Merge branch 'tcp-sw-rx-timestamps'

Mike Maloney says:

====================
net: Add software rx timestamp for TCP.

Add software rx timestamps for TCP, and a test to ensure consistency of
behavior between IP, UDP, and TCP implementation.

Changes since v1:
  -Initialize tss->ts[1] to 0 if caller requested any timestamps.
  -Fix test case to validate that tss->ts[1] is zero.
  -Fix tests to actually use a raw socket.
  -Fix --tcp flag to work on the test.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

8 files changed, 501 insertions, 6 deletions

diff --git a/include/net/tcp.h b/include/net/tcp.h
index a995004ae946..c614ff135b66 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -774,6 +774,12 @@ struct tcp_skb_cb {
 			u16	tcp_gso_segs;
 			u16	tcp_gso_size;
 		};
+
+		/* Used to stash the receive timestamp while this skb is in the
+		 * out of order queue, as skb->tstamp is overwritten by the
+		 * rbnode.
+		 */
+		ktime_t		swtstamp;
 	};
 	__u8		tcp_flags;	/* TCP header flags. (tcp[13])	*/
 
@@ -790,7 +796,8 @@ struct tcp_skb_cb {
 	__u8		ip_dsfield;	/* IPv4 tos or IPv6 dsfield	*/
 	__u8		txstamp_ack:1,	/* Record TX timestamp for ack? */
 			eor:1,		/* Is skb MSG_EOR marked? */
-			unused:6;
+			has_rxtstamp:1,	/* SKB has a RX timestamp	*/
+			unused:5;
 	__u32		ack_seq;	/* Sequence number ACK'd	*/
 	union {
 		struct {
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index d25e3bcca66b..0cce4472b4a1 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -269,6 +269,7 @@
 #include <linux/err.h>
 #include <linux/time.h>
 #include <linux/slab.h>
+#include <linux/errqueue.h>
 
 #include <net/icmp.h>
 #include <net/inet_common.h>
@@ -1695,6 +1696,61 @@ int tcp_peek_len(struct socket *sock)
 }
 EXPORT_SYMBOL(tcp_peek_len);
 
+static void tcp_update_recv_tstamps(struct sk_buff *skb,
+				    struct scm_timestamping *tss)
+{
+	if (skb->tstamp)
+		tss->ts[0] = ktime_to_timespec(skb->tstamp);
+	else
+		tss->ts[0] = (struct timespec) {0};
+
+	if (skb_hwtstamps(skb)->hwtstamp)
+		tss->ts[2] = ktime_to_timespec(skb_hwtstamps(skb)->hwtstamp);
+	else
+		tss->ts[2] = (struct timespec) {0};
+}
+
+/* Similar to __sock_recv_timestamp, but does not require an skb */
+void tcp_recv_timestamp(struct msghdr *msg, const struct sock *sk,
+			struct scm_timestamping *tss)
+{
+	struct timeval tv;
+	bool has_timestamping = false;
+
+	if (tss->ts[0].tv_sec || tss->ts[0].tv_nsec) {
+		if (sock_flag(sk, SOCK_RCVTSTAMP)) {
+			if (sock_flag(sk, SOCK_RCVTSTAMPNS)) {
+				put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMPNS,
+					 sizeof(tss->ts[0]), &tss->ts[0]);
+			} else {
+				tv.tv_sec = tss->ts[0].tv_sec;
+				tv.tv_usec = tss->ts[0].tv_nsec / 1000;
+
+				put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMP,
+					 sizeof(tv), &tv);
+			}
+		}
+
+		if (sk->sk_tsflags & SOF_TIMESTAMPING_SOFTWARE)
+			has_timestamping = true;
+		else
+			tss->ts[0] = (struct timespec) {0};
+	}
+
+	if (tss->ts[2].tv_sec || tss->ts[2].tv_nsec) {
+		if (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE)
+			has_timestamping = true;
+		else
+			tss->ts[2] = (struct timespec) {0};
+	}
+
+	if (has_timestamping) {
+		tss->ts[1] = (struct timespec) {0};
+		put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMPING,
+			 sizeof(*tss), tss);
+	}
+}
+
 /*
  *	This routine copies from a sock struct into the user buffer.
  *
@@ -1716,6 +1772,8 @@ int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock,
 	long timeo;
 	struct sk_buff *skb, *last;
 	u32 urg_hole = 0;
+	struct scm_timestamping tss;
+	bool has_tss = false;
 
 	if (unlikely(flags & MSG_ERRQUEUE))
 		return inet_recv_error(sk, msg, len, addr_len);
@@ -1911,6 +1969,10 @@ skip_copy:
 		if (used + offset < skb->len)
 			continue;
 
+		if (TCP_SKB_CB(skb)->has_rxtstamp) {
+			tcp_update_recv_tstamps(skb, &tss);
+			has_tss = true;
+		}
 		if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
 			goto found_fin_ok;
 		if (!(flags & MSG_PEEK))
@@ -1929,6 +1991,9 @@ skip_copy:
 	 * on connected socket. I was just happy when found this 8) --ANK
 	 */
 
+	if (has_tss)
+		tcp_recv_timestamp(msg, sk, &tss);
+
 	/* Clean up data we have read: This will do ACK frames. */
 	tcp_cleanup_rbuf(sk, copied);
 
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index d3421ee9a10a..568ccfd6dd37 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -4246,9 +4246,15 @@ static void tcp_sack_remove(struct tcp_sock *tp)
 	tp->rx_opt.num_sacks = num_sacks;
 }
 
+enum tcp_queue {
+	OOO_QUEUE,
+	RCV_QUEUE,
+};
+
 /**
  * tcp_try_coalesce - try to merge skb to prior one
  * @sk: socket
+ * @dest: destination queue
  * @to: prior buffer
  * @from: buffer to add in queue
  * @fragstolen: pointer to boolean
@@ -4260,6 +4266,7 @@ static void tcp_sack_remove(struct tcp_sock *tp)
  * Returns true if caller should free @from instead of queueing it
  */
 static bool tcp_try_coalesce(struct sock *sk,
+			     enum tcp_queue dest,
 			     struct sk_buff *to,
 			     struct sk_buff *from,
 			     bool *fragstolen)
@@ -4281,6 +4288,15 @@ static bool tcp_try_coalesce(struct sock *sk,
 	TCP_SKB_CB(to)->end_seq = TCP_SKB_CB(from)->end_seq;
 	TCP_SKB_CB(to)->ack_seq = TCP_SKB_CB(from)->ack_seq;
 	TCP_SKB_CB(to)->tcp_flags |= TCP_SKB_CB(from)->tcp_flags;
+
+	if (TCP_SKB_CB(from)->has_rxtstamp) {
+		TCP_SKB_CB(to)->has_rxtstamp = true;
+		if (dest == OOO_QUEUE)
+			TCP_SKB_CB(to)->swtstamp = TCP_SKB_CB(from)->swtstamp;
+		else
+			to->tstamp = from->tstamp;
+	}
+
 	return true;
 }
 
@@ -4315,6 +4331,9 @@ static void tcp_ofo_queue(struct sock *sk)
 		}
 		p = rb_next(p);
 		rb_erase(&skb->rbnode, &tp->out_of_order_queue);
+		/* Replace tstamp which was stomped by rbnode */
+		if (TCP_SKB_CB(skb)->has_rxtstamp)
+			skb->tstamp = TCP_SKB_CB(skb)->swtstamp;
 
 		if (unlikely(!after(TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt))) {
 			SOCK_DEBUG(sk, "ofo packet was already received\n");
@@ -4326,7 +4345,8 @@ static void tcp_ofo_queue(struct sock *sk)
 			   TCP_SKB_CB(skb)->end_seq);
 
 		tail = skb_peek_tail(&sk->sk_receive_queue);
-		eaten = tail && tcp_try_coalesce(sk, tail, skb, &fragstolen);
+		eaten = tail && tcp_try_coalesce(sk, RCV_QUEUE,
+						 tail, skb, &fragstolen);
 		tcp_rcv_nxt_update(tp, TCP_SKB_CB(skb)->end_seq);
 		fin = TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN;
 		if (!eaten)
@@ -4380,6 +4400,10 @@ static void tcp_data_queue_ofo(struct sock *sk, struct sk_buff *skb)
 		return;
 	}
 
+	/* Stash tstamp to avoid being stomped on by rbnode */
+	if (TCP_SKB_CB(skb)->has_rxtstamp)
+		TCP_SKB_CB(skb)->swtstamp = skb->tstamp;
+
 	inet_csk_schedule_ack(sk);
 
 	NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPOFOQUEUE);
@@ -4405,7 +4429,8 @@ static void tcp_data_queue_ofo(struct sock *sk, struct sk_buff *skb)
 	/* In the typical case, we are adding an skb to the end of the list.
 	 * Use of ooo_last_skb avoids the O(Log(N)) rbtree lookup.
 	 */
-	if (tcp_try_coalesce(sk, tp->ooo_last_skb, skb, &fragstolen)) {
+	if (tcp_try_coalesce(sk, OOO_QUEUE, tp->ooo_last_skb,
+			     skb, &fragstolen)) {
 coalesce_done:
 		tcp_grow_window(sk, skb);
 		kfree_skb_partial(skb, fragstolen);
@@ -4455,7 +4480,8 @@ coalesce_done:
 				__kfree_skb(skb1);
 				goto merge_right;
 			}
-		} else if (tcp_try_coalesce(sk, skb1, skb, &fragstolen)) {
+		} else if (tcp_try_coalesce(sk, OOO_QUEUE, skb1,
+					    skb, &fragstolen)) {
 			goto coalesce_done;
 		}
 		p = &parent->rb_right;
@@ -4506,7 +4532,8 @@ static int __must_check tcp_queue_rcv(struct sock *sk, struct sk_buff *skb, int
 
 	__skb_pull(skb, hdrlen);
 	eaten = (tail &&
-		 tcp_try_coalesce(sk, tail, skb, fragstolen)) ? 1 : 0;
+		 tcp_try_coalesce(sk, RCV_QUEUE, tail,
+				  skb, fragstolen)) ? 1 : 0;
 	tcp_rcv_nxt_update(tcp_sk(sk), TCP_SKB_CB(skb)->end_seq);
 	if (!eaten) {
 		__skb_queue_tail(&sk->sk_receive_queue, skb);
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 5af8b809dfbc..a63486afa7a7 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1637,6 +1637,8 @@ int tcp_v4_rcv(struct sk_buff *skb)
 	TCP_SKB_CB(skb)->tcp_tw_isn = 0;
 	TCP_SKB_CB(skb)->ip_dsfield = ipv4_get_dsfield(iph);
 	TCP_SKB_CB(skb)->sacked	 = 0;
+	TCP_SKB_CB(skb)->has_rxtstamp =
+			skb->tstamp || skb_hwtstamps(skb)->hwtstamp;
 
 lookup:
 	sk = __inet_lookup_skb(&tcp_hashinfo, skb, __tcp_hdrlen(th), th->source,
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index d79a1af3252e..abba3bc2a3d9 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1394,6 +1394,8 @@ static void tcp_v6_fill_cb(struct sk_buff *skb, const struct ipv6hdr *hdr,
 	TCP_SKB_CB(skb)->tcp_tw_isn = 0;
 	TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
 	TCP_SKB_CB(skb)->sacked = 0;
+	TCP_SKB_CB(skb)->has_rxtstamp =
+			skb->tstamp || skb_hwtstamps(skb)->hwtstamp;
 }
 
 static int tcp_v6_rcv(struct sk_buff *skb)
diff --git a/tools/testing/selftests/networking/timestamping/.gitignore b/tools/testing/selftests/networking/timestamping/.gitignore
index 9e69e982fb38..d9355035e746 100644
--- a/tools/testing/selftests/networking/timestamping/.gitignore
+++ b/tools/testing/selftests/networking/timestamping/.gitignore
@@ -1,3 +1,4 @@
 timestamping
+rxtimestamp
 txtimestamp
 hwtstamp_config
diff --git a/tools/testing/selftests/networking/timestamping/Makefile b/tools/testing/selftests/networking/timestamping/Makefile
index ccbb9edbbbb9..92fb8ee917c5 100644
--- a/tools/testing/selftests/networking/timestamping/Makefile
+++ b/tools/testing/selftests/networking/timestamping/Makefile
@@ -1,4 +1,6 @@
-TEST_PROGS := hwtstamp_config timestamping txtimestamp
+CFLAGS += -I../../../../../usr/include
+
+TEST_PROGS := hwtstamp_config rxtimestamp timestamping txtimestamp
 
 all: $(TEST_PROGS)
 
diff --git a/tools/testing/selftests/networking/timestamping/rxtimestamp.c b/tools/testing/selftests/networking/timestamping/rxtimestamp.c
new file mode 100644
index 000000000000..00f286661dcd
--- /dev/null
+++ b/tools/testing/selftests/networking/timestamping/rxtimestamp.c
@@ -0,0 +1,389 @@
+#include <errno.h>
+#include <error.h>
+#include <getopt.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.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>
+
+#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
+
+struct options {
+	int so_timestamp;
+	int so_timestampns;
+	int so_timestamping;
+};
+
+struct tstamps {
+	bool tstamp;
+	bool tstampns;
+	bool swtstamp;
+	bool hwtstamp;
+};
+
+struct socket_type {
+	char *friendly_name;
+	int type;
+	int protocol;
+	bool enabled;
+};
+
+struct test_case {
+	struct options sockopt;
+	struct tstamps expected;
+	bool enabled;
+};
+
+struct sof_flag {
+	int mask;
+	char *name;
+};
+
+static struct sof_flag sof_flags[] = {
+#define SOF_FLAG(f) { f, #f }
+	SOF_FLAG(SOF_TIMESTAMPING_SOFTWARE),
+	SOF_FLAG(SOF_TIMESTAMPING_RX_SOFTWARE),
+	SOF_FLAG(SOF_TIMESTAMPING_RX_HARDWARE),
+};
+
+static struct socket_type socket_types[] = {
+	{ "ip",		SOCK_RAW,	IPPROTO_EGP },
+	{ "udp",	SOCK_DGRAM,	IPPROTO_UDP },
+	{ "tcp",	SOCK_STREAM,	IPPROTO_TCP },
+};
+
+static struct test_case test_cases[] = {
+	{ {}, {} },
+	{
+		{ so_timestamp: 1 },
+		{ tstamp: true }
+	},
+	{
+		{ so_timestampns: 1 },
+		{ tstampns: true }
+	},
+	{
+		{ so_timestamp: 1, so_timestampns: 1 },
+		{ tstampns: true }
+	},
+	{
+		{ so_timestamping: SOF_TIMESTAMPING_RX_SOFTWARE },
+		{}
+	},
+	{
+		/* Loopback device does not support hw timestamps. */
+		{ so_timestamping: SOF_TIMESTAMPING_RX_HARDWARE },
+		{}
+	},
+	{
+		{ so_timestamping: SOF_TIMESTAMPING_SOFTWARE },
+		{}
+	},
+	{
+		{ so_timestamping: SOF_TIMESTAMPING_RX_SOFTWARE
+			| SOF_TIMESTAMPING_RX_HARDWARE },
+		{}
+	},
+	{
+		{ so_timestamping: SOF_TIMESTAMPING_SOFTWARE
+			| SOF_TIMESTAMPING_RX_SOFTWARE },
+		{ swtstamp: true }
+	},
+	{
+		{ so_timestamp: 1, so_timestamping: SOF_TIMESTAMPING_SOFTWARE
+			| SOF_TIMESTAMPING_RX_SOFTWARE },
+		{ tstamp: true, swtstamp: true }
+	},
+};
+
+static struct option long_options[] = {
+	{ "list_tests", no_argument, 0, 'l' },
+	{ "test_num", required_argument, 0, 'n' },
+	{ "op_size", required_argument, 0, 's' },
+	{ "tcp", no_argument, 0, 't' },
+	{ "udp", no_argument, 0, 'u' },
+	{ "ip", no_argument, 0, 'i' },
+};
+
+static int next_port = 19999;
+static int op_size = 10 * 1024;
+
+void print_test_case(struct test_case *t)
+{
+	int f = 0;
+
+	printf("sockopts {");
+	if (t->sockopt.so_timestamp)
+		printf(" SO_TIMESTAMP ");
+	if (t->sockopt.so_timestampns)
+		printf(" SO_TIMESTAMPNS ");
+	if (t->sockopt.so_timestamping) {
+		printf(" SO_TIMESTAMPING: {");
+		for (f = 0; f < ARRAY_SIZE(sof_flags); f++)
+			if (t->sockopt.so_timestamping & sof_flags[f].mask)
+				printf(" %s |", sof_flags[f].name);
+		printf("}");
+	}
+	printf("} expected cmsgs: {");
+	if (t->expected.tstamp)
+		printf(" SCM_TIMESTAMP ");
+	if (t->expected.tstampns)
+		printf(" SCM_TIMESTAMPNS ");
+	if (t->expected.swtstamp || t->expected.hwtstamp) {
+		printf(" SCM_TIMESTAMPING {");
+		if (t->expected.swtstamp)
+			printf("0");
+		if (t->expected.swtstamp && t->expected.hwtstamp)
+			printf(",");
+		if (t->expected.hwtstamp)
+			printf("2");
+		printf("}");
+	}
+	printf("}\n");
+}
+
+void do_send(int src)
+{
+	int r;
+	char *buf = malloc(op_size);
+
+	memset(buf, 'z', op_size);
+	r = write(src, buf, op_size);
+	if (r < 0)
+		error(1, errno, "Failed to sendmsg");
+
+	free(buf);
+}
+
+bool do_recv(int rcv, int read_size, struct tstamps expected)
+{
+	const int CMSG_SIZE = 1024;
+
+	struct scm_timestamping *ts;
+	struct tstamps actual = {};
+	char cmsg_buf[CMSG_SIZE];
+	struct iovec recv_iov;
+	struct cmsghdr *cmsg;
+	bool failed = false;
+	struct msghdr hdr;
+	int flags = 0;
+	int r;
+
+	memset(&hdr, 0, sizeof(hdr));
+	hdr.msg_iov = &recv_iov;
+	hdr.msg_iovlen = 1;
+	recv_iov.iov_base = malloc(read_size);
+	recv_iov.iov_len = read_size;
+
+	hdr.msg_control = cmsg_buf;
+	hdr.msg_controllen = sizeof(cmsg_buf);
+
+	r = recvmsg(rcv, &hdr, flags);
+	if (r < 0)
+		error(1, errno, "Failed to recvmsg");
+	if (r != read_size)
+		error(1, 0, "Only received %d bytes of payload.", r);
+
+	if (hdr.msg_flags & (MSG_TRUNC | MSG_CTRUNC))
+		error(1, 0, "Message was truncated.");
+
+	for (cmsg = CMSG_FIRSTHDR(&hdr); cmsg != NULL;
+	     cmsg = CMSG_NXTHDR(&hdr, cmsg)) {
+		if (cmsg->cmsg_level != SOL_SOCKET)
+			error(1, 0, "Unexpected cmsg_level %d",
+			      cmsg->cmsg_level);
+		switch (cmsg->cmsg_type) {
+		case SCM_TIMESTAMP:
+			actual.tstamp = true;
+			break;
+		case SCM_TIMESTAMPNS:
+			actual.tstampns = true;
+			break;
+		case SCM_TIMESTAMPING:
+			ts = (struct scm_timestamping *)CMSG_DATA(cmsg);
+			actual.swtstamp = !!ts->ts[0].tv_sec;
+			if (ts->ts[1].tv_sec != 0)
+				error(0, 0, "ts[1] should not be set.");
+			actual.hwtstamp = !!ts->ts[2].tv_sec;
+			break;
+		default:
+			error(1, 0, "Unexpected cmsg_type %d", cmsg->cmsg_type);
+		}
+	}
+
+#define VALIDATE(field) \
+	do { \
+		if (expected.field != actual.field) { \
+			if (expected.field) \
+				error(0, 0, "Expected " #field " to be set."); \
+			else \
+				error(0, 0, \
+				      "Expected " #field " to not be set."); \
+			failed = true; \
+		} \
+	} while (0)
+
+	VALIDATE(tstamp);
+	VALIDATE(tstampns);
+	VALIDATE(swtstamp);
+	VALIDATE(hwtstamp);
+#undef VALIDATE
+
+	free(recv_iov.iov_base);
+
+	return failed;
+}
+
+void config_so_flags(int rcv, struct options o)
+{
+	int on = 1;
+
+	if (setsockopt(rcv, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0)
+		error(1, errno, "Failed to enable SO_REUSEADDR");
+
+	if (o.so_timestamp &&
+	    setsockopt(rcv, SOL_SOCKET, SO_TIMESTAMP,
+		       &o.so_timestamp, sizeof(o.so_timestamp)) < 0)
+		error(1, errno, "Failed to enable SO_TIMESTAMP");
+
+	if (o.so_timestampns &&
+	    setsockopt(rcv, SOL_SOCKET, SO_TIMESTAMPNS,
+		       &o.so_timestampns, sizeof(o.so_timestampns)) < 0)
+		error(1, errno, "Failed to enable SO_TIMESTAMPNS");
+
+	if (o.so_timestamping &&
+	    setsockopt(rcv, SOL_SOCKET, SO_TIMESTAMPING,
+		       &o.so_timestamping, sizeof(o.so_timestamping)) < 0)
+		error(1, errno, "Failed to set SO_TIMESTAMPING");
+}
+
+bool run_test_case(struct socket_type s, struct test_case t)
+{
+	int port = (s.type == SOCK_RAW) ? 0 : next_port++;
+	int read_size = op_size;
+	struct sockaddr_in addr;
+	bool failed = false;
+	int src, dst, rcv;
+
+	src = socket(AF_INET, s.type, s.protocol);
+	if (src < 0)
+		error(1, errno, "Failed to open src socket");
+
+	dst = socket(AF_INET, s.type, s.protocol);
+	if (dst < 0)
+		error(1, errno, "Failed to open dst socket");
+
+	memset(&addr, 0, sizeof(addr));
+	addr.sin_family = AF_INET;
+	addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+	addr.sin_port = htons(port);
+
+	if (bind(dst, (struct sockaddr *)&addr, sizeof(addr)) < 0)
+		error(1, errno, "Failed to bind to port %d", port);
+
+	if (s.type == SOCK_STREAM && (listen(dst, 1) < 0))
+		error(1, errno, "Failed to listen");
+
+	if (connect(src, (struct sockaddr *)&addr, sizeof(addr)) < 0)
+		error(1, errno, "Failed to connect");
+
+	if (s.type == SOCK_STREAM) {
+		rcv = accept(dst, NULL, NULL);
+		if (rcv < 0)
+			error(1, errno, "Failed to accept");
+		close(dst);
+	} else {
+		rcv = dst;
+	}
+
+	config_so_flags(rcv, t.sockopt);
+	usleep(20000); /* setsockopt for SO_TIMESTAMPING is asynchronous */
+	do_send(src);
+
+	if (s.type == SOCK_RAW)
+		read_size += 20;  /* for IP header */
+	failed = do_recv(rcv, read_size, t.expected);
+
+	close(rcv);
+	close(src);
+
+	return failed;
+}
+
+int main(int argc, char **argv)
+{
+	bool all_protocols = true;
+	bool all_tests = true;
+	int arg_index = 0;
+	int failures = 0;
+	int s, t;
+	char opt;
+
+	while ((opt = getopt_long(argc, argv, "", long_options,
+				  &arg_index)) != -1) {
+		switch (opt) {
+		case 'l':
+			for (t = 0; t < ARRAY_SIZE(test_cases); t++) {
+				printf("%d\t", t);
+				print_test_case(&test_cases[t]);
+			}
+			return 0;
+		case 'n':
+			t = atoi(optarg);
+			if (t > ARRAY_SIZE(test_cases))
+				error(1, 0, "Invalid test case: %d", t);
+			all_tests = false;
+			test_cases[t].enabled = true;
+			break;
+		case 's':
+			op_size = atoi(optarg);
+			break;
+		case 't':
+			all_protocols = false;
+			socket_types[2].enabled = true;
+			break;
+		case 'u':
+			all_protocols = false;
+			socket_types[1].enabled = true;
+			break;
+		case 'i':
+			all_protocols = false;
+			socket_types[0].enabled = true;
+			break;
+		default:
+			error(1, 0, "Failed to parse parameters.");
+		}
+	}
+
+	for (s = 0; s < ARRAY_SIZE(socket_types); s++) {
+		if (!all_protocols && !socket_types[s].enabled)
+			continue;
+
+		printf("Testing %s...\n", socket_types[s].friendly_name);
+		for (t = 0; t < ARRAY_SIZE(test_cases); t++) {
+			if (!all_tests && !test_cases[t].enabled)
+				continue;
+
+			printf("Starting testcase %d...\n", t);
+			if (run_test_case(socket_types[s], test_cases[t])) {
+				failures++;
+				printf("FAILURE in test case ");
+				print_test_case(&test_cases[t]);
+			}
+		}
+	}
+	if (!failures)
+		printf("PASSED.\n");
+	return failures;
+}