABILITIES (TIPC_BCAST_SYNCH       |  \
-                                TIPC_BCAST_STATE_NACK  |  \
-                                TIPC_BCAST_RCAST       |  \
-                                TIPC_BLOCK_FLOWCTL     |  \
-                                TIPC_NODE_ID128        |  \
+#define TIPC_NODE_CAPABILITIES (TIPC_SYN_BIT           |  \
+                                TIPC_BCAST_SYNCH       |   \
+                                TIPC_BCAST_STATE_NACK  |   \
+                                TIPC_BCAST_RCAST       |   \
+                                TIPC_BLOCK_FLOWCTL     |   \
+                                TIPC_NODE_ID128        |   \
                                 TIPC_LINK_PROTO_SEQNO)
 #define INVALID_BEARER_ID -1