diff --git a/Documentation/networking/timestamping.rst b/Documentation/networking/timestamping.rst
index 8199e6917671..b37bfbfc7d79 100644
--- a/Documentation/networking/timestamping.rst
+++ b/Documentation/networking/timestamping.rst
@@ -194,6 +194,20 @@ SOF_TIMESTAMPING_OPT_ID:
   among all possibly concurrently outstanding timestamp requests for
   that socket.
 
+  The process can optionally override the default generated ID, by
+  passing a specific ID with control message SCM_TS_OPT_ID (not
+  supported for TCP sockets)::
+
+    struct msghdr *msg;
+    ...
+    cmsg			 = CMSG_FIRSTHDR(msg);
+    cmsg->cmsg_level		 = SOL_SOCKET;
+    cmsg->cmsg_type		 = SCM_TS_OPT_ID;
+    cmsg->cmsg_len		 = CMSG_LEN(sizeof(__u32));
+    *((__u32 *) CMSG_DATA(cmsg)) = opt_id;
+    err = sendmsg(fd, msg, 0);
+
+
 SOF_TIMESTAMPING_OPT_ID_TCP:
   Pass this modifier along with SOF_TIMESTAMPING_OPT_ID for new TCP
   timestamping applications. SOF_TIMESTAMPING_OPT_ID defines how the
diff --git a/arch/alpha/include/uapi/asm/socket.h b/arch/alpha/include/uapi/asm/socket.h
index 251b73c5481e..302507bf9b5d 100644
--- a/arch/alpha/include/uapi/asm/socket.h
+++ b/arch/alpha/include/uapi/asm/socket.h
@@ -146,6 +146,8 @@
 #define SCM_DEVMEM_DMABUF	SO_DEVMEM_DMABUF
 #define SO_DEVMEM_DONTNEED	80
 
+#define SCM_TS_OPT_ID		81
+
 #if !defined(__KERNEL__)
 
 #if __BITS_PER_LONG == 64
diff --git a/arch/mips/include/uapi/asm/socket.h b/arch/mips/include/uapi/asm/socket.h
index 8ab7582291ab..d118d4731580 100644
--- a/arch/mips/include/uapi/asm/socket.h
+++ b/arch/mips/include/uapi/asm/socket.h
@@ -157,6 +157,8 @@
 #define SCM_DEVMEM_DMABUF	SO_DEVMEM_DMABUF
 #define SO_DEVMEM_DONTNEED	80
 
+#define SCM_TS_OPT_ID		81
+
 #if !defined(__KERNEL__)
 
 #if __BITS_PER_LONG == 64
diff --git a/arch/parisc/include/uapi/asm/socket.h b/arch/parisc/include/uapi/asm/socket.h
index 38fc0b188e08..d268d69bfcd2 100644
--- a/arch/parisc/include/uapi/asm/socket.h
+++ b/arch/parisc/include/uapi/asm/socket.h
@@ -138,6 +138,8 @@
 #define SCM_DEVMEM_DMABUF	SO_DEVMEM_DMABUF
 #define SO_DEVMEM_DONTNEED	80
 
+#define SCM_TS_OPT_ID		0x404C
+
 #if !defined(__KERNEL__)
 
 #if __BITS_PER_LONG == 64
diff --git a/arch/sparc/include/uapi/asm/socket.h b/arch/sparc/include/uapi/asm/socket.h
index 57084ed2f3c4..113cd9f353e3 100644
--- a/arch/sparc/include/uapi/asm/socket.h
+++ b/arch/sparc/include/uapi/asm/socket.h
@@ -139,6 +139,8 @@
 #define SCM_DEVMEM_DMABUF        SO_DEVMEM_DMABUF
 #define SO_DEVMEM_DONTNEED       0x0059
 
+#define SCM_TS_OPT_ID            0x005a
+
 #if !defined(__KERNEL__)
 
 
diff --git a/include/net/inet_sock.h b/include/net/inet_sock.h
index 394c3b66065e..f01dd273bea6 100644
--- a/include/net/inet_sock.h
+++ b/include/net/inet_sock.h
@@ -174,6 +174,7 @@ struct inet_cork {
 	__s16			tos;
 	char			priority;
 	__u16			gso_size;
+	u32			ts_opt_id;
 	u64			transmit_time;
 	u32			mark;
 };
@@ -241,7 +242,8 @@ struct inet_sock {
 	struct inet_cork_full	cork;
 };
 
-#define IPCORK_OPT	1	/* ip-options has been held in ipcork.opt */
+#define IPCORK_OPT		1	/* ip-options has been held in ipcork.opt */
+#define IPCORK_TS_OPT_ID	2	/* ts_opt_id field is valid, overriding sk_tskey */
 
 enum {
 	INET_FLAGS_PKTINFO	= 0,
diff --git a/include/net/sock.h b/include/net/sock.h
index c58ca8dd561b..e282127092ab 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -954,6 +954,12 @@ enum sock_flags {
 };
 
 #define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) | (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE))
+/*
+ * The highest bit of sk_tsflags is reserved for kernel-internal
+ * SOCKCM_FLAG_TS_OPT_ID. There is a check in core/sock.c to control that
+ * SOF_TIMESTAMPING* values do not reach this reserved area
+ */
+#define SOCKCM_FLAG_TS_OPT_ID	BIT(31)
 
 static inline void sock_copy_flags(struct sock *nsk, const struct sock *osk)
 {
@@ -1796,6 +1802,7 @@ struct sockcm_cookie {
 	u64 transmit_time;
 	u32 mark;
 	u32 tsflags;
+	u32 ts_opt_id;
 };
 
 static inline void sockcm_init(struct sockcm_cookie *sockc,
@@ -2653,39 +2660,48 @@ static inline void sock_recv_cmsgs(struct msghdr *msg, struct sock *sk,
 		sock_write_timestamp(sk, 0);
 }
 
-void __sock_tx_timestamp(__u16 tsflags, __u8 *tx_flags);
+void __sock_tx_timestamp(__u32 tsflags, __u8 *tx_flags);
 
 /**
  * _sock_tx_timestamp - checks whether the outgoing packet is to be time stamped
  * @sk:		socket sending this packet
- * @tsflags:	timestamping flags to use
+ * @sockc:	pointer to socket cmsg cookie to get timestamping info
  * @tx_flags:	completed with instructions for time stamping
  * @tskey:      filled in with next sk_tskey (not for TCP, which uses seqno)
  *
  * Note: callers should take care of initial ``*tx_flags`` value (usually 0)
  */
-static inline void _sock_tx_timestamp(struct sock *sk, __u16 tsflags,
+static inline void _sock_tx_timestamp(struct sock *sk,
+				      const struct sockcm_cookie *sockc,
 				      __u8 *tx_flags, __u32 *tskey)
 {
+	__u32 tsflags = sockc->tsflags;
+
 	if (unlikely(tsflags)) {
 		__sock_tx_timestamp(tsflags, tx_flags);
 		if (tsflags & SOF_TIMESTAMPING_OPT_ID && tskey &&
-		    tsflags & SOF_TIMESTAMPING_TX_RECORD_MASK)
-			*tskey = atomic_inc_return(&sk->sk_tskey) - 1;
+		    tsflags & SOF_TIMESTAMPING_TX_RECORD_MASK) {
+			if (tsflags & SOCKCM_FLAG_TS_OPT_ID)
+				*tskey = sockc->ts_opt_id;
+			else
+				*tskey = atomic_inc_return(&sk->sk_tskey) - 1;
+		}
 	}
 	if (unlikely(sock_flag(sk, SOCK_WIFI_STATUS)))
 		*tx_flags |= SKBTX_WIFI_STATUS;
 }
 
-static inline void sock_tx_timestamp(struct sock *sk, __u16 tsflags,
+static inline void sock_tx_timestamp(struct sock *sk,
+				     const struct sockcm_cookie *sockc,
 				     __u8 *tx_flags)
 {
-	_sock_tx_timestamp(sk, tsflags, tx_flags, NULL);
+	_sock_tx_timestamp(sk, sockc, tx_flags, NULL);
 }
 
-static inline void skb_setup_tx_timestamp(struct sk_buff *skb, __u16 tsflags)
+static inline void skb_setup_tx_timestamp(struct sk_buff *skb,
+					  const struct sockcm_cookie *sockc)
 {
-	_sock_tx_timestamp(skb->sk, tsflags, &skb_shinfo(skb)->tx_flags,
+	_sock_tx_timestamp(skb->sk, sockc, &skb_shinfo(skb)->tx_flags,
 			   &skb_shinfo(skb)->tskey);
 }
 
diff --git a/include/uapi/asm-generic/socket.h b/include/uapi/asm-generic/socket.h
index 3b4e3e815602..deacfd6dd197 100644
--- a/include/uapi/asm-generic/socket.h
+++ b/include/uapi/asm-generic/socket.h
@@ -141,6 +141,8 @@
 #define SCM_DEVMEM_DMABUF	SO_DEVMEM_DMABUF
 #define SO_DEVMEM_DONTNEED	80
 
+#define SCM_TS_OPT_ID		81
+
 #if !defined(__KERNEL__)
 
 #if __BITS_PER_LONG == 64 || (defined(__x86_64__) && defined(__ILP32__))
diff --git a/net/can/raw.c b/net/can/raw.c
index 00533f64d69d..255c0a8f39d6 100644
--- a/net/can/raw.c
+++ b/net/can/raw.c
@@ -966,7 +966,7 @@ static int raw_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
 	skb->mark = READ_ONCE(sk->sk_mark);
 	skb->tstamp = sockc.transmit_time;
 
-	skb_setup_tx_timestamp(skb, sockc.tsflags);
+	skb_setup_tx_timestamp(skb, &sockc);
 
 	err = can_send(skb, ro->loopback);
 
diff --git a/net/core/sock.c b/net/core/sock.c
index 039be95c40cf..846f494a17cf 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -2899,6 +2899,8 @@ int __sock_cmsg_send(struct sock *sk, struct cmsghdr *cmsg,
 {
 	u32 tsflags;
 
+	BUILD_BUG_ON(SOF_TIMESTAMPING_LAST == (1 << 31));
+
 	switch (cmsg->cmsg_type) {
 	case SO_MARK:
 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
@@ -2927,6 +2929,17 @@ int __sock_cmsg_send(struct sock *sk, struct cmsghdr *cmsg,
 			return -EINVAL;
 		sockc->transmit_time = get_unaligned((u64 *)CMSG_DATA(cmsg));
 		break;
+	case SCM_TS_OPT_ID:
+		if (sk_is_tcp(sk))
+			return -EINVAL;
+		tsflags = READ_ONCE(sk->sk_tsflags);
+		if (!(tsflags & SOF_TIMESTAMPING_OPT_ID))
+			return -EINVAL;
+		if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
+			return -EINVAL;
+		sockc->ts_opt_id = *(u32 *)CMSG_DATA(cmsg);
+		sockc->tsflags |= SOCKCM_FLAG_TS_OPT_ID;
+		break;
 	/* SCM_RIGHTS and SCM_CREDENTIALS are semantically in SOL_UNIX. */
 	case SCM_RIGHTS:
 	case SCM_CREDENTIALS:
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 49811c9281d4..e5c55a95063d 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -973,7 +973,7 @@ static int __ip_append_data(struct sock *sk,
 	unsigned int maxfraglen, fragheaderlen, maxnonfragsize;
 	int csummode = CHECKSUM_NONE;
 	struct rtable *rt = dst_rtable(cork->dst);
-	bool paged, hold_tskey, extra_uref = false;
+	bool paged, hold_tskey = false, extra_uref = false;
 	unsigned int wmem_alloc_delta = 0;
 	u32 tskey = 0;
 
@@ -1049,10 +1049,15 @@ static int __ip_append_data(struct sock *sk,
 
 	cork->length += length;
 
-	hold_tskey = cork->tx_flags & SKBTX_ANY_TSTAMP &&
-		     READ_ONCE(sk->sk_tsflags) & SOF_TIMESTAMPING_OPT_ID;
-	if (hold_tskey)
-		tskey = atomic_inc_return(&sk->sk_tskey) - 1;
+	if (cork->tx_flags & SKBTX_ANY_TSTAMP &&
+	    READ_ONCE(sk->sk_tsflags) & SOF_TIMESTAMPING_OPT_ID) {
+		if (cork->flags & IPCORK_TS_OPT_ID) {
+			tskey = cork->ts_opt_id;
+		} else {
+			tskey = atomic_inc_return(&sk->sk_tskey) - 1;
+			hold_tskey = true;
+		}
+	}
 
 	/* So, what's going on in the loop below?
 	 *
@@ -1326,7 +1331,11 @@ static int ip_setup_cork(struct sock *sk, struct inet_cork *cork,
 	cork->priority = ipc->priority;
 	cork->transmit_time = ipc->sockc.transmit_time;
 	cork->tx_flags = 0;
-	sock_tx_timestamp(sk, ipc->sockc.tsflags, &cork->tx_flags);
+	sock_tx_timestamp(sk, &ipc->sockc, &cork->tx_flags);
+	if (ipc->sockc.tsflags & SOCKCM_FLAG_TS_OPT_ID) {
+		cork->flags |= IPCORK_TS_OPT_ID;
+		cork->ts_opt_id = ipc->sockc.ts_opt_id;
+	}
 
 	return 0;
 }
diff --git a/net/ipv4/raw.c b/net/ipv4/raw.c
index 474dfd263c8b..0e9e01967ec9 100644
--- a/net/ipv4/raw.c
+++ b/net/ipv4/raw.c
@@ -370,7 +370,7 @@ static int raw_send_hdrinc(struct sock *sk, struct flowi4 *fl4,
 
 	skb->ip_summed = CHECKSUM_NONE;
 
-	skb_setup_tx_timestamp(skb, sockc->tsflags);
+	skb_setup_tx_timestamp(skb, sockc);
 
 	if (flags & MSG_CONFIRM)
 		skb_set_dst_pending_confirm(skb, 1);
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 4f77bd862e95..82cc4a5633ce 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -477,15 +477,16 @@ void tcp_init_sock(struct sock *sk)
 }
 EXPORT_SYMBOL(tcp_init_sock);
 
-static void tcp_tx_timestamp(struct sock *sk, u16 tsflags)
+static void tcp_tx_timestamp(struct sock *sk, struct sockcm_cookie *sockc)
 {
 	struct sk_buff *skb = tcp_write_queue_tail(sk);
+	u32 tsflags = sockc->tsflags;
 
 	if (tsflags && skb) {
 		struct skb_shared_info *shinfo = skb_shinfo(skb);
 		struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
 
-		sock_tx_timestamp(sk, tsflags, &shinfo->tx_flags);
+		sock_tx_timestamp(sk, sockc, &shinfo->tx_flags);
 		if (tsflags & SOF_TIMESTAMPING_TX_ACK)
 			tcb->txstamp_ack = 1;
 		if (tsflags & SOF_TIMESTAMPING_TX_RECORD_MASK)
@@ -1321,7 +1322,7 @@ int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size)
 
 out:
 	if (copied) {
-		tcp_tx_timestamp(sk, sockc.tsflags);
+		tcp_tx_timestamp(sk, &sockc);
 		tcp_push(sk, flags, mss_now, tp->nonagle, size_goal);
 	}
 out_nopush:
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index f26841f1490f..205673179b3c 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -1401,8 +1401,11 @@ static int ip6_setup_cork(struct sock *sk, struct inet_cork_full *cork,
 	cork->base.gso_size = ipc6->gso_size;
 	cork->base.tx_flags = 0;
 	cork->base.mark = ipc6->sockc.mark;
-	sock_tx_timestamp(sk, ipc6->sockc.tsflags, &cork->base.tx_flags);
-
+	sock_tx_timestamp(sk, &ipc6->sockc, &cork->base.tx_flags);
+	if (ipc6->sockc.tsflags & SOCKCM_FLAG_TS_OPT_ID) {
+		cork->base.flags |= IPCORK_TS_OPT_ID;
+		cork->base.ts_opt_id = ipc6->sockc.ts_opt_id;
+	}
 	cork->base.length = 0;
 	cork->base.transmit_time = ipc6->sockc.transmit_time;
 
@@ -1433,7 +1436,7 @@ static int __ip6_append_data(struct sock *sk,
 	bool zc = false;
 	u32 tskey = 0;
 	struct rt6_info *rt = dst_rt6_info(cork->dst);
-	bool paged, hold_tskey, extra_uref = false;
+	bool paged, hold_tskey = false, extra_uref = false;
 	struct ipv6_txoptions *opt = v6_cork->opt;
 	int csummode = CHECKSUM_NONE;
 	unsigned int maxnonfragsize, headersize;
@@ -1543,10 +1546,15 @@ static int __ip6_append_data(struct sock *sk,
 			flags &= ~MSG_SPLICE_PAGES;
 	}
 
-	hold_tskey = cork->tx_flags & SKBTX_ANY_TSTAMP &&
-		     READ_ONCE(sk->sk_tsflags) & SOF_TIMESTAMPING_OPT_ID;
-	if (hold_tskey)
-		tskey = atomic_inc_return(&sk->sk_tskey) - 1;
+	if (cork->tx_flags & SKBTX_ANY_TSTAMP &&
+	    READ_ONCE(sk->sk_tsflags) & SOF_TIMESTAMPING_OPT_ID) {
+		if (cork->flags & IPCORK_TS_OPT_ID) {
+			tskey = cork->ts_opt_id;
+		} else {
+			tskey = atomic_inc_return(&sk->sk_tskey) - 1;
+			hold_tskey = true;
+		}
+	}
 
 	/*
 	 * Let's try using as much space as possible.
diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c
index 608fa9d05b55..8476a3944a88 100644
--- a/net/ipv6/raw.c
+++ b/net/ipv6/raw.c
@@ -629,7 +629,7 @@ static int rawv6_send_hdrinc(struct sock *sk, struct msghdr *msg, int length,
 
 	skb->ip_summed = CHECKSUM_NONE;
 
-	skb_setup_tx_timestamp(skb, sockc->tsflags);
+	skb_setup_tx_timestamp(skb, sockc);
 
 	if (flags & MSG_CONFIRM)
 		skb_set_dst_pending_confirm(skb, 1);
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index a705ec214254..f8942062f776 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -2118,7 +2118,7 @@ static int packet_sendmsg_spkt(struct socket *sock, struct msghdr *msg,
 	skb->priority = READ_ONCE(sk->sk_priority);
 	skb->mark = READ_ONCE(sk->sk_mark);
 	skb_set_delivery_type_by_clockid(skb, sockc.transmit_time, sk->sk_clockid);
-	skb_setup_tx_timestamp(skb, sockc.tsflags);
+	skb_setup_tx_timestamp(skb, &sockc);
 
 	if (unlikely(extra_len == 4))
 		skb->no_fcs = 1;
@@ -2650,7 +2650,7 @@ static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
 	skb->priority = READ_ONCE(po->sk.sk_priority);
 	skb->mark = READ_ONCE(po->sk.sk_mark);
 	skb_set_delivery_type_by_clockid(skb, sockc->transmit_time, po->sk.sk_clockid);
-	skb_setup_tx_timestamp(skb, sockc->tsflags);
+	skb_setup_tx_timestamp(skb, sockc);
 	skb_zcopy_set_nouarg(skb, ph.raw);
 
 	skb_reserve(skb, hlen);
@@ -3115,7 +3115,7 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len)
 		goto out_free;
 	}
 
-	skb_setup_tx_timestamp(skb, sockc.tsflags);
+	skb_setup_tx_timestamp(skb, &sockc);
 
 	if (!vnet_hdr.gso_type && (len > dev->mtu + reserve + extra_len) &&
 	    !packet_extra_vlan_len_allowed(dev, skb)) {
diff --git a/net/socket.c b/net/socket.c
index 601ad74930ef..3b1b65b9f471 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -687,7 +687,7 @@ void sock_release(struct socket *sock)
 }
 EXPORT_SYMBOL(sock_release);
 
-void __sock_tx_timestamp(__u16 tsflags, __u8 *tx_flags)
+void __sock_tx_timestamp(__u32 tsflags, __u8 *tx_flags)
 {
 	u8 flags = *tx_flags;
 
diff --git a/tools/include/uapi/asm-generic/socket.h b/tools/include/uapi/asm-generic/socket.h
index 54d9c8bf7c55..281df9139d2b 100644
--- a/tools/include/uapi/asm-generic/socket.h
+++ b/tools/include/uapi/asm-generic/socket.h
@@ -124,6 +124,8 @@
 #define SO_PASSPIDFD		76
 #define SO_PEERPIDFD		77
 
+#define SCM_TS_OPT_ID		78
+
 #if !defined(__KERNEL__)
 
 #if __BITS_PER_LONG == 64 || (defined(__x86_64__) && defined(__ILP32__))
diff --git a/tools/testing/selftests/net/txtimestamp.c b/tools/testing/selftests/net/txtimestamp.c
index d626f22f9550..dae91eb97d69 100644
--- a/tools/testing/selftests/net/txtimestamp.c
+++ b/tools/testing/selftests/net/txtimestamp.c
@@ -77,6 +77,8 @@ static bool cfg_epollet;
 static bool cfg_do_listen;
 static uint16_t dest_port = 9000;
 static bool cfg_print_nsec;
+static uint32_t ts_opt_id;
+static bool cfg_use_cmsg_opt_id;
 
 static struct sockaddr_in daddr;
 static struct sockaddr_in6 daddr6;
@@ -136,12 +138,13 @@ static void validate_key(int tskey, int tstype)
 	/* compare key for each subsequent request
 	 * must only test for one type, the first one requested
 	 */
-	if (saved_tskey == -1)
+	if (saved_tskey == -1 || cfg_use_cmsg_opt_id)
 		saved_tskey_type = tstype;
 	else if (saved_tskey_type != tstype)
 		return;
 
 	stepsize = cfg_proto == SOCK_STREAM ? cfg_payload_len : 1;
+	stepsize = cfg_use_cmsg_opt_id ? 0 : stepsize;
 	if (tskey != saved_tskey + stepsize) {
 		fprintf(stderr, "ERROR: key %d, expected %d\n",
 				tskey, saved_tskey + stepsize);
@@ -484,7 +487,7 @@ static void fill_header_udp(void *p, bool is_ipv4)
 
 static void do_test(int family, unsigned int report_opt)
 {
-	char control[CMSG_SPACE(sizeof(uint32_t))];
+	char control[2 * CMSG_SPACE(sizeof(uint32_t))];
 	struct sockaddr_ll laddr;
 	unsigned int sock_opt;
 	struct cmsghdr *cmsg;
@@ -624,18 +627,32 @@ static void do_test(int family, unsigned int report_opt)
 		msg.msg_iov = &iov;
 		msg.msg_iovlen = 1;
 
-		if (cfg_use_cmsg) {
+		if (cfg_use_cmsg || cfg_use_cmsg_opt_id) {
 			memset(control, 0, sizeof(control));
 
 			msg.msg_control = control;
-			msg.msg_controllen = sizeof(control);
+			msg.msg_controllen = cfg_use_cmsg * CMSG_SPACE(sizeof(uint32_t));
+			msg.msg_controllen += cfg_use_cmsg_opt_id * CMSG_SPACE(sizeof(uint32_t));
 
-			cmsg = CMSG_FIRSTHDR(&msg);
-			cmsg->cmsg_level = SOL_SOCKET;
-			cmsg->cmsg_type = SO_TIMESTAMPING;
-			cmsg->cmsg_len = CMSG_LEN(sizeof(uint32_t));
+			cmsg = NULL;
+			if (cfg_use_cmsg) {
+				cmsg = CMSG_FIRSTHDR(&msg);
+				cmsg->cmsg_level = SOL_SOCKET;
+				cmsg->cmsg_type = SO_TIMESTAMPING;
+				cmsg->cmsg_len = CMSG_LEN(sizeof(uint32_t));
+
+				*((uint32_t *)CMSG_DATA(cmsg)) = report_opt;
+			}
+			if (cfg_use_cmsg_opt_id) {
+				cmsg = cmsg ? CMSG_NXTHDR(&msg, cmsg) : CMSG_FIRSTHDR(&msg);
+				cmsg->cmsg_level = SOL_SOCKET;
+				cmsg->cmsg_type = SCM_TS_OPT_ID;
+				cmsg->cmsg_len = CMSG_LEN(sizeof(uint32_t));
+
+				*((uint32_t *)CMSG_DATA(cmsg)) = ts_opt_id;
+				saved_tskey = ts_opt_id;
+			}
 
-			*((uint32_t *) CMSG_DATA(cmsg)) = report_opt;
 		}
 
 		val = sendmsg(fd, &msg, 0);
@@ -685,6 +702,7 @@ static void __attribute__((noreturn)) usage(const char *filepath)
 			"  -L    listen on hostname and port\n"
 			"  -n:   set no-payload option\n"
 			"  -N:   print timestamps and durations in nsec (instead of usec)\n"
+			"  -o N: use SCM_TS_OPT_ID control message to provide N as tskey\n"
 			"  -p N: connect to port N\n"
 			"  -P:   use PF_PACKET\n"
 			"  -r:   use raw\n"
@@ -705,7 +723,7 @@ static void parse_opt(int argc, char **argv)
 	int c;
 
 	while ((c = getopt(argc, argv,
-				"46bc:CeEFhIl:LnNp:PrRS:t:uv:V:x")) != -1) {
+				"46bc:CeEFhIl:LnNo:p:PrRS:t:uv:V:x")) != -1) {
 		switch (c) {
 		case '4':
 			do_ipv6 = 0;
@@ -746,6 +764,10 @@ static void parse_opt(int argc, char **argv)
 		case 'N':
 			cfg_print_nsec = true;
 			break;
+		case 'o':
+			ts_opt_id = strtoul(optarg, NULL, 10);
+			cfg_use_cmsg_opt_id = true;
+			break;
 		case 'p':
 			dest_port = strtoul(optarg, NULL, 10);
 			break;
@@ -803,6 +825,8 @@ static void parse_opt(int argc, char **argv)
 		error(1, 0, "cannot ask for pktinfo over pf_packet");
 	if (cfg_busy_poll && cfg_use_epoll)
 		error(1, 0, "pass epoll or busy_poll, not both");
+	if (cfg_proto == SOCK_STREAM && cfg_use_cmsg_opt_id)
+		error(1, 0, "TCP sockets don't support SCM_TS_OPT_ID");
 
 	if (optind != argc - 1)
 		error(1, 0, "missing required hostname argument");
diff --git a/tools/testing/selftests/net/txtimestamp.sh b/tools/testing/selftests/net/txtimestamp.sh
index 25baca4b148e..fe4649bb8786 100755
--- a/tools/testing/selftests/net/txtimestamp.sh
+++ b/tools/testing/selftests/net/txtimestamp.sh
@@ -37,11 +37,13 @@ run_test_v4v6() {
 run_test_tcpudpraw() {
 	local -r args=$@
 
-	run_test_v4v6 ${args}		# tcp
-	run_test_v4v6 ${args} -u	# udp
-	run_test_v4v6 ${args} -r	# raw
-	run_test_v4v6 ${args} -R	# raw (IPPROTO_RAW)
-	run_test_v4v6 ${args} -P	# pf_packet
+	run_test_v4v6 ${args}		  # tcp
+	run_test_v4v6 ${args} -u	  # udp
+	run_test_v4v6 ${args} -u -o 42	  # udp with fixed tskey
+	run_test_v4v6 ${args} -r	  # raw
+	run_test_v4v6 ${args} -r -o 42	  # raw
+	run_test_v4v6 ${args} -R	  # raw (IPPROTO_RAW)
+	run_test_v4v6 ${args} -P	  # pf_packet
 }
 
 run_test_all() {