diff --git a/Documentation/networking/timestamping.txt b/Documentation/networking/timestamping.txt
new file mode 100644
index 0000000..a681a65
--- /dev/null
+++ b/Documentation/networking/timestamping.txt
@@ -0,0 +1,178 @@
+The existing interfaces for getting network packages time stamped are:
+
+* SO_TIMESTAMP
+  Generate time stamp for each incoming packet using the (not necessarily
+  monotonous!) system time. Result is returned via recv_msg() in a
+  control message as timeval (usec resolution).
+
+* SO_TIMESTAMPNS
+  Same time stamping mechanism as SO_TIMESTAMP, but returns result as
+  timespec (nsec resolution).
+
+* IP_MULTICAST_LOOP + SO_TIMESTAMP[NS]
+  Only for multicasts: approximate send time stamp by receiving the looped
+  packet and using its receive time stamp.
+
+The following interface complements the existing ones: receive time
+stamps can be generated and returned for arbitrary packets and much
+closer to the point where the packet is really sent. Time stamps can
+be generated in software (as before) or in hardware (if the hardware
+has such a feature).
+
+SO_TIMESTAMPING:
+
+Instructs the socket layer which kind of information is wanted. The
+parameter is an integer with some of the following bits set. Setting
+other bits is an error and doesn't change the current state.
+
+SOF_TIMESTAMPING_TX_HARDWARE:  try to obtain send time stamp in hardware
+SOF_TIMESTAMPING_TX_SOFTWARE:  if SOF_TIMESTAMPING_TX_HARDWARE is off or
+                               fails, then do it in software
+SOF_TIMESTAMPING_RX_HARDWARE:  return the original, unmodified time stamp
+                               as generated by the hardware
+SOF_TIMESTAMPING_RX_SOFTWARE:  if SOF_TIMESTAMPING_RX_HARDWARE is off or
+                               fails, then do it in software
+SOF_TIMESTAMPING_RAW_HARDWARE: return original raw hardware time stamp
+SOF_TIMESTAMPING_SYS_HARDWARE: return hardware time stamp transformed to
+                               the system time base
+SOF_TIMESTAMPING_SOFTWARE:     return system time stamp generated in
+                               software
+
+SOF_TIMESTAMPING_TX/RX determine how time stamps are generated.
+SOF_TIMESTAMPING_RAW/SYS determine how they are reported in the
+following control message:
+    struct scm_timestamping {
+           struct timespec systime;
+           struct timespec hwtimetrans;
+           struct timespec hwtimeraw;
+    };
+
+recvmsg() can be used to get this control message for regular incoming
+packets. For send time stamps the outgoing packet is looped back to
+the socket's error queue with the send time stamp(s) attached. It can
+be received with recvmsg(flags=MSG_ERRQUEUE). The call returns the
+original outgoing packet data including all headers preprended down to
+and including the link layer, the scm_timestamping control message and
+a sock_extended_err control message with ee_errno==ENOMSG and
+ee_origin==SO_EE_ORIGIN_TIMESTAMPING. A socket with such a pending
+bounced packet is ready for reading as far as select() is concerned.
+
+All three values correspond to the same event in time, but were
+generated in different ways. Each of these values may be empty (= all
+zero), in which case no such value was available. If the application
+is not interested in some of these values, they can be left blank to
+avoid the potential overhead of calculating them.
+
+systime is the value of the system time at that moment. This
+corresponds to the value also returned via SO_TIMESTAMP[NS]. If the
+time stamp was generated by hardware, then this field is
+empty. Otherwise it is filled in if SOF_TIMESTAMPING_SOFTWARE is
+set.
+
+hwtimeraw is the original hardware time stamp. Filled in if
+SOF_TIMESTAMPING_RAW_HARDWARE is set. No assumptions about its
+relation to system time should be made.
+
+hwtimetrans is the hardware time stamp transformed so that it
+corresponds as good as possible to system time. This correlation is
+not perfect; as a consequence, sorting packets received via different
+NICs by their hwtimetrans may differ from the order in which they were
+received. hwtimetrans may be non-monotonic even for the same NIC.
+Filled in if SOF_TIMESTAMPING_SYS_HARDWARE is set. Requires support
+by the network device and will be empty without that support.
+
+
+SIOCSHWTSTAMP:
+
+Hardware time stamping must also be initialized for each device driver
+that is expected to do hardware time stamping. The parameter is:
+
+struct hwtstamp_config {
+    int flags;           /* no flags defined right now, must be zero */
+    int tx_type;         /* HWTSTAMP_TX_* */
+    int rx_filter;       /* HWTSTAMP_FILTER_* */
+};
+
+Desired behavior is passed into the kernel and to a specific device by
+calling ioctl(SIOCSHWTSTAMP) with a pointer to a struct ifreq whose
+ifr_data points to a struct hwtstamp_config. The tx_type and
+rx_filter are hints to the driver what it is expected to do. If
+the requested fine-grained filtering for incoming packets is not
+supported, the driver may time stamp more than just the requested types
+of packets.
+
+A driver which supports hardware time stamping shall update the struct
+with the actual, possibly more permissive configuration. If the
+requested packets cannot be time stamped, then nothing should be
+changed and ERANGE shall be returned (in contrast to EINVAL, which
+indicates that SIOCSHWTSTAMP is not supported at all).
+
+Only a processes with admin rights may change the configuration. User
+space is responsible to ensure that multiple processes don't interfere
+with each other and that the settings are reset.
+
+/* possible values for hwtstamp_config->tx_type */
+enum {
+	/*
+	 * no outgoing packet will need hardware time stamping;
+	 * should a packet arrive which asks for it, no hardware
+	 * time stamping will be done
+	 */
+	HWTSTAMP_TX_OFF,
+
+	/*
+	 * enables hardware time stamping for outgoing packets;
+	 * the sender of the packet decides which are to be
+	 * time stamped by setting SOF_TIMESTAMPING_TX_SOFTWARE
+	 * before sending the packet
+	 */
+	HWTSTAMP_TX_ON,
+};
+
+/* possible values for hwtstamp_config->rx_filter */
+enum {
+	/* time stamp no incoming packet at all */
+	HWTSTAMP_FILTER_NONE,
+
+	/* time stamp any incoming packet */
+	HWTSTAMP_FILTER_ALL,
+
+        /* return value: time stamp all packets requested plus some others */
+        HWTSTAMP_FILTER_SOME,
+
+	/* PTP v1, UDP, any kind of event packet */
+	HWTSTAMP_FILTER_PTP_V1_L4_EVENT,
+
+        ...
+};
+
+
+DEVICE IMPLEMENTATION
+
+A driver which supports hardware time stamping must support the
+SIOCSHWTSTAMP ioctl. Time stamps for received packets must be stored
+in the skb with skb_hwtstamp_set().
+
+Time stamps for outgoing packets are to be generated as follows:
+- In hard_start_xmit(), check if skb_hwtstamp_check_tx_hardware()
+  returns non-zero. If yes, then the driver is expected
+  to do hardware time stamping.
+- If this is possible for the skb and requested, then declare
+  that the driver is doing the time stamping by calling
+  skb_hwtstamp_tx_in_progress(). A driver not supporting
+  hardware time stamping doesn't do that. A driver must never
+  touch sk_buff::tstamp! It is used to store how time stamping
+  for an outgoing packets is to be done.
+- As soon as the driver has sent the packet and/or obtained a
+  hardware time stamp for it, it passes the time stamp back by
+  calling skb_hwtstamp_tx() with the original skb, the raw
+  hardware time stamp and a handle to the device (necessary
+  to convert the hardware time stamp to system time). If obtaining
+  the hardware time stamp somehow fails, then the driver should
+  not fall back to software time stamping. The rationale is that
+  this would occur at a later time in the processing pipeline
+  than other software time stamping and therefore could lead
+  to unexpected deltas between time stamps.
+- If the driver did not call skb_hwtstamp_tx_in_progress(), then
+  dev_hard_start_xmit() checks whether software time stamping
+  is wanted as fallback and potentially generates the time stamp.
diff --git a/Documentation/networking/timestamping/.gitignore b/Documentation/networking/timestamping/.gitignore
new file mode 100644
index 0000000..71e81eb
--- /dev/null
+++ b/Documentation/networking/timestamping/.gitignore
@@ -0,0 +1 @@
+timestamping
diff --git a/Documentation/networking/timestamping/Makefile b/Documentation/networking/timestamping/Makefile
new file mode 100644
index 0000000..2a1489f
--- /dev/null
+++ b/Documentation/networking/timestamping/Makefile
@@ -0,0 +1,6 @@
+CPPFLAGS = -I../../../include
+
+timestamping: timestamping.c
+
+clean:
+	rm -f timestamping
diff --git a/Documentation/networking/timestamping/timestamping.c b/Documentation/networking/timestamping/timestamping.c
new file mode 100644
index 0000000..43d1431
--- /dev/null
+++ b/Documentation/networking/timestamping/timestamping.c
@@ -0,0 +1,533 @@
+/*
+ * This program demonstrates how the various time stamping features in
+ * the Linux kernel work. It emulates the behavior of a PTP
+ * implementation in stand-alone master mode by sending PTPv1 Sync
+ * multicasts once every second. It looks for similar packets, but
+ * beyond that doesn't actually implement PTP.
+ *
+ * Outgoing packets are time stamped with SO_TIMESTAMPING with or
+ * without hardware support.
+ *
+ * Incoming packets are time stamped with SO_TIMESTAMPING with or
+ * without hardware support, SIOCGSTAMP[NS] (per-socket time stamp) and
+ * SO_TIMESTAMP[NS].
+ *
+ * Copyright (C) 2009 Intel Corporation.
+ * Author: Patrick Ohly <patrick.ohly@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. * See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <string.h>
+
+#include <sys/time.h>
+#include <sys/socket.h>
+#include <sys/select.h>
+#include <sys/ioctl.h>
+#include <arpa/inet.h>
+#include <net/if.h>
+
+#include "asm/types.h"
+#include "linux/net_tstamp.h"
+#include "linux/errqueue.h"
+
+#ifndef SO_TIMESTAMPING
+# define SO_TIMESTAMPING         37
+# define SCM_TIMESTAMPING        SO_TIMESTAMPING
+#endif
+
+#ifndef SO_TIMESTAMPNS
+# define SO_TIMESTAMPNS 35
+#endif
+
+#ifndef SIOCGSTAMPNS
+# define SIOCGSTAMPNS 0x8907
+#endif
+
+#ifndef SIOCSHWTSTAMP
+# define SIOCSHWTSTAMP 0x89b0
+#endif
+
+static void usage(const char *error)
+{
+	if (error)
+		printf("invalid option: %s\n", error);
+	printf("timestamping interface option*\n\n"
+	       "Options:\n"
+	       "  IP_MULTICAST_LOOP - looping outgoing multicasts\n"
+	       "  SO_TIMESTAMP - normal software time stamping, ms resolution\n"
+	       "  SO_TIMESTAMPNS - more accurate software time stamping\n"
+	       "  SOF_TIMESTAMPING_TX_HARDWARE - hardware time stamping of outgoing packets\n"
+	       "  SOF_TIMESTAMPING_TX_SOFTWARE - software fallback for outgoing packets\n"
+	       "  SOF_TIMESTAMPING_RX_HARDWARE - hardware time stamping of incoming packets\n"
+	       "  SOF_TIMESTAMPING_RX_SOFTWARE - software fallback for incoming packets\n"
+	       "  SOF_TIMESTAMPING_SOFTWARE - request reporting of software time stamps\n"
+	       "  SOF_TIMESTAMPING_SYS_HARDWARE - request reporting of transformed HW time stamps\n"
+	       "  SOF_TIMESTAMPING_RAW_HARDWARE - request reporting of raw HW time stamps\n"
+	       "  SIOCGSTAMP - check last socket time stamp\n"
+	       "  SIOCGSTAMPNS - more accurate socket time stamp\n");
+	exit(1);
+}
+
+static void bail(const char *error)
+{
+	printf("%s: %s\n", error, strerror(errno));
+	exit(1);
+}
+
+static const unsigned char sync[] = {
+	0x00, 0x01, 0x00, 0x01,
+	0x5f, 0x44, 0x46, 0x4c,
+	0x54, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00,
+	0x01, 0x01,
+
+	/* fake uuid */
+	0x00, 0x01,
+	0x02, 0x03, 0x04, 0x05,
+
+	0x00, 0x01, 0x00, 0x37,
+	0x00, 0x00, 0x00, 0x08,
+	0x00, 0x00, 0x00, 0x00,
+	0x49, 0x05, 0xcd, 0x01,
+	0x29, 0xb1, 0x8d, 0xb0,
+	0x00, 0x00, 0x00, 0x00,
+	0x00, 0x01,
+
+	/* fake uuid */
+	0x00, 0x01,
+	0x02, 0x03, 0x04, 0x05,
+
+	0x00, 0x00, 0x00, 0x37,
+	0x00, 0x00, 0x00, 0x04,
+	0x44, 0x46, 0x4c, 0x54,
+	0x00, 0x00, 0xf0, 0x60,
+	0x00, 0x01, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x01,
+	0x00, 0x00, 0xf0, 0x60,
+	0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x04,
+	0x44, 0x46, 0x4c, 0x54,
+	0x00, 0x01,
+
+	/* fake uuid */
+	0x00, 0x01,
+	0x02, 0x03, 0x04, 0x05,
+
+	0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00
+};
+
+static void sendpacket(int sock, struct sockaddr *addr, socklen_t addr_len)
+{
+	struct timeval now;
+	int res;
+
+	res = sendto(sock, sync, sizeof(sync), 0,
+		addr, addr_len);
+	gettimeofday(&now, 0);
+	if (res < 0)
+		printf("%s: %s\n", "send", strerror(errno));
+	else
+		printf("%ld.%06ld: sent %d bytes\n",
+		       (long)now.tv_sec, (long)now.tv_usec,
+		       res);
+}
+
+static void printpacket(struct msghdr *msg, int res,
+			char *data,
+			int sock, int recvmsg_flags,
+			int siocgstamp, int siocgstampns)
+{
+	struct sockaddr_in *from_addr = (struct sockaddr_in *)msg->msg_name;
+	struct cmsghdr *cmsg;
+	struct timeval tv;
+	struct timespec ts;
+	struct timeval now;
+
+	gettimeofday(&now, 0);
+
+	printf("%ld.%06ld: received %s data, %d bytes from %s, %d bytes control messages\n",
+	       (long)now.tv_sec, (long)now.tv_usec,
+	       (recvmsg_flags & MSG_ERRQUEUE) ? "error" : "regular",
+	       res,
+	       inet_ntoa(from_addr->sin_addr),
+	       msg->msg_controllen);
+	for (cmsg = CMSG_FIRSTHDR(msg);
+	     cmsg;
+	     cmsg = CMSG_NXTHDR(msg, cmsg)) {
+		printf("   cmsg len %d: ", cmsg->cmsg_len);
+		switch (cmsg->cmsg_level) {
+		case SOL_SOCKET:
+			printf("SOL_SOCKET ");
+			switch (cmsg->cmsg_type) {
+			case SO_TIMESTAMP: {
+				struct timeval *stamp =
+					(struct timeval *)CMSG_DATA(cmsg);
+				printf("SO_TIMESTAMP %ld.%06ld",
+				       (long)stamp->tv_sec,
+				       (long)stamp->tv_usec);
+				break;
+			}
+			case SO_TIMESTAMPNS: {
+				struct timespec *stamp =
+					(struct timespec *)CMSG_DATA(cmsg);
+				printf("SO_TIMESTAMPNS %ld.%09ld",
+				       (long)stamp->tv_sec,
+				       (long)stamp->tv_nsec);
+				break;
+			}
+			case SO_TIMESTAMPING: {
+				struct timespec *stamp =
+					(struct timespec *)CMSG_DATA(cmsg);
+				printf("SO_TIMESTAMPING ");
+				printf("SW %ld.%09ld ",
+				       (long)stamp->tv_sec,
+				       (long)stamp->tv_nsec);
+				stamp++;
+				printf("HW transformed %ld.%09ld ",
+				       (long)stamp->tv_sec,
+				       (long)stamp->tv_nsec);
+				stamp++;
+				printf("HW raw %ld.%09ld",
+				       (long)stamp->tv_sec,
+				       (long)stamp->tv_nsec);
+				break;
+			}
+			default:
+				printf("type %d", cmsg->cmsg_type);
+				break;
+			}
+			break;
+		case IPPROTO_IP:
+			printf("IPPROTO_IP ");
+			switch (cmsg->cmsg_type) {
+			case IP_RECVERR: {
+				struct sock_extended_err *err =
+					(struct sock_extended_err *)CMSG_DATA(cmsg);
+				printf("IP_RECVERR ee_errno '%s' ee_origin %d => %s",
+					strerror(err->ee_errno),
+					err->ee_origin,
+#ifdef SO_EE_ORIGIN_TIMESTAMPING
+					err->ee_origin == SO_EE_ORIGIN_TIMESTAMPING ?
+					"bounced packet" : "unexpected origin"
+#else
+					"probably SO_EE_ORIGIN_TIMESTAMPING"
+#endif
+					);
+				if (res < sizeof(sync))
+					printf(" => truncated data?!");
+				else if (!memcmp(sync, data + res - sizeof(sync),
+							sizeof(sync)))
+					printf(" => GOT OUR DATA BACK (HURRAY!)");
+				break;
+			}
+			case IP_PKTINFO: {
+				struct in_pktinfo *pktinfo =
+					(struct in_pktinfo *)CMSG_DATA(cmsg);
+				printf("IP_PKTINFO interface index %u",
+					pktinfo->ipi_ifindex);
+				break;
+			}
+			default:
+				printf("type %d", cmsg->cmsg_type);
+				break;
+			}
+			break;
+		default:
+			printf("level %d type %d",
+				cmsg->cmsg_level,
+				cmsg->cmsg_type);
+			break;
+		}
+		printf("\n");
+	}
+
+	if (siocgstamp) {
+		if (ioctl(sock, SIOCGSTAMP, &tv))
+			printf("   %s: %s\n", "SIOCGSTAMP", strerror(errno));
+		else
+			printf("SIOCGSTAMP %ld.%06ld\n",
+			       (long)tv.tv_sec,
+			       (long)tv.tv_usec);
+	}
+	if (siocgstampns) {
+		if (ioctl(sock, SIOCGSTAMPNS, &ts))
+			printf("   %s: %s\n", "SIOCGSTAMPNS", strerror(errno));
+		else
+			printf("SIOCGSTAMPNS %ld.%09ld\n",
+			       (long)ts.tv_sec,
+			       (long)ts.tv_nsec);
+	}
+}
+
+static void recvpacket(int sock, int recvmsg_flags,
+		       int siocgstamp, int siocgstampns)
+{
+	char data[256];
+	struct msghdr msg;
+	struct iovec entry;
+	struct sockaddr_in from_addr;
+	struct {
+		struct cmsghdr cm;
+		char control[512];
+	} control;
+	int res;
+
+	memset(&msg, 0, sizeof(msg));
+	msg.msg_iov = &entry;
+	msg.msg_iovlen = 1;
+	entry.iov_base = data;
+	entry.iov_len = sizeof(data);
+	msg.msg_name = (caddr_t)&from_addr;
+	msg.msg_namelen = sizeof(from_addr);
+	msg.msg_control = &control;
+	msg.msg_controllen = sizeof(control);
+
+	res = recvmsg(sock, &msg, recvmsg_flags|MSG_DONTWAIT);
+	if (res < 0) {
+		printf("%s %s: %s\n",
+		       "recvmsg",
+		       (recvmsg_flags & MSG_ERRQUEUE) ? "error" : "regular",
+		       strerror(errno));
+	} else {
+		printpacket(&msg, res, data,
+			    sock, recvmsg_flags,
+			    siocgstamp, siocgstampns);
+	}
+}
+
+int main(int argc, char **argv)
+{
+	int so_timestamping_flags = 0;
+	int so_timestamp = 0;
+	int so_timestampns = 0;
+	int siocgstamp = 0;
+	int siocgstampns = 0;
+	int ip_multicast_loop = 0;
+	char *interface;
+	int i;
+	int enabled = 1;
+	int sock;
+	struct ifreq device;
+	struct ifreq hwtstamp;
+	struct hwtstamp_config hwconfig, hwconfig_requested;
+	struct sockaddr_in addr;
+	struct ip_mreq imr;
+	struct in_addr iaddr;
+	int val;
+	socklen_t len;
+	struct timeval next;
+
+	if (argc < 2)
+		usage(0);
+	interface = argv[1];
+
+	for (i = 2; i < argc; i++) {
+		if (!strcasecmp(argv[i], "SO_TIMESTAMP"))
+			so_timestamp = 1;
+		else if (!strcasecmp(argv[i], "SO_TIMESTAMPNS"))
+			so_timestampns = 1;
+		else if (!strcasecmp(argv[i], "SIOCGSTAMP"))
+			siocgstamp = 1;
+		else if (!strcasecmp(argv[i], "SIOCGSTAMPNS"))
+			siocgstampns = 1;
+		else if (!strcasecmp(argv[i], "IP_MULTICAST_LOOP"))
+			ip_multicast_loop = 1;
+		else if (!strcasecmp(argv[i], "SOF_TIMESTAMPING_TX_HARDWARE"))
+			so_timestamping_flags |= SOF_TIMESTAMPING_TX_HARDWARE;
+		else if (!strcasecmp(argv[i], "SOF_TIMESTAMPING_TX_SOFTWARE"))
+			so_timestamping_flags |= SOF_TIMESTAMPING_TX_SOFTWARE;
+		else if (!strcasecmp(argv[i], "SOF_TIMESTAMPING_RX_HARDWARE"))
+			so_timestamping_flags |= SOF_TIMESTAMPING_RX_HARDWARE;
+		else if (!strcasecmp(argv[i], "SOF_TIMESTAMPING_RX_SOFTWARE"))
+			so_timestamping_flags |= SOF_TIMESTAMPING_RX_SOFTWARE;
+		else if (!strcasecmp(argv[i], "SOF_TIMESTAMPING_SOFTWARE"))
+			so_timestamping_flags |= SOF_TIMESTAMPING_SOFTWARE;
+		else if (!strcasecmp(argv[i], "SOF_TIMESTAMPING_SYS_HARDWARE"))
+			so_timestamping_flags |= SOF_TIMESTAMPING_SYS_HARDWARE;
+		else if (!strcasecmp(argv[i], "SOF_TIMESTAMPING_RAW_HARDWARE"))
+			so_timestamping_flags |= SOF_TIMESTAMPING_RAW_HARDWARE;
+		else
+			usage(argv[i]);
+	}
+
+	sock = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
+	if (socket < 0)
+		bail("socket");
+
+	memset(&device, 0, sizeof(device));
+	strncpy(device.ifr_name, interface, sizeof(device.ifr_name));
+	if (ioctl(sock, SIOCGIFADDR, &device) < 0)
+		bail("getting interface IP address");
+
+	memset(&hwtstamp, 0, sizeof(hwtstamp));
+	strncpy(hwtstamp.ifr_name, interface, sizeof(hwtstamp.ifr_name));
+	hwtstamp.ifr_data = (void *)&hwconfig;
+	memset(&hwconfig, 0, sizeof(&hwconfig));
+	hwconfig.tx_type =
+		(so_timestamping_flags & SOF_TIMESTAMPING_TX_HARDWARE) ?
+		HWTSTAMP_TX_ON : HWTSTAMP_TX_OFF;
+	hwconfig.rx_filter =
+		(so_timestamping_flags & SOF_TIMESTAMPING_RX_HARDWARE) ?
+		HWTSTAMP_FILTER_PTP_V1_L4_SYNC : HWTSTAMP_FILTER_NONE;
+	hwconfig_requested = hwconfig;
+	if (ioctl(sock, SIOCSHWTSTAMP, &hwtstamp) < 0) {
+		if ((errno == EINVAL || errno == ENOTSUP) &&
+		    hwconfig_requested.tx_type == HWTSTAMP_TX_OFF &&
+		    hwconfig_requested.rx_filter == HWTSTAMP_FILTER_NONE)
+			printf("SIOCSHWTSTAMP: disabling hardware time stamping not possible\n");
+		else
+			bail("SIOCSHWTSTAMP");
+	}
+	printf("SIOCSHWTSTAMP: tx_type %d requested, got %d; rx_filter %d requested, got %d\n",
+	       hwconfig_requested.tx_type, hwconfig.tx_type,
+	       hwconfig_requested.rx_filter, hwconfig.rx_filter);
+
+	/* bind to PTP port */
+	addr.sin_family = AF_INET;
+	addr.sin_addr.s_addr = htonl(INADDR_ANY);
+	addr.sin_port = htons(319 /* PTP event port */);
+	if (bind(sock,
+		 (struct sockaddr *)&addr,
+		 sizeof(struct sockaddr_in)) < 0)
+		bail("bind");
+
+	/* set multicast group for outgoing packets */
+	inet_aton("224.0.1.130", &iaddr); /* alternate PTP domain 1 */
+	addr.sin_addr = iaddr;
+	imr.imr_multiaddr.s_addr = iaddr.s_addr;
+	imr.imr_interface.s_addr =
+		((struct sockaddr_in *)&device.ifr_addr)->sin_addr.s_addr;
+	if (setsockopt(sock, IPPROTO_IP, IP_MULTICAST_IF,
+		       &imr.imr_interface.s_addr, sizeof(struct in_addr)) < 0)
+		bail("set multicast");
+
+	/* join multicast group, loop our own packet */
+	if (setsockopt(sock, IPPROTO_IP, IP_ADD_MEMBERSHIP,
+		       &imr, sizeof(struct ip_mreq)) < 0)
+		bail("join multicast group");
+
+	if (setsockopt(sock, IPPROTO_IP, IP_MULTICAST_LOOP,
+		       &ip_multicast_loop, sizeof(enabled)) < 0) {
+		bail("loop multicast");
+	}
+
+	/* set socket options for time stamping */
+	if (so_timestamp &&
+		setsockopt(sock, SOL_SOCKET, SO_TIMESTAMP,
+			   &enabled, sizeof(enabled)) < 0)
+		bail("setsockopt SO_TIMESTAMP");
+
+	if (so_timestampns &&
+		setsockopt(sock, SOL_SOCKET, SO_TIMESTAMPNS,
+			   &enabled, sizeof(enabled)) < 0)
+		bail("setsockopt SO_TIMESTAMPNS");
+
+	if (so_timestamping_flags &&
+		setsockopt(sock, SOL_SOCKET, SO_TIMESTAMPING,
+			   &so_timestamping_flags,
+			   sizeof(so_timestamping_flags)) < 0)
+		bail("setsockopt SO_TIMESTAMPING");
+
+	/* request IP_PKTINFO for debugging purposes */
+	if (setsockopt(sock, SOL_IP, IP_PKTINFO,
+		       &enabled, sizeof(enabled)) < 0)
+		printf("%s: %s\n", "setsockopt IP_PKTINFO", strerror(errno));
+
+	/* verify socket options */
+	len = sizeof(val);
+	if (getsockopt(sock, SOL_SOCKET, SO_TIMESTAMP, &val, &len) < 0)
+		printf("%s: %s\n", "getsockopt SO_TIMESTAMP", strerror(errno));
+	else
+		printf("SO_TIMESTAMP %d\n", val);
+
+	if (getsockopt(sock, SOL_SOCKET, SO_TIMESTAMPNS, &val, &len) < 0)
+		printf("%s: %s\n", "getsockopt SO_TIMESTAMPNS",
+		       strerror(errno));
+	else
+		printf("SO_TIMESTAMPNS %d\n", val);
+
+	if (getsockopt(sock, SOL_SOCKET, SO_TIMESTAMPING, &val, &len) < 0) {
+		printf("%s: %s\n", "getsockopt SO_TIMESTAMPING",
+		       strerror(errno));
+	} else {
+		printf("SO_TIMESTAMPING %d\n", val);
+		if (val != so_timestamping_flags)
+			printf("   not the expected value %d\n",
+			       so_timestamping_flags);
+	}
+
+	/* send packets forever every five seconds */
+	gettimeofday(&next, 0);
+	next.tv_sec = (next.tv_sec + 1) / 5 * 5;
+	next.tv_usec = 0;
+	while (1) {
+		struct timeval now;
+		struct timeval delta;
+		long delta_us;
+		int res;
+		fd_set readfs, errorfs;
+
+		gettimeofday(&now, 0);
+		delta_us = (long)(next.tv_sec - now.tv_sec) * 1000000 +
+			(long)(next.tv_usec - now.tv_usec);
+		if (delta_us > 0) {
+			/* continue waiting for timeout or data */
+			delta.tv_sec = delta_us / 1000000;
+			delta.tv_usec = delta_us % 1000000;
+
+			FD_ZERO(&readfs);
+			FD_ZERO(&errorfs);
+			FD_SET(sock, &readfs);
+			FD_SET(sock, &errorfs);
+			printf("%ld.%06ld: select %ldus\n",
+			       (long)now.tv_sec, (long)now.tv_usec,
+			       delta_us);
+			res = select(sock + 1, &readfs, 0, &errorfs, &delta);
+			gettimeofday(&now, 0);
+			printf("%ld.%06ld: select returned: %d, %s\n",
+			       (long)now.tv_sec, (long)now.tv_usec,
+			       res,
+			       res < 0 ? strerror(errno) : "success");
+			if (res > 0) {
+				if (FD_ISSET(sock, &readfs))
+					printf("ready for reading\n");
+				if (FD_ISSET(sock, &errorfs))
+					printf("has error\n");
+				recvpacket(sock, 0,
+					   siocgstamp,
+					   siocgstampns);
+				recvpacket(sock, MSG_ERRQUEUE,
+					   siocgstamp,
+					   siocgstampns);
+			}
+		} else {
+			/* write one packet */
+			sendpacket(sock,
+				   (struct sockaddr *)&addr,
+				   sizeof(addr));
+			next.tv_sec += 5;
+			continue;
+		}
+	}
+
+	return 0;
+}
diff --git a/arch/alpha/include/asm/socket.h b/arch/alpha/include/asm/socket.h
index a1057c2..3641ec1 100644
--- a/arch/alpha/include/asm/socket.h
+++ b/arch/alpha/include/asm/socket.h
@@ -62,6 +62,9 @@
 
 #define SO_MARK			36
 
+#define SO_TIMESTAMPING		37
+#define SCM_TIMESTAMPING	SO_TIMESTAMPING
+
 /* O_NONBLOCK clashes with the bits used for socket types.  Therefore we
  * have to define SOCK_NONBLOCK to a different value here.
  */
diff --git a/arch/arm/include/asm/socket.h b/arch/arm/include/asm/socket.h
index 6817be9..537de4e 100644
--- a/arch/arm/include/asm/socket.h
+++ b/arch/arm/include/asm/socket.h
@@ -54,4 +54,7 @@
 
 #define SO_MARK			36
 
+#define SO_TIMESTAMPING		37
+#define SCM_TIMESTAMPING	SO_TIMESTAMPING
+
 #endif /* _ASM_SOCKET_H */
diff --git a/arch/avr32/include/asm/socket.h b/arch/avr32/include/asm/socket.h
index 35863f2..04c8606 100644
--- a/arch/avr32/include/asm/socket.h
+++ b/arch/avr32/include/asm/socket.h
@@ -54,4 +54,7 @@
 
 #define SO_MARK			36
 
+#define SO_TIMESTAMPING		37
+#define SCM_TIMESTAMPING	SO_TIMESTAMPING
+
 #endif /* __ASM_AVR32_SOCKET_H */
diff --git a/arch/blackfin/include/asm/socket.h b/arch/blackfin/include/asm/socket.h
index 2ca702e..fac7fe9 100644
--- a/arch/blackfin/include/asm/socket.h
+++ b/arch/blackfin/include/asm/socket.h
@@ -53,4 +53,7 @@
 
 #define SO_MARK			36
 
+#define SO_TIMESTAMPING		37
+#define SCM_TIMESTAMPING	SO_TIMESTAMPING
+
 #endif				/* _ASM_SOCKET_H */
diff --git a/arch/cris/include/asm/socket.h b/arch/cris/include/asm/socket.h
index 9df0ca8..d5cf740 100644
--- a/arch/cris/include/asm/socket.h
+++ b/arch/cris/include/asm/socket.h
@@ -56,6 +56,9 @@
 
 #define SO_MARK			36
 
+#define SO_TIMESTAMPING		37
+#define SCM_TIMESTAMPING	SO_TIMESTAMPING
+
 #endif /* _ASM_SOCKET_H */
 
 
diff --git a/arch/h8300/include/asm/socket.h b/arch/h8300/include/asm/socket.h
index da2520d..602518a7 100644
--- a/arch/h8300/include/asm/socket.h
+++ b/arch/h8300/include/asm/socket.h
@@ -54,4 +54,7 @@
 
 #define SO_MARK			36
 
+#define SO_TIMESTAMPING		37
+#define SCM_TIMESTAMPING	SO_TIMESTAMPING
+
 #endif /* _ASM_SOCKET_H */
diff --git a/arch/ia64/include/asm/socket.h b/arch/ia64/include/asm/socket.h
index d5ef0aa..7454212 100644
--- a/arch/ia64/include/asm/socket.h
+++ b/arch/ia64/include/asm/socket.h
@@ -63,4 +63,7 @@
 
 #define SO_MARK			36
 
+#define SO_TIMESTAMPING		37
+#define SCM_TIMESTAMPING	SO_TIMESTAMPING
+
 #endif /* _ASM_IA64_SOCKET_H */
diff --git a/arch/m68k/include/asm/socket.h b/arch/m68k/include/asm/socket.h
index dbc64e9..ca87f93 100644
--- a/arch/m68k/include/asm/socket.h
+++ b/arch/m68k/include/asm/socket.h
@@ -54,4 +54,7 @@
 
 #define SO_MARK			36
 
+#define SO_TIMESTAMPING		37
+#define SCM_TIMESTAMPING	SO_TIMESTAMPING
+
 #endif /* _ASM_SOCKET_H */
diff --git a/arch/mips/include/asm/socket.h b/arch/mips/include/asm/socket.h
index facc2d7..2abca17 100644
--- a/arch/mips/include/asm/socket.h
+++ b/arch/mips/include/asm/socket.h
@@ -75,6 +75,9 @@
 
 #define SO_MARK			36
 
+#define SO_TIMESTAMPING		37
+#define SCM_TIMESTAMPING	SO_TIMESTAMPING
+
 #ifdef __KERNEL__
 
 /** sock_type - Socket types
diff --git a/arch/parisc/include/asm/socket.h b/arch/parisc/include/asm/socket.h
index fba402c..885472b 100644
--- a/arch/parisc/include/asm/socket.h
+++ b/arch/parisc/include/asm/socket.h
@@ -54,6 +54,9 @@
 
 #define SO_MARK			0x401f
 
+#define SO_TIMESTAMPING		0x4020
+#define SCM_TIMESTAMPING	SO_TIMESTAMPING
+
 /* O_NONBLOCK clashes with the bits used for socket types.  Therefore we
  * have to define SOCK_NONBLOCK to a different value here.
  */
diff --git a/arch/powerpc/include/asm/socket.h b/arch/powerpc/include/asm/socket.h
index f5a4e168..1e5cfad 100644
--- a/arch/powerpc/include/asm/socket.h
+++ b/arch/powerpc/include/asm/socket.h
@@ -61,4 +61,7 @@
 
 #define SO_MARK			36
 
+#define SO_TIMESTAMPING		37
+#define SCM_TIMESTAMPING	SO_TIMESTAMPING
+
 #endif	/* _ASM_POWERPC_SOCKET_H */
diff --git a/arch/s390/include/asm/socket.h b/arch/s390/include/asm/socket.h
index c786ab6..02330c5 100644
--- a/arch/s390/include/asm/socket.h
+++ b/arch/s390/include/asm/socket.h
@@ -62,4 +62,7 @@
 
 #define SO_MARK			36
 
+#define SO_TIMESTAMPING		37
+#define SCM_TIMESTAMPING	SO_TIMESTAMPING
+
 #endif /* _ASM_SOCKET_H */
diff --git a/arch/sh/include/asm/socket.h b/arch/sh/include/asm/socket.h
index 6d4bf65..345653b 100644
--- a/arch/sh/include/asm/socket.h
+++ b/arch/sh/include/asm/socket.h
@@ -54,4 +54,7 @@
 
 #define SO_MARK			36
 
+#define SO_TIMESTAMPING		37
+#define SCM_TIMESTAMPING	SO_TIMESTAMPING
+
 #endif /* __ASM_SH_SOCKET_H */
diff --git a/arch/sparc/include/asm/socket.h b/arch/sparc/include/asm/socket.h
index bf50d0c..982a12f 100644
--- a/arch/sparc/include/asm/socket.h
+++ b/arch/sparc/include/asm/socket.h
@@ -50,6 +50,9 @@
 
 #define SO_MARK			0x0022
 
+#define SO_TIMESTAMPING		0x0023
+#define SCM_TIMESTAMPING	SO_TIMESTAMPING
+
 /* Security levels - as per NRL IPv6 - don't actually do anything */
 #define SO_SECURITY_AUTHENTICATION		0x5001
 #define SO_SECURITY_ENCRYPTION_TRANSPORT	0x5002
diff --git a/arch/x86/include/asm/socket.h b/arch/x86/include/asm/socket.h
index 8ab9cc8..ca8bf2c 100644
--- a/arch/x86/include/asm/socket.h
+++ b/arch/x86/include/asm/socket.h
@@ -54,4 +54,7 @@
 
 #define SO_MARK			36
 
+#define SO_TIMESTAMPING		37
+#define SCM_TIMESTAMPING	SO_TIMESTAMPING
+
 #endif /* _ASM_X86_SOCKET_H */
diff --git a/arch/xtensa/include/asm/socket.h b/arch/xtensa/include/asm/socket.h
index 6100682..dd1a7a4 100644
--- a/arch/xtensa/include/asm/socket.h
+++ b/arch/xtensa/include/asm/socket.h
@@ -65,4 +65,7 @@
 
 #define SO_MARK			36
 
+#define SO_TIMESTAMPING		37
+#define SCM_TIMESTAMPING	SO_TIMESTAMPING
+
 #endif	/* _XTENSA_SOCKET_H */
diff --git a/include/asm-frv/socket.h b/include/asm-frv/socket.h
index e51ca67..57c3d40 100644
--- a/include/asm-frv/socket.h
+++ b/include/asm-frv/socket.h
@@ -54,5 +54,8 @@
 
 #define SO_MARK			36
 
+#define SO_TIMESTAMPING		37
+#define SCM_TIMESTAMPING	SO_TIMESTAMPING
+
 #endif /* _ASM_SOCKET_H */
 
diff --git a/include/asm-m32r/socket.h b/include/asm-m32r/socket.h
index 9a0e200..be7ed58 100644
--- a/include/asm-m32r/socket.h
+++ b/include/asm-m32r/socket.h
@@ -54,4 +54,7 @@
 
 #define SO_MARK			36
 
+#define SO_TIMESTAMPING		37
+#define SCM_TIMESTAMPING	SO_TIMESTAMPING
+
 #endif /* _ASM_M32R_SOCKET_H */
diff --git a/include/asm-mn10300/socket.h b/include/asm-mn10300/socket.h
index 80af9c4..fb5daf4 100644
--- a/include/asm-mn10300/socket.h
+++ b/include/asm-mn10300/socket.h
@@ -54,4 +54,7 @@
 
 #define SO_MARK			36
 
+#define SO_TIMESTAMPING		37
+#define SCM_TIMESTAMPING	SO_TIMESTAMPING
+
 #endif /* _ASM_SOCKET_H */
diff --git a/include/linux/errqueue.h b/include/linux/errqueue.h
index ceb1454..ec12cc743 100644
--- a/include/linux/errqueue.h
+++ b/include/linux/errqueue.h
@@ -18,6 +18,7 @@
 #define SO_EE_ORIGIN_LOCAL	1
 #define SO_EE_ORIGIN_ICMP	2
 #define SO_EE_ORIGIN_ICMP6	3
+#define SO_EE_ORIGIN_TIMESTAMPING 4
 
 #define SO_EE_OFFENDER(ee)	((struct sockaddr*)((ee)+1))
 
diff --git a/include/linux/net_tstamp.h b/include/linux/net_tstamp.h
new file mode 100644
index 0000000..a3b8546
--- /dev/null
+++ b/include/linux/net_tstamp.h
@@ -0,0 +1,104 @@
+/*
+ * Userspace API for hardware time stamping of network packets
+ *
+ * Copyright (C) 2008,2009 Intel Corporation
+ * Author: Patrick Ohly <patrick.ohly@intel.com>
+ *
+ */
+
+#ifndef _NET_TIMESTAMPING_H
+#define _NET_TIMESTAMPING_H
+
+#include <linux/socket.h>   /* for SO_TIMESTAMPING */
+
+/* SO_TIMESTAMPING gets an integer bit field comprised of these values */
+enum {
+	SOF_TIMESTAMPING_TX_HARDWARE = (1<<0),
+	SOF_TIMESTAMPING_TX_SOFTWARE = (1<<1),
+	SOF_TIMESTAMPING_RX_HARDWARE = (1<<2),
+	SOF_TIMESTAMPING_RX_SOFTWARE = (1<<3),
+	SOF_TIMESTAMPING_SOFTWARE = (1<<4),
+	SOF_TIMESTAMPING_SYS_HARDWARE = (1<<5),
+	SOF_TIMESTAMPING_RAW_HARDWARE = (1<<6),
+	SOF_TIMESTAMPING_MASK =
+	(SOF_TIMESTAMPING_RAW_HARDWARE - 1) |
+	SOF_TIMESTAMPING_RAW_HARDWARE
+};
+
+/**
+ * struct hwtstamp_config - %SIOCSHWTSTAMP parameter
+ *
+ * @flags:	no flags defined right now, must be zero
+ * @tx_type:	one of HWTSTAMP_TX_*
+ * @rx_type:	one of one of HWTSTAMP_FILTER_*
+ *
+ * %SIOCSHWTSTAMP expects a &struct ifreq with a ifr_data pointer to
+ * this structure. dev_ifsioc() in the kernel takes care of the
+ * translation between 32 bit userspace and 64 bit kernel. The
+ * structure is intentionally chosen so that it has the same layout on
+ * 32 and 64 bit systems, don't break this!
+ */
+struct hwtstamp_config {
+	int flags;
+	int tx_type;
+	int rx_filter;
+};
+
+/* possible values for hwtstamp_config->tx_type */
+enum {
+	/*
+	 * No outgoing packet will need hardware time stamping;
+	 * should a packet arrive which asks for it, no hardware
+	 * time stamping will be done.
+	 */
+	HWTSTAMP_TX_OFF,
+
+	/*
+	 * Enables hardware time stamping for outgoing packets;
+	 * the sender of the packet decides which are to be
+	 * time stamped by setting %SOF_TIMESTAMPING_TX_SOFTWARE
+	 * before sending the packet.
+	 */
+	HWTSTAMP_TX_ON,
+};
+
+/* possible values for hwtstamp_config->rx_filter */
+enum {
+	/* time stamp no incoming packet at all */
+	HWTSTAMP_FILTER_NONE,
+
+	/* time stamp any incoming packet */
+	HWTSTAMP_FILTER_ALL,
+
+	/* return value: time stamp all packets requested plus some others */
+	HWTSTAMP_FILTER_SOME,
+
+	/* PTP v1, UDP, any kind of event packet */
+	HWTSTAMP_FILTER_PTP_V1_L4_EVENT,
+	/* PTP v1, UDP, Sync packet */
+	HWTSTAMP_FILTER_PTP_V1_L4_SYNC,
+	/* PTP v1, UDP, Delay_req packet */
+	HWTSTAMP_FILTER_PTP_V1_L4_DELAY_REQ,
+	/* PTP v2, UDP, any kind of event packet */
+	HWTSTAMP_FILTER_PTP_V2_L4_EVENT,
+	/* PTP v2, UDP, Sync packet */
+	HWTSTAMP_FILTER_PTP_V2_L4_SYNC,
+	/* PTP v2, UDP, Delay_req packet */
+	HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ,
+
+	/* 802.AS1, Ethernet, any kind of event packet */
+	HWTSTAMP_FILTER_PTP_V2_L2_EVENT,
+	/* 802.AS1, Ethernet, Sync packet */
+	HWTSTAMP_FILTER_PTP_V2_L2_SYNC,
+	/* 802.AS1, Ethernet, Delay_req packet */
+	HWTSTAMP_FILTER_PTP_V2_L2_DELAY_REQ,
+
+	/* PTP v2/802.AS1, any layer, any kind of event packet */
+	HWTSTAMP_FILTER_PTP_V2_EVENT,
+	/* PTP v2/802.AS1, any layer, Sync packet */
+	HWTSTAMP_FILTER_PTP_V2_SYNC,
+	/* PTP v2/802.AS1, any layer, Delay_req packet */
+	HWTSTAMP_FILTER_PTP_V2_DELAY_REQ,
+};
+
+#endif /* _NET_TIMESTAMPING_H */
diff --git a/include/linux/sockios.h b/include/linux/sockios.h
index abef759..241f179 100644
--- a/include/linux/sockios.h
+++ b/include/linux/sockios.h
@@ -122,6 +122,9 @@
 #define SIOCBRADDIF	0x89a2		/* add interface to bridge      */
 #define SIOCBRDELIF	0x89a3		/* remove interface from bridge */
 
+/* hardware time stamping: parameters in linux/net_tstamp.h */
+#define SIOCSHWTSTAMP   0x89b0
+
 /* Device private ioctl calls */
 
 /*