net-timestamp: move timestamp flags out of sk_flags

sk_flags is reaching its limit. New timestamping options will not fit.
Move all of them into a new field sk->sk_tsflags.

Added benefit is that this removes boilerplate code to convert between
SOF_TIMESTAMPING_.. and SOCK_TIMESTAMPING_.. in getsockopt/setsockopt.

SOCK_TIMESTAMPING_RX_SOFTWARE is also used to toggle the receive
timestamp logic (netstamp_needed). That can be simplified and this
last key removed, but will leave that for a separate patch.

Signed-off-by: Willem de Bruijn <willemb@google.com>

----

The u16 in sock can be moved into a 16-bit hole below sk_gso_max_segs,
though that scatters tstamp fields throughout the struct.
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/sock.c b/net/core/sock.c
index a741163..47c9377 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -848,22 +848,13 @@
 			ret = -EINVAL;
 			break;
 		}
-		sock_valbool_flag(sk, SOCK_TIMESTAMPING_TX_HARDWARE,
-				  val & SOF_TIMESTAMPING_TX_HARDWARE);
-		sock_valbool_flag(sk, SOCK_TIMESTAMPING_TX_SOFTWARE,
-				  val & SOF_TIMESTAMPING_TX_SOFTWARE);
-		sock_valbool_flag(sk, SOCK_TIMESTAMPING_RX_HARDWARE,
-				  val & SOF_TIMESTAMPING_RX_HARDWARE);
+		sk->sk_tsflags = val;
 		if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
 			sock_enable_timestamp(sk,
 					      SOCK_TIMESTAMPING_RX_SOFTWARE);
 		else
 			sock_disable_timestamp(sk,
 					       (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE));
-		sock_valbool_flag(sk, SOCK_TIMESTAMPING_SOFTWARE,
-				  val & SOF_TIMESTAMPING_SOFTWARE);
-		sock_valbool_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE,
-				  val & SOF_TIMESTAMPING_RAW_HARDWARE);
 		break;
 
 	case SO_RCVLOWAT:
@@ -1089,19 +1080,7 @@
 		break;
 
 	case SO_TIMESTAMPING:
-		v.val = 0;
-		if (sock_flag(sk, SOCK_TIMESTAMPING_TX_HARDWARE))
-			v.val |= SOF_TIMESTAMPING_TX_HARDWARE;
-		if (sock_flag(sk, SOCK_TIMESTAMPING_TX_SOFTWARE))
-			v.val |= SOF_TIMESTAMPING_TX_SOFTWARE;
-		if (sock_flag(sk, SOCK_TIMESTAMPING_RX_HARDWARE))
-			v.val |= SOF_TIMESTAMPING_RX_HARDWARE;
-		if (sock_flag(sk, SOCK_TIMESTAMPING_RX_SOFTWARE))
-			v.val |= SOF_TIMESTAMPING_RX_SOFTWARE;
-		if (sock_flag(sk, SOCK_TIMESTAMPING_SOFTWARE))
-			v.val |= SOF_TIMESTAMPING_SOFTWARE;
-		if (sock_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE))
-			v.val |= SOF_TIMESTAMPING_RAW_HARDWARE;
+		v.val = sk->sk_tsflags;
 		break;
 
 	case SO_RCVTIMEO: