fixes #469 SO_REUSEADDR should be enabled

fixes #468 TCP nodelay and keepalive should start usable
fixes #467 NN_RCVMAXSZ option does not work (compat)
fixes #465 Support NN_OPT_TCPNODELAY (compat)

This is a rather larger change set than I'd like, but when adding
support for legacy TCP keepalive, I found a number if issues using
the legacy TCP test (which we are introducing with this commit.)
This fixes the concerns that are relevant and addressible.

We have elected not to try to support to local address binding at this
time, and the IPv6 test case in the old code was wrong, so changes
relevant to that are commented out.

I've also updated the nng_compat manual page to reflect additional
caveats that folks should be aware of, including the previously
undocumented caveat around the NN_SNDBUF and NN_RCVBUF options.

9 files changed, 407 insertions, 11 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index bf08ca90..96eed693 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -274,6 +274,11 @@ if (CMAKE_SYSTEM_NAME MATCHES "Linux")
     add_definitions (-DNNG_PLATFORM_POSIX)
     add_definitions (-DNNG_PLATFORM_LINUX)
     add_definitions (-DNNG_USE_EVENTFD)
+    # Windows subsystem for Linux -- smells like Linux, but it has
+    # some differences (SO_REUSEADDR for one).
+    if (CMAKE_SYSTEM_VERSION MATCHES "Microsoft")
+        add_definitions (-DNNG_PLATFORM_WSL)
+    endif()
     set(NNG_PLATFORM_POSIX ON)
 
 elseif (CMAKE_SYSTEM_NAME MATCHES "Darwin")
diff --git a/docs/man/nng_compat.3compat.adoc b/docs/man/nng_compat.3compat.adoc
index f8472c3c..148f09d1 100644
--- a/docs/man/nng_compat.3compat.adoc
+++ b/docs/man/nng_compat.3compat.adoc
@@ -190,6 +190,23 @@ The following caveats apply when using the legacy API with _nng_.
   Specifically, there is no `nn_symbol()` function yet.
   (This may be addressed later if there is a need.)
 
+* The TCP transport (`tcp://` URLs) does not support specifying the local
+  address or interface when binding.  (This could be fixed in the future,
+  but most likely this will be available only using the new API.)
+
+* The values of `NN_RCVMAXSIZE` are constrained.
+  Specifically, values set larger than 2GB using the new API will be reported
+  as unlimited (`-1`) in the new API, and the value `0` will disable any
+  enforcement, just like `-1`.
+  (There is no practical reason to ever want to limit the receive size to
+  zero.)
+
+* This implementation counts buffers in terms of messages rather than bytes.
+  As a result, the buffer sizes accessed with `NN_SNDBUF` and `NN_RCVBUF` are
+  rounded up to a whole number of kilobytes, then divided by 1024, in order
+  to approximate buffering assuming 1 KB messages.
+  Few applications should need to adjust the default values.
+
 == SEE ALSO
 
 <<libnng.3#,libnng(3)>>,
diff --git a/src/compat/nanomsg/nn.c b/src/compat/nanomsg/nn.c
index 6755a8ea..564e60d8 100644
--- a/src/compat/nanomsg/nn.c
+++ b/src/compat/nanomsg/nn.c
@@ -64,7 +64,7 @@ static const struct {
 	{ NNG_ENOENT,	    ENOENT	  },
 	{ NNG_EPROTO,	    EPROTO	  },
 	{ NNG_EUNREACHABLE, EHOSTUNREACH  },
-	{ NNG_EADDRINVAL,   EADDRNOTAVAIL },
+	{ NNG_EADDRINVAL,   EINVAL        },
 	{ NNG_EPERM,	    EACCES	  },
 	{ NNG_EMSGSIZE,	    EMSGSIZE	  },
 	{ NNG_ECONNABORTED, ECONNABORTED  },
@@ -237,6 +237,8 @@ nn_socket(int domain, int protocol)
 		return (-1);
 	}
 
+	// Legacy sockets have nodelay disabled.
+	(void) nng_setopt_bool(sock, NNG_OPT_TCP_NODELAY, false);
 	return ((int) sock.id);
 }
 
@@ -747,6 +749,54 @@ nn_setignore(nng_socket s, const void *valp, size_t sz)
 }
 
 static int
+nn_settcpnodelay(nng_socket s, const void *valp, size_t sz)
+{
+	bool val;
+	int  ival;
+	int  rv;
+
+	if (sz != sizeof(ival)) {
+		errno = EINVAL;
+		return (-1);
+	}
+	memcpy(&ival, valp, sizeof(ival));
+	switch (ival) {
+	case 0:
+		val = false;
+		break;
+	case 1:
+		val = true;
+		break;
+	default:
+		nn_seterror(NNG_EINVAL);
+		return (-1);
+	}
+
+	if ((rv = nng_setopt_bool(s, NNG_OPT_TCP_NODELAY, val)) != 0) {
+		nn_seterror(rv);
+		return (-1);
+	}
+	return (0);
+}
+
+static int
+nn_gettcpnodelay(nng_socket s, void *valp, size_t *szp)
+{
+	bool val;
+	int  ival;
+	int  rv;
+
+	if ((rv = nng_getopt_bool(s, NNG_OPT_TCP_NODELAY, &val)) != 0) {
+		nn_seterror(rv);
+		return (-1);
+	}
+	ival = val ? 1 : 0;
+	memcpy(valp, &ival, *szp < sizeof(ival) ? *szp : sizeof(ival));
+	*szp = sizeof(ival);
+	return (0);
+}
+
+static int
 nn_getrcvbuf(nng_socket s, void *valp, size_t *szp)
 {
 	int cnt;
@@ -769,7 +819,7 @@ nn_setrcvbuf(nng_socket s, const void *valp, size_t sz)
 	int rv;
 
 	if (sz != sizeof(cnt)) {
-		nn_seterror(NNG_EINVAL);
+		errno = EINVAL;
 		return (-1);
 	}
 	memcpy(&cnt, valp, sizeof(cnt));
@@ -808,7 +858,7 @@ nn_setsndbuf(nng_socket s, const void *valp, size_t sz)
 	int rv;
 
 	if (sz != sizeof(cnt)) {
-		nn_seterror(NNG_EINVAL);
+		errno = EINVAL;
 		return (-1);
 	}
 	memcpy(&cnt, valp, sizeof(cnt));
@@ -824,6 +874,61 @@ nn_setsndbuf(nng_socket s, const void *valp, size_t sz)
 	return (0);
 }
 
+static int
+nn_setrcvmaxsz(nng_socket s, const void *valp, size_t sz)
+{
+	int    ival;
+	size_t val;
+	int    rv;
+
+	if (sz != sizeof(ival)) {
+		errno = EINVAL;
+		return (-1);
+	}
+	memcpy(&ival, valp, sizeof(ival));
+	if (ival == -1) {
+		val = 0;
+	} else if (ival >= 0) {
+		// Note that if the user sets 0, it disables the limit.
+		// This is a different semantic.
+		val = (size_t) ival;
+	} else {
+		errno = EINVAL;
+		return (-1);
+	}
+	if ((rv = nng_setopt_size(s, NNG_OPT_RECVMAXSZ, val)) != 0) {
+		nn_seterror(rv);
+		return (-1);
+	}
+	return (0);
+}
+
+static int
+nn_getrcvmaxsz(nng_socket s, void *valp, size_t *szp)
+{
+	int    ival;
+	int    rv;
+	size_t val;
+
+	if ((rv = nng_getopt_size(s, NNG_OPT_RECVMAXSZ, &val)) != 0) {
+		nn_seterror(rv);
+		return (-1);
+	}
+	// Legacy uses -1 to mean unlimited.  New code uses 0.  Note that
+	// as a consequence, we can't set a message limit of zero.
+	// We report any size beyond 2GB as effectively unlimited.
+	// There is an implicit assumption here that ints are 32-bits,
+	// but that's generally true of any platform we support.
+	if ((val == 0) || (val > 0x7FFFFFFF)) {
+		ival = -1;
+	} else {
+		ival = (int) val;
+	}
+	memcpy(valp, &ival, *szp < sizeof(ival) ? *szp : sizeof(ival));
+	*szp = sizeof(ival);
+	return (0);
+}
+
 // options which we convert -- most of the array is initialized at run time.
 static const struct {
 	int         nnlevel;
@@ -881,7 +986,8 @@ static const struct {
 	{
 	    .nnlevel = NN_SOL_SOCKET,
 	    .nnopt   = NN_RCVMAXSIZE,
-	    .opt     = NNG_OPT_RECVMAXSZ,
+	    .get     = nn_getrcvmaxsz,
+	    .set     = nn_setrcvmaxsz,
 	},
 	{
 	    .nnlevel = NN_SOL_SOCKET,
@@ -928,6 +1034,12 @@ static const struct {
 	    .nnopt   = NN_SURVEYOR_DEADLINE,
 	    .opt     = NNG_OPT_SURVEYOR_SURVEYTIME,
 	},
+	{
+	    .nnlevel = NN_TCP,
+	    .nnopt   = NN_TCP_NODELAY,
+	    .get     = nn_gettcpnodelay,
+	    .set     = nn_settcpnodelay,
+	}
 	// XXX: IPV4ONLY, SNDPRIO, RCVPRIO
 };
 
diff --git a/src/core/socket.c b/src/core/socket.c
index 3a209441..faca1b06 100644
--- a/src/core/socket.c
+++ b/src/core/socket.c
@@ -532,6 +532,7 @@ nni_sock_create(nni_sock **sp, const nni_proto *proto)
 {
 	int       rv;
 	nni_sock *s;
+	bool      on;
 
 	if ((s = NNI_ALLOC_STRUCT(s)) == NULL) {
 		return (NNG_ENOMEM);
@@ -587,6 +588,16 @@ nni_sock_create(nni_sock **sp, const nni_proto *proto)
 		return (rv);
 	}
 
+	// These we *attempt* to call so that we are likely to have initial
+	// values loaded.  They should not fail, but if they do we don't
+	// worry about it.
+	on = true;
+	(void) nni_sock_setopt(
+	    s, NNG_OPT_TCP_NODELAY, &on, sizeof(on), NNI_TYPE_BOOL);
+	on = false;
+	(void) nni_sock_setopt(
+	    s, NNG_OPT_TCP_KEEPALIVE, &on, sizeof(on), NNI_TYPE_BOOL);
+
 	if (s->s_sock_ops.sock_filter != NULL) {
 		nni_msgq_set_filter(
 		    s->s_urq, s->s_sock_ops.sock_filter, s->s_data);
diff --git a/src/platform/posix/posix_epdesc.c b/src/platform/posix/posix_epdesc.c
index 0065806d..dfb750d4 100644
--- a/src/platform/posix/posix_epdesc.c
+++ b/src/platform/posix/posix_epdesc.c
@@ -247,6 +247,16 @@ nni_posix_epdesc_listen(nni_posix_epdesc *ed)
 		return (rv);
 	}
 
+#if defined(SO_REUSEADDR) && !defined(NNG_PLATFORM_WSL)
+	if (ss->ss_family != AF_UNIX) {
+		int on = 1;
+		// If for some reason this doesn't work, it's probably ok.
+		// Second bind will fail.
+		(void) setsockopt(
+		    fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
+	}
+#endif
+
 	if (bind(fd, (struct sockaddr *) ss, len) < 0) {
 		rv = nni_plat_errno(errno);
 		nni_mtx_unlock(&ed->mtx);
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 03f09579..a0f54b5d 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -190,12 +190,13 @@ add_nng_compat_test(compat_iovec 5)
 add_nng_compat_test(compat_device 5)
 add_nng_compat_test(compat_pair 5)
 add_nng_compat_test(compat_pipeline 5)
+add_nng_compat_test(compat_poll 5)
 add_nng_compat_test(compat_reqrep 5)
 add_nng_compat_test(compat_survey 5)
 add_nng_compat_test(compat_reqttl 5)
 add_nng_compat_test(compat_shutdown 5)
 add_nng_compat_test(compat_surveyttl 5)
-add_nng_compat_test(compat_poll 5)
+add_nng_compat_test(compat_tcp 5)
 
 # These are special tests for compat mode, not inherited from the
 # legacy libnanomsg suite.
diff --git a/tests/compat_tcp.c b/tests/compat_tcp.c
new file mode 100644
index 00000000..fee271e9
--- /dev/null
+++ b/tests/compat_tcp.c
@@ -0,0 +1,238 @@
+/*
+    Copyright (c) 2012 Martin Sustrik  All rights reserved.
+    Copyright 2015 Garrett D'Amore <garrett@damore.org>
+    Copyright 2016 Franklin "Snaipe" Mathieu <franklinmathieu@gmail.com>
+
+    Permission is hereby granted, free of charge, to any person obtaining a copy
+    of this software and associated documentation files (the "Software"),
+    to deal in the Software without restriction, including without limitation
+    the rights to use, copy, modify, merge, publish, distribute, sublicense,
+    and/or sell copies of the Software, and to permit persons to whom
+    the Software is furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be included
+    in all copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+    THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+    FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+    IN THE SOFTWARE.
+*/
+
+#include <nanomsg/nn.h>
+#include <nanomsg/pair.h>
+#include <nanomsg/pubsub.h>
+#include <nanomsg/tcp.h>
+
+#include "compat_testutil.h"
+
+/*  Tests TCP transport. */
+
+int sc;
+
+int main (int argc, const char *argv[])
+{
+    int rc;
+    int sb;
+    int i;
+    int opt;
+    size_t sz;
+    int s1, s2;
+    void * dummy_buf;
+    char addr[128];
+    char socket_address[128];
+
+    int port = get_test_port(argc, argv);
+
+    test_addr_from(socket_address, "tcp", "127.0.0.1", port);
+
+    /*  Try closing bound but unconnected socket. */
+    sb = test_socket (AF_SP, NN_PAIR);
+    test_bind (sb, socket_address);
+    test_close (sb);
+
+    /*  Try closing a TCP socket while it not connected. At the same time
+        test specifying the local address for the connection. */
+    sc = test_socket (AF_SP, NN_PAIR);
+#if 0 // NNG doesn't support local binding
+    test_addr_from(addr, "tcp", "127.0.0.1;127.0.0.1", port);
+#else
+    test_addr_from(addr, "tcp", "127.0.0.1", port);
+#endif
+    test_connect (sc, addr);
+    test_close (sc);
+
+    /*  Open the socket anew. */
+    sc = test_socket (AF_SP, NN_PAIR);
+
+    /*  Check NODELAY socket option. */
+    sz = sizeof (opt);
+    rc = nn_getsockopt (sc, NN_TCP, NN_TCP_NODELAY, &opt, &sz);
+    errno_assert (rc == 0);
+    nn_assert (sz == sizeof (opt));
+    nn_assert (opt == 0);
+    opt = 2;
+    rc = nn_setsockopt (sc, NN_TCP, NN_TCP_NODELAY, &opt, sizeof (opt));
+    nn_assert (rc < 0 && nn_errno () == EINVAL);
+    opt = 1;
+    rc = nn_setsockopt (sc, NN_TCP, NN_TCP_NODELAY, &opt, sizeof (opt));
+    errno_assert (rc == 0);
+    sz = sizeof (opt);
+    rc = nn_getsockopt (sc, NN_TCP, NN_TCP_NODELAY, &opt, &sz);
+    errno_assert (rc == 0);
+    nn_assert (sz == sizeof (opt));
+    nn_assert (opt == 1);
+
+    /*  Try using invalid address strings. */
+    rc = nn_connect (sc, "tcp://*:");
+    nn_assert (rc < 0);
+    errno_assert (nn_errno () == EINVAL);
+    rc = nn_connect (sc, "tcp://*:1000000");
+    nn_assert (rc < 0);
+    errno_assert (nn_errno () == EINVAL);
+    rc = nn_connect (sc, "tcp://*:some_port");
+    nn_assert (rc < 0);
+#if 0 // NNG does not support local interfaces
+    rc = nn_connect (sc, "tcp://eth10000;127.0.0.1:5555");
+    nn_assert (rc < 0);
+    errno_assert (nn_errno () == ENODEV);
+#endif
+    rc = nn_connect (sc, "tcp://127.0.0.1");
+    nn_assert (rc < 0);
+    errno_assert (nn_errno () == EINVAL);
+#if 0 // NNG permits this -- the interface will get an ephemeral port
+    rc = nn_bind (sc, "tcp://127.0.0.1:");
+    nn_assert (rc < 0);
+    errno_assert (nn_errno () == EINVAL);
+#endif
+    rc = nn_bind (sc, "tcp://127.0.0.1:1000000");
+    nn_assert (rc < 0);
+    errno_assert (nn_errno () == EINVAL);
+#if 0 // NNG doesn't do interface binding here.
+    rc = nn_bind (sc, "tcp://eth10000:5555");
+    nn_assert (rc < 0);
+    errno_assert (nn_errno () == ENODEV);
+#endif
+    rc = nn_connect (sc, "tcp://:5555");
+    nn_assert (rc < 0);
+    errno_assert (nn_errno () == EINVAL);
+    rc = nn_connect (sc, "tcp://-hostname:5555");
+    nn_assert (rc < 0);
+    errno_assert (nn_errno () == EINVAL);
+    rc = nn_connect (sc, "tcp://abc.123.---.#:5555");
+    nn_assert (rc < 0);
+    errno_assert (nn_errno () == EINVAL);
+
+#if 0 // NNG is ok with this -- its a valid IPv6 address.
+    rc = nn_connect (sc, "tcp://[::1]:5555");
+    nn_assert (rc < 0);
+    errno_assert (nn_errno () == EINVAL);
+#endif
+
+    rc = nn_connect (sc, "tcp://abc...123:5555");
+    nn_assert (rc < 0);
+    errno_assert (nn_errno () == EINVAL);
+    rc = nn_connect (sc, "tcp://.123:5555");
+    nn_assert (rc < 0);
+    errno_assert (nn_errno () == EINVAL);
+
+    /*  Connect correctly. Do so before binding the peer socket. */
+    test_connect (sc, socket_address);
+
+    /*  Leave enough time for at least on re-connect attempt. */
+    nn_sleep (200);
+
+    sb = test_socket (AF_SP, NN_PAIR);
+    test_bind (sb, socket_address);
+
+    /*  Ping-pong test. */
+    for (i = 0; i != 100; ++i) {
+
+        test_send (sc, "ABC");
+        test_recv (sb, "ABC");
+
+        test_send (sb, "DEF");
+        test_recv (sc, "DEF");
+    }
+
+    /*  Batch transfer test. */
+    for (i = 0; i != 100; ++i) {
+        test_send (sc, "0123456789012345678901234567890123456789");
+    }
+    for (i = 0; i != 100; ++i) {
+        test_recv (sb, "0123456789012345678901234567890123456789");
+    }
+
+    test_close (sc);
+    test_close (sb);
+
+    /*  Test whether connection rejection is handled decently. */
+    sb = test_socket (AF_SP, NN_PAIR);
+    test_bind (sb, socket_address);
+    s1 = test_socket (AF_SP, NN_PAIR);
+    test_connect (s1, socket_address);
+    s2 = test_socket (AF_SP, NN_PAIR);
+    test_connect (s2, socket_address);
+    nn_sleep (100);
+    test_close (s2);
+    test_close (s1);
+    test_close (sb);
+
+    /*  Test two sockets binding to the same address. */
+    sb = test_socket (AF_SP, NN_PAIR);
+    test_bind (sb, socket_address);
+    s1 = test_socket (AF_SP, NN_PAIR);
+
+    rc = nn_bind (s1, socket_address);
+    nn_assert (rc < 0);
+    errno_assert (nn_errno () == EADDRINUSE);
+
+    sc = test_socket (AF_SP, NN_PAIR);
+    test_connect (sc, socket_address);
+    nn_sleep (100);
+    test_send (sb, "ABC");
+    test_recv (sc, "ABC");
+    test_close (sb);
+    test_close (sc);
+    test_close (s1);
+
+    /*  Test NN_RCVMAXSIZE limit */
+    sb = test_socket (AF_SP, NN_PAIR);
+    test_bind (sb, socket_address);
+    s1 = test_socket (AF_SP, NN_PAIR);
+    test_connect (s1, socket_address);
+    opt = 4;
+    rc = nn_setsockopt (sb, NN_SOL_SOCKET, NN_RCVMAXSIZE, &opt, sizeof (opt));
+    nn_assert (rc == 0);
+    nn_sleep (100);
+    test_send (s1, "ABC");
+    test_recv (sb, "ABC");
+    test_send (s1, "0123456789012345678901234567890123456789");
+    rc = nn_recv (sb, &dummy_buf, NN_MSG, NN_DONTWAIT);
+    nn_assert (rc < 0);
+    errno_assert (nn_errno () == EAGAIN);
+    test_close (sb);
+    test_close (s1);
+
+    /*  Test that NN_RCVMAXSIZE can be -1, but not lower */
+    sb = test_socket (AF_SP, NN_PAIR);
+    opt = -1;
+    rc = nn_setsockopt (sb, NN_SOL_SOCKET, NN_RCVMAXSIZE, &opt, sizeof (opt));
+    nn_assert (rc >= 0);
+    opt = -2;
+    rc = nn_setsockopt (sb, NN_SOL_SOCKET, NN_RCVMAXSIZE, &opt, sizeof (opt));
+    nn_assert (rc < 0);
+    errno_assert (nn_errno () == EINVAL);
+    test_close (sb);
+
+    /*  Test closing a socket that is waiting to connect. */
+    sc = test_socket (AF_SP, NN_PAIR);
+    test_connect (sc, socket_address);
+    nn_sleep (100);
+    test_close (sc);
+
+    return 0;
+}
diff --git a/tests/tcp.c b/tests/tcp.c
index d29ceb8d..0018fce7 100644
--- a/tests/tcp.c
+++ b/tests/tcp.c
@@ -134,7 +134,8 @@ TestMain("TCP Transport", {
 
 		So(nng_pair_open(&s) == 0);
 		Reset({ nng_close(s); });
-		So(nng_getopt_bool(s, NNG_OPT_TCP_NODELAY, &v) == NNG_ENOTSUP);
+		So(nng_getopt_bool(s, NNG_OPT_TCP_NODELAY, &v) == 0);
+		So(v == true);
 		So(nng_dialer_create(&d, s, "tcp://127.0.0.1:4999") == 0);
 		So(nng_dialer_getopt_bool(d, NNG_OPT_TCP_NODELAY, &v) == 0);
 		So(v == true);
@@ -183,8 +184,8 @@ TestMain("TCP Transport", {
 
 		So(nng_pair_open(&s) == 0);
 		Reset({ nng_close(s); });
-		So(nng_getopt_bool(s, NNG_OPT_TCP_KEEPALIVE, &v) ==
-		    NNG_ENOTSUP);
+		So(nng_getopt_bool(s, NNG_OPT_TCP_KEEPALIVE, &v) == 0);
+		So(v == false);
 		So(nng_dialer_create(&d, s, "tcp://127.0.0.1:4999") == 0);
 		So(nng_dialer_getopt_bool(d, NNG_OPT_TCP_KEEPALIVE, &v) == 0);
 		So(v == false);
diff --git a/tests/tls.c b/tests/tls.c
index 8ecf342a..1f1f244c 100644
--- a/tests/tls.c
+++ b/tests/tls.c
@@ -486,7 +486,8 @@ TestMain("TLS Transport", {
 
 		So(nng_pair_open(&s) == 0);
 		Reset({ nng_close(s); });
-		So(nng_getopt_bool(s, NNG_OPT_TCP_NODELAY, &v) == NNG_ENOTSUP);
+		So(nng_getopt_bool(s, NNG_OPT_TCP_NODELAY, &v) == 0);
+		So(v == true);
 		So(nng_dialer_create(&d, s, "tcp://127.0.0.1:4999") == 0);
 		So(nng_dialer_getopt_bool(d, NNG_OPT_TCP_NODELAY, &v) == 0);
 		So(v == true);
@@ -535,8 +536,8 @@ TestMain("TLS Transport", {
 
 		So(nng_pair_open(&s) == 0);
 		Reset({ nng_close(s); });
-		So(nng_getopt_bool(s, NNG_OPT_TCP_KEEPALIVE, &v) ==
-		    NNG_ENOTSUP);
+		So(nng_getopt_bool(s, NNG_OPT_TCP_KEEPALIVE, &v) == 0);
+		So(v == false);
 		So(nng_dialer_create(&d, s, "tcp://127.0.0.1:4999") == 0);
 		So(nng_dialer_getopt_bool(d, NNG_OPT_TCP_KEEPALIVE, &v) == 0);
 		So(v == false);