net: sock: extend SO_TIMESTAMPING for PHC binding

Since PTP virtual clock support is added, there can be
several PTP virtual clocks based on one PTP physical
clock for timestamping.

This patch is to extend SO_TIMESTAMPING API to support
PHC (PTP Hardware Clock) binding by adding a new flag
SOF_TIMESTAMPING_BIND_PHC. When PTP virtual clocks are
in use, user space can configure to bind one for
timestamping, but PTP physical clock is not supported
and not needed to bind.

This patch is preparation for timestamp conversion from
raw timestamp to a specific PTP virtual clock time in
core net.

Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>

include/net/sock.h

@@ -316,7 +316,9 @@ struct bpf_local_storage;
   *	@sk_timer: sock cleanup timer
   *	@sk_stamp: time stamp of last packet received
   *	@sk_stamp_seq: lock for accessing sk_stamp on 32 bit architectures only
-  *	@sk_tsflags: SO_TIMESTAMPING socket options
+  *	@sk_tsflags: SO_TIMESTAMPING flags
+  *	@sk_bind_phc: SO_TIMESTAMPING bind PHC index of PTP virtual clock
+  *	              for timestamping
   *	@sk_tskey: counter to disambiguate concurrent tstamp requests
   *	@sk_zckey: counter to order MSG_ZEROCOPY notifications
   *	@sk_socket: Identd and reporting IO signals
@@ -493,6 +495,7 @@ struct sock {
 	seqlock_t		sk_stamp_seq;
 #endif
 	u16			sk_tsflags;
+	int			sk_bind_phc;
 	u8			sk_shutdown;
 	u32			sk_tskey;
 	atomic_t		sk_zckey;
@@ -2744,7 +2747,8 @@ void sock_def_readable(struct sock *sk);
 
 int sock_bindtoindex(struct sock *sk, int ifindex, bool lock_sk);
 void sock_set_timestamp(struct sock *sk, int optname, bool valbool);
-int sock_set_timestamping(struct sock *sk, int optname, int val);
+int sock_set_timestamping(struct sock *sk, int optname, int val,
+			  sockptr_t optval, unsigned int optlen);
 
 void sock_enable_timestamps(struct sock *sk);
 void sock_no_linger(struct sock *sk);

include/uapi/linux/net_tstamp.h

@@ -13,7 +13,7 @@
 #include <linux/types.h>
 #include <linux/socket.h>   /* for SO_TIMESTAMPING */
 
-/* SO_TIMESTAMPING gets an integer bit field comprised of these values */
+/* SO_TIMESTAMPING flags */
 enum {
 	SOF_TIMESTAMPING_TX_HARDWARE = (1<<0),
 	SOF_TIMESTAMPING_TX_SOFTWARE = (1<<1),
@@ -30,8 +30,9 @@ enum {
 	SOF_TIMESTAMPING_OPT_STATS = (1<<12),
 	SOF_TIMESTAMPING_OPT_PKTINFO = (1<<13),
 	SOF_TIMESTAMPING_OPT_TX_SWHW = (1<<14),
+	SOF_TIMESTAMPING_BIND_PHC = (1<<15),
 
-	SOF_TIMESTAMPING_LAST = SOF_TIMESTAMPING_OPT_TX_SWHW,
+	SOF_TIMESTAMPING_LAST = SOF_TIMESTAMPING_BIND_PHC,
 	SOF_TIMESTAMPING_MASK = (SOF_TIMESTAMPING_LAST - 1) |
 				 SOF_TIMESTAMPING_LAST
 };
@@ -46,6 +47,18 @@ enum {
 					 SOF_TIMESTAMPING_TX_SCHED | \
 					 SOF_TIMESTAMPING_TX_ACK)
 
+/**
+ * struct so_timestamping - SO_TIMESTAMPING parameter
+ *
+ * @flags:	SO_TIMESTAMPING flags
+ * @bind_phc:	Index of PTP virtual clock bound to sock. This is available
+ *		if flag SOF_TIMESTAMPING_BIND_PHC is set.
+ */
+struct so_timestamping {
+	int flags;
+	int bind_phc;
+};
+
 /**
  * struct hwtstamp_config - %SIOCGHWTSTAMP and %SIOCSHWTSTAMP parameter
  *

net/core/sock.c

@@ -139,6 +139,8 @@
 #include <net/tcp.h>
 #include <net/busy_poll.h>
 
+#include <linux/ethtool.h>
+
 static DEFINE_MUTEX(proto_list_mutex);
 static LIST_HEAD(proto_list);
 
@@ -794,8 +796,53 @@ void sock_set_timestamp(struct sock *sk, int optname, bool valbool)
 	}
 }
 
-int sock_set_timestamping(struct sock *sk, int optname, int val)
+static int sock_timestamping_bind_phc(struct sock *sk, int phc_index)
 {
+	struct ethtool_phc_vclocks phc_vclocks = { };
+	struct net *net = sock_net(sk);
+	struct net_device *dev = NULL;
+	bool match = false;
+	int i;
+
+	if (sk->sk_bound_dev_if)
+		dev = dev_get_by_index(net, sk->sk_bound_dev_if);
+
+	if (!dev) {
+		pr_err("%s: sock not bind to device\n", __func__);
+		return -EOPNOTSUPP;
+	}
+
+	ethtool_op_get_phc_vclocks(dev, &phc_vclocks);
+
+	for (i = 0; i < phc_vclocks.num; i++) {
+		if (phc_vclocks.index[i] == phc_index) {
+			match = true;
+			break;
+		}
+	}
+
+	if (!match)
+		return -EINVAL;
+
+	sk->sk_bind_phc = phc_index;
+
+	return 0;
+}
+
+int sock_set_timestamping(struct sock *sk, int optname, int val,
+			  sockptr_t optval, unsigned int optlen)
+{
+	struct so_timestamping timestamping;
+	int ret;
+
+	if (optlen == sizeof(timestamping)) {
+		if (copy_from_sockptr(&timestamping, optval,
+				      sizeof(timestamping)))
+			return -EFAULT;
+
+		val = timestamping.flags;
+	}
+
 	if (val & ~SOF_TIMESTAMPING_MASK)
 		return -EINVAL;
 
@@ -816,6 +863,15 @@ int sock_set_timestamping(struct sock *sk, int optname, int val)
 	    !(val & SOF_TIMESTAMPING_OPT_TSONLY))
 		return -EINVAL;
 
+	if (optlen == sizeof(timestamping) &&
+	    val & SOF_TIMESTAMPING_BIND_PHC) {
+		ret = sock_timestamping_bind_phc(sk, timestamping.bind_phc);
+		if (ret)
+			return ret;
+	} else {
+		sk->sk_bind_phc = -1;
+	}
+
 	sk->sk_tsflags = val;
 	sock_valbool_flag(sk, SOCK_TSTAMP_NEW, optname == SO_TIMESTAMPING_NEW);
 
@@ -1057,7 +1113,7 @@ int sock_setsockopt(struct socket *sock, int level, int optname,
 
 	case SO_TIMESTAMPING_NEW:
 	case SO_TIMESTAMPING_OLD:
-		ret = sock_set_timestamping(sk, optname, val);
+		ret = sock_set_timestamping(sk, optname, val, optval, optlen);
 		break;
 
 	case SO_RCVLOWAT:
@@ -1332,6 +1388,7 @@ int sock_getsockopt(struct socket *sock, int level, int optname,
 		struct __kernel_old_timeval tm;
 		struct  __kernel_sock_timeval stm;
 		struct sock_txtime txtime;
+		struct so_timestamping timestamping;
 	} v;
 
 	int lv = sizeof(int);
@@ -1435,7 +1492,9 @@ int sock_getsockopt(struct socket *sock, int level, int optname,
 		break;
 
 	case SO_TIMESTAMPING_OLD:
-		v.val = sk->sk_tsflags;
+		lv = sizeof(v.timestamping);
+		v.timestamping.flags = sk->sk_tsflags;
+		v.timestamping.bind_phc = sk->sk_bind_phc;
 		break;
 
 	case SO_RCVTIMEO_OLD:

net/ethtool/common.c

@@ -398,6 +398,7 @@ const char sof_timestamping_names[][ETH_GSTRING_LEN] = {
 	[const_ilog2(SOF_TIMESTAMPING_OPT_STATS)]    = "option-stats",
 	[const_ilog2(SOF_TIMESTAMPING_OPT_PKTINFO)]  = "option-pktinfo",
 	[const_ilog2(SOF_TIMESTAMPING_OPT_TX_SWHW)]  = "option-tx-swhw",
+	[const_ilog2(SOF_TIMESTAMPING_BIND_PHC)]     = "bind-phc",
 };
 static_assert(ARRAY_SIZE(sof_timestamping_names) == __SOF_TIMESTAMPING_CNT);
 

net/mptcp/sockopt.c

@@ -140,7 +140,10 @@ static void mptcp_so_incoming_cpu(struct mptcp_sock *msk, int val)
 	mptcp_sol_socket_sync_intval(msk, SO_INCOMING_CPU, val);
 }
 
-static int mptcp_setsockopt_sol_socket_tstamp(struct mptcp_sock *msk, int optname, int val)
+static int mptcp_setsockopt_sol_socket_tstamp(struct mptcp_sock *msk,
+					      int optname, int val,
+					      sockptr_t optval,
+					      unsigned int optlen)
 {
 	sockptr_t optval = KERNEL_SOCKPTR(&val);
 	struct mptcp_subflow_context *subflow;
@@ -166,7 +169,7 @@ static int mptcp_setsockopt_sol_socket_tstamp(struct mptcp_sock *msk, int optnam
 			break;
 		case SO_TIMESTAMPING_NEW:
 		case SO_TIMESTAMPING_OLD:
-			sock_set_timestamping(sk, optname, val);
+			sock_set_timestamping(sk, optname, val, optval, optlen);
 			break;
 		}
 
@@ -207,7 +210,8 @@ static int mptcp_setsockopt_sol_socket_int(struct mptcp_sock *msk, int optname,
 	case SO_TIMESTAMPNS_NEW:
 	case SO_TIMESTAMPING_OLD:
 	case SO_TIMESTAMPING_NEW:
-		return mptcp_setsockopt_sol_socket_tstamp(msk, optname, val);
+		return mptcp_setsockopt_sol_socket_tstamp(msk, optname, val,
+							  optval, optlen);
 	}
 
 	return -ENOPROTOOPT;