tls: kernel TLS support

Software implementation of transport layer security, implemented using ULP
infrastructure.  tcp proto_ops are replaced with tls equivalents of sendmsg and
sendpage.

Only symmetric crypto is done in the kernel, keys are passed by setsockopt
after the handshake is complete.  All control messages are supported via CMSG
data - the actual symmetric encryption is the same, just the message type needs
to be passed separately.

For user API, please see Documentation patch.

Pieces that can be shared between hw and sw implementation
are in tls_main.c

Signed-off-by: Boris Pismenny <borisp@mellanox.com>
Signed-off-by: Ilya Lesokhin <ilyal@mellanox.com>
Signed-off-by: Aviad Yehezkel <aviadye@mellanox.com>
Signed-off-by: Dave Watson <davejwatson@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/socket.h b/include/linux/socket.h
index 0820274..8b13db5 100644
--- a/include/linux/socket.h
+++ b/include/linux/socket.h
@@ -334,6 +334,7 @@ struct ucred {
 #define SOL_ALG		279
 #define SOL_NFC		280
 #define SOL_KCM		281
+#define SOL_TLS		282
 
 /* IPX options */
 #define IPX_TYPE	1